performance/stat-prefetch: Add support code to implement lookup-behind.

- change sp_lookup and sp_lookup_cbk to support sending lookups when needed.
    lookups might need to be sent in fops like open, chmod, chown etc which
    operate on a path, since the actual lookup sent to stat-prefetch by its
    parent xlators is not propagated down the xlator tree if the path is
    cached.

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

BUG: 284 (performance actually decreases for 'ls -l' on a directory containing large number of files with stat-prefetch loaded)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=284

1 files changed, 15 insertions, 0 deletions

diff --git a/xlators/performance/stat-prefetch/src/stat-prefetch.h b/xlators/performance/stat-prefetch/src/stat-prefetch.h
index dd6b067c5..068ea7dfe 100644
--- a/xlators/performance/stat-prefetch/src/stat-prefetch.h
+++ b/xlators/performance/stat-prefetch/src/stat-prefetch.h
@@ -30,6 +30,10 @@
 #include "xlator.h"
 #include "rbthash.h"
 #include "hashfn.h"
+#include "call-stub.h"
+#include "locking.h"
+#include "inode.h"
+#include <libgen.h>
 
 struct sp_cache {
         rbthash_table_t *table;
@@ -55,9 +59,20 @@ struct sp_fd_ctx {
 };
 typedef struct sp_fd_ctx sp_fd_ctx_t;
 
+struct sp_inode_ctx {
+        char             looked_up;
+        char             lookup_in_progress;
+        int32_t          op_ret;
+        int32_t          op_errno;
+        gf_lock_t        lock;
+        struct list_head waiting_ops;
+};
+typedef struct sp_inode_ctx sp_inode_ctx_t;
+
 struct sp_local {
         loc_t  loc;
         fd_t  *fd;
+        char   is_lookup;
 };
 typedef struct sp_local sp_local_t;