[0.4.9] cherry-pick [FASTFAT] Lock DirResource when modifying an entry on disk.

Likely not optimal, but fixes some races conditions where
the directory is uninit in the middle of the write.

(cherry picked from commit fc788cf2fde7551a8e5068f2b061c3cad2004e9a)

diff --git a/drivers/filesystems/fastfat/finfo.c b/drivers/filesystems/fastfat/finfo.c
index d860cd6..af2e1ce 100644 (file)
--- a/drivers/filesystems/fastfat/finfo.c
+++ b/drivers/filesystems/fastfat/finfo.c
@@ -1552,6 +1552,7 @@ VfatSetInformation(
     PVFATFCB FCB;
     NTSTATUS Status = STATUS_SUCCESS;
     PVOID SystemBuffer;
+    BOOLEAN LockDir;
 
     /* PRECONDITION */
     ASSERT(IrpContext);
@@ -1593,7 +1594,14 @@ VfatSetInformation(
         DPRINT("Can set file size\n");
     }
 
-    if (FileInformationClass == FileRenameInformation)
+    LockDir = FALSE;
+    if (FileInformationClass == FileRenameInformation || FileInformationClass == FileAllocationInformation ||
+        FileInformationClass == FileEndOfFileInformation || FileInformationClass == FileBasicInformation)
+    {
+        LockDir = TRUE;
+    }
+
+    if (LockDir)
     {
         if (!ExAcquireResourceExclusiveLite(&((PDEVICE_EXTENSION)IrpContext->DeviceObject->DeviceExtension)->DirResource,
                                             BooleanFlagOn(IrpContext->Flags, IRPCONTEXT_CANWAIT)))
@@ -1607,7 +1615,7 @@ VfatSetInformation(
         if (!ExAcquireResourceExclusiveLite(&FCB->MainResource,
                                             BooleanFlagOn(IrpContext->Flags, IRPCONTEXT_CANWAIT)))
         {
-            if (FileInformationClass == FileRenameInformation)
+            if (LockDir)
             {
                 ExReleaseResourceLite(&((PDEVICE_EXTENSION)IrpContext->DeviceObject->DeviceExtension)->DirResource);
             }
@@ -1662,7 +1670,7 @@ VfatSetInformation(
         ExReleaseResourceLite(&FCB->MainResource);
     }
 
-    if (FileInformationClass == FileRenameInformation)
+    if (LockDir)
     {
         ExReleaseResourceLite(&((PDEVICE_EXTENSION)IrpContext->DeviceObject->DeviceExtension)->DirResource);
     }