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BUG: KCSAN: data-race in blk_mq_unfreeze_queue / blk_queue_enter

read-write to 0xffff88810266fd94 of 4 bytes by task 25931 on cpu 1:
 blk_mq_unfreeze_queue+0x34/0xb0 block/blk-mq.c:192
 loop_set_status+0x6c3/0x7f0 drivers/block/loop.c:1417
 lo_ioctl+0x74c/0x11b0 drivers/block/loop.c:1496
 __blkdev_driver_ioctl block/ioctl.c:228 [inline]
 blkdev_ioctl+0x1d6/0x3f0 block/ioctl.c:623
 block_ioctl+0x6d/0x80 fs/block_dev.c:1869
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810266fd94 of 4 bytes by task 25922 on cpu 0:
 blk_queue_enter+0x1ca/0x510 block/blk-core.c:466
 bio_queue_enter block/blk-core.c:482 [inline]
 __submit_bio_noacct_mq block/blk-core.c:1017 [inline]
 submit_bio_noacct+0x70e/0x930 block/blk-core.c:1059
 submit_bio+0x1f3/0x360 block/blk-core.c:1129
 submit_bh_wbc+0x38c/0x3d0 fs/buffer.c:3054
 __block_write_full_page+0x618/0x9e0 fs/buffer.c:1810
 block_write_full_page+0x15d/0x190 fs/buffer.c:2980
 blkdev_writepage+0x20/0x30 fs/block_dev.c:627
 __writepage+0x32/0xc0 mm/page-writeback.c:2311
 write_cache_pages+0x4bc/0x7f0 mm/page-writeback.c:2246
 generic_writepages+0x64/0xa0 mm/page-writeback.c:2337
 blkdev_writepages+0x19/0x20 fs/block_dev.c:1946
 do_writepages+0x7b/0x150 mm/page-writeback.c:2352
 __filemap_fdatawrite_range+0x19d/0x1d0 mm/filemap.c:422
 file_write_and_wait_range+0x9f/0x120 mm/filemap.c:761
 blkdev_fsync+0x42/0xa0 fs/block_dev.c:683
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2739 [inline]
 blkdev_write_iter+0x264/0x2a0 fs/block_dev.c:1907
 call_write_iter include/linux/fs.h:1903 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4b0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x42a/0x780 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:933
 splice_direct_to_actor+0x345/0x650 fs/splice.c:888
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x5db/0xca0 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 25922 Comm: syz-executor.3 Not tainted 5.10.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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