untangling do_lookup() - get rid of need_reval in !dentry case
authorAl Viro <viro@zeniv.linux.org.uk>
Fri, 30 Mar 2012 18:18:50 +0000 (14:18 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Sat, 31 Mar 2012 20:03:16 +0000 (16:03 -0400)
Everything arriving into if (!dentry) will have need_reval = 1.
Indeed, the only way to get there with need_reval reset to 0 would
be via
if (unlikely(d_need_lookup(dentry)))
goto unlazy;
if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
status = d_revalidate(dentry, nd);
if (unlikely(status <= 0)) {
if (status != -ECHILD)
need_reval = 0;
goto unlazy;
...
unlazy:
/* no assignments to dentry */
if (dentry && unlikely(d_need_lookup(dentry))) {
dput(dentry);
dentry = NULL;
}
and if d_need_lookup() had already been false the first time around, it
will remain false on the second call as well.

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

index 9ce43a358c33e047b95a3e2153351af824377ffd..14bb00a9fa9ade832edad719295c374b1466bb31 100644 (file)
@@ -1181,7 +1181,6 @@ retry:
                                return PTR_ERR(dentry);
                        }
                        /* known good */
-                       need_reval = 0;
                        status = 1;
                } else if (unlikely(d_need_lookup(dentry))) {
                        dentry = d_inode_lookup(parent, dentry, nd);
@@ -1190,10 +1189,8 @@ retry:
                                return PTR_ERR(dentry);
                        }
                        /* known good */
-                       need_reval = 0;
                        status = 1;
-               }
-               if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE) && need_reval)
+               } else if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE))
                        status = d_revalidate(dentry, nd);
                if (unlikely(status <= 0)) {
                        if (status < 0) {
@@ -1209,7 +1206,6 @@ retry:
                                        return PTR_ERR(dentry);
                                }
                                /* known good */
-                               need_reval = 0;
                                status = 1;
                        }
                }
@@ -1226,7 +1222,6 @@ retry:
                if (!d_invalidate(dentry)) {
                        dput(dentry);
                        dentry = NULL;
-                       need_reval = 1;
                        goto retry;
                }
        }