LCOV - code coverage report
Current view: top level - fs/jbd2 - commit.c (source / functions) Hit Total Coverage
Test: gcov_data_raspi2_real_modules_combined.info Lines: 299 392 76.3 %
Date: 2020-09-30 20:25:40 Functions: 9 11 81.8 %
Branches: 120 224 53.6 %

           Branch data     Line data    Source code
       1                 :            : // SPDX-License-Identifier: GPL-2.0+
       2                 :            : /*
       3                 :            :  * linux/fs/jbd2/commit.c
       4                 :            :  *
       5                 :            :  * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
       6                 :            :  *
       7                 :            :  * Copyright 1998 Red Hat corp --- All Rights Reserved
       8                 :            :  *
       9                 :            :  * Journal commit routines for the generic filesystem journaling code;
      10                 :            :  * part of the ext2fs journaling system.
      11                 :            :  */
      12                 :            : 
      13                 :            : #include <linux/time.h>
      14                 :            : #include <linux/fs.h>
      15                 :            : #include <linux/jbd2.h>
      16                 :            : #include <linux/errno.h>
      17                 :            : #include <linux/slab.h>
      18                 :            : #include <linux/mm.h>
      19                 :            : #include <linux/pagemap.h>
      20                 :            : #include <linux/jiffies.h>
      21                 :            : #include <linux/crc32.h>
      22                 :            : #include <linux/writeback.h>
      23                 :            : #include <linux/backing-dev.h>
      24                 :            : #include <linux/bio.h>
      25                 :            : #include <linux/blkdev.h>
      26                 :            : #include <linux/bitops.h>
      27                 :            : #include <trace/events/jbd2.h>
      28                 :            : 
      29                 :            : /*
      30                 :            :  * IO end handler for temporary buffer_heads handling writes to the journal.
      31                 :            :  */
      32                 :     102706 : static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
      33                 :            : {
      34                 :     102706 :         struct buffer_head *orig_bh = bh->b_private;
      35                 :            : 
      36                 :            :         BUFFER_TRACE(bh, "");
      37         [ +  - ]:     102706 :         if (uptodate)
      38                 :            :                 set_buffer_uptodate(bh);
      39                 :            :         else
      40                 :            :                 clear_buffer_uptodate(bh);
      41         [ +  + ]:     102706 :         if (orig_bh) {
      42                 :      97685 :                 clear_bit_unlock(BH_Shadow, &orig_bh->b_state);
      43                 :      97685 :                 smp_mb__after_atomic();
      44                 :      97685 :                 wake_up_bit(&orig_bh->b_state, BH_Shadow);
      45                 :            :         }
      46                 :     102706 :         unlock_buffer(bh);
      47                 :     102706 : }
      48                 :            : 
      49                 :            : /*
      50                 :            :  * When an ext4 file is truncated, it is possible that some pages are not
      51                 :            :  * successfully freed, because they are attached to a committing transaction.
      52                 :            :  * After the transaction commits, these pages are left on the LRU, with no
      53                 :            :  * ->mapping, and with attached buffers.  These pages are trivially reclaimable
      54                 :            :  * by the VM, but their apparent absence upsets the VM accounting, and it makes
      55                 :            :  * the numbers in /proc/meminfo look odd.
      56                 :            :  *
      57                 :            :  * So here, we have a buffer which has just come off the forget list.  Look to
      58                 :            :  * see if we can strip all buffers from the backing page.
      59                 :            :  *
      60                 :            :  * Called under lock_journal(), and possibly under journal_datalist_lock.  The
      61                 :            :  * caller provided us with a ref against the buffer, and we drop that here.
      62                 :            :  */
      63                 :          8 : static void release_buffer_page(struct buffer_head *bh)
      64                 :            : {
      65                 :            :         struct page *page;
      66                 :            : 
      67         [ +  - ]:          8 :         if (buffer_dirty(bh))
      68                 :            :                 goto nope;
      69         [ -  + ]:          8 :         if (atomic_read(&bh->b_count) != 1)
      70                 :            :                 goto nope;
      71                 :          0 :         page = bh->b_page;
      72         [ #  # ]:          0 :         if (!page)
      73                 :            :                 goto nope;
      74         [ #  # ]:          0 :         if (page->mapping)
      75                 :            :                 goto nope;
      76                 :            : 
      77                 :            :         /* OK, it's a truncated page */
      78         [ #  # ]:          0 :         if (!trylock_page(page))
      79                 :            :                 goto nope;
      80                 :            : 
      81                 :          0 :         get_page(page);
      82                 :          0 :         __brelse(bh);
      83                 :          0 :         try_to_free_buffers(page);
      84                 :          0 :         unlock_page(page);
      85                 :          0 :         put_page(page);
      86                 :          8 :         return;
      87                 :            : 
      88                 :            : nope:
      89                 :          8 :         __brelse(bh);
      90                 :            : }
      91                 :            : 
      92                 :       2524 : static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
      93                 :            : {
      94                 :            :         struct commit_header *h;
      95                 :            :         __u32 csum;
      96                 :            : 
      97         [ -  + ]:       2524 :         if (!jbd2_journal_has_csum_v2or3(j))
      98                 :       2524 :                 return;
      99                 :            : 
     100                 :          0 :         h = (struct commit_header *)(bh->b_data);
     101                 :          0 :         h->h_chksum_type = 0;
     102                 :          0 :         h->h_chksum_size = 0;
     103                 :          0 :         h->h_chksum[0] = 0;
     104                 :          0 :         csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
     105                 :          0 :         h->h_chksum[0] = cpu_to_be32(csum);
     106                 :            : }
     107                 :            : 
     108                 :            : /*
     109                 :            :  * Done it all: now submit the commit record.  We should have
     110                 :            :  * cleaned up our previous buffers by now, so if we are in abort
     111                 :            :  * mode we can now just skip the rest of the journal write
     112                 :            :  * entirely.
     113                 :            :  *
     114                 :            :  * Returns 1 if the journal needs to be aborted or 0 on success
     115                 :            :  */
     116                 :       2524 : static int journal_submit_commit_record(journal_t *journal,
     117                 :            :                                         transaction_t *commit_transaction,
     118                 :            :                                         struct buffer_head **cbh,
     119                 :            :                                         __u32 crc32_sum)
     120                 :            : {
     121                 :            :         struct commit_header *tmp;
     122                 :            :         struct buffer_head *bh;
     123                 :            :         int ret;
     124                 :            :         struct timespec64 now;
     125                 :            : 
     126                 :       2524 :         *cbh = NULL;
     127                 :            : 
     128         [ +  - ]:       2524 :         if (is_journal_aborted(journal))
     129                 :            :                 return 0;
     130                 :            : 
     131                 :       2524 :         bh = jbd2_journal_get_descriptor_buffer(commit_transaction,
     132                 :            :                                                 JBD2_COMMIT_BLOCK);
     133         [ +  - ]:       2524 :         if (!bh)
     134                 :            :                 return 1;
     135                 :            : 
     136                 :       2524 :         tmp = (struct commit_header *)bh->b_data;
     137                 :       2524 :         ktime_get_coarse_real_ts64(&now);
     138                 :       2524 :         tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
     139                 :       2524 :         tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
     140                 :            : 
     141         [ -  + ]:       2524 :         if (jbd2_has_feature_checksum(journal)) {
     142                 :          0 :                 tmp->h_chksum_type   = JBD2_CRC32_CHKSUM;
     143                 :          0 :                 tmp->h_chksum_size   = JBD2_CRC32_CHKSUM_SIZE;
     144                 :          0 :                 tmp->h_chksum[0]     = cpu_to_be32(crc32_sum);
     145                 :            :         }
     146                 :       2524 :         jbd2_commit_block_csum_set(journal, bh);
     147                 :            : 
     148                 :            :         BUFFER_TRACE(bh, "submit commit block");
     149                 :       2524 :         lock_buffer(bh);
     150                 :            :         clear_buffer_dirty(bh);
     151                 :            :         set_buffer_uptodate(bh);
     152                 :       2524 :         bh->b_end_io = journal_end_buffer_io_sync;
     153                 :            : 
     154   [ +  -  +  - ]:       5048 :         if (journal->j_flags & JBD2_BARRIER &&
     155                 :            :             !jbd2_has_feature_async_commit(journal))
     156                 :       2524 :                 ret = submit_bh(REQ_OP_WRITE,
     157                 :            :                         REQ_SYNC | REQ_PREFLUSH | REQ_FUA, bh);
     158                 :            :         else
     159                 :          0 :                 ret = submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
     160                 :            : 
     161                 :       2524 :         *cbh = bh;
     162                 :       2524 :         return ret;
     163                 :            : }
     164                 :            : 
     165                 :            : /*
     166                 :            :  * This function along with journal_submit_commit_record
     167                 :            :  * allows to write the commit record asynchronously.
