/* proc.c: /proc interface for AFS
 *
 * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "cell.h"
#include "volume.h"
#include <asm/uaccess.h>
#include "internal.h"

static struct proc_dir_entry *proc_afs;


static int afs_proc_cells_open(struct inode *inode, struct file *file);
static void *afs_proc_cells_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cells_next(struct seq_file *p, void *v, loff_t *pos);
static void afs_proc_cells_stop(struct seq_file *p, void *v);
static int afs_proc_cells_show(struct seq_file *m, void *v);
static ssize_t afs_proc_cells_write(struct file *file, const char *buf, size_t size, loff_t *_pos);

static struct seq_operations afs_proc_cells_ops = {
	.start	= afs_proc_cells_start,
	.next	= afs_proc_cells_next,
	.stop	= afs_proc_cells_stop,
	.show	= afs_proc_cells_show,
};

static struct file_operations afs_proc_cells_fops = {
	.open		= afs_proc_cells_open,
	.read		= seq_read,
	.write		= afs_proc_cells_write,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file);
static int afs_proc_cell_volumes_release(struct inode *inode, struct file *file);
static void *afs_proc_cell_volumes_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v, loff_t *pos);
static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v);
static int afs_proc_cell_volumes_show(struct seq_file *m, void *v);

static struct seq_operations afs_proc_cell_volumes_ops = {
	.start	= afs_proc_cell_volumes_start,
	.next	= afs_proc_cell_volumes_next,
	.stop	= afs_proc_cell_volumes_stop,
	.show	= afs_proc_cell_volumes_show,
};

static struct file_operations afs_proc_cell_volumes_fops = {
	.open		= afs_proc_cell_volumes_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= afs_proc_cell_volumes_release,
};

static int afs_proc_cell_vlservers_open(struct inode *inode, struct file *file);
static int afs_proc_cell_vlservers_release(struct inode *inode, struct file *file);
static void *afs_proc_cell_vlservers_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v, loff_t *pos);
static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v);
static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v);

static struct seq_operations afs_proc_cell_vlservers_ops = {
	.start	= afs_proc_cell_vlservers_start,
	.next	= afs_proc_cell_vlservers_next,
	.stop	= afs_proc_cell_vlservers_stop,
	.show	= afs_proc_cell_vlservers_show,
};

static struct file_operations afs_proc_cell_vlservers_fops = {
	.open		= afs_proc_cell_vlservers_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= afs_proc_cell_vlservers_release,
};

static int afs_proc_cell_servers_open(struct inode *inode, struct file *file);
static int afs_proc_cell_servers_release(struct inode *inode, struct file *file);
static void *afs_proc_cell_servers_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cell_servers_next(struct seq_file *p, void *v, loff_t *pos);
static void afs_proc_cell_servers_stop(struct seq_file *p, void *v);
static int afs_proc_cell_servers_show(struct seq_file *m, void *v);

static struct seq_operations afs_proc_cell_servers_ops = {
	.start	= afs_proc_cell_servers_start,
	.next	= afs_proc_cell_servers_next,
	.stop	= afs_proc_cell_servers_stop,
	.show	= afs_proc_cell_servers_show,
};

static struct file_operations afs_proc_cell_servers_fops = {
	.open		= afs_proc_cell_servers_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= afs_proc_cell_servers_release,
};

/*****************************************************************************/
/*
 * initialise the /proc/fs/afs/ directory
 */
int afs_proc_init(void)
{
	struct proc_dir_entry *p;

	_enter("");

	proc_afs = proc_mkdir("fs/afs",NULL);
	if (!proc_afs)
		goto error;
	proc_afs->owner = THIS_MODULE;

	p = create_proc_entry("cells",0,proc_afs);
	if (!p)
		goto error_proc;
	p->proc_fops = &afs_proc_cells_fops;
	p->owner = THIS_MODULE;

	_leave(" = 0");
	return 0;

