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2025-01-13md/md-bitmap: move bitmap_{start, end}write to md upper layerYu Kuai
There are two BUG reports that raid5 will hang at bitmap_startwrite([1],[2]), root cause is that bitmap start write and end write is unbalanced, it's not quite clear where, and while reviewing raid5 code, it's found that bitmap operations can be optimized. For example, for a 4 disks raid5, with chunksize=8k, if user issue a IO (0 + 48k) to the array: ┌────────────────────────────────────────────────────────────┐ │chunk 0 │ │ ┌────────────┬─────────────┬─────────────┬────────────┼ │ sh0 │A0: 0 + 4k │A1: 8k + 4k │A2: 16k + 4k │A3: P │ │ ┼────────────┼─────────────┼─────────────┼────────────┼ │ sh1 │B0: 4k + 4k │B1: 12k + 4k │B2: 20k + 4k │B3: P │ ┼──────┴────────────┴─────────────┴─────────────┴────────────┼ │chunk 1 │ │ ┌────────────┬─────────────┬─────────────┬────────────┤ │ sh2 │C0: 24k + 4k│C1: 32k + 4k │C2: P │C3: 40k + 4k│ │ ┼────────────┼─────────────┼─────────────┼────────────┼ │ sh3 │D0: 28k + 4k│D1: 36k + 4k │D2: P │D3: 44k + 4k│ └──────┴────────────┴─────────────┴─────────────┴────────────┘ Before this patch, 4 stripe head will be used, and each sh will attach bio for 3 disks, and each attached bio will trigger bitmap_startwrite() once, which means total 12 times. - 3 times (0 + 4k), for (A0, A1 and A2) - 3 times (4 + 4k), for (B0, B1 and B2) - 3 times (8 + 4k), for (C0, C1 and C3) - 3 times (12 + 4k), for (D0, D1 and D3) After this patch, md upper layer will calculate that IO range (0 + 48k) is corresponding to the bitmap (0 + 16k), and call bitmap_startwrite() just once. Noted that this patch will align bitmap ranges to the chunks, for example, if user issue a IO (0 + 4k) to array: - Before this patch, 1 time (0 + 4k), for A0; - After this patch, 1 time (0 + 8k) for chunk 0; Usually, one bitmap bit will represent more than one disk chunk, and this doesn't have any difference. And even if user really created a array that one chunk contain multiple bits, the overhead is that more data will be recovered after power failure. Also remove STRIPE_BITMAP_PENDING since it's not used anymore. [1] https://lore.kernel.org/all/CAJpMwyjmHQLvm6zg1cmQErttNNQPDAAXPKM3xgTjMhbfts986Q@mail.gmail.com/ [2] https://lore.kernel.org/all/ADF7D720-5764-4AF3-B68E-1845988737AA@flyingcircus.io/ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20250109015145.158868-6-yukuai1@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
2025-01-13md: add a new callback pers->bitmap_sector()Yu Kuai
This callback will be used in raid5 to convert io ranges from array to bitmap. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Xiao Ni <xni@redhat.com> Link: https://lore.kernel.org/r/20250109015145.158868-4-yukuai1@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
2024-11-05md: add a new helper rdev_blocked()Yu Kuai
The helper will be used in later patches for raid1/raid10/raid5, the difference is that Faulty rdev with unacknowledged bad block will not be considered blocked. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Tested-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com> Link: https://lore.kernel.org/r/20241031033114.3845582-2-yukuai1@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
2024-08-28Merge branch 'md-6.12-bitmap' into md-6.12Song Liu
From Yu Kuai (with minor changes by Song Liu): The background is that currently bitmap is using a global spin_lock, causing lock contention and huge IO performance degradation for all raid levels. However, it's impossible to implement a new lock free bitmap with current situation that md-bitmap exposes the internal implementation with lots of exported apis. Hence bitmap_operations is invented, to describe bitmap core implementation, and a new bitmap can be introduced with a new bitmap_operations, we only need to switch to the new one during initialization. And with this we can build bitmap as kernel module, but that's not our concern for now. This version was tested with mdadm tests and lvm2 tests. This set does not introduce new errors in these tests. * md-6.12-bitmap: (42 commits) md/md-bitmap: make in memory structure internal md/md-bitmap: merge md_bitmap_enabled() into bitmap_operations md/md-bitmap: merge md_bitmap_wait_behind_writes() into bitmap_operations md/md-bitmap: merge md_bitmap_free() into bitmap_operations md/md-bitmap: merge md_bitmap_set_pages() into struct bitmap_operations md/md-bitmap: merge md_bitmap_copy_from_slot() into struct bitmap_operation. md/md-bitmap: merge get_bitmap_from_slot() into bitmap_operations md/md-bitmap: merge md_bitmap_resize() into bitmap_operations md/md-bitmap: pass in mddev directly for md_bitmap_resize() md/md-bitmap: merge md_bitmap_daemon_work() into bitmap_operations md/md-bitmap: merge bitmap_unplug() into bitmap_operations md/md-bitmap: merge md_bitmap_unplug_async() into md_bitmap_unplug() md/md-bitmap: merge md_bitmap_sync_with_cluster() into bitmap_operations md/md-bitmap: merge md_bitmap_cond_end_sync() into bitmap_operations md/md-bitmap: merge md_bitmap_close_sync() into bitmap_operations md/md-bitmap: merge md_bitmap_end_sync() into bitmap_operations md/md-bitmap: remove the parameter 'aborted' for md_bitmap_end_sync() md/md-bitmap: merge md_bitmap_start_sync() into bitmap_operations md/md-bitmap: merge md_bitmap_endwrite() into bitmap_operations md/md-bitmap: merge md_bitmap_startwrite() into bitmap_operations ... Signed-off-by: Song Liu <song@kernel.org>
2024-08-27md: Remove flush handlingYu Kuai
For flush request, md has a special flush handling to merge concurrent flush request into single one, however, the whole mechanism is based on a disk level spin_lock 'mddev->lock'. And fsync can be called quite often in some user cases, for consequence, spin lock from IO fast path can cause performance degradation. Fortunately, the block layer already has flush handling to merge concurrent flush request, and it only acquires hctx level spin lock. (see details in blk-flush.c) This patch removes the flush handling in md, and converts to use general block layer flush handling in underlying disks. Flush test for 4 nvme raid10: start 128 threads to do fsync 100000 times, on arm64, see how long it takes. Test script: void* thread_func(void* arg) { int fd = *(int*)arg; for (int i = 0; i < FSYNC_COUNT; i++) { fsync(fd); } return NULL; } int main() { int fd = open("/dev/md0", O_RDWR); if (fd < 0) { perror("open"); exit(1); } pthread_t threads[THREADS]; struct timeval start, end; gettimeofday(&start, NULL); for (int i = 0; i < THREADS; i++) { pthread_create(&threads[i], NULL, thread_func, &fd); } for (int i = 0; i < THREADS; i++) { pthread_join(threads[i], NULL); } gettimeofday(&end, NULL); close(fd); long long elapsed = (end.tv_sec - start.tv_sec) * 1000000LL + (end.tv_usec - start.tv_usec); printf("Elapsed time: %lld microseconds\n", elapsed); return 0; } Test result: about 10 times faster: Before this patch: 50943374 microseconds After this patch: 5096347 microseconds Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20240827110616.3860190-1-yukuai1@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
2024-08-27md/md-bitmap: make in memory structure internalYu Kuai
Now that struct bitmap_page and bitmap is not used externally anymore, move them from md-bitmap.h to md-bitmap.c (expect that dm-raid is still using define marco 'COUNTER_MAX'). Also fix some checkpatch warnings. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20240826074452.1490072-43-yukuai1@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
2024-08-27md/md-bitmap: introduce struct bitmap_operationsYu Kuai
The structure is empty for now, and will be used in later patches to merge in bitmap operations, so that bitmap implementation won't be exposed. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20240826074452.1490072-12-yukuai1@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
2024-07-04md-cluster: Constify struct md_cluster_operationsChristophe JAILLET
'struct md_cluster_operations' is not modified in this driver. Constifying this structure moves some data to a read-only section, so increase overall security. On a x86_64, with allmodconfig, as an example: Before: ====== text data bss dec hex filename 51941 1442 80 53463 d0d7 drivers/md/md-cluster.o After: ===== text data bss dec hex filename 52133 1246 80 53459 d0d3 drivers/md/md-cluster.o Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/3727f3ce9693cae4e62ae6778ea13971df805479.1719173852.git.christophe.jaillet@wanadoo.fr
2024-06-26md: set md-specific flags for all queue limitsChristoph Hellwig
The md driver wants to enforce a number of flags for all devices, even when not inheriting them from the underlying devices. To make sure these flags survive the queue_limits_set calls that md uses to update the queue limits without deriving them form the previous limits add a new md_init_stacking_limits helper that calls blk_set_stacking_limits and sets these flags. Fixes: 1122c0c1cc71 ("block: move cache control settings out of queue->flags") Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20240626142637.300624-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-14Merge branch 'for-6.11/block-limits' into for-6.11/blockJens Axboe
Pull in block limits branch, which exists as a shared branch for both the block and SCSI tree. * for-6.11/block-limits: (26 commits) block: move integrity information into queue_limits block: invert the BLK_INTEGRITY_{GENERATE,VERIFY} flags block: bypass the STABLE_WRITES flag for protection information block: don't require stable pages for non-PI metadata block: use kstrtoul in flag_store block: factor out flag_{store,show} helper for integrity block: remove the blk_flush_integrity call in blk_integrity_unregister block: remove the blk_integrity_profile structure dm-integrity: use the nop integrity profile md/raid1: don't free conf on raid0_run failure md/raid0: don't free conf on raid0_run failure block: initialize integrity buffer to zero before writing it to media block: add special APIs for run-time disabling of discard and friends block: remove unused queue limits API sr: convert to the atomic queue limits API sd: convert to the atomic queue limits API sd: cleanup zoned queue limits initialization sd: factor out a sd_discard_mode helper sd: simplify the disable case in sd_config_discard sd: add a sd_disable_write_same helper ...
2024-06-14block: move integrity information into queue_limitsChristoph Hellwig
Move the integrity information into the queue limits so that it can be set atomically with other queue limits, and that the sysfs changes to the read_verify and write_generate flags are properly synchronized. This also allows to provide a more useful helper to stack the integrity fields, although it still is separate from the main stacking function as not all stackable devices want to inherit the integrity settings. Even with that it greatly simplifies the code in md and dm. Note that the integrity field is moved as-is into the queue limits. While there are good arguments for removing the separate blk_integrity structure, this would cause a lot of churn and might better be done at a later time if desired. However the integrity field in the queue_limits structure is now unconditional so that various ifdefs can be avoided or replaced with IS_ENABLED(). Given that tiny size of it that seems like a worthwhile trade off. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20240613084839.1044015-13-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-12md: pass in max_sectors for pers->sync_request()Yu Kuai
For different sync_action, sync_thread will use different max_sectors, see details in md_sync_max_sectors(), currently both md_do_sync() and pers->sync_request() in eatch iteration have to get the same max_sectors. Hence pass in max_sectors for pers->sync_request() to prevent redundant code. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240611132251.1967786-12-yukuai1@huaweicloud.com
2024-06-12md: replace last_sync_action with new enum typeYu Kuai
The only difference is that "none" is removed and initial last_sync_action will be idle. On the one hand, this value is introduced by commit c4a395514516 ("MD: Remember the last sync operation that was performed"), and the usage described in commit message is not affected. On the other hand, last_sync_action is not used in mdadm or mdmon, and none of the tests that I can find. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240611132251.1967786-10-yukuai1@huaweicloud.com
2024-06-12md: use new helpers in md_do_sync()Yu Kuai
