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acrn-kernel/fs/hppfs/hppfs_kern.c

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/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/dcache.h>
#include <linux/statfs.h>
#include <asm/uaccess.h>
#include <asm/fcntl.h>
#include "os.h"
static int init_inode(struct inode *inode, struct dentry *dentry);
struct hppfs_data {
struct list_head list;
char contents[PAGE_SIZE - sizeof(struct list_head)];
};
struct hppfs_private {
struct file *proc_file;
int host_fd;
loff_t len;
struct hppfs_data *contents;
};
struct hppfs_inode_info {
struct dentry *proc_dentry;
struct inode vfs_inode;
};
static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode)
{
return container_of(inode, struct hppfs_inode_info, vfs_inode);
}
#define HPPFS_SUPER_MAGIC 0xb00000ee
static const struct super_operations hppfs_sbops;
static int is_pid(struct dentry *dentry)
{
struct super_block *sb;
int i;
sb = dentry->d_sb;
if((sb->s_op != &hppfs_sbops) || (dentry->d_parent != sb->s_root))
return(0);
for(i = 0; i < dentry->d_name.len; i++){
if(!isdigit(dentry->d_name.name[i]))
return(0);
}
return(1);
}
static char *dentry_name(struct dentry *dentry, int extra)
{
struct dentry *parent;
char *root, *name;
const char *seg_name;
int len, seg_len;
len = 0;
parent = dentry;
while(parent->d_parent != parent){
if(is_pid(parent))
len += strlen("pid") + 1;
else len += parent->d_name.len + 1;
parent = parent->d_parent;
}
root = "proc";
len += strlen(root);
name = kmalloc(len + extra + 1, GFP_KERNEL);
if(name == NULL) return(NULL);
name[len] = '\0';
parent = dentry;
while(parent->d_parent != parent){
if(is_pid(parent)){
seg_name = "pid";
seg_len = strlen("pid");
}
else {
seg_name = parent->d_name.name;
seg_len = parent->d_name.len;
}
len -= seg_len + 1;
name[len] = '/';
strncpy(&name[len + 1], seg_name, seg_len);
parent = parent->d_parent;
}
strncpy(name, root, strlen(root));
return(name);
}
struct dentry_operations hppfs_dentry_ops = {
};
static int file_removed(struct dentry *dentry, const char *file)
{
char *host_file;
int extra, fd;
extra = 0;
if(file != NULL) extra += strlen(file) + 1;
host_file = dentry_name(dentry, extra + strlen("/remove"));
if(host_file == NULL){
printk("file_removed : allocation failed\n");
return(-ENOMEM);
}
if(file != NULL){
strcat(host_file, "/");
strcat(host_file, file);
}
strcat(host_file, "/remove");
fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
kfree(host_file);
if(fd > 0){
os_close_file(fd);
return(1);
}
return(0);
}
static void hppfs_read_inode(struct inode *ino)
{
struct inode *proc_ino;
if(HPPFS_I(ino)->proc_dentry == NULL)
return;
proc_ino = HPPFS_I(ino)->proc_dentry->d_inode;
ino->i_uid = proc_ino->i_uid;
ino->i_gid = proc_ino->i_gid;
ino->i_atime = proc_ino->i_atime;
ino->i_mtime = proc_ino->i_mtime;
ino->i_ctime = proc_ino->i_ctime;
ino->i_ino = proc_ino->i_ino;
ino->i_mode = proc_ino->i_mode;
ino->i_nlink = proc_ino->i_nlink;
ino->i_size = proc_ino->i_size;
ino->i_blocks = proc_ino->i_blocks;
}
static struct inode *hppfs_iget(struct super_block *sb)
{
struct inode *inode;
inode = iget_locked(sb, 0);
if (!inode)
return ERR_PTR(-ENOMEM);
if (inode->i_state & I_NEW) {
