dm snapshot: permit invalid activation
Allow invalid snapshots to be activated instead of failing.
This allows userspace to reinstate any given snapshot state - for
example after an unscheduled reboot - and clean up the invalid snapshot
at its leisure.
Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 8c25c2f..3d65917 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -489,11 +489,6 @@
/*
* Sanity checks.
*/
- if (!ps->valid) {
- DMWARN("snapshot is marked invalid");
- return -EINVAL;
- }
-
if (ps->version != SNAPSHOT_DISK_VERSION) {
DMWARN("unable to handle snapshot disk version %d",
ps->version);
@@ -501,6 +496,12 @@
}
/*
+ * Metadata are valid, but snapshot is invalidated
+ */
+ if (!ps->valid)
+ return 1;
+
+ /*
* Read the metadata.
*/
r = read_exceptions(ps);
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 1da4122..854891d 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -523,9 +523,12 @@
/* Metadata must only be loaded into one table at once */
r = s->store.read_metadata(&s->store);
- if (r) {
+ if (r < 0) {
ti->error = "Failed to read snapshot metadata";
goto bad6;
+ } else if (r > 0) {
+ s->valid = 0;
+ DMWARN("Snapshot is marked invalid.");
}
bio_list_init(&s->queued_bios);