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2020-04-06blk-mq: don't commit_rqs() if none were queuedKeith Busch1-3/+6
Unburden the drivers from checking if a call to commit_rqs() is valid by not calling it when there are no requests to commit. Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27block: simplify queue allocationChristoph Hellwig1-6/+2
Current make_request based drivers use either blk_alloc_queue_node or blk_alloc_queue to allocate a queue, and then set up the make_request_fn function pointer and a few parameters using the blk_queue_make_request helper. Simplify this by passing the make_request pointer to blk_alloc_queue, and while at it merge the _node variant into the main helper by always passing a node_id, and remove the superfluous gfp_mask parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27block: add a blk_mq_init_queue_data helperChristoph Hellwig1-1/+9
This allows a driver to pass a queuedata member before ->init_hctx is called. null_blk currently open codes this logic, but I'd rather have it in the core to ease future maintainance. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block: factor out requeue handling from dispatch codeJohannes Thumshirn1-11/+18
Factor out the requeue handling from the dispatch code, this will make subsequent addition of different requeueing schemes easier. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12block: remove unneeded argument from blk_alloc_flush_queueGuoqing Jiang1-2/+1
Remove 'q' from arguments since it is not used anymore after commit 7e992f847a08e ("block: remove non mq parts from the flush code"). Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-10blk-mq: Fix a recently introduced regression in blk_mq_realloc_hw_ctxs()Bart Van Assche1-1/+0
q->nr_hw_queues must only be updated once it is known that blk_mq_realloc_hw_ctxs() has succeeded. Otherwise it can happen that reallocation fails and that q->nr_hw_queues is larger than the number of allocated hardware queues. This patch fixes the following crash if increasing the number of hardware queues fails: BUG: KASAN: null-ptr-deref in blk_mq_map_swqueue+0x775/0x810 Write of size 8 at addr 0000000000000118 by task check/977 CPU: 3 PID: 977 Comm: check Not tainted 5.6.0-rc1-dbg+ #8 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: dump_stack+0xa5/0xe6 __kasan_report.cold+0x65/0x99 kasan_report+0x16/0x20 check_memory_region+0x140/0x1b0 memset+0x28/0x40 blk_mq_map_swqueue+0x775/0x810 blk_mq_update_nr_hw_queues+0x468/0x710 nullb_device_submit_queues_store+0xf7/0x1a0 [null_blk] configfs_write_file+0x1c4/0x250 [configfs] __vfs_write+0x4c/0x90 vfs_write+0x145/0x2c0 ksys_write+0xd7/0x180 __x64_sys_write+0x47/0x50 do_syscall_64+0x6f/0x2f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: ac0d6b926e74 ("block: Reduce the amount of memory required per request queue") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Cc: Keith Busch <kbusch@kernel.org> Cc: Johannes Thumshirn <jth@kernel.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-10blk-mq: Keep set->nr_hw_queues and set->map[].nr_queues in syncBart Van Assche1-0/+8
blk_mq_map_queues() and multiple .map_queues() implementations expect that set->map[HCTX_TYPE_DEFAULT].nr_queues is set to the number of hardware queues. Hence set .nr_queues before calling these functions. This patch fixes the following kernel warning: WARNING: CPU: 0 PID: 2501 at include/linux/cpumask.h:137 Call Trace: blk_mq_run_hw_queue+0x19d/0x350 block/blk-mq.c:1508 blk_mq_run_hw_queues+0x112/0x1a0 block/blk-mq.c:1525 blk_mq_requeue_work+0x502/0x780 block/blk-mq.c:775 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 Fixes: ed76e329d74a ("blk-mq: abstract out queue map") # v5.0 Reported-by: syzbot+d44e1b26ce5c3e77458d@syzkaller.appspotmail.com Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: Johannes Thumshirn <jth@kernel.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-02-26blk-mq: Remove some unused function argumentsJohn Garry1-6/+4
