fs/quota/quota_v2.c

   1 /*
   2  *      vfsv0 quota IO operations on file
   3  */
   4
   5 #include <linux/errno.h>
   6 #include <linux/fs.h>
   7 #include <linux/mount.h>
   8 #include <linux/dqblk_v2.h>
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/quotaops.h>
  14
  15 #include <asm/byteorder.h>
  16
  17 #include "quota_tree.h"
  18 #include "quotaio_v2.h"
  19
  20 MODULE_AUTHOR("Jan Kara");
  21 MODULE_DESCRIPTION("Quota format v2 support");
  22 MODULE_LICENSE("GPL");
  23
  24 #define __QUOTA_V2_PARANOIA
  25
  26 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
  27 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
  28 static int v2r0_is_id(void *dp, struct dquot *dquot);
  29 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
  30 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
  31 static int v2r1_is_id(void *dp, struct dquot *dquot);
  32
  33 static const struct qtree_fmt_operations v2r0_qtree_ops = {
  34         .mem2disk_dqblk = v2r0_mem2diskdqb,
  35         .disk2mem_dqblk = v2r0_disk2memdqb,
  36         .is_id = v2r0_is_id,
  37 };
  38
  39 static const struct qtree_fmt_operations v2r1_qtree_ops = {
  40         .mem2disk_dqblk = v2r1_mem2diskdqb,
  41         .disk2mem_dqblk = v2r1_disk2memdqb,
  42         .is_id = v2r1_is_id,
  43 };
  44
  45 #define QUOTABLOCK_BITS 10
  46 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
  47
  48 static inline qsize_t v2_stoqb(qsize_t space)
  49 {
  50         return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
  51 }
  52
  53 static inline qsize_t v2_qbtos(qsize_t blocks)
  54 {
  55         return blocks << QUOTABLOCK_BITS;
  56 }
  57
  58 static int v2_read_header(struct super_block *sb, int type,
  59                           struct v2_disk_dqheader *dqhead)
  60 {
  61         ssize_t size;
  62
  63         size = sb->s_op->quota_read(sb, type, (char *)dqhead,
  64                                     sizeof(struct v2_disk_dqheader), 0);
  65         if (size != sizeof(struct v2_disk_dqheader)) {
  66                 quota_error(sb, "Failed header read: expected=%zd got=%zd",
  67                             sizeof(struct v2_disk_dqheader), size);
  68                 return 0;
  69         }
  70         return 1;
  71 }
  72
  73 /* Check whether given file is really vfsv0 quotafile */
  74 static int v2_check_quota_file(struct super_block *sb, int type)
  75 {
  76         struct v2_disk_dqheader dqhead;
  77         static const uint quota_magics[] = V2_INITQMAGICS;
  78         static const uint quota_versions[] = V2_INITQVERSIONS;
  79
  80         if (!v2_read_header(sb, type, &dqhead))
  81                 return 0;
  82         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
  83             le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
  84                 return 0;
  85         return 1;
  86 }
  87
  88 /* Read information header from quota file */
  89 static int v2_read_file_info(struct super_block *sb, int type)
  90 {
  91         struct v2_disk_dqinfo dinfo;
  92         struct v2_disk_dqheader dqhead;
  93         struct quota_info *dqopt = sb_dqopt(sb);
  94         struct mem_dqinfo *info = &dqopt->info[type];
  95         struct qtree_mem_dqinfo *qinfo;
  96         ssize_t size;
  97         unsigned int version;
  98         int ret;
  99
 100         down_read(&dqopt->dqio_sem);
 101         if (!v2_read_header(sb, type, &dqhead)) {
 102                 ret = -1;
 103                 goto out;
 104         }
 105         version = le32_to_cpu(dqhead.dqh_version);
 106         if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
 107             (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) {
 108                 ret = -1;
 109                 goto out;
 110         }
 111
 112         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
 113                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 114         if (size != sizeof(struct v2_disk_dqinfo)) {
 115                 quota_error(sb, "Can't read info structure");
 116                 ret = -1;
 117                 goto out;
 118         }
 119         info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
 120         if (!info->dqi_priv) {
 121                 printk(KERN_WARNING
 122                        "Not enough memory for quota information structure.\n");
 123                 ret = -ENOMEM;
 124                 goto out;
 125         }
 126         qinfo = info->dqi_priv;
 127         if (version == 0) {
 128                 /* limits are stored as unsigned 32-bit data */
 129                 info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
 130                 info->dqi_max_ino_limit = 0xffffffff;
 131         } else {
 132                 /*
 133                  * Used space is stored as unsigned 64-bit value in bytes but
 134                  * quota core supports only signed 64-bit values so use that
 135                  * as a limit
 136                  */
 137                 info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
 138                 info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
 139         }
 140         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
 141         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
 142         /* No flags currently supported */
 143         info->dqi_flags = 0;
