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2020-04-23block, bfq: invoke flush_idle_tree after reparent_active_queues in pd_offlinePaolo Valente
commit 4d38a87fbb77fb9ff2ff4e914162a8ae6453eff5 upstream. In bfq_pd_offline(), the function bfq_flush_idle_tree() is invoked to flush the rb tree that contains all idle entities belonging to the pd (cgroup) being destroyed. In particular, bfq_flush_idle_tree() is invoked before bfq_reparent_active_queues(). Yet the latter may happen to add some entities to the idle tree. It happens if, in some of the calls to bfq_bfqq_move() performed by bfq_reparent_active_queues(), the queue to move is empty and gets expired. This commit simply reverses the invocation order between bfq_flush_idle_tree() and bfq_reparent_active_queues(). Tested-by: cki-project@redhat.com Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-23block, bfq: make reparent_leaf_entity actually work only on leaf entitiesPaolo Valente
commit 576682fa52cbd95deb3773449566274f206acc58 upstream. bfq_reparent_leaf_entity() reparents the input leaf entity (a leaf entity represents just a bfq_queue in an entity tree). Yet, the input entity is guaranteed to always be a leaf entity only in two-level entity trees. In this respect, because of the error fixed by commit 14afc5936197 ("block, bfq: fix overwrite of bfq_group pointer in bfq_find_set_group()"), all (wrongly collapsed) entity trees happened to actually have only two levels. After the latter commit, this does not hold any longer. This commit fixes this problem by modifying bfq_reparent_leaf_entity(), so that it searches an active leaf entity down the path that stems from the input entity. Such a leaf entity is guaranteed to exist when bfq_reparent_leaf_entity() is invoked. Tested-by: cki-project@redhat.com Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-23block, bfq: turn put_queue into release_process_ref in __bfq_bic_change_cgroupPaolo Valente
commit c8997736650060594845e42c5d01d3118aec8d25 upstream. A bfq_put_queue() may be invoked in __bfq_bic_change_cgroup(). The goal of this put is to release a process reference to a bfq_queue. But process-reference releases may trigger also some extra operation, and, to this goal, are handled through bfq_release_process_ref(). So, turn the invocation of bfq_put_queue() into an invocation of bfq_release_process_ref(). Tested-by: cki-project@redhat.com Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17block, bfq: fix use-after-free in bfq_idle_slice_timer_bodyZhiqiang Liu
[ Upstream commit 2f95fa5c955d0a9987ffdc3a095e2f4e62c5f2a9 ] In bfq_idle_slice_timer func, bfqq = bfqd->in_service_queue is not in bfqd-lock critical section. The bfqq, which is not equal to NULL in bfq_idle_slice_timer, may be freed after passing to bfq_idle_slice_timer_body. So we will access the freed memory. In addition, considering the bfqq may be in race, we should firstly check whether bfqq is in service before doing something on it in bfq_idle_slice_timer_body func. If the bfqq in race is not in service, it means the bfqq has been expired through __bfq_bfqq_expire func, and wait_request flags has been cleared in __bfq_bfqd_reset_in_service func. So we do not need to re-clear the wait_request of bfqq which is not in service. KASAN log is given as follows: [13058.354613] ================================================================== [13058.354640] BUG: KASAN: use-after-free in bfq_idle_slice_timer+0xac/0x290 [13058.354644] Read of size 8 at addr ffffa02cf3e63f78 by task fork13/19767 [13058.354646] [13058.354655] CPU: 96 PID: 19767 Comm: fork13 [13058.354661] Call trace: [13058.354667] dump_backtrace+0x0/0x310 [13058.354672] show_stack+0x28/0x38 [13058.354681] dump_stack+0xd8/0x108 [13058.354687] print_address_description+0x68/0x2d0 [13058.354690] kasan_report+0x124/0x2e0 [13058.354697] __asan_load8+0x88/0xb0 [13058.354702] bfq_idle_slice_timer+0xac/0x290 [13058.354707] __hrtimer_run_queues+0x298/0x8b8 [13058.354710] hrtimer_interrupt+0x1b8/0x678 [13058.354716] arch_timer_handler_phys+0x4c/0x78 [13058.354722] handle_percpu_devid_irq+0xf0/0x558 [13058.354731] generic_handle_irq+0x50/0x70 [13058.354735] __handle_domain_irq+0x94/0x110 [13058.354739] gic_handle_irq+0x8c/0x1b0 [13058.354742] el1_irq+0xb8/0x140 [13058.354748] do_wp_page+0x260/0xe28 [13058.354752] __handle_mm_fault+0x8ec/0x9b0 [13058.354756] handle_mm_fault+0x280/0x460 [13058.354762] do_page_fault+0x3ec/0x890 [13058.354765] do_mem_abort+0xc0/0x1b0 [13058.354768] el0_da+0x24/0x28 [13058.354770] [13058.354773] Allocated by task 19731: [13058.354780] kasan_kmalloc+0xe0/0x190 [13058.354784] kasan_slab_alloc+0x14/0x20 [13058.354788] kmem_cache_alloc_node+0x130/0x440 [13058.354793] bfq_get_queue+0x138/0x858 [13058.354797] bfq_get_bfqq_handle_split+0xd4/0x328 [13058.354801] bfq_init_rq+0x1f4/0x1180 [13058.354806] bfq_insert_requests+0x264/0x1c98 [13058.354811] blk_mq_sched_insert_requests+0x1c4/0x488 [13058.354818] blk_mq_flush_plug_list+0x2d4/0x6e0 [13058.354826] blk_flush_plug_list+0x230/0x548 [13058.354830] blk_finish_plug+0x60/0x80 [13058.354838] read_pages+0xec/0x2c0 [13058.354842] __do_page_cache_readahead+0x374/0x438 [13058.354846] ondemand_readahead+0x24c/0x6b0 [13058.354851] page_cache_sync_readahead+0x17c/0x2f8 [13058.354858] generic_file_buffered_read+0x588/0xc58 [13058.354862] generic_file_read_iter+0x1b4/0x278 [13058.354965] ext4_file_read_iter+0xa8/0x1d8 [ext4] [13058.354972] __vfs_read+0x238/0x320 [13058.354976] vfs_read+0xbc/0x1c0 [13058.354980] ksys_read+0xdc/0x1b8 [13058.354984] __arm64_sys_read+0x50/0x60 [13058.354990] el0_svc_common+0xb4/0x1d8 [13058.354994] el0_svc_handler+0x50/0xa8 [13058.354998] el0_svc+0x8/0xc [13058.354999] [13058.355001] Freed by task 19731: [13058.355007] __kasan_slab_free+0x120/0x228 [13058.355010] kasan_slab_free+0x10/0x18 [13058.355014] kmem_cache_free+0x288/0x3f0 [13058.355018] bfq_put_queue+0x134/0x208 [13058.355022] bfq_exit_icq_bfqq+0x164/0x348 [13058.355026] bfq_exit_icq+0x28/0x40 [13058.355030] ioc_exit_icq+0xa0/0x150 [13058.355035] put_io_context_active+0x250/0x438 [13058.355038] exit_io_context+0xd0/0x138 [13058.355045] do_exit+0x734/0xc58 [13058.355050] do_group_exit+0x78/0x220 [13058.355054] __wake_up_parent+0x0/0x50 [13058.355058] el0_svc_common+0xb4/0x1d8 [13058.355062] el0_svc_handler+0x50/0xa8 [13058.355066] el0_svc+0x8/0xc [13058.355067] [13058.355071] The buggy address belongs to the object at ffffa02cf3e63e70#012 which belongs to the cache bfq_queue of size 464 [13058.355075] The buggy address is located 264 bytes inside of#012 464-byte region [ffffa02cf3e63e70, ffffa02cf3e64040) [13058.355077] The buggy address belongs to the page: [13058.355083] page:ffff7e80b3cf9800 count:1 mapcount:0 mapping:ffff802db5c90780 index:0xffffa02cf3e606f0 compound_mapcount: 0 [13058.366175] flags: 0x2ffffe0000008100(slab|head) [13058.370781] raw: 2ffffe0000008100 ffff7e80b53b1408 ffffa02d730c1c90 ffff802db5c90780 [13058.370787] raw: ffffa02cf3e606f0 0000000000370023 00000001ffffffff 0000000000000000 [13058.370789] page dumped because: kasan: bad access detected [13058.370791] [13058.370792] Memory state around the buggy address: [13058.370797] ffffa02cf3e63e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fb fb [13058.370801] ffffa02cf3e63e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [13058.370805] >ffffa02cf3e63f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [13058.370808] ^ [13058.370811] ffffa02cf3e63f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [13058.370815] ffffa02cf3e64000: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [13058.370817] ================================================================== [13058.370820] Disabling lock debugging due to kernel taint Here, we directly pass the bfqd to bfq_idle_slice_timer_body func. -- V2->V3: rewrite the comment as suggested by Paolo Valente V1->V2: add one comment, and add Fixes and Reported-by tag. Fixes: aee69d78d ("block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler") Acked-by: Paolo Valente <paolo.valente@linaro.org> Reported-by: Wang Wang <wangwang2@huawei.com> Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> Signed-off-by: Feilong Lin <linfeilong@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-17block: Fix use-after-free issue accessing struct io_cqSahitya Tummala
[ Upstream commit 30a2da7b7e225ef6c87a660419ea04d3cef3f6a7 ] There is a potential race between ioc_release_fn() and ioc_clear_queue() as shown below, due to which below kernel crash is observed. It also can result into use-after-free issue. context#1: context#2: ioc_release_fn() __ioc_clear_queue() gets the same icq ->spin_lock(&ioc->lock); ->spin_lock(&ioc->lock); ->ioc_destroy_icq(icq); ->list_del_init(&icq->q_node); ->call_rcu(&icq->__rcu_head, icq_free_icq_rcu); ->spin_unlock(&ioc->lock); ->ioc_destroy_icq(icq); ->hlist_del_init(&icq->ioc_node); This results into below crash as this memory is now used by icq->__rcu_head in context#1. There is a chance that icq could be free'd as well. 22150.386550: <6> Unable to handle kernel write to read-only memory at virtual address ffffffaa8d31ca50 ... Call trace: 22150.607350: <2> ioc_destroy_icq+0x44/0x110 22150.611202: <2> ioc_clear_queue+0xac/0x148 22150.615056: <2> blk_cleanup_queue+0x11c/0x1a0 22150.619174: <2> __scsi_remove_device+0xdc/0x128 22150.623465: <2> scsi_forget_host+0x2c/0x78 22150.627315: <2> scsi_remove_host+0x7c/0x2a0 22150.631257: <2> usb_stor_disconnect+0x74/0xc8 22150.635371: <2> usb_unbind_interface+0xc8/0x278 22150.639665: <2> device_release_driver_internal+0x198/0x250 22150.644897: <2> device_release_driver+0x24/0x30 22150.649176: <2> bus_remove_device+0xec/0x140 22150.653204: <2> device_del+0x270/0x460 22150.656712: <2> usb_disable_device+0x120/0x390 22150.660918: <2> usb_disconnect+0xf4/0x2e0 22150.664684: <2> hub_event+0xd70/0x17e8 22150.668197: <2> process_one_work+0x210/0x480 22150.672222: <2> worker_thread+0x32c/0x4c8 Fix this by adding a new ICQ_DESTROYED flag in ioc_destroy_icq() to indicate this icq is once marked as destroyed. Also, ensure __ioc_clear_queue() is accessing icq within rcu_read_lock/unlock so that icq doesn't get free'd up while it is still using it. Signed-off-by: Sahitya Tummala <stummala@codeaurora.org> Co-developed-by: Pradeep P V K <ppvk@codeaurora.org> Signed-off-by: Pradeep P V K <ppvk@codeaurora.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-17block, bfq: move forward the getting of an extra ref in bfq_bfqq_movePaolo Valente
[ Upstream commit fd1bb3ae54a9a2e0c42709de861c69aa146b8955 ] Commit ecedd3d7e199 ("block, bfq: get extra ref to prevent a queue from being freed during a group move") gets an extra reference to a bfq_queue before possibly deactivating it (temporarily), in bfq_bfqq_move(). This prevents the bfq_queue from disappearing before being reactivated in its new group. Yet, the bfq_queue may also be expired (i.e., its service may be stopped) before the bfq_queue is deactivated. And also an expiration may lead to a premature freeing. This commit fixes this issue by simply moving forward the getting of the extra reference already introduced by commit ecedd3d7e199 ("block, bfq: get extra ref to prevent a queue from being freed during a group move"). Reported-by: cki-project@redhat.com Tested-by: cki-project@redhat.com Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-17block: keep bdi->io_pages in sync with max_sectors_kb for stacked devicesKonstantin Khlebnikov
[ Upstream commit e74d93e96d721c4297f2a900ad0191890d2fc2b0 ] Field bdi->io_pages added in commit 9491ae4aade6 ("mm: don't cap request size based on read-ahead setting") removes unneeded split of read requests. Stacked drivers do not call blk_queue_max_hw_sectors(). Instead they set limits of their devices by blk_set_stacking_limits() + disk_stack_limits(). Field bio->io_pages stays zero until user set max_sectors_kb via sysfs. This patch updates io_pages after merging limits in disk_stack_limits(). Commit c6d6e9b0f6b4 ("dm: do not allow readahead to limit IO size") fixed the same problem for device-mapper devices, this one fixes MD RAIDs. Fixes: 9491ae4aade6 ("mm: don't cap request size based on read-ahead setting") Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-13blk-mq: Keep set->nr_hw_queues and set->map[].nr_queues in syncBart Van Assche
