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
  47         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
  48                 return -EIO;
  49
  50         if (sb->s_flags & MS_RDONLY)
  51                 return -EROFS;
  52         WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
  53         journal = EXT4_SB(sb)->s_journal;
  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 (journal && is_journal_aborted(journal)) {
  60                 ext4_abort(sb, "Detected aborted journal");
  61                 return -EROFS;
  62         }
  63         return 0;
  64 }
  65
  66 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
  67                                   int type, int blocks, int rsv_blocks)
  68 {
  69         journal_t *journal;
  70         int err;
  71
  72         trace_ext4_journal_start(sb, blocks, rsv_blocks, _RET_IP_);
  73         err = ext4_journal_check_start(sb);
  74         if (err < 0)
  75                 return ERR_PTR(err);
  76
  77         journal = EXT4_SB(sb)->s_journal;
  78         if (!journal)
  79                 return ext4_get_nojournal();
  80         return jbd2__journal_start(journal, blocks, rsv_blocks, GFP_NOFS,
  81                                    type, line);
  82 }
  83
  84 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
  85 {
  86         struct super_block *sb;
  87         int err;
  88         int rc;
  89
  90         if (!ext4_handle_valid(handle)) {
  91                 ext4_put_nojournal(handle);
  92                 return 0;
  93         }
  94
  95         err = handle->h_err;
  96         if (!handle->h_transaction) {
  97                 rc = jbd2_journal_stop(handle);
  98                 return err ? err : rc;
  99         }
 100
 101         sb = handle->h_transaction->t_journal->j_private;
 102         rc = jbd2_journal_stop(handle);
 103
 104         if (!err)
 105                 err = rc;
 106         if (err)
 107                 __ext4_std_error(sb, where, line, err);
 108         return err;
 109 }
 110
 111 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 112                                         int type)
 113 {
 114         struct super_block *sb;
 115         int err;
 116
 117         if (!ext4_handle_valid(handle))
 118                 return ext4_get_nojournal();
 119
 120         sb = handle->h_journal->j_private;
 121         trace_ext4_journal_start_reserved(sb, handle->h_buffer_credits,
 122                                           _RET_IP_);
 123         err = ext4_journal_check_start(sb);
 124         if (err < 0) {
 125                 jbd2_journal_free_reserved(handle);
 126                 return ERR_PTR(err);
 127         }
 128
 129         err = jbd2_journal_start_reserved(handle, type, line);
 130         if (err < 0)
 131                 return ERR_PTR(err);
 132         return handle;
 133 }
 134
 135 static void ext4_journal_abort_handle(const char *caller, unsigned int line,
 136                                       const char *err_fn,
 137                                       struct buffer_head *bh,
 138                                       handle_t *handle, int err)
 139 {
 140         char nbuf[16];
 141         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 142
 143         BUG_ON(!ext4_handle_valid(handle));
 144
 145         if (bh)
 146                 BUFFER_TRACE(bh, "abort");
 147
 148         if (!handle->h_err)
 149                 handle->h_err = err;
 150
 151         if (is_handle_aborted(handle))
 152                 return;
 153
 154         printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 155                caller, line, errstr, err_fn);
 156
 157         jbd2_journal_abort_handle(handle);
 158 }
 159
 160 int __ext4_journal_get_write_access(const char *where, unsigned int line,
 161                                     handle_t *handle, struct buffer_head *bh)
 162 {
 163         int err = 0;
 164
 165         might_sleep();
 166
 167         if (ext4_handle_valid(handle)) {
 168                 struct super_block *sb;
 169
 170                 sb = handle->h_transaction->t_journal->j_private;
 171                 if (unlikely(ext4_forced_shutdown(EXT4_SB(sb)))) {
 172                         jbd2_journal_abort_handle(handle);
 173                         return -EIO;
 174                 }
 175                 err = jbd2_journal_get_write_access(handle, bh);
 176                 if (err)
 177                         ext4_journal_abort_handle(where, line, __func__, bh,
 178                                                   handle, err);
 179         }
 180         return err;
 181 }
 182
 183 /*
 184  * The ext4 forget function must perform a revoke if we are freeing data
 185  * which has been journaled.  Metadata (eg. indirect blocks) must be
 186  * revoked in all cases.
 187  *
 188  * "bh" may be NULL: a metadata block may have been freed from memory
 189  * but there may still be a record of it in the journal, and that record
 190  * still needs to be revoked.
 191  *
 192  * If the handle isn't valid we're not journaling, but we still need to
 193  * call into ext4_journal_revoke() to put the buffer head.
