f2fs: ensure node page reads complete before f2fs_put_super() finishes

In the Linux kernel, the following vulnerability has been resolved:

f2fs: ensure node page reads complete before f2fs_put_super() finishes

Xfstests generic/335, generic/336 sometimes crash with the following message:

F2FS-fs (dm-0): detect filesystem reference count leak during umount, type: 9, count: 1

------------[ cut here ]------------

kernel BUG at fs/f2fs/super.c:1939!

Oops: invalid opcode: 0000 [#1] SMP NOPTI

CPU: 1 UID: 0 PID: 609351 Comm: umount Tainted: G W 6.17.0-rc5-xfstests-g9dd1835ecda5 #1 PREEMPT(none)

Tainted: [W]=WARN

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014

RIP: 0010:f2fs_put_super+0x3b3/0x3c0

Call Trace:

<TASK>

generic_shutdown_super+0x7e/0x190

kill_block_super+0x1a/0x40

kill_f2fs_super+0x9d/0x190

deactivate_locked_super+0x30/0xb0

cleanup_mnt+0xba/0x150

task_work_run+0x5c/0xa0

exit_to_user_mode_loop+0xb7/0xc0

do_syscall_64+0x1ae/0x1c0

entry_SYSCALL_64_after_hwframe+0x76/0x7e

</TASK>

---[ end trace 0000000000000000 ]---

It appears that sometimes it is possible that f2fs_put_super() is called before

all node page reads are completed.

Adding a call to f2fs_wait_on_all_pages() for F2FS_RD_NODE fixes the problem.