Patch "shmem: fix compilation warnings on unused functions" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

shmem: fix compilation warnings on unused functions

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
shmem-fix-compilation-warnings-on-unused-functions.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: =?UTF-8?q?J=C3=A9r=C3=A9my=20Lefaure?= <[email protected]>
Date: Mon, 12 Dec 2016 16:43:23 -0800
Subject: shmem: fix compilation warnings on unused functions
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From: Jérémy Lefaure <[email protected]>

commit f1f5929cd9715c1cdfe07a890f12ac7d2c5304ec upstream.

Compiling shmem.c with SHMEM and TRANSAPRENT_HUGE_PAGECACHE enabled raises warnings on two unused functions when CONFIG_TMPFS and CONFIG_SYSFS are both disabled:

mm/shmem.c:390:20: warning: `shmem_format_huge' defined but not used [-Wunused-function]
static const char *shmem_format_huge(int huge)

                      ^~~~~~~~~~~~~~~~~
  mm/shmem.c:373:12: warning: `shmem_parse_huge' defined but not used [-Wunused-function]
   static int shmem_parse_huge(const char *str)
               ^~~~~~~~~~~~~~~~

A conditional compilation on tmpfs or sysfs removes the warnings.

---
 mm/shmem.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -370,6 +370,7 @@ static bool shmem_confirm_swap(struct ad
 
 int shmem_huge __read_mostly;
 
+#if defined(CONFIG_SYSFS) || defined(CONFIG_TMPFS)
 static int shmem_parse_huge(const char *str)
 {
 	if (!strcmp(str, "never"))

@@ -407,6 +408,7 @@ static const char *shmem_format_huge(int
 		return "bad_val";
 	}
 }
+#endif
 
 static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo,
 		struct shrink_control *sc, unsigned long nr_to_split)

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/x86-vm86-fix-unused-variable-warning-if-thp-is-disabled.patch queue-4.9/shmem-fix-compilation-warnings-on-unused-functions.patch queue-4.9/usb-musb-fix-compilation-warning-on-unused-function.patch