performance/stat-prefetch: lookup the path in stat if the it is not already looked-up.

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, 79 insertions, 0 deletions

diff --git a/xlators/performance/stat-prefetch/src/stat-prefetch.c b/xlators/performance/stat-prefetch/src/stat-prefetch.c
index 78b17566d..0748af310 100644
--- a/xlators/performance/stat-prefetch/src/stat-prefetch.c
+++ b/xlators/performance/stat-prefetch/src/stat-prefetch.c
@@ -2195,6 +2195,84 @@ unwind:
 
 
 int32_t
+sp_stat_helper (call_frame_t *frame, xlator_t *this, loc_t *loc)
+{
+        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 (loc->inode, this, &value);
+        if (ret == -1) {
+                gf_log (this->name, GF_LOG_DEBUG, "context not set in inode "
+                        "(%p)", loc->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_stbuf_cbk, FIRST_CHILD(this),
+                    FIRST_CHILD(this)->fops->stat, loc);
+
+        return 0;
+
+unwind:
+        SP_STACK_UNWIND (frame, -1, op_errno, NULL);
+        return 0;
+}
+
+
+int32_t
+sp_stat (call_frame_t *frame, xlator_t *this, loc_t *loc)
+{
+        int32_t         op_errno     = -1;
+        call_stub_t    *stub         = NULL;
+        char            can_wind     = 0, need_lookup = 0, need_unwind = 1;
+
+        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, loc, out, op_errno,
+                                        EINVAL);
+        GF_VALIDATE_OR_GOTO_WITH_ERROR (this->name, loc->inode, out,
+                                        op_errno, EINVAL);
+
+        stub = fop_stat_stub (frame, sp_stat_helper, loc);
+        if (stub == NULL) {
+                op_errno = ENOMEM;
+                gf_log (this->name, GF_LOG_ERROR, "out of memory");
+                goto out;
+        }
+
+        sp_process_inode_ctx (frame, this, loc, stub, &need_unwind,
+                              &need_lookup, &can_wind, &op_errno);
+
+out:
+        if (need_unwind) {
+                SP_STACK_UNWIND (frame, -1, op_errno, NULL);
+        } else if (need_lookup) {
+                STACK_WIND (frame, sp_lookup_cbk, FIRST_CHILD(this),
+                            FIRST_CHILD(this)->fops->lookup, loc, NULL);
+        } else if (can_wind) {
+                STACK_WIND (frame, sp_stbuf_cbk, FIRST_CHILD(this),
+                            FIRST_CHILD(this)->fops->stat, loc);
+        }
+        
+        return 0;
+}
+
+
+int32_t
 sp_release (xlator_t *this, fd_t *fd)
 {
         sp_fd_ctx_t *fd_ctx = NULL;
@@ -2274,6 +2352,7 @@ struct xlator_fops fops = {
         .checksum    = sp_checksum,
         .xattrop     = sp_xattrop,
         .fxattrop    = sp_fxattrop,
+        .stat        = sp_stat,
 };
 
 struct xlator_mops mops = {