[dm-devel] [PATCH 5/6] dm ioctl: introduce dm_get_verified_mdptr

[Mike Snitzer]

Factor all appropriate consumers of dm_get_mdptr() to use the
dm_get_verified_mdptr() rather than duplicate code.

Signed-off-by: Mike Snitzer <snitzer at redhat.com>
---
 drivers/md/dm-ioctl.c |   37 +++++++++++++++++++++++--------------
 1 file changed, 23 insertions(+), 14 deletions(-)

Index: linux-2.6/drivers/md/dm-ioctl.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-ioctl.c
+++ linux-2.6/drivers/md/dm-ioctl.c
@@ -174,6 +174,19 @@ static void free_cell(struct hash_cell *
 	}
 }
 
+static struct hash_cell *dm_get_verified_mdptr(struct mapped_device *md)
+{
+	struct hash_cell *hc;
+
+	hc = dm_get_mdptr(md);
+	if (!hc || hc->md != md) {
+		DMWARN("device has been removed from the dev hash table.");
+		return NULL;
+	}
+
+	return hc;
+}
+
 /*
  * The kdev_t and uuid of a device can never change once it is
  * initially inserted.
@@ -546,11 +559,9 @@ static struct dm_table *dm_get_inactive_
 	struct dm_table *table = NULL;
 
 	down_read(&_hash_lock);
-	hc = dm_get_mdptr(md);
-	if (!hc || hc->md != md) {
-		DMWARN("device has been removed from the dev hash table.");
+	hc = dm_get_verified_mdptr(md);
+	if (!hc)
 		goto out;
-	}
 
 	table = hc->new_map;
 	if (table)
@@ -876,8 +887,8 @@ static int do_resume(struct dm_ioctl *pa
 	dm_lock_resume(md);
 
 	down_write(&_hash_lock);
-	if (!hc || hc->md != md) {
-		DMWARN("device has been removed from the dev hash table.");
+	hc = dm_get_verified_mdptr(md);
+	if (!hc) {
 		up_write(&_hash_lock);
 		r = -ENXIO;
 		goto out;
@@ -1226,9 +1237,8 @@ static int table_load(struct dm_ioctl *p
 
 	/* stage inactive table */
 	down_write(&_hash_lock);
-	hc = dm_get_mdptr(md);
-	if (!hc || hc->md != md) {
-		DMWARN("device has been removed from the dev hash table.");
+	hc = dm_get_verified_mdptr(md);
+	if (!hc) {
 		dm_table_destroy(t);
 		up_write(&_hash_lock);
 		if (initial_table_load)
@@ -1277,9 +1287,8 @@ static int table_clear(struct dm_ioctl *
 	dm_lock_md_type(md); /* May need to clear md's type */
 
 	down_write(&_hash_lock);
-	hc = dm_get_mdptr(md);
-	if (!hc || hc->md != md) {
-		DMWARN("device has been removed from the dev hash table.");
+	hc = dm_get_verified_mdptr(md);
+	if (!hc) {
 		up_write(&_hash_lock);
 		r = -ENXIO;
 		goto out;
@@ -1736,8 +1745,8 @@ int dm_copy_name_and_uuid(struct mapped_
 		return -ENXIO;
 
 	mutex_lock(&dm_hash_cells_mutex);
-	hc = dm_get_mdptr(md);
-	if (!hc || hc->md != md) {
+	hc = dm_get_verified_mdptr(md);
+	if (!hc) {
 		r = -ENXIO;
 		goto out;
 	}