The struct blk_mq_hw_ctx pointer argument in blk_mq_put_tag(), blk_mq_poll_nsecs(), and blk_mq_poll_hybrid_sleep() is unused, so remove it. Overall obj code size shows a minor reduction, before: text data bss dec hex filename 27306 1312 0 28618 6fca block/blk-mq.o 4303 272 0 4575 11df block/blk-mq-tag.o after: 27282 1312 0 28594 6fb2 block/blk-mq.o 4311 272 0 4583 11e7 block/blk-mq-tag.o Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: John Garry <john.garry@huawei.com> -- This minor patch had been carried as part of the blk-mq shared tags RFC, I'd rather not carry it anymore as it required rebasing, so now or never.. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-02-25blk-mq: insert passthrough request into hctx->dispatch directlyMing Lei1-7/+11
For some reason, device may be in one situation which can't handle FS request, so STS_RESOURCE is always returned and the FS request will be added to hctx->dispatch. However passthrough request may be required at that time for fixing the problem. If passthrough request is added to scheduler queue, there isn't any chance for blk-mq to dispatch it given we prioritize requests in hctx->dispatch. Then the FS IO request may never be completed, and IO hang is caused. So passthrough request has to be added to hctx->dispatch directly for fixing the IO hang. Fix this issue by inserting passthrough request into hctx->dispatch directly together withing adding FS request to the tail of hctx->dispatch in blk_mq_dispatch_rq_list(). Actually we add FS request to tail of hctx->dispatch at default, see blk_mq_request_bypass_insert(). Then it becomes consistent with original legacy IO request path, in which passthrough request is always added to q->queue_head. Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-07blk-mq: Document functions for sending requestAndré Almeida1-2/+83
Add or improve documentation for function regarding creating and sending IO requests to the hardware. Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-19blk-mq: optimise blk_mq_flush_plug_list()Pavel Begunkov1-38/+19
Instead of using list_del_init() in a loop, that generates a lot of unnecessary memory read/writes, iterate from the first request of a batch and cut out a sublist with list_cut_before(). Apart from removing the list node initialisation part, this is more register-friendly, and the assembly uses the stack less intensively. list_empty() at the beginning is done with hope, that the compiler can optimise out the same check in the following list_splice_init(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-19blk-mq: optimise rq sort functionPavel Begunkov1-8/+4
Check "!=" in multi-layer comparisons. The same memory usage, fewer instructions, and 2 from 4 jumps are replaced with SETcc. Note, that list_sort() doesn't differ 0 and <0. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-13blk-mq: Delete blk_mq_has_free_tags() and blk_mq_can_queue()John Garry1-6/+0
These functions are not referenced, so delete them. Signed-off-by: John Garry <john.garry@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-01blk-mq: Make blk_mq_run_hw_queue() return voidJohn Garry1-6/+2
Since commit 97889f9ac24f ("blk-mq: remove synchronize_rcu() from blk_mq_del_queue_tag_set()"), the return value of blk_mq_run_hw_queue() is never checked, so make it return void, which very marginally simplifies the code. Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: John Garry <john.garry@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25blk-mq: remove needless goto from blk_mq_get_driver_tagAndré Almeida1-2/+1
The only usage of the label "done" is when (rq->tag != -1) at the beginning of the function. Rather than jumping to label, we can just remove this label and execute the code at the "if". Besides that, the code that would be executed after the label "done" is the return of the logical expression (rq->tag != -1) but since we are already inside the if, we now that this is true. Remove the label and replace the goto with the proper result of the label. Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25block: Reduce the amount of memory used for tag setsBart Van Assche1-17/+30