commit 6e66b49392419f3fe134e1be583323ef75da1e4b upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25block, bfq: fix overwrite of bfq_group pointer in bfq_find_set_group()Carlo Nonato
[ Upstream commit 14afc59361976c0ba39e3a9589c3eaa43ebc7e1d ] The bfq_find_set_group() function takes as input a blkcg (which represents a cgroup) and retrieves the corresponding bfq_group, then it updates the bfq internal group hierarchy (see comments inside the function for why this is needed) and finally it returns the bfq_group. In the hierarchy update cycle, the pointer holding the correct bfq_group that has to be returned is mistakenly used to traverse the hierarchy bottom to top, meaning that in each iteration it gets overwritten with the parent of the current group. Since the update cycle stops at root's children (depth = 2), the overwrite becomes a problem only if the blkcg describes a cgroup at a hierarchy level deeper than that (depth > 2). In this case the root's child that happens to be also an ancestor of the correct bfq_group is returned. The main consequence is that processes contained in a cgroup at depth greater than 2 are wrongly placed in the group described above by BFQ. This commits fixes this problem by using a different bfq_group pointer in the update cycle in order to avoid the overwrite of the variable holding the original group reference. Reported-by: Kwon Je Oh <kwonje.oh2@gmail.com> Signed-off-by: Carlo Nonato <carlo.nonato95@gmail.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-21blk-mq: insert flush request to the front of dispatch queueMing Lei
[ Upstream commit cc3200eac4c5eb11c3f34848a014d1f286316310 ] commit 01e99aeca397 ("blk-mq: insert passthrough request into hctx->dispatch directly") may change to add flush request to the tail of dispatch by applying the 'add_head' parameter of blk_mq_sched_insert_request. Turns out this way causes performance regression on NCQ controller because flush is non-NCQ command, which can't be queued when there is any in-flight NCQ command. When adding flush rq to the front of hctx->dispatch, it is easier to introduce extra time to flush rq's latency compared with adding to the tail of dispatch queue because of S_SCHED_RESTART, then chance of flush merge is increased, and less flush requests may be issued to controller. So always insert flush request to the front of dispatch queue just like before applying commit 01e99aeca397 ("blk-mq: insert passthrough request into hctx->dispatch directly"). Cc: Damien Le Moal <Damien.LeMoal@wdc.com> Cc: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Fixes: 01e99aeca397 ("blk-mq: insert passthrough request into hctx->dispatch directly") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-21blk-mq: insert passthrough request into hctx->dispatch directlyMing Lei
[ Upstream commit 01e99aeca3979600302913cef3f89076786f32c8 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-18blk-iocost: fix incorrect vtime comparison in iocg_is_idle()Tejun Heo
commit dcd6589b11d3b1e71f516a87a7b9646ed356b4c0 upstream. vtimes may wrap and time_before/after64() should be used to determine whether a given vtime is before or after another. iocg_is_idle() was incorrectly using plain "<" comparison do determine whether done_vtime is before vtime. Here, the only thing we're interested in is whether done_vtime matches vtime which indicates that there's nothing in flight. Let's test for inequality instead. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12block, bfq: remove ifdefs from around gets/puts of bfq groupsPaolo Valente
commit 4d8340d0d4d90e7ca367d18ec16c2fefa89a339c upstream. ifdefs around gets and puts of bfq groups reduce readability, remove them. Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12block, bfq: get a ref to a group when adding it to a service treePaolo Valente
commit db37a34c563bf4692b36990ae89005c031385e52 upstream. BFQ schedules generic entities, which may represent either bfq_queues or groups of bfq_queues. When an entity is inserted into a service tree, a reference must be taken, to make sure that the entity does not disappear while still referred in the tree. Unfortunately, such a reference is mistakenly taken only if the entity represents a bfq_queue. This commit takes a reference also in case the entity represents a group. Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Tested-by: Chris Evich <cevich@redhat.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12block, bfq: do not insert oom queue into position treePaolo Valente
[ Upstream commit 32c59e3a9a5a0b180dd015755d6d18ca31e55935 ] BFQ maintains an ordered list, implemented with an RB tree, of head-request positions of non-empty bfq_queues. This position tree, inherited from CFQ, is used to find bfq_queues that contain I/O close to each other. BFQ merges these bfq_queues into a single shared queue, if this boosts throughput on the device at hand. There is however a special-purpose bfq_queue that does not participate in queue merging, the oom bfq_queue. Yet, also this bfq_queue could be wrongly added to the position tree. So bfqq_find_close() could return the oom bfq_queue, which is a source of further troubles in an out-of-memory situation. This commit prevents the oom bfq_queue from being inserted into the position tree. Tested-by: Patrick Dung <patdung100@gmail.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-12block, bfq: get extra ref to prevent a queue from being freed during a group ↵Paolo Valente
