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_abort(sb, -journal->j_errno, "Detected aborted journal");
  84                 return -EROFS;
  85         }
  86         return 0;
  87 }
  88
  89 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
  90                                   int type, int blocks, int rsv_blocks,
  91                                   int revoke_creds)
  92 {
  93         journal_t *journal;
  94         int err;
  95
  96         trace_ext4_journal_start(sb, blocks, rsv_blocks, revoke_creds,
  97                                  _RET_IP_);
  98         err = ext4_journal_check_start(sb);
  99         if (err < 0)
 100                 return ERR_PTR(err);
 101
 102         journal = EXT4_SB(sb)->s_journal;
 103         if (!journal || (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
 104                 return ext4_get_nojournal();
 105         return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_creds,
 106                                    GFP_NOFS, type, line);
 107 }
 108
 109 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 110 {
 111         struct super_block *sb;
 112         int err;
 113         int rc;
 114
 115         if (!ext4_handle_valid(handle)) {
 116                 ext4_put_nojournal(handle);
 117                 return 0;
 118         }
 119
 120         err = handle->h_err;
 121         if (!handle->h_transaction) {
 122                 rc = jbd2_journal_stop(handle);
 123                 return err ? err : rc;
 124         }
 125
 126         sb = handle->h_transaction->t_journal->j_private;
 127         rc = jbd2_journal_stop(handle);
 128
 129         if (!err)
 130                 err = rc;
 131         if (err)
 132                 __ext4_std_error(sb, where, line, err);
 133         return err;
 134 }
 135
 136 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 137                                         int type)
 138 {
 139         struct super_block *sb;
 140         int err;
 141
 142         if (!ext4_handle_valid(handle))
 143                 return ext4_get_nojournal();
 144
 145         sb = handle->h_journal->j_private;
 146         trace_ext4_journal_start_reserved(sb,
 147                                 jbd2_handle_buffer_credits(handle), _RET_IP_);
 148         err = ext4_journal_check_start(sb);
 149         if (err < 0) {
 150                 jbd2_journal_free_reserved(handle);
 151                 return ERR_PTR(err);
 152         }
 153
 154         err = jbd2_journal_start_reserved(handle, type, line);
 155         if (err < 0)
 156                 return ERR_PTR(err);
 157         return handle;
 158 }
 159
 160 int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
 161                                   int extend_cred, int revoke_cred)
 162 {
 163         if (!ext4_handle_valid(handle))
 164                 return 0;
 165         if (jbd2_handle_buffer_credits(handle) >= check_cred &&
 166             handle->h_revoke_credits >= revoke_cred)
 167                 return 0;
 168         extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle));
 169         revoke_cred = max(0, revoke_cred - handle->h_revoke_credits);
 170         return ext4_journal_extend(handle, extend_cred, revoke_cred);
 171 }
 172
 173 static void ext4_journal_abort_handle(const char *caller, unsigned int line,
 174                                       const char *err_fn,
 175                                       struct buffer_head *bh,
 176                                       handle_t *handle, int err)
 177 {
 178         char nbuf[16];
 179         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 180
 181         BUG_ON(!ext4_handle_valid(handle));
 182
 183         if (bh)
 184                 BUFFER_TRACE(bh, "abort");
 185
 186         if (!handle->h_err)
 187                 handle->h_err = err;
 188
 189         if (is_handle_aborted(handle))
 190                 return;
 191
 192         printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 193                caller, line, errstr, err_fn);
 194
 195         jbd2_journal_abort_handle(handle);
 196 }
 197
 198 static void ext4_check_bdev_write_error(struct super_block *sb)
 199 {
 200         struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
 201         struct ext4_sb_info *sbi = EXT4_SB(sb);
 202         int err;
 203
 204         /*
 205          * If the block device has write error flag, it may have failed to
 206          * async write out metadata buffers in the background. In this case,
 207          * we could read old data from disk and write it out again, which
 208          * may lead to on-disk filesystem inconsistency.
 209          */
 210         if (errseq_check(&mapping->wb_err, READ_ONCE(sbi->s_bdev_wb_err))) {
 211                 spin_lock(&sbi->s_bdev_wb_lock);
 212                 err = errseq_check_and_advance(&mapping->wb_err, &sbi->s_bdev_wb_err);
 213                 spin_unlock(&sbi->s_bdev_wb_lock);
 214                 if (err)
 215                         ext4_error_err(sb, -err,
 216                                        "Error while async write back metadata");
 217         }
 218 }
 219
 220 int __ext4_journal_get_write_access(const char *where, unsigned int line,
 221                                     handle_t *handle, struct buffer_head *bh)
 222 {
 223         int err = 0;
 224
 225         might_sleep();
 226
 227         if (bh->b_bdev->bd_super)
 228                 ext4_check_bdev_write_error(bh->b_bdev->bd_super);
 229
 230         if (ext4_handle_valid(handle)) {
 231                 err = jbd2_journal_get_write_access(handle, bh);
 232                 if (err)
 233                         ext4_journal_abort_handle(where, line, __func__, bh,
 234                                                   handle, err);
 235         }
 236         return err;
 237 }
 238
 239 /*
 240  * The ext4 forget function must perform a revoke if we are freeing data
 241  * which has been journaled.  Metadata (eg. indirect blocks) must be
 242  * revoked in all cases.
