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authorPaul Clements <paul.clements@steeleye.com>2013-07-03 15:09:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 16:08:05 -0700
commitc378f70adbc1bbecd9e6db145019f14b2f688c7c (patch)
tree6b81f9cf54e812e10d6930ece08f3149dccbc535 /drivers/block
parent9532f149ee4532b5efc7e4a76381e1742805e1af (diff)
downloadlinux-c378f70adbc1bbecd9e6db145019f14b2f688c7c.tar.gz
nbd: correct disconnect behavior
Currently, when a disconnect is requested by the user (via NBD_DISCONNECT
ioctl) the return from NBD_DO_IT is undefined (it is usually one of
several error codes).  This means that nbd-client does not know if a
manual disconnect was performed or whether a network error occurred.
Because of this, nbd-client's persist mode (which tries to reconnect after
error, but not after manual disconnect) does not always work correctly.

This change fixes this by causing NBD_DO_IT to always return 0 if a user
requests a disconnect.  This means that nbd-client can correctly either
persist the connection (if an error occurred) or disconnect (if the user
requested it).

Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Acked-by: Rob Landley <rob@landley.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/nbd.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 7ed1308c42d3..2dc3b5153f0d 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -623,8 +623,10 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 		if (!nbd->sock)
 			return -EINVAL;
 
+		nbd->disconnect = 1;
+
 		nbd_send_req(nbd, &sreq);
-                return 0;
+		return 0;
 	}
  
 	case NBD_CLEAR_SOCK: {
@@ -654,6 +656,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 				nbd->sock = SOCKET_I(inode);
 				if (max_part > 0)
 					bdev->bd_invalidated = 1;
+				nbd->disconnect = 0; /* we're connected now */
 				return 0;
 			} else {
 				fput(file);
@@ -743,6 +746,8 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 		set_capacity(nbd->disk, 0);
 		if (max_part > 0)
 			ioctl_by_bdev(bdev, BLKRRPART, 0);
+		if (nbd->disconnect) /* user requested, ignore socket errors */
+			return 0;
 		return nbd->harderror;
 	}