On Tue, Feb 19, 2019 at 08:28:19AM -0800, Bart Van Assche wrote: > On Sun, 2019-02-17 at 21:11 +0800, Ming Lei wrote: > > The following patch should fix this issue: > > > > > > diff --git a/block/blk-merge.c b/block/blk-merge.c > > index bed065904677..066b66430523 100644 > > --- a/block/blk-merge.c > > +++ b/block/blk-merge.c > > @@ -363,13 +363,15 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, > > struct bio_vec bv, bvprv = { NULL }; > > int prev = 0; > > unsigned int seg_size, nr_phys_segs; > > - unsigned front_seg_size = bio->bi_seg_front_size; > > + unsigned front_seg_size; > > struct bio *fbio, *bbio; > > struct bvec_iter iter; > > > > if (!bio) > > return 0; > > > > + front_seg_size = bio->bi_seg_front_size; > > + > > switch (bio_op(bio)) { > > case REQ_OP_DISCARD: > > case REQ_OP_SECURE_ERASE: > > Hi Ming, > > With this patch applied test nvmeof-mp/002 fails as follows: > > [ 694.700400] kernel BUG at lib/sg_pool.c:103! > [ 694.705932] invalid opcode: 0000 [#1] PREEMPT SMP KASAN > [ 694.708297] CPU: 2 PID: 349 Comm: kworker/2:1H Tainted: G B 5.0.0-rc6-dbg+ #2 > [ 694.711730] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 > [ 694.715113] Workqueue: kblockd blk_mq_run_work_fn > [ 694.716894] RIP: 0010:sg_alloc_table_chained+0xe5/0xf0 > [ 694.758222] Call Trace: > [ 694.759645] nvme_rdma_queue_rq+0x2aa/0xcc0 [nvme_rdma] > [ 694.764915] blk_mq_try_issue_directly+0x2a5/0x4b0 > [ 694.771779] blk_insert_cloned_request+0x11e/0x1c0 > [ 694.778417] dm_mq_queue_rq+0x3d1/0x770 > [ 694.793400] blk_mq_dispatch_rq_list+0x5fc/0xb10 > [ 694.798386] blk_mq_sched_dispatch_requests+0x2f7/0x300 > [ 694.803180] __blk_mq_run_hw_queue+0xd6/0x180 > [ 694.808933] blk_mq_run_work_fn+0x27/0x30 > [ 694.810315] process_one_work+0x4f1/0xa40 > [ 694.813178] worker_thread+0x67/0x5b0 > [ 694.814487] kthread+0x1cf/0x1f0 > [ 694.819134] ret_from_fork+0x24/0x30 > > The code in sg_pool.c that triggers the BUG() statement is as follows: > > int sg_alloc_table_chained(struct sg_table *table, int nents, > struct scatterlist *first_chunk) > { > int ret; > > BUG_ON(!nents); > [ ... ] > > Bart. I can reproduce this issue("kernel BUG at lib/sg_pool.c:103") without mp-bvec patches, so looks it isn't the fault of this patchset. Thanks, Ming -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel