From: Karel Zak <kzak@redhat.com>
Date: Tue, 9 Mar 2010 14:48:11 +0000 (+0100)
Subject: libmount: add support for userdata and work with VFS tree
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=26b4f9e4551ca97334dd06114bf0f97a75c4ce81;p=util-linux

libmount: add support for userdata and work with VFS tree

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

diff --git a/shlibs/mount/src/fs.c b/shlibs/mount/src/fs.c
index fef61b0d..ae97b654 100644
--- a/shlibs/mount/src/fs.c
+++ b/shlibs/mount/src/fs.c
@@ -57,6 +57,33 @@ void mnt_free_fs(mnt_fs *fs)
 	free(fs);
 }
 
+/**
+ * mnt_fs_get_userdata:
+ * @fs: mnt_file instance
+ *
+ * Returns private data set by mnt_fs_set_userdata() or NULL.
+ */
+void *mnt_fs_get_userdata(mnt_fs *fs)
+{
+	return fs ? fs->userdata : NULL;
+}
+
+/**
+ * mnt_fs_set_userdata:
+ * @fs: mnt_file instance
+ *
+ * The "userdata" are library independent data.
+ *
+ * Returns 0 or -1 in case of error (if @fs is NULL).
+ */
+int mnt_fs_set_userdata(mnt_fs *fs, void *data)
+{
+	if (!fs)
+		return -1;
+	fs->userdata = data;
+	return 0;
+}
+
 /**
  * mnt_fs_get_srcpath:
  * @fs: mnt_file (fstab/mtab/mountinfo) fs
diff --git a/shlibs/mount/src/mount.h.in b/shlibs/mount/src/mount.h.in
index 585b9fca..4e918b83 100644
--- a/shlibs/mount/src/mount.h.in
+++ b/shlibs/mount/src/mount.h.in
@@ -212,6 +212,8 @@ extern int mnt_lock_file(mnt_lock *ml);
 /* fs.c */
 extern mnt_fs *mnt_new_fs(void);
 extern void mnt_free_fs(mnt_fs *ent);
+extern void *mnt_fs_get_userdata(mnt_fs *fs);
+extern int mnt_fs_set_userdata(mnt_fs *fs, void *data);
 extern const char *mnt_fs_get_source(mnt_fs *ent);
 extern int mnt_fs_set_source(mnt_fs *ent, const char *source);
 extern const char *mnt_fs_get_srcpath(mnt_fs *ent);
@@ -271,6 +273,9 @@ extern const char *mnt_tab_get_name(mnt_tab *tb);
 extern int mnt_tab_add_fs(mnt_tab *tb, mnt_fs *fs);
 extern int mnt_tab_remove_fs(mnt_tab *tb, mnt_fs *fs);
 extern int mnt_tab_next_fs(mnt_tab *tb, mnt_iter *itr, mnt_fs **fs);
+extern int mnt_tab_next_child_fs(mnt_tab *tb, mnt_iter *itr,
+	                        mnt_fs *parent, mnt_fs **chld);
+extern int mnt_tab_get_root_fs(mnt_tab *tb, mnt_fs **root);
 extern int mnt_tab_set_iter(mnt_tab *tb, mnt_iter *itr, mnt_fs *fs);
 
 extern mnt_fs *mnt_tab_find_target(mnt_tab *tb, const char *path, int direction);
diff --git a/shlibs/mount/src/mount.sym b/shlibs/mount/src/mount.sym
index 6740bbcd..5df37796 100644
--- a/shlibs/mount/src/mount.sym
+++ b/shlibs/mount/src/mount.sym
@@ -31,6 +31,7 @@ global:
 	mnt_fs_get_srcpath;
 	mnt_fs_get_tag;
 	mnt_fs_get_target;
+	mnt_fs_get_userdata;
 	mnt_fs_match_fstype;
 	mnt_fs_match_options;
 	mnt_fs_match_source;
@@ -42,6 +43,7 @@ global:
 	mnt_fs_set_passno;
 	mnt_fs_set_source;
 	mnt_fs_set_target;
+	mnt_fs_set_userdata;
 	mnt_fstype_is_netfs;
 	mnt_fstype_is_pseudofs;
 	mnt_get_builtin_optmap;
@@ -116,6 +118,8 @@ global:
 	mnt_tab_get_name;
 	mnt_tab_get_nents;
 	mnt_tab_get_nerrs;
+	mnt_tab_get_root_fs;
+	mnt_tab_next_child_fs;
 	mnt_tab_next_fs;
 	mnt_tab_parse_file;
 	mnt_tab_remove_fs;
diff --git a/shlibs/mount/src/mountP.h b/shlibs/mount/src/mountP.h
index e92ba701..4b4e5b5b 100644
--- a/shlibs/mount/src/mountP.h
+++ b/shlibs/mount/src/mountP.h
@@ -155,6 +155,8 @@ struct _mnt_fs {
 
 	int		flags;		/* MNT_FS_* flags */
 	int		lineno;		/* line number in the parental file */
+
+	void		*userdata;	/* library independent data */
 };
 
 /*
diff --git a/shlibs/mount/src/tab.c b/shlibs/mount/src/tab.c
index 2ae694b5..98c56602 100644
--- a/shlibs/mount/src/tab.c
+++ b/shlibs/mount/src/tab.c
@@ -209,6 +209,97 @@ int mnt_tab_remove_fs(mnt_tab *tb, mnt_fs *fs)
 	return 0;
 }
 
+/**
+ * mnt_tab_get_root_fs:
+ * @tb: mountinfo file (/proc/self/mountinfo)
+ * @root: returns pointer to the root filesystem (/)
+ *
+ * Returns: 0 on success or -1 case of error.
+ */
+int mnt_tab_get_root_fs(mnt_tab *tb, mnt_fs **root)
+{
+	mnt_iter itr;
+	mnt_fs *fs;
+	int root_id = 0;
+
+	assert(tb);
+	assert(root);
+
+	if (!tb || !root)
+		return -1;
+
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+	while(mnt_tab_next_fs(tb, &itr, &fs) == 0) {
+		int id = mnt_fs_get_parent_id(fs);
+		if (!id)
+			break;		/* @tab is not mountinfo file? */
+
+		if (!*root || id < root_id) {
+			*root = fs;
+			root_id = id;
+		}
+	}
+
+	return root_id ? 0 : -1;
+}
+
+/**
+ * mnt_tab_next_child_fs:
+ * @tb: mountinfo file (/proc/self/mountinfo)
+ * @parent: parental FS
+ * @chld: returns the next child filesystem
+ *
+ * Note that filesystems are returned in the order how was mounted (according to
+ * IDs in /proc/self/mountinfo).
+ *
+ * Returns 0 on success, -1 in case of error or 1 at end of list.
+ */
+int mnt_tab_next_child_fs(mnt_tab *tb, mnt_iter *itr,
+			mnt_fs *parent, mnt_fs **chld)
+{
+	mnt_fs *fs;
+	int parent_id, lastchld_id = 0, chld_id = 0;
+
+	if (!tb || !itr || !parent)
+		return -1;
+
+	parent_id = mnt_fs_get_id(parent);
+	if (!parent_id)
+		return -1;
+
+	/* get ID of the previously returned child */
+	if (itr->head && itr->p != itr->head) {
+		MNT_ITER_ITERATE(itr, fs, struct _mnt_fs, ents);
+		lastchld_id = mnt_fs_get_id(fs);
+	}
+
+	*chld = NULL;
+
+	mnt_reset_iter(itr, MNT_ITER_FORWARD);
+	while(mnt_tab_next_fs(tb, itr, &fs) == 0) {
+		int id;
+
+		if (mnt_fs_get_parent_id(fs) != parent_id)
+			continue;
+
+		id = mnt_fs_get_id(fs);
+
+		if ((!lastchld_id || id > lastchld_id) &&
+		    (!*chld || id < chld_id)) {
+			*chld = fs;
+			chld_id = id;
+		}
+	}
+
+	if (!chld_id)
+		return 1;	/* end of iterator */
+
+	/* set the iterator to the @chld for the next call */
+	mnt_tab_set_iter(tb, itr, *chld);
+
+	return 0;
+}
+
 /**
  * mnt_tab_next_fs:
  * @tb: tab pointer
@@ -290,6 +381,7 @@ int mnt_tab_find_next_fs(mnt_tab *tb, mnt_iter *itr,
 			return 0;
 	} while(1);
 
+	*fs = NULL;
 	return 1;
 }