Messages in this thread Patch in this message | | | Subject | Re: bio linked list corruption. | From | Jens Axboe <> | Date | Wed, 26 Oct 2016 16:52:55 -0600 |
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On 10/26/2016 04:40 PM, Dave Jones wrote: > On Wed, Oct 26, 2016 at 03:21:53PM -0700, Linus Torvalds wrote: > > > Could you try the attached patch? It adds a couple of sanity tests: > > > > - a number of tests to verify that 'rq->queuelist' isn't already on > > some queue when it is added to a queue > > > > - one test to verify that rq->mq_ctx is the same ctx that we have locked. > > > > I may be completely full of shit, and this patch may be pure garbage > > or "obviously will never trigger", but humor me. > > I gave it a shot too for shits & giggles. > This falls out during boot. > > [ 9.244030] EXT4-fs (sda4): mounted filesystem with ordered data mode. Opts: (null) > [ 9.271391] ------------[ cut here ]------------ > [ 9.278420] WARNING: CPU: 0 PID: 1 at block/blk-mq.c:1181 blk_sq_make_request+0x465/0x4a0 > [ 9.285613] CPU: 0 PID: 1 Comm: init Not tainted 4.9.0-rc2-think+ #4
Very odd, don't immediately see how that can happen. For testing, can you try and add the below patch? Just curious if that fixes the list corruption. Thing is, I don't see how ->mq_ctx and ctx are different in this path, but I can debug that on the side.
diff --git a/block/blk-mq.c b/block/blk-mq.c index ddc2eed64771..73b9462aa21f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1165,9 +1165,10 @@ static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx) }
static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, - struct blk_mq_ctx *ctx, struct request *rq, struct bio *bio) { + struct blk_mq_ctx *ctx = rq->mq_ctx; + if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) { blk_mq_bio_to_request(rq, bio); spin_lock(&ctx->lock); @@ -1338,7 +1339,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) goto done; }
- if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { + if (!blk_mq_merge_queue_io(data.hctx, rq, bio)) { /* * For a SYNC request, send it to the hardware immediately. For * an ASYNC request, just ensure that we run it later on. The @@ -1416,7 +1417,7 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) return cookie; }
- if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { + if (!blk_mq_merge_queue_io(data.hctx, rq, bio)) { /* * For a SYNC request, send it to the hardware immediately. For * an ASYNC request, just ensure that we run it later on. The -- Jens Axboe
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