[mirror_ubuntu-bionic-kernel.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"

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.
 */
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_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 const 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;

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

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

	PROC_I(inode)->fd = 0;
	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:
	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;
	
	de_get(&proc_root);
	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);
	de_put(&proc_root);
	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	23
7695650a	24	struct proc_dir_entry de_get(struct proc_dir_entry de)
1da177e4 LT	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	*/
7695650a	34	void de_put(struct proc_dir_entry *de)
1da177e4 LT	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
50953fe9	112	if (flags & SLAB_CTOR_CONSTRUCTOR)
1da177e4 LT	113	inode_init_once(&ei->vfs_inode);
	114	}
	115
	116	int __init proc_init_inodecache(void)
	117	{
	118	proc_inode_cachep = kmem_cache_create("proc_inode_cache",
	119	sizeof(struct proc_inode),
fffb60f9 PJ	120	0, (SLAB_RECLAIM_ACCOUNT\|
fffb60f9 PJ	121	SLAB_MEM_SPREAD),
1da177e4 LT	122	init_once, NULL);
	123	if (proc_inode_cachep == NULL)
	124	return -ENOMEM;
	125	return 0;
	126	}
	127
	128	static int proc_remount(struct super_block sb, int flags, char *data)
	129	{
	130	*flags \|= MS_NODIRATIME;
	131	return 0;
	132	}
	133
ee9b6d61	134	static const struct super_operations proc_sops = {
1da177e4 LT	135	.alloc_inode = proc_alloc_inode,
	136	.destroy_inode = proc_destroy_inode,
	137	.read_inode = proc_read_inode,
	138	.drop_inode = generic_delete_inode,
	139	.delete_inode = proc_delete_inode,
	140	.statfs = simple_statfs,
	141	.remount_fs = proc_remount,
	142	};
	143
	144	struct inode proc_get_inode(struct super_block sb, unsigned int ino,
	145	struct proc_dir_entry *de)
	146	{
	147	struct inode * inode;
	148
e9543659 KK	149	if (de != NULL && !try_module_get(de->owner))
	150	goto out_mod;
	151
1da177e4 LT	152	inode = iget(sb, ino);
1da177e4 LT	153	if (!inode)
e9543659 KK	154	goto out_ino;
e9543659 KK	155
77b14db5	156	PROC_I(inode)->fd = 0;
1da177e4 LT	157	PROC_I(inode)->pde = de;
	158	if (de) {
	159	if (de->mode) {
	160	inode->i_mode = de->mode;
	161	inode->i_uid = de->uid;
	162	inode->i_gid = de->gid;
	163	}
	164	if (de->size)
	165	inode->i_size = de->size;
	166	if (de->nlink)
	167	inode->i_nlink = de->nlink;
1da177e4 LT	168	if (de->proc_iops)
	169	inode->i_op = de->proc_iops;
	170	if (de->proc_fops)
	171	inode->i_fop = de->proc_fops;
	172	}
	173
1da177e4 LT	174	return inode;
1da177e4 LT	175
e9543659 KK	176	out_ino:
	177	if (de != NULL)
	178	module_put(de->owner);
	179	out_mod:
e9543659	180	return NULL;
1da177e4 LT	181	}
	182
	183	int proc_fill_super(struct super_block s, void data, int silent)
	184	{
	185	struct inode * root_inode;
	186
92d03285	187	s->s_flags \|= MS_NODIRATIME \| MS_NOSUID \| MS_NOEXEC;
1da177e4 LT	188	s->s_blocksize = 1024;
	189	s->s_blocksize_bits = 10;
	190	s->s_magic = PROC_SUPER_MAGIC;
	191	s->s_op = &proc_sops;
	192	s->s_time_gran = 1;
	193
7695650a	194	de_get(&proc_root);
1da177e4 LT	195	root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root);
	196	if (!root_inode)
	197	goto out_no_root;
1da177e4 LT	198	root_inode->i_uid = 0;
	199	root_inode->i_gid = 0;
	200	s->s_root = d_alloc_root(root_inode);
	201	if (!s->s_root)
	202	goto out_no_root;
	203	return 0;
	204
	205	out_no_root:
	206	printk("proc_read_super: get root inode failed\n");
	207	iput(root_inode);
7695650a	208	de_put(&proc_root);
1da177e4 LT	209	return -ENOMEM;
	210	}
	211	MODULE_LICENSE("GPL");