fs/ext4/ext4_jbd2.c

   1 /*
   2  * Interface between ext4 and JBD
   3  */
   4
   5 #include "ext4_jbd2.h"
   6
   7 #include <trace/events/ext4.h>
   8
   9 /* Just increment the non-pointer handle value */
  10 static handle_t *ext4_get_nojournal(void)
  11 {
  12         handle_t *handle = current->journal_info;
  13         unsigned long ref_cnt = (unsigned long)handle;
  14
  15         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
  16
  17         ref_cnt++;
  18         handle = (handle_t *)ref_cnt;
  19
  20         current->journal_info = handle;
  21         return handle;
  22 }
  23
  24
  25 /* Decrement the non-pointer handle value */
  26 static void ext4_put_nojournal(handle_t *handle)
  27 {
  28         unsigned long ref_cnt = (unsigned long)handle;
  29
  30         BUG_ON(ref_cnt == 0);
  31
  32         ref_cnt--;
  33         handle = (handle_t *)ref_cnt;
  34
  35         current->journal_info = handle;
  36 }
  37
  38 /*
  39  * Wrappers for jbd2_journal_start/end.
  40  */
  41 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
  42                                   int type, int nblocks)
  43 {
  44         journal_t *journal;
  45
  46         trace_ext4_journal_start(sb, nblocks, _RET_IP_);
  47         if (sb->s_flags & MS_RDONLY)
  48                 return ERR_PTR(-EROFS);
  49
  50         WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
  51         journal = EXT4_SB(sb)->s_journal;
  52         if (!journal)
  53                 return ext4_get_nojournal();
  54         /*
  55          * Special case here: if the journal has aborted behind our
  56          * backs (eg. EIO in the commit thread), then we still need to
  57          * take the FS itself readonly cleanly.
  58          */
  59         if (is_journal_aborted(journal)) {
  60                 ext4_abort(sb, "Detected aborted journal");
  61                 return ERR_PTR(-EROFS);
  62         }
  63         return jbd2__journal_start(journal, nblocks, GFP_NOFS, type, line);
  64 }
  65
  66 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
  67 {
  68         struct super_block *sb;
  69         int err;
  70         int rc;
  71
  72         if (!ext4_handle_valid(handle)) {
  73                 ext4_put_nojournal(handle);
  74                 return 0;
  75         }
  76         sb = handle->h_transaction->t_journal->j_private;
  77         err = handle->h_err;
  78         rc = jbd2_journal_stop(handle);
  79
  80         if (!err)
  81                 err = rc;
  82         if (err)
  83                 __ext4_std_error(sb, where, line, err);
  84         return err;
  85 }
  86
  87 void ext4_journal_abort_handle(const char *caller, unsigned int line,
  88                                const char *err_fn, struct buffer_head *bh,
  89                                handle_t *handle, int err)
  90 {
  91         char nbuf[16];
  92         const char *errstr = ext4_decode_error(NULL, err, nbuf);
  93
  94         BUG_ON(!ext4_handle_valid(handle));
  95
  96         if (bh)
  97                 BUFFER_TRACE(bh, "abort");
  98
  99         if (!handle->h_err)
 100                 handle->h_err = err;
 101
 102         if (is_handle_aborted(handle))
 103                 return;
 104
 105         printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 106                caller, line, errstr, err_fn);
 107
 108         jbd2_journal_abort_handle(handle);
 109 }
 110
 111 int __ext4_journal_get_write_access(const char *where, unsigned int line,
 112                                     handle_t *handle, struct buffer_head *bh)
 113 {
 114         int err = 0;
 115
 116         if (ext4_handle_valid(handle)) {
 117                 err = jbd2_journal_get_write_access(handle, bh);
 118                 if (err)
 119                         ext4_journal_abort_handle(where, line, __func__, bh,
 120                                                   handle, err);
 121         }
 122         return err;
 123 }
 124
 125 /*
 126  * The ext4 forget function must perform a revoke if we are freeing data
 127  * which has been journaled.  Metadata (eg. indirect blocks) must be
 128  * revoked in all cases.
 129  *
 130  * "bh" may be NULL: a metadata block may have been freed from memory
 131  * but there may still be a record of it in the journal, and that record
 132  * still needs to be revoked.
 133  *
 134  * If the handle isn't valid we're not journaling, but we still need to
 135  * call into ext4_journal_revoke() to put the buffer head.
