Merge remote-tracking branch 'device-mapper/for-next'
[karo-tx-linux.git] / drivers / md / dm-snap-persistent.c
index 046f6b8..3164b8b 100644 (file)
@@ -7,6 +7,7 @@
 
 #include "dm-exception-store.h"
 
+#include <linux/ctype.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
 #include <linux/vmalloc.h>
@@ -843,10 +844,10 @@ static void persistent_drop_snapshot(struct dm_exception_store *store)
                DMWARN("write header failed");
 }
 
-static int persistent_ctr(struct dm_exception_store *store,
-                         unsigned argc, char **argv)
+static int persistent_ctr(struct dm_exception_store *store, char *options)
 {
        struct pstore *ps;
+       int r;
 
        /* allocate the pstore */
        ps = kzalloc(sizeof(*ps), GFP_KERNEL);
@@ -868,14 +869,32 @@ static int persistent_ctr(struct dm_exception_store *store,
 
        ps->metadata_wq = alloc_workqueue("ksnaphd", WQ_MEM_RECLAIM, 0);
        if (!ps->metadata_wq) {
-               kfree(ps);
                DMERR("couldn't start header metadata update thread");
-               return -ENOMEM;
+               r = -ENOMEM;
+               goto err_workqueue;
+       }
+
+       if (options) {
+               char overflow = toupper(options[0]);
+               if (overflow == 'O')
+                       store->userspace_supports_overflow = true;
+               else {
+                       DMERR("Unsupported persistent store option: %s", options);
+                       r = -EINVAL;
+                       goto err_options;
+               }
        }
 
        store->context = ps;
 
        return 0;
+
+err_options:
+       destroy_workqueue(ps->metadata_wq);
+err_workqueue:
+       kfree(ps);
+
+       return r;
 }
 
 static unsigned persistent_status(struct dm_exception_store *store,
@@ -888,7 +907,8 @@ static unsigned persistent_status(struct dm_exception_store *store,
        case STATUSTYPE_INFO:
                break;
        case STATUSTYPE_TABLE:
-               DMEMIT(" P %llu", (unsigned long long)store->chunk_size);
+               DMEMIT(" %s %llu", store->userspace_supports_overflow ? "PO" : "P",
+                      (unsigned long long)store->chunk_size);
        }
 
        return sz;