[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>

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);

	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;
	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");
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
	22	extern void free_proc_entry(struct proc_dir_entry *);
	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;
	61	struct task_struct *tsk;
	62
fef26658 MF	63	truncate_inode_pages(&inode->i_data, 0);
fef26658 MF	64
1da177e4 LT	65	/* Let go of any associated process */
	66	tsk = PROC_I(inode)->task;
	67	if (tsk)
	68	put_task_struct(tsk);
	69
	70	/* Let go of any associated proc directory entry */
	71	de = PROC_I(inode)->pde;
	72	if (de) {
	73	if (de->owner)
	74	module_put(de->owner);
	75	de_put(de);
	76	}
	77	clear_inode(inode);
	78	}
	79
	80	struct vfsmount *proc_mnt;
	81
	82	static void proc_read_inode(struct inode * inode)
	83	{
	84	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	85	}
	86
	87	static kmem_cache_t * proc_inode_cachep;
	88
	89	static struct inode proc_alloc_inode(struct super_block sb)
	90	{
	91	struct proc_inode *ei;
	92	struct inode *inode;
	93
	94	ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, SLAB_KERNEL);
	95	if (!ei)
	96	return NULL;
	97	ei->task = NULL;
	98	ei->type = 0;
	99	ei->op.proc_get_link = NULL;
	100	ei->pde = NULL;
	101	inode = &ei->vfs_inode;
	102	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	103	return inode;
	104	}
	105
	106	static void proc_destroy_inode(struct inode *inode)
	107	{
	108	kmem_cache_free(proc_inode_cachep, PROC_I(inode));
	109	}
	110
	111	static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
	112	{
	113	struct proc_inode ei = (struct proc_inode ) foo;
	114
	115	if ((flags & (SLAB_CTOR_VERIFY\|SLAB_CTOR_CONSTRUCTOR)) ==
	116	SLAB_CTOR_CONSTRUCTOR)
	117	inode_init_once(&ei->vfs_inode);
	118	}
	119
	120	int __init proc_init_inodecache(void)
	121	{
	122	proc_inode_cachep = kmem_cache_create("proc_inode_cache",
	123	sizeof(struct proc_inode),
	124	0, SLAB_RECLAIM_ACCOUNT,
	125	init_once, NULL);
	126	if (proc_inode_cachep == NULL)
	127	return -ENOMEM;
	128	return 0;
129	}
130
131	static int proc_remount(struct super_block sb, int flags, char *data)
132	{
133	*flags \|= MS_NODIRATIME;
134	return 0;
135	}
136
137	static struct super_operations proc_sops = {
138	.alloc_inode = proc_alloc_inode,
139	.destroy_inode = proc_destroy_inode,
140	.read_inode = proc_read_inode,
141	.drop_inode = generic_delete_inode,
142	.delete_inode = proc_delete_inode,
143	.statfs = simple_statfs,
144	.remount_fs = proc_remount,
145	};
146
147	struct inode proc_get_inode(struct super_block sb, unsigned int ino,
148	struct proc_dir_entry *de)
149	{
150	struct inode * inode;
151
152	/*
153	* Increment the use count so the dir entry can't disappear.
154	*/
155	de_get(de);
156
157	WARN_ON(de && de->deleted);
158
e9543659 KK	159	if (de != NULL && !try_module_get(de->owner))
	160	goto out_mod;
	161
1da177e4 LT	162	inode = iget(sb, ino);
1da177e4 LT	163	if (!inode)
e9543659 KK	164	goto out_ino;
e9543659 KK	165
1da177e4 LT	166	PROC_I(inode)->pde = de;
	167	if (de) {
	168	if (de->mode) {
	169	inode->i_mode = de->mode;
	170	inode->i_uid = de->uid;
	171	inode->i_gid = de->gid;
	172	}
	173	if (de->size)
	174	inode->i_size = de->size;
	175	if (de->nlink)
	176	inode->i_nlink = de->nlink;
1da177e4 LT	177	if (de->proc_iops)
	178	inode->i_op = de->proc_iops;
	179	if (de->proc_fops)
	180	inode->i_fop = de->proc_fops;
	181	}
	182
1da177e4 LT	183	return inode;
1da177e4 LT	184
e9543659 KK	185	out_ino:
	186	if (de != NULL)
	187	module_put(de->owner);
	188	out_mod:
1da177e4	189	de_put(de);
e9543659	190	return NULL;
1da177e4 LT	191	}
	192
	193	int proc_fill_super(struct super_block s, void data, int silent)
	194	{
	195	struct inode * root_inode;
	196
	197	s->s_flags \|= MS_NODIRATIME;
	198	s->s_blocksize = 1024;
	199	s->s_blocksize_bits = 10;
	200	s->s_magic = PROC_SUPER_MAGIC;
	201	s->s_op = &proc_sops;
	202	s->s_time_gran = 1;
	203
	204	root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root);
	205	if (!root_inode)
	206	goto out_no_root;
	207	/*
	208	* Fixup the root inode's nlink value
	209	*/
	210	root_inode->i_nlink += nr_processes();
	211	root_inode->i_uid = 0;
	212	root_inode->i_gid = 0;
	213	s->s_root = d_alloc_root(root_inode);
	214	if (!s->s_root)
	215	goto out_no_root;
	216	return 0;
	217
	218	out_no_root:
	219	printk("proc_read_super: get root inode failed\n");
	220	iput(root_inode);
	221	return -ENOMEM;
	222	}
	223	MODULE_LICENSE("GPL");