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| author | Laurent Vivier <Laurent.Vivier@bull.net> | 2008-04-29 01:02:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-29 08:06:23 -0700 |
| commit | 48cf6061b30205b29b306bf9bc22dd6f0b091461 (patch) | |
| tree | bba7827177587a17160c29392651aa27aa7f98fd /include/linux/nbd.h | |
| parent | 8c4dd6068221cd1d0d90490ace80eb4344914a8c (diff) | |
| download | lwn-48cf6061b30205b29b306bf9bc22dd6f0b091461.tar.gz lwn-48cf6061b30205b29b306bf9bc22dd6f0b091461.zip | |
NBD: allow nbd to be used locally
This patch allows Network Block Device to be mounted locally (nbd-client to
nbd-server over 127.0.0.1).
It creates a kthread to avoid the deadlock described in NBD tools
documentation. So, if nbd-client hangs waiting for pages, the kblockd thread
can continue its work and free pages.
I have tested the patch to verify that it avoids the hang that always occurs
when writing to a localhost nbd connection. I have also tested to verify that
no performance degradation results from the additional thread and queue.
Patch originally from Laurent Vivier.
Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/nbd.h')
| -rw-r--r-- | include/linux/nbd.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/nbd.h b/include/linux/nbd.h index 986572081e19..69075517c511 100644 --- a/include/linux/nbd.h +++ b/include/linux/nbd.h @@ -56,9 +56,11 @@ struct nbd_device { int magic; spinlock_t queue_lock; - struct list_head queue_head;/* Requests are added here... */ + struct list_head queue_head; /* Requests waiting result */ struct request *active_req; wait_queue_head_t active_wq; + struct list_head waiting_queue; /* Requests to be sent */ + wait_queue_head_t waiting_wq; struct mutex tx_lock; struct gendisk *disk; |