linux/fs/adfs/dir.c
Linus Torvalds d2fbf4b6d5 Merge branch 'work.adfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull adfs updates from Al Viro:
 "More ADFS patches from Russell King"

* 'work.adfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs/adfs: add time stamp and file type helpers
  fs/adfs: super: limit idlen according to directory type
  fs/adfs: super: fix use-after-free bug
  fs/adfs: super: safely update options on remount
  fs/adfs: super: correct superblock flags
  fs/adfs: clean up indirect disc addresses and fragment IDs
  fs/adfs: clean up error message printing
  fs/adfs: use %pV for error messages
  fs/adfs: use format_version from disc_record
  fs/adfs: add helper to get filesystem size
  fs/adfs: add helper to get discrecord from map
  fs/adfs: correct disc record structure
2019-07-19 11:33:22 -07:00

280 lines
5.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/adfs/dir.c
*
* Copyright (C) 1999-2000 Russell King
*
* Common directory handling for ADFS
*/
#include "adfs.h"
/*
* For future. This should probably be per-directory.
*/
static DEFINE_RWLOCK(adfs_dir_lock);
void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj)
{
unsigned int dots, i;
/*
* RISC OS allows the use of '/' in directory entry names, so we need
* to fix these up. '/' is typically used for FAT compatibility to
* represent '.', so do the same conversion here. In any case, '.'
* will never be in a RISC OS name since it is used as the pathname
* separator. Handle the case where we may generate a '.' or '..'
* name, replacing the first character with '^' (the RISC OS "parent
* directory" character.)
*/
for (i = dots = 0; i < obj->name_len; i++)
if (obj->name[i] == '/') {
obj->name[i] = '.';
dots++;
}
if (obj->name_len <= 2 && dots == obj->name_len)
obj->name[0] = '^';
/*
* If the object is a file, and the user requested the ,xyz hex
* filetype suffix to the name, check the filetype and append.
*/
if (!(obj->attr & ADFS_NDA_DIRECTORY) && ADFS_SB(dir->sb)->s_ftsuffix) {
u16 filetype = adfs_filetype(obj->loadaddr);
if (filetype != ADFS_FILETYPE_NONE) {
obj->name[obj->name_len++] = ',';
obj->name[obj->name_len++] = hex_asc_lo(filetype >> 8);
obj->name[obj->name_len++] = hex_asc_lo(filetype >> 4);
obj->name[obj->name_len++] = hex_asc_lo(filetype >> 0);
}
}
}
static int
adfs_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct super_block *sb = inode->i_sb;
const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
struct object_info obj;
struct adfs_dir dir;
int ret = 0;
if (ctx->pos >> 32)
return 0;
ret = ops->read(sb, inode->i_ino, inode->i_size, &dir);
if (ret)
return ret;
if (ctx->pos == 0) {
if (!dir_emit_dot(file, ctx))
goto free_out;
ctx->pos = 1;
}
if (ctx->pos == 1) {
if (!dir_emit(ctx, "..", 2, dir.parent_id, DT_DIR))
goto free_out;
ctx->pos = 2;
}
read_lock(&adfs_dir_lock);
ret = ops->setpos(&dir, ctx->pos - 2);
if (ret)
goto unlock_out;
while (ops->getnext(&dir, &obj) == 0) {
if (!dir_emit(ctx, obj.name, obj.name_len,
obj.indaddr, DT_UNKNOWN))
break;
ctx->pos++;
}
unlock_out:
read_unlock(&adfs_dir_lock);
free_out:
ops->free(&dir);
return ret;
}
int
adfs_dir_update(struct super_block *sb, struct object_info *obj, int wait)
{
int ret = -EINVAL;
#ifdef CONFIG_ADFS_FS_RW
const 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->indaddr, 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);
if (wait) {
int err = ops->sync(&dir);
if (!ret)
ret = err;
}
ops->free(&dir);
out:
#endif
return ret;
}
static unsigned char adfs_tolower(unsigned char c)
{
if (c >= 'A' && c <= 'Z')
c += 'a' - 'A';
return c;
}
static int __adfs_compare(const unsigned char *qstr, u32 qlen,
const char *str, u32 len)
{
u32 i;
if (qlen != len)
return 1;
for (i = 0; i < qlen; i++)
if (adfs_tolower(qstr[i]) != adfs_tolower(str[i]))
return 1;
return 0;
}
static int adfs_dir_lookup_byname(struct inode *inode, const struct qstr *qstr,
struct object_info *obj)
{
struct super_block *sb = inode->i_sb;
const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
const unsigned char *name;
struct adfs_dir dir;
u32 name_len;
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! (%06x but got %06x)\n",
ADFS_I(inode)->parent_id, dir.parent_id);
ret = -EIO;
goto free_out;
}
obj->parent_id = inode->i_ino;
read_lock(&adfs_dir_lock);
ret = ops->setpos(&dir, 0);
if (ret)
goto unlock_out;
ret = -ENOENT;
name = qstr->name;
name_len = qstr->len;
while (ops->getnext(&dir, obj) == 0) {
if (!__adfs_compare(name, name_len, obj->name, obj->name_len)) {
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,
.iterate = adfs_readdir,
.fsync = generic_file_fsync,
};
static int
adfs_hash(const struct dentry *parent, struct qstr *qstr)
{
const unsigned char *name;
unsigned long hash;
u32 len;
if (qstr->len > ADFS_SB(parent->d_sb)->s_namelen)
return -ENAMETOOLONG;
len = qstr->len;
name = qstr->name;
hash = init_name_hash(parent);
while (len--)
hash = partial_name_hash(adfs_tolower(*name++), 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(const struct dentry *dentry, unsigned int len,
const char *str, const struct qstr *qstr)
{
return __adfs_compare(qstr->name, qstr->len, str, len);
}
const 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, unsigned int flags)
{
struct inode *inode = NULL;
struct object_info obj;
int error;
error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
if (error == 0) {
/*
* This only returns NULL if get_empty_inode
* fails.
*/
inode = adfs_iget(dir->i_sb, &obj);
if (!inode)
inode = ERR_PTR(-EACCES);
} else if (error != -ENOENT) {
inode = ERR_PTR(error);
}
return d_splice_alias(inode, dentry);
}
/*
* directories can handle most operations...
*/
const struct inode_operations adfs_dir_inode_operations = {
.lookup = adfs_lookup,
.setattr = adfs_notify_change,
};