fs/btrfs/ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/bio.h>
   8 #include <linux/buffer_head.h>
   9 #include <linux/file.h>
  10 #include <linux/fs.h>
  11 #include <linux/fsnotify.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/highmem.h>
  14 #include <linux/time.h>
  15 #include <linux/init.h>
  16 #include <linux/string.h>
  17 #include <linux/backing-dev.h>
  18 #include <linux/mount.h>
  19 #include <linux/mpage.h>
  20 #include <linux/namei.h>
  21 #include <linux/swap.h>
  22 #include <linux/writeback.h>
  23 #include <linux/compat.h>
  24 #include <linux/bit_spinlock.h>
  25 #include <linux/security.h>
  26 #include <linux/xattr.h>
  27 #include <linux/mm.h>
  28 #include <linux/slab.h>
  29 #include <linux/blkdev.h>
  30 #include <linux/uuid.h>
  31 #include <linux/btrfs.h>
  32 #include <linux/uaccess.h>
  33 #include <linux/iversion.h>
  34 #include "ctree.h"
  35 #include "disk-io.h"
  36 #include "transaction.h"
  37 #include "btrfs_inode.h"
  38 #include "print-tree.h"
  39 #include "volumes.h"
  40 #include "locking.h"
  41 #include "inode-map.h"
  42 #include "backref.h"
  43 #include "rcu-string.h"
  44 #include "send.h"
  45 #include "dev-replace.h"
  46 #include "props.h"
  47 #include "sysfs.h"
  48 #include "qgroup.h"
  49 #include "tree-log.h"
  50 #include "compression.h"
  51
  52 #ifdef CONFIG_64BIT
  53 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  54  * structures are incorrect, as the timespec structure from userspace
  55  * is 4 bytes too small. We define these alternatives here to teach
  56  * the kernel about the 32-bit struct packing.
  57  */
  58 struct btrfs_ioctl_timespec_32 {
  59         __u64 sec;
  60         __u32 nsec;
  61 } __attribute__ ((__packed__));
  62
  63 struct btrfs_ioctl_received_subvol_args_32 {
  64         char    uuid[BTRFS_UUID_SIZE];  /* in */
  65         __u64   stransid;               /* in */
  66         __u64   rtransid;               /* out */
  67         struct btrfs_ioctl_timespec_32 stime; /* in */
  68         struct btrfs_ioctl_timespec_32 rtime; /* out */
  69         __u64   flags;                  /* in */
  70         __u64   reserved[16];           /* in */
  71 } __attribute__ ((__packed__));
  72
  73 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  74                                 struct btrfs_ioctl_received_subvol_args_32)
  75 #endif
  76
  77 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  78 struct btrfs_ioctl_send_args_32 {
  79         __s64 send_fd;                  /* in */
  80         __u64 clone_sources_count;      /* in */
  81         compat_uptr_t clone_sources;    /* in */
  82         __u64 parent_root;              /* in */
  83         __u64 flags;                    /* in */
  84         __u64 reserved[4];              /* in */
  85 } __attribute__ ((__packed__));
  86
  87 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  88                                struct btrfs_ioctl_send_args_32)
  89 #endif
  90
  91 static int btrfs_clone(struct inode *src, struct inode *inode,
  92                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  93                        int no_time_update);
  94
  95 /* Mask out flags that are inappropriate for the given type of inode. */
  96 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
  97                 unsigned int flags)
  98 {
  99         if (S_ISDIR(inode->i_mode))
 100                 return flags;
 101         else if (S_ISREG(inode->i_mode))
 102                 return flags & ~FS_DIRSYNC_FL;
 103         else
 104                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 105 }
 106
 107 /*
 108  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 109  * ioctl.
 110  */
 111 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
 112 {
 113         unsigned int iflags = 0;
 114
 115         if (flags & BTRFS_INODE_SYNC)
 116                 iflags |= FS_SYNC_FL;
 117         if (flags & BTRFS_INODE_IMMUTABLE)
 118                 iflags |= FS_IMMUTABLE_FL;
 119         if (flags & BTRFS_INODE_APPEND)
 120                 iflags |= FS_APPEND_FL;
 121         if (flags & BTRFS_INODE_NODUMP)
 122                 iflags |= FS_NODUMP_FL;
 123         if (flags & BTRFS_INODE_NOATIME)
 124                 iflags |= FS_NOATIME_FL;
 125         if (flags & BTRFS_INODE_DIRSYNC)
 126                 iflags |= FS_DIRSYNC_FL;
 127         if (flags & BTRFS_INODE_NODATACOW)
 128                 iflags |= FS_NOCOW_FL;
 129
 130         if (flags & BTRFS_INODE_NOCOMPRESS)
 131                 iflags |= FS_NOCOMP_FL;
 132         else if (flags & BTRFS_INODE_COMPRESS)
 133                 iflags |= FS_COMPR_FL;
 134
 135         return iflags;
 136 }
 137
 138 /*
 139  * Update inode->i_flags based on the btrfs internal flags.
 140  */
 141 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 142 {
 143         struct btrfs_inode *binode = BTRFS_I(inode);
 144         unsigned int new_fl = 0;
 145
 146         if (binode->flags & BTRFS_INODE_SYNC)
 147                 new_fl |= S_SYNC;
 148         if (binode->flags & BTRFS_INODE_IMMUTABLE)
 149                 new_fl |= S_IMMUTABLE;
 150         if (binode->flags & BTRFS_INODE_APPEND)
 151                 new_fl |= S_APPEND;
 152         if (binode->flags & BTRFS_INODE_NOATIME)
 153                 new_fl |= S_NOATIME;
 154         if (binode->flags & BTRFS_INODE_DIRSYNC)
 155                 new_fl |= S_DIRSYNC;
 156
 157         set_mask_bits(&inode->i_flags,
 158                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 159                       new_fl);
 160 }
 161
 162 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 163 {
 164         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 165         unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
 166
 167         if (copy_to_user(arg, &flags, sizeof(flags)))
 168                 return -EFAULT;
 169         return 0;
 170 }
 171
 172 /* Check if @flags are a supported and valid set of FS_*_FL flags */
 173 static int check_fsflags(unsigned int flags)
 174 {
 175         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 176                       FS_NOATIME_FL | FS_NODUMP_FL | \
 177                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 178                       FS_NOCOMP_FL | FS_COMPR_FL |
 179                       FS_NOCOW_FL))
 180                 return -EOPNOTSUPP;
 181
 182         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 183                 return -EINVAL;
 184
 185         return 0;
 186 }
 187
 188 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 189 {
 190         struct inode *inode = file_inode(file);
 191         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 192         struct btrfs_inode *binode = BTRFS_I(inode);
 193         struct btrfs_root *root = binode->root;
 194         struct btrfs_trans_handle *trans;
 195         unsigned int fsflags, old_fsflags;
 196         int ret;
 197         u64 old_flags;
 198         unsigned int old_i_flags;
 199         umode_t mode;
 200
 201         if (!inode_owner_or_capable(inode))
 202                 return -EPERM;
 203
 204         if (btrfs_root_readonly(root))
 205                 return -EROFS;
 206
 207         if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
 208                 return -EFAULT;
 209
 210         ret = check_fsflags(fsflags);
 211         if (ret)
 212                 return ret;
 213
 214         ret = mnt_want_write_file(file);
 215         if (ret)
 216                 return ret;
 217
 218         inode_lock(inode);
 219
 220         old_flags = binode->flags;
 221         old_i_flags = inode->i_flags;
 222         mode = inode->i_mode;
 223
 224         fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
 225         old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
 226         if ((fsflags ^ old_fsflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 227                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 228                         ret = -EPERM;
 229                         goto out_unlock;
 230                 }
 231         }
 232
 233         if (fsflags & FS_SYNC_FL)
 234                 binode->flags |= BTRFS_INODE_SYNC;
 235         else
 236                 binode->flags &= ~BTRFS_INODE_SYNC;
 237         if (fsflags & FS_IMMUTABLE_FL)
 238                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 239         else
 240                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 241         if (fsflags & FS_APPEND_FL)
 242                 binode->flags |= BTRFS_INODE_APPEND;
 243         else
 244                 binode->flags &= ~BTRFS_INODE_APPEND;
 245         if (fsflags & FS_NODUMP_FL)
 246                 binode->flags |= BTRFS_INODE_NODUMP;
 247         else
 248                 binode->flags &= ~BTRFS_INODE_NODUMP;
 249         if (fsflags & FS_NOATIME_FL)
 250                 binode->flags |= BTRFS_INODE_NOATIME;
 251         else
 252                 binode->flags &= ~BTRFS_INODE_NOATIME;
 253         if (fsflags & FS_DIRSYNC_FL)
 254                 binode->flags |= BTRFS_INODE_DIRSYNC;
 255         else
 256                 binode->flags &= ~BTRFS_INODE_DIRSYNC;
 257         if (fsflags & FS_NOCOW_FL) {
 258                 if (S_ISREG(mode)) {
 259                         /*
 260                          * It's safe to turn csums off here, no extents exist.
 261                          * Otherwise we want the flag to reflect the real COW
 262                          * status of the file and will not set it.
 263                          */
 264                         if (inode->i_size == 0)
 265                                 binode->flags |= BTRFS_INODE_NODATACOW
 266                                               | BTRFS_INODE_NODATASUM;
 267                 } else {
 268                         binode->flags |= BTRFS_INODE_NODATACOW;
 269                 }
 270         } else {
 271                 /*
 272                  * Revert back under same assumptions as above
 273                  */
 274                 if (S_ISREG(mode)) {
 275                         if (inode->i_size == 0)
 276                                 binode->flags &= ~(BTRFS_INODE_NODATACOW
 277                                              | BTRFS_INODE_NODATASUM);
 278                 } else {
 279                         binode->flags &= ~BTRFS_INODE_NODATACOW;
 280                 }
 281         }
 282
 283         /*
 284          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 285          * flag may be changed automatically if compression code won't make
 286          * things smaller.
 287          */
 288         if (fsflags & FS_NOCOMP_FL) {
 289                 binode->flags &= ~BTRFS_INODE_COMPRESS;
 290                 binode->flags |= BTRFS_INODE_NOCOMPRESS;
 291
 292                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 293                 if (ret && ret != -ENODATA)
 294                         goto out_drop;
 295         } else if (fsflags & FS_COMPR_FL) {
 296                 const char *comp;
 297
 298                 binode->flags |= BTRFS_INODE_COMPRESS;
 299                 binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
 300
 301                 comp = btrfs_compress_type2str(fs_info->compress_type);
 302                 if (!comp || comp[0] == 0)
 303                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 304
 305                 ret = btrfs_set_prop(inode, "btrfs.compression",
 306                                      comp, strlen(comp), 0);
 307                 if (ret)
 308                         goto out_drop;
 309
 310         } else {
 311                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 312                 if (ret && ret != -ENODATA)
 313                         goto out_drop;
 314                 binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 315         }
 316
 317         trans = btrfs_start_transaction(root, 1);
 318         if (IS_ERR(trans)) {
 319                 ret = PTR_ERR(trans);
 320                 goto out_drop;
 321         }
 322
 323         btrfs_sync_inode_flags_to_i_flags(inode);
 324         inode_inc_iversion(inode);
 325         inode->i_ctime = current_time(inode);
 326         ret = btrfs_update_inode(trans, root, inode);
 327
 328         btrfs_end_transaction(trans);
 329  out_drop:
 330         if (ret) {
 331                 binode->flags = old_flags;
 332                 inode->i_flags = old_i_flags;
 333         }
 334
 335  out_unlock:
 336         inode_unlock(inode);
 337         mnt_drop_write_file(file);
 338         return ret;
 339 }
 340
 341 /*
 342  * Translate btrfs internal inode flags to xflags as expected by the
 343  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
 344  * silently dropped.
 345  */
 346 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
 347 {
 348         unsigned int xflags = 0;
 349
 350         if (flags & BTRFS_INODE_APPEND)
 351                 xflags |= FS_XFLAG_APPEND;
 352         if (flags & BTRFS_INODE_IMMUTABLE)
 353                 xflags |= FS_XFLAG_IMMUTABLE;
 354         if (flags & BTRFS_INODE_NOATIME)
 355                 xflags |= FS_XFLAG_NOATIME;
 356         if (flags & BTRFS_INODE_NODUMP)
 357                 xflags |= FS_XFLAG_NODUMP;
 358         if (flags & BTRFS_INODE_SYNC)
 359                 xflags |= FS_XFLAG_SYNC;
 360
 361         return xflags;
 362 }
 363
 364 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
 365 static int check_xflags(unsigned int flags)
 366 {
 367         if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
 368                       FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
 369                 return -EOPNOTSUPP;
 370         return 0;
 371 }
 372
 373 /*
 374  * Set the xflags from the internal inode flags. The remaining items of fsxattr
 375  * are zeroed.
 376  */
 377 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
 378 {
 379         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 380         struct fsxattr fa;
 381
 382         memset(&fa, 0, sizeof(fa));
 383         fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags);
 384
 385         if (copy_to_user(arg, &fa, sizeof(fa)))
 386                 return -EFAULT;
 387
 388         return 0;
 389 }
 390
 391 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
 392 {
 393         struct inode *inode = file_inode(file);
 394         struct btrfs_inode *binode = BTRFS_I(inode);
 395         struct btrfs_root *root = binode->root;
 396         struct btrfs_trans_handle *trans;
 397         struct fsxattr fa;
 398         unsigned old_flags;
 399         unsigned old_i_flags;
 400         int ret = 0;
 401
 402         if (!inode_owner_or_capable(inode))
 403                 return -EPERM;
 404
 405         if (btrfs_root_readonly(root))
 406                 return -EROFS;
 407
 408         memset(&fa, 0, sizeof(fa));
 409         if (copy_from_user(&fa, arg, sizeof(fa)))
 410                 return -EFAULT;
 411
 412         ret = check_xflags(fa.fsx_xflags);
 413         if (ret)
 414                 return ret;
 415
 416         if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
 417                 return -EOPNOTSUPP;
 418
 419         ret = mnt_want_write_file(file);
 420         if (ret)
 421                 return ret;
 422
 423         inode_lock(inode);
 424
 425         old_flags = binode->flags;
 426         old_i_flags = inode->i_flags;
 427
 428         /* We need the capabilities to change append-only or immutable inode */
 429         if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
 430              (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
 431             !capable(CAP_LINUX_IMMUTABLE)) {
 432                 ret = -EPERM;
 433                 goto out_unlock;
 434         }
 435
 436         if (fa.fsx_xflags & FS_XFLAG_SYNC)
 437                 binode->flags |= BTRFS_INODE_SYNC;
 438         else
 439                 binode->flags &= ~BTRFS_INODE_SYNC;
 440         if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
 441                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 442         else
 443                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 444         if (fa.fsx_xflags & FS_XFLAG_APPEND)
 445                 binode->flags |= BTRFS_INODE_APPEND;
 446         else
 447                 binode->flags &= ~BTRFS_INODE_APPEND;
 448         if (fa.fsx_xflags & FS_XFLAG_NODUMP)
 449                 binode->flags |= BTRFS_INODE_NODUMP;
 450         else
 451                 binode->flags &= ~BTRFS_INODE_NODUMP;
 452         if (fa.fsx_xflags & FS_XFLAG_NOATIME)
 453                 binode->flags |= BTRFS_INODE_NOATIME;
 454         else
 455                 binode->flags &= ~BTRFS_INODE_NOATIME;
 456
 457         /* 1 item for the inode */
 458         trans = btrfs_start_transaction(root, 1);
 459         if (IS_ERR(trans)) {
 460                 ret = PTR_ERR(trans);
 461                 goto out_unlock;
 462         }
 463
 464         btrfs_sync_inode_flags_to_i_flags(inode);
 465         inode_inc_iversion(inode);
 466         inode->i_ctime = current_time(inode);
 467         ret = btrfs_update_inode(trans, root, inode);
 468
 469         btrfs_end_transaction(trans);
 470
 471 out_unlock:
 472         if (ret) {
 473                 binode->flags = old_flags;
 474                 inode->i_flags = old_i_flags;
 475         }
 476
 477         inode_unlock(inode);
 478         mnt_drop_write_file(file);
 479
 480         return ret;
 481 }
 482
 483 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 484 {
 485         struct inode *inode = file_inode(file);
 486
 487         return put_user(inode->i_generation, arg);
 488 }
 489
 490 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 491 {
 492         struct inode *inode = file_inode(file);
 493         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 494         struct btrfs_device *device;
 495         struct request_queue *q;
 496         struct fstrim_range range;
 497         u64 minlen = ULLONG_MAX;
 498         u64 num_devices = 0;
 499         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 500         int ret;
 501
 502         if (!capable(CAP_SYS_ADMIN))
 503                 return -EPERM;
 504
 505         rcu_read_lock();
 506         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 507                                 dev_list) {
 508                 if (!device->bdev)
 509                         continue;
 510                 q = bdev_get_queue(device->bdev);
 511                 if (blk_queue_discard(q)) {
 512                         num_devices++;
 513                         minlen = min_t(u64, q->limits.discard_granularity,
 514                                      minlen);
 515                 }
 516         }
 517         rcu_read_unlock();
 518
 519         if (!num_devices)
 520                 return -EOPNOTSUPP;
 521         if (copy_from_user(&range, arg, sizeof(range)))
 522                 return -EFAULT;
 523         if (range.start > total_bytes ||
 524             range.len < fs_info->sb->s_blocksize)
 525                 return -EINVAL;
 526
 527         range.len = min(range.len, total_bytes - range.start);
 528         range.minlen = max(range.minlen, minlen);
 529         ret = btrfs_trim_fs(fs_info, &range);
 530         if (ret < 0)
 531                 return ret;
 532
 533         if (copy_to_user(arg, &range, sizeof(range)))
 534                 return -EFAULT;
 535
 536         return 0;
 537 }
 538
 539 int btrfs_is_empty_uuid(u8 *uuid)
 540 {
 541         int i;
 542
 543         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 544                 if (uuid[i])
 545                         return 0;
 546         }
 547         return 1;
 548 }
 549
 550 static noinline int create_subvol(struct inode *dir,
 551                                   struct dentry *dentry,
 552                                   const char *name, int namelen,
 553                                   u64 *async_transid,
 554                                   struct btrfs_qgroup_inherit *inherit)
 555 {
 556         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 557         struct btrfs_trans_handle *trans;
 558         struct btrfs_key key;
 559         struct btrfs_root_item *root_item;
 560         struct btrfs_inode_item *inode_item;
 561         struct extent_buffer *leaf;
 562         struct btrfs_root *root = BTRFS_I(dir)->root;
 563         struct btrfs_root *new_root;
 564         struct btrfs_block_rsv block_rsv;
 565         struct timespec cur_time = current_time(dir);
 566         struct inode *inode;
 567         int ret;
 568         int err;
 569         u64 objectid;
 570         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 571         u64 index = 0;
 572         uuid_le new_uuid;
 573
 574         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 575         if (!root_item)
 576                 return -ENOMEM;
 577
 578         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 579         if (ret)
 580                 goto fail_free;
 581
 582         /*
 583          * Don't create subvolume whose level is not zero. Or qgroup will be
 584          * screwed up since it assumes subvolume qgroup's level to be 0.
 585          */
 586         if (btrfs_qgroup_level(objectid)) {
 587                 ret = -ENOSPC;
 588                 goto fail_free;
 589         }
 590
 591         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 592         /*
 593          * The same as the snapshot creation, please see the comment
 594          * of create_snapshot().
