Commit 4b86a872 authored Oct 16, 2007 by Paul Clements Committed by Linus Torvalds Oct 17, 2007

NBD: set uninitialized devices to size 0



This fixes errors with utilities (such as LVM's vgscan) that try to scan all
devices.  Previously this would generate read errors when uninitialized nbd
devices were scanned:

# vgscan
   Reading all physical volumes.  This may take a while...
   /dev/nbd0: read failed after 0 of 1024 at 0: Input/output error
   /dev/nbd0: read failed after 0 of 1024 at 509804544: Input/output error
   /dev/nbd0: read failed after 0 of 2048 at 0: Input/output error
   /dev/nbd1: read failed after 0 of 1024 at 509804544: Input/output error
   /dev/nbd1: read failed after 0 of 2048 at 0: Input/output error

 From now on, uninitialized nbd devices will have size zero, which
prevents these errors.

Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent dff4982f

drivers/block/nbd.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -578,6 +578,9 @@ static int nbd_ioctl(struct inode inode, struct file file,
		printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name);
		if (file)
		fput(file);
		lo->bytesize = 0;
		inode->i_bdev->bd_inode->i_size = 0;
		set_capacity(lo->disk, 0);
		return lo->harderror;
		case NBD_CLEAR_QUE:
		/*
		@@ -655,14 +658,14 @@ static int __init nbd_init(void)
		mutex_init(&nbd_dev[i].tx_lock);
		init_waitqueue_head(&nbd_dev[i].active_wq);
		nbd_dev[i].blksize = 1024;
		nbd_dev[i].bytesize = 0x7ffffc00ULL << 10; /* 2TB */
		nbd_dev[i].bytesize = 0;
		disk->major = NBD_MAJOR;
		disk->first_minor = i;
		disk->fops = &nbd_fops;
		disk->private_data = &nbd_dev[i];
		disk->flags \|= GENHD_FL_SUPPRESS_PARTITION_INFO;
		sprintf(disk->disk_name, "nbd%d", i);
		set_capacity(disk, 0x7ffffc00ULL << 1); /* 2 TB */
		set_capacity(disk, 0);
		add_disk(disk);
		}

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