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2022-09-22md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5dLogan Gunthorpe1-0/+12
A complicated deadlock exists when using the journal and an elevated group_thrtead_cnt. It was found with loop devices, but its not clear whether it can be seen with real disks. The deadlock can occur simply by writing data with an fio script. When the deadlock occurs, multiple threads will hang in different ways: 1) The group threads will hang in the blk-wbt code with bios waiting to be submitted to the block layer: io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 __submit_bio+0xe6/0x100 submit_bio_noacct_nocheck+0x42e/0x470 submit_bio_noacct+0x4c2/0xbb0 ops_run_io+0x46b/0x1a30 handle_stripe+0xcd3/0x36b0 handle_active_stripes.constprop.0+0x6f6/0xa60 raid5_do_work+0x177/0x330 Or: io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 __submit_bio+0xe6/0x100 submit_bio_noacct_nocheck+0x42e/0x470 submit_bio_noacct+0x4c2/0xbb0 flush_deferred_bios+0x136/0x170 raid5_do_work+0x262/0x330 2) The r5l_reclaim thread will hang in the same way, submitting a bio to the block layer: io_schedule+0x70/0xb0 rq_qos_wait+0x153/0x210 wbt_wait+0x115/0x1b0 __rq_qos_throttle+0x38/0x60 blk_mq_submit_bio+0x589/0xcd0 __submit_bio+0xe6/0x100 submit_bio_noacct_nocheck+0x42e/0x470 submit_bio_noacct+0x4c2/0xbb0 submit_bio+0x3f/0xf0 md_super_write+0x12f/0x1b0 md_update_sb.part.0+0x7c6/0xff0 md_update_sb+0x30/0x60 r5l_do_reclaim+0x4f9/0x5e0 r5l_reclaim_thread+0x69/0x30b However, before hanging, the MD_SB_CHANGE_PENDING flag will be set for sb_flags in r5l_write_super_and_discard_space(). This flag will never be cleared because the submit_bio() call never returns. 3) Due to the MD_SB_CHANGE_PENDING flag being set, handle_stripe() will do no processing on any pending stripes and re-set STRIPE_HANDLE. This will cause the raid5d thread to enter an infinite loop, constantly trying to handle the same stripes stuck in the queue. The raid5d thread has a blk_plug that holds a number of bios that are also stuck waiting seeing the thread is in a loop that never schedules. These bios have been accounted for by blk-wbt thus preventing the other threads above from continuing when they try to submit bios. --Deadlock. To fix this, add the same wait_event() that is used in raid5_do_work() to raid5d() such that if MD_SB_CHANGE_PENDING is set, the thread will schedule and wait until the flag is cleared. The schedule action will flush the plug which will allow the r5l_reclaim thread to continue, thus preventing the deadlock. However, md_check_recovery() calls can also clear MD_SB_CHANGE_PENDING from the same thread and can thus deadlock if the thread is put to sleep. So avoid waiting if md_check_recovery() is being called in the loop. It's not clear when the deadlock was introduced, but the similar wait_event() call in raid5_do_work() was added in 2017 by this commit: 16d997b78b15 ("md/raid5: simplfy delaying of writes while metadata is updated.") Link: https://lore.kernel.org/r/7f3b87b6-b52a-f737-51d7-a4eec5c44112@deltatee.com Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org>
2022-09-22md/raid5: Remove unnecessary bio_put() in raid5_read_one_chunk()David Sloan1-1/+0
When running chunk-sized reads on disks with badblocks duplicate bio free/puts are observed: ============================================================================= BUG bio-200 (Not tainted): Object already free ----------------------------------------------------------------------------- Allocated in mempool_alloc_slab+0x17/0x20 age=3 cpu=2 pid=7504 __slab_alloc.constprop.0+0x5a/0xb0 kmem_cache_alloc+0x31e/0x330 mempool_alloc_slab+0x17/0x20 mempool_alloc+0x100/0x2b0 bio_alloc_bioset+0x181/0x460 do_mpage_readpage+0x776/0xd00 mpage_readahead+0x166/0x320 blkdev_readahead+0x15/0x20 read_pages+0x13f/0x5f0 page_cache_ra_unbounded+0x18d/0x220 force_page_cache_ra+0x181/0x1c0 page_cache_sync_ra+0x65/0xb0 filemap_get_pages+0x1df/0xaf0 filemap_read+0x1e1/0x700 blkdev_read_iter+0x1e5/0x330 