 595          */
 596         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
 597         if (ret)
 598                 goto fail_free;
 599
 600         trans = btrfs_start_transaction(root, 0);
 601         if (IS_ERR(trans)) {
 602                 ret = PTR_ERR(trans);
 603                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 604                 goto fail_free;
 605         }
 606         trans->block_rsv = &block_rsv;
 607         trans->bytes_reserved = block_rsv.size;
 608
 609         ret = btrfs_qgroup_inherit(trans, fs_info, 0, objectid, inherit);
 610         if (ret)
 611                 goto fail;
 612
 613         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 614         if (IS_ERR(leaf)) {
 615                 ret = PTR_ERR(leaf);
 616                 goto fail;
 617         }
 618
 619         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
 620         btrfs_set_header_bytenr(leaf, leaf->start);
 621         btrfs_set_header_generation(leaf, trans->transid);
 622         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 623         btrfs_set_header_owner(leaf, objectid);
 624
 625         write_extent_buffer_fsid(leaf, fs_info->fsid);
 626         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
 627         btrfs_mark_buffer_dirty(leaf);
 628
 629         inode_item = &root_item->inode;
 630         btrfs_set_stack_inode_generation(inode_item, 1);
 631         btrfs_set_stack_inode_size(inode_item, 3);
 632         btrfs_set_stack_inode_nlink(inode_item, 1);
 633         btrfs_set_stack_inode_nbytes(inode_item,
 634                                      fs_info->nodesize);
 635         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 636
 637         btrfs_set_root_flags(root_item, 0);
 638         btrfs_set_root_limit(root_item, 0);
 639         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 640
 641         btrfs_set_root_bytenr(root_item, leaf->start);
 642         btrfs_set_root_generation(root_item, trans->transid);
 643         btrfs_set_root_level(root_item, 0);
 644         btrfs_set_root_refs(root_item, 1);
 645         btrfs_set_root_used(root_item, leaf->len);
 646         btrfs_set_root_last_snapshot(root_item, 0);
 647
 648         btrfs_set_root_generation_v2(root_item,
 649                         btrfs_root_generation(root_item));
 650         uuid_le_gen(&new_uuid);
 651         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 652         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 653         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 654         root_item->ctime = root_item->otime;
 655         btrfs_set_root_ctransid(root_item, trans->transid);
 656         btrfs_set_root_otransid(root_item, trans->transid);
 657
 658         btrfs_tree_unlock(leaf);
 659         free_extent_buffer(leaf);
 660         leaf = NULL;
 661
 662         btrfs_set_root_dirid(root_item, new_dirid);
 663
 664         key.objectid = objectid;
 665         key.offset = 0;
 666         key.type = BTRFS_ROOT_ITEM_KEY;
 667         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 668                                 root_item);
 669         if (ret)
 670                 goto fail;
 671
 672         key.offset = (u64)-1;
 673         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 674         if (IS_ERR(new_root)) {
 675                 ret = PTR_ERR(new_root);
 676                 btrfs_abort_transaction(trans, ret);
 677                 goto fail;
 678         }
 679
 680         btrfs_record_root_in_trans(trans, new_root);
 681
 682         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 683         if (ret) {
 684                 /* We potentially lose an unused inode item here */
 685                 btrfs_abort_transaction(trans, ret);
 686                 goto fail;
 687         }
 688
 689         mutex_lock(&new_root->objectid_mutex);
 690         new_root->highest_objectid = new_dirid;
 691         mutex_unlock(&new_root->objectid_mutex);
 692
 693         /*
 694          * insert the directory item
 695          */
 696         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 697         if (ret) {
 698                 btrfs_abort_transaction(trans, ret);
 699                 goto fail;
 700         }
 701
 702         ret = btrfs_insert_dir_item(trans, root,
 703                                     name, namelen, BTRFS_I(dir), &key,
 704                                     BTRFS_FT_DIR, index);
 705         if (ret) {
 706                 btrfs_abort_transaction(trans, ret);
 707                 goto fail;
 708         }
 709
 710         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 711         ret = btrfs_update_inode(trans, root, dir);
 712         BUG_ON(ret);
 713
 714         ret = btrfs_add_root_ref(trans, fs_info,
 715                                  objectid, root->root_key.objectid,
 716                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 717         BUG_ON(ret);
 718
 719         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 720                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 721         if (ret)
 722                 btrfs_abort_transaction(trans, ret);
 723
 724 fail:
 725         kfree(root_item);
 726         trans->block_rsv = NULL;
 727         trans->bytes_reserved = 0;
 728         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 729
 730         if (async_transid) {
 731                 *async_transid = trans->transid;
 732                 err = btrfs_commit_transaction_async(trans, 1);
 733                 if (err)
 734                         err = btrfs_commit_transaction(trans);
 735         } else {
 736                 err = btrfs_commit_transaction(trans);
 737         }
 738         if (err && !ret)
 739                 ret = err;
 740
 741         if (!ret) {
 742                 inode = btrfs_lookup_dentry(dir, dentry);
 743                 if (IS_ERR(inode))
 744                         return PTR_ERR(inode);
 745                 d_instantiate(dentry, inode);
 746         }
 747         return ret;
 748
 749 fail_free:
 750         kfree(root_item);
 751         return ret;
 752 }
 753
 754 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 755                            struct dentry *dentry,
 756                            u64 *async_transid, bool readonly,
 757                            struct btrfs_qgroup_inherit *inherit)
 758 {
 759         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 760         struct inode *inode;
 761         struct btrfs_pending_snapshot *pending_snapshot;
 762         struct btrfs_trans_handle *trans;
 763         int ret;
 764
 765         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 766                 return -EINVAL;
 767
 768         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 769         if (!pending_snapshot)
 770                 return -ENOMEM;
 771
 772         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 773                         GFP_KERNEL);
 774         pending_snapshot->path = btrfs_alloc_path();
 775         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 776                 ret = -ENOMEM;
 777                 goto free_pending;
 778         }
 779
 780         atomic_inc(&root->will_be_snapshotted);
 781         smp_mb__after_atomic();
 782         /* wait for no snapshot writes */
 783         wait_event(root->subv_writers->wait,
 784                    percpu_counter_sum(&root->subv_writers->counter) == 0);
 785
 786         ret = btrfs_start_delalloc_inodes(root);
 787         if (ret)
 788                 goto dec_and_free;
 789
 790         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 791
 792         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 793                              BTRFS_BLOCK_RSV_TEMP);
 794         /*
 795          * 1 - parent dir inode
 796          * 2 - dir entries
 797          * 1 - root item
 798          * 2 - root ref/backref
 799          * 1 - root of snapshot
 800          * 1 - UUID item
 801          */
 802         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 803                                         &pending_snapshot->block_rsv, 8,
 804                                         false);
 805         if (ret)
 806                 goto dec_and_free;
 807
 808         pending_snapshot->dentry = dentry;
 809         pending_snapshot->root = root;
 810         pending_snapshot->readonly = readonly;
 811         pending_snapshot->dir = dir;
 812         pending_snapshot->inherit = inherit;
 813
 814         trans = btrfs_start_transaction(root, 0);
 815         if (IS_ERR(trans)) {
 816                 ret = PTR_ERR(trans);
 817                 goto fail;
 818         }
 819
 820         spin_lock(&fs_info->trans_lock);
 821         list_add(&pending_snapshot->list,
 822                  &trans->transaction->pending_snapshots);
 823         spin_unlock(&fs_info->trans_lock);
 824         if (async_transid) {
 825                 *async_transid = trans->transid;
 826                 ret = btrfs_commit_transaction_async(trans, 1);
 827                 if (ret)
 828                         ret = btrfs_commit_transaction(trans);
 829         } else {
 830                 ret = btrfs_commit_transaction(trans);
 831         }
 832         if (ret)
 833                 goto fail;
 834
 835         ret = pending_snapshot->error;
 836         if (ret)
 837                 goto fail;
 838
 839         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 840         if (ret)
 841                 goto fail;
 842
 843         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 844         if (IS_ERR(inode)) {
 845                 ret = PTR_ERR(inode);
 846                 goto fail;
 847         }
 848
 849         d_instantiate(dentry, inode);
 850         ret = 0;
 851 fail:
 852         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 853 dec_and_free:
 854         if (atomic_dec_and_test(&root->will_be_snapshotted))
 855                 wake_up_var(&root->will_be_snapshotted);
 856 free_pending:
 857         kfree(pending_snapshot->root_item);
 858         btrfs_free_path(pending_snapshot->path);
 859         kfree(pending_snapshot);
 860
 861         return ret;
 862 }
 863
 864 /*  copy of may_delete in fs/namei.c()
 865  *      Check whether we can remove a link victim from directory dir, check
 866  *  whether the type of victim is right.
 867  *  1. We can't do it if dir is read-only (done in permission())
 868  *  2. We should have write and exec permissions on dir
 869  *  3. We can't remove anything from append-only dir
 870  *  4. We can't do anything with immutable dir (done in permission())
 871  *  5. If the sticky bit on dir is set we should either
 872  *      a. be owner of dir, or
 873  *      b. be owner of victim, or
 874  *      c. have CAP_FOWNER capability
 875  *  6. If the victim is append-only or immutable we can't do anything with
 876  *     links pointing to it.
 877  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 878  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 879  *  9. We can't remove a root or mountpoint.
 880  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 881  *     nfs_async_unlink().
 882  */
 883
 884 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 885 {
 886         int error;
 887
 888         if (d_really_is_negative(victim))
 889                 return -ENOENT;
 890
 891         BUG_ON(d_inode(victim->d_parent) != dir);
 892         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 893
 894         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 895         if (error)
 896                 return error;
 897         if (IS_APPEND(dir))
 898                 return -EPERM;
 899         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 900             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 901                 return -EPERM;
 902         if (isdir) {
 903                 if (!d_is_dir(victim))
 904                         return -ENOTDIR;
 905                 if (IS_ROOT(victim))
 906                         return -EBUSY;
 907         } else if (d_is_dir(victim))
 908                 return -EISDIR;
 909         if (IS_DEADDIR(dir))
 910                 return -ENOENT;
 911         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 912                 return -EBUSY;
 913         return 0;
 914 }
 915
 916 /* copy of may_create in fs/namei.c() */
 917 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 918 {
 919         if (d_really_is_positive(child))
 920                 return -EEXIST;
 921         if (IS_DEADDIR(dir))
 922                 return -ENOENT;
 923         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 924 }
 925
 926 /*
 927  * Create a new subvolume below @parent.  This is largely modeled after
 928  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 929  * inside this filesystem so it's quite a bit simpler.
 930  */
 931 static noinline int btrfs_mksubvol(const struct path *parent,
 932                                    const char *name, int namelen,
 933                                    struct btrfs_root *snap_src,
 934                                    u64 *async_transid, bool readonly,
 935                                    struct btrfs_qgroup_inherit *inherit)
 936 {
 937         struct inode *dir = d_inode(parent->dentry);
 938         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 939         struct dentry *dentry;
 940         int error;
 941
 942         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 943         if (error == -EINTR)
 944                 return error;
 945
 946         dentry = lookup_one_len(name, parent->dentry, namelen);
 947         error = PTR_ERR(dentry);
 948         if (IS_ERR(dentry))
 949                 goto out_unlock;
 950
 951         error = btrfs_may_create(dir, dentry);
 952         if (error)
 953                 goto out_dput;
 954
 955         /*
 956          * even if this name doesn't exist, we may get hash collisions.
 957          * check for them now when we can safely fail
 958          */
 959         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 960                                                dir->i_ino, name,
 961                                                namelen);
 962         if (error)
 963                 goto out_dput;
 964
 965         down_read(&fs_info->subvol_sem);
 966
 967         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 968                 goto out_up_read;
 969
 970         if (snap_src) {
 971                 error = create_snapshot(snap_src, dir, dentry,
 972                                         async_transid, readonly, inherit);
 973         } else {
 974                 error = create_subvol(dir, dentry, name, namelen,
 975                                       async_transid, inherit);
 976         }
 977         if (!error)
 978                 fsnotify_mkdir(dir, dentry);
 979 out_up_read:
 980         up_read(&fs_info->subvol_sem);
 981 out_dput:
 982         dput(dentry);
 983 out_unlock:
 984         inode_unlock(dir);
 985         return error;
 986 }
 987
 988 /*
 989  * When we're defragging a range, we don't want to kick it off again
 990  * if it is really just waiting for delalloc to send it down.
 991  * If we find a nice big extent or delalloc range for the bytes in the
 992  * file you want to defrag, we return 0 to let you know to skip this
 993  * part of the file
 994  */
 995 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 996 {
 997         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 998         struct extent_map *em = NULL;
 999         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1000         u64 end;
1001
1002         read_lock(&em_tree->lock);
1003         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1004         read_unlock(&em_tree->lock);
1005
1006         if (em) {
1007                 end = extent_map_end(em);
1008                 free_extent_map(em);
1009                 if (end - offset > thresh)
1010                         return 0;
1011         }
1012         /* if we already have a nice delalloc here, just stop */
1013         thresh /= 2;
1014         end = count_range_bits(io_tree, &offset, offset + thresh,
1015                                thresh, EXTENT_DELALLOC, 1);
1016         if (end >= thresh)
1017                 return 0;
1018         return 1;
1019 }
1020
1021 /*
1022  * helper function to walk through a file and find extents
1023  * newer than a specific transid, and smaller than thresh.
1024  *
1025  * This is used by the defragging code to find new and small
1026  * extents
1027  */
1028 static int find_new_extents(struct btrfs_root *root,
1029                             struct inode *inode, u64 newer_than,
1030                             u64 *off, u32 thresh)
1031 {
1032         struct btrfs_path *path;
1033         struct btrfs_key min_key;
1034         struct extent_buffer *leaf;
1035         struct btrfs_file_extent_item *extent;
1036         int type;
1037         int ret;
1038         u64 ino = btrfs_ino(BTRFS_I(inode));
1039
1040         path = btrfs_alloc_path();
1041         if (!path)
1042                 return -ENOMEM;
1043
1044         min_key.objectid = ino;
1045         min_key.type = BTRFS_EXTENT_DATA_KEY;
1046         min_key.offset = *off;
1047
1048         while (1) {
1049                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
1050                 if (ret != 0)
1051                         goto none;
1052 process_slot:
1053                 if (min_key.objectid != ino)
1054                         goto none;
1055                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1056                         goto none;
1057
1058                 leaf = path->nodes[0];
1059                 extent = btrfs_item_ptr(leaf, path->slots[0],
1060                                         struct btrfs_file_extent_item);
1061
1062                 type = btrfs_file_extent_type(leaf, extent);
1063                 if (type == BTRFS_FILE_EXTENT_REG &&
1064                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1065                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
1066                         *off = min_key.offset;
1067                         btrfs_free_path(path);
1068                         return 0;
1069                 }
1070
1071                 path->slots[0]++;
1072                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
1073                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1074                         goto process_slot;
1075                 }
1076
1077                 if (min_key.offset == (u64)-1)
1078                         goto none;
1079
1080                 min_key.offset++;
1081                 btrfs_release_path(path);
1082         }
1083 none:
1084         btrfs_free_path(path);
1085         return -ENOENT;
1086 }
1087
1088 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1089 {
1090         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1091         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1092         struct extent_map *em;
1093         u64 len = PAGE_SIZE;
1094
1095         /*
1096          * hopefully we have this extent in the tree already, try without
1097          * the full extent lock
1098          */
1099         read_lock(&em_tree->lock);
1100         em = lookup_extent_mapping(em_tree, start, len);
1101         read_unlock(&em_tree->lock);
1102
1103         if (!em) {
1104                 struct extent_state *cached = NULL;
1105                 u64 end = start + len - 1;
1106
1107                 /* get the big lock and read metadata off disk */
1108                 lock_extent_bits(io_tree, start, end, &cached);
1109                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1110                 unlock_extent_cached(io_tree, start, end, &cached);
1111
1112                 if (IS_ERR(em))
1113                         return NULL;
1114         }
1115
1116         return em;
1117 }
1118
1119 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1120 {
1121         struct extent_map *next;
1122         bool ret = true;
1123
1124         /* this is the last extent */
1125         if (em->start + em->len >= i_size_read(inode))
1126                 return false;
1127
1128         next = defrag_lookup_extent(inode, em->start + em->len);
1129         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1130                 ret = false;
1131         else if ((em->block_start + em->block_len == next->block_start) &&
1132                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1133                 ret = false;
1134
1135         free_extent_map(next);
1136         return ret;
1137 }
1138
1139 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1140                                u64 *last_len, u64 *skip, u64 *defrag_end,
1141                                int compress)
1142 {
1143         struct extent_map *em;
1144         int ret = 1;
1145         bool next_mergeable = true;
1146         bool prev_mergeable = true;
1147
1148         /*
1149          * make sure that once we start defragging an extent, we keep on
1150          * defragging it
1151          */
1152         if (start < *defrag_end)
1153                 return 1;
1154
1155         *skip = 0;
1156
1157         em = defrag_lookup_extent(inode, start);
1158         if (!em)
1159                 return 0;
1160
1161         /* this will cover holes, and inline extents */
1162         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1163                 ret = 0;
1164                 goto out;
1165         }
1166
1167         if (!*defrag_end)
1168                 prev_mergeable = false;
1169
1170         next_mergeable = defrag_check_next_extent(inode, em);
1171         /*
1172          * we hit a real extent, if it is big or the next extent is not a
1173          * real extent, don't bother defragging it
1174          */
1175         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1176             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1177                 ret = 0;
1178 out:
1179         /*
1180          * last_len ends up being a counter of how many bytes we've defragged.
1181          * every time we choose not to defrag an extent, we reset *last_len
1182          * so that the next tiny extent will force a defrag.
1183          *
1184          * The end result of this is that tiny extents before a single big
1185          * extent will force at least part of that big extent to be defragged.
1186          */
1187         if (ret) {
1188                 *defrag_end = extent_map_end(em);
1189         } else {
1190                 *last_len = 0;
1191                 *skip = extent_map_end(em);
1192                 *defrag_end = 0;
1193         }
1194
1195         free_extent_map(em);
1196         return ret;
1197 }
1198
1199 /*
1200  * it doesn't do much good to defrag one or two pages
1201  * at a time.  This pulls in a nice chunk of pages
1202  * to COW and defrag.
1203  *
1204  * It also makes sure the delalloc code has enough
1205  * dirty data to avoid making new small extents as part
1206  * of the defrag
1207  *
1208  * It's a good idea to start RA on this range
1209  * before calling this.
1210  */
1211 static int cluster_pages_for_defrag(struct inode *inode,
1212                                     struct page **pages,
1213                                     unsigned long start_index,
1214                                     unsigned long num_pages)
1215 {
1216         unsigned long file_end;
1217         u64 isize = i_size_read(inode);
1218         u64 page_start;
1219         u64 page_end;
1220         u64 page_cnt;
1221         int ret;
1222         int i;
1223         int i_done;
1224         struct btrfs_ordered_extent *ordered;
1225         struct extent_state *cached_state = NULL;
1226         struct extent_io_tree *tree;
1227         struct extent_changeset *data_reserved = NULL;
1228         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1229
1230         file_end = (isize - 1) >> PAGE_SHIFT;
1231         if (!isize || start_index > file_end)
1232                 return 0;
1233
1234         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1235
1236         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1237                         start_index << PAGE_SHIFT,
1238                         page_cnt << PAGE_SHIFT);
1239         if (ret)
1240                 return ret;
1241         i_done = 0;
1242         tree = &BTRFS_I(inode)->io_tree;
1243
1244         /* step one, lock all the pages */
1245         for (i = 0; i < page_cnt; i++) {
1246                 struct page *page;
1247 again:
1248                 page = find_or_create_page(inode->i_mapping,
1249                                            start_index + i, mask);
1250                 if (!page)
1251                         break;
1252
1253                 page_start = page_offset(page);
1254                 page_end = page_start + PAGE_SIZE - 1;
1255                 while (1) {
1256                         lock_extent_bits(tree, page_start, page_end,
1257                                          &cached_state);
1258                         ordered = btrfs_lookup_ordered_extent(inode,
1259                                                               page_start);
1260                         unlock_extent_cached(tree, page_start, page_end,
1261                                              &cached_state);
1262                         if (!ordered)
1263                                 break;
1264
1265                         unlock_page(page);
1266                         btrfs_start_ordered_extent(inode, ordered, 1);
1267                         btrfs_put_ordered_extent(ordered);
1268                         lock_page(page);
1269                         /*
1270                          * we unlocked the page above, so we need check if
1271                          * it was released or not.
1272                          */
1273                         if (page->mapping != inode->i_mapping) {
1274                                 unlock_page(page);
1275                                 put_page(page);
1276                                 goto again;
1277                         }
1278                 }
1279
1280                 if (!PageUptodate(page)) {
1281                         btrfs_readpage(NULL, page);
1282                         lock_page(page);
1283                         if (!PageUptodate(page)) {
1284                                 unlock_page(page);
1285                                 put_page(page);
1286                                 ret = -EIO;
1287                                 break;
1288                         }
1289                 }
1290
1291                 if (page->mapping != inode->i_mapping) {
1292                         unlock_page(page);
1293                         put_page(page);
1294                         goto again;
1295                 }
1296
1297                 pages[i] = page;
1298                 i_done++;
1299         }
1300         if (!i_done || ret)
1301                 goto out;
1302
1303         if (!(inode->i_sb->s_flags & SB_ACTIVE))
1304                 goto out;
1305
1306         /*
1307          * so now we have a nice long stream of locked
1308          * and up to date pages, lets wait on them
1309          */
1310         for (i = 0; i < i_done; i++)
1311                 wait_on_page_writeback(pages[i]);
1312
1313         page_start = page_offset(pages[0]);
1314         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1315
1316         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1317                          page_start, page_end - 1, &cached_state);
1318         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1319                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1320                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1321                           &cached_state);
1322
1323         if (i_done != page_cnt) {
1324                 spin_lock(&BTRFS_I(inode)->lock);
1325                 BTRFS_I(inode)->outstanding_extents++;
1326                 spin_unlock(&BTRFS_I(inode)->lock);
1327                 btrfs_delalloc_release_space(inode, data_reserved,
1328                                 start_index << PAGE_SHIFT,
1329                                 (page_cnt - i_done) << PAGE_SHIFT, true);
1330         }
1331
1332
1333         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1334                           &cached_state);
1335
1336         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1337                              page_start, page_end - 1, &cached_state);
1338
1339         for (i = 0; i < i_done; i++) {
1340                 clear_page_dirty_for_io(pages[i]);
1341                 ClearPageChecked(pages[i]);
1342                 set_page_extent_mapped(pages[i]);
1343                 set_page_dirty(pages[i]);
1344                 unlock_page(pages[i]);
1345                 put_page(pages[i]);
1346         }
1347         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1348                                        false);
1349         extent_changeset_free(data_reserved);
1350         return i_done;
1351 out:
1352         for (i = 0; i < i_done; i++) {
1353                 unlock_page(pages[i]);
1354                 put_page(pages[i]);
1355         }
1356         btrfs_delalloc_release_space(inode, data_reserved,
1357                         start_index << PAGE_SHIFT,
1358                         page_cnt << PAGE_SHIFT, true);
1359         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1360                                        true);
1361         extent_changeset_free(data_reserved);
1362         return ret;
1363
1364 }
1365
1366 int btrfs_defrag_file(struct inode *inode, struct file *file,
1367                       struct btrfs_ioctl_defrag_range_args *range,
1368                       u64 newer_than, unsigned long max_to_defrag)
1369 {
1370         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1371         struct btrfs_root *root = BTRFS_I(inode)->root;
1372         struct file_ra_state *ra = NULL;
1373         unsigned long last_index;
1374         u64 isize = i_size_read(inode);
1375         u64 last_len = 0;
1376         u64 skip = 0;
1377         u64 defrag_end = 0;
1378         u64 newer_off = range->start;
1379         unsigned long i;
1380         unsigned long ra_index = 0;
1381         int ret;
1382         int defrag_count = 0;
1383         int compress_type = BTRFS_COMPRESS_ZLIB;
1384         u32 extent_thresh = range->extent_thresh;
1385         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1386         unsigned long cluster = max_cluster;
1387         u64 new_align = ~((u64)SZ_128K - 1);
1388         struct page **pages = NULL;
1389         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1390
1391         if (isize == 0)
1392                 return 0;
1393
1394         if (range->start >= isize)
1395                 return -EINVAL;
1396
1397         if (do_compress) {
1398                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1399                         return -EINVAL;
1400                 if (range->compress_type)
1401                         compress_type = range->compress_type;
1402         }
1403
1404         if (extent_thresh == 0)
1405                 extent_thresh = SZ_256K;
1406
1407         /*
1408          * If we were not given a file, allocate a readahead context. As
1409          * readahead is just an optimization, defrag will work without it so
1410          * we don't error out.
1411          */
1412         if (!file) {
1413                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1414                 if (ra)
1415                         file_ra_state_init(ra, inode->i_mapping);
1416         } else {
1417                 ra = &file->f_ra;
1418         }
1419
1420         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1421         if (!pages) {
1422                 ret = -ENOMEM;
1423                 goto out_ra;
1424         }
1425
1426         /* find the last page to defrag */
1427         if (range->start + range->len > range->start) {
1428                 last_index = min_t(u64, isize - 1,
1429                          range->start + range->len - 1) >> PAGE_SHIFT;
1430         } else {
1431                 last_index = (isize - 1) >> PAGE_SHIFT;
1432         }
1433
1434         if (newer_than) {
1435                 ret = find_new_extents(root, inode, newer_than,
1436                                        &newer_off, SZ_64K);
1437                 if (!ret) {
1438                         range->start = newer_off;
1439                         /*
1440                          * we always align our defrag to help keep
1441                          * the extents in the file evenly spaced
1442                          */
1443                         i = (newer_off & new_align) >> PAGE_SHIFT;
1444                 } else
1445                         goto out_ra;
1446         } else {
1447                 i = range->start >> PAGE_SHIFT;
1448         }
1449         if (!max_to_defrag)
1450                 max_to_defrag = last_index - i + 1;
1451
1452         /*
1453          * make writeback starts from i, so the defrag range can be
1454          * written sequentially.
