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 /* Just increment the non-pointer handle value */
  11 static handle_t *ext4_get_nojournal(void)
  12 {
  13         handle_t *handle = current->journal_info;
  14         unsigned long ref_cnt = (unsigned long)handle;
  15
  16         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
  17
  18         ref_cnt++;
  19         handle = (handle_t *)ref_cnt;
  20
  21         current->journal_info = handle;
  22         return handle;
  23 }
  24
  25
  26 /* Decrement the non-pointer handle value */
  27 static void ext4_put_nojournal(handle_t *handle)
  28 {
  29         unsigned long ref_cnt = (unsigned long)handle;
  30
  31         BUG_ON(ref_cnt == 0);
  32
  33         ref_cnt--;
  34         handle = (handle_t *)ref_cnt;
  35
  36         current->journal_info = handle;
  37 }
  38
  39 /*
  40  * Wrappers for jbd2_journal_start/end.
  41  */
  42 static int ext4_journal_check_start(struct super_block *sb)
  43 {
  44         journal_t *journal;
  45
  46         might_sleep();
  47
  48         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
  49                 return -EIO;
  50
  51         if (sb_rdonly(sb))
  52                 return -EROFS;
  53         WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
  54         journal = EXT4_SB(sb)->s_journal;
  55         /*
  56          * Special case here: if the journal has aborted behind our
  57          * backs (eg. EIO in the commit thread), then we still need to
  58          * take the FS itself readonly cleanly.
  59          */
  60         if (journal && is_journal_aborted(journal)) {
  61                 ext4_abort(sb, "Detected aborted journal");
  62                 return -EROFS;
  63         }
  64         return 0;
  65 }
  66
  67 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
  68                                   int type, int blocks, int rsv_blocks,
  69                                   int revoke_creds)
  70 {
  71         journal_t *journal;
  72         int err;
  73
  74         trace_ext4_journal_start(sb, blocks, rsv_blocks, revoke_creds,
  75                                  _RET_IP_);
  76         err = ext4_journal_check_start(sb);
  77         if (err < 0)
  78                 return ERR_PTR(err);
  79
  80         journal = EXT4_SB(sb)->s_journal;
  81         if (!journal)
  82                 return ext4_get_nojournal();
  83         return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_creds,
  84                                    GFP_NOFS, type, line);
  85 }
  86
  87 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
  88 {
  89         struct super_block *sb;
  90         int err;
  91         int rc;
  92
  93         if (!ext4_handle_valid(handle)) {
  94                 ext4_put_nojournal(handle);
  95                 return 0;
  96         }
  97
  98         err = handle->h_err;
  99         if (!handle->h_transaction) {
 100                 rc = jbd2_journal_stop(handle);
 101                 return err ? err : rc;
 102         }
 103
 104         sb = handle->h_transaction->t_journal->j_private;
 105         rc = jbd2_journal_stop(handle);
 106
 107         if (!err)
 108                 err = rc;
 109         if (err)
 110                 __ext4_std_error(sb, where, line, err);
 111         return err;
 112 }
 113
 114 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 115                                         int type)
 116 {
 117         struct super_block *sb;
 118         int err;
 119
 120         if (!ext4_handle_valid(handle))
 121                 return ext4_get_nojournal();
 122
 123         sb = handle->h_journal->j_private;
 124         trace_ext4_journal_start_reserved(sb,
 125                                 jbd2_handle_buffer_credits(handle), _RET_IP_);
 126         err = ext4_journal_check_start(sb);
 127         if (err < 0) {
 128                 jbd2_journal_free_reserved(handle);
 129                 return ERR_PTR(err);
 130         }
 131
 132         err = jbd2_journal_start_reserved(handle, type, line);
 133         if (err < 0)
 134                 return ERR_PTR(err);
 135         return handle;
 136 }
 137
 138 int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
 139                                   int extend_cred, int revoke_cred)
 140 {
 141         if (!ext4_handle_valid(handle))
 142                 return 0;
 143         if (jbd2_handle_buffer_credits(handle) >= check_cred &&
 144             handle->h_revoke_credits >= revoke_cred)
 145                 return 0;
 146         extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle));
 147         revoke_cred = max(0, revoke_cred - handle->h_revoke_credits);
 148         return ext4_journal_extend(handle, extend_cred, revoke_cred);
 149 }
 150
 151 static void ext4_journal_abort_handle(const char *caller, unsigned int line,
 152                                       const char *err_fn,
 153                                       struct buffer_head *bh,
 154                                       handle_t *handle, int err)
 155 {
 156         char nbuf[16];
 157         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 158
 159         BUG_ON(!ext4_handle_valid(handle));
 160
 161         if (bh)
 162                 BUFFER_TRACE(bh, "abort");
 163
 164         if (!handle->h_err)
 165                 handle->h_err = err;
 166
 167         if (is_handle_aborted(handle))
 168                 return;
 169
 170         printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 171                caller, line, errstr, err_fn);
 172
 173         jbd2_journal_abort_handle(handle);
 174 }
 175
 176 int __ext4_journal_get_write_access(const char *where, unsigned int line,
 177                                     handle_t *handle, struct buffer_head *bh)
 178 {
 179         int err = 0;
 180
 181         might_sleep();
 182
 183         if (ext4_handle_valid(handle)) {
 184                 err = jbd2_journal_get_write_access(handle, bh);
 185                 if (err)
 186                         ext4_journal_abort_handle(where, line, __func__, bh,
 187                                                   handle, err);
 188         }
 189         return err;
 190 }
 191
 192 /*
 193  * The ext4 forget function must perform a revoke if we are freeing data
 194  * which has been journaled.  Metadata (eg. indirect blocks) must be
 195  * revoked in all cases.
