SERVER-7045 check all extents in validate command, report results

Move the Extent::validates() routine from pdfile.h to pdfile.cpp, make
it return messages for errors it finds, call it for every extent instead
of just for the first extent.  Check extent DiskLoc against 'myLoc'.

4 files changed, 53 insertions, 11 deletions

diff --git a/src/mongo/db/compact.cpp b/src/mongo/db/compact.cpp
index 4c258ef62a7..847a77b01e0 100644
--- a/src/mongo/db/compact.cpp
+++ b/src/mongo/db/compact.cpp
@@ -63,7 +63,7 @@ namespace mongo {
 
         Extent *e = diskloc.ext();
         e->assertOk();
-        verify( e->validates() );
+        verify( e->validates(diskloc) );
         unsigned skipped = 0;
 
         {
diff --git a/src/mongo/db/dbcommands_admin.cpp b/src/mongo/db/dbcommands_admin.cpp
index b1b46e8c0b0..2bedc168264 100644
--- a/src/mongo/db/dbcommands_admin.cpp
+++ b/src/mongo/db/dbcommands_admin.cpp
@@ -203,11 +203,13 @@ namespace mongo {
                 while( !el.isNull() ) {
                     Extent *e = el.ext();
                     e->assertOk();
-                    el = e->xnext;
-                    ne++;
                     if ( full )
                         extentData << e->dump();
-                    
+                    if (!e->validates(el, &errors)) {
+                        valid = false;
+                    }
+                    el = e->xnext;
+                    ne++;
                     killCurrentOp.checkForInterrupt();
                 }
                 result.append("extentCount", ne);
@@ -231,9 +233,13 @@ namespace mongo {
 
                 try {
                     result.append("firstExtentDetails", d->firstExtent.ext()->dump());
-
-                    valid = valid && d->firstExtent.ext()->validates() && 
-                        d->firstExtent.ext()->xprev.isNull();
+                    if (!d->firstExtent.ext()->xprev.isNull()) {
+                        StringBuilder sb;
+                        sb << "'xprev' pointer in first extent " << d->firstExtent.toString()
+                           << " is not null";
+                        errors << sb.str();
+                        valid=false;
+                    }
                 }
                 catch (...) {
                     errors << "exception firstextent";
diff --git a/src/mongo/db/pdfile.cpp b/src/mongo/db/pdfile.cpp
index 701616014e0..3967e158e6d 100644
--- a/src/mongo/db/pdfile.cpp
+++ b/src/mongo/db/pdfile.cpp
@@ -700,6 +700,45 @@ namespace mongo {
         return emptyLoc;
     }
 
+        bool Extent::validates(const DiskLoc diskLoc, BSONArrayBuilder* errors) {
+            bool extentOk = true;
+            if (myLoc != diskLoc) {
+                if (errors) {
+                    StringBuilder sb;
+                    sb << "extent " << diskLoc.toString()
+                       << " self-pointer is " << myLoc.toString();
+                    *errors << sb.str();
+                }
+                extentOk = false;
+            }
+            if (firstRecord.isNull() != lastRecord.isNull()) {
+                if (errors) {
+                    StringBuilder sb;
+                    if (firstRecord.isNull()) {
+                        sb << "in extent " << diskLoc.toString()
+                           << ", firstRecord is null but lastRecord is "
+                           << lastRecord.toString();
+                    }
+                    else {
+                        sb << "in extent " << diskLoc.toString()
+                           << ", firstRecord is " << firstRecord.toString()
+                           << " but lastRecord is null";
+                    }
+                    *errors << sb.str();
+                }
+                extentOk = false;
+            }
+            if (length < 0) {
+                if (errors) {
+                    StringBuilder sb;
+                    sb << "negative length extent " << diskLoc.toString();
+                    *errors << sb.str();
+                }
+                extentOk = false;
+            }
+            return extentOk;
+        }
+
     /*
       Record* Extent::newRecord(int len) {
       if( firstEmptyRegion.isNull() )8
diff --git a/src/mongo/db/pdfile.h b/src/mongo/db/pdfile.h
index d1904f928b9..af224bac8da 100644
--- a/src/mongo/db/pdfile.h
+++ b/src/mongo/db/pdfile.h
@@ -330,10 +330,7 @@ namespace mongo {
 
         static int HeaderSize() { return sizeof(Extent)-4; }
 
-        bool validates() {
-            return !(firstRecord.isNull() ^ lastRecord.isNull()) &&
-                   length >= 0 && !myLoc.isNull();
-        }
+        bool validates(const DiskLoc diskLoc, BSONArrayBuilder* errors = NULL);
 
         BSONObj dump() {
             return BSON( "loc" << myLoc.toString() << "xnext" << xnext.toString() << "xprev" << xprev.toString()