[linux-2.6-block.git] / fs / proc / inode.c

/*
 *  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>

#include "internal.h"

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;

	truncate_inode_pages(&inode->i_data, 0);

	/* Stop tracking associated processes */
	put_pid(PROC_I(inode)->pid);

	/* 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 struct kmem_cache * 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, GFP_KERNEL);
	if (!ei)
		return NULL;
	ei->pid = NULL;
	ei->fd = 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, struct kmem_cache * 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|
						SLAB_MEM_SPREAD),
					     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);

	if (de != NULL && !try_module_get(de->owner))
		goto out_mod;

	inode = iget(sb, ino);
	if (!inode)
		goto out_ino;

	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 (de->proc_iops)
			inode->i_op = de->proc_iops;
		if (de->proc_fops)
			inode->i_fop = de->proc_fops;
	}

	return inode;

out_ino:
	if (de != NULL)
		module_put(de->owner);
out_mod:
	de_put(de);
	return NULL;
}			

int proc_fill_super(struct super_block *s, void *data, int silent)
{
	struct inode * root_inode;

	s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC;
	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;
	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");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/proc/inode.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	*/
	6
	7	#include <linux/time.h>
	8	#include <linux/proc_fs.h>
	9	#include <linux/kernel.h>
	10	#include <linux/mm.h>
	11	#include <linux/string.h>
	12	#include <linux/stat.h>
	13	#include <linux/file.h>
	14	#include <linux/limits.h>
	15	#include <linux/init.h>
	16	#include <linux/module.h>
	17	#include <linux/smp_lock.h>
	18
	19	#include <asm/system.h>
	20	#include <asm/uaccess.h>
	21
fee781e6	22	#include "internal.h"
1da177e4 LT	23
	24	static inline struct proc_dir_entry * de_get(struct proc_dir_entry *de)
	25	{
	26	if (de)
	27	atomic_inc(&de->count);
	28	return de;
	29	}
	30
	31	/*
	32	* Decrements the use count and checks for deferred deletion.
	33	*/
	34	static void de_put(struct proc_dir_entry *de)
	35	{
	36	if (de) {
	37	lock_kernel();
	38	if (!atomic_read(&de->count)) {
	39	printk("de_put: entry %s already free!\n", de->name);
	40	unlock_kernel();
	41	return;
	42	}
	43
	44	if (atomic_dec_and_test(&de->count)) {
	45	if (de->deleted) {
	46	printk("de_put: deferred delete of %s\n",
	47	de->name);
	48	free_proc_entry(de);
	49	}
	50	}
	51	unlock_kernel();
	52	}
	53	}
	54
	55	/*
	56	* Decrement the use count of the proc_dir_entry.
	57	*/
	58	static void proc_delete_inode(struct inode *inode)
	59	{
	60	struct proc_dir_entry *de;
1da177e4	61
fef26658 MF	62	truncate_inode_pages(&inode->i_data, 0);
fef26658 MF	63
99f89551	64	/* Stop tracking associated processes */
13b41b09	65	put_pid(PROC_I(inode)->pid);
1da177e4 LT	66
	67	/* Let go of any associated proc directory entry */
	68	de = PROC_I(inode)->pde;
	69	if (de) {
	70	if (de->owner)
	71	module_put(de->owner);
	72	de_put(de);
	73	}
	74	clear_inode(inode);
	75	}
	76
	77	struct vfsmount *proc_mnt;
	78
	79	static void proc_read_inode(struct inode * inode)
	80	{
	81	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	82	}
	83
e18b890b	84	static struct kmem_cache * proc_inode_cachep;
1da177e4 LT	85
	86	static struct inode proc_alloc_inode(struct super_block sb)
	87	{
	88	struct proc_inode *ei;
	89	struct inode *inode;
