kernel/linux.git/block, branch v5.10.141

blk-mq: fix io hung due to missing commit_rqs

2022-08-31T15:15:24+00:00

commit 65fac0d54f374625b43a9d6ad1f2c212bd41f518 upstream. Currently, in virtio_scsi, if 'bd->last' is not set to true while dispatching request, such io will stay in driver's queue, and driver will wait for block layer to dispatch more rqs. However, if block layer failed to dispatch more rq, it should trigger commit_rqs to inform driver. There is a problem in blk_mq_try_issue_list_directly() that commit_rqs won't be called: // assume that queue_depth is set to 1, list contains two rq blk_mq_try_issue_list_directly blk_mq_request_issue_directly // dispatch first rq // last is false __blk_mq_try_issue_directly blk_mq_get_dispatch_budget // succeed to get first budget __blk_mq_issue_directly scsi_queue_rq cmd->flags |= SCMD_LAST virtscsi_queuecommand kick = (sc->flags & SCMD_LAST) != 0 // kick is false, first rq won't issue to disk queued++ blk_mq_request_issue_directly // dispatch second rq __blk_mq_try_issue_directly blk_mq_get_dispatch_budget // failed to get second budget ret == BLK_STS_RESOURCE blk_mq_request_bypass_insert // errors is still 0 if (!list_empty(list) || errors && ...) // won't pass, commit_rqs won't be called In this situation, first rq relied on second rq to dispatch, while second rq relied on first rq to complete, thus they will both hung. Fix the problem by also treat 'BLK_STS_*RESOURCE' as 'errors' since it means that request is not queued successfully. Same problem exists in blk_mq_dispatch_rq_list(), 'BLK_STS_*RESOURCE' can't be treated as 'errors' here, fix the problem by calling commit_rqs if queue_rq return 'BLK_STS_*RESOURCE'. Fixes: d666ba98f849 ("blk-mq: add mq_ops->commit_rqs()") Signed-off-by: Yu Kuai Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20220726122224.1790882-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: remove the request_queue to argument request based tracepoints

2022-08-21T13:15:36+00:00

[ Upstream commit a54895fa057c67700270777f7661d8d3c7fda88a ] The request_queue can trivially be derived from the request. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Chaitanya Kulkarni Acked-by: Tejun Heo Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-mq: don't create hctx debugfs dir until q->debugfs_dir is created

2022-08-21T13:15:35+00:00

[ Upstream commit f3ec5d11554778c24ac8915e847223ed71d104fc ] blk_mq_debugfs_register_hctx() can be called by blk_mq_update_nr_hw_queues when gendisk isn't added yet, such as nvme tcp. Fixes the warning of 'debugfs: Directory 'hctx0' with parent '/' already present!' which can be observed reliably when running blktests nvme/005. Fixes: 6cfc0081b046 ("blk-mq: no need to check return value of debugfs_create functions") Reported-by: Yi Zhang Signed-off-by: Ming Lei Tested-by: Yi Zhang Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220711090808.259682-1-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: fix infinite loop for invalid zone append

2022-08-21T13:15:34+00:00

[ Upstream commit b82d9fa257cb3725c49d94d2aeafc4677c34448a ] Returning 0 early from __bio_iov_append_get_pages() for the max_append_sectors warning just creates an infinite loop since 0 means success, and the bio will never fill from the unadvancing iov_iter. We could turn the return into an error value, but it will already be turned into an error value later on, so just remove the warning. Clearly no one ever hit it anyway. Fixes: 0512a75b98f84 ("block: Introduce REQ_OP_ZONE_APPEND") Signed-off-by: Keith Busch Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20220610195830.3574005-2-kbusch@fb.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: Fix handling of offline queues in blk_mq_alloc_request_hctx()

2022-06-22T12:13:17+00:00

[ Upstream commit 14dc7a18abbe4176f5626c13c333670da8e06aa1 ] This patch prevents that test nvme/004 triggers the following: UBSAN: array-index-out-of-bounds in block/blk-mq.h:135:9 index 512 is out of range for type 'long unsigned int [512]' Call Trace: show_stack+0x52/0x58 dump_stack_lvl+0x49/0x5e dump_stack+0x10/0x12 ubsan_epilogue+0x9/0x3b __ubsan_handle_out_of_bounds.cold+0x44/0x49 blk_mq_alloc_request_hctx+0x304/0x310 __nvme_submit_sync_cmd+0x70/0x200 [nvme_core] nvmf_connect_io_queue+0x23e/0x2a0 [nvme_fabrics] nvme_loop_connect_io_queues+0x8d/0xb0 [nvme_loop] nvme_loop_create_ctrl+0x58e/0x7d0 [nvme_loop] nvmf_create_ctrl+0x1d7/0x4d0 [nvme_fabrics] nvmf_dev_write+0xae/0x111 [nvme_fabrics] vfs_write+0x144/0x560 ksys_write+0xb7/0x140 __x64_sys_write+0x42/0x50 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Cc: Christoph Hellwig Cc: Ming Lei Fixes: 20e4d8139319 ("blk-mq: simplify queue mapping & schedule with each possisble CPU") Signed-off-by: Bart Van Assche Reviewed-by: Christoph Hellwig Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20220615210004.1031820-1-bvanassche@acm.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: fix bio_clone_blkg_association() to associate with proper blkcg_gq

