diff options
author | Denis V. Lunev <den@openvz.org> | 2015-11-19 09:42:01 +0300 |
---|---|---|
committer | Juan Quintela <quintela@redhat.com> | 2015-11-19 11:50:00 +0100 |
commit | e9ff957ac26e0e11869a3568cfa7423ae33c51e7 (patch) | |
tree | 202f78903d148296e9bd8a86814b47e10426816e | |
parent | 5df5416e639cd75bd85d243af41387c2418fa580 (diff) |
snapshot: create helper to test that block drivers supports snapshots
The patch enforces proper locking for this operation.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
-rw-r--r-- | block/snapshot.c | 24 | ||||
-rw-r--r-- | include/block/snapshot.h | 8 | ||||
-rw-r--r-- | migration/savevm.c | 17 |
3 files changed, 36 insertions, 13 deletions
diff --git a/block/snapshot.c b/block/snapshot.c index 89500f2f18..d929d08913 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -356,3 +356,27 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs, return ret; } + + +/* Group operations. All block drivers are involved. + * These functions will properly handle dataplane (take aio_context_acquire + * when appropriate for appropriate block drivers) */ + +bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs) +{ + bool ok = true; + BlockDriverState *bs = NULL; + + while (ok && (bs = bdrv_next(bs))) { + AioContext *ctx = bdrv_get_aio_context(bs); + + aio_context_acquire(ctx); + if (bdrv_is_inserted(bs) && !bdrv_is_read_only(bs)) { + ok = bdrv_can_snapshot(bs); + } + aio_context_release(ctx); + } + + *first_bad_bs = bs; + return ok; +} diff --git a/include/block/snapshot.h b/include/block/snapshot.h index 770d9bbc8c..6195c9c8be 100644 --- a/include/block/snapshot.h +++ b/include/block/snapshot.h @@ -75,4 +75,12 @@ int bdrv_snapshot_load_tmp(BlockDriverState *bs, int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs, const char *id_or_name, Error **errp); + + +/* Group operations. All block drivers are involved. + * These functions will properly handle dataplane (take aio_context_acquire + * when appropriate for appropriate block drivers */ + +bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs); + #endif diff --git a/migration/savevm.c b/migration/savevm.c index d90e228568..4646aa1178 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1958,19 +1958,10 @@ void hmp_savevm(Monitor *mon, const QDict *qdict) const char *name = qdict_get_try_str(qdict, "name"); Error *local_err = NULL; - /* Verify if there is a device that doesn't support snapshots and is writable */ - bs = NULL; - while ((bs = bdrv_next(bs))) { - - if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { - continue; - } - - if (!bdrv_can_snapshot(bs)) { - monitor_printf(mon, "Device '%s' is writable but does not support snapshots.\n", - bdrv_get_device_name(bs)); - return; - } + if (!bdrv_all_can_snapshot(&bs)) { + monitor_printf(mon, "Device '%s' is writable but does not " + "support snapshots.\n", bdrv_get_device_name(bs)); + return; } bs = find_vmstate_bs(); |