Fixes possible underflows when dealing with unusable blocks.
Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx>
---
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 9b3d9977cd1ef..a39cc4ffeb4b1 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -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)))
- 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 = 0;
+ else
+ avail_user_block_count -= sbi->unusable_block_count;
+ }
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;
}
--
2.22.0.rc1.257.g3120a18244-goog
