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/*
* linux/fs/hfs/dir_dbl.c
*
* Copyright (C) 1995-1997 Paul H. Hargrove
* This file may be distributed under the terms of the GNU General Public License.
*
* This file contains the inode_operations and file_operations
* structures for HFS directories.
*
* Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
*
* "XXX" in a comment is a note to myself to consider changing something.
*
* In function preconditions the term "valid" applied to a pointer to
* a structure means that the pointer is non-NULL and the structure it
* points to has all fields initialized to consistent values.
*/
#include "hfs.h"
#include <linux/hfs_fs_sb.h>
#include <linux/hfs_fs_i.h>
#include <linux/hfs_fs.h>
/*================ Forward declarations ================*/
static struct dentry *dbl_lookup(struct inode *, struct dentry *);
static int dbl_readdir(struct file *, void *, filldir_t);
static int dbl_create(struct inode *, struct dentry *, int);
static int dbl_mkdir(struct inode *, struct dentry *, int);
static int dbl_unlink(struct inode *, struct dentry *);
static int dbl_rmdir(struct inode *, struct dentry *);
static int dbl_rename(struct inode *, struct dentry *,
struct inode *, struct dentry *);
/*================ Global variables ================*/
#define DOT_LEN 1
#define DOT_DOT_LEN 2
#define ROOTINFO_LEN 8
#define PCNT_ROOTINFO_LEN 9
const struct hfs_name hfs_dbl_reserved1[] = {
{DOT_LEN, "."},
{DOT_DOT_LEN, ".."},
{0, ""},
};
const struct hfs_name hfs_dbl_reserved2[] = {
{ROOTINFO_LEN, "RootInfo"},
{PCNT_ROOTINFO_LEN, "%RootInfo"},
{0, ""},
};
#define DOT (&hfs_dbl_reserved1[0])
#define DOT_DOT (&hfs_dbl_reserved1[1])
#define ROOTINFO (&hfs_dbl_reserved2[0])
#define PCNT_ROOTINFO (&hfs_dbl_reserved2[1])
struct file_operations hfs_dbl_dir_operations = {
read: generic_read_dir,
readdir: dbl_readdir,
fsync: file_fsync,
};
struct inode_operations hfs_dbl_dir_inode_operations = {
create: dbl_create,
lookup: dbl_lookup,
unlink: dbl_unlink,
mkdir: dbl_mkdir,
rmdir: dbl_rmdir,
rename: dbl_rename,
setattr: hfs_notify_change,
};
/*================ File-local functions ================*/
/*
* is_hdr()
*/
static int is_hdr(struct inode *dir, const char *name, int len)
{
int retval = 0;
if (name[0] == '%') {
struct hfs_cat_entry *entry = HFS_I(dir)->entry;
struct hfs_cat_entry *victim;
struct hfs_name cname;
struct hfs_cat_key key;
hfs_nameout(dir, &cname, name+1, len-1);
hfs_cat_build_key(entry->cnid, &cname, &key);
if ((victim = hfs_cat_get(entry->mdb, &key))) {
hfs_cat_put(victim);
retval = 1;
}
}
return retval;
}
/*
* dbl_lookup()
*
* This is the lookup() entry in the inode_operations structure for
* HFS directories in the AppleDouble scheme. The purpose is to
* generate the inode corresponding to an entry in a directory, given
* the inode for the directory and the name (and its length) of the
* entry.