hppfs_read_inode(inode);
unlock_new_inode(inode);
}
return inode;
}
static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
struct nameidata *nd)
{
struct dentry *proc_dentry, *new, *parent;
struct inode *inode;
int err, deleted;
deleted = file_removed(dentry, NULL);
if(deleted < 0)
return(ERR_PTR(deleted));
else if(deleted)
return(ERR_PTR(-ENOENT));
err = -ENOMEM;
parent = HPPFS_I(ino)->proc_dentry;
mutex_lock(&parent->d_inode->i_mutex);
proc_dentry = d_lookup(parent, &dentry->d_name);
if(proc_dentry == NULL){
proc_dentry = d_alloc(parent, &dentry->d_name);
if(proc_dentry == NULL){
mutex_unlock(&parent->d_inode->i_mutex);
goto out;
}
new = (*parent->d_inode->i_op->lookup)(parent->d_inode,
proc_dentry, NULL);
if(new){
dput(proc_dentry);
proc_dentry = new;
}
}
mutex_unlock(&parent->d_inode->i_mutex);
if(IS_ERR(proc_dentry))
return(proc_dentry);
inode = hppfs_iget(ino->i_sb);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_dput;
}
err = init_inode(inode, proc_dentry);
if(err)
goto out_put;
hppfs_read_inode(inode);
d_add(dentry, inode);
dentry->d_op = &hppfs_dentry_ops;
return(NULL);
out_put:
iput(inode);
out_dput:
dput(proc_dentry);
out:
return(ERR_PTR(err));
}
static const struct inode_operations hppfs_file_iops = {
};
static ssize_t read_proc(struct file *file, char __user *buf, ssize_t count,
loff_t *ppos, int is_user)
{
ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
ssize_t n;
read = file->f_path.dentry->d_inode->i_fop->read;
if(!is_user)
set_fs(KERNEL_DS);
n = (*read)(file, buf, count, &file->f_pos);
if(!is_user)
set_fs(USER_DS);
if(ppos) *ppos = file->f_pos;
return n;
}
static ssize_t hppfs_read_file(int fd, char __user *buf, ssize_t count)
{
ssize_t n;
int cur, err;
char *new_buf;
n = -ENOMEM;
new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
if(new_buf == NULL){
printk("hppfs_read_file : kmalloc failed\n");
goto out;
}
n = 0;
while(count > 0){
cur = min_t(ssize_t, count, PAGE_SIZE);
err = os_read_file(fd, new_buf, cur);
if(err < 0){
printk("hppfs_read : read failed, errno = %d\n",
err);
n = err;
goto out_free;
}
else if(err == 0)
break;
if(copy_to_user(buf, new_buf, err)){
n = -EFAULT;
goto out_free;
}
n += err;
count -= err;
}
out_free:
kfree(new_buf);
out:
return n;
}
static ssize_t hppfs_read(struct file *file, char __user *buf, size_t count,
loff_t *ppos)
{
struct hppfs_private *hppfs = file->private_data;
struct hppfs_data *data;
loff_t off;
int err;
if(hppfs->contents != NULL){
if(*ppos >= hppfs->len) return(0);
data = hppfs->contents;
off = *ppos;
while(off >= sizeof(data->contents)){
data = list_entry(data->list.next, struct hppfs_data,
list);
off -= sizeof(data->contents);
}
if(off + count > hppfs->len)
count = hppfs->len - off;
copy_to_user(buf, &data->contents[off], count);
*ppos += count;
}
else if(hppfs->host_fd != -1){
err = os_seek_file(hppfs->host_fd, *ppos);
if(err){
printk("hppfs_read : seek failed, errno = %d\n", err);
return(err);
}
count = hppfs_read_file(hppfs->host_fd, buf, count);
if(count > 0)
*ppos += count;
}
else count = read_proc(hppfs->proc_file, buf, count, ppos, 1);
return(count);
}
static ssize_t hppfs_write(struct file *file, const char __user *buf, size_t len,
loff_t *ppos)
{
