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BUG: KCSAN: data-race in filemap_read / generic_write_end

write to 0xffff88810ad7b278 of 8 bytes by task 4082 on cpu 0:
 i_size_write include/linux/fs.h:886 [inline]
 generic_write_end+0xb4/0x360 fs/buffer.c:2168
 ext4_da_write_end+0x4bd/0x630 fs/ext4/inode.c:3175
 generic_perform_write+0x253/0x3d0 mm/filemap.c:3784
 ext4_buffered_write_iter+0x234/0x3e0 fs/ext4/file.c:285
 ext4_file_write_iter+0x2d2/0x1270
 call_write_iter include/linux/fs.h:2189 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x45a/0x750 fs/read_write.c:584
 ksys_write+0xeb/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810ad7b278 of 8 bytes by task 4092 on cpu 1:
 i_size_read include/linux/fs.h:864 [inline]
 filemap_read+0xfb2/0x14b0 mm/filemap.c:2707
 generic_file_read_iter+0x76/0x320 mm/filemap.c:2841
 ext4_file_read_iter+0x1cc/0x290
 call_read_iter include/linux/fs.h:2183 [inline]
 generic_file_splice_read+0xe3/0x290 fs/splice.c:309
 do_splice_to fs/splice.c:793 [inline]
 splice_direct_to_actor+0x25a/0x5f0 fs/splice.c:865
 do_splice_direct+0x104/0x180 fs/splice.c:974
 do_sendfile+0x3b8/0x950 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+0x110/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000f51000 -> 0x0000000000f52000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4092 Comm: syz-executor.2 Not tainted 6.2.0-rc8-syzkaller-00151-g925cf0457d7e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
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