From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 30 Mar 2012 18:18:50 +0000 (-0400)
Subject: untangling do_lookup() - get rid of need_reval in !dentry case
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=08b0ab7c20f767187ae635d51bdd9d262ebe8357;p=openwrt%2Fstaging%2Fblogic.git

untangling do_lookup() - get rid of need_reval in !dentry case

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>
---

diff --git a/fs/namei.c b/fs/namei.c
index 9ce43a358c33..14bb00a9fa9a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -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;
 		}
 	}