ide: Set BSY bit during FLUSH

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>
(cherry picked from commit f68ec8379e88502b4841a110c070e9b118d3151c)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/hw/ide/core.c b/hw/ide/core.c
index c7a80413be5fe90433d39e339faa3e0645c968f8..9926d9202bc88a72d856acc82d1f39f9db73d192 100644 (file)
--- 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);
 }