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

From: Mark Brown <[email-masked]>
Date: Wed, 25 Mar 2026 12:32:23 +0000

Hi all,

After merging the vfs-brauner tree, today's linux-next build
(arm64 kselftest) failed like this:

In file included from listns_efault_test.c:23:
../pidfd/pidfd.h:229:19: error: static declaration of 'wait_for_pid' follows non-static declaration
  229 | static inline int wait_for_pid(pid_t pid)
      |                   ^~~~~~~~~~~~
In file included from listns_efault_test.c:22:
../filesystems/utils.h:47:12: note: previous declaration of 'wait_for_pid' with type 'int(pid_t)' {aka 'int(int)'}
   47 | extern int wait_for_pid(pid_t pid);
      |            ^~~~~~~~~~~~

ie, a new instance of a similar issue (probably masked by the build
system with the earlier issue).  This is due to a conflict with the
preexisting wait_for_pid() in pidfd.h triggered by:

   32f54f2bbccfd (selftests/filesystems: add tests for empty mount namespaces)

I am continuing to use the tree from next-20260312.