From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43690) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VKPgv-0001wf-6Q for qemu-devel@nongnu.org; Fri, 13 Sep 2013 05:29:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VKPgm-0004S3-Ob for qemu-devel@nongnu.org; Fri, 13 Sep 2013 05:29:29 -0400 Received: from mx.ipv6.kamp.de ([2a02:248:0:51::16]:41617 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VKPgm-0004Rj-Dk for qemu-devel@nongnu.org; Fri, 13 Sep 2013 05:29:20 -0400 Message-ID: <5232DAE5.50201@kamp.de> Date: Fri, 13 Sep 2013 11:29:09 +0200 From: Peter Lieven MIME-Version: 1.0 References: <1378481953-23099-1-git-send-email-stefanha@redhat.com> <1378481953-23099-40-git-send-email-stefanha@redhat.com> <5232C61F.4010502@kamp.de> <5232D62A.2030506@dlhnet.de> <5232D679.90407@redhat.com> <5232D760.7000200@kamp.de> <5232D828.4010202@redhat.com> In-Reply-To: <5232D828.4010202@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PULL 39/42] block: look for zero blocks in bs->file List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Anthony Liguori , Peter Lieven , qemu-devel@nongnu.org, Stefan Hajnoczi On 13.09.2013 11:17, Paolo Bonzini wrote: > Il 13/09/2013 11:14, Peter Lieven ha scritto: >> On 13.09.2013 11:10, Paolo Bonzini wrote: >>> Il 13/09/2013 11:08, Peter Lieven ha scritto: >>>> On 13.09.2013 10:00, Peter Lieven wrote: >>>>> On 06.09.2013 17:39, Stefan Hajnoczi wrote: >>>>>> From: Paolo Bonzini >>>>>> >>>>>> Reviewed-by: Eric Blake >>>>>> Signed-off-by: Paolo Bonzini >>>>>> Signed-off-by: Stefan Hajnoczi >>>>>> --- >>>>>> block.c | 16 +++++++++++++++- >>>>>> 1 file changed, 15 insertions(+), 1 deletion(-) >>>>>> >>>>>> diff --git a/block.c b/block.c >>>>>> index 3c39769..a325efc 100644 >>>>>> --- a/block.c >>>>>> +++ b/block.c >>>>>> @@ -3075,7 +3075,7 @@ static int64_t coroutine_fn >>>>>> bdrv_co_get_block_status(BlockDriverState *bs, >>>>>> { >>>>>> int64_t length; >>>>>> int64_t n; >>>>>> - int64_t ret; >>>>>> + int64_t ret, ret2; >>>>>> length = bdrv_getlength(bs); >>>>>> if (length < 0) { >>>>>> @@ -3117,6 +3117,20 @@ static int64_t coroutine_fn >>>>>> bdrv_co_get_block_status(BlockDriverState *bs, >>>>>> } >>>>>> } >>>>>> } >>>>>> + >>>>>> + if (bs->file && >>>>>> + (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) && >>>>>> + (ret & BDRV_BLOCK_OFFSET_VALID)) { >>>>>> + ret2 = bdrv_co_get_block_status(bs->file, ret >> >>>>>> BDRV_SECTOR_BITS, >>>>>> + *pnum, pnum); >>>>>> + if (ret2 >= 0) { >>>>>> + /* Ignore errors. This is just providing extra >>>>>> information, it >>>>>> + * is useful but not necessary. >>>>>> + */ >>>>>> + ret |= (ret2 & BDRV_BLOCK_ZERO); >>>>>> + } >>>>>> + } >>>>>> + >>>>>> return ret; >>>>>> } >>>>> for allocated blocks in iscsi this actually leads to 2 call outs to >>>>> iscsi_get_block_status. >>>>> >>>>> because the raw driver passes the get_block_status request to bs->file. >>>>> >>>> correct patch? >>> Correct but a bit hackish... Stefan, Kevin, any ideas? >> add a BDRV_BLOCK_RAW flag to the get_block_status flags? > Perhaps, but then hide it so it's never returned by the block.c > bdrv_get_block_status API. or directly comparing if the bdrv->drv->format_name is "raw"... also hackish, but avoids iterating through all drivers. Peter