[src/yamt-pagecache]: src/sys/miscfs/genfs tweak integrity_sync cases

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e7c3c01c5cd5
branches:  yamt-pagecache
changeset: 770893:e7c3c01c5cd5
user:      yamt <yamt%NetBSD.org@localhost>
date:      Fri Nov 02 08:30:05 2012 +0000

description:
tweak integrity_sync cases
some comments

diffstat:

 sys/miscfs/genfs/genfs_io.c |  21 +++++++++++++++------
 1 files changed, 15 insertions(+), 6 deletions(-)

diffs (63 lines):

diff -r a3ffe1b422c3 -r e7c3c01c5cd5 sys/miscfs/genfs/genfs_io.c
--- a/sys/miscfs/genfs/genfs_io.c       Fri Nov 02 08:26:33 2012 +0000
+++ b/sys/miscfs/genfs/genfs_io.c       Fri Nov 02 08:30:05 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: genfs_io.c,v 1.53.2.16 2012/08/01 22:34:15 yamt Exp $  */
+/*     $NetBSD: genfs_io.c,v 1.53.2.17 2012/11/02 08:30:05 yamt Exp $  */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1993
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: genfs_io.c,v 1.53.2.16 2012/08/01 22:34:15 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: genfs_io.c,v 1.53.2.17 2012/11/02 08:30:05 yamt Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -844,7 +844,8 @@
        bool tryclean;          /* try to pull off from the syncer's list */
        bool onworklst;
        const bool integrity_sync =
-           (origflags & (PGO_LAZY|PGO_SYNCIO)) == PGO_SYNCIO;
+           (origflags & (PGO_LAZY|PGO_SYNCIO|PGO_CLEANIT)) ==
+           (PGO_SYNCIO|PGO_CLEANIT);
        const bool dirtyonly = (origflags & (PGO_DEACTIVATE|PGO_FREE)) == 0;
 
        UVMHIST_FUNC("genfs_putpages"); UVMHIST_CALLED(ubchist);
@@ -943,8 +944,11 @@
                bool protected;
 
                /*
-                * if we are asked to sync for integrity, we should wait on
-                * pages being written back by another threads as well.
+                * if !dirtyonly, iterate over all resident pages in the range.
+                *
+                * if dirtyonly, only possibly dirty pages are interested.
+                * however, if we are asked to sync for integrity, we should
+                * wait on pages being written back by another threads as well.
                 */
 
                pg = uvm_page_array_fill_and_peek(&a, uobj, nextoff, 0,
@@ -1011,7 +1015,7 @@
                         * don't bother to wait on other's activities
                         * unless we are asked to sync for integrity.
                         */
-                       if (!integrity_sync) {
+                       if (!integrity_sync && (flags & PGO_RECLAIM) == 0) {
                                wasclean = false;
                                nextoff = pg->offset + PAGE_SIZE;
                                uvm_page_array_advance(&a);
@@ -1152,6 +1156,11 @@
                         *
                         * pass our cached array of pages so that hopefully
                         * uvn_findpages can find some good pages in it.
+                        * the array a was filled above with the one of
+                        * following sets of flags:
+                        *      0
+                        *      UVM_PAGE_ARRAY_FILL_DIRTY
+                        *      UVM_PAGE_ARRAY_FILL_DIRTY|WRITEBACK
                         */
 
                        nforw = maxpages - nback - 1;