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| author | Zhang Yi <yi.zhang@huawei.com> | 2025-02-17 14:59:55 +0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2025-03-18 00:15:25 -0400 |
| commit | 18aba2adb3e2a676fff0d81e51f5045f3c636666 (patch) | |
| tree | 96a617fef375252735424cc3ee6146d7c81832d1 | |
| parent | 08be56fec0588972f6fd4a3ce4ced3265de43dd8 (diff) | |
| download | linux-stable-18aba2adb3e2a676fff0d81e51f5045f3c636666.tar.gz linux-stable-18aba2adb3e2a676fff0d81e51f5045f3c636666.tar.bz2 linux-stable-18aba2adb3e2a676fff0d81e51f5045f3c636666.zip | |
jbd2: fix off-by-one while erasing journal
In __jbd2_journal_erase(), the block_stop parameter includes the last
block of a contiguous region; however, the calculation of byte_stop is
incorrect, as it does not account for the bytes in that last block.
Consequently, the page cache is not cleared properly, which occasionally
causes the ext4/050 test to fail.
Since block_stop operates on inclusion semantics, it involves repeated
increments and decrements by 1, significantly increasing the complexity
of the calculations. Optimize the calculation and fix the incorrect
byte_stop by make both block_stop and byte_stop to use exclusion
semantics.
This fixes a failure in fstests ext4/050.
Fixes: 01d5d96542fd ("ext4: add discard/zeroout flags to journal flush")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250217065955.3829229-1-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | fs/jbd2/journal.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index ff41a31e2bc9..445f2bddd17c 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1964,17 +1964,15 @@ static int __jbd2_journal_erase(journal_t *journal, unsigned int flags) return err; } - if (block_start == ~0ULL) { - block_start = phys_block; - block_stop = block_start - 1; - } + if (block_start == ~0ULL) + block_stop = block_start = phys_block; /* * last block not contiguous with current block, * process last contiguous region and return to this block on * next loop */ - if (phys_block != block_stop + 1) { + if (phys_block != block_stop) { block--; } else { block_stop++; @@ -1993,11 +1991,10 @@ static int __jbd2_journal_erase(journal_t *journal, unsigned int flags) */ byte_start = block_start * journal->j_blocksize; byte_stop = block_stop * journal->j_blocksize; - byte_count = (block_stop - block_start + 1) * - journal->j_blocksize; + byte_count = (block_stop - block_start) * journal->j_blocksize; truncate_inode_pages_range(journal->j_dev->bd_mapping, - byte_start, byte_stop); + byte_start, byte_stop - 1); if (flags & JBD2_JOURNAL_FLUSH_DISCARD) { err = blkdev_issue_discard(journal->j_dev, @@ -2012,7 +2009,7 @@ static int __jbd2_journal_erase(journal_t *journal, unsigned int flags) } if (unlikely(err != 0)) { - pr_err("JBD2: (error %d) unable to wipe journal at physical blocks %llu - %llu", + pr_err("JBD2: (error %d) unable to wipe journal at physical blocks [%llu, %llu)", err, block_start, block_stop); return err; } |