- 13 Jun, 2023 28 commits
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Yu Kuai authored
If bitmap is enabled, bitmap must update before submitting write io, this is why unplug callback must move these io to 'conf->pending_io_list' if 'current->bio_list' is not empty, which will suffer performance degradation. A new helper md_bitmap_unplug_async() is introduced to submit bitmap io in a kworker, so that submit bitmap io in raid10_unplug() doesn't require that 'current->bio_list' is empty. This patch prepare to limit the number of plugged bio. Signed-off-by:
Yu Kuai <yukuai3@huawei.com> Signed-off-by:
Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230529131106.2123367-6-yukuai1@huaweicloud.com
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Yu Kuai authored
Commit 6cce3b23 ("[PATCH] md: write intent bitmap support for raid10") add bitmap support, and it changed that write io is submitted through daemon thread because bitmap need to be updated before write io. And later, plug is used to fix performance regression because all the write io will go to demon thread, which means io can't be issued concurrently. However, if bitmap is not enabled, the write io should not go to daemon thread in the first place, and plug is not needed as well. Fixes: 6cce3b23 ("[PATCH] md: write intent bitmap support for raid10") Signed-off-by:
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Yu Kuai authored
There are multiple places to do the same thing, factor out a helper to prevent redundant code, and the helper will be used in following patch as well. Signed-off-by:
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Yu Kuai authored
The code in raid1 and raid10 is identical, prepare to limit the number of plugged bios. Signed-off-by:
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Yu Kuai authored
Currently, there is no limit for raid1/raid10 plugged bio. While flushing writes, raid1 has cond_resched() while raid10 doesn't, and too many writes can cause soft lockup. Follow up soft lockup can be triggered easily with writeback test for raid10 with ramdisks: watchdog: BUG: soft lockup - CPU#10 stuck for 27s! [md0_raid10:1293] Call Trace: <TASK> call_rcu+0x16/0x20 put_object+0x41/0x80 __delete_object+0x50/0x90 delete_object_full+0x2b/0x40 kmemleak_free+0x46/0xa0 slab_free_freelist_hook.constprop.0+0xed/0x1a0 kmem_cache_free+0xfd/0x300 mempool_free_slab+0x1f/0x30 mempool_free+0x3a/0x100 bio_free+0x59/0x80 bio_put+0xcf/0x2c0 free_r10bio+0xbf/0xf0 raid_end_bio_io+0x78/0xb0 one_write_done+0x8a/0xa0 raid10_end_write_request+0x1b4/0x430 bio_endio+0x175/0x320 brd_submit_bio+0x3b9/0x9b7 [brd] __submit_bio+0x69/0xe0 submit_bio_noacct_nocheck+0x1e6/0x5a0 submit_bio_noacct+0x38c/0x7e0 flush_pending_writes+0xf0/0x240 raid10d+0xac/0x1ed0 Fix the problem by adding cond_resched() to raid10 like what raid1 did. Note that unlimited plugged bio still need to be optimized, for example, in the case of lots of dirty pages writeback, this will take lots of memory and io will spend a long time in plug, hence io latency is bad. Signed-off-by:
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Li Nan authored
When removing a disk with replacement, the replacement will be used to replace rdev. During this process, there is a brief window in which both rdev and replacement are read as NULL in raid10_write_request(). This will result in io not being submitted but it should be. //remove //write raid10_remove_disk raid10_write_request mirror->rdev = NULL read rdev -> NULL mirror->rdev = mirror->replacement mirror->replacement = NULL read replacement -> NULL Fix it by reading replacement first and rdev later, meanwhile, use smp_mb() to prevent memory reordering. Fixes: 475b0321 ("md/raid10: writes should get directed to replacement as well as original.") Signed-off-by:
Li Nan <linan122@huawei.com> Reviewed-by:
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Li Nan authored
In raid10_sync_request(), if data cannot be read from any disk for recovery, it will go to 'giveup' and let 'chunks_skipped' + 1. After multiple 'giveup', when 'chunks_skipped >= geo.raid_disks', it will return 'max_sector', indicating that the recovery has been completed. However, the recovery is just aborted and the data remains inconsistent. Fix it by setting mirror->recovery_disabled, which will prevent the spare disk from being added to this mirror. The same issue also exists during resync, it will be fixed afterwards. Signed-off-by:
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Li Nan authored
