From 21cb1d99bcc77252e6426010bcc6433f75b581bb Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Wed, 11 Mar 2015 13:42:48 -0400 Subject: [PATCH] f2fs: fix to cover sentry_lock for block allocation 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 --- 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 3e80bd69d4a0..eafaf728236b 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);