block/quorum: Support BDRV_REQ_WRITE_UNCHANGED

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>
master
Max Reitz 2018-04-21 15:29:25 +02:00
parent 7adcf59fec
commit 1b1a920b71
1 changed files with 13 additions and 6 deletions

View File

@ -115,6 +115,7 @@ struct QuorumAIOCB {
/* Request metadata */
uint64_t offset;
uint64_t bytes;
int flags;
QEMUIOVector *qiov; /* calling IOV */
@ -157,7 +158,8 @@ 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);
@ -168,6 +170,7 @@ 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),
@ -271,9 +274,11 @@ 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--;
@ -673,7 +678,7 @@ 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;
@ -699,7 +704,7 @@ 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 {
@ -719,7 +724,7 @@ 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++) {
@ -961,6 +966,8 @@ 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;