1455          */
1456         if (i < inode->i_mapping->writeback_index)
1457                 inode->i_mapping->writeback_index = i;
1458
1459         while (i <= last_index && defrag_count < max_to_defrag &&
1460                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1461                 /*
1462                  * make sure we stop running if someone unmounts
1463                  * the FS
1464                  */
1465                 if (!(inode->i_sb->s_flags & SB_ACTIVE))
1466                         break;
1467
1468                 if (btrfs_defrag_cancelled(fs_info)) {
1469                         btrfs_debug(fs_info, "defrag_file cancelled");
1470                         ret = -EAGAIN;
1471                         break;
1472                 }
1473
1474                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1475                                          extent_thresh, &last_len, &skip,
1476                                          &defrag_end, do_compress)){
1477                         unsigned long next;
1478                         /*
1479                          * the should_defrag function tells us how much to skip
1480                          * bump our counter by the suggested amount
1481                          */
1482                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1483                         i = max(i + 1, next);
1484                         continue;
1485                 }
1486
1487                 if (!newer_than) {
1488                         cluster = (PAGE_ALIGN(defrag_end) >>
1489                                    PAGE_SHIFT) - i;
1490                         cluster = min(cluster, max_cluster);
1491                 } else {
1492                         cluster = max_cluster;
1493                 }
1494
1495                 if (i + cluster > ra_index) {
1496                         ra_index = max(i, ra_index);
1497                         if (ra)
1498                                 page_cache_sync_readahead(inode->i_mapping, ra,
1499                                                 file, ra_index, cluster);
1500                         ra_index += cluster;
1501                 }
1502
1503                 inode_lock(inode);
1504                 if (do_compress)
1505                         BTRFS_I(inode)->defrag_compress = compress_type;
1506                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1507                 if (ret < 0) {
1508                         inode_unlock(inode);
1509                         goto out_ra;
1510                 }
1511
1512                 defrag_count += ret;
1513                 balance_dirty_pages_ratelimited(inode->i_mapping);
1514                 inode_unlock(inode);
1515
1516                 if (newer_than) {
1517                         if (newer_off == (u64)-1)
1518                                 break;
1519
1520                         if (ret > 0)
1521                                 i += ret;
1522
1523                         newer_off = max(newer_off + 1,
1524                                         (u64)i << PAGE_SHIFT);
1525
1526                         ret = find_new_extents(root, inode, newer_than,
1527                                                &newer_off, SZ_64K);
1528                         if (!ret) {
1529                                 range->start = newer_off;
1530                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1531                         } else {
1532                                 break;
1533                         }
1534                 } else {
1535                         if (ret > 0) {
1536                                 i += ret;
1537                                 last_len += ret << PAGE_SHIFT;
1538                         } else {
1539                                 i++;
1540                                 last_len = 0;
1541                         }
1542                 }
1543         }
1544
1545         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1546                 filemap_flush(inode->i_mapping);
1547                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1548                              &BTRFS_I(inode)->runtime_flags))
1549                         filemap_flush(inode->i_mapping);
1550         }
1551
1552         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1553                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1554         } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1555                 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1556         }
1557
1558         ret = defrag_count;
1559
1560 out_ra:
1561         if (do_compress) {
1562                 inode_lock(inode);
1563                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1564                 inode_unlock(inode);
1565         }
1566         if (!file)
1567                 kfree(ra);
1568         kfree(pages);
1569         return ret;
1570 }
1571
1572 static noinline int btrfs_ioctl_resize(struct file *file,
1573                                         void __user *arg)
1574 {
1575         struct inode *inode = file_inode(file);
1576         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1577         u64 new_size;
1578         u64 old_size;
1579         u64 devid = 1;
1580         struct btrfs_root *root = BTRFS_I(inode)->root;
1581         struct btrfs_ioctl_vol_args *vol_args;
1582         struct btrfs_trans_handle *trans;
1583         struct btrfs_device *device = NULL;
1584         char *sizestr;
1585         char *retptr;
1586         char *devstr = NULL;
1587         int ret = 0;
1588         int mod = 0;
1589
1590         if (!capable(CAP_SYS_ADMIN))
1591                 return -EPERM;
1592
1593         ret = mnt_want_write_file(file);
1594         if (ret)
1595                 return ret;
1596
1597         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1598                 mnt_drop_write_file(file);
1599                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1600         }
1601
1602         vol_args = memdup_user(arg, sizeof(*vol_args));
1603         if (IS_ERR(vol_args)) {
1604                 ret = PTR_ERR(vol_args);
1605                 goto out;
1606         }
1607
1608         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1609
1610         sizestr = vol_args->name;
1611         devstr = strchr(sizestr, ':');
1612         if (devstr) {
1613                 sizestr = devstr + 1;
1614                 *devstr = '\0';
1615                 devstr = vol_args->name;
1616                 ret = kstrtoull(devstr, 10, &devid);
1617                 if (ret)
1618                         goto out_free;
1619                 if (!devid) {
1620                         ret = -EINVAL;
1621                         goto out_free;
1622                 }
1623                 btrfs_info(fs_info, "resizing devid %llu", devid);
1624         }
1625
1626         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1627         if (!device) {
1628                 btrfs_info(fs_info, "resizer unable to find device %llu",
1629                            devid);
1630                 ret = -ENODEV;
1631                 goto out_free;
1632         }
1633
1634         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1635                 btrfs_info(fs_info,
1636                            "resizer unable to apply on readonly device %llu",
1637                        devid);
1638                 ret = -EPERM;
1639                 goto out_free;
1640         }
1641
1642         if (!strcmp(sizestr, "max"))
1643                 new_size = device->bdev->bd_inode->i_size;
1644         else {
1645                 if (sizestr[0] == '-') {
1646                         mod = -1;
1647                         sizestr++;
1648                 } else if (sizestr[0] == '+') {
1649                         mod = 1;
1650                         sizestr++;
1651                 }
1652                 new_size = memparse(sizestr, &retptr);
1653                 if (*retptr != '\0' || new_size == 0) {
1654                         ret = -EINVAL;
1655                         goto out_free;
1656                 }
1657         }
1658
1659         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1660                 ret = -EPERM;
1661                 goto out_free;
1662         }
1663
1664         old_size = btrfs_device_get_total_bytes(device);
1665
1666         if (mod < 0) {
1667                 if (new_size > old_size) {
1668                         ret = -EINVAL;
1669                         goto out_free;
1670                 }
1671                 new_size = old_size - new_size;
1672         } else if (mod > 0) {
1673                 if (new_size > ULLONG_MAX - old_size) {
1674                         ret = -ERANGE;
1675                         goto out_free;
1676                 }
1677                 new_size = old_size + new_size;
1678         }
1679
1680         if (new_size < SZ_256M) {
1681                 ret = -EINVAL;
1682                 goto out_free;
1683         }
1684         if (new_size > device->bdev->bd_inode->i_size) {
1685                 ret = -EFBIG;
1686                 goto out_free;
1687         }
1688
1689         new_size = round_down(new_size, fs_info->sectorsize);
1690
1691         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1692                           rcu_str_deref(device->name), new_size);
1693
1694         if (new_size > old_size) {
1695                 trans = btrfs_start_transaction(root, 0);
1696                 if (IS_ERR(trans)) {
1697                         ret = PTR_ERR(trans);
1698                         goto out_free;
1699                 }
1700                 ret = btrfs_grow_device(trans, device, new_size);
1701                 btrfs_commit_transaction(trans);
1702         } else if (new_size < old_size) {
1703                 ret = btrfs_shrink_device(device, new_size);
1704         } /* equal, nothing need to do */
1705
1706 out_free:
1707         kfree(vol_args);
1708 out:
1709         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1710         mnt_drop_write_file(file);
1711         return ret;
1712 }
1713
1714 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1715                                 const char *name, unsigned long fd, int subvol,
1716                                 u64 *transid, bool readonly,
1717                                 struct btrfs_qgroup_inherit *inherit)
1718 {
1719         int namelen;
1720         int ret = 0;
1721
1722         if (!S_ISDIR(file_inode(file)->i_mode))
1723                 return -ENOTDIR;
1724
1725         ret = mnt_want_write_file(file);
1726         if (ret)
1727                 goto out;
1728
1729         namelen = strlen(name);
1730         if (strchr(name, '/')) {
1731                 ret = -EINVAL;
1732                 goto out_drop_write;
1733         }
1734
1735         if (name[0] == '.' &&
1736            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1737                 ret = -EEXIST;
1738                 goto out_drop_write;
1739         }
1740
1741         if (subvol) {
1742                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1743                                      NULL, transid, readonly, inherit);
1744         } else {
1745                 struct fd src = fdget(fd);
1746                 struct inode *src_inode;
1747                 if (!src.file) {
1748                         ret = -EINVAL;
1749                         goto out_drop_write;
1750                 }
1751
1752                 src_inode = file_inode(src.file);
1753                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1754                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1755                                    "Snapshot src from another FS");
1756                         ret = -EXDEV;
1757                 } else if (!inode_owner_or_capable(src_inode)) {
1758                         /*
1759                          * Subvolume creation is not restricted, but snapshots
1760                          * are limited to own subvolumes only
1761                          */
1762                         ret = -EPERM;
1763                 } else {
1764                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1765                                              BTRFS_I(src_inode)->root,
1766                                              transid, readonly, inherit);
1767                 }
1768                 fdput(src);
1769         }
1770 out_drop_write:
1771         mnt_drop_write_file(file);
1772 out:
1773         return ret;
1774 }
1775
1776 static noinline int btrfs_ioctl_snap_create(struct file *file,
1777                                             void __user *arg, int subvol)
1778 {
1779         struct btrfs_ioctl_vol_args *vol_args;
1780         int ret;
1781
1782         if (!S_ISDIR(file_inode(file)->i_mode))
1783                 return -ENOTDIR;
1784
1785         vol_args = memdup_user(arg, sizeof(*vol_args));
1786         if (IS_ERR(vol_args))
1787                 return PTR_ERR(vol_args);
1788         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1789
1790         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1791                                               vol_args->fd, subvol,
1792                                               NULL, false, NULL);
1793
1794         kfree(vol_args);
1795         return ret;
1796 }
1797
1798 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1799                                                void __user *arg, int subvol)
1800 {
1801         struct btrfs_ioctl_vol_args_v2 *vol_args;
1802         int ret;
1803         u64 transid = 0;
1804         u64 *ptr = NULL;
1805         bool readonly = false;
1806         struct btrfs_qgroup_inherit *inherit = NULL;
1807
1808         if (!S_ISDIR(file_inode(file)->i_mode))
1809                 return -ENOTDIR;
1810
1811         vol_args = memdup_user(arg, sizeof(*vol_args));
1812         if (IS_ERR(vol_args))
1813                 return PTR_ERR(vol_args);
1814         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1815
1816         if (vol_args->flags &
1817             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1818               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1819                 ret = -EOPNOTSUPP;
1820                 goto free_args;
1821         }
1822
1823         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1824                 ptr = &transid;
1825         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1826                 readonly = true;
1827         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1828                 if (vol_args->size > PAGE_SIZE) {
1829                         ret = -EINVAL;
1830                         goto free_args;
1831                 }
1832                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1833                 if (IS_ERR(inherit)) {
1834                         ret = PTR_ERR(inherit);
1835                         goto free_args;
1836                 }
1837         }
1838
1839         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1840                                               vol_args->fd, subvol, ptr,
1841                                               readonly, inherit);
1842         if (ret)
1843                 goto free_inherit;
1844
1845         if (ptr && copy_to_user(arg +
1846                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1847                                         transid),
1848                                 ptr, sizeof(*ptr)))
1849                 ret = -EFAULT;
1850
1851 free_inherit:
1852         kfree(inherit);
1853 free_args:
1854         kfree(vol_args);
1855         return ret;
1856 }
1857
1858 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1859                                                 void __user *arg)
1860 {
1861         struct inode *inode = file_inode(file);
1862         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1863         struct btrfs_root *root = BTRFS_I(inode)->root;
1864         int ret = 0;
1865         u64 flags = 0;
1866
1867         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1868                 return -EINVAL;
1869
1870         down_read(&fs_info->subvol_sem);
1871         if (btrfs_root_readonly(root))
1872                 flags |= BTRFS_SUBVOL_RDONLY;
1873         up_read(&fs_info->subvol_sem);
1874
1875         if (copy_to_user(arg, &flags, sizeof(flags)))
1876                 ret = -EFAULT;
1877
1878         return ret;
1879 }
1880
1881 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1882                                               void __user *arg)
1883 {
1884         struct inode *inode = file_inode(file);
1885         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1886         struct btrfs_root *root = BTRFS_I(inode)->root;
1887         struct btrfs_trans_handle *trans;
1888         u64 root_flags;
1889         u64 flags;
1890         int ret = 0;
1891
1892         if (!inode_owner_or_capable(inode))
1893                 return -EPERM;
1894
1895         ret = mnt_want_write_file(file);
1896         if (ret)
1897                 goto out;
1898
1899         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1900                 ret = -EINVAL;
1901                 goto out_drop_write;
1902         }
1903
1904         if (copy_from_user(&flags, arg, sizeof(flags))) {
1905                 ret = -EFAULT;
1906                 goto out_drop_write;
1907         }
1908
1909         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1910                 ret = -EINVAL;
1911                 goto out_drop_write;
1912         }
1913
1914         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1915                 ret = -EOPNOTSUPP;
1916                 goto out_drop_write;
1917         }
1918
1919         down_write(&fs_info->subvol_sem);
1920
1921         /* nothing to do */
1922         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1923                 goto out_drop_sem;
1924
1925         root_flags = btrfs_root_flags(&root->root_item);
1926         if (flags & BTRFS_SUBVOL_RDONLY) {
1927                 btrfs_set_root_flags(&root->root_item,
1928                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1929         } else {
1930                 /*
1931                  * Block RO -> RW transition if this subvolume is involved in
1932                  * send
1933                  */
1934                 spin_lock(&root->root_item_lock);
1935                 if (root->send_in_progress == 0) {
1936                         btrfs_set_root_flags(&root->root_item,
1937                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1938                         spin_unlock(&root->root_item_lock);
1939                 } else {
1940                         spin_unlock(&root->root_item_lock);
1941                         btrfs_warn(fs_info,
1942                                    "Attempt to set subvolume %llu read-write during send",
1943                                    root->root_key.objectid);
1944                         ret = -EPERM;
1945                         goto out_drop_sem;
1946                 }
1947         }
1948
1949         trans = btrfs_start_transaction(root, 1);
1950         if (IS_ERR(trans)) {
1951                 ret = PTR_ERR(trans);
1952                 goto out_reset;
1953         }
1954
1955         ret = btrfs_update_root(trans, fs_info->tree_root,
1956                                 &root->root_key, &root->root_item);
1957         if (ret < 0) {
1958                 btrfs_end_transaction(trans);
1959                 goto out_reset;
1960         }
1961
1962         ret = btrfs_commit_transaction(trans);
1963
1964 out_reset:
1965         if (ret)
1966                 btrfs_set_root_flags(&root->root_item, root_flags);
1967 out_drop_sem:
1968         up_write(&fs_info->subvol_sem);
1969 out_drop_write:
1970         mnt_drop_write_file(file);
1971 out:
1972         return ret;
1973 }
1974
1975 static noinline int key_in_sk(struct btrfs_key *key,
1976                               struct btrfs_ioctl_search_key *sk)
1977 {
1978         struct btrfs_key test;
1979         int ret;
1980
1981         test.objectid = sk->min_objectid;
1982         test.type = sk->min_type;
1983         test.offset = sk->min_offset;
1984
1985         ret = btrfs_comp_cpu_keys(key, &test);
1986         if (ret < 0)
1987                 return 0;
1988
1989         test.objectid = sk->max_objectid;
1990         test.type = sk->max_type;
1991         test.offset = sk->max_offset;
1992
1993         ret = btrfs_comp_cpu_keys(key, &test);
1994         if (ret > 0)
1995                 return 0;
1996         return 1;
1997 }
1998
1999 static noinline int copy_to_sk(struct btrfs_path *path,
2000                                struct btrfs_key *key,
2001                                struct btrfs_ioctl_search_key *sk,
2002                                size_t *buf_size,
2003                                char __user *ubuf,
2004                                unsigned long *sk_offset,
2005                                int *num_found)
2006 {
2007         u64 found_transid;
2008         struct extent_buffer *leaf;
2009         struct btrfs_ioctl_search_header sh;
2010         struct btrfs_key test;
2011         unsigned long item_off;
2012         unsigned long item_len;
2013         int nritems;
2014         int i;
2015         int slot;
2016         int ret = 0;
2017
2018         leaf = path->nodes[0];
2019         slot = path->slots[0];
2020         nritems = btrfs_header_nritems(leaf);
2021
2022         if (btrfs_header_generation(leaf) > sk->max_transid) {
2023                 i = nritems;
2024                 goto advance_key;
2025         }
2026         found_transid = btrfs_header_generation(leaf);
2027
2028         for (i = slot; i < nritems; i++) {
2029                 item_off = btrfs_item_ptr_offset(leaf, i);
2030                 item_len = btrfs_item_size_nr(leaf, i);
2031
2032                 btrfs_item_key_to_cpu(leaf, key, i);
2033                 if (!key_in_sk(key, sk))
2034                         continue;
2035
2036                 if (sizeof(sh) + item_len > *buf_size) {
2037                         if (*num_found) {
2038                                 ret = 1;
2039                                 goto out;
2040                         }
2041
2042                         /*
2043                          * return one empty item back for v1, which does not
2044                          * handle -EOVERFLOW
2045                          */
2046
2047                         *buf_size = sizeof(sh) + item_len;
2048                         item_len = 0;
2049                         ret = -EOVERFLOW;
2050                 }
2051
2052                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2053                         ret = 1;
2054                         goto out;
2055                 }
2056
2057                 sh.objectid = key->objectid;
2058                 sh.offset = key->offset;
2059                 sh.type = key->type;
2060                 sh.len = item_len;
2061                 sh.transid = found_transid;
2062
2063                 /* copy search result header */
2064                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2065                         ret = -EFAULT;
2066                         goto out;
2067                 }
2068
2069                 *sk_offset += sizeof(sh);
2070
2071                 if (item_len) {
2072                         char __user *up = ubuf + *sk_offset;
2073                         /* copy the item */
2074                         if (read_extent_buffer_to_user(leaf, up,
2075                                                        item_off, item_len)) {
2076                                 ret = -EFAULT;
2077                                 goto out;
2078                         }
2079
2080                         *sk_offset += item_len;
2081                 }
2082                 (*num_found)++;
2083
2084                 if (ret) /* -EOVERFLOW from above */
2085                         goto out;
2086
2087                 if (*num_found >= sk->nr_items) {
2088                         ret = 1;
2089                         goto out;
2090                 }
2091         }
2092 advance_key:
2093         ret = 0;
2094         test.objectid = sk->max_objectid;
2095         test.type = sk->max_type;
2096         test.offset = sk->max_offset;
2097         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2098                 ret = 1;
2099         else if (key->offset < (u64)-1)
2100                 key->offset++;
2101         else if (key->type < (u8)-1) {
2102                 key->offset = 0;
2103                 key->type++;
2104         } else if (key->objectid < (u64)-1) {
2105                 key->offset = 0;
2106                 key->type = 0;
2107                 key->objectid++;
2108         } else
2109                 ret = 1;
2110 out:
2111         /*
2112          *  0: all items from this leaf copied, continue with next
2113          *  1: * more items can be copied, but unused buffer is too small
2114          *     * all items were found
2115          *     Either way, it will stops the loop which iterates to the next
2116          *     leaf
2117          *  -EOVERFLOW: item was to large for buffer
2118          *  -EFAULT: could not copy extent buffer back to userspace
2119          */
2120         return ret;
2121 }
2122
2123 static noinline int search_ioctl(struct inode *inode,
2124                                  struct btrfs_ioctl_search_key *sk,
2125                                  size_t *buf_size,
2126                                  char __user *ubuf)
2127 {
2128         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2129         struct btrfs_root *root;
2130         struct btrfs_key key;
2131         struct btrfs_path *path;
2132         int ret;
2133         int num_found = 0;
2134         unsigned long sk_offset = 0;
2135
2136         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2137                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2138                 return -EOVERFLOW;
2139         }
2140
2141         path = btrfs_alloc_path();
2142         if (!path)
2143                 return -ENOMEM;
2144
2145         if (sk->tree_id == 0) {
2146                 /* search the root of the inode that was passed */
2147                 root = BTRFS_I(inode)->root;
2148         } else {
2149                 key.objectid = sk->tree_id;
2150                 key.type = BTRFS_ROOT_ITEM_KEY;
2151                 key.offset = (u64)-1;
2152                 root = btrfs_read_fs_root_no_name(info, &key);
2153                 if (IS_ERR(root)) {
2154                         btrfs_free_path(path);
2155                         return PTR_ERR(root);
2156                 }
2157         }
2158
2159         key.objectid = sk->min_objectid;
2160         key.type = sk->min_type;
2161         key.offset = sk->min_offset;
2162
2163         while (1) {
2164                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2165                 if (ret != 0) {
2166                         if (ret > 0)
2167                                 ret = 0;
2168                         goto err;
2169                 }
2170                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2171                                  &sk_offset, &num_found);
2172                 btrfs_release_path(path);
2173                 if (ret)
2174                         break;
2175
2176         }
2177         if (ret > 0)
2178                 ret = 0;
2179 err:
2180         sk->nr_items = num_found;
2181         btrfs_free_path(path);
2182         return ret;
2183 }
2184
2185 static noinline int btrfs_ioctl_tree_search(struct file *file,
2186                                            void __user *argp)
2187 {
2188         struct btrfs_ioctl_search_args __user *uargs;
2189         struct btrfs_ioctl_search_key sk;
2190         struct inode *inode;
2191         int ret;
2192         size_t buf_size;
2193
2194         if (!capable(CAP_SYS_ADMIN))
2195                 return -EPERM;
2196
2197         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2198
2199         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2200                 return -EFAULT;
2201
2202         buf_size = sizeof(uargs->buf);
2203
2204         inode = file_inode(file);
2205         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2206
2207         /*
2208          * In the origin implementation an overflow is handled by returning a
2209          * search header with a len of zero, so reset ret.
2210          */
2211         if (ret == -EOVERFLOW)
2212                 ret = 0;
2213
2214         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2215                 ret = -EFAULT;
2216         return ret;
2217 }
2218
2219 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2220                                                void __user *argp)
2221 {
2222         struct btrfs_ioctl_search_args_v2 __user *uarg;
2223         struct btrfs_ioctl_search_args_v2 args;
2224         struct inode *inode;
2225         int ret;
2226         size_t buf_size;
2227         const size_t buf_limit = SZ_16M;
2228
2229         if (!capable(CAP_SYS_ADMIN))
2230                 return -EPERM;
2231
2232         /* copy search header and buffer size */
2233         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2234         if (copy_from_user(&args, uarg, sizeof(args)))
2235                 return -EFAULT;
2236
2237         buf_size = args.buf_size;
2238
2239         /* limit result size to 16MB */
2240         if (buf_size > buf_limit)
2241                 buf_size = buf_limit;
2242
2243         inode = file_inode(file);
2244         ret = search_ioctl(inode, &args.key, &buf_size,
2245                            (char __user *)(&uarg->buf[0]));
2246         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2247                 ret = -EFAULT;
2248         else if (ret == -EOVERFLOW &&
2249                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2250                 ret = -EFAULT;
2251
2252         return ret;
2253 }
2254
2255 /*
2256  * Search INODE_REFs to identify path name of 'dirid' directory
2257  * in a 'tree_id' tree. and sets path name to 'name'.
