- Mar 31, 2022
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Jakob Koschel authored
To move the list iterator variable into the list_for_each_entry_*() macro in the future it should be avoided to use the list iterator variable after the loop body. To *never* use the list iterator variable after the loop it was concluded to use a separate iterator variable instead of a found boolean [1]. Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Signed-off-by:
Jakob Koschel <jakobkoschel@gmail.com> Link: https://lore.kernel.org/r/20220331091218.641532-1-jakobkoschel@gmail.com [axboe: move lookup to where return value is checked] Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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- Mar 11, 2022
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Jens Axboe authored
We used to sort the plug list if we had multiple queues before dispatching requests to the IO scheduler. This usually isn't needed, but for certain workloads that interleave requests to disks, it's a less efficient to process the plug list one-by-one if everything is interleaved. Don't sort the list, but skip through it and flush out entries that have the same target at the same time. Fixes: df87eb0f ("block: get rid of plug list sorting") Reported-and-tested-by:
Song Liu <song@kernel.org> Reviewed-by:
Song Liu <songliubraving@fb.com> Signed-off-by:
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- Mar 08, 2022
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Ming Lei authored
The queue's top debugfs dir is removed from blk_release_queue(), so all hctx's debugfs dirs are removed from there. Given blk_mq_exit_queue() is only called from blk_cleanup_queue(), it isn't necessary to remove hctx debugfs from blk_mq_exit_queue(). So remove it from blk_mq_exit_queue(). Signed-off-by:
Ming Lei <ming.lei@redhat.com> Signed-off-by:
Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220308055200.735835-11-hch@lst.de Signed-off-by:
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Ming Lei authored
To simplify further changes allow for double calling blk_mq_free_rqs on a queue. Signed-off-by:
Bart Van Assche <bvanassche@acm.org> Reviewed-by:
Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20220308055200.735835-3-hch@lst.de Signed-off-by:
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Christoph Hellwig authored
I/O accounting buckets I/O into the read/write/discard categories into which passthrough I/O does not fit at all. It also accounts to the block_device, which may not even exist for passthrough I/O. Signed-off-by:
Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by:
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Ming Lei authored
First code becomes more clean by switching to xarray from plain array. Second use-after-free on q->queue_hw_ctx can be fixed because queue_for_each_hw_ctx() may be run when updating nr_hw_queues is in-progress. With this patch, q->hctx_table is defined as xarray, and this structure will share same lifetime with request queue, so queue_for_each_hw_ctx() can use q->hctx_table to lookup hctx reliably. Reported-by:
Yu Kuai <yukuai3@huawei.com> Signed-off-by:
Hannes Reinecke <hare@suse.de> Reviewed-by:
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Ming Lei authored
It is inevitable to cause use-after-free on q->queue_hw_ctx between queue_for_each_hw_ctx() and blk_mq_update_nr_hw_queues(). And converting to xarray can fix the uaf, meantime code gets cleaner. Prepare for converting q->queue_hctx_ctx into xarray, one thing is that xa_for_each() can only accept 'unsigned long' as index, so changes type of hctx index of queue_for_each_hw_ctx() into 'unsigned long'. Reviewed-by:
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Ming Lei authored
queue map can be changed when updating nr_hw_queues, so we need to reconfigure queue's poll capability. Add one helper for doing this job. Reviewed-by:
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Ming Lei authored
blk_mq_alloc_and_init_hctx() has already taken reuse into account, so no need to do it outside, then we can simplify blk_mq_realloc_hw_ctxs(). Reviewed-by:
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Ming Lei authored
The current code always uses default queue map and hw queue index for figuring out the numa node for hw queue, this way isn't correct because blk-mq supports three queue maps, and the correct queue map should be used for the specified hw queue. Reviewed-by:
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Shin'ichiro Kawasaki authored
Commit 9d497e29 ("block: don't protect submit_bio_checks by q_usage_counter") moved blk_mq_attempt_bio_merge and rq_qos_throttle calls out of q_usage_counter protection. However, these functions require q_usage_counter protection. The blk_mq_attempt_bio_merge call without the protection resulted in blktests block/005 failure with KASAN null- ptr-deref or use-after-free at bio merge. The rq_qos_throttle call without the protection caused kernel hang at qos throttle. To fix the failures, move the blk_mq_attempt_bio_merge and rq_qos_throttle calls back to q_usage_counter protection. Fixes: 9d497e29 ("block: don't protect submit_bio_checks by q_usage_counter") Signed-off-by:
Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Link: https://lore.kernel.org/r/20220308080915.3473689-1-shinichiro.kawasaki@wdc.com Reviewed-by:
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- Mar 07, 2022
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Christoph Hellwig authored
With the NVMe support for this gone, there are no consumers of these hints left, so remove them. Signed-off-by:
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- Feb 16, 2022
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David Jeffery authored
When blk_mq_delay_run_hw_queues sets an hctx to run in the future, it can reset the delay length for an already pending delayed work run_work. This creates a scenario where multiple hctx may have their queues set to run, but if one runs first and finds nothing to do, it can reset the delay of another hctx and stall the other hctx's ability to run requests. To avoid this I/O stall when an hctx's run_work is already pending, leave it untouched to run at its current designated time rather than extending its delay. The work will still run which keeps closed the race calling blk_mq_delay_run_hw_queues is needed for while also avoiding the I/O stall. Signed-off-by:
David Jeffery <djeffery@redhat.com> Reviewed-by:
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Ming Lei authored
blk_crypto_bio_prep() is called for both bio based and blk-mq drivers, so move it out of blk-mq.c, then we can unify this kind of handling. Reviewed-by:
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Christoph Hellwig authored
The request must be submitted to the queue it was allocated for, so remove the extra request_queue argument. Signed-off-by:
Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20220215100540.3892965-4-hch@lst.de Signed-off-by:
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Christoph Hellwig authored
Fold blk_cloned_rq_check_limits into its only caller. Signed-off-by:
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Christoph Hellwig authored
The code to stack blk-mq drivers is only used by dm-multipath, and will preferably stay that way. Make it optional and only selected by device mapper, so that the buildbots more easily catch abuses like the one that slipped in in the ufs driver in the last merged window. Another positive side effects is that kernel builds without device mapper shrink a little bit as well. Signed-off-by:
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- Feb 11, 2022
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Yang Shi authored
Currently, rasdaemon uses the existing tracepoint block_rq_complete and filters out non-error cases in order to capture block disk errors. But there are a few problems with this approach: 1. Even kernel trace filter could do the filtering work, there is still some overhead after we enable this tracepoint. 2. The filter is merely based on errno, which does not align with kernel logic to check the errors for print_req_error(). 3. block_rq_complete only provides dev major and minor to identify the block device, it is not convenient to use in user-space. So introduce a new tracepoint block_rq_error just for the error case. With this patch, rasdaemon could switch to block_rq_error. Since the new tracepoint has the similar implementation with block_rq_complete, so move the existing code from TRACE_EVENT block_rq_complete() into new event class block_rq_completion(). Then add event for block_rq_complete and block_rq_err respectively from the newly created event class per the suggestion from Chaitanya Kulkarni. Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@infradead.org> Reviewed-by:
Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by:
Yang Shi <shy828301@gmail.com> Reviewed-by:
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Pankaj Raghav authored
Zone append command needs special handling to update the bi_sector field in the bio struct with the actual position of the data in the device. It is stored in __sector field of the request struct. Fixes: 5581a5dd ("block: add completion handler for fast path") Signed-off-by:
Pankaj Raghav <p.raghav@samsung.com> Reviewed-by:
Adam Manzanares <a.manzanares@samsung.com> Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220211093425.43262-2-p.raghav@samsung.com Signed-off-by:
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- Feb 04, 2022
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Christoph Hellwig authored
