Commit 49bac897 authored by Johannes Thumshirn's avatar Johannes Thumshirn Committed by David Sterba
Browse files

btrfs: add metadata_uuid to FS_INFO ioctl 



Add retrieval of the filesystem's metadata UUID to the fsinfo ioctl.
This is driven by setting the BTRFS_FS_INFO_FLAG_METADATA_UUID flag in
btrfs_ioctl_fs_info_args::flags.

Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Signed-off-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 0fb408a5

fs/btrfs/ioctl.c

+6 −0
Original line number Diff line number Diff line
@@ -3252,6 +3252,12 @@ static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info, 
		fi_args->flags |= BTRFS_FS_INFO_FLAG_GENERATION;

	}



	if (flags_in & BTRFS_FS_INFO_FLAG_METADATA_UUID) {

		memcpy(&fi_args->metadata_uuid, fs_devices->metadata_uuid,

		       sizeof(fi_args->metadata_uuid));

		fi_args->flags |= BTRFS_FS_INFO_FLAG_METADATA_UUID;

	}



	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))

		ret = -EFAULT;

include/uapi/linux/btrfs.h

+4 −1
Original line number Diff line number Diff line
@@ -252,6 +252,8 @@ struct btrfs_ioctl_dev_info_args { 


/* Request information about filesystem generation */

#define BTRFS_FS_INFO_FLAG_GENERATION			(1 << 1)

/* Request information about filesystem metadata UUID */

#define BTRFS_FS_INFO_FLAG_METADATA_UUID		(1 << 2)



struct btrfs_ioctl_fs_info_args {

	__u64 max_id;				/* out */
@@ -265,7 +267,8 @@ struct btrfs_ioctl_fs_info_args { 
	__u16 csum_size;			/* out */

	__u64 flags;				/* in/out */

	__u64 generation;			/* out */

	__u8 reserved[960];			/* pad to 1k */

	__u8 metadata_uuid[BTRFS_FSID_SIZE];	/* out */

	__u8 reserved[944];			/* pad to 1k */

};



/*

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