 136  */
 137 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 138                   int is_metadata, struct inode *inode,
 139                   struct buffer_head *bh, ext4_fsblk_t blocknr)
 140 {
 141         int err;
 142
 143         might_sleep();
 144
 145         trace_ext4_forget(inode, is_metadata, blocknr);
 146         BUFFER_TRACE(bh, "enter");
 147
 148         jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
 149                   "data mode %x\n",
 150                   bh, is_metadata, inode->i_mode,
 151                   test_opt(inode->i_sb, DATA_FLAGS));
 152
 153         /* In the no journal case, we can just do a bforget and return */
 154         if (!ext4_handle_valid(handle)) {
 155                 bforget(bh);
 156                 return 0;
 157         }
 158
 159         /* Never use the revoke function if we are doing full data
 160          * journaling: there is no need to, and a V1 superblock won't
 161          * support it.  Otherwise, only skip the revoke on un-journaled
 162          * data blocks. */
 163
 164         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 165             (!is_metadata && !ext4_should_journal_data(inode))) {
 166                 if (bh) {
 167                         BUFFER_TRACE(bh, "call jbd2_journal_forget");
 168                         err = jbd2_journal_forget(handle, bh);
 169                         if (err)
 170                                 ext4_journal_abort_handle(where, line, __func__,
 171                                                           bh, handle, err);
 172                         return err;
 173                 }
 174                 return 0;
 175         }
 176
 177         /*
 178          * data!=journal && (is_metadata || should_journal_data(inode))
 179          */
 180         BUFFER_TRACE(bh, "call jbd2_journal_revoke");
 181         err = jbd2_journal_revoke(handle, blocknr, bh);
 182         if (err) {
 183                 ext4_journal_abort_handle(where, line, __func__,
 184                                           bh, handle, err);
 185                 __ext4_abort(inode->i_sb, where, line,
 186                            "error %d when attempting revoke", err);
 187         }
 188         BUFFER_TRACE(bh, "exit");
 189         return err;
 190 }
 191
 192 int __ext4_journal_get_create_access(const char *where, unsigned int line,
 193                                 handle_t *handle, struct buffer_head *bh)
 194 {
 195         int err = 0;
 196
 197         if (ext4_handle_valid(handle)) {
 198                 err = jbd2_journal_get_create_access(handle, bh);
 199                 if (err)
 200                         ext4_journal_abort_handle(where, line, __func__,
 201                                                   bh, handle, err);
 202         }
 203         return err;
 204 }
 205
 206 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 207                                  handle_t *handle, struct inode *inode,
 208                                  struct buffer_head *bh)
 209 {
 210         int err = 0;
 211
 212         if (ext4_handle_valid(handle)) {
 213                 err = jbd2_journal_dirty_metadata(handle, bh);
 214                 if (err) {
 215                         /* Errors can only happen if there is a bug */
 216                         handle->h_err = err;
 217                         __ext4_journal_stop(where, line, handle);
 218                 }
 219         } else {
 220                 if (inode)
 221                         mark_buffer_dirty_inode(bh, inode);
 222                 else
 223                         mark_buffer_dirty(bh);
 224                 if (inode && inode_needs_sync(inode)) {
 225                         sync_dirty_buffer(bh);
 226                         if (buffer_req(bh) && !buffer_uptodate(bh)) {
 227                                 struct ext4_super_block *es;
 228
 229                                 es = EXT4_SB(inode->i_sb)->s_es;
 230                                 es->s_last_error_block =
 231                                         cpu_to_le64(bh->b_blocknr);
 232                                 ext4_error_inode(inode, where, line,
 233                                                  bh->b_blocknr,
 234                                         "IO error syncing itable block");
 235                                 err = -EIO;
 236                         }
 237                 }
 238         }
 239         return err;
 240 }
 241
 242 int __ext4_handle_dirty_super(const char *where, unsigned int line,
 243                               handle_t *handle, struct super_block *sb)
 244 {
 245         struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
 246         int err = 0;
 247
 248         ext4_superblock_csum_set(sb);
 249         if (ext4_handle_valid(handle)) {
 250                 err = jbd2_journal_dirty_metadata(handle, bh);
 251                 if (err)
 252                         ext4_journal_abort_handle(where, line, __func__,
 253                                                   bh, handle, err);
 254         } else
 255                 mark_buffer_dirty(bh);
 256         return err;
 257 }