syzbot

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BUG: KCSAN: data-race in ext4_mark_iloc_dirty / ext4_setattr

write to 0xffff8881061ce868 of 8 bytes by task 7845 on cpu 0:
 ext4_setattr+0xbf3/0xec0 fs/ext4/inode.c:5452
 notify_change+0x8a3/0xa80 fs/attr.c:398
 do_truncate fs/open.c:64 [inline]
 do_sys_ftruncate+0x405/0x4c0 fs/open.c:196
 __do_sys_ftruncate fs/open.c:207 [inline]
 __se_sys_ftruncate fs/open.c:205 [inline]
 __x64_sys_ftruncate+0x2f/0x40 fs/open.c:205
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881061ce868 of 8 bytes by task 7833 on cpu 1:
 ext4_encode_extra_time fs/ext4/ext4.h:887 [inline]
 ext4_do_update_inode fs/ext4/inode.c:5075 [inline]
 ext4_mark_iloc_dirty+0x6a5/0x1750 fs/ext4/inode.c:5724
 __ext4_mark_inode_dirty+0x4db/0x5b0 fs/ext4/inode.c:5918
 ext4_dirty_inode+0x86/0xa0 fs/ext4/inode.c:5947
 __mark_inode_dirty+0x77/0x6c0 fs/fs-writeback.c:2274
 generic_update_time fs/inode.c:1765 [inline]
 update_time fs/inode.c:1778 [inline]
 touch_atime+0x170/0x240 fs/inode.c:1849
 file_accessed include/linux/fs.h:2458 [inline]
 filemap_read+0x11c9/0x1230 mm/filemap.c:2638
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2717
 ext4_file_read_iter+0x1db/0x290 fs/ext4/file.c:73
 call_read_iter include/linux/fs.h:2110 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7833 Comm: syz-executor.2 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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