#if 0
 error_cells:
	remove_proc_entry("cells",proc_afs);
#endif
 error_proc:
	remove_proc_entry("fs/afs",NULL);
 error:
	_leave(" = -ENOMEM");
	return -ENOMEM;

} /* end afs_proc_init() */

/*****************************************************************************/
/*
 * clean up the /proc/fs/afs/ directory
 */
void afs_proc_cleanup(void)
{
	remove_proc_entry("cells",proc_afs);

	remove_proc_entry("fs/afs",NULL);

} /* end afs_proc_cleanup() */

/*****************************************************************************/
/*
 * open "/proc/fs/afs/cells" which provides a summary of extant cells
 */
static int afs_proc_cells_open(struct inode *inode, struct file *file)
{
	struct seq_file *m;
	int ret;

	ret = seq_open(file,&afs_proc_cells_ops);
	if (ret<0)
		return ret;

	m = file->private_data;
	m->private = PDE(inode)->data;

	return 0;
} /* end afs_proc_cells_open() */

/*****************************************************************************/
/*
 * set up the iterator to start reading from the cells list and return the first item
 */
static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
{
	struct list_head *_p;
	loff_t pos = *_pos;

	/* lock the list against modification */
	down_read(&afs_proc_cells_sem);

	/* allow for the header line */
	if (!pos)
		return (void *)1;
	pos--;

	/* find the n'th element in the list */
	list_for_each(_p,&afs_proc_cells)
		if (!pos--)
			break;

	return _p!=&afs_proc_cells ? _p : NULL;
} /* end afs_proc_cells_start() */

/*****************************************************************************/
/*
 * move to next cell in cells list
 */
static void *afs_proc_cells_next(struct seq_file *p, void *v, loff_t *pos)
{
	struct list_head *_p;

	(*pos)++;

	_p = v;
	_p = v==(void*)1 ? afs_proc_cells.next : _p->next;

	return _p!=&afs_proc_cells ? _p : NULL;
} /* end afs_proc_cells_next() */

/*****************************************************************************/
/*
 * clean up after reading from the cells list
 */
static void afs_proc_cells_stop(struct seq_file *p, void *v)
{
	up_read(&afs_proc_cells_sem);

} /* end afs_proc_cells_stop() */

/*****************************************************************************/
/*
 * display a header line followed by a load of cell lines
 */
static int afs_proc_cells_show(struct seq_file *m, void *v)
{
	afs_cell_t *cell = list_entry(v,afs_cell_t,proc_link);

	/* display header on line 1 */
	if (v == (void *)1) {
		seq_puts(m, "USE NAME\n");
		return 0;
	}

	/* display one cell per line on subsequent lines */
	seq_printf(m,"%3d %s\n",atomic_read(&cell->usage),cell->name);

	return 0;
} /* end afs_proc_cells_show() */

/*****************************************************************************/
/*
 * handle writes to /proc/fs/afs/cells
 * - to add cells: echo "add <cellname> <IP>[:<IP>][:<IP>]*
 */
static ssize_t afs_proc_cells_write(struct file *file, const char *buf, size_t size, loff_t *_pos)
{
	char *kbuf, *name, *args;
	int ret;

	/* start by dragging the command into memory */
	if (size<=1 || size>=PAGE_SIZE)
		return -EINVAL;

	kbuf = kmalloc(size+1,GFP_KERNEL);
	if (!kbuf)
		return -ENOMEM;

	ret = -EFAULT;
	if (copy_from_user(kbuf,buf,size)!=0)
		goto done;
	kbuf[size] = 0;

	/* trim to first NL */
	name = memchr(kbuf,'\n',size);
	if (name) *name = 0;

	/* split into command, name and argslist */
	name = strchr(kbuf,' ');
	if (!name) goto inval;
	do { *name++ = 0; } while(*name==' ');
	if (!*name) goto inval;

	args = strchr(name,' ');
	if (!args) goto inval;
	do { *args++ = 0; } while(*args==' ');
	if (!*args) goto inval;

