public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-18 22:14:16 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

jbd2: fix off-by-one while erasing journal

Browse source 
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: 01d5d96542 ("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>
This commit is contained in:
Zhang Yi 2025-02-17 14:59:55 +08:00 • committed by Theodore Ts'o
parent 08be56fec0
commit 18aba2adb3
1 changed files with 6 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
fs/jbd2/journal.c
View file

@ -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;
}