untangling do_lookup() - eliminate a loop.

d_lookup() *will* fail after successful d_invalidate(), if we are
holding i_mutex all along.  IOW, we don't need to jump back to
l: - we know what path will be taken there and can do that (i.e.
d_alloc_and_lookup()) directly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 8 insertions, 4 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 48fc0fb8c9d1..9ce43a358c33 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1173,7 +1173,6 @@ retry:
                 BUG_ON(nd->inode != dir);
 
                 mutex_lock(&dir->i_mutex);
-l:
                 dentry = d_lookup(parent, name);
                 if (likely(!dentry)) {
                         dentry = d_alloc_and_lookup(parent, name, nd);
@@ -1204,9 +1203,14 @@ l:
                         }
                         if (!d_invalidate(dentry)) {
                                 dput(dentry);
-                                dentry = NULL;
-                                need_reval = 1;
-                                goto l;
+                                dentry = d_alloc_and_lookup(parent, name, nd);
+                                if (IS_ERR(dentry)) {
+                                        mutex_unlock(&dir->i_mutex);
+                                        return PTR_ERR(dentry);
+                                }
+                                /* known good */
+                                need_reval = 0;
+                                status = 1;
                         }
                 }
                 mutex_unlock(&dir->i_mutex);