qemu-kvm/SOURCES/kvm-block-mirror-conservative-mirror_exit-refactor.patch

142 lines
4.9 KiB
Diff

From 6b97fd0b69ecf0e1bebafa6bc607ae60b9ab252e Mon Sep 17 00:00:00 2001
From: John Snow <jsnow@redhat.com>
Date: Tue, 25 Sep 2018 22:34:21 +0100
Subject: [PATCH 18/28] block/mirror: conservative mirror_exit refactor
RH-Author: John Snow <jsnow@redhat.com>
Message-id: <20180925223431.24791-16-jsnow@redhat.com>
Patchwork-id: 82270
O-Subject: [RHEL8/rhel qemu-kvm PATCH 15/25] block/mirror: conservative mirror_exit refactor
Bugzilla: 1632939
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
For purposes of minimum code movement, refactor the mirror_exit
callback to use the post-finalization callbacks in a trivial way.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20180906130225.5118-7-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
[mreitz: Added comment for the mirror_exit() function]
Signed-off-by: Max Reitz <mreitz@redhat.com>
(cherry picked from commit 737efc1eda23b904fbe0e66b37715fb0e5c3e58b)
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
Conflicts:
block/mirror.c: context conflict on job properties
---
block/mirror.c | 44 +++++++++++++++++++++++++++++++++-----------
1 file changed, 33 insertions(+), 11 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index 057db7c..163b1d4 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -71,6 +71,7 @@ typedef struct MirrorBlockJob {
int target_cluster_size;
int max_iov;
bool initial_zeroing_ongoing;
+ bool prepared;
} MirrorBlockJob;
typedef struct MirrorOp {
@@ -480,7 +481,12 @@ static void mirror_wait_for_all_io(MirrorBlockJob *s)
}
}
-static void mirror_exit(Job *job)
+/**
+ * mirror_exit_common: handle both abort() and prepare() cases.
+ * for .prepare, returns 0 on success and -errno on failure.
+ * for .abort cases, denoted by abort = true, MUST return 0.
+ */
+static int mirror_exit_common(Job *job)
{
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);
BlockJob *bjob = &s->common;
@@ -489,7 +495,13 @@ static void mirror_exit(Job *job)
BlockDriverState *target_bs = blk_bs(s->target);
BlockDriverState *mirror_top_bs = s->mirror_top_bs;
Error *local_err = NULL;
- int ret = job->ret;
+ bool abort = job->ret < 0;
+ int ret = 0;
+
+ if (s->prepared) {
+ return 0;
+ }
+ s->prepared = true;
bdrv_release_dirty_bitmap(src, s->dirty_bitmap);
@@ -514,7 +526,7 @@ static void mirror_exit(Job *job)
* required before it could become a backing file of target_bs. */
bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL,
&error_abort);
- if (ret == 0 && s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) {
+ if (!abort && s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) {
BlockDriverState *backing = s->is_none_mode ? src : s->base;
if (backing_bs(target_bs) != backing) {
bdrv_set_backing_hd(target_bs, backing, &local_err);
@@ -530,11 +542,8 @@ static void mirror_exit(Job *job)
aio_context_acquire(replace_aio_context);
}
- if (s->should_complete && ret == 0) {
- BlockDriverState *to_replace = src;
- if (s->to_replace) {
- to_replace = s->to_replace;
- }
+ if (s->should_complete && !abort) {
+ BlockDriverState *to_replace = s->to_replace ?: src;
if (bdrv_get_flags(target_bs) != bdrv_get_flags(to_replace)) {
bdrv_reopen(target_bs, bdrv_get_flags(to_replace), NULL);
@@ -581,7 +590,18 @@ static void mirror_exit(Job *job)
bdrv_unref(mirror_top_bs);
bdrv_unref(src);
- job->ret = ret;
+ return ret;
+}
+
+static int mirror_prepare(Job *job)
+{
+ return mirror_exit_common(job);
+}
+
+static void mirror_abort(Job *job)
+{
+ int ret = mirror_exit_common(job);
+ assert(ret == 0);
}
static void mirror_throttle(MirrorBlockJob *s)
@@ -986,7 +1006,8 @@ static const BlockJobDriver mirror_job_driver = {
.user_resume = block_job_user_resume,
.drain = block_job_drain,
.run = mirror_run,
- .exit = mirror_exit,
+ .prepare = mirror_prepare,
+ .abort = mirror_abort,
.pause = mirror_pause,
.complete = mirror_complete,
},
@@ -1002,7 +1023,8 @@ static const BlockJobDriver commit_active_job_driver = {
.user_resume = block_job_user_resume,
.drain = block_job_drain,
.run = mirror_run,
- .exit = mirror_exit,
+ .prepare = mirror_prepare,
+ .abort = mirror_abort,
.pause = mirror_pause,
.complete = mirror_complete,
},
--
1.8.3.1