Re: [PATCH v2 2/8] linux-user: Add support for a group of btrfs ioctls used for snapshots

[Laurent Vivier]

Le 03/08/2020 à 11:46, 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>
> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
> ---
>  linux-user/ioctls.h       | 8 ++++++++
>  linux-user/syscall_defs.h | 2 ++
>  2 files changed, 10 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 67a3c110b6..16966c323f 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,\
> 

Applied to my linux-user-for-5.2 branch.

Thanks,
Laurent