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Message-ID: <4F1BE548.3000800@kernel.dk>
Date: Sun, 22 Jan 2012 11:30:32 +0100
From: Jens Axboe <axboe@...nel.dk>
To: Christian Kujau <lists@...dbynature.de>
CC: LKML <linux-kernel@...r.kernel.org>, peterz@...radead.org,
dm-devel@...hat.com
Subject: Re: BUG: spinlock trylock failure on UP on CPU#0, vgchange/936
On 01/21/2012 11:35 PM, Christian Kujau wrote:
> On Sat, 21 Jan 2012 at 13:46, Jens Axboe wrote:
>> Can you try and pull:
>>
>> git://git.kernel.dk/linux-block.git for-linus
>>
>> and see if it helps?
>
> Pulled, compiled, bootet - but the BUG: stays. Please see .config and full
> dmesg: http://nerdbynature.de/bits/3.2.0/ (the 3.3.0-rc1 files)
>
> Note that I don't have an actual problem here: the machine (PowerBook G4)
> is booting & running fine, I'm currently not using any LVM devices, so
> it's merely the BUG: being printed during bootup I'm whining about.
What about with this on top?
diff --git a/block/blk-core.c b/block/blk-core.c
index e6c05a9..75eba5c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1283,7 +1283,7 @@ static bool attempt_plug_merge(struct request_queue *q, struct bio *bio,
if (rq->q != q)
continue;
- el_ret = elv_try_merge(rq, bio);
+ el_ret = blk_try_merge(rq, bio);
if (el_ret == ELEVATOR_BACK_MERGE) {
ret = bio_attempt_back_merge(q, rq, bio);
if (ret)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index cfcc37c..ee9ec90 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -471,3 +471,59 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
{
return attempt_merge(q, rq, next);
}
+
+int blk_rq_merge_ok(struct request *rq, struct bio *bio)
+{
+ if (!rq_mergeable(rq))
+ return 0;
+
+ /*
+ * Don't merge file system requests and discard requests
+ */
+ if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD))
+ return 0;
+
+ /*
+ * Don't merge discard requests and secure discard requests
+ */
+ if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE))
+ return 0;
+
+ /*
+ * different data direction or already started, don't merge
+ */
+ if (bio_data_dir(bio) != rq_data_dir(rq))
+ return 0;
+
+ /*
+ * must be same device and not a special request
+ */
+ if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special)
+ return 0;
+
+ /*
+ * only merge integrity protected bio into ditto rq
+ */
+ if (bio_integrity(bio) != blk_integrity_rq(rq))
+ return 0;
+
+ return 1;
+}
+EXPORT_SYMBOL(blk_rq_merge_ok);
+
+int blk_try_merge(struct request *__rq, struct bio *bio)
+{
+ int ret = ELEVATOR_NO_MERGE;
+
+ /*
+ * we can merge and sequence is ok, check if it's possible
+ */
+ if (blk_rq_merge_ok(__rq, bio)) {
+ if (blk_rq_pos(__rq) + blk_rq_sectors(__rq) == bio->bi_sector)
+ ret = ELEVATOR_BACK_MERGE;
+ else if (blk_rq_pos(__rq) - bio_sectors(bio) == bio->bi_sector)
+ ret = ELEVATOR_FRONT_MERGE;
+ }
+
+ return ret;
+}
diff --git a/block/blk.h b/block/blk.h
index 7efd772..a117fa9 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -137,6 +137,8 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
struct request *next);
void blk_recalc_rq_segments(struct request *rq);
void blk_rq_set_mixed_merge(struct request *rq);
+int blk_rq_merge_ok(struct request *rq, struct bio *bio);
+int blk_try_merge(struct request *rq, struct bio *bio);
void blk_queue_congestion_threshold(struct request_queue *q);
diff --git a/block/elevator.c b/block/elevator.c
index 91e18f8..a1a75f7 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -72,39 +72,8 @@ static int elv_iosched_allow_merge(struct request *rq, struct bio *bio)
*/
int elv_rq_merge_ok(struct request *rq, struct bio *bio)
{
- if (!rq_mergeable(rq))
+ if (!blk_rq_merge_ok(rq, bio))
return 0;
-
- /*
- * Don't merge file system requests and discard requests
- */
- if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD))
- return 0;
-
- /*
- * Don't merge discard requests and secure discard requests
- */
- if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE))
- return 0;
-
- /*
- * different data direction or already started, don't merge
- */
- if (bio_data_dir(bio) != rq_data_dir(rq))
- return 0;
-
- /*
- * must be same device and not a special request
- */
- if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special)
- return 0;
-
- /*
- * only merge integrity protected bio into ditto rq
- */
- if (bio_integrity(bio) != blk_integrity_rq(rq))
- return 0;
-
if (!elv_iosched_allow_merge(rq, bio))
return 0;
@@ -114,19 +83,13 @@ EXPORT_SYMBOL(elv_rq_merge_ok);
int elv_try_merge(struct request *__rq, struct bio *bio)
{
- int ret = ELEVATOR_NO_MERGE;
-
/*
* we can merge and sequence is ok, check if it's possible
*/
- if (elv_rq_merge_ok(__rq, bio)) {
- if (blk_rq_pos(__rq) + blk_rq_sectors(__rq) == bio->bi_sector)
- ret = ELEVATOR_BACK_MERGE;
- else if (blk_rq_pos(__rq) - bio_sectors(bio) == bio->bi_sector)
- ret = ELEVATOR_FRONT_MERGE;
- }
+ if (elv_rq_merge_ok(__rq, bio))
+ return blk_try_merge(__rq, bio);
- return ret;
+ return ELEVATOR_NO_MERGE;
}
static struct elevator_type *elevator_find(const char *name)
--
Jens Axboe
--
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