==================================================================
BUG: KCSAN: data-race in blk_mq_sched_dispatch_requests / blk_mq_sched_dispatch_requests

read-write to 0xffff888100197150 of 8 bytes by task 30145 on cpu 0:
 blk_mq_sched_dispatch_requests+0x8a/0x100 block/blk-mq-sched.c:327
 blk_mq_run_hw_queue+0x2a4/0x4c0 block/blk-mq.c:2264
 blk_mq_flush_plug_list+0x7b6/0xdc0 block/blk-mq.c:2812
 __blk_flush_plug+0x210/0x260 block/blk-core.c:1150
 blk_finish_plug+0x47/0x60 block/blk-core.c:1174
 __iomap_dio_rw+0xc69/0x1090 fs/iomap/direct-io.c:667
 iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:748
 ext4_dio_read_iter fs/ext4/file.c:94 [inline]
 ext4_file_read_iter+0x21c/0x2a0 fs/ext4/file.c:145
 call_read_iter include/linux/fs.h:2014 [inline]
 copy_splice_read+0x26b/0x4b0 fs/splice.c:364
 vfs_splice_read fs/splice.c:992 [inline]
 splice_direct_to_actor+0x2aa/0x690 fs/splice.c:1069
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read-write to 0xffff888100197150 of 8 bytes by task 30142 on cpu 1:
 blk_mq_sched_dispatch_requests+0x8a/0x100 block/blk-mq-sched.c:327
 blk_mq_run_hw_queue+0x2a4/0x4c0 block/blk-mq.c:2264
 blk_mq_flush_plug_list+0x7b6/0xdc0 block/blk-mq.c:2812
 __blk_flush_plug+0x210/0x260 block/blk-core.c:1150
 blk_finish_plug+0x47/0x60 block/blk-core.c:1174
 ext4_do_writepages+0x1bc7/0x2100 fs/ext4/inode.c:2736
 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]
 file_write_and_wait_range+0xf4/0x190 mm/filemap.c:778
 ext4_sync_file+0x133/0x6c0 fs/ext4/fsync.c:158
 vfs_fsync_range+0x111/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2653 [inline]
 ext4_buffered_write_iter+0x334/0x370 fs/ext4/file.c:305
 ext4_file_write_iter+0x297/0xe10
 do_iter_write+0x4ad/0x770 fs/read_write.c:860
 vfs_iter_write+0x56/0x70 fs/read_write.c:901
 iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
 splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1316 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0xbd/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000017e56 -> 0x0000000000017e57

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 30142 Comm: syz-executor.2 Not tainted 6.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================