[PATCH] dm table: store md

Store an up-pointer to the owning struct mapped_device in every table when it
is created.

Access it with:
  struct mapped_device *dm_table_get_md(struct dm_table *t)

Tables linked to md must be destroyed before the md itself.

Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 3d121cbc2fde..b99df48cffed 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1007,18 +1007,18 @@ void dm_get(struct mapped_device *md)
 
 void dm_put(struct mapped_device *md)
 {
-        struct dm_table *map = dm_get_table(md);
+        struct dm_table *map;
 
         if (atomic_dec_and_test(&md->holders)) {
+                map = dm_get_table(md);
                 if (!dm_suspended(md)) {
                         dm_table_presuspend_targets(map);
                         dm_table_postsuspend_targets(map);
                 }
                 __unbind(md);
+                dm_table_put(map);
                 free_dev(md);
         }
-
-        dm_table_put(map);
 }
 
 /*