 194  */
 195 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 196                   int is_metadata, struct inode *inode,
 197                   struct buffer_head *bh, ext4_fsblk_t blocknr)
 198 {
 199         int err;
 200
 201         might_sleep();
 202
 203         trace_ext4_forget(inode, is_metadata, blocknr);
 204         BUFFER_TRACE(bh, "enter");
 205
 206         jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
 207                   "data mode %x\n",
 208                   bh, is_metadata, inode->i_mode,
 209                   test_opt(inode->i_sb, DATA_FLAGS));
 210
 211         /* In the no journal case, we can just do a bforget and return */
 212         if (!ext4_handle_valid(handle)) {
 213                 bforget(bh);
 214                 return 0;
 215         }
 216
 217         /* Never use the revoke function if we are doing full data
 218          * journaling: there is no need to, and a V1 superblock won't
 219          * support it.  Otherwise, only skip the revoke on un-journaled
 220          * data blocks. */
 221
 222         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 223             (!is_metadata && !ext4_should_journal_data(inode))) {
 224                 if (bh) {
 225                         BUFFER_TRACE(bh, "call jbd2_journal_forget");
 226                         err = jbd2_journal_forget(handle, bh);
 227                         if (err)
 228                                 ext4_journal_abort_handle(where, line, __func__,
 229                                                           bh, handle, err);
 230                         return err;
 231                 }
 232                 return 0;
 233         }
 234
 235         /*
 236          * data!=journal && (is_metadata || should_journal_data(inode))
 237          */
 238         BUFFER_TRACE(bh, "call jbd2_journal_revoke");
 239         err = jbd2_journal_revoke(handle, blocknr, bh);
 240         if (err) {
 241                 ext4_journal_abort_handle(where, line, __func__,
 242                                           bh, handle, err);
 243                 __ext4_abort(inode->i_sb, where, line,
 244                            "error %d when attempting revoke", err);
 245         }
 246         BUFFER_TRACE(bh, "exit");
 247         return err;
 248 }
 249
 250 int __ext4_journal_get_create_access(const char *where, unsigned int line,
 251                                 handle_t *handle, struct buffer_head *bh)
 252 {
 253         int err = 0;
 254
 255         if (ext4_handle_valid(handle)) {
 256                 err = jbd2_journal_get_create_access(handle, bh);
 257                 if (err)
 258                         ext4_journal_abort_handle(where, line, __func__,
 259                                                   bh, handle, err);
 260         }
 261         return err;
 262 }
 263
 264 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 265                                  handle_t *handle, struct inode *inode,
 266                                  struct buffer_head *bh)
 267 {
 268         int err = 0;
 269
 270         might_sleep();
 271
 272         set_buffer_meta(bh);
 273         set_buffer_prio(bh);
 274         if (ext4_handle_valid(handle)) {
 275                 err = jbd2_journal_dirty_metadata(handle, bh);
 276                 /* Errors can only happen due to aborted journal or a nasty bug */
 277                 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
 278                         ext4_journal_abort_handle(where, line, __func__, bh,
 279                                                   handle, err);
 280                         if (inode == NULL) {
 281                                 pr_err("EXT4: jbd2_journal_dirty_metadata "
 282                                        "failed: handle type %u started at "
 283                                        "line %u, credits %u/%u, errcode %d",
 284                                        handle->h_type,
 285                                        handle->h_line_no,
 286                                        handle->h_requested_credits,
 287                                        handle->h_buffer_credits, err);
 288                                 return err;
 289                         }
 290                         ext4_error_inode(inode, where, line,
 291                                          bh->b_blocknr,
 292                                          "journal_dirty_metadata failed: "
 293                                          "handle type %u started at line %u, "
 294                                          "credits %u/%u, errcode %d",
 295                                          handle->h_type,
 296                                          handle->h_line_no,
 297                                          handle->h_requested_credits,
 298                                          handle->h_buffer_credits, err);
 299                 }
 300         } else {
 301                 if (inode)
 302                         mark_buffer_dirty_inode(bh, inode);
 303                 else
 304                         mark_buffer_dirty(bh);
 305                 if (inode && inode_needs_sync(inode)) {
 306                         sync_dirty_buffer(bh);
 307                         if (buffer_req(bh) && !buffer_uptodate(bh)) {
 308                                 struct ext4_super_block *es;
 309
 310                                 es = EXT4_SB(inode->i_sb)->s_es;
 311                                 es->s_last_error_block =
 312                                         cpu_to_le64(bh->b_blocknr);
 313                                 ext4_error_inode(inode, where, line,
 314                                                  bh->b_blocknr,
 315                                         "IO error syncing itable block");
 316                                 err = -EIO;
 317                         }
 318                 }
 319         }
 320         return err;
 321 }
 322
 323 int __ext4_handle_dirty_super(const char *where, unsigned int line,
 324                               handle_t *handle, struct super_block *sb)
 325 {
 326         struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
 327         int err = 0;
 328
 329         ext4_superblock_csum_set(sb);
 330         if (ext4_handle_valid(handle)) {
 331                 err = jbd2_journal_dirty_metadata(handle, bh);
 332                 if (err)
 333                         ext4_journal_abort_handle(where, line, __func__,
 334                                                   bh, handle, err);
 335         } else
 336                 mark_buffer_dirty(bh);
 337         return err;
 338 }