Commit a4c3ecaa authored by Daniel Rosenberg's avatar Daniel Rosenberg Committed by Jaegeuk Kim
Browse files

f2fs: Fix accounting for unusable blocks 



Fixes possible underflows when dealing with unusable blocks.

Signed-off-by: default avatarDaniel Rosenberg <drosen@google.com>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 9a9aecaa

fs/f2fs/f2fs.h

+10 −5
Original line number Diff line number Diff line
@@ -1769,8 +1769,12 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi, 


	if (!__allow_reserved_blocks(sbi, inode, true))

		avail_user_block_count -= F2FS_OPTION(sbi).root_reserved_blocks;

	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)))

	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {

		if (avail_user_block_count > sbi->unusable_block_count)

			avail_user_block_count -= sbi->unusable_block_count;

		else

			avail_user_block_count = 0;

	}

	if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {

		diff = sbi->total_valid_block_count - avail_user_block_count;

		if (diff > *count)
@@ -1970,7 +1974,7 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi, 
					struct inode *inode, bool is_inode)

{

	block_t	valid_block_count;

	unsigned int valid_node_count;

	unsigned int valid_node_count, user_block_count;

	int err;



	if (is_inode) {
@@ -1997,10 +2001,11 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi, 


	if (!__allow_reserved_blocks(sbi, inode, false))

		valid_block_count += F2FS_OPTION(sbi).root_reserved_blocks;

	user_block_count = sbi->user_block_count;

	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)))

		valid_block_count += sbi->unusable_block_count;

		user_block_count -= sbi->unusable_block_count;



	if (unlikely(valid_block_count > sbi->user_block_count)) {

	if (unlikely(valid_block_count > user_block_count)) {

		spin_unlock(&sbi->stat_lock);

		goto enospc;

	}