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path: root/drivers/md/md.c
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2024-02-25md: port block device access to fileChristian Brauner
Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-4-adbd023e19cc@kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-19block: pass a queue_limits argument to blk_alloc_diskChristoph Hellwig
Pass a queue_limits to blk_alloc_disk and apply it if non-NULL. This will allow allocating queues with valid queue limits instead of setting the values one at a time later. Also change blk_alloc_disk to return an ERR_PTR instead of just NULL which can't distinguish errors. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Link: https://lore.kernel.org/r/20240215071055.2201424-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-15md: Don't suspend the array for interrupted reshapeYu Kuai
md_start_sync() will suspend the array if there are spares that can be added or removed from conf, however, if reshape is still in progress, this won't happen at all or data will be corrupted(remove_and_add_spares won't be called from md_choose_sync_action for reshape), hence there is no need to suspend the array if reshape is not done yet. Meanwhile, there is a potential deadlock for raid456: 1) reshape is interrupted; 2) set one of the disk WantReplacement, and add a new disk to the array, however, recovery won't start until the reshape is finished; 3) then issue an IO across reshpae position, this IO will wait for reshape to make progress; 4) continue to reshape, then md_start_sync() found there is a spare disk that can be added to conf, mddev_suspend() is called; Step 4 and step 3 is waiting for each other, deadlock triggered. Noted this problem is found by code review, and it's not reporduced yet. Fix this porblem by don't suspend the array for interrupted reshape, this is safe because conf won't be changed until reshape is done. Fixes: bc08041b32ab ("md: suspend array in md_start_sync() if array need reconfiguration") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240201092559.910982-6-yukuai1@huaweicloud.com
2024-02-15md: Don't register sync_thread for reshape directlyYu Kuai
Currently, if reshape is interrupted, then reassemble the array will register sync_thread directly from pers->run(), in this case 'MD_RECOVERY_RUNNING' is set directly, however, there is no guarantee that md_do_sync() will be executed, hence stop_sync_thread() will hang because 'MD_RECOVERY_RUNNING' can't be cleared. Last patch make sure that md_do_sync() will set MD_RECOVERY_DONE, however, following hang can still be triggered by dm-raid test shell/lvconvert-raid-reshape.sh occasionally: [root@fedora ~]# cat /proc/1982/stack [<0>] stop_sync_thread+0x1ab/0x270 [md_mod] [<0>] md_frozen_sync_thread+0x5c/0xa0 [md_mod] [<0>] raid_presuspend+0x1e/0x70 [dm_raid] [<0>] dm_table_presuspend_targets+0x40/0xb0 [dm_mod] [<0>] __dm_destroy+0x2a5/0x310 [dm_mod] [<0>] dm_destroy+0x16/0x30 [dm_mod] [<0>] dev_remove+0x165/0x290 [dm_mod] [<0>] ctl_ioctl+0x4bb/0x7b0 [dm_mod] [<0>] dm_ctl_ioctl+0x11/0x20 [dm_mod] [<0>] vfs_ioctl+0x21/0x60 [<0>] __x64_sys_ioctl+0xb9/0xe0 [<0>] do_syscall_64+0xc6/0x230 [<0>] entry_SYSCALL_64_after_hwframe+0x6c/0x74 Meanwhile mddev->recovery is: MD_RECOVERY_RUNNING | MD_RECOVERY_INTR | MD_RECOVERY_RESHAPE | MD_RECOVERY_FROZEN Fix this problem by remove the code to register sync_thread directly from raid10 and raid5. And let md_check_recovery() to register sync_thread. Fixes: f67055780caa ("[PATCH] md: Checkpoint and allow restart of raid5 reshape") Fixes: f52f5c71f3d4 ("md: fix stopping sync thread") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240201092559.910982-5-yukuai1@huaweicloud.com
2024-02-15md: Make sure md_do_sync() will set MD_RECOVERY_DONEYu Kuai
stop_sync_thread() will interrupt md_do_sync(), and md_do_sync() must set MD_RECOVERY_DONE, so that follow up md_check_recovery() will unregister sync_thread, clear MD_RECOVERY_RUNNING and wake up stop_sync_thread(). If MD_RECOVERY_WAIT is set or the array is read-only, md_do_sync() will return without setting MD_RECOVERY_DONE, and after commit f52f5c71f3d4 ("md: fix stopping sync thread"), dm-raid switch from md_reap_sync_thread() to stop_sync_thread() to unregister sync_thread from md_stop() and md_stop_writes(), causing the test shell/lvconvert-raid-reshape.sh hang. We shouldn't switch back to md_reap_sync_thread() because it's problematic in the first place. Fix the problem by making sure md_do_sync() will set MD_RECOVERY_DONE. Reported-by: Mikulas Patocka <mpatocka@redhat.com> Closes: https://lore.kernel.org/all/ece2b06f-d647-6613-a534-ff4c9bec1142@redhat.com/ Fixes: d5d885fd514f ("md: introduce new personality funciton start()") Fixes: 5fd6c1dce06e ("[PATCH] md: allow checkpoint of recovery with version-1 superblock") Fixes: f52f5c71f3d4 ("md: fix stopping sync thread") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240201092559.910982-4-yukuai1@huaweicloud.com
2024-02-15md: Don't ignore read-only array in md_check_recovery()Yu Kuai
