4 files changed, 65 insertions, 82 deletions

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 765c3a28077a..d91a3a0b2325 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -227,33 +227,24 @@ static int handle_create(const char *nodename, umode_t mode, struct device *dev)
 
 static int dev_rmdir(const char *name)
 {
-        struct nameidata nd;
+        struct path parent;
         struct dentry *dentry;
         int err;
 
-        err = kern_path_parent(name, &nd);
-        if (err)
-                return err;
-
-        mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
-        dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
-        if (!IS_ERR(dentry)) {
-                if (dentry->d_inode) {
-                        if (dentry->d_inode->i_private == &thread)
-                                err = vfs_rmdir(nd.path.dentry->d_inode,
-                                                dentry);
-                        else
-                                err = -EPERM;
-                } else {
-                        err = -ENOENT;
-                }
-                dput(dentry);
+        dentry = kern_path_locked(name, &parent);
+        if (IS_ERR(dentry))
+                return PTR_ERR(dentry);
+        if (dentry->d_inode) {
+                if (dentry->d_inode->i_private == &thread)
+                        err = vfs_rmdir(parent.dentry->d_inode, dentry);
+                else
+                        err = -EPERM;
         } else {
-                err = PTR_ERR(dentry);
+                err = -ENOENT;
         }
-
-        mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-        path_put(&nd.path);
+        dput(dentry);
+        mutex_unlock(&parent.dentry->d_inode->i_mutex);
+        path_put(&parent);
         return err;
 }
 
@@ -305,50 +296,43 @@ static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *sta
 
 static int handle_remove(const char *nodename, struct device *dev)
 {
-        struct nameidata nd;
+        struct path parent;
         struct dentry *dentry;
-        struct kstat stat;
         int deleted = 1;
         int err;
 
-        err = kern_path_parent(nodename, &nd);
-        if (err)
-                return err;
+        dentry = kern_path_locked(nodename, &parent);
+        if (IS_ERR(dentry))
+                return PTR_ERR(dentry);
 
-        mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
-        dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
-        if (!IS_ERR(dentry)) {
-                if (dentry->d_inode) {
-                        err = vfs_getattr(nd.path.mnt, dentry, &stat);
-                        if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
-                                struct iattr newattrs;
-                                /*
-                                 * before unlinking this node, reset permissions
-                                 * of possible references like hardlinks
-                                 */
-                                newattrs.ia_uid = 0;
-                                newattrs.ia_gid = 0;
-                                newattrs.ia_mode = stat.mode & ~0777;
-                                newattrs.ia_valid =
-                                        ATTR_UID|ATTR_GID|ATTR_MODE;
-                                mutex_lock(&dentry->d_inode->i_mutex);
-                                notify_change(dentry, &newattrs);
-                                mutex_unlock(&dentry->d_inode->i_mutex);
-                                err = vfs_unlink(nd.path.dentry->d_inode,
-                                                 dentry);
-                                if (!err || err == -ENOENT)
-                                        deleted = 1;
-                        }
-                } else {
-                        err = -ENOENT;
+        if (dentry->d_inode) {
+                struct kstat stat;
+                err = vfs_getattr(parent.mnt, dentry, &stat);
+                if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
+                        struct iattr newattrs;
+                        /*
+                         * before unlinking this node, reset permissions
+                         * of possible references like hardlinks
+                         */
+                        newattrs.ia_uid = 0;
+                        newattrs.ia_gid = 0;
+                        newattrs.ia_mode = stat.mode & ~0777;
+                        newattrs.ia_valid =
+                                ATTR_UID|ATTR_GID|ATTR_MODE;
+                        mutex_lock(&dentry->d_inode->i_mutex);
+                        notify_change(dentry, &newattrs);
+                        mutex_unlock(&dentry->d_inode->i_mutex);
+                        err = vfs_unlink(parent.dentry->d_inode, dentry);
+                        if (!err || err == -ENOENT)
+                                deleted = 1;
                 }
-                dput(dentry);
         } else {
-                err = PTR_ERR(dentry);
+                err = -ENOENT;
         }
-        mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+        dput(dentry);
+        mutex_unlock(&parent.dentry->d_inode->i_mutex);
 
-        path_put(&nd.path);
+        path_put(&parent);
         if (deleted && strchr(nodename, '/'))
                 delete_path(nodename);
         return err;
diff --git a/fs/namei.c b/fs/namei.c
index 5abab9176903..6b29a51bef5d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1814,9 +1814,27 @@ static int do_path_lookup(int dfd, const char *name,
         return retval;
 }
 
-int kern_path_parent(const char *name, struct nameidata *nd)
+/* does lookup, returns the object with parent locked */
+struct dentry *kern_path_locked(const char *name, struct path *path)
 {
-        return do_path_lookup(AT_FDCWD, name, LOOKUP_PARENT, nd);
+        struct nameidata nd;
+        struct dentry *d;
+        int err = do_path_lookup(AT_FDCWD, name, LOOKUP_PARENT, &nd);
+        if (err)
+                return ERR_PTR(err);
+        if (nd.last_type != LAST_NORM) {
+                path_put(&nd.path);
+                return ERR_PTR(-EINVAL);
+        }
+        mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
+        d = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
+        if (IS_ERR(d)) {
+                mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+                path_put(&nd.path);
+                return d;
+        }
+        *path = nd.path;
+        return d;
 }
 
 int kern_path(const char *name, unsigned int flags, struct path *path)
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 23d859879210..f5931489e150 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -67,7 +67,7 @@ extern int kern_path(const char *, unsigned, struct path *);
 
 extern struct dentry *kern_path_create(int, const char *, struct path *, int);
 extern struct dentry *user_path_create(int, const char __user *, struct path *, int);
-extern int kern_path_parent(const char *, struct nameidata *);
+extern struct dentry *kern_path_locked(const char *, struct path *);
 extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
                            const char *, unsigned int, struct path *);
 
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index e683869365d9..3823281401b5 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -355,34 +355,15 @@ static void audit_remove_parent_watches(struct audit_parent *parent)
 /* Get path information necessary for adding watches. */
 static int audit_get_nd(struct audit_watch *watch, struct path *parent)
 {
-        struct nameidata nd;
-        struct dentry *d;
-        int err;
-
-        err = kern_path_parent(watch->path, &nd);
-        if (err)
-                return err;
-
-        if (nd.last_type != LAST_NORM) {
-                path_put(&nd.path);
-                return -EINVAL;
-        }
-
-        mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
-        d = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
-        if (IS_ERR(d)) {
-                mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-                path_put(&nd.path);
+        struct dentry *d = kern_path_locked(watch->path, parent);
+        if (IS_ERR(d))
                 return PTR_ERR(d);
-        }
+        mutex_unlock(&parent->dentry->d_inode->i_mutex);
         if (d->d_inode) {
                 /* update watch filter fields */
                 watch->dev = d->d_inode->i_sb->s_dev;
                 watch->ino = d->d_inode->i_ino;
         }
-        mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-
-        *parent = nd.path;
         dput(d);
         return 0;
 }