syzbot

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BUG: KCSAN: data-race in __blk_mq_alloc_driver_tag / bt_tags_for_each

write to 0xffff88810297afa0 of 4 bytes by task 29577 on cpu 1:
 __blk_mq_alloc_driver_tag+0x180/0x380 block/blk-mq.c:1784
 blk_mq_get_driver_tag block/blk-mq.h:354 [inline]
 blk_mq_prep_dispatch_rq block/blk-mq.c:1954 [inline]
 blk_mq_dispatch_rq_list+0x1f8/0x1090 block/blk-mq.c:2034
 __blk_mq_sched_dispatch_requests+0x1ce/0xd20 block/blk-mq-sched.c:301
 blk_mq_sched_dispatch_requests+0x99/0x100 block/blk-mq-sched.c:333
 blk_mq_run_hw_queue+0x2a4/0x4c0 block/blk-mq.c:2264
 blk_mq_get_tag+0x21f/0x590 block/blk-mq-tag.c:170
 __blk_mq_alloc_requests+0x642/0x9e0 block/blk-mq.c:501
 blk_mq_get_new_requests block/blk-mq.c:2884 [inline]
 blk_mq_submit_bio+0x468/0xd90 block/blk-mq.c:2982
 __submit_bio+0x11c/0x350 block/blk-core.c:607
 __submit_bio_noacct_mq block/blk-core.c:686 [inline]
 submit_bio_noacct_nocheck+0x4ad/0x5e0 block/blk-core.c:715
 submit_bio_noacct+0x70c/0x8c0 block/blk-core.c:809
 submit_bio+0xb7/0xc0 block/blk-core.c:842
 ext4_io_submit fs/ext4/page-io.c:378 [inline]
 io_submit_add_bh fs/ext4/page-io.c:419 [inline]
 ext4_bio_write_folio+0x6c0/0x9a0 fs/ext4/page-io.c:563
 mpage_submit_folio fs/ext4/inode.c:1875 [inline]
 mpage_map_and_submit_buffers fs/ext4/inode.c:2121 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2260 [inline]
 ext4_do_writepages+0x139f/0x2100 fs/ext4/inode.c:2685
 ext4_writepages+0x15e/0x2e0 fs/ext4/inode.c:2774
 do_writepages+0x1c2/0x340 mm/page-writeback.c:2553
 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:387
 __filemap_fdatawrite_range mm/filemap.c:420 [inline]
 __filemap_fdatawrite mm/filemap.c:426 [inline]
 filemap_flush+0x95/0xc0 mm/filemap.c:453
 ext4_alloc_da_blocks+0x50/0x130 fs/ext4/inode.c:3077
 ext4_release_file+0x5f/0x1c0 fs/ext4/file.c:169
 __fput+0x299/0x630 fs/file_table.c:394
 ____fput+0x15/0x20 fs/file_table.c:422
 task_work_run+0x135/0x1a0 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x604/0x16d0 kernel/exit.c:869
 do_group_exit+0x101/0x150 kernel/exit.c:1018
 get_signal+0xf4e/0x10a0 kernel/signal.c:2904
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:309
 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:309
 irqentry_exit+0x12/0x40 kernel/entry/common.c:412
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

read to 0xffff88810297afa0 of 4 bytes by task 23915 on cpu 0:
 blk_mq_find_and_get_req block/blk-mq-tag.c:260 [inline]
 bt_tags_iter block/blk-mq-tag.c:356 [inline]
 __sbitmap_for_each_set include/linux/sbitmap.h:281 [inline]
 sbitmap_for_each_set include/linux/sbitmap.h:302 [inline]
 bt_tags_for_each+0x2e2/0x500 block/blk-mq-tag.c:391
 __blk_mq_all_tag_iter block/blk-mq-tag.c:402 [inline]
 blk_mq_tagset_busy_iter+0x114/0x150 block/blk-mq-tag.c:446
 scsi_host_busy+0x4f/0x80 drivers/scsi/hosts.c:604
 scsi_host_queue_ready drivers/scsi/scsi_lib.c:1341 [inline]
 scsi_queue_rq+0x310/0x1a30 drivers/scsi/scsi_lib.c:1735
 blk_mq_dispatch_rq_list+0x2d9/0x1090 block/blk-mq.c:2049
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline]
 blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline]
 __blk_mq_sched_dispatch_requests+0x5ec/0xd20 block/blk-mq-sched.c:309
 blk_mq_sched_dispatch_requests+0x99/0x100 block/blk-mq-sched.c:333
 blk_mq_run_hw_queue+0x2a4/0x4c0 block/blk-mq.c:2264
 blk_mq_get_tag+0x479/0x590 block/blk-mq-tag.c:170
 __blk_mq_alloc_requests+0x642/0x9e0 block/blk-mq.c:501
 blk_mq_get_new_requests block/blk-mq.c:2884 [inline]
 blk_mq_submit_bio+0x468/0xd90 block/blk-mq.c:2982
 __submit_bio+0x11c/0x350 block/blk-core.c:607
 __submit_bio_noacct_mq block/blk-core.c:686 [inline]
 submit_bio_noacct_nocheck+0x449/0x5e0 block/blk-core.c:715
 submit_bio_noacct+0x70c/0x8c0 block/blk-core.c:809
 submit_bio+0xb7/0xc0 block/blk-core.c:842
 ext4_io_submit+0x8a/0xa0 fs/ext4/page-io.c:378
 ext4_do_writepages+0xb3a/0x2100 fs/ext4/inode.c:2705
 ext4_writepages+0x15e/0x2e0 fs/ext4/inode.c:2774
 do_writepages+0x1c2/0x340 mm/page-writeback.c:2553
 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:387
 __filemap_fdatawrite_range mm/filemap.c:420 [inline]
 __filemap_fdatawrite mm/filemap.c:426 [inline]
 filemap_flush+0x95/0xc0 mm/filemap.c:453
 ext4_alloc_da_blocks+0x50/0x130 fs/ext4/inode.c:3077
 ext4_release_file+0x5f/0x1c0 fs/ext4/file.c:169
 __fput+0x299/0x630 fs/file_table.c:394
 ____fput+0x15/0x20 fs/file_table.c:422
 task_work_run+0x135/0x1a0 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x604/0x16d0 kernel/exit.c:869
 do_group_exit+0x101/0x150 kernel/exit.c:1018
 get_signal+0xf4e/0x10a0 kernel/signal.c:2904
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:309
 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:309
 irqentry_exit+0x12/0x40 kernel/entry/common.c:412
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

value changed: 0xffffffff -> 0x00001a52

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 23915 Comm: syz-executor.3 Not tainted 6.7.0-rc8-syzkaller-00055-g5eff55d725a4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
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