From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Clements , Rob Landley , Andrew Morton , Linus Torvalds , Rui Xiang Subject: [PATCH 3.4 64/99] nbd: correct disconnect behavior Date: Fri, 7 Mar 2014 17:08:00 -0800 Message-Id: <20140308010613.649452661@linuxfoundation.org> In-Reply-To: <20140308010611.468206150@linuxfoundation.org> References: <20140308010611.468206150@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paul Clements 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 [xr: Backported to 3.4: adjust context] Signed-off-by: Rui Xiang Signed-off-by: Greg Kroah-Hartman --- drivers/block/nbd.c | 8 +++++++- include/linux/nbd.h | 1 + 2 files changed, 8 insertions(+), 1 deletion(-) --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -590,8 +590,11 @@ static int __nbd_ioctl(struct block_devi nbd_cmd(&sreq) = NBD_CMD_DISC; if (!nbd->sock) return -EINVAL; + + nbd->disconnect = 1; + nbd_send_req(nbd, &sreq); - return 0; + return 0; } case NBD_CLEAR_SOCK: { @@ -620,6 +623,7 @@ static int __nbd_ioctl(struct block_devi 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); @@ -691,6 +695,8 @@ static int __nbd_ioctl(struct block_devi 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; } --- 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