*/
static struct dentry *dbl_lookup(struct inode * dir, struct dentry *dentry)
{
struct hfs_name cname;
struct hfs_cat_entry *entry;
struct hfs_cat_key key;
struct inode *inode = NULL;
dentry->d_op = &hfs_dentry_operations;
entry = HFS_I(dir)->entry;
/* Perform name-mangling */
hfs_nameout(dir, &cname, dentry->d_name.name, dentry->d_name.len);
/* no need to check for "." or ".." */
/* Check for "%RootInfo" if in the root directory. */
if ((entry->cnid == htonl(HFS_ROOT_CNID)) &&
hfs_streq(cname.Name, cname.Len,
PCNT_ROOTINFO->Name, PCNT_ROOTINFO_LEN)) {
++entry->count; /* __hfs_iget() eats one */
inode = hfs_iget(entry, HFS_DBL_HDR, dentry);
goto done;
}
/* Do an hfs_iget() on the mangled name. */
hfs_cat_build_key(entry->cnid, &cname, &key);
inode = hfs_iget(hfs_cat_get(entry->mdb, &key), HFS_DBL_NORM, dentry);
/* Try as a header if not found and first character is '%' */
if (!inode && (dentry->d_name.name[0] == '%')) {
hfs_nameout(dir, &cname, dentry->d_name.name+1,
dentry->d_name.len-1);
hfs_cat_build_key(entry->cnid, &cname, &key);
inode = hfs_iget(hfs_cat_get(entry->mdb, &key),
HFS_DBL_HDR, dentry);
}
done:
d_add(dentry, inode);
return NULL;
}
/*
* dbl_readdir()
*
* This is the readdir() entry in the file_operations structure for
* HFS directories in the AppleDouble scheme. The purpose is to
* enumerate the entries in a directory, given the inode of the
* directory and a (struct file *), the 'f_pos' field of which
* indicates the location in the directory. The (struct file *) is
* updated so that the next call with the same 'dir' and 'filp'
* arguments will produce the next directory entry. The entries are
* returned in 'dirent', which is "filled-in" by calling filldir().
* This allows the same readdir() function be used for different
* formats. We try to read in as many entries as we can before
* filldir() refuses to take any more.
*
* XXX: In the future it may be a good idea to consider not generating
* metadata files for covered directories since the data doesn't
* correspond to the mounted directory. However this requires an
* iget() for every directory which could be considered an excessive
* amount of overhead. Since the inode for a mount point is always
* in-core this is another argument for a call to get an inode if it
* is in-core or NULL if it is not.
*/
static int dbl_readdir(struct file * filp,
void * dirent, filldir_t filldir)
{
struct hfs_brec brec;
struct hfs_cat_entry *entry;
struct inode *dir = filp->f_dentry->d_inode;
entry = HFS_I(dir)->entry;
if (filp->f_pos == 0) {
/* Entry 0 is for "." */
if (filldir(dirent, DOT->Name, DOT_LEN, 0, dir->i_ino,
DT_DIR)) {
return 0;
}
filp->f_pos = 1;
}
if (filp->f_pos == 1) {
/* Entry 1 is for ".." */
if (filldir(dirent, DOT_DOT->Name, DOT_DOT_LEN, 1,
hfs_get_hl(entry->key.ParID), DT_DIR)) {
return 0;
}
filp->f_pos = 2;
}
if (filp->f_pos < (dir->i_size - 1)) {
hfs_u32 cnid;
hfs_u8 type;
if (hfs_cat_open(entry, &brec) ||
hfs_cat_next(entry, &brec, (filp->f_pos - 1) >> 1,
&cnid, &type)) {
return 0;
}
while (filp->f_pos < (dir->i_size - 1)) {
unsigned char tmp_name[HFS_NAMEMAX + 1];
ino_t ino;
int is_hdr = (filp->f_pos & 1);
unsigned int len;
if (is_hdr) {
ino = ntohl(cnid) | HFS_DBL_HDR;
tmp_name[0] = '%';
len = 1 + hfs_namein(dir, tmp_name + 1,
&((struct hfs_cat_key *)brec.key)->CName);
} else {
if (hfs_cat_next(entry, &brec, 1,
&cnid, &type)) {
return 0;
}
ino = ntohl(cnid);
len = hfs_namein(dir, tmp_name,
&((struct hfs_cat_key *)brec.key)->CName);
}
if (filldir(dirent, tmp_name, len, filp->f_pos, ino,
DT_UNKNOWN)) {
hfs_cat_close(entry, &brec);
return 0;
}
++filp->f_pos;
}
hfs_cat_close(entry, &brec);
}
if (filp->f_pos == (dir->i_size - 1)) {
if (entry->cnid == htonl(HFS_ROOT_CNID)) {
/* In root dir last entry is for "%RootInfo" */
if (filldir(dirent, PCNT_ROOTINFO->Name,
PCNT_ROOTINFO_LEN, filp->f_pos,
ntohl(entry->cnid) | HFS_DBL_HDR,
DT_UNKNOWN)) {
return 0;
}
}
++filp->f_pos;
}
return 0;
}
/*
* dbl_create()
*
* This is the create() entry in the inode_operations structure for
* AppleDouble directories. The purpose is to create a new file in
* a directory and return a corresponding inode, given the inode for
* the directory and the name (and its length) of the new file.