2258  */
2259 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2260                                 u64 tree_id, u64 dirid, char *name)
2261 {
2262         struct btrfs_root *root;
2263         struct btrfs_key key;
2264         char *ptr;
2265         int ret = -1;
2266         int slot;
2267         int len;
2268         int total_len = 0;
2269         struct btrfs_inode_ref *iref;
2270         struct extent_buffer *l;
2271         struct btrfs_path *path;
2272
2273         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2274                 name[0]='\0';
2275                 return 0;
2276         }
2277
2278         path = btrfs_alloc_path();
2279         if (!path)
2280                 return -ENOMEM;
2281
2282         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2283
2284         key.objectid = tree_id;
2285         key.type = BTRFS_ROOT_ITEM_KEY;
2286         key.offset = (u64)-1;
2287         root = btrfs_read_fs_root_no_name(info, &key);
2288         if (IS_ERR(root)) {
2289                 ret = PTR_ERR(root);
2290                 goto out;
2291         }
2292
2293         key.objectid = dirid;
2294         key.type = BTRFS_INODE_REF_KEY;
2295         key.offset = (u64)-1;
2296
2297         while (1) {
2298                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2299                 if (ret < 0)
2300                         goto out;
2301                 else if (ret > 0) {
2302                         ret = btrfs_previous_item(root, path, dirid,
2303                                                   BTRFS_INODE_REF_KEY);
2304                         if (ret < 0)
2305                                 goto out;
2306                         else if (ret > 0) {
2307                                 ret = -ENOENT;
2308                                 goto out;
2309                         }
2310                 }
2311
2312                 l = path->nodes[0];
2313                 slot = path->slots[0];
2314                 btrfs_item_key_to_cpu(l, &key, slot);
2315
2316                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2317                 len = btrfs_inode_ref_name_len(l, iref);
2318                 ptr -= len + 1;
2319                 total_len += len + 1;
2320                 if (ptr < name) {
2321                         ret = -ENAMETOOLONG;
2322                         goto out;
2323                 }
2324
2325                 *(ptr + len) = '/';
2326                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2327
2328                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2329                         break;
2330
2331                 btrfs_release_path(path);
2332                 key.objectid = key.offset;
2333                 key.offset = (u64)-1;
2334                 dirid = key.objectid;
2335         }
2336         memmove(name, ptr, total_len);
2337         name[total_len] = '\0';
2338         ret = 0;
2339 out:
2340         btrfs_free_path(path);
2341         return ret;
2342 }
2343
2344 static int btrfs_search_path_in_tree_user(struct inode *inode,
2345                                 struct btrfs_ioctl_ino_lookup_user_args *args)
2346 {
2347         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2348         struct super_block *sb = inode->i_sb;
2349         struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2350         u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2351         u64 dirid = args->dirid;
2352         unsigned long item_off;
2353         unsigned long item_len;
2354         struct btrfs_inode_ref *iref;
2355         struct btrfs_root_ref *rref;
2356         struct btrfs_root *root;
2357         struct btrfs_path *path;
2358         struct btrfs_key key, key2;
2359         struct extent_buffer *leaf;
2360         struct inode *temp_inode;
2361         char *ptr;
2362         int slot;
2363         int len;
2364         int total_len = 0;
2365         int ret;
2366
2367         path = btrfs_alloc_path();
2368         if (!path)
2369                 return -ENOMEM;
2370
2371         /*
2372          * If the bottom subvolume does not exist directly under upper_limit,
2373          * construct the path in from the bottom up.
2374          */
2375         if (dirid != upper_limit.objectid) {
2376                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2377
2378                 key.objectid = treeid;
2379                 key.type = BTRFS_ROOT_ITEM_KEY;
2380                 key.offset = (u64)-1;
2381                 root = btrfs_read_fs_root_no_name(fs_info, &key);
2382                 if (IS_ERR(root)) {
2383                         ret = PTR_ERR(root);
2384                         goto out;
2385                 }
2386
2387                 key.objectid = dirid;
2388                 key.type = BTRFS_INODE_REF_KEY;
2389                 key.offset = (u64)-1;
2390                 while (1) {
2391                         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2392                         if (ret < 0) {
2393                                 goto out;
2394                         } else if (ret > 0) {
2395                                 ret = btrfs_previous_item(root, path, dirid,
2396                                                           BTRFS_INODE_REF_KEY);
2397                                 if (ret < 0) {
2398                                         goto out;
2399                                 } else if (ret > 0) {
2400                                         ret = -ENOENT;
2401                                         goto out;
2402                                 }
2403                         }
2404
2405                         leaf = path->nodes[0];
2406                         slot = path->slots[0];
2407                         btrfs_item_key_to_cpu(leaf, &key, slot);
2408
2409                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2410                         len = btrfs_inode_ref_name_len(leaf, iref);
2411                         ptr -= len + 1;
2412                         total_len += len + 1;
2413                         if (ptr < args->path) {
2414                                 ret = -ENAMETOOLONG;
2415                                 goto out;
2416                         }
2417
2418                         *(ptr + len) = '/';
2419                         read_extent_buffer(leaf, ptr,
2420                                         (unsigned long)(iref + 1), len);
2421
2422                         /* Check the read+exec permission of this directory */
2423                         ret = btrfs_previous_item(root, path, dirid,
2424                                                   BTRFS_INODE_ITEM_KEY);
2425                         if (ret < 0) {
2426                                 goto out;
2427                         } else if (ret > 0) {
2428                                 ret = -ENOENT;
2429                                 goto out;
2430                         }
2431
2432                         leaf = path->nodes[0];
2433                         slot = path->slots[0];
2434                         btrfs_item_key_to_cpu(leaf, &key2, slot);
2435                         if (key2.objectid != dirid) {
2436                                 ret = -ENOENT;
2437                                 goto out;
2438                         }
2439
2440                         temp_inode = btrfs_iget(sb, &key2, root, NULL);
2441                         ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2442                         iput(temp_inode);
2443                         if (ret) {
2444                                 ret = -EACCES;
2445                                 goto out;
2446                         }
2447
2448                         if (key.offset == upper_limit.objectid)
2449                                 break;
2450                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2451                                 ret = -EACCES;
2452                                 goto out;
2453                         }
2454
2455                         btrfs_release_path(path);
2456                         key.objectid = key.offset;
2457                         key.offset = (u64)-1;
2458                         dirid = key.objectid;
2459                 }
2460
2461                 memmove(args->path, ptr, total_len);
2462                 args->path[total_len] = '\0';
2463                 btrfs_release_path(path);
2464         }
2465
2466         /* Get the bottom subvolume's name from ROOT_REF */
2467         root = fs_info->tree_root;
2468         key.objectid = treeid;
2469         key.type = BTRFS_ROOT_REF_KEY;
2470         key.offset = args->treeid;
2471         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2472         if (ret < 0) {
2473                 goto out;
2474         } else if (ret > 0) {
2475                 ret = -ENOENT;
2476                 goto out;
2477         }
2478
2479         leaf = path->nodes[0];
2480         slot = path->slots[0];
2481         btrfs_item_key_to_cpu(leaf, &key, slot);
2482
2483         item_off = btrfs_item_ptr_offset(leaf, slot);
2484         item_len = btrfs_item_size_nr(leaf, slot);
2485         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2486         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2487         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2488                 ret = -EINVAL;
2489                 goto out;
2490         }
2491
2492         /* Copy subvolume's name */
2493         item_off += sizeof(struct btrfs_root_ref);
2494         item_len -= sizeof(struct btrfs_root_ref);
2495         read_extent_buffer(leaf, args->name, item_off, item_len);
2496         args->name[item_len] = 0;
2497
2498 out:
2499         btrfs_free_path(path);
2500         return ret;
2501 }
2502
2503 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2504                                            void __user *argp)
2505 {
2506          struct btrfs_ioctl_ino_lookup_args *args;
2507          struct inode *inode;
2508         int ret = 0;
2509
2510         args = memdup_user(argp, sizeof(*args));
2511         if (IS_ERR(args))
2512                 return PTR_ERR(args);
2513
2514         inode = file_inode(file);
2515
2516         /*
2517          * Unprivileged query to obtain the containing subvolume root id. The
2518          * path is reset so it's consistent with btrfs_search_path_in_tree.
2519          */
2520         if (args->treeid == 0)
2521                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2522
2523         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2524                 args->name[0] = 0;
2525                 goto out;
2526         }
2527
2528         if (!capable(CAP_SYS_ADMIN)) {
2529                 ret = -EPERM;
2530                 goto out;
2531         }
2532
2533         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2534                                         args->treeid, args->objectid,
2535                                         args->name);
2536
2537 out:
2538         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2539                 ret = -EFAULT;
2540
2541         kfree(args);
2542         return ret;
2543 }
2544
2545 /*
2546  * Version of ino_lookup ioctl (unprivileged)
2547  *
2548  * The main differences from ino_lookup ioctl are:
2549  *
2550  *   1. Read + Exec permission will be checked using inode_permission() during
2551  *      path construction. -EACCES will be returned in case of failure.
2552  *   2. Path construction will be stopped at the inode number which corresponds
2553  *      to the fd with which this ioctl is called. If constructed path does not
2554  *      exist under fd's inode, -EACCES will be returned.
2555  *   3. The name of bottom subvolume is also searched and filled.
2556  */
2557 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2558 {
2559         struct btrfs_ioctl_ino_lookup_user_args *args;
2560         struct inode *inode;
2561         int ret;
2562
2563         args = memdup_user(argp, sizeof(*args));
2564         if (IS_ERR(args))
2565                 return PTR_ERR(args);
2566
2567         inode = file_inode(file);
2568
2569         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2570             BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2571                 /*
2572                  * The subvolume does not exist under fd with which this is
2573                  * called
2574                  */
2575                 kfree(args);
2576                 return -EACCES;
2577         }
2578
2579         ret = btrfs_search_path_in_tree_user(inode, args);
2580
2581         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2582                 ret = -EFAULT;
2583
2584         kfree(args);
2585         return ret;
2586 }
2587
2588 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2589 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2590 {
2591         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2592         struct btrfs_fs_info *fs_info;
2593         struct btrfs_root *root;
2594         struct btrfs_path *path;
2595         struct btrfs_key key;
2596         struct btrfs_root_item *root_item;
2597         struct btrfs_root_ref *rref;
2598         struct extent_buffer *leaf;
2599         unsigned long item_off;
2600         unsigned long item_len;
2601         struct inode *inode;
2602         int slot;
2603         int ret = 0;
2604
2605         path = btrfs_alloc_path();
2606         if (!path)
2607                 return -ENOMEM;
2608
2609         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2610         if (!subvol_info) {
2611                 btrfs_free_path(path);
2612                 return -ENOMEM;
2613         }
2614
2615         inode = file_inode(file);
2616         fs_info = BTRFS_I(inode)->root->fs_info;
2617
2618         /* Get root_item of inode's subvolume */
2619         key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2620         key.type = BTRFS_ROOT_ITEM_KEY;
2621         key.offset = (u64)-1;
2622         root = btrfs_read_fs_root_no_name(fs_info, &key);
2623         if (IS_ERR(root)) {
2624                 ret = PTR_ERR(root);
2625                 goto out;
2626         }
2627         root_item = &root->root_item;
2628
2629         subvol_info->treeid = key.objectid;
2630
2631         subvol_info->generation = btrfs_root_generation(root_item);
2632         subvol_info->flags = btrfs_root_flags(root_item);
2633
2634         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2635         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2636                                                     BTRFS_UUID_SIZE);
2637         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2638                                                     BTRFS_UUID_SIZE);
2639
2640         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2641         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2642         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2643
2644         subvol_info->otransid = btrfs_root_otransid(root_item);
2645         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2646         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2647
2648         subvol_info->stransid = btrfs_root_stransid(root_item);
2649         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2650         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2651
2652         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2653         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2654         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2655
2656         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2657                 /* Search root tree for ROOT_BACKREF of this subvolume */
2658                 root = fs_info->tree_root;
2659
2660                 key.type = BTRFS_ROOT_BACKREF_KEY;
2661                 key.offset = 0;
2662                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2663                 if (ret < 0) {
2664                         goto out;
2665                 } else if (path->slots[0] >=
2666                            btrfs_header_nritems(path->nodes[0])) {
2667                         ret = btrfs_next_leaf(root, path);
2668                         if (ret < 0) {
2669                                 goto out;
2670                         } else if (ret > 0) {
2671                                 ret = -EUCLEAN;
2672                                 goto out;
2673                         }
2674                 }
2675
2676                 leaf = path->nodes[0];
2677                 slot = path->slots[0];
2678                 btrfs_item_key_to_cpu(leaf, &key, slot);
2679                 if (key.objectid == subvol_info->treeid &&
2680                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2681                         subvol_info->parent_id = key.offset;
2682
2683                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2684                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2685
2686                         item_off = btrfs_item_ptr_offset(leaf, slot)
2687                                         + sizeof(struct btrfs_root_ref);
2688                         item_len = btrfs_item_size_nr(leaf, slot)
2689                                         - sizeof(struct btrfs_root_ref);
2690                         read_extent_buffer(leaf, subvol_info->name,
2691                                            item_off, item_len);
2692                 } else {
2693                         ret = -ENOENT;
2694                         goto out;
2695                 }
2696         }
2697
2698         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2699                 ret = -EFAULT;
2700
2701 out:
2702         btrfs_free_path(path);
2703         kzfree(subvol_info);
2704         return ret;
2705 }
2706
2707 /*
2708  * Return ROOT_REF information of the subvolume containing this inode
2709  * except the subvolume name.
2710  */
2711 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2712 {
2713         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2714         struct btrfs_root_ref *rref;
2715         struct btrfs_root *root;
2716         struct btrfs_path *path;
2717         struct btrfs_key key;
2718         struct extent_buffer *leaf;
2719         struct inode *inode;
2720         u64 objectid;
2721         int slot;
2722         int ret;
2723         u8 found;
2724
2725         path = btrfs_alloc_path();
2726         if (!path)
2727                 return -ENOMEM;
2728
2729         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2730         if (IS_ERR(rootrefs)) {
2731                 btrfs_free_path(path);
2732                 return PTR_ERR(rootrefs);
2733         }
2734
2735         inode = file_inode(file);
2736         root = BTRFS_I(inode)->root->fs_info->tree_root;
2737         objectid = BTRFS_I(inode)->root->root_key.objectid;
2738
2739         key.objectid = objectid;
2740         key.type = BTRFS_ROOT_REF_KEY;
2741         key.offset = rootrefs->min_treeid;
2742         found = 0;
2743
2744         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2745         if (ret < 0) {
2746                 goto out;
2747         } else if (path->slots[0] >=
2748                    btrfs_header_nritems(path->nodes[0])) {
2749                 ret = btrfs_next_leaf(root, path);
2750                 if (ret < 0) {
2751                         goto out;
2752                 } else if (ret > 0) {
2753                         ret = -EUCLEAN;
2754                         goto out;
2755                 }
2756         }
2757         while (1) {
2758                 leaf = path->nodes[0];
2759                 slot = path->slots[0];
2760
2761                 btrfs_item_key_to_cpu(leaf, &key, slot);
2762                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2763                         ret = 0;
2764                         goto out;
2765                 }
2766
2767                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2768                         ret = -EOVERFLOW;
2769                         goto out;
2770                 }
2771
2772                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2773                 rootrefs->rootref[found].treeid = key.offset;
2774                 rootrefs->rootref[found].dirid =
2775                                   btrfs_root_ref_dirid(leaf, rref);
2776                 found++;
2777
2778                 ret = btrfs_next_item(root, path);
2779                 if (ret < 0) {
2780                         goto out;
2781                 } else if (ret > 0) {
2782                         ret = -EUCLEAN;
2783                         goto out;
2784                 }
2785         }
2786
2787 out:
2788         if (!ret || ret == -EOVERFLOW) {
2789                 rootrefs->num_items = found;
2790                 /* update min_treeid for next search */
2791                 if (found)
2792                         rootrefs->min_treeid =
2793                                 rootrefs->rootref[found - 1].treeid + 1;
2794                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2795                         ret = -EFAULT;
2796         }
2797
2798         kfree(rootrefs);
2799         btrfs_free_path(path);
2800
2801         return ret;
2802 }
2803
2804 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2805                                              void __user *arg)
2806 {
2807         struct dentry *parent = file->f_path.dentry;
2808         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2809         struct dentry *dentry;
2810         struct inode *dir = d_inode(parent);
2811         struct inode *inode;
2812         struct btrfs_root *root = BTRFS_I(dir)->root;
2813         struct btrfs_root *dest = NULL;
2814         struct btrfs_ioctl_vol_args *vol_args;
2815         int namelen;
2816         int err = 0;
2817
2818         if (!S_ISDIR(dir->i_mode))
2819                 return -ENOTDIR;
2820
2821         vol_args = memdup_user(arg, sizeof(*vol_args));
2822         if (IS_ERR(vol_args))
2823                 return PTR_ERR(vol_args);
2824
2825         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2826         namelen = strlen(vol_args->name);
2827         if (strchr(vol_args->name, '/') ||
2828             strncmp(vol_args->name, "..", namelen) == 0) {
2829                 err = -EINVAL;
2830                 goto out;
2831         }
2832
2833         err = mnt_want_write_file(file);
2834         if (err)
2835                 goto out;
2836
2837
2838         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2839         if (err == -EINTR)
2840                 goto out_drop_write;
2841         dentry = lookup_one_len(vol_args->name, parent, namelen);
2842         if (IS_ERR(dentry)) {
2843                 err = PTR_ERR(dentry);
2844                 goto out_unlock_dir;
2845         }
2846
2847         if (d_really_is_negative(dentry)) {
2848                 err = -ENOENT;
2849                 goto out_dput;
2850         }
2851
2852         inode = d_inode(dentry);
2853         dest = BTRFS_I(inode)->root;
2854         if (!capable(CAP_SYS_ADMIN)) {
2855                 /*
2856                  * Regular user.  Only allow this with a special mount
2857                  * option, when the user has write+exec access to the
2858                  * subvol root, and when rmdir(2) would have been
2859                  * allowed.
2860                  *
2861                  * Note that this is _not_ check that the subvol is
2862                  * empty or doesn't contain data that we wouldn't
2863                  * otherwise be able to delete.
2864                  *
2865                  * Users who want to delete empty subvols should try
2866                  * rmdir(2).
2867                  */
2868                 err = -EPERM;
2869                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2870                         goto out_dput;
2871
2872                 /*
2873                  * Do not allow deletion if the parent dir is the same
2874                  * as the dir to be deleted.  That means the ioctl
2875                  * must be called on the dentry referencing the root
2876                  * of the subvol, not a random directory contained
2877                  * within it.
