From: Yongpeng Yang When sb_min_blocksize() returns 0 and the return value is not checked, it may lead to a situation where sb->s_blocksize is 0 when accessing the filesystem super block. After commit a64e5a596067bd ("bdev: add back PAGE_SIZE block size validation for sb_set_blocksize()"), this becomes more likely to happen when the block device’s logical_block_size is larger than PAGE_SIZE and the filesystem is unformatted. Add the __must_check attribute to ensure callers always check the return value. Cc: # v6.15 Suggested-by: Matthew Wilcox Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Yongpeng Yang --- block/bdev.c | 2 +- include/linux/fs.h | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/block/bdev.c b/block/bdev.c index 810707cca970..638f0cd458ae 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -231,7 +231,7 @@ int sb_set_blocksize(struct super_block *sb, int size) EXPORT_SYMBOL(sb_set_blocksize); -int sb_min_blocksize(struct super_block *sb, int size) +int __must_check sb_min_blocksize(struct super_block *sb, int size) { int minsize = bdev_logical_block_size(sb->s_bdev); if (size < minsize) diff --git a/include/linux/fs.h b/include/linux/fs.h index c895146c1444..3ea98c6cce81 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3423,8 +3423,8 @@ static inline void remove_inode_hash(struct inode *inode) extern void inode_sb_list_add(struct inode *inode); extern void inode_add_lru(struct inode *inode); -extern int sb_set_blocksize(struct super_block *, int); -extern int sb_min_blocksize(struct super_block *, int); +int sb_set_blocksize(struct super_block *sb, int size); +int __must_check sb_min_blocksize(struct super_block *sb, int size); int generic_file_mmap(struct file *, struct vm_area_struct *); int generic_file_mmap_prepare(struct vm_area_desc *desc); -- 2.43.0