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| author | Paul Clements <paul.clements@steeleye.com> | 2013-07-03 15:09:04 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-11 16:10:06 -0700 |
| commit | 50e97121b728014dfbc34f07d1ac5a507466a2b7 (patch) | |
| tree | 09bd01313569381c361418a1fb7715f2c883f7aa /drivers | |
| parent | b0f9634dcc55be0ad7cfbc96c790bad780bd463d (diff) | |
| download | lwn-50e97121b728014dfbc34f07d1ac5a507466a2b7.tar.gz lwn-50e97121b728014dfbc34f07d1ac5a507466a2b7.zip | |
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>
[xr: Backported to 3.4: adjust context]
Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/block/nbd.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 386d40e3cf48..d724da52153b 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -590,8 +590,11 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, 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_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); @@ -691,6 +695,8 @@ 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; } |