2878                  */
2879                 err = -EINVAL;
2880                 if (root == dest)
2881                         goto out_dput;
2882
2883                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2884                 if (err)
2885                         goto out_dput;
2886         }
2887
2888         /* check if subvolume may be deleted by a user */
2889         err = btrfs_may_delete(dir, dentry, 1);
2890         if (err)
2891                 goto out_dput;
2892
2893         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2894                 err = -EINVAL;
2895                 goto out_dput;
2896         }
2897
2898         inode_lock(inode);
2899         err = btrfs_delete_subvolume(dir, dentry);
2900         inode_unlock(inode);
2901         if (!err)
2902                 d_delete(dentry);
2903
2904 out_dput:
2905         dput(dentry);
2906 out_unlock_dir:
2907         inode_unlock(dir);
2908 out_drop_write:
2909         mnt_drop_write_file(file);
2910 out:
2911         kfree(vol_args);
2912         return err;
2913 }
2914
2915 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2916 {
2917         struct inode *inode = file_inode(file);
2918         struct btrfs_root *root = BTRFS_I(inode)->root;
2919         struct btrfs_ioctl_defrag_range_args *range;
2920         int ret;
2921
2922         ret = mnt_want_write_file(file);
2923         if (ret)
2924                 return ret;
2925
2926         if (btrfs_root_readonly(root)) {
2927                 ret = -EROFS;
2928                 goto out;
2929         }
2930
2931         switch (inode->i_mode & S_IFMT) {
2932         case S_IFDIR:
2933                 if (!capable(CAP_SYS_ADMIN)) {
2934                         ret = -EPERM;
2935                         goto out;
2936                 }
2937                 ret = btrfs_defrag_root(root);
2938                 break;
2939         case S_IFREG:
2940                 if (!(file->f_mode & FMODE_WRITE)) {
2941                         ret = -EINVAL;
2942                         goto out;
2943                 }
2944
2945                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2946                 if (!range) {
2947                         ret = -ENOMEM;
2948                         goto out;
2949                 }
2950
2951                 if (argp) {
2952                         if (copy_from_user(range, argp,
2953                                            sizeof(*range))) {
2954                                 ret = -EFAULT;
2955                                 kfree(range);
2956                                 goto out;
2957                         }
2958                         /* compression requires us to start the IO */
2959                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2960                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2961                                 range->extent_thresh = (u32)-1;
2962                         }
2963                 } else {
2964                         /* the rest are all set to zero by kzalloc */
2965                         range->len = (u64)-1;
2966                 }
2967                 ret = btrfs_defrag_file(file_inode(file), file,
2968                                         range, BTRFS_OLDEST_GENERATION, 0);
2969                 if (ret > 0)
2970                         ret = 0;
2971                 kfree(range);
2972                 break;
2973         default:
2974                 ret = -EINVAL;
2975         }
2976 out:
2977         mnt_drop_write_file(file);
2978         return ret;
2979 }
2980
2981 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2982 {
2983         struct btrfs_ioctl_vol_args *vol_args;
2984         int ret;
2985
2986         if (!capable(CAP_SYS_ADMIN))
2987                 return -EPERM;
2988
2989         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
2990                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2991
2992         vol_args = memdup_user(arg, sizeof(*vol_args));
2993         if (IS_ERR(vol_args)) {
2994                 ret = PTR_ERR(vol_args);
2995                 goto out;
2996         }
2997
2998         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2999         ret = btrfs_init_new_device(fs_info, vol_args->name);
3000
3001         if (!ret)
3002                 btrfs_info(fs_info, "disk added %s", vol_args->name);
3003
3004         kfree(vol_args);
3005 out:
3006         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3007         return ret;
3008 }
3009
3010 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3011 {
3012         struct inode *inode = file_inode(file);
3013         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3014         struct btrfs_ioctl_vol_args_v2 *vol_args;
3015         int ret;
3016
3017         if (!capable(CAP_SYS_ADMIN))
3018                 return -EPERM;
3019
3020         ret = mnt_want_write_file(file);
3021         if (ret)
3022                 return ret;
3023
3024         vol_args = memdup_user(arg, sizeof(*vol_args));
3025         if (IS_ERR(vol_args)) {
3026                 ret = PTR_ERR(vol_args);
3027                 goto err_drop;
3028         }
3029
3030         /* Check for compatibility reject unknown flags */
3031         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) {
3032                 ret = -EOPNOTSUPP;
3033                 goto out;
3034         }
3035
3036         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3037                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3038                 goto out;
3039         }
3040
3041         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3042                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3043         } else {
3044                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3045                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3046         }
3047         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3048
3049         if (!ret) {
3050                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3051                         btrfs_info(fs_info, "device deleted: id %llu",
3052                                         vol_args->devid);
3053                 else
3054                         btrfs_info(fs_info, "device deleted: %s",
3055                                         vol_args->name);
3056         }
3057 out:
3058         kfree(vol_args);
3059 err_drop:
3060         mnt_drop_write_file(file);
3061         return ret;
3062 }
3063
3064 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3065 {
3066         struct inode *inode = file_inode(file);
3067         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3068         struct btrfs_ioctl_vol_args *vol_args;
3069         int ret;
3070
3071         if (!capable(CAP_SYS_ADMIN))
3072                 return -EPERM;
3073
3074         ret = mnt_want_write_file(file);
3075         if (ret)
3076                 return ret;
3077
3078         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3079                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3080                 goto out_drop_write;
3081         }
3082
3083         vol_args = memdup_user(arg, sizeof(*vol_args));
3084         if (IS_ERR(vol_args)) {
3085                 ret = PTR_ERR(vol_args);
3086                 goto out;
3087         }
3088
3089         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3090         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3091
3092         if (!ret)
3093                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3094         kfree(vol_args);
3095 out:
3096         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3097 out_drop_write:
3098         mnt_drop_write_file(file);
3099
3100         return ret;
3101 }
3102
3103 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3104                                 void __user *arg)
3105 {
3106         struct btrfs_ioctl_fs_info_args *fi_args;
3107         struct btrfs_device *device;
3108         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3109         int ret = 0;
3110
3111         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3112         if (!fi_args)
3113                 return -ENOMEM;
3114
3115         rcu_read_lock();
3116         fi_args->num_devices = fs_devices->num_devices;
3117
3118         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3119                 if (device->devid > fi_args->max_id)
3120                         fi_args->max_id = device->devid;
3121         }
3122         rcu_read_unlock();
3123
3124         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
3125         fi_args->nodesize = fs_info->nodesize;
3126         fi_args->sectorsize = fs_info->sectorsize;
3127         fi_args->clone_alignment = fs_info->sectorsize;
3128
3129         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3130                 ret = -EFAULT;
3131
3132         kfree(fi_args);
3133         return ret;
3134 }
3135
3136 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3137                                  void __user *arg)
3138 {
3139         struct btrfs_ioctl_dev_info_args *di_args;
3140         struct btrfs_device *dev;
3141         int ret = 0;
3142         char *s_uuid = NULL;
3143
3144         di_args = memdup_user(arg, sizeof(*di_args));
3145         if (IS_ERR(di_args))
3146                 return PTR_ERR(di_args);
3147
3148         if (!btrfs_is_empty_uuid(di_args->uuid))
3149                 s_uuid = di_args->uuid;
3150
3151         rcu_read_lock();
3152         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
3153
3154         if (!dev) {
3155                 ret = -ENODEV;
3156                 goto out;
3157         }
3158
3159         di_args->devid = dev->devid;
3160         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3161         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3162         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3163         if (dev->name) {
3164                 struct rcu_string *name;
3165
3166                 name = rcu_dereference(dev->name);
3167                 strncpy(di_args->path, name->str, sizeof(di_args->path) - 1);
3168                 di_args->path[sizeof(di_args->path) - 1] = 0;
3169         } else {
3170                 di_args->path[0] = '\0';
3171         }
3172
3173 out:
3174         rcu_read_unlock();
3175         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3176                 ret = -EFAULT;
3177
3178         kfree(di_args);
3179         return ret;
3180 }
3181
3182 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
3183 {
3184         struct page *page;
3185
3186         page = grab_cache_page(inode->i_mapping, index);
3187         if (!page)
3188                 return ERR_PTR(-ENOMEM);
3189
3190         if (!PageUptodate(page)) {
3191                 int ret;
3192
3193                 ret = btrfs_readpage(NULL, page);
3194                 if (ret)
3195                         return ERR_PTR(ret);
3196                 lock_page(page);
3197                 if (!PageUptodate(page)) {
3198                         unlock_page(page);
3199                         put_page(page);
3200                         return ERR_PTR(-EIO);
3201                 }
3202                 if (page->mapping != inode->i_mapping) {
3203                         unlock_page(page);
3204                         put_page(page);
3205                         return ERR_PTR(-EAGAIN);
3206                 }
3207         }
3208
3209         return page;
3210 }
3211
3212 static int gather_extent_pages(struct inode *inode, struct page **pages,
3213                                int num_pages, u64 off)
3214 {
3215         int i;
3216         pgoff_t index = off >> PAGE_SHIFT;
3217
3218         for (i = 0; i < num_pages; i++) {
3219 again:
3220                 pages[i] = extent_same_get_page(inode, index + i);
3221                 if (IS_ERR(pages[i])) {
3222                         int err = PTR_ERR(pages[i]);
3223
3224                         if (err == -EAGAIN)
3225                                 goto again;
3226                         pages[i] = NULL;
3227                         return err;
3228                 }
3229         }
3230         return 0;
3231 }
3232
3233 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
3234                              bool retry_range_locking)
3235 {
3236         /*
3237          * Do any pending delalloc/csum calculations on inode, one way or
3238          * another, and lock file content.
3239          * The locking order is:
3240          *
3241          *   1) pages
3242          *   2) range in the inode's io tree
3243          */
3244         while (1) {
3245                 struct btrfs_ordered_extent *ordered;
3246                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3247                 ordered = btrfs_lookup_first_ordered_extent(inode,
3248                                                             off + len - 1);
3249                 if ((!ordered ||
3250                      ordered->file_offset + ordered->len <= off ||
3251                      ordered->file_offset >= off + len) &&
3252                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
3253                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
3254                         if (ordered)
3255                                 btrfs_put_ordered_extent(ordered);
3256                         break;
3257                 }
3258                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3259                 if (ordered)
3260                         btrfs_put_ordered_extent(ordered);
3261                 if (!retry_range_locking)
3262                         return -EAGAIN;
3263                 btrfs_wait_ordered_range(inode, off, len);
3264         }
3265         return 0;
3266 }
3267
3268 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
3269 {
3270         inode_unlock(inode1);
3271         inode_unlock(inode2);
3272 }
3273
3274 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
3275 {
3276         if (inode1 < inode2)
3277                 swap(inode1, inode2);
3278
3279         inode_lock_nested(inode1, I_MUTEX_PARENT);
3280         inode_lock_nested(inode2, I_MUTEX_CHILD);
3281 }
3282
3283 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
3284                                       struct inode *inode2, u64 loff2, u64 len)
3285 {
3286         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3287         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3288 }
3289
3290 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
3291                                     struct inode *inode2, u64 loff2, u64 len,
3292                                     bool retry_range_locking)
3293 {
3294         int ret;
3295
3296         if (inode1 < inode2) {
3297                 swap(inode1, inode2);
3298                 swap(loff1, loff2);
3299         }
3300         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
3301         if (ret)
3302                 return ret;
3303         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
3304         if (ret)
3305                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
3306                               loff1 + len - 1);
3307         return ret;
3308 }
3309
3310 struct cmp_pages {
3311         int             num_pages;
3312         struct page     **src_pages;
3313         struct page     **dst_pages;
3314 };
3315
3316 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
3317 {
3318         int i;
3319         struct page *pg;
3320
3321         for (i = 0; i < cmp->num_pages; i++) {
3322                 pg = cmp->src_pages[i];
3323                 if (pg) {
3324                         unlock_page(pg);
3325                         put_page(pg);
3326                 }
3327                 pg = cmp->dst_pages[i];
3328                 if (pg) {
3329                         unlock_page(pg);
3330                         put_page(pg);
3331                 }
3332         }
3333 }
3334
3335 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
3336                                   struct inode *dst, u64 dst_loff,
3337                                   u64 len, struct cmp_pages *cmp)
3338 {
3339         int ret;
3340         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
3341
3342         cmp->num_pages = num_pages;
3343
3344         ret = gather_extent_pages(src, cmp->src_pages, num_pages, loff);
3345         if (ret)
3346                 goto out;
3347
3348         ret = gather_extent_pages(dst, cmp->dst_pages, num_pages, dst_loff);
3349
3350 out:
3351         if (ret)
3352                 btrfs_cmp_data_free(cmp);
3353         return ret;
3354 }
3355
3356 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3357 {
3358         int ret = 0;
3359         int i;
3360         struct page *src_page, *dst_page;
3361         unsigned int cmp_len = PAGE_SIZE;
3362         void *addr, *dst_addr;
3363
3364         i = 0;
3365         while (len) {
3366                 if (len < PAGE_SIZE)
3367                         cmp_len = len;
3368
3369                 BUG_ON(i >= cmp->num_pages);
3370
3371                 src_page = cmp->src_pages[i];
3372                 dst_page = cmp->dst_pages[i];
3373                 ASSERT(PageLocked(src_page));
3374                 ASSERT(PageLocked(dst_page));
3375
3376                 addr = kmap_atomic(src_page);
3377                 dst_addr = kmap_atomic(dst_page);
3378
3379                 flush_dcache_page(src_page);
3380                 flush_dcache_page(dst_page);
3381
3382                 if (memcmp(addr, dst_addr, cmp_len))
3383                         ret = -EBADE;
3384
3385                 kunmap_atomic(addr);
3386                 kunmap_atomic(dst_addr);
3387
3388                 if (ret)
3389                         break;
3390
3391                 len -= cmp_len;
3392                 i++;
3393         }
3394
3395         return ret;
3396 }
3397
3398 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3399                                      u64 olen)
3400 {
3401         u64 len = *plen;
3402         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3403
3404         if (off + olen > inode->i_size || off + olen < off)
3405                 return -EINVAL;
3406
3407         /* if we extend to eof, continue to block boundary */
3408         if (off + len == inode->i_size)
3409                 *plen = len = ALIGN(inode->i_size, bs) - off;
3410
3411         /* Check that we are block aligned - btrfs_clone() requires this */
3412         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3413                 return -EINVAL;
3414
3415         return 0;
3416 }
3417
3418 static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
3419                                    struct inode *dst, u64 dst_loff,
3420                                    struct cmp_pages *cmp)
3421 {
3422         int ret;
3423         u64 len = olen;
3424         bool same_inode = (src == dst);
3425         u64 same_lock_start = 0;
3426         u64 same_lock_len = 0;
3427
3428         ret = extent_same_check_offsets(src, loff, &len, olen);
3429         if (ret)
3430                 return ret;
3431
3432         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3433         if (ret)
3434                 return ret;
3435
3436         if (same_inode) {
3437                 /*
3438                  * Single inode case wants the same checks, except we
3439                  * don't want our length pushed out past i_size as
3440                  * comparing that data range makes no sense.
3441                  *
3442                  * extent_same_check_offsets() will do this for an
3443                  * unaligned length at i_size, so catch it here and
3444                  * reject the request.
3445                  *
3446                  * This effectively means we require aligned extents
3447                  * for the single-inode case, whereas the other cases
3448                  * allow an unaligned length so long as it ends at
3449                  * i_size.
3450                  */
3451                 if (len != olen)
3452                         return -EINVAL;
3453
3454                 /* Check for overlapping ranges */
3455                 if (dst_loff + len > loff && dst_loff < loff + len)
3456                         return -EINVAL;
3457
3458                 same_lock_start = min_t(u64, loff, dst_loff);
3459                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3460         }
3461
3462 again:
3463         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, cmp);
3464         if (ret)
3465                 return ret;
3466
3467         if (same_inode)
3468                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3469                                         false);
3470         else
3471                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3472                                                false);
3473         /*
3474          * If one of the inodes has dirty pages in the respective range or
3475          * ordered extents, we need to flush dellaloc and wait for all ordered
3476          * extents in the range. We must unlock the pages and the ranges in the
3477          * io trees to avoid deadlocks when flushing delalloc (requires locking
3478          * pages) and when waiting for ordered extents to complete (they require
3479          * range locking).
3480          */
3481         if (ret == -EAGAIN) {
3482                 /*
3483                  * Ranges in the io trees already unlocked. Now unlock all
3484                  * pages before waiting for all IO to complete.
3485                  */
3486                 btrfs_cmp_data_free(cmp);
3487                 if (same_inode) {
3488                         btrfs_wait_ordered_range(src, same_lock_start,
3489                                                  same_lock_len);
3490                 } else {
3491                         btrfs_wait_ordered_range(src, loff, len);
3492                         btrfs_wait_ordered_range(dst, dst_loff, len);
3493                 }
3494                 goto again;
3495         }
3496         ASSERT(ret == 0);
3497         if (WARN_ON(ret)) {
3498                 /* ranges in the io trees already unlocked */
3499                 btrfs_cmp_data_free(cmp);
3500                 return ret;
3501         }
3502
3503         /* pass original length for comparison so we stay within i_size */
3504         ret = btrfs_cmp_data(olen, cmp);
3505         if (ret == 0)
3506                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3507
3508         if (same_inode)
3509                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3510                               same_lock_start + same_lock_len - 1);
3511         else
3512                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3513
3514         btrfs_cmp_data_free(cmp);
3515
3516         return ret;
3517 }
3518
3519 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3520
3521 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3522                              struct inode *dst, u64 dst_loff)
3523 {
3524         int ret;
3525         struct cmp_pages cmp;
3526         int num_pages = PAGE_ALIGN(BTRFS_MAX_DEDUPE_LEN) >> PAGE_SHIFT;
3527         bool same_inode = (src == dst);
3528         u64 i, tail_len, chunk_count;
3529
3530         if (olen == 0)
3531                 return 0;
3532
3533         if (same_inode)
3534                 inode_lock(src);
3535         else
3536                 btrfs_double_inode_lock(src, dst);
3537
3538         /* don't make the dst file partly checksummed */
3539         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3540             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3541                 ret = -EINVAL;
3542                 goto out_unlock;
3543         }
3544
3545         tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
3546         chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
3547         if (chunk_count == 0)
3548                 num_pages = PAGE_ALIGN(tail_len) >> PAGE_SHIFT;
3549
3550         /*
3551          * If deduping ranges in the same inode, locking rules make it
3552          * mandatory to always lock pages in ascending order to avoid deadlocks
3553          * with concurrent tasks (such as starting writeback/delalloc).
3554          */
3555         if (same_inode && dst_loff < loff)
3556                 swap(loff, dst_loff);
3557
3558         /*
3559          * We must gather up all the pages before we initiate our extent
3560          * locking. We use an array for the page pointers. Size of the array is
3561          * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
3562          */
3563         cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3564                                        GFP_KERNEL | __GFP_ZERO);
3565         cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3566                                        GFP_KERNEL | __GFP_ZERO);
3567         if (!cmp.src_pages || !cmp.dst_pages) {
3568                 ret = -ENOMEM;
3569                 goto out_free;
3570         }
3571
3572         for (i = 0; i < chunk_count; i++) {
3573                 ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
3574                                               dst, dst_loff, &cmp);
3575                 if (ret)
3576                         goto out_unlock;
3577
3578                 loff += BTRFS_MAX_DEDUPE_LEN;
3579                 dst_loff += BTRFS_MAX_DEDUPE_LEN;
3580         }
3581
3582         if (tail_len > 0)
3583                 ret = btrfs_extent_same_range(src, loff, tail_len, dst,
3584                                               dst_loff, &cmp);
3585
3586 out_unlock:
3587         if (same_inode)
3588                 inode_unlock(src);
3589         else
3590                 btrfs_double_inode_unlock(src, dst);
3591
3592 out_free:
3593         kvfree(cmp.src_pages);
3594         kvfree(cmp.dst_pages);
3595
3596         return ret;
3597 }
3598
3599 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3600                                 struct file *dst_file, u64 dst_loff)
3601 {
3602         struct inode *src = file_inode(src_file);
3603         struct inode *dst = file_inode(dst_file);
3604         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3605         ssize_t res;
3606
3607         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3608                 /*
3609                  * Btrfs does not support blocksize < page_size. As a
3610                  * result, btrfs_cmp_data() won't correctly handle
3611                  * this situation without an update.
3612                  */
3613                 return -EINVAL;
3614         }
3615
3616         res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3617         if (res)
3618                 return res;
3619         return olen;
3620 }
3621
3622 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3623                                      struct inode *inode,
3624                                      u64 endoff,
3625                                      const u64 destoff,
3626                                      const u64 olen,
3627                                      int no_time_update)
3628 {
3629         struct btrfs_root *root = BTRFS_I(inode)->root;
3630         int ret;
3631
3632         inode_inc_iversion(inode);
3633         if (!no_time_update)
3634                 inode->i_mtime = inode->i_ctime = current_time(inode);
3635         /*
3636          * We round up to the block size at eof when determining which
3637          * extents to clone above, but shouldn't round up the file size.
3638          */
3639         if (endoff > destoff + olen)
3640                 endoff = destoff + olen;
3641         if (endoff > inode->i_size)
3642                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3643
3644         ret = btrfs_update_inode(trans, root, inode);
3645         if (ret) {
3646                 btrfs_abort_transaction(trans, ret);
3647                 btrfs_end_transaction(trans);
3648                 goto out;
3649         }
3650         ret = btrfs_end_transaction(trans);
3651 out:
3652         return ret;
3653 }
3654
3655 static void clone_update_extent_map(struct btrfs_inode *inode,
3656                                     const struct btrfs_trans_handle *trans,
3657                                     const struct btrfs_path *path,
3658                                     const u64 hole_offset,
3659                                     const u64 hole_len)
3660 {
3661         struct extent_map_tree *em_tree = &inode->extent_tree;
3662         struct extent_map *em;
3663         int ret;
3664
3665         em = alloc_extent_map();
3666         if (!em) {
3667                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3668                 return;
3669         }
3670
3671         if (path) {
3672                 struct btrfs_file_extent_item *fi;
3673
3674                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3675                                     struct btrfs_file_extent_item);
3676                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3677                 em->generation = -1;
3678                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3679                     BTRFS_FILE_EXTENT_INLINE)
3680                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3681                                         &inode->runtime_flags);
3682         } else {
3683                 em->start = hole_offset;
3684                 em->len = hole_len;
3685                 em->ram_bytes = em->len;
3686                 em->orig_start = hole_offset;
3687                 em->block_start = EXTENT_MAP_HOLE;
3688                 em->block_len = 0;
3689                 em->orig_block_len = 0;
3690                 em->compress_type = BTRFS_COMPRESS_NONE;
3691                 em->generation = trans->transid;
3692         }
3693
3694         while (1) {
3695                 write_lock(&em_tree->lock);
3696                 ret = add_extent_mapping(em_tree, em, 1);
3697                 write_unlock(&em_tree->lock);
3698                 if (ret != -EEXIST) {
3699                         free_extent_map(em);
3700                         break;
3701                 }
3702                 btrfs_drop_extent_cache(inode, em->start,
3703                                         em->start + em->len - 1, 0);
3704         }
3705
3706         if (ret)
3707                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3708 }
3709
3710 /*
3711  * Make sure we do not end up inserting an inline extent into a file that has
3712  * already other (non-inline) extents. If a file has an inline extent it can
3713  * not have any other extents and the (single) inline extent must start at the
3714  * file offset 0. Failing to respect these rules will lead to file corruption,
3715  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3716  *
3717  * We can have extents that have been already written to disk or we can have
3718  * dirty ranges still in delalloc, in which case the extent maps and items are
3719  * created only when we run delalloc, and the delalloc ranges might fall outside
3720  * the range we are currently locking in the inode's io tree. So we check the
3721  * inode's i_size because of that (i_size updates are done while holding the
3722  * i_mutex, which we are holding here).
3723  * We also check to see if the inode has a size not greater than "datal" but has
3724  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3725  * protected against such concurrent fallocate calls by the i_mutex).
3726  *
3727  * If the file has no extents but a size greater than datal, do not allow the
3728  * copy because we would need turn the inline extent into a non-inline one (even
3729  * with NO_HOLES enabled). If we find our destination inode only has one inline
3730  * extent, just overwrite it with the source inline extent if its size is less
3731  * than the source extent's size, or we could copy the source inline extent's
3732  * data into the destination inode's inline extent if the later is greater then
3733  * the former.
3734  */
3735 static int clone_copy_inline_extent(struct inode *dst,
3736                                     struct btrfs_trans_handle *trans,
3737                                     struct btrfs_path *path,
3738                                     struct btrfs_key *new_key,
3739                                     const u64 drop_start,
3740                                     const u64 datal,
3741                                     const u64 skip,
3742                                     const u64 size,
3743                                     char *inline_data)
3744 {
3745         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3746         struct btrfs_root *root = BTRFS_I(dst)->root;
3747         const u64 aligned_end = ALIGN(new_key->offset + datal,
3748                                       fs_info->sectorsize);
3749         int ret;
3750         struct btrfs_key key;
3751
3752         if (new_key->offset > 0)
3753                 return -EOPNOTSUPP;
3754
3755         key.objectid = btrfs_ino(BTRFS_I(dst));
3756         key.type = BTRFS_EXTENT_DATA_KEY;
3757         key.offset = 0;
3758         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3759         if (ret < 0) {
3760                 return ret;
3761         } else if (ret > 0) {
3762                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3763                         ret = btrfs_next_leaf(root, path);
3764                         if (ret < 0)
3765                                 return ret;
3766                         else if (ret > 0)
3767                                 goto copy_inline_extent;
3768                 }
3769                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3770                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3771                     key.type == BTRFS_EXTENT_DATA_KEY) {
3772                         ASSERT(key.offset > 0);
3773                         return -EOPNOTSUPP;
3774                 }
3775         } else if (i_size_read(dst) <= datal) {
3776                 struct btrfs_file_extent_item *ei;
3777                 u64 ext_len;
3778
3779                 /*
3780                  * If the file size is <= datal, make sure there are no other
3781                  * extents following (can happen do to an fallocate call with
3782                  * the flag FALLOC_FL_KEEP_SIZE).
3783                  */
3784                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3785                                     struct btrfs_file_extent_item);
3786                 /*
3787                  * If it's an inline extent, it can not have other extents
3788                  * following it.
3789                  */
3790                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3791                     BTRFS_FILE_EXTENT_INLINE)
3792                         goto copy_inline_extent;
3793
3794                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3795                 if (ext_len > aligned_end)
3796                         return -EOPNOTSUPP;
3797
3798                 ret = btrfs_next_item(root, path);
3799                 if (ret < 0) {
3800                         return ret;
3801                 } else if (ret == 0) {
3802                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3803                                               path->slots[0]);
3804                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3805                             key.type == BTRFS_EXTENT_DATA_KEY)
3806                                 return -EOPNOTSUPP;
3807                 }
3808         }
3809
3810 copy_inline_extent:
3811         /*
3812          * We have no extent items, or we have an extent at offset 0 which may
3813          * or may not be inlined. All these cases are dealt the same way.
