- 28 Sep, 2022 1 commit
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Christoph Hellwig authored
As far as I can tell there is no need for the staged setup in dasd, so allocate the tagset and the disk with the queue in dasd_gendisk_alloc. Signed-off-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
Stefan Haberland <sth@linux.ibm.com> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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- 27 Sep, 2022 20 commits
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Christoph Hellwig authored
blkg_conf_prep just creates a new blkg structure, there is no real need to update the lookup hint which should only be done on a successful lookup in the I/O path. Suggested-by:
Tejun Heo <tj@kernel.org> Signed-off-by:
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Keith Busch authored
The hctx's run_work may be racing with the elevator switch when reinitializing hardware queues. The queue is merely frozen in this context, but that only prevents requests from allocating and doesn't stop the hctx work from running. The work may get an elevator pointer that's being torn down, and can result in use-after-free errors and kernel panics (example below). Use the quiesced elevator switch instead, and make the previous one static since it is now only used locally. nvme nvme0: resetting controller nvme nvme0: 32/0/0 default/read/poll queues BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 80000020c8861067 P4D 80000020c8861067 PUD 250f8c8067 PMD 0 Oops: 0000 [#1] SMP PTI Workqueue: kblockd blk_mq_run_work_fn RIP: 0010:kyber_has_work+0x29/0x70 ... Call Trace: __blk_mq_do_dispatch_sched+0x83/0x2b0 __blk_mq_sched_dispatch_requests+0x12e/0x170 blk_mq_sched_dispatch_requests+0x30/0x60 __blk_mq_run_hw_queue+0x2b/0x50 process_one_work+0x1ef/0x380 worker_thread+0x2d/0x3e0 Signed-off-by:
Keith Busch <kbusch@kernel.org> Reviewed-by:
Ming Lei <ming.lei@redhat.com> Reviewed-by:
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Christoph Hellwig authored
Replace blk_queue_nowait with a bdev_nowait helpers that takes the block_device given that the I/O submission path should not have to look into the request_queue. Signed-off-by:
Pankaj Raghav <p.raghav@samsung.com> Link: https://lore.kernel.org/r/20220927075815.269694-1-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Prepare for storing the blkcg information in the gendisk instead of the request_queue. Signed-off-by:
Andreas Herrmann <aherrmann@suse.de> Acked-by:
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Christoph Hellwig authored
Pass the gendisk to blkcg_schedule_throttle as part of moving the blk-cgroup infrastructure to be gendisk based. Remove the unused !BLK_CGROUP stub while we're at it. Signed-off-by:
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Christoph Hellwig authored
Pass the gendisk to blkg_destroy_all as part of moving the blk-cgroup infrastructure to be gendisk based. Signed-off-by:
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Christoph Hellwig authored
Pass the gendisk to blk_throtl_cancel_bios as part of moving the blk-cgroup infrastructure to be gendisk based. Signed-off-by:
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Christoph Hellwig authored
Pass the gendisk to blk_throtl_register_queue as part of moving the blk-cgroup infrastructure to be gendisk based. Signed-off-by:
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Christoph Hellwig authored
Pass the gendisk to blk_throtl_init and blk_throtl_exit as part of moving the blk-cgroup infrastructure to be gendisk based. Signed-off-by:
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Christoph Hellwig authored
Use a local disk variable instead of retrieving the disk and request_queue over and over by various means. Signed-off-by:
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Christoph Hellwig authored
Pass the gendisk to blk_iocost_init as part of moving the blk-cgroup infrastructure to be gendisk based. Signed-off-by:
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Christoph Hellwig authored
Just directly dereference the disk name instead of going through multiple hoops to find the same value. Signed-off-by:
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Christoph Hellwig authored
Pass the gendisk to blk_iolatency_init as part of moving the blk-cgroup infrastructure to be gendisk based. Signed-off-by:
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Christoph Hellwig authored
Pass the gendisk to blk_ioprio_init and blk_ioprio_exit as part of moving the blk-cgroup infrastructure to be gendisk based. Signed-off-by:
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Christoph Hellwig authored
