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 static int ext4_journal_check_start(struct super_block *sb)
  42 {
  43         journal_t *journal;
  44
  45         might_sleep();
  46         if (sb->s_flags & MS_RDONLY)
  47                 return -EROFS;
  48         WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
  49         journal = EXT4_SB(sb)->s_journal;
  50         /*
  51          * Special case here: if the journal has aborted behind our
  52          * backs (eg. EIO in the commit thread), then we still need to
  53          * take the FS itself readonly cleanly.
  54          */
  55         if (journal && is_journal_aborted(journal)) {
  56                 ext4_abort(sb, "Detected aborted journal");
  57                 return -EROFS;
  58         }
  59         return 0;
  60 }
  61
  62 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
  63                                   int type, int blocks, int rsv_blocks)
  64 {
  65         journal_t *journal;
  66         int err;
  67
  68         trace_ext4_journal_start(sb, blocks, rsv_blocks, _RET_IP_);
  69         err = ext4_journal_check_start(sb);
  70         if (err < 0)
  71                 return ERR_PTR(err);
  72
  73         journal = EXT4_SB(sb)->s_journal;
  74         if (!journal)
  75                 return ext4_get_nojournal();
  76         return jbd2__journal_start(journal, blocks, rsv_blocks, GFP_NOFS,
  77                                    type, line);
  78 }
  79
  80 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
  81 {
  82         struct super_block *sb;
  83         int err;
  84         int rc;
  85
  86         if (!ext4_handle_valid(handle)) {
  87                 ext4_put_nojournal(handle);
  88                 return 0;
  89         }
  90         sb = handle->h_transaction->t_journal->j_private;
  91         err = handle->h_err;
  92         rc = jbd2_journal_stop(handle);
  93
  94         if (!err)
  95                 err = rc;
  96         if (err)
  97                 __ext4_std_error(sb, where, line, err);
  98         return err;
  99 }
 100
 101 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 102                                         int type)
 103 {
 104         struct super_block *sb;
 105         int err;
 106
 107         if (!ext4_handle_valid(handle))
 108                 return ext4_get_nojournal();
 109
 110         sb = handle->h_journal->j_private;
 111         trace_ext4_journal_start_reserved(sb, handle->h_buffer_credits,
 112                                           _RET_IP_);
 113         err = ext4_journal_check_start(sb);
 114         if (err < 0) {
 115                 jbd2_journal_free_reserved(handle);
 116                 return ERR_PTR(err);
 117         }
 118
 119         err = jbd2_journal_start_reserved(handle, type, line);
 120         if (err < 0)
 121                 return ERR_PTR(err);
 122         return handle;
 123 }
 124
 125 void ext4_journal_abort_handle(const char *caller, unsigned int line,
 126                                const char *err_fn, struct buffer_head *bh,
 127                                handle_t *handle, int err)
 128 {
 129         char nbuf[16];
 130         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 131
 132         BUG_ON(!ext4_handle_valid(handle));
 133
 134         if (bh)
 135                 BUFFER_TRACE(bh, "abort");
 136
 137         if (!handle->h_err)
 138                 handle->h_err = err;
 139
 140         if (is_handle_aborted(handle))
 141                 return;
 142
 143         printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 144                caller, line, errstr, err_fn);
 145
 146         jbd2_journal_abort_handle(handle);
 147 }
 148
 149 int __ext4_journal_get_write_access(const char *where, unsigned int line,
 150                                     handle_t *handle, struct buffer_head *bh)
 151 {
 152         int err = 0;
 153
 154         might_sleep();
 155
 156         if (ext4_handle_valid(handle)) {
 157                 err = jbd2_journal_get_write_access(handle, bh);
 158                 if (err)
 159                         ext4_journal_abort_handle(where, line, __func__, bh,
 160                                                   handle, err);
 161         }
 162         return err;
 163 }
 164
 165 /*
 166  * The ext4 forget function must perform a revoke if we are freeing data
 167  * which has been journaled.  Metadata (eg. indirect blocks) must be
 168  * revoked in all cases.
 169  *
 170  * "bh" may be NULL: a metadata block may have been freed from memory
 171  * but there may still be a record of it in the journal, and that record
 172  * still needs to be revoked.
 173  *
 174  * If the handle isn't valid we're not journaling, but we still need to
 175  * call into ext4_journal_revoke() to put the buffer head.
