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 /block/snapshot.c | |
| parent | 5df5416e639cd75bd85d243af41387c2418fa580 (diff) | |
| download | qemu-e9ff957ac26e0e11869a3568cfa7423ae33c51e7.zip | |
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>
Diffstat (limited to 'block/snapshot.c')
| -rw-r--r-- | block/snapshot.c | 24 |
1 files changed, 24 insertions, 0 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; +} |