1 files changed, 47 insertions, 23 deletions

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 2fd1ed101748..292f127cae0a 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -231,8 +231,10 @@ static void brd_do_discard(struct brd_device *brd, sector_t sector, u32 size)
 	xa_lock(&brd->brd_pages);
 	while (size >= PAGE_SIZE && aligned_sector < rd_size * 2) {
 		page = __xa_erase(&brd->brd_pages, aligned_sector >> PAGE_SECTORS_SHIFT);
-		if (page)
+		if (page) {
 			__free_page(page);
+			brd->brd_nr_pages--;
+		}
 		aligned_sector += PAGE_SECTORS;
 		size -= PAGE_SIZE;
 	}
@@ -316,8 +318,40 @@ __setup("ramdisk_size=", ramdisk_size);
  * (should share code eventually).
  */
 static LIST_HEAD(brd_devices);
+static DEFINE_MUTEX(brd_devices_mutex);
 static struct dentry *brd_debugfs_dir;
 
+static struct brd_device *brd_find_or_alloc_device(int i)
+{
+	struct brd_device *brd;
+
+	mutex_lock(&brd_devices_mutex);
+	list_for_each_entry(brd, &brd_devices, brd_list) {
+		if (brd->brd_number == i) {
+			mutex_unlock(&brd_devices_mutex);
+			return ERR_PTR(-EEXIST);
+		}
+	}
+
+	brd = kzalloc(sizeof(*brd), GFP_KERNEL);
+	if (!brd) {
+		mutex_unlock(&brd_devices_mutex);
+		return ERR_PTR(-ENOMEM);
+	}
+	brd->brd_number	= i;
+	list_add_tail(&brd->brd_list, &brd_devices);
+	mutex_unlock(&brd_devices_mutex);
+	return brd;
+}
+
+static void brd_free_device(struct brd_device *brd)
+{
+	mutex_lock(&brd_devices_mutex);
+	list_del(&brd->brd_list);
+	mutex_unlock(&brd_devices_mutex);
+	kfree(brd);
+}
+
 static int brd_alloc(int i)
 {
 	struct brd_device *brd;
@@ -340,14 +374,9 @@ static int brd_alloc(int i)
 					  BLK_FEAT_NOWAIT,
 	};
 
-	list_for_each_entry(brd, &brd_devices, brd_list)
-		if (brd->brd_number == i)
-			return -EEXIST;
-	brd = kzalloc(sizeof(*brd), GFP_KERNEL);
-	if (!brd)
-		return -ENOMEM;
-	brd->brd_number		= i;
-	list_add_tail(&brd->brd_list, &brd_devices);
+	brd = brd_find_or_alloc_device(i);
+	if (IS_ERR(brd))
+		return PTR_ERR(brd);
 
 	xa_init(&brd->brd_pages);
 
@@ -378,8 +407,7 @@ static int brd_alloc(int i)
 out_cleanup_disk:
 	put_disk(disk);
 out_free_dev:
-	list_del(&brd->brd_list);
-	kfree(brd);
+	brd_free_device(brd);
 	return err;
 }
 
@@ -398,8 +426,7 @@ static void brd_cleanup(void)
 		del_gendisk(brd->brd_disk);
 		put_disk(brd->brd_disk);
 		brd_free_pages(brd);
-		list_del(&brd->brd_list);
-		kfree(brd);
+		brd_free_device(brd);
 	}
 }
 
@@ -426,16 +453,6 @@ static int __init brd_init(void)
 {
 	int err, i;
 
-	brd_check_and_reset_par();
-
-	brd_debugfs_dir = debugfs_create_dir("ramdisk_pages", NULL);
-
-	for (i = 0; i < rd_nr; i++) {
-		err = brd_alloc(i);
-		if (err)
-			goto out_free;
-	}
-
 	/*
 	 * brd module now has a feature to instantiate underlying device
 	 * structure on-demand, provided that there is an access dev node.
@@ -451,11 +468,18 @@ static int __init brd_init(void)
 	 *	dynamically.
 	 */
 
+	brd_check_and_reset_par();
+
+	brd_debugfs_dir = debugfs_create_dir("ramdisk_pages", NULL);
+
 	if (__register_blkdev(RAMDISK_MAJOR, "ramdisk", brd_probe)) {
 		err = -EIO;
 		goto out_free;
 	}
 
+	for (i = 0; i < rd_nr; i++)
+		brd_alloc(i);
+
 	pr_info("brd: module loaded\n");
 	return 0;