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2025-10-29block: use int to store blk_stack_limits() return valueQianfeng Rong
[ Upstream commit b0b4518c992eb5f316c6e40ff186cbb7a5009518 ] Change the 'ret' variable in blk_stack_limits() from unsigned int to int, as it needs to store negative value -1. Storing the negative error codes in unsigned type, or performing equality comparisons (e.g., ret == -1), doesn't cause an issue at runtime [1] but can be confusing. Additionally, assigning negative error codes to unsigned type may trigger a GCC warning when the -Wsign-conversion flag is enabled. No effect on runtime. Link: https://lore.kernel.org/all/x3wogjf6vgpkisdhg3abzrx7v7zktmdnfmqeih5kosszmagqfs@oh3qxrgzkikf/ #1 Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com> Reviewed-by: John Garry <john.g.garry@oracle.com> Fixes: fe0b393f2c0a ("block: Correct handling of bottom device misaligment") Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20250902130930.68317-1-rongqianfeng@vivo.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-29blk-mq: check kobject state_in_sysfs before deleting in blk_mq_unregister_hctxLi Nan
[ Upstream commit 4c7ef92f6d4d08a27d676e4c348f4e2922cab3ed ] In __blk_mq_update_nr_hw_queues() the return value of blk_mq_sysfs_register_hctxs() is not checked. If sysfs creation for hctx fails, later changing the number of hw_queues or removing disk will trigger the following warning: kernfs: can not remove 'nr_tags', no directory WARNING: CPU: 2 PID: 637 at fs/kernfs/dir.c:1707 kernfs_remove_by_name_ns+0x13f/0x160 Call Trace: remove_files.isra.1+0x38/0xb0 sysfs_remove_group+0x4d/0x100 sysfs_remove_groups+0x31/0x60 __kobject_del+0x23/0xf0 kobject_del+0x17/0x40 blk_mq_unregister_hctx+0x5d/0x80 blk_mq_sysfs_unregister_hctxs+0x94/0xd0 blk_mq_update_nr_hw_queues+0x124/0x760 nullb_update_nr_hw_queues+0x71/0xf0 [null_blk] nullb_device_submit_queues_store+0x92/0x120 [null_blk] kobjct_del() was called unconditionally even if sysfs creation failed. Fix it by checkig the kobject creation statusbefore deleting it. Fixes: 477e19dedc9d ("blk-mq: adjust debugfs and sysfs register when updating nr_hw_queues") Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20250826084854.1030545-1-linan666@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10block: fix 'kmem_cache of name 'bio-108' already exists'Ming Lei
[ Upstream commit b654f7a51ffb386131de42aa98ed831f8c126546 ] Device mapper bioset often has big bio_slab size, which can be more than 1000, then 8byte can't hold the slab name any more, cause the kmem_cache allocation warning of 'kmem_cache of name 'bio-108' already exists'. Fix the warning by extending bio_slab->name to 12 bytes, but fix output of /proc/slabinfo Reported-by: Guangwu Zhang <guazhang@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20250228132656.2838008-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-13partitions: mac: fix handling of bogus partition tableJann Horn
commit 80e648042e512d5a767da251d44132553fe04ae0 upstream. Fix several issues in partition probing: - The bailout for a bad partoffset must use put_dev_sector(), since the preceding read_part_sector() succeeded. - If the partition table claims a silly sector size like 0xfff bytes (which results in partition table entries straddling sector boundaries), bail out instead of accessing out-of-bounds memory. - We must not assume that the partition table contains proper NUL termination - use strnlen() and strncmp() instead of strlen() and strcmp(). Cc: stable@vger.kernel.org Signed-off-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/r/20250214-partition-mac-v1-1-c1c626dffbd5@google.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13partitions: ldm: remove the initial kernel-doc notationRandy Dunlap
[ Upstream commit e494e451611a3de6ae95f99e8339210c157d70fb ] Remove the file's first comment describing what the file is. This comment is not in kernel-doc format so it causes a kernel-doc warning. ldm.h:13: warning: expecting prototype for ldm(). Prototype was for _FS_PT_LDM_H_() instead Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Richard Russon (FlatCap) <ldm@flatcap.org> Cc: linux-ntfs-dev@lists.sourceforge.net Cc: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20250111062758.910458-1-rdunlap@infradead.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-19blk-iocost: Avoid using clamp() on inuse in __propagate_weights()Nathan Chancellor
[ Upstream commit 57e420c84f9ab55ba4c5e2ae9c5f6c8e1ea834d2 ] After a recent change to clamp() and its variants [1] that increases the coverage of the check that high is greater than low because it can be done through inlining, certain build configurations (such as s390 defconfig) fail to build with clang with: block/blk-iocost.c:1101:11: error: call to '__compiletime_assert_557' declared with 'error' attribute: clamp() low limit 1 greater than high limit active 1101 | inuse = clamp_t(u32, inuse, 1, active); | ^ include/linux/minmax.h:218:36: note: expanded from macro 'clamp_t' 218 | #define clamp_t(type, val, lo, hi) __careful_clamp(type, val, lo, hi) | ^ include/linux/minmax.h:195:2: note: expanded from macro '__careful_clamp' 195 | __clamp_once(type, val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_)) | ^ include/linux/minmax.h:188:2: note: expanded from macro '__clamp_once' 188 | BUILD_BUG_ON_MSG(statically_true(ulo > uhi), \ | ^ __propagate_weights() is called with an active value of zero in ioc_check_iocgs(), which results in the high value being less than the low value, which is undefined because the value returned depends on the order of the comparisons. The purpose of this expression is to ensure inuse is not more than active and at least 1. This could be written more simply with a ternary expression that uses min(inuse, active) as the condition so that the value of that condition can be used if it is not zero and one if it is. Do this conversion to resolve the error and add a comment to deter people from turning this back into clamp(). Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Link: https://lore.kernel.org/r/34d53778977747f19cce2abb287bb3e6@AcuMS.aculab.com/ [1] Suggested-by: David Laight <david.laight@aculab.com> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Closes: https://lore.kernel.org/llvm/CA+G9fYsD7mw13wredcZn0L-KBA3yeoVSTuxnss-AEWMN3ha0cA@mail.gmail.com/ Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202412120322.3GfVe3vF-lkp@intel.com/ Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-19blk-iocost: fix weight updates of inner active iocgsTejun Heo
