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/*
* linux/fs/proc/inode.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/time.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/limits.h>
#include <linux/init.h>
#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 *);
static inline struct proc_dir_entry * de_get(struct proc_dir_entry *de)
{
if (de)
atomic_inc(&de->count);
return de;
}
/*
* Decrements the use count and checks for deferred deletion.
*/
static void de_put(struct proc_dir_entry *de)
{
if (de) {
lock_kernel();
if (!atomic_read(&de->count)) {
printk("de_put: entry %s already free!\n", de->name);
unlock_kernel();
return;
}
if (atomic_dec_and_test(&de->count)) {
if (de->deleted) {
printk("de_put: deferred delete of %s\n",
de->name);
free_proc_entry(de);
}
}
unlock_kernel();
}
}
/*
* Decrement the use count of the proc_dir_entry.
*/
static void proc_delete_inode(struct inode *inode)
{
struct proc_dir_entry *de;
struct task_struct *tsk;
truncate_inode_pages(&inode->i_data, 0);
/* Let go of any associated process */
tsk = PROC_I(inode)->task;
if (tsk)
put_task_struct(tsk);
/* Let go of any associated proc directory entry */
de = PROC_I(inode)->pde;
if (de) {
if (de->owner)
module_put(de->owner);
de_put(de);
}
clear_inode(inode);
}
struct vfsmount *proc_mnt;
static void proc_read_inode(struct inode * inode)
{
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
}
static kmem_cache_t * proc_inode_cachep;
static struct inode *proc_alloc_inode(struct super_block *sb)
{
struct proc_inode *ei;
struct inode *inode;
ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, SLAB_KERNEL);
if (!ei)
return NULL;
ei->task = NULL;
ei->type = 0;
ei->op.proc_get_link = NULL;
ei->pde = NULL;
inode = &ei->vfs_inode;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
return inode;
}
static void proc_destroy_inode(struct inode *inode)
{
kmem_cache_free(proc_inode_cachep, PROC_I(inode));
}
static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
{
struct proc_inode *ei = (struct proc_inode *) foo;
if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
SLAB_CTOR_CONSTRUCTOR)
inode_init_once(&ei->vfs_inode);
}
int __init proc_init_inodecache(void)
{
proc_inode_cachep = kmem_cache_create("proc_inode_cache",
sizeof(struct proc_inode),
0, SLAB_RECLAIM_ACCOUNT,
init_once, NULL);
if (proc_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static int proc_remount(struct super_block *sb, int *flags, char *data)
{
*flags |= MS_NODIRATIME;
return 0;
}
static struct super_operations proc_sops = {
.alloc_inode = proc_alloc_inode,
.destroy_inode = proc_destroy_inode,
.read_inode = proc_read_inode,
.drop_inode = generic_delete_inode,
.delete_inode = proc_delete_inode,
.statfs = simple_statfs,
.remount_fs = proc_remount,
};
struct inode *proc_get_inode(struct super_block *sb, unsigned int ino,
struct proc_dir_entry *de)
{
struct inode * inode;
/*
* Increment the use count so the dir entry can't disappear.
*/
de_get(de);
WARN_ON(de && de->deleted);
inode = iget(sb, ino);
if (!inode)
goto out_fail;
PROC_I(inode)->pde = 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 (!try_module_get(de->owner))
goto out_fail;
if (de->proc_iops)
inode->i_op = de->proc_iops;
if (de->proc_fops)
inode->i_fop = de->proc_fops;
}
out:
return inode;
out_fail:
de_put(de);
goto out;
}
int proc_fill_super(struct super_block *s, void *data, int silent)
{
struct inode * root_inode;
s->s_flags |= MS_NODIRATIME;
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
s->s_magic = PROC_SUPER_MAGIC;
s->s_op = &proc_sops;
s->s_time_gran = 1;
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
*/
root_inode->i_nlink += nr_processes();
root_inode->i_uid = 0;
root_inode->i_gid = 0;
s->s_root = d_alloc_root(root_inode);
if (!s->s_root)
goto out_no_root;
return 0;
out_no_root:
printk("proc_read_super: get root inode failed\n");
iput(root_inode);
return -ENOMEM;
}
MODULE_LICENSE("GPL");
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