linux-IllusionX/fs/adfs/dir.c
Arjan van de Ven 754661f143 [PATCH] mark struct inode_operations const 1
Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:46 -08:00

301 lines
5.7 KiB
C

/*
* 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,
.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,
};