- 27 Jul, 2023 31 commits
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Jack Wang authored
wake_up is called unconditionally in a few paths such as make_request(), which cause lock contention under high concurrency workload like below raid1_end_write_request wake_up __wake_up_common_lock spin_lock_irqsave Improve performance by only call wake_up() if waitqueue is not empty Fio test script: [global] name=random reads and writes ioengine=libaio direct=1 readwrite=randrw rwmixread=70 iodepth=64 buffered=0 filename=/dev/md0 size=1G runtime=30 time_based randrepeat=0 norandommap refill_buffers ramp_time=10 bs=4k numjobs=400 group_reporting=1 [job1] Test result with 2 ramdisk in raid1 on a Intel Broadwell 56 cores server. Before this patch With this patch READ BW=4621MB/s BW=7337MB/s WRITE BW=1980MB/s BW=3144MB/s The patch is inspired by Yu Kuai's change for raid10: https://lore.kernel.org/r/20230621105728.1268542-1-yukuai1@huaweicloud.com Cc: Yu Kuai <yukuai3@huawei.com> Signed-off-by:Jack Wang <jinpu.wang@ionos.com> Reviewed-by:
Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20230705113227.148494-1-jinpu.wang@ionos.comSigned-off-by:
Song Liu <song@kernel.org>
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Yu Kuai authored
memalloc_noio_save() is called for the first mddev_suspend(), and repeated mddev_suspend() only increase 'suspended'. However, memalloc_noio_restore() is also called for the first mddev_resume(), which means that memory reclaim will be enabled before the last mddev_resume() is called, while the array is still suspended. Fix this problem by restore 'noio_flag' for the last mddev_resume(). Fixes: 78f57ef9 ("md: use memalloc scope APIs in mddev_suspend()/mddev_resume()") Signed-off-by:
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Yu Kuai authored
Some levels doesn't implement "pers->quiesce", for example raid0_quiesce() is empty, and now that all levels will drop 'active_io' until io is done, wait for 'active_io' to be 0 is enough to make sure all normal io is done, and percpu_ref_kill() for 'active_io' will make sure no new normal io can be dispatched. There is no need to call "pers->quiesce" anymore from mddev_suspend(). Signed-off-by:
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Li Nan authored
In fix_read_error(), 'success' will be checked immediately after assigning it, if it is set to 1 then the loop will break. Checking it again in condition of loop is redundant. Clean it up. Signed-off-by:
Li Nan <linan122@huawei.com> Reviewed-by:
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Li Nan authored
We dereference r10_bio->read_slot too many times in fix_read_error(). Optimize it by using a variable to store read_slot. Signed-off-by:
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Li Nan authored
New disk should be added to "removed" position first instead of to be a replacement. Commit 6090368a ("md/raid10: prioritize adding disk to 'removed' mirror") has fixed this issue for raid10. Fix it for raid1 now. Signed-off-by:
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Yu Kuai authored
use md_account_bio() to enable io accounting, also make sure mddev_suspend() will wait for all io to be done. Signed-off-by:
Xiao Ni <xni@redhat.com> Signed-off-by:
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Yu Kuai authored
use md_account_bio() to enable io accounting, also make sure mddev_suspend() will wait for all io to be done. Signed-off-by:
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Yu Kuai authored
use md_account_bio() to enable io accounting, also make sure mddev_suspend() will wait for all io to be done. Signed-off-by:
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Yu Kuai authored
Make sure that 'active_io' will represent inflight io instead of io that is dispatching, and io accounting from all levels will be consistent. Signed-off-by:
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Yu Kuai authored
Two problems can be fixed this way: 1) 'active_io' will represent inflight io instead of io that is dispatching. 2) If io accounting is enabled or disabled while io is still inflight, bio_start_io_acct() and bio_end_io_acct() is not balanced and io inflight counter will be leaked. Signed-off-by:
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Yu Kuai authored
Io will only be accounted as done from raid5_align_endio() if the io succeeded, and io inflight counter will be leaked if such io failed. Fix this problem by switching to use md_account_bio() for io accounting. Signed-off-by:
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Yu Kuai authored
Currently, 'active_io' is grabbed before make_reqeust() is called, and it's dropped immediately make_reqeust() returns. Hence 'active_io' actually means io is dispatching, not io is inflight. For raid0 and raid456 that io accounting is enabled, 'active_io' will also be grabbed when bio is cloned for io accounting, and this 'active_io' is dropped until io is done. Always clone new bio so that 'active_io' will mean that io is inflight, raid1 and raid10 will switch to use this method in later patches. Now that bio will be cloned even if io accounting is disabled, also rename related structure from '*_acct_*' to '*_clone_*'. Signed-off-by:
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Yu Kuai authored
'io_acct_set' is only used for raid0 and raid456, prepare to use it for raid1 and raid10, so that io accounting from different levels can be consistent. By the way, follow up patches will also use this io clone mechanism to make sure 'active_io' represents in flight io, not io that is dispatching, so that mddev_suspend will wait for io to be done as designed. Signed-off-by:
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Christoph Hellwig authored
The support for bitmaps on files is a very bad idea abusing various kernel APIs, and fundamentally requires the file to not be on the actual array without a way to check that this is actually the case. Add a deprecation warning to see if we might be able to eventually drop it. Signed-off-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
Hannes Reinecke <hare@suse.de> Reviewed-by:
Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by:
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Christoph Hellwig authored
The support for write intent bitmaps in files on an external files in md is a hot mess that abuses ->bmap to map file offsets into physical device objects, and also abuses buffer_heads in a creative way. Make this code optional so that MD can be built into future kernels without buffer_head support, and so that we can eventually deprecate it. Note this does not affect the internal bitmap support, which has none of the problems. Signed-off-by:
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Christoph Hellwig authored
The md driver allocates pages for storing the bitmap file data, which are not page cache pages, and then stores the page granularity file offset in page->index, which is a field that isn't really valid except for page cache pages. Use a separate index for the superblock, and use the scheme used at read size to recalculate the index for the bitmap pages instead. Signed-off-by:
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Christoph Hellwig authored
Diretly apply mddev->bitmap_info.offset to the sector number to read instead of doing that in both callers. Signed-off-by:
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Christoph Hellwig authored
Convert read_sb_page to the normal kernel coding style, calculate the target sector only once, and add a local iosize variable to make the call to sync_page_io more readable. Signed-off-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by:
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Christoph Hellwig authored
Split the confusing loop in md_bitmap_init_from_disk that iterates over all chunks but also needs to read and map the pages into three separate loops: one that iterates over the pages to read them, a second optional one to iterate over the pages to mark them invalid if the bitmaps are out of date, and a final one that actually iterates over the chunks. Reported-by:
kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202306160552.smw0qbmb-lkp@intel.com/Signed-off-by:
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Christoph Hellwig authored
Make the difference to read_sb_page clear. Signed-off-by:
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Christoph Hellwig authored
Split the file write code out of write_page into a separate helper. Signed-off-by:
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Christoph Hellwig authored
Don't bother allocating an extra buffer in the I/O failure handler and instead use the printk built-in format to print the last 4 path name components. Signed-off-by:
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Christoph Hellwig authored
Just a small tidyup to prepare for bigger changes. Signed-off-by:
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Christoph Hellwig authored
Set BITMAP_WRITE_ERROR directly in write_sb_page instead of propagating the error to the caller and setting it there. Signed-off-by:
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Yu Kuai authored
For md_check_recovery(): 1) if 'MD_RECOVERY_RUNING' is not set, register new sync_thread. 2) if 'MD_RECOVERY_RUNING' is set: a) if 'MD_RECOVERY_DONE' is not set, don't do anything, wait for md_do_sync() to be done. b) if 'MD_RECOVERY_DONE' is set, unregister sync_thread. Current code expects that sync_thread is not NULL, otherwise new sync_thread will be registered, which will corrupt the array. Make sure md_check_recovery() won't register new sync_thread if 'MD_RECOVERY_RUNING' is still set, and a new WARN_ON_ONCE() is added for the above corruption, Signed-off-by:
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Yu Kuai authored
md_reap_sync_thread() is just replaced with wait_event(resync_wait, ...) from action_store(), just make sure action_store() will still wait for everything to be done in md_reap_sync_thread(). Signed-off-by:
