diff options
author | Thorsten Knabe <linux@thorsten-knabe.de> | 2014-08-23 17:47:38 +0400 |
---|---|---|
committer | Jiri Slaby <jslaby@suse.cz> | 2014-11-13 21:02:16 +0300 |
commit | 63550e4be59837925cc1bee167bee83a90ce974c (patch) | |
tree | fe08554948be1e738171918f87bb91fd69724126 /arch/um | |
parent | ec84c5e8a19be56aa297f195885e0303a956230f (diff) | |
download | linux-63550e4be59837925cc1bee167bee83a90ce974c.tar.xz |
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: Jiri Slaby <jslaby@suse.cz>
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){ |