block: Forward 'discard' to temporary overlay

[Qemu-devel] [PATCH for-4.0] block: Forward 'discard' to temporary overlay

Posted by Kevin Wolf 5 years, 1 month ago

When bdrv_temp_snapshot_options() is called for snapshot=on, the
'discard' option in the options QDict hasn't been parsed and merged into
the flags yet. So copy the dict entry to make sure that the temporary
overlay enables discard when it was requested for the drive.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block.c b/block.c
index 3050854528..16615bc876 100644
--- a/block.c
+++ b/block.c
@@ -950,8 +950,9 @@ static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options,
     qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
     qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on");
 
-    /* Copy the read-only option from the parent */
+    /* Copy the read-only and discard options from the parent */
     qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
+    qdict_copy_default(child_options, parent_options, BDRV_OPT_DISCARD);
 
     /* aio=native doesn't work for cache.direct=off, so disable it for the
      * temporary snapshot */
-- 
2.20.1

Re: [Qemu-devel] [PATCH for-4.0] block: Forward 'discard' to temporary overlay

Posted by Eric Blake 5 years, 1 month ago

On 4/4/19 10:07 AM, Kevin Wolf wrote:
> When bdrv_temp_snapshot_options() is called for snapshot=on, the
> 'discard' option in the options QDict hasn't been parsed and merged into
> the flags yet. So copy the dict entry to make sure that the temporary
> overlay enables discard when it was requested for the drive.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

> 
> diff --git a/block.c b/block.c
> index 3050854528..16615bc876 100644
> --- a/block.c
> +++ b/block.c
> @@ -950,8 +950,9 @@ static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options,
>      qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
>      qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on");
>  
> -    /* Copy the read-only option from the parent */
> +    /* Copy the read-only and discard options from the parent */
>      qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
> +    qdict_copy_default(child_options, parent_options, BDRV_OPT_DISCARD);
>  
>      /* aio=native doesn't work for cache.direct=off, so disable it for the
>       * temporary snapshot */
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH for-4.0] block: Forward 'discard' to temporary overlay

Posted by Stefano Garzarella 5 years, 1 month ago

On Thu, Apr 04, 2019 at 05:07:46PM +0200, Kevin Wolf wrote:
> When bdrv_temp_snapshot_options() is called for snapshot=on, the
> 'discard' option in the options QDict hasn't been parsed and merged into
> the flags yet. So copy the dict entry to make sure that the temporary
> overlay enables discard when it was requested for the drive.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Re: [Qemu-devel] [Qemu-block] [PATCH for-4.0] block: Forward 'discard' to temporary overlay

Posted by Alberto Garcia 5 years, 1 month ago

On Thu 04 Apr 2019 05:07:46 PM CEST, Kevin Wolf wrote:
> When bdrv_temp_snapshot_options() is called for snapshot=on, the
> 'discard' option in the options QDict hasn't been parsed and merged into
> the flags yet. So copy the dict entry to make sure that the temporary
> overlay enables discard when it was requested for the drive.
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Reviewed-by: Alberto Garcia <berto@igalia.com>

Berto