linux-user: Add support for a group of btrfs ioctls used for snapshots

This patch implements functionality for following ioctls:

BTRFS_IOC_SNAP_CREATE - Creating a subvolume snapshot

    Create a snapshot of a btrfs subvolume. The snapshot is created using the
    ioctl's third argument that is a pointer to a 'struct btrfs_ioctl_vol_args'
    (which was mentioned in the previous patch). Before calling this ioctl,
    the fields of the structure should be filled with aproppriate values for
    the file descriptor and path of the subvolume for which the snapshot is to
    be created.

BTRFS_IOC_SNAP_DESTROY - Removing a subvolume snapshot

    Delete a snapshot of a btrfs subvolume. The snapshot is deleted using the
    ioctl's third argument that is a pointer to a 'struct btrfs_ioctl_vol_args'
    (which was mentioned in the previous patch). Before calling this ioctl,
    the fields of the structure should be filled with aproppriate values for
    the file descriptor and path of the subvolume for which the snapshot is to
    be deleted.

Implementation notes:

    Since the thunk type 'struct btrfs_ioctl_vol_args' is defined in the
    previous patch, the implementation for these ioctls was straightforward.

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Tested-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200823195014.116226-3-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
master
Filip Bozuta 2020-08-23 21:50:08 +02:00 committed by Laurent Vivier
parent d6092e085d
commit 527e8d8fe0
3 changed files with 12 additions and 1 deletions

View File

@ -174,10 +174,18 @@
IOCTL(FS_IOC32_GETVERSION, IOC_R, MK_PTR(TYPE_INT))
IOCTL(FS_IOC32_SETVERSION, IOC_W, MK_PTR(TYPE_INT))
#ifdef BTRFS_IOC_SNAP_CREATE
IOCTL(BTRFS_IOC_SNAP_CREATE, IOC_W,
MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_vol_args)))
#endif
#ifdef BTRFS_IOC_SUBVOL_CREATE
IOCTL(BTRFS_IOC_SUBVOL_CREATE, IOC_W,
MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_vol_args)))
#endif
#ifdef BTRFS_IOC_SNAP_DESTROY
IOCTL(BTRFS_IOC_SNAP_DESTROY, IOC_W,
MK_PTR(MK_STRUCT(STRUCT_btrfs_ioctl_vol_args)))
#endif
#ifdef BTRFS_IOC_SUBVOL_GETFLAGS
IOCTL(BTRFS_IOC_SUBVOL_GETFLAGS, IOC_R, MK_PTR(TYPE_ULONGLONG))
#endif

View File

@ -1006,7 +1006,9 @@ struct target_rtc_pll_info {
#define TARGET_FS_IOC32_SETVERSION TARGET_IOW('v', 2, int)
/* btrfs ioctls */
#define TARGET_BTRFS_IOC_SNAP_CREATE TARGET_IOWU(BTRFS_IOCTL_MAGIC, 1)
#define TARGET_BTRFS_IOC_SUBVOL_CREATE TARGET_IOWU(BTRFS_IOCTL_MAGIC, 14)
#define TARGET_BTRFS_IOC_SNAP_DESTROY TARGET_IOWU(BTRFS_IOCTL_MAGIC, 15)
#define TARGET_BTRFS_IOC_SUBVOL_GETFLAGS TARGET_IOR(BTRFS_IOCTL_MAGIC, 25,\
abi_ullong)
#define TARGET_BTRFS_IOC_SUBVOL_SETFLAGS TARGET_IOW(BTRFS_IOCTL_MAGIC, 26,\

View File

@ -358,7 +358,8 @@ STRUCT(blkpg_partition,
MK_ARRAY(TYPE_CHAR, BLKPG_DEVNAMELTH), /* devname */
MK_ARRAY(TYPE_CHAR, BLKPG_VOLNAMELTH)) /* volname */
#ifdef BTRFS_IOC_SUBVOL_CREATE
#if defined(BTRFS_IOC_SUBVOL_CREATE) || defined(BTRFS_IOC_SNAP_CREATE) || \
defined(BTRFS_IOC_SNAP_DESTROY)
STRUCT(btrfs_ioctl_vol_args,
TYPE_LONGLONG, /* fd */
MK_ARRAY(TYPE_CHAR, BTRFS_PATH_NAME_MAX + 1)) /* name */