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2023-04-13blk-mq: directly poll requestsKeith Busch1-3/+1
commit 38a8c4d1d45006841f0643f4cb29b5e50758837c upstream. Polling needs a bio with a valid bi_bdev, but neither of those are guaranteed for polled driver requests. Make request based polling directly use blk-mq's polling function instead. When executing a request from a polled hctx, we know the request's cookie, and that it's from a live blk-mq queue that supports polling, so we can safely skip everything that bio_poll provides. Cc: stable@kernel.org Reported-by: Martin Belanger <Martin.Belanger@dell.com> Reported-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Tested-by: Daniel Wagner <dwagner@suse.de> Revieded-by: Daniel Wagner <dwagner@suse.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Link: https://lore.kernel.org/r/20230331180056.1155862-1-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22block: do not reverse request order when flushing plug listJan Kara1-2/+3
[ Upstream commit 34e0a279a993debaff03158fc2fbf6a00c093643 ] Commit 26fed4ac4eab ("block: flush plug based on hardware and software queue order") changed flushing of plug list to submit requests one device at a time. However while doing that it also started using list_add_tail() instead of list_add() used previously thus effectively submitting requests in reverse order. Also when forming a rq_list with remaining requests (in case two or more devices are used), we effectively reverse the ordering of the plug list for each device we process. Submitting requests in reverse order has negative impact on performance for rotational disks (when BFQ is not in use). We observe 10-25% regression in random 4k write throughput, as well as ~20% regression in MariaDB OLTP benchmark on rotational storage on btrfs filesystem. Fix the problem by preserving ordering of the plug list when inserting requests into the queuelist as well as by appending to requeue_list instead of prepending to it. Fixes: 26fed4ac4eab ("block: flush plug based on hardware and software queue order") Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230313093002.11756-1-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10blk-mq: Fix potential io hung for shared sbitmap per tagsetKemeng Shi1-2/+4
[ Upstream commit 47df9ce95cd568d3f84218c4f65e9fbd4dfeda55 ] Commit f906a6a0f4268 ("blk-mq: improve tag waiting setup for non-shared tags") mark restart for unshared tags for improvement. At that time, tags is only shared betweens queues and we can check if tags is shared by test BLK_MQ_F_TAG_SHARED. Afterwards, commit 32bc15afed04b ("blk-mq: Facilitate a shared sbitmap per tagset") enabled tags share betweens hctxs inside a queue. We only mark restart for shared hctxs inside a queue and may cause io hung if there is no tag currently allocated by hctxs going to be marked restart. Wait on sbitmap_queue instead of mark restart for shared hctxs case to fix this. Fixes: 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per tagset") Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10blk-mq: wait on correct sbitmap_queue in blk_mq_mark_tag_waitKemeng Shi1-1/+5
[ Upstream commit 98b99e9412d0cde8c7b442bf5efb09528a2ede8b ] For shared queues case, we will only wait on bitmap_tags if we fail to get driver tag. However, rq could be from breserved_tags, then two problems will occur: 1. io hung if no tag is currently allocated from bitmap_tags. 2. unnecessary wakeup when tag is freed to bitmap_tags while no tag is freed to breserved_tags. Wait on the bitmap which rq from to fix this. Fixes: f906a6a0f426 ("blk-mq: improve tag waiting setup for non-shared tags") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10blk-mq: avoid sleep in blk_mq_alloc_request_hctxKemeng Shi1-1/+2
[ Upstream commit 6ee858a3d3270a68902d66bb47c151a83622535c ] Commit 1f5bd336b9150 ("blk-mq: add blk_mq_alloc_request_hctx") add blk_mq_alloc_request_hctx to send commands to a specific queue. If BLK_MQ_REQ_NOWAIT is not set in tag allocation, we may change to different hctx after sleep and get tag from unexpected hctx. So BLK_MQ_REQ_NOWAIT must be set in flags for blk_mq_alloc_request_hctx. After commit 600c3b0cea784 ("blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx"), blk_mq_alloc_request_hctx return -EINVAL if both BLK_MQ_REQ_NOWAIT and BLK_MQ_REQ_RESERVED are not set instead of if BLK_MQ_REQ_NOWAIT is not set. So if BLK_MQ_REQ_NOWAIT is not set and BLK_MQ_REQ_RESERVED is set, blk_mq_alloc_request_hctx could alloc tag from unexpected hctx. I guess what we need here is that return -EINVAL if either BLK_MQ_REQ_NOWAIT or BLK_MQ_REQ_RESERVED is not set. Currently both BLK_MQ_REQ_NOWAIT and BLK_MQ_REQ_RESERVED will be set if specific hctx is needed in nvme_auth_submit, nvmf_connect_io_queue and nvmf_connect_admin_queue. Fix the potential BLK_MQ_REQ_NOWAIT missed case in future. Fixes: 600c3b0cea78 ("blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-06block: fix hctx checks for batch allocationPavel Begunkov1-1/+5
