fs: move path_put on failure out of ->follow_link

Currently the non-nd_set_link based versions of ->follow_link are expected
to do a path_put(&nd->path) on failure.  This calling convention is unexpected,
undocumented and doesn't match what the nd_set_link-based instances do.

Move the path_put out of the only non-nd_set_link based ->follow_link
instance into the caller.

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

diff --git a/fs/namei.c b/fs/namei.c
index 6b29a51bef5dc720869b99a6a85d42ab6d703c69..a9b94c62c303807434e18374eb85b6ffee7b5675 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -624,7 +624,7 @@ follow_link(struct path *link, struct nameidata *nd, void **p)
        *p = dentry->d_inode->i_op->follow_link(dentry, nd);
        error = PTR_ERR(*p);
        if (IS_ERR(*p))
-               goto out_put_link;
+               goto out_put_nd_path;
 
        error = 0;
        s = nd_get_link(nd);
@@ -646,7 +646,6 @@ follow_link(struct path *link, struct nameidata *nd, void **p)
 
 out_put_nd_path:
        path_put(&nd->path);
-out_put_link:
        path_put(link);
        return error;
 }

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 8eaa5ea1c61339ba9781c8d1cad58859e5649e66..3bd5ac1ff0181147a6c4c59380eb0963aec6f1d4 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1427,16 +1427,20 @@ static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
        struct inode *inode = dentry->d_inode;
+       struct path path;
        int error = -EACCES;
 
-       /* We don't need a base pointer in the /proc filesystem */
-       path_put(&nd->path);
-
        /* Are we allowed to snoop on the tasks file descriptors? */
        if (!proc_fd_access_allowed(inode))
                goto out;
 
-       error = PROC_I(inode)->op.proc_get_link(dentry, &nd->path);
+       error = PROC_I(inode)->op.proc_get_link(dentry, &path);
+       if (error)
+               goto out;
+
+       path_put(&nd->path);
+       nd->path = path;
+       return NULL;
 out:
        return ERR_PTR(error);
 }