Commit 1a855a06 ("md: fix bug with re-adding of partially recovered device.") only add device which is set to In_sync. But it let devices without metadata cannot be added when they should be. Commit bf572541 ("md: fix regression with re-adding devices to arrays with no metadata") fix the above issue, it set device without metadata to In_sync when add new disk. However, after commit f466722c ("md: Change handling of save_raid_disk and metadata update during recovery.") deletes changes of the first patch, setting In_sync for devcie without metadata is meanless because the flag will be cleared soon and will not be used during this period. Clean it up. Signed-off-by:
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Li Nan authored
When add a new disk to raid10, it will traverse conf->mirror from start and find one of the following mirror to add: 1. mirror->rdev is set to WantReplacement and it have no replacement, set new disk to mirror->replacement. 2. no mirror->rdev, set new disk to mirror->rdev. There is a array as below (sda is set to WantReplacement): Number Major Minor RaidDevice State 0 8 0 0 active sync set-A /dev/sda - 0 0 1 removed 2 8 32 2 active sync set-A /dev/sdc 3 8 48 3 active sync set-B /dev/sdd Use 'mdadm --add' to add a new disk to this array, the new disk will become sda's replacement instead of add to removed position, which is confusing for users. Meanwhile, after new disk recovery success, sda will be set to Faulty. Prioritize adding disk to 'removed' mirror is a better choice. In the above scenario, the behavior is the same as before, except sda will not be deleted. Before other disks are added, continued use sda is more reliable. Signed-off-by: -
Li Nan authored
'need_recover' and 'mrdev' are equivalent in raid10_sync_request(), and inc mrdev->nr_pending is unreasonable if don't need recovery. Replace 'need_recover' with 'mrdev', and only inc nr_pending when needed. Signed-off-by:
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Li Nan authored
There are two check of 'mreplace' in raid10_sync_request(). In the first check, 'need_replace' will be set and 'mreplace' will be used later if no-Faulty 'mreplace' exists, In the second check, 'mreplace' will be set to NULL if it is Faulty, but 'need_replace' will not be changed accordingly. null-ptr-deref occurs if Faulty is set between two check. Fix it by merging two checks into one. And replace 'need_replace' with 'mreplace' because their values are always the same. Fixes: ee37d731 ("md/raid10: Fix raid10 replace hang when new added disk faulty") Signed-off-by:
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Yu Kuai authored
When recovery is interrupted (reboot, etc.) check for MD_RECOVERY_RUNNING is not enough to tell recovery is in progress. Also check recovery_cp before starting reshape. Signed-off-by:
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Yu Kuai authored
Currently, there are many places that md_thread can be accessed without protection, following are known scenarios that can cause null-ptr-dereference or uaf: 1) sync_thread that is allocated and started from md_start_sync() 2) mddev->thread can be accessed directly from timeout_store() and md_bitmap_daemon_work() 3) md_unregister_thread() from action_store(). Currently, a global spinlock 'pers_lock' is borrowed to protect 'mddev->thread' in some places, this problem can be fixed likewise, however, use a global lock for all the cases is not good. Fix this problem by protecting all md_thread with rcu. Signed-off-by:
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Yu Kuai authored
Register/unregister 'mddev->thread' are both under 'reconfig_mutex', however, some context didn't hold the mutex to access mddev->thread, which can cause null-ptr-deference: 1) md_bitmap_daemon_work() can be called from md_check_recovery() where 'reconfig_mutex' is not held, deference 'mddev->thread' might cause null-ptr-deference, because md_unregister_thread() reset the pointer before stopping the thread. 2) timeout_store() access 'mddev->thread' multiple times, null-ptr-deference can be triggered if 'mddev->thread' is reset in the middle. This patch factor out a helper to set timeout, the new helper always check if 'mddev->thread' is null first, so that problem 1 can be fixed. Now that this helper only access 'mddev->thread' once, but it's possible that 'mddev->thread' can be freed while this helper is still in progress, hence the problem is not fixed yet. Follow up patches will fix this by protecting md_thread with rcu. Signed-off-by:
