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(sb)))
  71                 return -EIO;
  72
  73         if (WARN_ON_ONCE(sb_rdonly(sb)))
  74                 return -EROFS;
  75
  76         WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
  77         journal = EXT4_SB(sb)->s_journal;
  78         /*
  79          * Special case here: if the journal has aborted behind our
  80          * backs (eg. EIO in the commit thread), then we still need to
  81          * take the FS itself readonly cleanly.
  82          */
  83         if (journal && is_journal_aborted(journal)) {
  84                 ext4_abort(sb, -journal->j_errno, "Detected aborted journal");
  85                 return -EROFS;
  86         }
  87         return 0;
  88 }
  89
  90 handle_t *__ext4_journal_start_sb(struct inode *inode,
  91                                   struct super_block *sb, unsigned int line,
  92                                   int type, int blocks, int rsv_blocks,
  93                                   int revoke_creds)
  94 {
  95         journal_t *journal;
  96         int err;
  97         if (inode)
  98                 trace_ext4_journal_start_inode(inode, blocks, rsv_blocks,
  99                                         revoke_creds, type,
 100                                         _RET_IP_);
 101         else
 102                 trace_ext4_journal_start_sb(sb, blocks, rsv_blocks,
 103                                         revoke_creds, type,
 104                                         _RET_IP_);
 105         err = ext4_journal_check_start(sb);
 106         if (err < 0)
 107                 return ERR_PTR(err);
 108
 109         journal = EXT4_SB(sb)->s_journal;
 110         if (!journal || (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
 111                 return ext4_get_nojournal();
 112         return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_creds,
 113                                    GFP_NOFS, type, line);
 114 }
 115
 116 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 117 {
 118         struct super_block *sb;
 119         int err;
 120         int rc;
 121
 122         if (!ext4_handle_valid(handle)) {
 123                 ext4_put_nojournal(handle);
 124                 return 0;
 125         }
 126
 127         err = handle->h_err;
 128         if (!handle->h_transaction) {
 129                 rc = jbd2_journal_stop(handle);
 130                 return err ? err : rc;
 131         }
 132
 133         sb = handle->h_transaction->t_journal->j_private;
 134         rc = jbd2_journal_stop(handle);
 135
 136         if (!err)
 137                 err = rc;
 138         if (err)
 139                 __ext4_std_error(sb, where, line, err);
 140         return err;
 141 }
 142
 143 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 144                                         int type)
 145 {
 146         struct super_block *sb;
 147         int err;
 148
 149         if (!ext4_handle_valid(handle))
 150                 return ext4_get_nojournal();
 151
 152         sb = handle->h_journal->j_private;
 153         trace_ext4_journal_start_reserved(sb,
 154                                 jbd2_handle_buffer_credits(handle), _RET_IP_);
 155         err = ext4_journal_check_start(sb);
 156         if (err < 0) {
 157                 jbd2_journal_free_reserved(handle);
 158                 return ERR_PTR(err);
 159         }
 160
 161         err = jbd2_journal_start_reserved(handle, type, line);
 162         if (err < 0)
 163                 return ERR_PTR(err);
 164         return handle;
 165 }
 166
 167 int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
 168                                   int extend_cred, int revoke_cred)
 169 {
 170         if (!ext4_handle_valid(handle))
 171                 return 0;
 172         if (is_handle_aborted(handle))
 173                 return -EROFS;
 174         if (jbd2_handle_buffer_credits(handle) >= check_cred &&
 175             handle->h_revoke_credits >= revoke_cred)
 176                 return 0;
 177         extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle));
 178         revoke_cred = max(0, revoke_cred - handle->h_revoke_credits);
 179         return ext4_journal_extend(handle, extend_cred, revoke_cred);
 180 }
 181
 182 static void ext4_journal_abort_handle(const char *caller, unsigned int line,
 183                                       const char *err_fn,
 184                                       struct buffer_head *bh,
 185                                       handle_t *handle, int err)
 186 {
 187         char nbuf[16];
 188         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 189
 190         BUG_ON(!ext4_handle_valid(handle));
 191
 192         if (bh)
 193                 BUFFER_TRACE(bh, "abort");
 194
 195         if (!handle->h_err)
 196                 handle->h_err = err;
 197
 198         if (is_handle_aborted(handle))
 199                 return;
 200
 201         printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 202                caller, line, errstr, err_fn);
 203
 204         jbd2_journal_abort_handle(handle);
 205 }
 206
 207 static void ext4_check_bdev_write_error(struct super_block *sb)
 208 {
 209         struct address_space *mapping = sb->s_bdev->bd_mapping;
 210         struct ext4_sb_info *sbi = EXT4_SB(sb);
 211         int err;
 212
 213         /*
 214          * If the block device has write error flag, it may have failed to
 215          * async write out metadata buffers in the background. In this case,
 216          * we could read old data from disk and write it out again, which
 217          * may lead to on-disk filesystem inconsistency.