Pass the gendisk to blkcg_init_disk and blkcg_exit_disk as part of moving the blk-cgroup infrastructure to be gendisk based. Also remove the rather pointless kerneldoc comments for these internal functions with a single caller each. Signed-off-by:
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Christoph Hellwig authored
The combinations of an error check with an ERR_PTR return and a lookup with a NULL return leads to ugly handling of the return values in the callers. Just open coding the check and the lookup is much simpler. Signed-off-by:
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Christoph Hellwig authored
Add a fully inlined blkg_lookup as the extra two checks aren't going to generated a lot more code vs the call to the slowpath routine, and open code the hint update in the two callers that care. Signed-off-by:
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Christoph Hellwig authored
Use blkg_lookup instead of open coding it. Signed-off-by:
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Christoph Hellwig authored
Just open code it in the only caller and drop the unused !BLK_CGROUP stub. Signed-off-by:
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Christoph Hellwig authored
When blk_throtl_init fails, we need to call blk_ioprio_exit. Switch to proper goto based unwinding to fix this. Signed-off-by:
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- 24 Sep, 2022 9 commits
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Liu Song authored
High-performance NVMe devices usually support a large hw queues, which ensures a 1:1 mapping of hctx and ctx. In this case there will be no remote request, so we don't need to care about it. Signed-off-by:
Liu Song <liusong@linux.alibaba.com> Link: https://lore.kernel.org/r/1663731123-81536-1-git-send-email-liusong@linux.alibaba.comSigned-off-by:
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Yu Kuai authored
"tg->has_rules" is extended to "tg->has_rules_iops/bps", thus bios that don't need to be throttled can be checked accurately. With this patch, bio will be throttled if: 1) Bio is read/write, and corresponding read/write iops limit exist. 2) If corresponding doesn't exist, corresponding bps limit exist and bio is not throttled before. Signed-off-by:
Yu Kuai <yukuai3@huawei.com> Acked-by:
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Yu Kuai authored
Currently, "tg->has_rules" and "tg->flags & THROTL_TG_HAS_IOPS_LIMIT" both try to bypass bios that don't need to be throttled, however, they are a little redundant and both not perfect: 1) "tg->has_rules" only distinguish read and write, but not iops and bps limit. 2) "tg->flags & THROTL_TG_HAS_IOPS_LIMIT" only check if iops limit exist, read and write is not distinguished, and bps limit is not checked. tg->has_rules will extended to distinguish bps and iops in the following patch. There is no need to keep the flag. Signed-off-by:
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ZiyangZhang authored
START_USER_RECOVERY and END_USER_RECOVERY are two new control commands to support user recovery feature. After a crash, user should send START_USER_RECOVERY, it will: (1) check if (a)current ublk_device is UBLK_S_DEV_QUIESCED which was set by quiesce_work and (b)chardev is released (2) reinit all ubqs, including: (a) put the task_struct and reset ->ubq_daemon to NULL. (b) reset all ublk_io. (3) reset ub->mm to NULL. Then, user should start a new process and send FETCH_REQ on each ubq_daemon. Finally, user should send END_USER_RECOVERY, it will: (1) wait for all new ubq_daemons getting ready. (2) update ublksrv_pid (3) unquiesce the request queue and expect incoming ublk_queue_rq() (4) convert ub's state to UBLK_S_DEV_LIVE Note: we can handle STOP_DEV between START_USER_RECOVERY and END_USER_RECOVERY. This is helpful to users who cannot start new process after sending START_USER_RECOVERY ctrl-cmd. Signed-off-by:ZiyangZhang <ZiyangZhang@linux.alibaba.com> Reviewed-by:
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ZiyangZhang authored
UBLK_F_USER_RECOVERY_REISSUE implies that: With a dying ubq_daemon, ublk_drv let monitor_work requeues rq issued to userspace(ublksrv) before the ubq_daemon is dying. UBLK_F_USER_RECOVERY_REISSUE is designed for backends which: (1) tolerate double-write since ublk_drv may issue the same rq twice. (2) does not let frontend users get I/O error, such as read-only FS and VM backend. Signed-off-by: -
ZiyangZhang authored
