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[Qemu-devel] [PATCH 05/11] snapshot: create bdrv_all_find_snapshot helpe
From: |
Denis V. Lunev |
Subject: |
[Qemu-devel] [PATCH 05/11] snapshot: create bdrv_all_find_snapshot helper |
Date: |
Wed, 4 Nov 2015 20:19:36 +0300 |
to check that snapshot is available for all loaded block drivers. The
ability to switch to snapshot is verified separately using
bdrv_all_can_snapshot.
The patch also ensures proper locking.
Signed-off-by: Denis V. Lunev <address@hidden>
CC: Juan Quintela <address@hidden>
CC: Stefan Hajnoczi <address@hidden>
CC: Kevin Wolf <address@hidden>
---
block/snapshot.c | 20 ++++++++++++++++++
include/block/snapshot.h | 1 +
migration/savevm.c | 55 +++++++++++++-----------------------------------
3 files changed, 36 insertions(+), 40 deletions(-)
diff --git a/block/snapshot.c b/block/snapshot.c
index 639074f..bb3bfd5 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -426,3 +426,23 @@ int bdrv_all_goto_snapshot(const char *name,
BlockDriverState **first_bad_bs)
*first_bad_bs = bs;
return err;
}
+
+int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs)
+{
+ QEMUSnapshotInfo sn;
+ int err = 0;
+ BlockDriverState *bs = NULL;
+
+ while ((bs = bdrv_next(bs)) && err == 0) {
+ AioContext *ctx = bdrv_get_aio_context(bs);
+
+ aio_context_acquire(ctx);
+ if (bdrv_is_inserted(bs) && !bdrv_is_read_only(bs)) {
+ err = bdrv_snapshot_find(bs, &sn, name);
+ }
+ aio_context_release(ctx);
+ }
+
+ *first_bad_bs = bs;
+ return err;
+}
diff --git a/include/block/snapshot.h b/include/block/snapshot.h
index 9c54b7c..44c3a38 100644
--- a/include/block/snapshot.h
+++ b/include/block/snapshot.h
@@ -86,5 +86,6 @@ bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs);
int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bsd_bs,
Error **err);
int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bsd_bs);
+int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs);
#endif
diff --git a/migration/savevm.c b/migration/savevm.c
index 101dff5..4e469ef 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1383,6 +1383,18 @@ int load_vmstate(const char *name)
QEMUFile *f;
int ret;
+ if (!bdrv_all_can_snapshot(&bs)) {
+ error_report("Device '%s' is writable but does not support snapshots.",
+ bdrv_get_device_name(bs));
+ return -ENOTSUP;
+ }
+ ret = bdrv_all_find_snapshot(name, &bs);
+ if (ret < 0) {
+ error_report("Device '%s' does not have the requested snapshot '%s'",
+ bdrv_get_device_name(bs), name);
+ return ret;
+ }
+
bs_vm_state = find_vmstate_bs();
if (!bs_vm_state) {
error_report("No block device supports snapshots");
@@ -1399,29 +1411,6 @@ int load_vmstate(const char *name)
return -EINVAL;
}
- /* 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))) {
-
- if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
- continue;
- }
-
- if (!bdrv_can_snapshot(bs)) {
- error_report("Device '%s' is writable but does not support
snapshots.",
- bdrv_get_device_name(bs));
- return -ENOTSUP;
- }
-
- ret = bdrv_snapshot_find(bs, &sn, name);
- if (ret < 0) {
- error_report("Device '%s' does not have the requested snapshot
'%s'",
- bdrv_get_device_name(bs), name);
- return ret;
- }
- }
-
/* Flush all IO requests so they don't interfere with the new state. */
bdrv_drain_all();
@@ -1475,8 +1464,8 @@ void hmp_delvm(Monitor *mon, const QDict *qdict)
void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
{
BlockDriverState *bs, *bs1;
- QEMUSnapshotInfo *sn_tab, *sn, s, *sn_info = &s;
- int nb_sns, i, ret, available;
+ QEMUSnapshotInfo *sn_tab, *sn;
+ int nb_sns, i;
int total;
int *available_snapshots;
@@ -1500,21 +1489,7 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
available_snapshots = g_new0(int, nb_sns);
total = 0;
for (i = 0; i < nb_sns; i++) {
- sn = &sn_tab[i];
- available = 1;
- bs1 = NULL;
-
- while ((bs1 = bdrv_next(bs1))) {
- if (bdrv_can_snapshot(bs1) && bs1 != bs) {
- ret = bdrv_snapshot_find(bs1, sn_info, sn->id_str);
- if (ret < 0) {
- available = 0;
- break;
- }
- }
- }
-
- if (available) {
+ if (bdrv_all_find_snapshot(sn_tab[i].id_str, &bs1) == 0) {
available_snapshots[total] = i;
total++;
}
--
2.5.0
- [Qemu-devel] [PATCH 02/11] snapshot: return error code from bdrv_snapshot_delete_by_id_or_name, (continued)
- [Qemu-devel] [PATCH 02/11] snapshot: return error code from bdrv_snapshot_delete_by_id_or_name, Denis V. Lunev, 2015/11/04
- [Qemu-devel] [PATCH 01/11] snapshot: create helper to test that block drivers supports snapshots, Denis V. Lunev, 2015/11/04
- [Qemu-devel] [PATCH 04/11] snapshot: create bdrv_all_goto_snapshot helper, Denis V. Lunev, 2015/11/04
- [Qemu-devel] [PATCH 07/11] migration: reorder processing in hmp_savevm, Denis V. Lunev, 2015/11/04
- [Qemu-devel] [PATCH 05/11] snapshot: create bdrv_all_find_snapshot helper,
Denis V. Lunev <=
- [Qemu-devel] [PATCH 08/11] migration: implement bdrv_all_find_vmstate_bs and bdrv_unlock helpers, Denis V. Lunev, 2015/11/04
- [Qemu-devel] [PATCH 09/11] migration: add missed aio_context_acquire for state writing/reading, Denis V. Lunev, 2015/11/04
- [Qemu-devel] [PATCH 06/11] migration: drop find_vmstate_bs check in hmp_delvm, Denis V. Lunev, 2015/11/04
- [Qemu-devel] [PATCH 11/11] monitor: add missed aio_context_acquire into vm_completion call, Denis V. Lunev, 2015/11/04
- [Qemu-devel] [PATCH 10/11] snapshot: create bdrv_all_create_snapshot helper, Denis V. Lunev, 2015/11/04
- Re: [Qemu-devel] [PATCH 2.5 v5 0/11] dataplane snapshot fixes, Stefan Hajnoczi, 2015/11/06