move [ Upstream commit ecedd3d7e19911ab8fe42f17b77c0a30fe7f4db3 ] In bfq_bfqq_move(), the bfq_queue, say Q, to be moved to a new group may happen to be deactivated in the scheduling data structures of the source group (and then activated in the destination group). If Q is referred only by the data structures in the source group when the deactivation happens, then Q is freed upon the deactivation. This commit addresses this issue by getting an extra reference before the possible deactivation, and releasing this extra reference after Q has been moved. Tested-by: Chris Evich <cevich@redhat.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24block, bfq: do not plug I/O for bfq_queues with no proc refsPaolo Valente
[ Upstream commit f718b093277df582fbf8775548a4f163e664d282 ] Commit 478de3380c1c ("block, bfq: deschedule empty bfq_queues not referred by any process") fixed commit 3726112ec731 ("block, bfq: re-schedule empty queues if they deserve I/O plugging") by descheduling an empty bfq_queue when it remains with not process reference. Yet, this still left a case uncovered: an empty bfq_queue with not process reference that remains in service. This happens for an in-service sync bfq_queue that is deemed to deserve I/O-dispatch plugging when it remains empty. Yet no new requests will arrive for such a bfq_queue if no process sends requests to it any longer. Even worse, the bfq_queue may happen to be prematurely freed while still in service (because there may remain no reference to it any longer). This commit solves this problem by preventing I/O dispatch from being plugged for the in-service bfq_queue, if the latter has no process reference (the bfq_queue is then prevented from remaining in service). Fixes: 3726112ec731 ("block, bfq: re-schedule empty queues if they deserve I/O plugging") Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Reported-by: Patrick Dung <patdung100@gmail.com> Tested-by: Patrick Dung <patdung100@gmail.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-26block: fix memleak of bio integrity dataJustin Tee
[ Upstream commit ece841abbed2da71fa10710c687c9ce9efb6bf69 ] 7c20f11680a4 ("bio-integrity: stop abusing bi_end_io") moves bio_integrity_free from bio_uninit() to bio_integrity_verify_fn() and bio_endio(). This way looks wrong because bio may be freed without calling bio_endio(), for example, blk_rq_unprep_clone() is called from dm_mq_queue_rq() when the underlying queue of dm-mpath is busy. So memory leak of bio integrity data is caused by commit 7c20f11680a4. Fixes this issue by re-adding bio_integrity_free() to bio_uninit(). Fixes: 7c20f11680a4 ("bio-integrity: stop abusing bi_end_io") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by Justin Tee <justin.tee@broadcom.com> Add commit log, and simplify/fix the original patch wroten by Justin. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-23block: Fix the type of 'sts' in bsg_queue_rq()Bart Van Assche
commit c44a4edb20938c85b64a256661443039f5bffdea upstream. This patch fixes the following sparse warnings: block/bsg-lib.c:269:19: warning: incorrect type in initializer (different base types) block/bsg-lib.c:269:19: expected int sts block/bsg-lib.c:269:19: got restricted blk_status_t [usertype] block/bsg-lib.c:286:16: warning: incorrect type in return expression (different base types) block/bsg-lib.c:286:16: expected restricted blk_status_t block/bsg-lib.c:286:16: got int [assigned] sts Cc: Martin Wilck <mwilck@suse.com> Fixes: d46fe2cb2dce ("block: drop device references in bsg_queue_rq()") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23block: fix an integer overflow in logical block sizeMikulas Patocka
commit ad6bf88a6c19a39fb3b0045d78ea880325dfcf15 upstream. Logical block size has type unsigned short. That means that it can be at most 32768. However, there are architectures that can run with 64k pages (for example arm64) and on these architectures, it may be possible to create block devices with 64k block size. For exmaple (run this on an architecture with 64k pages): Mount will fail with this error because it tries to read the superblock using 2-sector access: device-mapper: writecache: I/O is not aligned, sector 2, size 1024, block size 65536 EXT4-fs (dm-0): unable to read superblock This patch changes the logical block size from unsigned short to unsigned int to avoid the overflow. Cc: stable@vger.kernel.org Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-17fs: move guard_bio_eod() after bio_set_op_attrsMing Lei
commit 83c9c547168e8b914ea6398430473a4de68c52cc upstream. Commit 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod") adds bio_truncate() for handling bio EOD. However, bio_truncate() doesn't use the passed 'op' parameter from guard_bio_eod's callers. So bio_trunacate() may retrieve wrong 'op', and zering pages may not be done for READ bio. Fixes this issue by moving guard_bio_eod() after bio_set_op_attrs() in submit_bh_wbc() so that bio_truncate() can always retrieve correct op info. Meantime remove the 'op' parameter from guard_bio_eod() because it isn't used any more. Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: linux-fsdevel@vger.kernel.org Fixes: 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fold in kerneldoc and bio_op() change. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-12block: fix memleak when __blk_rq_map_user_iov() is failedYang Yingliang