*/
static int dbl_create(struct inode * dir, struct dentry *dentry,
int mode)
{
int error;
if (is_hdr(dir, dentry->d_name.name, dentry->d_name.len)) {
error = -EEXIST;
} else {
error = hfs_create(dir, dentry, mode);
}
return error;
}
/*
* dbl_mkdir()
*
* This is the mkdir() entry in the inode_operations structure for
* AppleDouble directories. The purpose is to create a new directory
* in a directory, given the inode for the parent directory and the
* name (and its length) of the new directory.
*/
static int dbl_mkdir(struct inode * parent, struct dentry *dentry,
int mode)
{
int error;
if (is_hdr(parent, dentry->d_name.name, dentry->d_name.len)) {
error = -EEXIST;
} else {
error = hfs_mkdir(parent, dentry, mode);
}
return error;
}
/*
* dbl_unlink()
*
* This is the unlink() entry in the inode_operations structure for
* AppleDouble directories. The purpose is to delete an existing
* file, given the inode for the parent directory and the name
* (and its length) of the existing file.
*/
static int dbl_unlink(struct inode * dir, struct dentry *dentry)
{
int error;
error = hfs_unlink(dir, dentry);
if ((error == -ENOENT) && is_hdr(dir, dentry->d_name.name,
dentry->d_name.len)) {
error = -EPERM;
}
return error;
}
/*
* dbl_rmdir()
*
* This is the rmdir() entry in the inode_operations structure for
* AppleDouble directories. The purpose is to delete an existing
* directory, given the inode for the parent directory and the name
* (and its length) of the existing directory.
*/
static int dbl_rmdir(struct inode * parent, struct dentry *dentry)
{
int error;
error = hfs_rmdir(parent, dentry);
if ((error == -ENOENT) && is_hdr(parent, dentry->d_name.name,
dentry->d_name.len)) {
error = -ENOTDIR;
}
return error;
}
/*
* dbl_rename()
*
* This is the rename() entry in the inode_operations structure for
* AppleDouble directories. The purpose is to rename an existing
* file or directory, given the inode for the current directory and
* the name (and its length) of the existing file/directory and the
* inode for the new directory and the name (and its length) of the
* new file/directory.
*
* XXX: how do we handle must_be_dir?
*/
static int dbl_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int error;
if (is_hdr(new_dir, new_dentry->d_name.name,
new_dentry->d_name.len)) {
error = -EPERM;
} else {
error = hfs_rename(old_dir, old_dentry,
new_dir, new_dentry);
if ((error == -ENOENT) /*&& !must_be_dir*/ &&
is_hdr(old_dir, old_dentry->d_name.name,
old_dentry->d_name.len)) {
error = -EPERM;
}
}
return error;
}
/* due to the dcache caching negative dentries for non-existent files,
* we need to drop those entries when a file silently gets created.
* as far as i can tell, the calls that need to do this are the file
* related calls (create, rename, and mknod). the directory calls
* should be immune. the relevant calls in dir.c call drop_dentry
* upon successful completion. */
void hfs_dbl_drop_dentry(struct dentry *dentry, const ino_t type)
{
unsigned char tmp_name[HFS_NAMEMAX + 1];
struct dentry *de = NULL;
switch (type) {
case HFS_DBL_HDR:
/* given %name, look for name. i don't think this happens. */
de = hfs_lookup_dentry(dentry->d_parent,
dentry->d_name.name + 1, dentry->d_name.len - 1);
break;
case HFS_DBL_DATA:
/* given name, look for %name */
tmp_name[0] = '%';
strncpy(tmp_name + 1, dentry->d_name.name, HFS_NAMELEN - 1);
de = hfs_lookup_dentry(dentry->d_parent,
tmp_name, dentry->d_name.len + 1);
}
if (de) {
if (!de->d_inode)
d_drop(de);
dput(de);
}
}
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