Instead of allocating an array of size nr_cpu_ids for set->tags, allocate an array of size set->nr_hw_queues. This patch improves behavior that was introduced by commit 868f2f0b7206 ("blk-mq: dynamic h/w context count"). Reallocating tag sets from inside __blk_mq_update_nr_hw_queues() is safe because: - All request queues that share the tag sets are frozen before the tag sets are reallocated. - blk_mq_queue_tag_busy_iter() holds q->q_usage_counter while active and hence is serialized against __blk_mq_update_nr_hw_queues(). Cc: Keith Busch <keith.busch@intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25block: Reduce the amount of memory required per request queueBart Van Assche1-7/+17
Instead of always allocating at least nr_cpu_ids hardware queues per request queue, reallocate q->queue_hw_ctx if it has to grow. This patch improves behavior that was introduced by commit 868f2f0b7206 ("blk-mq: dynamic h/w context count"). Cc: Keith Busch <keith.busch@intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25block: Remove the synchronize_rcu() call from __blk_mq_update_nr_hw_queues()Bart Van Assche1-4/+0
Since the blk_mq_{,un}freeze_queue() calls in __blk_mq_update_nr_hw_queues() already serialize __blk_mq_update_nr_hw_queues() against blk_mq_queue_tag_busy_iter(), the synchronize_rcu() call in __blk_mq_update_nr_hw_queues() is not necessary. Hence remove it. Note: the synchronize_rcu() call in __blk_mq_update_nr_hw_queues() was introduced by commit f5bbbbe4d635 ("blk-mq: sync the update nr_hw_queues with blk_mq_queue_tag_busy_iter"). Commit 530ca2c9bd69 ("blk-mq: Allow blocking queue tag iter callbacks") removed the rcu_read_{,un}lock() calls that correspond to the synchronize_rcu() call in __blk_mq_update_nr_hw_queues(). Reviewed-by: Ming Lei <ming.lei@redhat.com> Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07blk-mq: Embed counters into struct mq_inflightPavel Begunkov1-7/+6
Store inflight counters immediately in struct mq_inflight. That's type-safer and removes extra indirection. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07blk-mq: Reuse callback in blk_mq_in_flight*()Pavel Begunkov1-18/+3
Reuse a more generic callback in both blk_mq_in_flight() and blk_mq_in_flight_rw(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07blk-mq: Inline status checkersPavel Begunkov1-12/+0
blk_mq_request_completed() and blk_mq_request_started() are short, inline it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07block: Remove request_queue.nr_queuesBart Van Assche1-3/+3
Commit 897bb0c7f1ea ("blk-mq: Use proper cpumask iterator"; v4.6) removed the last use of request_queue.nr_queues from outside blk_mq_init_allocate_queue(). Remove this member variable to make struct request_queue smaller. This patch does not change any functionality. Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27blk-mq: apply normal plugging for HDDMing Lei1-1/+5
Some HDD drive may expose multiple hardware queues, such as MegraRaid. Let's apply the normal plugging for such devices because sequential IO may benefit a lot from plug merging. Cc: Bart Van Assche <bvanassche@acm.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Dave Chinner <dchinner@redhat.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27blk-mq: honor IO scheduler for multiqueue devicesMing Lei1-2/+4
If a device is using multiple queues, the IO scheduler may be bypassed. This may hurt performance for some slow MQ devices, and it also breaks zoned devices which depend on mq-deadline for respecting the write order in one zone. Don't bypass io scheduler if we have one setup. This patch can double sequential write performance basically on MQ scsi_debug when mq-deadline is applied. Cc: Bart Van Assche <bvanassche@acm.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Dave Chinner <dchinner@redhat.com> Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27block: fix null pointer dereference in blk_mq_rq_timed_out()Yufen Yu1-1/+4
We got a null pointer deference BUG_ON in blk_mq_rq_timed_out() as following: [ 108.825472] BUG: kernel NULL pointer dereference, address: 0000000000000040 [ 108.827059] PGD 0 P4D 0 [ 108.827313] Oops: 0000 [#1] SMP PTI [ 108.827657] CPU: 6 PID: 198 Comm: kworker/6:1H Not tainted 5.3.0-rc8+ #431 [ 108.829503] Workqueue: kblockd blk_mq_timeout_work [ 108.829913] RIP: 0010:blk_mq_check_expired+0x258/0x330 [ 108.838191] Call Trace: [ 108.838406] bt_iter+0x74/0x80 [ 108.838665] blk_mq_queue_tag_busy_iter+0x204/0x450 [ 108.839074] ? __switch_to_asm+0x34/0x70 [ 108.839405] ? blk_mq_stop_hw_queue+0x40/0x40 [ 108.839823] ? blk_mq_stop_hw_queue+0x40/0x40 [ 108.840273] ? syscall_return_via_sysret+0xf/0x7f [ 108.840732] blk_mq_timeout_work+0x74/0x200 [ 108.841151] process_one_work+0x297/0x680 [ 108.841550] worker_thread+0x29c/0x6f0 [ 108.841926] ? rescuer_thread+0x580/0x580 [ 108.842344] kthread+0x16a/0x1a0 [ 108.842666] ? kthread_flush_work+0x170/0x170 [ 108.843100] ret_from_fork+0x35/0x40 The bug is caused by the race between timeout handle and completion for flush request. When timeout handle function blk_mq_rq_timed_out() try to read 'req->q->mq_ops', the 'req' have completed and reinitiated by next flush request, which would call blk_rq_init() to clear 'req' as 0. After commit 12f5b93145 ("blk-mq: Remove generation seqeunce"), normal requests lifetime are protected by refcount. Until 'rq->ref' drop to zero, the request can really be free. Thus, these requests cannot been reused before timeout handle finish. However, flush request has defined .end_io and rq->end_io() is still called even if 'rq->ref' doesn't drop to zero. After that, the 'flush_rq' can be reused by the next flush request handle, resulting in null pointer deference BUG ON. We fix this problem by covering flush request with 'rq->ref'. If the refcount is not zero, flush_end_io() return and wait the last holder recall it. To record the request status, we add a new entry 'rq_status', which will be used in flush_end_io(). Cc: Christoph Hellwig <hch@infradead.org> Cc: Keith Busch <keith.busch@intel.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: stable@vger.kernel.org # v4.18+ Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Yufen Yu <yuyufen@huawei.com> ------- v2: - move rq_status from struct request to struct blk_flush_queue v3: - remove unnecessary '{}' pair. v4: - let spinlock to protect 'fq->rq_status' v5: - move rq_status after flush_running_idx member of struct blk_flush_queue Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-18block: centralize PI remapping logic to the block layerMax Gurtovoy1-0/+6
Currently t10_pi_prepare/t10_pi_complete functions are called during the NVMe and SCSi layers command preparetion/completion, but their actual place should be the block layer since T10-PI is a general data integrity feature that is used by block storage protocols. Introduce .prepare_fn and .complete_fn callbacks within the integrity profile that each type can implement according to its needs. Suggested-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Suggested-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Fixed to not call queue integrity functions if BLK_DEV_INTEGRITY isn't defined in the config. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-18Merge tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-blockLinus Torvalds1-34/+35
Pull block updates from Jens Axboe: - Two NVMe pull requests: - ana log parse fix from Anton - nvme quirks support for Apple devices from Ben - fix missing bio completion tracing for multipath stack devices from Hannes and Mikhail - IP TOS settings for nvme rdma and tcp transports from Israel - rq_dma_dir cleanups from Israel - tracing for Get LBA Status command from Minwoo - Some nvme-tcp cleanups from Minwoo, Potnuri and Myself - Some consolidation between the fabrics transports for handling the CAP register - reset race with ns scanning fix for fabrics (move fabrics commands to a dedicated request queue with a different lifetime from the admin request queue)." - controller reset and namespace scan races fixes - nvme discovery log change uevent support - naming improvements from Keith - multiple discovery controllers reject fix from James - some regular cleanups from various people - Series fixing (and re-fixing) null_blk debug printing and nr_devices checks (André) - A few pull requests from Song, with fixes from Andy, Guoqing, Guilherme, Neil, Nigel, and Yufen. - REQ_OP_ZONE_RESET_ALL support (Chaitanya) - Bio merge handling unification (Christoph) - Pick default elevator correctly for devices with special needs (Damien) - Block stats fixes (Hou) - Timeout and support devices nbd fixes (Mike) - Series fixing races around elevator switching and device add/remove (Ming) - sed-opal cleanups (Revanth) - Per device weight support for BFQ (Fam) - Support for blk-iocost, a new model that can properly account cost of IO workloads. (Tejun) - blk-cgroup writeback fixes (Tejun) - paride queue init fixes (zhengbin) - blk_set_runtime_active() cleanup (Stanley) - Block segment mapping optimizations (Bart) - lightnvm fixes (Hans/Minwoo/YueHaibing) - Various little fixes and cleanups * tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-block: (186 commits) null_blk: format pr_* logs with pr_fmt null_blk: match the type of parameter nr_devices null_blk: do not fail the module load with zero devices block: also check RQF_STATS in blk_mq_need_time_stamp() block: make rq sector size accessible for block stats bfq: Fix bfq linkage error raid5: use bio_end_sector in r5_next_bio raid5: remove STRIPE_OPS_REQ_PENDING md: add feature flag MD_FEATURE_RAID0_LAYOUT md/raid0: avoid RAID0 data corruption due to layout confusion. raid5: don't set STRIPE_HANDLE to stripe which is in batch list raid5: don't increment read_errors on EILSEQ return nvmet: fix a wrong error status returned in error log page nvme: send discovery log page change events to userspace nvme: add uevent variables for controller devices nvme: enable aen regardless of the presence of I/O queues nvme-fabrics: allow discovery subsystems accept a kato nvmet: Use PTR_ERR_OR_ZERO() in nvmet_init_discovery() nvme: Remove redundant assignment of cq vector nvme: Assign subsys instance from first ctrl ...
2019-09-17Merge branch 'timers-core-for-linus' of ↵Linus Torvalds1-3/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core timer updates from Thomas Gleixner: "Timers and timekeeping updates: - A large overhaul of the posix CPU timer code which is a preparation for moving the CPU timer expiry out into task work so it can be properly accounted on the task/process. An update to the bogus permission checks will come later during the merge window as feedback was not complete before heading of for travel. - Switch the timerqueue code to use cached rbtrees and get rid of the homebrewn caching of the leftmost node. - Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a single function - Implement the separation of hrtimers to be forced to expire in hard interrupt context even when PREEMPT_RT is enabled and mark the affected timers accordingly. - Implement a mechanism for hrtimers and the timer wheel to protect RT against priority inversion and live lock issues when a (hr)timer which should be canceled is currently executing the callback. Instead of infinitely spinning, the task which tries to cancel the timer blocks on a per cpu base expiry lock which is held and released by the (hr)timer expiry code. - Enable the Hyper-V TSC page based sched_clock for Hyper-V guests resulting in faster access to timekeeping functions. - Updates to various clocksource/clockevent drivers and their device tree bindings. - The usual small improvements all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) posix-cpu-timers: Fix permission check regression posix-cpu-timers: Always clear head pointer on dequeue hrtimer: Add a missing bracket and hide `migration_base' on !SMP posix-cpu-timers: Make expiry_active check actually work correctly posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build tick: Mark sched_timer to expire in hard interrupt context hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n posix-cpu-timers: Utilize timerqueue for storage posix-cpu-timers: Move state tracking to struct posix_cputimers posix-cpu-timers: Deduplicate rlimit handling posix-cpu-timers: Remove pointless comparisons posix-cpu-timers: Get rid of 64bit divisions posix-cpu-timers: Consolidate timer expiry further posix-cpu-timers: Get rid of zero checks rlimit: Rewrite non-sensical RLIMIT_CPU comment posix-cpu-timers: Respect INFINITY for hard RTTIME limit posix-cpu-timers: Switch thread group sampling to array posix-cpu-timers: Restructure expiry array posix-cpu-timers: Remove cputime_expires ...
2019-09-16block: also check RQF_STATS in blk_mq_need_time_stamp()Hou Tao1-3/+3
In __blk_mq_end_request() if block stats needs update, we should ensure now is valid instead of 0 even when iostat is disabled. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-16block: make rq sector size accessible for block statsHou Tao1-6/+5
Currently rq->data_len will be decreased by partial completion or zeroed by completion, so when blk_stat_add() is invoked, data_len will be zero and there will never be samples in poll_cb because blk_mq_poll_stats_bkt() will return -1 if data_len is zero. We could move blk_stat_add() back to __blk_mq_complete_request(), but that would make the effort of trying to call ktime_get_ns() once in vain. Instead we can reuse throtl_size field, and use it for both block stats and block throttle, and adjust the logic in blk_mq_poll_stats_bkt() accordingly. Fixes: 4bc6339a583c ("block: move blk_stat_add() to __blk_mq_end_request()") Tested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-06block: Delay default elevator initializationDamien Le Moal1-3/+9
When elevator_init_mq() is called from blk_mq_init_allocated_queue(), the only information known about the device is the number of hardware queues as the block device scan by the device driver is not completed yet for most drivers. The device type and elevator required features are not set yet, preventing to correctly select the default elevator most suitable for the device. This currently affects all multi-queue zoned block devices which default to the "none" elevator instead of the required "mq-deadline" elevator. These drives currently include host-managed SMR disks connected to a smartpqi HBA and null_blk block devices with zoned mode enabled. Upcoming NVMe Zoned Namespace devices will also be affected. Fix this by adding the boolean elevator_init argument to blk_mq_init_allocated_queue() to control the execution of elevator_init_mq(). Two cases exist: 1) elevator_init = false is used for calls to blk_mq_init_allocated_queue() within blk_mq_init_queue(). In this case, a call to elevator_init_mq() is added to __device_add_disk(), resulting in the delayed initialization of the queue elevator after the device driver finished probing the device information. This effectively allows elevator_init_mq() access to more information about the device. 2) elevator_init = true preserves the current behavior of initializing the elevator directly from blk_mq_init_allocated_queue(). This case is used for the special request based DM devices where the device gendisk is created before the queue initialization and device information (e.g. queue limits) is already known when the queue initialization is executed. Additionally, to make sure that the elevator initialization is never done while requests are in-flight (there should be none when the device driver calls device_add_disk()), freeze and quiesce the device request queue before calling blk_mq_init_sched() in elevator_init_mq(). Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-06block: Change elevator_init_mq() to always succeedDamien Le Moal1-7/+1
If the default elevator chosen is mq-deadline, elevator_init_mq() may return an error if mq-deadline initialization fails, leading to blk_mq_init_allocated_queue() returning an error, which in turn will cause the block device initialization to fail and the device not being exposed. Instead of taking such extreme measure, handle mq-deadline initialization failures in the same manner as when mq-deadline is not available (no module to load), that is, default to the "none" scheduler. With this change, elevator_init_mq() return type can be changed to void. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-06block: Cleanup elevator_init_mq() useDamien Le Moal1-5/+3
Instead of checking a queue tag_set BLK_MQ_F_NO_SCHED flag before calling elevator_init_mq() to make sure that the queue supports IO scheduling, use the elevator.c function elv_support_iosched() in elevator_init_mq(). This does not introduce any functional change but ensure that elevator_init_mq() does the right thing based on the queue settings. Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-29blk-mq: add optional request->alloc_time_nsTejun Heo1-2/+11