Make code cleaner. and also use the action_name directly in kernel log: - "check" instead of "data-check" - "repair" instead of "requested-resync" Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240611132251.1967786-9-yukuai1@huaweicloud.com
2024-06-12md: don't fail action_store() if sync_thread is not registeredYu Kuai
MD_RECOVERY_RUNNING will always be set when trying to register a new sync_thread, however, if md_start_sync() turns out to do nothing, MD_RECOVERY_RUNNING will be cleared in this case. And during the race window, action_store() will return -EBUSY, which will cause some mdadm tests to fail. For example: The test 07reshape5intr will add a new disk to array, then start reshape: mdadm /dev/md0 --add /dev/xxx mdadm --grow /dev/md0 -n 3 And add_bound_rdev() from mdadm --add will set MD_RECOVERY_NEEDED, then during the race windown, mdadm --grow will fail. Fix the problem by waiting in action_store() during the race window, fail only if 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/20240611132251.1967786-8-yukuai1@huaweicloud.com
2024-06-12md: add new helpers for sync_actionYu Kuai
The new helpers will get current sync_action of the array, will be used in later patches to make code cleaner. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240611132251.1967786-4-yukuai1@huaweicloud.com
2024-06-12md: add a new enum type sync_actionYu Kuai
In order to make code related to sync_thread cleaner in following patches, also add detail comment about each sync action. And also prepare to remove the related recovery_flags in the fulture. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240611132251.1967786-3-yukuai1@huaweicloud.com
2024-06-12md: rearrange recovery_flagsYu Kuai
Currently there are lots of flags with the same confusing prefix "MD_REOCVERY_", and there are two main types of flags, sync thread runnng status, I prefer prefix "SYNC_THREAD_", and sync thread action, I perfer prefix "SYNC_ACTION_". For now, rearrange and update comment to improve code readability, there are no functional changes. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240611132251.1967786-2-yukuai1@huaweicloud.com
2024-06-10md: change the return value type of md_write_start to voidLi Nan
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 <linan122@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240525185257.3896201-2-linan666@huaweicloud.com
2024-05-07md: Revert "md: Fix overflow in is_mddev_idle"Li Nan
This reverts commit 3f9f231236ce7e48780d8a4f1f8cb9fae2df1e4e. Using 64bit for 'sync_io' is unnecessary from the gendisk side. This overflow will not cause any functional impact, except for a UBSAN warning. Solving this overflow requires introducing additional calculations and checks which are not necessary. So just keep using 32bit for 'sync_io'. Signed-off-by: Li Nan <linan122@huawei.com> Link: https://lore.kernel.org/r/20240507023103.781816-1-linan666@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-08md: don't account sync_io if iostats of the disk is disabledLi Nan
If iostats is disabled, disk_stats will not be updated and part_stat_read_accum() only returns a constant value. In this case, continuing to count sync_io and to check is_mddev_idle() is no longer meaningful. Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20240117031946.2324519-3-linan666@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
2024-04-08md: Fix overflow in is_mddev_idleLi Nan
UBSAN reports this problem: UBSAN: Undefined behaviour in drivers/md/md.c:8175:15 signed integer overflow: -2147483291 - 2072033152 cannot be represented in type 'int' Call trace: dump_backtrace+0x0/0x310 show_stack+0x28/0x38 dump_stack+0xec/0x15c ubsan_epilogue+0x18/0x84 handle_overflow+0x14c/0x19c __ubsan_handle_sub_overflow+0x34/0x44 is_mddev_idle+0x338/0x3d8 md_do_sync+0x1bb8/0x1cf8 md_thread+0x220/0x288 kthread+0x1d8/0x1e0 ret_from_fork+0x10/0x18 'curr_events' will overflow when stat accum or 'sync_io' is greater than INT_MAX. Fix it by changing sync_io, last_events and curr_events to 64bit. Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20240117031946.2324519-2-linan666@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
2024-03-11Merge tag 'for-6.9/block-20240310' of git://git.kernel.dk/linuxLinus Torvalds
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 ...
