| From | Luis Henriques <> | Subject | [PATCH 39/98] nbd: correct disconnect behavior | Date | Thu, 11 Jul 2013 15:24:09 +0100 |
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3.5.7.17 -stable review patch. If anyone has any objections, please let me know.
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From: Paul Clements <paul.clements@steeleye.com>
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> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- 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 e1d49fc..35fc569 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 *nbd, if (!nbd->sock) return -EINVAL; + nbd->disconnect = 1; + nbd_send_req(nbd, &sreq); - return 0; + return 0; } case NBD_CLEAR_SOCK: { @@ -629,6 +631,7 @@ 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); @@ -701,6 +704,8 @@ 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 d146ca1..e6fe174 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 -- 1.8.1.2
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