f2fs: Fix type of section block count variables (123aaf77) · Commits · 戴 / test

Commit ("f2fs: get the right gc victim section when section has several segments") added code to count blocks of each section using variables with type 'unsigned short', which has 2 bytes size in many systems. However, the counts can be larger than the 2 bytes range and type conversion results in wrong values. Especially when the f2fs sections have blocks as many as USHRT_MAX + 1, the count is handled as 0. This triggers eternal loop in init_dirty_segmap() at mount system call. Fix this by changing the type of the variables to block_t. Fixes: ("f2fs: get the right gc victim section when section has several segments") Signed-off-by:

Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reviewed-by:

Chao Yu <yuchao0@huawei.com> Signed-off-by:

Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/segment.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -799,7 +799,7 @@ static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,

		if (__is_large_section(sbi)) {
		unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
		unsigned short valid_blocks =
		block_t valid_blocks =
		get_valid_blocks(sbi, segno, true);

		f2fs_bug_on(sbi, unlikely(!valid_blocks \|\|
		@@ -815,7 +815,7 @@ static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
		enum dirty_type dirty_type)
		{
		struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
		unsigned short valid_blocks;
		block_t valid_blocks;

		if (test_and_clear_bit(segno, dirty_i->dirty_segmap[dirty_type]))
		dirty_i->nr_dirty[dirty_type]--;
		@@ -4316,8 +4316,8 @@ static void init_dirty_segmap(struct f2fs_sb_info *sbi)
		struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
		struct free_segmap_info *free_i = FREE_I(sbi);
		unsigned int segno = 0, offset = 0, secno;
		unsigned short valid_blocks;
		unsigned short blks_per_sec = BLKS_PER_SEC(sbi);
		block_t valid_blocks;
		block_t blks_per_sec = BLKS_PER_SEC(sbi);

		while (1) {
		/* find dirty segment based on free segmap */

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