There are currently two start time timestamps - start_time_ns and io_start_time_ns. The former marks the request allocation and and the second issue-to-device time. The planned io.weight controller needs to measure the total time bios take to execute after it leaves rq_qos including the time spent waiting for request to become available, which can easily dominate on saturated devices. This patch adds request->alloc_time_ns which records when the request allocation attempt started. As it isn't used for the usual stats, make it optional behind CONFIG_BLK_RQ_ALLOC_TIME and QUEUE_FLAG_RQ_ALLOC_TIME so that it can be compiled out when there are no users and it's active only on queues which need it even when compiled in. v2: s/pre_start_time/alloc_time/ and add CONFIG_BLK_RQ_ALLOC_TIME gating as suggested by Jens. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-27blk-mq: don't hold q->sysfs_lock in blk_mq_map_swqueueMing Lei1-7/+0
blk_mq_map_swqueue() is called from blk_mq_init_allocated_queue() and blk_mq_update_nr_hw_queues(). For the former caller, the kobject isn't exposed to userspace yet. For the latter caller, hctx sysfs entries and debugfs are un-registered before updating nr_hw_queues. On the other hand, commit 2f8f1336a48b ("blk-mq: always free hctx after request queue is freed") moves freeing hctx into queue's release handler, so there won't be race with queue release path too. So don't hold q->sysfs_lock in blk_mq_map_swqueue(). Cc: Christoph Hellwig <hch@infradead.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-15block: remove REQ_NOWAIT_INLINEJens Axboe1-6/+2
We had a few issues with this code, and there's still a problem around how we deal with error handling for chained/split bios. For now, just revert the code and we'll try again with a thoroug solution. This reverts commits: e15c2ffa1091 ("block: fix O_DIRECT error handling for bio fragments") 0eb6ddfb865c ("block: Fix __blkdev_direct_IO() for bio fragments") 6a43074e2f46 ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO") 893a1c97205a ("blk-mq: allow REQ_NOWAIT to return an error inline") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-12blk-mq: Fix memory leak in blk_mq_init_allocated_queue error handlingzhengbin1-3/+6
If blk_mq_init_allocated_queue->elevator_init_mq fails, need to release the previously requested resources. Fixes: d34849913819 ("blk-mq-sched: allow setting of default IO scheduler") Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-12blk-mq: move cancel of requeue_work to the front of blk_exit_queuezhengbin1-2/+0
blk_exit_queue will free elevator_data, while blk_mq_requeue_work will access it. Move cancel of requeue_work to the front of blk_exit_queue to avoid use-after-free. blk_exit_queue blk_mq_requeue_work __elevator_exit blk_mq_run_hw_queues blk_mq_exit_sched blk_mq_run_hw_queue dd_exit_queue blk_mq_hctx_has_pending kfree(elevator_data) blk_mq_sched_has_work dd_has_work Fixes: fbc2a15e3433 ("blk-mq: move cancel of requeue_work into blk_mq_release") Cc: stable@vger.kernel.org Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-05blk-mq: remove blk_mq_complete_request_syncMing Lei1-7/+0
blk_mq_tagset_wait_completed_request() has been applied for waiting for completed request's fn, so not necessary to use blk_mq_complete_request_sync() any more. Cc: Max Gurtovoy <maxg@mellanox.com> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Keith Busch <keith.busch@intel.com> Cc: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-05blk-mq: introduce blk_mq_request_completed()Ming Lei1-0/+6
NVMe needs this function to decide if one request to be aborted has been completed in normal IO path already. So introduce it. Cc: Max Gurtovoy <maxg@mellanox.com> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Keith Busch <keith.busch@intel.com> Cc: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-01hrtimer/treewide: Use hrtimer_sleeper_start_expires()Thomas Gleixner1-1/+1
hrtimer_sleepers will gain a scheduling class dependent treatment on PREEMPT_RT. Use the new hrtimer_sleeper_start_expires() function to make that possible. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2019-08-01hrtimer: Consolidate hrtimer_init() + hrtimer_init_sleeper() callsSebastian Andrzej Siewior1-2/+1
hrtimer_init_sleeper() calls require prior initialisation of the hrtimer object which is embedded into the hrtimer_sleeper. Combine the initialization and spare a function call. Fixup all call sites. This is also a preparatory change for PREEMPT_RT to do hrtimer sleeper specific initializations of the embedded hrtimer without modifying any of the call sites. No functional change. [ anna-maria: Minor cleanups ] [ tglx: Adopted to the removal of the task argument of hrtimer_init_sleeper() and trivial polishing. Folded a fix from Stephen Rothwell for the vsoc code ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190726185752.887468908@linutronix.de
2019-07-31hrtimer: Remove task argument from hrtimer_init_sleeper()Thomas Gleixner1-1/+1