     168                 :            :  */
     169                 :       2524 : static int journal_wait_on_commit_record(journal_t *journal,
     170                 :            :                                          struct buffer_head *bh)
     171                 :            : {
     172                 :            :         int ret = 0;
     173                 :            : 
     174                 :            :         clear_buffer_dirty(bh);
     175                 :       2524 :         wait_on_buffer(bh);
     176                 :            : 
     177         [ -  + ]:       2524 :         if (unlikely(!buffer_uptodate(bh)))
     178                 :            :                 ret = -EIO;
     179                 :       2524 :         put_bh(bh);            /* One for getblk() */
     180                 :            : 
     181                 :       2524 :         return ret;
     182                 :            : }
     183                 :            : 
     184                 :            : /*
     185                 :            :  * write the filemap data using writepage() address_space_operations.
     186                 :            :  * We don't do block allocation here even for delalloc. We don't
     187                 :            :  * use writepages() because with delayed allocation we may be doing
     188                 :            :  * block allocation in writepages().
     189                 :            :  */
     190                 :          0 : static int journal_submit_inode_data_buffers(struct address_space *mapping,
     191                 :            :                 loff_t dirty_start, loff_t dirty_end)
     192                 :            : {
     193                 :            :         int ret;
     194                 :          0 :         struct writeback_control wbc = {
     195                 :            :                 .sync_mode =  WB_SYNC_ALL,
     196                 :          0 :                 .nr_to_write = mapping->nrpages * 2,
     197                 :            :                 .range_start = dirty_start,
     198                 :            :                 .range_end = dirty_end,
     199                 :            :         };
     200                 :            : 
     201                 :          0 :         ret = generic_writepages(mapping, &wbc);
     202                 :          0 :         return ret;
     203                 :            : }
     204                 :            : 
     205                 :            : /*
     206                 :            :  * Submit all the data buffers of inode associated with the transaction to
     207                 :            :  * disk.
     208                 :            :  *
     209                 :            :  * We are in a committing transaction. Therefore no new inode can be added to
     210                 :            :  * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
     211                 :            :  * operate on from being released while we write out pages.
     212                 :            :  */
     213                 :       2524 : static int journal_submit_data_buffers(journal_t *journal,
     214                 :            :                 transaction_t *commit_transaction)
     215                 :            : {
     216                 :            :         struct jbd2_inode *jinode;
     217                 :            :         int err, ret = 0;
     218                 :            :         struct address_space *mapping;
     219                 :            : 
     220                 :            :         spin_lock(&journal->j_list_lock);
     221         [ +  + ]:      14989 :         list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
     222                 :      12465 :                 loff_t dirty_start = jinode->i_dirty_start;
     223                 :      12465 :                 loff_t dirty_end = jinode->i_dirty_end;
     224                 :            : 
     225         [ +  - ]:      12465 :                 if (!(jinode->i_flags & JI_WRITE_DATA))
     226                 :      12465 :                         continue;
     227                 :          0 :                 mapping = jinode->i_vfs_inode->i_mapping;
     228                 :          0 :                 jinode->i_flags |= JI_COMMIT_RUNNING;
     229                 :            :                 spin_unlock(&journal->j_list_lock);
     230                 :            :                 /*
     231                 :            :                  * submit the inode data buffers. We use writepage
     232                 :            :                  * instead of writepages. Because writepages can do
     233                 :            :                  * block allocation  with delalloc. We need to write
     234                 :            :                  * only allocated blocks here.
     235                 :            :                  */
     236                 :          0 :                 trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
     237                 :          0 :                 err = journal_submit_inode_data_buffers(mapping, dirty_start,
     238                 :            :                                 dirty_end);
     239         [ #  # ]:          0 :                 if (!ret)
     240                 :            :                         ret = err;
     241                 :            :                 spin_lock(&journal->j_list_lock);
     242         [ #  # ]:          0 :                 J_ASSERT(jinode->i_transaction == commit_transaction);
     243                 :          0 :                 jinode->i_flags &= ~JI_COMMIT_RUNNING;
     244                 :          0 :                 smp_mb();
     245                 :          0 :                 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
     246                 :            :         }
     247                 :            :         spin_unlock(&journal->j_list_lock);
     248                 :       2524 :         return ret;
     249                 :            : }
     250                 :            : 
     251                 :            : /*
     252                 :            :  * Wait for data submitted for writeout, refile inodes to proper
     253                 :            :  * transaction if needed.
     254                 :            :  *
     255                 :            :  */
     256                 :       2524 : static int journal_finish_inode_data_buffers(journal_t *journal,
     257                 :            :                 transaction_t *commit_transaction)
     258                 :            : {
     259                 :            :         struct jbd2_inode *jinode, *next_i;
     260                 :            :         int err, ret = 0;
     261                 :            : 
     262                 :            :         /* For locking, see the comment in journal_submit_data_buffers() */
     263                 :            :         spin_lock(&journal->j_list_lock);
     264         [ +  + ]:      14989 :         list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
     265                 :      12465 :                 loff_t dirty_start = jinode->i_dirty_start;
     266                 :      12465 :                 loff_t dirty_end = jinode->i_dirty_end;
     267                 :            : 
     268         [ -  + ]:      12465 :                 if (!(jinode->i_flags & JI_WAIT_DATA))
     269                 :          0 :                         continue;
     270                 :      12465 :                 jinode->i_flags |= JI_COMMIT_RUNNING;
     271                 :            :                 spin_unlock(&journal->j_list_lock);
     272                 :      12465 :                 err = filemap_fdatawait_range_keep_errors(
     273                 :      12465 :                                 jinode->i_vfs_inode->i_mapping, dirty_start,
     274                 :            :                                 dirty_end);
     275         [ +  - ]:      12465 :                 if (!ret)
     276                 :            :                         ret = err;
     277                 :            :                 spin_lock(&journal->j_list_lock);
     278                 :      12465 :                 jinode->i_flags &= ~JI_COMMIT_RUNNING;
     279                 :      12465 :                 smp_mb();
     280                 :      12465 :                 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
     281                 :            :         }
     282                 :            : 
     283                 :            :         /* Now refile inode to proper lists */
     284         [ +  + ]:      14989 :         list_for_each_entry_safe(jinode, next_i,
     285                 :            :                                  &commit_transaction->t_inode_list, i_list) {
     286                 :            :                 list_del(&jinode->i_list);
     287         [ -  + ]:      12465 :                 if (jinode->i_next_transaction) {
     288                 :          0 :                         jinode->i_transaction = jinode->i_next_transaction;
     289                 :          0 :                         jinode->i_next_transaction = NULL;
     290                 :          0 :                         list_add(&jinode->i_list,
     291                 :            :                                 &jinode->i_transaction->t_inode_list);
     292                 :            :                 } else {
     293                 :      12465 :                         jinode->i_transaction = NULL;
     294                 :      12465 :                         jinode->i_dirty_start = 0;
     295                 :      12465 :                         jinode->i_dirty_end = 0;
     296                 :            :                 }
     297                 :            :         }
     298                 :            :         spin_unlock(&journal->j_list_lock);
     299                 :            : 
     300                 :       2524 :         return ret;
     301                 :            : }
     302                 :            : 
     303                 :          0 : static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
     304                 :            : {
     305                 :          0 :         struct page *page = bh->b_page;
     306                 :            :         char *addr;
     307                 :            :         __u32 checksum;
     308                 :            : 
     309                 :          0 :         addr = kmap_atomic(page);
     310                 :          0 :         checksum = crc32_be(crc32_sum,
     311                 :          0 :                 (void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
     312                 :            :         kunmap_atomic(addr);
     313                 :            : 
     314                 :          0 :         return checksum;
     315                 :            : }
     316                 :            : 
     317                 :            : static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
     318                 :            :                                    unsigned long long block)
     319                 :            : {
     320                 :      97685 :         tag->t_blocknr = cpu_to_be32(block & (u32)~0);
     321         [ -  + ]:      97685 :         if (jbd2_has_feature_64bit(j))
     322                 :          0 :                 tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
     323                 :            : }
     324                 :            : 
     325                 :      97685 : static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
     326                 :            :                                     struct buffer_head *bh, __u32 sequence)
     327                 :            : {
     328                 :            :         journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
     329                 :      97685 :         struct page *page = bh->b_page;
     330                 :            :         __u8 *addr;
     331                 :            :         __u32 csum32;
     332                 :            :         __be32 seq;
     333                 :            : 
     334         [ -  + ]:      97685 :         if (!jbd2_journal_has_csum_v2or3(j))
     335                 :      97685 :                 return;
     336                 :            : 
     337                 :          0 :         seq = cpu_to_be32(sequence);
     338                 :          0 :         addr = kmap_atomic(page);
     339                 :          0 :         csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
     340                 :          0 :         csum32 = jbd2_chksum(j, csum32, addr + offset_in_page(bh->b_data),
     341                 :            :                              bh->b_size);
     342                 :            :         kunmap_atomic(addr);
     343                 :            : 
     344         [ #  # ]:          0 :         if (jbd2_has_feature_csum3(j))
     345                 :          0 :                 tag3->t_checksum = cpu_to_be32(csum32);
     346                 :            :         else
     347                 :          0 :                 tag->t_checksum = cpu_to_be16(csum32);
     348                 :            : }
     349                 :            : /*
     350                 :            :  * jbd2_journal_commit_transaction
     351                 :            :  *
     352                 :            :  * The primary function for committing a transaction to the log.  This
     353                 :            :  * function is called by the journal thread to begin a complete commit.
     354                 :            :  */
     355                 :       2524 : void jbd2_journal_commit_transaction(journal_t *journal)
     356                 :            : {
     357                 :            :         struct transaction_stats_s stats;
     358                 :            :         transaction_t *commit_transaction;
     359                 :            :         struct journal_head *jh;
     360                 :            :         struct buffer_head *descriptor;
     361                 :       2524 :         struct buffer_head **wbuf = journal->j_wbuf;
     362                 :            :         int bufs;
     363                 :            :         int flags;
     364                 :            :         int err;
     365                 :            :         unsigned long long blocknr;
     366                 :            :         ktime_t start_time;
     367                 :            :         u64 commit_time;
     368                 :            :         char *tagp = NULL;
     369                 :            :         journal_block_tag_t *tag = NULL;
     370                 :            :         int space_left = 0;
     371                 :            :         int first_tag = 0;
     372                 :            :         int tag_flag;
     373                 :            :         int i;
     374                 :       2524 :         int tag_bytes = journal_tag_bytes(journal);
     375                 :       2524 :         struct buffer_head *cbh = NULL; /* For transactional checksums */
     376                 :            :         __u32 crc32_sum = ~0;
     377                 :            :         struct blk_plug plug;
     378                 :            :         /* Tail of the journal */
     379                 :            :         unsigned long first_block;
     380                 :            :         tid_t first_tid;
     381                 :            :         int update_tail;
     382                 :            :         int csum_size = 0;
     383                 :       2524 :         LIST_HEAD(io_bufs);
     384                 :       2524 :         LIST_HEAD(log_bufs);
     385                 :            : 
     386         [ -  + ]:       2524 :         if (jbd2_journal_has_csum_v2or3(journal))
     387                 :            :                 csum_size = sizeof(struct jbd2_journal_block_tail);
     388                 :            : 
     389                 :            :         /*
     390                 :            :          * First job: lock down the current transaction and wait for
     391                 :            :          * all outstanding updates to complete.
     392                 :            :          */
     393                 :            : 
     394                 :            :         /* Do we need to erase the effects of a prior jbd2_journal_flush? */
     395         [ +  + ]:       2524 :         if (journal->j_flags & JBD2_FLUSHED) {
     396                 :            :                 jbd_debug(3, "super block updated\n");
     397                 :        207 :                 mutex_lock_io(&journal->j_checkpoint_mutex);
     398                 :            :                 /*
     399                 :            :                  * We hold j_checkpoint_mutex so tail cannot change under us.
     400                 :            :                  * We don't need any special data guarantees for writing sb
     401                 :            :                  * since journal is empty and it is ok for write to be
     402                 :            :                  * flushed only with transaction commit.
     403                 :            :                  */
     404                 :        207 :                 jbd2_journal_update_sb_log_tail(journal,
     405                 :            :                                                 journal->j_tail_sequence,
     406                 :            :                                                 journal->j_tail,
     407                 :            :                                                 REQ_SYNC);
     408                 :        207 :                 mutex_unlock(&journal->j_checkpoint_mutex);
     409                 :            :         } else {
     410                 :            :                 jbd_debug(3, "superblock not updated\n");
     411                 :            :         }
     412                 :            : 
     413         [ -  + ]:       2524 :         J_ASSERT(journal->j_running_transaction != NULL);
     414         [ -  + ]:       2524 :         J_ASSERT(journal->j_committing_transaction == NULL);
     415                 :            : 
     416                 :            :         commit_transaction = journal->j_running_transaction;
     417                 :            : 
     418                 :       2524 :         trace_jbd2_start_commit(journal, commit_transaction);
     419                 :            :         jbd_debug(1, "JBD2: starting commit of transaction %d\n",
     420                 :            :                         commit_transaction->t_tid);
     421                 :            : 
     422                 :       2524 :         write_lock(&journal->j_state_lock);
     423         [ -  + ]:       2524 :         J_ASSERT(commit_transaction->t_state == T_RUNNING);
     424                 :       2524 :         commit_transaction->t_state = T_LOCKED;
     425                 :            : 
     426                 :       2524 :         trace_jbd2_commit_locking(journal, commit_transaction);
     427                 :       2524 :         stats.run.rs_wait = commit_transaction->t_max_wait;
     428                 :       2524 :         stats.run.rs_request_delay = 0;
     429                 :       2524 :         stats.run.rs_locked = jiffies;
     430         [ +  + ]:       2524 :         if (commit_transaction->t_requested)
     431                 :       1593 :                 stats.run.rs_request_delay =
     432                 :       1593 :                         jbd2_time_diff(commit_transaction->t_requested,
     433                 :            :                                        stats.run.rs_locked);
     434                 :       5048 :         stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
     435                 :            :                                               stats.run.rs_locked);
     436                 :            : 
     437                 :            :         spin_lock(&commit_transaction->t_handle_lock);
     438         [ +  + ]:       2760 :         while (atomic_read(&commit_transaction->t_updates)) {
     439                 :        472 :                 DEFINE_WAIT(wait);
     440                 :            : 
     441                 :        236 :                 prepare_to_wait(&journal->j_wait_updates, &wait,
     442                 :            :                                         TASK_UNINTERRUPTIBLE);
     443         [ +  - ]:        236 :                 if (atomic_read(&commit_transaction->t_updates)) {
     444                 :            :                         spin_unlock(&commit_transaction->t_handle_lock);
     445                 :            :                         write_unlock(&journal->j_state_lock);
     446                 :        236 :                         schedule();
     447                 :        236 :                         write_lock(&journal->j_state_lock);
     448                 :            :                         spin_lock(&commit_transaction->t_handle_lock);
     449                 :            :                 }
     450                 :        236 :                 finish_wait(&journal->j_wait_updates, &wait);
     451                 :            :         }
     452                 :            :         spin_unlock(&commit_transaction->t_handle_lock);
     453                 :       2524 :         commit_transaction->t_state = T_SWITCH;
     454                 :            :         write_unlock(&journal->j_state_lock);
     455                 :            : 
     456         [ +  - ]:       2524 :         J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <=
     457                 :            :                         journal->j_max_transaction_buffers);
     458                 :            : 
     459                 :            :         /*
     460                 :            :          * First thing we are allowed to do is to discard any remaining
     461                 :            :          * BJ_Reserved buffers.  Note, it is _not_ permissible to assume
     462                 :            :          * that there are no such buffers: if a large filesystem
     463                 :            :          * operation like a truncate needs to split itself over multiple
     464                 :            :          * transactions, then it may try to do a jbd2_journal_restart() while
     465                 :            :          * there are still BJ_Reserved buffers outstanding.  These must
     466                 :            :          * be released cleanly from the current transaction.