	/* determine command to perform */
	_debug("cmd=%s name=%s args=%s",kbuf,name,args);

	if (strcmp(kbuf,"add")==0) {
		afs_cell_t *cell;
		ret = afs_cell_create(name,args,&cell);
		if (ret<0)
			goto done;

		printk("kAFS: Added new cell '%s'\n",name);
	}
	else {
		goto inval;
	}

	ret = size;

 done:
	kfree(kbuf);
	_leave(" = %d",ret);
	return ret;

 inval:
	ret = -EINVAL;
	printk("kAFS: Invalid Command on /proc/fs/afs/cells file\n");
	goto done;
} /* end afs_proc_cells_write() */

/*****************************************************************************/
/*
 * initialise /proc/fs/afs/<cell>/
 */
int afs_proc_cell_setup(afs_cell_t *cell)
{
	struct proc_dir_entry *p;

	_enter("%p{%s}",cell,cell->name);

	cell->proc_dir = proc_mkdir(cell->name,proc_afs);
	if (!cell->proc_dir)
		return -ENOMEM;

	p = create_proc_entry("servers",0,cell->proc_dir);
	if (!p)
		goto error_proc;
	p->proc_fops = &afs_proc_cell_servers_fops;
	p->owner = THIS_MODULE;
	p->data = cell;

	p = create_proc_entry("vlservers",0,cell->proc_dir);
	if (!p)
		goto error_servers;
	p->proc_fops = &afs_proc_cell_vlservers_fops;
	p->owner = THIS_MODULE;
	p->data = cell;

	p = create_proc_entry("volumes",0,cell->proc_dir);
	if (!p)
		goto error_vlservers;
	p->proc_fops = &afs_proc_cell_volumes_fops;
	p->owner = THIS_MODULE;
	p->data = cell;

	_leave(" = 0");
	return 0;

 error_vlservers:
	remove_proc_entry("vlservers",cell->proc_dir);
 error_servers:
	remove_proc_entry("servers",cell->proc_dir);
 error_proc:
	remove_proc_entry(cell->name,proc_afs);
	_leave(" = -ENOMEM");
	return -ENOMEM;
} /* end afs_proc_cell_setup() */

/*****************************************************************************/
/*
 * remove /proc/fs/afs/<cell>/
 */
void afs_proc_cell_remove(afs_cell_t *cell)
{
	_enter("");

	remove_proc_entry("volumes",cell->proc_dir);
	remove_proc_entry("vlservers",cell->proc_dir);
	remove_proc_entry("servers",cell->proc_dir);
	remove_proc_entry(cell->name,proc_afs);

	_leave("");
} /* end afs_proc_cell_remove() */

/*****************************************************************************/
/*
 * open "/proc/fs/afs/<cell>/volumes" which provides a summary of extant cells
 */
static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file)
{
	struct seq_file *m;
	afs_cell_t *cell;
	int ret;

	cell = afs_get_cell_maybe((afs_cell_t**)&PDE(inode)->data);
	if (!cell)
		return -ENOENT;

	ret = seq_open(file,&afs_proc_cell_volumes_ops);
	if (ret<0)
		return ret;

	m = file->private_data;
	m->private = cell;

	return 0;
} /* end afs_proc_cell_volumes_open() */

/*****************************************************************************/
/*
 * close the file and release the ref to the cell
 */
static int afs_proc_cell_volumes_release(struct inode *inode, struct file *file)
{
	afs_cell_t *cell = PDE(inode)->data;
	int ret;

	ret = seq_release(inode,file);

	afs_put_cell(cell);

	return ret;
} /* end afs_proc_cell_volumes_release() */

/*****************************************************************************/
/*
 * set up the iterator to start reading from the cells list and return the first item
 */
static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
{
	struct list_head *_p;
	afs_cell_t *cell = m->private;
	loff_t pos = *_pos;

	_enter("cell=%p pos=%Ld",cell,*_pos);

	/* lock the list against modification */
	down_read(&cell->vl_sem);

	/* allow for the header line */
	if (!pos)
		return (void *)1;
	pos--;

