OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

um: ubd: Fix for processes stuck in D state forever 

commit 2a2361228c 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>
This commit is contained in:
Thorsten Knabe 2014-08-23 15:47:38 +02:00 committed by Greg Kroah-Hartman
parent 119947ac0a
commit c8f7124034
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/um/drivers/ubd_kern.c
View File

@ -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){