file_systems: Add O_DIRECTORY checks to many filesystems that were missing them.

This doesn't get all the filesystems that were missing these checks
(e.g. I didn't adjust the more "WIP" filesystems like XFS and BTRFS)
but it does get most of them.

src/add-ons/kernel/file_systems/exfat/kernel_interface.cpp

@@ -461,6 +461,8 @@ exfat_open(fs_volume* /*_volume*/, fs_vnode* _node, int openMode,
 	// any data from it.
 	if (inode->IsDirectory() && (openMode & O_RWMASK) != 0)
 		return B_IS_A_DIRECTORY;
+	if ((openMode & O_DIRECTORY) != 0 && !inode->IsDirectory())
+		return B_NOT_A_DIRECTORY;
 
 	status_t status = inode->CheckPermissions(open_mode_to_access(openMode));
 	if (status != B_OK)

src/add-ons/kernel/file_systems/ext2/kernel_interface.cpp

@@ -1147,6 +1147,8 @@ ext2_open(fs_volume* _volume, fs_vnode* _node, int openMode, void** _cookie)
 	// any data from it.
 	if (inode->IsDirectory() && (openMode & O_RWMASK) != 0)
 		return B_IS_A_DIRECTORY;
+	if ((openMode & O_DIRECTORY) != 0 && !inode->IsDirectory())
+		return B_NOT_A_DIRECTORY;
 
 	status_t status =  inode->CheckPermissions(open_mode_to_access(openMode));
 	if (status != B_OK)

src/add-ons/kernel/file_systems/iso9660/kernel_interface.cpp

@@ -511,11 +511,16 @@ fs_read_stat(fs_volume* _volume, fs_vnode* _node, struct stat* st)
 static status_t
 fs_open(fs_volume* /*_volume*/, fs_vnode* _node, int openMode, void** /*cookie*/)
 {
+	iso9660_inode* node = (iso9660_inode*)_node->private_node;
+
 	// Do not allow any of the write-like open modes to get by
 	if ((openMode & O_RWMASK) == O_WRONLY || (openMode & O_RWMASK) == O_RDWR
 		|| (openMode & O_TRUNC) != 0 || (openMode & O_CREAT) != 0)
 		return EROFS;
 
+	if ((openMode & O_DIRECTORY) != 0 && (node->flags & ISO_IS_DIR) == 0)
+		return B_NOT_A_DIRECTORY;
+
 	return B_OK;
 }
 

src/add-ons/kernel/file_systems/nfs4/kernel_interface.cpp

@@ -838,6 +838,11 @@ nfs4_open(fs_volume* volume, fs_vnode* vnode, int openMode, void** _cookie)
 	if (inode == NULL)
 		return B_ENTRY_NOT_FOUND;
 
+	if (inode->Type() == S_IFDIR && (openMode & O_RWMASK) != O_RDONLY)
+		return B_IS_A_DIRECTORY;
+	if ((openMode & O_DIRECTORY) != 0 && inode->Type() != S_IFDIR)
+		return B_NOT_A_DIRECTORY;
+
 	if (inode->Type() == S_IFDIR || inode->Type() == S_IFLNK) {
 		*_cookie = NULL;
 		return B_OK;

src/add-ons/kernel/file_systems/packagefs/kernel_interface.cpp

@@ -423,6 +423,8 @@ packagefs_open(fs_volume* fsVolume, fs_vnode* fsNode, int openMode,
 	// check the open mode and permissions
 	if (S_ISDIR(node->Mode()) && (openMode & O_RWMASK) != O_RDONLY)
 		return B_IS_A_DIRECTORY;
+	if ((openMode & O_DIRECTORY) != 0 && !S_ISDIR(node->Mode()))
+		return B_NOT_A_DIRECTORY;
 
 	if ((openMode & O_RWMASK) != O_RDONLY)
 		return B_NOT_ALLOWED;

src/add-ons/kernel/file_systems/ufs2/kernel_interface.cpp

@@ -263,8 +263,10 @@ ufs2_open(fs_volume * _volume, fs_vnode *_node, int openMode,
 
 	// opening a directory read-only is allowed, although you can't read
 	// any data from it.
-	if (inode->IsDirectory() && (openMode & O_RWMASK) != 0)
+	if (inode->IsDirectory() && (openMode & O_RWMASK) != O_RDONLY)
 		return B_IS_A_DIRECTORY;
+	if ((openMode & O_DIRECTORY) != 0 && !inode->IsDirectory())
+		return B_NOT_A_DIRECTORY;
 
 	status_t status =  inode->CheckPermissions(open_mode_to_access(openMode)
 		| (openMode & O_TRUNC ? W_OK : 0));