1 files changed, 50 insertions, 16 deletions

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index bc31bb7072a2..637c5bda2387 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -990,7 +990,7 @@ loop_set_status_from_info(struct loop_device *lo,
 	return 0;
 }
 
-static int loop_configure(struct loop_device *lo, fmode_t mode,
+static int loop_configure(struct loop_device *lo, blk_mode_t mode,
 			  struct block_device *bdev,
 			  const struct loop_config *config)
 {
@@ -1014,8 +1014,8 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	 * If we don't hold exclusive handle for the device, upgrade to it
 	 * here to avoid changing device under exclusive owner.
 	 */
-	if (!(mode & FMODE_EXCL)) {
-		error = bd_prepare_to_claim(bdev, loop_configure);
+	if (!(mode & BLK_OPEN_EXCL)) {
+		error = bd_prepare_to_claim(bdev, loop_configure, NULL);
 		if (error)
 			goto out_putf;
 	}
@@ -1050,7 +1050,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	if (error)
 		goto out_unlock;
 
-	if (!(file->f_mode & FMODE_WRITE) || !(mode & FMODE_WRITE) ||
+	if (!(file->f_mode & FMODE_WRITE) || !(mode & BLK_OPEN_WRITE) ||
 	    !file->f_op->write_iter)
 		lo->lo_flags |= LO_FLAGS_READ_ONLY;
 
@@ -1116,7 +1116,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	if (partscan)
 		loop_reread_partitions(lo);
 
-	if (!(mode & FMODE_EXCL))
+	if (!(mode & BLK_OPEN_EXCL))
 		bd_abort_claiming(bdev, loop_configure);
 
 	return 0;
@@ -1124,7 +1124,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 out_unlock:
 	loop_global_unlock(lo, is_loop);
 out_bdev:
-	if (!(mode & FMODE_EXCL))
+	if (!(mode & BLK_OPEN_EXCL))
 		bd_abort_claiming(bdev, loop_configure);
 out_putf:
 	fput(file);
@@ -1528,7 +1528,7 @@ static int lo_simple_ioctl(struct loop_device *lo, unsigned int cmd,
 	return err;
 }
 
-static int lo_ioctl(struct block_device *bdev, fmode_t mode,
+static int lo_ioctl(struct block_device *bdev, blk_mode_t mode,
 	unsigned int cmd, unsigned long arg)
 {
 	struct loop_device *lo = bdev->bd_disk->private_data;
@@ -1563,24 +1563,22 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
 		return loop_clr_fd(lo);
 	case LOOP_SET_STATUS:
 		err = -EPERM;
-		if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
+		if ((mode & BLK_OPEN_WRITE) || capable(CAP_SYS_ADMIN))
 			err = loop_set_status_old(lo, argp);
-		}
 		break;
 	case LOOP_GET_STATUS:
 		return loop_get_status_old(lo, argp);
 	case LOOP_SET_STATUS64:
 		err = -EPERM;
-		if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
+		if ((mode & BLK_OPEN_WRITE) || capable(CAP_SYS_ADMIN))
 			err = loop_set_status64(lo, argp);
-		}
 		break;
 	case LOOP_GET_STATUS64:
 		return loop_get_status64(lo, argp);
 	case LOOP_SET_CAPACITY:
 	case LOOP_SET_DIRECT_IO:
 	case LOOP_SET_BLOCK_SIZE:
-		if (!(mode & FMODE_WRITE) && !capable(CAP_SYS_ADMIN))
+		if (!(mode & BLK_OPEN_WRITE) && !capable(CAP_SYS_ADMIN))
 			return -EPERM;
 		fallthrough;
 	default:
@@ -1691,7 +1689,7 @@ loop_get_status_compat(struct loop_device *lo,
 	return err;
 }
 
-static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
+static int lo_compat_ioctl(struct block_device *bdev, blk_mode_t mode,
 			   unsigned int cmd, unsigned long arg)
 {
 	struct loop_device *lo = bdev->bd_disk->private_data;
@@ -1727,7 +1725,7 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
 }
 #endif
 
-static void lo_release(struct gendisk *disk, fmode_t mode)
+static void lo_release(struct gendisk *disk)
 {
 	struct loop_device *lo = disk->private_data;
 
@@ -1777,14 +1775,43 @@ static const struct block_device_operations lo_fops = {
 /*
  * If max_loop is specified, create that many devices upfront.
  * This also becomes a hard limit. If max_loop is not specified,
+ * the default isn't a hard limit (as before commit 85c50197716c
+ * changed the default value from 0 for max_loop=0 reasons), just
  * create CONFIG_BLK_DEV_LOOP_MIN_COUNT loop devices at module
  * init time. Loop devices can be requested on-demand with the
  * /dev/loop-control interface, or be instantiated by accessing
  * a 'dead' device node.
  */
 static int max_loop = CONFIG_BLK_DEV_LOOP_MIN_COUNT;
-module_param(max_loop, int, 0444);
+
+#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
+static bool max_loop_specified;
+
+static int max_loop_param_set_int(const char *val,
+				  const struct kernel_param *kp)
+{
+	int ret;
+
+	ret = param_set_int(val, kp);
+	if (ret < 0)
+		return ret;
+
+	max_loop_specified = true;
+	return 0;
+}
+
+static const struct kernel_param_ops max_loop_param_ops = {
+	.set = max_loop_param_set_int,
+	.get = param_get_int,
+};
+
+module_param_cb(max_loop, &max_loop_param_ops, &max_loop, 0444);
 MODULE_PARM_DESC(max_loop, "Maximum number of loop devices");
+#else
+module_param(max_loop, int, 0444);
+MODULE_PARM_DESC(max_loop, "Initial number of loop devices");
+#endif
+
 module_param(max_part, int, 0444);
 MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device");
 
@@ -2095,14 +2122,18 @@ static void loop_remove(struct loop_device *lo)
 	put_disk(lo->lo_disk);
 }
 
+#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
 static void loop_probe(dev_t dev)
 {
 	int idx = MINOR(dev) >> part_shift;
 
-	if (max_loop && idx >= max_loop)
+	if (max_loop_specified && max_loop && idx >= max_loop)
 		return;
 	loop_add(idx);
 }
+#else
+#define loop_probe NULL
+#endif /* !CONFIG_BLOCK_LEGACY_AUTOLOAD */
 
 static int loop_control_remove(int idx)
 {
@@ -2283,6 +2314,9 @@ module_exit(loop_exit);
 static int __init max_loop_setup(char *str)
 {
 	max_loop = simple_strtol(str, NULL, 0);
+#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
+	max_loop_specified = true;
+#endif
 	return 1;
 }