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2021-11-12blk-mq: fix filesystem I/O request allocationMing Lei1-9/+30
submit_bio_checks() may update bio->bi_opf, so we have to initialize blk_mq_alloc_data.cmd_flags with bio->bi_opf after submit_bio_checks() returns when allocating new request. In case of using cached request, fallback to allocate new request if cached rq isn't compatible with the incoming bio, otherwise change rq->cmd_flags with incoming bio->bi_opf. Fixes: 900e080752025f00 ("block: move queue enter logic into blk_mq_submit_bio()") Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-11blk-mq: rename blk_attempt_bio_mergeMing Lei1-4/+6
It is very annoying to have two block layer functions which share same name, so rename blk_attempt_bio_merge in blk-mq.c as blk_mq_attempt_bio_merge. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211111085134.345235-3-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-09Merge tag 'for-5.16/block-2021-11-09' of git://git.kernel.dk/linux-blockLinus Torvalds1-57/+130
Pull block fixes from Jens Axboe: - Set of fixes for the batched tag allocation (Ming, me) - add_disk() error handling fix (Luis) - Nested queue quiesce fixes (Ming) - Shared tags init error handling fix (Ye) - Misc cleanups (Jean, Ming, me) * tag 'for-5.16/block-2021-11-09' of git://git.kernel.dk/linux-block: nvme: wait until quiesce is done scsi: make sure that request queue queiesce and unquiesce balanced scsi: avoid to quiesce sdev->request_queue two times blk-mq: add one API for waiting until quiesce is done blk-mq: don't free tags if the tag_set is used by other device in queue initialztion block: fix device_add_disk() kobject_create_and_add() error handling block: ensure cached plug request matches the current queue block: move queue enter logic into blk_mq_submit_bio() block: make bio_queue_enter() fast-path available inline block: split request allocation components into helpers block: have plug stored requests hold references to the queue blk-mq: update hctx->nr_active in blk_mq_end_request_batch() blk-mq: add RQF_ELV debug entry blk-mq: only try to run plug merge if request has same queue with incoming bio block: move RQF_ELV setting into allocators dm: don't stop request queue after the dm device is suspended block: replace always false argument with 'false' block: assign correct tag before doing prefetch of request blk-mq: fix redundant check of !e expression
2021-11-09blk-mq: add one API for waiting until quiesce is doneMing Lei1-8/+20
Some drivers(NVMe, SCSI) need to call quiesce and unquiesce in pair, but it is hard to switch to this style, so these drivers need one atomic flag for helping to balance quiesce and unquiesce. When quiesce is in-progress, the driver still needs to wait until the quiesce is done, so add API of blk_mq_wait_quiesce_done() for these drivers. Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20211109071144.181581-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-08blk-mq: don't free tags if the tag_set is used by other device in queue ↵Ye Bin1-1/+5
initialztion We got UAF report on v5.10 as follows: [ 1446.674930] ================================================================== [ 1446.675970] BUG: KASAN: use-after-free in blk_mq_get_driver_tag+0x9a4/0xa90 [ 1446.676902] Read of size 8 at addr ffff8880185afd10 by task kworker/1:2/12348 [ 1446.677851] [ 1446.678073] CPU: 1 PID: 12348 Comm: kworker/1:2 Not tainted 5.10.0-10177-gc9c81b1e346a #2 [ 1446.679168] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 1446.680692] Workqueue: kthrotld blk_throtl_dispatch_work_fn [ 1446.681448] Call Trace: [ 1446.681800] dump_stack+0x9b/0xce [ 1446.682916] print_address_description.constprop.6+0x3e/0x60 [ 1446.685999] kasan_report.cold.9+0x22/0x3a [ 1446.687186] blk_mq_get_driver_tag+0x9a4/0xa90 [ 1446.687785] blk_mq_dispatch_rq_list+0x21a/0x1d40 [ 1446.692576] __blk_mq_do_dispatch_sched+0x394/0x830 [ 1446.695758] __blk_mq_sched_dispatch_requests+0x398/0x4f0 [ 1446.698279] blk_mq_sched_dispatch_requests+0xdf/0x140 [ 1446.698967] __blk_mq_run_hw_queue+0xc0/0x270 [ 1446.699561] __blk_mq_delay_run_hw_queue+0x4cc/0x550 [ 1446.701407] blk_mq_run_hw_queue+0x13b/0x2b0 [ 1446.702593] blk_mq_sched_insert_requests+0x1de/0x390 [ 1446.703309] blk_mq_flush_plug_list+0x4b4/0x760 [ 1446.705408] blk_flush_plug_list+0x2c5/0x480 [ 1446.708471] blk_finish_plug+0x55/0xa0 [ 1446.708980] blk_throtl_dispatch_work_fn+0x23b/0x2e0 [ 1446.711236] process_one_work+0x6d4/0xfe0 [ 1446.711778] worker_thread+0x91/0xc80 [ 1446.713400] kthread+0x32d/0x3f0 [ 1446.714362] ret_from_fork+0x1f/0x30 [ 1446.714846] [ 1446.715062] Allocated by task 1: [ 1446.715509] kasan_save_stack+0x19/0x40 [ 1446.716026] __kasan_kmalloc.constprop.1+0xc1/0xd0 [ 1446.716673] blk_mq_init_tags+0x6d/0x330 [ 1446.717207] blk_mq_alloc_rq_map+0x50/0x1c0 [ 1446.717769] __blk_mq_alloc_map_and_request+0xe5/0x320 [ 1446.718459] blk_mq_alloc_tag_set+0x679/0xdc0 [ 1446.719050] scsi_add_host_with_dma.cold.3+0xa0/0x5db [ 1446.719736] virtscsi_probe+0x7bf/0xbd0 [ 1446.720265] virtio_dev_probe+0x402/0x6c0 [ 1446.720808] really_probe+0x276/0xde0 [ 1446.721320] driver_probe_device+0x267/0x3d0 [ 1446.721892] device_driver_attach+0xfe/0x140 [ 1446.722491] __driver_attach+0x13a/0x2c0 [ 1446.723037] bus_for_each_dev+0x146/0x1c0 [ 1446.723603] bus_add_driver+0x3fc/0x680 [ 1446.724145] driver_register+0x1c0/0x400 [ 1446.724693] init+0xa2/0xe8 [ 1446.725091] do_one_initcall+0x9e/0x310 [ 1446.725626] kernel_init_freeable+0xc56/0xcb9 [ 1446.726231] kernel_init+0x11/0x198 [ 1446.726714] ret_from_fork+0x1f/0x30 [ 1446.727212] [ 1446.727433] Freed by task 26992: [ 1446.727882] kasan_save_stack+0x19/0x40 [ 1446.728420] kasan_set_track+0x1c/0x30 [ 1446.728943] kasan_set_free_info+0x1b/0x30 [ 1446.729517] __kasan_slab_free+0x111/0x160 [ 1446.730084] kfree+0xb8/0x520 [ 1446.730507] blk_mq_free_map_and_requests+0x10b/0x1b0 [ 1446.731206] blk_mq_realloc_hw_ctxs+0x8cb/0x15b0 [ 1446.731844] blk_mq_init_allocated_queue+0x374/0x1380 [ 1446.732540] blk_mq_init_queue_data+0x7f/0xd0 [ 1446.733155] scsi_mq_alloc_queue+0x45/0x170 [ 1446.733730] scsi_alloc_sdev+0x73c/0xb20 [ 1446.734281] scsi_probe_and_add_lun+0x9a6/0x2d90 [ 1446.734916] __scsi_scan_target+0x208/0xc50 [ 1446.735500] scsi_scan_channel.part.3+0x113/0x170 [ 1446.736149] scsi_scan_host_selected+0x25a/0x360 [ 1446.736783] store_scan+0x290/0x2d0 [ 1446.737275] dev_attr_store+0x55/0x80 [ 1446.737782] sysfs_kf_write+0x132/0x190 [ 1446.738313] kernfs_fop_write_iter+0x319/0x4b0 [ 1446.738921] new_sync_write+0x40e/0x5c0 [ 1446.739429] vfs_write+0x519/0x720 [ 1446.739877] ksys_write+0xf8/0x1f0 [ 1446.740332] do_syscall_64+0x2d/0x40 [ 1446.740802] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1446.741462] [ 1446.741670] The buggy address belongs to the object at ffff8880185afd00 [ 1446.741670] which belongs to the cache kmalloc-256 of size 256 [ 1446.743276] The buggy address is located 16 bytes inside of [ 1446.743276] 256-byte region [ffff8880185afd00, ffff8880185afe00) [ 1446.744765] The buggy address belongs to the page: [ 1446.745416] page:ffffea0000616b00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x185ac [ 1446.746694] head:ffffea0000616b00 order:2 compound_mapcount:0 compound_pincount:0 [ 1446.747719] flags: 0x1fffff80010200(slab|head) [ 1446.748337] raw: 001fffff80010200 ffffea00006a3208 ffffea000061bf08 ffff88801004f240 [ 1446.749404] raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 [ 1446.750455] page dumped because: kasan: bad access detected [ 1446.751227] [ 1446.751445] Memory state around the buggy address: [ 1446.752102] ffff8880185afc00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1446.753090] ffff8880185afc80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1446.754079] >ffff8880185afd00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1446.755065] ^ [ 1446.755589] ffff8880185afd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1446.756574] ffff8880185afe00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1446.757566] ================================================================== Flag 'BLK_MQ_F_TAG_QUEUE_SHARED' will be set if the second device on the same host initializes it's queue successfully. However, if the second device failed to allocate memory in blk_mq_alloc_and_init_hctx() from blk_mq_realloc_hw_ctxs() from blk_mq_init_allocated_queue(), __blk_mq_free_map_and_rqs() will be called on error path, and if 'BLK_MQ_TAG_HCTX_SHARED' is not set, 'tag_set->tags' will be freed while it's still used by the first device. To fix this issue we move release newly allocated hardware context from blk_mq_realloc_hw_ctxs to __blk_mq_update_nr_hw_queues. As there is needn't to release hardware context in blk_mq_init_allocated_queue. Fixes: 868f2f0b7206 ("blk-mq: dynamic h/w context count") Signed-off-by: Ye Bin <yebin10@huawei.com> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211108074019.1058843-1-yebin10@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-04block: ensure cached plug request matches the current queueJens Axboe1-1/+1
If we're driving multiple devices, we could have pre-populated the cache for a different device. Ensure that the empty request matches the current queue. Fixes: 47c122e35d7e ("block: pre-allocate requests if plug is started and is a batch") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-04block: move queue enter logic into blk_mq_submit_bio()Jens Axboe1-19/+41
Retain the old logic for the fops based submit, but for our internal blk_mq_submit_bio(), move the queue entering logic into the core function itself. We need to be a bit careful if going into the scheduler, as a scheduler or queue mappings can arbitrarily change before we have entered the queue. Have the bio scheduler mapping do that separately, it's a very cheap operation compared to actually doing merging locking and lookups. Reviewed-by: Christoph Hellwig <hch@lst.de> [axboe: update to check merge post submit_bio_checks() doing remap...] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-04block: split request allocation components into helpersJens Axboe1-23/+48
This is in preparation for a fix, but serves as a cleanup as well moving the cached vs regular alloc logic out of blk_mq_submit_bio(). Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-04block: have plug stored requests hold references to the queueJens Axboe1-3/+4
Requests that were stored in the cache deliberately didn't hold an enter reference to the queue, instead we grabbed one every time we pulled a request out of there. That made for awkward logic on freeing the remainder of the cached list, if needed, where we had to artificially raise the queue usage count before each free. Grab references up front for cached plug requests. That's safer, and also more efficient. Fixes: 47c122e35d7e ("block: pre-allocate requests if plug is started and is a batch") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-03blk-mq: update hctx->nr_active in blk_mq_end_request_batch()Ming Lei1-0/+7
In case of shared tags and none io sched, batched completion still may be run into, and hctx->nr_active is accounted when getting driver tag, so it has to be updated in blk_mq_end_request_batch(). Otherwise, hctx->nr_active may become same with queue depth, then hctx_may_queue() always return false, then io hang is caused. Fixes the issue by updating the counter in batched way. Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Fixes: f794f3351f26 ("block: add support for blk_mq_end_request_batch()") Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211102153619.3627505-4-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-03block: move RQF_ELV setting into allocatorsJens Axboe1-6/+8
It's not safe to do this before blk_queue_enter(), as the scheduler state could have changed in between. Hence move the RQF_ELV setting into the allocators, where we know the queue is already entered. Suggested-by: Ming Lei <ming.lei@redhat.com> Reported-by: Yi Zhang <yi.zhang@redhat.com> Reported-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-02block: replace always false argument with 'false'Jens Axboe1-1/+1
A previous commit fixed up the condition for doing direct issue, but that left the 'from_schedule' argument dead inside the branch. Replace it with 'false'. Fixes: ff1552232b36 ("blk-mq: don't issue request directly in case that current is to be blocked") Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-02block: assign correct tag before doing prefetch of requestJens Axboe1-1/+1
Ensure that current tag is correctly assigned before attempting to prefetch the first cacheline of the request. Fixes: 92aff191cc5b ("block: prefetch request to be initialized") Reported-and-tested-by: syzbot+cd20829ac44b92bf6ed0@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-01Merge tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-blockLinus Torvalds1-366/+668
Pull block updates from Jens Axboe: - mq-deadline accounting improvements (Bart) - blk-wbt timer fix (Andrea) - Untangle the block layer includes (Christoph) - Rework the poll support to be bio based, which will enable adding support for polling for bio based drivers (Christoph) - Block layer core support for multi-actuator drives (Damien) - blk-crypto improvements (Eric) - Batched tag allocation support (me) - Request completion batching support (me) - Plugging improvements (me) - Shared tag set improvements (John) - Concurrent queue quiesce support (Ming) - Cache bdev in ->private_data for block devices (Pavel) - bdev dio improvements (Pavel) - Block device invalidation and block size improvements (Xie) - Various cleanups, fixes, and improvements (Christoph, Jackie, Masahira, Tejun, Yu, Pavel, Zheng, me) * tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block: (174 commits) blk-mq-debugfs: Show active requests per queue for shared tags block: improve readability of blk_mq_end_request_batch() virtio-blk: Use blk_validate_block_size() to validate block size loop: Use blk_validate_block_size() to validate block size nbd: Use blk_validate_block_size() to validate block size block: Add a helper to validate the block size block: re-flow blk_mq_rq_ctx_init() block: prefetch request to be initialized block: pass in blk_mq_tags to blk_mq_rq_ctx_init() block: add rq_flags to struct blk_mq_alloc_data block: add async version of bio_set_polled block: kill DIO_MULTI_BIO block: kill unused polling bits in __blkdev_direct_IO() block: avoid extra iter advance with async iocb block: Add independent access ranges support blk-mq: don't issue request directly in case that current is to be blocked sbitmap: silence data race warning blk-cgroup: synchronize blkg creation against policy deactivation block: refactor bio_iov_bvec_set() block: add single bio async direct IO helper ...
