performance/stat-prefetch: change behaviour of sp_lookup when xattr_req is not NULL.

- if the xattr_req is empty (fuse just creates an empty dictionary and
    sends along lookup) we can still use the cache prefetched during readdir,
    since we need not fill the reply dictionary.

Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 221 (stat prefetch implementation)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=221

1 files changed, 28 insertions, 8 deletions

diff --git a/xlators/performance/stat-prefetch/src/stat-prefetch.c b/xlators/performance/stat-prefetch/src/stat-prefetch.c
index 10d0869a5..1056d29e2 100644
--- a/xlators/performance/stat-prefetch/src/stat-prefetch.c
+++ b/xlators/performance/stat-prefetch/src/stat-prefetch.c
@@ -539,23 +539,43 @@ out:
 }
 
 
+void
+sp_is_empty (dict_t *this, char *key, data_t *value, void *data)
+{
+        char *ptr = data;
+
+        if (ptr && *ptr) {
+                *ptr = 0;
+        }
+}
+
+
 int32_t
 sp_lookup (call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *xattr_req)
 {
-        sp_local_t   *local      = NULL;
         gf_dirent_t   dirent;     
-        int32_t       ret        = -1, op_ret = -1, op_errno = EINVAL; 
-        sp_cache_t   *cache      = NULL;
-        struct stat  *postparent = NULL, *buf = NULL;
-        uint64_t      value      = 0; 
-        call_frame_t *wind_frame = NULL;
-        char          lookup_behind = 0;
+        sp_local_t   *local           = NULL;
+        int32_t       ret             = -1, op_ret = -1, op_errno = EINVAL; 
+        sp_cache_t   *cache           = NULL;
+        struct stat  *postparent      = NULL, *buf = NULL;
+        uint64_t      value           = 0; 
+        call_frame_t *wind_frame      = NULL;
+        char          lookup_behind   = 0;
+        char          xattr_req_empty = 1;
 
         if (loc == NULL) {
                 goto unwind;
         }
 
-        if (xattr_req || (loc->parent == NULL) || (loc->name == NULL)) {
+        if ((loc->parent == NULL) || (loc->name == NULL)) {
+                goto wind;
+        }
+
+        if (xattr_req != NULL) {
+                dict_foreach (xattr_req, sp_is_empty, &xattr_req_empty);
+        }
+
+        if (!xattr_req_empty) {
                 goto wind;
         }