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BUG: KCSAN: data-race in ext4_dio_write_end_io / filemap_read

write to 0xffff88813402ec88 of 8 bytes by task 27833 on cpu 1:
 i_size_write include/linux/fs.h:911 [inline]
 ext4_dio_write_end_io+0xd3/0x100 fs/ext4/file.c:399
 iomap_dio_complete+0xb8/0x3c0 fs/iomap/direct-io.c:88
 iomap_dio_rw+0x4e/0x70 fs/iomap/direct-io.c:652
 ext4_dio_write_iter fs/ext4/file.c:568 [inline]
 ext4_file_write_iter+0xa0e/0x11a0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2157 [inline]
 do_iter_readv_writev+0x2cd/0x370 fs/read_write.c:729
 do_iter_write+0x192/0x5c0 fs/read_write.c:855
 vfs_iter_write+0x4c/0x70 fs/read_write.c:896
 iter_file_splice_write+0x40a/0x750 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x650 fs/splice.c:891
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x618/0xb90 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1314 [inline]
 __se_sys_sendfile64 fs/read_write.c:1300 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1300
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813402ec88 of 8 bytes by task 27846 on cpu 0:
 i_size_read include/linux/fs.h:889 [inline]
 filemap_read+0xd45/0x1210 mm/filemap.c:2625
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2764
 ext4_file_read_iter+0x1db/0x290 fs/ext4/file.c:73
 call_read_iter include/linux/fs.h:2151 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x651/0x730 fs/read_write.c:485
 ksys_read+0xce/0x180 fs/read_write.c:623
 __do_sys_read fs/read_write.c:633 [inline]
 __se_sys_read fs/read_write.c:631 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:631
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000000000001ee00 -> 0x0000000000020000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 27846 Comm: syz-executor.0 Tainted: G        W         5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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