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/*
* linux/fs/proc/inode.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/file.h>
#include <linux/locks.h>
#include <linux/limits.h>
#define __NO_VERSION__
#include <linux/module.h>
#include <linux/smp_lock.h>
#include <asm/system.h>
#include <asm/uaccess.h>
extern void free_proc_entry(struct proc_dir_entry *);
struct proc_dir_entry * de_get(struct proc_dir_entry *de)
{
if (de)
de->count++;
return de;
}
/*
* Decrements the use count and checks for deferred deletion.
*/
void de_put(struct proc_dir_entry *de)
{
if (de) {
lock_kernel(); /* FIXME: count should be atomic_t */
if (!de->count) {
printk("de_put: entry %s already free!\n", de->name);
return;
}
if (!--de->count) {
if (de->deleted) {
printk("de_put: deferred delete of %s\n",
de->name);
free_proc_entry(de);
}
}
unlock_kernel();
}
}
static void proc_put_inode(struct inode *inode)
{
/*
* Kill off unused inodes ... VFS will unhash and
* delete the inode if we set i_nlink to zero.
*/
if (inode->i_count == 1)
inode->i_nlink = 0;
}
/*
* Decrement the use count of the proc_dir_entry.
*/
static void proc_delete_inode(struct inode *inode)
{
struct proc_dir_entry *de = inode->u.generic_ip;
inode->i_state = I_CLEAR;
if (PROC_INODE_PROPER(inode)) {
proc_pid_delete_inode(inode);
return;
}
if (de) {
if (de->owner)
__MOD_DEC_USE_COUNT(de->owner);
de_put(de);
}
}
struct super_block *proc_super_blocks = NULL;
static void proc_put_super(struct super_block *sb)
{
struct super_block **p = &proc_super_blocks;
while (*p != sb) {
if (!*p) /* should never happen */
return;
p = (struct super_block **)&(*p)->u.generic_sbp;
}
*p = (struct super_block *)(*p)->u.generic_sbp;
}
static void proc_write_inode(struct inode * inode)
{
}
static void proc_read_inode(struct inode * inode)
{
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
}
static int proc_statfs(struct super_block *sb, struct statfs *buf, int bufsiz)
{
struct statfs tmp;
tmp.f_type = PROC_SUPER_MAGIC;
tmp.f_bsize = PAGE_SIZE/sizeof(long);
tmp.f_blocks = 0;
tmp.f_bfree = 0;
tmp.f_bavail = 0;
tmp.f_files = 0;
tmp.f_ffree = 0;
tmp.f_namelen = NAME_MAX;
return copy_to_user(buf, &tmp, bufsiz) ? -EFAULT : 0;
}
static struct super_operations proc_sops = {
proc_read_inode,
proc_write_inode,
proc_put_inode,
proc_delete_inode, /* delete_inode(struct inode *) */
NULL,
proc_put_super,
NULL,
proc_statfs,
NULL
};
static int parse_options(char *options,uid_t *uid,gid_t *gid)
{
char *this_char,*value;
*uid = current->uid;
*gid = current->gid;
if (!options) return 1;
for (this_char = strtok(options,","); this_char; this_char = strtok(NULL,",")) {
if ((value = strchr(this_char,'=')) != NULL)
*value++ = 0;
if (!strcmp(this_char,"uid")) {
if (!value || !*value)
return 0;
*uid = simple_strtoul(value,&value,0);
if (*value)
return 0;
}
else if (!strcmp(this_char,"gid")) {
if (!value || !*value)
return 0;
*gid = simple_strtoul(value,&value,0);
if (*value)
return 0;
}
else return 1;
}
return 1;
}
struct inode * proc_get_inode(struct super_block * sb, int ino,
struct proc_dir_entry * de)
{
struct inode * inode;
/*
* Increment the use count so the dir entry can't disappear.
*/
de_get(de);
#if 1
/* shouldn't ever happen */
if (de && de->deleted)
printk("proc_iget: using deleted entry %s, count=%d\n", de->name, de->count);
#endif
inode = iget(sb, ino);
if (!inode)
goto out_fail;
inode->u.generic_ip = (void *) de;
if (de) {
if (de->mode) {
inode->i_mode = de->mode;
inode->i_uid = de->uid;
inode->i_gid = de->gid;
}
if (de->size)
inode->i_size = de->size;
if (de->nlink)
inode->i_nlink = de->nlink;
if (de->owner)
__MOD_INC_USE_COUNT(de->owner);
if (S_ISBLK(de->mode)||S_ISCHR(de->mode)||S_ISFIFO(de->mode))
init_special_inode(inode,de->mode,kdev_t_to_nr(de->rdev));
else if (de->ops)
inode->i_op = de->ops;
}
out:
return inode;
out_fail:
de_put(de);
goto out;
}
struct super_block *proc_read_super(struct super_block *s,void *data,
int silent)
{
struct inode * root_inode;
struct task_struct *p;
lock_super(s);
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
s->s_magic = PROC_SUPER_MAGIC;
s->s_op = &proc_sops;
root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root);
if (!root_inode)
goto out_no_root;
/*
* Fixup the root inode's nlink value
*/
read_lock(&tasklist_lock);
for_each_task(p) if (p->pid) root_inode->i_nlink++;
read_unlock(&tasklist_lock);
s->s_root = d_alloc_root(root_inode);
if (!s->s_root)
goto out_no_root;
parse_options(data, &root_inode->i_uid, &root_inode->i_gid);
s->u.generic_sbp = (void*) proc_super_blocks;
proc_super_blocks = s;
unlock_super(s);
return s;
out_no_root:
printk("proc_read_super: get root inode failed\n");
iput(root_inode);
s->s_dev = 0;
unlock_super(s);
return NULL;
}
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