linux/fs/minix/namei.c
Linus Torvalds 397aa6b63f Merge branch 'work.minix' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull minix updates from Al Viro:
 "Assorted fixes - mostly Christoph's"

* 'work.minix' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  minix_rename(): minix_delete_entry() might fail
  minix: don't flush page immediately for DIRSYNC directories
  minix: fix error handling in minix_set_link
  minix: fix error handling in minix_delete_entry
  minix: move releasing pages into unlink and rename
  minix: make minix_new_inode() return error as ERR_PTR(-E...)
2023-02-24 19:01:15 -08:00

272 lines
5.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/minix/namei.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include "minix.h"
static int add_nondir(struct dentry *dentry, struct inode *inode)
{
int err = minix_add_link(dentry, inode);
if (!err) {
d_instantiate(dentry, inode);
return 0;
}
inode_dec_link_count(inode);
iput(inode);
return err;
}
static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
{
struct inode * inode = NULL;
ino_t ino;
if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen)
return ERR_PTR(-ENAMETOOLONG);
ino = minix_inode_by_name(dentry);
if (ino)
inode = minix_iget(dir->i_sb, ino);
return d_splice_alias(inode, dentry);
}
static int minix_mknod(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t rdev)
{
struct inode *inode;
if (!old_valid_dev(rdev))
return -EINVAL;
inode = minix_new_inode(dir, mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
minix_set_inode(inode, rdev);
mark_inode_dirty(inode);
return add_nondir(dentry, inode);
}
static int minix_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
struct file *file, umode_t mode)
{
struct inode *inode = minix_new_inode(dir, mode);
if (IS_ERR(inode))
return finish_open_simple(file, PTR_ERR(inode));
minix_set_inode(inode, 0);
mark_inode_dirty(inode);
d_tmpfile(file, inode);
return finish_open_simple(file, 0);
}
static int minix_create(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
return minix_mknod(&nop_mnt_idmap, dir, dentry, mode, 0);
}
static int minix_symlink(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, const char *symname)
{
int i = strlen(symname)+1;
struct inode * inode;
int err;
if (i > dir->i_sb->s_blocksize)
return -ENAMETOOLONG;
inode = minix_new_inode(dir, S_IFLNK | 0777);
if (IS_ERR(inode))
return PTR_ERR(inode);
minix_set_inode(inode, 0);
err = page_symlink(inode, symname, i);
if (unlikely(err)) {
inode_dec_link_count(inode);
iput(inode);
return err;
}
return add_nondir(dentry, inode);
}
static int minix_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 minix_mkdir(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
struct inode * inode;
int err;
inode = minix_new_inode(dir, S_IFDIR | mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode_inc_link_count(dir);
minix_set_inode(inode, 0);
inode_inc_link_count(inode);
err = minix_make_empty(inode, dir);
if (err)
goto out_fail;
err = minix_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);
inode_dec_link_count(dir);
goto out;
}
static int minix_unlink(struct inode * dir, struct dentry *dentry)
{
struct inode * inode = d_inode(dentry);
struct page * page;
struct minix_dir_entry * de;
int err;
de = minix_find_entry(dentry, &page);
if (!de)
return -ENOENT;
err = minix_delete_entry(de, page);
kunmap(page);
put_page(page);
if (err)
return err;
inode->i_ctime = dir->i_ctime;
inode_dec_link_count(inode);
return 0;
}
static int minix_rmdir(struct inode * dir, struct dentry *dentry)
{
struct inode * inode = d_inode(dentry);
int err = -ENOTEMPTY;
if (minix_empty_dir(inode)) {
err = minix_unlink(dir, dentry);
if (!err) {
inode_dec_link_count(dir);
inode_dec_link_count(inode);
}
}
return err;
}
static int minix_rename(struct mnt_idmap *idmap,
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 minix_dir_entry * dir_de = NULL;
struct page * old_page;
struct minix_dir_entry * old_de;
int err = -ENOENT;
if (flags & ~RENAME_NOREPLACE)
return -EINVAL;
old_de = minix_find_entry(old_dentry, &old_page);
if (!old_de)
goto out;
if (S_ISDIR(old_inode->i_mode)) {
err = -EIO;
dir_de = minix_dotdot(old_inode, &dir_page);
if (!dir_de)
goto out_old;
}
if (new_inode) {
struct page * new_page;
struct minix_dir_entry * new_de;
err = -ENOTEMPTY;
if (dir_de && !minix_empty_dir(new_inode))
goto out_dir;
err = -ENOENT;
new_de = minix_find_entry(new_dentry, &new_page);
if (!new_de)
goto out_dir;
err = minix_set_link(new_de, new_page, old_inode);
kunmap(new_page);
put_page(new_page);
if (err)
goto out_dir;
new_inode->i_ctime = current_time(new_inode);
if (dir_de)
drop_nlink(new_inode);
inode_dec_link_count(new_inode);
} else {
err = minix_add_link(new_dentry, old_inode);
if (err)
goto out_dir;
if (dir_de)
inode_inc_link_count(new_dir);
}
err = minix_delete_entry(old_de, old_page);
if (err)
goto out_dir;
mark_inode_dirty(old_inode);
if (dir_de) {
err = minix_set_link(dir_de, dir_page, new_dir);
if (!err)
inode_dec_link_count(old_dir);
}
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 minix_dir_inode_operations = {
.create = minix_create,
.lookup = minix_lookup,
.link = minix_link,
.unlink = minix_unlink,
.symlink = minix_symlink,
.mkdir = minix_mkdir,
.rmdir = minix_rmdir,
.mknod = minix_mknod,
.rename = minix_rename,
.getattr = minix_getattr,
.tmpfile = minix_tmpfile,
};