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/*
* 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 under the CAP scheme.
*
* Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
*
* The source code distribution of the Columbia AppleTalk Package for
* UNIX, version 6.0, (CAP) was used as a specification of the
* location and format of files used by CAP's Aufs. No code from CAP
* appears in hfs_fs. hfs_fs is not a work ``derived'' from CAP in
* the sense of intellectual property law.
*
* "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 *cap_lookup(struct inode *, struct dentry *);
static int cap_readdir(struct file *, void *, filldir_t);
/*================ Global variables ================*/
#define DOT_LEN 1
#define DOT_DOT_LEN 2
#define DOT_RESOURCE_LEN 9
#define DOT_FINDERINFO_LEN 11
#define DOT_ROOTINFO_LEN 9
const struct hfs_name hfs_cap_reserved1[] = {
{DOT_LEN, "."},
{DOT_DOT_LEN, ".."},
{DOT_RESOURCE_LEN, ".resource"},
{DOT_FINDERINFO_LEN, ".finderinfo"},
{0, ""},
};
const struct hfs_name hfs_cap_reserved2[] = {
{DOT_ROOTINFO_LEN, ".rootinfo"},
{0, ""},
};
#define DOT (&hfs_cap_reserved1[0])
#define DOT_DOT (&hfs_cap_reserved1[1])
#define DOT_RESOURCE (&hfs_cap_reserved1[2])
#define DOT_FINDERINFO (&hfs_cap_reserved1[3])
#define DOT_ROOTINFO (&hfs_cap_reserved2[0])
struct file_operations hfs_cap_dir_operations = {
read: generic_read_dir,
readdir: cap_readdir,
fsync: file_fsync,
};
struct inode_operations hfs_cap_ndir_inode_operations = {
create: hfs_create,
lookup: cap_lookup,
unlink: hfs_unlink,
mkdir: hfs_mkdir,
rmdir: hfs_rmdir,
rename: hfs_rename,
setattr: hfs_notify_change,
};
struct inode_operations hfs_cap_fdir_inode_operations = {
lookup: cap_lookup,
setattr: hfs_notify_change,
};
struct inode_operations hfs_cap_rdir_inode_operations = {
create: hfs_create,
lookup: cap_lookup,
setattr: hfs_notify_change,
};
/*================ File-local functions ================*/
/*
* cap_lookup()
*
* This is the lookup() entry in the inode_operations structure for
* HFS directories in the CAP 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 *cap_lookup(struct inode * dir, struct dentry *dentry)
{
ino_t dtype;
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;
dtype = HFS_ITYPE(dir->i_ino);
/* Perform name-mangling */
hfs_nameout(dir, &cname, dentry->d_name.name,
dentry->d_name.len);
/* no need to check for "." or ".." */
/* Check for special directories if in a normal directory.
Note that cap_dupdir() does an iput(dir). */
if (dtype==HFS_CAP_NDIR) {
/* Check for ".resource", ".finderinfo" and ".rootinfo" */
if (hfs_streq(cname.Name, cname.Len,
DOT_RESOURCE->Name, DOT_RESOURCE_LEN)) {
++entry->count; /* __hfs_iget() eats one */
inode = hfs_iget(entry, HFS_CAP_RDIR, dentry);
goto done;
} else if (hfs_streq(cname.Name, cname.Len,
DOT_FINDERINFO->Name,
DOT_FINDERINFO_LEN)) {
++entry->count; /* __hfs_iget() eats one */
inode = hfs_iget(entry, HFS_CAP_FDIR, dentry);
goto done;
} else if ((entry->cnid == htonl(HFS_ROOT_CNID)) &&
hfs_streq(cname.Name, cname.Len,
DOT_ROOTINFO->Name, DOT_ROOTINFO_LEN)) {
++entry->count; /* __hfs_iget() eats one */
inode = hfs_iget(entry, HFS_CAP_FNDR, 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_I(dir)->file_type, dentry);
