From c378f70adbc1bbecd9e6db145019f14b2f688c7c Mon Sep 17 00:00:00 2001 From: Paul Clements Date: Wed, 3 Jul 2013 15:09:04 -0700 Subject: [PATCH] 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 Acked-by: Rob Landley Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 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; } diff --git a/include/linux/nbd.h b/include/linux/nbd.h index 4871170a04a0..ae4981ebd18e 100644 --- a/include/linux/nbd.h +++ b/include/linux/nbd.h @@ -41,6 +41,7 @@ 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 -- 2.30.2