vfs_read+0x42a/0x570 Freed in mempool_free_slab+0x17/0x20 age=3 cpu=2 pid=7504 kmem_cache_free+0x46d/0x490 mempool_free_slab+0x17/0x20 mempool_free+0x66/0x190 bio_free+0x78/0x90 bio_put+0x100/0x1a0 raid5_make_request+0x2259/0x2450 md_handle_request+0x402/0x600 md_submit_bio+0xd9/0x120 __submit_bio+0x11f/0x1b0 submit_bio_noacct_nocheck+0x204/0x480 submit_bio_noacct+0x32e/0xc70 submit_bio+0x98/0x1a0 mpage_readahead+0x250/0x320 blkdev_readahead+0x15/0x20 read_pages+0x13f/0x5f0 page_cache_ra_unbounded+0x18d/0x220 Slab 0xffffea000481b600 objects=21 used=0 fp=0xffff8881206d8940 flags=0x17ffffc0010201(locked|slab|head|node=0|zone=2|lastcpupid=0x1fffff) CPU: 0 PID: 34525 Comm: kworker/u24:2 Not tainted 6.0.0-rc2-localyes-265166-gf11c5343fa3f #143 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: raid5wq raid5_do_work Call Trace: <TASK> dump_stack_lvl+0x5a/0x78 dump_stack+0x10/0x16 print_trailer+0x158/0x165 object_err+0x35/0x50 free_debug_processing.cold+0xb7/0xbe __slab_free+0x1ae/0x330 kmem_cache_free+0x46d/0x490 mempool_free_slab+0x17/0x20 mempool_free+0x66/0x190 bio_free+0x78/0x90 bio_put+0x100/0x1a0 mpage_end_io+0x36/0x150 bio_endio+0x2fd/0x360 md_end_io_acct+0x7e/0x90 bio_endio+0x2fd/0x360 handle_failed_stripe+0x960/0xb80 handle_stripe+0x1348/0x3760 handle_active_stripes.constprop.0+0x72a/0xaf0 raid5_do_work+0x177/0x330 process_one_work+0x616/0xb20 worker_thread+0x2bd/0x6f0 kthread+0x179/0x1b0 ret_from_fork+0x22/0x30 </TASK> The double free is caused by an unnecessary bio_put() in the if(is_badblock(...)) error path in raid5_read_one_chunk(). The error path was moved ahead of bio_alloc_clone() in c82aa1b76787c ("md/raid5: move checking badblock before clone bio in raid5_read_one_chunk"). The previous code checked and freed align_bio which required a bio_put. After the move that is no longer needed as raid_bio is returned to the control of the common io path which performs its own endio resulting in a double free on bad device blocks. Fixes: c82aa1b76787c ("md/raid5: move checking badblock before clone bio in raid5_read_one_chunk") Signed-off-by: David Sloan <david.sloan@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Guoqing Jiang <Guoqing.jiang@linux.dev> Signed-off-by: Song Liu <song@kernel.org>
2022-09-22md/raid5: Ensure stripe_fill happens on non-read IO with journalLogan Gunthorpe1-1/+1
When doing degrade/recover tests using the journal a kernel BUG is hit at drivers/md/raid5.c:4381 in handle_parity_checks5(): BUG_ON(!test_bit(R5_UPTODATE, &dev->flags)); This was found to occur because handle_stripe_fill() was skipped for stripes in the journal due to a condition in that function. Thus blocks were not fetched and R5_UPTODATE was not set when the code reached handle_parity_checks5(). To fix this, don't skip handle_stripe_fill() unless the stripe is for read. Fixes: 07e83364845e ("md/r5cache: shift complex rmw from read path to write path") Link: https://lore.kernel.org/linux-raid/e05c4239-41a9-d2f7-3cfa-4aa9d2cea8c1@deltatee.com/ Suggested-by: Song Liu <song@kernel.org> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org>
2022-09-22md/raid5: Don't read ->active_stripes if it's not neededLogan Gunthorpe1-3/+2
The atomic_read() is not needed in many cases so only do the read after the first checks are done. Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org>
2022-09-22md/raid5: Cleanup prototype of raid5_get_active_stripe()Logan Gunthorpe1-23/+26
Drop the three bools in the prototype of raid5_get_active_stripe() and replace them with a flags parameter. At the same time, drop the distinction with __raid5_get_active_stripe(). Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org>
2022-09-22md/raid5: Refactor raid5_get_active_stripe()Logan Gunthorpe1-41/+41
Refactor raid5_get_active_stripe() without the gotos with an explicit infinite loop and some additional nesting. Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org>
2022-08-05Merge tag 'mm-stable-2022-08-03' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ...
