From a3f3c2cb19e33574f3566843cba7e3ad253dc9af Mon Sep 17 00:00:00 2001
From: Max Reitz <mreitz@redhat.com>
Date: Mon, 18 Jun 2018 16:12:08 +0200
Subject: [PATCH 041/268] block/quorum: Support BDRV_REQ_WRITE_UNCHANGED
RH-Author: Max Reitz <mreitz@redhat.com>
Message-id: <20180618161212.14444-7-mreitz@redhat.com>
Patchwork-id: 80770
O-Subject: [RHV-7.6 qemu-kvm-rhev PATCH 06/10] block/quorum: Support BDRV_REQ_WRITE_UNCHANGED
Bugzilla: 1518738
RH-Acked-by: John Snow <jsnow@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
We just need to forward it to quorum's children (except in case of a
rewrite because of corruption), but for that we first have to support
flags in child requests at all.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180421132929.21610-6-mreitz@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
(cherry picked from commit 1b1a920b713af6af795d49d0e3d2a8a65020bf82)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
block/quorum.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/block/quorum.c b/block/quorum.c
index f1f39ba..0d90a02 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -116,6 +116,7 @@ struct QuorumAIOCB {
/* Request metadata */
uint64_t offset;
uint64_t bytes;
+ int flags;
QEMUIOVector *qiov; /* calling IOV */
@@ -158,7 +159,8 @@ static bool quorum_64bits_compare(QuorumVoteValue *a, QuorumVoteValue *b)
static QuorumAIOCB *quorum_aio_get(BlockDriverState *bs,
QEMUIOVector *qiov,
uint64_t offset,
- uint64_t bytes)
+ uint64_t bytes,
+ int flags)
{
BDRVQuorumState *s = bs->opaque;
QuorumAIOCB *acb = g_new(QuorumAIOCB, 1);
@@ -169,6 +171,7 @@ static QuorumAIOCB *quorum_aio_get(BlockDriverState *bs,
.bs = bs,
.offset = offset,
.bytes = bytes,
+ .flags = flags,
.qiov = qiov,
.votes.compare = quorum_sha256_compare,
.votes.vote_list = QLIST_HEAD_INITIALIZER(acb.votes.vote_list),
@@ -272,9 +275,11 @@ static void quorum_rewrite_entry(void *opaque)
BDRVQuorumState *s = acb->bs->opaque;
/* Ignore any errors, it's just a correction attempt for already
- * corrupted data. */
+ * corrupted data.
+ * Mask out BDRV_REQ_WRITE_UNCHANGED because this overwrites the
+ * area with different data from the other children. */
bdrv_co_pwritev(s->children[co->idx], acb->offset, acb->bytes,
- acb->qiov, 0);
+ acb->qiov, acb->flags & ~BDRV_REQ_WRITE_UNCHANGED);
/* Wake up the caller after the last rewrite */
acb->rewrite_count--;
@@ -674,7 +679,7 @@ static int quorum_co_preadv(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, QEMUIOVector *qiov, int flags)
{
BDRVQuorumState *s = bs->opaque;
- QuorumAIOCB *acb = quorum_aio_get(bs, qiov, offset, bytes);
+ QuorumAIOCB *acb = quorum_aio_get(bs, qiov, offset, bytes, flags);
int ret;
acb->is_read = true;
@@ -700,7 +705,7 @@ static void write_quorum_entry(void *opaque)
sacb->bs = s->children[i]->bs;
sacb->ret = bdrv_co_pwritev(s->children[i], acb->offset, acb->bytes,
- acb->qiov, 0);
+ acb->qiov, acb->flags);
if (sacb->ret == 0) {
acb->success_count++;
} else {
@@ -720,7 +725,7 @@ static int quorum_co_pwritev(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, QEMUIOVector *qiov, int flags)
{
BDRVQuorumState *s = bs->opaque;
- QuorumAIOCB *acb = quorum_aio_get(bs, qiov, offset, bytes);
+ QuorumAIOCB *acb = quorum_aio_get(bs, qiov, offset, bytes, flags);
int i, ret;
for (i = 0; i < s->num_children; i++) {
@@ -962,6 +967,8 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
}
s->next_child_index = s->num_children;
+ bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
+
g_free(opened);
goto exit;
--
1.8.3.1