block: limit disk max sectors to (LLONG_MAX >> 9)

Kernel `loff_t` is defined as `long long int`, so we can't support disk
which size is > LLONG_MAX.

There are many virtual block drivers, and hardware may report bad capacity
too, so limit max sectors to (LLONG_MAX >> 9) for avoiding potential
trouble.

Signed-off-by: Ming Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

Author: Ming Lei

block/blk.h

@@ -13,6 +13,8 @@
 
 struct elevator_type;
 
+#define	BLK_DEV_MAX_SECTORS	(LLONG_MAX >> 9)
+
 /* Max future timer expiry for timeouts */
 #define BLK_MAX_TIMEOUT		(5 * HZ)
 

block/genhd.c

@@ -58,6 +58,13 @@ static DEFINE_IDA(ext_devt_ida);
 
 void set_capacity(struct gendisk *disk, sector_t sectors)
 {
+	if (sectors > BLK_DEV_MAX_SECTORS) {
+		pr_warn_once("%s: truncate capacity from %lld to %lld\n",
+				disk->disk_name, sectors,
+				BLK_DEV_MAX_SECTORS);
+		sectors = BLK_DEV_MAX_SECTORS;
+	}
+
 	bdev_set_nr_sectors(disk->part0, sectors);
 }
 EXPORT_SYMBOL(set_capacity);
@@ -400,6 +407,9 @@ int __must_check add_disk_fwnode(struct device *parent, struct gendisk *disk,
 	struct device *ddev = disk_to_dev(disk);
 	int ret;
 
+	if (WARN_ON_ONCE(bdev_nr_sectors(disk->part0) > BLK_DEV_MAX_SECTORS))
+		return -EINVAL;
+
 	if (queue_is_mq(disk->queue)) {
 		/*
 		 * ->submit_bio and ->poll_bio are bypassed for blk-mq drivers.