 196  *
 197  * "bh" may be NULL: a metadata block may have been freed from memory
 198  * but there may still be a record of it in the journal, and that record
 199  * still needs to be revoked.
 200  *
 201  * If the handle isn't valid we're not journaling, but we still need to
 202  * call into ext4_journal_revoke() to put the buffer head.
 203  */
 204 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 205                   int is_metadata, struct inode *inode,
 206                   struct buffer_head *bh, ext4_fsblk_t blocknr)
 207 {
 208         int err;
 209
 210         might_sleep();
 211
 212         trace_ext4_forget(inode, is_metadata, blocknr);
 213         BUFFER_TRACE(bh, "enter");
 214
 215         jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
 216                   "data mode %x\n",
 217                   bh, is_metadata, inode->i_mode,
 218                   test_opt(inode->i_sb, DATA_FLAGS));
 219
 220         /* In the no journal case, we can just do a bforget and return */
 221         if (!ext4_handle_valid(handle)) {
 222                 bforget(bh);
 223                 return 0;
 224         }
 225
 226         /* Never use the revoke function if we are doing full data
 227          * journaling: there is no need to, and a V1 superblock won't
 228          * support it.  Otherwise, only skip the revoke on un-journaled
 229          * data blocks. */
 230
 231         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 232             (!is_metadata && !ext4_should_journal_data(inode))) {
 233                 if (bh) {
 234                         BUFFER_TRACE(bh, "call jbd2_journal_forget");
 235                         err = jbd2_journal_forget(handle, bh);
 236                         if (err)
 237                                 ext4_journal_abort_handle(where, line, __func__,
 238                                                           bh, handle, err);
 239                         return err;
 240                 }
 241                 return 0;
 242         }
 243
 244         /*
 245          * data!=journal && (is_metadata || should_journal_data(inode))
 246          */
 247         BUFFER_TRACE(bh, "call jbd2_journal_revoke");
 248         err = jbd2_journal_revoke(handle, blocknr, bh);
 249         if (err) {
 250                 ext4_journal_abort_handle(where, line, __func__,
 251                                           bh, handle, err);
 252                 __ext4_abort(inode->i_sb, where, line,
 253                            "error %d when attempting revoke", err);
 254         }
 255         BUFFER_TRACE(bh, "exit");
 256         return err;
 257 }
 258
 259 int __ext4_journal_get_create_access(const char *where, unsigned int line,
 260                                 handle_t *handle, struct buffer_head *bh)
 261 {
 262         int err = 0;
 263
 264         if (ext4_handle_valid(handle)) {
 265                 err = jbd2_journal_get_create_access(handle, bh);
 266                 if (err)
 267                         ext4_journal_abort_handle(where, line, __func__,
 268                                                   bh, handle, err);
 269         }
 270         return err;
 271 }
 272
 273 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 274                                  handle_t *handle, struct inode *inode,
 275                                  struct buffer_head *bh)
 276 {
 277         int err = 0;
 278
 279         might_sleep();
 280
 281         set_buffer_meta(bh);
 282         set_buffer_prio(bh);
 283         if (ext4_handle_valid(handle)) {
 284                 err = jbd2_journal_dirty_metadata(handle, bh);
 285                 /* Errors can only happen due to aborted journal or a nasty bug */
 286                 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
 287                         ext4_journal_abort_handle(where, line, __func__, bh,
 288                                                   handle, err);
 289                         if (inode == NULL) {
 290                                 pr_err("EXT4: jbd2_journal_dirty_metadata "
 291                                        "failed: handle type %u started at "
 292                                        "line %u, credits %u/%u, errcode %d",
 293                                        handle->h_type,
 294                                        handle->h_line_no,
 295                                        handle->h_requested_credits,
 296                                        jbd2_handle_buffer_credits(handle), err);
 297                                 return err;
 298                         }
 299                         ext4_error_inode(inode, where, line,
 300                                          bh->b_blocknr,
 301                                          "journal_dirty_metadata failed: "
 302                                          "handle type %u started at line %u, "
 303                                          "credits %u/%u, errcode %d",
 304                                          handle->h_type,
 305                                          handle->h_line_no,
 306                                          handle->h_requested_credits,
 307                                          jbd2_handle_buffer_credits(handle),
 308                                          err);
 309                 }
 310         } else {
 311                 if (inode)
 312                         mark_buffer_dirty_inode(bh, inode);
 313                 else
 314                         mark_buffer_dirty(bh);
 315                 if (inode && inode_needs_sync(inode)) {
 316                         sync_dirty_buffer(bh);
 317                         if (buffer_req(bh) && !buffer_uptodate(bh)) {
 318                                 struct ext4_super_block *es;
 319
 320                                 es = EXT4_SB(inode->i_sb)->s_es;
 321                                 es->s_last_error_block =
 322                                         cpu_to_le64(bh->b_blocknr);
 323                                 ext4_error_inode(inode, where, line,
 324                                                  bh->b_blocknr,
 325                                         "IO error syncing itable block");
 326                                 err = -EIO;
 327                         }
 328                 }
 329         }
 330         return err;
 331 }
 332
 333 int __ext4_handle_dirty_super(const char *where, unsigned int line,
 334                               handle_t *handle, struct super_block *sb)
 335 {
 336         struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
 337         int err = 0;
 338
 339         ext4_superblock_csum_set(sb);
 340         if (ext4_handle_valid(handle)) {
 341                 err = jbd2_journal_dirty_metadata(handle, bh);
 342                 if (err)
 343                         ext4_journal_abort_handle(where, line, __func__,
 344                                                   bh, handle, err);
 345         } else
 346                 mark_buffer_dirty(bh);
 347         return err;
 348 }