Introduce path_put()

* Add path_put() functions for releasing a reference to the dentry and
  vfsmount of a struct path in the right order

* Switch from path_release(nd) to path_put(&nd->path)

* Rename dput_path() to path_put_conditional()

[akpm@linux-foundation.org: fix cifs]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 31 insertions, 25 deletions

diff --git a/fs/namei.c b/fs/namei.c
index c9b05a71c39c..b0df7ea733d7 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -362,11 +362,18 @@ int deny_write_access(struct file * file)
 	return 0;
 }
 
-void path_release(struct nameidata *nd)
+/**
+ * path_put - put a reference to a path
+ * @path: path to put the reference to
+ *
+ * Given a path decrement the reference count to the dentry and the vfsmount.
+ */
+void path_put(struct path *path)
 {
-	dput(nd->path.dentry);
-	mntput(nd->path.mnt);
+	dput(path->dentry);
+	mntput(path->mnt);
 }
+EXPORT_SYMBOL(path_put);
 
 /**
  * release_open_intent - free up open intent resources
@@ -551,7 +558,7 @@ static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *l
 		goto fail;
 
 	if (*link == '/') {
-		path_release(nd);
+		path_put(&nd->path);
 		if (!walk_init_root(link, nd))
 			/* weird __emul_prefix() stuff did it */
 			goto out;
@@ -567,18 +574,18 @@ out:
 	 */
 	name = __getname();
 	if (unlikely(!name)) {
-		path_release(nd);
+		path_put(&nd->path);
 		return -ENOMEM;
 	}
 	strcpy(name, nd->last.name);
 	nd->last.name = name;
 	return 0;
 fail:
-	path_release(nd);
+	path_put(&nd->path);
 	return PTR_ERR(link);
 }
 
-static inline void dput_path(struct path *path, struct nameidata *nd)
+static void path_put_conditional(struct path *path, struct nameidata *nd)
 {
 	dput(path->dentry);
 	if (path->mnt != nd->path.mnt)
@@ -651,8 +658,8 @@ static inline int do_follow_link(struct path *path, struct nameidata *nd)
 	nd->depth--;
 	return err;
 loop:
-	dput_path(path, nd);
-	path_release(nd);
+	path_put_conditional(path, nd);
+	path_put(&nd->path);
 	return err;
 }
 
@@ -993,10 +1000,10 @@ return_reval:
 return_base:
 		return 0;
 out_dput:
-		dput_path(&next, nd);
+		path_put_conditional(&next, nd);
 		break;
 	}
-	path_release(nd);
+	path_put(&nd->path);
 return_err:
 	return err;
 }
@@ -1070,7 +1077,7 @@ static int __emul_lookup_dentry(const char *name, struct nameidata *nd)
 				mntput(old_mnt);
 				return 1;
 			}
-			path_release(nd);
+			path_put(&nd->path);
 		}
 		nd->path.dentry = old_dentry;
 		nd->path.mnt = old_mnt;
@@ -1230,7 +1237,7 @@ static int __path_lookup_intent_open(int dfd, const char *name,
 	if (IS_ERR(nd->intent.open.file)) {
 		if (err == 0) {
 			err = PTR_ERR(nd->intent.open.file);
-			path_release(nd);
+			path_put(&nd->path);
 		}
 	} else if (err != 0)
 		release_open_intent(nd);
@@ -1806,11 +1813,11 @@ ok:
 	return 0;
 
 exit_dput:
-	dput_path(&path, nd);
+	path_put_conditional(&path, nd);
 exit:
 	if (!IS_ERR(nd->intent.open.file))
 		release_open_intent(nd);
-	path_release(nd);
+	path_put(&nd->path);
 	return error;
 
 do_link:
@@ -1979,7 +1986,7 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode,
 		dput(dentry);
 	}
 	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-	path_release(&nd);
+	path_put(&nd.path);
 out:
 	putname(tmp);
 
@@ -2039,7 +2046,7 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
 	dput(dentry);
 out_unlock:
 	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-	path_release(&nd);
+	path_put(&nd.path);
 out:
 	putname(tmp);
 out_err:
@@ -2147,7 +2154,7 @@ static long do_rmdir(int dfd, const char __user *pathname)
 exit2:
 	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
 exit1:
-	path_release(&nd);
+	path_put(&nd.path);
 exit:
 	putname(name);
 	return error;
@@ -2231,7 +2238,7 @@ static long do_unlinkat(int dfd, const char __user *pathname)
 	if (inode)
 		iput(inode);	/* truncate the inode here */
 exit1:
-	path_release(&nd);
+	path_put(&nd.path);
 exit:
 	putname(name);
 	return error;
@@ -2308,7 +2315,7 @@ asmlinkage long sys_symlinkat(const char __user *oldname,
 	dput(dentry);
 out_unlock:
 	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
-	path_release(&nd);
+	path_put(&nd.path);
 out:
 	putname(to);
 out_putname:
@@ -2404,9 +2411,9 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
 out_unlock:
 	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
 out_release:
-	path_release(&nd);
+	path_put(&nd.path);
 out:
-	path_release(&old_nd);
+	path_put(&old_nd.path);
 exit:
 	putname(to);
 
@@ -2634,9 +2641,9 @@ exit4:
 exit3:
 	unlock_rename(new_dir, old_dir);
 exit2:
-	path_release(&newnd);
+	path_put(&newnd.path);
 exit1:
-	path_release(&oldnd);
+	path_put(&oldnd.path);
 exit:
 	return error;
 }
@@ -2810,7 +2817,6 @@ EXPORT_SYMBOL(page_symlink);
 EXPORT_SYMBOL(page_symlink_inode_operations);
 EXPORT_SYMBOL(path_lookup);
 EXPORT_SYMBOL(vfs_path_lookup);
-EXPORT_SYMBOL(path_release);
 EXPORT_SYMBOL(permission);
 EXPORT_SYMBOL(vfs_permission);
 EXPORT_SYMBOL(file_permission);