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>
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 7ed1308..2dc3b51 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -623,8 +623,10 @@
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 @@
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 @@
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;
}
