From b5f8e9877feee4ae448f5d2294278548ac6a06ba Mon Sep 17 00:00:00 2001 From: Paul Clements Date: Wed, 3 Jul 2013 15:09:04 -0700 Subject: [PATCH 1/1] 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 Acked-by: Rob Landley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.2: adjust device pointer name] Signed-off-by: Ben Hutchings --- drivers/block/nbd.c | 7 ++++++- include/linux/nbd.h | 1 + 2 files changed, 7 insertions(+), 1 deletion(-) 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 -- 2.39.2