1 files changed, 26 insertions, 16 deletions

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index b7f51e4594f8..dba1c32e1ddf 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -35,10 +35,6 @@
  */
 struct brd_device {
 	int		brd_number;
-	int		brd_refcnt;
-	loff_t		brd_offset;
-	loff_t		brd_sizelimit;
-	unsigned	brd_blocksize;
 
 	struct request_queue	*brd_queue;
 	struct gendisk		*brd_disk;
@@ -440,11 +436,11 @@ static int rd_nr;
 int rd_size = CONFIG_BLK_DEV_RAM_SIZE;
 static int max_part;
 static int part_shift;
-module_param(rd_nr, int, 0);
+module_param(rd_nr, int, S_IRUGO);
 MODULE_PARM_DESC(rd_nr, "Maximum number of brd devices");
-module_param(rd_size, int, 0);
+module_param(rd_size, int, S_IRUGO);
 MODULE_PARM_DESC(rd_size, "Size of each RAM disk in kbytes.");
-module_param(max_part, int, 0);
+module_param(max_part, int, S_IRUGO);
 MODULE_PARM_DESC(max_part, "Maximum number of partitions per RAM disk");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR);
@@ -552,7 +548,7 @@ static struct kobject *brd_probe(dev_t dev, int *part, void *data)
 	struct kobject *kobj;
 
 	mutex_lock(&brd_devices_mutex);
-	brd = brd_init_one(dev & MINORMASK);
+	brd = brd_init_one(MINOR(dev) >> part_shift);
 	kobj = brd ? get_disk(brd->brd_disk) : ERR_PTR(-ENOMEM);
 	mutex_unlock(&brd_devices_mutex);
 
@@ -575,25 +571,39 @@ static int __init brd_init(void)
 	 *
 	 * (1) if rd_nr is specified, create that many upfront, and this
 	 *     also becomes a hard limit.
-	 * (2) if rd_nr is not specified, create 1 rd device on module
-	 *     load, user can further extend brd device by create dev node
-	 *     themselves and have kernel automatically instantiate actual
-	 *     device on-demand.
+	 * (2) if rd_nr is not specified, create CONFIG_BLK_DEV_RAM_COUNT
+	 *     (default 16) rd device on module load, user can further
+	 *     extend brd device by create dev node themselves and have
+	 *     kernel automatically instantiate actual device on-demand.
 	 */
 
 	part_shift = 0;
-	if (max_part > 0)
+	if (max_part > 0) {
 		part_shift = fls(max_part);
 
+		/*
+		 * Adjust max_part according to part_shift as it is exported
+		 * to user space so that user can decide correct minor number
+		 * if [s]he want to create more devices.
+		 *
+		 * Note that -1 is required because partition 0 is reserved
+		 * for the whole disk.
+		 */
+		max_part = (1UL << part_shift) - 1;
+	}
+
+	if ((1UL << part_shift) > DISK_MAX_PARTS)
+		return -EINVAL;
+
 	if (rd_nr > 1UL << (MINORBITS - part_shift))
 		return -EINVAL;
 
 	if (rd_nr) {
 		nr = rd_nr;
-		range = rd_nr;
+		range = rd_nr << part_shift;
 	} else {
 		nr = CONFIG_BLK_DEV_RAM_COUNT;
-		range = 1UL << (MINORBITS - part_shift);
+		range = 1UL << MINORBITS;
 	}
 
 	if (register_blkdev(RAMDISK_MAJOR, "ramdisk"))
@@ -632,7 +642,7 @@ static void __exit brd_exit(void)
 	unsigned long range;
 	struct brd_device *brd, *next;
 
-	range = rd_nr ? rd_nr :  1UL << (MINORBITS - part_shift);
+	range = rd_nr ? rd_nr << part_shift : 1UL << MINORBITS;
 
 	list_for_each_entry_safe(brd, next, &brd_devices, brd_list)
 		brd_del_one(brd);