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2020-03-20block: add bio_truncate to fix guard_bio_eodMing Lei
commit 85a8ce62c2eabe28b9d76ca4eecf37922402df93 upstream. 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: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-02-05Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
2020-01-31blk-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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-01-31blk-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: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-01-20Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
2020-01-19block: 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: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-01-19block: check bi_size overflow before mergeJunichi Nomura
commit e3a5d8e386c3fb973fa75f2403622a8f3640ec06 upstream. __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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2020-01-15Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
2020-01-09block, bfq: deschedule empty bfq_queues not referred by any processPaolo Valente
commit 478de3380c1c7dbb0f65f545ee0185848413f3fe upstream. 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-12-29Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
2019-12-29blkcg: make blkcg_print_stat() print stats only for online blkgsTejun Heo
commit b0814361a25cba73a224548843ed92d8ea78715a upstream. 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-25Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
2019-11-25blk-rq-qos: fix first node deletion of rq_qos_del()Tejun Heo
commit 307f4065b9d7c1e887e8bdfb2487e4638559fea1 upstream. 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-10Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
2019-11-09blk-wbt: fix performance regression in wbt scale_up/scale_downHarshad Shirwadkar
commit b84477d3ebb96294f87dc3161e53fa8fe22d9bfd upstream. 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-11-09blk-mq: move lockdep_assert_held() into elevator_exitMing Lei
commit 284b94be1925dbe035ce5218d8b5c197321262c7 upstream. Commit c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq") removes q->sysfs_lock from elevator_init_mq(), but forgot to deal with lockdep_assert_held() called in blk_mq_sched_free_requests() which is run in failure path of elevator_init_mq(). blk_mq_sched_free_requests() is called in the following 3 functions: elevator_init_mq() elevator_exit() blk_cleanup_queue() In blk_cleanup_queue(), blk_mq_sched_free_requests() is followed exactly by 'mutex_lock(&q->sysfs_lock)'. So moving the lockdep_assert_held() from blk_mq_sched_free_requests() into elevator_exit() for fixing the report by syzbot. Reported-by: syzbot+da3b7677bb913dc1b737@syzkaller.appspotmail.com Fixed: c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq") Reviewed-by: Bart Van Assche <bvanassche@acm.org> 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-10-10Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
2019-10-05block: fix null pointer dereference in blk_mq_rq_timed_out()Yufen Yu
commit 8d6996630c03d7ceeabe2611378fea5ca1c3f1b3 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> ------- 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>
2019-10-05block: mq-deadline: Fix queue restart handlingDamien Le Moal
commit cb8acabbe33b110157955a7425ee876fb81e6bbc upstream. Commit 7211aef86f79 ("block: mq-deadline: Fix write completion handling") added a call to blk_mq_sched_mark_restart_hctx() in dd_dispatch_request() to make sure that write request dispatching does not stall when all target zones are locked. This fix left a subtle race when a write completion happens during a dispatch execution on another CPU: CPU 0: Dispatch CPU1: write completion dd_dispatch_request() lock(&dd->lock); ... lock(&dd->zone_lock); dd_finish_request() rq = find request lock(&dd->zone_lock); unlock(&dd->zone_lock); zone write unlock unlock(&dd->zone_lock); ... __blk_mq_free_request check restart flag (not set) -> queue not run ... if (!rq && have writes) blk_mq_sched_mark_restart_hctx() unlock(&dd->lock) Since the dispatch context finishes after the write request completion handling, marking the queue as needing a restart is not seen from __blk_mq_free_request() and blk_mq_sched_restart() not executed leading to the dispatch stall under 100% write workloads. Fix this by moving the call to blk_mq_sched_mark_restart_hctx() from dd_dispatch_request() into dd_finish_request() under the zone lock to ensure full mutual exclusion between write request dispatch selection and zone unlock on write request completion. Fixes: 7211aef86f79 ("block: mq-deadline: Fix write completion handling") Cc: stable@vger.kernel.org Reported-by: Hans Holmberg <Hans.Holmberg@wdc.com> Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-05block: make rq sector size accessible for block statsHou Tao
