bfs_create() now only checks for write access in the parent directory if a

file really has to be created, thanks to Ingo for reporting this.
Inode::Create() now checks for write access to the inode when O_TRUNC is set.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@10272 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/kernel/file_systems/bfs/Inode.cpp

@@ -2109,6 +2109,11 @@ Inode::Create(Transaction &transaction, Inode *parent, const char *name, int32 m
 				return B_NOT_ALLOWED;
 
 			if (openMode & O_TRUNC) {
+				// we need write access in order to truncate the file
+				status = inode->CheckPermission(W_OK);
+				if (status != B_OK)
+					return status;
+
 				// truncate the existing file
 				WriteLocked locked(inode->Lock());
 
@@ -2131,6 +2136,10 @@ Inode::Create(Transaction &transaction, Inode *parent, const char *name, int32 m
 	} else if (parent && (mode & S_ATTR_DIR) == 0)
 		return B_BAD_VALUE;
 
+	// do we have the power to create new files at all?
+	if (parent != NULL && (status = parent->CheckPermissions(W_OK)) != B_OK)
+		RETURN_ERROR(status);
+
 	// allocate space for the new inode
 	InodeAllocator allocator(transaction);
 	block_run run;

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

@@ -726,10 +726,6 @@ bfs_create(void *_ns, void *_directory, const char *name, int omode, int mode,
 	if (!directory->IsDirectory())
 		RETURN_ERROR(B_BAD_TYPE);
 
-	status_t status = directory->CheckPermissions(W_OK);
-	if (status < B_OK)
-		RETURN_ERROR(status);
-
 	// We are creating the cookie at this point, so that we don't have
 	// to remove the inode if we don't have enough free memory later...
 	file_cookie *cookie = (file_cookie *)malloc(sizeof(file_cookie));