diff options
| author | Thorsten Knabe <linux@thorsten-knabe.de> | 2014-08-23 15:47:38 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-14 08:59:49 -0800 |
| commit | c8f712403473828d7a72882025114ef42491b1ae (patch) | |
| tree | 6753651ab7f5539c76f2e25777b71babdad2aa50 /arch/um | |
| parent | 119947ac0a0929f3602d6015c49116ea67cbc617 (diff) | |
um: ubd: Fix for processes stuck in D state forever
commit 2a2361228c5e6d8c1733f00653481de918598e50 upstream.
Starting with Linux 3.12 processes get stuck in D state forever in
UserModeLinux under sync heavy workloads. This bug was introduced by
commit 805f11a0d5 (um: ubd: Add REQ_FLUSH suppport).
Fix bug by adding a check if FLUSH request was successfully submitted to
the I/O thread and keeping the FLUSH request on the request queue on
submission failures.
Fixes: 805f11a0d5 (um: ubd: Add REQ_FLUSH suppport)
Signed-off-by: Thorsten Knabe <linux@thorsten-knabe.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/drivers/ubd_kern.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 3716e6952554..e8ab93c3e638 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -1277,7 +1277,7 @@ static void do_ubd_request(struct request_queue *q) while(1){ struct ubd *dev = q->queuedata; - if(dev->end_sg == 0){ + if(dev->request == NULL){ struct request *req = blk_fetch_request(q); if(req == NULL) return; @@ -1299,7 +1299,8 @@ static void do_ubd_request(struct request_queue *q) return; } prepare_flush_request(req, io_req); - submit_request(io_req, dev); + if (submit_request(io_req, dev) == false) + return; } while(dev->start_sg < dev->end_sg){ |