INFO: task hung in gfs2_glock_nq on v7.3-rc2

[CJ <firefly0158@163.com>]

Hi,


syzbot reported "INFO: task hung in gfs2_glock_nq" on Linux 6.1. The same failure is still
reproducible on v7.3-rc2 with the adapted reproducer described below.


The reproducer mounts a crafted GFS2 meta image, keeps a directory descriptor alive, and performs path lookups in the mounted filesystem. The adapted syz program keeps the image and mount call unchanged and adds explicit openat lookups for GFS2 meta entries, making the recorded lookup path deterministic.


The target console reports a hung task blocked in gfs2_glock_wait and gfs2_glock_nq, reached from __gfs2_lookup through lookup_slow.


The lookup remains blocked while acquiring the directory glock. The report shows a reproducible wait condition, not a bisected root cause.


This is a follow-up for the existing syzbot report https://syzkaller.appspot.com/bug?extid=90f9c53a8e1181aa3f4b, not a
bisected root cause. The target report shares
11 key frames with the source crash report.


Reproducer:
 syz reproducer: https://pastebin.com/raw/11YeJKmY


console output: https://pastebin.com/raw/wze6L4ca
kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=872c04466179833f


Kernel:
  HEAD commit: df2908090cda368b01ff43709f51890076c56157
  git tree: linux-stable
  kernel version: 7.3.0-rc2
  tested tag: v7.3-rc2


Let me know if you need more details or testing.


Thanks.