3814          */
3815         if (i_size_read(dst) > datal) {
3816                 /*
3817                  * If the destination inode has an inline extent...
3818                  * This would require copying the data from the source inline
3819                  * extent into the beginning of the destination's inline extent.
3820                  * But this is really complex, both extents can be compressed
3821                  * or just one of them, which would require decompressing and
3822                  * re-compressing data (which could increase the new compressed
3823                  * size, not allowing the compressed data to fit anymore in an
3824                  * inline extent).
3825                  * So just don't support this case for now (it should be rare,
3826                  * we are not really saving space when cloning inline extents).
3827                  */
3828                 return -EOPNOTSUPP;
3829         }
3830
3831         btrfs_release_path(path);
3832         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3833         if (ret)
3834                 return ret;
3835         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3836         if (ret)
3837                 return ret;
3838
3839         if (skip) {
3840                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3841
3842                 memmove(inline_data + start, inline_data + start + skip, datal);
3843         }
3844
3845         write_extent_buffer(path->nodes[0], inline_data,
3846                             btrfs_item_ptr_offset(path->nodes[0],
3847                                                   path->slots[0]),
3848                             size);
3849         inode_add_bytes(dst, datal);
3850
3851         return 0;
3852 }
3853
3854 /**
3855  * btrfs_clone() - clone a range from inode file to another
3856  *
3857  * @src: Inode to clone from
3858  * @inode: Inode to clone to
3859  * @off: Offset within source to start clone from
3860  * @olen: Original length, passed by user, of range to clone
3861  * @olen_aligned: Block-aligned value of olen
3862  * @destoff: Offset within @inode to start clone
3863  * @no_time_update: Whether to update mtime/ctime on the target inode
3864  */
3865 static int btrfs_clone(struct inode *src, struct inode *inode,
3866                        const u64 off, const u64 olen, const u64 olen_aligned,
3867                        const u64 destoff, int no_time_update)
3868 {
3869         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3870         struct btrfs_root *root = BTRFS_I(inode)->root;
3871         struct btrfs_path *path = NULL;
3872         struct extent_buffer *leaf;
3873         struct btrfs_trans_handle *trans;
3874         char *buf = NULL;
3875         struct btrfs_key key;
3876         u32 nritems;
3877         int slot;
3878         int ret;
3879         const u64 len = olen_aligned;
3880         u64 last_dest_end = destoff;
3881
3882         ret = -ENOMEM;
3883         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3884         if (!buf)
3885                 return ret;
3886
3887         path = btrfs_alloc_path();
3888         if (!path) {
3889                 kvfree(buf);
3890                 return ret;
3891         }
3892
3893         path->reada = READA_FORWARD;
3894         /* clone data */
3895         key.objectid = btrfs_ino(BTRFS_I(src));
3896         key.type = BTRFS_EXTENT_DATA_KEY;
3897         key.offset = off;
3898
3899         while (1) {
3900                 u64 next_key_min_offset = key.offset + 1;
3901
3902                 /*
3903                  * note the key will change type as we walk through the
3904                  * tree.
3905                  */
3906                 path->leave_spinning = 1;
3907                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3908                                 0, 0);
3909                 if (ret < 0)
3910                         goto out;
3911                 /*
3912                  * First search, if no extent item that starts at offset off was
3913                  * found but the previous item is an extent item, it's possible
3914                  * it might overlap our target range, therefore process it.
3915                  */
3916                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3917                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3918                                               path->slots[0] - 1);
3919                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3920                                 path->slots[0]--;
3921                 }
3922
3923                 nritems = btrfs_header_nritems(path->nodes[0]);
3924 process_slot:
3925                 if (path->slots[0] >= nritems) {
3926                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3927                         if (ret < 0)
3928                                 goto out;
3929                         if (ret > 0)
3930                                 break;
3931                         nritems = btrfs_header_nritems(path->nodes[0]);
3932                 }
3933                 leaf = path->nodes[0];
3934                 slot = path->slots[0];
3935
3936                 btrfs_item_key_to_cpu(leaf, &key, slot);
3937                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3938                     key.objectid != btrfs_ino(BTRFS_I(src)))
3939                         break;
3940
3941                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3942                         struct btrfs_file_extent_item *extent;
3943                         int type;
3944                         u32 size;
3945                         struct btrfs_key new_key;
3946                         u64 disko = 0, diskl = 0;
3947                         u64 datao = 0, datal = 0;
3948                         u8 comp;
3949                         u64 drop_start;
3950
3951                         extent = btrfs_item_ptr(leaf, slot,
3952                                                 struct btrfs_file_extent_item);
3953                         comp = btrfs_file_extent_compression(leaf, extent);
3954                         type = btrfs_file_extent_type(leaf, extent);
3955                         if (type == BTRFS_FILE_EXTENT_REG ||
3956                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3957                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3958                                                                       extent);
3959                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3960                                                                  extent);
3961                                 datao = btrfs_file_extent_offset(leaf, extent);
3962                                 datal = btrfs_file_extent_num_bytes(leaf,
3963                                                                     extent);
3964                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3965                                 /* take upper bound, may be compressed */
3966                                 datal = btrfs_file_extent_ram_bytes(leaf,
3967                                                                     extent);
3968                         }
3969
3970                         /*
3971                          * The first search might have left us at an extent
3972                          * item that ends before our target range's start, can
3973                          * happen if we have holes and NO_HOLES feature enabled.
3974                          */
3975                         if (key.offset + datal <= off) {
3976                                 path->slots[0]++;
3977                                 goto process_slot;
3978                         } else if (key.offset >= off + len) {
3979                                 break;
3980                         }
3981                         next_key_min_offset = key.offset + datal;
3982                         size = btrfs_item_size_nr(leaf, slot);
3983                         read_extent_buffer(leaf, buf,
3984                                            btrfs_item_ptr_offset(leaf, slot),
3985                                            size);
3986
3987                         btrfs_release_path(path);
3988                         path->leave_spinning = 0;
3989
3990                         memcpy(&new_key, &key, sizeof(new_key));
3991                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
3992                         if (off <= key.offset)
3993                                 new_key.offset = key.offset + destoff - off;
3994                         else
3995                                 new_key.offset = destoff;
3996
3997                         /*
3998                          * Deal with a hole that doesn't have an extent item
3999                          * that represents it (NO_HOLES feature enabled).
4000                          * This hole is either in the middle of the cloning
4001                          * range or at the beginning (fully overlaps it or
4002                          * partially overlaps it).
4003                          */
4004                         if (new_key.offset != last_dest_end)
4005                                 drop_start = last_dest_end;
4006                         else
4007                                 drop_start = new_key.offset;
4008
4009                         /*
4010                          * 1 - adjusting old extent (we may have to split it)
4011                          * 1 - add new extent
4012                          * 1 - inode update
4013                          */
4014                         trans = btrfs_start_transaction(root, 3);
4015                         if (IS_ERR(trans)) {
4016                                 ret = PTR_ERR(trans);
4017                                 goto out;
4018                         }
4019
4020                         if (type == BTRFS_FILE_EXTENT_REG ||
4021                             type == BTRFS_FILE_EXTENT_PREALLOC) {
4022                                 /*
4023                                  *    a  | --- range to clone ---|  b
4024                                  * | ------------- extent ------------- |
4025                                  */
4026
4027                                 /* subtract range b */
4028                                 if (key.offset + datal > off + len)
4029                                         datal = off + len - key.offset;
4030
4031                                 /* subtract range a */
4032                                 if (off > key.offset) {
4033                                         datao += off - key.offset;
4034                                         datal -= off - key.offset;
4035                                 }
4036
4037                                 ret = btrfs_drop_extents(trans, root, inode,
4038                                                          drop_start,
4039                                                          new_key.offset + datal,
4040                                                          1);
4041                                 if (ret) {
4042                                         if (ret != -EOPNOTSUPP)
4043                                                 btrfs_abort_transaction(trans,
4044                                                                         ret);
4045                                         btrfs_end_transaction(trans);
4046                                         goto out;
4047                                 }
4048
4049                                 ret = btrfs_insert_empty_item(trans, root, path,
4050                                                               &new_key, size);
4051                                 if (ret) {
4052                                         btrfs_abort_transaction(trans, ret);
4053                                         btrfs_end_transaction(trans);
4054                                         goto out;
4055                                 }
4056
4057                                 leaf = path->nodes[0];
4058                                 slot = path->slots[0];
4059                                 write_extent_buffer(leaf, buf,
4060                                             btrfs_item_ptr_offset(leaf, slot),
4061                                             size);
4062
4063                                 extent = btrfs_item_ptr(leaf, slot,
4064                                                 struct btrfs_file_extent_item);
4065
4066                                 /* disko == 0 means it's a hole */
4067                                 if (!disko)
4068                                         datao = 0;
4069
4070                                 btrfs_set_file_extent_offset(leaf, extent,
4071                                                              datao);
4072                                 btrfs_set_file_extent_num_bytes(leaf, extent,
4073                                                                 datal);
4074
4075                                 if (disko) {
4076                                         inode_add_bytes(inode, datal);
4077                                         ret = btrfs_inc_extent_ref(trans,
4078                                                         root,
4079                                                         disko, diskl, 0,
4080                                                         root->root_key.objectid,
4081                                                         btrfs_ino(BTRFS_I(inode)),
4082                                                         new_key.offset - datao);
4083                                         if (ret) {
4084                                                 btrfs_abort_transaction(trans,
4085                                                                         ret);
4086                                                 btrfs_end_transaction(trans);
4087                                                 goto out;
4088
4089                                         }
4090                                 }
4091                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
4092                                 u64 skip = 0;
4093                                 u64 trim = 0;
4094
4095                                 if (off > key.offset) {
4096                                         skip = off - key.offset;
4097                                         new_key.offset += skip;
4098                                 }
4099
4100                                 if (key.offset + datal > off + len)
4101                                         trim = key.offset + datal - (off + len);
4102
4103                                 if (comp && (skip || trim)) {
4104                                         ret = -EINVAL;
4105                                         btrfs_end_transaction(trans);
4106                                         goto out;
4107                                 }
4108                                 size -= skip + trim;
4109                                 datal -= skip + trim;
4110
4111                                 ret = clone_copy_inline_extent(inode,
4112                                                                trans, path,
4113                                                                &new_key,
4114                                                                drop_start,
4115                                                                datal,
4116                                                                skip, size, buf);
4117                                 if (ret) {
4118                                         if (ret != -EOPNOTSUPP)
4119                                                 btrfs_abort_transaction(trans,
4120                                                                         ret);
4121                                         btrfs_end_transaction(trans);
4122                                         goto out;
4123                                 }
4124                                 leaf = path->nodes[0];
4125                                 slot = path->slots[0];
4126                         }
4127
4128                         /* If we have an implicit hole (NO_HOLES feature). */
4129                         if (drop_start < new_key.offset)
4130                                 clone_update_extent_map(BTRFS_I(inode), trans,
4131                                                 NULL, drop_start,
4132                                                 new_key.offset - drop_start);
4133
4134                         clone_update_extent_map(BTRFS_I(inode), trans,
4135                                         path, 0, 0);
4136
4137                         btrfs_mark_buffer_dirty(leaf);
4138                         btrfs_release_path(path);
4139
4140                         last_dest_end = ALIGN(new_key.offset + datal,
4141                                               fs_info->sectorsize);
4142                         ret = clone_finish_inode_update(trans, inode,
4143                                                         last_dest_end,
4144                                                         destoff, olen,
4145                                                         no_time_update);
4146                         if (ret)
4147                                 goto out;
4148                         if (new_key.offset + datal >= destoff + len)
4149                                 break;
4150                 }
4151                 btrfs_release_path(path);
4152                 key.offset = next_key_min_offset;
4153
4154                 if (fatal_signal_pending(current)) {
4155                         ret = -EINTR;
4156                         goto out;
4157                 }
4158         }
4159         ret = 0;
4160
4161         if (last_dest_end < destoff + len) {
4162                 /*
4163                  * We have an implicit hole (NO_HOLES feature is enabled) that
4164                  * fully or partially overlaps our cloning range at its end.
4165                  */
4166                 btrfs_release_path(path);
4167
4168                 /*
4169                  * 1 - remove extent(s)
4170                  * 1 - inode update
4171                  */
4172                 trans = btrfs_start_transaction(root, 2);
4173                 if (IS_ERR(trans)) {
4174                         ret = PTR_ERR(trans);
4175                         goto out;
4176                 }
4177                 ret = btrfs_drop_extents(trans, root, inode,
4178                                          last_dest_end, destoff + len, 1);
4179                 if (ret) {
4180                         if (ret != -EOPNOTSUPP)
4181                                 btrfs_abort_transaction(trans, ret);
4182                         btrfs_end_transaction(trans);
4183                         goto out;
4184                 }
4185                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
4186                                 last_dest_end,
4187                                 destoff + len - last_dest_end);
4188                 ret = clone_finish_inode_update(trans, inode, destoff + len,
4189                                                 destoff, olen, no_time_update);
4190         }
4191
4192 out:
4193         btrfs_free_path(path);
4194         kvfree(buf);
4195         return ret;
4196 }
4197
4198 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
4199                                         u64 off, u64 olen, u64 destoff)
4200 {
4201         struct inode *inode = file_inode(file);
4202         struct inode *src = file_inode(file_src);
4203         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4204         struct btrfs_root *root = BTRFS_I(inode)->root;
4205         int ret;
4206         u64 len = olen;
4207         u64 bs = fs_info->sb->s_blocksize;
4208         int same_inode = src == inode;
4209
4210         /*
4211          * TODO:
4212          * - split compressed inline extents.  annoying: we need to
4213          *   decompress into destination's address_space (the file offset
4214          *   may change, so source mapping won't do), then recompress (or
4215          *   otherwise reinsert) a subrange.
4216          *
4217          * - split destination inode's inline extents.  The inline extents can
4218          *   be either compressed or non-compressed.
4219          */
4220
4221         if (btrfs_root_readonly(root))
4222                 return -EROFS;
4223
4224         if (file_src->f_path.mnt != file->f_path.mnt ||
4225             src->i_sb != inode->i_sb)
4226                 return -EXDEV;
4227
4228         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
4229                 return -EISDIR;
4230
4231         if (!same_inode) {
4232                 btrfs_double_inode_lock(src, inode);
4233         } else {
4234                 inode_lock(src);
4235         }
4236
4237         /* don't make the dst file partly checksummed */
4238         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
4239             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
4240                 ret = -EINVAL;
4241                 goto out_unlock;
4242         }
4243
4244         /* determine range to clone */
4245         ret = -EINVAL;
4246         if (off + len > src->i_size || off + len < off)
4247                 goto out_unlock;
4248         if (len == 0)
4249                 olen = len = src->i_size - off;
4250         /* if we extend to eof, continue to block boundary */
4251         if (off + len == src->i_size)
4252                 len = ALIGN(src->i_size, bs) - off;
4253
4254         if (len == 0) {
4255                 ret = 0;
4256                 goto out_unlock;
4257         }
4258
4259         /* verify the end result is block aligned */
4260         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
4261             !IS_ALIGNED(destoff, bs))
4262                 goto out_unlock;
4263
4264         /* verify if ranges are overlapped within the same file */
4265         if (same_inode) {
4266                 if (destoff + len > off && destoff < off + len)
4267                         goto out_unlock;
4268         }
4269
4270         if (destoff > inode->i_size) {
4271                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
4272                 if (ret)
4273                         goto out_unlock;
4274         }
4275
4276         /*
4277          * Lock the target range too. Right after we replace the file extent
4278          * items in the fs tree (which now point to the cloned data), we might
4279          * have a worker replace them with extent items relative to a write
4280          * operation that was issued before this clone operation (i.e. confront
4281          * with inode.c:btrfs_finish_ordered_io).
4282          */
4283         if (same_inode) {
4284                 u64 lock_start = min_t(u64, off, destoff);
4285                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
4286
4287                 ret = lock_extent_range(src, lock_start, lock_len, true);
4288         } else {
4289                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
4290                                                true);
4291         }
4292         ASSERT(ret == 0);
4293         if (WARN_ON(ret)) {
4294                 /* ranges in the io trees already unlocked */
4295                 goto out_unlock;
4296         }
4297
4298         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
4299
4300         if (same_inode) {
4301                 u64 lock_start = min_t(u64, off, destoff);
4302                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
4303
4304                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
4305         } else {
4306                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
4307         }
4308         /*
4309          * Truncate page cache pages so that future reads will see the cloned
4310          * data immediately and not the previous data.