2022-08-02drivers:md:fix a potential use-after-free bugWentao_Liang1-1/+1
In line 2884, "raid5_release_stripe(sh);" drops the reference to sh and may cause sh to be released. However, sh is subsequently used in lines 2886 "if (sh->batch_head && sh != sh->batch_head)". This may result in an use-after-free bug. It can be fixed by moving "raid5_release_stripe(sh);" to the bottom of the function. Signed-off-by: Wentao_Liang <Wentao_Liang_g@163.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Ensure batch_last is released before sleeping for quiesceLogan Gunthorpe1-8/+28
A race condition exists where if raid5_quiesce() is called in the middle of a request that has set batch_last, it will deadlock. batch_last will hold a reference to a stripe when raid5_quiesce() is called. This will cause the next raid5_get_active_stripe() call to sleep waiting for the quiesce to finish, but the raid5_quiesce() thread will wait for active_stripes to go to zero which will never happen because request thread is waiting for the quiesce to stop. Fix this by creating a special __raid5_get_active_stripe() function which takes the request context and clears the last_batch before sleeping. While we're at it, change the arguments of raid5_get_active_stripe() to bools. Fixes: 3312e6c887fe ("md/raid5: Keep a reference to last stripe_head for batch") Reported-by: David Sloan <David.Sloan@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Move stripe_request_ctx upLogan Gunthorpe1-27/+27
Move stripe_request_ctx up. No functional changes intended. This will be necessary in the next patch to release the batch_last in the context before sleeping. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Drop unnecessary call to r5c_check_stripe_cache_usage()Logan Gunthorpe1-1/+0
Now that raid5_get_active_stripe() has been refactored it is appearant that r5c_check_stripe_cache_usage() doesn't need to be called in the wait_for_stripe branch. r5c_check_stripe_cache_usage() will only conditionally call r5l_wake_reclaim(), but that function is called two lines later. Drop the call for cleanup. Reported-by: Martin Oliveira <martin.oliveira@eideticom.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Make is_inactive_blocked() helperLogan Gunthorpe1-5/+19
The logic to wait_for_stripe is difficult to parse being on so many lines and with confusing operator precedence. Move it to a helper function to make it easier to read. No functional changes intended. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Refactor raid5_get_active_stripe()Logan Gunthorpe1-31/+36
Refactor the raid5_get_active_stripe() to read more linearly in the order it's typically executed. The init_stripe() call is called if a free stripe is found and the function is exited early which removes a lot of if (sh) checks and unindents the following code. Remove the while loop in favour of the 'goto retry' pattern, which reduces indentation further. And use a 'goto wait_for_stripe' instead of an additional indent seeing it is the unusual path and this makes the code easier to read. No functional changes intended. Will make subsequent changes in patches easier to understand. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02raid5: fix duplicate checks for rdev->saved_raid_diskJackie Liu1-2/+1
'first' will always be greater than or equal to 0, it is unnecessary to repeat the 0 check, clean it up. Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Convert prepare_to_wait() to wait_woken() apiLogan Gunthorpe1-7/+6
raid5_get_active_stripe() can sleep in various situations and it is called by make_stripe_request() while inside the prepare_to_wait()/finish_wait() section. Nested waits like this are not supported. This was noticed while making other changes that add different sleeps to raid5_get_active_stripe() that caused a WARNING with CONFIG_DEBUG_ATOMIC_SLEEP. No ill effects have been noticed with the code as is, but theoretically a nested and here could cause a dead lock so it should be fixed. To fix this, convert the prepare_to_wait() call to use wake_woken() which supports nested sleeps. Link: https://lwn.net/Articles/628628/ Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Fix sectors_to_do bitmap overflow in raid5_make_request()Logan Gunthorpe1-8/+11
For unaligned IO that have nearly maximum sectors, the number of stripes will end up being one greater than the size of the bitmap. When this happens, the last stripe in the IO will not be processed as it should be, resulting in data corruption. However, this is not normally seen when the backing block devices have 4K physical block sizes since the block layer will split the request before that happens. To fix this increase the bitmap size by one bit and ensure the full number of stripes are checked when calling find_first_bit(). Reported-by: David Sloan <David.Sloan@eideticom.com> Fixes: 7e55c60acfbb ("md/raid5: Pivot raid5_make_request()") Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Increase restriction on max segments per requestLogan Gunthorpe1-0/+3
The block layer defaults the maximum segments to 128, which means requests tend to get split around the 512KB depending on how many pages can be merged. There's no such restriction in the raid5 code so increase the limit to USHRT_MAX so that larger requests can be sent as one. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Improve debug printsLogan Gunthorpe1-2/+6
Add a debug print for raid5_make_request() so that each request is printed and add the logical sector number to the debug print in __add_stripe_bio(). Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Pivot raid5_make_request()Logan Gunthorpe1-6/+83
raid5_make_request() loops through every page in the request, finds the appropriate stripe and adds the bio for that page in the disk. This causes a great deal of contention on the hash_lock and extra work seeing each stripe must be found once for every data disk. The number of times a stripe must be found can be reduced by pivoting raid5_make_request() so that it loops through every stripe and then loops through every disk in that stripe to see if the bio must be added. This reduces the number of times the hash lock must be taken by a factor equal to the number of data disks. To accomplish this, the logical sectors that have already been added must be tracked. Tracking them is done with a bitmap: the bits for all pages are set at the start of the request and each bit is cleared once the bio is added to a stripe. Finding the next sector to be done is then just a call to find_first_bit() so that sectors that have been done can simply be skipped. One minor downside is that the maximum sectors for a request must be limited so that the bitmap can be appropriately sized on the stack. This limit is arbitrarily chosen to be 256 stripe pages which works out to 1MB if PAGE_SIZE == DEFAULT_STRIPE_SIZE. This doesn't actually restrict the maximum request further seeing the default block queue settings are used which restricts the number of segments to 128 (which results in request sizes that are approximately 512KB). Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Check all disks in a stripe_head for reshape progressLogan Gunthorpe1-14/+39
When testing if a previous stripe has had reshape expand past it, use the earliest or latest logical sector in all the disks for that stripe head. This will allow adding multiple disks at a time in a subesquent patch. To do this cleaner, refactor the check into a helper function called stripe_ahead_of_reshape(). Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Refactor add_stripe_bio()Logan Gunthorpe1-30/+56
Factor out two helper functions from add_stripe_bio(): one to check for overlap (stripe_bio_overlaps()), and one to actually add the bio to the stripe (__add_stripe_bio()). The latter function will always succeed. This will be useful in the next patch so that overlap can be checked for multiple disks before adding any Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Keep a reference to last stripe_head for batchLogan Gunthorpe1-12/+40
When batching, every stripe head has to find the previous stripe head to add to the batch list. This involves taking the hash lock which is highly contended during IO. Instead of finding the previous stripe_head each time, store a reference to the previous stripe_head in a pointer so that it doesn't require taking the contended lock another time. The reference to the previous stripe must be released before scheduling and waiting for work to get done. Otherwise, it can hold up raid5_activate_delayed() and deadlock. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Refactor for loop in raid5_make_request() into while loopLogan Gunthorpe1-4/+5
