vfs: do_last(): separate O_CREAT specific code

Check O_CREAT on the slow lookup paths where necessary.  This allows the rest to
be shared with plain open.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index 68742e3..12ed297 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2274,22 +2274,23 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
                        inode = path->dentry->d_inode;
                }
                goto finish_lookup;
-       }
-
-       /* create side of things */
-       /*
-        * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED has been
-        * cleared when we got to the last component we are about to look up
-        */
-       error = complete_walk(nd);
-       if (error)
-               return ERR_PTR(error);
+       } else {
+               /* create side of things */
+               /*
+                * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED
+                * has been cleared when we got to the last component we are
+                * about to look up
+                */
+               error = complete_walk(nd);
+               if (error)
+                       return ERR_PTR(error);
 
-       audit_inode(pathname, dir);
-       error = -EISDIR;
-       /* trailing slashes? */
-       if (nd->last.name[nd->last.len])
-               goto exit;
+               audit_inode(pathname, dir);
+               error = -EISDIR;
+               /* trailing slashes? */
+               if (nd->last.name[nd->last.len])
+                       goto exit;
+       }
 
 retry_lookup:
        mutex_lock(&dir->d_inode->i_mutex);
@@ -2305,7 +2306,7 @@ retry_lookup:
        path->mnt = nd->path.mnt;
 
        /* Negative dentry, just create the file */
-       if (!dentry->d_inode) {
+       if (!dentry->d_inode && (open_flag & O_CREAT)) {
                umode_t mode = op->mode;
                if (!IS_POSIXACL(dir->d_inode))
                        mode &= ~current_umask();