Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/sysv/namei.c
 *
 *  minix/namei.c
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  coh/namei.c
 *  Copyright (C) 1993  Pascal Haible, Bruno Haible
 *
 *  sysv/namei.c
 *  Copyright (C) 1993  Bruno Haible
 *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
 */
 
#include <linux/pagemap.h>
#include "sysv.h"
 
static int add_nondir(struct dentry *dentry, struct inode *inode)
{
<------>int err = sysv_add_link(dentry, inode);
<------>if (!err) {
<------><------>d_instantiate(dentry, inode);
<------><------>return 0;
<------>}
<------>inode_dec_link_count(inode);
<------>iput(inode);
<------>return err;
}
 
static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
{
<------>struct inode * inode = NULL;
<------>ino_t ino;
 
<------>if (dentry->d_name.len > SYSV_NAMELEN)
<------><------>return ERR_PTR(-ENAMETOOLONG);
<------>ino = sysv_inode_by_name(dentry);
<------>if (ino)
<------><------>inode = sysv_iget(dir->i_sb, ino);
<------>return d_splice_alias(inode, dentry);
}
 
static int sysv_mknod(struct inode * dir, struct dentry * dentry, umode_t mode, dev_t rdev)
{
<------>struct inode * inode;
<------>int err;
 
<------>if (!old_valid_dev(rdev))
<------><------>return -EINVAL;
 
<------>inode = sysv_new_inode(dir, mode);
<------>err = PTR_ERR(inode);
 
<------>if (!IS_ERR(inode)) {
<------><------>sysv_set_inode(inode, rdev);
<------><------>mark_inode_dirty(inode);
<------><------>err = add_nondir(dentry, inode);
<------>}
<------>return err;
}
 
static int sysv_create(struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
{
<------>return sysv_mknod(dir, dentry, mode, 0);
}
 
static int sysv_symlink(struct inode * dir, struct dentry * dentry, 
<------>const char * symname)
{
<------>int err = -ENAMETOOLONG;
<------>int l = strlen(symname)+1;
<------>struct inode * inode;
 
<------>if (l > dir->i_sb->s_blocksize)
<------><------>goto out;
 
<------>inode = sysv_new_inode(dir, S_IFLNK|0777);
<------>err = PTR_ERR(inode);
<------>if (IS_ERR(inode))
<------><------>goto out;
<------>
<------>sysv_set_inode(inode, 0);
<------>err = page_symlink(inode, symname, l);
<------>if (err)
<------><------>goto out_fail;
 
<------>mark_inode_dirty(inode);
<------>err = add_nondir(dentry, inode);
out:
<------>return err;
 
out_fail:
<------>inode_dec_link_count(inode);
<------>iput(inode);
<------>goto out;
}
 
static int sysv_link(struct dentry * old_dentry, struct inode * dir, 
<------>struct dentry * dentry)
{
<------>struct inode *inode = d_inode(old_dentry);
 
<------>inode->i_ctime = current_time(inode);
<------>inode_inc_link_count(inode);
<------>ihold(inode);
 
<------>return add_nondir(dentry, inode);
}
 
static int sysv_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
{
<------>struct inode * inode;
<------>int err;
 
<------>inode_inc_link_count(dir);
 
<------>inode = sysv_new_inode(dir, S_IFDIR|mode);
<------>err = PTR_ERR(inode);
<------>if (IS_ERR(inode))
<------><------>goto out_dir;
 
<------>sysv_set_inode(inode, 0);
 
<------>inode_inc_link_count(inode);
 
<------>err = sysv_make_empty(inode, dir);
<------>if (err)
<------><------>goto out_fail;
 
<------>err = sysv_add_link(dentry, inode);
<------>if (err)
<------><------>goto out_fail;
 
        d_instantiate(dentry, inode);
out:
<------>return err;
 
out_fail:
<------>inode_dec_link_count(inode);
<------>inode_dec_link_count(inode);
<------>iput(inode);
out_dir:
<------>inode_dec_link_count(dir);
<------>goto out;
}
 
static int sysv_unlink(struct inode * dir, struct dentry * dentry)
{
<------>struct inode * inode = d_inode(dentry);
<------>struct page * page;
<------>struct sysv_dir_entry * de;
<------>int err = -ENOENT;
 
