Commented by: Diane Downie (dianedownie)

Before and after fbserver.log that illustrate the problems and code changes that detect the problem. (FB Developers may be aware of a better to address this issue that has been present since 1.5.)

Commented by: Diane Downie (dianedownie)

Added Readme.txt to the archive.

Commented by: @hvlad

Diane, thank you for contribution.
I reworked your patch for validation.cpp, please test it on corrupted database you have

Index: jrd/validation.cpp

RCS file: /cvsroot/firebird/firebird2/src/jrd/validation.cpp,v
retrieving revision 1.16
diff -u -w -b -r1.16 validation.cpp
--- jrd/validation.cpp 6 Apr 2006 08:18:42 -0000 1.16
+++ jrd/validation.cpp 13 Feb 2007 09:03:52 -0000
@@ -647,7 +647,8 @@
"Transaction inventory pages confused, sequence %ld",
"Relation has %ld orphan backversions (%ld in use)",
"Index %d is corrupt (missing entries)",
- "Index %d has orphan child page at page %ld"
+ "Index %d has orphan child page at page %ld",
+ "Index %d has a circular reference at page %ld"
};

@@ -1430,11 +1431,16 @@
SCHAR flags = 0;
UCHAR* pointer;
IndexNode node, lastNode;
+ PageBitmap visited_pages; // used to check circular page references, Diane Downie 2/9/07

while \(next\) \{
	WIN window\(\-1\);
	btree\_page\* page = 0;
	fetch\_page\(tdbb, control, next, pag\_index, &window, &page\);

+
+ // remember each page for circular reference detection
+ visited_pages.set(next);
+
if ((next != page_number) &&
(page->btr_header.pag_flags & BTR_FLAG_COPY_MASK) !=
(flags & BTR_FLAG_COPY_MASK))
@@ -1686,6 +1692,13 @@
nullKeyHandled = !(unique && null_key);
}

+ // check for circular referenes
+ if (next && visited_pages.test(next))
+ {
+ corrupt(tdbb, control, VAL_INDEX_CYCLE, relation,
+ id + 1, next);
+ next = 0;
+ }
CCH_RELEASE(tdbb, &window);
}

Commented by: Diane Downie (dianedownie)

Yes, your reworked changs also allowed the database to be recovered.
Thanks,
-Diane

Commented by: @pmakowski

Reporter said that it is ok, so we can close

Commented by: @pcisar

Reopened to update ticket information.