All callers hand in 'current' and that's the only task pointer which actually makes sense. Remove the task argument and set current in the function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190726185752.791885290@linutronix.de
2019-07-23block: blk-mq: Remove blk_mq_sched_started_request and started_requestMarcos Paulo de Souza1-2/+0
blk_mq_sched_completed_request is a function that checks if the elevator related to the request has started_request implemented, but currently, none of the available IO schedulers implement started_request, so remove both. Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-22blk-mq: allow REQ_NOWAIT to return an error inlineJens Axboe1-2/+6
By default, if a caller sets REQ_NOWAIT and we need to block, we'll return -EAGAIN through the bio->bi_end_io() callback. For some use cases, this makes it hard to use. Allow a caller to ask for inline return of errors related to blocking by also setting REQ_NOWAIT_INLINE. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-10block: Disable write plugging for zoned block devicesDamien Le Moal1-1/+1
Simultaneously writing to a sequential zone of a zoned block device from multiple contexts requires mutual exclusion for BIO issuing to ensure that writes happen sequentially. However, even for a well behaved user correctly implementing such synchronization, BIO plugging may interfere and result in BIOs from the different contextx to be reordered if plugging is done outside of the mutual exclusion section, e.g. the plug was started by a function higher in the call chain than the function issuing BIOs. Context A Context B | blk_start_plug() | ... | seq_write_zone() | mutex_lock(zone) | bio-0->bi_iter.bi_sector = zone->wp | zone->wp += bio_sectors(bio-0) | submit_bio(bio-0) | bio-1->bi_iter.bi_sector = zone->wp | zone->wp += bio_sectors(bio-1) | submit_bio(bio-1) | mutex_unlock(zone) | return | -----------------------> | seq_write_zone() | mutex_lock(zone) | bio-2->bi_iter.bi_sector = zone->wp | zone->wp += bio_sectors(bio-2) | submit_bio(bio-2) | mutex_unlock(zone) | <------------------------- | | blk_finish_plug() In the above example, despite the mutex synchronization ensuring the correct BIO issuing order 0, 1, 2, context A BIOs 0 and 1 end up being issued after BIO 2 of context B, when the plug is released with blk_finish_plug(). While this problem can be addressed using the blk_flush_plug_list() function (in the above example, the call must be inserted before the zone mutex lock is released), a simple generic solution in the block layer avoid this additional code in all zoned block device user code. The simple generic solution implemented with this patch is to introduce the internal helper function blk_mq_plug() to access the current context plug on BIO submission. This helper returns the current plug only if the target device is not a zoned block device or if the BIO to be plugged is not a write operation. Otherwise, the caller context plug is ignored and NULL returned, resulting is all writes to zoned block device to never be plugged. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-03blk-mq: simplify blk_mq_make_request()Bart Van Assche1-8/+2
Move the blk_mq_bio_to_request() call in front of the if-statement. Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-03blk-mq: remove blk_mq_put_ctx()Bart Van Assche1-13/+3
No code that occurs between blk_mq_get_ctx() and blk_mq_put_ctx() depends on preemption being disabled for its correctness. Since removing the CPU preemption calls does not measurably affect performance, simplify the blk-mq code by removing the blk_mq_put_ctx() function and also by not disabling preemption in blk_mq_get_ctx(). Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: remove the bi_phys_segments field in struct bioChristoph Hellwig1-11/+12
We only need the number of segments in the blk-mq submission path. Remove the field from struct bio, and return it from a variant of blk_queue_split instead of that it can passed as an argument to those functions that need the value. This also means we stop recounting segments except for cloning and partial segments. To keep the number of arguments in this how path down remove pointless struct request_queue arguments from any of the functions that had it and grew a nr_segs argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: remove blk_init_request_from_bioChristoph Hellwig1-1/+6
lightnvm should have never used this function, as it is sending passthrough requests, so switch it to blk_rq_append_bio like all the other passthrough request users. Inline blk_init_request_from_bio into the only remaining caller. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com> Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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