[ Upstream commit e9f4eee9a0023ba22db9560d4cc6ee63f933dae8 ] When the weight of an active iocg is updated, weight_updated() is called which in turn calls __propagate_weights() to update the active and inuse weights so that the effective hierarchical weights are update accordingly. The current implementation is incorrect for inner active nodes. For an active leaf iocg, inuse can be any value between 1 and active and the difference represents how much the iocg is donating. When weight is updated, as long as inuse is clamped between 1 and the new weight, we're alright and this is what __propagate_weights() currently implements. However, that's not how an active inner node's inuse is set. An inner node's inuse is solely determined by the ratio between the sums of inuse's and active's of its children - ie. they're results of propagating the leaves' active and inuse weights upwards. __propagate_weights() incorrectly applies the same clamping as for a leaf when an active inner node's weight is updated. Consider a hierarchy which looks like the following with saturating workloads in AA and BB. R / \ A B | | AA BB 1. For both A and B, active=100, inuse=100, hwa=0.5, hwi=0.5. 2. echo 200 > A/io.weight 3. __propagate_weights() update A's active to 200 and leave inuse at 100 as it's already between 1 and the new active, making A:active=200, A:inuse=100. As R's active_sum is updated along with A's active, A:hwa=2/3, B:hwa=1/3. However, because the inuses didn't change, the hwi's remain unchanged at 0.5. 4. The weight of A is now twice that of B but AA and BB still have the same hwi of 0.5 and thus are doing the same amount of IOs. Fix it by making __propgate_weights() always calculate the inuse of an active inner iocg based on the ratio of child_inuse_sum to child_active_sum. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Dan Schatzberg <dschatzberg@fb.com> Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Cc: stable@vger.kernel.org # v5.4+ Link: https://lore.kernel.org/r/YJsxnLZV1MnBcqjj@slm.duckdns.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Stable-dep-of: 57e420c84f9a ("blk-iocost: Avoid using clamp() on inuse in __propagate_weights()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-19blk-iocost: clamp inuse and skip noops in __propagate_weights()Tejun Heo
[ Upstream commit db84a72af6be422abf2089a5896293590dda5066 ] __propagate_weights() currently expects the callers to clamp inuse within [1, active], which is needlessly fragile. The inuse adjustment logic is going to be revamped, in preparation, let's make __propagate_weights() clamp inuse on entry. Also, make it avoid weight updates altogether if neither active or inuse is changed. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Stable-dep-of: 57e420c84f9a ("blk-iocost: Avoid using clamp() on inuse in __propagate_weights()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14block: fix ordering between checking BLK_MQ_S_STOPPED request addingMuchun Song
commit 96a9fe64bfd486ebeeacf1e6011801ffe89dae18 upstream. Supposing first scenario with a virtio_blk driver. CPU0 CPU1 blk_mq_try_issue_directly() __blk_mq_issue_directly() q->mq_ops->queue_rq() virtio_queue_rq() blk_mq_stop_hw_queue() virtblk_done() blk_mq_request_bypass_insert() 1) store blk_mq_start_stopped_hw_queue() clear_bit(BLK_MQ_S_STOPPED) 3) store blk_mq_run_hw_queue() if (!blk_mq_hctx_has_pending()) 4) load return blk_mq_sched_dispatch_requests() blk_mq_run_hw_queue() if (!blk_mq_hctx_has_pending()) return blk_mq_sched_dispatch_requests() if (blk_mq_hctx_stopped()) 2) load return __blk_mq_sched_dispatch_requests() Supposing another scenario. CPU0 CPU1 blk_mq_requeue_work() blk_mq_insert_request() 1) store virtblk_done() blk_mq_start_stopped_hw_queue() blk_mq_run_hw_queues() clear_bit(BLK_MQ_S_STOPPED) 3) store blk_mq_run_hw_queue() if (!blk_mq_hctx_has_pending()) 4) load return blk_mq_sched_dispatch_requests() if (blk_mq_hctx_stopped()) 2) load continue blk_mq_run_hw_queue() Both scenarios are similar, the full memory barrier should be inserted between 1) and 2), as well as between 3) and 4) to make sure that either CPU0 sees BLK_MQ_S_STOPPED is cleared or CPU1 sees dispatch list. Otherwise, either CPU will not rerun the hardware queue causing starvation of the request. The easy way to fix it is to add the essential full memory barrier into helper of blk_mq_hctx_stopped(). In order to not affect the fast path (hardware queue is not stopped most of the time), we only insert the barrier into the slow path. Actually, only slow path needs to care about missing of dispatching the request to the low-level device driver. Fixes: 320ae51feed5 ("blk-mq: new multi-queue block IO queueing mechanism") Cc: stable@vger.kernel.org Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20241014092934.53630-4-songmuchun@bytedance.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-08blk-rq-qos: fix crash on rq_qos_wait vs. rq_qos_wake_function raceOmar Sandoval
commit e972b08b91ef48488bae9789f03cfedb148667fb upstream. We're seeing crashes from rq_qos_wake_function that look like this: BUG: unable to handle page fault for address: ffffafe180a40084 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 100000067 P4D 100000067 PUD 10027c067 PMD 10115d067 PTE 0 Oops: Oops: 0002 [#1] PREEMPT SMP PTI CPU: 17 UID: 0 PID: 0 Comm: swapper/17 Not tainted 6.12.0-rc3-00013-geca631b8fe80 #11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:_raw_spin_lock_irqsave+0x1d/0x40 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 54 9c 41 5c fa 65 ff 05 62 97 30 4c 31 c0 ba 01 00 00 00 <f0> 0f b1 17 75 0a 4c 89 e0 41 5c c3 cc cc cc cc 89 c6 e8 2c 0b 00 RSP: 0018:ffffafe180580ca0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffffafe180a3f7a8 RCX: 0000000000000011 RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffffafe180a40084 RBP: 0000000000000000 R08: 00000000001e7240 R09: 0000000000000011 R10: 0000000000000028 R11: 0000000000000888 R12: 0000000000000002 R13: ffffafe180a40084 R14: 0000000000000000 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff9aaf1f280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffafe180a40084 CR3: 000000010e428002 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <IRQ> try_to_wake_up+0x5a/0x6a0 rq_qos_wake_function+0x71/0x80 __wake_up_common+0x75/0xa0 __wake_up+0x36/0x60 scale_up.part.0+0x50/0x110 wb_timer_fn+0x227/0x450 ... So rq_qos_wake_function() calls wake_up_process(data->task), which calls try_to_wake_up(), which faults in raw_spin_lock_irqsave(&p->pi_lock). p comes from data->task, and data comes from the waitqueue entry, which is stored on the waiter's stack in rq_qos_wait(). Analyzing the core dump with drgn, I found that the waiter had already woken up and moved on to a completely unrelated code path, clobbering what was previously data->task. Meanwhile, the waker was passing the clobbered garbage in data->task to wake_up_process(), leading to the crash. What's happening is that in between rq_qos_wake_function() deleting the waitqueue entry and calling wake_up_process(), rq_qos_wait() is finding that it already got a token and returning. The race looks like this: rq_qos_wait() rq_qos_wake_function() ============================================================== prepare_to_wait_exclusive() data->got_token = true; list_del_init(&curr->entry); if (data.got_token) break; finish_wait(&rqw->wait, &data.wq); ^- returns immediately because list_empty_careful(&wq_entry->entry) is true ... return, go do something else ... wake_up_process(data->task) (NO LONGER VALID!)-^ Normally, finish_wait() is supposed to synchronize against the waker. But, as noted above, it is returning immediately because the waitqueue entry has already been removed from the waitqueue. The bug is that rq_qos_wake_function() is accessing the waitqueue entry AFTER deleting it. Note that autoremove_wake_function() wakes the waiter and THEN deletes the waitqueue entry, which is the proper order. Fix it by swapping the order. We also need to use list_del_init_careful() to match the list_empty_careful() in finish_wait(). Fixes: 38cfb5a45ee0 ("blk-wbt: improve waking of tasks") Cc: stable@vger.kernel.org Signed-off-by: Omar Sandoval <osandov@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/d3bee2463a67b1ee597211823bf7ad3721c26e41.1729014591.git.osandov@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-08block, bfq: don't break merge chain in bfq_split_bfqq()Yu Kuai
