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[Qemu-devel] [PULL 09/14] snapshot: create bdrv_all_find_snapshot helper
From: |
Juan Quintela |
Subject: |
[Qemu-devel] [PULL 09/14] snapshot: create bdrv_all_find_snapshot helper |
Date: |
Thu, 19 Nov 2015 12:21:04 +0100 |
From: "Denis V. Lunev" <address@hidden>
to check that snapshot is available for all loaded block drivers.
The check bs != bs1 in hmp_info_snapshots is an optimization. The check
for availability of this snapshot will return always true as the list
of snapshots was collected from that image.
The patch also ensures proper locking.
Signed-off-by: Denis V. Lunev <address@hidden>
Reviewed-by: Fam Zheng <address@hidden>
Reviewed-by: Juan Quintela <address@hidden>
CC: Stefan Hajnoczi <address@hidden>
CC: Kevin Wolf <address@hidden>
Tested-by: Greg Kurz <address@hidden>
Signed-off-by: Juan Quintela <address@hidden>
---
block/snapshot.c | 20 ++++++++++++++++++++
include/block/snapshot.h | 1 +
migration/savevm.c | 42 +++++++++---------------------------------
3 files changed, 30 insertions(+), 33 deletions(-)
diff --git a/block/snapshot.c b/block/snapshot.c
index 9f07a63..eae4730 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -423,3 +423,23 @@ 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 (err == 0 && (bs = bdrv_next(bs))) {
+ AioContext *ctx = bdrv_get_aio_context(bs);
+
+ aio_context_acquire(ctx);
+ if (bdrv_can_snapshot(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 0a176c7..10ee582 100644
--- a/include/block/snapshot.h
+++ b/include/block/snapshot.h
@@ -85,5 +85,6 @@ 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 2ecc1b3..4e6d578 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2056,6 +2056,12 @@ int load_vmstate(const char *name)
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) {
@@ -2073,22 +2079,6 @@ 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_can_snapshot(bs)) {
- continue;
- }
-
- 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();
@@ -2142,8 +2132,8 @@ 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;
@@ -2167,21 +2157,7 @@ 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] [PULL 00/14] Migration pull request, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 02/14] migration: Dead assignment of current_time, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 01/14] Set last_sent_block, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 03/14] Unneeded NULL check, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 04/14] snapshot: create helper to test that block drivers supports snapshots, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 05/14] snapshot: return error code from bdrv_snapshot_delete_by_id_or_name, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 07/14] snapshot: create bdrv_all_goto_snapshot helper, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 08/14] migration: factor our snapshottability check in load_vmstate, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 06/14] snapshot: create bdrv_all_delete_snapshot helper, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 09/14] snapshot: create bdrv_all_find_snapshot helper,
Juan Quintela <=
- [Qemu-devel] [PULL 10/14] migration: drop find_vmstate_bs check in hmp_delvm, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 11/14] snapshot: create bdrv_all_create_snapshot helper, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 12/14] migration: reorder processing in hmp_savevm, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 14/14] migration: normalize locking in migration/savevm.c, Juan Quintela, 2015/11/19
- [Qemu-devel] [PULL 13/14] migration: implement bdrv_all_find_vmstate_bs helper, Juan Quintela, 2015/11/19
- Re: [Qemu-devel] [PULL 00/14] Migration pull request, Peter Maydell, 2015/11/19