X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-linux.git;a=blobdiff_plain;f=drivers%2Fmd%2Fdm-snap-persistent.c;h=3164b8bce2948591999f429e4633235c1f7b1062;hp=046f6b81e6e6d7aff657e5a0ff1f977714b36be2;hb=927055c8b5b79a051bcff8e6c968139358821d6e;hpb=aad9ae4550755edc020b5c511a8b54f0104b2f47

diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index 046f6b81e6e6..3164b8bce294 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -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;