[ Upstream commit 42c306ed723321af4003b2a41bb73728cab54f85 ] Consider the following scenario: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \-------------\ \-------------\ \--------------\| V V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 1 2 4 If Process 1 issue a new IO and bfqq2 is found, and then bfq_init_rq() decide to spilt bfqq2 by bfq_split_bfqq(). Howerver, procress reference of bfqq2 is 1 and bfq_split_bfqq() just clear the coop flag, which will break the merge chain. Expected result: caller will allocate a new bfqq for BIC1 Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) | | | \-------------\ \--------------\| V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 ref 0 0 1 3 Since the condition is only used for the last bfqq4 when the previous bfqq2 and bfqq3 are already splited. Fix the problem by checking if bfqq is the last one in the merge chain as well. Fixes: 36eca8948323 ("block, bfq: add Early Queue Merge (EQM)") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20240902130329.3787024-4-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-08block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()Yu Kuai
[ Upstream commit 0e456dba86c7f9a19792204a044835f1ca2c8dbb ] Consider the following merge chain: Process 1 Process 2 Process 3 Process 4 (BIC1) (BIC2) (BIC3) (BIC4) Λ | | | \--------------\ \-------------\ \-------------\| V V V bfqq1--------->bfqq2---------->bfqq3----------->bfqq4 IO from Process 1 will get bfqf2 from BIC1 first, then bfq_setup_cooperator() will found bfqq2 already merged to bfqq3 and then handle this IO from bfqq3. However, the merge chain can be much deeper and bfqq3 can be merged to other bfqq as well. Fix this problem by iterating to the last bfqq in bfq_setup_cooperator(). Fixes: 36eca8948323 ("block, bfq: add Early Queue Merge (EQM)") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20240902130329.3787024-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-08block, bfq: fix possible UAF for bfqq->bic with merge chainYu Kuai
[ Upstream commit 18ad4df091dd5d067d2faa8fce1180b79f7041a7 ] 1) initial state, three tasks: Process 1 Process 2 Process 3 (BIC1) (BIC2) (BIC3) | Λ | Λ | Λ | | | | | | V | V | V | bfqq1 bfqq2 bfqq3 process ref: 1 1 1 2) bfqq1 merged to bfqq2: Process 1 Process 2 Process 3 (BIC1) (BIC2) (BIC3) | | | Λ \--------------\| | | V V | bfqq1--------->bfqq2 bfqq3 process ref: 0 2 1 3) bfqq2 merged to bfqq3: Process 1 Process 2 Process 3 (BIC1) (BIC2) (BIC3) here -> Λ | | \--------------\ \-------------\| V V bfqq1--------->bfqq2---------->bfqq3 process ref: 0 1 3 In this case, IO from Process 1 will get bfqq2 from BIC1 first, and then get bfqq3 through merge chain, and finially handle IO by bfqq3. Howerver, current code will think bfqq2 is owned by BIC1, like initial state, and set bfqq2->bic to BIC1. bfq_insert_request -> by Process 1 bfqq = bfq_init_rq(rq) bfqq = bfq_get_bfqq_handle_split bfqq = bic_to_bfqq -> get bfqq2 from BIC1 bfqq->ref++ rq->elv.priv[0] = bic rq->elv.priv[1] = bfqq if (bfqq_process_refs(bfqq) == 1) bfqq->bic = bic -> record BIC1 to bfqq2 __bfq_insert_request new_bfqq = bfq_setup_cooperator -> get bfqq3 from bfqq2->new_bfqq bfqq_request_freed(bfqq) new_bfqq->ref++ rq->elv.priv[1] = new_bfqq -> handle IO by bfqq3 Fix the problem by checking bfqq is from merge chain fist. And this might fix a following problem reported by our syzkaller(unreproducible): ================================================================== BUG: KASAN: slab-use-after-free in bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline] BUG: KASAN: slab-use-after-free in bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline] BUG: KASAN: slab-use-after-free in bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889 Write of size 1 at addr ffff888123839eb8 by task kworker/0:1H/18595 CPU: 0 PID: 18595 Comm: kworker/0:1H Tainted: G L 6.6.0-07439-gba2303cacfda #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Workqueue: kblockd blk_mq_requeue_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x10d/0x610 mm/kasan/report.c:475 kasan_report+0x8e/0xc0 mm/kasan/report.c:588 bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline] bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline] bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889 bfq_get_bfqq_handle_split+0x169/0x5d0 block/bfq-iosched.c:6757 bfq_init_rq block/bfq-iosched.c:6876 [inline] bfq_insert_request block/bfq-iosched.c:6254 [inline] bfq_insert_requests+0x1112/0x5cf0 block/bfq-iosched.c:6304 blk_mq_insert_request+0x290/0x8d0 block/blk-mq.c:2593 blk_mq_requeue_work+0x6bc/0xa70 block/blk-mq.c:1502 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700 worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305 </TASK> Allocated by task 20776: kasan_save_stack+0x20/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3458 [inline] kmem_cache_alloc_node+0x1a4/0x6f0 mm/slub.c:3503 ioc_create_icq block/blk-ioc.c:370 [inline] ioc_find_get_icq+0x180/0xaa0 block/blk-ioc.c:436 bfq_prepare_request+0x39/0xf0 block/bfq-iosched.c:6812 blk_mq_rq_ctx_init.isra.7+0x6ac/0xa00 block/blk-mq.c:403 __blk_mq_alloc_requests+0xcc0/0x1070 block/blk-mq.c:517 blk_mq_get_new_requests block/blk-mq.c:2940 [inline] blk_mq_submit_bio+0x624/0x27c0 block/blk-mq.c:3042 __submit_bio+0x331/0x6f0 block/blk-core.c:624 __submit_bio_noacct_mq block/blk-core.c:703 [inline] submit_bio_noacct_nocheck+0x816/0xb40 block/blk-core.c:732 submit_bio_noacct+0x7a6/0x1b50 block/blk-core.c:826 xlog_write_iclog+0x7d5/0xa00 fs/xfs/xfs_log.c:1958 xlog_state_release_iclog+0x3b8/0x720 fs/xfs/xfs_log.c:619 xlog_cil_push_work+0x19c5/0x2270 fs/xfs/xfs_log_cil.c:1330 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700 worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305 Freed by task 946: kasan_save_stack+0x20/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x50 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] __kasan_slab_free+0x12c/0x1c0 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1815 [inline] slab_free_freelist_hook mm/slub.c:1841 [inline] slab_free mm/slub.c:3786 [inline] kmem_cache_free+0x118/0x6f0 mm/slub.c:3808 rcu_do_batch+0x35c/0xe30 kernel/rcu/tree.c:2189 rcu_core+0x819/0xd90 kernel/rcu/tree.c:2462 __do_softirq+0x1b0/0x7a2 kernel/softirq.c:553 Last potentially related work creation: kasan_save_stack+0x20/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2712 [inline] call_rcu+0xce/0x1020 kernel/rcu/tree.c:2826 ioc_destroy_icq+0x54c/0x830 block/blk-ioc.c:105 ioc_release_fn+0xf0/0x360 block/blk-ioc.c:124 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700 worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305 Second to last potentially related work creation: kasan_save_stack+0x20/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2712 [inline] call_rcu+0xce/0x1020 kernel/rcu/tree.c:2826 ioc_destroy_icq+0x54c/0x830 block/blk-ioc.c:105 ioc_release_fn+0xf0/0x360 block/blk-ioc.c:124 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700 worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305 The buggy address belongs to the object at ffff888123839d68 which belongs to the