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2020-06-17block: update hctx map when use multiple mapsWeiping Zhang1-1/+3
There is an issue when tune the number for read and write queues, if the total queue count was not changed. The hctx->type cannot be updated, since __blk_mq_update_nr_hw_queues will return directly if the total queue count has not been changed. Reproduce: dmesg | grep "default/read/poll" [ 2.607459] nvme nvme0: 48/0/0 default/read/poll queues cat /sys/kernel/debug/block/nvme0n1/hctx*/type | sort | uniq -c 48 default tune the write queues to 24: echo 24 > /sys/module/nvme/parameters/write_queues echo 1 > /sys/block/nvme0n1/device/reset_controller dmesg | grep "default/read/poll" [ 433.547235] nvme nvme0: 24/24/0 default/read/poll queues cat /sys/kernel/debug/block/nvme0n1/hctx*/type | sort | uniq -c 48 default The driver's hardware queue mapping is not same as block layer. Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-07blk-mq: split out a __blk_mq_get_driver_tag helperChristoph Hellwig1-29/+0
Allocation of the driver tag in the case of using a scheduler shares very little code with the "normal" tag allocation. Split out a new helper to streamline this path, and untangle it from the complex normal tag allocation. This way also avoids to fail driver tag allocation because of inactive hctx during cpu hotplug, and fixes potential hang risk. Fixes: bf0beec0607d ("blk-mq: drain I/O when all CPUs in a hctx are offline") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: John Garry <john.garry@huawei.com> Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: drain I/O when all CPUs in a hctx are offlineMing Lei1-2/+110
Most of blk-mq drivers depend on managed IRQ's auto-affinity to setup up queue mapping. Thomas mentioned the following point[1]: "That was the constraint of managed interrupts from the very beginning: The driver/subsystem has to quiesce the interrupt line and the associated queue _before_ it gets shutdown in CPU unplug and not fiddle with it until it's restarted by the core when the CPU is plugged in again." However, current blk-mq implementation doesn't quiesce hw queue before the last CPU in the hctx is shutdown. Even worse, CPUHP_BLK_MQ_DEAD is a cpuhp state handled after the CPU is down, so there isn't any chance to quiesce the hctx before shutting down the CPU. Add new CPUHP_AP_BLK_MQ_ONLINE state to stop allocating from blk-mq hctxs where the last CPU goes away, and wait for completion of in-flight requests. This guarantees that there is no inflight I/O before shutting down the managed IRQ. Add a BLK_MQ_F_STACKING and set it for dm-rq and loop, so we don't need to wait for completion of in-flight requests from these drivers to avoid a potential dead-lock. It is safe to do this for stacking drivers as those do not use interrupts at all and their I/O completions are triggered by underlying devices I/O completion. [1] https://lore.kernel.org/linux-block/alpine.DEB.2.21.1904051331270.1802@nanos.tec.linutronix.de/ [hch: different retry mechanism, merged two patches, minor cleanups] Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctxChristoph Hellwig1-21/+23
blk_mq_alloc_request_hctx is only used for NVMeoF connect commands, so tailor it to the specific requirements, and don't bother the general fast path code with its special twinkles. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: use BLK_MQ_NO_TAG in more placesChristoph Hellwig1-7/+7
Replace various magic -1 constants for tags with BLK_MQ_NO_TAG. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAGChristoph Hellwig1-1/+1
To prepare for wider use of this constant give it a more applicable name. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: move more request initialization to blk_mq_rq_ctx_initChristoph Hellwig1-17/+19
Don't split request initialization between __blk_mq_alloc_request and blk_mq_rq_ctx_init. Also remove the op argument as it can be derived from the blk_mq_alloc_data structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: simplify the blk_mq_get_request calling conventionChristoph Hellwig1-14/+22
The bio argument is entirely unused, and the request_queue can be passed through the alloc_data, given that it needs to be filled out for the low-level tag allocation anyway. Also rename the function to __blk_mq_alloc_request as the switch between get and alloc in the call chains is rather confusing. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: remove the bio argument to ->prepare_requestChristoph Hellwig1-1/+1
None of the I/O schedulers actually needs it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: blk-mq: provide forced completion methodKeith Busch1-2/+13
Drivers may need to bypass error injection for error recovery. Rename __blk_mq_complete_request() to blk_mq_force_complete_rq() and export that function so drivers may skip potential fake timeouts after they've reclaimed lost requests. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: add a blk_account_io_merge_bio helperKonstantin Khlebnikov1-1/+1
Move the non-"new_io" branch of blk_account_io_start() into separate function. Fix merge accounting for discards (they were counted as write merges). The new blk_account_io_merge_bio() doesn't call update_io_ticks() unlike blk_account_io_start(), as there is no reason for that. [hch: rebased] Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19blk-mq: allow blk_mq_make_request to consume the q_usage_counter referenceChristoph Hellwig1-6/+7
blk_mq_make_request currently needs to grab an q_usage_counter reference when allocating a request. This is because the block layer grabs one before calling blk_mq_make_request, but also releases it as soon as blk_mq_make_request returns. Remove the blk_queue_exit call after blk_mq_make_request returns, and instead let it consume the reference. This works perfectly fine for the block layer caller, just device mapper needs an extra reference as the old problem still persists there. Open code blk_queue_enter_live in device mapper, as there should be no other callers and this allows better documenting why we do a non-try get. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19blk-mq: remove a pointless queue enter pair in blk_mq_alloc_request_hctxChristoph Hellwig1-3/+0
No need for two queue references. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19blk-mq: remove a pointless queue enter pair in blk_mq_alloc_requestChristoph Hellwig1-3/+0
No need for two queue references. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19blk-mq: move the call to blk_queue_enter_live out of blk_mq_get_requestChristoph Hellwig1-11/+16
Move the blk_queue_enter_live calls into the callers, where they can successively be cleaned up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14block: Inline encryption support for blk-mqSatya Tangirala1-0/+13
We must have some way of letting a storage device driver know what encryption context it should use for en/decrypting a request. However, it's the upper layers (like the filesystem/fscrypt) that know about and manages encryption contexts. As such, when the upper layer submits a bio to the block layer, and this bio eventually reaches a device driver with support for inline encryption, the device driver will need to have been told the encryption context for that bio. We want to communicate the encryption context from the upper layer to the storage device along with the bio, when the bio is submitted to the block layer. To do this, we add a struct bio_crypt_ctx to struct bio, which can represent an encryption context (note that we can't use the bi_private field in struct bio to do this because that field does not function to pass information across layers in the storage stack). We also introduce various functions to manipulate the bio_crypt_ctx and make the bio/request merging logic aware of the