[PATCH] block/blkio: use FUA flag on write zeroes only if supported

[PATCH] block/blkio: use FUA flag on write zeroes only if supported

[Stefano Garzarella]

libblkio supports BLKIO_REQ_FUA with write zeros requests only since
version 1.4.0, so let's inform the block layer that the blkio driver
supports it only in this case. Otherwise we can have runtime errors
as reported in https://issues.redhat.com/browse/RHEL-32878

Fixes: fd66dbd424 ("blkio: add libblkio block driver")
Cc: qemu-stable@nongnu.org
Buglink: https://issues.redhat.com/browse/RHEL-32878
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 meson.build   | 2 ++
 block/blkio.c | 6 ++++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/meson.build b/meson.build
index c2a050b844..81ecd4bae7 100644
--- a/meson.build
+++ b/meson.build
@@ -2305,6 +2305,8 @@ config_host_data.set('CONFIG_BLKIO', blkio.found())
 if blkio.found()
   config_host_data.set('CONFIG_BLKIO_VHOST_VDPA_FD',
                        blkio.version().version_compare('>=1.3.0'))
+  config_host_data.set('CONFIG_BLKIO_WRITE_ZEROS_FUA',
+                       blkio.version().version_compare('>=1.4.0'))
 endif
 config_host_data.set('CONFIG_CURL', curl.found())
 config_host_data.set('CONFIG_CURSES', curses.found())
diff --git a/block/blkio.c b/block/blkio.c
index 3d9a2e764c..e0e765af63 100644
--- a/block/blkio.c
+++ b/block/blkio.c
@@ -899,8 +899,10 @@ static int blkio_open(BlockDriverState *bs, QDict *options, int flags,
     }
 
     bs->supported_write_flags = BDRV_REQ_FUA | BDRV_REQ_REGISTERED_BUF;
-    bs->supported_zero_flags = BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP |
-                               BDRV_REQ_NO_FALLBACK;
+    bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK;
+#ifdef CONFIG_BLKIO_WRITE_ZEROS_FUA
+    bs->supported_zero_flags |= BDRV_REQ_FUA;
+#endif
 
     qemu_mutex_init(&s->blkio_lock);
     qemu_co_mutex_init(&s->bounce_lock);
-- 
2.45.2

Re: [PATCH] block/blkio: use FUA flag on write zeroes only if supported

[Eric Blake]

On Thu, Aug 08, 2024 at 10:05:45AM GMT, Stefano Garzarella wrote:
> libblkio supports BLKIO_REQ_FUA with write zeros requests only since
> version 1.4.0, so let's inform the block layer that the blkio driver
> supports it only in this case. Otherwise we can have runtime errors
> as reported in https://issues.redhat.com/browse/RHEL-32878
> 
> Fixes: fd66dbd424 ("blkio: add libblkio block driver")
> Cc: qemu-stable@nongnu.org
> Buglink: https://issues.redhat.com/browse/RHEL-32878
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
>  meson.build   | 2 ++
>  block/blkio.c | 6 ++++--
>  2 files changed, 6 insertions(+), 2 deletions(-)

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

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.
Virtualization:  qemu.org | libguestfs.org

Re: [PATCH] block/blkio: use FUA flag on write zeroes only if supported

[Philippe Mathieu-Daudé]

On 8/8/24 10:05, Stefano Garzarella wrote:
> libblkio supports BLKIO_REQ_FUA with write zeros requests only since
> version 1.4.0, so let's inform the block layer that the blkio driver
> supports it only in this case. Otherwise we can have runtime errors
> as reported in https://issues.redhat.com/browse/RHEL-32878
> 
> Fixes: fd66dbd424 ("blkio: add libblkio block driver")
> Cc: qemu-stable@nongnu.org
> Buglink: https://issues.redhat.com/browse/RHEL-32878
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
>   meson.build   | 2 ++
>   block/blkio.c | 6 ++++--
>   2 files changed, 6 insertions(+), 2 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH] block/blkio: use FUA flag on write zeroes only if supported

[Stefan Hajnoczi]

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On Thu, Aug 08, 2024 at 10:05:45AM +0200, Stefano Garzarella wrote:
> libblkio supports BLKIO_REQ_FUA with write zeros requests only since
> version 1.4.0, so let's inform the block layer that the blkio driver
> supports it only in this case. Otherwise we can have runtime errors
> as reported in https://issues.redhat.com/browse/RHEL-32878
> 
> Fixes: fd66dbd424 ("blkio: add libblkio block driver")
> Cc: qemu-stable@nongnu.org
> Buglink: https://issues.redhat.com/browse/RHEL-32878
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
>  meson.build   | 2 ++
>  block/blkio.c | 6 ++++--
>  2 files changed, 6 insertions(+), 2 deletions(-)

Thanks, applied to my block tree:
https://gitlab.com/stefanha/qemu/commits/block

Stefan

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