==================================================================
BUG: KCSAN: data-race in __jbd2_journal_file_buffer / jbd2_journal_dirty_metadata

write to 0xffff8881076093a8 of 8 bytes by task 4802 on cpu 0:
 __jbd2_journal_file_buffer+0x18d/0x380 fs/jbd2/transaction.c:2518
 __jbd2_journal_refile_buffer+0x155/0x230 fs/jbd2/transaction.c:2612
 jbd2_journal_commit_transaction+0x24b6/0x3290 fs/jbd2/commit.c:1084
 kjournald2+0x263/0x480 fs/jbd2/journal.c:213
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff8881076093a8 of 8 bytes by task 11278 on cpu 1:
 jbd2_journal_dirty_metadata+0x17f/0x670 fs/jbd2/transaction.c:1486
 __ext4_handle_dirty_metadata+0xc6/0x590 fs/ext4/ext4_jbd2.c:331
 ext4_do_update_inode fs/ext4/inode.c:5141 [inline]
 ext4_mark_iloc_dirty+0x12f2/0x16f0 fs/ext4/inode.c:5724
 __ext4_mark_inode_dirty+0x4db/0x5e0 fs/ext4/inode.c:5918
 ext4_dirty_inode+0x86/0xa0 fs/ext4/inode.c:5947
 __mark_inode_dirty+0x72/0x6f0 fs/fs-writeback.c:2274
 generic_update_time fs/inode.c:1766 [inline]
 update_time fs/inode.c:1779 [inline]
 touch_atime+0x1b3/0x2d0 fs/inode.c:1850
 file_accessed include/linux/fs.h:2319 [inline]
 filemap_read+0x74f/0x7b0 mm/filemap.c:2530
 generic_file_read_iter+0x82/0x410 mm/filemap.c:2609
 ext4_file_read_iter+0x2e0/0x420 fs/ext4/file.c:74
 call_read_iter include/linux/fs.h:1971 [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+0x7a6/0xe20 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1319 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1311
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11278 Comm: syz-executor.3 Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================