bio_crypt_ctx. We also make changes to blk-mq to make it handle bios with encryption contexts. blk-mq can merge many bios into the same request. These bios need to have contiguous data unit numbers (the necessary changes to blk-merge are also made to ensure this) - as such, it suffices to keep the data unit number of just the first bio, since that's all a storage driver needs to infer the data unit number to use for each data block in each bio in a request. blk-mq keeps track of the encryption context to be used for all the bios in a request with the request's rq_crypt_ctx. When the first bio is added to an empty request, blk-mq will program the encryption context of that bio into the request_queue's keyslot manager, and store the returned keyslot in the request's rq_crypt_ctx. All the functions to operate on encryption contexts are in blk-crypto.c. Upper layers only need to call bio_crypt_set_ctx with the encryption key, algorithm and data_unit_num; they don't have to worry about getting a keyslot for each encryption context, as blk-mq/blk-crypto handles that. Blk-crypto also makes it possible for request-based layered devices like dm-rq to make use of inline encryption hardware by cloning the rq_crypt_ctx and programming a keyslot in the new request_queue when necessary. Note that any user of the block layer can submit bios with an encryption context, such as filesystems, device-mapper targets, etc. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: Introduce REQ_OP_ZONE_APPENDKeith Busch1-0/+27
Define REQ_OP_ZONE_APPEND to append-write sectors to a zone of a zoned block device. This is a no-merge write operation. A zone append write BIO must: * Target a zoned block device * Have a sector position indicating the start sector of the target zone * The target zone must be a sequential write zone * The BIO must not cross a zone boundary * The BIO size must not be split to ensure that a single range of LBAs is written with a single command. Implement these checks in generic_make_request_checks() using the helper function blk_check_zone_append(). To avoid write append BIO splitting, introduce the new max_zone_append_sectors queue limit attribute and ensure that a BIO size is always lower than this limit. Export this new limit through sysfs and check these limits in bio_full(). Also when a LLDD can't dispatch a request to a specific zone, it will return BLK_STS_ZONE_RESOURCE indicating this request needs to be delayed, e.g. because the zone it will be dispatched to is still write-locked. If this happens set the request aside in a local list to continue trying dispatching requests such as READ requests or a WRITE/ZONE_APPEND requests targetting other zones. This way we can still keep a high queue depth without starving other requests even if one request can't be served due to zone write-locking. Finally, make sure that the bio sector position indicates the actual write position as indicated by the device on completion. Signed-off-by: Keith Busch <kbusch@kernel.org> [ jth: added zone-append specific add_page and merge_page helpers ] Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: reset mapping if failed to update hardware queue countWeiping Zhang1-1/+1
When we increase hardware queue count, blk_mq_update_queue_map will reset the mapping between cpu and hardware queue base on the hardware queue count(set->nr_hw_queues). The mapping cannot be reset if it encounters error in blk_mq_realloc_hw_ctxs, but the fallback flow will continue using it, then blk_mq_map_swqueue will touch a invalid memory, because the mapping points to a wrong hctx. blktest block/030: null_blk: module loaded Increasing nr_hw_queues to 8 fails, fallback to 1 ================================================================== BUG: KASAN: null-ptr-deref in blk_mq_map_swqueue+0x2f2/0x830 Read of size 8 at addr 0000000000000128 by task nproc/8541 CPU: 5 PID: 8541 Comm: nproc Not tainted 