syzbot

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BUG: KCSAN: data-race in blk_mq_sched_dispatch_requests / blk_mq_sched_dispatch_requests

read-write to 0xffff8881023e9358 of 8 bytes by task 13284 on cpu 0:
 blk_mq_sched_dispatch_requests+0x80/0xf0 block/blk-mq-sched.c:333
 __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_flush_plug+0x25a/0x2b0 block/blk-core.c:1137
 blk_finish_plug+0x44/0x60 block/blk-core.c:1161
 __iomap_dio_rw+0xd27/0x1000 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:587 [inline]
 ext4_file_write_iter+0xa36/0x11b0 fs/ext4/file.c:698
 do_iter_write+0x494/0x750 fs/read_write.c:861
 vfs_iter_write+0x4c/0x70 fs/read_write.c:902
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:931
 splice_direct_to_actor+0x305/0x620 fs/splice.c:886
 do_splice_direct+0xfb/0x180 fs/splice.c:974
 do_sendfile+0x3bf/0x910 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309
 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+0x63/0xcd

read-write to 0xffff8881023e9358 of 8 bytes by task 13266 on cpu 1:
 blk_mq_sched_dispatch_requests+0x80/0xf0 block/blk-mq-sched.c:333
 __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_flush_plug+0x25a/0x2b0 block/blk-core.c:1137
 blk_finish_plug+0x44/0x60 block/blk-core.c:1161
 __iomap_dio_rw+0xd27/0x1000 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:587 [inline]
 ext4_file_write_iter+0xa36/0x11b0 fs/ext4/file.c:698
 do_iter_write+0x494/0x750 fs/read_write.c:861
 vfs_iter_write+0x4c/0x70 fs/read_write.c:902
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:931
 splice_direct_to_actor+0x305/0x620 fs/splice.c:886
 do_splice_direct+0xfb/0x180 fs/splice.c:974
 do_sendfile+0x3bf/0x910 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309
 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+0x63/0xcd

value changed: 0x0000000000004637 -> 0x0000000000004638

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13266 Comm: syz-executor.0 Tainted: G        W          6.2.0-rc6-syzkaller-00011-gc0b67534c95c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
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syz-executor.0 (13266) used greatest stack depth: 10368 bytes left