[ Upstream commit 3d24430694077313c75c6b89f618db09943621e4 ] Currently rq->data_len will be decreased by partial completion or zeroed by completion, so when blk_stat_add() is invoked, data_len will be zero and there will never be samples in poll_cb because blk_mq_poll_stats_bkt() will return -1 if data_len is zero. We could move blk_stat_add() back to __blk_mq_complete_request(), but that would make the effort of trying to call ktime_get_ns() once in vain. Instead we can reuse throtl_size field, and use it for both block stats and block throttle, and adjust the logic in blk_mq_poll_stats_bkt() accordingly. Fixes: 4bc6339a583c ("block: move blk_stat_add() to __blk_mq_end_request()") Tested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05blk-mq: Fix memory leak in blk_mq_init_allocated_queue error handlingzhengbin
[ Upstream commit 73d9c8d4c0017e21e1ff519474ceb1450484dc9a ] If blk_mq_init_allocated_queue->elevator_init_mq fails, need to release the previously requested resources. Fixes: d34849913819 ("blk-mq-sched: allow setting of default IO scheduler") Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-09Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
2019-08-29block, bfq: handle NULL return value by bfq_init_rq()Paolo Valente
[ Upstream commit fd03177c33b287c6541f4048f1d67b7b45a1abc9 ] As reported in [1], the call bfq_init_rq(rq) may return NULL in case of OOM (in particular, if rq->elv.icq is NULL because memory allocation failed in failed in ioc_create_icq()). This commit handles this circumstance. [1] https://lkml.org/lkml/2019/7/22/824 Cc: Hsin-Yi Wang <hsinyi@google.com> Cc: Nicolas Boichat <drinkcat@chromium.org> Cc: Doug Anderson <dianders@chromium.org> Reported-by: Guenter Roeck <linux@roeck-us.net> Reported-by: Hsin-Yi Wang <hsinyi@google.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> 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>
2019-08-27Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
2019-08-25blk-mq: move cancel of requeue_work to the front of blk_exit_queuezhengbin
commit e26cc08265dda37d2acc8394604f220ef412299d upstream. blk_exit_queue will free elevator_data, while blk_mq_requeue_work will access it. Move cancel of requeue_work to the front of blk_exit_queue to avoid use-after-free. blk_exit_queue blk_mq_requeue_work __elevator_exit blk_mq_run_hw_queues blk_mq_exit_sched blk_mq_run_hw_queue dd_exit_queue blk_mq_hctx_has_pending kfree(elevator_data) blk_mq_sched_has_work dd_has_work Fixes: fbc2a15e3433 ("blk-mq: move cancel of requeue_work into blk_mq_release") Cc: stable@vger.kernel.org Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-19Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
2019-08-16rq-qos: use a mb for got_tokenJosef Bacik
[ Upstream commit ac38297f7038cd5b80d66f8809c7bbf5b70031f3 ] Oleg noticed that our checking of data.got_token is unsafe in the cleanup case, and should really use a memory barrier. Use a wmb on the write side, and a rmb() on the read side. We don't need one in the main loop since we're saved by set_current_state(). Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-16rq-qos: set ourself TASK_UNINTERRUPTIBLE after we scheduleJosef Bacik
[ Upstream commit d14a9b389a86a5154b704bc88ce8dd37c701456a ] In case we get a spurious wakeup we need to make sure to re-set ourselves to TASK_UNINTERRUPTIBLE so we don't busy wait. Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-16rq-qos: don't reset has_sleepers on spurious wakeupsJosef Bacik
[ Upstream commit 64e7ea875ef63b2801be7954cf7257d1bfccc266 ] If we raced with somebody else getting an inflight counter we could fail to get an inflight counter with no sleepers on the list, and thus need to go to sleep. In this case has_sleepers should be true because we are now relying on the waker to get our inflight counter for us. And in the case of spurious wakeups we'd still want this to be the case. So set has_sleepers to true if we went to sleep to make sure we're woken up the proper way. Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-12Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
2019-08-12Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
2019-07-31block/bio-integrity: fix a memory leak bugWenwen Wang
