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BUG: KCSAN: data-race in blk_mq_dispatch_rq_list / blk_mq_do_dispatch_sched

write to 0xffff888101bd5af8 of 4 bytes by task 23921 on cpu 0:
 blk_mq_update_dispatch_busy block/blk-mq.c:1912 [inline]
 blk_mq_dispatch_rq_list+0x1171/0x1290 block/blk-mq.c:2152
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:173 [inline]
 blk_mq_do_dispatch_sched+0x49d/0x7f0 block/blk-mq-sched.c:187
 __blk_mq_sched_dispatch_requests+0x1cd/0x270
 blk_mq_sched_dispatch_requests+0x8f/0xf0 block/blk-mq-sched.c:339
 __blk_mq_run_hw_queue+0x8b/0x150 block/blk-mq.c:2174
 __blk_mq_delay_run_hw_queue+0x15b/0x2e0 block/blk-mq.c:2250
 blk_mq_run_hw_queue+0x1be/0x350 block/blk-mq.c:2298
 blk_mq_get_tag+0x44d/0x570 block/blk-mq-tag.c:163
 __blk_mq_alloc_requests+0x5f0/0x710 block/blk-mq.c:526
 blk_mq_get_new_requests block/blk-mq.c:2878 [inline]
 blk_mq_submit_bio+0x57a/0xea0 block/blk-mq.c:2969
 __submit_bio block/blk-core.c:602 [inline]
 __submit_bio_noacct_mq block/blk-core.c:679 [inline]
 submit_bio_noacct_nocheck+0x83d/0xaa0 block/blk-core.c:696
 submit_bio_noacct+0x6a5/0x810 block/blk-core.c:802
 submit_bio+0xfb/0x110 block/blk-core.c:838
 ext4_io_submit+0x86/0xa0 fs/ext4/page-io.c:378
 ext4_do_writepages+0xb9d/0x1e70 fs/ext4/inode.c:2897
 ext4_writepages+0x11b/0x240 fs/ext4/inode.c:2965
 do_writepages+0x1db/0x350 mm/page-writeback.c:2581
 filemap_fdatawrite_wbc+0xd6/0xf0 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 __filemap_fdatawrite mm/filemap.c:427 [inline]
 filemap_flush+0x93/0xc0 mm/filemap.c:454
 ext4_alloc_da_blocks+0x47/0x100 fs/ext4/inode.c:3219
 ext4_release_file+0x5b/0x1d0 fs/ext4/file.c:158
 __fput+0x245/0x570 fs/file_table.c:320
 ____fput+0x11/0x20 fs/file_table.c:348
 task_work_run+0xde/0x110 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x5a0/0x16e0 kernel/exit.c:867
 do_group_exit+0xfe/0x140 kernel/exit.c:1012
 get_signal+0xb4b/0xc70 kernel/signal.c:2859
 arch_do_signal_or_restart+0x85/0x290 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x69/0x90 kernel/entry/common.c:203
 irqentry_exit_to_user_mode+0x5/0x10 kernel/entry/common.c:309
 irqentry_exit+0xe/0x40 kernel/entry/common.c:412
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

read to 0xffff888101bd5af8 of 4 bytes by task 25 on cpu 1:
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:100 [inline]
 blk_mq_do_dispatch_sched+0xc9/0x7f0 block/blk-mq-sched.c:187
 __blk_mq_sched_dispatch_requests+0x1cd/0x270
 blk_mq_sched_dispatch_requests+0x8f/0xf0 block/blk-mq-sched.c:339
 __blk_mq_run_hw_queue+0x8b/0x150 block/blk-mq.c:2174
 __blk_mq_delay_run_hw_queue+0x15b/0x2e0 block/blk-mq.c:2250
 blk_mq_run_hw_queue+0x1be/0x350 block/blk-mq.c:2298
 blk_mq_sched_insert_requests+0x220/0x300 block/blk-mq-sched.c:493
 blk_mq_dispatch_plug_list+0x1e9/0x2c0 block/blk-mq.c:2758
 blk_mq_flush_plug_list+0x38a/0x3e0 block/blk-mq.c:2800
 blk_add_rq_to_plug+0x142/0x390 block/blk-mq.c:1296
 blk_mq_submit_bio+0x8ec/0xea0 block/blk-mq.c:2994
 __submit_bio block/blk-core.c:602 [inline]
 __submit_bio_noacct_mq block/blk-core.c:679 [inline]
 submit_bio_noacct_nocheck+0x83d/0xaa0 block/blk-core.c:696
 submit_bio_noacct+0x6a5/0x810 block/blk-core.c:802
 submit_bio+0xfb/0x110 block/blk-core.c:838
 ext4_io_submit+0x86/0xa0 fs/ext4/page-io.c:378
 ext4_do_writepages+0xb9d/0x1e70 fs/ext4/inode.c:2897
 ext4_writepages+0x11b/0x240 fs/ext4/inode.c:2965
 do_writepages+0x1db/0x350 mm/page-writeback.c:2581
 __writeback_single_inode+0x81/0x590 fs/fs-writeback.c:1598
 writeback_sb_inodes+0x4dd/0xa30 fs/fs-writeback.c:1889
 wb_writeback+0x26b/0x650 fs/fs-writeback.c:2063
 wb_do_writeback+0x101/0x600 fs/fs-writeback.c:2206
 wb_workfn+0x88/0x260 fs/fs-writeback.c:2246
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

value changed: 0x00000003 -> 0x00000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-00376-g7c6984405241-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: writeback wb_workfn (flush-8:0)
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