[ Upstream commit 3b7995a98ad76da5597b488fa84aa5a56d43b608 ] When I doing fuzzy test, get the memleak report: BUG: memory leak unreferenced object 0xffff88837af80000 (size 4096): comm "memleak", pid 3557, jiffies 4294817681 (age 112.499s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 20 00 00 00 10 01 00 00 00 00 00 00 01 00 00 00 ............... backtrace: [<000000001c894df8>] bio_alloc_bioset+0x393/0x590 [<000000008b139a3c>] bio_copy_user_iov+0x300/0xcd0 [<00000000a998bd8c>] blk_rq_map_user_iov+0x2f1/0x5f0 [<000000005ceb7f05>] blk_rq_map_user+0xf2/0x160 [<000000006454da92>] sg_common_write.isra.21+0x1094/0x1870 [<00000000064bb208>] sg_write.part.25+0x5d9/0x950 [<000000004fc670f6>] sg_write+0x5f/0x8c [<00000000b0d05c7b>] __vfs_write+0x7c/0x100 [<000000008e177714>] vfs_write+0x1c3/0x500 [<0000000087d23f34>] ksys_write+0xf9/0x200 [<000000002c8dbc9d>] do_syscall_64+0x9f/0x4f0 [<00000000678d8e9a>] entry_SYSCALL_64_after_hwframe+0x49/0xbe If __blk_rq_map_user_iov() is failed in blk_rq_map_user_iov(), the bio(s) which is allocated before this failing will leak. The refcount of the bio(s) is init to 1 and increased to 2 by calling bio_get(), but __blk_rq_unmap_user() only decrease it to 1, so the bio cannot be freed. Fix it by calling blk_rq_unmap_user(). Reviewed-by: Bob Liu <bob.liu@oracle.com> Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-12block: Fix a lockdep complaint triggered by request queue flushingBart Van Assche
[ Upstream commit b3c6a59975415bde29cfd76ff1ab008edbf614a9 ] Avoid that running test nvme/012 from the blktests suite triggers the following false positive lockdep complaint: ============================================ WARNING: possible recursive locking detected 5.0.0-rc3-xfstests-00015-g1236f7d60242 #841 Not tainted -------------------------------------------- ksoftirqd/1/16 is trying to acquire lock: 000000000282032e (&(&fq->mq_flush_lock)->rlock){..-.}, at: flush_end_io+0x4e/0x1d0 but task is already holding lock: 00000000cbadcbc2 (&(&fq->mq_flush_lock)->rlock){..-.}, at: flush_end_io+0x4e/0x1d0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&fq->mq_flush_lock)->rlock); lock(&(&fq->mq_flush_lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by ksoftirqd/1/16: #0: 00000000cbadcbc2 (&(&fq->mq_flush_lock)->rlock){..-.}, at: flush_end_io+0x4e/0x1d0 stack backtrace: CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.0.0-rc3-xfstests-00015-g1236f7d60242 #841 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: dump_stack+0x67/0x90 __lock_acquire.cold.45+0x2b4/0x313 lock_acquire+0x98/0x160 _raw_spin_lock_irqsave+0x3b/0x80 flush_end_io+0x4e/0x1d0 blk_mq_complete_request+0x76/0x110 nvmet_req_complete+0x15/0x110 [nvmet] nvmet_bio_done+0x27/0x50 [nvmet] blk_update_request+0xd7/0x2d0 blk_mq_end_request+0x1a/0x100 blk_flush_complete_seq+0xe5/0x350 flush_end_io+0x12f/0x1d0 blk_done_softirq+0x9f/0xd0 __do_softirq+0xca/0x440 run_ksoftirqd+0x24/0x50 smpboot_thread_fn+0x113/0x1e0 kthread+0x121/0x140 ret_from_fork+0x3a/0x50 Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-12block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAITRoman Penyaev
[ Upstream commit c58c1f83436b501d45d4050fd1296d71a9760bcb ] Non-mq devs do not honor REQ_NOWAIT so give a chance to the caller to repeat request gracefully on -EAGAIN error. The problem is well reproduced using io_uring: mkfs.ext4 /dev/ram0 mount /dev/ram0 /mnt # Preallocate a file dd if=/dev/zero of=/mnt/file bs=1M count=1 # Start fio with io_uring and get -EIO fio --rw=write --ioengine=io_uring --size=1M --direct=1 --name=job --filename=/mnt/file Signed-off-by: Roman Penyaev <rpenyaev@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09compat_ioctl: block: handle BLKGETZONESZ/BLKGETNRZONESArnd Bergmann
commit 21d37340912d74b1222d43c11aa9dd0687162573 upstream. These were added to blkdev_ioctl() in v4.20 but not blkdev_compat_ioctl, so add them now. Cc: <stable@vger.kernel.org> # v4.20+ Fixes: 72cd87576d1d ("block: Introduce BLKGETZONESZ ioctl") Fixes: 65e4e3eee83d ("block: Introduce BLKGETNRZONES ioctl") Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-09compat_ioctl: block: handle BLKREPORTZONE/BLKRESETZONEArnd Bergmann
commit 673bdf8ce0a387ef585c13b69a2676096c6edfe9 upstream. These were added to blkdev_ioctl() but not blkdev_compat_ioctl, so add them now. Cc: <stable@vger.kernel.org> # v4.10+ Fixes: 3ed05a987e0f ("blk-zoned: implement ioctls") Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-09compat_ioctl: block: handle Persistent ReservationsArnd Bergmann
commit b2c0fcd28772f99236d261509bcd242135677965 upstream. These were added to blkdev_ioctl() in linux-5.5 but not blkdev_compat_ioctl, so add them now. Cc: <stable@vger.kernel.org> # v4.4+ Fixes: bbd3e064362e ("block: add an API for Persistent Reservations") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fold in followup patch from Arnd with missing pr.h header include. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-09block: add bio_truncate to fix guard_bio_eodMing Lei
[ Upstream commit 85a8ce62c2eabe28b9d76ca4eecf37922402df93 ] Some filesystem, such as vfat, may send bio which crosses device boundary, and the worse thing is that the IO request starting within device boundaries can contain more than one segment past EOD. Commit dce30ca9e3b6 ("fs: fix guard_bio_eod to check for real EOD errors") tries to fix this issue by returning -EIO for this situation. However, this way lets fs user code lose chance to handle -EIO, then sync_inodes_sb() may hang for ever. Also the current truncating on last segment is dangerous by updating the last bvec, given bvec table becomes not immutable any more, and fs bio users may not retrieve the truncated pages via bio_for_each_segment_all() in its .end_io callback. Fixes this issue by supporting multi-segment truncating. And the approach is simpler: - just update bio size since block layer can make correct bvec with the updated bio size. Then bvec table becomes really immutable. - zero all truncated segments for read bio Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: linux-fsdevel@vger.kernel.org Fixed-by: dce30ca9e3b6 ("fs: fix guard_bio_eod to check for real EOD errors") Reported-by: syzbot+2b9e54155c8c25d8d165@syzkaller.appspotmail.com Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31iocost: over-budget forced IOs should schedule async delayTejun Heo