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Yu Kuai authored
md_wakeup_thread() can handle the case that pass in md_thread is NULL, the only difference is that md_wakeup_thread() will be called when current timeout is 'MAX_SCHEDULE_TIMEOUT', this should not matter because timeout_store() is not hot path, and the daemon process is woke up more than demand from other context already. Prepare to factor out a helper to set timeout. Signed-off-by:
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Yu Kuai authored
md_wakeup_thread() handle the case that pass in md_thread is NULL, there is no need to check this. Signed-off-by:
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Yu Kuai authored
md_wakeup_thread() can't wakeup md_thread->tsk if md_thread->run is still in progress, and in some cases md_thread->tsk need to be woke up directly, like md_set_readonly() and do_md_stop(). Commit 9dfbdafd ("md: unlock mddev before reap sync_thread in action_store") introduce a new scenario where unregister sync_thread is not protected by 'reconfig_mutex', this can cause null-ptr-deference in theroy: t1: md_set_readonly t2: action_store md_unregister_thread // 'reconfig_mutex' is not held // 'reconfig_mutex' is held by caller if (mddev->sync_thread) thread = *threadp *threadp = NULL wake_up_process(mddev->sync_thread->tsk) // null-ptr-deference Fix this problem by factoring out a helper to wake up md_thread directly, so that 'sync_thread' won't be accessed multiple times from the reader side. This helper also prepare to protect md_thread with rcu. Noted that later patches is going to fix that unregister sync_thread is not protected by 'reconfig_mutex' from action_store(). Signed-off-by:
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Yu Kuai authored
Commit 5792a285 ("[PATCH] md: avoid a deadlock when removing a device from an md array via sysfs") delays the deletion of rdev, however, this introduces a window that rdev can be added again while the deletion is not done yet, and sysfs will complain about duplicate filename. Follow up patches try to fix this problem by flushing workqueue, however, flush_rdev_wq() is just dead code, the progress in md_kick_rdev_from_array(): 1) list_del_rcu(&rdev->same_set); 2) synchronize_rcu(); 3) queue_work(md_rdev_misc_wq, &rdev->del_work); So in flush_rdev_wq(), if rdev is found in the list, work_pending() can never pass, in the meantime, if work is queued, then rdev can never be found in the list. flush_rdev_wq() can be replaced by flush_workqueue() directly, however, this approach is not good: - the workqueue is global, this synchronization for all raid disks is not necessary. - flush_workqueue can't be called under 'reconfig_mutex', there is still a small window between flush_workqueue() and mddev_lock() that other contexts can queue new work, hence the problem is not solved completely. sysfs already has apis to support delete itself through writer, and these apis, specifically sysfs_break/unbreak_active_protection(), is used to support deleting rdev synchronously. Therefore, the above commit can be reverted, and sysfs duplicate filename can be avoided. A new mdadm regression test is proposed as well([1]). [1] https://lore.kernel.org/linux-raid/20230428062845.1975462-1-yukuai1@huaweicloud.com/ Fixes: 5792a285 ("[PATCH] md: avoid a deadlock when removing a device from an md array via sysfs") Signed-off-by:
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Li Nan authored
There is no input check when echo md/max_read_errors and overflow might occur. Add check of input number. Fixes: 1e50915f ("raid: improve MD/raid10 handling of correctable read errors.") Signed-off-by:
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Li Nan authored
There is no input check when echo md/safe_mode_delay in safe_delay_store(). And msec might also overflow when HZ < 1000 in safe_delay_show(), Fix it by checking overflow in safe_delay_store() and use unsigned long conversion in safe_delay_show(). Fixes: 72e02075 ("md: factor out parsing of fixed-point numbers") Signed-off-by:
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Yu Kuai authored