<------>de = sysv_find_entry(dentry, &page);
<------>if (!de)
<------><------>goto out;
 
<------>err = sysv_delete_entry (de, page);
<------>if (err)
<------><------>goto out;
 
<------>inode->i_ctime = dir->i_ctime;
<------>inode_dec_link_count(inode);
out:
<------>return err;
}
 
static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
{
<------>struct inode *inode = d_inode(dentry);
<------>int err = -ENOTEMPTY;
 
<------>if (sysv_empty_dir(inode)) {
<------><------>err = sysv_unlink(dir, dentry);
<------><------>if (!err) {
<------><------><------>inode->i_size = 0;
<------><------><------>inode_dec_link_count(inode);
<------><------><------>inode_dec_link_count(dir);
<------><------>}
<------>}
<------>return err;
}
 
/*
 * Anybody can rename anything with this: the permission checks are left to the
 * higher-level routines.
 */
static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
<------><------>       struct inode * new_dir, struct dentry * new_dentry,
<------><------>       unsigned int flags)
{
<------>struct inode * old_inode = d_inode(old_dentry);
<------>struct inode * new_inode = d_inode(new_dentry);
<------>struct page * dir_page = NULL;
<------>struct sysv_dir_entry * dir_de = NULL;
<------>struct page * old_page;
<------>struct sysv_dir_entry * old_de;
<------>int err = -ENOENT;
 
<------>if (flags & ~RENAME_NOREPLACE)
<------><------>return -EINVAL;
 
<------>old_de = sysv_find_entry(old_dentry, &old_page);
<------>if (!old_de)
<------><------>goto out;
 
<------>if (S_ISDIR(old_inode->i_mode)) {
<------><------>err = -EIO;
<------><------>dir_de = sysv_dotdot(old_inode, &dir_page);
<------><------>if (!dir_de)
<------><------><------>goto out_old;
<------>}
 
<------>if (new_inode) {
<------><------>struct page * new_page;
<------><------>struct sysv_dir_entry * new_de;
 
<------><------>err = -ENOTEMPTY;
<------><------>if (dir_de && !sysv_empty_dir(new_inode))
<------><------><------>goto out_dir;
 
<------><------>err = -ENOENT;
<------><------>new_de = sysv_find_entry(new_dentry, &new_page);
<------><------>if (!new_de)
<------><------><------>goto out_dir;
<------><------>sysv_set_link(new_de, new_page, old_inode);
<------><------>new_inode->i_ctime = current_time(new_inode);
<------><------>if (dir_de)
<------><------><------>drop_nlink(new_inode);
<------><------>inode_dec_link_count(new_inode);
<------>} else {
<------><------>err = sysv_add_link(new_dentry, old_inode);
<------><------>if (err)
<------><------><------>goto out_dir;
<------><------>if (dir_de)
<------><------><------>inode_inc_link_count(new_dir);
<------>}
 
<------>sysv_delete_entry(old_de, old_page);
<------>mark_inode_dirty(old_inode);
 
<------>if (dir_de) {
<------><------>sysv_set_link(dir_de, dir_page, new_dir);
<------><------>inode_dec_link_count(old_dir);
<------>}
<------>return 0;
 
out_dir:
<------>if (dir_de) {
<------><------>kunmap(dir_page);
<------><------>put_page(dir_page);
<------>}
out_old:
<------>kunmap(old_page);
<------>put_page(old_page);
out:
<------>return err;
}
 
/*
 * directories can handle most operations...
 */
const struct inode_operations sysv_dir_inode_operations = {
<------>.create		= sysv_create,
<------>.lookup		= sysv_lookup,
<------>.link		= sysv_link,
<------>.unlink		= sysv_unlink,
<------>.symlink	= sysv_symlink,
<------>.mkdir		= sysv_mkdir,
<------>.rmdir		= sysv_rmdir,
<------>.mknod		= sysv_mknod,
<------>.rename		= sysv_rename,
<------>.getattr	= sysv_getattr,
};