	/* find the n'th element in the list */
	list_for_each(_p,&cell->vl_list)
		if (!pos--)
			break;

	return _p!=&cell->vl_list ? _p : NULL;
} /* end afs_proc_cell_volumes_start() */

/*****************************************************************************/
/*
 * move to next cell in cells list
 */
static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v, loff_t *_pos)
{
	struct list_head *_p;
	afs_cell_t *cell = p->private;

	_enter("cell=%p pos=%Ld",cell,*_pos);

	(*_pos)++;

	_p = v;
	_p = v==(void*)1 ? cell->vl_list.next : _p->next;

	return _p!=&cell->vl_list ? _p : NULL;
} /* end afs_proc_cell_volumes_next() */

/*****************************************************************************/
/*
 * clean up after reading from the cells list
 */
static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v)
{
	afs_cell_t *cell = p->private;

	up_read(&cell->vl_sem);

} /* end afs_proc_cell_volumes_stop() */

/*****************************************************************************/
/*
 * display a header line followed by a load of volume lines
 */
static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
{
	afs_vlocation_t *vlocation = list_entry(v,afs_vlocation_t,link);

	/* display header on line 1 */
	if (v == (void *)1) {
		seq_puts(m, "USE VLID[0]  VLID[1]  VLID[2]  NAME\n");
		return 0;
	}

	/* display one cell per line on subsequent lines */
	seq_printf(m,"%3d %08x %08x %08x %s\n",
		   atomic_read(&vlocation->usage),
		   vlocation->vldb.vid[0],
		   vlocation->vldb.vid[1],
		   vlocation->vldb.vid[2],
		   vlocation->vldb.name
		   );

	return 0;
} /* end afs_proc_cell_volumes_show() */

/*****************************************************************************/
/*
 * open "/proc/fs/afs/<cell>/vlservers" which provides a list of volume location server
 */
static int afs_proc_cell_vlservers_open(struct inode *inode, struct file *file)
{
	struct seq_file *m;
	afs_cell_t *cell;
	int ret;

	cell = afs_get_cell_maybe((afs_cell_t**)&PDE(inode)->data);
	if (!cell)
		return -ENOENT;

	ret = seq_open(file,&afs_proc_cell_vlservers_ops);
	if (ret<0)
		return ret;

	m = file->private_data;
	m->private = cell;

	return 0;
} /* end afs_proc_cell_vlservers_open() */

/*****************************************************************************/
/*
 * close the file and release the ref to the cell
 */
static int afs_proc_cell_vlservers_release(struct inode *inode, struct file *file)
{
	afs_cell_t *cell = PDE(inode)->data;
	int ret;

	ret = seq_release(inode,file);

	afs_put_cell(cell);

	return ret;
} /* end afs_proc_cell_vlservers_release() */

/*****************************************************************************/
/*
 * set up the iterator to start reading from the cells list and return the first item
 */
static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
{
	afs_cell_t *cell = m->private;
	loff_t pos = *_pos;

	_enter("cell=%p pos=%Ld",cell,*_pos);

	/* lock the list against modification */
	down_read(&cell->vl_sem);

	/* allow for the header line */
	if (!pos)
		return (void *)1;
	pos--;

	if (pos>=cell->vl_naddrs)
		return NULL;

	return &cell->vl_addrs[pos];
} /* end afs_proc_cell_vlservers_start() */

/*****************************************************************************/
/*
 * move to next cell in cells list
 */
static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v, loff_t *_pos)
{
	afs_cell_t *cell = p->private;
	loff_t pos;

	_enter("cell=%p{nad=%u} pos=%Ld",cell,cell->vl_naddrs,*_pos);

	pos = *_pos;
	(*_pos)++;
	if (pos>=cell->vl_naddrs)
		return NULL;

	return &cell->vl_addrs[pos];
} /* end afs_proc_cell_vlservers_next() */

/*****************************************************************************/
/*
 * clean up after reading from the cells list
 */
static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v)
{
	afs_cell_t *cell = p->private;

	up_read(&cell->vl_sem);

