fs/ext4/ext4_jbd2.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Interface between ext4 and JBD
   4  */
   5
   6 #include "ext4_jbd2.h"
   7
   8 #include <trace/events/ext4.h>
   9
  10 int ext4_inode_journal_mode(struct inode *inode)
  11 {
  12         if (EXT4_JOURNAL(inode) == NULL)
  13                 return EXT4_INODE_WRITEBACK_DATA_MODE;  /* writeback */
  14         /* We do not support data journalling with delayed allocation */
  15         if (!S_ISREG(inode->i_mode) ||
  16             ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE) ||
  17             test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
  18             (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) &&
  19             !test_opt(inode->i_sb, DELALLOC))) {
  20                 /* We do not support data journalling for encrypted data */
  21                 if (S_ISREG(inode->i_mode) && IS_ENCRYPTED(inode))
  22                         return EXT4_INODE_ORDERED_DATA_MODE;  /* ordered */
  23                 return EXT4_INODE_JOURNAL_DATA_MODE;    /* journal data */
  24         }
  25         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
  26                 return EXT4_INODE_ORDERED_DATA_MODE;    /* ordered */
  27         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
  28                 return EXT4_INODE_WRITEBACK_DATA_MODE;  /* writeback */
  29         BUG();
  30 }
  31
  32 /* Just increment the non-pointer handle value */
  33 static handle_t *ext4_get_nojournal(void)
  34 {
  35         handle_t *handle = current->journal_info;
  36         unsigned long ref_cnt = (unsigned long)handle;
  37
  38         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
  39
  40         ref_cnt++;
  41         handle = (handle_t *)ref_cnt;
  42
  43         current->journal_info = handle;
  44         return handle;
  45 }
  46
  47
  48 /* Decrement the non-pointer handle value */
  49 static void ext4_put_nojournal(handle_t *handle)
  50 {
  51         unsigned long ref_cnt = (unsigned long)handle;
  52
  53         BUG_ON(ref_cnt == 0);
  54
  55         ref_cnt--;
  56         handle = (handle_t *)ref_cnt;
  57
  58         current->journal_info = handle;
  59 }
  60
  61 /*
  62  * Wrappers for jbd2_journal_start/end.
  63  */
  64 static int ext4_journal_check_start(struct super_block *sb)
  65 {
  66         journal_t *journal;
  67
  68         might_sleep();
  69
  70         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
  71                 return -EIO;
  72
  73         if (sb_rdonly(sb))
  74                 return -EROFS;
  75         WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
  76         journal = EXT4_SB(sb)->s_journal;
  77         /*
  78          * Special case here: if the journal has aborted behind our
  79          * backs (eg. EIO in the commit thread), then we still need to
  80          * take the FS itself readonly cleanly.
  81          */
  82         if (journal && is_journal_aborted(journal)) {
  83                 ext4_set_errno(sb, -journal->j_errno);
  84                 ext4_abort(sb, "Detected aborted journal");
  85                 return -EROFS;
  86         }
  87         return 0;
  88 }
  89
  90 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
  91                                   int type, int blocks, int rsv_blocks,
  92                                   int revoke_creds)
  93 {
  94         journal_t *journal;
  95         int err;
  96
  97         trace_ext4_journal_start(sb, blocks, rsv_blocks, revoke_creds,
  98                                  _RET_IP_);
  99         err = ext4_journal_check_start(sb);
 100         if (err < 0)
 101                 return ERR_PTR(err);
 102
 103         journal = EXT4_SB(sb)->s_journal;
 104         if (!journal)
 105                 return ext4_get_nojournal();
 106         return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_creds,
 107                                    GFP_NOFS, type, line);
 108 }
 109
 110 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 111 {
 112         struct super_block *sb;
 113         int err;
 114         int rc;
 115
 116         if (!ext4_handle_valid(handle)) {
 117                 ext4_put_nojournal(handle);
 118                 return 0;
 119         }
 120
 121         err = handle->h_err;
 122         if (!handle->h_transaction) {
 123                 rc = jbd2_journal_stop(handle);
 124                 return err ? err : rc;
 125         }
 126
 127         sb = handle->h_transaction->t_journal->j_private;
 128         rc = jbd2_journal_stop(handle);
 129
 130         if (!err)
 131                 err = rc;
 132         if (err)
 133                 __ext4_std_error(sb, where, line, err);
 134         return err;
 135 }
 136
 137 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 138                                         int type)
 139 {
 140         struct super_block *sb;
 141         int err;
 142
 143         if (!ext4_handle_valid(handle))
 144                 return ext4_get_nojournal();
 145
 146         sb = handle->h_journal->j_private;
 147         trace_ext4_journal_start_reserved(sb,
 148                                 jbd2_handle_buffer_credits(handle), _RET_IP_);
 149         err = ext4_journal_check_start(sb);
 150         if (err < 0) {
 151                 jbd2_journal_free_reserved(handle);
 152                 return ERR_PTR(err);
 153         }
 154
 155         err = jbd2_journal_start_reserved(handle, type, line);
 156         if (err < 0)
 157                 return ERR_PTR(err);
 158         return handle;
 159 }
 160
 161 int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
 162                                   int extend_cred, int revoke_cred)
 163 {
 164         if (!ext4_handle_valid(handle))
 165                 return 0;
 166         if (jbd2_handle_buffer_credits(handle) >= check_cred &&
 167             handle->h_revoke_credits >= revoke_cred)
 168                 return 0;
 169         extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle));
 170         revoke_cred = max(0, revoke_cred - handle->h_revoke_credits);
 171         return ext4_journal_extend(handle, extend_cred, revoke_cred);
 172 }
 173
 174 static void ext4_journal_abort_handle(const char *caller, unsigned int line,
 175                                       const char *err_fn,
 176                                       struct buffer_head *bh,
 177                                       handle_t *handle, int err)
 178 {
 179         char nbuf[16];
 180         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 181
 182         BUG_ON(!ext4_handle_valid(handle));
 183
 184         if (bh)
 185                 BUFFER_TRACE(bh, "abort");
 186
 187         if (!handle->h_err)
 188                 handle->h_err = err;
 189
 190         if (is_handle_aborted(handle))
 191                 return;
 192
 193         printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 194                caller, line, errstr, err_fn);
 195
 196         jbd2_journal_abort_handle(handle);
 197 }
 198
 199 int __ext4_journal_get_write_access(const char *where, unsigned int line,
 200                                     handle_t *handle, struct buffer_head *bh)
 201 {
 202         int err = 0;
 203
 204         might_sleep();
 205
 206         if (ext4_handle_valid(handle)) {
 207                 err = jbd2_journal_get_write_access(handle, bh);
 208                 if (err)
 209                         ext4_journal_abort_handle(where, line, __func__, bh,
 210                                                   handle, err);
 211         }
 212         return err;
 213 }
 214
 215 /*
 216  * The ext4 forget function must perform a revoke if we are freeing data
 217  * which has been journaled.  Metadata (eg. indirect blocks) must be
 218  * revoked in all cases.
 219  *
 220  * "bh" may be NULL: a metadata block may have been freed from memory
 221  * but there may still be a record of it in the journal, and that record
 222  * still needs to be revoked.
 223  *
 224  * If the handle isn't valid we're not journaling, but we still need to
 225  * call into ext4_journal_revoke() to put the buffer head.