struct hppfs_private *data = file->private_data;
struct file *proc_file = data->proc_file;
ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
int err;
write = proc_file->f_path.dentry->d_inode->i_fop->write;
proc_file->f_pos = file->f_pos;
err = (*write)(proc_file, buf, len, &proc_file->f_pos);
file->f_pos = proc_file->f_pos;
return(err);
}
static int open_host_sock(char *host_file, int *filter_out)
{
char *end;
int fd;
end = &host_file[strlen(host_file)];
strcpy(end, "/rw");
*filter_out = 1;
fd = os_connect_socket(host_file);
if(fd > 0)
return(fd);
strcpy(end, "/r");
*filter_out = 0;
fd = os_connect_socket(host_file);
return(fd);
}
static void free_contents(struct hppfs_data *head)
{
struct hppfs_data *data;
struct list_head *ele, *next;
if(head == NULL) return;
list_for_each_safe(ele, next, &head->list){
data = list_entry(ele, struct hppfs_data, list);
kfree(data);
}
kfree(head);
}
static struct hppfs_data *hppfs_get_data(int fd, int filter,
struct file *proc_file,
struct file *hppfs_file,
loff_t *size_out)
{
struct hppfs_data *data, *new, *head;
int n, err;
err = -ENOMEM;
data = kmalloc(sizeof(*data), GFP_KERNEL);
if(data == NULL){
printk("hppfs_get_data : head allocation failed\n");
goto failed;
}
INIT_LIST_HEAD(&data->list);
head = data;
*size_out = 0;
if(filter){
while((n = read_proc(proc_file, data->contents,
sizeof(data->contents), NULL, 0)) > 0)
os_write_file(fd, data->contents, n);
err = os_shutdown_socket(fd, 0, 1);
if(err){
printk("hppfs_get_data : failed to shut down "
"socket\n");
goto failed_free;
}
}
while(1){
n = os_read_file(fd, data->contents, sizeof(data->contents));
if(n < 0){
err = n;
printk("hppfs_get_data : read failed, errno = %d\n",
err);
goto failed_free;
}
else if(n == 0)
break;
*size_out += n;
if(n < sizeof(data->contents))
break;
new = kmalloc(sizeof(*data), GFP_KERNEL);
if(new == 0){
printk("hppfs_get_data : data allocation failed\n");
err = -ENOMEM;
goto failed_free;
}
INIT_LIST_HEAD(&new->list);
list_add(&new->list, &data->list);
data = new;
}
return(head);
failed_free:
free_contents(head);
failed:
return(ERR_PTR(err));
}
static struct hppfs_private *hppfs_data(void)
{
struct hppfs_private *data;
data = kmalloc(sizeof(*data), GFP_KERNEL);
if(data == NULL)
return(data);
*data = ((struct hppfs_private ) { .host_fd = -1,
.len = -1,
.contents = NULL } );
return(data);
}
static int file_mode(int fmode)
{
if(fmode == (FMODE_READ | FMODE_WRITE))
return(O_RDWR);
if(fmode == FMODE_READ)
return(O_RDONLY);
if(fmode == FMODE_WRITE)
return(O_WRONLY);
return(0);
}
static int hppfs_open(struct inode *inode, struct file *file)
{
struct hppfs_private *data;
struct dentry *proc_dentry;
char *host_file;
int err, fd, type, filter;
err = -ENOMEM;
data = hppfs_data();
if(data == NULL)
goto out;
host_file = dentry_name(file->f_path.dentry, strlen("/rw"));
if(host_file == NULL)
goto out_free2;
proc_dentry = HPPFS_I(inode)->proc_dentry;
/* XXX This isn't closed anywhere */
data->proc_file = dentry_open(dget(proc_dentry), NULL,
file_mode(file->f_mode));
err = PTR_ERR(data->proc_file);
if(IS_ERR(data->proc_file))
goto out_free1;
type = os_file_type(host_file);
if(type == OS_TYPE_FILE){
fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
