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2023-07-14block: queue data commands from the flush state machine at the headChristoph Hellwig
We used to insert the data commands following a pre-flush to the head of the queue until commit 1e82fadfc6b ("blk-mq: do not do head insertions post-pre-flush commands"). Not doing this seems to cause hangs of such commands on NFS workloads when exported from file systems with SATA SSDs. I have no idea why this would starve these workloads, but doing a semantic revert of this patch (which looks quite different due to various other changes) fixes the hangs. Fixes: 1e82fadfc6b ("blk-mq: do not do head insertions post-pre-flush commands") Reported-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Chuck Lever <chuck.lever@oracle.com> Link: https://lore.kernel.org/r/20230714143014.11879-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-19blk-mq: don't use the requeue list to queue flush commandsChristoph Hellwig
Currently both requeues of commands that were already sent to the driver and flush commands submitted from the flush state machine share the same requeue_list struct request_queue, despite requeues doing head insertions and flushes not. Switch to using two separate lists instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230519044050.107790-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-19blk-mq: do not do head insertions post-pre-flush commandsChristoph Hellwig
blk_flush_complete_seq currently queues requests that write data after a pre-flush from the flush state machine at the head of the queue. This doesn't really make sense, as the original request bypassed all queue lists by directly diverting to blk_insert_flush from blk_mq_submit_bio. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230519044050.107790-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-19blk-mq: defer to the normal submission path for post-flush requestsChristoph Hellwig
Requests with the FUA bit on hardware without FUA support need a post flush before returning to the caller, but they can still be sent using the normal I/O path after initializing the flush-related fields and end I/O handler. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20230519044050.107790-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-19blk-mq: defer to the normal submission path for non-flush flush commandsChristoph Hellwig
If blk_insert_flush decides that a command does not need to use the flush state machine, return false and let blk_mq_submit_bio handle it the normal way (including using an I/O scheduler) instead of doing a bypass insert. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230519044050.107790-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-19blk-mq: reflow blk_insert_flushChristoph Hellwig
Use a switch statement to decide on the disposition of a flush request instead of multiple if statements, out of which one does checks that are more complex than required. Also warn on a malformed request early on instead of doing a BUG_ON later. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20230519044050.107790-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-19blk-mq: factor out a blk_rq_init_flush helperChristoph Hellwig
Factor out a helper from blk_insert_flush that initializes the flush machine related fields in struct request, and don't bother with the full memset as there's just a few fields to initialize, and all but one already have explicit initializers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20230519044050.107790-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-16blk-mq: fix the blk_mq_add_to_requeue_list call in blk_kick_flushChristoph Hellwig
Commit b12e5c6c755a accidentally changes blk_kick_flush to do a head insert into the requeue list, fix this up. Fixes: b12e5c6c755a ("blk-mq: pass a flags argument to blk_mq_add_to_requeue_list") Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230416073553.966161-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-13blk-mq: pass a flags argument to blk_mq_add_to_requeue_listChristoph Hellwig
Replace the boolean at_head argument with the same flags that are already passed to blk_mq_insert_request. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230413064057.707578-21-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-13blk-mq: pass a flags argument to blk_mq_request_bypass_insertChristoph Hellwig
Replace the boolean at_head argument with the same flags that are already passed to blk_mq_insert_request. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230413064057.707578-19-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-13blk-mq: don't kick the requeue_list in blk_mq_add_to_requeue_listChristoph Hellwig
blk_mq_add_to_requeue_list takes a bool parameter to control how to kick the requeue list at the end of the function. Move the call to blk_mq_kick_requeue_list to the callers that want it instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230413064057.707578-17-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-13blk-mq: don't run the hw_queue from blk_mq_request_bypass_insertChristoph Hellwig
blk_mq_request_bypass_insert takes a bool parameter to control how to run the queue at the end of the function. Move the blk_mq_run_hw_queue call to the callers that want it instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230413064057.707578-16-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-13blk-mq: remove blk_flush_queue_rqChristoph Hellwig
