[reactos] 96/100: [NTOS:MM] Fix regression of MmCanFileBeTruncated

[Jérôme Gardou]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=c0bf352069bd0c1b0d51da...

commit c0bf352069bd0c1b0d51da64c48fda70bb3ba92a
Author:     Jérôme Gardou [e-mail]
AuthorDate: Mon Feb 1 18:20:18 2021 +0100
Commit:     Jérôme Gardou [e-mail]
CommitDate: Wed Feb 3 09:41:24 2021 +0100

[NTOS:MM] Fix regression of MmCanFileBeTruncated
---
 ntoskrnl/mm/section.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/ntoskrnl/mm/section.c b/ntoskrnl/mm/section.c
index d848e337038..62da435122e 100644
--- a/ntoskrnl/mm/section.c
+++ b/ntoskrnl/mm/section.c
@@ -4115,7 +4115,7 @@ MmCanFileBeTruncated (IN PSECTION_OBJECT_POINTERS SectionObjectPointer,
     }

MmLockSectionSegment(Segment);
-    if ((Segment->SectionCount == 1) && (SectionObjectPointer->SharedCacheMap != NULL))
+    if ((Segment->SectionCount == 0) || ((Segment->SectionCount == 1) && (SectionObjectPointer->SharedCacheMap != NULL)))
     {
         /* If the cache is the only one holding a reference to the segment, then it's fine to resize */
         Ret = TRUE;
@@ -4124,6 +4124,12 @@ MmCanFileBeTruncated (IN PSECTION_OBJECT_POINTERS SectionObjectPointer,
     {
         /* We can't shrink, but we can extend */
         Ret = NewFileSize->QuadPart >= Segment->RawLength.QuadPart;
+#if DBG
+        if (!Ret)
+        {
+            DPRINT1("Cannot truncate data: New Size %I64d, Segment Size %I64d\n", NewFileSize->QuadPart, Segment->RawLength.QuadPart);
+        }
+#endif
     }
     MmUnlockSectionSegment(Segment);
     MmDereferenceSegment(Segment);