4311          */
4312         truncate_inode_pages_range(&inode->i_data,
4313                                 round_down(destoff, PAGE_SIZE),
4314                                 round_up(destoff + len, PAGE_SIZE) - 1);
4315 out_unlock:
4316         if (!same_inode)
4317                 btrfs_double_inode_unlock(src, inode);
4318         else
4319                 inode_unlock(src);
4320         return ret;
4321 }
4322
4323 int btrfs_clone_file_range(struct file *src_file, loff_t off,
4324                 struct file *dst_file, loff_t destoff, u64 len)
4325 {
4326         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
4327 }
4328
4329 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4330 {
4331         struct inode *inode = file_inode(file);
4332         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4333         struct btrfs_root *root = BTRFS_I(inode)->root;
4334         struct btrfs_root *new_root;
4335         struct btrfs_dir_item *di;
4336         struct btrfs_trans_handle *trans;
4337         struct btrfs_path *path;
4338         struct btrfs_key location;
4339         struct btrfs_disk_key disk_key;
4340         u64 objectid = 0;
4341         u64 dir_id;
4342         int ret;
4343
4344         if (!capable(CAP_SYS_ADMIN))
4345                 return -EPERM;
4346
4347         ret = mnt_want_write_file(file);
4348         if (ret)
4349                 return ret;
4350
4351         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4352                 ret = -EFAULT;
4353                 goto out;
4354         }
4355
4356         if (!objectid)
4357                 objectid = BTRFS_FS_TREE_OBJECTID;
4358
4359         location.objectid = objectid;
4360         location.type = BTRFS_ROOT_ITEM_KEY;
4361         location.offset = (u64)-1;
4362
4363         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4364         if (IS_ERR(new_root)) {
4365                 ret = PTR_ERR(new_root);
4366                 goto out;
4367         }
4368         if (!is_fstree(new_root->objectid)) {
4369                 ret = -ENOENT;
4370                 goto out;
4371         }
4372
4373         path = btrfs_alloc_path();
4374         if (!path) {
4375                 ret = -ENOMEM;
4376                 goto out;
4377         }
4378         path->leave_spinning = 1;
4379
4380         trans = btrfs_start_transaction(root, 1);
4381         if (IS_ERR(trans)) {
4382                 btrfs_free_path(path);
4383                 ret = PTR_ERR(trans);
4384                 goto out;
4385         }
4386
4387         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4388         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4389                                    dir_id, "default", 7, 1);
4390         if (IS_ERR_OR_NULL(di)) {
4391                 btrfs_free_path(path);
4392                 btrfs_end_transaction(trans);
4393                 btrfs_err(fs_info,
4394                           "Umm, you don't have the default diritem, this isn't going to work");
4395                 ret = -ENOENT;
4396                 goto out;
4397         }
4398
4399         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4400         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4401         btrfs_mark_buffer_dirty(path->nodes[0]);
4402         btrfs_free_path(path);
4403
4404         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4405         btrfs_end_transaction(trans);
4406 out:
4407         mnt_drop_write_file(file);
4408         return ret;
4409 }
4410
4411 static void get_block_group_info(struct list_head *groups_list,
4412                                  struct btrfs_ioctl_space_info *space)
4413 {
4414         struct btrfs_block_group_cache *block_group;
4415
4416         space->total_bytes = 0;
4417         space->used_bytes = 0;
4418         space->flags = 0;
4419         list_for_each_entry(block_group, groups_list, list) {
4420                 space->flags = block_group->flags;
4421                 space->total_bytes += block_group->key.offset;
4422                 space->used_bytes +=
4423                         btrfs_block_group_used(&block_group->item);
4424         }
4425 }
4426
4427 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4428                                    void __user *arg)
4429 {
4430         struct btrfs_ioctl_space_args space_args;
4431         struct btrfs_ioctl_space_info space;
4432         struct btrfs_ioctl_space_info *dest;
4433         struct btrfs_ioctl_space_info *dest_orig;
4434         struct btrfs_ioctl_space_info __user *user_dest;
4435         struct btrfs_space_info *info;
4436         static const u64 types[] = {
4437                 BTRFS_BLOCK_GROUP_DATA,
4438                 BTRFS_BLOCK_GROUP_SYSTEM,
4439                 BTRFS_BLOCK_GROUP_METADATA,
4440                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4441         };
4442         int num_types = 4;
4443         int alloc_size;
4444         int ret = 0;
4445         u64 slot_count = 0;
4446         int i, c;
4447
4448         if (copy_from_user(&space_args,
4449                            (struct btrfs_ioctl_space_args __user *)arg,
4450                            sizeof(space_args)))
4451                 return -EFAULT;
4452
4453         for (i = 0; i < num_types; i++) {
4454                 struct btrfs_space_info *tmp;
4455
4456                 info = NULL;
4457                 rcu_read_lock();
4458                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4459                                         list) {
4460                         if (tmp->flags == types[i]) {
4461                                 info = tmp;
4462                                 break;
4463                         }
4464                 }
4465                 rcu_read_unlock();
4466
4467                 if (!info)
4468                         continue;
4469
4470                 down_read(&info->groups_sem);
4471                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4472                         if (!list_empty(&info->block_groups[c]))
4473                                 slot_count++;
4474                 }
4475                 up_read(&info->groups_sem);
4476         }
4477
4478         /*
4479          * Global block reserve, exported as a space_info
4480          */
4481         slot_count++;
4482
4483         /* space_slots == 0 means they are asking for a count */
4484         if (space_args.space_slots == 0) {
4485                 space_args.total_spaces = slot_count;
4486                 goto out;
4487         }
4488
4489         slot_count = min_t(u64, space_args.space_slots, slot_count);
4490
4491         alloc_size = sizeof(*dest) * slot_count;
4492
4493         /* we generally have at most 6 or so space infos, one for each raid
4494          * level.  So, a whole page should be more than enough for everyone
4495          */
4496         if (alloc_size > PAGE_SIZE)
4497                 return -ENOMEM;
4498
4499         space_args.total_spaces = 0;
4500         dest = kmalloc(alloc_size, GFP_KERNEL);
4501         if (!dest)
4502                 return -ENOMEM;
4503         dest_orig = dest;
4504
4505         /* now we have a buffer to copy into */
4506         for (i = 0; i < num_types; i++) {
4507                 struct btrfs_space_info *tmp;
4508
4509                 if (!slot_count)
4510                         break;
4511
4512                 info = NULL;
4513                 rcu_read_lock();
4514                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4515                                         list) {
4516                         if (tmp->flags == types[i]) {
4517                                 info = tmp;
4518                                 break;
4519                         }
4520                 }
4521                 rcu_read_unlock();
4522
4523                 if (!info)
4524                         continue;
4525                 down_read(&info->groups_sem);
4526                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4527                         if (!list_empty(&info->block_groups[c])) {
4528                                 get_block_group_info(&info->block_groups[c],
4529                                                      &space);
4530                                 memcpy(dest, &space, sizeof(space));
4531                                 dest++;
4532                                 space_args.total_spaces++;
4533                                 slot_count--;
4534                         }
4535                         if (!slot_count)
4536                                 break;
4537                 }
4538                 up_read(&info->groups_sem);
4539         }
4540
4541         /*
4542          * Add global block reserve
4543          */
4544         if (slot_count) {
4545                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4546
4547                 spin_lock(&block_rsv->lock);
4548                 space.total_bytes = block_rsv->size;
4549                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4550                 spin_unlock(&block_rsv->lock);
4551                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4552                 memcpy(dest, &space, sizeof(space));
4553                 space_args.total_spaces++;
4554         }
4555
4556         user_dest = (struct btrfs_ioctl_space_info __user *)
4557                 (arg + sizeof(struct btrfs_ioctl_space_args));
4558
4559         if (copy_to_user(user_dest, dest_orig, alloc_size))
4560                 ret = -EFAULT;
4561
4562         kfree(dest_orig);
4563 out:
4564         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4565                 ret = -EFAULT;
4566
4567         return ret;
4568 }
4569
4570 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4571                                             void __user *argp)
4572 {
4573         struct btrfs_trans_handle *trans;
4574         u64 transid;
4575         int ret;
4576
4577         trans = btrfs_attach_transaction_barrier(root);
4578         if (IS_ERR(trans)) {
4579                 if (PTR_ERR(trans) != -ENOENT)
4580                         return PTR_ERR(trans);
4581
4582                 /* No running transaction, don't bother */
4583                 transid = root->fs_info->last_trans_committed;
4584                 goto out;
4585         }
4586         transid = trans->transid;
4587         ret = btrfs_commit_transaction_async(trans, 0);
4588         if (ret) {
4589                 btrfs_end_transaction(trans);
4590                 return ret;
4591         }
4592 out:
4593         if (argp)
4594                 if (copy_to_user(argp, &transid, sizeof(transid)))
4595                         return -EFAULT;
4596         return 0;
4597 }
4598
4599 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4600                                            void __user *argp)
4601 {
4602         u64 transid;
4603
4604         if (argp) {
4605                 if (copy_from_user(&transid, argp, sizeof(transid)))
4606                         return -EFAULT;
4607         } else {
4608                 transid = 0;  /* current trans */
4609         }
4610         return btrfs_wait_for_commit(fs_info, transid);
4611 }
4612
4613 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4614 {
4615         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4616         struct btrfs_ioctl_scrub_args *sa;
4617         int ret;
4618
4619         if (!capable(CAP_SYS_ADMIN))
4620                 return -EPERM;
4621
4622         sa = memdup_user(arg, sizeof(*sa));
4623         if (IS_ERR(sa))
4624                 return PTR_ERR(sa);
4625
4626         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4627                 ret = mnt_want_write_file(file);
4628                 if (ret)
4629                         goto out;
4630         }
4631
4632         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4633                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4634                               0);
4635
4636         if (copy_to_user(arg, sa, sizeof(*sa)))
4637                 ret = -EFAULT;
4638
4639         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4640                 mnt_drop_write_file(file);
4641 out:
4642         kfree(sa);
4643         return ret;
4644 }
4645
4646 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4647 {
4648         if (!capable(CAP_SYS_ADMIN))
4649                 return -EPERM;
4650
4651         return btrfs_scrub_cancel(fs_info);
4652 }
4653
4654 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4655                                        void __user *arg)
4656 {
4657         struct btrfs_ioctl_scrub_args *sa;
4658         int ret;
4659
4660         if (!capable(CAP_SYS_ADMIN))
4661                 return -EPERM;
4662
4663         sa = memdup_user(arg, sizeof(*sa));
4664         if (IS_ERR(sa))
4665                 return PTR_ERR(sa);
4666
4667         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4668
4669         if (copy_to_user(arg, sa, sizeof(*sa)))
4670                 ret = -EFAULT;
4671
4672         kfree(sa);
4673         return ret;
4674 }
4675
4676 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4677                                       void __user *arg)
4678 {
4679         struct btrfs_ioctl_get_dev_stats *sa;
4680         int ret;
4681
4682         sa = memdup_user(arg, sizeof(*sa));
4683         if (IS_ERR(sa))
4684                 return PTR_ERR(sa);
4685
4686         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4687                 kfree(sa);
4688                 return -EPERM;
4689         }
4690
4691         ret = btrfs_get_dev_stats(fs_info, sa);
4692
4693         if (copy_to_user(arg, sa, sizeof(*sa)))
4694                 ret = -EFAULT;
4695
4696         kfree(sa);
4697         return ret;
4698 }
4699
4700 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4701                                     void __user *arg)
4702 {
4703         struct btrfs_ioctl_dev_replace_args *p;
4704         int ret;
4705
4706         if (!capable(CAP_SYS_ADMIN))
4707                 return -EPERM;
4708
4709         p = memdup_user(arg, sizeof(*p));
4710         if (IS_ERR(p))
4711                 return PTR_ERR(p);
4712
4713         switch (p->cmd) {
4714         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4715                 if (sb_rdonly(fs_info->sb)) {
4716                         ret = -EROFS;
4717                         goto out;
4718                 }
4719                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4720                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4721                 } else {
4722                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4723                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4724                 }
4725                 break;
4726         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4727                 btrfs_dev_replace_status(fs_info, p);
4728                 ret = 0;
4729                 break;
4730         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4731                 p->result = btrfs_dev_replace_cancel(fs_info);
4732                 ret = 0;
4733                 break;
4734         default:
4735                 ret = -EINVAL;
4736                 break;
4737         }
4738
4739         if (copy_to_user(arg, p, sizeof(*p)))
4740                 ret = -EFAULT;
4741 out:
4742         kfree(p);
4743         return ret;
4744 }
4745
4746 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4747 {
4748         int ret = 0;
4749         int i;
4750         u64 rel_ptr;
4751         int size;
4752         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4753         struct inode_fs_paths *ipath = NULL;
4754         struct btrfs_path *path;
4755
4756         if (!capable(CAP_DAC_READ_SEARCH))
4757                 return -EPERM;
4758
4759         path = btrfs_alloc_path();
4760         if (!path) {
4761                 ret = -ENOMEM;
4762                 goto out;
4763         }
4764
4765         ipa = memdup_user(arg, sizeof(*ipa));
4766         if (IS_ERR(ipa)) {
4767                 ret = PTR_ERR(ipa);
4768                 ipa = NULL;
4769                 goto out;
4770         }
4771
4772         size = min_t(u32, ipa->size, 4096);
4773         ipath = init_ipath(size, root, path);
4774         if (IS_ERR(ipath)) {
4775                 ret = PTR_ERR(ipath);
4776                 ipath = NULL;
4777                 goto out;
4778         }
4779
4780         ret = paths_from_inode(ipa->inum, ipath);
4781         if (ret < 0)
4782                 goto out;
4783
4784         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4785                 rel_ptr = ipath->fspath->val[i] -
4786                           (u64)(unsigned long)ipath->fspath->val;
4787                 ipath->fspath->val[i] = rel_ptr;
4788         }
4789
4790         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4791                            ipath->fspath, size);
4792         if (ret) {
4793                 ret = -EFAULT;
4794                 goto out;
4795         }
4796
4797 out:
4798         btrfs_free_path(path);
4799         free_ipath(ipath);
4800         kfree(ipa);
4801
4802         return ret;
4803 }
4804
4805 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4806 {
4807         struct btrfs_data_container *inodes = ctx;
4808         const size_t c = 3 * sizeof(u64);
4809
4810         if (inodes->bytes_left >= c) {
4811                 inodes->bytes_left -= c;
4812                 inodes->val[inodes->elem_cnt] = inum;
4813                 inodes->val[inodes->elem_cnt + 1] = offset;
4814                 inodes->val[inodes->elem_cnt + 2] = root;
4815                 inodes->elem_cnt += 3;
4816         } else {
4817                 inodes->bytes_missing += c - inodes->bytes_left;
4818                 inodes->bytes_left = 0;
4819                 inodes->elem_missed += 3;
4820         }
4821
4822         return 0;
4823 }
4824
4825 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4826                                         void __user *arg, int version)
4827 {
4828         int ret = 0;
4829         int size;
4830         struct btrfs_ioctl_logical_ino_args *loi;
4831         struct btrfs_data_container *inodes = NULL;
4832         struct btrfs_path *path = NULL;
4833         bool ignore_offset;
4834
4835         if (!capable(CAP_SYS_ADMIN))
4836                 return -EPERM;
4837
4838         loi = memdup_user(arg, sizeof(*loi));
4839         if (IS_ERR(loi))
4840                 return PTR_ERR(loi);
4841
4842         if (version == 1) {
4843                 ignore_offset = false;
4844                 size = min_t(u32, loi->size, SZ_64K);
4845         } else {
4846                 /* All reserved bits must be 0 for now */
4847                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4848                         ret = -EINVAL;
4849                         goto out_loi;
4850                 }
4851                 /* Only accept flags we have defined so far */
4852                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4853                         ret = -EINVAL;
4854                         goto out_loi;
4855                 }
4856                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4857                 size = min_t(u32, loi->size, SZ_16M);
4858         }
4859
4860         path = btrfs_alloc_path();
4861         if (!path) {
4862                 ret = -ENOMEM;
4863                 goto out;
4864         }
4865
4866         inodes = init_data_container(size);
4867         if (IS_ERR(inodes)) {
4868                 ret = PTR_ERR(inodes);
4869                 inodes = NULL;
4870                 goto out;
4871         }
4872
4873         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4874                                           build_ino_list, inodes, ignore_offset);
4875         if (ret == -EINVAL)
4876                 ret = -ENOENT;
4877         if (ret < 0)
4878                 goto out;
4879
4880         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4881                            size);
4882         if (ret)
4883                 ret = -EFAULT;
4884
4885 out:
4886         btrfs_free_path(path);
4887         kvfree(inodes);
4888 out_loi:
4889         kfree(loi);
4890
4891         return ret;
4892 }
4893
4894 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4895                                struct btrfs_ioctl_balance_args *bargs)
4896 {
4897         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4898
4899         bargs->flags = bctl->flags;
4900
4901         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4902                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4903         if (atomic_read(&fs_info->balance_pause_req))
4904                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4905         if (atomic_read(&fs_info->balance_cancel_req))
4906                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4907
4908         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4909         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4910         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4911
4912         spin_lock(&fs_info->balance_lock);
4913         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4914         spin_unlock(&fs_info->balance_lock);
4915 }
4916
4917 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4918 {
4919         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4920         struct btrfs_fs_info *fs_info = root->fs_info;
4921         struct btrfs_ioctl_balance_args *bargs;
4922         struct btrfs_balance_control *bctl;
4923         bool need_unlock; /* for mut. excl. ops lock */
4924         int ret;
4925
4926         if (!capable(CAP_SYS_ADMIN))
4927                 return -EPERM;
4928
4929         ret = mnt_want_write_file(file);
4930         if (ret)
4931                 return ret;
4932
4933 again:
4934         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4935                 mutex_lock(&fs_info->balance_mutex);
4936                 need_unlock = true;
4937                 goto locked;
4938         }
4939
4940         /*
4941          * mut. excl. ops lock is locked.  Three possibilities:
4942          *   (1) some other op is running
4943          *   (2) balance is running
4944          *   (3) balance is paused -- special case (think resume)
4945          */
4946         mutex_lock(&fs_info->balance_mutex);
4947         if (fs_info->balance_ctl) {
4948                 /* this is either (2) or (3) */
4949                 if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4950                         mutex_unlock(&fs_info->balance_mutex);
4951                         /*
4952                          * Lock released to allow other waiters to continue,
4953                          * we'll reexamine the status again.
4954                          */
4955                         mutex_lock(&fs_info->balance_mutex);
4956
4957                         if (fs_info->balance_ctl &&
4958                             !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4959                                 /* this is (3) */
4960                                 need_unlock = false;
4961                                 goto locked;
4962                         }
4963
4964                         mutex_unlock(&fs_info->balance_mutex);
4965                         goto again;
4966                 } else {
4967                         /* this is (2) */
4968                         mutex_unlock(&fs_info->balance_mutex);
4969                         ret = -EINPROGRESS;
4970                         goto out;
4971                 }
4972         } else {
4973                 /* this is (1) */
4974                 mutex_unlock(&fs_info->balance_mutex);
4975                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4976                 goto out;
4977         }
4978
4979 locked:
4980         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4981
4982         if (arg) {
4983                 bargs = memdup_user(arg, sizeof(*bargs));
4984                 if (IS_ERR(bargs)) {
4985                         ret = PTR_ERR(bargs);
4986                         goto out_unlock;
4987                 }
4988
4989                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4990                         if (!fs_info->balance_ctl) {
4991                                 ret = -ENOTCONN;
4992                                 goto out_bargs;
4993                         }
4994
4995                         bctl = fs_info->balance_ctl;
4996                         spin_lock(&fs_info->balance_lock);
4997                         bctl->flags |= BTRFS_BALANCE_RESUME;
4998                         spin_unlock(&fs_info->balance_lock);
4999
5000                         goto do_balance;
5001                 }
5002         } else {
5003                 bargs = NULL;
5004         }
5005
5006         if (fs_info->balance_ctl) {
5007                 ret = -EINPROGRESS;
5008                 goto out_bargs;
5009         }
5010
5011         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
5012         if (!bctl) {
5013                 ret = -ENOMEM;
5014                 goto out_bargs;
5015         }
5016
5017         if (arg) {
5018                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
5019                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
5020                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
5021
5022                 bctl->flags = bargs->flags;
5023         } else {
5024                 /* balance everything - no filters */
5025                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
5026         }
5027
5028         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
5029                 ret = -EINVAL;
5030                 goto out_bctl;
5031         }
5032
5033 do_balance:
5034         /*
5035          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
5036          * btrfs_balance.  bctl is freed in reset_balance_state, or, if
5037          * restriper was paused all the way until unmount, in free_fs_info.
5038          * The flag should be cleared after reset_balance_state.
5039          */
5040         need_unlock = false;
5041
5042         ret = btrfs_balance(fs_info, bctl, bargs);
5043         bctl = NULL;
5044
5045         if (arg) {
5046                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
5047                         ret = -EFAULT;
5048         }
5049
5050 out_bctl:
5051         kfree(bctl);
5052 out_bargs:
5053         kfree(bargs);
5054 out_unlock:
5055         mutex_unlock(&fs_info->balance_mutex);
5056         if (need_unlock)
5057                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
5058 out:
5059         mnt_drop_write_file(file);
5060         return ret;
5061 }
5062
5063 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
5064 {
5065         if (!capable(CAP_SYS_ADMIN))
5066                 return -EPERM;
5067
5068         switch (cmd) {
5069         case BTRFS_BALANCE_CTL_PAUSE:
5070                 return btrfs_pause_balance(fs_info);
5071         case BTRFS_BALANCE_CTL_CANCEL:
5072                 return btrfs_cancel_balance(fs_info);
5073         }
5074
5075         return -EINVAL;
5076 }
5077
5078 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
5079                                          void __user *arg)
5080 {
5081         struct btrfs_ioctl_balance_args *bargs;
5082         int ret = 0;
5083
5084         if (!capable(CAP_SYS_ADMIN))
5085                 return -EPERM;
5086
5087         mutex_lock(&fs_info->balance_mutex);
5088         if (!fs_info->balance_ctl) {
5089                 ret = -ENOTCONN;
5090                 goto out;
5091         }
5092
5093         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
5094         if (!bargs) {
5095                 ret = -ENOMEM;
5096                 goto out;
5097         }
5098
5099         btrfs_update_ioctl_balance_args(fs_info, bargs);
5100
5101         if (copy_to_user(arg, bargs, sizeof(*bargs)))
5102                 ret = -EFAULT;
5103
5104         kfree(bargs);
5105 out:
5106         mutex_unlock(&fs_info->balance_mutex);
5107         return ret;
5108 }
5109
5110 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
5111 {
5112         struct inode *inode = file_inode(file);
5113         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5114         struct btrfs_ioctl_quota_ctl_args *sa;
5115         struct btrfs_trans_handle *trans = NULL;
5116         int ret;
5117         int err;
5118
5119         if (!capable(CAP_SYS_ADMIN))
5120                 return -EPERM;
5121
5122         ret = mnt_want_write_file(file);
5123         if (ret)
5124                 return ret;
5125
5126         sa = memdup_user(arg, sizeof(*sa));
5127         if (IS_ERR(sa)) {
5128                 ret = PTR_ERR(sa);
5129                 goto drop_write;
5130         }
5131
5132         down_write(&fs_info->subvol_sem);
5133         trans = btrfs_start_transaction(fs_info->tree_root, 2);
5134         if (IS_ERR(trans)) {
5135                 ret = PTR_ERR(trans);
5136                 goto out;
5137         }
5138
5139         switch (sa->cmd) {
5140         case BTRFS_QUOTA_CTL_ENABLE:
5141                 ret = btrfs_quota_enable(trans, fs_info);
5142                 break;
5143         case BTRFS_QUOTA_CTL_DISABLE:
5144                 ret = btrfs_quota_disable(trans, fs_info);
5145                 break;
5146         default:
5147                 ret = -EINVAL;
5148                 break;
5149         }
5150
5151         err = btrfs_commit_transaction(trans);
5152         if (err && !ret)
5153                 ret = err;
5154 out:
5155         kfree(sa);
5156         up_write(&fs_info->subvol_sem);
5157 drop_write:
5158         mnt_drop_write_file(file);
5159         return ret;
5160 }
5161
5162 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
5163 {
5164         struct inode *inode = file_inode(file);
5165         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5166         struct btrfs_root *root = BTRFS_I(inode)->root;
5167         struct btrfs_ioctl_qgroup_assign_args *sa;
5168         struct btrfs_trans_handle *trans;
5169         int ret;
5170         int err;
5171
5172         if (!capable(CAP_SYS_ADMIN))
5173                 return -EPERM;
5174
5175         ret = mnt_want_write_file(file);
5176         if (ret)
5177                 return ret;
5178
5179         sa = memdup_user(arg, sizeof(*sa));
5180         if (IS_ERR(sa)) {
5181                 ret = PTR_ERR(sa);
5182                 goto drop_write;
5183         }
5184
5185         trans = btrfs_join_transaction(root);
5186         if (IS_ERR(trans)) {
5187                 ret = PTR_ERR(trans);
5188                 goto out;
5189         }
5190
5191         if (sa->assign) {
5192                 ret = btrfs_add_qgroup_relation(trans, fs_info,
5193                                                 sa->src, sa->dst);
5194         } else {
5195                 ret = btrfs_del_qgroup_relation(trans, fs_info,
5196                                                 sa->src, sa->dst);
