Luna/kernel/src/fs/VFS.cpp

#define MODULE "vfs"

#include "fs/VFS.h"
#include "log/Log.h"
#include "std/string.h"

static VFS::Node* vfs_root;

ssize_t VFS::read(Node* node, size_t offset, size_t length, char* buffer)
{
    if (!node)
    {
        kwarnln("read() failed: trying to read from nullptr");
        return -1;
    }
    if (!node->read_func)
    {
        kwarnln("read() failed: the chosen node doesn't support reading");
        return -1;
    }

    kdbgln("read(): node %s (inode %ld), offset %zd, %zd bytes, into %p", node->name, node->inode, offset, length,
           (void*)buffer);

    return node->read_func(node, offset, length, buffer);
}

VFS::Node* VFS::open(const char* filename)
{
    if (!vfs_root)
    {
        kwarnln("open() failed: root not mounted");
        return 0;
    }
    if (!vfs_root->find_func)
    {
        kwarnln("open() failed: root doesn't support finding files");
        return 0;
    }

    kinfoln("open(): opening %s", filename);

    return vfs_root->find_func(vfs_root, filename);
}

void VFS::mount_root(Node* root)
{
    if (!root)
    {
        kwarnln("mount_root() failed: attempted to mount nullptr");
        return;
    }
    if (vfs_root)
    {
        kwarnln("mount_root() failed: root filesystem already mounted");
        return;
    }
    kinfoln("mounting node '%s' as vfs root", root->name);
    vfs_root = root;
}

VFS::Node* VFS::root()
{
    return vfs_root;
}