From 40fdd783ec707e61c285e081816bd2df54dfede4 Mon Sep 17 00:00:00 2001

From: Filip Bozuta <Filip.Bozuta@syrmia.com>

Date: Thu, 3 Sep 2020 01:26:55 +0200

Subject: [PATCH 3/9] linux-user: Add support for a group of btrfs ioctls used

 for snapshots

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

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>

---

 linux-user/ioctls.h        | 8 ++++++++

 linux-user/syscall_defs.h  | 2 ++

 linux-user/syscall_types.h | 3 ++-

 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h

index 12d1444224..f33a99f8b6 100644

--- a/linux-user/ioctls.h

+++ b/linux-user/ioctls.h

@@ -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

diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h

index 2757956dfa..a945e12547 100644

--- a/linux-user/syscall_defs.h

+++ b/linux-user/syscall_defs.h

@@ -968,7 +968,9 @@ 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,\

diff --git a/linux-user/syscall_types.h b/linux-user/syscall_types.h

index db61dbc1b3..038cd7869b 100644

--- a/linux-user/syscall_types.h

+++ b/linux-user/syscall_types.h

@@ -354,7 +354,8 @@ 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 */

-- 

2.26.2