linux/include/linux/statfs.h
Amir Goldstein 9591c3a34f 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 <damien.lemoal@wdc.com>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-04-19 16:03:15 +02:00

62 lines
1.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_STATFS_H
#define _LINUX_STATFS_H
#include <linux/types.h>
#include <asm/statfs.h>
#include <asm/byteorder.h>
struct kstatfs {
long f_type;
long f_bsize;
u64 f_blocks;
u64 f_bfree;
u64 f_bavail;
u64 f_files;
u64 f_ffree;
__kernel_fsid_t f_fsid;
long f_namelen;
long f_frsize;
long f_flags;
long f_spare[4];
};
/*
* Definitions for the flag in f_flag.
*
* Generally these flags are equivalent to the MS_ flags used in the mount
* ABI. The exception is ST_VALID which has the same value as MS_REMOUNT
* which doesn't make any sense for statfs.
*/
#define ST_RDONLY 0x0001 /* mount read-only */
#define ST_NOSUID 0x0002 /* ignore suid and sgid bits */
#define ST_NODEV 0x0004 /* disallow access to device special files */
#define ST_NOEXEC 0x0008 /* disallow program execution */
#define ST_SYNCHRONOUS 0x0010 /* writes are synced at once */
#define ST_VALID 0x0020 /* f_flags support is implemented */
#define ST_MANDLOCK 0x0040 /* allow mandatory locks on an FS */
/* 0x0080 used for ST_WRITE in glibc */
/* 0x0100 used for ST_APPEND in glibc */
/* 0x0200 used for ST_IMMUTABLE in glibc */
#define ST_NOATIME 0x0400 /* do not update access times */
#define ST_NODIRATIME 0x0800 /* do not update directory access times */
#define ST_RELATIME 0x1000 /* update atime relative to mtime/ctime */
#define ST_NOSYMFOLLOW 0x2000 /* do not follow symlinks */
struct dentry;
extern int vfs_get_fsid(struct dentry *dentry, __kernel_fsid_t *fsid);
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