5.7.0-rc4-dbg+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack+0xa5/0xe6 __kasan_report.cold+0x65/0xbb kasan_report+0x45/0x60 check_memory_region+0x15e/0x1c0 __kasan_check_read+0x15/0x20 blk_mq_map_swqueue+0x2f2/0x830 __blk_mq_update_nr_hw_queues+0x3df/0x690 blk_mq_update_nr_hw_queues+0x32/0x50 nullb_device_submit_queues_store+0xde/0x160 [null_blk] configfs_write_file+0x1c4/0x250 [configfs] __vfs_write+0x4c/0x90 vfs_write+0x14b/0x2d0 ksys_write+0xdd/0x180 __x64_sys_write+0x47/0x50 do_syscall_64+0x6f/0x310 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com> Tested-by: Bart van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09block: rename blk_mq_alloc_rq_mapsWeiping Zhang1-2/+2
rename blk_mq_alloc_rq_maps to blk_mq_alloc_map_and_requests, this function allocs both map and request, make function name align with funtion. Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09block: rename __blk_mq_alloc_rq_mapWeiping Zhang1-3/+4
rename __blk_mq_alloc_rq_map to __blk_mq_alloc_map_and_request, actually it alloc both map and request, make function name align with function. Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09block: alloc map and request for new hardware queueMing Lei1-12/+12
Alloc new map and request for new hardware queue when increse hardware queue count. Before this patch, it will show a warning for each new hardware queue, but it's not enough, these hctx have no maps and reqeust, when a bio was mapped to these hardware queue, it will trigger kernel panic when get request from these hctx. Test environment: * A NVMe disk supports 128 io queues * 96 cpus in system A corner case can always trigger this panic, there are 96 io queues allocated for HCTX_TYPE_DEFAULT type, the corresponding kernel log: nvme nvme0: 96/0/0 default/read/poll queues. Now we set nvme write queues to 96, then nvme will alloc others(32) queues for read, but blk_mq_update_nr_hw_queues does not alloc map and request for these new added io queues. So when process read nvme disk, it will trigger kernel panic when get request from these hardware context. Reproduce script: nr=$(expr `cat /sys/block/nvme0n1/device/queue_count` - 1) echo $nr > /sys/module/nvme/parameters/write_queues echo 1 > /sys/block/nvme0n1/device/reset_controller dd if=/dev/nvme0n1 of=/dev/null bs=4K count=1 [ 8040.805626] ------------[ cut here ]------------ [ 8040.805627] WARNING: CPU: 82 PID: 12921 at block/blk-mq.c:2578 blk_mq_map_swqueue+0x2b6/0x2c0 [ 8040.805627] Modules linked in: nvme nvme_core nf_conntrack_netlink xt_addrtype br_netfilter overlay xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nft_counter nf_nat_tftp nf_conntrack_tftp nft_masq nf_tables_set nft_fib_inet nft_f ib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack tun bridge nf_defrag_ipv6 nf_defrag_ipv4 stp llc ip6_tables ip_tables nft_compat rfkill ip_set nf_tables nfne tlink sunrpc intel_rapl_msr intel_rapl_common skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass ipmi_ssif crct10dif_pclmul crc32_pclmul iTCO_wdt iTCO_vendor_support ghash_clmulni_intel intel_ cstate intel_uncore raid0 joydev intel_rapl_perf ipmi_si pcspkr mei_me ioatdma sg ipmi_devintf mei i2c_i801 dca lpc_ich ipmi_msghandler acpi_power_meter acpi_pad xfs libcrc32c sd_mod ast i2c_algo_bit drm_vram_helper drm_ttm_helper ttm d rm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops [ 8040.805637] ahci drm i40e libahci crc32c_intel libata t10_pi wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: nvme_core] [ 8040.805640] CPU: 82 PID: 12921 Comm: kworker/u194:2 Kdump: loaded Tainted: G W 5.6.0-rc5.78317c+ #2 [ 8040.805640] Hardware name: Inspur SA5212M5/YZMB-00882-104, BIOS 4.0.9 08/27/2019 [ 8040.805641] Workqueue: nvme-reset-wq nvme_reset_work [nvme] [ 8040.805642] RIP: 0010:blk_mq_map_swqueue+0x2b6/0x2c0 [ 8040.805643] Code: 00 00 00 00 00 41 83 c5 01 44 39 6d 50 77 b8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 8b bb 98 00 00 00 89 