commit d7bd15a138aef3be227818aad9c501e43c89c8c5 upstream. When over-budget IOs are force-issued through root cgroup, iocg_kick_delay() adjusts the async delay accordingly but doesn't actually schedule async throttle for the issuing task. This bug is pretty well masked because sooner or later the offending threads are gonna get directly throttled on regular IOs or have async delay scheduled by mem_cgroup_throttle_swaprate(). However, it can affect control quality on filesystem metadata heavy operations. Let's fix it by invoking blkcg_schedule_throttle() when iocg_kick_delay() says async delay is needed. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Cc: stable@vger.kernel.org Reported-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21block: fix "check bi_size overflow before merge"Andreas Gruenbacher
commit cc90bc68422318eb8e75b15cd74bc8d538a7df29 upstream. This partially reverts commit e3a5d8e386c3fb973fa75f2403622a8f3640ec06. Commit e3a5d8e386c3 ("check bi_size overflow before merge") adds a bio_full check to __bio_try_merge_page. This will cause __bio_try_merge_page to fail when the last bi_io_vec has been reached. Instead, what we want here is only the bi_size overflow check. Fixes: e3a5d8e386c3 ("block: check bi_size overflow before merge") Cc: stable@vger.kernel.org # v5.4+ Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17blk-mq: make sure that line break can be printedMing Lei
commit d2c9be89f8ebe7ebcc97676ac40f8dec1cf9b43a upstream. 8962842ca5ab ("blk-mq: avoid sysfs buffer overflow with too many CPU cores") avoids sysfs buffer overflow, and reserves one character for line break. However, the last snprintf() doesn't get correct 'size' parameter passed in, so fixed it. Fixes: 8962842ca5ab ("blk-mq: avoid sysfs buffer overflow with too many CPU cores") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Cc: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17blk-mq: avoid sysfs buffer overflow with too many CPU coresMing Lei
commit 8962842ca5abdcf98e22ab3b2b45a103f0408b95 upstream. It is reported that sysfs buffer overflow can be triggered if the system has too many CPU cores(>841 on 4K PAGE_SIZE) when showing CPUs of hctx via /sys/block/$DEV/mq/$N/cpu_list. Use snprintf to avoid the potential buffer overflow. This version doesn't change the attribute format, and simply stops showing CPU numbers if the buffer is going to overflow. Cc: stable@vger.kernel.org Fixes: 676141e48af7("blk-mq: don't dump CPU -> hw queue map on driver load") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-14iocost: check active_list of all the ancestors in iocg_activate()Jiufei Xue
There is a bug that checking the same active_list over and over again in iocg_activate(). The intention of the code was checking whether all the ancestors and self have already been activated. So fix it. Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-14block, bfq: deschedule empty bfq_queues not referred by any processPaolo Valente
Since commit 3726112ec731 ("block, bfq: re-schedule empty queues if they deserve I/O plugging"), to prevent the service guarantees of a bfq_queue from being violated, the bfq_queue may be left busy, i.e., scheduled for service, even if empty (see comments in __bfq_bfqq_expire() for details). But, if no process will send requests to the bfq_queue any longer, then there is no point in keeping the bfq_queue scheduled for service. In addition, keeping the bfq_queue scheduled for service, but with no process reference any longer, may cause the bfq_queue to be freed when descheduled from service. But this is assumed to never happen, and causes a UAF if it happens. This, in turn, caused crashes [1, 2]. This commit fixes this issue by descheduling an empty bfq_queue when it remains with not process reference. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1767539 [2] https://bugzilla.kernel.org/show_bug.cgi?id=205447 Fixes: 3726112ec731 ("block, bfq: re-schedule empty queues if they deserve I/O plugging") Reported-by: Chris Evich <cevich@redhat.com> Reported-by: Patrick Dung <patdung100@gmail.com> Reported-by: Thorsten Schubert <tschubert@bafh.org> Tested-by: Thorsten Schubert <tschubert@bafh.org> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-12block: check bi_size overflow before mergeJunichi Nomura
__bio_try_merge_page() may merge a page to bio without bio_full() check and cause bi_size overflow. The overflow typically ends up with sd_init_command() warning on zero segment request with call trace like this: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1986 at drivers/scsi/scsi_lib.c:1025 scsi_init_io+0x156/0x180 CPU: 2 PID: 1986 Comm: kworker/2:1H Kdump: loaded Not tainted 5.4.0-rc7 #1 Workqueue: kblockd blk_mq_run_work_fn RIP: 0010:scsi_init_io+0x156/0x180 RSP: 0018:ffffa11487663bf0 EFLAGS: 00010246 RAX: 00000000002be0a0 RBX: ffff8e6e9ff30118 RCX: 0000000000000000 RDX: 00000000ffffffe1 RSI: 0000000000000000 RDI: ffff8e6e9ff30118 RBP: ffffa11487663c18 R08: ffffa11487663d28 R09: ffff8e6e9ff30150 R10: 0000000000000001 R11: 0000000000000000 R12: ffff8e6e9ff30000 R13: 0000000000000001 R14: ffff8e74a1cf1800 R15: ffff8e6e9ff30000 FS: 0000000000000000(0000) GS:ffff8e6ea7680000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff18cf0fe8 CR3: 0000000659f0a001 CR4: 00000000001606e0 Call Trace: sd_init_command+0x326/0xb40 [sd_mod] scsi_queue_rq+0x502/0xaa0 ? blk_mq_get_driver_tag+0xe7/0x120 blk_mq_dispatch_rq_list+0x256/0x5a0 ? elv_rb_del+0x24/0x30 ? deadline_remove_request+0x7b/0xc0 blk_mq_do_dispatch_sched+0xa3/0x140 blk_mq_sched_dispatch_requests+0xfb/0x170 __blk_mq_run_hw_queue+0x81/0x130 blk_mq_run_work_fn+0x1b/0x20 process_one_work+0x179/0x390 worker_thread+0x4f/0x3e0 kthread+0x105/0x140 ? max_active_store+0x80/0x80 ? kthread_bind+0x20/0x20 ret_from_fork+0x35/0x40 ---[ end trace f9036abf5af4a4d3 ]--- blk_update_request: I/O error, dev sdd, sector 2875552 op 0x1:(WRITE) flags 0x0 phys_seg 0 prio class 0 XFS (sdd1): writeback error on sector 2875552 __bio_try_merge_page() should check the overflow before actually doing merge. Fixes: 07173c3ec276c ("block: enable multipage bvecs") Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-06blkcg: make blkcg_print_stat() print stats only for online blkgsTejun Heo
blkcg_print_stat() iterates blkgs under RCU and doesn't test whether the blkg is online. This can call into pd_stat_fn() on a pd which is still being initialized leading to an oops. The heaviest operation - recursively summing up rwstat counters - is already done while holding the queue_lock. Expand queue_lock to cover the other operations and skip the blkg if it isn't online yet. The online state is protected by both blkcg and queue locks, so this guarantees that only online blkgs are processed. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Roman Gushchin <guro@fb.com> Cc: Josef Bacik <jbacik@fb.com> Fixes: 903d23f0a354 ("blk-cgroup: allow controllers to output their own stats") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-31iocost: don't nest spin_lock_irq in ioc_weight_write()Dan Carpenter
