From: Andrey Shinkevich via <qemu-devel@nongnu.org>
To: 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,
vsementsov@virtuozzo.com, andrey.shinkevich@virtuozzo.com
Subject: [PATCH v10 5/9] copy-on-read: limit guest COR activity to base in COR driver
Date: Tue, 29 Sep 2020 15:38:25 +0300 [thread overview]
Message-ID: <1601383109-110988-6-git-send-email-andrey.shinkevich@virtuozzo.com> (raw)
In-Reply-To: <1601383109-110988-1-git-send-email-andrey.shinkevich@virtuozzo.com>
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 */
+ 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;
}
--
1.8.3.1
next prev parent reply other threads:[~2020-09-29 12:51 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 ` Andrey Shinkevich via [this message]
2020-10-05 14:58 ` [PATCH v10 5/9] copy-on-read: limit guest COR activity to base in " Vladimir Sementsov-Ogievskiy
2020-10-05 16:45 ` Andrey Shinkevich
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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