[PATCH] IDE error handling fixes
In 2.6.15.1 I encountered some IDE crashes when unplugging IDE cables to
emulate disk errors. Below is a patch against 2.6.16 which I think still
applies.
1. The first BUG_ON could trigger when a PREFLUSH IO fails (it would
fail the original barrier request which hasn't been marked REQ_STARTED
yet).
2. the rq could have been dequeued already (same as 1).
3. HWGROUP(drive)->rq could be NULL because of the ide_error() several
lines earlier.
Signed-off-by: Hua Zhong <hzhong@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 38479a29..8d26619 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -59,8 +59,6 @@
{
int ret = 1;
- BUG_ON(!blk_rq_started(rq));
-
/*
* if failfast is set on a request, override number of sectors and
* complete the whole request right now
@@ -82,7 +80,8 @@
if (!end_that_request_first(rq, uptodate, nr_sectors)) {
add_disk_randomness(rq->rq_disk);
- blkdev_dequeue_request(rq);
+ if (!list_empty(&rq->queuelist))
+ blkdev_dequeue_request(rq);
HWGROUP(drive)->rq = NULL;
end_that_request_last(rq, uptodate);
ret = 0;
@@ -1346,6 +1345,10 @@
* make sure request is sane
*/
rq = HWGROUP(drive)->rq;
+
+ if (!rq)
+ goto out;
+
HWGROUP(drive)->rq = NULL;
rq->errors = 0;