In the following call stack, f2fs changes the bitmap for dirty segments and # of
dirty sentries without grabbing sit_i->sentry_lock.
This can result in mismatch on bitmap and # of dirty sentries, since if there
are some direct_io operations.
In allocate_data_block,
- __allocate_new_segments
- mutex_lock(&curseg->curseg_mutex);
- s_ops->allocate_segment
- new_curseg/change_curseg
- reset_curseg
- __set_sit_entry_type
- __mark_sit_entry_dirty
- set_bit(dirty_sentries_bitmap)
- dirty_sentries++;
Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
---
fs/f2fs/segment.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 3e80bd6..eafaf72 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1167,6 +1167,7 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct
page *page,
curseg = CURSEG_I(sbi, type);
mutex_lock(&curseg->curseg_mutex);
+ mutex_lock(&sit_i->sentry_lock);
/* direct_io'ed data is aligned to the segment for better performance */
if (direct_io && curseg->next_blkoff)
@@ -1181,7 +1182,6 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct
page *page,
*/
__add_sum_entry(sbi, type, sum);
- mutex_lock(&sit_i->sentry_lock);
__refresh_next_blkoff(sbi, curseg);
stat_inc_block_count(sbi, curseg);
--
2.1.1
------------------------------------------------------------------------------
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