libfs: Add libfs_put_dots and put_dir definitions

Small helpers for getdirent implementations to use.

Signed-off-by: Pedro Falcato <[email protected]>

kernel/kernel/fs/libfs.c

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2024 Pedro Falcato
+ * This file is part of Onyx, and is released under the terms of the GPLv2 License
+ * check LICENSE at the root directory for more information
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ */
+#include <onyx/dentry.h>
+#include <onyx/libfs.h>
+#include <onyx/vfs.h>
+
+off_t libfs_put_dots(struct dirent *buf, off_t off, struct dentry *dent)
+{
+    struct dentry *parent = NULL;
+    struct inode *ino;
+    const char *name = NULL;
+
+    DCHECK(off < 2);
+    if (off == 0)
+    {
+        /* . , fallthrough */
+        name = ".";
+    }
+    else if (off == 1)
+    {
+        /* .. */
+        parent = dentry_parent(dent);
+        if (parent)
+            dent = parent;
+        name = "..";
+    }
+
+    ino = dent->d_inode;
+    put_dir(name, off, ino->i_inode, IFTODT(ino->i_mode), buf);
+    if (parent)
+        dput(parent);
+    return off + 1;
+}
+
+void put_dir(const char *name, off_t off, ino_t ino, unsigned int dtype, struct dirent *buf)
+{
+    size_t len = strlen(name);
+    memcpy(buf->d_name, name, len);
+    buf->d_name[len] = '\0';
+    buf->d_off = off;
+    buf->d_ino = ino;
+    buf->d_type = dtype;
+    buf->d_reclen = sizeof(struct dirent) - (256 - (len + 1));
+}