1 files changed, 21 insertions, 6 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 8cb8e0abfb33..77263681dde2 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -201,7 +201,7 @@ static DEFINE_SPINLOCK(rbd_dev_list_lock);
 static LIST_HEAD(rbd_client_list);              /* clients */
 static DEFINE_SPINLOCK(rbd_client_list_lock);
 
-static int __rbd_init_snaps_header(struct rbd_device *rbd_dev);
+static int rbd_dev_snap_devs_update(struct rbd_device *rbd_dev);
 static void rbd_dev_release(struct device *dev);
 static ssize_t rbd_snap_add(struct device *dev,
                             struct device_attribute *attr,
@@ -1848,7 +1848,7 @@ static int __rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver)
         WARN_ON(strcmp(rbd_dev->header.object_prefix, h.object_prefix));
         kfree(h.object_prefix);
 
-        ret = __rbd_init_snaps_header(rbd_dev);
+        ret = rbd_dev_snap_devs_update(rbd_dev);
 
         up_write(&rbd_dev->header_rwsem);
 
@@ -1880,7 +1880,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev)
                 return rc;
 
         /* no need to lock here, as rbd_dev is not registered yet */
-        rc = __rbd_init_snaps_header(rbd_dev);
+        rc = rbd_dev_snap_devs_update(rbd_dev);
         if (rc)
                 return rc;
 
@@ -2184,7 +2184,7 @@ err:
  * snapshot id, highest id first.  (Snapshots in the rbd_dev's list
  * are also maintained in that order.)
  */
-static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
+static int rbd_dev_snap_devs_update(struct rbd_device *rbd_dev)
 {
         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
         const u32 snap_count = snapc->num_snaps;
@@ -2193,6 +2193,7 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
         struct list_head *links = head->next;
         u32 index = 0;
 
+        dout("%s: snap count is %u\n", __func__, (unsigned int) snap_count);
         while (index < snap_count || links != head) {
                 u64 snap_id;
                 struct rbd_snap *snap;
@@ -2211,6 +2212,9 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
                         if (rbd_dev->snap_id == snap->id)
                                 rbd_dev->snap_exists = false;
                         __rbd_remove_snap_dev(snap);
+                        dout("%ssnap id %llu has been removed\n",
+                                rbd_dev->snap_id == snap->id ? "mapped " : "",
+                                (unsigned long long) snap->id);
 
                         /* Done with this list entry; advance */
 
@@ -2218,6 +2222,8 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
                         continue;
                 }
 
+                dout("entry %u: snap_id = %llu\n", (unsigned int) snap_count,
+                        (unsigned long long) snap_id);
                 if (!snap || (snap_id != CEPH_NOSNAP && snap->id < snap_id)) {
                         struct rbd_snap *new_snap;
 
@@ -2225,11 +2231,17 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
 
                         new_snap = __rbd_add_snap_dev(rbd_dev, index,
                                                         snap_name);
-                        if (IS_ERR(new_snap))
-                                return PTR_ERR(new_snap);
+                        if (IS_ERR(new_snap)) {
+                                int err = PTR_ERR(new_snap);
+
+                                dout("  failed to add dev, error %d\n", err);
+
+                                return err;
+                        }
 
                         /* New goes before existing, or at end of list */
 
+                        dout("  added dev%s\n", snap ? "" : " at end\n");
                         if (snap)
                                 list_add_tail(&new_snap->node, &snap->node);
                         else
@@ -2237,6 +2249,8 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
                 } else {
                         /* Already have this one */
 
+                        dout("  already present\n");
+
                         rbd_assert(snap->size ==
                                         rbd_dev->header.snap_sizes[index]);
                         rbd_assert(!strcmp(snap->name, snap_name));
@@ -2251,6 +2265,7 @@ static int __rbd_init_snaps_header(struct rbd_device *rbd_dev)
                 index++;
                 snap_name += strlen(snap_name) + 1;
         }
+        dout("%s: done\n", __func__);
 
         return 0;
 }