Re: [PATCH 3/6] vfs: open_exec cleanup

On Mon, May 19, 2008 at 12:01:49AM +0200, Marcin Slusarz wrote:
> open_exec is needlessly indented, calls ERR_PTR with 0 argument
> (which is not valid errno) and jumps into middle of function
> just to return value.
> So clean it up a bit.

Still looks rather messy.  See below for a better version.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/exec.c b/fs/exec.c
index 0ba5d35..346e3f6 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -656,38 +656,40 @@ EXPORT_SYMBOL(setup_arg_pages);
 struct file *open_exec(const char *name)
 {
        struct nameidata nd;
-       int err;
        struct file *file;
+       int err;
 
-       err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC);
-       file = ERR_PTR(err);
-
-       if (!err) {
-               struct inode *inode = nd.path.dentry->d_inode;
-               file = ERR_PTR(-EACCES);
-               if (S_ISREG(inode->i_mode)) {
-                       int err = vfs_permission(&nd, MAY_EXEC | MAY_OPEN);
-                       file = ERR_PTR(err);
-                       if (!err) {
-                               file = nameidata_to_filp(&nd,
-                                                       O_RDONLY|O_LARGEFILE);
-                               if (!IS_ERR(file)) {
-                                       err = deny_write_access(file);
-                                       if (err) {
-                                               fput(file);
-                                               file = ERR_PTR(err);
-                                       }
-                               }
-out:
-                               return file;
-                       }
-               }
-               release_open_intent(&nd);
-               path_put(&nd.path);
+       err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd,
+                               FMODE_READ|FMODE_EXEC);
+       if (err)
+               goto out;
+
+       err = -EACCES;
+       if (!S_ISREG(nd.path.dentry->d_inode->i_mode))
+               goto out_path_put;
+
+       err = vfs_permission(&nd, MAY_EXEC | MAY_OPEN);
+       if (err)
+               goto out_path_put;
+
+       file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE);
+       if (IS_ERR(file))
+               return file;
+
+       err = deny_write_access(file);
+       if (err) {
+               fput(file);
+               goto out;
        }
-       goto out;
-}
 
+       return file;
+
+ out_path_put:
+       release_open_intent(&nd);
+       path_put(&nd.path);
+ out:
+       return ERR_PTR(err);
+}
 EXPORT_SYMBOL(open_exec);
 
 int kernel_read(struct file *file, unsigned long offset,