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/*
* linux/fs/minix/namei.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/fs.h>
#include <linux/minix_fs.h>
#include <linux/pagemap.h>
static inline void inc_count(struct inode *inode)
{
inode->i_nlink++;
mark_inode_dirty(inode);
}
static inline void dec_count(struct inode *inode)
{
inode->i_nlink--;
mark_inode_dirty(inode);
}
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;
}
dec_count(inode);
iput(inode);
return err;
}
static int minix_hash(struct dentry *dentry, struct qstr *qstr)
{
unsigned long hash;
int i;
const unsigned char *name;
i = dentry->d_inode->i_sb->u.minix_sb.s_namelen;
if (i >= qstr->len)
return 0;
/* Truncate the name in place, avoids having to define a compare
function. */
qstr->len = i;
name = qstr->name;
hash = init_name_hash();
while (i--)
hash = partial_name_hash(*name++, hash);
qstr->hash = end_name_hash(hash);
return 0;
}
struct dentry_operations minix_dentry_operations = {
d_hash: minix_hash,
};
static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry)
{
struct inode * inode = NULL;
ino_t ino;
dentry->d_op = dir->i_sb->s_root->d_op;
if (dentry->d_name.len > dir->i_sb->u.minix_sb.s_namelen)
return ERR_PTR(-ENAMETOOLONG);
ino = minix_inode_by_name(dentry);
if (ino) {
inode = iget(dir->i_sb, ino);
if (!inode)
return ERR_PTR(-EACCES);
}
d_add(dentry, inode);
return NULL;
}
static int minix_mknod(struct inode * dir, struct dentry *dentry, int mode, int rdev)
{
int error;
struct inode * inode = minix_new_inode(dir, &error);
if (inode) {
inode->i_mode = mode;
minix_set_inode(inode, rdev);
mark_inode_dirty(inode);
error = add_nondir(dentry, inode);
}
return error;
}
static int minix_create(struct inode * dir, struct dentry *dentry, int mode)
{
return minix_mknod(dir, dentry, mode, 0);
}
static int minix_symlink(struct inode * dir, struct dentry *dentry,
const char * symname)
{
int err = -ENAMETOOLONG;
int i = strlen(symname)+1;
struct inode * inode;
if (i > dir->i_sb->s_blocksize)
goto out;
inode = minix_new_inode(dir, &err);
if (!inode)
goto out;
inode->i_mode = S_IFLNK | 0777;
minix_set_inode(inode, 0);
err = block_symlink(inode, symname, i);
if (err)
goto out_fail;
err = add_nondir(dentry, inode);
out:
return err;
out_fail:
dec_count(inode);
iput(inode);
goto out;
}
static int minix_link(struct dentry * old_dentry, struct inode * dir,
struct dentry *dentry)
{
struct inode *inode = old_dentry->d_inode;
if (S_ISDIR(inode->i_mode))
return -EPERM;
if (inode->i_nlink >= inode->i_sb->u.minix_sb.s_link_max)
return -EMLINK;
inode->i_ctime = CURRENT_TIME;
inc_count(inode);
atomic_inc(&inode->i_count);
return add_nondir(dentry, inode);
}
static int minix_mkdir(struct inode * dir, struct dentry *dentry, int mode)
{
struct inode * inode;
int err = -EMLINK;
if (dir->i_nlink >= dir->i_sb->u.minix_sb.s_link_max)
goto out;
inc_count(dir);
inode = minix_new_inode(dir, &err);
if (!inode)
goto out_dir;
inode->i_mode = S_IFDIR | mode;
if (dir->i_mode & S_ISGID)
inode->i_mode |= S_ISGID;
minix_set_inode(inode, 0);
inc_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:
dec_count(inode);
dec_count(inode);
iput(inode);
out_dir:
dec_count(dir);
goto out;
}
static int minix_unlink(struct inode * dir, struct dentry *dentry)
{
int err = -ENOENT;
struct inode * inode = dentry->d_inode;
struct page * page;
struct minix_dir_entry * de;
de = minix_find_entry(dentry, &page);
if (!de)
goto end_unlink;
err = minix_delete_entry(de, page);
if (err)
goto end_unlink;
inode->i_ctime = dir->i_ctime;
dec_count(inode);
end_unlink:
return err;
}
static int minix_rmdir(struct inode * dir, struct dentry *dentry)
{
struct inode * inode = dentry->d_inode;
int err = -ENOTEMPTY;
if (minix_empty_dir(inode)) {
err = minix_unlink(dir, dentry);
if (!err) {
dec_count(dir);
dec_count(inode);
}
}
return err;
}
static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
struct inode * new_dir, struct dentry *new_dentry)
{
struct minix_sb_info * info = &old_dir->i_sb->u.minix_sb;
struct inode * old_inode = old_dentry->d_inode;
struct inode * new_inode = new_dentry->d_inode;
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;
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;
inc_count(old_inode);
minix_set_link(new_de, new_page, old_inode);
new_inode->i_ctime = CURRENT_TIME;
if (dir_de)
new_inode->i_nlink--;
dec_count(new_inode);
} else {
if (dir_de) {
err = -EMLINK;
if (new_dir->i_nlink >= info->s_link_max)
goto out_dir;
}
inc_count(old_inode);
err = minix_add_link(new_dentry, old_inode);
if (err) {
dec_count(old_inode);
goto out_dir;
}
if (dir_de)
inc_count(new_dir);
}
minix_delete_entry(old_de, old_page);
dec_count(old_inode);
if (dir_de) {
minix_set_link(dir_de, dir_page, new_dir);
dec_count(old_dir);
}
return 0;
out_dir:
if (dir_de) {
kunmap(dir_page);
page_cache_release(dir_page);
}
out_old:
kunmap(old_page);
page_cache_release(old_page);
out:
return err;
}
/*
* directories can handle most operations...
*/
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,
};
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