Commit 227468fc authored by Chi Zhiling's avatar Chi Zhiling Committed by Namjae Jeon
Browse files

exfat: introduce exfat_chain_advance helper 



Introduce exfat_chain_advance() to walk a exfat_chain structure by a
given step, updating both ->dir and ->size fields atomically. This
helper handles both ALLOC_NO_FAT_CHAIN and ALLOC_FAT_CHAIN modes with
proper boundary checking.

Suggested-by: default avatarYuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: default avatarChi Zhiling <chizhiling@kylinos.cn>
Reviewed-by: default avatarSungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: default avatarYuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
parent f764c589

fs/exfat/exfat_fs.h

+21 −0
Original line number Diff line number Diff line
@@ -552,6 +552,27 @@ int exfat_read_volume_label(struct super_block *sb, 
int exfat_write_volume_label(struct super_block *sb,

			     struct exfat_uni_name *label);



static inline int exfat_chain_advance(struct super_block *sb,

		struct exfat_chain *chain, unsigned int step)

{

	unsigned int clu = chain->dir;



	if (unlikely(chain->size < step))

		return -EIO;



	if (exfat_cluster_walk(sb, &clu, step, chain->flags))

		return -EIO;



	chain->size -= step;



	if (chain->size == 0 && chain->flags == ALLOC_NO_FAT_CHAIN)

		chain->dir = EXFAT_EOF_CLUSTER;

	else

		chain->dir = clu;



	return 0;

}



/* inode.c */

extern const struct inode_operations exfat_file_inode_operations;

void exfat_sync_inode(struct inode *inode);