Re: [BUG REPORT] Kernel panic on 3.9.0-rc7-4-gbb33db7

[Tejun Heo <tj@kernel.org>]

Hello, Wanlong.

On Thu, Apr 18, 2013 at 10:45:10PM +0800, Wanlong Gao wrote:
> OK, but I should capture it tomorrow morning because this remote machine has already panicked
> and need hard reboot.

Can you please apply the following patch when you try the next time
and report the kernel log?  It should prevent the oops from happening
and dump information on at least who are the involved parties.

Thanks.

diff --git a/block/blk-core.c b/block/blk-core.c
index 074b758..d5efebe 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -150,6 +150,8 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
 }
 EXPORT_SYMBOL(blk_rq_init);
 
+
+
 static void req_bio_endio(struct request *rq, struct bio *bio,
 			  unsigned int nbytes, int error)
 {
@@ -174,8 +176,15 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
 		bio_integrity_advance(bio, nbytes);
 
 	/* don't actually finish bio if it's part of flush sequence */
-	if (bio->bi_size == 0 && !(rq->cmd_flags & REQ_FLUSH_SEQ))
+	if (bio->bi_size == 0 && !(rq->cmd_flags & REQ_FLUSH_SEQ)) {
+		if (bio->bi_bdev && (unsigned long)bio->bi_bdev < 4096) {
+			printk_ratelimited("XXX req_bio_endio: queue %s bio=%p bi_bdev=%p bi_end_io=%pf\n",
+					   (rq->q && rq->q->backing_dev_info.dev) ?
+					   dev_name(rq->q->backing_dev_info.dev) : "<unknown>",
+					   bio, bio->bi_bdev, bio->bi_end_io);
+		}
 		bio_endio(bio, error);
+	}
 }
 
 void blk_dump_rq_flags(struct request *rq, char *msg)
diff --git a/fs/bio.c b/fs/bio.c
index bb5768f..da64e5a 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1428,7 +1428,10 @@ void bio_endio(struct bio *bio, int error)
 	else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
 		error = -EIO;
 
-	trace_block_bio_complete(bio, error);
+	if (bio->bi_bdev && (unsigned long)bio->bi_bdev < 4096)
+		printk_ratelimited("XXX bio_endio: skipping TP for %p\n", bio);
+	else
+		trace_block_bio_complete(bio, error);
 
 	if (bio->bi_end_io)
 		bio->bi_end_io(bio, error);