[ Upstream commit e7bf90e5afe3aa1d1282c1635a49e17a32c4ecec ] In bio_integrity_prep(), a kernel buffer is allocated through kmalloc() to hold integrity metadata. Later on, the buffer will be attached to the bio structure through bio_integrity_add_page(), which returns the number of bytes of integrity metadata attached. Due to unexpected situations, bio_integrity_add_page() may return 0. As a result, bio_integrity_prep() needs to be terminated with 'false' returned to indicate this error. However, the allocated kernel buffer is not freed on this execution path, leading to a memory leak. To fix this issue, free the allocated buffer before returning from bio_integrity_prep(). Reviewed-by: Ming Lei <ming.lei@redhat.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-31block: init flush rq ref count to 1Josef Bacik
[ Upstream commit b554db147feea39617b533ab6bca247c91c6198a ] We discovered a problem in newer kernels where a disconnect of a NBD device while the flush request was pending would result in a hang. This is because the blk mq timeout handler does if (!refcount_inc_not_zero(&rq->ref)) return true; to determine if it's ok to run the timeout handler for the request. Flush_rq's don't have a ref count set, so we'd skip running the timeout handler for this request and it would just sit there in limbo forever. Fix this by always setting the refcount of any request going through blk_init_rq() to 1. I tested this with a nbd-server that dropped flush requests to verify that it hung, and then tested with this patch to verify I got the timeout as expected and the error handling kicked in. Thanks, Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-28block: Limit zone array allocation sizeDamien Le Moal
commit 26202928fafad8bda8b478edb7e62c885be623d7 upstream. Limit the size of the struct blk_zone array used in blk_revalidate_disk_zones() to avoid memory allocation failures leading to disk revalidation failure. Also further reduce the likelyhood of such failures by using kvcalloc() (that is vmalloc()) instead of allocating contiguous pages with alloc_pages(). Fixes: 515ce6061312 ("scsi: sd_zbc: Fix sd_zbc_report_zones() buffer allocation") Fixes: e76239a3748c ("block: add a report_zones method") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-27Merge branch 'v5.2/standard/base' into v5.2/standard/preempt-rt/baseBruce Ashfield
2019-07-26blkcg: update blkcg_print_stat() to handle larger outputsTejun Heo
commit f539da82f2158916e154d206054e0efd5df7ab61 upstream. Depending on the number of devices, blkcg stats can go over the default seqfile buf size. seqfile normally retries with a larger buffer but since the ->pd_stat() addition, blkcg_print_stat() doesn't tell seqfile that overflow has happened and the output gets printed truncated. Fix it by calling seq_commit() w/ -1 on possible overflows. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 903d23f0a354 ("blk-cgroup: allow controllers to output their own stats") Cc: stable@vger.kernel.org # v4.19+ Cc: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26blk-iolatency: clear use_delay when io.latency is set to zeroTejun Heo
commit 5de0073fcd50cc1f150895a7bb04d3cf8067b1d7 upstream. If use_delay was non-zero when the latency target of a cgroup was set to zero, it will stay stuck until io.latency is enabled on the cgroup again. This keeps readahead disabled for the cgroup impacting performance negatively. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Josef Bacik <jbacik@fb.com> Fixes: d70675121546 ("block: introduce blk-iolatency io controller") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26blk-throttle: fix zero wait time for iops throttled groupKonstantin Khlebnikov
commit 3a10f999ffd464d01c5a05592a15470a3c4bbc36 upstream. After commit 991f61fe7e1d ("Blk-throttle: reduce tail io latency when iops limit is enforced") wait time could be zero even if group is throttled and cannot issue requests right now. As a result throtl_select_dispatch() turns into busy-loop under irq-safe queue spinlock. Fix is simple: always round up target time to the next throttle slice. Fixes: 991f61fe7e1d ("Blk-throttle: reduce tail io latency when iops limit is enforced") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26block: Fix potential overflow in blk_report_zones()Damien Le Moal
commit 113ab72ed4794c193509a97d7c6d32a6886e1682 upstream. For large values of the number of zones reported and/or large zone sizes, the sector increment calculated with blk_queue_zone_sectors(q) * n in blk_report_zones() loop can overflow the unsigned int type used for the calculation as both "n" and blk_queue_zone_sectors() value are unsigned int. E.g. for a device with 256 MB zones (524288 sectors), overflow happens with 8192 or more zones reported. Changing the return type of blk_queue_zone_sectors() to sector_t, fixes this problem and avoids overflow problem for all other callers of this helper too. The same change is also applied to the bdev_zone_sectors() helper. Fixes: e76239a3748c ("block: add a report_zones method") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26block: Allow mapping of vmalloc-ed buffersDamien Le Moal
commit b4c5875d36178e8df409bdce232f270cac89fafe upstream. To allow the SCSI subsystem scsi_execute_req() function to issue requests using large buffers that are better allocated with vmalloc() rather than kmalloc(), modify bio_map_kern() to allow passing a buffer allocated with vmalloc(). To do so, detect vmalloc-ed buffers using is_vmalloc_addr(). For vmalloc-ed buffers, flush the buffer using flush_kernel_vmap_range(), use vmalloc_to_page() instead of virt_to_page() to obtain the pages of the buffer, and invalidate the buffer addresses with invalidate_kernel_vmap_range() on completion of read BIOs. This last point is executed using the function bio_invalidate_vmalloc_pages() which is defined only if the architecture defines ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE, that is, if the architecture actually needs the invalidation done. Fixes: 515ce6061312 ("scsi: sd_zbc: Fix sd_zbc_report_zones() buffer allocation") Fixes: e76239a3748c ("block: add a report_zones method") Cc: stable@vger.kernel.org Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26blk-iolatency: fix STS_AGAIN handlingDennis Zhou
[ Upstream commit c9b3007feca018d3f7061f5d5a14cb00766ffe9b ] The iolatency controller is based on rq_qos. It increments on rq_qos_throttle() and decrements on either rq_qos_cleanup() or rq_qos_done_bio(). a3fb01ba5af0 fixes the double accounting issue where blk_mq_make_request() may call both rq_qos_cleanup() and rq_qos_done_bio() on REQ_NO_WAIT. So checking STS_AGAIN prevents the double decrement. The above works upstream as the only way we can get STS_AGAIN is from blk_mq_get_request() failing. The STS_AGAIN handling isn't a real problem as bio_endio() skipping only happens on reserved tag allocation failures which can only be caused by driver bugs and already triggers WARN. However, the fix creates a not so great dependency on how STS_AGAIN can be propagated. Internally, we (Facebook) carry a patch that kills read ahead if a cgroup is io congested or a fatal signal is pending. This combined with chained bios progagate their bi_status to the parent is not already set can can cause the parent bio to not clean up properly even though it was successful. This consequently leaks the inflight counter and can hang all IOs under that blkg. To nip the adverse interaction early, this removes the rq_qos_cleanup() callback in iolatency in favor of cleaning up always on the rq_qos_done_bio() path. Fixes: a3fb01ba5af0 ("blk-iolatency: only account submitted bios") Debugged-by: Tejun Heo <tj@kernel.org> Debugged-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Dennis Zhou <dennis@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-26block, bfq: fix rq_in_driver check in bfq_update_inject_limitPaolo Valente
[ Upstream commit db599f9ed9bd31b018b6c48ad7c6b21d5b790ecf ] One of the cases where the parameters for injection may be updated is when there are no more in-flight I/O requests. The number of in-flight requests is stored in the field bfqd->rq_in_driver of the descriptor bfqd of the device. So, the controlled condition is bfqd->rq_in_driver == 0. Unfortunately, this is wrong because, the instruction that checks this condition is in the code path that handles the completion of a request, and, in particular, the instruction is executed before bfqd->rq_in_driver is decremented in such a code path. This commit fixes this issue by just replacing 0 with 1 in the comparison. Reported-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu> Tested-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu> 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>
2019-07-26blk-iolatency: only account submitted biosDennis Zhou
[ Upstream commit a3fb01ba5af066521f3f3421839e501bb2c71805 ] As is, iolatency recognizes done_bio and cleanup as ending paths. If a request is marked REQ_NOWAIT and fails to get a request, the bio is cleaned up via rq_qos_cleanup() and ended in bio_wouldblock_error(). This results in underflowing the inflight counter. Fix this by only accounting bios that were actually submitted. Signed-off-by: Dennis Zhou <dennis@kernel.org> Cc: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-22block: Use cpu_chill() for retry loopsThomas Gleixner