Usually if the array is not read-write, md_check_recovery() won't register new sync_thread in the first place. And if the array is read-write and sync_thread is registered, md_set_readonly() will unregister sync_thread before setting the array read-only. md/raid follow this behavior hence there is no problem. After commit f52f5c71f3d4 ("md: fix stopping sync thread"), following hang can be triggered by test shell/integrity-caching.sh: 1) array is read-only. dm-raid update super block: rs_update_sbs ro = mddev->ro mddev->ro = 0 -> set array read-write md_update_sb 2) register new sync thread concurrently. 3) dm-raid set array back to read-only: rs_update_sbs mddev->ro = ro 4) stop the array: raid_dtr md_stop stop_sync_thread set_bit(MD_RECOVERY_INTR, &mddev->recovery); md_wakeup_thread_directly(mddev->sync_thread); wait_event(..., !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) 5) sync thread done: md_do_sync set_bit(MD_RECOVERY_DONE, &mddev->recovery); md_wakeup_thread(mddev->thread); 6) daemon thread can't unregister sync thread: md_check_recovery if (!md_is_rdwr(mddev) && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery)) return; -> -> MD_RECOVERY_RUNNING can't be cleared, hence step 4 hang; The root cause is that dm-raid manipulate 'mddev->ro' by itself, however, dm-raid really should stop sync thread before setting the array read-only. Unfortunately, I need to read more code before I can refacter the handler of 'mddev->ro' in dm-raid, hence let's fix the problem the easy way for now to prevent dm-raid regression. Reported-by: Mikulas Patocka <mpatocka@redhat.com> Closes: https://lore.kernel.org/all/9801e40-8ac7-e225-6a71-309dcf9dc9aa@redhat.com/ Fixes: ecbfb9f118bc ("dm raid: add raid level takeover support") Fixes: f52f5c71f3d4 ("md: fix stopping sync thread") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240201092559.910982-3-yukuai1@huaweicloud.com
2024-02-15md: Don't ignore suspended array in md_check_recovery()Yu Kuai
mddev_suspend() never stop sync_thread, hence it doesn't make sense to ignore suspended array in md_check_recovery(), which might cause sync_thread can't be unregistered. After commit f52f5c71f3d4 ("md: fix stopping sync thread"), following hang can be triggered by test shell/integrity-caching.sh: 1) suspend the array: raid_postsuspend mddev_suspend 2) stop the array: raid_dtr md_stop __md_stop_writes stop_sync_thread set_bit(MD_RECOVERY_INTR, &mddev->recovery); md_wakeup_thread_directly(mddev->sync_thread); wait_event(..., !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) 3) sync thread done: md_do_sync set_bit(MD_RECOVERY_DONE, &mddev->recovery); md_wakeup_thread(mddev->thread); 4) daemon thread can't unregister sync thread: md_check_recovery if (mddev->suspended) return; -> return directly md_read_sync_thread clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery); -> MD_RECOVERY_RUNNING can't be cleared, hence step 2 hang; This problem is not just related to dm-raid, fix it by ignoring suspended array in md_check_recovery(). And follow up patches will improve dm-raid better to frozen sync thread during suspend. Reported-by: Mikulas Patocka <mpatocka@redhat.com> Closes: https://lore.kernel.org/all/8fb335e-6d2c-dbb5-d7-ded8db5145a@redhat.com/ Fixes: 68866e425be2 ("MD: no sync IO while suspended") Fixes: f52f5c71f3d4 ("md: fix stopping sync thread") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240201092559.910982-2-yukuai1@huaweicloud.com
2024-02-12md: fix kmemleak of rdev->serialLi Nan
If kobject_add() is fail in bind_rdev_to_array(), 'rdev->serial' will be alloc not be freed, and kmemleak occurs. unreferenced object 0xffff88815a350000 (size 49152): comm "mdadm", pid 789, jiffies 4294716910 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc f773277a): [<0000000058b0a453>] kmemleak_alloc+0x61/0xe0 [<00000000366adf14>] __kmalloc_large_node+0x15e/0x270 [<000000002e82961b>] __kmalloc_node.cold+0x11/0x7f [<00000000f206d60a>] kvmalloc_node+0x74/0x150 [<0000000034bf3363>] rdev_init_serial+0x67/0x170 [<0000000010e08fe9>] mddev_create_serial_pool+0x62/0x220 [<00000000c3837bf0>] bind_rdev_to_array+0x2af/0x630 [<0000000073c28560>] md_add_new_disk+0x400/0x9f0 [<00000000770e30ff>] md_ioctl+0x15bf/0x1c10 [<000000006cfab718>] blkdev_ioctl+0x191/0x3f0 [<0000000085086a11>] vfs_ioctl+0x22/0x60 [<0000000018b656fe>] __x64_sys_ioctl+0xba/0xe0 [<00000000e54e675e>] do_syscall_64+0x71/0x150 [<000000008b0ad622>] entry_SYSCALL_64_after_hwframe+0x6c/0x74 Fixes: 963c555e75b0 ("md: introduce mddev_create/destroy_wb_pool for the change of member device") Signed-off-by: Li Nan <linan122@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240208085556.2412922-1-linan666@huaweicloud.com
2024-02-07md: Fix missing release of 'active_io' for flushYu Kuai
submit_flushes atomic_set(&mddev->flush_pending, 1); rdev_for_each_rcu(rdev, mddev) atomic_inc(&mddev->flush_pending); bi->bi_end_io = md_end_flush submit_bio(bi); /* flush io is done first */ md_end_flush if (atomic_dec_and_test(&mddev->flush_pending)) percpu_ref_put(&mddev->active_io) -> active_io is not released if (atomic_dec_and_test(&mddev->flush_pending)) -> missing release of active_io For consequence, mddev_suspend() will wait for 'active_io' to be zero forever. Fix this problem by releasing 'active_io' in submit_flushes() if 'flush_pending' is decreased to zero. Fixes: fa2bbff7b0b4 ("md: synchronize flush io with array reconfiguration") Cc: stable@vger.kernel.org # v6.1+ Reported-by: Blazej Kucman <blazej.kucman@linux.intel.com> Closes: https://lore.kernel.org/lkml/20240130172524.0000417b@linux.intel.com/ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240201092559.910982-7-yukuai1@huaweicloud.com
