Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[karo-tx-linux.git] / drivers / md / dm-snap.c

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index c0bcd6516dfe17f8e7a06ec8c66d1e1d5801f133..c06b74e91cd6aeef00ef4eefae9953d4d8c8f91b 100644 (file)
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1098,7 +1098,7 @@ static void stop_merge(struct dm_snapshot *s)
 }
 
 /*
- * Construct a snapshot mapping: <origin_dev> <COW-dev> <p/n> <chunk-size>
+ * Construct a snapshot mapping: <origin_dev> <COW-dev> <p|po|n> <chunk-size>
  */
 static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 {
@@ -1302,6 +1302,7 @@ static void __handover_exceptions(struct dm_snapshot *snap_src,
 
        u.store_swap = snap_dest->store;
        snap_dest->store = snap_src->store;
+       snap_dest->store->userspace_supports_overflow = u.store_swap->userspace_supports_overflow;
        snap_src->store = u.store_swap;
 
        snap_dest->store->snap = snap_dest;
@@ -1739,8 +1740,11 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio)
 
                        pe = __find_pending_exception(s, pe, chunk);
                        if (!pe) {
-                               s->snapshot_overflowed = 1;
-                               DMERR("Snapshot overflowed: Unable to allocate exception.");
+                               if (s->store->userspace_supports_overflow) {
+                                       s->snapshot_overflowed = 1;
+                                       DMERR("Snapshot overflowed: Unable to allocate exception.");
+                               } else
+                                       __invalidate_snapshot(s, -ENOMEM);
                                r = -EIO;
                                goto out_unlock;
                        }
@@ -2365,7 +2369,7 @@ static struct target_type origin_target = {
 
 static struct target_type snapshot_target = {
        .name    = "snapshot",
-       .version = {1, 14, 0},
+       .version = {1, 15, 0},
        .module  = THIS_MODULE,
        .ctr     = snapshot_ctr,
        .dtr     = snapshot_dtr,
@@ -2379,7 +2383,7 @@ static struct target_type snapshot_target = {
 
 static struct target_type merge_target = {
        .name    = dm_snapshot_merge_target_name,
-       .version = {1, 3, 0},
+       .version = {1, 4, 0},
        .module  = THIS_MODULE,
        .ctr     = snapshot_ctr,
        .dtr     = snapshot_dtr,