From 6a004bd33c1e69a16161e33dc91d520202fd545a Mon Sep 17 00:00:00 2001
From: Rene Gollent <anevilyak@gmail.com>
Date: Sun, 31 May 2009 05:55:54 +0000
Subject: [PATCH] When we dynamically create a mount point directory, add a
 special marker subdirectory in it so the disk system knows the directory was
 not created by the user. When unmounting, look for the marker and remove the
 mountpoint directory if found. This fixes the issue where mount / unmount /
 mounting a volume via Tracker would result in extra empty dirs in the rootfs.
 Ideally I'd rather solve this by being able to tag the mount points with
 attributes, but this isn't currently possible since the attribute overlay is
 a module and thus not available when mounting the rootfs.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30934 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/kits/storage/disk_device/Partition.cpp | 29 +++++++++++++++++++---
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/src/kits/storage/disk_device/Partition.cpp b/src/kits/storage/disk_device/Partition.cpp
index d35301fd4d..c54fed92bc 100644
--- a/src/kits/storage/disk_device/Partition.cpp
+++ b/src/kits/storage/disk_device/Partition.cpp
@@ -41,6 +41,7 @@
 
 using std::nothrow;
 
+static const char *skAutoCreatePrefix = "_HaikuAutoCreated";
 
 /*!	\class BPartition
 	\brief A BPartition object represent a partition and provides a lot of
@@ -546,7 +547,7 @@ BPartition::Mount(const char* mountPoint, uint32 mountFlags,
 
 	// create a mount point, if none is given
 	bool deleteMountPoint = false;
-	BPath mountPointPath;
+	BPath mountPointPath, markerPath;
 	if (!mountPoint) {
 		// get a unique mount point
 		error = GetMountPoint(&mountPointPath);
@@ -554,10 +555,17 @@ BPartition::Mount(const char* mountPoint, uint32 mountFlags,
 			return error;
 
 		mountPoint = mountPointPath.Path();
-
+		markerPath = mountPointPath;
+		markerPath.Append(skAutoCreatePrefix);
+		
 		// create the directory
 		if (mkdir(mountPoint, S_IRWXU | S_IRWXG | S_IRWXO) < 0)
 			return errno;
+			
+		if (mkdir(markerPath.Path(), S_IRWXU | S_IRWXG | S_IRWXO) < 0) {
+			rmdir(mountPoint);
+			return errno;
+		}
 
 		deleteMountPoint = true;
 	}
@@ -567,8 +575,10 @@ BPartition::Mount(const char* mountPoint, uint32 mountFlags,
 		mountFlags, parameters);
 
 	// delete the mount point on error, if we created it
-	if (device < B_OK && deleteMountPoint)
+	if (device < B_OK && deleteMountPoint) {
+		rmdir(markerPath.Path());
 		rmdir(mountPoint);
+	}
 
 	// update object, if successful
 	if (device >= 0)
@@ -605,9 +615,20 @@ BPartition::Unmount(uint32 unmountFlags)
 	status = fs_unmount_volume(path.Path(), unmountFlags);
 
 	// update object, if successful
-	if (status == B_OK)
+	if (status == B_OK) {
 		status = Device()->Update();
 
+		// Check if we created this mount point on the fly.
+		// If so, clean it up.
+		BPath markerPath = path;
+		markerPath.Append(skAutoCreatePrefix);
+		BEntry pathEntry (markerPath.Path());
+		if (pathEntry.InitCheck() == B_OK && pathEntry.Exists()) {
+			rmdir(markerPath.Path());
+			rmdir(path.Path());
+		}
+	}
+
 	return status;
 }