syzbot

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BUG: KCSAN: data-race in blk_mq_dispatch_rq_list / blk_mq_do_dispatch_sched

write to 0xffff8881019382f8 of 4 bytes by task 15150 on cpu 0:
 blk_mq_dispatch_rq_list+0xfdb/0x11f0
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:172 [inline]
 blk_mq_do_dispatch_sched+0x4de/0x820 block/blk-mq-sched.c:186
 __blk_mq_sched_dispatch_requests+0x1c1/0x260
 blk_mq_sched_dispatch_requests+0x93/0x100 block/blk-mq-sched.c:338
 __blk_mq_run_hw_queue+0x8e/0x110 block/blk-mq.c:2175
 __blk_mq_delay_run_hw_queue+0xb3/0x3a0 block/blk-mq.c:2251
 blk_mq_run_hw_queue+0x19f/0x330 block/blk-mq.c:2299
 blk_mq_get_tag+0x479/0x590 block/blk-mq-tag.c:163
 __blk_mq_alloc_requests+0x5a8/0x6d0 block/blk-mq.c:526
 blk_mq_get_new_requests block/blk-mq.c:2862 [inline]
 blk_mq_submit_bio+0x4ad/0xe60 block/blk-mq.c:2957
 __submit_bio+0x130/0x360 block/blk-core.c:602
 __submit_bio_noacct_mq block/blk-core.c:679 [inline]
 submit_bio_noacct_nocheck+0x4cd/0x600 block/blk-core.c:708
 submit_bio_noacct+0x76f/0x900 block/blk-core.c:807
 submit_bio+0x101/0x110 block/blk-core.c:843
 ext4_io_submit fs/ext4/page-io.c:378 [inline]
 io_submit_add_bh fs/ext4/page-io.c:421 [inline]
 ext4_bio_write_page+0x7a1/0xcf0 fs/ext4/page-io.c:566
 mpage_submit_page fs/ext4/inode.c:2129 [inline]
 mpage_map_and_submit_buffers fs/ext4/inode.c:2374 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2513 [inline]
 ext4_do_writepages+0x138c/0x2140 fs/ext4/inode.c:2876
 ext4_writepages+0x130/0x260 fs/ext4/inode.c:2964
 do_writepages+0x1c5/0x340 mm/page-writeback.c:2551
 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:390
 __filemap_fdatawrite_range mm/filemap.c:423 [inline]
 __filemap_fdatawrite mm/filemap.c:429 [inline]
 filemap_flush+0x95/0xc0 mm/filemap.c:456
 ext4_alloc_da_blocks+0x50/0x130 fs/ext4/inode.c:3218
 ext4_release_file+0x5f/0x1c0 fs/ext4/file.c:158
 __fput+0x245/0x570 fs/file_table.c:321
 ____fput+0x15/0x20 fs/file_table.c:349
 task_work_run+0x123/0x160 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x5d7/0x1660 kernel/exit.c:869
 do_group_exit+0x101/0x150 kernel/exit.c:1019
 get_signal+0xeb1/0xff0 kernel/signal.c:2859
 arch_do_signal_or_restart+0x89/0x2a0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 irqentry_exit_to_user_mode+0x9/0x20 kernel/entry/common.c:310
 irqentry_exit+0x12/0x40 kernel/entry/common.c:413
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

read to 0xffff8881019382f8 of 4 bytes by task 14923 on cpu 1:
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:99 [inline]
 blk_mq_do_dispatch_sched+0xc8/0x820 block/blk-mq-sched.c:186
 __blk_mq_sched_dispatch_requests+0x1c1/0x260
 blk_mq_sched_dispatch_requests+0x93/0x100 block/blk-mq-sched.c:338
 __blk_mq_run_hw_queue+0x8e/0x110 block/blk-mq.c:2175
 __blk_mq_delay_run_hw_queue+0xb3/0x3a0 block/blk-mq.c:2251
 blk_mq_run_hw_queue+0x19f/0x330 block/blk-mq.c:2299
 blk_mq_get_tag+0x479/0x590 block/blk-mq-tag.c:163
 __blk_mq_alloc_requests+0x5a8/0x6d0 block/blk-mq.c:526
 blk_mq_get_new_requests block/blk-mq.c:2862 [inline]
 blk_mq_submit_bio+0x4ad/0xe60 block/blk-mq.c:2957
 __submit_bio+0x130/0x360 block/blk-core.c:602
 __submit_bio_noacct_mq block/blk-core.c:679 [inline]
 submit_bio_noacct_nocheck+0x469/0x600 block/blk-core.c:708
 submit_bio_noacct+0x76f/0x900 block/blk-core.c:807
 submit_bio+0x101/0x110 block/blk-core.c:843
 ext4_io_submit+0x8a/0xa0 fs/ext4/page-io.c:378
 ext4_do_writepages+0xb3a/0x2140 fs/ext4/inode.c:2896
 ext4_writepages+0x130/0x260 fs/ext4/inode.c:2964
 do_writepages+0x1c5/0x340 mm/page-writeback.c:2551
 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:390
 __filemap_fdatawrite_range mm/filemap.c:423 [inline]
 __filemap_fdatawrite mm/filemap.c:429 [inline]
 filemap_flush+0x95/0xc0 mm/filemap.c:456
 ext4_alloc_da_blocks+0x50/0x130 fs/ext4/inode.c:3218
 ext4_release_file+0x5f/0x1c0 fs/ext4/file.c:158
 __fput+0x245/0x570 fs/file_table.c:321
 ____fput+0x15/0x20 fs/file_table.c:349
 task_work_run+0x123/0x160 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x5d7/0x1660 kernel/exit.c:869
 do_group_exit+0x101/0x150 kernel/exit.c:1019
 get_signal+0xeb1/0xff0 kernel/signal.c:2859
 arch_do_signal_or_restart+0x89/0x2a0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 irqentry_exit_to_user_mode+0x9/0x20 kernel/entry/common.c:310
 irqentry_exit+0x12/0x40 kernel/entry/common.c:413
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

value changed: 0x00000007 -> 0x00000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14923 Comm: syz-executor.4 Not tainted 6.3.0-rc7-syzkaller-00189-g2caeeb9d4a1b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
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