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