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[Qemu-devel] [PULL 06/48] mirror: Error out when a BDS would get two BBs
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 06/48] mirror: Error out when a BDS would get two BBs |
Date: |
Fri, 18 Dec 2015 16:07:12 +0100 |
bdrv_replace_in_backing_chain() asserts that not both old and new
BlockDdriverState have a BlockBackend attached to them because both
would have to end up pointing to the new BDS and we don't support more
than one BB per BDS yet.
Before we can safely allow references to existing nodes as backing
files, we need to make sure that even if a backing file has a BB on it,
this doesn't crash qemu.
There are probably also some cases with the 'replaces' option set where
drive-mirror could fail this assertion today. They are fixed with this
error check as well.
Signed-off-by: Kevin Wolf <address@hidden>
Reviewed-by: Max Reitz <address@hidden>
---
block/mirror.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/block/mirror.c b/block/mirror.c
index 0e8f556..8e3f524 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -18,6 +18,7 @@
#include "qapi/qmp/qerror.h"
#include "qemu/ratelimit.h"
#include "qemu/bitmap.h"
+#include "qemu/error-report.h"
#define SLICE_TIME 100000000ULL /* ns */
#define MAX_IN_FLIGHT 16
@@ -370,11 +371,22 @@ static void mirror_exit(BlockJob *job, void *opaque)
if (s->to_replace) {
to_replace = s->to_replace;
}
+
+ /* This was checked in mirror_start_job(), but meanwhile one of the
+ * nodes could have been newly attached to a BlockBackend. */
+ if (to_replace->blk && s->target->blk) {
+ error_report("block job: Can't create node with two
BlockBackends");
+ data->ret = -EINVAL;
+ goto out;
+ }
+
if (bdrv_get_flags(s->target) != bdrv_get_flags(to_replace)) {
bdrv_reopen(s->target, bdrv_get_flags(to_replace), NULL);
}
bdrv_replace_in_backing_chain(to_replace, s->target);
}
+
+out:
if (s->to_replace) {
bdrv_op_unblock_all(s->to_replace, s->replace_blocker);
error_free(s->replace_blocker);
@@ -705,6 +717,7 @@ static void mirror_start_job(BlockDriverState *bs,
BlockDriverState *target,
bool is_none_mode, BlockDriverState *base)
{
MirrorBlockJob *s;
+ BlockDriverState *replaced_bs;
if (granularity == 0) {
granularity = bdrv_get_default_bitmap_granularity(target);
@@ -728,6 +741,21 @@ static void mirror_start_job(BlockDriverState *bs,
BlockDriverState *target,
buf_size = DEFAULT_MIRROR_BUF_SIZE;
}
+ /* We can't support this case as long as the block layer can't handle
+ * multiple BlockBackends per BlockDriverState. */
+ if (replaces) {
+ replaced_bs = bdrv_lookup_bs(replaces, replaces, errp);
+ if (replaced_bs == NULL) {
+ return;
+ }
+ } else {
+ replaced_bs = bs;
+ }
+ if (replaced_bs->blk && target->blk) {
+ error_setg(errp, "Can't create node with two BlockBackends");
+ return;
+ }
+
s = block_job_create(driver, bs, speed, cb, opaque, errp);
if (!s) {
return;
--
1.8.3.1
- [Qemu-devel] [PULL 23/48] qemu-iotests: Test cache mode option inheritance, (continued)
- [Qemu-devel] [PULL 23/48] qemu-iotests: Test cache mode option inheritance, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 32/48] qcow2: Invoke refcount order amendment function, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 42/48] qemu-iotests: s390x: fix test 051, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 02/48] iotests: 124: move incremental failure test, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 01/48] iotests: 124: Split into two test classes, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 47/48] qemu-img: abort when full_backing_filename not present, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 28/48] qcow2: Use abort() instead of assert(false), Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 21/48] blkdebug: Enable reopen, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 05/48] block: Fix reopen with semantically overlapping options, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 43/48] qemu-iotests: s390x: fix test 068, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 06/48] mirror: Error out when a BDS would get two BBs,
Kevin Wolf <=
- [Qemu-devel] [PULL 34/48] iotests: Extend test 112 for qemu-img amend, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 07/48] block: Allow references for backing files, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 27/48] qcow2: Use error_report() in qcow2_amend_options(), Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 36/48] raw-posix: Make aio=native option binding, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 13/48] block: reopen: Document option precedence and refactor accordingly, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 18/48] qemu-iotests: Remove cache mode test without medium, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 25/48] progress: Allow regressing progress, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 08/48] block: Consider all block layer options in append_open_options, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 22/48] qemu-iotests: Try setting cache mode for children, Kevin Wolf, 2015/12/18
- [Qemu-devel] [PULL 04/48] qcow2: Add .bdrv_join_options callback, Kevin Wolf, 2015/12/18