Just call blk_mq_add_to_requeue_list directly from the two callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230413064057.707578-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-13blk-mq: include <linux/blk-mq.h> in block/blk-mq.hChristoph Hellwig
block/blk-mq.h needs various definitions from <linux/blk-mq.h>, include it there instead of relying on the source files to include both. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230413064057.707578-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-13blk-mq: remove blk-mq-tag.hChristoph Hellwig
blk-mq-tag.h is always included by blk-mq.h, and causes recursive inclusion hell with further changes. Just merge it into blk-mq.h instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20230413064057.707578-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-30block: change request end_io handler to pass back a return valueJens Axboe
Everything is just converted to returning RQ_END_IO_NONE, and there should be no functional changes with this patch. In preparation for allowing the end_io handler to pass ownership back to the block layer, rather than retain ownership of the request. Reviewed-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-30block: kill deprecated BUG_ON() in the flush handlingJens Axboe
We've never had any useful reports from this BUG_ON(), and in fact a number of the BUG_ON()'s in the flush handling need to be turned into more graceful handling. In preparation for allowing batched completions of the end_io handling, where we can enter the flush completion with queuelist having been reused for the batch, get rid of this BUG_ON(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-14block: Use the new blk_opf_t typeBart Van Assche
Use the new blk_opf_t type for arguments and variables that represent request flags or a bitwise combination of a request operation and request flags. Rename the function arguments and also a structure member that hold a request operation and flags from 'rw' into 'opf'. This patch does not change any functionality. Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-7-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02block: pass a block_device and opf to bio_initChristoph Hellwig
Pass the block_device that we plan to use this bio for and the operation to bio_init to optimize the assignment. A NULL block_device can be passed, both for the passthrough case on a raw request_queue and to temporarily avoid refactoring some nasty code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220124091107.642561-19-hch@lst.de 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>
2021-11-29block: Fix fsync always failed if once failedYe Bin
We do test with inject error fault base on v4.19, after test some time we found sync /dev/sda always failed. [root@localhost] sync /dev/sda sync: error syncing '/dev/sda': Input/output error scsi log as follows: [19069.812296] sd 0:0:0:0: [sda] tag#64 Send: scmd 0x00000000d03a0b6b [19069.812302] sd 0:0:0:0: [sda] tag#64 CDB: Synchronize Cache(10) 35 00 00 00 00 00 00 00 00 00 [19069.812533] sd 0:0:0:0: [sda] tag#64 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK [19069.812536] sd 0:0:0:0: [sda] tag#64 CDB: Synchronize Cache(10) 35 00 00 00 00 00 00 00 00 00 [19069.812539] sd 0:0:0:0: [sda] tag#64 scsi host busy 1 failed 0 [19069.812542] sd 0:0:0:0: Notifying upper driver of completion (result 0) [19069.812546] sd 0:0:0:0: [sda] tag#64 sd_done: completed 0 of 0 bytes [19069.812549] sd 0:0:0:0: [sda] tag#64 0 sectors total, 0 bytes done. [19069.812564] print_req_error: I/O error, dev sda, sector 0 ftrace log as follows: rep-306069 [007] .... 19654.923315: block_bio_queue: 8,0 FWS 0 + 0 [rep] rep-306069 [007] .... 19654.923333: block_getrq: 8,0 FWS 0 + 0 [rep] kworker/7:1H-250 [007] .... 19654.923352: block_rq_issue: 8,0 FF 0 () 0 + 0 [kworker/7:1H] <idle>-0 [007] ..s. 19654.923562: block_rq_complete: 8,0 FF () 18446744073709551615 + 0 [0] <idle>-0 [007] d.s. 19654.923576: block_rq_complete: 8,0 WS () 0 + 0 [-5] As 8d6996630c03 introduce 'fq->rq_status', this data only update when 'flush_rq' reference count isn't zero. If flush request once failed and record error code in 'fq->rq_status'. If there is no chance to update 'fq->rq_status',then do fsync will always failed. To address this issue reset 'fq->rq_status' after return error code to upper layer. Fixes: 8d6996630c03("block: fix null pointer dereference in blk_mq_rq_timed_out()") Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20211129012659.1553733-1-yebin10@huawei.com 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: 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>
2021-11-29block: move blk_get_flush_queue to blk-flush.cChristoph Hellwig
blk_get_flush_queue is only used in blk-flush.c, so move it there. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211123185312.1432157-2-hch@lst.de 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>
2021-10-19blk-mq: don't handle non-flush requests in blk_insert_flushChristoph Hellwig
Return to the normal blk_mq_submit_bio flow if the bio did not end up actually being a flush because the device didn't support it. Note that this is basically impossible to hit without special instrumentation given that submit_bio_checks already clears these flags usually, so we'd need a tight race to actually hit this code path. With this the call to blk_mq_run_hw_queue for the flush requests can be removed given that the actual flush requests are always issued via the requeue workqueue which runs the queue unconditionally. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211019122553.2467817-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-17blk-mq: fix is_flush_rqMing Lei