With USER_RECOVERY feature enabled, the monitor_work schedules quiesce_work after finding a dying ubq_daemon. The monitor_work should also abort all rqs issued to userspace before the ubq_daemon is dying. The quiesce_work's job is to: (1) quiesce request queue. (2) check if there is any INFLIGHT rq. If so, we retry until all these rqs are requeued and become IDLE. These rqs should be requeued by ublk_queue_rq(), task work, io_uring fallback wq or monitor_work. (3) complete all ioucmds by calling io_uring_cmd_done(). We are safe to do so because no ioucmd can be referenced now. (5) set ub's state to UBLK_S_DEV_QUIESCED, which means we are ready for recovery. This state is exposed to userspace by GET_DEV_INFO. The driver can always handle STOP_DEV and cleanup everything no matter ub's state is LIVE or QUIESCED. After ub's state is UBLK_S_DEV_QUIESCED, user can recover with new process. Note: we do not change the default behavior with reocvery feature disabled. monitor_work still schedules stop_work and abort inflight rqs. And finally ublk_device is released. Signed-off-by: -
ZiyangZhang authored
With recovery feature enabled, in ublk_queue_rq or task work (in exit_task_work or fallback wq), we requeue rqs instead of ending(aborting) them. Besides, No matter recovery feature is enabled or disabled, we schedule monitor_work immediately. Signed-off-by:
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ZiyangZhang authored
Define some macros for recovery feature. UBLK_S_DEV_QUIESCED implies that ublk_device is quiesced and is ready for recovery. This state can be observed by userspace. UBLK_F_USER_RECOVERY implies that: (1) ublk_drv enables recovery feature. It won't let monitor_work to automatically abort rqs and release the device. (2) With a dying ubq_daemon, ublk_drv ends(aborts) rqs issued to userspace(ublksrv) before crash. (3) With a dying ubq_daemon, in task work and ublk_queue_rq(), ublk_drv requeues rqs. Signed-off-by: -
ZiyangZhang authored
This check is not atomic. So with recovery feature, ubq_daemon may be modified simultaneously by recovery task. Instead, check 'current' is safe here because 'current' never changes. Also add comment explaining this check, which is really important for understanding recovery feature. Signed-off-by:
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- 23 Sep, 2022 1 commit
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Jens Axboe authored
Merge branch 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-6.1/block Pull MD updates and fixes from Song: "1. Various raid5 fix and clean up, by Logan Gunthorpe and David Sloan. 2. Raid10 performance optimization, by Yu Kuai." * 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md: md: Fix spelling mistake in comments of r5l_log md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d md/raid10: convert resync_lock to use seqlock md/raid10: fix improper BUG_ON() in raise_barrier() md/raid10: prevent unnecessary calls to wake_up() in fast path md/raid10: don't modify 'nr_waitng' in wait_barrier() for the case nowait md/raid10: factor out code from wait_barrier() to stop_waiting_barrier() md: Remove extra mddev_get() in md_seq_start() md/raid5: Remove unnecessary bio_put() in raid5_read_one_chunk() md/raid5: Ensure stripe_fill happens on non-read IO with journal md/raid5: Don't read ->active_stripes if it's not needed md/raid5: Cleanup prototype of raid5_get_active_stripe() md/raid5: Drop extern on function declarations in raid5.h md/raid5: Refactor raid5_get_active_stripe() md: Replace snprintf with scnprintf md/raid10: fix compile warning md/raid5: Fix spelling mistakes in comments
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- 22 Sep, 2022 9 commits
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Zhou nan authored
Fix spelling of dones't in comments. Signed-off-by:
Zhou nan <zhounan@nfschina.com> Signed-off-by:
Song Liu <song@kernel.org>
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Logan Gunthorpe authored
A complicated deadlock exists when using the journal and an elevated group_thrtead_cnt. It was found with loop devices, but its not clear whether it can be seen with real disks. The deadlock can occur simply by writing data with an fio script. When the deadlock occurs, multiple threads will hang in different ways: 1) The group threads will hang in the blk-wbt code with bios waiting to be submitted to the block layer: io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 __submit_bio+0xe6/0x100 submit_bio_noacct_nocheck+0x42e/0x470 submit_bio_noacct+0x4c2/0xbb0 ops_run_io+0x46b/0x1a30 handle_stripe+0xcd3/0x36b0 handle_active_stripes.constprop.0+0x6f6/0xa60 raid5_do_work+0x177/0x330 Or: io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 __submit_bio+0xe6/0x100 submit_bio_noacct_nocheck+0x42e/0x470 submit_bio_noacct+0x4c2/0xbb0 flush_deferred_bios+0x136/0x170 raid5_do_work+0x262/0x330 2) The r5l_reclaim thread will hang in the same way, submitting a bio to the block layer: io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 __submit_bio+0xe6/0x100 submit_bio_noacct_nocheck+0x42e/0x470 submit_bio_noacct+0x4c2/0xbb0 submit_bio+0x3f/0xf0 md_super_write+0x12f/0x1b0 md_update_sb.part.0+0x7c6/0xff0 md_update_sb+0x30/0x60 r5l_do_reclaim+0x4f9/0x5e0 r5l_reclaim_thread+0x69/0x30b However, before hanging, the MD_SB_CHANGE_PENDING flag will be set for sb_flags in r5l_write_super_and_discard_space(). This flag will never be cleared because the submit_bio() call never returns. 3) Due to the MD_SB_CHANGE_PENDING flag being set, handle_stripe() will do no processing on any pending stripes and re-set STRIPE_HANDLE. This will cause the raid5d thread to enter an infinite loop, constantly trying to handle the same stripes stuck in the queue. The raid5d thread has a blk_plug that holds a number of bios that are also stuck waiting seeing the thread is in a loop that never schedules. These bios have been accounted for by blk-wbt thus preventing the other threads above from continuing when they try to submit bios. --Deadlock. To fix this, add the same wait_event() that is used in raid5_do_work() to raid5d() such that if MD_SB_CHANGE_PENDING is set, the thread will schedule and wait until the flag is cleared. The schedule action will flush the plug which will allow the r5l_reclaim thread to continue, thus preventing the deadlock. However, md_check_recovery() calls can also clear MD_SB_CHANGE_PENDING from the same thread and can thus deadlock if the thread is put to sleep. So avoid waiting if md_check_recovery() is being called in the loop. It's not clear when the deadlock was introduced, but the similar wait_event() call in raid5_do_work() was added in 2017 by this commit: 16d997b7 ("md/raid5: simplfy delaying of writes while metadata is updated.") Link: https://lore.kernel.org/r/7f3b87b6-b52a-f737-51d7-a4eec5c44112@deltatee.comSigned-off-by:Logan Gunthorpe <logang@deltatee.com> Signed-off-by:
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Song Liu authored
This patchset tries to avoid that two locks are held unconditionally in hot path. Test environment: Architecture: aarch64 Huawei KUNPENG 920 x86 Intel(R) Xeon(R) Platinum 8380 Raid10 initialize: mdadm --create /dev/md0 --level 10 --bitmap none --raid-devices 4 \ /dev/nvme0n1 /dev/nvme1n1 /dev/nvme2n1 /dev/nvme3n1 Test cmd: (task set -c 0-15) fio -name=0 -ioengine=libaio -direct=1 -\ group_reporting=1 -randseed=2022 -rwmixread=70 -refill_buffers \ -filename=/dev/md0 -numjobs=16 -runtime=60s -bs=4k -iodepth=256 \ -rw=randread Test result: aarch64: before this patchset: 3.2 GiB/s bind node before this patchset: 6.9 Gib/s after this patchset: 7.9 Gib/s bind node after this patchset: 8.0 Gib/s x86:(bind node is not tested yet) before this patchset: 7.0 GiB/s after this patchset : 9.3 GiB/s Please noted that in the test machine, memory access latency is very bad across nodes compare to local node in aarch64, which is why bandwidth while bind node is much better. -
Yu Kuai authored
Currently, wait_barrier() will hold 'resync_lock' to read 'conf->barrier', and io can't be dispatched until 'barrier' is dropped. Since holding the 'barrier' is not common, convert 'resync_lock' to use seqlock so that holding lock can be avoided in fast path. Signed-off-by:
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Yu Kuai authored
'conf->barrier' is protected by 'conf->resync_lock', reading 'conf->barrier' without holding the lock is wrong. Signed-off-by:
Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by:
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Yu Kuai authored
Currently, wake_up() is called unconditionally in fast path such as raid10_make_request(), which will cause lock contention under high concurrency: raid10_make_request wake_up __wake_up_common_lock spin_lock_irqsave Improve performance by only call wake_up() if waitqueue is not empty in allow_barrier() and raid10_make_request(). Signed-off-by:
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Yu Kuai authored
For the case nowait in wait_barrier(), there is no point to increase nr_waiting and then decrease it. Signed-off-by:
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Yu Kuai authored
Currently the nasty condition in wait_barrier() is hard to read. This patch factors out the condition into a function. There are no functional changes. Signed-off-by:
Paul Menzel <pmenzel@molgen.mpg.de> Reviewed-by:
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Logan Gunthorpe authored
A regression is seen where mddev devices stay permanently after they are stopped due to an elevated reference count. This was tracked down to an extra mddev_get() in md_seq_start(). It only happened rarely because most of the time the md_seq_start() is called with a zero offset. The path with an extra mddev_get() only happens when it starts with a non-zero offset. The commit noted below changed an mddev_get() to check its success but inadvertently left the original call in. Remove the extra call. Fixes: 12a6caf2 ("md: only delete entries from all_mddevs when the disk is freed") Signed-off-by:
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