kernel/git/stable/linux-stable.git/drivers/md/raid5.c, branch linux-6.10.y

md/raid5: avoid BUG_ON() while continue reshape after reassembling

2024-08-14T13:34:06+00:00

[ Upstream commit 305a5170dc5cf3d395bb4c4e9239bca6d0b54b49 ] Currently, mdadm support --revert-reshape to abort the reshape while reassembling, as the test 07revert-grow. However, following BUG_ON() can be triggerred by the test: kernel BUG at drivers/md/raid5.c:6278! invalid opcode: 0000 [#1] PREEMPT SMP PTI irq event stamp: 158985 CPU: 6 PID: 891 Comm: md0_reshape Not tainted 6.9.0-03335-g7592a0b0049a #94 RIP: 0010:reshape_request+0x3f1/0xe60 Call Trace: raid5_sync_request+0x43d/0x550 md_do_sync+0xb7a/0x2110 md_thread+0x294/0x2b0 kthread+0x147/0x1c0 ret_from_fork+0x59/0x70 ret_from_fork_asm+0x1a/0x30 Root cause is that --revert-reshape update the raid_disks from 5 to 4, while reshape position is still set, and after reassembling the array, reshape position will be read from super block, then during reshape the checking of 'writepos' that is caculated by old reshape position will fail. Fix this panic the easy way first, by converting the BUG_ON() to WARN_ON(), and stop the reshape if checkings fail. Noted that mdadm must fix --revert-shape as well, and probably md/raid should enhance metadata validation as well, however this means reassemble will fail and there must be user tools to fix the wrong metadata. Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240611132251.1967786-13-yukuai1@huaweicloud.com Signed-off-by: Sasha Levin

md: change the return value type of md_write_start to void

2024-08-14T13:34:06+00:00

[ Upstream commit 03e792eaf18ec2e93e2c623f9f1a4bdb97fe4126 ] Commit cc27b0c78c79 ("md: fix deadlock between mddev_suspend() and md_write_start()") aborted md_write_start() with false when mddev is suspended, which fixed a deadlock if calling mddev_suspend() with holding reconfig_mutex(). Since mddev_suspend() now includes lockdep_assert_not_held(), it no longer holds the reconfig_mutex. This makes previous abort unnecessary. Now, remove unnecessary abort and change function return value to void. Signed-off-by: Li Nan Reviewed-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240525185257.3896201-2-linan666@huaweicloud.com Signed-off-by: Sasha Levin

md/raid5: fix spares errors about rcu usage

2024-08-03T07:00:32+00:00

commit 2314c2e3a70521f055dd011245dccf6fd97c7ee0 upstream. As commit ad8606702f26 ("md/raid5: remove rcu protection to access rdev from conf") explains, rcu protection can be removed, however, there are three places left, there won't be any real problems. drivers/md/raid5.c:8071:24: error: incompatible types in comparison expression (different address spaces): drivers/md/raid5.c:8071:24: struct md_rdev [noderef] __rcu * drivers/md/raid5.c:8071:24: struct md_rdev * drivers/md/raid5.c:7569:25: error: incompatible types in comparison expression (different address spaces): drivers/md/raid5.c:7569:25: struct md_rdev [noderef] __rcu * drivers/md/raid5.c:7569:25: struct md_rdev * drivers/md/raid5.c:7573:25: error: incompatible types in comparison expression (different address spaces): drivers/md/raid5.c:7573:25: struct md_rdev [noderef] __rcu * drivers/md/raid5.c:7573:25: struct md_rdev * Fixes: ad8606702f26 ("md/raid5: remove rcu protection to access rdev from conf") Cc: stable@vger.kernel.org Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240615085143.1648223-1-yukuai1@huaweicloud.com Signed-off-by: Greg Kroah-Hartman

md/raid5: recheck if reshape has finished with device_lock held

2024-08-03T06:59:13+00:00

[ Upstream commit 25b3a8237a03ec0b67b965b52d74862e77ef7115 ] When handling an IO request, MD checks if a reshape is currently happening, and if so, where the IO sector is in relation to the reshape progress. MD uses conf->reshape_progress for both of these tasks. When the reshape finishes, conf->reshape_progress is set to MaxSector. If this occurs after MD checks if the reshape is currently happening but before it calls ahead_of_reshape(), then ahead_of_reshape() will end up comparing the IO sector against MaxSector. During a backwards reshape, this will make MD think the IO sector is in the area not yet reshaped, causing it to use the previous configuration, and map the IO to the sector where that data was before the reshape. This bug can be triggered by running the lvm2 lvconvert-raid-reshape-linear_to_raid6-single-type.sh test in a loop, although it's very hard to reproduce. Fix this by factoring the code that checks where the IO sector is in relation to the reshape out to a helper called get_reshape_loc(), which reads reshape_progress and reshape_safe while holding the device_lock, and then rechecks if the reshape has finished before calling ahead_of_reshape with the saved values. Also use the helper during the REQ_NOWAIT check to see if the location is inside of the reshape region. Fixes: fef9c61fdfabf ("md/raid5: change reshape-progress measurement to cope with reshaping backwards.") Signed-off-by: Benjamin Marzinski Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240702151802.1632010-1-bmarzins@redhat.com Signed-off-by: Sasha Levin

md/raid5: fix deadlock that raid5d() wait for itself to clear MD_SB_CHANGE_PENDING

