From a4c3ecaaadac5693f555cfef1c9eecf4c39df818 Mon Sep 17 00:00:00 2001 From: Daniel Rosenberg Date: Wed, 29 May 2019 17:49:05 -0700 Subject: [PATCH] f2fs: Fix accounting for unusable blocks Fixes possible underflows when dealing with unusable blocks. Signed-off-by: Daniel Rosenberg Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- 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 9b3d9977cd1e..9a2a1b49c3ef 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 -= 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; }