==================================================================
BUG: KCSAN: data-race in blk_mq_dispatch_rq_list / blk_mq_dispatch_rq_list

read to 0xffff8881027d8168 of 8 bytes by task 345 on cpu 0:
 blk_mq_dispatch_rq_list+0xac8/0x1080 block/blk-mq.c:1393
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:201 [inline]
 blk_mq_do_dispatch_sched+0x3b5/0x640 block/blk-mq-sched.c:214
 __blk_mq_sched_dispatch_requests+0x1eb/0x290
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:360
 __blk_mq_run_hw_queue+0xbc/0x140 block/blk-mq.c:1487
 __blk_mq_delay_run_hw_queue+0x163/0x2f0 block/blk-mq.c:1564
 blk_mq_run_hw_queue+0x22c/0x250 block/blk-mq.c:1617
 blk_mq_sched_insert_requests+0x12b/0x1f0 block/blk-mq-sched.c:513
 blk_mq_flush_plug_list+0x302/0x3d0 block/blk-mq.c:1942
 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1726
 blk_finish_plug+0x44/0x60 block/blk-core.c:1743
 jbd2_journal_commit_transaction+0x1bac/0x3430 fs/jbd2/commit.c:838
 kjournald2+0x268/0x490 fs/jbd2/journal.c:213
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30

write to 0xffff8881027d8168 of 8 bytes by task 12028 on cpu 1:
 blk_mq_dispatch_rq_list+0xadb/0x1080 block/blk-mq.c:1393
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:201 [inline]
 blk_mq_do_dispatch_sched+0x3b5/0x640 block/blk-mq-sched.c:214
 __blk_mq_sched_dispatch_requests+0x1eb/0x290
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:360
 __blk_mq_run_hw_queue+0xbc/0x140 block/blk-mq.c:1487
 __blk_mq_delay_run_hw_queue+0x163/0x2f0 block/blk-mq.c:1564
 blk_mq_run_hw_queue+0x22c/0x250 block/blk-mq.c:1617
 blk_mq_sched_insert_requests+0x12b/0x1f0 block/blk-mq-sched.c:513
 blk_mq_flush_plug_list+0x302/0x3d0 block/blk-mq.c:1942
 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1726
 blk_finish_plug+0x44/0x60 block/blk-core.c:1743
 ext4_writepages+0x18f1/0x1d70 fs/ext4/inode.c:2849
 do_writepages+0x26b/0x3c0 mm/page-writeback.c:2364
 filemap_fdatawrite_wbc mm/filemap.c:400 [inline]
 __filemap_fdatawrite_range mm/filemap.c:433 [inline]
 file_write_and_wait_range+0x1ae/0x240 mm/filemap.c:810
 ext4_sync_file+0x105/0x670 fs/ext4/fsync.c:151
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2955 [inline]
 ext4_buffered_write_iter+0x3af/0x400 fs/ext4/file.c:277
 ext4_file_write_iter+0x2e7/0x11f0
 __kernel_write+0x32e/0x5e0 fs/read_write.c:539
 do_acct_process+0xb27/0xcc0 kernel/acct.c:519
 slow_acct_process kernel/acct.c:578 [inline]
 acct_process+0x1ed/0x260 kernel/acct.c:602
 do_exit+0x3f9/0x14a0 kernel/exit.c:815
 do_group_exit+0x19b/0x1a0 kernel/exit.c:922
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:933
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:931
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:931
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000006507 -> 0x0000000000006508

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12028 Comm: syz-executor.0 Not tainted 5.15.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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syz-executor.0 (12028) used greatest stack depth: 10064 bytes left