kernel/drivers/md/md-bitmap.c, branch linux-6.9.y

md: fix resync softlockup when bitmap size is less than array size

2024-05-30T07:44:10Z

[ Upstream commit f0e729af2eb6bee9eb58c4df1087f14ebaefe26b ] Is is reported that for dm-raid10, lvextend + lvchange --syncaction will trigger following softlockup: kernel:watchdog: BUG: soft lockup - CPU#3 stuck for 26s! [mdX_resync:6976] CPU: 7 PID: 3588 Comm: mdX_resync Kdump: loaded Not tainted 6.9.0-rc4-next-20240419 #1 RIP: 0010:_raw_spin_unlock_irq+0x13/0x30 Call Trace: md_bitmap_start_sync+0x6b/0xf0 raid10_sync_request+0x25c/0x1b40 [raid10] md_do_sync+0x64b/0x1020 md_thread+0xa7/0x170 kthread+0xcf/0x100 ret_from_fork+0x30/0x50 ret_from_fork_asm+0x1a/0x30 And the detailed process is as follows: md_do_sync j = mddev->resync_min while (j < max_sectors) sectors = raid10_sync_request(mddev, j, &skipped) if (!md_bitmap_start_sync(..., &sync_blocks)) // md_bitmap_start_sync set sync_blocks to 0 return sync_blocks + sectors_skippe; // sectors = 0; j += sectors; // j never change Root cause is that commit 301867b1c168 ("md/raid10: check slab-out-of-bounds in md_bitmap_get_counter") return early from md_bitmap_get_counter(), without setting returned blocks. Fix this problem by always set returned blocks from md_bitmap_get_counter"(), as it used to be. Noted that this patch just fix the softlockup problem in kernel, the case that bitmap size doesn't match array size still need to be fixed. Fixes: 301867b1c168 ("md/raid10: check slab-out-of-bounds in md_bitmap_get_counter") Reported-and-tested-by: Nigel Croxon Closes: https://lore.kernel.org/all/71ba5272-ab07-43ba-8232-d2da642acb4e@redhat.com/ Signed-off-by: Yu Kuai Link: https://lore.kernel.org/r/20240422065824.2516-1-yukuai1@huaweicloud.com Signed-off-by: Song Liu Signed-off-by: Sasha Levin

md: add a mddev_add_trace_msg helper

2024-03-06T16:59:52Z

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

md/md-bitmap: fix incorrect usage for sb_index

2024-02-26T21:34:44Z

Commit d7038f951828 ("md-bitmap: don't use ->index for pages backing the bitmap file") removed page->index from bitmap code, but left wrong code logic for clustered-md. current code never set slot offset for cluster nodes, will sometimes cause crash in clustered env. Call trace (partly): md_bitmap_file_set_bit+0x110/0x1d8 [md_mod] md_bitmap_startwrite+0x13c/0x240 [md_mod] raid1_make_request+0x6b0/0x1c08 [raid1] md_handle_request+0x1dc/0x368 [md_mod] md_submit_bio+0x80/0xf8 [md_mod] __submit_bio+0x178/0x300 submit_bio_noacct_nocheck+0x11c/0x338 submit_bio_noacct+0x134/0x614 submit_bio+0x28/0xdc submit_bh_wbc+0x130/0x1cc submit_bh+0x1c/0x28 Fixes: d7038f951828 ("md-bitmap: don't use ->index for pages backing the bitmap file") Cc: stable@vger.kernel.org # v6.6+ Signed-off-by: Heming Zhao Reviewed-by: Christoph Hellwig Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240223121128.28985-1-heming.zhao@suse.com

md: cleanup mddev_create/destroy_serial_pool()

2023-10-11T01:49:51Z

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 Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20231010151958.145896-15-yukuai1@huaweicloud.com

md: use new apis to suspend array before mddev_create/destroy_serial_pool

2023-10-11T01:49:50Z

mddev_create/destroy_serial_pool() will be called from several places where mddev_suspend() will be called later. Prepare to remove the mddev_suspend() from mddev_create/destroy_serial_pool(). Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20231010151958.145896-14-yukuai1@huaweicloud.com

md/md-bitmap: use new apis to suspend array for location_store()

2023-10-11T01:49:50Z

Convert to use new apis, the old apis will be removed eventually. This is not hot path, so performance is not concerned. Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20231010151958.145896-8-yukuai1@huaweicloud.com

md-bitmap: suspend array earlier in location_store()

2023-09-22T17:28:27Z

Now that mddev_suspend() doean't rely on 'mddev->pers' to be set, it's safe to call mddev_suspend() earlier. This will also be helper to refactor mddev_suspend() later. Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230825030956.1527023-6-yukuai1@huaweicloud.com

md-bitmap: remove the checking of 'pers->quiesce' from location_store()

2023-09-22T17:28:27Z

After commit 4d27e927344a ("md: don't quiesce in mddev_suspend()"), there is no need to check 'pers->quiesce' before calling mddev_suspend(). Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230825030956.1527023-5-yukuai1@huaweicloud.com

md/md-bitmap: hold 'reconfig_mutex' in backlog_store()

2023-07-27T07:13:30Z

Several reasons why 'reconfig_mutex' should be held: 1) rdev_for_each() is not safe to be called without the lock, because rdev can be removed concurrently. 2) mddev_destroy_serial_pool() and mddev_create_serial_pool() should not be called concurrently. 3) mddev_suspend() from mddev_destroy/create_serial_pool() should be protected by the lock. Fixes: 10c92fca636e ("md-bitmap: create and destroy wb_info_pool with the change of backlog") Signed-off-by: Yu Kuai Link: https://lore.kernel.org/r/20230706083727.608914-3-yukuai1@huaweicloud.com Signed-off-by: Song Liu

md/md-bitmap: remove unnecessary local variable in backlog_store()

2023-07-27T07:13:30Z

Local variable is definied first in the beginning of backlog_store(), there is no need to define it again. Fixes: 8c13ab115b57 ("md/bitmap: don't set max_write_behind if there is no write mostly device") Signed-off-by: Yu Kuai Link: https://lore.kernel.org/r/20230706083727.608914-2-yukuai1@huaweicloud.com Signed-off-by: Song Liu