Re: [PATCH 2/4] linux-user: Add support for a group of btrfs ioctls used for snapshots

[Laurent Vivier <laurent@vivier.eu>]

Le 09/07/2020 à 17:52, Filip Bozuta a écrit :
> 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>
> ---
>  linux-user/ioctls.h       | 8 ++++++++
>  linux-user/syscall_defs.h | 4 ++++
>  2 files changed, 12 insertions(+)
> 
> diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h
> index 544184ff95..2422675dd0 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 c11bcc6ba9..21d8909fd6 100644
> --- a/linux-user/syscall_defs.h
> +++ b/linux-user/syscall_defs.h
> @@ -968,8 +968,12 @@ struct target_rtc_pll_info {
>  #define TARGET_FS_IOC32_SETVERSION TARGET_IOW('v', 2, int)
>  
>  /* btrfs ioctls */
> +#define TARGET_BTRFS_IOC_SNAP_CREATE            TARGET_IOW(BTRFS_IOCTL_MAGIC, \
> +                                                1, struct btrfs_ioctl_vol_args)
>  #define TARGET_BTRFS_IOC_SUBVOL_CREATE          TARGET_IOW(BTRFS_IOCTL_MAGIC, \
>                                                 14, struct btrfs_ioctl_vol_args)
> +#define TARGET_BTRFS_IOC_SNAP_DESTROY           TARGET_IOW(BTRFS_IOCTL_MAGIC, \
> +                                               15, struct btrfs_ioctl_vol_args)
>  #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, \
> 

Like for patch 1, use TARGET_IOWU().

with that changed:
Reviewed-by: Laurent Vivier <laurent@vivier.eu>

Thanks,
Laurent