2024-02-05md: use RCU lock to protect traversal in md_spares_need_change()Li Lingfeng
Since md_start_sync() will be called without the protect of mddev_lock, and it can run concurrently with array reconfiguration, traversal of rdev in it should be protected by RCU lock. Commit bc08041b32ab ("md: suspend array in md_start_sync() if array need reconfiguration") added md_spares_need_change() to md_start_sync(), casusing use of rdev without any protection. Fix this by adding RCU lock in md_spares_need_change(). Fixes: bc08041b32ab ("md: suspend array in md_start_sync() if array need reconfiguration") Cc: stable@vger.kernel.org # 6.7+ Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240104133629.1277517-1-lilingfeng@huaweicloud.com
2024-02-05md: get rdev->mddev with READ_ONCE()Li Lingfeng
Users may get rdev->mddev by sysfs while rdev is releasing. So use both READ_ONCE() and WRITE_ONCE() to prevent load/store tearing and to read/write mddev atomically. Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231229070500.3602712-1-lilingfeng@huaweicloud.com
2024-02-05md: remove redundant md_wakeup_thread()Yu Kuai
On the one hand, mddev_unlock() will call md_wakeup_thread() unconditionally; on the other hand, md_check_recovery() can't make progress if 'reconfig_mutex' can't be grabbed. Hence, it really doesn't make sense to wake up daemon thread while 'reconfig_mutex' is still grabbed. Remove all the md_wakup_thread() for 'mddev->thread' while 'reconfig_mtuex' is still grabbed. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231228125553.2697765-3-yukuai1@huaweicloud.com
2024-02-05md: remove redundant check of 'mddev->sync_thread'Yu Kuai
The lifetime of sync_thread: 1) Set MD_RECOVERY_NEEDED and wake up daemon thread (by ioctl/sysfs or other events); 2) Daemon thread woke up, md_check_recovery() found that MD_RECOVERY_NEEDED is set: a) try to grab reconfig_mutex; b) set MD_RECOVERY_RUNNING; c) clear MD_RECOVERY_NEEDED, and then queue sync_work; 3) md_start_sync() choose sync_action, then register sync_thread; 4) md_do_sync() is done, set MD_RECOVERY_DONE and wake up daemon thread; 5) Daemon thread woke up, md_check_recovery() found that MD_RECOVERY_DONE is set: a) try to grab reconfig_mutex; b) unregister sync_thread; c) clear MD_RECOVERY_RUNNING and MD_RECOVERY_DONE; Hence there is no such case that MD_RECOVERY_RUNNING is not set, while sync_thread is registered. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231228125553.2697765-2-yukuai1@huaweicloud.com
2024-01-18Merge tag 'for-6.8/block-2024-01-18' of git://git.kernel.dk/linuxLinus Torvalds
Pull block fixes from Jens Axboe: - NVMe pull request via Keith: - tcp, fc, and rdma target fixes (Maurizio, Daniel, Hannes, Christoph) - discard fixes and improvements (Christoph) - timeout debug improvements (Keith, Max) - various cleanups (Daniel, Max, Giuxen) - trace event string fixes (Arnd) - shadow doorbell setup on reset fix (William) - a write zeroes quirk for SK Hynix (Jim) - MD pull request via Song: - Sparse warning since v6.0 (Bart) - /proc/mdstat regression since v6.7 (Yu Kuai) - Use symbolic error value (Christian) - IO Priority documentation update (Christian) - Fix for accessing queue limits without having entered the queue (Christoph, me) - Fix for loop dio support (Christoph) - Move null_blk off deprecated ida interface (Christophe) - Ensure nbd initializes full msghdr (Eric) - Fix for a regression with the folio conversion, which is now easier to hit because of an unrelated change (Matthew) - Remove redundant check in virtio-blk (Li) - Fix for a potential hang in sbitmap (Ming) - Fix for partial zone appending (Damien) - Misc changes and fixes (Bart, me, Kemeng, Dmitry) * tag 'for-6.8/block-2024-01-18' of git://git.kernel.dk/linux: (45 commits) Documentation: block: ioprio: Update schedulers loop: fix the the direct I/O support check when used on top of block devices blk-mq: Remove the hctx 'run' debugfs attribute nbd: always initialize struct msghdr completely block: Fix iterating over an empty bio with bio_for_each_folio_all block: bio-integrity: fix kcalloc() arguments order virtio_blk: remove duplicate check if queue is broken in virtblk_done sbitmap: remove stale comment in sbq_calc_wake_batch block: Correct a documentation comment in blk-cgroup.c null_blk: Remove usage of the deprecated ida_simple_xx() API block: ensure we hold a queue reference when using queue limits blk-mq: rename blk_mq_can_use_cached_rq block: print symbolic error name instead of error code blk-mq: fix IO hang from sbitmap wakeup race nvmet-rdma: avoid circular locking dependency on install_queue() nvmet-tcp: avoid circular locking dependency on install_queue() nvme-pci: set doorbell config before unquiescing block: fix partial zone append completion handling in req_bio_endio() block/iocost: silence warning on 'last_period' potentially being unused md/raid1: Use blk_opf_t for read and write operations ...
