[PATCH] switch nbd

NB: nbd_ioctl() appears to be racy; BKL is held, but doesn't really
help, AFAICS.  Left as-is for now, but it'll need fixing.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/block/nbd.c

@@ -557,10 +557,11 @@ static void do_nbd_request(struct request_queue * q)
 	}
 }
 
-static int nbd_ioctl(struct inode *inode, struct file *file,
+static int nbd_ioctl(struct block_device *bdev, fmode_t mode,
 		     unsigned int cmd, unsigned long arg)
 {
-	struct nbd_device *lo = inode->i_bdev->bd_disk->private_data;
+	struct nbd_device *lo = bdev->bd_disk->private_data;
+	struct file *file;
 	int error;
 	struct request sreq ;
 	struct task_struct *thread;
@@ -612,8 +613,7 @@ static int nbd_ioctl(struct inode *inode, struct file *file,
 		error = -EINVAL;
 		file = fget(arg);
 		if (file) {
-			struct block_device *bdev = inode->i_bdev;
-			inode = file->f_path.dentry->d_inode;
+			struct inode *inode = file->f_path.dentry->d_inode;
 			if (S_ISSOCK(inode->i_mode)) {
 				lo->file = file;
 				lo->sock = SOCKET_I(inode);
@@ -628,14 +628,14 @@ static int nbd_ioctl(struct inode *inode, struct file *file,
 	case NBD_SET_BLKSIZE:
 		lo->blksize = arg;
 		lo->bytesize &= ~(lo->blksize-1);
-		inode->i_bdev->bd_inode->i_size = lo->bytesize;
-		set_blocksize(inode->i_bdev, lo->blksize);
+		bdev->bd_inode->i_size = lo->bytesize;
+		set_blocksize(bdev, lo->blksize);
 		set_capacity(lo->disk, lo->bytesize >> 9);
 		return 0;
 	case NBD_SET_SIZE:
 		lo->bytesize = arg & ~(lo->blksize-1);
-		inode->i_bdev->bd_inode->i_size = lo->bytesize;
-		set_blocksize(inode->i_bdev, lo->blksize);
+		bdev->bd_inode->i_size = lo->bytesize;
+		set_blocksize(bdev, lo->blksize);
 		set_capacity(lo->disk, lo->bytesize >> 9);
 		return 0;
 	case NBD_SET_TIMEOUT:
@@ -643,8 +643,8 @@ static int nbd_ioctl(struct inode *inode, struct file *file,
 		return 0;
 	case NBD_SET_SIZE_BLOCKS:
 		lo->bytesize = ((u64) arg) * lo->blksize;
-		inode->i_bdev->bd_inode->i_size = lo->bytesize;
-		set_blocksize(inode->i_bdev, lo->blksize);
+		bdev->bd_inode->i_size = lo->bytesize;
+		set_blocksize(bdev, lo->blksize);
 		set_capacity(lo->disk, lo->bytesize >> 9);
 		return 0;
 	case NBD_DO_IT:
@@ -666,10 +666,10 @@ static int nbd_ioctl(struct inode *inode, struct file *file,
 		if (file)
 			fput(file);
 		lo->bytesize = 0;
-		inode->i_bdev->bd_inode->i_size = 0;
+		bdev->bd_inode->i_size = 0;
 		set_capacity(lo->disk, 0);
 		if (max_part > 0)
-			ioctl_by_bdev(inode->i_bdev, BLKRRPART, 0);
+			ioctl_by_bdev(bdev, BLKRRPART, 0);
 		return lo->harderror;
 	case NBD_CLEAR_QUE:
 		/*
@@ -680,7 +680,7 @@ static int nbd_ioctl(struct inode *inode, struct file *file,
 		return 0;
 	case NBD_PRINT_DEBUG:
 		printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n",
-			inode->i_bdev->bd_disk->disk_name,
+			bdev->bd_disk->disk_name,
 			lo->queue_head.next, lo->queue_head.prev,
 			&lo->queue_head);
 		return 0;
@@ -691,7 +691,7 @@ static int nbd_ioctl(struct inode *inode, struct file *file,
 static struct block_device_operations nbd_fops =
 {
 	.owner =	THIS_MODULE,
-	.__ioctl =	nbd_ioctl,
+	.locked_ioctl =	nbd_ioctl,
 };
 
 /*