is_flush_rq() is called from bt_iter()/bt_tags_iter(), and runs the following check: hctx->fq->flush_rq == req but the passed hctx from bt_iter()/bt_tags_iter() may be NULL because: 1) memory re-order in blk_mq_rq_ctx_init(): rq->mq_hctx = data->hctx; ... refcount_set(&rq->ref, 1); OR 2) tag re-use and ->rqs[] isn't updated with new request. Fix the issue by re-writing is_flush_rq() as: return rq->end_io == flush_end_io; which turns out simpler to follow and immune to data race since we have ordered WRITE rq->end_io and refcount_set(&rq->ref, 1). Fixes: 2e315dc07df0 ("blk-mq: grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter") Cc: "Blank-Burian, Markus, Dr." <blankburian@uni-muenster.de> Cc: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20210818010925.607383-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-17blk-mq: fix kernel panic during iterating over flush requestMing Lei
For fixing use-after-free during iterating over requests, we grabbed request's refcount before calling ->fn in commit 2e315dc07df0 ("blk-mq: grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter"). Turns out this way may cause kernel panic when iterating over one flush request: 1) old flush request's tag is just released, and this tag is reused by one new request, but ->rqs[] isn't updated yet 2) the flush request can be re-used for submitting one new flush command, so blk_rq_init() is called at the same time 3) meantime blk_mq_queue_tag_busy_iter() is called, and old flush request is retrieved from ->rqs[tag]; when blk_mq_put_rq_ref() is called, flush_rq->end_io may not be updated yet, so NULL pointer dereference is triggered in blk_mq_put_rq_ref(). Fix the issue by calling refcount_set(&flush_rq->ref, 1) after flush_rq->end_io is set. So far the only other caller of blk_rq_init() is scsi_ioctl_reset() in which the request doesn't enter block IO stack and the request reference count isn't used, so the change is safe. Fixes: 2e315dc07df0 ("blk-mq: grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter") Reported-by: "Blank-Burian, Markus, Dr." <blankburian@uni-muenster.de> Tested-by: "Blank-Burian, Markus, Dr." <blankburian@uni-muenster.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.garry@huawei.com> Link: https://lore.kernel.org/r/20210811142624.618598-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-05-24block: avoid double io accounting for flush requestMing Lei
For flush request, rq->end_io() may be called two times, one is from timeout handling(blk_mq_check_expired()), another is from normal completion(__blk_mq_end_request()). Move blk_account_io_flush() after flush_rq->ref drops to zero, so io accounting can be done just once for flush request. Fixes: b68663186577 ("block: add iostat counters for flush requests") Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: John Garry <john.garry@huawei.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20210511152236.763464-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-27block: use an on-stack bio in blkdev_issue_flushChristoph Hellwig
There is no point in allocating memory for a synchronous flush. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-16Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: "Another series of killing more code than what is being added, again thanks to Christoph's relentless cleanups and tech debt tackling. This contains: - blk-iocost improvements (Baolin Wang) - part0 iostat fix (Jeffle Xu) - Disable iopoll for split bios (Jeffle Xu) - block tracepoint cleanups (Christoph Hellwig) - Merging of struct block_device and hd_struct (Christoph Hellwig) - Rework/cleanup of how block device sizes are updated (Christoph Hellwig) - Simplification of gendisk lookup and removal of block device aliasing (Christoph Hellwig) - Block device ioctl cleanups (Christoph Hellwig) - Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig) - Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig) - sbitmap improvements (Pavel Begunkov) - Hybrid polling fix (Pavel Begunkov) - bvec iteration improvements (Pavel Begunkov) - Zone revalidation fixes (Damien Le Moal) - blk-throttle limit fix (Yu Kuai) - Various little fixes" * tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits) blk-mq: fix msec comment from micro to milli seconds blk-mq: update arg in comment of blk_mq_map_queue blk-mq: add helper allocating tagset->tags Revert "block: Fix a lockdep complaint triggered by request queue flushing" nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class blk-mq: add new API of blk_mq_hctx_set_fq_lock_class block: disable iopoll for split bio block: Improve blk_revalidate_disk_zones() checks sbitmap: simplify wrap check sbitmap: replace CAS with atomic and sbitmap: remove swap_lock sbitmap: optimise sbitmap_deferred_clear() blk-mq: skip hybrid polling if iopoll doesn't spin blk-iocost: Factor out the base vrate change into a separate function blk-iocost: Factor out the active iocgs' state check into a separate function blk-iocost: Move the usage ratio calculation to the correct place blk-iocost: Remove unnecessary advance declaration blk-iocost: Fix some typos in comments blktrace: fix up a kerneldoc comment block: remove the request_queue to argument request based tracepoints ...
