/*
   * proc/fs/generic.c --- generic routines for the proc-fs
   *
   * This file contains generic proc-fs routines for handling
   * directories and files.
   * 
   * Copyright (C) 1991, 1992 Linus Torvalds.
   * Copyright (C) 1997 Theodore Ts'o
   */
  
  #include <linux/errno.h>
  #include <linux/time.h>
  #include <linux/proc_fs.h>
  #include <linux/stat.h>

  #include <linux/mm.h>

  #include <linux/module.h>

  #include <linux/slab.h>

  #include <linux/mount.h>

  #include <linux/init.h>
  #include <linux/idr.h>
  #include <linux/namei.h>
  #include <linux/bitops.h>

  #include <linux/spinlock.h>

  #include <linux/completion.h>

  #include <asm/uaccess.h>

  #include "internal.h"

  DEFINE_SPINLOCK(proc_subdir_lock);

  static int proc_match(unsigned int len, const char *name, struct proc_dir_entry *de)

  {
  	if (de->namelen != len)
  		return 0;
  	return !memcmp(name, de->name, len);
  }

  /* buffer size is one page but our output routines use some slack for overruns */
  #define PROC_BLOCK_SIZE	(PAGE_SIZE - 1024)
  
  static ssize_t

  __proc_file_read(struct file *file, char __user *buf, size_t nbytes,

  	       loff_t *ppos)
  {

  	struct inode * inode = file->f_path.dentry->d_inode;

  	char 	*page;
  	ssize_t	retval=0;
  	int	eof=0;
  	ssize_t	n, count;
  	char	*start;
  	struct proc_dir_entry * dp;

  	unsigned long long pos;
  
  	/*
  	 * Gaah, please just use "seq_file" instead. The legacy /proc
  	 * interfaces cut loff_t down to off_t for reads, and ignore
  	 * the offset entirely for writes..
  	 */
  	pos = *ppos;
  	if (pos > MAX_NON_LFS)
  		return 0;
  	if (nbytes > MAX_NON_LFS - pos)
  		nbytes = MAX_NON_LFS - pos;

  
  	dp = PDE(inode);

  	if (!(page = (char*) __get_free_page(GFP_TEMPORARY)))

  		return -ENOMEM;
  
  	while ((nbytes > 0) && !eof) {
  		count = min_t(size_t, PROC_BLOCK_SIZE, nbytes);
  
  		start = NULL;

  		if (dp->read_proc) {

  			/*
  			 * How to be a proc read function
  			 * ------------------------------
  			 * Prototype:
  			 *    int f(char *buffer, char **start, off_t offset,
  			 *          int count, int *peof, void *dat)
  			 *
  			 * Assume that the buffer is "count" bytes in size.
  			 *
  			 * If you know you have supplied all the data you
  			 * have, set *peof.
  			 *
  			 * You have three ways to return data:
  			 * 0) Leave *start = NULL.  (This is the default.)
  			 *    Put the data of the requested offset at that
  			 *    offset within the buffer.  Return the number (n)
  			 *    of bytes there are from the beginning of the
  			 *    buffer up to the last byte of data.  If the
  			 *    number of supplied bytes (= n - offset) is 
  			 *    greater than zero and you didn't signal eof
  			 *    and the reader is prepared to take more data
  			 *    you will be called again with the requested
  			 *    offset advanced by the number of bytes 
  			 *    absorbed.  This interface is useful for files
  			 *    no larger than the buffer.
  			 * 1) Set *start = an unsigned long value less than
  			 *    the buffer address but greater than zero.
  			 *    Put the data of the requested offset at the
  			 *    beginning of the buffer.  Return the number of
  			 *    bytes of data placed there.  If this number is
  			 *    greater than zero and you didn't signal eof
  			 *    and the reader is prepared to take more data
  			 *    you will be called again with the requested
  			 *    offset advanced by *start.  This interface is
  			 *    useful when you have a large file consisting
  			 *    of a series of blocks which you want to count
  			 *    and return as wholes.
  			 *    (Hack by Paul.Russell@rustcorp.com.au)
  			 * 2) Set *start = an address within the buffer.
  			 *    Put the data of the requested offset at *start.
  			 *    Return the number of bytes of data placed there.
  			 *    If this number is greater than zero and you
  			 *    didn't signal eof and the reader is prepared to
  			 *    take more data you will be called again with the
  			 *    requested offset advanced by the number of bytes
  			 *    absorbed.
  			 */
  			n = dp->read_proc(page, &start, *ppos,
  					  count, &eof, dp->data);
  		} else
  			break;
  