2021-10-28block: improve readability of blk_mq_end_request_batch()Jens Axboe1-6/+6
It's faster and easier to read if we tolerate cur_hctx being NULL in the "when to flush" condition. Rename last_hctx to cur_hctx while at it, as it better describes the role of that variable. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-27block: re-flow blk_mq_rq_ctx_init()Jens Axboe1-12/+12
Now that we have flags passed in, we can do a final re-arrange of the flow of blk_mq_rq_ctx_init() so we're always writing request in the order in which it is laid out. Signed-off-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20211019153300.623322-5-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-27block: prefetch request to be initializedJens Axboe1-0/+1
Now we have the tags available in __blk_mq_alloc_requests_batch(), we can start fetching the first request cacheline before calling into the request initialization. Signed-off-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20211019153300.623322-4-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-27block: pass in blk_mq_tags to blk_mq_rq_ctx_init()Jens Axboe1-11/+14
Instead of getting this from data for every invocation of request initialization, pass it in as an argument instead. Signed-off-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20211019153300.623322-3-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-27block: add rq_flags to struct blk_mq_alloc_dataJens Axboe1-10/+10
There's a hole here we can use, and it's faster to set this earlier rather than need to check q->elevator multiple times. Signed-off-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20211019153300.623322-2-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-26block: schedule queue restart after BLK_STS_ZONE_RESOURCENaohiro Aota1-4/+9
When dispatching a zone append write request to a SCSI zoned block device, if the target zone of the request is already locked, the device driver will return BLK_STS_ZONE_RESOURCE and the request will be pushed back to the hctx dipatch queue. The queue will be marked as RESTART in dd_finish_request() and restarted in __blk_mq_free_request(). However, this restart applies to the hctx of the completed request. If the requeued request is on a different hctx, dispatch will no be retried until another request is submitted or the next periodic queue run triggers, leading to up to 30 seconds latency for the requeued request. Fix this problem by scheduling a queue restart similarly to the BLK_STS_RESOURCE case or when we cannot get the budget. Also, consolidate the checks into the "need_resource" variable to simplify the condition. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Niklas Cassel <Niklas.Cassel@wdc.com> Link: https://lore.kernel.org/r/20211026165127.4151055-1-naohiro.aota@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-26blk-mq: don't issue request directly in case that current is to be blockedMing Lei1-1/+1
When flushing plug list in case that current will be blocked, we can't issue request directly because ->queue_rq() may sleep, otherwise scheduler may complain. Fixes: dc5fc361d891 ("block: attempt direct issue of plug list") Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211026082257.2889890-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-22block: fix req_bio_endio append error handlingPavel Begunkov1-1/+1
Shinichiro Kawasaki reports that there is a bug in a recent req_bio_endio() patch causing problems with zonefs. As Shinichiro suggested, inverse the condition in zone append path to resemble how it was before: fail when it's not fully completed. Fixes: 478eb72b815f3 ("block: optimise req_bio_endio()") Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/344ea4e334aace9148b41af5f2426da38c8aa65a.1634914228.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-21block: clean up blk_mq_submit_bio() mergingPavel Begunkov1-8/+7
Combine blk_mq_sched_bio_merge() and blk_attempt_plug_merge() under a common if, so we don't check it twice. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/daedc90d4029a5d1d73344771632b1faca3aaf81.1634755800.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-20blk-mq: only flush requests from the plug in blk_mq_submit_bioChristoph Hellwig1-1/+1
Replace the call to blk_flush_plug_list in blk_mq_submit_bio with a direct call to blk_mq_flush_plug_list. This means we do not flush plug callback from stackable devices, which doesn't really help with the accumulated requests anyway, and it also means the cached requests aren't freed here as they can still be used later on. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211020144119.142582-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-20block: remove inaccurate requeue checkJens Axboe1-1/+0
This check is meant to catch cases where a requeue is attempted on a request that is still inserted. It's never really been useful to catch any misuse, and now it's actively wrong. Outside of that, this should not be a BUG_ON() to begin with. Remove the check as it's now causing active harm, as requeue off the plug path will trigger it even though the request state is just fine. Reported-by: Yi Zhang <yi.zhang@redhat.com> Link: https://lore.kernel.org/linux-block/CAHj4cs80zAUc2grnCZ015-2Rvd-=gXRfB_dFKy=RTm+wRo09HQ@mail.gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-20block: optimise req_bio_endio()Pavel Begunkov1-9/+7