	90
e94b1766	91	ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
1da177e4 LT	92	if (!ei)
1da177e4 LT	93	return NULL;
13b41b09	94	ei->pid = NULL;
aed7a6c4	95	ei->fd = 0;
1da177e4 LT	96	ei->op.proc_get_link = NULL;
	97	ei->pde = NULL;
	98	inode = &ei->vfs_inode;
	99	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	100	return inode;
	101	}
	102
	103	static void proc_destroy_inode(struct inode *inode)
	104	{
	105	kmem_cache_free(proc_inode_cachep, PROC_I(inode));
	106	}
	107
e18b890b	108	static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
1da177e4 LT	109	{
	110	struct proc_inode ei = (struct proc_inode ) foo;
	111
	112	if ((flags & (SLAB_CTOR_VERIFY\|SLAB_CTOR_CONSTRUCTOR)) ==
	113	SLAB_CTOR_CONSTRUCTOR)
	114	inode_init_once(&ei->vfs_inode);
	115	}
	116
	117	int __init proc_init_inodecache(void)
	118	{
	119	proc_inode_cachep = kmem_cache_create("proc_inode_cache",
	120	sizeof(struct proc_inode),
fffb60f9 PJ	121	0, (SLAB_RECLAIM_ACCOUNT\|
fffb60f9 PJ	122	SLAB_MEM_SPREAD),
1da177e4 LT	123	init_once, NULL);
	124	if (proc_inode_cachep == NULL)
	125	return -ENOMEM;
	126	return 0;
	127	}
	128
	129	static int proc_remount(struct super_block sb, int flags, char *data)
	130	{
	131	*flags \|= MS_NODIRATIME;
	132	return 0;
	133	}
	134
	135	static struct super_operations proc_sops = {
	136	.alloc_inode = proc_alloc_inode,
	137	.destroy_inode = proc_destroy_inode,
	138	.read_inode = proc_read_inode,
	139	.drop_inode = generic_delete_inode,
	140	.delete_inode = proc_delete_inode,
	141	.statfs = simple_statfs,
	142	.remount_fs = proc_remount,
	143	};
	144
	145	struct inode proc_get_inode(struct super_block sb, unsigned int ino,
	146	struct proc_dir_entry *de)
	147	{
	148	struct inode * inode;
	149
	150	/*
	151	* Increment the use count so the dir entry can't disappear.
	152	*/
	153	de_get(de);
	154
	155	WARN_ON(de && de->deleted);
	156
e9543659 KK	157	if (de != NULL && !try_module_get(de->owner))
	158	goto out_mod;
	159
1da177e4 LT	160	inode = iget(sb, ino);
1da177e4 LT	161	if (!inode)
e9543659 KK	162	goto out_ino;
e9543659 KK	163
1da177e4 LT	164	PROC_I(inode)->pde = de;
	165	if (de) {
	166	if (de->mode) {
	167	inode->i_mode = de->mode;
	168	inode->i_uid = de->uid;
	169	inode->i_gid = de->gid;
	170	}
	171	if (de->size)
	172	inode->i_size = de->size;
	173	if (de->nlink)
	174	inode->i_nlink = de->nlink;
1da177e4 LT	175	if (de->proc_iops)
	176	inode->i_op = de->proc_iops;
	177	if (de->proc_fops)
	178	inode->i_fop = de->proc_fops;
	179	}
	180
1da177e4 LT	181	return inode;
1da177e4 LT	182
e9543659 KK	183	out_ino:
	184	if (de != NULL)
	185	module_put(de->owner);
	186	out_mod:
1da177e4	187	de_put(de);
e9543659	188	return NULL;
1da177e4 LT	189	}
	190
	191	int proc_fill_super(struct super_block s, void data, int silent)
	192	{
	193	struct inode * root_inode;
	194
92d03285	195	s->s_flags \|= MS_NODIRATIME \| MS_NOSUID \| MS_NOEXEC;
1da177e4 LT	196	s->s_blocksize = 1024;
	197	s->s_blocksize_bits = 10;
	198	s->s_magic = PROC_SUPER_MAGIC;
	199	s->s_op = &proc_sops;
	200	s->s_time_gran = 1;
	201
	202	root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root);
	203	if (!root_inode)
	204	goto out_no_root;
1da177e4 LT	205	root_inode->i_uid = 0;
	206	root_inode->i_gid = 0;
	207	s->s_root = d_alloc_root(root_inode);
	208	if (!s->s_root)
	209	goto out_no_root;
	210	return 0;
	211
	212	out_no_root:
	213	printk("proc_read_super: get root inode failed\n");
	214	iput(root_inode);
	215	return -ENOMEM;
	216	}
	217	MODULE_LICENSE("GPL");