  		if (n == 0)   /* end of file */
  			break;
  		if (n < 0) {  /* error */
  			if (retval == 0)
  				retval = n;
  			break;
  		}
  
  		if (start == NULL) {
  			if (n > PAGE_SIZE) {
  				printk(KERN_ERR
  				       "proc_file_read: Apparent buffer overflow!
  ");
  				n = PAGE_SIZE;
  			}
  			n -= *ppos;
  			if (n <= 0)
  				break;
  			if (n > count)
  				n = count;
  			start = page + *ppos;
  		} else if (start < page) {
  			if (n > PAGE_SIZE) {
  				printk(KERN_ERR
  				       "proc_file_read: Apparent buffer overflow!
  ");
  				n = PAGE_SIZE;
  			}
  			if (n > count) {
  				/*
  				 * Don't reduce n because doing so might
  				 * cut off part of a data block.
  				 */
  				printk(KERN_WARNING
  				       "proc_file_read: Read count exceeded
  ");
  			}
  		} else /* start >= page */ {
  			unsigned long startoff = (unsigned long)(start - page);
  			if (n > (PAGE_SIZE - startoff)) {
  				printk(KERN_ERR
  				       "proc_file_read: Apparent buffer overflow!
  ");
  				n = PAGE_SIZE - startoff;
  			}
  			if (n > count)
  				n = count;
  		}
  		
   		n -= copy_to_user(buf, start < page ? page : start, n);
  		if (n == 0) {
  			if (retval == 0)
  				retval = -EFAULT;
  			break;
  		}
  
  		*ppos += start < page ? (unsigned long)start : n;
  		nbytes -= n;
  		buf += n;
  		retval += n;
  	}
  	free_page((unsigned long) page);
  	return retval;
  }
  
  static ssize_t

  proc_file_read(struct file *file, char __user *buf, size_t nbytes,
  	       loff_t *ppos)
  {
  	struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
  	ssize_t rv = -EIO;
  
  	spin_lock(&pde->pde_unload_lock);
  	if (!pde->proc_fops) {
  		spin_unlock(&pde->pde_unload_lock);
  		return rv;
  	}
  	pde->pde_users++;
  	spin_unlock(&pde->pde_unload_lock);
  
  	rv = __proc_file_read(file, buf, nbytes, ppos);
  
  	pde_users_dec(pde);
  	return rv;
  }
  
  static ssize_t

  proc_file_write(struct file *file, const char __user *buffer,
  		size_t count, loff_t *ppos)
  {

  	struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
  	ssize_t rv = -EIO;
  
  	if (pde->write_proc) {
  		spin_lock(&pde->pde_unload_lock);
  		if (!pde->proc_fops) {
  			spin_unlock(&pde->pde_unload_lock);
  			return rv;
  		}
  		pde->pde_users++;
  		spin_unlock(&pde->pde_unload_lock);

  		/* FIXME: does this routine need ppos?  probably... */
  		rv = pde->write_proc(file, buffer, count, pde->data);
  		pde_users_dec(pde);
  	}
  	return rv;

  }
  
  
  static loff_t
  proc_file_lseek(struct file *file, loff_t offset, int orig)
  {

  	loff_t retval = -EINVAL;
  	switch (orig) {
  	case 1:
  		offset += file->f_pos;
  	/* fallthrough */
  	case 0:
  		if (offset < 0 || offset > MAX_NON_LFS)
  			break;
  		file->f_pos = retval = offset;
  	}
  	return retval;