2024-03-06md: remove mddev->queueChristoph Hellwig
Just use the request_queue from the gendisk pointer in the relatively few places that sill need it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed--by: Song Liu <song@kernel.org> Tested-by: Song Liu <song@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240303140150.5435-11-hch@lst.de
2024-03-06md: add queue limit helpersChristoph Hellwig
Add a few helpers that wrap the block queue limits API for use in MD. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed--by: Song Liu <song@kernel.org> Tested-by: Song Liu <song@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240303140150.5435-5-hch@lst.de
2024-03-06md: add a mddev_is_dm helperChristoph Hellwig
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 <hch@lst.de> Reviewed--by: Song Liu <song@kernel.org> Tested-by: Song Liu <song@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240303140150.5435-4-hch@lst.de
2024-03-06md: add a mddev_add_trace_msg helperChristoph Hellwig
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 <hch@lst.de> Reviewed--by: Song Liu <song@kernel.org> Tested-by: Song Liu <song@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240303140150.5435-3-hch@lst.de
2024-03-06md: add a mddev_trace_remap helperChristoph Hellwig
Add a helper to trace bio remapping that hides some argument dereferences and the check for a DM-mapped MD device. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed--by: Song Liu <song@kernel.org> Tested-by: Song Liu <song@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240303140150.5435-2-hch@lst.de
2024-03-05dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent ↵Yu Kuai
with reshape For raid456, if reshape is still in progress, then IO across reshape position will wait for reshape to make progress. However, for dm-raid, in following cases reshape will never make progress hence IO will hang: 1) the array is read-only; 2) MD_RECOVERY_WAIT is set; 3) MD_RECOVERY_FROZEN is set; After commit c467e97f079f ("md/raid6: use valid sector values to determine if an I/O should wait on the reshape") fix the problem that IO across reshape position doesn't wait for reshape, the dm-raid test shell/lvconvert-raid-reshape.sh start to hang: [root@fedora ~]# cat /proc/979/stack [<0>] wait_woken+0x7d/0x90 [<0>] raid5_make_request+0x929/0x1d70 [raid456] [<0>] md_handle_request+0xc2/0x3b0 [md_mod] [<0>] raid_map+0x2c/0x50 [dm_raid] [<0>] __map_bio+0x251/0x380 [dm_mod] [<0>] dm_submit_bio+0x1f0/0x760 [dm_mod] [<0>] __submit_bio+0xc2/0x1c0 [<0>] submit_bio_noacct_nocheck+0x17f/0x450 [<0>] submit_bio_noacct+0x2bc/0x780 [<0>] submit_bio+0x70/0xc0 [<0>] mpage_readahead+0x169/0x1f0 [<0>] blkdev_readahead+0x18/0x30 [<0>] read_pages+0x7c/0x3b0 [<0>] page_cache_ra_unbounded+0x1ab/0x280 [<0>] force_page_cache_ra+0x9e/0x130 [<0>] page_cache_sync_ra+0x3b/0x110 [<0>] filemap_get_pages+0x143/0xa30 [<0>] filemap_read+0xdc/0x4b0 [<0>] blkdev_read_iter+0x75/0x200 [<0>] vfs_read+0x272/0x460 [<0>] ksys_read+0x7a/0x170 [<0>] __x64_sys_read+0x1c/0x30 [<0>] do_syscall_64+0xc6/0x230 [<0>] entry_SYSCALL_64_after_hwframe+0x6c/0x74 This is because reshape can't make progress. For md/raid, the problem doesn't exist because register new sync_thread doesn't rely on the IO to be done any more: 1) If array is read-only, it can switch to read-write by ioctl/sysfs; 2) md/raid never set MD_RECOVERY_WAIT; 3) If MD_RECOVERY_FROZEN is set, mddev_suspend() doesn't hold 'reconfig_mutex', hence it can be cleared and reshape can continue by sysfs api 'sync_action'. However, I'm not sure yet how to avoid the problem in dm-raid yet. This patch on the one hand make sure raid_message() can't change sync_thread() through raid_message() after presuspend(), on the other hand detect the above 3 cases before wait for IO do be done in dm_suspend(), and let dm-raid requeue those IO. Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Xiao Ni <xni@redhat.com> Acked-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240305072306.2562024-9-yukuai1@huaweicloud.com
2024-03-05dm-raid: add a new helper prepare_suspend() in md_personalityYu Kuai
