[PATCH] device-mapper ioctl: event on rename

After changing the name of a mapped device, trigger a dm event.  (For
userspace multipath tools.)

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, 10 insertions, 0 deletions

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 07d44e19536e..3e327db57310 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -270,6 +270,7 @@ static int dm_hash_rename(const char *old, const char *new)
 {
         char *new_name, *old_name;
         struct hash_cell *hc;
+        struct dm_table *table;
 
         /*
          * duplicate new.
@@ -317,6 +318,15 @@ static int dm_hash_rename(const char *old, const char *new)
         /* rename the device node in devfs */
         register_with_devfs(hc);
 
+        /*
+         * Wake up any dm event waiters.
+         */
+        table = dm_get_table(hc->md);
+        if (table) {
+                dm_table_event(table);
+                dm_table_put(table);
+        }
+
         up_write(&_hash_lock);
         kfree(old_name);
         return 0;