[src/trunk]: src/sys/uvm uobj->pgops->pgo_get doing PGO_SYNCIO returns a uobj...

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

details:   https://anonhg.NetBSD.org/src/rev/f3e8b7c69932
branches:  trunk
changeset: 751376:f3e8b7c69932
user:      uebayasi <uebayasi%NetBSD.org@localhost>
date:      Tue Feb 02 18:49:23 2010 +0000

description:
uobj->pgops->pgo_get doing PGO_SYNCIO returns a uobjpage whose uobj backpointer
refers to another "uobj" used to call pgo_get.  Revert the wrong assertion
I made.  My bad.

(This and pgo_get's possible ERESTART return value check is the only 2 behavioral
changes I made.)

Reported by drochner@, thanks.

diffstat:

 sys/uvm/uvm_fault.c |  60 +++++++++++++++++++++++++---------------------------
 1 files changed, 29 insertions(+), 31 deletions(-)

diffs (220 lines):

diff -r ee8baa887e2b -r f3e8b7c69932 sys/uvm/uvm_fault.c
--- a/sys/uvm/uvm_fault.c       Tue Feb 02 17:40:43 2010 +0000
+++ b/sys/uvm/uvm_fault.c       Tue Feb 02 18:49:23 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_fault.c,v 1.155 2010/02/02 17:40:43 uebayasi Exp $ */
+/*     $NetBSD: uvm_fault.c,v 1.156 2010/02/02 18:49:23 uebayasi Exp $ */
 
 /*
  *
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_fault.c,v 1.155 2010/02/02 17:40:43 uebayasi Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_fault.c,v 1.156 2010/02/02 18:49:23 uebayasi Exp $");
 
 #include "opt_uvmhist.h"
 
@@ -725,10 +725,10 @@
     struct vm_anon **);
 static int uvm_fault_lower_generic1(
     struct uvm_faultinfo *, struct uvm_faultctx *,
-    struct vm_page *);
+    struct uvm_object *, struct vm_page *);
 static int uvm_fault_lower_generic2(
     struct uvm_faultinfo *, struct uvm_faultctx *,
-    struct vm_page *);
+    struct uvm_object *, struct vm_page *);
 
 int
 uvm_fault_internal(struct vm_map *orig_map, vaddr_t vaddr,
@@ -1206,7 +1206,7 @@
        } else {
                uvm_fault_lower_generic_lookup(ufi, flt, pages);
        }
-       return uvm_fault_lower_generic1(ufi, flt, pages[flt->centeridx]);
+       return uvm_fault_lower_generic1(ufi, flt, uobj, pages[flt->centeridx]);
 }
 
 static int
@@ -1322,11 +1322,10 @@
 static int
 uvm_fault_lower_generic1(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page *uobjpage)
+       struct uvm_object *uobj, struct vm_page *uobjpage)
 {
 #ifdef DIAGNOSTIC
        struct vm_amap *amap = ufi->entry->aref.ar_amap;
-       struct uvm_object *uobj = ufi->entry->object.uvm_obj;
 #endif
 
        /* locked: maps(read), amap(if there), uobj(if !null), uobjpage(if !null) */
@@ -1353,7 +1352,7 @@
         * redirect case 2: if we are not shadowed, go to case 2.
         */
 
-       return uvm_fault_lower_generic2(ufi, flt, uobjpage);
+       return uvm_fault_lower_generic2(ufi, flt, uobj, uobjpage);
 }
 
 static int
@@ -1685,19 +1684,19 @@
 static int
 uvm_fault_lower_generic_io(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page **ruobjpage);
+       struct uvm_object **ruobj, struct vm_page **ruobjpage);
 static int
 uvm_fault_lower_generic3(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page *uobjpage, bool promote);
+       struct uvm_object *uobj, struct vm_page *uobjpage, bool promote);
 static int
 uvm_fault_lower_generic_direct(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page *uobjpage);
+       struct uvm_object *uobj, struct vm_page *uobjpage);
 static int
 uvm_fault_lower_generic_promote(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page *uobjpage);
+       struct uvm_object *uobj, struct vm_page *uobjpage);
 static int
 uvm_fault_lower_generic_enter(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
@@ -1712,12 +1711,11 @@
 static int
 uvm_fault_lower_generic2(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page *uobjpage)
+       struct uvm_object *uobj, struct vm_page *uobjpage)
 {
 #ifdef DIAGNOSTIC
        struct vm_amap * const amap = ufi->entry->aref.ar_amap;
 #endif
-       struct uvm_object * const uobj = ufi->entry->object.uvm_obj;
        bool promote;
        int error;
 
@@ -1763,20 +1761,20 @@
                /* update rusage counters */
                curlwp->l_ru.ru_minflt++;
        } else {
-               error = uvm_fault_lower_generic_io(ufi, flt, &uobjpage);
+               error = uvm_fault_lower_generic_io(ufi, flt, &uobj, &uobjpage);
                if (error != 0)
                        return error;
        }
-       return uvm_fault_lower_generic3(ufi, flt, uobjpage, promote);
+       return uvm_fault_lower_generic3(ufi, flt, uobj, uobjpage, promote);
 }
 
 static int
 uvm_fault_lower_generic_io(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page **ruobjpage)
+       struct uvm_object **ruobj, struct vm_page **ruobjpage)
 {
        struct vm_amap * const amap = ufi->entry->aref.ar_amap;
-       struct uvm_object * const uobj = ufi->entry->object.uvm_obj;
+       struct uvm_object *uobj = *ruobj;
        struct vm_page *uobjpage;
        bool locked;
        int gotpages;
@@ -1838,7 +1836,10 @@
        locked = uvmfault_relock(ufi);
        if (locked && amap)
                amap_lock(amap);
-       KASSERT(uobj == uobjpage->uobject);
+
+       /* might be changed */
+       uobj = uobjpage->uobject;
+
        mutex_enter(&uobj->vmobjlock);
 
        /* locked(locked): maps(read), amap(if !null), uobj, uobjpage */
@@ -1888,6 +1889,7 @@
 
        /* locked: maps(read), amap(if !null), uobj, uobjpage */
 
+       *ruobj = uobj;
        *ruobjpage = uobjpage;
        return 0;
 }
@@ -1895,11 +1897,10 @@
 int
 uvm_fault_lower_generic3(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page *uobjpage, bool promote)
+       struct uvm_object *uobj, struct vm_page *uobjpage, bool promote)
 {
 #ifdef DIAGNOSTIC
        struct vm_amap * const amap = ufi->entry->aref.ar_amap;
-       struct uvm_object * const uobj = ufi->entry->object.uvm_obj;
 #endif
        int error;
 
@@ -1924,9 +1925,9 @@
            (uobjpage->flags & PG_CLEAN) != 0);
 
        if (promote == false) {
-               error = uvm_fault_lower_generic_direct(ufi, flt, uobjpage);
+               error = uvm_fault_lower_generic_direct(ufi, flt, uobj, uobjpage);
        } else {
-               error = uvm_fault_lower_generic_promote(ufi, flt, uobjpage);
+               error = uvm_fault_lower_generic_promote(ufi, flt, uobj, uobjpage);
        }
        return error;
 }
@@ -1934,14 +1935,13 @@
 static int
 uvm_fault_lower_generic_direct_loan(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page **rpg, struct vm_page **ruobjpage);
+       struct uvm_object *uobj, struct vm_page **rpg, struct vm_page **ruobjpage);
 
 int
 uvm_fault_lower_generic_direct(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page *uobjpage)
+       struct uvm_object *uobj, struct vm_page *uobjpage)
 {
-       struct uvm_object * const uobj = ufi->entry->object.uvm_obj;
        struct vm_page *pg;
 
        /*
@@ -1967,7 +1967,7 @@
         */
 
        if (uobjpage->loan_count) {
-               uvm_fault_lower_generic_direct_loan(ufi, flt, &pg, &uobjpage);
+               uvm_fault_lower_generic_direct_loan(ufi, flt, uobj, &pg, &uobjpage);
        }
        KASSERT(pg == uobjpage);
 
@@ -1977,10 +1977,9 @@
 static int
 uvm_fault_lower_generic_direct_loan(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page **rpg, struct vm_page **ruobjpage)
+       struct uvm_object *uobj, struct vm_page **rpg, struct vm_page **ruobjpage)
 {
        struct vm_amap * const amap = ufi->entry->aref.ar_amap;
-       struct uvm_object * const uobj = ufi->entry->object.uvm_obj;
        struct vm_page *pg;
        struct vm_page *uobjpage = *ruobjpage;
 
@@ -2020,10 +2019,9 @@
 int
 uvm_fault_lower_generic_promote(
        struct uvm_faultinfo *ufi, struct uvm_faultctx *flt,
-       struct vm_page *uobjpage)
+       struct uvm_object *uobj, struct vm_page *uobjpage)
 {
        struct vm_amap * const amap = ufi->entry->aref.ar_amap;
-       struct uvm_object *uobj = ufi->entry->object.uvm_obj;
        struct vm_anon *anon;
        struct vm_page *pg;
        int error;