[ Upstream commit 7746564793978fe2f43b18a302b22dca0ad3a0e8 ] When there are no read queues read requests will be assigned a default queue on allocation. However, blk_mq_get_cached_request() is not prepared for that and will fail all attempts to grab read requests from the cache. Worst case it doubles the number of requests allocated, roughly half of which will be returned by blk_mq_free_plug_rqs(). It only affects batched allocations and so is io_uring specific. For reference, QD8 t/io_uring benchmark improves by 20-35%. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/80d4511011d7d4751b4cf6375c4e38f237d935e3.1673955390.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18block: handle bio_split_to_limits() NULL returnJens Axboe1-1/+4
commit 613b14884b8595e20b9fac4126bf627313827fbe upstream. This can't happen right now, but in preparation for allowing bio_split_to_limits() returning NULL if it ended the bio, check for it in all the callers. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-31blk-mq: avoid double ->queue_rq() because of early timeoutDavid Jeffery1-12/+44
[ Upstream commit 82c229476b8f6afd7e09bc4dc77d89dc19ff7688 ] David Jeffery found one double ->queue_rq() issue, so far it can be triggered in VM use case because of long vmexit latency or preempt latency of vCPU pthread or long page fault in vCPU pthread, then block IO req could be timed out before queuing the request to hardware but after calling blk_mq_start_request() during ->queue_rq(), then timeout handler may handle it by requeue, then double ->queue_rq() is caused, and kernel panic. So far, it is driver's responsibility to cover the race between timeout and completion, so it seems supposed to be solved in driver in theory, given driver has enough knowledge. But it is really one common problem, lots of driver could have similar issue, and could be hard to fix all affected drivers, even it isn't easy for driver to handle the race. So David suggests this patch by draining in-progress ->queue_rq() for solving this issue. Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Keith Busch <kbusch@kernel.org> Cc: virtualization@lists.linux-foundation.org Cc: Bart Van Assche <bvanassche@acm.org> Signed-off-by: David Jeffery <djeffery@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20221026051957.358818-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-23blk-mq: fix queue reference leak on blk_mq_alloc_disk_for_queue failureChristoph Hellwig1-1/+6
Drop the request queue reference just acquired when __alloc_disk_node failed. Fixes: 6f8191fdf41d ("block: simplify disk shutdown") Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Link: https://lore.kernel.org/r/20221122072753.426077-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-01block: blk_add_rq_to_plug(): clear stale 'last' after flushAl Viro1-0/+1
blk_mq_flush_plug_list() empties ->mq_list and request we'd peeked there before that call is gone; in any case, we are not dealing with a mix of requests for different queues now - there's no requests left in the plug. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-31blk-mq: Fix kmemleak in blk_mq_init_allocated_queueChen Jun1-3/+1
There is a kmemleak caused by modprobe null_blk.ko unreferenced object 0xffff8881acb1f000 (size 1024): comm "modprobe", pid 836, jiffies 4294971190 (age 27.068s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff 00 53 99 9e ff ff ff ff .........S...... backtrace: [<000000004a10c249>] kmalloc_node_trace+0x22/0x60 [<00000000648f7950>] blk_mq_alloc_and_init_hctx+0x289/0x350 [<00000000af06de0e>] blk_mq_realloc_hw_ctxs+0x2fe/0x3d0 [<00000000e00c1872>] blk_mq_init_allocated_queue+0x48c/0x1440 [<00000000d16b4e68>] __blk_mq_alloc_disk+0xc8/0x1c0 [<00000000d10c98c3>] 0xffffffffc450d69d [<00000000b9299f48>] 0xffffffffc4538392 [<0000000061c39ed6>] do_one_initcall+0xd0/0x4f0 [<00000000b389383b>] do_init_module+0x1a4/0x680 [<0000000087cf3542>] load_module+0x6249/0x7110 [<00000000beba61b8>] __do_sys_finit_module+0x140/0x200 [<00000000fdcfff51>] do_syscall_64+0x35/0x80 [<000000003c0f1f71>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 That is because q->ma_ops is set to NULL before blk_release_queue is called. blk_mq_init_queue_data blk_mq_init_allocated_queue blk_mq_realloc_hw_ctxs for (i = 0; i < set->nr_hw_queues; i++) { old_hctx = xa_load(&q->hctx_table, i); if (!blk_mq_alloc_and_init_hctx(.., i, ..)) [1] if (!old_hctx) break; xa_for_each_start(&q->hctx_table, j, hctx, j) blk_mq_exit_hctx(q, set, hctx, j); [2] if (!q->nr_hw_queues) [3] goto err_hctxs; err_exit: q->mq_ops = NULL; [4] blk_put_queue blk_release_queue if (queue_is_mq(q)) [5] blk_mq_release(q); [1]: blk_mq_alloc_and_init_hctx failed at i != 0. [2]: The hctxs allocated by [1] are moved to q->unused_hctx_list and will be cleaned up in blk_mq_release. [3]: q->nr_hw_queues is 0. [4]: Set q->mq_ops to NULL. [5]: queue_is_mq returns false due to [4]. And blk_mq_release will not be called. The hctxs in q->unused_hctx_list are leaked. To fix it, call blk_release_queue in exception path. Fixes: 2f8f1336a48b ("blk-mq: always free hctx after request queue is freed") Signed-off-by: Yuan Can <yuancan@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20221031031242.94107-1-chenjun102@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-28blk-mq: Properly init requests from blk_mq_alloc_request_hctx()John Garry1-1/+6
Function blk_mq_alloc_request_hctx() is missing zeroing/init of rq->bio, biotail, __sector, and __data_len members, which blk_mq_alloc_request() has, so duplicate what we do in blk_mq_alloc_request(). Fixes: 1f5bd336b9150 ("blk-mq: add blk_mq_alloc_request_hctx") Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/1666780513-121650-1-git-send-email-john.garry@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-17blk-mq: fix null pointer dereference in blk_mq_clear_rq_mapping()Yu Kuai1-2/+5
Our syzkaller report a null pointer dereference, root cause is following: __blk_mq_alloc_map_and_rqs set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs blk_mq_alloc_map_and_rqs blk_mq_alloc_rqs // failed due to oom alloc_pages_node // set->tags[hctx_idx] is still NULL blk_mq_free_rqs drv_tags = set->tags[hctx_idx]; // null pointer dereference is triggered blk_mq_clear_rq_mapping(drv_tags, ...) This is because commit 63064be150e4 ("blk-mq: Add blk_mq_alloc_map_and_rqs()") merged the two steps: 1) set->tags[hctx_idx] = blk_mq_alloc_rq_map() 2) blk_mq_alloc_rqs(..., set->tags[hctx_idx]) into one step: set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs() Since tags is not initialized yet in this case, fix the problem by checking if tags is NULL pointer in blk_mq_clear_rq_mapping(). Fixes: 63064be150e4 ("blk-mq: Add blk_mq_alloc_map_and_rqs()") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: John Garry <john.garry@huawei.com> Link: https://lore.kernel.org/r/20221011142253.4015966-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-30block: allow end_io based requests in the completion batch handlingJens Axboe1-2/+11
With end_io handlers now being able to potentially pass ownership of the request upon completion, we can allow requests with end_io handlers in the batch completion handling. Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Co-developed-by: Stefan Roesch <shr@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-30block: change request end_io handler to pass back a return valueJens Axboe1-5/+9
Everything is just converted to returning RQ_END_IO_NONE, and there should be no functional changes with this patch. In preparation for allowing the end_io handler to pass ownership back to the block layer, rather than retain ownership of the request. Reviewed-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-30block: enable batched allocation for blk_mq_alloc_request()Jens Axboe1-9/+71
The filesystem IO path can take advantage of allocating batches of requests, if the underlying submitter tells the block layer about it through the blk_plug. For passthrough IO, the exported API is the blk_mq_alloc_request() helper, and that one does not allow for request caching. Wire up request caching for blk_mq_alloc_request(), which is generally done without having a bio available upfront. Tested-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-30Merge branch 'for-6.1/io_uring' into for-6.1/passthroughJens Axboe1-1/+2
* for-6.1/io_uring: (56 commits) io_uring/net: fix notif cqe reordering io_uring/net: don't update msg_name if not provided io_uring: don't gate task_work run on TIF_NOTIFY_SIGNAL io_uring/rw: defer fsnotify calls to task context io_uring/net: fix fast_iov assignment in io_setup_async_msg() io_uring/net: fix non-zc send with address io_uring/net: don't skip notifs for failed requests io_uring/rw: don't lose short results on io_setup_async_rw() io_uring/rw: fix unexpected link breakage io_uring/net: fix cleanup double free free_iov init io_uring: fix CQE reordering io_uring/net: fix UAF in io_sendrecv_fail() selftest/net: adjust io_uring sendzc notif handling io_uring: ensure local task_work marks task as running io_uring/net: zerocopy sendmsg io_uring/net: combine fail handlers io_uring/net: rename io_sendzc() io_uring/net: support non-zerocopy sendto io_uring/net: refactor io_setup_async_addr io_uring/net: don't lose partial send_zc on fail ...
2022-09-30Merge branch 'for-6.1/block' into for-6.1/passthroughJens Axboe1-13/+19
* for-6.1/block: (162 commits) sbitmap: fix lockup while swapping block: add rationale for not using blk_mq_plug() when applicable block: adapt blk_mq_plug() to not plug for writes that require a zone lock s390/dasd: use blk_mq_alloc_disk blk-cgroup: don't update the blkg lookup hint in blkg_conf_prep nvmet: don't look at the request_queue in nvmet_bdev_set_limits nvmet: don't look at the request_queue in nvmet_bdev_zone_mgmt_emulate_all blk-mq: use quiesced elevator switch when reinitializing queues block: replace blk_queue_nowait with bdev_nowait nvme: remove nvme_ctrl_init_connect_q nvme-loop: use the tagset alloc/free helpers nvme-loop: store the generic nvme_ctrl in set->driver_data nvme-loop: initialize sqsize later nvme-fc: use the tagset alloc/free helpers nvme-fc: store the generic nvme_ctrl in set->driver_data nvme-fc: keep ctrl->sqsize in sync with opts->queue_size nvme-rdma: use the tagset alloc/free helpers nvme-rdma: store the generic nvme_ctrl in set->driver_data nvme-tcp: use the tagset alloc/free helpers nvme-tcp: store the generic nvme_ctrl in set->driver_data ... Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-29block: add rationale for not using blk_mq_plug() when applicablePankaj Raghav1-0/+6
There are two places in the block layer at the moment where blk_mq_plug() helper could be used instead of directly accessing the plug from struct current. In both these cases, directly accessing the plug should not have any consequences for zoned devices. Make the intent explicit by adding comments instead of introducing unwanted checks with blk_mq_plug() helper.[1] [1] https://lore.kernel.org/linux-block/f6e54907-1035-2b2c-6387-ed178be05ccb@kernel.dk/ Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Suggested-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20220929144141.140077-1-p.raghav@samsung.com [axboe: fixup multi-line comment style] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-27blk-mq: use quiesced elevator switch when reinitializing queuesKeith Busch1-3/+3
The hctx's run_work may be racing with the elevator switch when reinitializing hardware queues. The queue is merely frozen in this context, but that only prevents requests from allocating and doesn't stop the hctx work from running. The work may get an elevator pointer that's being torn down, and can result in use-after-free errors and kernel panics (example below). Use the quiesced elevator switch instead, and make the previous one static since it is now only used locally. nvme nvme0: resetting controller nvme nvme0: 32/0/0 default/read/poll queues BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 80000020c8861067 P4D 80000020c8861067 PUD 250f8c8067 PMD 0 Oops: 0000 [#1] SMP PTI Workqueue: kblockd blk_mq_run_work_fn RIP: 0010:kyber_has_work+0x29/0x70 ... Call Trace: __blk_mq_do_dispatch_sched+0x83/0x2b0 __blk_mq_sched_dispatch_requests+0x12e/0x170 blk_mq_sched_dispatch_requests+0x30/0x60 __blk_mq_run_hw_queue+0x2b/0x50 process_one_work+0x1ef/0x380 worker_thread+0x2d/0x3e0 Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220927155652.3260724-1-kbusch@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-24blk-mq: don't redirect completion for hctx withs only one ctx mappingLiu Song1-3/+5
High-performance NVMe devices usually support a large hw queues, which ensures a 1:1 mapping of hctx and ctx. In this case there will be no remote request, so we don't need to care about it. Signed-off-by: Liu Song <liusong@linux.alibaba.com> Link: https://lore.kernel.org/r/1663731123-81536-1-git-send-email-liusong@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21block: export blk_rq_is_pollKanchan Joshi1-1/+2
