From a3b61053bcfdb7175706635089f97c56ef157d96 Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Thu, 23 Jun 2011 22:34:03 +0000
Subject: [PATCH] [VFATLIB] - Lock the volume before formatting to prevent
 concurrent access during formatting - This should (in theory) fix our
 formatting issue on mounted devices but currently we don't support
 FSCTL_LOCK_VOLUME in our FS drivers

svn path=/trunk/; revision=52435
---
 reactos/lib/fslib/vfatlib/vfatlib.c | 30 +++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/reactos/lib/fslib/vfatlib/vfatlib.c b/reactos/lib/fslib/vfatlib/vfatlib.c
index 11847b2c688..c8c9c54f388 100644
--- a/reactos/lib/fslib/vfatlib/vfatlib.c
+++ b/reactos/lib/fslib/vfatlib/vfatlib.c
@@ -194,6 +194,21 @@ VfatFormat(IN PUNICODE_STRING DriveRoot,
         Context.Percent = 0;
         Callback (PROGRESS, 0, (PVOID)&Context.Percent);
     }
+    
+    Status = NtFsControlFile(FileHandle,
+                             NULL,
+                             NULL,
+                             NULL,
+                             &Iosb,
+                             FSCTL_LOCK_VOLUME,
+                             NULL,
+                             0,
+                             NULL,
+                             0);
+    if (!NT_SUCCESS(Status))
+    {
+        DPRINT1("WARNING: Failed to lock volume for formatting! Format may fail! (Status: 0x%x)\n", Status);
+    }
 
     if (PartitionInfo.PartitionType == PARTITION_FAT_12)
     {
@@ -235,6 +250,21 @@ VfatFormat(IN PUNICODE_STRING DriveRoot,
     {
         Status = STATUS_INVALID_PARAMETER;
     }
+    
+    Status = NtFsControlFile(FileHandle,
+                             NULL,
+                             NULL,
+                             NULL,
+                             &Iosb,
+                             FSCTL_UNLOCK_VOLUME,
+                             NULL,
+                             0,
+                             NULL,
+                             0);
+    if (!NT_SUCCESS(Status))
+    {
+        DPRINT1("Failed to unlock volume (Status: 0x%x)\n", Status);
+    }
 
     NtClose(FileHandle);