d6 e8 8c 81 03 00 eb 83 <0f> 0b e9 52 ff ff ff 0f 1f 00 0f 1f 44 00 00 41 57 48 89 f1 41 56 [ 8040.805643] RSP: 0018:ffffba590d2e7d48 EFLAGS: 00010246 [ 8040.805643] RAX: 0000000000000000 RBX: ffff9f013e1ba800 RCX: 000000000000003d [ 8040.805644] RDX: ffff9f00ffff6000 RSI: 0000000000000003 RDI: ffff9ed200246d90 [ 8040.805644] RBP: ffff9f00f6a79860 R08: 0000000000000000 R09: 000000000000003d [ 8040.805645] R10: 0000000000000001 R11: ffff9f0138c3d000 R12: ffff9f00fb3a9008 [ 8040.805645] R13: 000000000000007f R14: ffffffff96822660 R15: 000000000000005f [ 8040.805645] FS: 0000000000000000(0000) GS:ffff9f013fa80000(0000) knlGS:0000000000000000 [ 8040.805646] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8040.805646] CR2: 00007f7f397fa6f8 CR3: 0000003d8240a002 CR4: 00000000007606e0 [ 8040.805647] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 8040.805647] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 8040.805647] PKRU: 55555554 [ 8040.805647] Call Trace: [ 8040.805649] blk_mq_update_nr_hw_queues+0x31b/0x390 [ 8040.805650] nvme_reset_work+0xb4b/0xeab [nvme] [ 8040.805651] process_one_work+0x1a7/0x370 [ 8040.805652] worker_thread+0x1c9/0x380 [ 8040.805653] ? max_active_store+0x80/0x80 [ 8040.805655] kthread+0x112/0x130 [ 8040.805656] ? __kthread_parkme+0x70/0x70 [ 8040.805657] ret_from_fork+0x35/0x40 [ 8040.805658] ---[ end trace b5f13b1e73ccb5d3 ]--- [ 8229.365135] BUG: kernel NULL pointer dereference, address: 0000000000000004 [ 8229.365165] #PF: supervisor read access in kernel mode [ 8229.365178] #PF: error_code(0x0000) - not-present page [ 8229.365191] PGD 0 P4D 0 [ 8229.365201] Oops: 0000 [#1] SMP PTI [ 8229.365212] CPU: 77 PID: 13024 Comm: dd Kdump: loaded Tainted: G W 5.6.0-rc5.78317c+ #2 [ 8229.365232] Hardware name: Inspur SA5212M5/YZMB-00882-104, BIOS 4.0.9 08/27/2019 [ 8229.365253] RIP: 0010:blk_mq_get_tag+0x227/0x250 [ 8229.365265] Code: 44 24 04 44 01 e0 48 8b 74 24 38 65 48 33 34 25 28 00 00 00 75 33 48 83 c4 40 5b 5d 41 5c 41 5d 41 5e c3 48 8d 68 10 4c 89 ef <44> 8b 60 04 48 89 ee e8 dd f9 ff ff 83 f8 ff 75 c8 e9 67 fe ff ff [ 8229.365304] RSP: 0018:ffffba590e977970 EFLAGS: 00010246 [ 8229.365317] RAX: 0000000000000000 RBX: ffff9f00f6a79860 RCX: ffffba590e977998 [ 8229.365333] RDX: 0000000000000000 RSI: ffff9f012039b140 RDI: ffffba590e977a38 [ 8229.365349] RBP: 0000000000000010 R08: ffffda58ff94e190 R09: ffffda58ff94e198 [ 8229.365365] R10: 0000000000000011 R11: ffff9f00f6a79860 R12: 0000000000000000 [ 8229.365381] R13: ffffba590e977a38 R14: ffff9f012039b140 R15: 0000000000000001 [ 8229.365397] FS: 00007f481c230580(0000) GS:ffff9f013f940000(0000) knlGS:0000000000000000 [ 8229.365415] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8229.365428] CR2: 0000000000000004 CR3: 0000005f35e26004 CR4: 00000000007606e0 [ 8229.365444] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 8229.365460] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 8229.365476] PKRU: 55555554 [ 8229.365484] Call Trace: [ 8229.365498] ? finish_wait+0x80/0x80 [ 8229.365512] blk_mq_get_request+0xcb/0x3f0 [ 8229.365525] blk_mq_make_request+0x143/0x5d0 [ 8229.365538] generic_make_request+0xcf/0x310 [ 8229.365553] ? scan_shadow_nodes+0x30/0x30 [ 8229.365564] submit_bio+0x3c/0x150 [ 8229.365576] mpage_readpages+0x163/0x1a0 [ 8229.365588] ? blkdev_direct_IO+0x490/0x490 [ 8229.365601] read_pages+0x6b/0x190 [ 8229.365612] __do_page_cache_readahead+0x1c1/0x1e0 [ 8229.365626] ondemand_readahead+0x182/0x2f0 [ 8229.365639] generic_file_buffered_read+0x590/0xab0 [ 8229.365655] new_sync_read+0x12a/0x1c0 [ 8229.365666] vfs_read+0x8a/0x140 [ 8229.365676] ksys_read+0x59/0xd0 [ 8229.365688] do_syscall_64+0x55/0x1d0 [ 8229.365700] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com> Tested-by: Weiping Zhang <zhangweiping@didiglobal.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09block: save previous hardware queue count before udpateWeiping Zhang1-1/+1
