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