syzbot

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BUG: KCSAN: data-race in __ext4_journal_start_sb / jbd2_journal_commit_transaction

write to 0xffff888102575000 of 8 bytes by task 4817 on cpu 1:
 jbd2_journal_commit_transaction+0x228/0x3290 fs/jbd2/commit.c:443
 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 0xffff888102575000 of 8 bytes by task 12477 on cpu 0:
 is_journal_aborted include/linux/jbd2.h:1647 [inline]
 ext4_journal_check_start fs/ext4/ext4_jbd2.c:82 [inline]
 __ext4_journal_start_sb+0xf2/0x310 fs/ext4/ext4_jbd2.c:98
 __ext4_new_inode+0xc6c/0x2fe0 fs/ext4/ialloc.c:1077
 ext4_symlink+0x2d1/0x780 fs/ext4/namei.c:3347
 vfs_symlink+0xbe/0x170 fs/namei.c:4176
 do_symlinkat+0x11e/0x2b0 fs/namei.c:4206
 __do_sys_symlink fs/namei.c:4227 [inline]
 __se_sys_symlink fs/namei.c:4225 [inline]
 __x64_sys_symlink+0x32/0x40 fs/namei.c:4225
 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: 0 PID: 12477 Comm: syz-executor.4 Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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