     467                 :            :          *
     468                 :            :          * In this case, the filesystem must still reserve write access
     469                 :            :          * again before modifying the buffer in the new transaction, but
     470                 :            :          * we do not require it to remember exactly which old buffers it
     471                 :            :          * has reserved.  This is consistent with the existing behaviour
     472                 :            :          * that multiple jbd2_journal_get_write_access() calls to the same
     473                 :            :          * buffer are perfectly permissible.
     474                 :            :          */
     475         [ -  + ]:       2524 :         while (commit_transaction->t_reserved_list) {
     476                 :            :                 jh = commit_transaction->t_reserved_list;
     477                 :            :                 JBUFFER_TRACE(jh, "reserved, unused: refile");
     478                 :            :                 /*
     479                 :            :                  * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
     480                 :            :                  * leave undo-committed data.
     481                 :            :                  */
     482         [ #  # ]:          0 :                 if (jh->b_committed_data) {
     483                 :            :                         struct buffer_head *bh = jh2bh(jh);
     484                 :            : 
     485                 :            :                         jbd_lock_bh_state(bh);
     486                 :          0 :                         jbd2_free(jh->b_committed_data, bh->b_size);
     487                 :          0 :                         jh->b_committed_data = NULL;
     488                 :            :                         jbd_unlock_bh_state(bh);
     489                 :            :                 }
     490                 :          0 :                 jbd2_journal_refile_buffer(journal, jh);
     491                 :            :         }
     492                 :            : 
     493                 :            :         /*
     494                 :            :          * Now try to drop any written-back buffers from the journal's
     495                 :            :          * checkpoint lists.  We do this *before* commit because it potentially
     496                 :            :          * frees some memory
     497                 :            :          */
     498                 :            :         spin_lock(&journal->j_list_lock);
     499                 :       2524 :         __jbd2_journal_clean_checkpoint_list(journal, false);
     500                 :            :         spin_unlock(&journal->j_list_lock);
     501                 :            : 
     502                 :            :         jbd_debug(3, "JBD2: commit phase 1\n");
     503                 :            : 
     504                 :            :         /*
     505                 :            :          * Clear revoked flag to reflect there is no revoked buffers
     506                 :            :          * in the next transaction which is going to be started.
     507                 :            :          */
     508                 :       2524 :         jbd2_clear_buffer_revoked_flags(journal);
     509                 :            : 
     510                 :            :         /*
     511                 :            :          * Switch to a new revoke table.
     512                 :            :          */
     513                 :       2524 :         jbd2_journal_switch_revoke_table(journal);
     514                 :            : 
     515                 :            :         /*
     516                 :            :          * Reserved credits cannot be claimed anymore, free them
     517                 :            :          */
     518                 :       2524 :         atomic_sub(atomic_read(&journal->j_reserved_credits),
     519                 :            :                    &commit_transaction->t_outstanding_credits);
     520                 :            : 
     521                 :       2524 :         write_lock(&journal->j_state_lock);
     522                 :       2524 :         trace_jbd2_commit_flushing(journal, commit_transaction);
     523                 :       2524 :         stats.run.rs_flushing = jiffies;
     524                 :       5048 :         stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
     525                 :            :                                              stats.run.rs_flushing);
     526                 :            : 
     527                 :       2524 :         commit_transaction->t_state = T_FLUSH;
     528                 :       2524 :         journal->j_committing_transaction = commit_transaction;
     529                 :       2524 :         journal->j_running_transaction = NULL;
     530                 :       2524 :         start_time = ktime_get();
     531                 :       2524 :         commit_transaction->t_log_start = journal->j_head;
     532                 :       2524 :         wake_up(&journal->j_wait_transaction_locked);
     533                 :            :         write_unlock(&journal->j_state_lock);
     534                 :            : 
     535                 :            :         jbd_debug(3, "JBD2: commit phase 2a\n");
     536                 :            : 
     537                 :            :         /*
     538                 :            :          * Now start flushing things to disk, in the order they appear
     539                 :            :          * on the transaction lists.  Data blocks go first.
     540                 :            :          */
     541                 :       2524 :         err = journal_submit_data_buffers(journal, commit_transaction);
     542         [ -  + ]:       2524 :         if (err)
     543                 :          0 :                 jbd2_journal_abort(journal, err);
     544                 :            : 
     545                 :       2524 :         blk_start_plug(&plug);
     546                 :       2524 :         jbd2_journal_write_revoke_records(commit_transaction, &log_bufs);
     547                 :            : 
     548                 :            :         jbd_debug(3, "JBD2: commit phase 2b\n");
     549                 :            : 
     550                 :            :         /*
     551                 :            :          * Way to go: we have now written out all of the data for a
     552                 :            :          * transaction!  Now comes the tricky part: we need to write out
     553                 :            :          * metadata.  Loop over the transaction's entire buffer list:
     554                 :            :          */
     555                 :       2524 :         write_lock(&journal->j_state_lock);
     556                 :       2524 :         commit_transaction->t_state = T_COMMIT;
     557                 :            :         write_unlock(&journal->j_state_lock);
     558                 :            : 
     559                 :       2524 :         trace_jbd2_commit_logging(journal, commit_transaction);
     560                 :       2524 :         stats.run.rs_logging = jiffies;
     561                 :       5048 :         stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing,
     562                 :            :                                                stats.run.rs_logging);
     563                 :       2524 :         stats.run.rs_blocks =
     564                 :            :                 atomic_read(&commit_transaction->t_outstanding_credits);
     565                 :       2524 :         stats.run.rs_blocks_logged = 0;
     566                 :            : 
     567         [ +  - ]:       5048 :         J_ASSERT(commit_transaction->t_nr_buffers <=
     568                 :            :                  atomic_read(&commit_transaction->t_outstanding_credits));
     569                 :            : 
     570                 :            :         err = 0;
     571                 :            :         bufs = 0;
     572                 :            :         descriptor = NULL;
     573         [ +  + ]:     100209 :         while (commit_transaction->t_buffers) {
     574                 :            : 
     575                 :            :                 /* Find the next buffer to be journaled... */
     576                 :            : 
     577                 :            :                 jh = commit_transaction->t_buffers;
     578                 :            : 
     579                 :            :                 /* If we're in abort mode, we just un-journal the buffer and
     580                 :            :                    release it. */
     581                 :            : 
     582         [ -  + ]:      97685 :                 if (is_journal_aborted(journal)) {
     583                 :            :                         clear_buffer_jbddirty(jh2bh(jh));
     584                 :            :                         JBUFFER_TRACE(jh, "journal is aborting: refile");
     585         [ #  # ]:          0 :                         jbd2_buffer_abort_trigger(jh,
     586                 :          0 :                                                   jh->b_frozen_data ?