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Yu Kuai authored
Our test found a following deadlock in raid10: 1) Issue a normal write, and such write failed: raid10_end_write_request set_bit(R10BIO_WriteError, &r10_bio->state) one_write_done reschedule_retry // later from md thread raid10d handle_write_completed list_add(&r10_bio->retry_list, &conf->bio_end_io_list) // later from md thread raid10d if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) list_move(conf->bio_end_io_list.prev, &tmp) r10_bio = list_first_entry(&tmp, struct r10bio, retry_list) raid_end_bio_io(r10_bio) Dependency chain 1: normal io is waiting for updating superblock 2) Trigger a recovery: raid10_sync_request raise_barrier Dependency chain 2: sync thread is waiting for normal io 3) echo idle/frozen to sync_action: action_store mddev_lock md_unregister_thread kthread_stop Dependency chain 3: drop 'reconfig_mutex' is waiting for sync thread 4) md thread can't update superblock: raid10d md_check_recovery if (mddev_trylock(mddev)) md_update_sb Dependency chain 4: update superblock is waiting for 'reconfig_mutex' Hence cyclic dependency exist, in order to fix the problem, we must break one of them. Dependency 1 and 2 can't be broken because they are foundation design. Dependency 4 may be possible if it can be guaranteed that no io can be inflight, however, this requires a new mechanism which seems complex. Dependency 3 is a good choice, because idle/frozen only requires sync thread to finish, which can be done asynchronously that is already implemented, and 'reconfig_mutex' is not needed anymore. This patch switch 'idle' and 'frozen' to wait sync thread to be done asynchronously, and this patch also add a sequence counter to record how many times sync thread is done, so that 'idle' won't keep waiting on new started sync thread. Noted that raid456 has similiar deadlock([1]), and it's verified[2] this deadlock can be fixed by this patch as well. [1] https://lore.kernel.org/linux-raid/5ed54ffc-ce82-bf66-4eff-390cb23bc1ac@molgen.mpg.de/T/#t [2] https://lore.kernel.org/linux-raid/e9067438-d713-f5f3-0d3d-9e6b0e9efa0e@huaweicloud.com/Signed-off-by: -
Yu Kuai authored
Currently, for idle and frozen, action_store will hold 'reconfig_mutex' and call md_reap_sync_thread() to stop sync thread, however, this will cause deadlock (explained in the next patch). In order to fix the problem, following patch will release 'reconfig_mutex' and wait on 'resync_wait', like md_set_readonly() and do_md_stop() does. Consider that action_store() will set/clear 'MD_RECOVERY_FROZEN' unconditionally, which might cause unexpected problems, for example, frozen just set 'MD_RECOVERY_FROZEN' and is still in progress, while 'idle' clear 'MD_RECOVERY_FROZEN' and new sync thread is started, which might starve in progress frozen. A mutex is added to synchronize idle and frozen from action_store(). Signed-off-by:
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Yu Kuai authored
Prepare to handle 'idle' and 'frozen' differently to fix a deadlock, there are no functional changes except that MD_RECOVERY_RUNNING is checked again after 'reconfig_mutex' is held. Signed-off-by:
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Yu Kuai authored
This reverts commit 9dfbdafd. Because it will introduce a defect that sync_thread can be running while MD_RECOVERY_RUNNING is cleared, which will cause some unexpected problems, for example: list_add corruption. prev->next should be next (ffff0001ac1daba0), but was ffff0000ce1a02a0. (prev=ffff0000ce1a02a0). Call trace: __list_add_valid+0xfc/0x140 insert_work+0x78/0x1a0 __queue_work+0x500/0xcf4 queue_work_on+0xe8/0x12c md_check_recovery+0xa34/0xf30 raid10d+0xb8/0x900 [raid10] md_thread+0x16c/0x2cc kthread+0x1a4/0x1ec ret_from_fork+0x10/0x18 This is because work is requeued while it's still inside workqueue: t1: t2: action_store mddev_lock if (mddev->sync_thread) mddev_unlock md_unregister_thread // first sync_thread is done md_check_recovery mddev_try_lock /* * once MD_RECOVERY_DONE is set, new sync_thread * can start. */ set_bit(MD_RECOVERY_RUNNING, &mddev->recovery) INIT_WORK(&mddev->del_work, md_start_sync) queue_work(md_misc_wq, &mddev->del_work) test_and_set_bit(WORK_STRUCT_PENDING_BIT, ...) // set pending bit insert_work list_add_tail mddev_unlock mddev_lock_nointr md_reap_sync_thread // MD_RECOVERY_RUNNING is cleared mddev_unlock t3: // before queued work started from t2 md_check_recovery // MD_RECOVERY_RUNNING is not set, a new sync_thread can be started INIT_WORK(&mddev->del_work, md_start_sync) work->data = 0 // work pending bit is cleared queue_work(md_misc_wq, &mddev->del_work) insert_work list_add_tail // list is corrupted The above commit is reverted to fix the problem, the deadlock this commit tries to fix will be fixed in following patches. Signed-off-by:
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- 26 Jul, 2023 1 commit
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Jinyoung Choi authored
If a problem occurs in the process of creating an integrity payload, the status of bio is always BLK_STS_RESOURCE. Reviewed-by:
Jinyoung Choi <j-young.choi@samsung.com> Reviewed-by:
"Martin K. Petersen" <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20230725051839epcms2p8e4d20ad6c51326ad032e8406f59d0aaa@epcms2p8Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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- 25 Jul, 2023 8 commits
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Bart Van Assche authored
blk_mq_run_queue() runs the queue asynchronously if BLK_MQ_F_BLOCKING has been set. This is suboptimal since running the queue asynchronously is slower than running the queue synchronously. This patch modifies blk_mq_run_queue() as follows if BLK_MQ_F_BLOCKING has been set: - Run the queue synchronously if it is allowed to sleep. - Run the queue asynchronously if it is not allowed to sleep. Additionally, blk_mq_run_hw_queue(hctx, false) calls are modified into blk_mq_run_hw_queue(hctx, hctx->flags & BLK_MQ_F_BLOCKING) if the caller may be invoked from atomic context. The following caller chains have been reviewed: blk_mq_run_hw_queue(hctx, false) blk_mq_get_tag() /* may sleep, hence the functions it calls may also sleep */ blk_execute_rq() /* may sleep */ blk_mq_run_hw_queues(q, async=false) blk_freeze_queue_start() /* may sleep */ blk_mq_requeue_work() /* may sleep */ scsi_kick_queue() scsi_requeue_run_queue() /* may sleep */ scsi_run_host_queues() scsi_ioctl_reset() /* may sleep */ blk_mq_insert_requests(hctx, ctx, list, run_queue_async=false) blk_mq_dispatch_plug_list(plug, from_sched=false) blk_mq_flush_plug_list(plug, from_schedule=false) __blk_flush_plug(plug, from_schedule=false) blk_add_rq_to_plug() blk_mq_submit_bio() /* may sleep if REQ_NOWAIT has not been set */ blk_mq_plug_issue_direct() blk_mq_flush_plug_list() /* see above */ blk_mq_dispatch_plug_list(plug, from_sched=false) blk_mq_flush_plug_list() /* see above */ blk_mq_try_issue_directly() blk_mq_submit_bio() /* may sleep if REQ_NOWAIT has not been set */ blk_mq_try_issue_list_directly(hctx, list) blk_mq_insert_requests() /* see above */ Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by:Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20230721172731.955724-4-bvanassche@acm.orgSigned-off-by:
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Bart Van Assche authored
blk_mq_kick_requeue_list() calls blk_mq_run_hw_queues() asynchronously. Leave out the direct blk_mq_run_hw_queues() call. This patch causes scsi_run_queue() to call blk_mq_run_hw_queues() asynchronously instead of synchronously. Since scsi_run_queue() is not called from the hot I/O submission path, this patch does not affect the hot path. This patch prepares for allowing blk_mq_run_hw_queue() to sleep if BLK_MQ_F_BLOCKING has been set. scsi_run_queue() may be called from atomic context and must not sleep. Hence the removal of the blk_mq_run_hw_queues(q, false) call. See also scsi_unblock_requests(). Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by:
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Bart Van Assche authored
Inline scsi_kick_queue() to prepare for modifying the second argument passed to blk_mq_run_hw_queues(). Reviewed-by:
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Christoph Hellwig authored
There is no good reason to pass the bio to bio_try_merge_hw_seg. Just pass the current bvec and rename the function to bvec_try_merge_hw_page. This will allow reusing this function for supporting multi-page integrity payload bvecs. Signed-off-by:
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Christoph Hellwig authored
The update of bi_size is the only thing in __bio_try_merge_page that needs a bio. Move it to the callers, and merge __bio_try_merge_page and page_is_mergeable into a single bvec_try_merge_page that only takes the current bvec instead of a full bio. This will allow reusing this function for supporting multi-page integrity payload bvecs. Signed-off-by:
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Christoph Hellwig authored
bio_add_page already checks that there is space in bi_size a little earlier. So after we failed to add to an existing segment, just check that there is another one available instead of duplicating the bi_size check. Signed-off-by:
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Christoph Hellwig authored
Checking for availability in bi_size in a function that attempts to merge into an existing segment is a bit odd, as the limit also applies when adding a new segment. This code works fine as we always call __bio_try_merge_page, but contributes to sub-optimal calling conventions and doesn't lead to clear code. Move it to two of the callers instead, the third one already has a more strict check that includes max_hw_segments anyway. Signed-off-by:
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Christoph Hellwig authored
Move the bi_vcnt out of __bio_try_merge_page and into the two callers that don't already have it in preparation for additional changes to __bio_try_merge_page. Signed-off-by:
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