cache bfq_io_cq of size 1360 The buggy address is located 336 bytes inside of freed 1360-byte region [ffff888123839d68, ffff88812383a2b8) The buggy address belongs to the physical page: page:ffffea00048e0e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88812383f588 pfn:0x123838 head:ffffea00048e0e00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x17ffffc0000a40(workingset|slab|head|node=0|zone=2|lastcpupid=0x1fffff) page_type: 0xffffffff() raw: 0017ffffc0000a40 ffff88810588c200 ffffea00048ffa10 ffff888105889488 raw: ffff88812383f588 0000000000150006 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888123839d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888123839e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888123839e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888123839f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888123839f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Fixes: 36eca8948323 ("block, bfq: add Early Queue Merge (EQM)") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20240902130329.3787024-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-12block: initialize integrity buffer to zero before writing it to mediaChristoph Hellwig
commit 899ee2c3829c5ac14bfc7d3c4a5846c0b709b78f upstream. Metadata added by bio_integrity_prep is using plain kmalloc, which leads to random kernel memory being written media. For PI metadata this is limited to the app tag that isn't used by kernel generated metadata, but for non-PI metadata the entire buffer leaks kernel memory. Fix this by adding the __GFP_ZERO flag to allocations for writes. Fixes: 7ba1ba12eeef ("block: Block layer data integrity support") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20240613084839.1044015-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Shivani Agarwal <shivani.agarwal@broadcom.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-13block: prevent division by zero in blk_rq_stat_sum()Roman Smirnov
[ Upstream commit 93f52fbeaf4b676b21acfe42a5152620e6770d02 ] The expression dst->nr_samples + src->nr_samples may have zero value on overflow. It is necessary to add a check to avoid division by zero. Found by Linux Verification Center (linuxtesting.org) with Svace. Signed-off-by: Roman Smirnov <r.smirnov@omp.ru> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru> Link: https://lore.kernel.org/r/20240305134509.23108-1-r.smirnov@omp.ru Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26block: sed-opal: handle empty atoms when parsing responseGreg Joyce
[ Upstream commit 5429c8de56f6b2bd8f537df3a1e04e67b9c04282 ] The SED Opal response parsing function response_parse() does not handle the case of an empty atom in the response. This causes the entry count to be too high and the response fails to be parsed. Recognizing, but ignoring, empty atoms allows response handling to succeed. Signed-off-by: Greg Joyce <gjoyce@linux.ibm.com> Link: https://lore.kernel.org/r/20240216210417.3526064-2-gjoyce@linux.ibm.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23blk-mq: fix IO hang from sbitmap wakeup raceMing Lei
[ Upstream commit 5266caaf5660529e3da53004b8b7174cab6374ed ] In blk_mq_mark_tag_wait(), __add_wait_queue() may be re-ordered with the following blk_mq_get_driver_tag() in case of getting driver tag failure. Then in __sbitmap_queue_wake_up(), waitqueue_active() may not observe the added waiter in blk_mq_mark_tag_wait() and wake up nothing, meantime blk_mq_mark_tag_wait() can't get driver tag successfully. This issue can be reproduced by running the following test in loop, and fio hang can be observed in < 30min when running it on my test VM in laptop. modprobe -r scsi_debug modprobe scsi_debug delay=0 dev_size_mb=4096 max_queue=1 host_max_queue=1 submit_queues=4 dev=`ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block/* | head -1 | xargs basename` fio --filename=/dev/"$dev" --direct=1 --rw=randrw --bs=4k --iodepth=1 \ --runtime=100 --numjobs=40 --time_based --name=test \ --ioengine=libaio Fix the issue by adding one explicit barrier in blk_mq_mark_tag_wait(), which is just fine in case of running out of tag. Cc: Jan Kara <jack@suse.cz> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Reported-by: Changhui Zhong <czhong@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20240112122626.4181044-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23block: prevent an integer overflow in bvec_try_merge_hw_pageChristoph Hellwig
[ Upstream commit 3f034c374ad55773c12dd8f3c1607328e17c0072 ] Reordered a check to avoid a possible overflow when adding len to bv_len. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20231204173419.782378-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23block: Remove special-casing of compound pagesMatthew Wilcox (Oracle)
commit 1b151e2435fc3a9b10c8946c6aebe9f3e1938c55 upstream. The special casing was originally added in pre-git history; reproducing the commit log here: > commit a318a92567d77 > Author: Andrew Morton <akpm@osdl.org> > Date: Sun Sep 21 01:42:22 2003 -0700 > > [PATCH] Speed up direct-io hugetlbpage handling > > This patch short-circuits all the direct-io page dirtying logic for > higher-order pages. Without this, we pointlessly bounce BIOs up to > keventd all the time. In the last twenty years, compound pages have become used for more than just hugetlb. Rewrite these functions to operate on folios instead of pages and remove the special case for hugetlbfs; I don't think it's needed any more (and if it is, we can put it back in as a call to folio_test_hugetlb()). This was found by inspection; as far as I can tell, this bug can lead to pages used as the destination of a direct I/O read not being marked as dirty. If those pages are then reclaimed by the MM without being dirtied for some other reason, they won't be written out. Then when they're faulted back in, they will not contain the data they should. It'll take a pretty unusual setup to produce this problem with several races all going the wrong way. This problem predates the folio work; it could for example have been triggered by mmaping a THP in tmpfs and using that as the target of an O_DIRECT read. Fixes: 800d8c63b2e98 ("shmem: add huge pages support") Cc: <stable@vger.kernel.org> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-20blk-throttle: fix lockdep warning of "cgroup_mutex or RCU read lock required!"Ming Lei
[ Upstream commit 27b13e209ddca5979847a1b57890e0372c1edcee ] Inside blkg_for_each_descendant_pre(), both css_for_each_descendant_pre() and blkg_lookup() requires RCU read lock, and either cgroup_assert_mutex_or_rcu_locked() or rcu_read_lock_held() is called. Fix the warning by adding rcu read lock. Reported-by: Changhui Zhong <czhong@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20231117023527.3188627-2-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-27block/partition: fix signedness issue for Amiga partitionsMichael Schmitz
commit 7eb1e47696aa231b1a567846bbe3a1e1befe1854 upstream. Making 'blk' sector_t (i.e. 64 bit if LBD support is active) fails the 'blk>0' test in the partition block loop if a value of (signed int) -1 is used to mark the end of the partition block list. Explicitly cast 'blk' to signed int to allow use of -1 to terminate the partition block linked list. Fixes: b6f3f28f604b ("block: add overflow checks for Amiga partition support") Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Link: https://lore.kernel.org/r/024ce4fa-cc6d-50a2-9aae-3701d0ebf668@xenosoft.de Signed-off-by: Michael Schmitz <schmitzmic@gmail.com> Reviewed-by: Martin Steigerwald <martin@lichtvoll.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-27block: add overflow checks for Amiga partition supportMichael Schmitz