     587                 :            :                                                   jh->b_frozen_triggers :
     588                 :            :                                                   jh->b_triggers);
     589                 :          0 :                         jbd2_journal_refile_buffer(journal, jh);
     590                 :            :                         /* If that was the last one, we need to clean up
     591                 :            :                          * any descriptor buffers which may have been
     592                 :            :                          * already allocated, even if we are now
     593                 :            :                          * aborting. */
     594         [ #  # ]:          0 :                         if (!commit_transaction->t_buffers)
     595                 :            :                                 goto start_journal_io;
     596                 :          0 :                         continue;
     597                 :            :                 }
     598                 :            : 
     599                 :            :                 /* Make sure we have a descriptor block in which to
     600                 :            :                    record the metadata buffer. */
     601                 :            : 
     602         [ +  + ]:      97685 :                 if (!descriptor) {
     603         [ -  + ]:       2497 :                         J_ASSERT (bufs == 0);
     604                 :            : 
     605                 :            :                         jbd_debug(4, "JBD2: get descriptor\n");
     606                 :            : 
     607                 :       2497 :                         descriptor = jbd2_journal_get_descriptor_buffer(
     608                 :            :                                                         commit_transaction,
     609                 :            :                                                         JBD2_DESCRIPTOR_BLOCK);
     610         [ -  + ]:       2497 :                         if (!descriptor) {
     611                 :          0 :                                 jbd2_journal_abort(journal, -EIO);
     612                 :          0 :                                 continue;
     613                 :            :                         }
     614                 :            : 
     615                 :            :                         jbd_debug(4, "JBD2: got buffer %llu (%p)\n",
     616                 :            :                                 (unsigned long long)descriptor->b_blocknr,
     617                 :            :                                 descriptor->b_data);
     618                 :       2497 :                         tagp = &descriptor->b_data[sizeof(journal_header_t)];
     619                 :       2497 :                         space_left = descriptor->b_size -
     620                 :            :                                                 sizeof(journal_header_t);
     621                 :            :                         first_tag = 1;
     622                 :            :                         set_buffer_jwrite(descriptor);
     623                 :            :                         set_buffer_dirty(descriptor);
     624                 :       2497 :                         wbuf[bufs++] = descriptor;
     625                 :            : 
     626                 :            :                         /* Record it so that we can wait for IO
     627                 :            :                            completion later */
     628                 :            :                         BUFFER_TRACE(descriptor, "ph3: file as descriptor");
     629                 :            :                         jbd2_file_log_bh(&log_bufs, descriptor);
     630                 :            :                 }
     631                 :            : 
     632                 :            :                 /* Where is the buffer to be written? */
     633                 :            : 
     634                 :      97685 :                 err = jbd2_journal_next_log_block(journal, &blocknr);
     635                 :            :                 /* If the block mapping failed, just abandon the buffer
     636                 :            :                    and repeat this loop: we'll fall into the
     637                 :            :                    refile-on-abort condition above. */
     638         [ -  + ]:      97685 :                 if (err) {
     639                 :          0 :                         jbd2_journal_abort(journal, err);
     640                 :          0 :                         continue;
     641                 :            :                 }
     642                 :            : 
     643                 :            :                 /*
     644                 :            :                  * start_this_handle() uses t_outstanding_credits to determine
     645                 :            :                  * the free space in the log, but this counter is changed
     646                 :            :                  * by jbd2_journal_next_log_block() also.
     647                 :            :                  */
     648                 :            :                 atomic_dec(&commit_transaction->t_outstanding_credits);
     649                 :            : 
     650                 :            :                 /* Bump b_count to prevent truncate from stumbling over
     651                 :            :                    the shadowed buffer!  @@@ This can go if we ever get
     652                 :            :                    rid of the shadow pairing of buffers. */
     653                 :      97685 :                 atomic_inc(&jh2bh(jh)->b_count);
     654                 :            : 
     655                 :            :                 /*
     656                 :            :                  * Make a temporary IO buffer with which to write it out
     657                 :            :                  * (this will requeue the metadata buffer to BJ_Shadow).
     658                 :            :                  */
     659                 :      97685 :                 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
     660                 :            :                 JBUFFER_TRACE(jh, "ph3: write metadata");
     661                 :     195370 :                 flags = jbd2_journal_write_metadata_buffer(commit_transaction,
     662                 :      97685 :                                                 jh, &wbuf[bufs], blocknr);
     663         [ -  + ]:      97685 :                 if (flags < 0) {
     664                 :          0 :                         jbd2_journal_abort(journal, flags);
     665                 :          0 :                         continue;
     666                 :            :                 }
     667                 :      97685 :                 jbd2_file_log_bh(&io_bufs, wbuf[bufs]);
     668                 :            : 
     669                 :            :                 /* Record the new block's tag in the current descriptor
     670                 :            :                    buffer */
     671                 :            : 
     672                 :            :                 tag_flag = 0;
     673         [ -  + ]:      97685 :                 if (flags & 1)
     674                 :            :                         tag_flag |= JBD2_FLAG_ESCAPE;
     675         [ +  + ]:      97685 :                 if (!first_tag)
     676                 :      95188 :                         tag_flag |= JBD2_FLAG_SAME_UUID;
     677                 :            : 
     678                 :            :                 tag = (journal_block_tag_t *) tagp;
     679                 :      97685 :                 write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
     680                 :      97685 :                 tag->t_flags = cpu_to_be16(tag_flag);
     681                 :      97685 :                 jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
     682                 :            :                                         commit_transaction->t_tid);
     683                 :      97685 :                 tagp += tag_bytes;
     684                 :      97685 :                 space_left -= tag_bytes;
     685                 :      97685 :                 bufs++;
     686                 :            : 
     687         [ +  + ]:      97685 :                 if (first_tag) {
     688                 :       2497 :                         memcpy (tagp, journal->j_uuid, 16);
     689                 :       2497 :                         tagp += 16;
     690                 :       2497 :                         space_left -= 16;
     691                 :            :                         first_tag = 0;
     692                 :            :                 }
     693                 :            : 
     694                 :            :                 /* If there's no more to do, or if the descriptor is full,
     695                 :            :                    let the IO rip! */
     696                 :            : 
     697   [ +  -  +  + ]:     195370 :                 if (bufs == journal->j_wbufsize ||
     698         [ -  + ]:     192873 :                     commit_transaction->t_buffers == NULL ||
     699                 :      95188 :                     space_left < tag_bytes + 16 + csum_size) {
     700                 :            : 
     701                 :            :                         jbd_debug(4, "JBD2: Submit %d IOs\n", bufs);
     702                 :            : 
     703                 :            :                         /* Write an end-of-descriptor marker before
     704                 :            :                            submitting the IOs.  "tag" still points to
     705                 :            :                            the last tag we set up. */
     706                 :            : 
     707                 :       2497 :                         tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
     708                 :            : start_journal_io:
     709         [ +  - ]:       2497 :                         if (descriptor)
     710                 :       2497 :                                 jbd2_descriptor_block_csum_set(journal,
     711                 :            :                                                         descriptor);
     712                 :            : 
     713         [ +  + ]:     100182 :                         for (i = 0; i < bufs; i++) {
     714                 :     100182 :                                 struct buffer_head *bh = wbuf[i];
     715                 :            :                                 /*
     716                 :            :                                  * Compute checksum.
     717                 :            :                                  */
     718         [ -  + ]:     100182 :                                 if (jbd2_has_feature_checksum(journal)) {
     719                 :          0 :                                         crc32_sum =
     720                 :            :                                             jbd2_checksum_data(crc32_sum, bh);
     721                 :            :                                 }
     722                 :            : 
     723                 :     100182 :                                 lock_buffer(bh);
     724                 :            :                                 clear_buffer_dirty(bh);
     725                 :            :                                 set_buffer_uptodate(bh);
     726                 :     100182 :                                 bh->b_end_io = journal_end_buffer_io_sync;
     727                 :     100182 :                                 submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
     728                 :            :                         }
     729                 :       2497 :                         cond_resched();
     730                 :            : 
     731                 :            :                         /* Force a new descriptor to be generated next
     732                 :            :                            time round the loop. */
     733                 :            :                         descriptor = NULL;
     734                 :            :                         bufs = 0;
     735                 :            :                 }
     736                 :            :         }
     737                 :            : 
     738                 :       2524 :         err = journal_finish_inode_data_buffers(journal, commit_transaction);
     739         [ -  + ]:       2524 :         if (err) {
     740                 :          0 :                 printk(KERN_WARNING
     741                 :            :                         "JBD2: Detected IO errors while flushing file data "
     742                 :          0 :                        "on %s\n", journal->j_devname);
     743         [ #  # ]:          0 :                 if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
     744                 :          0 :                         jbd2_journal_abort(journal, err);
     745                 :            :                 err = 0;
     746                 :            :         }
     747                 :            : 
     748                 :            :         /*
     749                 :            :          * Get current oldest transaction in the log before we issue flush
     750                 :            :          * to the filesystem device. After the flush we can be sure that
     751                 :            :          * blocks of all older transactions are checkpointed to persistent
     752                 :            :          * storage and we will be safe to update journal start in the
     753                 :            :          * superblock with the numbers we get here.