This code causes a static analysis warning: block/blk-iocost.c:2113 ioc_weight_write() error: double lock 'irq' We disable IRQs in blkg_conf_prep() and re-enable them in blkg_conf_finish(). IRQ disable/enable should not be nested because that means the IRQs will be enabled at the first unlock instead of the second one. Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-15blk-rq-qos: fix first node deletion of rq_qos_del()Tejun Heo
rq_qos_del() incorrectly assigns the node being deleted to the head if it was the first on the list in the !prev path. Fix it by iterating with ** instead. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Josef Bacik <josef@toxicpanda.com> Fixes: a79050434b45 ("blk-rq-qos: refactor out common elements of blk-wbt") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-15blkcg: Fix multiple bugs in blkcg_activate_policy()Tejun Heo
blkcg_activate_policy() has the following bugs. * cf09a8ee19ad ("blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()") added @blkcg to ->pd_alloc_fn(); however, blkcg_activate_policy() ends up using pd's allocated for the root blkcg for all preallocations, so ->pd_init_fn() for non-root blkcgs can be passed in pd's which are allocated for the root blkcg. For blk-iocost, this means that ->pd_init_fn() can write beyond the end of the allocated object as it determines the length of the flex array at the end based on the blkcg's nesting level. * Each pd is initialized as they get allocated. If alloc fails, the policy will get freed with pd's initialized on it. * After the above partial failure, the partial pds are not freed. This patch fixes all the above issues by * Restructuring blkcg_activate_policy() so that alloc and init passes are separate. Init takes place only after all allocs succeeded and on failure all allocated pds are freed. * Unifying and fixing the cleanup of the remaining pd_prealloc. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: cf09a8ee19ad ("blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-14block: Fix elv_support_iosched()Damien Le Moal
A BIO based request queue does not have a tag_set, which prevent testing for the flag BLK_MQ_F_NO_SCHED indicating that the queue does not require an elevator. This leads to an incorrect initialization of a default elevator in some cases such as BIO based null_blk (queue_mode == BIO) with zoned mode enabled as the default elevator in this case is mq-deadline instead of "none". Fix this by testing for a NULL queue mq_ops field which indicates that the queue is BIO based and should not have an elevator. Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-06blk-wbt: fix performance regression in wbt scale_up/scale_downHarshad Shirwadkar
scale_up wakes up waiters after scaling up. But after scaling max, it should not wake up more waiters as waiters will not have anything to do. This patch fixes this by making scale_up (and also scale_down) return when threshold is reached. This bug causes increased fdatasync latency when fdatasync and dd conv=sync are performed in parallel on 4.19 compared to 4.14. This bug was introduced during refactoring of blk-wbt code. Fixes: a79050434b45 ("blk-rq-qos: refactor out common elements of blk-wbt") Cc: stable@vger.kernel.org Cc: Josef Bacik <jbacik@fb.com> Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-03block: sed-opal: fix sparse warning: convert __be64 dataRandy Dunlap
sparse warns about incorrect type when using __be64 data. It is not being converted to CPU-endian but it should be. Fixes these sparse warnings: ../block/sed-opal.c:375:20: warning: incorrect type in assignment (different base types) ../block/sed-opal.c:375:20: expected unsigned long long [usertype] align ../block/sed-opal.c:375:20: got restricted __be64 const [usertype] alignment_granularity ../block/sed-opal.c:376:25: warning: incorrect type in assignment (different base types) ../block/sed-opal.c:376:25: expected unsigned long long [usertype] lowest_lba ../block/sed-opal.c:376:25: got restricted __be64 const [usertype] lowest_aligned_lba Fixes: 455a7b238cd6 ("block: Add Sed-opal library") Cc: Scott Bauer <scott.bauer@intel.com> Cc: Rafael Antognolli <rafael.antognolli@intel.com> Cc: linux-block@vger.kernel.org Reviewed-by: Jon Derrick <jonathan.derrick@intel.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-03block: sed-opal: fix sparse warning: obsolete array init.Randy Dunlap
Fix sparse warning: (missing '=') ../block/sed-opal.c:133:17: warning: obsolete array initializer, use C99 syntax Fixes: ff91064ea37c ("block: sed-opal: check size of shadow mbr") Cc: linux-block@vger.kernel.org Cc: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de> Cc: David Kozub <zub@linux.fjfi.cvut.cz> Reviewed-by: Scott Bauer <sbauer@plzdonthack.me> Reviewed-by: Revanth Rajashekar <revanth.rajashekar@intel.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27blk-mq: apply normal plugging for HDDMing Lei