If reshape is in progress and io across reshape_position is issued, such io will wait for reshape to make progress(see details in the case that make_stripe_request() return STRIPE_SCHEDULE_AND_RETRY). It has been reported several times that if system reboot while growing raid5 to raid6, array assemble will hang infinitely([1, 2]). This is because following deadlock is triggered: 1) a normal io is waiting for reshape to progress, this io can be from system-udevd or mdadm. 2) while assemble, mdadm tries to suspend the array, hence 'reconfig_mutex' is held and mddev_suspend() must wait for normal io to be done. 3) daemon thread can't start reshape because 'reconfig_mutex' can't be held. 1) and 3) is unbreakable because they're foundation design. In order to break 2), following is possible solutions that I can think of: a) Let mddev_suspend() fail is not a good option, because this will break many scenarios since mddev_suspend() doesn't fail before. b) Fail the io that is waiting for reshape to make progress from mddev_suspend(). c) Return false for the io that is waiting for reshape to make progress from raid5_make_request(), and these io will wait for suspend to be done in md_handle_request(), where 'active_io' is not grabbed. c) sounds better than b), however, b) is used because it's easy and straightforward, and it's verified that mdadm can assemble in this case. On the other hand, c) breaks the logic that mddev_suspend() will wait for submitted io to be completely handled. Fix the problem by checking reshape in mddev_suspend(), if reshape can't make progress and there are still some io waiting for reshape, fail those io. [1] https://lore.kernel.org/all/CAFig2csUV2QiomUhj_t3dPOgV300dbQ6XtM9ygKPdXJFSH__Nw@mail.gmail.com/ [2] https://lore.kernel.org/all/CAO2ABipzbw6QL5eNa44CQHjiVa-LTvS696Mh9QaTw+qsUKFUCw@mail.gmail.com/Reported-by:
Jove <jovetoo@gmail.com> Reported-by:
David Gilmour <dgilmour76@gmail.com> Signed-off-by:
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Yu Kuai authored
There are no functional changes, the new api will be used later to do special handling for raid456 in md_suspend(). Signed-off-by:
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Yu Kuai authored
The two apis will be used later to fix a deadlock in raid456, there are no functional changes. Signed-off-by:
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Yu Kuai authored
Currently, if reshape is interrupted, echo "reshape" to sync_action will restart reshape from scratch, for example: echo frozen > sync_action echo reshape > sync_action This will corrupt data before reshape_position if the array is growing, fix the problem by continue reshape from reshape_position. Reported-by:
Peter Neuwirth <reddunur@online.de> Link: https://lore.kernel.org/linux-raid/e2f96772-bfbc-f43b-6da1-f520e5164536@online.de/Signed-off-by:
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Yu Kuai authored
If reshape is interrupted(for example, echo frozen to sync_action), then rdev replacement can be set. It's safe because reshape is always prior to resync in md_check_recovery(). However, if system reboots, then kernel will complain cannot handle concurrent replacement and reshape and this array is not able to assemble anymore. Fix this problem by don't allow replacement until reshape is done. Reported-by:
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Li Nan authored
If we write a large number to md/bitmap_set_bits, md_bitmap_checkpage() will return -EINVAL because 'page >= bitmap->pages', but the return value was not checked immediately in md_bitmap_get_counter() in order to set *blocks value and slab-out-of-bounds occurs. Move check of 'page >= bitmap->pages' to md_bitmap_get_counter() and return directly if true. Fixes: ef425673 ("md/bitmap: optimise scanning of empty bitmaps.") Signed-off-by:
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Arnd Bergmann authored
The raid6 syndrome functions are generated for different sizes and have no generic prototype, while in the inner functions have a prototype in a header that cannot be included from the correct file. In both cases, the compiler warns about missing prototypes: lib/raid6/recov_neon_inner.c:27:6: warning: no previous prototype for '__raid6_2data_recov_neon' [-Wmissing-prototypes] lib/raid6/recov_neon_inner.c:77:6: warning: no previous prototype for '__raid6_datap_recov_neon' [-Wmissing-prototypes] lib/raid6/neon1.c:56:6: warning: no previous prototype for 'raid6_neon1_gen_syndrome_real' [-Wmissing-prototypes] lib/raid6/neon1.c:86:6: warning: no previous prototype for 'raid6_neon1_xor_syndrome_real' [-Wmissing-prototypes] lib/raid6/neon2.c:56:6: warning: no previous prototype for 'raid6_neon2_gen_syndrome_real' [-Wmissing-prototypes] lib/raid6/neon2.c:97:6: warning: no previous prototype for 'raid6_neon2_xor_syndrome_real' [-Wmissing-prototypes] lib/raid6/neon4.c:56:6: warning: no previous prototype for 'raid6_neon4_gen_syndrome_real' [-Wmissing-prototypes] lib/raid6/neon4.c:119:6: warning: no previous prototype for 'raid6_neon4_xor_syndrome_real' [-Wmissing-prototypes] lib/raid6/neon8.c:56:6: warning: no previous prototype for 'raid6_neon8_gen_syndrome_real' [-Wmissing-prototypes] lib/raid6/neon8.c:163:6: warning: no previous prototype for 'raid6_neon8_xor_syndrome_real' [-Wmissing-prototypes] Add a new header file that contains the prototypes for both to avoid the warnings. Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Christoph Hellwig authored
