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BUG: KCSAN: data-race in wbt_wait / wbt_wait

write to 0xffff888141feb740 of 8 bytes by task 17734 on cpu 1:
 wb_timestamp block/blk-wbt.c:89 [inline]
 wbt_wait+0x12b/0x2b0 block/blk-wbt.c:579
 __rq_qos_throttle+0x39/0x70 block/blk-rq-qos.c:72
 rq_qos_throttle block/blk-rq-qos.h:182 [inline]
 blk_mq_submit_bio+0x253/0x1060 block/blk-mq.c:2185
 __submit_bio_noacct_mq block/blk-core.c:1014 [inline]
 submit_bio_noacct+0x7c2/0x9a0 block/blk-core.c:1047
 submit_bio+0x200/0x370 block/blk-core.c:1118
 xfs_buf_ioapply_map+0x3ee/0x510 fs/xfs/xfs_buf.c:1539
 _xfs_buf_ioapply+0x10a/0x330 fs/xfs/xfs_buf.c:1620
 __xfs_buf_submit+0x1ee/0x600 fs/xfs/xfs_buf.c:1689
 xfs_buf_submit fs/xfs/xfs_buf.c:61 [inline]
 xfs_buf_read_uncached+0x120/0x1c0 fs/xfs/xfs_buf.c:935
 xfs_readsb+0xd6/0x3b0 fs/xfs/xfs_mount.c:302
 xfs_fs_fill_super+0x33b/0xeb0 fs/xfs/xfs_super.c:1418
 get_tree_bdev+0x2c2/0x3d0 fs/super.c:1292
 xfs_fs_get_tree+0x18/0x20 fs/xfs/xfs_super.c:1639
 vfs_get_tree+0x4a/0x1a0 fs/super.c:1497
 do_new_mount fs/namespace.c:2903 [inline]
 path_mount+0x11b9/0x1c00 fs/namespace.c:3233
 do_mount fs/namespace.c:3246 [inline]
 __do_sys_mount fs/namespace.c:3454 [inline]
 __se_sys_mount+0x23d/0x2e0 fs/namespace.c:3431
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3431
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888141feb740 of 8 bytes by task 21787 on cpu 0:
 wb_timestamp block/blk-wbt.c:88 [inline]
 wbt_wait+0xcf/0x2b0 block/blk-wbt.c:579
 __rq_qos_throttle+0x39/0x70 block/blk-rq-qos.c:72
 rq_qos_throttle block/blk-rq-qos.h:182 [inline]
 blk_mq_submit_bio+0x253/0x1060 block/blk-mq.c:2185
 __submit_bio_noacct_mq block/blk-core.c:1014 [inline]
 submit_bio_noacct+0x7c2/0x9a0 block/blk-core.c:1047
 submit_bio+0x200/0x370 block/blk-core.c:1118
 mpage_bio_submit fs/mpage.c:66 [inline]
 mpage_readahead+0x2ef/0x330 fs/mpage.c:393
 blkdev_readahead+0x18/0x20 fs/block_dev.c:645
 read_pages+0x9c/0x6e0 mm/readahead.c:130
 page_cache_ra_unbounded+0x46c/0x4c0 mm/readahead.c:238
 do_page_cache_ra mm/readahead.c:267 [inline]
 force_page_cache_ra+0x226/0x260 mm/readahead.c:298
 page_cache_sync_ra+0x178/0x1a0 mm/readahead.c:572
 page_cache_sync_readahead include/linux/pagemap.h:840 [inline]
 filemap_get_pages+0x1ba/0x660 mm/filemap.c:2375
 filemap_read+0x1ba/0x7b0 mm/filemap.c:2458
 generic_file_read_iter+0x82/0x410 mm/filemap.c:2609
 blkdev_read_iter+0xb3/0xc0 fs/block_dev.c:1723
 call_read_iter include/linux/fs.h:1971 [inline]
 new_sync_read fs/read_write.c:415 [inline]
 vfs_read+0x565/0x5d0 fs/read_write.c:496
 ksys_read+0xce/0x180 fs/read_write.c:634
 __do_sys_read fs/read_write.c:644 [inline]
 __se_sys_read fs/read_write.c:642 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:642
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 21787 Comm: systemd-udevd Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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