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From: Alberto Garcia <berto@igalia.com>
To: Max Reitz <mreitz@redhat.com>, qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Nir Soffer <nsoffer@redhat.com>,
	qemu-block@nongnu.org
Subject: Re: [PATCH v2 4/4] qcow2: Use BDRV_SECTOR_SIZE instead of the hardcoded value
Date: Sat, 18 Jan 2020 19:07:49 +0100	[thread overview]
Message-ID: <w51muak3afe.fsf@maestria.local.igalia.com> (raw)
In-Reply-To: <02552511-6fcf-d678-362c-707ce6d73659@redhat.com>

On Tue 14 Jan 2020 03:15:48 PM CET, Max Reitz <mreitz@redhat.com> wrote:
>> @@ -3836,7 +3837,7 @@ qcow2_co_copy_range_from(BlockDriverState *bs,
>>          case QCOW2_CLUSTER_NORMAL:
>>              child = s->data_file;
>>              copy_offset += offset_into_cluster(s, src_offset);
>> -            if ((copy_offset & 511) != 0) {
>> +            if (!QEMU_IS_ALIGNED(copy_offset, BDRV_SECTOR_SIZE)) {
>
> Hm.  I don’t get this one.

Ok, this came with Fam's "qemu-img convert with copy offloading" series:

   https://lists.gnu.org/archive/html/qemu-block/2018-06/msg00015.html

and qemu-img uses sectors here:

   blk_co_copy_range(..., sector_num << BDRV_SECTOR_BITS,
                     n << BDRV_SECTOR_BITS, ...)

so I guess that's why the check is there. Again, I think this should be
bl.request_alignment, because as far as I can tell copy_file_range()
works just fine unless O_DIRECT is used.

Berto


      parent reply	other threads:[~2020-01-18 18:08 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-09 19:12 [PATCH v2 0/4] qcow2: Misc BDRV_SECTOR_SIZE updates Alberto Garcia
2020-01-09 19:12 ` [PATCH v2 1/4] qcow2: Require that the virtual size is a multiple of the sector size Alberto Garcia
2020-01-14 13:01   ` Max Reitz
2020-01-14 13:20     ` Alberto Garcia
2020-01-14 13:47       ` Max Reitz
2020-01-14 13:58         ` Alberto Garcia
2020-01-14 14:03           ` Max Reitz
2020-01-16 14:24             ` Alberto Garcia
2020-01-09 19:13 ` [PATCH v2 2/4] qcow2: Don't round the L1 table allocation up to " Alberto Garcia
2020-01-14 13:46   ` Max Reitz
2020-01-09 19:13 ` [PATCH v2 3/4] qcow2: Tighten cluster_offset alignment assertions Alberto Garcia
2020-01-10 12:14   ` Alberto Garcia
2020-01-14 13:58     ` Max Reitz
2020-01-14 13:56   ` Max Reitz
2020-01-09 19:13 ` [PATCH v2 4/4] qcow2: Use BDRV_SECTOR_SIZE instead of the hardcoded value Alberto Garcia
2020-01-14 14:15   ` Max Reitz
2020-01-16 23:26     ` Alberto Garcia
2020-01-17  9:12       ` Max Reitz
2020-01-17  9:55         ` Kevin Wolf
2020-01-17 11:01           ` Max Reitz
2020-01-17 11:51             ` Kevin Wolf
2020-01-17 14:34               ` Alberto Garcia
2020-01-18 18:07     ` Alberto Garcia [this message]

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