diff options
| author | Kent Overstreet <[email protected]> | 2024-02-06 21:56:17 -0500 |
|---|---|---|
| committer | Christian Brauner <[email protected]> | 2024-02-08 21:20:11 +0100 |
| commit | 41bcbe59c3b3fa7171dd2e3a365e6d5154198f30 (patch) | |
| tree | c179abc2f94423a98962ab1b3ed03d8058a15bb6 /include/uapi/linux | |
| parent | dd9019604cdaaff1327bfd36737230f912e2780d (diff) | |
fs: FS_IOC_GETUUID
Add a new generic ioctls for querying the filesystem UUID.
These are lifted versions of the ext4 ioctls, with one change: we're not
using a flexible array member, because UUIDs will never be more than 16
bytes.
This patch adds a generic implementation of FS_IOC_GETFSUUID, which
reads from super_block->s_uuid. We're not lifting SETFSUUID from ext4 -
that can be done on offline filesystems by the people who need it,
trying to do it online is just asking for too much trouble.
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Darrick J. Wong <[email protected]>
Cc: Theodore Ts'o <[email protected]>
Cc: [email protected]
Signed-off-by: Kent Overstreet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>
Diffstat (limited to 'include/uapi/linux')
| -rw-r--r-- | include/uapi/linux/fs.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 48ad69f7722e..40880ce99d02 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -64,6 +64,19 @@ struct fstrim_range { __u64 minlen; }; +/* + * We include a length field because some filesystems (vfat) have an identifier + * that we do want to expose as a UUID, but doesn't have the standard length. + * + * We use a fixed size buffer beacuse this interface will, by fiat, never + * support "UUIDs" longer than 16 bytes; we don't want to force all downstream + * users to have to deal with that. + */ +struct fsuuid2 { + __u8 len; + __u8 uuid[16]; +}; + /* extent-same (dedupe) ioctls; these MUST match the btrfs ioctl definitions */ #define FILE_DEDUPE_RANGE_SAME 0 #define FILE_DEDUPE_RANGE_DIFFERS 1 @@ -215,6 +228,8 @@ struct fsxattr { #define FS_IOC_FSSETXATTR _IOW('X', 32, struct fsxattr) #define FS_IOC_GETFSLABEL _IOR(0x94, 49, char[FSLABEL_MAX]) #define FS_IOC_SETFSLABEL _IOW(0x94, 50, char[FSLABEL_MAX]) +/* Returns the external filesystem UUID, the same one blkid returns */ +#define FS_IOC_GETFSUUID _IOR(0x15, 0, struct fsuuid2) /* * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS) |