2022-06-09T08:21:31+00:00

commit 22b106e5355d6e7a9c3b5cb5ed4ef22ae585ea94 upstream. Commit d92c370a16cb ("block: really clone the block cgroup in bio_clone_blkg_association") changed bio_clone_blkg_association() to just clone bio->bi_blkg reference from source to destination bio. This is however wrong if the source and destination bios are against different block devices because struct blkcg_gq is different for each bdev-blkcg pair. This will result in IOs being accounted (and throttled as a result) multiple times against the same device (src bdev) while throttling of the other device (dst bdev) is ignored. In case of BFQ the inconsistency can even result in crashes in bfq_bic_update_cgroup(). Fix the problem by looking up correct blkcg_gq for the cloned bio. Reported-by: Logan Gunthorpe Reported-and-tested-by: Donald Buczek Fixes: d92c370a16cb ("block: really clone the block cgroup in bio_clone_blkg_association") CC: stable@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20220602081242.7731-1-jack@suse.cz Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bfq: Make sure bfqg for which we are queueing requests is online

2022-06-09T08:21:31+00:00

commit 075a53b78b815301f8d3dd1ee2cd99554e34f0dd upstream. Bios queued into BFQ IO scheduler can be associated with a cgroup that was already offlined. This may then cause insertion of this bfq_group into a service tree. But this bfq_group will get freed as soon as last bio associated with it is completed leading to use after free issues for service tree users. Fix the problem by making sure we always operate on online bfq_group. If the bfq_group associated with the bio is not online, we pick the first online parent. CC: stable@vger.kernel.org Fixes: e21b7a0b9887 ("block, bfq: add full hierarchical scheduling and cgroups support") Tested-by: "yukuai (C)" Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220401102752.8599-9-jack@suse.cz Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bfq: Get rid of __bio_blkcg() usage

2022-06-09T08:21:31+00:00

commit 4e54a2493e582361adc3bfbf06c7d50d19d18837 upstream. BFQ usage of __bio_blkcg() is a relict from the past. Furthermore if bio would not be associated with any blkcg, the usage of __bio_blkcg() in BFQ is prone to races with the task being migrated between cgroups as __bio_blkcg() calls at different places could return different blkcgs. Convert BFQ to the new situation where bio->bi_blkg is initialized in bio_set_dev() and thus practically always valid. This allows us to save blkcg_gq lookup and noticeably simplify the code. CC: stable@vger.kernel.org Fixes: 0fe061b9f03c ("blkcg: fix ref count issue with bio_blkcg() using task_css") Tested-by: "yukuai (C)" Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220401102752.8599-8-jack@suse.cz Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bfq: Remove pointless bfq_init_rq() calls

2022-06-09T08:21:30+00:00

commit 5f550ede5edf846ecc0067be1ba80514e6fe7f8e upstream. We call bfq_init_rq() from request merging functions where requests we get should have already gone through bfq_init_rq() during insert and anyway we want to do anything only if the request is already tracked by BFQ. So replace calls to bfq_init_rq() with RQ_BFQQ() instead to simply skip requests untracked by BFQ. We move bfq_init_rq() call in bfq_insert_request() a bit earlier to cover request merging and thus can transfer FIFO position in case of a merge. CC: stable@vger.kernel.org Tested-by: "yukuai (C)" Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220401102752.8599-6-jack@suse.cz Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bfq: Drop pointless unlock-lock pair

2022-06-09T08:21:30+00:00

commit fc84e1f941b91221092da5b3102ec82da24c5673 upstream. In bfq_insert_request() we unlock bfqd->lock only to call trace_block_rq_insert() and then lock bfqd->lock again. This is really pointless since tracing is disabled if we really care about performance and even if the tracepoint is enabled, it is a quick call. CC: stable@vger.kernel.org Tested-by: "yukuai (C)" Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220401102752.8599-5-jack@suse.cz Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman