From 34e748aa7dc2215fd2d8f03e491f1a2a450ba5d0 Mon Sep 17 00:00:00 2001

From: Max Reitz <mreitz@redhat.com>

Date: Mon, 18 Jun 2018 16:12:08 +0200

Subject: [PATCH 32/54] 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