commit b6f3f28f604ba3de4724ad82bea6adb1300c0b5f upstream. The Amiga partition parser module uses signed int for partition sector address and count, which will overflow for disks larger than 1 TB. Use u64 as type for sector address and size to allow using disks up to 2 TB without LBD support, and disks larger than 2 TB with LBD. The RBD format allows to specify disk sizes up to 2^128 bytes (though native OS limitations reduce this somewhat, to max 2^68 bytes), so check for u64 overflow carefully to protect against overflowing sector_t. Bail out if sector addresses overflow 32 bits on kernels without LBD support. This bug was reported originally in 2012, and the fix was created by the RDB author, Joanne Dow <jdow@earthlink.net>. A patch had been discussed and reviewed on linux-m68k at that time but never officially submitted (now resubmitted as patch 1 in this series). This patch adds additional error checking and warning messages. Reported-by: Martin Steigerwald <Martin@lichtvoll.de> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=43511 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Message-ID: <201206192146.09327.Martin@lichtvoll.de> Cc: <stable@vger.kernel.org> # 5.2 Signed-off-by: Michael Schmitz <schmitzmic@gmail.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Christoph Hellwig <hch@infradead.org> Link: https://lore.kernel.org/r/20230620201725.7020-4-schmitzmic@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-27block: fix signed int overflow in Amiga partition supportMichael Schmitz
commit fc3d092c6bb48d5865fec15ed5b333c12f36288c upstream. The Amiga partition parser module uses signed int for partition sector address and count, which will overflow for disks larger than 1 TB. Use sector_t as type for sector address and size to allow using disks up to 2 TB without LBD support, and disks larger than 2 TB with LBD. This bug was reported originally in 2012, and the fix was created by the RDB author, Joanne Dow <jdow@earthlink.net>. A patch had been discussed and reviewed on linux-m68k at that time but never officially submitted. This patch differs from Joanne's patch only in its use of sector_t instead of unsigned int. No checking for overflows is done (see patch 3 of this series for that). Reported-by: Martin Steigerwald <Martin@lichtvoll.de> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=43511 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Message-ID: <201206192146.09327.Martin@lichtvoll.de> Cc: <stable@vger.kernel.org> # 5.2 Signed-off-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Martin Steigerwald <Martin@lichtvoll.de> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230620201725.7020-2-schmitzmic@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14block/blk-iocost (gcc13): keep large values in a new enumJiri Slaby (SUSE)
commit ff1cc97b1f4c10db224f276d9615b22835b8c424 upstream. Since gcc13, each member of an enum has the same type as the enum [1]. And that is inherited from its members. Provided: VTIME_PER_SEC_SHIFT = 37, VTIME_PER_SEC = 1LLU << VTIME_PER_SEC_SHIFT, ... AUTOP_CYCLE_NSEC = 10LLU * NSEC_PER_SEC, the named type is unsigned long. This generates warnings with gcc-13: block/blk-iocost.c: In function 'ioc_weight_prfill': block/blk-iocost.c:3037:37: error: format '%u' expects argument of type 'unsigned int', but argument 4 has type 'long unsigned int' block/blk-iocost.c: In function 'ioc_weight_show': block/blk-iocost.c:3047:34: error: format '%u' expects argument of type 'unsigned int', but argument 3 has type 'long unsigned int' So split the anonymous enum with large values to a separate enum, so that they don't affect other members. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36113 Cc: Martin Liska <mliska@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: cgroups@vger.kernel.org Cc: linux-block@vger.kernel.org Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20221213120826.17446-1-jirislaby@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14blk-iocost: avoid 64-bit division in ioc_timer_fnArnd Bergmann
commit 5f2779dfa7b8cc7dfd4a1b6586d86e0d193266f3 upstream. The behavior of 'enum' types has changed in gcc-13, so now the UNBUSY_THR_PCT constant is interpreted as a 64-bit number because it is defined as part of the same enum definition as some other constants that do not fit within a 32-bit integer. This in turn leads to some inefficient code on 32-bit architectures as well as a link error: arm-linux-gnueabi/bin/arm-linux-gnueabi-ld: block/blk-iocost.o: in function `ioc_timer_fn': blk-iocost.c:(.text+0x68e8): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: blk-iocost.c:(.text+0x6908): undefined reference to `__aeabi_uldivmod' Split the enum definition to keep the 64-bit timing constants in a separate enum type from those constants that can clearly fit within a smaller type. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230118080706.3303186-1-arnd@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-09treewide: Remove uninitialized_var() usageKees Cook
commit 3f649ab728cda8038259d8f14492fe400fbab911 upstream. Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-11blk-iocost: fix divide by 0 error in calc_lcoefs()Li Nan
[ Upstream commit 984af1e66b4126cf145153661cc24c213e2ec231 ] echo max of u64 to cost.model can cause divide by 0 error. # echo 8:0 rbps=18446744073709551615 > /sys/fs/cgroup/io.cost.model divide error: 0000 [#1] PREEMPT SMP RIP: 0010:calc_lcoefs+0x4c/0xc0 Call Trace: <TASK> ioc_refresh_params+0x2b3/0x4f0 ioc_cost_model_write+0x3cb/0x4c0 ? _copy_from_iter+0x6d/0x6c0 ? kernfs_fop_write_iter+0xfc/0x270 cgroup_file_write+0xa0/0x200 kernfs_fop_write_iter+0x17d/0x270 vfs_write+0x414/0x620 ksys_write+0x73/0x160 __x64_sys_write+0x1e/0x30 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd calc_lcoefs() uses the input value of cost.model in DIV_ROUND_UP_ULL, overflow would happen if bps plus IOC_PAGE_SIZE is greater than ULLONG_MAX, it can cause divide by 0 error. Fix the problem by setting basecost Signed-off-by: Li Nan <linan122@huawei.com> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230117070806.3857142-5-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11block: bio-integrity: Copy flags when bio_integrity_payload is clonedMartin K. Petersen
[ Upstream commit b6a4bdcda430e3ca43bbb9cb1d4d4d34ebe15c40 ] Make sure to copy the flags when a bio_integrity_payload is cloned. Otherwise per-I/O properties such as IP checksum flag will not be passed down to the HBA driver. Since the integrity buffer is owned by the original bio, the BIP_BLOCK_INTEGRITY flag needs to be masked off to avoid a double free in the completion path. Fixes: aae7df50190a ("block: Integrity checksum flag") Fixes: b1f01388574c ("block: Relocate bio integrity flags") Reported-by: Saurav Kashyap <skashyap@marvell.com> Tested-by: Saurav Kashyap <skashyap@marvell.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20230215171801.21062-1-martin.petersen@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11blk-mq: correct stale comment of .get_budgetKemeng Shi
