diff mbox series

[20/21] parallels: naive implementation of parallels_co_pwrite_zeroes

Message ID 20230915184130.403366-23-den@openvz.org
State New
Headers show
Series implement discard operation for Parallels images | expand

Commit Message

Denis V. Lunev Sept. 15, 2023, 6:41 p.m. UTC 
The zero flag is missed in the Parallels format specification. We can
resort to discard if we have no backing file.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 block/parallels.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Comments

Alexander Ivanov Sept. 18, 2023, 3:10 p.m. UTC | #1 
On 9/15/23 20:41, Denis V. Lunev wrote:
> The zero flag is missed in the Parallels format specification. We can
> resort to discard if we have no backing file.
>
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> ---
>   block/parallels.c | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
>
> diff --git a/block/parallels.c b/block/parallels.c
> index 83cb8d6722..a098e2cbc2 100644
> --- a/block/parallels.c
> +++ b/block/parallels.c
> @@ -583,6 +583,19 @@ done:
>       return ret;
>   }
>   
> +static int coroutine_fn GRAPH_RDLOCK
> +parallels_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
> +                           BdrvRequestFlags flags)
> +{
> +    /*
> +     * The zero flag is missed in the Parallels format specification. We can
> +     * resort to discard if we have no backing file (this condition is checked
> +     * inside parallels_co_pdiscard().
> +     */
> +    return parallels_co_pdiscard(bs, offset, bytes);
> +}
> +
> +
>   static void parallels_check_unclean(BlockDriverState *bs,
>                                       BdrvCheckResult *res,
>                                       BdrvCheckMode fix)
> @@ -1456,6 +1469,7 @@ static BlockDriver bdrv_parallels = {
>       .bdrv_co_create_opts        = parallels_co_create_opts,
>       .bdrv_co_check              = parallels_co_check,
>       .bdrv_co_pdiscard           = parallels_co_pdiscard,
> +    .bdrv_co_pwrite_zeroes      = parallels_co_pwrite_zeroes,
>   };
>   
>   static void bdrv_parallels_init(void)

Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
diff mbox series

Patch

diff --git a/block/parallels.c b/block/parallels.c
index 83cb8d6722..a098e2cbc2 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -583,6 +583,19 @@  done:
     return ret;
 }
 
+static int coroutine_fn GRAPH_RDLOCK
+parallels_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                           BdrvRequestFlags flags)
+{
+    /*
+     * The zero flag is missed in the Parallels format specification. We can
+     * resort to discard if we have no backing file (this condition is checked
+     * inside parallels_co_pdiscard().
+     */
+    return parallels_co_pdiscard(bs, offset, bytes);
+}
+
+
 static void parallels_check_unclean(BlockDriverState *bs,
                                     BdrvCheckResult *res,
                                     BdrvCheckMode fix)
@@ -1456,6 +1469,7 @@  static BlockDriver bdrv_parallels = {
     .bdrv_co_create_opts        = parallels_co_create_opts,
     .bdrv_co_check              = parallels_co_check,
     .bdrv_co_pdiscard           = parallels_co_pdiscard,
+    .bdrv_co_pwrite_zeroes      = parallels_co_pwrite_zeroes,
 };
 
 static void bdrv_parallels_init(void)