libmount: add mnt_fs_streq_srcpath()

We have to be careful with "none" or another dummy sources for pseudo
filesystems. These strings should be canonicalized or compared as a
paths.

The function is not exported by library API.

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

libmount/src/fs.c

@@ -350,6 +350,23 @@ int mnt_fs_set_source(struct libmnt_fs *fs, const char *source)
 	return rc;
 }
 
+int mnt_fs_streq_srcpath(struct libmnt_fs *fs, const char *path)
+{
+	const char *p = mnt_fs_get_srcpath(fs);
+
+	if (p == NULL && path == NULL)
+		return 1;
+	if (p == NULL || path == NULL)
+		return 0;
+
+	if (mnt_fs_is_pseudofs(fs))
+		/* don't think about pseudo-fs source as about path */
+		return strcmp(p, path) == 0;
+
+	return streq_except_trailing_slash(p, path);
+}
+
+
 /**
  * mnt_fs_get_tag:
  * @fs: fs
@@ -1143,10 +1160,6 @@ int mnt_fs_match_target(struct libmnt_fs *fs, const char *target,
  * 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,
@@ -1158,15 +1171,15 @@ int mnt_fs_match_source(struct libmnt_fs *fs, const char *source,
 	if (!fs)
 		return 0;
 
-	/* undefined source -- "none" in /proc */
-	if (source == NULL && fs->source == NULL)
+	/* 1) native paths... */
+	if (mnt_fs_streq_srcpath(fs, source) == 1)
 		return 1;
 
-	if (source == NULL || fs->source == NULL)
+	if (!source || !fs->source)
 		return 0;
 
-	/* 1) native paths/tags */
-	if (streq_except_trailing_slash(source, fs->source))
+	/* ... and tags */
+	if (fs->tagname && strcmp(source, fs->source) == 0)
 		return 1;
 
 	if (!cache)
@@ -1180,7 +1193,7 @@ int mnt_fs_match_source(struct libmnt_fs *fs, const char *source,
 
 	/* 2) canonicalized and native */
 	src = mnt_fs_get_srcpath(fs);
-	if (src && streq_except_trailing_slash(cn, src))
+	if (src && mnt_fs_streq_srcpath(fs, cn))
 		return 1;
 
 	/* 3) canonicalized and canonicalized */

libmount/src/mountP.h

@@ -366,6 +366,7 @@ extern int mnt_optstr_fix_user(char **optstr);
 extern struct libmnt_fs *mnt_copy_mtab_fs(const struct libmnt_fs *fs);
 extern int __mnt_fs_set_source_ptr(struct libmnt_fs *fs, char *source);
 extern int __mnt_fs_set_fstype_ptr(struct libmnt_fs *fs, char *fstype);
+extern int mnt_fs_streq_srcpath(struct libmnt_fs *fs, const char *path);
 
 /* context.c */
 extern int mnt_context_prepare_srcpath(struct libmnt_context *cxt);

libmount/src/tab.c

@@ -500,16 +500,10 @@ struct libmnt_fs *mnt_table_find_srcpath(struct libmnt_table *tb, const char *pa
 	/* 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 || !strcmp(src, "none")))
-			return fs;			/* source is "none" */
-		if (path && p && streq_except_trailing_slash(p, path))
+		if (mnt_fs_streq_srcpath(fs, path))
 			return fs;
-		if (!p && src)
-			ntags++;			/* mnt_fs_get_srcpath() returs nothing, it's TAG */
+		if (mnt_fs_get_tag(fs, NULL, NULL) == 0)
+			ntags++;
 	}
 
 	if (!path || !tb->cache || !(cn = mnt_resolve_path(path, tb->cache)))
@@ -519,8 +513,7 @@ struct libmnt_fs *mnt_table_find_srcpath(struct libmnt_table *tb, const char *pa
 	if (ntags < mnt_table_get_nents(tb)) {
 		mnt_reset_iter(&itr, direction);
 		while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
-			p = mnt_fs_get_srcpath(fs);
-			if (p && streq_except_trailing_slash(p, cn))
+			if (mnt_fs_streq_srcpath(fs, cn))
 				return fs;
 		}
 	}
@@ -860,18 +853,14 @@ int mnt_table_is_fs_mounted(struct libmnt_table *tb, struct libmnt_fs *fstab_fs)
 		mnt_reset_iter(&itr, MNT_ITER_FORWARD);
 
 		while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
-			const char *s = mnt_fs_get_srcpath(fs),
-				   *t = mnt_fs_get_target(fs),
+			const char *t = mnt_fs_get_target(fs),
 				   *r = mnt_fs_get_root(fs);
 
-			/*
-			 * Note that kernel can add tailing slash to the
-			 * network filesystem source paths.
-			 */
-			if (t && s && r &&
-			    streq_except_trailing_slash(t, tgt) &&
-			    streq_except_trailing_slash(s, src) &&
-			    strcmp(r, root) == 0)
+			if (t && r
+			    && mnt_fs_get_srcpath(fs)
+			    && mnt_fs_streq_srcpath(fs, src)
+			    && streq_except_trailing_slash(t, tgt)
+			    && strcmp(r, root) == 0)
 				break;
 		}
 		if (fs)

libmount/src/tab_parse.c

@@ -741,7 +741,7 @@ static struct libmnt_fs *mnt_table_merge_user_fs(struct libmnt_table *tb, struct
 		 */
 		if (s && t && r &&
 		    strcmp(t, target) == 0 &&
-		    streq_except_trailing_slash(s, src) &&
+		    mnt_fs_streq_srcpath(fs, src) &&
 		    strcmp(r, root) == 0)
 			break;
 	}

sys-utils/mount.c

@@ -423,7 +423,7 @@ try_readonly:
 				const char *s = mnt_fs_get_srcpath(fs),
 					   *t = mnt_fs_get_target(fs);
 
-				if (t && s && streq_except_trailing_slash(s, src))
+				if (t && s && mnt_fs_streq_strpath(fs, src))
 					fprintf(stderr, _(
 						"       %s is already mounted on %s\n"), s, t);
 			}