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Commit 2096f759 authored by Al Viro's avatar Al Viro
Browse files

New helper: path_is_under(path1, path2) 



Analog of is_subdir for vfsmount,dentry pairs, moved from audit_tree.c

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 495d6c9c

fs/dcache.c

+24 −0
Original line number Diff line number Diff line
@@ -2191,6 +2191,30 @@ int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry) 
	return result;

}



int path_is_under(struct path *path1, struct path *path2)

{

	struct vfsmount *mnt = path1->mnt;

	struct dentry *dentry = path1->dentry;

	int res;

	spin_lock(&vfsmount_lock);

	if (mnt != path2->mnt) {

		for (;;) {

			if (mnt->mnt_parent == mnt) {

				spin_unlock(&vfsmount_lock);

				return 0;

			}

			if (mnt->mnt_parent == path2->mnt)

				break;

			mnt = mnt->mnt_parent;

		}

		dentry = mnt->mnt_mountpoint;

	}

	res = is_subdir(dentry, path2->dentry);

	spin_unlock(&vfsmount_lock);

	return res;

}

EXPORT_SYMBOL(path_is_under);



void d_genocide(struct dentry *root)

{

	struct dentry *this_parent = root;

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -2126,6 +2126,7 @@ extern struct file * open_exec(const char *); 
 

/* fs/dcache.c -- generic fs support functions */

extern int is_subdir(struct dentry *, struct dentry *);

extern int path_is_under(struct path *, struct path *);

extern ino_t find_inode_number(struct dentry *, struct qstr *);



#include <linux/err.h>

kernel/audit_tree.c

+12 −39
Original line number Diff line number Diff line
@@ -603,22 +603,6 @@ skip_it: 
	mutex_unlock(&audit_filter_mutex);

}



static int is_under(struct vfsmount *mnt, struct dentry *dentry,

		    struct path *path)

{

	if (mnt != path->mnt) {

		for (;;) {

			if (mnt->mnt_parent == mnt)

				return 0;

			if (mnt->mnt_parent == path->mnt)

					break;

			mnt = mnt->mnt_parent;

		}

		dentry = mnt->mnt_mountpoint;

	}

	return is_subdir(dentry, path->dentry);

}



int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op)

{
@@ -714,29 +698,24 @@ int audit_tag_tree(char *old, char *new) 
{

	struct list_head cursor, barrier;

	int failed = 0;

	struct path path;

	struct path path1, path2;

	struct vfsmount *tagged;

	struct list_head list;

	struct vfsmount *mnt;

	struct dentry *dentry;

	int err;



	err = kern_path(new, 0, &path);

	err = kern_path(new, 0, &path2);

	if (err)

		return err;

	tagged = collect_mounts(&path);

	path_put(&path);

	tagged = collect_mounts(&path2);

	path_put(&path2);

	if (!tagged)

		return -ENOMEM;



	err = kern_path(old, 0, &path);

	err = kern_path(old, 0, &path1);

	if (err) {

		drop_collected_mounts(tagged);

		return err;

	}

	mnt = mntget(path.mnt);

	dentry = dget(path.dentry);

	path_put(&path);



	list_add_tail(&list, &tagged->mnt_list);
@@ -747,6 +726,7 @@ int audit_tag_tree(char *old, char *new) 
	while (cursor.next != &tree_list) {

		struct audit_tree *tree;

		struct vfsmount *p;

		int good_one = 0;



		tree = container_of(cursor.next, struct audit_tree, list);

		get_tree(tree);
@@ -754,23 +734,17 @@ int audit_tag_tree(char *old, char *new) 
		list_add(&cursor, &tree->list);

		mutex_unlock(&audit_filter_mutex);



		err = kern_path(tree->pathname, 0, &path);

		if (err) {

			put_tree(tree);

			mutex_lock(&audit_filter_mutex);

			continue;

		err = kern_path(tree->pathname, 0, &path2);

		if (!err) {

			good_one = path_is_under(&path1, &path2);

			path_put(&path2);

		}



		spin_lock(&vfsmount_lock);

		if (!is_under(mnt, dentry, &path)) {

			spin_unlock(&vfsmount_lock);

			path_put(&path);

		if (!good_one) {

			put_tree(tree);

			mutex_lock(&audit_filter_mutex);

			continue;

		}

		spin_unlock(&vfsmount_lock);

		path_put(&path);



		list_for_each_entry(p, &list, mnt_list) {

			failed = tag_chunk(p->mnt_root->d_inode, tree);
@@ -820,8 +794,7 @@ int audit_tag_tree(char *old, char *new) 
	list_del(&cursor);

	list_del(&list);

	mutex_unlock(&audit_filter_mutex);

	dput(dentry);

	mntput(mnt);

	path_put(&path1);

	drop_collected_mounts(tagged);

	return failed;

}