Pass a block_device to bio_clone_fast and __bio_clone_fast and give the functions more suitable names. Signed-off-by:
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- Jan 26, 2022
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Yu Kuai authored
If blk_mq_request_issue_directly() failed from blk_insert_cloned_request(), the request will be accounted start. Currently, blk_insert_cloned_request() is only called by dm, and such request won't be accounted done by dm. In normal path, io will be accounted start from blk_mq_bio_to_request(), when the request is allocated, and such io will be accounted done from __blk_mq_end_request_acct() whether it succeeded or failed. Thus add blk_account_io_done() to fix the problem. Signed-off-by:
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- Jan 18, 2022
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Christoph Hellwig authored
bio_clone_fast() sets the cloned bio to have the same ->bi_bdev as the source bio. This means that when request-based dm called setup_clone(), the cloned bio had its ->bi_bdev pointing to the dm device. After Commit 0b6e522c ("blk-mq: use ->bi_bdev for I/O accounting") __blk_account_io_start() started using the request's ->bio->bi_bdev for I/O accounting, if it was set. This caused IO going to the underlying devices to use the dm device for their I/O accounting. Set up the proper ->bi_bdev in blk_rq_prep_clone based on the whole device bdev for the queue the request is cloned onto. Fixes: 0b6e522c ("blk-mq: use ->bi_bdev for I/O accounting") Reported-by:
Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by:
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- Jan 15, 2022
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Yury Norov authored
cpumask_first() is a more effective analogue of 'next' version if n == -1 (which means start == 0). This patch replaces 'next' with 'first' where things look trivial. There's no cpumask_first_zero() function, so create it. Signed-off-by:
Yury Norov <yury.norov@gmail.com> Tested-by:
Wolfram Sang <wsa+renesas@sang-engineering.com>
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- Jan 09, 2022
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Ming Lei authored
Commit cc9c884d ("block: call submit_bio_checks under q_usage_counter") uses q_usage_counter to protect submit_bio_checks for avoiding IO after disk is deleted by del_gendisk(). Turns out the protection isn't necessary, because once blk_mq_freeze_queue_wait() in del_gendisk() returns: 1) all in-flight IO has been done 2) all new IO will be failed in __bio_queue_enter() because q_usage_counter is dead, and GD_DEAD is set 3) both disk and request queue instance are safe since caller of submit_bio() guarantees that the disk can't be closed. Once submit_bio_checks() needn't the protection of q_usage_counter, we can move submit_bio_checks before calling blk_mq_submit_bio() and ->submit_bio(). With this change, we needn't to throttle queue with holding one allocated request, then precise driver tag or request won't be wasted in throttling. Meantime we can unify the bio check for both bio based and request based driver. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by:
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- Dec 20, 2021
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Keith Busch authored
The low level drivers don't expect to see new requests after a successful quiesce completes. Check the queue quiesce state within the rcu protected area prior to calling the driver's queue_rqs(). Fixes: 3c67d44d ("block: add mq_ops->queue_rqs hook") Signed-off-by:
Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20211220205919.180191-1-kbusch@kernel.org Signed-off-by:
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- Dec 16, 2021
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Jens Axboe authored
If we have a list of requests in our plug list, send it to the driver in one go, if possible. The driver must set mq_ops->queue_rqs() to support this, if not the usual one-by-one path is used. Reviewed-by:
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Jens Axboe authored
The batched completions only deal with non-partial requests anyway, and it doesn't deal with any requests that have errors. Add a completion handler that assumes it's a full request and that it's all being ended successfully. Reviewed-by:
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- Dec 06, 2021
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John Garry authored
The only user of blk_mq_hw_ctx blk_mq_hw_ctx argument is blk_mq_rq_inflight(). Function blk_mq_rq_inflight() uses the hctx to find the associated request queue to match against the request. However this same check is already done in caller bt_iter(), so drop this check. With that change there are no more users of busy_iter_fn blk_mq_hw_ctx argument, so drop the argument. Reviewed-by Hannes Reinecke <hare@suse.de> Signed-off-by:
John Garry <john.garry@huawei.com> Reviewed-by:
Kashyap Desai <kashyap.desai@broadcom.com> Link: https://lore.kernel.org/r/1638794990-137490-2-git-send-email-john.garry@huawei.com Signed-off-by:
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Ming Lei authored
blk_mq_run_dispatch_ops() is defined as one macro, and plug->mq_list will be changed when running 'dispatch_ops', so add one local variable for holding request queue. Reported-and-tested-by:
Yi Zhang <yi.zhang@redhat.com> Fixes: 4cafe86c ("blk-mq: run dispatch lock once in case of issuing from list") Signed-off-by:
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Ming Lei authored
The operation protected via blk_mq_run_dispatch_ops() in blk_mq_run_hw_queue won't sleep, so don't run might_sleep() for it. Reported-and-tested-by:
Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by:
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- Dec 03, 2021
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Ming Lei authored
It isn't necessary to call blk_mq_run_dispatch_ops() once for issuing single request directly, and enough to do it one time when issuing from whole list. Signed-off-by:
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Ming Lei authored
We have switched to allocate srcu into request queue, so it is fine to pass request queue to blk_mq_run_dispatch_ops(). Signed-off-by:
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Ming Lei authored
In case of BLK_MQ_F_BLOCKING, per-hctx srcu is used to protect dispatch critical area. However, this srcu instance stays at the end of hctx, and it often takes standalone cacheline, often cold. Inside srcu_read_lock() and srcu_read_unlock(), WRITE is always done on the indirect percpu variable which is allocated from heap instead of being embedded, srcu->srcu_idx is read only in srcu_read_lock(). It doesn't matter if srcu structure stays in hctx or request queue. So switch to per-request-queue srcu for protecting dispatch, and this way simplifies quiesce a lot, not mention quiesce is always done on the request queue wide. Signed-off-by:
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Ming Lei authored
Remove hctx_lock and hctx_unlock, and add one helper of blk_mq_run_dispatch_ops() to run code block defined in dispatch_ops with rcu/srcu read held. Compared with hctx_lock()/hctx_unlock(): 1) remove 2 branch to 1, so we just need to check (hctx->flags & BLK_MQ_F_BLOCKING) once when running one dispatch_ops 2) srcu_idx needn't to be touched in case of non-blocking 3) might_sleep_if() can be moved to the blocking branch Also put the added blk_mq_run_dispatch_ops() in private header, so that the following patch can use it out of blk-mq.c. Signed-off-by:
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Jens Axboe authored
refcount_t is not as expensive as it used to be, but it's still more expensive than the io_uring method of using atomic_t and just checking for potential over/underflow. This borrows that same implementation, which in turn is based on the mm implementation from Linus. Reviewed-by:
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- Dec 02, 2021
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Jens Axboe authored
When we attempt to merge off the cached request path, we return NULL if successful. This makes the caller believe that it's should allocate a new request, and hence we end up with the bio both merged and associated with a new request. This, predictably, leads to all sorts of crashes. Pass in a pointer to the bio pointer, and clear it for the merge case. Then the caller knows that the bio is already queued, and no new requests need to get allocated. Fixes: 5b13bc8a ("blk-mq: cleanup request allocation") Reviewed-by:
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Jens Axboe authored
Expected case is returning a request, just check for success and return the request rather than having an error label. Signed-off-by:
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- Nov 29, 2021
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Christoph Hellwig authored
Remove the gendisk aregument to blk_execute_rq and blk_execute_rq_nowait given that it is unused now. Also convert the boolean at_head parameter to actually use the bool type while touching the prototype. Signed-off-by:
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Christoph Hellwig authored
Just use the disk attached to the request_queue instead. Signed-off-by:
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Christoph Hellwig authored
After the prepare side has been moved to the only I/O scheduler that cares, do the same for the cleanup and the NULL initialization. Signed-off-by:
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