2024-01-11Merge tag 'for-6.8/block-2024-01-08' of git://git.kernel.dk/linuxLinus Torvalds
Pull block updates from Jens Axboe: "Pretty quiet round this time around. This contains: - NVMe updates via Keith: - nvme fabrics spec updates (Guixin, Max) - nvme target udpates (Guixin, Evan) - nvme attribute refactoring (Daniel) - nvme-fc numa fix (Keith) - MD updates via Song: - Fix/Cleanup RCU usage from conf->disks[i].rdev (Yu Kuai) - Fix raid5 hang issue (Junxiao Bi) - Add Yu Kuai as Reviewer of the md subsystem - Remove deprecated flavors (Song Liu) - raid1 read error check support (Li Nan) - Better handle events off-by-1 case (Alex Lyakas) - Efficiency improvements for passthrough (Kundan) - Support for mapping integrity data directly (Keith) - Zoned write fix (Damien) - rnbd fixes (Kees, Santosh, Supriti) - Default to a sane discard size granularity (Christoph) - Make the default max transfer size naming less confusing (Christoph) - Remove support for deprecated host aware zoned model (Christoph) - Misc fixes (me, Li, Matthew, Min, Ming, Randy, liyouhong, Daniel, Bart, Christoph)" * tag 'for-6.8/block-2024-01-08' of git://git.kernel.dk/linux: (78 commits) block: Treat sequential write preferred zone type as invalid block: remove disk_clear_zoned sd: remove the !ZBC && blk_queue_is_zoned case in sd_read_block_characteristics drivers/block/xen-blkback/common.h: Fix spelling typo in comment blk-cgroup: fix rcu lockdep warning in blkg_lookup() blk-cgroup: don't use removal safe list iterators block: floor the discard granularity to the physical block size mtd_blkdevs: use the default discard granularity bcache: use the default discard granularity zram: use the default discard granularity null_blk: use the default discard granularity nbd: use the default discard granularity ubd: use the default discard granularity block: default the discard granularity to sector size bcache: discard_granularity should not be smaller than a sector block: remove two comments in bio_split_discard block: rename and document BLK_DEF_MAX_SECTORS loop: don't abuse BLK_DEF_MAX_SECTORS aoe: don't abuse BLK_DEF_MAX_SECTORS null_blk: don't cap max_hw_sectors to BLK_DEF_MAX_SECTORS ...
2024-01-09md: Fix md_seq_ops() regressionsYu Kuai
Commit cf1b6d4441ff ("md: simplify md_seq_ops") introduce following regressions: 1) If list all_mddevs is emptly, personalities and unused devices won't be showed to user anymore. 2) If seq_file buffer overflowed from md_seq_show(), then md_seq_start() will be called again, hence personalities will be showed to user again. 3) If seq_file buffer overflowed from md_seq_stop(), seq_read_iter() doesn't handle this, hence unused devices won't be showed to user. Fix above problems by printing personalities and unused devices in md_seq_show(). Fixes: cf1b6d4441ff ("md: simplify md_seq_ops") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240109133957.2975272-1-yukuai1@huaweicloud.com
2023-12-19md: Remove deprecated CONFIG_MD_MULTIPATHSong Liu
md-multipath has been marked as deprecated for 2.5 years. Remove it. Cc: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Neil Brown <neilb@suse.de> Cc: Guoqing Jiang <guoqing.jiang@linux.dev> Cc: Mateusz Grzonka <mateusz.grzonka@intel.com> Cc: Jes Sorensen <jes@trained-monkey.org> Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20231214222107.2016042-3-song@kernel.org
2023-12-19md: Remove deprecated CONFIG_MD_LINEARSong Liu
md-linear has been marked as deprecated for 2.5 years. Remove it. Cc: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Neil Brown <neilb@suse.de> Cc: Guoqing Jiang <guoqing.jiang@linux.dev> Cc: Mateusz Grzonka <mateusz.grzonka@intel.com> Cc: Jes Sorensen <jes@trained-monkey.org> Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20231214222107.2016042-2-song@kernel.org
2023-12-18dm-raid: delay flushing event_work() after reconfig_mutex is releasedYu Kuai
After commit db5e653d7c9f ("md: delay choosing sync action to md_start_sync()"), md_start_sync() will hold 'reconfig_mutex', however, in order to make sure event_work is done, __md_stop() will flush workqueue with reconfig_mutex grabbed, hence if sync_work is still pending, deadlock will be triggered. Fortunately, former pacthes to fix stopping sync_thread already make sure all sync_work is done already, hence such deadlock is not possible anymore. However, in order not to cause confusions for people by this implicit dependency, delay flushing event_work to dm-raid where 'reconfig_mutex' is not held, and add some comments to emphasize that the workqueue can't be flushed with 'reconfig_mutex'. Fixes: db5e653d7c9f ("md: delay choosing sync action to md_start_sync()") Depends-on: f52f5c71f3d4 ("md: fix stopping sync thread") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Xiao Ni <xni@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-12-15md: Whenassemble the array, consult the superblock of the freshest deviceAlex Lyakas