The for loop with retry label can be more cleanly expressed as a while loop by moving the logical_sector increment into the success path. No functional changes intended. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Move read_seqcount_begin() into make_stripe_request()Logan Gunthorpe1-7/+5
Now that prepare_to_wait() isn't in the way, move read_sequcount_begin() into make_stripe_request(). No functional changes intended. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Drop the do_prepare flag in raid5_make_request()Logan Gunthorpe1-6/+2
prepare_to_wait() can be reasonably called after schedule instead of setting a flag and preparing in the next loop iteration. This means that prepare_to_wait() will be called before read_seqcount_begin(), but there shouldn't be any reason that the order matters here. On the first iteration of the loop prepare_to_wait() is already called first. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Factor out helper from raid5_make_request() loopLogan Gunthorpe1-98/+133
Factor out the inner loop of raid5_make_request() into it's own helper called make_stripe_request(). The helper returns a number of statuses: SUCCESS, RETRY, SCHEDULE_AND_RETRY and FAIL. This makes the code a bit easier to understand and allows the SCHEDULE_AND_RETRY path to be made common. A context structure is added to contain do_flush. It will be used more in subsequent patches for state that needs to be kept outside the loop. No functional changes intended. This will be cleaned up further in subsequent patches to untangle the gen_lock and do_prepare logic further. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Move common stripe get code into new find_get_stripe() helperLogan Gunthorpe1-67/+64
Both uses of find_stripe() require a fairly complicated dance to increment the reference count. Move this into a common find_get_stripe() helper. No functional changes intended. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Move stripe_add_to_batch_list() call out of add_stripe_bio()Logan Gunthorpe1-2/+3
stripe_add_to_batch_list() is better done in the loop in make_request instead of inside add_stripe_bio(). This is clearer and allows for storing the batch_head state outside the loop in a subsequent patch. The call to add_stripe_bio() in retry_aligned_read() is for read and batching only applies to write. So it's impossible for batching to happen at that call site. No functional changes intended. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Refactor raid5_make_request loopLogan Gunthorpe1-54/+55
Break immediately if raid5_get_active_stripe() returns NULL and deindent the rest of the loop. Annotate this check with an unlikely(). This makes the code easier to read and reduces the indentation level. No functional changes intended. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Factor out ahead_of_reshape() functionLogan Gunthorpe1-12/+15
There are a few uses of an ugly ternary operator in raid5_make_request() to check if a sector is a head of a reshape sector. Factor this out into a simple helper called ahead_of_reshape(). No functional changes intended. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: Make logic blocking check consistent with logic that blocksLogan Gunthorpe1-1/+1
The check in raid5_make_request differs very slightly from the logic that causes it to block lower down. This likely does not cause a bug as the check is fuzzy anyway (as reshape may move on between the first check and the subsequent check). However, make it consistent so it can be cleaned up in a subsequent patch. The condition which causes the schedule is: !(mddev->reshape_backwards ? logical_sector < conf->reshape_progress : logical_sector >= conf->reshape_progress) && (mddev->reshape_backwards ? logical_sector < conf->reshape_safe : logical_sector >= conf->reshape_safe) The condition that causes the early bailout is made to match this. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02md/raid5: suspend the array for calls to log_exit()Logan Gunthorpe1-1/+4