5197         }
5198
5199         /* update qgroup status and info */
5200         err = btrfs_run_qgroups(trans, fs_info);
5201         if (err < 0)
5202                 btrfs_handle_fs_error(fs_info, err,
5203                                       "failed to update qgroup status and info");
5204         err = btrfs_end_transaction(trans);
5205         if (err && !ret)
5206                 ret = err;
5207
5208 out:
5209         kfree(sa);
5210 drop_write:
5211         mnt_drop_write_file(file);
5212         return ret;
5213 }
5214
5215 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
5216 {
5217         struct inode *inode = file_inode(file);
5218         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5219         struct btrfs_root *root = BTRFS_I(inode)->root;
5220         struct btrfs_ioctl_qgroup_create_args *sa;
5221         struct btrfs_trans_handle *trans;
5222         int ret;
5223         int err;
5224
5225         if (!capable(CAP_SYS_ADMIN))
5226                 return -EPERM;
5227
5228         ret = mnt_want_write_file(file);
5229         if (ret)
5230                 return ret;
5231
5232         sa = memdup_user(arg, sizeof(*sa));
5233         if (IS_ERR(sa)) {
5234                 ret = PTR_ERR(sa);
5235                 goto drop_write;
5236         }
5237
5238         if (!sa->qgroupid) {
5239                 ret = -EINVAL;
5240                 goto out;
5241         }
5242
5243         trans = btrfs_join_transaction(root);
5244         if (IS_ERR(trans)) {
5245                 ret = PTR_ERR(trans);
5246                 goto out;
5247         }
5248
5249         if (sa->create) {
5250                 ret = btrfs_create_qgroup(trans, fs_info, sa->qgroupid);
5251         } else {
5252                 ret = btrfs_remove_qgroup(trans, fs_info, sa->qgroupid);
5253         }
5254
5255         err = btrfs_end_transaction(trans);
5256         if (err && !ret)
5257                 ret = err;
5258
5259 out:
5260         kfree(sa);
5261 drop_write:
5262         mnt_drop_write_file(file);
5263         return ret;
5264 }
5265
5266 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
5267 {
5268         struct inode *inode = file_inode(file);
5269         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5270         struct btrfs_root *root = BTRFS_I(inode)->root;
5271         struct btrfs_ioctl_qgroup_limit_args *sa;
5272         struct btrfs_trans_handle *trans;
5273         int ret;
5274         int err;
5275         u64 qgroupid;
5276
5277         if (!capable(CAP_SYS_ADMIN))
5278                 return -EPERM;
5279
5280         ret = mnt_want_write_file(file);
5281         if (ret)
5282                 return ret;
5283
5284         sa = memdup_user(arg, sizeof(*sa));
5285         if (IS_ERR(sa)) {
5286                 ret = PTR_ERR(sa);
5287                 goto drop_write;
5288         }
5289
5290         trans = btrfs_join_transaction(root);
5291         if (IS_ERR(trans)) {
5292                 ret = PTR_ERR(trans);
5293                 goto out;
5294         }
5295
5296         qgroupid = sa->qgroupid;
5297         if (!qgroupid) {
5298                 /* take the current subvol as qgroup */
5299                 qgroupid = root->root_key.objectid;
5300         }
5301
5302         ret = btrfs_limit_qgroup(trans, fs_info, qgroupid, &sa->lim);
5303
5304         err = btrfs_end_transaction(trans);
5305         if (err && !ret)
5306                 ret = err;
5307
5308 out:
5309         kfree(sa);
5310 drop_write:
5311         mnt_drop_write_file(file);
5312         return ret;
5313 }
5314
5315 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5316 {
5317         struct inode *inode = file_inode(file);
5318         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5319         struct btrfs_ioctl_quota_rescan_args *qsa;
5320         int ret;
5321
5322         if (!capable(CAP_SYS_ADMIN))
5323                 return -EPERM;
5324
5325         ret = mnt_want_write_file(file);
5326         if (ret)
5327                 return ret;
5328
5329         qsa = memdup_user(arg, sizeof(*qsa));
5330         if (IS_ERR(qsa)) {
5331                 ret = PTR_ERR(qsa);
5332                 goto drop_write;
5333         }
5334
5335         if (qsa->flags) {
5336                 ret = -EINVAL;
5337                 goto out;
5338         }
5339
5340         ret = btrfs_qgroup_rescan(fs_info);
5341
5342 out:
5343         kfree(qsa);
5344 drop_write:
5345         mnt_drop_write_file(file);
5346         return ret;
5347 }
5348
5349 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5350 {
5351         struct inode *inode = file_inode(file);
5352         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5353         struct btrfs_ioctl_quota_rescan_args *qsa;
5354         int ret = 0;
5355
5356         if (!capable(CAP_SYS_ADMIN))
5357                 return -EPERM;
5358
5359         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5360         if (!qsa)
5361                 return -ENOMEM;
5362
5363         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5364                 qsa->flags = 1;
5365                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5366         }
5367
5368         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5369                 ret = -EFAULT;
5370
5371         kfree(qsa);
5372         return ret;
5373 }
5374
5375 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5376 {
5377         struct inode *inode = file_inode(file);
5378         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5379
5380         if (!capable(CAP_SYS_ADMIN))
5381                 return -EPERM;
5382
5383         return btrfs_qgroup_wait_for_completion(fs_info, true);
5384 }
5385
5386 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5387                                             struct btrfs_ioctl_received_subvol_args *sa)
5388 {
5389         struct inode *inode = file_inode(file);
5390         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5391         struct btrfs_root *root = BTRFS_I(inode)->root;
5392         struct btrfs_root_item *root_item = &root->root_item;
5393         struct btrfs_trans_handle *trans;
5394         struct timespec ct = current_time(inode);
5395         int ret = 0;
5396         int received_uuid_changed;
5397
5398         if (!inode_owner_or_capable(inode))
5399                 return -EPERM;
5400
5401         ret = mnt_want_write_file(file);
5402         if (ret < 0)
5403                 return ret;
5404
5405         down_write(&fs_info->subvol_sem);
5406
5407         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5408                 ret = -EINVAL;
5409                 goto out;
5410         }
5411
5412         if (btrfs_root_readonly(root)) {
5413                 ret = -EROFS;
5414                 goto out;
5415         }
5416
5417         /*
5418          * 1 - root item
5419          * 2 - uuid items (received uuid + subvol uuid)
5420          */
5421         trans = btrfs_start_transaction(root, 3);
5422         if (IS_ERR(trans)) {
5423                 ret = PTR_ERR(trans);
5424                 trans = NULL;
5425                 goto out;
5426         }
5427
5428         sa->rtransid = trans->transid;
5429         sa->rtime.sec = ct.tv_sec;
5430         sa->rtime.nsec = ct.tv_nsec;
5431
5432         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5433                                        BTRFS_UUID_SIZE);
5434         if (received_uuid_changed &&
5435             !btrfs_is_empty_uuid(root_item->received_uuid)) {
5436                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
5437                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5438                                           root->root_key.objectid);
5439                 if (ret && ret != -ENOENT) {
5440                         btrfs_abort_transaction(trans, ret);
5441                         btrfs_end_transaction(trans);
5442                         goto out;
5443                 }
5444         }
5445         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5446         btrfs_set_root_stransid(root_item, sa->stransid);
5447         btrfs_set_root_rtransid(root_item, sa->rtransid);
5448         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5449         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5450         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5451         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5452
5453         ret = btrfs_update_root(trans, fs_info->tree_root,
5454                                 &root->root_key, &root->root_item);
5455         if (ret < 0) {
5456                 btrfs_end_transaction(trans);
5457                 goto out;
5458         }
5459         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5460                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
5461                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5462                                           root->root_key.objectid);
5463                 if (ret < 0 && ret != -EEXIST) {
5464                         btrfs_abort_transaction(trans, ret);
5465                         btrfs_end_transaction(trans);
5466                         goto out;
5467                 }
5468         }
5469         ret = btrfs_commit_transaction(trans);
5470 out:
5471         up_write(&fs_info->subvol_sem);
5472         mnt_drop_write_file(file);
5473         return ret;
5474 }
5475
5476 #ifdef CONFIG_64BIT
5477 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5478                                                 void __user *arg)
5479 {
5480         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5481         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5482         int ret = 0;
5483
5484         args32 = memdup_user(arg, sizeof(*args32));
5485         if (IS_ERR(args32))
5486                 return PTR_ERR(args32);
5487
5488         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5489         if (!args64) {
5490                 ret = -ENOMEM;
5491                 goto out;
5492         }
5493
5494         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5495         args64->stransid = args32->stransid;
5496         args64->rtransid = args32->rtransid;
5497         args64->stime.sec = args32->stime.sec;
5498         args64->stime.nsec = args32->stime.nsec;
5499         args64->rtime.sec = args32->rtime.sec;
5500         args64->rtime.nsec = args32->rtime.nsec;
5501         args64->flags = args32->flags;
5502
5503         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5504         if (ret)
5505                 goto out;
5506
5507         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5508         args32->stransid = args64->stransid;
5509         args32->rtransid = args64->rtransid;
5510         args32->stime.sec = args64->stime.sec;
5511         args32->stime.nsec = args64->stime.nsec;
5512         args32->rtime.sec = args64->rtime.sec;
5513         args32->rtime.nsec = args64->rtime.nsec;
5514         args32->flags = args64->flags;
5515
5516         ret = copy_to_user(arg, args32, sizeof(*args32));
5517         if (ret)
5518                 ret = -EFAULT;
5519
5520 out:
5521         kfree(args32);
5522         kfree(args64);
5523         return ret;
5524 }
5525 #endif
5526
5527 static long btrfs_ioctl_set_received_subvol(struct file *file,
5528                                             void __user *arg)
5529 {
5530         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5531         int ret = 0;
5532
5533         sa = memdup_user(arg, sizeof(*sa));
5534         if (IS_ERR(sa))
5535                 return PTR_ERR(sa);
5536
5537         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5538
5539         if (ret)
5540                 goto out;
5541
5542         ret = copy_to_user(arg, sa, sizeof(*sa));
5543         if (ret)
5544                 ret = -EFAULT;
5545
5546 out:
5547         kfree(sa);
5548         return ret;
5549 }
5550
5551 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5552 {
5553         struct inode *inode = file_inode(file);
5554         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5555         size_t len;
5556         int ret;
5557         char label[BTRFS_LABEL_SIZE];
5558
5559         spin_lock(&fs_info->super_lock);
5560         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5561         spin_unlock(&fs_info->super_lock);
5562
5563         len = strnlen(label, BTRFS_LABEL_SIZE);
5564
5565         if (len == BTRFS_LABEL_SIZE) {
5566                 btrfs_warn(fs_info,
5567                            "label is too long, return the first %zu bytes",
5568                            --len);
5569         }
5570
5571         ret = copy_to_user(arg, label, len);
5572
5573         return ret ? -EFAULT : 0;
5574 }
5575
5576 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5577 {
5578         struct inode *inode = file_inode(file);
5579         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5580         struct btrfs_root *root = BTRFS_I(inode)->root;
5581         struct btrfs_super_block *super_block = fs_info->super_copy;
5582         struct btrfs_trans_handle *trans;
5583         char label[BTRFS_LABEL_SIZE];
5584         int ret;
5585
5586         if (!capable(CAP_SYS_ADMIN))
5587                 return -EPERM;
5588
5589         if (copy_from_user(label, arg, sizeof(label)))
5590                 return -EFAULT;
5591
5592         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5593                 btrfs_err(fs_info,
5594                           "unable to set label with more than %d bytes",
5595                           BTRFS_LABEL_SIZE - 1);
5596                 return -EINVAL;
5597         }
5598
5599         ret = mnt_want_write_file(file);
5600         if (ret)
5601                 return ret;
5602
5603         trans = btrfs_start_transaction(root, 0);
5604         if (IS_ERR(trans)) {
5605                 ret = PTR_ERR(trans);
5606                 goto out_unlock;
5607         }
5608
5609         spin_lock(&fs_info->super_lock);
5610         strcpy(super_block->label, label);
5611         spin_unlock(&fs_info->super_lock);
5612         ret = btrfs_commit_transaction(trans);
5613
5614 out_unlock:
5615         mnt_drop_write_file(file);
5616         return ret;
5617 }
5618
5619 #define INIT_FEATURE_FLAGS(suffix) \
5620         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5621           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5622           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5623
5624 int btrfs_ioctl_get_supported_features(void __user *arg)
5625 {
5626         static const struct btrfs_ioctl_feature_flags features[3] = {
5627                 INIT_FEATURE_FLAGS(SUPP),
5628                 INIT_FEATURE_FLAGS(SAFE_SET),
5629                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5630         };
5631
5632         if (copy_to_user(arg, &features, sizeof(features)))
5633                 return -EFAULT;
5634
5635         return 0;
5636 }
5637
5638 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5639 {
5640         struct inode *inode = file_inode(file);
5641         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5642         struct btrfs_super_block *super_block = fs_info->super_copy;
5643         struct btrfs_ioctl_feature_flags features;
5644
5645         features.compat_flags = btrfs_super_compat_flags(super_block);
5646         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5647         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5648
5649         if (copy_to_user(arg, &features, sizeof(features)))
5650                 return -EFAULT;
5651
5652         return 0;
5653 }
5654
5655 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5656                               enum btrfs_feature_set set,
5657                               u64 change_mask, u64 flags, u64 supported_flags,
5658                               u64 safe_set, u64 safe_clear)
5659 {
5660         const char *type = btrfs_feature_set_names[set];
5661         char *names;
5662         u64 disallowed, unsupported;
5663         u64 set_mask = flags & change_mask;
5664         u64 clear_mask = ~flags & change_mask;
5665
5666         unsupported = set_mask & ~supported_flags;
5667         if (unsupported) {
5668                 names = btrfs_printable_features(set, unsupported);
5669                 if (names) {
5670                         btrfs_warn(fs_info,
5671                                    "this kernel does not support the %s feature bit%s",
5672                                    names, strchr(names, ',') ? "s" : "");
5673                         kfree(names);
5674                 } else
5675                         btrfs_warn(fs_info,
5676                                    "this kernel does not support %s bits 0x%llx",
5677                                    type, unsupported);
5678                 return -EOPNOTSUPP;
5679         }
5680
5681         disallowed = set_mask & ~safe_set;
5682         if (disallowed) {
5683                 names = btrfs_printable_features(set, disallowed);
5684                 if (names) {
5685                         btrfs_warn(fs_info,
5686                                    "can't set the %s feature bit%s while mounted",
5687                                    names, strchr(names, ',') ? "s" : "");
5688                         kfree(names);
5689                 } else
5690                         btrfs_warn(fs_info,
5691                                    "can't set %s bits 0x%llx while mounted",
5692                                    type, disallowed);
5693                 return -EPERM;
5694         }
5695
5696         disallowed = clear_mask & ~safe_clear;
5697         if (disallowed) {
5698                 names = btrfs_printable_features(set, disallowed);
5699                 if (names) {
5700                         btrfs_warn(fs_info,
5701                                    "can't clear the %s feature bit%s while mounted",
5702                                    names, strchr(names, ',') ? "s" : "");
5703                         kfree(names);
5704                 } else
5705                         btrfs_warn(fs_info,
5706                                    "can't clear %s bits 0x%llx while mounted",
5707                                    type, disallowed);
5708                 return -EPERM;
5709         }
5710
5711         return 0;
5712 }
5713
5714 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5715 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5716                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5717                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5718                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5719
5720 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5721 {
5722         struct inode *inode = file_inode(file);
5723         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5724         struct btrfs_root *root = BTRFS_I(inode)->root;
5725         struct btrfs_super_block *super_block = fs_info->super_copy;
5726         struct btrfs_ioctl_feature_flags flags[2];
5727         struct btrfs_trans_handle *trans;
5728         u64 newflags;
5729         int ret;
5730
5731         if (!capable(CAP_SYS_ADMIN))
5732                 return -EPERM;
5733
5734         if (copy_from_user(flags, arg, sizeof(flags)))
5735                 return -EFAULT;
5736
5737         /* Nothing to do */
5738         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5739             !flags[0].incompat_flags)
5740                 return 0;
5741
5742         ret = check_feature(fs_info, flags[0].compat_flags,
5743                             flags[1].compat_flags, COMPAT);
5744         if (ret)
5745                 return ret;
5746
5747         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5748                             flags[1].compat_ro_flags, COMPAT_RO);
5749         if (ret)
5750                 return ret;
5751
5752         ret = check_feature(fs_info, flags[0].incompat_flags,
5753                             flags[1].incompat_flags, INCOMPAT);
5754         if (ret)
5755                 return ret;
5756
5757         ret = mnt_want_write_file(file);
5758         if (ret)
5759                 return ret;
5760
5761         trans = btrfs_start_transaction(root, 0);
5762         if (IS_ERR(trans)) {
5763                 ret = PTR_ERR(trans);
5764                 goto out_drop_write;
5765         }
5766
5767         spin_lock(&fs_info->super_lock);
5768         newflags = btrfs_super_compat_flags(super_block);
5769         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5770         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5771         btrfs_set_super_compat_flags(super_block, newflags);
5772
5773         newflags = btrfs_super_compat_ro_flags(super_block);
5774         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5775         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5776         btrfs_set_super_compat_ro_flags(super_block, newflags);
5777
5778         newflags = btrfs_super_incompat_flags(super_block);
5779         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5780         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5781         btrfs_set_super_incompat_flags(super_block, newflags);
5782         spin_unlock(&fs_info->super_lock);
5783
5784         ret = btrfs_commit_transaction(trans);
5785 out_drop_write:
5786         mnt_drop_write_file(file);
5787
5788         return ret;
5789 }
5790
5791 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5792 {
5793         struct btrfs_ioctl_send_args *arg;
5794         int ret;
5795
5796         if (compat) {
5797 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5798                 struct btrfs_ioctl_send_args_32 args32;
5799
5800                 ret = copy_from_user(&args32, argp, sizeof(args32));
5801                 if (ret)
5802                         return -EFAULT;
5803                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5804                 if (!arg)
5805                         return -ENOMEM;
5806                 arg->send_fd = args32.send_fd;
5807                 arg->clone_sources_count = args32.clone_sources_count;
5808                 arg->clone_sources = compat_ptr(args32.clone_sources);
5809                 arg->parent_root = args32.parent_root;
5810                 arg->flags = args32.flags;
5811                 memcpy(arg->reserved, args32.reserved,
5812                        sizeof(args32.reserved));
5813 #else
5814                 return -ENOTTY;
5815 #endif
5816         } else {
5817                 arg = memdup_user(argp, sizeof(*arg));
5818                 if (IS_ERR(arg))
5819                         return PTR_ERR(arg);
5820         }
5821         ret = btrfs_ioctl_send(file, arg);
5822         kfree(arg);
5823         return ret;
5824 }
5825
5826 long btrfs_ioctl(struct file *file, unsigned int
5827                 cmd, unsigned long arg)
5828 {
5829         struct inode *inode = file_inode(file);
5830         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5831         struct btrfs_root *root = BTRFS_I(inode)->root;
5832         void __user *argp = (void __user *)arg;
5833
5834         switch (cmd) {
5835         case FS_IOC_GETFLAGS:
5836                 return btrfs_ioctl_getflags(file, argp);
5837         case FS_IOC_SETFLAGS:
5838                 return btrfs_ioctl_setflags(file, argp);
5839         case FS_IOC_GETVERSION:
5840                 return btrfs_ioctl_getversion(file, argp);
5841         case FITRIM:
5842                 return btrfs_ioctl_fitrim(file, argp);
5843         case BTRFS_IOC_SNAP_CREATE:
5844                 return btrfs_ioctl_snap_create(file, argp, 0);
5845         case BTRFS_IOC_SNAP_CREATE_V2:
5846                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5847         case BTRFS_IOC_SUBVOL_CREATE:
5848                 return btrfs_ioctl_snap_create(file, argp, 1);
5849         case BTRFS_IOC_SUBVOL_CREATE_V2:
5850                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5851         case BTRFS_IOC_SNAP_DESTROY:
5852                 return btrfs_ioctl_snap_destroy(file, argp);
5853         case BTRFS_IOC_SUBVOL_GETFLAGS:
5854                 return btrfs_ioctl_subvol_getflags(file, argp);
5855         case BTRFS_IOC_SUBVOL_SETFLAGS:
5856                 return btrfs_ioctl_subvol_setflags(file, argp);
5857         case BTRFS_IOC_DEFAULT_SUBVOL:
5858                 return btrfs_ioctl_default_subvol(file, argp);
5859         case BTRFS_IOC_DEFRAG:
5860                 return btrfs_ioctl_defrag(file, NULL);
5861         case BTRFS_IOC_DEFRAG_RANGE:
5862                 return btrfs_ioctl_defrag(file, argp);
5863         case BTRFS_IOC_RESIZE:
5864                 return btrfs_ioctl_resize(file, argp);
5865         case BTRFS_IOC_ADD_DEV:
5866                 return btrfs_ioctl_add_dev(fs_info, argp);
5867         case BTRFS_IOC_RM_DEV:
5868                 return btrfs_ioctl_rm_dev(file, argp);
5869         case BTRFS_IOC_RM_DEV_V2:
5870                 return btrfs_ioctl_rm_dev_v2(file, argp);
5871         case BTRFS_IOC_FS_INFO:
5872                 return btrfs_ioctl_fs_info(fs_info, argp);
5873         case BTRFS_IOC_DEV_INFO:
5874                 return btrfs_ioctl_dev_info(fs_info, argp);
5875         case BTRFS_IOC_BALANCE:
5876                 return btrfs_ioctl_balance(file, NULL);
5877         case BTRFS_IOC_TREE_SEARCH:
5878                 return btrfs_ioctl_tree_search(file, argp);
5879         case BTRFS_IOC_TREE_SEARCH_V2:
5880                 return btrfs_ioctl_tree_search_v2(file, argp);
5881         case BTRFS_IOC_INO_LOOKUP:
5882                 return btrfs_ioctl_ino_lookup(file, argp);
5883         case BTRFS_IOC_INO_PATHS:
5884                 return btrfs_ioctl_ino_to_path(root, argp);
5885         case BTRFS_IOC_LOGICAL_INO:
5886                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5887         case BTRFS_IOC_LOGICAL_INO_V2:
5888                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5889         case BTRFS_IOC_SPACE_INFO:
5890                 return btrfs_ioctl_space_info(fs_info, argp);
5891         case BTRFS_IOC_SYNC: {
5892                 int ret;
5893
5894                 ret = btrfs_start_delalloc_roots(fs_info, -1);
5895                 if (ret)
5896                         return ret;
5897                 ret = btrfs_sync_fs(inode->i_sb, 1);
5898                 /*
5899                  * The transaction thread may want to do more work,
5900                  * namely it pokes the cleaner kthread that will start
5901                  * processing uncleaned subvols.
5902                  */
5903                 wake_up_process(fs_info->transaction_kthread);
5904                 return ret;
5905         }
5906         case BTRFS_IOC_START_SYNC:
5907                 return btrfs_ioctl_start_sync(root, argp);
5908         case BTRFS_IOC_WAIT_SYNC:
5909                 return btrfs_ioctl_wait_sync(fs_info, argp);
5910         case BTRFS_IOC_SCRUB:
5911                 return btrfs_ioctl_scrub(file, argp);
5912         case BTRFS_IOC_SCRUB_CANCEL:
5913                 return btrfs_ioctl_scrub_cancel(fs_info);
5914         case BTRFS_IOC_SCRUB_PROGRESS:
5915                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5916         case BTRFS_IOC_BALANCE_V2:
5917                 return btrfs_ioctl_balance(file, argp);
5918         case BTRFS_IOC_BALANCE_CTL:
5919                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5920         case BTRFS_IOC_BALANCE_PROGRESS:
5921                 return btrfs_ioctl_balance_progress(fs_info, argp);
5922         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5923                 return btrfs_ioctl_set_received_subvol(file, argp);
5924 #ifdef CONFIG_64BIT
5925         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5926                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5927 #endif
5928         case BTRFS_IOC_SEND:
5929                 return _btrfs_ioctl_send(file, argp, false);
5930 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5931         case BTRFS_IOC_SEND_32:
5932                 return _btrfs_ioctl_send(file, argp, true);
5933 #endif
5934         case BTRFS_IOC_GET_DEV_STATS:
5935                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5936         case BTRFS_IOC_QUOTA_CTL:
5937                 return btrfs_ioctl_quota_ctl(file, argp);
5938         case BTRFS_IOC_QGROUP_ASSIGN:
5939                 return btrfs_ioctl_qgroup_assign(file, argp);
5940         case BTRFS_IOC_QGROUP_CREATE:
5941                 return btrfs_ioctl_qgroup_create(file, argp);
5942         case BTRFS_IOC_QGROUP_LIMIT:
5943                 return btrfs_ioctl_qgroup_limit(file, argp);
5944         case BTRFS_IOC_QUOTA_RESCAN:
5945                 return btrfs_ioctl_quota_rescan(file, argp);
5946         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5947                 return btrfs_ioctl_quota_rescan_status(file, argp);
5948         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5949                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5950         case BTRFS_IOC_DEV_REPLACE:
5951                 return btrfs_ioctl_dev_replace(fs_info, argp);
5952         case BTRFS_IOC_GET_FSLABEL:
5953                 return btrfs_ioctl_get_fslabel(file, argp);
5954         case BTRFS_IOC_SET_FSLABEL:
5955                 return btrfs_ioctl_set_fslabel(file, argp);
5956         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5957                 return btrfs_ioctl_get_supported_features(argp);
5958         case BTRFS_IOC_GET_FEATURES:
5959                 return btrfs_ioctl_get_features(file, argp);
5960         case BTRFS_IOC_SET_FEATURES:
5961                 return btrfs_ioctl_set_features(file, argp);
5962         case FS_IOC_FSGETXATTR:
5963                 return btrfs_ioctl_fsgetxattr(file, argp);
5964         case FS_IOC_FSSETXATTR:
5965                 return btrfs_ioctl_fssetxattr(file, argp);
5966         case BTRFS_IOC_GET_SUBVOL_INFO:
5967                 return btrfs_ioctl_get_subvol_info(file, argp);
5968         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5969                 return btrfs_ioctl_get_subvol_rootref(file, argp);
5970         case BTRFS_IOC_INO_LOOKUP_USER:
5971                 return btrfs_ioctl_ino_lookup_user(file, argp);
5972         }
5973
5974         return -ENOTTY;
5975 }
5976
5977 #ifdef CONFIG_COMPAT
5978 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5979 {
5980         /*
5981          * These all access 32-bit values anyway so no further
5982          * handling is necessary.
5983          */
5984         switch (cmd) {
5985         case FS_IOC32_GETFLAGS:
5986                 cmd = FS_IOC_GETFLAGS;
5987                 break;
5988         case FS_IOC32_SETFLAGS:
5989                 cmd = FS_IOC_SETFLAGS;
5990                 break;
5991         case FS_IOC32_GETVERSION:
5992                 cmd = FS_IOC_GETVERSION;
5993                 break;
5994         }
5995
5996         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5997 }
5998 #endif