Some HDD drive may expose multiple hardware queues, such as MegraRaid. Let's apply the normal plugging for such devices because sequential IO may benefit a lot from plug merging. Cc: Bart Van Assche <bvanassche@acm.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Dave Chinner <dchinner@redhat.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27blk-mq: honor IO scheduler for multiqueue devicesMing Lei
If a device is using multiple queues, the IO scheduler may be bypassed. This may hurt performance for some slow MQ devices, and it also breaks zoned devices which depend on mq-deadline for respecting the write order in one zone. Don't bypass io scheduler if we have one setup. This patch can double sequential write performance basically on MQ scsi_debug when mq-deadline is applied. Cc: Bart Van Assche <bvanassche@acm.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Dave Chinner <dchinner@redhat.com> Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27block: fix null pointer dereference in blk_mq_rq_timed_out()Yufen Yu
We got a null pointer deference BUG_ON in blk_mq_rq_timed_out() as following: [ 108.825472] BUG: kernel NULL pointer dereference, address: 0000000000000040 [ 108.827059] PGD 0 P4D 0 [ 108.827313] Oops: 0000 [#1] SMP PTI [ 108.827657] CPU: 6 PID: 198 Comm: kworker/6:1H Not tainted 5.3.0-rc8+ #431 [ 108.829503] Workqueue: kblockd blk_mq_timeout_work [ 108.829913] RIP: 0010:blk_mq_check_expired+0x258/0x330 [ 108.838191] Call Trace: [ 108.838406] bt_iter+0x74/0x80 [ 108.838665] blk_mq_queue_tag_busy_iter+0x204/0x450 [ 108.839074] ? __switch_to_asm+0x34/0x70 [ 108.839405] ? blk_mq_stop_hw_queue+0x40/0x40 [ 108.839823] ? blk_mq_stop_hw_queue+0x40/0x40 [ 108.840273] ? syscall_return_via_sysret+0xf/0x7f [ 108.840732] blk_mq_timeout_work+0x74/0x200 [ 108.841151] process_one_work+0x297/0x680 [ 108.841550] worker_thread+0x29c/0x6f0 [ 108.841926] ? rescuer_thread+0x580/0x580 [ 108.842344] kthread+0x16a/0x1a0 [ 108.842666] ? kthread_flush_work+0x170/0x170 [ 108.843100] ret_from_fork+0x35/0x40 The bug is caused by the race between timeout handle and completion for flush request. When timeout handle function blk_mq_rq_timed_out() try to read 'req->q->mq_ops', the 'req' have completed and reinitiated by next flush request, which would call blk_rq_init() to clear 'req' as 0. After commit 12f5b93145 ("blk-mq: Remove generation seqeunce"), normal requests lifetime are protected by refcount. Until 'rq->ref' drop to zero, the request can really be free. Thus, these requests cannot been reused before timeout handle finish. However, flush request has defined .end_io and rq->end_io() is still called even if 'rq->ref' doesn't drop to zero. After that, the 'flush_rq' can be reused by the next flush request handle, resulting in null pointer deference BUG ON. We fix this problem by covering flush request with 'rq->ref'. If the refcount is not zero, flush_end_io() return and wait the last holder recall it. To record the request status, we add a new entry 'rq_status', which will be used in flush_end_io(). Cc: Christoph Hellwig <hch@infradead.org> Cc: Keith Busch <keith.busch@intel.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: stable@vger.kernel.org # v4.18+ Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Yufen Yu <yuyufen@huawei.com> ------- v2: - move rq_status from struct request to struct blk_flush_queue v3: - remove unnecessary '{}' pair. v4: - let spinlock to protect 'fq->rq_status' v5: - move rq_status after flush_running_idx member of struct blk_flush_queue Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27rq-qos: get rid of redundant wbt_update_limits()Yufen Yu
We have updated limits after calling wbt_set_min_lat(). No need to update again. Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-26iocost: bump up default latency targets for hard disksTejun Heo
The default hard disk param sets latency targets at 50ms. As the default target percentiles are zero, these don't directly regulate vrate; however, they're still used to calculate the period length - 100ms in this case. This is excessively low. A SATA drive with QD32 saturated with random IOs can easily reach avg completion latency of several hundred msecs. A period duration which is substantially lower than avg completion latency can lead to wildly fluctuating vrate. Let's bump up the default latency targets to 250ms so that the period duration is sufficiently long. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-26iocost: improve nr_lagging handlingTejun Heo
Some IOs may span multiple periods. As latencies are collected on completion, the inbetween periods won't register them and may incorrectly decide to increase vrate. nr_lagging tracks these IOs to avoid those situations. Currently, whenever there are IOs which are spanning from the previous period, busy_level is reset to 0 if negative thus suppressing vrate increase. This has the following two problems. * When latency target percentiles aren't set, vrate adjustment should only be governed by queue depth depletion; however, the current code keeps nr_lagging active which pulls in latency results and can keep down vrate unexpectedly. * When lagging condition is detected, it resets the entire negative busy_level. This turned out to be way too aggressive on some devices which sometimes experience extended latencies on a small subset of commands. In addition, a lagging IO will be accounted as latency target miss on completion anyway and resetting busy_level amplifies its impact unnecessarily. This patch fixes the above two problems by disabling nr_lagging counting when latency target percentiles aren't set and blocking vrate increases when there are lagging IOs while leaving busy_level as-is. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-26iocost: better trace vrate changesTejun Heo
vrate_adj tracepoint traces vrate changes; however, it does so only when busy_level is non-zero. busy_level turning to zero can sometimes be as interesting an event. This patch also enables vrate_adj tracepoint on other vrate related events - busy_level changes and non-zero nr_lagging. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>