This is in preparation to support iopoll for nvme passthrough. Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20220823161443.49436-4-joshi.k@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-05blk-mq: remove unneeded needs_restart checkMiaohe Lin1-1/+1
If code reaches here, needs_restart must be true. Remove this unneeded needs_restart check. No functional change intended. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Link: https://lore.kernel.org/r/20220905101950.4606-1-linmiaohe@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-22block: Change the return type of blk_mq_map_queues() into voidBart Van Assche1-6/+4
Since blk_mq_map_queues() and the .map_queues() callbacks always return 0, change their return type into void. Most callers ignore the returned value anyway. Cc: Christoph Hellwig <hch@lst.de> Cc: Jason Wang <jasowang@redhat.com> Cc: Keith Busch <kbusch@kernel.org> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: John Garry <john.garry@huawei.com> Acked-by: Md Haris Iqbal <haris.iqbal@ionos.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Link: https://lore.kernel.org/r/20220815170043.19489-3-bvanassche@acm.org [axboe: fold in fix from Bart] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-19blk-mq: fix io hung due to missing commit_rqsYu Kuai1-2/+3
Currently, in virtio_scsi, if 'bd->last' is not set to true while dispatching request, such io will stay in driver's queue, and driver will wait for block layer to dispatch more rqs. However, if block layer failed to dispatch more rq, it should trigger commit_rqs to inform driver. There is a problem in blk_mq_try_issue_list_directly() that commit_rqs won't be called: // assume that queue_depth is set to 1, list contains two rq blk_mq_try_issue_list_directly blk_mq_request_issue_directly // dispatch first rq // last is false __blk_mq_try_issue_directly blk_mq_get_dispatch_budget // succeed to get first budget __blk_mq_issue_directly scsi_queue_rq cmd->flags |= SCMD_LAST virtscsi_queuecommand kick = (sc->flags & SCMD_LAST) != 0 // kick is false, first rq won't issue to disk queued++ blk_mq_request_issue_directly // dispatch second rq __blk_mq_try_issue_directly blk_mq_get_dispatch_budget // failed to get second budget ret == BLK_STS_RESOURCE blk_mq_request_bypass_insert // errors is still 0 if (!list_empty(list) || errors && ...) // won't pass, commit_rqs won't be called In this situation, first rq relied on second rq to dispatch, while second rq relied on first rq to complete, thus they will both hung. Fix the problem by also treat 'BLK_STS_*RESOURCE' as 'errors' since it means that request is not queued successfully. Same problem exists in blk_mq_dispatch_rq_list(), 'BLK_STS_*RESOURCE' can't be treated as 'errors' here, fix the problem by calling commit_rqs if queue_rq return 'BLK_STS_*RESOURCE'. Fixes: d666ba98f849 ("blk-mq: add mq_ops->commit_rqs()") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220726122224.1790882-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-18blk-mq: run queue no matter whether the request is the last requestYufen Yu1-1/+1
We do test on a virtio scsi device (/dev/sda) and the default mq scheduler is 'none'. We found a IO hung as following: blk_finish_plug blk_mq_plug_issue_direct scsi_mq_get_budget //get budget_token fail and sdev->restarts=1 scsi_end_request scsi_run_queue_async //sdev->restart=0 and run queue blk_mq_request_bypass_insert //add request to hctx->dispatch list //continue to dispath plug list blk_mq_dispatch_plug_list blk_mq_try_issue_list_directly //success issue all requests from plug list After .get_budget fail, scsi_mq_get_budget will increase 'restarts'. Normally, it will run hw queue when io complete and set 'restarts' as 0. But if we run queue before adding request to the dispatch list and blk_mq_dispatch_plug_list also success issue all requests, then on one will run queue, and the request will be stall in the dispatch list and cannot complete forever. It is wrong to use last request of plug list to decide if run queue is needed since all the remained requests in plug list may be from other hctxs. To fix the bug, pass run_queue as true always to blk_mq_request_bypass_insert(). Fix-suggested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Yufen Yu <yuyufen@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Fixes: dc5fc361d891 ("block: attempt direct issue of plug list") Link: https://lore.kernel.org/r/20220803023355.3687360-1-yuyufen@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-18blk-mq: remove unused function blk_mq_queue_stopped()Yu Kuai1-20/+0