[ Upstream commit 01542f651a9f58a9b176c3d3dc3eefbacee53b78 ] Commit 88022d7201e96 ("blk-mq: don't handle failure in .get_budget") remove BLK_STS_RESOURCE return value and we only check if we can get the budget from .get_budget() now. Correct stale comment that ".get_budget() returns BLK_STS_NO_RESOURCE" to ".get_budget() fails to get the budget". Fixes: 88022d7201e9 ("blk-mq: don't handle failure in .get_budget") Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11blk-mq: wait on correct sbitmap_queue in blk_mq_mark_tag_waitKemeng Shi
[ Upstream commit 98b99e9412d0cde8c7b442bf5efb09528a2ede8b ] For shared queues case, we will only wait on bitmap_tags if we fail to get driver tag. However, rq could be from breserved_tags, then two problems will occur: 1. io hung if no tag is currently allocated from bitmap_tags. 2. unnecessary wakeup when tag is freed to bitmap_tags while no tag is freed to breserved_tags. Wait on the bitmap which rq from to fix this. Fixes: f906a6a0f426 ("blk-mq: improve tag waiting setup for non-shared tags") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11blk-mq: remove stale comment for blk_mq_sched_mark_restart_hctxKemeng Shi
[ Upstream commit c31e76bcc379182fe67a82c618493b7b8868c672 ] Commit 97889f9ac24f8 ("blk-mq: remove synchronize_rcu() from blk_mq_del_queue_tag_set()") remove handle of TAG_SHARED in restart, then shared_hctx_restart counted for how many hardware queues are marked for restart is removed too. Remove the stale comment that we still count hardware queues need restart. Fixes: 97889f9ac24f ("blk-mq: remove synchronize_rcu() from blk_mq_del_queue_tag_set()") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11block: Limit number of items taken from the I/O scheduler in one goSalman Qazi
[ Upstream commit 28d65729b050977d8a9125e6726871e83bd22124 ] Flushes bypass the I/O scheduler and get added to hctx->dispatch in blk_mq_sched_bypass_insert. This can happen while a kworker is running hctx->run_work work item and is past the point in blk_mq_sched_dispatch_requests where hctx->dispatch is checked. The blk_mq_do_dispatch_sched call is not guaranteed to end in bounded time, because the I/O scheduler can feed an arbitrary number of commands. Since we have only one hctx->run_work, the commands waiting in hctx->dispatch will wait an arbitrary length of time for run_work to be rerun. A similar phenomenon exists with dispatches from the software queue. The solution is to poll hctx->dispatch in blk_mq_do_dispatch_sched and blk_mq_do_dispatch_ctx and return from the run_work handler and let it rerun. Signed-off-by: Salman Qazi <sqazi@google.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Stable-dep-of: c31e76bcc379 ("blk-mq: remove stale comment for blk_mq_sched_mark_restart_hctx") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-06blk-cgroup: fix missing pd_online_fn() while activating policyYu Kuai
[ Upstream commit e3ff8887e7db757360f97634e0d6f4b8e27a8c46 ] If the policy defines pd_online_fn(), it should be called after pd_init_fn(), like blkg_create(). Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230103112833.2013432-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-06block: fix and cleanup bio_check_roChristoph Hellwig
commit 57e95e4670d1126c103305bcf34a9442f49f6d6a upstream. Don't use a WARN_ON when printing a potentially user triggered condition. Also don't print the partno when the block device name already includes it, and use the %pg specifier to simplify printing the block device name. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220304180105.409765-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18blk-mq: fix possible memleak when register 'hctx' failedYe Bin
[ Upstream commit 4b7a21c57b14fbcd0e1729150189e5933f5088e9 ] There's issue as follows when do fault injection test: unreferenced object 0xffff888132a9f400 (size 512): comm "insmod", pid 308021, jiffies 4324277909 (age 509.733s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 08 f4 a9 32 81 88 ff ff ...........2.... 08 f4 a9 32 81 88 ff ff 00 00 00 00 00 00 00 00 ...2............ backtrace: [<00000000e8952bb4>] kmalloc_node_trace+0x22/0xa0 [<00000000f9980e0f>] blk_mq_alloc_and_init_hctx+0x3f1/0x7e0 [<000000002e719efa>] blk_mq_realloc_hw_ctxs+0x1e6/0x230 [<000000004f1fda40>] blk_mq_init_allocated_queue+0x27e/0x910 [<00000000287123ec>] __blk_mq_alloc_disk+0x67/0xf0 [<00000000a2a34657>] 0xffffffffa2ad310f [<00000000b173f718>] 0xffffffffa2af824a [<0000000095a1dabb>] do_one_initcall+0x87/0x2a0 [<00000000f32fdf93>] do_init_module+0xdf/0x320 [<00000000cbe8541e>] load_module+0x3006/0x3390 [<0000000069ed1bdb>] __do_sys_finit_module+0x113/0x1b0 [<00000000a1a29ae8>] do_syscall_64+0x35/0x80 [<000000009cd878b0>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fault injection context as follows: kobject_add blk_mq_register_hctx blk_mq_sysfs_register blk_register_queue device_add_disk null_add_dev.part.0 [null_blk] As 'blk_mq_register_hctx' may already add some objects when failed halfway, but there isn't do fallback, caller don't know which objects add failed. To solve above issue just do fallback when add objects failed halfway in 'blk_mq_register_hctx'. Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20221117022940.873959-1-yebin@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-19block: unhash blkdev part inode when the part is deletedMing Lei
v5.11 changes the blkdev lookup mechanism completely since commit 22ae8ce8b892 ("block: simplify bdev/disk lookup in blkdev_get"), and small part of the change is to unhash part bdev inode when deleting partition. Turns out this kind of change does fix one nasty issue in case of BLOCK_EXT_MAJOR: 1) when one partition is deleted & closed, disk_put_part() is always called before bdput(bdev), see blkdev_put(); so the part's devt can be freed & re-used before the inode is dropped 2) then new partition with same devt can be created just before the inode in 1) is dropped, then the old inode/bdev structurein 1) is re-used for this new partition, this way causes use-after-free and kernel panic. It isn't possible to backport the whole big patchset of "merge struct block_device and struct hd_struct v4" for addressing this issue. https://lore.kernel.org/linux-block/20201128161510.347752-1-hch@lst.de/ So fixes it by unhashing part bdev in delete_partition(), and this way is actually aligned with v5.11+'s behavior. Backported from the following 5.10.y commit: 5f2f77560591 ("block: unhash blkdev part inode when the part is deleted") Reported-by: Shiwei Cui <cuishw@inspur.com> Tested-by: Shiwei Cui <cuishw@inspur.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08block, bfq: fix null pointer dereference in bfq_bio_bfqg()Yu Kuai
