diff options
| author | Paul Clements <paul.clements@steeleye.com> | 2012-09-17 14:09:02 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-02 10:29:59 -0700 |
| commit | 547ee164a63242ef14c41410615aa60aa164fce2 (patch) | |
| tree | 8cf97cd29fd887a7bf7f02353701b386cd61efe2 /drivers/block | |
| parent | 9fd0132a29b4e40e5cf5ff82a02227b7f603bba7 (diff) | |
nbd: clear waiting_queue on shutdown
commit fded4e090c60100d709318896c79816d68d5b47d upstream.
Fix a serious but uncommon bug in nbd which occurs when there is heavy
I/O going to the nbd device while, at the same time, a failure (server,
network) or manual disconnect of the nbd connection occurs.
There is a small window between the time that the nbd_thread is stopped
and the socket is shutdown where requests can continue to be queued to
nbd's internal waiting_queue. When this happens, those requests are
never completed or freed.
The fix is to clear the waiting_queue on shutdown of the nbd device, in
the same way that the nbd request queue (queue_head) is already being
cleared.
Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/nbd.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 061427a75d37..3c4c225d1981 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -445,6 +445,14 @@ static void nbd_clear_que(struct nbd_device *nbd) req->errors++; nbd_end_request(req); } + + while (!list_empty(&nbd->waiting_queue)) { + req = list_entry(nbd->waiting_queue.next, struct request, + queuelist); + list_del_init(&req->queuelist); + req->errors++; + nbd_end_request(req); + } } @@ -594,6 +602,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, nbd->file = NULL; nbd_clear_que(nbd); BUG_ON(!list_empty(&nbd->queue_head)); + BUG_ON(!list_empty(&nbd->waiting_queue)); if (file) fput(file); return 0; |