if(fd >= 0)
data->host_fd = fd;
else printk("hppfs_open : failed to open '%s', errno = %d\n",
host_file, -fd);
data->contents = NULL;
}
else if(type == OS_TYPE_DIR){
fd = open_host_sock(host_file, &filter);
if(fd > 0){
data->contents = hppfs_get_data(fd, filter,
data->proc_file,
file, &data->len);
if(!IS_ERR(data->contents))
data->host_fd = fd;
}
else printk("hppfs_open : failed to open a socket in "
"'%s', errno = %d\n", host_file, -fd);
}
kfree(host_file);
file->private_data = data;
return(0);
out_free1:
kfree(host_file);
out_free2:
free_contents(data->contents);
kfree(data);
out:
return(err);
}
static int hppfs_dir_open(struct inode *inode, struct file *file)
{
struct hppfs_private *data;
struct dentry *proc_dentry;
int err;
err = -ENOMEM;
data = hppfs_data();
if(data == NULL)
goto out;
proc_dentry = HPPFS_I(inode)->proc_dentry;
data->proc_file = dentry_open(dget(proc_dentry), NULL,
file_mode(file->f_mode));
err = PTR_ERR(data->proc_file);
if(IS_ERR(data->proc_file))
goto out_free;
file->private_data = data;
return(0);
out_free:
kfree(data);
out:
return(err);
}
static loff_t hppfs_llseek(struct file *file, loff_t off, int where)
{
struct hppfs_private *data = file->private_data;
struct file *proc_file = data->proc_file;
loff_t (*llseek)(struct file *, loff_t, int);
loff_t ret;
llseek = proc_file->f_path.dentry->d_inode->i_fop->llseek;
if(llseek != NULL){
ret = (*llseek)(proc_file, off, where);
if(ret < 0)
return(ret);
}
return(default_llseek(file, off, where));
}
static const struct file_operations hppfs_file_fops = {
.owner = NULL,
.llseek = hppfs_llseek,
.read = hppfs_read,
.write = hppfs_write,
.open = hppfs_open,
};
struct hppfs_dirent {
void *vfs_dirent;
filldir_t filldir;
struct dentry *dentry;
};
static int hppfs_filldir(void *d, const char *name, int size,
loff_t offset, u64 inode, unsigned int type)
{
struct hppfs_dirent *dirent = d;
if(file_removed(dirent->dentry, name))
return(0);
return((*dirent->filldir)(dirent->vfs_dirent, name, size, offset,
inode, type));
}
static int hppfs_readdir(struct file *file, void *ent, filldir_t filldir)
{
struct hppfs_private *data = file->private_data;
struct file *proc_file = data->proc_file;
int (*readdir)(struct file *, void *, filldir_t);
struct hppfs_dirent dirent = ((struct hppfs_dirent)
{ .vfs_dirent = ent,
.filldir = filldir,
.dentry = file->f_path.dentry } );
int err;
readdir = proc_file->f_path.dentry->d_inode->i_fop->readdir;
proc_file->f_pos = file->f_pos;
err = (*readdir)(proc_file, &dirent, hppfs_filldir);
file->f_pos = proc_file->f_pos;
return(err);
}
static int hppfs_fsync(struct file *file, struct dentry *dentry, int datasync)
{
return(0);
}
static const struct file_operations hppfs_dir_fops = {
.owner = NULL,
.readdir = hppfs_readdir,
.open = hppfs_dir_open,
.fsync = hppfs_fsync,
};
static int hppfs_statfs(struct dentry *dentry, struct kstatfs *sf)
{
sf->f_blocks = 0;
sf->f_bfree = 0;
sf->f_bavail = 0;
sf->f_files = 0;
sf->f_ffree = 0;
sf->f_type = HPPFS_SUPER_MAGIC;
return(0);
}
static struct inode *hppfs_alloc_inode(struct super_block *sb)
{
struct hppfs_inode_info *hi;
hi = kmalloc(sizeof(*hi), GFP_KERNEL);
if(hi == NULL)
return(NULL);
*hi = ((struct hppfs_inode_info) { .proc_dentry = NULL });
