performance/stat-prefetch: lookup oldloc->path in link if it has not already been looked up.

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, 83 insertions, 12 deletions

diff --git a/xlators/performance/stat-prefetch/src/stat-prefetch.c b/xlators/performance/stat-prefetch/src/stat-prefetch.c
index baa6fa6db14..eef56a7719c 100644
--- a/xlators/performance/stat-prefetch/src/stat-prefetch.c
+++ b/xlators/performance/stat-prefetch/src/stat-prefetch.c
@@ -1472,35 +1472,106 @@ out:
 
 
 int32_t
+sp_link_helper (call_frame_t *frame, xlator_t *this, loc_t *oldloc,
+                loc_t *newloc)
+{
+        uint64_t        value     = 0;
+        sp_inode_ctx_t *inode_ctx = NULL;
+        int32_t         ret       = 0, op_ret = -1, op_errno = -1;
+         
+        ret = inode_ctx_get (oldloc->inode, this, &value);
+        if (ret == -1) {
+                gf_log (this->name, GF_LOG_DEBUG, "context not set in inode "
+                        "(%p)", oldloc->inode);
+                op_errno = EINVAL;
+                goto unwind;
+        }
+
+        inode_ctx = (sp_inode_ctx_t *)(long) value;
+        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, inode_ctx, unwind, op_errno,
+                                        EINVAL);
+
+        LOCK (&inode_ctx->lock);
+        {
+                op_ret = inode_ctx->op_ret;
+                op_errno = inode_ctx->op_errno;
+        }
+        UNLOCK (&inode_ctx->lock);
+
+        if (op_ret == -1) {
+                goto unwind;
+        }
+
+        STACK_WIND (frame, sp_new_entry_cbk, FIRST_CHILD(this),
+                    FIRST_CHILD(this)->fops->link, oldloc, newloc);
+
+        return 0;
+
+unwind:
+        SP_STACK_UNWIND (frame, -1, op_errno, NULL, NULL, NULL, NULL);
+        return 0;
+}
+
+
+int32_t
 sp_link (call_frame_t *frame, xlator_t *this, loc_t *oldloc, loc_t *newloc)
 {
-        int32_t     ret = 0, op_errno = EINVAL;
+        call_stub_t *stub     = NULL;
+        int32_t      ret      = 0, op_errno = -1; 
+        char         can_wind = 0, need_lookup = 0, need_unwind = 1;
 
-        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc, unwind, op_errno,
+        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc, out, op_errno,
                                         EINVAL);
-        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc->parent, unwind,
+        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc->parent, out,
                                         op_errno, EINVAL);
-        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc->path, unwind,
+        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc->path, out,
                                         op_errno, EINVAL);
-        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc->name, unwind,
+        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc->name, out,
                                         op_errno, EINVAL);
-        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc->inode, unwind,
+        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc->inode, out,
+                                        op_errno, EINVAL);
+
+        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc, out, op_errno,
+                                        EINVAL);
+        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, newloc->parent, out,
                                         op_errno, EINVAL);
 
         ret = sp_cache_remove_parent_entry (frame, this, (char *)newloc->path);
         if (ret == -1) {
                 op_errno = ENOMEM;
                 gf_log (this->name, GF_LOG_ERROR, "out of memory");
-                goto unwind;
+                goto out;
         }
 
-	STACK_WIND (frame, sp_new_entry_cbk, FIRST_CHILD(this),
-                    FIRST_CHILD(this)->fops->link, oldloc, newloc);
+        stub = fop_link_stub (frame, sp_link_helper, oldloc, newloc);
+        if (stub == NULL) {
+                op_errno = ENOMEM;
+                gf_log (this->name, GF_LOG_ERROR, "out of memory");
+                goto out;
+        }
 
-        return 0;
+        sp_process_inode_ctx (frame, this, oldloc, stub, &need_unwind,
+                              &need_lookup, &can_wind, &op_errno);
 
-unwind:
-        SP_STACK_UNWIND (frame, -1, op_errno, oldloc->inode, NULL);
+        /*
+         * no need to process context in newloc->inode for following reasons:
+         * 1. if dentry corresponding to newloc->path was cached, sp_lookup
+         *    would've unwound indicating success and link fop itself would've
+         *    not been called.
+         * 2. if dentry corresponding to newloc->path was not cached, lookup
+         *    would've anyways be sent to underlying translators in sp_lookup. 
+         */
+out:
+        if (need_unwind) {
+                SP_STACK_UNWIND (frame, -1, op_errno, NULL, NULL, NULL, NULL);
+        } else if (need_lookup) {
+                STACK_WIND (frame, sp_lookup_cbk, FIRST_CHILD(this),
+                            FIRST_CHILD(this)->fops->lookup, oldloc, NULL);
+        } else if (can_wind) {
+                STACK_WIND (frame, sp_new_entry_cbk, FIRST_CHILD(this),
+                            FIRST_CHILD(this)->fops->link, oldloc, newloc);
+        }
+         
         return 0;
 }