Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm snapshot: extend exception store functions
  dm snapshot: split out exception store implementations
  dm snapshot: rename struct exception_store
  dm snapshot: separate out exception store interface
  dm mpath: move trigger_event to system workqueue
  dm: add name and uuid to sysfs
  dm table: rework reference counting
  dm: support barriers on simple devices
  dm request: extend target interface
  dm request: add caches
  dm ioctl: allow dm_copy_name_and_uuid to return only one field
  dm log: ensure log bitmap fits on log device
  dm log: move region_size validation
  dm log: avoid reinitialising io_req on every operation
  dm: consolidate target deregistration error handling
  dm raid1: fix error count
  dm log: fix dm_io_client leak on error paths
  dm snapshot: change yield to msleep
  dm table: drop reference at unbind

1 files changed, 28 insertions, 20 deletions

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 6c96db26b87c..65ff82ff124e 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -9,6 +9,7 @@
 #include <linux/blkdev.h>
 #include <linux/ctype.h>
 #include <linux/device-mapper.h>
+#include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/kdev_t.h>
@@ -20,6 +21,7 @@
 #include <linux/log2.h>
 #include <linux/dm-kcopyd.h>
 
+#include "dm-exception-store.h"
 #include "dm-snap.h"
 #include "dm-bio-list.h"
 
@@ -428,8 +430,13 @@ out:
         list_add(&new_e->hash_list, e ? &e->hash_list : l);
 }
 
-int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new)
+/*
+ * Callback used by the exception stores to load exceptions when
+ * initialising.
+ */
+static int dm_add_exception(void *context, chunk_t old, chunk_t new)
 {
+        struct dm_snapshot *s = context;
         struct dm_snap_exception *e;
 
         e = alloc_exception();
@@ -658,7 +665,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         spin_lock_init(&s->tracked_chunk_lock);
 
         /* Metadata must only be loaded into one table at once */
-        r = s->store.read_metadata(&s->store);
+        r = s->store.read_metadata(&s->store, dm_add_exception, (void *)s);
         if (r < 0) {
                 ti->error = "Failed to read snapshot metadata";
                 goto bad_load_and_register;
@@ -735,7 +742,7 @@ static void snapshot_dtr(struct dm_target *ti)
         unregister_snapshot(s);
 
         while (atomic_read(&s->pending_exceptions_count))
-                yield();
+                msleep(1);
         /*
          * Ensure instructions in mempool_destroy aren't reordered
          * before atomic_read.
@@ -888,10 +895,10 @@ static void pending_complete(struct dm_snap_pending_exception *pe, int success)
 
         /*
          * Check for conflicting reads. This is extremely improbable,
-         * so yield() is sufficient and there is no need for a wait queue.
+         * so msleep(1) is sufficient and there is no need for a wait queue.
          */
         while (__chunk_is_tracked(s, pe->e.old_chunk))
-                yield();
+                msleep(1);
 
         /*
          * Add a proper exception, and remove the
@@ -1404,6 +1411,12 @@ static int __init dm_snapshot_init(void)
 {
         int r;
 
+        r = dm_exception_store_init();
+        if (r) {
+                DMERR("Failed to initialize exception stores");
+                return r;
+        }
+
         r = dm_register_target(&snapshot_target);
         if (r) {
                 DMERR("snapshot target register failed %d", r);
@@ -1452,39 +1465,34 @@ static int __init dm_snapshot_init(void)
 
         return 0;
 
-      bad_pending_pool:
+bad_pending_pool:
         kmem_cache_destroy(tracked_chunk_cache);
-      bad5:
+bad5:
         kmem_cache_destroy(pending_cache);
-      bad4:
+bad4:
         kmem_cache_destroy(exception_cache);
-      bad3:
+bad3:
         exit_origin_hash();
-      bad2:
+bad2:
         dm_unregister_target(&origin_target);
-      bad1:
+bad1:
         dm_unregister_target(&snapshot_target);
         return r;
 }
 
 static void __exit dm_snapshot_exit(void)
 {
-        int r;
-
         destroy_workqueue(ksnapd);
 
-        r = dm_unregister_target(&snapshot_target);
-        if (r)
-                DMERR("snapshot unregister failed %d", r);
-
-        r = dm_unregister_target(&origin_target);
-        if (r)
-                DMERR("origin unregister failed %d", r);
+        dm_unregister_target(&snapshot_target);
+        dm_unregister_target(&origin_target);
 
         exit_origin_hash();
         kmem_cache_destroy(pending_cache);
         kmem_cache_destroy(exception_cache);
         kmem_cache_destroy(tracked_chunk_cache);
+
+        dm_exception_store_exit();
 }
 
 /* Module hooks */