blk_mq_queue_stopped() doesn't have any caller, which was found by code coverage test, thus remove it. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20220818063555.3741222-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-03block: pass struct queue_limits to the bio splitting helpersChristoph Hellwig1-2/+2
Allow using the splitting helpers on just a queue_limits instead of a full request_queue structure. This will eventually allow file systems or remapping drivers to split REQ_OP_ZONE_APPEND bios based on limits calculated as the minimum common capabilities over multiple devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220727162300.3089193-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-03block: change the blk_queue_bounce calling conventionChristoph Hellwig1-1/+1
The double indirect bio leads to somewhat suboptimal code generation. Instead return the (original or split) bio, and make sure the request_queue arguments to the lower level helpers is passed after the bio to avoid constant reshuffling of the argument passing registers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220727162300.3089193-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-03block: change the blk_queue_split calling conventionChristoph Hellwig1-2/+2
The double indirect bio leads to somewhat suboptimal code generation. Instead return the (original or split) bio, and make sure the request_queue arguments to the lower level helpers is passed after the bio to avoid constant reshuffling of the argument passing registers. Also give it and the helpers used to implement it more descriptive names. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220727162300.3089193-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-21blk-mq: fix error handling in __blk_mq_alloc_diskChristoph Hellwig1-1/+1
To fully clean up the queue if the disk allocation fails we need to call blk_mq_destroy_queue and not just blk_put_queue. Fixes: 6f8191fdf41d ("block: simplify disk shutdown") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220720130541.1323531-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-14block: Use the new blk_opf_t typeBart Van Assche1-7/+8
Use the new blk_opf_t type for arguments and variables that represent request flags or a bitwise combination of a request operation and request flags. Rename the function arguments and also a structure member that hold a request operation and flags from 'rw' into 'opf'. This patch does not change any functionality. Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-7-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-06block: simplify blk_mq_plugChristoph Hellwig1-1/+1
Drop the unused q argument, and invert the check to move the exception into a branch and the regular path as the normal return. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220706070350.1703384-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-06blk-mq: Drop 'reserved' arg of busy_tag_iter_fnJohn Garry1-6/+4
We no longer use the 'reserved' arg in busy_tag_iter_fn for any iter function so it may be dropped. Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> #nvme Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/1657109034-206040-6-git-send-email-john.garry@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-06blk-mq: Drop blk_mq_ops.timeout 'reserved' argJohn Garry1-3/+3
With new API blk_mq_is_reserved_rq() we can tell if a request is from the reserved pool, so stop passing 'reserved' arg. There is actually only a single user of that arg for all the callback implementations, which can use blk_mq_is_reserved_rq() instead. This will also allow us to stop passing the same 'reserved' around the blk-mq iter functions next. Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/1657109034-206040-4-git-send-email-john.garry@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-06blk-mq: Add a flag for reserved requestsJohn Garry1-0/+6
Add a flag for reserved requests so that drivers may know this for any special handling. Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/1657109034-206040-3-git-send-email-john.garry@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-28blk-mq: rename blk_mq_sysfs_{,un}registerChristoph Hellwig1-2/+2