 226  */
 227 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 228                   int is_metadata, struct inode *inode,
 229                   struct buffer_head *bh, ext4_fsblk_t blocknr)
 230 {
 231         int err;
 232
 233         might_sleep();
 234
 235         trace_ext4_forget(inode, is_metadata, blocknr);
 236         BUFFER_TRACE(bh, "enter");
 237
 238         jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
 239                   "data mode %x\n",
 240                   bh, is_metadata, inode->i_mode,
 241                   test_opt(inode->i_sb, DATA_FLAGS));
 242
 243         /* In the no journal case, we can just do a bforget and return */
 244         if (!ext4_handle_valid(handle)) {
 245                 bforget(bh);
 246                 return 0;
 247         }
 248
 249         /* Never use the revoke function if we are doing full data
 250          * journaling: there is no need to, and a V1 superblock won't
 251          * support it.  Otherwise, only skip the revoke on un-journaled
 252          * data blocks. */
 253
 254         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 255             (!is_metadata && !ext4_should_journal_data(inode))) {
 256                 if (bh) {
 257                         BUFFER_TRACE(bh, "call jbd2_journal_forget");
 258                         err = jbd2_journal_forget(handle, bh);
 259                         if (err)
 260                                 ext4_journal_abort_handle(where, line, __func__,
 261                                                           bh, handle, err);
 262                         return err;
 263                 }
 264                 return 0;
 265         }
 266
 267         /*
 268          * data!=journal && (is_metadata || should_journal_data(inode))
 269          */
 270         BUFFER_TRACE(bh, "call jbd2_journal_revoke");
 271         err = jbd2_journal_revoke(handle, blocknr, bh);
 272         if (err) {
 273                 ext4_journal_abort_handle(where, line, __func__,
 274                                           bh, handle, err);
 275                 ext4_set_errno(inode->i_sb, -err);
 276                 __ext4_abort(inode->i_sb, where, line,
 277                            "error %d when attempting revoke", err);
 278         }
 279         BUFFER_TRACE(bh, "exit");
 280         return err;
 281 }
 282
 283 int __ext4_journal_get_create_access(const char *where, unsigned int line,
 284                                 handle_t *handle, struct buffer_head *bh)
 285 {
 286         int err = 0;
 287
 288         if (ext4_handle_valid(handle)) {
 289                 err = jbd2_journal_get_create_access(handle, bh);
 290                 if (err)
 291                         ext4_journal_abort_handle(where, line, __func__,
 292                                                   bh, handle, err);
 293         }
 294         return err;
 295 }
 296
 297 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 298                                  handle_t *handle, struct inode *inode,
 299                                  struct buffer_head *bh)
 300 {
 301         int err = 0;
 302
 303         might_sleep();
 304
 305         set_buffer_meta(bh);
 306         set_buffer_prio(bh);
 307         if (ext4_handle_valid(handle)) {
 308                 err = jbd2_journal_dirty_metadata(handle, bh);
 309                 /* Errors can only happen due to aborted journal or a nasty bug */
 310                 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
 311                         ext4_journal_abort_handle(where, line, __func__, bh,
 312                                                   handle, err);
 313                         if (inode == NULL) {
 314                                 pr_err("EXT4: jbd2_journal_dirty_metadata "
 315                                        "failed: handle type %u started at "
 316                                        "line %u, credits %u/%u, errcode %d",
 317                                        handle->h_type,
 318                                        handle->h_line_no,
 319                                        handle->h_requested_credits,
 320                                        jbd2_handle_buffer_credits(handle), err);
 321                                 return err;
 322                         }
 323                         ext4_error_inode(inode, where, line,
 324                                          bh->b_blocknr,
 325                                          "journal_dirty_metadata failed: "
 326                                          "handle type %u started at line %u, "
 327                                          "credits %u/%u, errcode %d",
 328                                          handle->h_type,
 329                                          handle->h_line_no,
 330                                          handle->h_requested_credits,
 331                                          jbd2_handle_buffer_credits(handle),
 332                                          err);
 333                 }
 334         } else {
 335                 if (inode)
 336                         mark_buffer_dirty_inode(bh, inode);
 337                 else
 338                         mark_buffer_dirty(bh);
 339                 if (inode && inode_needs_sync(inode)) {
 340                         sync_dirty_buffer(bh);
 341                         if (buffer_req(bh) && !buffer_uptodate(bh)) {
 342                                 struct ext4_super_block *es;
 343
 344                                 es = EXT4_SB(inode->i_sb)->s_es;
 345                                 es->s_last_error_block =
 346                                         cpu_to_le64(bh->b_blocknr);
 347                                 ext4_set_errno(inode->i_sb, EIO);
 348                                 ext4_error_inode(inode, where, line,
 349                                                  bh->b_blocknr,
 350                                         "IO error syncing itable block");
 351                                 err = -EIO;
 352                         }
 353                 }
 354         }
 355         return err;
 356 }
 357
 358 int __ext4_handle_dirty_super(const char *where, unsigned int line,
 359                               handle_t *handle, struct super_block *sb)
 360 {
 361         struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
 362         int err = 0;
 363
 364         ext4_superblock_csum_set(sb);
 365         if (ext4_handle_valid(handle)) {
 366                 err = jbd2_journal_dirty_metadata(handle, bh);
 367                 if (err)
 368                         ext4_journal_abort_handle(where, line, __func__,
 369                                                   bh, handle, err);
 370         } else
 371                 mark_buffer_dirty(bh);
 372         return err;
 373 }