2020-12-07Revert "block: Fix a lockdep complaint triggered by request queue flushing"Ming Lei
This reverts commit b3c6a59975415bde29cfd76ff1ab008edbf614a9. Now we can avoid nvme-loop lockdep warning of 'lockdep possible recursive locking' by nvme-loop's lock class, no need to apply dynamically allocated lock class key, so revert commit b3c6a5997541("block: Fix a lockdep complaint triggered by request queue flushing"). This way fixes horrible SCSI probe delay issue on megaraid_sas, and it is reported the whole probe may take more than half an hour. Tested-by: Kashyap Desai <kashyap.desai@broadcom.com> Reported-by: Qian Cai <cai@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Sumit Saxena <sumit.saxena@broadcom.com> Cc: John Garry <john.garry@huawei.com> Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-07blk-mq: add new API of blk_mq_hctx_set_fq_lock_classMing Lei
flush_end_io() may be called recursively from some driver, such as nvme-loop, so lockdep may complain 'possible recursive locking'. Commit b3c6a5997541("block: Fix a lockdep complaint triggered by request queue flushing") tried to address this issue by assigning dynamically allocated per-flush-queue lock class. This solution adds synchronize_rcu() for each hctx's release handler, and causes horrible SCSI MQ probe delay(more than half an hour on megaraid sas). Add new API of blk_mq_hctx_set_fq_lock_class() for these drivers, so we just need to use driver specific lock class for avoiding the lockdep warning of 'possible recursive locking'. Tested-by: Kashyap Desai <kashyap.desai@broadcom.com> Reported-by: Qian Cai <cai@redhat.com> Cc: Sumit Saxena <sumit.saxena@broadcom.com> Cc: John Garry <john.garry@huawei.com> Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01block: switch partition lookup to use struct block_deviceChristoph Hellwig
Use struct block_device to lookup partitions on a disk. This removes all usage of struct hd_struct from the I/O path. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: Chao Yu <yuchao0@huawei.com> [f2fs] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01block: allocate struct hd_struct as part of struct bdev_inodeChristoph Hellwig
Allocate hd_struct together with struct block_device to pre-load the lifetime rule changes in preparation of merging the two structures. Note that part0 was previously embedded into struct gendisk, but is a separate allocation now, and already points to the block_device instead of the hd_struct. The lifetime of struct gendisk is still controlled by the struct device embedded in the part0 hd_struct. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-13block: mark flush request as IDLE when it is really finishedMing Lei
For avoiding use-after-free on flush request, we call its .end_io() from both timeout code path and __blk_mq_end_request(). When flush request's ref doesn't drop to zero, it is still used, we can't mark it as IDLE, so fix it by marking IDLE when its refcount drops to zero really. Fixes: 65ff5cd04551 ("blk-mq: mark flush request as IDLE in flush_end_io()") Signed-off-by: Ming Lei <ming.lei@redhat.com> Cc: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-30blk-mq: mark flush request as IDLE in flush_end_io()Ming Lei
Mark flush request as IDLE in its .end_io(), aligning it with how normal requests behave. The flush request stays in in-flight tags if we're not using an IO scheduler, so we need to change its state into IDLE. Otherwise, we will hang in blk_mq_tagset_wait_completed_request() during error recovery because flush the request state is kept as COMPLETED. Reported-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Yi Zhang <yi.zhang@redhat.com> Cc: Chao Leng <lengchao@huawei.com> Cc: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-11block: fix double account of flush request's driver tagMing Lei
In case of none scheduler, we share data request's driver tag for flush request, so have to mark the flush request as INFLIGHT for avoiding double account of this driver tag. Fixes: 568f27006577 ("blk-mq: centralise related handling into blk_mq_get_driver_tag") Reported-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Matthew Wilcox <willy@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-17block: defer flush request no matter whether we have elevatorYufen Yu