     754                 :            :          */
     755                 :       2524 :         update_tail =
     756                 :            :                 jbd2_journal_get_log_tail(journal, &first_tid, &first_block);
     757                 :            : 
     758                 :       2524 :         write_lock(&journal->j_state_lock);
     759         [ +  + ]:       2524 :         if (update_tail) {
     760                 :       2096 :                 long freed = first_block - journal->j_tail;
     761                 :            : 
     762         [ -  + ]:       2096 :                 if (first_block < journal->j_tail)
     763                 :          0 :                         freed += journal->j_last - journal->j_first;
     764                 :            :                 /* Update tail only if we free significant amount of space */
     765         [ +  - ]:       2096 :                 if (freed < journal->j_maxlen / 4)
     766                 :            :                         update_tail = 0;
     767                 :            :         }
     768         [ -  + ]:       2524 :         J_ASSERT(commit_transaction->t_state == T_COMMIT);
     769                 :       2524 :         commit_transaction->t_state = T_COMMIT_DFLUSH;
     770                 :            :         write_unlock(&journal->j_state_lock);
     771                 :            : 
     772                 :            :         /* 
     773                 :            :          * If the journal is not located on the file system device,
     774                 :            :          * then we must flush the file system device before we issue
     775                 :            :          * the commit record
     776                 :            :          */
     777   [ +  +  -  + ]:       3832 :         if (commit_transaction->t_need_data_flush &&
     778         [ #  # ]:       1308 :             (journal->j_fs_dev != journal->j_dev) &&
     779                 :          0 :             (journal->j_flags & JBD2_BARRIER))
     780                 :          0 :                 blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL);
     781                 :            : 
     782                 :            :         /* Done it all: now write the commit record asynchronously. */
     783         [ -  + ]:       2524 :         if (jbd2_has_feature_async_commit(journal)) {
     784                 :          0 :                 err = journal_submit_commit_record(journal, commit_transaction,
     785                 :            :                                                  &cbh, crc32_sum);
     786         [ #  # ]:          0 :                 if (err)
     787                 :          0 :                         jbd2_journal_abort(journal, err);
     788                 :            :         }
     789                 :            : 
     790                 :       2524 :         blk_finish_plug(&plug);
     791                 :            : 
     792                 :            :         /* Lo and behold: we have just managed to send a transaction to
     793                 :            :            the log.  Before we can commit it, wait for the IO so far to
     794                 :            :            complete.  Control buffers being written are on the
     795                 :            :            transaction's t_log_list queue, and metadata buffers are on
     796                 :            :            the io_bufs list.
     797                 :            : 
     798                 :            :            Wait for the buffers in reverse order.  That way we are
     799                 :            :            less likely to be woken up until all IOs have completed, and
     800                 :            :            so we incur less scheduling load.
     801                 :            :         */
     802                 :            : 
     803                 :            :         jbd_debug(3, "JBD2: commit phase 3\n");
     804                 :            : 
     805         [ +  + ]:     102733 :         while (!list_empty(&io_bufs)) {
     806                 :      97685 :                 struct buffer_head *bh = list_entry(io_bufs.prev,
     807                 :            :                                                     struct buffer_head,
     808                 :            :                                                     b_assoc_buffers);
     809                 :            : 
     810                 :      97685 :                 wait_on_buffer(bh);
     811                 :      97685 :                 cond_resched();
     812                 :            : 
     813         [ -  + ]:      97685 :                 if (unlikely(!buffer_uptodate(bh)))
     814                 :            :                         err = -EIO;
     815                 :            :                 jbd2_unfile_log_bh(bh);
     816                 :      97685 :                 stats.run.rs_blocks_logged++;
     817                 :            : 
     818                 :            :                 /*
     819                 :            :                  * The list contains temporary buffer heads created by
     820                 :            :                  * jbd2_journal_write_metadata_buffer().
     821                 :            :                  */
     822                 :            :                 BUFFER_TRACE(bh, "dumping temporary bh");
     823                 :      97685 :                 __brelse(bh);
     824         [ -  + ]:      97685 :                 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
     825                 :      97685 :                 free_buffer_head(bh);
     826                 :            : 
     827                 :            :                 /* We also have to refile the corresponding shadowed buffer */
     828                 :      97685 :                 jh = commit_transaction->t_shadow_list->b_tprev;
     829                 :            :                 bh = jh2bh(jh);
     830                 :            :                 clear_buffer_jwrite(bh);
     831         [ -  + ]:      97685 :                 J_ASSERT_BH(bh, buffer_jbddirty(bh));
     832         [ -  + ]:      97685 :                 J_ASSERT_BH(bh, !buffer_shadow(bh));
     833                 :            : 
     834                 :            :                 /* The metadata is now released for reuse, but we need
     835                 :            :                    to remember it against this transaction so that when
     836                 :            :                    we finally commit, we can do any checkpointing
     837                 :            :                    required. */
     838                 :            :                 JBUFFER_TRACE(jh, "file as BJ_Forget");
     839                 :      97685 :                 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
     840                 :            :                 JBUFFER_TRACE(jh, "brelse shadowed buffer");
     841                 :      97685 :                 __brelse(bh);
     842                 :            :         }
     843                 :            : 
     844         [ +  - ]:       2524 :         J_ASSERT (commit_transaction->t_shadow_list == NULL);
     845                 :            : 
     846                 :            :         jbd_debug(3, "JBD2: commit phase 4\n");
     847                 :            : 
     848                 :            :         /* Here we wait for the revoke record and descriptor record buffers */
     849         [ +  + ]:       5233 :         while (!list_empty(&log_bufs)) {
     850                 :            :                 struct buffer_head *bh;
     851                 :            : 
     852                 :       2709 :                 bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers);
     853                 :       2709 :                 wait_on_buffer(bh);
     854                 :       2709 :                 cond_resched();
     855                 :            : 
     856         [ -  + ]:       2709 :                 if (unlikely(!buffer_uptodate(bh)))
     857                 :            :                         err = -EIO;
     858                 :            : 
     859                 :            :                 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
     860                 :            :                 clear_buffer_jwrite(bh);
     861                 :            :                 jbd2_unfile_log_bh(bh);
     862                 :       2709 :                 stats.run.rs_blocks_logged++;
     863                 :       2709 :                 __brelse(bh);           /* One for getblk */
     864                 :            :                 /* AKPM: bforget here */
     865                 :            :         }
     866                 :            : 
     867         [ -  + ]:       2524 :         if (err)
     868                 :          0 :                 jbd2_journal_abort(journal, err);
     869                 :            : 
     870                 :            :         jbd_debug(3, "JBD2: commit phase 5\n");
     871                 :       2524 :         write_lock(&journal->j_state_lock);
     872         [ -  + ]:       2524 :         J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH);
     873                 :       2524 :         commit_transaction->t_state = T_COMMIT_JFLUSH;
     874                 :            :         write_unlock(&journal->j_state_lock);
     875                 :            : 
     876         [ +  - ]:       2524 :         if (!jbd2_has_feature_async_commit(journal)) {
     877                 :       2524 :                 err = journal_submit_commit_record(journal, commit_transaction,
     878                 :            :                                                 &cbh, crc32_sum);
     879         [ -  + ]:       2524 :                 if (err)
     880                 :          0 :                         jbd2_journal_abort(journal, err);
     881                 :            :         }
     882         [ +  - ]:       2524 :         if (cbh)
     883                 :       2524 :                 err = journal_wait_on_commit_record(journal, cbh);
     884                 :       2524 :         stats.run.rs_blocks_logged++;
     885   [ -  +  #  # ]:       2524 :         if (jbd2_has_feature_async_commit(journal) &&
     886                 :          0 :             journal->j_flags & JBD2_BARRIER) {
     887                 :          0 :                 blkdev_issue_flush(journal->j_dev, GFP_NOFS, NULL);
     888                 :            :         }
     889                 :            : 
     890         [ -  + ]:       2524 :         if (err)
     891                 :          0 :                 jbd2_journal_abort(journal, err);
     892                 :            : 
     893                 :            :         /*
     894                 :            :          * Now disk caches for filesystem device are flushed so we are safe to
     895                 :            :          * erase checkpointed transactions from the log by updating journal
     896                 :            :          * superblock.
