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/* SPDX-License-Identifier: GPL-2.0-or-later */
/* Copyright (C) 2026 Richard Qin */
/*
* ramfs/inode.cc — RamFS inode operations
*
* A simple in-memory filesystem (like Linux tmpfs without swap).
* All data lives in memory via the page cache.
*/
#include <lume/fs.h>
#include <lume/dcache.h>
#include <lume/file.h>
#include <lume/slab.h>
#include <lume/errno.h>
#include <lume/fs_types.h>
/* Forward declarations */
extern file_operations ramfs_file_operations;
extern file_operations ramfs_dir_operations;
extern inode_operations ramfs_dir_inode_operations;
/* ================================================================== */
/* ramfs_get_inode — allocate + init an inode for ramfs */
/* ================================================================== */
inode* ramfs_get_inode(super_block* sb, const inode* dir, uint32 mode, uint32 rdev)
{
inode* ip = new_inode(sb);
if (!ip) return nullptr;
inode_init_owner(ip, dir, mode);
/* TODO: set timestamps to current time when we have a time source */
switch (mode & S_IFMT) {
case S_IFREG:
ip->i_op = nullptr; /* regular files don't need inode_ops for Phase 1 */
ip->i_fop = &ramfs_file_operations;
break;
case S_IFDIR:
ip->i_op = &ramfs_dir_inode_operations;
ip->i_fop = &ramfs_dir_operations;
inc_nlink(ip); /* directories start with nlink=2 (. and parent's link) */
break;
case S_IFLNK:
/* Symlink: stub for Phase 1 */
break;
default:
/* Character/block devices: i_rdev */
ip->i_rdev = rdev;
break;
}
return ip;
}
/* ================================================================== */
/* Directory inode operations */
/* ================================================================== */
static dentry* ramfs_lookup(inode* dir, dentry* de, unsigned int flags)
{
(void)dir;
(void)flags;
/* For ramfs, everything is in dcache. If we get here, it means
* d_lookup() already failed, so this is a negative dentry.
* Just return nullptr to let the caller see de->d_inode == NULL. */
return nullptr;
}
static int ramfs_create(inode* dir, dentry* de, uint32 mode, bool excl)
{
(void)excl;
inode* ip = ramfs_get_inode(dir->i_sb, dir, mode | S_IFREG, 0);
if (!ip) return -ENOMEM;
d_instantiate(de, ip);
dget(de);
dir->i_size += de->d_name.len;
mark_inode_dirty(dir);
return 0;
}
static int ramfs_mkdir(inode* dir, dentry* de, uint32 mode)
{
inode* ip = ramfs_get_inode(dir->i_sb, dir, mode | S_IFDIR, 0);
if (!ip) return -ENOMEM;
d_instantiate(de, ip);
dget(de);
inc_nlink(dir);
dir->i_size += de->d_name.len;
mark_inode_dirty(dir);
return 0;
}
static int ramfs_rmdir(inode* dir, dentry* de)
{
/* Check if directory is empty */
if (!list_empty(&de->d_children))
return -ENOTEMPTY;
drop_nlink(de->d_inode); /* remove . link */
drop_nlink(de->d_inode); /* remove parent's link */
drop_nlink(dir);
d_delete(de);
dir->i_size -= de->d_name.len;
mark_inode_dirty(dir);
return 0;
}
static int ramfs_unlink(inode* dir, dentry* de)
{
drop_nlink(de->d_inode);
d_delete(de);
dir->i_size -= de->d_name.len;
mark_inode_dirty(dir);
return 0;
}
static int ramfs_link(dentry* old_de, inode* dir, dentry* new_de)
{
inode* ip = old_de->d_inode;
if (!ip) return -ENOENT;
inc_nlink(ip);
ihold(ip);
d_instantiate(new_de, ip);
dget(new_de);
dir->i_size += new_de->d_name.len;
mark_inode_dirty(dir);
return 0;
}
static int ramfs_mknod(inode* dir, dentry* de, uint32 mode, uint32 rdev)
{
inode* ip = ramfs_get_inode(dir->i_sb, dir, mode, rdev);
if (!ip) return -ENOMEM;
d_instantiate(de, ip);
dget(de);
dir->i_size += de->d_name.len;
mark_inode_dirty(dir);
return 0;
}
inode_operations ramfs_dir_inode_operations;
void ramfs_dir_inode_ops_init()
{
ramfs_dir_inode_operations.lookup = ramfs_lookup;
ramfs_dir_inode_operations.create = ramfs_create;
ramfs_dir_inode_operations.link = ramfs_link;
ramfs_dir_inode_operations.unlink = ramfs_unlink;
ramfs_dir_inode_operations.symlink = nullptr;
ramfs_dir_inode_operations.mkdir = ramfs_mkdir;
ramfs_dir_inode_operations.rmdir = ramfs_rmdir;
ramfs_dir_inode_operations.mknod = ramfs_mknod;
ramfs_dir_inode_operations.rename = nullptr;
ramfs_dir_inode_operations.setattr = nullptr;
ramfs_dir_inode_operations.getattr = nullptr;
ramfs_dir_inode_operations.get_link = nullptr;
ramfs_dir_inode_operations.permission = nullptr;
}
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