Add a _hctx postfix to better describe what the functions do, match the debugfs equivalents and release the old names for functions that should be using them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220628171850.1313069-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-28block: simplify disk shutdownChristoph Hellwig1-2/+41
Set the queue dying flag and call blk_mq_exit_queue from del_gendisk for all disks that do not have separately allocated queues, and thus remove the need to call blk_cleanup_queue for them. Rename blk_cleanup_disk to blk_mq_destroy_queue to make it clear that this function is intended only for separately allocated blk-mq queues. This saves an extra queue freeze for devices without a separately allocated queue. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20220619060552.1850436-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-27block: Always initialize bio IO priority on submitJan Kara1-0/+3
Currently, IO priority set in task's IO context is not reflected in the bio->bi_ioprio for most IO (only io_uring and direct IO set it). This results in odd results where process is submitting some bios with one priority and other bios with a different (unset) priority and due to differing priorities bios cannot be merged. Make sure bio->bi_ioprio is always set on bio submission. Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220623074840.5960-9-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-27block: Initialize bio priority earlierJan Kara1-2/+2
Bio's IO priority needs to be initialized before we try to merge the bio with other bios. Otherwise we could merge bios which would otherwise receive different IO priorities leading to possible QoS issues. Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220623074840.5960-8-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-27blk-ioprio: Convert from rqos policy to direct callJan Kara1-0/+8
Convert blk-ioprio handling from a rqos policy to a direct call from blk_mq_submit_bio(). Firstly, blk-ioprio is not much of a rqos policy anyway, it just needs a hook in bio submission path to set the bio's IO priority. Secondly, the rqos .track hook gets actually called too late for blk-ioprio purposes and introducing a special rqos hook just for blk-ioprio looks even weirder. Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220623074840.5960-7-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-27blk-mq: Don't disable preemption around __blk_mq_run_hw_queue().Sebastian Andrzej Siewior1-5/+1
__blk_mq_delay_run_hw_queue() disables preemption to get a stable current CPU number and then invokes __blk_mq_run_hw_queue() if the CPU number is part the mask. __blk_mq_run_hw_queue() acquires a spin_lock_t which is a sleeping lock on PREEMPT_RT and can't be acquired with disabled preemption. It is not required for correctness to invoke __blk_mq_run_hw_queue() on a CPU matching hctx->cpumask. Both (async and direct requests) can run on a CPU not matching hctx->cpumask. The CPU mask without disabling preemption and invoking __blk_mq_run_hw_queue(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/YrLSEiNvagKJaDs5@linutronix.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-27block: Make blk_mq_get_sq_hctx() select the proper hardware queue typeBart Van Assche1-1/+1
Since the introduction of blk_mq_get_hctx_type() the operation type in the second argument of blk_mq_get_hctx_type() matters. The introduction of blk_mq_get_hctx_type() caused blk_mq_get_sq_hctx() to select a hardware queue of type HCTX_TYPE_READ instead of HCTX_TYPE_DEFAULT. Switch to hardware queue type HCTX_TYPE_DEFAULT since HCTX_TYPE_READ should only be used for read requests. Cc: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220615225549.1054905-4-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-21block: pop cached rq before potentially blocking rq_qos_throttle()Jens Axboe1-3/+8
If rq_qos_throttle() ends up blocking, then we will have invalidated and flushed our current plug. Since blk_mq_get_cached_request() hasn't popped the cached request off the plug list just yet, we end holding a pointer to a request that is no longer valid. This insta-crashes with rq->mq_hctx being NULL in the validity checks just after. Pop the request off the cached list before doing rq_qos_throttle() to avoid using a potentially stale request. Fixes: 0a5aa8d161d1 ("block: fix blk_mq_attempt_bio_merge and rq_qos_throttle protection") Reported-by: Dylan Yudaken <dylany@fb.com> Tested-by: Dylan Yudaken <dylany@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-16blk-mq: don't clear flush_rq from tags->rqs[]Ming Lei1-2/+3
