diff mbox

[PULL,20/26] ide: Set BSY bit during FLUSH

Message ID 1370606325-10680-21-git-send-email-stefanha@redhat.com
State New
Headers show

Commit Message

Stefan Hajnoczi June 7, 2013, 11:58 a.m. UTC 
From: Andreas Färber <afaerber@suse.de>

The implementation of the ATA FLUSH command invokes a flush at the block
layer, which may on raw files on POSIX entail a synchronous fdatasync().
This may in some cases take so long that the SLES 11 SP1 guest driver
reports I/O errors and filesystems get corrupted or remounted read-only.

Avoid this by setting BUSY_STAT, so that the guest is made aware we are
in the middle of an operation and no ATA commands are attempted to be
processed concurrently.

Addresses BNC#637297.

Suggested-by: Gonglei (Arei) <arei.gonglei@huawei.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/ide/core.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Paolo Bonzini June 7, 2013, 12:10 p.m. UTC | #1 
Il 07/06/2013 07:58, Stefan Hajnoczi ha scritto:
> From: Andreas Färber <afaerber@suse.de>
> 
> The implementation of the ATA FLUSH command invokes a flush at the block
> layer, which may on raw files on POSIX entail a synchronous fdatasync().
> This may in some cases take so long that the SLES 11 SP1 guest driver
> reports I/O errors and filesystems get corrupted or remounted read-only.
> 
> Avoid this by setting BUSY_STAT, so that the guest is made aware we are
> in the middle of an operation and no ATA commands are attempted to be
> processed concurrently.
> 
> Addresses BNC#637297.
> 
> Suggested-by: Gonglei (Arei) <arei.gonglei@huawei.com>
> Signed-off-by: Andreas Färber <afaerber@suse.de>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  hw/ide/core.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/ide/core.c b/hw/ide/core.c
> index c7a8041..9926d92 100644
> --- a/hw/ide/core.c
> +++ b/hw/ide/core.c
> @@ -814,6 +814,7 @@ void ide_flush_cache(IDEState *s)
>          return;
>      }
>  
> +    s->status |= BUSY_STAT;
>      bdrv_acct_start(s->bs, &s->acct, 0, BDRV_ACCT_FLUSH);
>      bdrv_aio_flush(s->bs, ide_flush_cb, s);
>  }
> 

Cc: qemu-stable@nongnu.org
diff mbox

Patch

diff --git a/hw/ide/core.c b/hw/ide/core.c
index c7a8041..9926d92 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -814,6 +814,7 @@  void ide_flush_cache(IDEState *s)
         return;
     }
 
+    s->status |= BUSY_STAT;
     bdrv_acct_start(s->bs, &s->acct, 0, BDRV_ACCT_FLUSH);
     bdrv_aio_flush(s->bs, ide_flush_cb, s);
 }