Upon assembling the array, both kernel and mdadm allow the devices to have event counter difference of 1, and still consider them as up-to-date. However, a device whose event count is behind by 1, may in fact not be up-to-date, and array resync with such a device may cause data corruption. To avoid this, consult the superblock of the freshest device about the status of a device, whose event counter is behind by 1. Signed-off-by: Alex Lyakas <alex.lyakas@zadara.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/1702470271-16073-1-git-send-email-alex.lyakas@zadara.com
2023-12-07md: split MD_RECOVERY_NEEDED out of mddev_resumeYu Kuai
New mddev_resume() calls are added to synchronize IO with array reconfiguration, however, this introduces a performance regression while adding it in md_start_sync(): 1) someone sets MD_RECOVERY_NEEDED first; 2) daemon thread grabs reconfig_mutex, then clears MD_RECOVERY_NEEDED and queues a new sync work; 3) daemon thread releases reconfig_mutex; 4) in md_start_sync a) check that there are spares that can be added/removed, then suspend the array; b) remove_and_add_spares may not be called, or called without really add/remove spares; c) resume the array, then set MD_RECOVERY_NEEDED again! Loop between 2 - 4, then mddev_suspend() will be called quite often, for consequence, normal IO will be quite slow. Fix this problem by don't set MD_RECOVERY_NEEDED again in md_start_sync(), hence the loop will be broken. Fixes: bc08041b32ab ("md: suspend array in md_start_sync() if array need reconfiguration") Suggested-by: Song Liu <song@kernel.org> Reported-by: Janpieter Sollie <janpieter.sollie@edpnet.be> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218200 Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231207020724.2797445-1-yukuai1@huaweicloud.com
2023-12-06md: fix stopping sync threadYu Kuai
Currently sync thread is stopped from multiple contex: - idle_sync_thread - frozen_sync_thread - __md_stop_writes - md_set_readonly - do_md_stop And there are some problems: 1) sync_work is flushed while reconfig_mutex is grabbed, this can deadlock because the work function will grab reconfig_mutex as well. 2) md_reap_sync_thread() can't be called directly while md_do_sync() is not finished yet, for example, commit 130443d60b1b ("md: refactor idle/frozen_sync_thread() to fix deadlock"). 3) If MD_RECOVERY_RUNNING is not set, there is no need to stop sync_thread at all because sync_thread must not be registered. Factor out a helper stop_sync_thread(), so that above contex will behave the same. Fix 1) by flushing sync_work after reconfig_mutex is released, before waiting for sync_thread to be done; Fix 2) bt letting daemon thread to unregister sync_thread; Fix 3) by always checking MD_RECOVERY_RUNNING first. Fixes: db5e653d7c9f ("md: delay choosing sync action to md_start_sync()") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231205094215.1824240-4-yukuai1@huaweicloud.com
2023-12-06md: don't leave 'MD_RECOVERY_FROZEN' in error path of md_set_readonly()Yu Kuai
If md_set_readonly() failed, the array could still be read-write, however 'MD_RECOVERY_FROZEN' could still be set, which leave the array in an abnormal state that sync or recovery can't continue anymore. Hence make sure the flag is cleared after md_set_readonly() returns. Fixes: 88724bfa68be ("md: wait for pending superblock updates before switching to read-only") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Xiao Ni <xni@redhat.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231205094215.1824240-3-yukuai1@huaweicloud.com
2023-12-06md: fix missing flush of sync_workYu Kuai
Commit ac619781967b ("md: use separate work_struct for md_start_sync()") use a new sync_work to replace del_work, however, stop_sync_thread() and __md_stop_writes() was trying to wait for sync_thread to be done, hence they should switch to use sync_work as well. Noted that md_start_sync() from sync_work will grab 'reconfig_mutex', hence other contex can't held the same lock to flush work, and this will be fixed in later patches. Fixes: ac619781967b ("md: use separate work_struct for md_start_sync()") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Xiao Ni <xni@redhat.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231205094215.1824240-2-yukuai1@huaweicloud.com
2023-12-01md: synchronize flush io with array reconfigurationYu Kuai
Currently rcu is used to protect iterating rdev from submit_flushes(): submit_flushes remove_and_add_spares synchronize_rcu pers->hot_remove_disk() rcu_read_lock() rdev_for_each_rcu if (rdev->raid_disk >= 0) rdev->radi_disk = -1; atomic_inc(&rdev->nr_pending) rcu_read_unlock() bi = bio_alloc_bioset() bi->bi_end_io = md_end_flush bi->private = rdev submit_bio // issue io for removed rdev Fix this problem by grabbing 'acive_io' before iterating rdev, make sure that remove_and_add_spares() won't concurrent with submit_flushes(). Fixes: a2826aa92e2e ("md: support barrier requests on all personalities.") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231129020234.1586910-1-yukuai1@huaweicloud.com
2023-11-27md: remove flag RemoveSynchronizedYu Kuai