 176  */
 177 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 178                   int is_metadata, struct inode *inode,
 179                   struct buffer_head *bh, ext4_fsblk_t blocknr)
 180 {
 181         int err;
 182
 183         might_sleep();
 184
 185         trace_ext4_forget(inode, is_metadata, blocknr);
 186         BUFFER_TRACE(bh, "enter");
 187
 188         jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
 189                   "data mode %x\n",
 190                   bh, is_metadata, inode->i_mode,
 191                   test_opt(inode->i_sb, DATA_FLAGS));
 192
 193         /* In the no journal case, we can just do a bforget and return */
 194         if (!ext4_handle_valid(handle)) {
 195                 bforget(bh);
 196                 return 0;
 197         }
 198
 199         /* Never use the revoke function if we are doing full data
 200          * journaling: there is no need to, and a V1 superblock won't
 201          * support it.  Otherwise, only skip the revoke on un-journaled
 202          * data blocks. */
 203
 204         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 205             (!is_metadata && !ext4_should_journal_data(inode))) {
 206                 if (bh) {
 207                         BUFFER_TRACE(bh, "call jbd2_journal_forget");
 208                         err = jbd2_journal_forget(handle, bh);
 209                         if (err)
 210                                 ext4_journal_abort_handle(where, line, __func__,
 211                                                           bh, handle, err);
 212                         return err;
 213                 }
 214                 return 0;
 215         }
 216
 217         /*
 218          * data!=journal && (is_metadata || should_journal_data(inode))
 219          */
 220         BUFFER_TRACE(bh, "call jbd2_journal_revoke");
 221         err = jbd2_journal_revoke(handle, blocknr, bh);
 222         if (err) {
 223                 ext4_journal_abort_handle(where, line, __func__,
 224                                           bh, handle, err);
 225                 __ext4_abort(inode->i_sb, where, line,
 226                            "error %d when attempting revoke", err);
 227         }
 228         BUFFER_TRACE(bh, "exit");
 229         return err;
 230 }
 231
 232 int __ext4_journal_get_create_access(const char *where, unsigned int line,
 233                                 handle_t *handle, struct buffer_head *bh)
 234 {
 235         int err = 0;
 236
 237         if (ext4_handle_valid(handle)) {
 238                 err = jbd2_journal_get_create_access(handle, bh);
 239                 if (err)
 240                         ext4_journal_abort_handle(where, line, __func__,
 241                                                   bh, handle, err);
 242         }
 243         return err;
 244 }
 245
 246 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 247                                  handle_t *handle, struct inode *inode,
 248                                  struct buffer_head *bh)
 249 {
 250         int err = 0;
 251
 252         might_sleep();
 253
 254         set_buffer_meta(bh);
 255         set_buffer_prio(bh);
 256         if (ext4_handle_valid(handle)) {
 257                 err = jbd2_journal_dirty_metadata(handle, bh);
 258                 /* Errors can only happen if there is a bug */
 259                 if (WARN_ON_ONCE(err)) {
 260                         ext4_journal_abort_handle(where, line, __func__, bh,
 261                                                   handle, err);
 262                 }
 263         } else {
 264                 if (inode)
 265                         mark_buffer_dirty_inode(bh, inode);
 266                 else
 267                         mark_buffer_dirty(bh);
 268                 if (inode && inode_needs_sync(inode)) {
 269                         sync_dirty_buffer(bh);
 270                         if (buffer_req(bh) && !buffer_uptodate(bh)) {
 271                                 struct ext4_super_block *es;
 272
 273                                 es = EXT4_SB(inode->i_sb)->s_es;
 274                                 es->s_last_error_block =
 275                                         cpu_to_le64(bh->b_blocknr);
 276                                 ext4_error_inode(inode, where, line,
 277                                                  bh->b_blocknr,
 278                                         "IO error syncing itable block");
 279                                 err = -EIO;
 280                         }
 281                 }
 282         }
 283         return err;
 284 }
 285
 286 int __ext4_handle_dirty_super(const char *where, unsigned int line,
 287                               handle_t *handle, struct super_block *sb)
 288 {
 289         struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
 290         int err = 0;
 291
 292         ext4_superblock_csum_set(sb);
 293         if (ext4_handle_valid(handle)) {
 294                 err = jbd2_journal_dirty_metadata(handle, bh);
 295                 if (err)
 296                         ext4_journal_abort_handle(where, line, __func__,
 297                                                   bh, handle, err);
 298         } else
 299                 mark_buffer_dirty(bh);
 300         return err;
 301 }