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| author | Paul Clements <paul.clements@steeleye.com> | 2013-07-03 15:09:04 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-07-27 05:34:29 +0100 |
| commit | b5f8e9877feee4ae448f5d2294278548ac6a06ba (patch) | |
| tree | 0cebb52c50aaaa7be00d29117cf70d3ef4ed606e | |
| parent | c8b425eba162f29a3544ad8d137194428a9e7411 (diff) | |
| download | lwn-b5f8e9877feee4ae448f5d2294278548ac6a06ba.tar.gz lwn-b5f8e9877feee4ae448f5d2294278548ac6a06ba.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>
[bwh: Backported to 3.2: adjust device pointer name]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/block/nbd.c | 7 | ||||
| -rw-r--r-- | include/linux/nbd.h | 1 |
2 files changed, 7 insertions, 1 deletions
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 |