2024-04-09T03:59:19+00:00

Xiao reported that lvm2 test lvconvert-raid-takeover.sh can hang with small possibility, the root cause is exactly the same as commit bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"") However, Dan reported another hang after that, and junxiao investigated the problem and found out that this is caused by plugged bio can't issue from raid5d(). Current implementation in raid5d() has a weird dependence: 1) md_check_recovery() from raid5d() must hold 'reconfig_mutex' to clear MD_SB_CHANGE_PENDING; 2) raid5d() handles IO in a deadloop, until all IO are issued; 3) IO from raid5d() must wait for MD_SB_CHANGE_PENDING to be cleared; This behaviour is introduce before v2.6, and for consequence, if other context hold 'reconfig_mutex', and md_check_recovery() can't update super_block, then raid5d() will waste one cpu 100% by the deadloop, until 'reconfig_mutex' is released. Refer to the implementation from raid1 and raid10, fix this problem by skipping issue IO if MD_SB_CHANGE_PENDING is still set after md_check_recovery(), daemon thread will be woken up when 'reconfig_mutex' is released. Meanwhile, the hang problem will be fixed as well. Fixes: 5e2cf333b7bd ("md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d") Cc: stable@vger.kernel.org # v5.19+ Reported-and-tested-by: Dan Moulding Closes: https://lore.kernel.org/all/20240123005700.9302-1-dan@danm.net/ Investigated-by: Junxiao Bi Signed-off-by: Yu Kuai Link: https://lore.kernel.org/r/20240322081005.1112401-1-yukuai1@huaweicloud.com Signed-off-by: Song Liu

Merge tag 'for-6.9/block-20240310' of git://git.kernel.dk/linux

2024-03-11T18:43:44+00:00

Pull block updates from Jens Axboe: - MD pull requests via Song: - Cleanup redundant checks (Yu Kuai) - Remove deprecated headers (Marc Zyngier, Song Liu) - Concurrency fixes (Li Lingfeng) - Memory leak fix (Li Nan) - Refactor raid1 read_balance (Yu Kuai, Paul Luse) - Clean up and fix for md_ioctl (Li Nan) - Other small fixes (Gui-Dong Han, Heming Zhao) - MD atomic limits (Christoph) - NVMe pull request via Keith: - RDMA target enhancements (Max) - Fabrics fixes (Max, Guixin, Hannes) - Atomic queue_limits usage (Christoph) - Const use for class_register (Ricardo) - Identification error handling fixes (Shin'ichiro, Keith) - Improvement and cleanup for cached request handling (Christoph) - Moving towards atomic queue limits. Core changes and driver bits so far (Christoph) - Fix UAF issues in aoeblk (Chun-Yi) - Zoned fix and cleanups (Damien) - s390 dasd cleanups and fixes (Jan, Miroslav) - Block issue timestamp caching (me) - noio scope guarding for zoned IO (Johannes) - block/nvme PI improvements (Kanchan) - Ability to terminate long running discard loop (Keith) - bdev revalidation fix (Li) - Get rid of old nr_queues hack for kdump kernels (Ming) - Support for async deletion of ublk (Ming) - Improve IRQ bio recycling (Pavel) - Factor in CPU capacity for remote vs local completion (Qais) - Add shared_tags configfs entry for null_blk (Shin'ichiro - Fix for a regression in page refcounts introduced by the folio unification (Tony) - Misc fixes and cleanups (Arnd, Colin, John, Kunwu, Li, Navid, Ricardo, Roman, Tang, Uwe) * tag 'for-6.9/block-20240310' of git://git.kernel.dk/linux: (221 commits) block: partitions: only define function mac_fix_string for CONFIG_PPC_PMAC block/swim: Convert to platform remove callback returning void cdrom: gdrom: Convert to platform remove callback returning void block: remove disk_stack_limits md: remove mddev->queue md: don't initialize queue limits md/raid10: use the atomic queue limit update APIs md/raid5: use the atomic queue limit update APIs md/raid1: use the atomic queue limit update APIs md/raid0: use the atomic queue limit update APIs md: add queue limit helpers md: add a mddev_is_dm helper md: add a mddev_add_trace_msg helper md: add a mddev_trace_remap helper bcache: move calculation of stripe_size and io_opt into bcache_device_init virtio_blk: Do not use disk_set_max_open/active_zones() aoe: fix the potential use-after-free problem in aoecmd_cfg_pkts block: move capacity validation to blkpg_do_ioctl() block: prevent division by zero in blk_rq_stat_sum() drbd: atomically update queue limits in drbd_reconsider_queue_parameters ...

md: remove mddev->queue

2024-03-06T16:59:53+00:00

Just use the request_queue from the gendisk pointer in the relatively few places that sill need it. Signed-off-by: Christoph Hellwig Reviewed--by: Song Liu Tested-by: Song Liu Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240303140150.5435-11-hch@lst.de

md/raid5: use the atomic queue limit update APIs

2024-03-06T16:59:53+00:00

Build the queue limits outside the queue and apply them using queue_limits_set. To make the code more obvious also split the queue limits handling into separate helpers. Signed-off-by: Christoph Hellwig Reviewed--by: Song Liu Tested-by: Song Liu Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240303140150.5435-8-hch@lst.de

md: add a mddev_is_dm helper

2024-03-06T16:59:53+00:00

Add a helper to check for a DM-mapped MD device instead of using the obfuscated ->gendisk or ->queue NULL checks. Signed-off-by: Christoph Hellwig Reviewed--by: Song Liu Tested-by: Song Liu Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240303140150.5435-4-hch@lst.de

md: add a mddev_add_trace_msg helper

2024-03-06T16:59:52+00:00

Add a small wrapper around blk_add_trace_msg that hides some argument dereferences and the check for a DM-mapped MD device. Signed-off-by: Christoph Hellwig Reviewed--by: Song Liu Tested-by: Song Liu Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240303140150.5435-3-hch@lst.de