From: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
qemu-block@nongnu.org
Cc: qemu-devel@nongnu.org, kwolf@redhat.com, mreitz@redhat.com,
stefanha@redhat.com, fam@euphon.net, jsnow@redhat.com,
armbru@redhat.com, eblake@redhat.com, den@openvz.org
Subject: Re: [PATCH v10 5/9] copy-on-read: limit guest COR activity to base in COR driver
Date: Mon, 5 Oct 2020 19:45:51 +0300 [thread overview]
Message-ID: <d2e965a0-8b21-c8fe-1c91-f545177369a0@virtuozzo.com> (raw)
In-Reply-To: <ab11d5f1-0832-ced7-cee7-c791d65b7131@virtuozzo.com>
On 05.10.2020 17:58, Vladimir Sementsov-Ogievskiy wrote:
> 29.09.2020 15:38, Andrey Shinkevich wrote:
>> Limit the guest's COR operations by the base node in the backing chain
>> when the base node name is given. It will be useful for a block stream
>> job when the COR-filter is applied.
>>
>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
>> ---
>> block/copy-on-read.c | 38 ++++++++++++++++++++++++++++++++++++--
>> 1 file changed, 36 insertions(+), 2 deletions(-)
>>
>> diff --git a/block/copy-on-read.c b/block/copy-on-read.c
>> index e04092f..f53f7e0 100644
>> --- a/block/copy-on-read.c
>> +++ b/block/copy-on-read.c
>> @@ -121,8 +121,42 @@ static int coroutine_fn
>> cor_co_preadv_part(BlockDriverState *bs,
>> size_t qiov_offset,
>> int flags)
>> {
>> - return bdrv_co_preadv_part(bs->file, offset, bytes, qiov,
>> qiov_offset,
>> - flags | BDRV_REQ_COPY_ON_READ);
>> + int64_t n = 0;
>> + int64_t size = offset + bytes;
>> + int local_flags;
>> + int ret;
>> + BDRVStateCOR *state = bs->opaque;
>> +
>> + if (!state->base_bs) {
>> + return bdrv_co_preadv_part(bs->file, offset, bytes, qiov,
>> qiov_offset,
>> + flags | BDRV_REQ_COPY_ON_READ);
>> + }
>> +
>> + while (offset < size) {
>> + local_flags = flags;
>> +
>> + /* In case of failure, try to copy-on-read anyway */
>
> But you add the flag only in case of success.. On any failure of furhter
> is*allocated calls we should set the flag.
Yes, thanks.
Andrey
>
>> + ret = bdrv_is_allocated(bs->file->bs, offset, bytes, &n);
>> + if (!ret) {
>> + ret = bdrv_is_allocated_above(bdrv_cow_bs(bs->file->bs),
>> + state->base_bs, false,
>> offset, n, &n);
>> + if (ret > 0) {
>> + local_flags |= BDRV_REQ_COPY_ON_READ;
>> + }
>> + }
>> +
>> + ret = bdrv_co_preadv_part(bs->file, offset, n, qiov,
>> qiov_offset,
>> + local_flags);
>> + if (ret < 0) {
>> + return ret;
>> + }
>> +
>> + offset += n;
>> + qiov_offset += n;
>> + bytes -= n;
>> + }
>> +
>> + return 0;
>> }
>>
>
>
next prev parent reply other threads:[~2020-10-05 16:47 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-29 12:38 [PATCH v10 0/9] Apply COR-filter to the block-stream permanently Andrey Shinkevich via
2020-09-29 12:38 ` [PATCH v10 1/9] copy-on-read: Support preadv/pwritev_part functions Andrey Shinkevich via
2020-09-29 12:38 ` [PATCH v10 2/9] copy-on-read: add filter append/drop functions Andrey Shinkevich via
2020-10-05 13:34 ` Vladimir Sementsov-Ogievskiy
2020-10-05 16:23 ` Andrey Shinkevich
2020-09-29 12:38 ` [PATCH v10 3/9] qapi: add filter-node-name to block-stream Andrey Shinkevich via
2020-09-29 12:38 ` [PATCH v10 4/9] copy-on-read: pass base node name to COR driver Andrey Shinkevich via
2020-10-05 14:50 ` Vladimir Sementsov-Ogievskiy
2020-09-29 12:38 ` [PATCH v10 5/9] copy-on-read: limit guest COR activity to base in " Andrey Shinkevich via
2020-10-05 14:58 ` Vladimir Sementsov-Ogievskiy
2020-10-05 16:45 ` Andrey Shinkevich [this message]
2020-10-05 18:18 ` Andrey Shinkevich
2020-09-29 12:38 ` [PATCH v10 6/9] copy-on-read: skip non-guest reads if no copy needed Andrey Shinkevich via
2020-10-07 10:06 ` Vladimir Sementsov-Ogievskiy
2020-10-07 19:01 ` Andrey Shinkevich
2020-10-07 19:28 ` Vladimir Sementsov-Ogievskiy
2020-10-09 12:56 ` Andrey Shinkevich
2020-09-29 12:38 ` [PATCH v10 7/9] stream: skip filters when writing backing file name to QCOW2 header Andrey Shinkevich via
2020-10-07 10:14 ` Vladimir Sementsov-Ogievskiy
2020-09-29 12:38 ` [PATCH v10 8/9] block: remove unused backing-file name parameter Andrey Shinkevich via
2020-10-07 10:21 ` Vladimir Sementsov-Ogievskiy
2020-10-07 19:32 ` Andrey Shinkevich
2020-09-29 12:38 ` [PATCH v10 9/9] block: apply COR-filter to block-stream jobs Andrey Shinkevich via
2020-10-07 17:27 ` Andrey Shinkevich
2020-10-07 17:39 ` Andrey Shinkevich
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