Commit 7520872c0cf4 ("block: don't defer flushes on blk-mq + scheduling") tried to fix deadlock for cycled wait between flush requests and data request into flush_data_in_flight. The former holded all driver tags and wait for data request completion, but the latter can not complete for waiting free driver tags. After commit 923218f6166a ("blk-mq: don't allocate driver tag upfront for flush rq"), flush requests will not get driver tag before queuing into flush queue. * With elevator, flush request just get sched_tags before inserting flush queue. It will not get driver tag until issue them to driver. data request on list fq->flush_data_in_flight will complete in the end. * Without elevator, each flush request will get a driver tag when allocate request. Then data request on fq->flush_data_in_flight don't worry about lacking driver tag. In both of these cases, cycled wait cannot be true. So we may allow to defer flush request. Signed-off-by: Yufen Yu <yuyufen@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-08blk-mq: centralise related handling into blk_mq_get_driver_tagMing Lei
Move .nr_active update and request assignment into blk_mq_get_driver_tag(), all are good to do during getting driver tag. Meantime blk-flush related code is simplified and flush request needn't to update the request table manually any more. Signed-off-by: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01Revert "blk-mq: put driver tag when this request is completed"Jens Axboe
This reverts commits the following commits: 37f4a24c2469a10a4c16c641671bd766e276cf9f 723bf178f158abd1ce6069cb049581b3cb003aab 36a3df5a4574d5ddf59804fcd0c4e9654c514d9a The last one is the culprit, but we have to go a bit deeper to get this to revert cleanly. There's been a report that this breaks some MMC setups [1], and also causes an issue with swap [2]. Until this can be figured out, revert the offending commits. [1] https://lore.kernel.org/linux-block/57fb09b1-54ba-f3aa-f82c-d709b0e6b281@samsung.com/ [2] https://lore.kernel.org/linux-block/20200702043721.GA1087@lca.pw/ Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-30blk-mq: centralise related handling into blk_mq_get_driver_tagMing Lei
Move .nr_active update and request assignment into blk_mq_get_driver_tag(), all are good to do during getting driver tag. Meantime blk-flush related code is simplified and flush request needn't to update the request table manually any more. Signed-off-by: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29blk-mq: put driver tag when this request is completedMing Lei
It is natural to release driver tag when this request is completed by LLD or device since its purpose is for LLD use. One big benefit is that the released tag can be re-used quicker since bio_endio() may take too long. Meantime we don't need to release driver tag for flush request. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-22block: remove the disk and queue NULL checks in blkdev_issue_flushChristoph Hellwig
Both of these never can be NULL for a live block device. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-22block: remove the error_sector argument to blkdev_issue_flushChristoph Hellwig
The argument isn't used by any caller, and drivers don't fill out bi_sector for flush requests either. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19block: Remove unused flush_queue_delayed in struct blk_flush_queueBaolin Wang
The flush_queue_delayed was introdued to hold queue if flush is running for non-queueable flush drive by commit 3ac0cc450870 ("hold queue if flush is running for non-queueable flush drive"), but the non mq parts of the flush code had been removed by commit 7e992f847a08 ("block: remove non mq parts from the flush code"), as well as removing the usage of the flush_queue_delayed flag. Thus remove the unused flush_queue_delayed flag. Signed-off-by: Baolin Wang <baolin.wang7@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27Revert "blkdev: check for valid request queue before issuing flush"Christoph Hellwig
This reverts commit f10d9f617a65905c556c3b37c9b9646ae7d04ed7. We can't have queues without a make_request_fn any more (and the loop device uses blk-mq these days anyway..). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12block: cleanup comment for blk_flush_complete_seqGuoqing Jiang
Remove the comment about return value, since it is not valid after commit 404b8f5a03d84 ("block: cleanup kick/queued handling"). 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>
2020-03-12block: remove unneeded argument from blk_alloc_flush_queueGuoqing Jiang
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>
2020-02-24blk-mq: insert passthrough request into hctx->dispatch directlyMing Lei
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>