From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:60835) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UhFG5-0003uo-T2 for qemu-devel@nongnu.org; Tue, 28 May 2013 04:28:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UhFG2-0002j3-UA for qemu-devel@nongnu.org; Tue, 28 May 2013 04:27:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54603) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UhFG2-0002hr-JF for qemu-devel@nongnu.org; Tue, 28 May 2013 04:27:50 -0400 Date: Tue, 28 May 2013 10:27:43 +0200 From: Kevin Wolf Message-ID: <20130528082743.GC2854@dhcp-200-207.str.redhat.com> References: <1369729127-24499-1-git-send-email-afaerber@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <1369729127-24499-1-git-send-email-afaerber@suse.de> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] ide: Set BSY bit during FLUSH List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andreas =?iso-8859-1?Q?F=E4rber?= Cc: stefano.stabellini@eu.citrix.com, stefanha@gmail.com, Heiko Rommel , qemu-devel@nongnu.org, Bruce Rogers , arei.gonglei@huawei.com, pbonzini@redhat.com Am 28.05.2013 um 10:18 hat Andreas F=E4rber geschrieben: > The implementation of the ATA FLUSH command invokes a flush at the bloc= k > 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. >=20 > 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. >=20 > Addresses BNC#637297. >=20 > Suggested-by: Gonglei (Arei) > Signed-off-by: Andreas F=E4rber > --- > hw/ide/core.c | 3 +++ > 1 file changed, 3 insertions(+) >=20 > diff --git a/hw/ide/core.c b/hw/ide/core.c > index c7a8041..bf1ff18 100644 > --- a/hw/ide/core.c > +++ b/hw/ide/core.c > @@ -795,6 +795,8 @@ static void ide_flush_cb(void *opaque, int ret) > { > IDEState *s =3D opaque; > =20 > + s->status &=3D ~BUSY_STAT; > + This part is unnecessary, the status is already reset. > if (ret < 0) { > /* XXX: What sector number to set here? */ > if (ide_handle_rw_error(s, -ret, BM_STATUS_RETRY_FLUSH)) { > @@ -814,6 +816,7 @@ void ide_flush_cache(IDEState *s) > return; > } > =20 > + s->status |=3D BUSY_STAT; > bdrv_acct_start(s->bs, &s->acct, 0, BDRV_ACCT_FLUSH); > bdrv_aio_flush(s->bs, ide_flush_cb, s); > } This should fix the bug, however in an one-off way. I was planning to fix it by setting BSY for all commands and having an explicit command completion everywhere. This part is a mess currently in IDE. The other part why I haven't sent a fix yet is that I don't have a test case for it. I guess I need to extend blkdebug first before this can be reliably tested by qtest. Kevin