windows-afsd-dir-prefetch-20081226

LICENSE MIT

when prefetching the directory buffers do not call cm_FlushFile to
discard locally modified buffers.  Instead just set the cm_scache_t
bufDataVersionLow to the current version.  out of date buffers will
therefore be ignored without requiring that locks be dropped and
reacquired and without searching all of the buffers associated with
the directory.

diff --git a/src/WINNT/afsd/cm_dir.c b/src/WINNT/afsd/cm_dir.c
index 5f2439c1e3dabbe65c51e85516653a711ea5d7b9..ceb92ff33808063d862c8280e6310de3e00fdcc2 100644 (file)
--- a/src/WINNT/afsd/cm_dir.c
+++ b/src/WINNT/afsd/cm_dir.c
@@ -600,6 +600,8 @@ cm_DirLookup(cm_dirOp_t * op, char *entry, cm_fid_t * cfid)
     LARGE_INTEGER       start;
     LARGE_INTEGER       end;
 
+    lock_AssertNone(&op->scp->rw);
+
     QueryPerformanceCounter(&start);
 
     osi_Log2(afsd_logp, "cm_DirLookup for op 0x%p, entry[%s]",
@@ -1498,13 +1500,8 @@ cm_DirPrefetchBuffers(cm_dirOp_t * op)
        contents just to make sure that we don't end up with buffers
        that was locally modified. */
 
-    if (op->scp->flags & CM_SCACHEFLAG_LOCAL) {
-        lock_ReleaseWrite(&op->scp->rw);
-        code = cm_FlushFile(op->scp, op->userp, &op->req);
-        if (code != 0)
-            return code;
-        lock_ObtainWrite(&op->scp->rw);
-    }
+    if (op->scp->flags & CM_SCACHEFLAG_LOCAL)
+        op->scp->bufDataVersionLow = op->scp->dataVersion;
 
     offset = ConvertLongToLargeInteger(0);
     while (LargeIntegerLessThan(offset, op->scp->length)) {