Add back the accidentally dropped mode parameter. Fixes: b60f7635788a ("swim3: fix the floppy_locked_ioctl prototype") Reported-by:Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230613154309.327557-1-hch@lst.deSigned-off-by:
Jens Axboe <axboe@kernel.dk>
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- 12 Jun, 2023 12 commits
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Yu Kuai authored
In __blk_mq_tag_busy/idle(), updating 'active_queues' and calculating 'wake_batch' is not atomic: t1: t2: _blk_mq_tag_busy blk_mq_tag_busy inc active_queues // assume 1->2 inc active_queues // 2 -> 3 blk_mq_update_wake_batch // calculate based on 3 blk_mq_update_wake_batch /* calculate based on 2, while active_queues is actually 3. */ Fix this problem by protecting them wih 'tags->lock', this is not a hot path, so performance should not be concerned. And now that all writers are inside the lock, switch 'actives_queues' from atomic to unsigned int. Fixes: 180dccb0 ("blk-mq: fix tag_get wait task can't be awakened") Signed-off-by:
Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230610023043.2559121-1-yukuai1@huaweicloud.comSigned-off-by:
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Christoph Hellwig authored
FMODE_NDELAY, FMODE_EXCL and FMODE_WRITE_IOCTL were only used for block internal purposed and are now entirely unused, so remove them. Signed-off-by:
Hannes Reinecke <hare@suse.de> Reviewed-by:
Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20230608110258.189493-31-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Store the file struct used as the holder in file->private_data as an indicator that this file descriptor was opened exclusively to remove the last use of FMODE_EXCL. Signed-off-by:
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Christoph Hellwig authored
Always use I_BDEV(file->f_mapping->host) to find the bdev for a file to free up file->private_data for other uses. Signed-off-by:
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Christoph Hellwig authored
The only overlap between the block open flags mapped into the fmode_t and other uses of fmode_t are FMODE_READ and FMODE_WRITE. Define a new blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and ->ioctl and stop abusing fmode_t. Signed-off-by: -
Christoph Hellwig authored
A few ioctl handlers have fmode_t arguments that are entirely unused, remove them. Signed-off-by:
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Christoph Hellwig authored
All these helpers are only used in core block code, so move them out of the public header. Signed-off-by:
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Christoph Hellwig authored
This code has been dead forever, make sure it doesn't show up in code searches. Signed-off-by:
Richard Weinberger <richard@nod.at> Link: https://lore.kernel.org/r/20230608110258.189493-25-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Stop passing the fmode_t around and just use a simple bool to track if an export is read-only. Signed-off-by:
Jack Wang <jinpu.wang@ionos.com> Link: https://lore.kernel.org/r/20230608110258.189493-24-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Instead of propagating the fmode_t, just use a bool to track if a mtd block device was opened for writing. Signed-off-by:
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Christoph Hellwig authored
Instead of passing a fmode_t and only checking it fo0r FMODE_WRITE, pass a bool open_for_write to prepare for callers that won't have the fmode_t. Signed-off-by:
Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20230608110258.189493-22-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Instead of passing a fmode_t and only checking it for FMODE_WRITE, pass a bool open_for_write to prepare for callers that won't have the fmode_t. Signed-off-by:
Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by:
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