[ Upstream commit f02be9002c480cd3ec0fcf184ad27cf531bd6ece ] Out test found a following problem in kernel 5.10, and the same problem should exist in mainline: BUG: kernel NULL pointer dereference, address: 0000000000000094 PGD 0 P4D 0 Oops: 0000 [#1] SMP CPU: 7 PID: 155 Comm: kworker/7:1 Not tainted 5.10.0-01932-g19e0ace2ca1d-dirty 4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-b4 Workqueue: kthrotld blk_throtl_dispatch_work_fn RIP: 0010:bfq_bio_bfqg+0x52/0xc0 Code: 94 00 00 00 00 75 2e 48 8b 40 30 48 83 05 35 06 c8 0b 01 48 85 c0 74 3d 4b RSP: 0018:ffffc90001a1fba0 EFLAGS: 00010002 RAX: ffff888100d60400 RBX: ffff8881132e7000 RCX: 0000000000000000 RDX: 0000000000000017 RSI: ffff888103580a18 RDI: ffff888103580a18 RBP: ffff8881132e7000 R08: 0000000000000000 R09: ffffc90001a1fe10 R10: 0000000000000a20 R11: 0000000000034320 R12: 0000000000000000 R13: ffff888103580a18 R14: ffff888114447000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88881fdc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000094 CR3: 0000000100cdb000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bfq_bic_update_cgroup+0x3c/0x350 ? ioc_create_icq+0x42/0x270 bfq_init_rq+0xfd/0x1060 bfq_insert_requests+0x20f/0x1cc0 ? ioc_create_icq+0x122/0x270 blk_mq_sched_insert_requests+0x86/0x1d0 blk_mq_flush_plug_list+0x193/0x2a0 blk_flush_plug_list+0x127/0x170 blk_finish_plug+0x31/0x50 blk_throtl_dispatch_work_fn+0x151/0x190 process_one_work+0x27c/0x5f0 worker_thread+0x28b/0x6b0 ? rescuer_thread+0x590/0x590 kthread+0x153/0x1b0 ? kthread_flush_work+0x170/0x170 ret_from_fork+0x1f/0x30 Modules linked in: CR2: 0000000000000094 ---[ end trace e2e59ac014314547 ]--- RIP: 0010:bfq_bio_bfqg+0x52/0xc0 Code: 94 00 00 00 00 75 2e 48 8b 40 30 48 83 05 35 06 c8 0b 01 48 85 c0 74 3d 4b RSP: 0018:ffffc90001a1fba0 EFLAGS: 00010002 RAX: ffff888100d60400 RBX: ffff8881132e7000 RCX: 0000000000000000 RDX: 0000000000000017 RSI: ffff888103580a18 RDI: ffff888103580a18 RBP: ffff8881132e7000 R08: 0000000000000000 R09: ffffc90001a1fe10 R10: 0000000000000a20 R11: 0000000000034320 R12: 0000000000000000 R13: ffff888103580a18 R14: ffff888114447000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88881fdc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000094 CR3: 0000000100cdb000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Root cause is quite complex: 1) use bfq elevator for the test device. 2) create a cgroup CG 3) config blk throtl in CG blkg_conf_prep blkg_create 4) create a thread T1 and issue async io in CG: bio_init bio_associate_blkg ... submit_bio submit_bio_noacct blk_throtl_bio -> io is throttled // io submit is done 5) switch elevator: bfq_exit_queue blkcg_deactivate_policy list_for_each_entry(blkg, &q->blkg_list, q_node) blkg->pd[] = NULL // bfq policy is removed 5) thread t1 exist, then remove the cgroup CG: blkcg_unpin_online blkcg_destroy_blkgs blkg_destroy list_del_init(&blkg->q_node) // blkg is removed from queue list 6) switch elevator back to bfq bfq_init_queue bfq_create_group_hierarchy blkcg_activate_policy list_for_each_entry_reverse(blkg, &q->blkg_list) // blkg is removed from list, hence bfq policy is still NULL 7) throttled io is dispatched to bfq: bfq_insert_requests bfq_init_rq bfq_bic_update_cgroup bfq_bio_bfqg bfqg = blkg_to_bfqg(blkg) // bfqg is NULL because bfq policy is NULL The problem is only possible in bfq because only bfq can be deactivated and activated while queue is online, while others can only be deactivated while the device is removed. Fix the problem in bfq by checking if blkg is online before calling blkg_to_bfqg(). Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20221108103434.2853269-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-25block: sed-opal: kmalloc the cmd/resp buffersSerge Semin
[ Upstream commit f829230dd51974c1f4478900ed30bb77ba530b40 ] In accordance with [1] the DMA-able memory buffers must be cacheline-aligned otherwise the cache writing-back and invalidation performed during the mapping may cause the adjacent data being lost. It's specifically required for the DMA-noncoherent platforms [2]. Seeing the opal_dev.{cmd,resp} buffers are implicitly used for DMAs in the NVME and SCSI/SD drivers in framework of the nvme_sec_submit() and sd_sec_submit() methods respectively they must be cacheline-aligned to prevent the denoted problem. One of the option to guarantee that is to kmalloc the buffers [2]. Let's explicitly allocate them then instead of embedding into the opal_dev structure instance. Note this fix was inspired by the commit c94b7f9bab22 ("nvme-hwmon: kmalloc the NVME SMART log buffer"). [1] Documentation/core-api/dma-api.rst [2] Documentation/core-api/dma-api-howto.rst Fixes: 455a7b238cd6 ("block: Add Sed-opal library") Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221107203944.31686-1-Sergey.Semin@baikalelectronics.ru Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-10block, bfq: protect 'bfqd->queued' by 'bfqd->lock'Yu Kuai
commit 181490d5321806e537dc5386db5ea640b826bf78 upstream. If bfq_schedule_dispatch() is called from bfq_idle_slice_timer_body(), then 'bfqd->queued' is read without holding 'bfqd->lock'. This is wrong since it can be wrote concurrently. Fix the problem by holding 'bfqd->lock' in such case. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220513023507.2625717-2-yukuai3@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Cc: Khazhy Kumykov <khazhy@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25blk-mq: don't create hctx debugfs dir until q->debugfs_dir is createdMing Lei
[ 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 <yi.zhang@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Yi Zhang <yi.zhang@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220711090808.259682-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14block: fix bio_clone_blkg_association() to associate with proper blkcg_gqJan Kara
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 <logang@deltatee.com> Reported-and-tested-by: Donald Buczek <buczek@molgen.mpg.de> Fixes: d92c370a16cb ("block: really clone the block cgroup in bio_clone_blkg_association") CC: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220602081242.7731-1-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14bfq: Make sure bfqg for which we are queueing requests is onlineJan Kara
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)" <yukuai3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220401102752.8599-9-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14bfq: Get rid of __bio_blkcg() usageJan Kara
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)" <yukuai3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220401102752.8599-8-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14bfq: Remove pointless bfq_init_rq() callsJan Kara
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)" <yukuai3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220401102752.8599-6-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14bfq: Drop pointless unlock-lock pairJan Kara
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)" <yukuai3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220401102752.8599-5-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14bfq: Avoid merging queues with different parentsJan Kara