First, get rid of an extra branch and chain error checks. Also reshuffle it with bio_advance(), so it goes closer to the final check, with that the compiler loads rq->rq_flags only once, and also doesn't reload bio->bi_iter.bi_size if bio_advance() didn't actually advanced the iter. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19blk-mq: support concurrent queue quiesce/unquiesceMing Lei1-3/+19
blk_mq_quiesce_queue() has been used a bit wide now, so far we don't support concurrent/nested quiesce. One biggest issue is that unquiesce can happen unexpectedly in case that quiesce/unquiesce are run concurrently from more than one context. This patch introduces q->mq_quiesce_depth to deal concurrent quiesce, and we only unquiesce queue when it is the last/outer-most one of all contexts. Several kernel panic issue has been reported[1][2][3] when running stress quiesce test. And this patch has been verified in these reports. [1] https://lore.kernel.org/linux-block/9b21c797-e505-3821-4f5b-df7bf9380328@huawei.com/T/#m1fc52431fad7f33b1ffc3f12c4450e4238540787 [2] https://lore.kernel.org/linux-block/9b21c797-e505-3821-4f5b-df7bf9380328@huawei.com/T/#m10ad90afeb9c8cc318334190a7c24c8b5c5e0722 [3] https://listman.redhat.com/archives/dm-devel/2021-September/msg00189.html Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211014081710.1871747-7-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19block: inline fast path of driver tag allocationJens Axboe1-5/+3
If we don't use an IO scheduler or have shared tags, then we don't need to call into this external function at all. This saves ~2% for such a setup. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19blk-mq: don't handle non-flush requests in blk_insert_flushChristoph Hellwig1-8/+6
Return to the normal blk_mq_submit_bio flow if the bio did not end up actually being a flush because the device didn't support it. Note that this is basically impossible to hit without special instrumentation given that submit_bio_checks already clears these flags usually, so we'd need a tight race to actually hit this code path. With this the call to blk_mq_run_hw_queue for the flush requests can be removed given that the actual flush requests are always issued via the requeue workqueue which runs the queue unconditionally. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211019122553.2467817-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19block: attempt direct issue of plug listJens Axboe1-0/+60
If we have just one queue type in the plug list, then we can extend our direct issue to cover a full plug list as well. This allows sending a batch of requests for direct issue, which is more efficient than doing one-at-a-time kind of issue. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19block: change plugging to use a singly linked listJens Axboe1-35/+45
Use a singly linked list for the blk_plug. This saves 8 bytes in the blk_plug struct, and makes for faster list manipulations than doubly linked lists. As we don't use the doubly linked lists for anything, singly linked is just fine. This yields a bump in default (merging enabled) performance from 7.0 to 7.1M IOPS, and ~7.5M IOPS with merging disabled. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19block: move blk_mq_tag_to_rq() inlineJens Axboe1-11/+0
This is in the fast path of driver issue or completion, and it's a single array index operation. Move it inline to avoid a function call for it. This does mean making struct blk_mq_tags block layer public, but there's not really much in there. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19block: get rid of plug list sortingJens Axboe1-19/+0
Even if we have multiple queues in the plug list, chances that they are very interspersed is minimal. Don't bother spending CPU cycles sorting the list. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19block: return whether or not to unplug through booleanJens Axboe1-7/+9
Instead of returning the same queue request through a request pointer, use a boolean to accomplish the same. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19block: don't call blk_status_to_errno in blk_update_requestChristoph Hellwig1-1/+1
We only need to call it to resolve the blk_status_t -> errno mapping for tracing, so move the conversion into the tracepoints that are not called at all when tracing isn't enabled. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19block: fix too broad elevator check in blk_mq_free_request()Jens Axboe1-1/+1
We added RQF_ELV to tell whether there's an IO scheduler attached, and RQF_ELVPRIV tells us whether there's an IO scheduler with private data attached. Don't check RQF_ELV in blk_mq_free_request(), what we care about here is just if we have scheduler private data attached. This fixes a boot crash Fixes: 2ff0682da6e0 ("block: store elevator state in request") Reported-by: Yi Zhang <yi.zhang@redhat.com> Reported-by: syzbot+eb8104072aeab6cc1195@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: add support for blk_mq_end_request_batch()Jens Axboe1-19/+63
Instead of calling blk_mq_end_request() on a single request, add a helper that takes the new struct io_comp_batch and completes any request stored in there. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: add a struct io_comp_batch argument to fops->iopoll()Jens Axboe1-4/+5