     897                 :            :          */
     898         [ -  + ]:       2524 :         if (update_tail)
     899                 :          0 :                 jbd2_update_log_tail(journal, first_tid, first_block);
     900                 :            : 
     901                 :            :         /* End of a transaction!  Finally, we can do checkpoint
     902                 :            :            processing: any buffers committed as a result of this
     903                 :            :            transaction can be removed from any checkpoint list it was on
     904                 :            :            before. */
     905                 :            : 
     906                 :            :         jbd_debug(3, "JBD2: commit phase 6\n");
     907                 :            : 
     908         [ -  + ]:       5048 :         J_ASSERT(list_empty(&commit_transaction->t_inode_list));
     909         [ -  + ]:       2524 :         J_ASSERT(commit_transaction->t_buffers == NULL);
     910         [ -  + ]:       2524 :         J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
     911         [ +  - ]:       2524 :         J_ASSERT(commit_transaction->t_shadow_list == NULL);
     912                 :            : 
     913                 :            : restart_loop:
     914                 :            :         /*
     915                 :            :          * As there are other places (journal_unmap_buffer()) adding buffers
     916                 :            :          * to this list we have to be careful and hold the j_list_lock.
     917                 :            :          */
     918                 :            :         spin_lock(&journal->j_list_lock);
     919         [ +  + ]:     100217 :         while (commit_transaction->t_forget) {
     920                 :            :                 transaction_t *cp_transaction;
     921                 :            :                 struct buffer_head *bh;
     922                 :            :                 int try_to_free = 0;
     923                 :            : 
     924                 :            :                 jh = commit_transaction->t_forget;
     925                 :            :                 spin_unlock(&journal->j_list_lock);
     926                 :            :                 bh = jh2bh(jh);
     927                 :            :                 /*
     928                 :            :                  * Get a reference so that bh cannot be freed before we are
     929                 :            :                  * done with it.
     930                 :            :                  */
     931                 :            :                 get_bh(bh);
     932                 :            :                 jbd_lock_bh_state(bh);
     933         [ -  + ]:      97693 :                 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction);
     934                 :            : 
     935                 :            :                 /*
     936                 :            :                  * If there is undo-protected committed data against
     937                 :            :                  * this buffer, then we can remove it now.  If it is a
     938                 :            :                  * buffer needing such protection, the old frozen_data
     939                 :            :                  * field now points to a committed version of the
     940                 :            :                  * buffer, so rotate that field to the new committed
     941                 :            :                  * data.
     942                 :            :                  *
     943                 :            :                  * Otherwise, we can just throw away the frozen data now.
     944                 :            :                  *
     945                 :            :                  * We also know that the frozen data has already fired
     946                 :            :                  * its triggers if they exist, so we can clear that too.
     947                 :            :                  */
     948         [ -  + ]:      97693 :                 if (jh->b_committed_data) {
     949                 :          0 :                         jbd2_free(jh->b_committed_data, bh->b_size);
     950                 :          0 :                         jh->b_committed_data = NULL;
     951         [ #  # ]:          0 :                         if (jh->b_frozen_data) {
     952                 :          0 :                                 jh->b_committed_data = jh->b_frozen_data;
     953                 :          0 :                                 jh->b_frozen_data = NULL;
     954                 :          0 :                                 jh->b_frozen_triggers = NULL;
     955                 :            :                         }
     956         [ +  + ]:      97693 :                 } else if (jh->b_frozen_data) {
     957                 :        214 :                         jbd2_free(jh->b_frozen_data, bh->b_size);
     958                 :        214 :                         jh->b_frozen_data = NULL;
     959                 :        214 :                         jh->b_frozen_triggers = NULL;
     960                 :            :                 }
     961                 :            : 
     962                 :            :                 spin_lock(&journal->j_list_lock);
     963                 :      97693 :                 cp_transaction = jh->b_cp_transaction;
     964         [ +  + ]:      97693 :                 if (cp_transaction) {
     965                 :            :                         JBUFFER_TRACE(jh, "remove from old cp transaction");
     966                 :      26361 :                         cp_transaction->t_chp_stats.cs_dropped++;
     967                 :      26361 :                         __jbd2_journal_remove_checkpoint(jh);
     968                 :            :                 }
     969                 :            : 
     970                 :            :                 /* Only re-checkpoint the buffer_head if it is marked
     971                 :            :                  * dirty.  If the buffer was added to the BJ_Forget list
     972                 :            :                  * by jbd2_journal_forget, it may no longer be dirty and
     973                 :            :                  * there's no point in keeping a checkpoint record for
     974                 :            :                  * it. */
     975                 :            : 
     976                 :            :                 /*
     977                 :            :                  * A buffer which has been freed while still being journaled
     978                 :            :                  * by a previous transaction, refile the buffer to BJ_Forget of
     979                 :            :                  * the running transaction. If the just committed transaction
     980                 :            :                  * contains "add to orphan" operation, we can completely
     981                 :            :                  * invalidate the buffer now. We are rather through in that
     982                 :            :                  * since the buffer may be still accessible when blocksize <
     983                 :            :                  * pagesize and it is attached to the last partial page.
     984                 :            :                  */
     985   [ -  +  #  # ]:      97693 :                 if (buffer_freed(bh) && !jh->b_next_transaction) {
     986                 :            :                         struct address_space *mapping;
     987                 :            : 
     988                 :            :                         clear_buffer_freed(bh);
     989                 :            :                         clear_buffer_jbddirty(bh);
     990                 :            : 
     991                 :            :                         /*
     992                 :            :                          * Block device buffers need to stay mapped all the
     993                 :            :                          * time, so it is enough to clear buffer_jbddirty and
     994                 :            :                          * buffer_freed bits. For the file mapping buffers (i.e.
     995                 :            :                          * journalled data) we need to unmap buffer and clear
     996                 :            :                          * more bits. We also need to be careful about the check
     997                 :            :                          * because the data page mapping can get cleared under
     998                 :            :                          * our hands. Note that if mapping == NULL, we don't
     999                 :            :                          * need to make buffer unmapped because the page is
    1000                 :            :                          * already detached from the mapping and buffers cannot
    1001                 :            :                          * get reused.
    1002                 :            :                          */
    1003                 :          0 :                         mapping = READ_ONCE(bh->b_page->mapping);
    1004   [ #  #  #  # ]:          0 :                         if (mapping && !sb_is_blkdev_sb(mapping->host->i_sb)) {
    1005                 :            :                                 clear_buffer_mapped(bh);
    1006                 :            :                                 clear_buffer_new(bh);
    1007                 :            :                                 clear_buffer_req(bh);
    1008                 :          0 :                                 bh->b_bdev = NULL;
    1009                 :            :                         }
    1010                 :            :                 }
    1011                 :            : 
    1012         [ +  + ]:      97693 :                 if (buffer_jbddirty(bh)) {
    1013                 :            :                         JBUFFER_TRACE(jh, "add to new checkpointing trans");
    1014                 :      97685 :                         __jbd2_journal_insert_checkpoint(jh, commit_transaction);
    1015         [ -  + ]:      97685 :                         if (is_journal_aborted(journal))
    1016                 :            :                                 clear_buffer_jbddirty(bh);
    1017                 :            :                 } else {
    1018         [ -  + ]:          8 :                         J_ASSERT_BH(bh, !buffer_dirty(bh));
    1019                 :            :                         /*
    1020                 :            :                          * The buffer on BJ_Forget list and not jbddirty means
    1021                 :            :                          * it has been freed by this transaction and hence it
    1022                 :            :                          * could not have been reallocated until this
    1023                 :            :                          * transaction has committed. *BUT* it could be
    1024                 :            :                          * reallocated once we have written all the data to
    1025                 :            :                          * disk and before we process the buffer on BJ_Forget
    1026                 :            :                          * list.