There are no functional changes for now, prepare to fix a deadlock for dm-raid456. Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Xiao Ni <xni@redhat.com> Acked-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240305072306.2562024-8-yukuai1@huaweicloud.com
2024-03-05md: add a new helper reshape_interrupted()Yu Kuai
The helper will be used for dm-raid456 later to detect the case that reshape can't make progress. Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Xiao Ni <xni@redhat.com> Acked-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240305072306.2562024-5-yukuai1@huaweicloud.com
2024-03-05md: export helper md_is_rdwr()Yu Kuai
There are no functional changes for now, prepare to fix a deadlock for dm-raid456. Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Xiao Ni <xni@redhat.com> Acked-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240305072306.2562024-4-yukuai1@huaweicloud.com
2024-03-05md: export helpers to stop sync_threadYu Kuai
Add new helpers: void md_idle_sync_thread(struct mddev *mddev); void md_frozen_sync_thread(struct mddev *mddev); void md_unfrozen_sync_thread(struct mddev *mddev); The helpers will be used in dm-raid in later patches to fix regressions and prevent calling md_reap_sync_thread() directly. Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Xiao Ni <xni@redhat.com> Acked-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240305072306.2562024-3-yukuai1@huaweicloud.com
2024-02-29md/raid1: record nonrot rdevs while adding/removing rdevs to confYu Kuai
For raid1, each read will iterate all the rdevs from conf and check if any rdev is non-rotational, then choose rdev with minimal IO inflight if so, or rdev with closest distance otherwise. Disk nonrot info can be changed through sysfs entry: /sys/block/[disk_name]/queue/rotational However, consider that this should only be used for testing, and user really shouldn't do this in real life. Record the number of non-rotational disks in conf, to avoid checking each rdev in IO fast path and simplify read_balance() a little bit. Co-developed-by: Paul Luse <paul.e.luse@linux.intel.com> Signed-off-by: Paul Luse <paul.e.luse@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/20240229095714.926789-4-yukuai1@huaweicloud.com
2024-02-29md: add a new helper rdev_has_badblock()Yu Kuai
The current api is_badblock() must pass in 'first_bad' and 'bad_sectors', however, many caller just want to know if there are badblocks or not, and these caller must define two local variable that will never be used. Add a new helper rdev_has_badblock() that will only return if there are badblocks or not, remove unnecessary local variables and replace is_badblock() with the new helper in many places. There are no functional changes, and the new helper will also be used later to refactor read_balance(). Co-developed-by: Paul Luse <paul.e.luse@linux.intel.com> Signed-off-by: Paul Luse <paul.e.luse@linux.intel.com> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Xiao Ni <xni@redhat.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240229095714.926789-2-yukuai1@huaweicloud.com
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>
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
2023-11-01Merge 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
2023-10-10md: 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: 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: add new helpers to suspend/resume and lock/unlock arrayYu Kuai
The new helpers suspend the array first and then lock the array, Prepare to refactor from: mddev_lock/lock_nointr mddev_suspend ... mddev_resuem mddev_lock With: mddev_suspend_and_lock/lock_nointr ... mddev_unlock_and_resume After all the use cases is refactored, mddev_suspend/resume() will be removed. And mddev_suspend_and_lock() will also replace mddev_lock() for the case that the array will be reconfigured, in order to synchronize with io to prevent problems in many corner cases. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231010151958.145896-6-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
2023-09-22md: initialize 'writes_pending' while allocating mddevYu Kuai
