If GET_SEGNO return NULL_SEGNO for some unecpected case, update_sit_entry will access invalid memory address, cause system crash. It is better to do sanity check about GET_SEGNO just like update_segment_mtime & locate_dirty_segment.
Also remove some redundant judgment code. Signed-off-by: Zhiguo Niu <zhiguo....@unisoc.com> --- fs/f2fs/segment.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index c616e7a..f8a823f 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -2407,6 +2407,8 @@ static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del) #endif segno = GET_SEGNO(sbi, blkaddr); + if (segno == NULL_SEGNO) + return; se = get_seg_entry(sbi, segno); new_vblocks = se->valid_blocks + del; @@ -3504,8 +3506,7 @@ int f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, * since SSR needs latest valid block information. */ update_sit_entry(sbi, *new_blkaddr, 1); - if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO) - update_sit_entry(sbi, old_blkaddr, -1); + update_sit_entry(sbi, old_blkaddr, -1); /* * If the current segment is full, flush it out and replace it with a -- 1.9.1 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel