original development tree for Linux kernel GTP module; now long in mainline.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

302 lines
5.8 KiB

/*
* linux/fs/adfs/dir.c
*
* Copyright (C) 1999-2000 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Common directory handling for ADFS
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/adfs_fs.h>
#include <linux/time.h>
#include <linux/stat.h>
#include <linux/spinlock.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h> /* for file_fsync() */
#include "adfs.h"
/*
* For future. This should probably be per-directory.
*/
static DEFINE_RWLOCK(adfs_dir_lock);
static int
adfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct super_block *sb = inode->i_sb;
struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
struct object_info obj;
struct adfs_dir dir;
int ret = 0;
lock_kernel();
if (filp->f_pos >> 32)
goto out;
ret = ops->read(sb, inode->i_ino, inode->i_size, &dir);
if (ret)
goto out;
switch ((unsigned long)filp->f_pos) {
case 0:
if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
goto free_out;
filp->f_pos += 1;
case 1:
if (filldir(dirent, "..", 2, 1, dir.parent_id, DT_DIR) < 0)
goto free_out;
filp->f_pos += 1;
default:
break;
}
read_lock(&adfs_dir_lock);
ret = ops->setpos(&dir, filp->f_pos - 2);
if (ret)
goto unlock_out;
while (ops->getnext(&dir, &obj) == 0) {
if (filldir(dirent, obj.name, obj.name_len,
filp->f_pos, obj.file_id, DT_UNKNOWN) < 0)
goto unlock_out;
filp->f_pos += 1;
}
unlock_out:
read_unlock(&adfs_dir_lock);
free_out:
ops->free(&dir);
out:
unlock_kernel();
return ret;
}
int
adfs_dir_update(struct super_block *sb, struct object_info *obj)
{
int ret = -EINVAL;
#ifdef CONFIG_ADFS_FS_RW
struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
struct adfs_dir dir;
printk(KERN_INFO "adfs_dir_update: object %06X in dir %06X\n",
obj->file_id, obj->parent_id);
if (!ops->update) {
ret = -EINVAL;
goto out;
}
ret = ops->read(sb, obj->parent_id, 0, &dir);
if (ret)
goto out;
write_lock(&adfs_dir_lock);
ret = ops->update(&dir, obj);
write_unlock(&adfs_dir_lock);
ops->free(&dir);
out:
#endif
return ret;
}
static int
adfs_match(struct qstr *name, struct object_info *obj)
{
int i;
if (name->len != obj->name_len)
return 0;
for (i = 0; i < name->len; i++) {
char c1, c2;
c1 = name->name[i];
c2 = obj->name[i];
if (c1 >= 'A' && c1 <= 'Z')
c1 += 'a' - 'A';
if (c2 >= 'A' && c2 <= 'Z')
c2 += 'a' - 'A';
if (c1 != c2)
return 0;
}
return 1;
}
static int
adfs_dir_lookup_byname(struct inode *inode, struct qstr *name, struct object_info *obj)
{
struct super_block *sb = inode->i_sb;
struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
struct adfs_dir dir;
int ret;
ret = ops->read(sb, inode->i_ino, inode->i_size, &dir);
if (ret)
goto out;
if (ADFS_I(inode)->parent_id != dir.parent_id) {
adfs_error(sb, "parent directory changed under me! (%lx but got %lx)\n",
ADFS_I(inode)->parent_id, dir.parent_id);
ret = -EIO;
goto free_out;
}
obj->parent_id = inode->i_ino;
/*
* '.' is handled by reserved_lookup() in fs/namei.c
*/
if (name->len == 2 && name->name[0] == '.' && name->name[1] == '.') {
/*
* Currently unable to fill in the rest of 'obj',
* but this is better than nothing. We need to
* ascend one level to find it's parent.
*/
obj->name_len = 0;
obj->file_id = obj->parent_id;
goto free_out;
}
read_lock(&adfs_dir_lock);
ret = ops->setpos(&dir, 0);
if (ret)
goto unlock_out;
ret = -ENOENT;
while (ops->getnext(&dir, obj) == 0) {
if (adfs_match(name, obj)) {
ret = 0;
break;
}
}
unlock_out:
read_unlock(&adfs_dir_lock);
free_out:
ops->free(&dir);
out:
return ret;
}
const struct file_operations adfs_dir_operations = {
.read = generic_read_dir,
.llseek = generic_file_llseek,
.readdir = adfs_readdir,
.fsync = file_fsync,
};
static int
adfs_hash(struct dentry *parent, struct qstr *qstr)
{
const unsigned int name_len = ADFS_SB(parent->d_sb)->s_namelen;
const unsigned char *name;
unsigned long hash;
int i;
if (qstr->len < name_len)
return 0;
/*
* Truncate the name in place, avoids
* having to define a compare function.
*/
qstr->len = i = name_len;
name = qstr->name;
hash = init_name_hash();
while (i--) {
char c;
c = *name++;
if (c >= 'A' && c <= 'Z')
c += 'a' - 'A';
hash = partial_name_hash(c, hash);
}
qstr->hash = end_name_hash(hash);
return 0;
}
/*
* Compare two names, taking note of the name length
* requirements of the underlying filesystem.
*/
static int
adfs_compare(struct dentry *parent, struct qstr *entry, struct qstr *name)
{
int i;
if (entry->len != name->len)
return 1;
for (i = 0; i < name->len; i++) {
char a, b;
a = entry->name[i];
b = name->name[i];
if (a >= 'A' && a <= 'Z')
a += 'a' - 'A';
if (b >= 'A' && b <= 'Z')
b += 'a' - 'A';
if (a != b)
return 1;
}
return 0;
}
struct dentry_operations adfs_dentry_operations = {
.d_hash = adfs_hash,
.d_compare = adfs_compare,
};
static struct dentry *
adfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = NULL;
struct object_info obj;
int error;
dentry->d_op = &adfs_dentry_operations;
lock_kernel();
error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
if (error == 0) {
error = -EACCES;
/*
* This only returns NULL if get_empty_inode
* fails.
*/
inode = adfs_iget(dir->i_sb, &obj);
if (inode)
error = 0;
}
unlock_kernel();
d_add(dentry, inode);
return ERR_PTR(error);
}
/*
* directories can handle most operations...
*/
const struct inode_operations adfs_dir_inode_operations = {
.lookup = adfs_lookup,
.setattr = adfs_notify_change,
};