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2022-03-08block: fix blk_mq_attempt_bio_merge and rq_qos_throttle protectionShin'ichiro Kawasaki
Commit 9d497e2941c3 ("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: 9d497e2941c3 ("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: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-11block: Add handling for zone append command in blk_complete_requestPankaj Raghav
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: 5581a5ddfe8d ("block: add completion handler for fast path") Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-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: Jens Axboe <axboe@kernel.dk>
2022-01-26blk-mq: fix missing blk_account_io_done() in error pathYu Kuai
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: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220126012132.3111551-1-yukuai3@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-01-23Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linuxLinus Torvalds
Pull bitmap updates from Yury Norov: - introduce for_each_set_bitrange() - use find_first_*_bit() instead of find_next_*_bit() where possible - unify for_each_bit() macros * tag 'bitmap-5.17-rc1' of git://github.com/norov/linux: vsprintf: rework bitmap_list_string lib: bitmap: add performance test for bitmap_print_to_pagebuf bitmap: unify find_bit operations mm/percpu: micro-optimize pcpu_is_populated() Replace for_each_*_bit_from() with for_each_*_bit() where appropriate find: micro-optimize for_each_{set,clear}_bit() include/linux: move for_each_bit() macros from bitops.h to find.h cpumask: replace cpumask_next_* with cpumask_first_* where appropriate tools: sync tools/bitmap with mother linux all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate cpumask: use find_first_and_bit() lib: add find_first_and_bit() arch: remove GENERIC_FIND_FIRST_BIT entirely include: move find.h from asm_generic to linux bitops: move find_bit_*_le functions from le.h to find.h bitops: protect find_first_{,zero}_bit properly
2022-01-18block: assign bi_bdev for cloned bios in blk_rq_prep_cloneChristoph Hellwig
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 0b6e522cdc4a ("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: 0b6e522cdc4a ("blk-mq: use ->bi_bdev for I/O accounting") Reported-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> [hch: the commit message is mostly from a different patch from Benjamin] Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com> Link: https://lore.kernel.org/r/20220118070444.1241739-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-01-15cpumask: replace cpumask_next_* with cpumask_first_* where appropriateYury Norov
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>
2022-01-09block: don't protect submit_bio_checks by q_usage_counterMing Lei
Commit cc9c884dd7f4 ("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: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220104134223.590803-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-20blk-mq: blk-mq: check quiesce state before queue_rqsKeith Busch
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: 3c67d44de787 ("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: Jens Axboe <axboe@kernel.dk>
2021-12-16block: add mq_ops->queue_rqs hookJens Axboe
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: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: add completion handler for fast pathJens Axboe
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: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-06blk-mq: Drop busy_iter_fn blk_mq_hw_ctx argumentJohn Garry
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: Ming Lei <ming.lei@redhat.com> Tested-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: Jens Axboe <axboe@kernel.dk>
2021-12-06blk-mq: don't use plug->mq_list->q directly in blk_mq_run_dispatch_ops()Ming Lei
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: 4cafe86c9267 ("blk-mq: run dispatch lock once in case of issuing from list") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-06blk-mq: don't run might_sleep() if the operation needn't blockingMing Lei
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: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-03blk-mq: run dispatch lock once in case of issuing from listMing Lei
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: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211203131534.3668411-5-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-03blk-mq: pass request queue to blk_mq_run_dispatch_opsMing Lei
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: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211203131534.3668411-4-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-03blk-mq: move srcu from blk_mq_hw_ctx to request_queueMing Lei
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: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211203131534.3668411-3-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-03blk-mq: remove hctx_lock and hctx_unlockMing Lei
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: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211203131534.3668411-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-03block: switch to atomic_t for request referencesJens Axboe
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: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-02block: fix double bio queue when merging in cached request pathJens Axboe
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: 5b13bc8a3fd5 ("blk-mq: cleanup request allocation") Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-02block: get rid of useless goto and label in blk_mq_get_new_requests()Jens Axboe
Expected case is returning a request, just check for success and return the request rather than having an error label. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: remove the gendisk argument to blk_execute_rqChristoph Hellwig
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: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20211126121802.2090656-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: remove the ->rq_disk field in struct requestChristoph Hellwig
