Subject: linux-next: build failure after merge of the ext4 tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 9 Oct 2018 10:51:02 +1100

Hi Ted,

After merging the ext4 tree, today's linux-next build (arm
multi_v7_defconfig) failed like this:

In file included from include/linux/srcu.h:33,
                 from include/linux/notifier.h:16,
                 from include/linux/memory_hotplug.h:7,
                 from include/linux/mmzone.h:752,
                 from include/linux/gfp.h:6,
                 from include/linux/umh.h:4,
                 from include/linux/kmod.h:22,
                 from include/linux/module.h:13,
                 from fs/ext4/super.c:20:
fs/ext4/super.c: In function 'get_qf_name':
fs/ext4/super.c:931:40: error: 'struct ext4_sb_info' has no member named 's_qf_names'; did you mean 's_mb_maxs'?
  return rcu_dereference_protected(sbi->s_qf_names[type],
                                        ^~~~~~~~~~
include/linux/rcupdate.h:358:12: note: in definition of macro '__rcu_dereference_protected'
  ((typeof(*p) __force __kernel *)(p)); \
            ^
fs/ext4/super.c:931:9: note: in expansion of macro 'rcu_dereference_protected'
  return rcu_dereference_protected(sbi->s_qf_names[type],
         ^~~~~~~~~~~~~~~~~~~~~~~~~
fs/ext4/super.c:931:40: error: 'struct ext4_sb_info' has no member named 's_qf_names'; did you mean 's_mb_maxs'?
  return rcu_dereference_protected(sbi->s_qf_names[type],
                                        ^~~~~~~~~~
include/linux/rcupdate.h:358:35: note: in definition of macro '__rcu_dereference_protected'
  ((typeof(*p) __force __kernel *)(p)); \
                                   ^
fs/ext4/super.c:931:9: note: in expansion of macro 'rcu_dereference_protected'
  return rcu_dereference_protected(sbi->s_qf_names[type],
         ^~~~~~~~~~~~~~~~~~~~~~~~~
fs/ext4/super.c: In function 'parse_options':
fs/ext4/super.c:1976:26: warning: unused variable 'grp_qf_name' [-Wunused-variable]
  char *p, *usr_qf_name, *grp_qf_name;
                          ^~~~~~~~~~~
fs/ext4/super.c:1976:12: warning: unused variable 'usr_qf_name' [-Wunused-variable]
  char *p, *usr_qf_name, *grp_qf_name;
            ^~~~~~~~~~~

Caused by commit

  cc1ee227e890 ("ext4: fix use-after-free race in ext4_remount()'s error path")

# CONFIG_QUOTA is not set

I have reverted that commit for today.

-- 
Cheers,
Stephen Rothwell