blk_mq_realloc_tag_set_tags will update set->nr_hw_queues, so save old set->nr_hw_queues before call this function. Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09block: free both rq_map and requestWeiping Zhang1-1/+1
Allocation: __blk_mq_alloc_rq_map blk_mq_alloc_rq_map blk_mq_alloc_rq_map tags = blk_mq_init_tags : kzalloc_node: tags->rqs = kcalloc_node tags->static_rqs = kcalloc_node blk_mq_alloc_rqs p = alloc_pages_node tags->static_rqs[i] = p + offset; Free: blk_mq_free_rq_map kfree(tags->rqs); kfree(tags->static_rqs); blk_mq_free_tags kfree(tags); The page allocated in blk_mq_alloc_rqs cannot be released, so we should use blk_mq_free_map_and_requests here. blk_mq_free_map_and_requests blk_mq_free_rqs __free_pages : cleanup for blk_mq_alloc_rqs blk_mq_free_rq_map : cleanup for blk_mq_alloc_rq_map Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-25block: bypass ->make_request_fn for blk-mq driversChristoph Hellwig1-2/+2
Call blk_mq_make_request when no ->make_request_fn is set. This is safe now that blk_alloc_queue always sets up the pointer for make_request based drivers. This avoids an indirect call in the blk-mq driver I/O fast path, which is rather expensive due to spectre mitigations. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-22block: move dma_pad handling from blk_rq_map_sg into the callersChristoph Hellwig1-1/+0
There are only two callers of blk_rq_map_sg/__blk_rq_map_sg that set the dma_pad value in the queue. Move the handling into those callers instead of burdening the common code, and move the ->extra_len field from struct request to struct scsi_cmnd. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-22block: move dma drain handling to scsiChristoph Hellwig1-11/+0
Don't burden the common block code with with specifics of the libata DMA draining mechanism. Instead move most of the code to the scsi midlayer. That also means the nr_phys_segments adjustments in the blk-mq fast path can go away entirely, given that SCSI never looks at nr_phys_segments after mapping the request to a scatterlist. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20blk-mq: Add blk_mq_delay_run_hw_queues() API callDouglas Anderson1-0/+19
We have: * blk_mq_run_hw_queue() * blk_mq_delay_run_hw_queue() * blk_mq_run_hw_queues() ...but not blk_mq_delay_run_hw_queues(), presumably because nobody needed it before now. Since we need it for a later patch in this series, add it. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20blk-mq: In blk_mq_dispatch_rq_list() "no budget" is a reason to kickDouglas Anderson1-2/+6
In blk_mq_dispatch_rq_list(), if blk_mq_sched_needs_restart() returns true and the driver returns BLK_STS_RESOURCE then we'll kick the queue. However, there's another case where we might need to kick it. If we were unable to get budget we can be in much the same state as when the driver returns BLK_STS_RESOURCE, so we should treat it the same. It should be noted that even if we add a whole bunch of extra kicking to the queue in other patches this patch is still important. Specifically any kicking that happened before we re-spliced leftover requests into 'hctx->dispatch' wouldn't have found any work, so we really need to make sure we kick ourselves after we've done the splicing. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-16blk-mq: Put driver tag in blk_mq_dispatch_rq_list() when no budgetJohn Garry1-1/+3
If in blk_mq_dispatch_rq_list() we find no budget, then we break of the dispatch loop, but the request may keep the driver tag, evaulated in 'nxt' in the previous loop iteration. Fix by putting the driver tag for that request. Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: John Garry <john.garry@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
2020-02-24blk-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>
2020-01-06blk-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>
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