Just use the disk attached to the request_queue instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20211126121802.2090656-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: move the remaining elv.icq handling to the I/O schedulerChristoph Hellwig
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: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211126115817.2087431-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29blk-mq: use bio->bi_opf after bio is checkedMing Lei
bio->bi_opf isn't finalized before checking the bio, so use it after submit_bio_checks() returns. Fixes: 5b13bc8a3fd5 ("blk-mq: cleanup request allocation") Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29blk-mq: cleanup request allocationChristoph Hellwig
Refactor the request alloction so that blk_mq_get_cached_request tries to find a cached request first, and the entirely separate and now self contained blk_mq_get_new_requests allocates one or more requests if that is not possible. There is a small change in behavior as submit_bio_checks is called twice now if a cached request is present but can't be used, but that is a small price to pay for unwinding this code. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211124062856.1444266-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: don't include <linux/part_stat.h> in blk.hChristoph Hellwig
Not needed, shift it into the source files that need it instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211123185312.1432157-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29blk_mq: remove repeated includesGuo Zhengkui
Remove a repeated "#include<linux/sched/sysctl.h>". Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20211123063340.25882-1-guozhengkui@vivo.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: move io_context creation into where it's neededJens Axboe
The only user of the io_context for IO is BFQ, yet we put the checking and logic of it into the normal IO path. Put the creation into blk_mq_sched_assign_ioc(), and have BFQ use that helper. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: only allocate poll_stats if there's a user of themJens Axboe
This is essentially never used, yet it's about 1/3rd of the total queue size. Allocate it when needed, and don't embed it in the queue. Kill the queue flag for this while at it, since we can just check the assigned pointer now. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29blk-mq: move more plug handling from blk_mq_submit_bio into blk_add_rq_to_plugChristoph Hellwig
Keep all the functionality for adding a request to a plug in a single place. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211123160443.1315598-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29blk-mq: simplify the plug handling in blk_mq_submit_bioChristoph Hellwig
blk_mq_submit_bio has two different plug cases, one that uses full plugging and a limited plugging one. The limited plugging case is only used for a corner case that does not matter in real life: - no ->commit_rqs (so not NVMe) - no shared tags (so not SCSI) - not rotational (so no old disk or floppy driver) - must have multiple queues (so no eMMC) Remove the limited merging case and all the related junk to simplify blk_mq_submit_bio and the functions called from it. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211123160443.1315598-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: move blk_print_req_error to blk-mq.cChristoph Hellwig
This function is only used by the request completion path. Factor out a blk_status_to_str to keep blk_errors private in blk-core.c. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20211117061404.331732-11-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: move blk_dump_rq_flags to blk-mq.cChristoph Hellwig
blk_dump_rq_flags deals with a request, so move it to blk-mq.c. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20211117061404.331732-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: move blk_account_io_{start,done} to blk-mq.cChristoph Hellwig
These are only used for request based I/O, so move them where they are used. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20211117061404.331732-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: move blk_steal_bios to blk-mq.cChristoph Hellwig
Keep all the request based code together. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20211117061404.331732-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: move blk_rq_init to blk-mq.cChristoph Hellwig
blk_rq_init deals with a request structure, so move it to blk-mq.c Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20211117061404.331732-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: move request based cloning helpers to blk-mq.cChristoph Hellwig
Keep all the request based code together. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20211117061404.331732-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29blk-mq: move blk_mq_flush_plug_listChristoph Hellwig
Move blk_mq_flush_plug_list and blk_mq_plug_issue_direct down in blk-mq.c to prepare for marking blk_mq_request_issue_directly static without the need of a forward declaration. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20211117061404.331732-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-29block: remove blk-exec.cChristoph Hellwig
All this code is tightly coupled to the blk-mq core, so move it there. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20211117061404.331732-4-hch@lst.de [axboe: remove doc generation for blk-exec.c] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-26block: call rq_qos_done() before ref check in batch completionsJens Axboe
We need to call rq_qos_done() regardless of whether or not we're freeing the request or not, as the reference count doesn't cover the IO completion tracking. Fixes: f794f3351f26 ("block: add support for blk_mq_end_request_batch()") Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reported-by: Kenneth R. Crudup <kenny@panix.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-19blk-mq: don't insert FUA request with data into scheduler queueMing Lei
