[ Upstream commit a4c3ecaaadac5693f555cfef1c9eecf4c39df818 ]
Fixes possible underflows when dealing with unusable blocks.
Signed-off-by: Daniel Rosenberg drosen@google.com Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/f2fs.h | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index d1b64cb77326..9e6721e15b24 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1767,8 +1767,12 @@ 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))) - avail_user_block_count -= sbi->unusable_block_count; + 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) @@ -1968,7 +1972,7 @@ 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) { @@ -1995,10 +1999,11 @@ 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; }