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Index: head/sys/vm/vm_fault.c
===================================================================
--- head/sys/vm/vm_fault.c
+++ head/sys/vm/vm_fault.c
@@ -795,6 +795,57 @@
return (KERN_SUCCESS);
}
+static int
+vm_fault_relookup(struct faultstate *fs)
+{
+ vm_object_t retry_object;
+ vm_pindex_t retry_pindex;
+ vm_prot_t retry_prot;
+ int result;
+
+ if (!vm_map_trylock_read(fs->map))
+ return (KERN_RESTART);
+
+ fs->lookup_still_valid = true;
+ if (fs->map->timestamp == fs->map_generation)
+ return (KERN_SUCCESS);
+
+ result = vm_map_lookup_locked(&fs->map, fs->vaddr, fs->fault_type,
+ &fs->entry, &retry_object, &retry_pindex, &retry_prot,
+ &fs->wired);
+ if (result != KERN_SUCCESS) {
+ /*
+ * If retry of map lookup would have blocked then
+ * retry fault from start.
+ */
+ if (result == KERN_FAILURE)
+ return (KERN_RESTART);
+ return (result);
+ }
+ if (retry_object != fs->first_object ||
+ retry_pindex != fs->first_pindex)
+ return (KERN_RESTART);
+
+ /*
+ * Check whether the protection has changed or the object has
+ * been copied while we left the map unlocked. Changing from
+ * read to write permission is OK - we leave the page
+ * write-protected, and catch the write fault. Changing from
+ * write to read permission means that we can't mark the page
+ * write-enabled after all.
+ */
+ fs->prot &= retry_prot;
+ fs->fault_type &= retry_prot;
+ if (fs->prot == 0)
+ return (KERN_RESTART);
+
+ /* Reassert because wired may have changed. */
+ KASSERT(fs->wired || (fs->fault_flags & VM_FAULT_WIRE) == 0,
+ ("!wired && VM_FAULT_WIRE"));
+
+ return (KERN_SUCCESS);
+}
+
/*
* Wait/Retry if the page is busy. We have to do this if the page is
* either exclusive or shared busy because the vm_pager may be using
@@ -837,10 +888,8 @@
{
struct faultstate fs;
struct domainset *dset;
- vm_object_t next_object, retry_object;
+ vm_object_t next_object;
vm_offset_t e_end, e_start;
- vm_pindex_t retry_pindex;
- vm_prot_t retry_prot;
int ahead, alloc_req, behind, cluster_offset, faultcount;
int nera, oom, result, rv;
u_char behavior;
@@ -1363,56 +1412,12 @@
* lookup.
*/
if (!fs.lookup_still_valid) {
- if (!vm_map_trylock_read(fs.map)) {
+ result = vm_fault_relookup(&fs);
+ if (result != KERN_SUCCESS) {
fault_deallocate(&fs);
- goto RetryFault;
- }
- fs.lookup_still_valid = true;
- if (fs.map->timestamp != fs.map_generation) {
- result = vm_map_lookup_locked(&fs.map, vaddr, fs.fault_type,
- &fs.entry, &retry_object, &retry_pindex, &retry_prot,
- &fs.wired);
-
- /*
- * If we don't need the page any longer, put it on the inactive
- * list (the easiest thing to do here). If no one needs it,
- * pageout will grab it eventually.
- */
- if (result != KERN_SUCCESS) {
- fault_deallocate(&fs);
-
- /*
- * If retry of map lookup would have blocked then
- * retry fault from start.
- */
- if (result == KERN_FAILURE)
- goto RetryFault;
- return (result);
- }
- if ((retry_object != fs.first_object) ||
- (retry_pindex != fs.first_pindex)) {
- fault_deallocate(&fs);
+ if (result == KERN_RESTART)
goto RetryFault;
- }
-
- /*
- * Check whether the protection has changed or the object has
- * been copied while we left the map unlocked. Changing from
- * read to write permission is OK - we leave the page
- * write-protected, and catch the write fault. Changing from
- * write to read permission means that we can't mark the page
- * write-enabled after all.
- */
- fs.prot &= retry_prot;
- fs.fault_type &= retry_prot;
- if (fs.prot == 0) {
- fault_deallocate(&fs);
- goto RetryFault;
- }
-
- /* Reassert because wired may have changed. */
- KASSERT(fs.wired || (fs.fault_flags & VM_FAULT_WIRE) == 0,
- ("!wired && VM_FAULT_WIRE"));
+ return (result);
}
}
VM_OBJECT_ASSERT_UNLOCKED(fs.object);
Index: head/sys/vm/vm_param.h
===================================================================
--- head/sys/vm/vm_param.h
+++ head/sys/vm/vm_param.h
@@ -114,6 +114,7 @@
#define KERN_NOT_RECEIVER 7
#define KERN_NO_ACCESS 8
#define KERN_OUT_OF_BOUNDS 9
+#define KERN_RESTART 10
#ifndef PA_LOCK_COUNT
#ifdef SMP

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