 243  *
 244  * "bh" may be NULL: a metadata block may have been freed from memory
 245  * but there may still be a record of it in the journal, and that record
 246  * still needs to be revoked.
 247  *
 248  * If the handle isn't valid we're not journaling, but we still need to
 249  * call into ext4_journal_revoke() to put the buffer head.
 250  */
 251 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 252                   int is_metadata, struct inode *inode,
 253                   struct buffer_head *bh, ext4_fsblk_t blocknr)
 254 {
 255         int err;
 256
 257         might_sleep();
 258
 259         trace_ext4_forget(inode, is_metadata, blocknr);
 260         BUFFER_TRACE(bh, "enter");
 261
 262         jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
 263                   "data mode %x\n",
 264                   bh, is_metadata, inode->i_mode,
 265                   test_opt(inode->i_sb, DATA_FLAGS));
 266
 267         /* In the no journal case, we can just do a bforget and return */
 268         if (!ext4_handle_valid(handle)) {
 269                 bforget(bh);
 270                 return 0;
 271         }
 272
 273         /* Never use the revoke function if we are doing full data
 274          * journaling: there is no need to, and a V1 superblock won't
 275          * support it.  Otherwise, only skip the revoke on un-journaled
 276          * data blocks. */
 277
 278         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 279             (!is_metadata && !ext4_should_journal_data(inode))) {
 280                 if (bh) {
 281                         BUFFER_TRACE(bh, "call jbd2_journal_forget");
 282                         err = jbd2_journal_forget(handle, bh);
 283                         if (err)
 284                                 ext4_journal_abort_handle(where, line, __func__,
 285                                                           bh, handle, err);
 286                         return err;
 287                 }
 288                 return 0;
 289         }
 290
 291         /*
 292          * data!=journal && (is_metadata || should_journal_data(inode))
 293          */
 294         BUFFER_TRACE(bh, "call jbd2_journal_revoke");
 295         err = jbd2_journal_revoke(handle, blocknr, bh);
 296         if (err) {
 297                 ext4_journal_abort_handle(where, line, __func__,
 298                                           bh, handle, err);
 299                 __ext4_error(inode->i_sb, where, line, true, -err, 0,
 300                              "error %d when attempting revoke", err);
 301         }
 302         BUFFER_TRACE(bh, "exit");
 303         return err;
 304 }
 305
 306 int __ext4_journal_get_create_access(const char *where, unsigned int line,
 307                                 handle_t *handle, struct buffer_head *bh)
 308 {
 309         int err = 0;
 310
 311         if (ext4_handle_valid(handle)) {
 312                 err = jbd2_journal_get_create_access(handle, bh);
 313                 if (err)
 314                         ext4_journal_abort_handle(where, line, __func__,
 315                                                   bh, handle, err);
 316         }
 317         return err;
 318 }
 319
 320 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 321                                  handle_t *handle, struct inode *inode,
 322                                  struct buffer_head *bh)
 323 {
 324         int err = 0;
 325
 326         might_sleep();
 327
 328         set_buffer_meta(bh);
 329         set_buffer_prio(bh);
 330         if (ext4_handle_valid(handle)) {
 331                 err = jbd2_journal_dirty_metadata(handle, bh);
 332                 /* Errors can only happen due to aborted journal or a nasty bug */
 333                 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
 334                         ext4_journal_abort_handle(where, line, __func__, bh,
 335                                                   handle, err);
 336                         if (inode == NULL) {
 337                                 pr_err("EXT4: jbd2_journal_dirty_metadata "
 338                                        "failed: handle type %u started at "
 339                                        "line %u, credits %u/%u, errcode %d",
 340                                        handle->h_type,
 341                                        handle->h_line_no,
 342                                        handle->h_requested_credits,
 343                                        jbd2_handle_buffer_credits(handle), err);
 344                                 return err;
 345                         }
 346                         ext4_error_inode(inode, where, line,
 347                                          bh->b_blocknr,
 348                                          "journal_dirty_metadata failed: "
 349                                          "handle type %u started at line %u, "
 350                                          "credits %u/%u, errcode %d",
 351                                          handle->h_type,
 352                                          handle->h_line_no,
 353                                          handle->h_requested_credits,
 354                                          jbd2_handle_buffer_credits(handle),
 355                                          err);
 356                 }
 357         } else {
 358                 set_buffer_uptodate(bh);
 359                 if (inode)
 360                         mark_buffer_dirty_inode(bh, inode);
 361                 else
 362                         mark_buffer_dirty(bh);
 363                 if (inode && inode_needs_sync(inode)) {
 364                         sync_dirty_buffer(bh);
 365                         if (buffer_req(bh) && !buffer_uptodate(bh)) {
 366                                 ext4_error_inode_err(inode, where, line,
 367                                                      bh->b_blocknr, EIO,
 368                                         "IO error syncing itable block");
 369                                 err = -EIO;
 370                         }
 371                 }
 372         }
 373         return err;
 374 }