struct io_comp_batch contains a list head and a completion handler, which will allow completions to more effciently completed batches of IO. For now, no functional changes in this patch, we just define the io_comp_batch structure and add the argument to the file_operations iopoll handler. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: provide helpers for rq_list manipulationJens Axboe1-14/+5
Instead of open-coding the list additions, traversal, and removal, provide a basic set of helpers. Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: remove some blk_mq_hw_ctx debugfs entriesJens Axboe1-16/+0
Just like the blk_mq_ctx counterparts, we've got a bunch of counters in here that are only for debugfs and are of questionnable value. They are: - dispatched, index of how many requests were dispatched in one go - poll_{considered,invoked,success}, which track poll sucess rates. We're confident in the iopoll implementation at this point, don't bother tracking these. As a bonus, this shrinks each hardware queue from 576 bytes to 512 bytes, dropping a whole cacheline. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: remove debugfs blk_mq_ctx dispatched/merged/completed attributesJens Axboe1-3/+0
These were added as part of early days debugging for blk-mq, and they are not really useful anymore. Rather than spend cycles updating them, just get rid of them. As a bonus, this shrinks the per-cpu software queue size from 256b to 192b. That's a whole cacheline less. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: cache rq_flags inside blk_mq_rq_ctx_init()Pavel Begunkov1-6/+8
Add a local variable for rq_flags, it helps to compile out some of rq_flags reloads. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: blk_mq_rq_ctx_init cache ctx/q/hctxPavel Begunkov1-5/+9
We should have enough of registers in blk_mq_rq_ctx_init(), store them in local vars, so we don't keep reloading them. note: keeping q->elevator may look unnecessary, but it's also used inside inlined blk_mq_tags_from_data(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: skip elevator fields init for non-elv queuePavel Begunkov1-14/+14
Don't init rq->hash and rq->rb_node in blk_mq_rq_ctx_init() if there is no elevator. Also, move some other initialisers that imply barriers to the end, so the compiler is free to rearrange and optimise other the rest of them. note: fold in a change from Jens leaving queue_list unconditional, as it might lead to problems otherwise. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: store elevator state in requestJens Axboe1-9/+11
Add an rq private RQF_ELV flag, which tells the block layer that this request was initialized on a queue that has an IO scheduler attached. This allows for faster checking in the fast path, rather than having to deference rq->q later on. Elevator switching does full quiesce of the queue before detaching an IO scheduler, so it's safe to cache this in the request itself. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: move update request helpers into blk-mq.cJens Axboe1-0/+144
For some reason we still have them in blk-core, with the rest of the request completion being in blk-mq. That causes and out-of-line call for each completion. Move them into blk-mq.c instead, where they belong. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: convert the rest of block to bdev_get_queuePavel Begunkov1-1/+1
Convert bdev->bd_disk->queue to bdev_get_queue(), it's uses a cached queue pointer and so is faster. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/addf6ea988c04213697ba3684c853e4ed7642a39.1634219547.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: handle fast path of bio splitting inlineJens Axboe1-2/+3
The fast path is no splitting needed. Separate the handling into a check part we can inline, and an out-of-line handling path if we do need to split. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: switch polling to be bio basedChristoph Hellwig1-49/+23
Replace the blk_poll interface that requires the caller to keep a queue and cookie from the submissions with polling based on the bio. Polling for the bio itself leads to a few advantages: - the cookie construction can made entirely private in blk-mq.c - the caller does not need to remember the request_queue and cookie separately and thus sidesteps their lifetime issues - keeping the device and the cookie inside the bio allows to trivially support polling BIOs remapping by stacking drivers - a lot of code to propagate the cookie back up the submission path can be removed entirely. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Mark Wunderlich <mark.wunderlich@intel.com> Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: rename REQ_HIPRI to REQ_POLLEDChristoph Hellwig1-2/+2
Unlike the RWF_HIPRI userspace ABI which is intentionally kept vague, the bio flag is specific to the polling implementation, so rename and document it properly. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Tested-by: Mark Wunderlich <mark.wunderlich@intel.com> Link: https://lore.kernel.org/r/20211012111226.760968-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
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