From: Karel Zak <kzak@redhat.com>
Date: Tue, 26 Apr 2011 14:32:09 +0000 (+0200)
Subject: libmount: support NULL source path for mnt_table_find_* functions
X-Git-Tag: v2.20-rc1~321
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f12aac6e3e440166917092a83cd76a6300077abd;p=thirdparty%2Futil-linux.git

libmount: support NULL source path for mnt_table_find_* functions

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

diff --git a/shlibs/mount/src/fs.c b/shlibs/mount/src/fs.c
index c7a4fce025..21b7ab95d2 100644
--- a/shlibs/mount/src/fs.c
+++ b/shlibs/mount/src/fs.c
@@ -1107,7 +1107,7 @@ int mnt_fs_match_target(struct libmnt_fs *fs, const char *target, struct libmnt_
 /**
  * mnt_fs_match_source:
  * @fs: filesystem
- * @source: tag or path (device or so)
+ * @source: tag or path (device or so) or NULL
  * @cache: tags/paths cache or NULL
  *
  * Possible are four attempts:
@@ -1119,6 +1119,10 @@ int mnt_fs_match_target(struct libmnt_fs *fs, const char *target, struct libmnt_
  * The 2nd, 3rd and 4th attempts are not performed when @cache is NULL. The
  * 2nd and 3rd attempts are not performed if @fs->source is tag.
  *
+ * Note that valid source path is NULL; the libmount uses NULL instead of
+ * "none".  The "none" is used in /proc/{mounts,self/mountninfo} for pseudo
+ * filesystems.
+ *
  * Returns: 1 if @fs source is equal to @source else 0.
  */
 int mnt_fs_match_source(struct libmnt_fs *fs, const char *source, struct libmnt_cache *cache)
@@ -1126,7 +1130,14 @@ int mnt_fs_match_source(struct libmnt_fs *fs, const char *source, struct libmnt_
 	char *cn;
 	const char *src, *t, *v;
 
-	if (!fs || !source || !fs->source)
+	if (!fs)
+		return 0;
+
+	/* undefined source -- "none" in /proc */
+	if (source == NULL && fs->source == NULL)
+		return 1;
+
+	if (source == NULL || fs->source == NULL)
 		return 0;
 
 	/* 1) native paths/tags */
diff --git a/shlibs/mount/src/tab.c b/shlibs/mount/src/tab.c
index 2d2e72fd1e..fff56b7e06 100644
--- a/shlibs/mount/src/tab.c
+++ b/shlibs/mount/src/tab.c
@@ -461,7 +461,7 @@ struct libmnt_fs *mnt_table_find_target(struct libmnt_table *tb, const char *pat
 /**
  * mnt_table_find_srcpath:
  * @tb: tab pointer
- * @path: source path (devname or dirname)
+ * @path: source path (devname or dirname) or NULL
  * @direction: MNT_ITER_{FORWARD,BACKWARD}
  *
  * Try to lookup an entry in given tab, possible are four iterations, first
@@ -471,6 +471,10 @@ struct libmnt_fs *mnt_table_find_target(struct libmnt_table *tb, const char *pat
  * The 2nd, 3rd and 4th iterations are not performed when @tb cache is not
  * set (see mnt_table_set_cache()).
  *
+ * Note that valid source path is NULL; the libmount uses NULL instead of
+ * "none".  The "none" is used in /proc/{mounts,self/mountninfo} for pseudo
+ * filesystems.
+ *
  * Returns: a tab entry or NULL.
  */
 struct libmnt_fs *mnt_table_find_srcpath(struct libmnt_table *tb, const char *path, int direction)
@@ -482,22 +486,25 @@ struct libmnt_fs *mnt_table_find_srcpath(struct libmnt_table *tb, const char *pa
 	const char *p;
 
 	assert(tb);
-	assert(path);
 
 	DBG(TAB, mnt_debug_h(tb, "lookup srcpath: %s", path));
 
 	/* native paths */
 	mnt_reset_iter(&itr, direction);
 	while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
+		const char *src = mnt_fs_get_source(fs);
+
 		p = mnt_fs_get_srcpath(fs);
+
+		if (path == NULL && src == NULL)
+			return fs;			/* source is "none" */
 		if (p && strcmp(p, path) == 0)
 			return fs;
-		if (!p)
-			/* mnt_fs_get_srcpath() returs nothing, it's TAG */
-			ntags++;
+		if (!p && src)
+			ntags++;			/* mnt_fs_get_srcpath() returs nothing, it's TAG */
 	}
 
-	if (!tb->cache || !(cn = mnt_resolve_path(path, tb->cache)))
+	if (!path || !tb->cache || !(cn = mnt_resolve_path(path, tb->cache)))
 		return NULL;
 
 	/* canonicalized paths in struct libmnt_table */
@@ -619,19 +626,19 @@ struct libmnt_fs *mnt_table_find_tag(struct libmnt_table *tb, const char *tag,
  *
  * Returns: a tab entry or NULL.
  */
-struct libmnt_fs *mnt_table_find_source(struct libmnt_table *tb, const char *source, int direction)
+struct libmnt_fs *mnt_table_find_source(struct libmnt_table *tb,
+					const char *source, int direction)
 {
 	struct libmnt_fs *fs = NULL;
 
 	assert(tb);
-	assert(source);
 
-	if (!tb || !source)
+	if (!tb)
 		return NULL;
 
 	DBG(TAB, mnt_debug_h(tb, "lookup SOURCE: %s", source));
 
-	if (strchr(source, '=')) {
+	if (source && strchr(source, '=')) {
 		char *tag, *val;
 
 		if (blkid_parse_tag_string(source, &tag, &val) == 0) {
@@ -661,16 +668,15 @@ struct libmnt_fs *mnt_table_find_source(struct libmnt_table *tb, const char *sou
  * Returns: a tab entry or NULL.
  */
 struct libmnt_fs *mnt_table_find_pair(struct libmnt_table *tb, const char *source,
-			const char *target, int direction)
+				      const char *target, int direction)
 {
 	struct libmnt_fs *fs = NULL;
 	struct libmnt_iter itr;
 
 	assert(tb);
-	assert(source);
 	assert(target);
 
-	if (!tb || !source || !target)
+	if (!tb || !target)
 		return NULL;
 
 	DBG(TAB, mnt_debug_h(tb, "lookup SOURCE: %s TARGET: %s", source, target));
diff --git a/shlibs/mount/src/tab_update.c b/shlibs/mount/src/tab_update.c
index d514641845..5abb566b59 100644
--- a/shlibs/mount/src/tab_update.c
+++ b/shlibs/mount/src/tab_update.c
@@ -153,7 +153,7 @@ int mnt_update_is_ready(struct libmnt_update *upd)
  * mnt_update_set_fs:
  * @upd: update handler
  * @mountflags: MS_* flags
- * @target: umount target, must be num for mount
+ * @target: umount target, must be NULL for mount
  * @fs: mount filesystem description, must be NULL for umount
  *
  * Returns: <0 in case on error, 0 on success, 1 if update is unnecessary.