    1027                 :            :                          */
    1028         [ +  - ]:          8 :                         if (!jh->b_next_transaction)
    1029                 :            :                                 try_to_free = 1;
    1030                 :            :                 }
    1031                 :            :                 JBUFFER_TRACE(jh, "refile or unfile buffer");
    1032                 :      97693 :                 __jbd2_journal_refile_buffer(jh);
    1033                 :            :                 jbd_unlock_bh_state(bh);
    1034         [ +  + ]:      97693 :                 if (try_to_free)
    1035                 :          8 :                         release_buffer_page(bh);        /* Drops bh reference */
    1036                 :            :                 else
    1037                 :      97685 :                         __brelse(bh);
    1038                 :      97693 :                 cond_resched_lock(&journal->j_list_lock);
    1039                 :            :         }
    1040                 :            :         spin_unlock(&journal->j_list_lock);
    1041                 :            :         /*
    1042                 :            :          * This is a bit sleazy.  We use j_list_lock to protect transition
    1043                 :            :          * of a transaction into T_FINISHED state and calling
    1044                 :            :          * __jbd2_journal_drop_transaction(). Otherwise we could race with
    1045                 :            :          * other checkpointing code processing the transaction...
    1046                 :            :          */
    1047                 :       2524 :         write_lock(&journal->j_state_lock);
    1048                 :            :         spin_lock(&journal->j_list_lock);
    1049                 :            :         /*
    1050                 :            :          * Now recheck if some buffers did not get attached to the transaction
    1051                 :            :          * while the lock was dropped...
    1052                 :            :          */
    1053         [ -  + ]:       2524 :         if (commit_transaction->t_forget) {
    1054                 :            :                 spin_unlock(&journal->j_list_lock);
    1055                 :            :                 write_unlock(&journal->j_state_lock);
    1056                 :            :                 goto restart_loop;
    1057                 :            :         }
    1058                 :            : 
    1059                 :            :         /* Add the transaction to the checkpoint list
    1060                 :            :          * __journal_remove_checkpoint() can not destroy transaction
    1061                 :            :          * under us because it is not marked as T_FINISHED yet */
    1062         [ +  + ]:       2524 :         if (journal->j_checkpoint_transactions == NULL) {
    1063                 :        264 :                 journal->j_checkpoint_transactions = commit_transaction;
    1064                 :        264 :                 commit_transaction->t_cpnext = commit_transaction;
    1065                 :        264 :                 commit_transaction->t_cpprev = commit_transaction;
    1066                 :            :         } else {
    1067                 :       2260 :                 commit_transaction->t_cpnext =
    1068                 :            :                         journal->j_checkpoint_transactions;
    1069                 :       2260 :                 commit_transaction->t_cpprev =
    1070                 :       2260 :                         commit_transaction->t_cpnext->t_cpprev;
    1071                 :       2260 :                 commit_transaction->t_cpnext->t_cpprev =
    1072                 :            :                         commit_transaction;
    1073                 :       2260 :                 commit_transaction->t_cpprev->t_cpnext =
    1074                 :            :                                 commit_transaction;
    1075                 :            :         }
    1076                 :            :         spin_unlock(&journal->j_list_lock);
    1077                 :            : 
    1078                 :            :         /* Done with this transaction! */
    1079                 :            : 
    1080                 :            :         jbd_debug(3, "JBD2: commit phase 7\n");
    1081                 :            : 
    1082         [ -  + ]:       2524 :         J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH);
    1083                 :            : 
    1084                 :       2524 :         commit_transaction->t_start = jiffies;
    1085                 :       5048 :         stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,
    1086                 :            :                                               commit_transaction->t_start);
    1087                 :            : 
    1088                 :            :         /*
    1089                 :            :          * File the transaction statistics
    1090                 :            :          */
    1091                 :       2524 :         stats.ts_tid = commit_transaction->t_tid;
    1092                 :       2524 :         stats.run.rs_handle_count =
    1093                 :            :                 atomic_read(&commit_transaction->t_handle_count);
    1094                 :       5048 :         trace_jbd2_run_stats(journal->j_fs_dev->bd_dev,
    1095                 :       2524 :                              commit_transaction->t_tid, &stats.run);
    1096                 :       2524 :         stats.ts_requested = (commit_transaction->t_requested) ? 1 : 0;
    1097                 :            : 
    1098                 :       2524 :         commit_transaction->t_state = T_COMMIT_CALLBACK;
    1099         [ -  + ]:       2524 :         J_ASSERT(commit_transaction == journal->j_committing_transaction);
    1100                 :       2524 :         journal->j_commit_sequence = commit_transaction->t_tid;
    1101                 :       2524 :         journal->j_committing_transaction = NULL;
    1102                 :       2524 :         commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
    1103                 :            : 
    1104                 :            :         /*
    1105                 :            :          * weight the commit time higher than the average time so we don't
    1106                 :            :          * react too strongly to vast changes in the commit time
    1107                 :            :          */
    1108         [ +  + ]:       2524 :         if (likely(journal->j_average_commit_time))
    1109                 :       4634 :                 journal->j_average_commit_time = (commit_time +
    1110                 :       4634 :                                 journal->j_average_commit_time*3) / 4;
    1111                 :            :         else
    1112                 :        207 :                 journal->j_average_commit_time = commit_time;
    1113                 :            : 
    1114                 :            :         write_unlock(&journal->j_state_lock);
    1115                 :            : 
    1116         [ +  - ]:       2524 :         if (journal->j_commit_callback)
    1117                 :       2524 :                 journal->j_commit_callback(journal, commit_transaction);
    1118                 :            : 
    1119                 :       2524 :         trace_jbd2_end_commit(journal, commit_transaction);
    1120                 :            :         jbd_debug(1, "JBD2: commit %d complete, head %d\n",
    1121                 :            :                   journal->j_commit_sequence, journal->j_tail_sequence);
    1122                 :            : 
    1123                 :       2524 :         write_lock(&journal->j_state_lock);
    1124                 :            :         spin_lock(&journal->j_list_lock);
    1125                 :       2524 :         commit_transaction->t_state = T_FINISHED;
    1126                 :            :         /* Check if the transaction can be dropped now that we are finished */
    1127   [ +  +  +  - ]:       2551 :         if (commit_transaction->t_checkpoint_list == NULL &&
    1128                 :         27 :             commit_transaction->t_checkpoint_io_list == NULL) {
    1129                 :         27 :                 __jbd2_journal_drop_transaction(journal, commit_transaction);
    1130                 :         27 :                 jbd2_journal_free_transaction(commit_transaction);
    1131                 :            :         }
    1132                 :            :         spin_unlock(&journal->j_list_lock);
    1133                 :            :         write_unlock(&journal->j_state_lock);
    1134                 :       2524 :         wake_up(&journal->j_wait_done_commit);
    1135                 :            : 
    1136                 :            :         /*
    1137                 :            :          * Calculate overall stats
    1138                 :            :          */
    1139                 :            :         spin_lock(&journal->j_history_lock);
    1140                 :       2524 :         journal->j_stats.ts_tid++;
    1141                 :       2524 :         journal->j_stats.ts_requested += stats.ts_requested;
    1142                 :       2524 :         journal->j_stats.run.rs_wait += stats.run.rs_wait;
    1143                 :       2524 :         journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay;
    1144                 :       2524 :         journal->j_stats.run.rs_running += stats.run.rs_running;
    1145                 :       2524 :         journal->j_stats.run.rs_locked += stats.run.rs_locked;
    1146                 :       2524 :         journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
    1147                 :       2524 :         journal->j_stats.run.rs_logging += stats.run.rs_logging;
    1148                 :       2524 :         journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
    1149                 :       2524 :         journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
    1150                 :       2524 :         journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
    1151                 :            :         spin_unlock(&journal->j_history_lock);
    1152                 :       2524 : }

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