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BUG: KCSAN: data-race in __mark_inode_dirty / writeback_single_inode

write to 0xffff88810a976850 of 8 bytes by task 3766 on cpu 0:
 writeback_single_inode+0x109/0x580 fs/fs-writeback.c:1705
 sync_inode_metadata+0x52/0x70 fs/fs-writeback.c:2764
 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline]
 ext4_sync_file+0x349/0x6d0 fs/ext4/fsync.c:170
 vfs_fsync_range+0x107/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2891 [inline]
 ext4_buffered_write_iter+0x398/0x3e0 fs/ext4/file.c:292
 ext4_file_write_iter+0x2c7/0x1170
 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 to 0xffff88810a976850 of 8 bytes by task 3750 on cpu 1:
 __mark_inode_dirty+0x186/0x730 fs/fs-writeback.c:2430
 mark_buffer_dirty+0x16f/0x390 fs/buffer.c:1109
 __block_commit_write+0x11d/0x1c0 fs/buffer.c:2065
 block_write_end+0x42/0xb0 fs/buffer.c:2144
 ext4_write_end+0x12b/0x7c0 fs/ext4/inode.c:1315
 ext4_da_write_end+0x6d/0x620 fs/ext4/inode.c:3063
 generic_perform_write+0x264/0x3f0 mm/filemap.c:3764
 ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:285
 ext4_file_write_iter+0x2c7/0x1170
 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: 0x0000000000000007 -> 0x0000000000000084

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3750 Comm: syz-executor.3 Not tainted 6.1.0-rc8-syzkaller-00003-gbce9332220bd-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
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