 144         qinfo->dqi_sb = sb;
 145         qinfo->dqi_type = type;
 146         qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
 147         qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
 148         qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
 149         qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
 150         qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
 151         qinfo->dqi_qtree_depth = qtree_depth(qinfo);
 152         if (version == 0) {
 153                 qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
 154                 qinfo->dqi_ops = &v2r0_qtree_ops;
 155         } else {
 156                 qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
 157                 qinfo->dqi_ops = &v2r1_qtree_ops;
 158         }
 159         ret = 0;
 160 out:
 161         up_read(&dqopt->dqio_sem);
 162         return ret;
 163 }
 164
 165 /* Write information header to quota file */
 166 static int v2_write_file_info(struct super_block *sb, int type)
 167 {
 168         struct v2_disk_dqinfo dinfo;
 169         struct quota_info *dqopt = sb_dqopt(sb);
 170         struct mem_dqinfo *info = &dqopt->info[type];
 171         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 172         ssize_t size;
 173
 174         down_write(&dqopt->dqio_sem);
 175         spin_lock(&dq_data_lock);
 176         info->dqi_flags &= ~DQF_INFO_DIRTY;
 177         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 178         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 179         /* No flags currently supported */
 180         dinfo.dqi_flags = cpu_to_le32(0);
 181         spin_unlock(&dq_data_lock);
 182         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 183         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 184         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 185         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 186                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 187         up_write(&dqopt->dqio_sem);
 188         if (size != sizeof(struct v2_disk_dqinfo)) {
 189                 quota_error(sb, "Can't write info structure");
 190                 return -1;
 191         }
 192         return 0;
 193 }
 194
 195 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
 196 {
 197         struct v2r0_disk_dqblk *d = dp, empty;
 198         struct mem_dqblk *m = &dquot->dq_dqb;
 199
 200         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 201         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 202         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 203         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 204         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 205         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 206         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 207         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 208         /* We need to escape back all-zero structure */
 209         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
 210         empty.dqb_itime = cpu_to_le64(1);
 211         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
 212                 m->dqb_itime = 0;
 213 }
 214
 215 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 216 {
 217         struct v2r0_disk_dqblk *d = dp;
 218         struct mem_dqblk *m = &dquot->dq_dqb;
 219         struct qtree_mem_dqinfo *info =
 220                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 221
 222         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 223         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 224         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 225         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 226         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 227         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 228         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 229         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 230         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 231         if (qtree_entry_unused(info, dp))
 232                 d->dqb_itime = cpu_to_le64(1);
 233 }
 234
 235 static int v2r0_is_id(void *dp, struct dquot *dquot)
 236 {
 237         struct v2r0_disk_dqblk *d = dp;
 238         struct qtree_mem_dqinfo *info =
 239                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 240
 241         if (qtree_entry_unused(info, dp))
 242                 return 0;
 243         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 244                                 le32_to_cpu(d->dqb_id)),
 245                       dquot->dq_id);
 246 }
 247
 248 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
 249 {
 250         struct v2r1_disk_dqblk *d = dp, empty;
 251         struct mem_dqblk *m = &dquot->dq_dqb;
 252
 253         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
 254         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
 255         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
 256         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 257         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
 258         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
 259         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 260         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 261         /* We need to escape back all-zero structure */