rcu is not used correctly here, because synchronize_rcu() is called before replacing old value, for example: remove_and_add_spares // other path synchronize_rcu // called before replacing old value set_bit(RemoveSynchronized) rcu_read_lock() rdev = conf->mirros[].rdev pers->hot_remove_disk conf->mirros[].rdev = NULL; if (!test_bit(RemoveSynchronized)) synchronize_rcu /* * won't be called, and won't wait * for concurrent readers to be done. */ // access rdev after remove_and_add_spares() rcu_read_unlock() Fortunately, there is a separate rcu protection to prevent such rdev to be freed: md_kick_rdev_from_array //other path rcu_read_lock() rdev = conf->mirros[].rdev list_del_rcu(&rdev->same_set) rcu_read_unlock() /* * rdev can be removed from conf, but * rdev won't be freed. */ synchronize_rcu() free rdev Hence remove this useless flag and prepare to remove rcu protection to access rdev from 'conf'. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231125081604.3939938-2-yukuai1@huaweicloud.com
2023-11-27md: bypass block throttle for superblock updateJunxiao Bi
commit 5e2cf333b7bd ("md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d") introduced a hung bug and will be reverted in next patch, since the issue that commit is fixing is due to md superblock write is throttled by wbt, to fix it, we can have superblock write bypass block layer throttle. Fixes: 5e2cf333b7bd ("md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d") Cc: stable@vger.kernel.org # v5.19+ Suggested-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231108182216.73611-1-junxiao.bi@oracle.com
2023-11-19md: fix bi_status reporting in md_end_clone_ioSong Liu
md_end_clone_io() may overwrite error status in orig_bio->bi_status with BLK_STS_OK. This could happen when orig_bio has BIO_CHAIN (split by md_submit_bio => bio_split_to_limits, for example). As a result, upper layer may miss error reported from md (or the device) and consider the failed IO was successful. Fix this by only update orig_bio->bi_status when current bio reports error and orig_bio is BLK_STS_OK. This is the same behavior as __bio_chain_endio(). Fixes: 10764815ff47 ("md: add io accounting for raid0 and raid5") Cc: stable@vger.kernel.org # v5.14+ Reported-by: Bhanu Victor DiCara <00bvd0+linux@gmail.com> Closes: https://lore.kernel.org/regressions/5727380.DvuYhMxLoT@bvd0/ Signed-off-by: Song Liu <song@kernel.org> Tested-by: Xiao Ni <xni@redhat.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
2023-11-01Merge tag 'sysctl-6.7-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull sysctl updates from Luis Chamberlain: "To help make the move of sysctls out of kernel/sysctl.c not incur a size penalty sysctl has been changed to allow us to not require the sentinel, the final empty element on the sysctl array. Joel Granados has been doing all this work. On the v6.6 kernel we got the major infrastructure changes required to support this. For v6.7-rc1 we have all arch/ and drivers/ modified to remove the sentinel. Both arch and driver changes have been on linux-next for a bit less than a month. It is worth re-iterating the value: - this helps reduce the overall build time size of the kernel and run time memory consumed by the kernel by about ~64 bytes per array - the extra 64-byte penalty is no longer inncurred now when we move sysctls out from kernel/sysctl.c to their own files For v6.8-rc1 expect removal of all the sentinels and also then the unneeded check for procname == NULL. The last two patches are fixes recently merged by Krister Johansen which allow us again to use softlockup_panic early on boot. This used to work but the alias work broke it. This is useful for folks who want to detect softlockups super early rather than wait and spend money on cloud solutions with nothing but an eventual hung kernel. Although this hadn't gone through linux-next it's also a stable fix, so we might as well roll through the fixes now" * tag 'sysctl-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (23 commits) watchdog: move softlockup_panic back to early_param proc: sysctl: prevent aliased sysctls from getting passed to init intel drm: Remove now superfluous sentinel element from ctl_table array Drivers: hv: Remove now superfluous sentinel element from ctl_table array raid: Remove now superfluous sentinel element from ctl_table array fw loader: Remove the now superfluous sentinel element from ctl_table array sgi-xp: Remove the now superfluous sentinel element from ctl_table array vrf: Remove the now superfluous sentinel element from ctl_table array char-misc: Remove the now superfluous sentinel element from ctl_table array infiniband: Remove the now superfluous sentinel element from ctl_table array macintosh: Remove the now superfluous sentinel element from ctl_table array parport: Remove the now superfluous sentinel element from ctl_table array scsi: Remove now superfluous sentinel element from ctl_table array tty: Remove now superfluous sentinel element from ctl_table array xen: Remove now superfluous sentinel element from ctl_table array hpet: Remove now superfluous sentinel element from ctl_table array c-sky: Remove now superfluous sentinel element from ctl_talbe array powerpc: Remove now superfluous sentinel element from ctl_table arrays riscv: Remove now superfluous sentinel element from ctl_table array x86/vdso: Remove now superfluous sentinel element from ctl_table array ...