inode_init_once(&hi->vfs_inode);
return(&hi->vfs_inode);
}
void hppfs_delete_inode(struct inode *ino)
{
clear_inode(ino);
}
static void hppfs_destroy_inode(struct inode *inode)
{
kfree(HPPFS_I(inode));
}
static const struct super_operations hppfs_sbops = {
.alloc_inode = hppfs_alloc_inode,
.destroy_inode = hppfs_destroy_inode,
.delete_inode = hppfs_delete_inode,
.statfs = hppfs_statfs,
};
static int hppfs_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
struct file *proc_file;
struct dentry *proc_dentry;
int ret;
proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY);
if (IS_ERR(proc_file))
return PTR_ERR(proc_file);
ret = proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer, buflen);
fput(proc_file);
return ret;
}
static void* hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct file *proc_file;
struct dentry *proc_dentry;
void *ret;
proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY);
if (IS_ERR(proc_file))
return proc_file;
ret = proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd);
fput(proc_file);
return ret;
}
static const struct inode_operations hppfs_dir_iops = {
.lookup = hppfs_lookup,
};
static const struct inode_operations hppfs_link_iops = {
.readlink = hppfs_readlink,
.follow_link = hppfs_follow_link,
};
static int init_inode(struct inode *inode, struct dentry *dentry)
{
if(S_ISDIR(dentry->d_inode->i_mode)){
inode->i_op = &hppfs_dir_iops;
inode->i_fop = &hppfs_dir_fops;
}
else if(S_ISLNK(dentry->d_inode->i_mode)){
inode->i_op = &hppfs_link_iops;
inode->i_fop = &hppfs_file_fops;
}
else {
inode->i_op = &hppfs_file_iops;
inode->i_fop = &hppfs_file_fops;
}
HPPFS_I(inode)->proc_dentry = dentry;
return(0);
}
static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
{
struct inode *root_inode;
struct file_system_type *procfs;
struct super_block *proc_sb;
int err;
err = -ENOENT;
procfs = get_fs_type("proc");
if(procfs == NULL)
goto out;
if(list_empty(&procfs->fs_supers))
goto out;
proc_sb = list_entry(procfs->fs_supers.next, struct super_block,
s_instances);
sb->s_blocksize = 1024;
sb->s_blocksize_bits = 10;
sb->s_magic = HPPFS_SUPER_MAGIC;
sb->s_op = &hppfs_sbops;
root_inode = hppfs_iget(sb);
if (IS_ERR(root_inode)) {
err = PTR_ERR(root_inode);
goto out;
}
err = init_inode(root_inode, proc_sb->s_root);
if(err)
goto out_put;
err = -ENOMEM;
sb->s_root = d_alloc_root(root_inode);
if(sb->s_root == NULL)
goto out_put;
hppfs_read_inode(root_inode);
return(0);
out_put:
iput(root_inode);
out:
return(err);
}
static int hppfs_read_super(struct file_system_type *type,
int flags, const char *dev_name,
void *data, struct vfsmount *mnt)
{
return get_sb_nodev(type, flags, data, hppfs_fill_super, mnt);
}
static struct file_system_type hppfs_type = {
.owner = THIS_MODULE,
.name = "hppfs",
.get_sb = hppfs_read_super,
.kill_sb = kill_anon_super,
.fs_flags = 0,
};
static int __init init_hppfs(void)
{
return(register_filesystem(&hppfs_type));
}
static void __exit exit_hppfs(void)
{
unregister_filesystem(&hppfs_type);
}
module_init(init_hppfs)
module_exit(exit_hppfs)
MODULE_LICENSE("GPL");
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/
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