From b64ec075bded2b30bcd90af5aa5256d2237c885d Mon Sep 17 00:00:00 2001 From: Tomohiro Misono Date: Mon, 21 May 2018 10:09:42 +0900 Subject: btrfs: Add unprivileged ioctl which returns subvolume information Add new unprivileged ioctl BTRFS_IOC_GET_SUBVOL_INFO which returns the information of subvolume containing this inode. (i.e. returns the information in ROOT_ITEM and ROOT_BACKREF.) Reviewed-by: Gu Jinxiang Tested-by: Gu Jinxiang Signed-off-by: Tomohiro Misono [ minor style fixes, update struct comments ] Signed-off-by: David Sterba --- include/uapi/linux/btrfs.h | 62 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) (limited to 'include/uapi/linux/btrfs.h') diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index c8d99b9ca550..f8f20d72b852 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -725,6 +725,66 @@ struct btrfs_ioctl_send_args { __u64 reserved[4]; /* in */ }; +/* + * Information about a fs tree root. + * + * All items are filled by the ioctl + */ +struct btrfs_ioctl_get_subvol_info_args { + /* Id of this subvolume */ + __u64 treeid; + + /* Name of this subvolume, used to get the real name at mount point */ + char name[BTRFS_VOL_NAME_MAX + 1]; + + /* + * Id of the subvolume which contains this subvolume. + * Zero for top-level subvolume or a deleted subvolume. + */ + __u64 parent_id; + + /* + * Inode number of the directory which contains this subvolume. + * Zero for top-level subvolume or a deleted subvolume + */ + __u64 dirid; + + /* Latest transaction id of this subvolume */ + __u64 generation; + + /* Flags of this subvolume */ + __u64 flags; + + /* UUID of this subvolume */ + __u8 uuid[BTRFS_UUID_SIZE]; + + /* + * UUID of the subvolume of which this subvolume is a snapshot. + * All zero for a non-snapshot subvolume. + */ + __u8 parent_uuid[BTRFS_UUID_SIZE]; + + /* + * UUID of the subvolume from which this subvolume was received. + * All zero for non-received subvolume. + */ + __u8 received_uuid[BTRFS_UUID_SIZE]; + + /* Transaction id indicating when change/create/send/receive happened */ + __u64 ctransid; + __u64 otransid; + __u64 stransid; + __u64 rtransid; + /* Time corresponding to c/o/s/rtransid */ + struct btrfs_ioctl_timespec ctime; + struct btrfs_ioctl_timespec otime; + struct btrfs_ioctl_timespec stime; + struct btrfs_ioctl_timespec rtime; + + /* Must be zero */ + __u64 reserved[8]; +}; + /* Error codes as returned by the kernel */ enum btrfs_err_code { BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET = 1, @@ -843,5 +903,7 @@ enum btrfs_err_code { struct btrfs_ioctl_vol_args_v2) #define BTRFS_IOC_LOGICAL_INO_V2 _IOWR(BTRFS_IOCTL_MAGIC, 59, \ struct btrfs_ioctl_logical_ino_args) +#define BTRFS_IOC_GET_SUBVOL_INFO _IOR(BTRFS_IOCTL_MAGIC, 60, \ + struct btrfs_ioctl_get_subvol_info_args) #endif /* _UAPI_LINUX_BTRFS_H */ -- cgit v1.2.3