2023-11-01Merge tag 'for-6.7/block-2023-10-30' of git://git.kernel.dk/linuxLinus Torvalds
Pull block updates from Jens Axboe: - Improvements to the queue_rqs() support, and adding null_blk support for that as well (Chengming) - Series improving badblocks support (Coly) - Key store support for sed-opal (Greg) - IBM partition string handling improvements (Jan) - Make number of ublk devices supported configurable (Mike) - Cancelation improvements for ublk (Ming) - MD pull requests via Song: - Handle timeout in md-cluster, by Denis Plotnikov - Cleanup pers->prepare_suspend, by Yu Kuai - Rewrite mddev_suspend(), by Yu Kuai - Simplify md_seq_ops, by Yu Kuai - Reduce unnecessary locking array_state_store(), by Mariusz Tkaczyk - Make rdev add/remove independent from daemon thread, by Yu Kuai - Refactor code around quiesce() and mddev_suspend(), by Yu Kuai - NVMe pull request via Keith: - nvme-auth updates (Mark) - nvme-tcp tls (Hannes) - nvme-fc annotaions (Kees) - Misc cleanups and improvements (Jiapeng, Joel) * tag 'for-6.7/block-2023-10-30' of git://git.kernel.dk/linux: (95 commits) block: ublk_drv: Remove unused function md: cleanup pers->prepare_suspend() nvme-auth: allow mixing of secret and hash lengths nvme-auth: use transformed key size to create resp nvme-auth: alloc nvme_dhchap_key as single buffer nvmet-tcp: use 'spin_lock_bh' for state_lock() powerpc/pseries: PLPKS SED Opal keystore support block: sed-opal: keystore access for SED Opal keys block:sed-opal: SED Opal keystore ublk: simplify aborting request ublk: replace monitor with cancelable uring_cmd ublk: quiesce request queue when aborting queue ublk: rename mm_lock as lock ublk: move ublk_cancel_dev() out of ub->mutex ublk: make sure io cmd handled in submitter task context ublk: don't get ublk device reference in ublk_abort_queue() ublk: Make ublks_max configurable ublk: Limit dev_id/ub_number values md-cluster: check for timeout while a new disk adding nvme: rework NVME_AUTH Kconfig selection ...
2023-10-28md: Convert to bdev_open_by_dev()Jan Kara
Convert md to use bdev_open_by_dev() and pass the handle around. We also don't need the 'Holder' flag anymore so remove it. CC: linux-raid@vger.kernel.org CC: Song Liu <song@kernel.org> Acked-by: Song Liu <song@kernel.org> Acked-by: Christoph Hellwig <hch@lst.de> Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-11-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-18md: cleanup pers->prepare_suspend()Yu Kuai
pers->prepare_suspend() is not used anymore and can be removed. Reverts following three commit: - commit 431e61257d63 ("md: export md_is_rdwr() and is_md_suspended()") - commit 3e00777d5157 ("md: add a new api prepare_suspend() in md_personality") - commit 868bba54a3bc ("md/raid5: fix a deadlock in the case that reshape is interrupted") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231016100240.540474-1-yukuai1@huaweicloud.com
2023-10-11raid: Remove now superfluous sentinel element from ctl_table arrayJoel Granados
This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove sentinel from raid_table Signed-off-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-10-10md: rename __mddev_suspend/resume() back to mddev_suspend/resume()Yu Kuai
Now that the old apis are removed, __mddev_suspend/resume() can be renamed to their original names. This is done by: sed -i "s/__mddev_suspend/mddev_suspend/g" *.[ch] sed -i "s/__mddev_resume/mddev_resume/g" *.[ch] Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-20-yukuai1@huaweicloud.com
2023-10-10md: remove old apis to suspend the arrayYu Kuai
Now that mddev_suspend() and mddev_resume() is not used anywhere, remove them, and remove 'MD_ALLOW_SB_UPDATE' and 'MD_UPDATING_SB' as well. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-19-yukuai1@huaweicloud.com
2023-10-10md: suspend array in md_start_sync() if array need reconfigurationYu Kuai
So that io won't concurrent with array reconfiguration, and it's safe to suspend the array directly because normal io won't rely on md_start_sync(). Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-18-yukuai1@huaweicloud.com
2023-10-10md: cleanup mddev_create/destroy_serial_pool()Yu Kuai
Now that except for stopping the array, all the callers already suspend the array, there is no need to suspend anymore, hence remove the second parameter. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-15-yukuai1@huaweicloud.com
2023-10-10md: use new apis to suspend array before mddev_create/destroy_serial_poolYu Kuai
mddev_create/destroy_serial_pool() will be called from several places where mddev_suspend() will be called later. Prepare to remove the mddev_suspend() from mddev_create/destroy_serial_pool(). Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-14-yukuai1@huaweicloud.com
2023-10-10md: use new apis to suspend array for ioctls involed array reconfigurationYu Kuai
'reconfig_mutex' will be grabbed before these ioctls, suspend array before holding the lock, so that io won't concurrent with array reconfiguration through ioctls. This is not hot path, so performance is not concerned. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-13-yukuai1@huaweicloud.com
2023-10-10md: use new apis to suspend array for adding/removing rdev from state_store()Yu Kuai
User can write 'remove' and 're-add' to trigger array reconfiguration through sysfs, suspend array in this case so that io won't concurrent with array reconfiguration. And now that all the caller of add_bound_rdev() alread suspend the array, remove mddev_suspend/resume() from add_bound_rdev() as well. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-12-yukuai1@huaweicloud.com
2023-10-10md: use new apis to suspend array for sysfs apisYu Kuai
Convert to use new apis in following sysfs apis: - level_store - suspend_lo_store - suspend_hi_store - serialize_policy_store These are not hot path, so performance is not concerned. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-11-yukuai1@huaweicloud.com
2023-10-10md: add new helpers to suspend/resume arrayYu Kuai