 262         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
 263         empty.dqb_itime = cpu_to_le64(1);
 264         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
 265                 m->dqb_itime = 0;
 266 }
 267
 268 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 269 {
 270         struct v2r1_disk_dqblk *d = dp;
 271         struct mem_dqblk *m = &dquot->dq_dqb;
 272         struct qtree_mem_dqinfo *info =
 273                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 274
 275         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 276         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
 277         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
 278         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 279         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
 280         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 281         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 282         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 283         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 284         if (qtree_entry_unused(info, dp))
 285                 d->dqb_itime = cpu_to_le64(1);
 286 }
 287
 288 static int v2r1_is_id(void *dp, struct dquot *dquot)
 289 {
 290         struct v2r1_disk_dqblk *d = dp;
 291         struct qtree_mem_dqinfo *info =
 292                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 293
 294         if (qtree_entry_unused(info, dp))
 295                 return 0;
 296         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 297                                 le32_to_cpu(d->dqb_id)),
 298                       dquot->dq_id);
 299 }
 300
 301 static int v2_read_dquot(struct dquot *dquot)
 302 {
 303         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 304         int ret;
 305
 306         down_read(&dqopt->dqio_sem);
 307         ret = qtree_read_dquot(
 308                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 309                         dquot);
 310         up_read(&dqopt->dqio_sem);
 311         return ret;
 312 }
 313
 314 static int v2_write_dquot(struct dquot *dquot)
 315 {
 316         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 317         int ret;
 318         bool alloc = false;
 319
 320         /*
 321          * If space for dquot is already allocated, we don't need any
 322          * protection as we'll only overwrite the place of dquot. We are
 323          * still protected by concurrent writes of the same dquot by
 324          * dquot->dq_lock.
 325          */
 326         if (!dquot->dq_off) {
 327                 alloc = true;
 328                 down_write(&dqopt->dqio_sem);
 329         }
 330         ret = qtree_write_dquot(
 331                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 332                         dquot);
 333         if (alloc)
 334                 up_write(&dqopt->dqio_sem);
 335         return ret;
 336 }
 337
 338 static int v2_release_dquot(struct dquot *dquot)
 339 {
 340         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 341         int ret;
 342
 343         down_write(&dqopt->dqio_sem);
 344         ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 345         up_write(&dqopt->dqio_sem);
 346
 347         return ret;
 348 }
 349
 350 static int v2_free_file_info(struct super_block *sb, int type)
 351 {
 352         kfree(sb_dqinfo(sb, type)->dqi_priv);
 353         return 0;
 354 }
 355
 356 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
 357 {
 358         struct quota_info *dqopt = sb_dqopt(sb);
 359         int ret;
 360
 361         down_read(&dqopt->dqio_sem);
 362         ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
 363         up_read(&dqopt->dqio_sem);
 364         return ret;
 365 }
 366
 367 static const struct quota_format_ops v2_format_ops = {
 368         .check_quota_file       = v2_check_quota_file,
 369         .read_file_info         = v2_read_file_info,
 370         .write_file_info        = v2_write_file_info,
 371         .free_file_info         = v2_free_file_info,
 372         .read_dqblk             = v2_read_dquot,
 373         .commit_dqblk           = v2_write_dquot,
 374         .release_dqblk          = v2_release_dquot,
 375         .get_next_id            = v2_get_next_id,
 376 };
 377
 378 static struct quota_format_type v2r0_quota_format = {
 379         .qf_fmt_id      = QFMT_VFS_V0,
 380         .qf_ops         = &v2_format_ops,
 381         .qf_owner       = THIS_MODULE
 382 };
 383
 384 static struct quota_format_type v2r1_quota_format = {
 385         .qf_fmt_id      = QFMT_VFS_V1,
 386         .qf_ops         = &v2_format_ops,
 387         .qf_owner       = THIS_MODULE
 388 };
 389
 390 static int __init init_v2_quota_format(void)
 391 {
 392         int ret;
 393
 394         ret = register_quota_format(&v2r0_quota_format);
 395         if (ret)
 396                 return ret;
 397         return register_quota_format(&v2r1_quota_format);
 398 }
 399
 400 static void __exit exit_v2_quota_format(void)
 401 {
 402         unregister_quota_format(&v2r0_quota_format);
 403         unregister_quota_format(&v2r1_quota_format);
 404 }
 405
 406 module_init(init_v2_quota_format);
 407 module_exit(exit_v2_quota_format);