What about this? Is it simple enough for you keeping lock around
qemu_fopen_bdrv/qemu_fclose as suggested in patch 1?
This is not tested at all, just sent as an idea for a discussion.
Signed-off-by: Denis V. Lunev <d...@openvz.org>
CC: Stefan Hajnoczi <stefa...@redhat.com>
CC: Juan Quintela <quint...@redhat.com>
---
block.c | 17 +++++++++++++++++
include/block/block.h | 2 ++
migration/savevm.c | 23 +++++++++++++++--------
monitor.c | 2 +-
4 files changed, 35 insertions(+), 9 deletions(-)
diff --git a/block.c b/block.c
index 044897e..d376ec2 100644
--- a/block.c
+++ b/block.c
@@ -2741,6 +2741,23 @@ BlockDriverState *bdrv_next(BlockDriverState *bs)
return QTAILQ_NEXT(bs, device_list);
}
+BlockDriverState *bdrv_next_lock(BlockDriverState *bs)
+{
+ if (bs != NULL) {
+ aio_context_release(bdrv_get_aio_context(bs));
+ }
+ bs = bdrv_next(bs);
+ if (bs != NULL) {
+ aio_context_acquire(bdrv_get_aio_context(bs));
+ }
+ return bs;
+}
+
+void bdrv_unlock(BlockDriverState *bs)
+{
+ aio_context_release(bdrv_get_aio_context(bs));
+}
+
const char *bdrv_get_node_name(const BlockDriverState *bs)
{
return bs->node_name;
diff --git a/include/block/block.h b/include/block/block.h
index 610db92..b29dd5b 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -401,6 +401,8 @@ BlockDriverState *bdrv_lookup_bs(const char *device,
bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
BlockDriverState *bdrv_next_node(BlockDriverState *bs);
BlockDriverState *bdrv_next(BlockDriverState *bs);
+BlockDriverState *bdrv_next_lock(BlockDriverState *bs);
+void bdrv_unlock(BlockDriverState *bs);
int bdrv_is_encrypted(BlockDriverState *bs);
int bdrv_key_required(BlockDriverState *bs);
int bdrv_set_key(BlockDriverState *bs, const char *key);
diff --git a/migration/savevm.c b/migration/savevm.c
index dbcc39a..cf06a10 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1240,8 +1240,9 @@ out:
static BlockDriverState *find_vmstate_bs(void)
{
BlockDriverState *bs = NULL;
- while ((bs = bdrv_next(bs))) {
+ while ((bs = bdrv_next_lock(bs))) {
if (bdrv_can_snapshot(bs)) {
+ bdrv_unlock(bs);
return bs;
}
}
@@ -1258,11 +1259,12 @@ static int del_existing_snapshots(Monitor *mon, const
char *name)
Error *err = NULL;
bs = NULL;
- while ((bs = bdrv_next(bs))) {
+ while ((bs = bdrv_next_lock(bs))) {
if (bdrv_can_snapshot(bs) &&
bdrv_snapshot_find(bs, snapshot, name) >= 0) {
bdrv_snapshot_delete_by_id_or_name(bs, name, &err);
if (err) {
+ bdrv_unlock(bs);
monitor_printf(mon,
"Error while deleting snapshot on device '%s':"
" %s\n",
@@ -1292,13 +1294,14 @@ void hmp_savevm(Monitor *mon, const QDict *qdict)
/* Verify if there is a device that doesn't support snapshots and is
writable */
bs = NULL;
- while ((bs = bdrv_next(bs))) {
+ while ((bs = bdrv_next_lock(bs))) {
if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
continue;
}
if (!bdrv_can_snapshot(bs)) {
+ bdrv_unlock(bs);
monitor_printf(mon, "Device '%s' is writable but does not support
snapshots.\n",
bdrv_get_device_name(bs));
return;
@@ -1365,7 +1368,7 @@ void hmp_savevm(Monitor *mon, const QDict *qdict)
/* create the snapshots */
bs1 = NULL;
- while ((bs1 = bdrv_next(bs1))) {
+ while ((bs1 = bdrv_next_lock(bs1))) {
if (bdrv_can_snapshot(bs1)) {
/* Write VM state size only to the image that contains the state */
sn->vm_state_size = (bs == bs1 ? vm_state_size : 0);
@@ -1436,13 +1439,14 @@ int load_vmstate(const char *name)
/* Verify if there is any device that doesn't support snapshots and is
writable and check if the requested snapshot is available too. */
bs = NULL;
- while ((bs = bdrv_next(bs))) {
+ while ((bs = bdrv_next_lock(bs))) {
if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
continue;
}
if (!bdrv_can_snapshot(bs)) {
+ bdrv_unlock(bs);
error_report("Device '%s' is writable but does not support
snapshots.",
bdrv_get_device_name(bs));
return -ENOTSUP;
@@ -1450,6 +1454,7 @@ int load_vmstate(const char *name)
ret = bdrv_snapshot_find(bs, &sn, name);
if (ret < 0) {
+ bdrv_unlock(bs);
error_report("Device '%s' does not have the requested snapshot
'%s'",
bdrv_get_device_name(bs), name);
return ret;
@@ -1460,10 +1465,11 @@ int load_vmstate(const char *name)
bdrv_drain_all();
bs = NULL;
- while ((bs = bdrv_next(bs))) {
+ while ((bs = bdrv_next_lock(bs))) {
if (bdrv_can_snapshot(bs)) {
ret = bdrv_snapshot_goto(bs, name);
if (ret < 0) {
+ bdrv_unlock(bs);
error_report("Error %d while activating snapshot '%s' on '%s'",
ret, name, bdrv_get_device_name(bs));
return ret;
@@ -1504,7 +1510,7 @@ void hmp_delvm(Monitor *mon, const QDict *qdict)
}
bs = NULL;
- while ((bs = bdrv_next(bs))) {
+ while ((bs = bdrv_next_lock(bs))) {
if (bdrv_can_snapshot(bs)) {
err = NULL;
bdrv_snapshot_delete_by_id_or_name(bs, name, &err);
@@ -1552,10 +1558,11 @@ void hmp_info_snapshots(Monitor *mon, const QDict
*qdict)
available = 1;
bs1 = NULL;
- while ((bs1 = bdrv_next(bs1))) {
+ while ((bs1 = bdrv_next_lock(bs1))) {
if (bdrv_can_snapshot(bs1) && bs1 != bs) {
ret = bdrv_snapshot_find(bs1, sn_info, sn->id_str);
if (ret < 0) {
+ bdrv_unlock(bs);
available = 0;
break;
}
diff --git a/monitor.c b/monitor.c
index 301a143..ea1a917 100644
--- a/monitor.c
+++ b/monitor.c
@@ -3374,7 +3374,7 @@ static void vm_completion(ReadLineState *rs, const char
*str)
len = strlen(str);
readline_set_completion_index(rs, len);
- while ((bs = bdrv_next(bs))) {
+ while ((bs = bdrv_next_lock(bs))) {
SnapshotInfoList *snapshots, *snapshot;
if (!bdrv_can_snapshot(bs)) {
--
2.1.4