/* Don't return a resource fork for a directory */
if (inode && (dtype == HFS_CAP_RDIR) &&
(HFS_I(inode)->entry->type == HFS_CDR_DIR)) {
iput(inode); /* this does an hfs_cat_put */
inode = NULL;
}
done:
d_add(dentry, inode);
return NULL;
}
/*
* cap_readdir()
*
* This is the readdir() entry in the file_operations structure for
* HFS directories in the CAP 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 dirent 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 cap_readdir(struct file * filp,
void * dirent, filldir_t filldir)
{
ino_t type;
int skip_dirs;
struct hfs_brec brec;
struct hfs_cat_entry *entry;
struct inode *dir = filp->f_dentry->d_inode;
entry = HFS_I(dir)->entry;
type = HFS_ITYPE(dir->i_ino);
skip_dirs = (type == HFS_CAP_RDIR);
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 ".." */
hfs_u32 cnid;
if (type == HFS_CAP_NDIR) {
cnid = hfs_get_nl(entry->key.ParID);
} else {
cnid = entry->cnid;
}
if (filldir(dirent, DOT_DOT->Name,
DOT_DOT_LEN, 1, ntohl(cnid), DT_DIR)) {
return 0;
}
filp->f_pos = 2;
}
if (filp->f_pos < (dir->i_size - 3)) {
hfs_u32 cnid;
hfs_u8 type;
if (hfs_cat_open(entry, &brec) ||
hfs_cat_next(entry, &brec, filp->f_pos - 2, &cnid, &type)) {
return 0;
}
while (filp->f_pos < (dir->i_size - 3)) {
if (hfs_cat_next(entry, &brec, 1, &cnid, &type)) {
return 0;
}
if (!skip_dirs || (type != HFS_CDR_DIR)) {
ino_t ino;
unsigned int len;
unsigned char tmp_name[HFS_NAMEMAX];
ino = ntohl(cnid) | HFS_I(dir)->file_type;
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 - 3)) {
if ((entry->cnid == htonl(HFS_ROOT_CNID)) &&
(type == HFS_CAP_NDIR)) {
/* In root dir last-2 entry is for ".rootinfo" */
if (filldir(dirent, DOT_ROOTINFO->Name,
DOT_ROOTINFO_LEN, filp->f_pos,
ntohl(entry->cnid) | HFS_CAP_FNDR,
DT_UNKNOWN)) {
return 0;
}
}
++filp->f_pos;
}
if (filp->f_pos == (dir->i_size - 2)) {
if (type == HFS_CAP_NDIR) {
/* In normal dirs last-1 entry is for ".finderinfo" */
if (filldir(dirent, DOT_FINDERINFO->Name,
DOT_FINDERINFO_LEN, filp->f_pos,
ntohl(entry->cnid) | HFS_CAP_FDIR,
DT_UNKNOWN)) {
return 0;
}
}
++filp->f_pos;
}
if (filp->f_pos == (dir->i_size - 1)) {
if (type == HFS_CAP_NDIR) {
/* In normal dirs last entry is for ".resource" */
if (filldir(dirent, DOT_RESOURCE->Name,
DOT_RESOURCE_LEN, filp->f_pos,
ntohl(entry->cnid) | HFS_CAP_RDIR,
DT_UNKNOWN)) {
return 0;
}
}
++filp->f_pos;
}
return 0;
}
/* 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_cap_drop_dentry(struct dentry *dentry, const ino_t type)
{
if (type == HFS_CAP_DATA) { /* given name */
hfs_drop_special(dentry->d_parent, DOT_FINDERINFO, dentry);
hfs_drop_special(dentry->d_parent, DOT_RESOURCE, dentry);
} else {
struct dentry *de;
/* given {.resource,.finderinfo}/name, look for name */
if ((de = hfs_lookup_dentry(dentry->d_parent->d_parent,
dentry->d_name.name, dentry->d_name.len))) {
if (!de->d_inode)
d_drop(de);
dput(de);
}
switch (type) {
case HFS_CAP_RSRC: /* given .resource/name */
/* look for .finderinfo/name */
hfs_drop_special(dentry->d_parent->d_parent, DOT_FINDERINFO,
dentry);
break;
case HFS_CAP_FNDR: /* given .finderinfo/name. i don't this
* happens. */
/* look for .resource/name */
hfs_drop_special(dentry->d_parent->d_parent, DOT_RESOURCE,
dentry);
break;
}
}
}
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