 218          */
 219         if (errseq_check(&mapping->wb_err, READ_ONCE(sbi->s_bdev_wb_err))) {
 220                 spin_lock(&sbi->s_bdev_wb_lock);
 221                 err = errseq_check_and_advance(&mapping->wb_err, &sbi->s_bdev_wb_err);
 222                 spin_unlock(&sbi->s_bdev_wb_lock);
 223                 if (err)
 224                         ext4_error_err(sb, -err,
 225                                        "Error while async write back metadata");
 226         }
 227 }
 228
 229 int __ext4_journal_get_write_access(const char *where, unsigned int line,
 230                                     handle_t *handle, struct super_block *sb,
 231                                     struct buffer_head *bh,
 232                                     enum ext4_journal_trigger_type trigger_type)
 233 {
 234         int err;
 235
 236         might_sleep();
 237
 238         if (ext4_handle_valid(handle)) {
 239                 err = jbd2_journal_get_write_access(handle, bh);
 240                 if (err) {
 241                         ext4_journal_abort_handle(where, line, __func__, bh,
 242                                                   handle, err);
 243                         return err;
 244                 }
 245         } else
 246                 ext4_check_bdev_write_error(sb);
 247         if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
 248                 return 0;
 249         BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
 250         jbd2_journal_set_triggers(bh,
 251                 &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
 252         return 0;
 253 }
 254
 255 /*
 256  * The ext4 forget function must perform a revoke if we are freeing data
 257  * which has been journaled.  Metadata (eg. indirect blocks) must be
 258  * revoked in all cases.
 259  *
 260  * "bh" may be NULL: a metadata block may have been freed from memory
 261  * but there may still be a record of it in the journal, and that record
 262  * still needs to be revoked.
