From 9591c3a34f7722bd77f42c98d76fd5a5bad465f0 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Mon, 22 Mar 2021 19:39:43 +0200 Subject: fs: introduce a wrapper uuid_to_fsid() Some filesystem's use a digest of their uuid for f_fsid. Create a simple wrapper for this open coded folding. Filesystems that have a non null uuid but use the block device number for f_fsid may also consider using this helper. [JK: Added missing asm/byteorder.h include] Link: https://lore.kernel.org/r/20210322173944.449469-2-amir73il@gmail.com Acked-by: Damien Le Moal Reviewed-by: Christian Brauner Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara --- include/linux/statfs.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/statfs.h') diff --git a/include/linux/statfs.h b/include/linux/statfs.h index 20f695b90aab..02c862686ea3 100644 --- a/include/linux/statfs.h +++ b/include/linux/statfs.h @@ -4,6 +4,7 @@ #include #include +#include struct kstatfs { long f_type; @@ -50,4 +51,11 @@ static inline __kernel_fsid_t u64_to_fsid(u64 v) return (__kernel_fsid_t){.val = {(u32)v, (u32)(v>>32)}}; } +/* Fold 16 bytes uuid to 64 bit fsid */ +static inline __kernel_fsid_t uuid_to_fsid(__u8 *uuid) +{ + return u64_to_fsid(le64_to_cpup((void *)uuid) ^ + le64_to_cpup((void *)(uuid + sizeof(u64)))); +} + #endif -- cgit v1.2.3