From: Karel Zak <kzak@redhat.com>
Date: Thu, 10 Jan 2013 14:58:52 +0000 (+0100)
Subject: libmount: add mnt_fs_get_propagation()
X-Git-Tag: v2.23-rc1~355
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4b9d67a23d8db22ad6772cdb7af94b02f9a59b22;p=thirdparty%2Futil-linux.git

libmount: add mnt_fs_get_propagation()

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libmount/docs/libmount-sections.txt b/libmount/docs/libmount-sections.txt
index f69a63b8ac..6a00ea413b 100644
--- a/libmount/docs/libmount-sections.txt
+++ b/libmount/docs/libmount-sections.txt
@@ -174,6 +174,7 @@ mnt_fs_get_options
 mnt_fs_get_parent_id
 mnt_fs_get_passno
 mnt_fs_get_priority
+mnt_fs_get_propagation
 mnt_fs_get_root
 mnt_fs_get_size
 mnt_fs_get_source
diff --git a/libmount/src/fs.c b/libmount/src/fs.c
index 5c1a1074a0..232a2f6188 100644
--- a/libmount/src/fs.c
+++ b/libmount/src/fs.c
@@ -489,6 +489,41 @@ static int mnt_fs_get_flags(struct libmnt_fs *fs)
 	return fs ? fs->flags : 0;
 }
 
+/**
+ * mnt_fs_get_propagation:
+ * @fs: mountinfo entry
+ * @flags: returns propagation MS_* flags as present in mountinfo file
+ *
+ * Note that this function set @flags to zero if not found any propagation flag
+ * in mountinfo file. The kernel default is MS_PRIVATE, this flag is not stored
+ * in the mountinfo file.
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_fs_get_propagation(struct libmnt_fs *fs, unsigned long *flags)
+{
+	if (!fs || !flags)
+		return -EINVAL;
+
+	*flags = 0;
+
+	if (!fs->opt_fields)
+		return 0;
+
+	 /*
+	 * The optional fields format is incompatible with mount options
+	 * ... we have to parse the field here.
+	 */
+	*flags |= strstr(fs->opt_fields, "shared:") ? MS_SHARED : MS_PRIVATE;
+
+	if (strstr(fs->opt_fields, "master:"))
+		*flags |= MS_SLAVE;
+	if (strstr(fs->opt_fields, "unbindable"))
+		*flags |= MS_UNBINDABLE;
+
+	return 0;
+}
+
 /**
  * mnt_fs_is_kernel:
  * @fs: filesystem
diff --git a/libmount/src/libmount.h.in b/libmount/src/libmount.h.in
index b93011aa88..e716f8f0cf 100644
--- a/libmount/src/libmount.h.in
+++ b/libmount/src/libmount.h.in
@@ -330,6 +330,8 @@ extern const char *mnt_fs_get_options(struct libmnt_fs *fs)
 extern const char *mnt_fs_get_optional_fields(struct libmnt_fs *fs)
 			__ul_attribute__((nonnull))
 			__ul_attribute__((warn_unused_result));
+extern int mnt_fs_get_propagation(struct libmnt_fs *fs, unsigned long *flags);
+
 extern int mnt_fs_set_options(struct libmnt_fs *fs, const char *optstr);
 extern int mnt_fs_append_options(struct libmnt_fs *fs, const char *optstr);
 extern int mnt_fs_prepend_options(struct libmnt_fs *fs, const char *optstr);
diff --git a/libmount/src/libmount.sym b/libmount/src/libmount.sym
index ecb3e01f78..68b272a8d0 100644
--- a/libmount/src/libmount.sym
+++ b/libmount/src/libmount.sym
@@ -252,4 +252,5 @@ global:
 MOUNT_2.23 {
 global:
 	mnt_fs_get_optional_fields;
+	mnt_fs_get_propagation;
 } MOUNT_2.22;