Retry loops on RT might loop forever when the modifying side was preempted. Steven also observed a live lock when there was a concurrent priority boosting going on. Use cpu_chill() instead of cpu_relax() to let the system make progress. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2019-07-22block/mq: don't complete requests via IPISebastian Andrzej Siewior
The IPI runs in hardirq context and there are sleeping locks. Assume caches are shared and complete them on the local CPU. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2019-07-22block/mq: do not invoke preempt_disable()Sebastian Andrzej Siewior
preempt_disable() and get_cpu() don't play well together with the sleeping locks it tries to allocate later. It seems to be enough to replace it with get_cpu_light() and migrate_disable(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2019-07-22block: mq: use cpu_light()Sebastian Andrzej Siewior
there is a might sleep splat because get_cpu() disables preemption and later we grab a lock. As a workaround for this we use get_cpu_light(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2019-07-22softirq: Check preemption after reenabling interruptsThomas Gleixner
raise_softirq_irqoff() disables interrupts and wakes the softirq daemon, but after reenabling interrupts there is no preemption check, so the execution of the softirq thread might be delayed arbitrarily. In principle we could add that check to local_irq_enable/restore, but that's overkill as the rasie_softirq_irqoff() sections are the only ones which show this behaviour. Reported-by: Carsten Emde <cbe@osadl.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2019-07-22hrtimer: consolidate hrtimer_init() + hrtimer_init_sleeper() callsSebastian Andrzej Siewior
hrtimer_init_sleeper() calls require a prior initialisation of the hrtimer object with hrtimer_init(). Lets make the initialisation of the hrtimer object part of hrtimer_init_sleeper(). To remain consistent consider init_on_stack as well. Beside adapting the hrtimer_init_sleeper[_on_stack]() functions, call sites need to be updated as well. Link: http://lkml.kernel.org/r/20180703092541.2870-1-anna-maria@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> [anna-maria: Updating the commit message, add staging/android/vsoc.c] Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
2019-07-22block: blk-mq: move blk_queue_usage_counter_release() into process contextSebastian Andrzej Siewior
| BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:914 | in_atomic(): 1, irqs_disabled(): 0, pid: 255, name: kworker/u257:6 | 5 locks held by kworker/u257:6/255: | #0: ("events_unbound"){.+.+.+}, at: [<ffffffff8108edf1>] process_one_work+0x171/0x5e0 | #1: ((&entry->work)){+.+.+.}, at: [<ffffffff8108edf1>] process_one_work+0x171/0x5e0 | #2: (&shost->scan_mutex){+.+.+.}, at: [<ffffffffa000faa3>] __scsi_add_device+0xa3/0x130 [scsi_mod] | #3: (&set->tag_list_lock){+.+...}, at: [<ffffffff812f09fa>] blk_mq_init_queue+0x96a/0xa50 | #4: (rcu_read_lock_sched){......}, at: [<ffffffff8132887d>] percpu_ref_kill_and_confirm+0x1d/0x120 | Preemption disabled at:[<ffffffff812eff76>] blk_mq_freeze_queue_start+0x56/0x70 | | CPU: 2 PID: 255 Comm: kworker/u257:6 Not tainted 3.18.7-rt0+ #1 | Workqueue: events_unbound async_run_entry_fn | 0000000000000003 ffff8800bc29f998 ffffffff815b3a12 0000000000000000 | 0000000000000000 ffff8800bc29f9b8 ffffffff8109aa16 ffff8800bc29fa28 | ffff8800bc5d1bc8 ffff8800bc29f9e8 ffffffff815b8dd4 ffff880000000000 | Call Trace: | [<ffffffff815b3a12>] dump_stack+0x4f/0x7c | [<ffffffff8109aa16>] __might_sleep+0x116/0x190 | [<ffffffff815b8dd4>] rt_spin_lock+0x24/0x60 | [<ffffffff810b6089>] __wake_up+0x29/0x60 | [<ffffffff812ee06e>] blk_mq_usage_counter_release+0x1e/0x20 | [<ffffffff81328966>] percpu_ref_kill_and_confirm+0x106/0x120 | [<ffffffff812eff76>] blk_mq_freeze_queue_start+0x56/0x70 | [<ffffffff812f0000>] blk_mq_update_tag_set_depth+0x40/0xd0 | [<ffffffff812f0a1c>] blk_mq_init_queue+0x98c/0xa50 | [<ffffffffa000dcf0>] scsi_mq_alloc_queue+0x20/0x60 [scsi_mod] | [<ffffffffa000ea35>] scsi_alloc_sdev+0x2f5/0x370 [scsi_mod] | [<ffffffffa000f494>] scsi_probe_and_add_lun+0x9e4/0xdd0 [scsi_mod] | [<ffffffffa000fb26>] __scsi_add_device+0x126/0x130 [scsi_mod] | [<ffffffffa013033f>] ata_scsi_scan_host+0xaf/0x200 [libata] | [<ffffffffa012b5b6>] async_port_probe+0x46/0x60 [libata] | [<ffffffff810978fb>] async_run_entry_fn+0x3b/0xf0 | [<ffffffff8108ee81>] process_one_work+0x201/0x5e0 percpu_ref_kill_and_confirm() invokes blk_mq_usage_counter_release() in a rcu-sched region. swait based wake queue can't be used due to wake_up_all() usage and disabled interrupts in !RT configs (as reported by Corey Minyard). The wq_has_sleeper() check has been suggested by Peter Zijlstra. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>