commit 364b61818f65 ("blk-mq: clearing flush request reference in tags->rqs[]") is added to clear the to-be-free flush request from tags->rqs[] for avoiding use-after-free on the flush rq. Yu Kuai reported that blk_mq_clear_flush_rq_mapping() slows down boot time by ~8s because running scsi probe which may create and remove lots of unpresent LUNs on megaraid-sas which uses BLK_MQ_F_TAG_HCTX_SHARED and each request queue has lots of hw queues. Improve the situation by not running blk_mq_clear_flush_rq_mapping if disk isn't added when there can't be any flush request issued. Reviewed-by: Christoph Hellwig <hch@lst.de> Reported-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220616014401.817001-4-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-16blk-mq: avoid to touch q->elevator without any protectionMing Lei1-16/+2
q->elevator is referred in blk_mq_has_sqsched() without any protection, no .q_usage_counter is held, no queue srcu and rcu read lock is held, so potential use-after-free may be triggered. Fix the issue by adding one queue flag for checking if the elevator uses single queue style dispatch. Meantime the elevator feature flag of ELEVATOR_F_MQ_AWARE isn't needed any more. Cc: Jan Kara <jack@suse.cz> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220616014401.817001-3-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-16blk-mq: protect q->elevator by ->sysfs_lock in blk_mq_elv_switch_noneMing Lei1-1/+3
elevator can be tore down by sysfs switch interface or disk release, so hold ->sysfs_lock before referring to q->elevator, then potential use-after-free can be avoided. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220616014401.817001-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-16block: Fix handling of offline queues in blk_mq_alloc_request_hctx()Bart Van Assche1-0/+2
This patch prevents that test nvme/004 triggers the following: UBSAN: array-index-out-of-bounds in block/blk-mq.h:135:9 index 512 is out of range for type 'long unsigned int [512]' Call Trace: show_stack+0x52/0x58 dump_stack_lvl+0x49/0x5e dump_stack+0x10/0x12 ubsan_epilogue+0x9/0x3b __ubsan_handle_out_of_bounds.cold+0x44/0x49 blk_mq_alloc_request_hctx+0x304/0x310 __nvme_submit_sync_cmd+0x70/0x200 [nvme_core] nvmf_connect_io_queue+0x23e/0x2a0 [nvme_fabrics] nvme_loop_connect_io_queues+0x8d/0xb0 [nvme_loop] nvme_loop_create_ctrl+0x58e/0x7d0 [nvme_loop] nvmf_create_ctrl+0x1d7/0x4d0 [nvme_fabrics] nvmf_dev_write+0xae/0x111 [nvme_fabrics] vfs_write+0x144/0x560 ksys_write+0xb7/0x140 __x64_sys_write+0x42/0x50 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Fixes: 20e4d8139319 ("blk-mq: simplify queue mapping & schedule with each possisble CPU") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220615210004.1031820-1-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-03Merge tag 'for-5.19/block-exec-2022-06-02' of git://git.kernel.dk/linux-blockLinus Torvalds1-64/+49
Pull block request execute cleanups from Jens Axboe: "This change was advertised in the initial core block pull request, but didn't actually make that branch as we deferred it to a post-merge pull request to avoid a bunch of cross branch issues. This series cleans up the block execute path quite nicely" * tag 'for-5.19/block-exec-2022-06-02' of git://git.kernel.dk/linux-block: blk-mq: remove the done argument to blk_execute_rq_nowait blk-mq: avoid a mess of casts for blk_end_sync_rq blk-mq: remove __blk_execute_rq_nowait
2022-06-03Merge tag 'for-5.19/block-2022-06-02' of git://git.kernel.dk/linux-blockLinus Torvalds1-5/+5
Pull block fixes from Jens Axboe: "Just a collection of fixes that have been queued up since the initial merge window pull request, the majority of which are targeted for stable as well. One bio_set fix that fixes an issue with the dm adoption of cached bio structs that got introduced in this merge window" * tag 'for-5.19/block-2022-06-02' of git://git.kernel.dk/linux-block: block: Fix potential deadlock in blk_ia_range_sysfs_show() block: fix bio_clone_blkg_association() to associate with proper blkcg_gq block: remove useless BUG_ON() in blk_mq_put_tag() blk-mq: do not update io_ticks with passthrough requests block: make bioset_exit() fully resilient against being called twice block: use bio_queue_enter instead of blk_queue_enter in bio_poll block: document BLK_STS_AGAIN usage block: take destination bvec offsets into account in bio_copy_data_iter blk-iolatency: Fix inflight count imbalances and IO hangs on offline blk-mq: don't touch ->tagset in blk_mq_get_sq_hctx