The raid5-cache code relies on there being no IO in flight when log_exit() is called. There are two places where this is not guaranteed so add mddev_suspend() and mddev_resume() calls to these sites. The site in raid5_change_consistency_policy() is in the error path, and another similar call site already has suspend/resume calls just below it; so it should be equally safe to make that change here. There is one remaining site in raid5_remove_disk() that we call log_exit() without suspending the array. Unfortunately, as the comment stated, we cannot call mddev_suspend from raid5d. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02Merge tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+2
Pull block updates from Jens Axboe: - Improve the type checking of request flags (Bart) - Ensure queue mapping for a single queues always picks the right queue (Bart) - Sanitize the io priority handling (Jan) - rq-qos race fix (Jinke) - Reserved tags handling improvements (John) - Separate memory alignment from file/disk offset aligment for O_DIRECT (Keith) - Add new ublk driver, userspace block driver using io_uring for communication with the userspace backend (Ming) - Use try_cmpxchg() to cleanup the code in various spots (Uros) - Finally remove bdevname() (Christoph) - Clean up the zoned device handling (Christoph) - Clean up independent access range support (Christoph) - Clean up and improve block sysfs handling (Christoph) - Clean up and improve teardown of block devices. This turns the usual two step process into something that is simpler to implement and handle in block drivers (Christoph) - Clean up chunk size handling (Christoph) - Misc cleanups and fixes (Bart, Bo, Dan, GuoYong, Jason, Keith, Liu, Ming, Sebastian, Yang, Ying) * tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block: (178 commits) ublk_drv: fix double shift bug ublk_drv: make sure that correct flags(features) returned to userspace ublk_drv: fix error handling of ublk_add_dev ublk_drv: fix lockdep warning block: remove __blk_get_queue block: call blk_mq_exit_queue from disk_release for never added disks blk-mq: fix error handling in __blk_mq_alloc_disk ublk: defer disk allocation ublk: rewrite ublk_ctrl_get_queue_affinity to not rely on hctx->cpumask ublk: fold __ublk_create_dev into ublk_ctrl_add_dev ublk: cleanup ublk_ctrl_uring_cmd ublk: simplify ublk_ch_open and ublk_ch_release ublk: remove the empty open and release block device operations ublk: remove UBLK_IO_F_PREFLUSH ublk: add a MAINTAINERS entry block: don't allow the same type rq_qos add more than once mmc: fix disk/queue leak in case of adding disk failure ublk_drv: fix an IS_ERR() vs NULL check ublk: remove UBLK_IO_F_INTEGRITY ublk_drv: remove unneeded semicolon ...
2022-07-22Merge tag 'block-5.19-2022-07-21' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+3
Pull block fix from Jens Axboe: "Just a single fix for missing error propagation for an allocation failure in raid5" * tag 'block-5.19-2022-07-21' of git://git.kernel.dk/linux-block: md/raid5: missing error code in setup_conf()
2022-07-19md/raid5: missing error code in setup_conf()Dan Carpenter1-1/+3
Return -ENOMEM if the allocation fails. Don't return success. Fixes: 8fbcba6b999b ("md/raid5: Cleanup setup_conf() error returns") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Song Liu <song@kernel.org>
2022-07-14md/raid5: Use the enum req_op and blk_opf_t typesBart Van Assche1-1/+2
Improve static type checking by using the enum req_op type for variables that represent a request operation and the new blk_opf_t type for variables that represent request flags. Acked-by: Song Liu <song@kernel.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-37-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-03mm: shrinkers: provide shrinkers with namesRoman Gushchin1-1/+1
Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: <subsystem>-<shrinker_type>[:<instance>]-<id> For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 [roman.gushchin@linux.dev: fix build warnings] Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle Reported-by: kernel test robot <lkp@intel.com> Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-29dm raid: fix KASAN warning in raid5_add_disksMikulas Patocka1-0/+1
There's a KASAN warning in raid5_add_disk when running the LVM testsuite. The warning happens in the test lvconvert-raid-reshape-linear_to_raid6-single-type.sh. We fix the warning by verifying that rdev->saved_raid_disk is within limits. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-06-29dm raid: fix KASAN warning in raid5_remove_diskMikulas Patocka1-1/+4