commit c1cee4ab36acef271be9101590756ed0c0c374d9 upstream. It can happen that the parent of a bfqq changes between the moment we decide two queues are worth to merge (and set bic->stable_merge_bfqq) and the moment bfq_setup_merge() is called. This can happen e.g. because the process submitted IO for a different cgroup and thus bfqq got reparented. It can even happen that the bfqq we are merging with has parent cgroup that is already offline and going to be destroyed in which case the merge can lead to use-after-free issues such as: BUG: KASAN: use-after-free in __bfq_deactivate_entity+0x9cb/0xa50 Read of size 8 at addr ffff88800693c0c0 by task runc:[2:INIT]/10544 CPU: 0 PID: 10544 Comm: runc:[2:INIT] Tainted: G E 5.15.2-0.g5fb85fd-default #1 openSUSE Tumbleweed (unreleased) f1f3b891c72369aebecd2e43e4641a6358867c70 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x46/0x5a print_address_description.constprop.0+0x1f/0x140 ? __bfq_deactivate_entity+0x9cb/0xa50 kasan_report.cold+0x7f/0x11b ? __bfq_deactivate_entity+0x9cb/0xa50 __bfq_deactivate_entity+0x9cb/0xa50 ? update_curr+0x32f/0x5d0 bfq_deactivate_entity+0xa0/0x1d0 bfq_del_bfqq_busy+0x28a/0x420 ? resched_curr+0x116/0x1d0 ? bfq_requeue_bfqq+0x70/0x70 ? check_preempt_wakeup+0x52b/0xbc0 __bfq_bfqq_expire+0x1a2/0x270 bfq_bfqq_expire+0xd16/0x2160 ? try_to_wake_up+0x4ee/0x1260 ? bfq_end_wr_async_queues+0xe0/0xe0 ? _raw_write_unlock_bh+0x60/0x60 ? _raw_spin_lock_irq+0x81/0xe0 bfq_idle_slice_timer+0x109/0x280 ? bfq_dispatch_request+0x4870/0x4870 __hrtimer_run_queues+0x37d/0x700 ? enqueue_hrtimer+0x1b0/0x1b0 ? kvm_clock_get_cycles+0xd/0x10 ? ktime_get_update_offsets_now+0x6f/0x280 hrtimer_interrupt+0x2c8/0x740 Fix the problem by checking that the parent of the two bfqqs we are merging in bfq_setup_merge() is the same. Link: https://lore.kernel.org/linux-block/20211125172809.GC19572@quack2.suse.cz/ CC: stable@vger.kernel.org Fixes: 430a67f9d616 ("block, bfq: merge bursts of newly-created queues") Tested-by: "yukuai (C)" <yukuai3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220401102752.8599-2-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14blk-iolatency: Fix inflight count imbalances and IO hangs on offlineTejun Heo
commit 8a177a36da6c54c98b8685d4f914cb3637d53c0d upstream. iolatency needs to track the number of inflight IOs per cgroup. As this tracking can be expensive, it is disabled when no cgroup has iolatency configured for the device. To ensure that the inflight counters stay balanced, iolatency_set_limit() freezes the request_queue while manipulating the enabled counter, which ensures that no IO is in flight and thus all counters are zero. Unfortunately, iolatency_set_limit() isn't the only place where the enabled counter is manipulated. iolatency_pd_offline() can also dec the counter and trigger disabling. As this disabling happens without freezing the q, this can easily happen while some IOs are in flight and thus leak the counts. This can be easily demonstrated by turning on iolatency on an one empty cgroup while IOs are in flight in other cgroups and then removing the cgroup. Note that iolatency shouldn't have been enabled elsewhere in the system to ensure that removing the cgroup disables iolatency for the whole device. The following keeps flipping on and off iolatency on sda: echo +io > /sys/fs/cgroup/cgroup.subtree_control while true; do mkdir -p /sys/fs/cgroup/test echo '8:0 target=100000' > /sys/fs/cgroup/test/io.latency sleep 1 rmdir /sys/fs/cgroup/test sleep 1 done and there's concurrent fio generating direct rand reads: fio --name test --filename=/dev/sda --direct=1 --rw=randread \ --runtime=600 --time_based --iodepth=256 --numjobs=4 --bs=4k while monitoring with the following drgn script: while True: for css in css_for_each_descendant_pre(prog['blkcg_root'].css.address_of_()): for pos in hlist_for_each(container_of(css, 'struct blkcg', 'css').blkg_list): blkg = container_of(pos, 'struct blkcg_gq', 'blkcg_node') pd = blkg.pd[prog['blkcg_policy_iolatency'].plid] if pd.value_() == 0: continue iolat = container_of(pd, 'struct iolatency_grp', 'pd') inflight = iolat.rq_wait.inflight.counter.value_() if inflight: print(f'inflight={inflight} {disk_name(blkg.q.disk).decode("utf-8")} ' f'{cgroup_path(css.cgroup).decode("utf-8")}') time.sleep(1) The monitoring output looks like the following: inflight=1 sda /user.slice inflight=1 sda /user.slice ... inflight=14 sda /user.slice inflight=13 sda /user.slice inflight=17 sda /user.slice inflight=15 sda /user.slice inflight=18 sda /user.slice inflight=17 sda /user.slice inflight=20 sda /user.slice inflight=19 sda /user.slice <- fio stopped, inflight stuck at 19 inflight=19 sda /user.slice inflight=19 sda /user.slice If a cgroup with stuck inflight ends up getting throttled, the throttled IOs will never get issued as there's no completion event to wake it up leading to an indefinite hang. This patch fixes the bug by unifying enable handling into a work item which is automatically kicked off from iolatency_set_min_lat_nsec() which is called from both iolatency_set_limit() and iolatency_pd_offline() paths. Punting to a work item is necessary as iolatency_pd_offline() is called under spinlocks while freezing a request_queue requires a sleepable context. This also simplifies the code reducing LOC sans the comments and avoids the unnecessary freezes which were happening whenever a cgroup's latency target is newly set or cleared. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Liu Bo <bo.liu@linux.alibaba.com> Fixes: 8c772a9bfc7c ("blk-iolatency: fix IO hang due to negative inflight counter") Cc: stable@vger.kernel.org # v5.0+ Link: https://lore.kernel.org/r/Yn9ScX6Nx2qIiQQi@slm.duckdns.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14bfq: Track whether bfq_group is still onlineJan Kara
commit 09f871868080c33992cd6a9b72a5ca49582578fa upstream. Track whether bfq_group is still online. We cannot rely on blkcg_gq->online because that gets cleared only after all policies are offlined and we need something that gets updated already under bfqd->lock when we are cleaning up our bfq_group to be able to guarantee that when we see online bfq_group, it will stay online while we are holding bfqd->lock lock. CC: stable@vger.kernel.org Tested-by: "yukuai (C)" <yukuai3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220401102752.8599-7-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14bfq: Update cgroup information before merging bioJan Kara
commit ea591cd4eb270393810e7be01feb8fde6a34fbbe upstream. When the process is migrated to a different cgroup (or in case of writeback just starts submitting bios associated with a different cgroup) bfq_merge_bio() can operate with stale cgroup information in bic. Thus the bio can be merged to a request from a different cgroup or it can result in merging of bfqqs for different cgroups or bfqqs of already dead cgroups and causing possible use-after-free issues. Fix the problem by updating cgroup information in bfq_merge_bio(). CC: stable@vger.kernel.org Fixes: e21b7a0b9887 ("block, bfq: add full hierarchical scheduling and cgroups support") Tested-by: "yukuai (C)" <yukuai3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220401102752.8599-4-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14bfq: Split shared queues on move between cgroupsJan Kara
commit 3bc5e683c67d94bd839a1da2e796c15847b51b69 upstream. When bfqq is shared by multiple processes it can happen that one of the processes gets moved to a different cgroup (or just starts submitting IO for different cgroup). In case that happens we need to split the merged bfqq as otherwise we will have IO for multiple cgroups in one bfqq and we will just account IO time to wrong entities etc. Similarly if the bfqq is scheduled to merge with another bfqq but the merge didn't happen yet, cancel the merge as it need not be valid anymore. CC: stable@vger.kernel.org Fixes: e21b7a0b9887 ("block, bfq: add full hierarchical scheduling and cgroups support") Tested-by: "yukuai (C)" <yukuai3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220401102752.8599-3-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>