1 files changed, 51 insertions, 6 deletions

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 8f56a54cf0ce..75fe9493e6af 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -17,6 +17,8 @@
 #include <linux/mutex.h>
 #include <asm/atomic.h>
 
+#define DM_MSG_PREFIX "table"
+
 #define MAX_DEPTH 16
 #define NODE_SIZE L1_CACHE_BYTES
 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
@@ -237,6 +239,44 @@ int dm_table_create(struct dm_table **result, int mode,
         return 0;
 }
 
+int dm_create_error_table(struct dm_table **result, struct mapped_device *md)
+{
+        struct dm_table *t;
+        sector_t dev_size = 1;
+        int r;
+
+        /*
+         * Find current size of device.
+         * Default to 1 sector if inactive.
+         */
+        t = dm_get_table(md);
+        if (t) {
+                dev_size = dm_table_get_size(t);
+                dm_table_put(t);
+        }
+
+        r = dm_table_create(&t, FMODE_READ, 1, md);
+        if (r)
+                return r;
+
+        r = dm_table_add_target(t, "error", 0, dev_size, NULL);
+        if (r)
+                goto out;
+
+        r = dm_table_complete(t);
+        if (r)
+                goto out;
+
+        *result = t;
+
+out:
+        if (r)
+                dm_table_put(t);
+
+        return r;
+}
+EXPORT_SYMBOL_GPL(dm_create_error_table);
+
 static void free_devices(struct list_head *devices)
 {
         struct list_head *tmp, *next;
@@ -590,6 +630,12 @@ int dm_split_args(int *argc, char ***argvp, char *input)
         unsigned array_size = 0;
 
         *argc = 0;
+
+        if (!input) {
+                *argvp = NULL;
+                return 0;
+        }
+
         argv = realloc_argv(&array_size, argv);
         if (!argv)
                 return -ENOMEM;
@@ -671,15 +717,14 @@ int dm_table_add_target(struct dm_table *t, const char *type,
         memset(tgt, 0, sizeof(*tgt));
 
         if (!len) {
-                tgt->error = "zero-length target";
-                DMERR("%s", tgt->error);
+                DMERR("%s: zero-length target", dm_device_name(t->md));
                 return -EINVAL;
         }
 
         tgt->type = dm_get_target_type(type);
         if (!tgt->type) {
-                tgt->error = "unknown target type";
-                DMERR("%s", tgt->error);
+                DMERR("%s: %s: unknown target type", dm_device_name(t->md),
+                      type);
                 return -EINVAL;
         }
 
@@ -716,7 +761,7 @@ int dm_table_add_target(struct dm_table *t, const char *type,
         return 0;
 
  bad:
-        DMERR("%s", tgt->error);
+        DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
         dm_put_target_type(tgt->type);
         return r;
 }
@@ -802,7 +847,7 @@ sector_t dm_table_get_size(struct dm_table *t)
 
 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
 {
-        if (index > t->num_targets)
+        if (index >= t->num_targets)
                 return NULL;
 
         return t->targets + index;