} /* end afs_proc_cell_vlservers_stop() */

/*****************************************************************************/
/*
 * display a header line followed by a load of volume lines
 */
static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
{
	struct in_addr *addr = v;

	/* display header on line 1 */
	if (v == (struct in_addr *)1) {
		seq_puts(m,"ADDRESS\n");
		return 0;
	}

	/* display one cell per line on subsequent lines */
	seq_printf(m,"%u.%u.%u.%u\n",NIPQUAD(addr->s_addr));

	return 0;
} /* end afs_proc_cell_vlservers_show() */

/*****************************************************************************/
/*
 * open "/proc/fs/afs/<cell>/servers" which provides a summary of active servers
 */
static int afs_proc_cell_servers_open(struct inode *inode, struct file *file)
{
	struct seq_file *m;
	afs_cell_t *cell;
	int ret;

	cell = afs_get_cell_maybe((afs_cell_t**)&PDE(inode)->data);
	if (!cell)
		return -ENOENT;

	ret = seq_open(file,&afs_proc_cell_servers_ops);
	if (ret<0)
		return ret;

	m = file->private_data;
	m->private = cell;

	return 0;
} /* end afs_proc_cell_servers_open() */

/*****************************************************************************/
/*
 * close the file and release the ref to the cell
 */
static int afs_proc_cell_servers_release(struct inode *inode, struct file *file)
{
	afs_cell_t *cell = PDE(inode)->data;
	int ret;

	ret = seq_release(inode,file);

	afs_put_cell(cell);

	return ret;
} /* end afs_proc_cell_servers_release() */

/*****************************************************************************/
/*
 * set up the iterator to start reading from the cells list and return the first item
 */
static void *afs_proc_cell_servers_start(struct seq_file *m, loff_t *_pos)
{
	struct list_head *_p;
	afs_cell_t *cell = m->private;
	loff_t pos = *_pos;

	_enter("cell=%p pos=%Ld",cell,*_pos);

	/* lock the list against modification */
	read_lock(&cell->sv_lock);

	/* allow for the header line */
	if (!pos)
		return (void *)1;
	pos--;

	/* find the n'th element in the list */
	list_for_each(_p,&cell->sv_list)
		if (!pos--)
			break;

	return _p!=&cell->sv_list ? _p : NULL;
} /* end afs_proc_cell_servers_start() */

/*****************************************************************************/
/*
 * move to next cell in cells list
 */
static void *afs_proc_cell_servers_next(struct seq_file *p, void *v, loff_t *_pos)
{
	struct list_head *_p;
	afs_cell_t *cell = p->private;

	_enter("cell=%p pos=%Ld",cell,*_pos);

	(*_pos)++;

	_p = v;
	_p = v==(void*)1 ? cell->sv_list.next : _p->next;

	return _p!=&cell->sv_list ? _p : NULL;
} /* end afs_proc_cell_servers_next() */

/*****************************************************************************/
/*
 * clean up after reading from the cells list
 */
static void afs_proc_cell_servers_stop(struct seq_file *p, void *v)
{
	afs_cell_t *cell = p->private;

	read_unlock(&cell->sv_lock);

} /* end afs_proc_cell_servers_stop() */

/*****************************************************************************/
/*
 * display a header line followed by a load of volume lines
 */
static int afs_proc_cell_servers_show(struct seq_file *m, void *v)
{
	afs_server_t *server = list_entry(v,afs_server_t,link);
	char ipaddr[20];

	/* display header on line 1 */
	if (v == (void *)1) {
		seq_puts(m, "USE ADDR            STATE\n");
		return 0;
	}

	/* display one cell per line on subsequent lines */
	sprintf(ipaddr,"%u.%u.%u.%u",NIPQUAD(server->addr));
	seq_printf(m,"%3d %-15.15s %5d\n",
		   atomic_read(&server->usage),
		   ipaddr,
		   server->fs_state
		   );

	return 0;
} /* end afs_proc_cell_servers_show() */
