rbd: clean up a few things in the refresh path
This includes a few relatively small fixes I found while examining
the code that refreshes image information.
This resolves:
http://tracker.ceph.com/issues/5040
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index cb728a0..d4902c5 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2860,7 +2860,7 @@
(unsigned int)opcode);
ret = rbd_dev_refresh(rbd_dev);
if (ret)
- rbd_warn(rbd_dev, ": header refresh error (%d)\n", ret);
+ rbd_warn(rbd_dev, "header refresh error (%d)\n", ret);
rbd_obj_notify_ack(rbd_dev, notify_id);
}
@@ -3340,8 +3340,8 @@
int ret;
rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
- mapping_size = rbd_dev->mapping.size;
mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+ mapping_size = rbd_dev->mapping.size;
if (rbd_dev->image_format == 1)
ret = rbd_dev_v1_header_info(rbd_dev);
else
@@ -3814,6 +3814,7 @@
void *end;
u64 pool_id;
char *image_id;
+ u64 snap_id;
u64 overlap;
int ret;
@@ -3873,24 +3874,56 @@
(unsigned long long)pool_id, U32_MAX);
goto out_err;
}
- parent_spec->pool_id = pool_id;
image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
if (IS_ERR(image_id)) {
ret = PTR_ERR(image_id);
goto out_err;
}
- parent_spec->image_id = image_id;
- ceph_decode_64_safe(&p, end, parent_spec->snap_id, out_err);
+ ceph_decode_64_safe(&p, end, snap_id, out_err);
ceph_decode_64_safe(&p, end, overlap, out_err);
- if (overlap) {
- rbd_spec_put(rbd_dev->parent_spec);
+ /*
+ * The parent won't change (except when the clone is
+ * flattened, already handled that). So we only need to
+ * record the parent spec we have not already done so.
+ */
+ if (!rbd_dev->parent_spec) {
+ parent_spec->pool_id = pool_id;
+ parent_spec->image_id = image_id;
+ parent_spec->snap_id = snap_id;
rbd_dev->parent_spec = parent_spec;
parent_spec = NULL; /* rbd_dev now owns this */
- rbd_dev->parent_overlap = overlap;
- } else {
- rbd_warn(rbd_dev, "ignoring parent of clone with overlap 0\n");
+ }
+
+ /*
+ * We always update the parent overlap. If it's zero we
+ * treat it specially.
+ */
+ rbd_dev->parent_overlap = overlap;
+ smp_mb();
+ if (!overlap) {
+
+ /* A null parent_spec indicates it's the initial probe */
+
+ if (parent_spec) {
+ /*
+ * The overlap has become zero, so the clone
+ * must have been resized down to 0 at some
+ * point. Treat this the same as a flatten.
+ */
+ rbd_dev_parent_put(rbd_dev);
+ pr_info("%s: clone image now standalone\n",
+ rbd_dev->disk->disk_name);
+ } else {
+ /*
+ * For the initial probe, if we find the
+ * overlap is zero we just pretend there was
+ * no parent image.
+ */
+ rbd_warn(rbd_dev, "ignoring parent of "
+ "clone with overlap 0\n");
+ }
}
out:
ret = 0;