Advantages for new apis: - reconfig_mutex is not required; - the weird logical that suspend array hold 'reconfig_mutex' for mddev_check_recovery() to update superblock is not needed; - the specail handling, 'pers->prepare_suspend', for raid456 is not needed; - It's safe to be called at any time once mddev is allocated, and it's designed to be used from slow path where array configuration is changed; - the new helpers is designed to be called before mddev_lock(), hence it support to be interrupted by user as well. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-5-yukuai1@huaweicloud.com
2023-10-10md: replace is_md_suspended() with 'mddev->suspended' in md_check_recovery()Yu Kuai
Prepare to cleanup pers->prepare_suspend(), which is used to fix a deadlock in raid456 by returning error for io that is waiting for reshape to make progress in mddev_suspend(). This change will allow reshape to make progress while waiting for io to be done in mddev_suspend() in following patches. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-4-yukuai1@huaweicloud.com
2023-10-10md: use READ_ONCE/WRITE_ONCE for 'suspend_lo' and 'suspend_hi'Yu Kuai
Protect 'suspend_lo' and 'suspend_hi' with READ_ONCE/WRITE_ONCE to prevent reading abnormal values. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-2-yukuai1@huaweicloud.com
2023-09-28md: do not require mddev_lock() for all options in array_state_store()Mariusz Tkaczyk
We don't need to lock device to reject not supported request in array_state_store(). No functional changes intended. There are differences between ioctl and sysfs handling during stopping. With this change, it will be easier to add additional steps which needs to be completed before mddev_lock() is taken. Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230928125517.12356-1-mariusz.tkaczyk@linux.intel.com
2023-09-27md: simplify md_seq_opsYu Kuai
Before this patch, the implementation is hacky and hard to understand: 1) md_seq_start set pos to 1; 2) md_seq_show found pos is 1, then print Personalities; 3) md_seq_next found pos is 1, then it update pos to the first mddev; 4) md_seq_show found pos is not 1 or 2, show mddev; 5) md_seq_next found pos is not 1 or 2, update pos to next mddev; 6) loop 4-5 until the last mddev, then md_seq_next update pos to 2; 7) md_seq_show found pos is 2, then print unused devices; 8) md_seq_next found pos is 2, stop; This patch remove the magic value and use seq_list_start/next/stop() directly, and move printing "Personalities" to md_seq_start(), "unsed devices" to md_seq_stop(): 1) md_seq_start print Personalities, and then set pos to first mddev; 2) md_seq_show show mddev; 3) md_seq_next update pos to next mddev; 4) loop 2-3 until the last mddev; 5) md_seq_stop print unsed devices; Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230927061241.1552837-3-yukuai1@huaweicloud.com
2023-09-27md: factor out a helper from mddev_put()Yu Kuai
There are no functional changes, prepare to simplify md_seq_ops in next patch. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230927061241.1552837-2-yukuai1@huaweicloud.com
2023-09-25md: replace deprecated strncpy with memcpyJustin Stitt
`strncpy` is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. There are three such strncpy uses that this patch addresses: The respective destination buffers are: 1) mddev->clevel 2) clevel 3) mddev->metadata_type We expect mddev->clevel to be NUL-terminated due to its use with format strings: | ret = sprintf(page, "%s\n", mddev->clevel); Furthermore, we can see that mddev->clevel is not expected to be NUL-padded as `md_clean()` merely set's its first byte to NULL -- not the entire buffer: | static void md_clean(struct mddev *mddev) | { | mddev->array_sectors = 0; | mddev->external_size = 0; | ... | mddev->level = LEVEL_NONE; | mddev->clevel[0] = 0; | ... A suitable replacement for this instance is `memcpy` as we know the number of bytes to copy and perform manual NUL-termination at a specified offset. This really decays to just a byte copy from one buffer to another. `strscpy` is also a considerable replacement but using `slen` as the length argument would result in truncation of the last byte unless something like `slen + 1` was provided which isn't the most idiomatic strscpy usage. For the next case, the destination buffer `clevel` is expected to be NUL-terminated based on its usage within kstrtol() which expects NUL-terminated strings. Note that, in context, this code removes a trailing newline which is seemingly not required as kstrtol() can handle trailing newlines implicitly. However, there exists further usage of clevel (or buf) that would also like to have the newline removed. All in all, with similar reasoning to the first case, let's just use memcpy as this is just a byte copy and NUL-termination is handled manually. The third and final case concerning `mddev->metadata_type` is more or less the same as the other two. We expect that it be NUL-terminated based on its usage with seq_printf: | seq_printf(seq, " super external:%s", | mddev->metadata_type); ... and we can surmise that NUL-padding isn't required either due to how it is handled in md_clean(): | static void md_clean(struct mddev *mddev) | { | ... | mddev->metadata_type[0] = 0; | ... So really, all these instances have precisely calculated lengths and purposeful NUL-termination so we can just use memcpy to remove ambiguity surrounding strncpy. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230925-strncpy-drivers-md-md-c-v1-1-2b0093b89c2b@google.com
2023-09-22md: don't check 'mddev->pers' and 'pers->quiesce' from suspend_lo_store()Yu Kuai
Now that mddev_suspend() doean't rely on 'mddev->pers' to be set, it's safe to remove such checking. This will also allow the array to be suspended even before the array is ran. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230825030956.1527023-8-yukuai1@huaweicloud.com
2023-09-22md: don't check 'mddev->pers' from suspend_hi_store()Yu Kuai
Now that mddev_suspend() doean't rely on 'mddev->pers' to be set, it's safe to remove such checking. This will also allow the array to be suspended even before the array is ran. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230825030956.1527023-7-yukuai1@huaweicloud.com