0001-mount-Add-support-for-nosymfollow-mount-option.patch

From 3ab4fbf9faa71bc414b1e86d89296b263738a9af Mon Sep 17 00:00:00 2001
From: Mattias Nissler <mnissler@chromium.org>
Date: Thu, 17 Nov 2016 14:47:51 +0100
Subject: [PATCH] mount: Add support for "nosymfollow" mount option.

This adds support for the "nosymfollow" mount option, which indicates
that symlinks should not be traversed on the mount this option is
applied to.

Signed-off-by: Mattias Nissler <mnissler@chromium.org>
---
 libmount/src/context_mount.c | 2 ++
 libmount/src/libmount.h.in   | 3 +++
 libmount/src/optmap.c        | 4 ++++
 3 files changed, 9 insertions(+)

diff --git a/libmount/src/context_mount.c b/libmount/src/context_mount.c
index a7ea832..fd1f27b 100644
--- a/libmount/src/context_mount.c
+++ b/libmount/src/context_mount.c
@@ -389,6 +389,8 @@ static int generate_helper_optstr(struct libmnt_context *cxt, char **optstr)
 			mnt_optstr_append_option(optstr, "suid", NULL);
 		if (!(cxt->mountflags & MS_NODEV))
 			mnt_optstr_append_option(optstr, "dev", NULL);
+		if (!(cxt->mountflags & MS_NOSYMFOLLOW))
+			mnt_optstr_append_option(optstr, "symfollow", NULL);
 	}
 
 
diff --git a/libmount/src/libmount.h.in b/libmount/src/libmount.h.in
index 86ff150..8008732 100644
--- a/libmount/src/libmount.h.in
+++ b/libmount/src/libmount.h.in
@@ -844,6 +844,9 @@ extern int mnt_context_set_syscall_status(struct libmnt_context *cxt, int status
 #ifndef MS_LAZYTIME
 #define MS_LAZYTIME     (1<<25) /* Update the on-disk [acm]times lazily */
 #endif
+#ifndef MS_NOSYMFOLLOW
+#define MS_NOSYMFOLLOW	(1<<26)	/* Don't follow symlinks */
+#endif
 
 
 /*
diff --git a/libmount/src/optmap.c b/libmount/src/optmap.c
index f827e04..cbc382c 100644
--- a/libmount/src/optmap.c
+++ b/libmount/src/optmap.c
@@ -127,6 +127,10 @@ static const struct libmnt_optmap linux_flags_map[] =
    { "shared",      MS_SHARED,              MNT_NOHLPS | MNT_NOMTAB }, /* Shared */
    { "rshared",     MS_SHARED | MS_REC,     MNT_NOHLPS | MNT_NOMTAB },
 #endif
+#ifdef MS_NOSYMFOLLOW
+   { "symfollow", MS_NOSYMFOLLOW, MNT_INVERT }, /* Don't follow symlinks */
+   { "nosymfollow", MS_NOSYMFOLLOW },
+#endif
    { NULL, 0, 0 }
 };
 
-- 
2.8.0.rc3.226.g39d4020