We never insert flush request into scheduler queue before. Recently commit d92ca9d8348f ("blk-mq: don't handle non-flush requests in blk_insert_flush") tries to handle FUA data request as normal request. This way has caused warning[1] in mq-deadline dd_exit_sched() or io hang in case of kyber since RQF_ELVPRIV isn't set for flush request, then ->finish_request won't be called. Fix the issue by inserting FUA data request with blk_mq_request_bypass_insert() when the device supports FUA, just like what we did before. [1] https://lore.kernel.org/linux-block/CAHj4cs-_vkTW=dAzbZYGxpEWSpzpcmaNeY1R=vH311+9vMUSdg@mail.gmail.com/ Reported-by: Yi Zhang <yi.zhang@redhat.com> Fixes: d92ca9d8348f ("blk-mq: don't handle non-flush requests in blk_insert_flush") Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20211118153041.2163228-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-15blk-mq: cancel blk-mq dispatch work in both blk_cleanup_queue and disk_release()Ming Lei
For avoiding to slow down queue destroy, we don't call blk_mq_quiesce_queue() in blk_cleanup_queue(), instead of delaying to cancel dispatch work in blk_release_queue(). However, this way has caused kernel oops[1], reported by Changhui. The log shows that scsi_device can be freed before running blk_release_queue(), which is expected too since scsi_device is released after the scsi disk is closed and the scsi_device is removed. Fixes the issue by canceling blk-mq dispatch work in both blk_cleanup_queue() and disk_release(): 1) when disk_release() is run, the disk has been closed, and any sync dispatch activities have been done, so canceling dispatch work is enough to quiesce filesystem I/O dispatch activity. 2) in blk_cleanup_queue(), we only focus on passthrough request, and passthrough request is always explicitly allocated & freed by its caller, so once queue is frozen, all sync dispatch activity for passthrough request has been done, then it is enough to just cancel dispatch work for avoiding any dispatch activity. [1] kernel panic log [12622.769416] BUG: kernel NULL pointer dereference, address: 0000000000000300 [12622.777186] #PF: supervisor read access in kernel mode [12622.782918] #PF: error_code(0x0000) - not-present page [12622.788649] PGD 0 P4D 0 [12622.791474] Oops: 0000 [#1] PREEMPT SMP PTI [12622.796138] CPU: 10 PID: 744 Comm: kworker/10:1H Kdump: loaded Not tainted 5.15.0+ #1 [12622.804877] Hardware name: Dell Inc. PowerEdge R730/0H21J3, BIOS 1.5.4 10/002/2015 [12622.813321] Workqueue: kblockd blk_mq_run_work_fn [12622.818572] RIP: 0010:sbitmap_get+0x75/0x190 [12622.823336] Code: 85 80 00 00 00 41 8b 57 08 85 d2 0f 84 b1 00 00 00 45 31 e4 48 63 cd 48 8d 1c 49 48 c1 e3 06 49 03 5f 10 4c 8d 6b 40 83 f0 01 <48> 8b 33 44 89 f2 4c 89 ef 0f b6 c8 e8 fa f3 ff ff 83 f8 ff 75 58 [12622.844290] RSP: 0018:ffffb00a446dbd40 EFLAGS: 00010202 [12622.850120] RAX: 0000000000000001 RBX: 0000000000000300 RCX: 0000000000000004 [12622.858082] RDX: 0000000000000006 RSI: 0000000000000082 RDI: ffffa0b7a2dfe030 [12622.866042] RBP: 0000000000000004 R08: 0000000000000001 R09: ffffa0b742721334 [12622.874003] R10: 0000000000000008 R11: 0000000000000008 R12: 0000000000000000 [12622.881964] R13: 0000000000000340 R14: 0000000000000000 R15: ffffa0b7a2dfe030 [12622.889926] FS: 0000000000000000(0000) GS:ffffa0baafb40000(0000) knlGS:0000000000000000 [12622.898956] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [12622.905367] CR2: 0000000000000300 CR3: 0000000641210001 CR4: 00000000001706e0 [12622.913328] Call Trace: [12622.916055] <TASK> [12622.918394] scsi_mq_get_budget+0x1a/0x110 [12622.922969] __blk_mq_do_dispatch_sched+0x1d4/0x320 [12622.928404] ? pick_next_task_fair+0x39/0x390 [12622.933268] __blk_mq_sched_dispatch_requests+0xf4/0x140 [12622.939194] blk_mq_sched_dispatch_requests+0x30/0x60 [12622.944829] __blk_mq_run_hw_queue+0x30/0xa0 [12622.949593] process_one_work+0x1e8/0x3c0 [12622.954059] worker_thread+0x50/0x3b0 [12622.958144] ? rescuer_thread+0x370/0x370 [12622.962616] kthread+0x158/0x180 [12622.966218] ? set_kthread_struct+0x40/0x40 [12622.970884] ret_from_fork+0x22/0x30 [12622.974875] </TASK> [12622.977309] Modules linked in: scsi_debug rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs sunrpc dm_multipath intel_rapl_msr intel_rapl_common dell_wmi_descriptor sb_edac rfkill video x86_pkg_temp_thermal intel_powerclamp dcdbas coretemp kvm_intel kvm mgag200 irqbypass i2c_algo_bit rapl drm_kms_helper ipmi_ssif intel_cstate intel_uncore syscopyarea sysfillrect sysimgblt fb_sys_fops pcspkr cec mei_me lpc_ich mei ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter drm fuse xfs libcrc32c sr_mod cdrom sd_mod t10_pi sg ixgbe ahci libahci crct10dif_pclmul crc32_pclmul crc32c_intel libata megaraid_sas ghash_clmulni_intel tg3 wdat_wdt mdio dca wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_debug] Reported-by: ChanghuiZhong <czhong@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: linux-scsi@vger.kernel.org Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211116014343.610501-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-15block: fix missing queue put in error pathJens Axboe
If we fail the submission queue checks, we don't put the queue afterwards. This can cause various issues like stalls on scheduler switch or failure to remove the device, or like in the original bug report, timeout waiting for the device on reboot/restart. While in there, fix a few whitespace discrepancies in the surrounding code. Link: https://bugzilla.kernel.org/show_bug.cgi?id=215039 Fixes: b637108a4022 ("blk-mq: fix filesystem I/O request allocation") Reported-and-tested-by: Stephen Smith <stephenmsmith@blueyonder.co.uk> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-12blk-mq: fix filesystem I/O request allocationMing Lei
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 Lei
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 Torvalds
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 Lei
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 Bin
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 Axboe
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 Axboe
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>