syzbot

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BUG: KCSAN: data-race in blk_mq_sched_dispatch_requests / blk_mq_sched_dispatch_requests

read-write to 0xffff888102abeb58 of 8 bytes by task 2368 on cpu 1:
 blk_mq_sched_dispatch_requests+0x80/0xf0 block/blk-mq-sched.c:333
 __blk_mq_run_hw_queue+0x7e/0x100 block/blk-mq.c:2025
 __blk_mq_delay_run_hw_queue+0x194/0x390 block/blk-mq.c:2102
 blk_mq_run_hw_queue+0x180/0x310 block/blk-mq.c:2153
 blk_mq_sched_insert_requests+0x1cb/0x2a0 block/blk-mq-sched.c:493
 blk_mq_dispatch_plug_list+0x1e9/0x2c0 block/blk-mq.c:2648
 blk_mq_flush_plug_list+0x2ea/0x340 block/blk-mq.c:2690
 __blk_flush_plug+0x25a/0x2b0 block/blk-core.c:1219
 blk_finish_plug+0x44/0x60 block/blk-core.c:1243
 __iomap_dio_rw+0xc6d/0xf50 fs/iomap/direct-io.c:609
 iomap_dio_rw+0x3c/0x80 fs/iomap/direct-io.c:689
 ext4_dio_write_iter fs/ext4/file.c:566 [inline]
 ext4_file_write_iter+0xa51/0x1210 fs/ext4/file.c:677
 do_iter_readv_writev+0x27b/0x300
 do_iter_write+0x16f/0x5c0 fs/read_write.c:852
 vfs_iter_write+0x4c/0x70 fs/read_write.c:893
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x660 fs/splice.c:891
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3ad/0x900 fs/read_write.c:1246
 __do_sys_sendfile64 fs/read_write.c:1311 [inline]
 __se_sys_sendfile64 fs/read_write.c:1297 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read-write to 0xffff888102abeb58 of 8 bytes by task 9 on cpu 0:
 blk_mq_sched_dispatch_requests+0x80/0xf0 block/blk-mq-sched.c:333
 __blk_mq_run_hw_queue+0x7e/0x100 block/blk-mq.c:2025
 blk_mq_run_work_fn+0x3d/0x50 block/blk-mq.c:2363
 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

value changed: 0x0000000000001138 -> 0x0000000000001139

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9 Comm: kworker/0:1H Not tainted 5.18.0-syzkaller-10037-g7e284070abe5-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: kblockd blk_mq_run_work_fn
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