Currently 'writes_pending' is initialized in pers->run for raid1/5/10, and it's freed while deleing mddev, instead of pers->free. pers->run can be called multiple times before mddev is deleted, and a helper mddev_init_writes_pending() is used to prevent 'writes_pending' to be initialized multiple times, this usage is safe but a litter weird. On the other hand, 'writes_pending' is only initialized for raid1/5/10, however, it's used in common layer, for example: array_state_store set_in_sync if (!mddev->in_sync) -> in_sync is used for all levels // access writes_pending There might be some implicit dependency that I don't recognized to make sure 'writes_pending' can only be accessed for raid1/5/10, but there are no comments about that. By the way, it make sense to initialize 'writes_pending' in common layer because there are already three levels use it. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230825030956.1527023-3-yukuai1@huaweicloud.com
2023-09-22md: initialize 'active_io' while allocating mddevYu Kuai
'active_io' is used for mddev_suspend() and it's initialized in md_run(), this restrict that 'reconfig_mutex' must be held and "mddev->pers" must be set before calling mddev_suspend(). Initialize 'active_io' early so that mddev_suspend() is safe to call once mddev is allocated, this will be helpful to refactor 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/20230825030956.1527023-2-yukuai1@huaweicloud.com
2023-09-22md: use separate work_struct for md_start_sync()Yu Kuai
It's a little weird to borrow 'del_work' for md_start_sync(), declare a new work_struct 'sync_work' for md_start_sync(). Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Xiao Ni <xni@redhat.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230825031622.1530464-2-yukuai1@huaweicloud.com
2023-09-08md: fix warning for holder mismatch from export_rdev()Yu Kuai
Commit a1d767191096 ("md: use mddev->external to select holder in export_rdev()") fix the problem that 'claim_rdev' is used for blkdev_get_by_dev() while 'rdev' is used for blkdev_put(). However, if mddev->external is changed from 0 to 1, then 'rdev' is used for blkdev_get_by_dev() while 'claim_rdev' is used for blkdev_put(). And this problem can be reporduced reliably by following: New file: mdadm/tests/23rdev-lifetime devname=${dev0##*/} devt=`cat /sys/block/$devname/dev` pid="" runtime=2 clean_up_test() { pill -9 $pid echo clear > /sys/block/md0/md/array_state } trap 'clean_up_test' EXIT add_by_sysfs() { while true; do echo $devt > /sys/block/md0/md/new_dev done } remove_by_sysfs(){ while true; do echo remove > /sys/block/md0/md/dev-${devname}/state done } echo md0 > /sys/module/md_mod/parameters/new_array || die "create md0 failed" add_by_sysfs & pid="$pid $!" remove_by_sysfs & pid="$pid $!" sleep $runtime exit 0 Test cmd: ./test --save-logs --logdir=/tmp/ --keep-going --dev=loop --tests=23rdev-lifetime Test result: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 960 at block/bdev.c:618 blkdev_put+0x27c/0x330 Modules linked in: multipath md_mod loop CPU: 0 PID: 960 Comm: test Not tainted 6.5.0-rc2-00121-g01e55c376936-dirty #50 RIP: 0010:blkdev_put+0x27c/0x330 Call Trace: <TASK> export_rdev.isra.23+0x50/0xa0 [md_mod] mddev_unlock+0x19d/0x300 [md_mod] rdev_attr_store+0xec/0x190 [md_mod] sysfs_kf_write+0x52/0x70 kernfs_fop_write_iter+0x19a/0x2a0 vfs_write+0x3b5/0x770 ksys_write+0x74/0x150 __x64_sys_write+0x22/0x30 do_syscall_64+0x40/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fix the problem by recording if 'rdev' is used as holder. Fixes: a1d767191096 ("md: use mddev->external to select holder in export_rdev()") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230825025532.1523008-3-yukuai1@huaweicloud.com
2023-08-15md: Hold mddev->reconfig_mutex when trying to get mddev->sync_threadLi Lingfeng
Commit ba9d9f1a707f ("Revert "md: unlock mddev before reap sync_thread in action_store"") removed the scenario of calling md_unregister_thread() without holding mddev->reconfig_mutex, so add a lock holding check before acquiring mddev->sync_thread by passing mdev to md_unregister_thread(). Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20230803071711.2546560-1-lilingfeng@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
generated by cgit (git 2.34.1) at 2025-07-15 17:33:03 +0000