There's a KASAN warning in raid5_remove_disk when running the LVM testsuite. We fix this warning by verifying that the "number" variable is within limits. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-05-22md: remove most calls to bdevnameChristoph Hellwig1-21/+16
Use the %pg format specifier to save on stack consumption and code size. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org>
2022-05-03raid5: don't set the discard_alignment queue limitChristoph Hellwig1-1/+0
The discard_alignment queue limit is named a bit misleading means the offset into the block device at which the discard granularity starts. Setting it to the discard granularity as done by raid5 is mostly harmless but also useless. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Song Liu <song@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20220418045314.360785-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-25md/raid5: Annotate functions that hold device_lock with __must_holdLogan Gunthorpe1-5/+17
A handful of functions note the device_lock must be held with a comment but this is not comprehensive. Many other functions hold the lock when taken so add an __must_hold() to each call to annotate when the lock is held. This makes it a bit easier to analyse device_lock. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org>
2022-04-25md/raid5: Annotate rdev/replacement access when mddev_lock is heldLogan Gunthorpe1-22/+43
The mddev_lock should be held during raid5_remove_disk() which is when the rdev/replacement pointers are modified. So any access to these pointers marked __rcu should be safe whenever the mddev_lock is held. There are numerous such access that currently produce sparse warnings. Add a helper function, rdev_mdlock_deref() that wraps rcu_dereference_protected() in all these instances. This annotation fixes a number of sparse warnings. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org>
2022-04-25md/raid5: Annotate rdev/replacement accesses when nr_pending is elevatedLogan Gunthorpe1-9/+19
There are a number of accesses to __rcu variables that should be safe because nr_pending in the disk is known to be elevated. Create a wrapper around rcu_dereference_protected() to annotate these accesses and verify that nr_pending is non-zero. This fixes a number of sparse warnings. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org>
2022-04-25md/raid5: Add __rcu annotation to struct disk_infoLogan Gunthorpe1-20/+26
rdev and replacement are protected in some circumstances with rcu_dereference and synchronize_rcu (in raid5_remove_disk()). However, they were not annotated with __rcu so a sparse warning is emitted for every rcu_dereference() call. Add the __rcu annotation and fix up the initialization with RCU_INIT_POINTER, all pointer modifications with rcu_assign_pointer(), a few cases where the pointer value is tested with rcu_access_pointer() and one case where READ_ONCE() is used instead of rcu_dereference(), a case in print_raid5_conf() that should have rcu_dereference() and rcu_read_[un]lock() calls. Additional sparse issues will be fixed up in further commits. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org>
2022-04-25md/raid5: Cleanup setup_conf() error returnsLogan Gunthorpe1-7/+11
Be more careful about the error returns. Most errors in this function are actually ENOMEM, but it forcibly returns EIO if conf has been allocated. Instead return ret and ensure it is set appropriately before each goto abort. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org>
2022-04-25raid5: introduce MD_BROKENMariusz Tkaczyk1-25/+22
Raid456 module had allowed to achieve failed state. It was fixed by fb73b357fb9 ("raid5: block failing device if raid will be failed"). This fix introduces a bug, now if raid5 fails during IO, it may result with a hung task without completion. Faulty flag on the device is necessary to process all requests and is checked many times, mainly in analyze_stripe(). Allow to set faulty on drive again and set MD_BROKEN if raid is failed. As a result, this level is allowed to achieve failed state again, but communication with userspace (via -EBUSY status) will be preserved. This restores possibility to fail array via #mdadm --set-faulty command and will be fixed by additional verification on mdadm side. Reproduction steps: mdadm -CR imsm -e imsm -n 3 /dev/nvme[0-2]n1 mdadm -CR r5 -e imsm -l5 -n3 /dev/nvme[0-2]n1 --assume-clean mkfs.xfs /dev/md126 -f mount /dev/md126 /mnt/root/ fio --filename=/mnt/root/file --size=5GB --direct=1 --rw=randrw --bs=64k --ioengine=libaio --iodepth=64 --runtime=240 --numjobs=4 --time_based --group_reporting --name=throughput-test-job --eta-newline=1 & echo 1 > /sys/block/nvme2n1/device/device/remove echo 1 > /sys/block/nvme1n1/device/device/remove [ 1475.787779] Call Trace: [ 1475.793111] __schedule+0x2a6/0x700 [ 1475.799460] schedule+0x38/0xa0 [ 1475.805454] raid5_get_active_stripe+0x469/0x5f0 [raid456] [ 1475.813856] ? finish_wait+0x80/0x80 [ 1475.820332] raid5_make_request+0x180/0xb40 [raid456] [ 1475.828281] ? finish_wait+0x80/0x80 [ 1475.834727] ? finish_wait+0x80/0x80 [ 1475.841127] ? finish_wait+0x80/0x80 [ 1475.847480] md_handle_request+0x119/0x190 [ 1475.854390] md_make_request+0x8a/0x190 [ 1475.861041] generic_make_request+0xcf/0x310 [ 1475.868145] submit_bio+0x3c/0x160 [ 1475.874355] iomap_dio_submit_bio.isra.20+0x51/0x60 [ 1475.882070] iomap_dio_bio_actor+0x175/0x390 [ 1475.889149] iomap_apply+0xff/0x310 [ 1475.895447] ? iomap_dio_bio_actor+0x390/0x390 [ 1475.902736] ? iomap_dio_bio_actor+0x390/0x390 [ 1475.909974] iomap_dio_rw+0x2f2/0x490 [ 1475.916415] ? iomap_dio_bio_actor+0x390/0x390 [ 1475.923680] ? atime_needs_update+0x77/0xe0 [ 1475.930674] ? xfs_file_dio_aio_read+0x6b/0xe0 [xfs] [ 1475.938455] xfs_file_dio_aio_read+0x6b/0xe0 [xfs] [ 1475.946084] xfs_file_read_iter+0xba/0xd0 [xfs] [ 1475.953403] aio_read+0xd5/0x180 [ 1475.959395] ? _cond_resched+0x15/0x30 [ 1475.965907] io_submit_one+0x20b/0x3c0 [ 1475.972398] __x64_sys_io_submit+0xa2/0x180 [ 1475.979335] ? do_io_getevents+0x7c/0xc0 [ 1475.986009] do_syscall_64+0x5b/0x1a0 [ 1475.992419] entry_SYSCALL_64_after_hwframe+0x65/0xca [ 1476.000255] RIP: 0033:0x7f11fc27978d [ 1476.006631] Code: Bad RIP value. [ 1476.073251] INFO: task fio:3877 blocked for more than 120 seconds. Cc: stable@vger.kernel.org Fixes: fb73b357fb9 ("raid5: block failing device if raid will be failed") Reviewd-by: Xiao Ni <xni@redhat.com> Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com> Signed-off-by: Song Liu <song@kernel.org>
2022-04-17block: remove QUEUE_FLAG_DISCARDChristoph Hellwig1-8/+4
Just use a non-zero max_discard_sectors as an indicator for discard support, similar to what is done for write zeroes. The only places where needs special attention is the RAID5 driver, which must clear discard support for security reasons by default, even if the default stacking rules would allow for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd] Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390] Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: David Sterba <dsterba@suse.com> [btrfs] Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-17block: add a bdev_nonrot helperChristoph Hellwig1-1/+1
Add a helper to check the nonrot flag based on the block_device instead of having to poke into the block layer internal request_queue. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: David Sterba <dsterba@suse.com> [btrfs] Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220415045258.199825-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-03-26Merge tag 'for-5.18/write-streams-2022-03-18' of git://git.kernel.dk/linux-blockLinus Torvalds1-6/+0
Pull NVMe write streams removal from Jens Axboe: "This removes the write streams support in NVMe. No vendor ever really shipped working support for this, and they are not interested in supporting it. With the NVMe support gone, we have nothing in the tree that supports this. Remove passing around of the hints. The only discussion point in this patchset imho is the fact that the file specific write hint setting/getting fcntl helpers will now return -1/EINVAL like they did before we supported write hints. No known applications use these functions, I only know of one prototype that I help do for RocksDB, and that's not used. That said, with a change like this, it's always a bit controversial. Alternatively, we could just make them return 0 and pretend it worked. It's placement based hints after all" * tag 'for-5.18/write-streams-2022-03-18' of git://git.kernel.dk/linux-block: fs: remove fs.f_write_hint fs: remove kiocb.ki_hint block: remove the per-bio/request write hint nvme: remove support or stream based temperature hint