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authorPaul Clements <paul.clements@steeleye.com>2013-07-03 15:09:04 -0700
committerBen Hutchings <ben@decadent.org.uk>2013-07-27 05:34:29 +0100
commitb5f8e9877feee4ae448f5d2294278548ac6a06ba (patch)
tree0cebb52c50aaaa7be00d29117cf70d3ef4ed606e
parentc8b425eba162f29a3544ad8d137194428a9e7411 (diff)
nbd: correct disconnect behavior
commit c378f70adbc1bbecd9e6db145019f14b2f688c7c upstream. 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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust device pointer name] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--drivers/block/nbd.c7
-rw-r--r--include/linux/nbd.h1
2 files changed, 7 insertions, 1 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 4d62fe076b89..5fb6885516fa 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -598,8 +598,10 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo,
if (!lo->sock)
return -EINVAL;
+ lo->disconnect = 1;
+
nbd_send_req(lo, &sreq);
- return 0;
+ return 0;
}
case NBD_CLEAR_SOCK: {
@@ -629,6 +631,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo,
lo->sock = SOCKET_I(inode);
if (max_part > 0)
bdev->bd_invalidated = 1;
+ lo->disconnect = 0; /* we're connected now */
return 0;
} else {
fput(file);
@@ -701,6 +704,8 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo,
set_capacity(lo->disk, 0);
if (max_part > 0)
ioctl_by_bdev(bdev, BLKRRPART, 0);
+ if (lo->disconnect) /* user requested, ignore socket errors */
+ return 0;
return lo->harderror;
}
diff --git a/include/linux/nbd.h b/include/linux/nbd.h
index d146ca10c0f5..e6fe17431b95 100644
--- a/include/linux/nbd.h
+++ b/include/linux/nbd.h
@@ -68,6 +68,7 @@ struct nbd_device {
u64 bytesize;
pid_t pid; /* pid of nbd-client, if attached */
int xmit_timeout;
+ int disconnect; /* a disconnect has been requested by user */
};
#endif