dm: add dm_deleting_md function

Add dm_deleting_md to check whether or not a given mapped
device is currently being deleted.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

2 files changed, 12 insertions, 2 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 233a2e9156a3..16f759fe04fe 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -329,6 +329,11 @@ static void __exit dm_exit(void)
 /*
  * Block device functions
  */
+int dm_deleting_md(struct mapped_device *md)
+{
+        return test_bit(DMF_DELETING, &md->flags);
+}
+
 static int dm_blk_open(struct block_device *bdev, fmode_t mode)
 {
         struct mapped_device *md;
@@ -340,7 +345,7 @@ static int dm_blk_open(struct block_device *bdev, fmode_t mode)
                 goto out;
 
         if (test_bit(DMF_FREEING, &md->flags) ||
-            test_bit(DMF_DELETING, &md->flags)) {
+            dm_deleting_md(md)) {
                 md = NULL;
                 goto out;
         }
@@ -2659,7 +2664,7 @@ struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
                 return NULL;
 
         if (test_bit(DMF_FREEING, &md->flags) ||
-            test_bit(DMF_DELETING, &md->flags))
+            dm_deleting_md(md))
                 return NULL;
 
         dm_get(md);
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 4a95e8fa3607..604a5f2a2383 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -89,6 +89,11 @@ int dm_target_iterate(void (*iter_func)(struct target_type *tt,
 int dm_split_args(int *argc, char ***argvp, char *input);
 
 /*
+ * Is this mapped_device being deleted?
+ */
+int dm_deleting_md(struct mapped_device *md);
+
+/*
  * The device-mapper can be driven through one of two interfaces;
  * ioctl or filesystem, depending which patch you have applied.
  */