From 794dfeca493e6f62240c6a4bb321186564876930 Mon Sep 17 00:00:00 2001
From: Casey Bodley <cbodley@citi.umich.edu>
Date: Mon, 11 Oct 2010 16:07:53 -0400
Subject: [PATCH] name cache: lookup semantics match nfs41_lookup() on NOENT

previously, when the name cache encountered a missing/negative/expired entry, it returned the previous two entries as 'target' and 'parent', and nfs41_lookup() started new lookups from the filehandle in 'target'.  this differs from nfs41_lookup(), which on NOENT will return NULL for the 'target' and the previous entry as 'parent'.  modified name_cache_lookup() to do the same, and updated nfs41_lookup() to start new lookups from the filehandle in 'parent'

now when nfs41_lookup() gets the is_negative flag from nfs41_name_cache_lookup(), it can just return the error without needing to copy the 'target' to 'parent'

Signed-off-by: Casey Bodley <cbodley@umich.edu>
---
 daemon/lookup.c     | 10 +++++-----
 daemon/name_cache.c | 14 +++++++-------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/daemon/lookup.c b/daemon/lookup.c
index 8f81b0b..17a800f 100644
--- a/daemon/lookup.c
+++ b/daemon/lookup.c
@@ -458,14 +458,14 @@ int nfs41_lookup(
     if (status == NO_ERROR || negative)
         goto out;
 
-    if (target_out->fh.len) {
+    if (parent_out->fh.len) {
         /* start where the name cache left off */
-        if (target_out != &target) {
+        if (&parent != parent_out) {
             /* must make a copy for server_start, because
-             * server_lookup_loop() will overwrite target_out */
-            path_fh_copy(&target, target_out);
+             * server_lookup_loop() will overwrite parent_out */
+            path_fh_copy(&parent, parent_out);
         }
-        server_start = &target;
+        server_start = &parent;
     } else {
         /* start with PUTROOTFH */
         server_start = NULL;
diff --git a/daemon/name_cache.c b/daemon/name_cache.c
index dd5f128..3d55ddf 100644
--- a/daemon/name_cache.c
+++ b/daemon/name_cache.c
@@ -595,7 +595,7 @@ static int name_cache_lookup(
     OUT OPTIONAL struct name_cache_entry **target_out,
     OUT OPTIONAL bool_t *is_negative)
 {
-    struct name_cache_entry *parent, *target, *tmp;
+    struct name_cache_entry *parent, *target;
     nfs41_component component;
     const char *path_pos;
     int status = NO_ERROR;
@@ -613,17 +613,16 @@ static int name_cache_lookup(
     }
 
     while (next_component(path_pos, path_end, &component)) {
-        tmp = name_cache_search(cache, target, &component);
-        if (tmp == NULL || (skip_invis && entry_invis(tmp, is_negative))) {
+        parent = target;
+        target = name_cache_search(cache, parent, &component);
+        path_pos = component.name + component.len;
+        if (target == NULL || (skip_invis && entry_invis(target, is_negative))) {
             if (is_last_component(component.name, path_end))
                 status = ERROR_FILE_NOT_FOUND;
             else
                 status = ERROR_PATH_NOT_FOUND;
             break;
         }
-        parent = target;
-        target = tmp;
-        path_pos = component.name + component.len;
     }
 out:
     if (remaining_path_out) *remaining_path_out = component.name;
@@ -812,7 +811,8 @@ int nfs41_name_cache_lookup(
 
     if (parent_out) copy_fh(parent_out, parent);
     if (target_out) copy_fh(target_out, target);
-    if (info_out && target) copy_attrs(info_out, target->attributes);
+    if (info_out && target && target->attributes)
+        copy_attrs(info_out, target->attributes);
 
 out_unlock:
     ReleaseSRWLockShared(&cache->lock);