 263  */
 264 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 265                   int is_metadata, struct inode *inode,
 266                   struct buffer_head *bh, ext4_fsblk_t blocknr)
 267 {
 268         int err;
 269
 270         might_sleep();
 271
 272         trace_ext4_forget(inode, is_metadata, blocknr);
 273         BUFFER_TRACE(bh, "enter");
 274
 275         ext4_debug("forgetting bh %p: is_metadata=%d, mode %o, data mode %x\n",
 276                   bh, is_metadata, inode->i_mode,
 277                   test_opt(inode->i_sb, DATA_FLAGS));
 278
 279         /* In the no journal case, we can just do a bforget and return */
 280         if (!ext4_handle_valid(handle)) {
 281                 bforget(bh);
 282                 return 0;
 283         }
 284
 285         /* Never use the revoke function if we are doing full data
 286          * journaling: there is no need to, and a V1 superblock won't
 287          * support it.  Otherwise, only skip the revoke on un-journaled
 288          * data blocks. */
 289
 290         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 291             (!is_metadata && !ext4_should_journal_data(inode))) {
 292                 if (bh) {
 293                         BUFFER_TRACE(bh, "call jbd2_journal_forget");
 294                         err = jbd2_journal_forget(handle, bh);
 295                         if (err)
 296                                 ext4_journal_abort_handle(where, line, __func__,
 297                                                           bh, handle, err);
 298                         return err;
 299                 }
 300                 return 0;
 301         }
 302
 303         /*
 304          * data!=journal && (is_metadata || should_journal_data(inode))
 305          */
 306         BUFFER_TRACE(bh, "call jbd2_journal_revoke");
 307         err = jbd2_journal_revoke(handle, blocknr, bh);
 308         if (err) {
 309                 ext4_journal_abort_handle(where, line, __func__,
 310                                           bh, handle, err);
 311                 __ext4_error(inode->i_sb, where, line, true, -err, 0,
 312                              "error %d when attempting revoke", err);
 313         }
 314         BUFFER_TRACE(bh, "exit");
 315         return err;
 316 }
 317
 318 int __ext4_journal_get_create_access(const char *where, unsigned int line,
 319                                 handle_t *handle, struct super_block *sb,
 320                                 struct buffer_head *bh,
 321                                 enum ext4_journal_trigger_type trigger_type)
 322 {
 323         int err;
 324
 325         if (!ext4_handle_valid(handle))
 326                 return 0;
 327
 328         err = jbd2_journal_get_create_access(handle, bh);
 329         if (err) {
 330                 ext4_journal_abort_handle(where, line, __func__, bh, handle,
 331                                           err);
 332                 return err;
 333         }
 334         if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
 335                 return 0;
 336         BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
 337         jbd2_journal_set_triggers(bh,
 338                 &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
 339         return 0;
 340 }
 341
 342 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 343                                  handle_t *handle, struct inode *inode,
 344                                  struct buffer_head *bh)
 345 {
 346         int err = 0;
 347
 348         might_sleep();
 349
 350         set_buffer_meta(bh);
 351         set_buffer_prio(bh);
 352         set_buffer_uptodate(bh);
 353         if (ext4_handle_valid(handle)) {
 354                 err = jbd2_journal_dirty_metadata(handle, bh);
 355                 /* Errors can only happen due to aborted journal or a nasty bug */
 356                 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
 357                         ext4_journal_abort_handle(where, line, __func__, bh,
 358                                                   handle, err);
 359                         if (inode == NULL) {
 360                                 pr_err("EXT4: jbd2_journal_dirty_metadata "
 361                                        "failed: handle type %u started at "
 362                                        "line %u, credits %u/%u, errcode %d",
 363                                        handle->h_type,
 364                                        handle->h_line_no,
 365                                        handle->h_requested_credits,
 366                                        jbd2_handle_buffer_credits(handle), err);
 367                                 return err;
 368                         }
 369                         ext4_error_inode(inode, where, line,
 370                                          bh->b_blocknr,
 371                                          "journal_dirty_metadata failed: "
 372                                          "handle type %u started at line %u, "
 373                                          "credits %u/%u, errcode %d",
 374                                          handle->h_type,
 375                                          handle->h_line_no,
 376                                          handle->h_requested_credits,
 377                                          jbd2_handle_buffer_credits(handle),
 378                                          err);
 379                 }
 380         } else {
 381                 if (inode)
 382                         mark_buffer_dirty_inode(bh, inode);
 383                 else
 384                         mark_buffer_dirty(bh);
 385                 if (inode && inode_needs_sync(inode)) {
 386                         sync_dirty_buffer(bh);
 387                         if (buffer_req(bh) && !buffer_uptodate(bh)) {
 388                                 ext4_error_inode_err(inode, where, line,
 389                                                      bh->b_blocknr, EIO,
 390                                         "IO error syncing itable block");
 391                                 err = -EIO;
 392                         }
 393                 }
 394         }
 395         return err;
 396 }