  }

  static const struct file_operations proc_file_operations = {
  	.llseek		= proc_file_lseek,
  	.read		= proc_file_read,
  	.write		= proc_file_write,
  };

  static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
  {
  	struct inode *inode = dentry->d_inode;
  	struct proc_dir_entry *de = PDE(inode);
  	int error;
  
  	error = inode_change_ok(inode, iattr);
  	if (error)

  		return error;

  	if ((iattr->ia_valid & ATTR_SIZE) &&
  	    iattr->ia_size != i_size_read(inode)) {
  		error = vmtruncate(inode, iattr->ia_size);
  		if (error)
  			return error;
  	}
  
  	setattr_copy(inode, iattr);
  	mark_inode_dirty(inode);

  	
  	de->uid = inode->i_uid;
  	de->gid = inode->i_gid;
  	de->mode = inode->i_mode;

  	return 0;

  }

  static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
  			struct kstat *stat)
  {
  	struct inode *inode = dentry->d_inode;
  	struct proc_dir_entry *de = PROC_I(inode)->pde;
  	if (de && de->nlink)

  		set_nlink(inode, de->nlink);

  
  	generic_fillattr(inode, stat);
  	return 0;
  }

  static const struct inode_operations proc_file_inode_operations = {

  	.setattr	= proc_notify_change,
  };
  
  /*
   * This function parses a name such as "tty/driver/serial", and
   * returns the struct proc_dir_entry for "/proc/tty/driver", and
   * returns "serial" in residual.
   */

  static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
  			     const char **residual)

  {
  	const char     		*cp = name, *next;
  	struct proc_dir_entry	*de;

  	unsigned int		len;

  	de = *ret;
  	if (!de)
  		de = &proc_root;

  	while (1) {
  		next = strchr(cp, '/');
  		if (!next)
  			break;
  
  		len = next - cp;
  		for (de = de->subdir; de ; de = de->next) {
  			if (proc_match(len, cp, de))
  				break;
  		}

  		if (!de) {
  			WARN(1, "name '%s'
  ", name);

  			return -ENOENT;

  		}

  		cp += len + 1;
  	}
  	*residual = cp;
  	*ret = de;

  	return 0;
  }
  
  static int xlate_proc_name(const char *name, struct proc_dir_entry **ret,
  			   const char **residual)
  {
  	int rv;
  
  	spin_lock(&proc_subdir_lock);
  	rv = __xlate_proc_name(name, ret, residual);

  	spin_unlock(&proc_subdir_lock);

  	return rv;

  }

  static DEFINE_IDA(proc_inum_ida);

  static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */

  #define PROC_DYNAMIC_FIRST 0xF0000000U

  
  /*
   * Return an inode number between PROC_DYNAMIC_FIRST and
   * 0xffffffff, or zero on failure.
   */
  static unsigned int get_inode_number(void)
  {

  	unsigned int i;

  	int error;
  
  retry:

  	if (ida_pre_get(&proc_inum_ida, GFP_KERNEL) == 0)

  		return 0;
  
  	spin_lock(&proc_inum_lock);

  	error = ida_get_new(&proc_inum_ida, &i);

  	spin_unlock(&proc_inum_lock);
  	if (error == -EAGAIN)
  		goto retry;
  	else if (error)
  		return 0;

  	if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
  		spin_lock(&proc_inum_lock);

  		ida_remove(&proc_inum_ida, i);

  		spin_unlock(&proc_inum_lock);

  		return 0;

  	}
  	return PROC_DYNAMIC_FIRST + i;

  }
  
  static void release_inode_number(unsigned int inum)
  {

  	spin_lock(&proc_inum_lock);

  	ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);

  	spin_unlock(&proc_inum_lock);
  }

  static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)

  {
  	nd_set_link(nd, PDE(dentry->d_inode)->data);

  	return NULL;

  }

  static const struct inode_operations proc_link_inode_operations = {

  	.readlink	= generic_readlink,
  	.follow_link	= proc_follow_link,
  };
  
  /*
   * As some entries in /proc are volatile, we want to 
   * get rid of unused dentries.  This could be made 
   * smarter: we could keep a "volatile" flag in the 
   * inode to indicate which ones to keep.
   */

  static int proc_delete_dentry(const struct dentry * dentry)

  {
  	return 1;
  }

  static const struct dentry_operations proc_dentry_operations =

  {
  	.d_delete	= proc_delete_dentry,
  };
  
  /*
   * Don't create negative dentries here, return -ENOENT by hand
   * instead.
   */

  struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
  		struct dentry *dentry)

  {
  	struct inode *inode = NULL;

  	int error = -ENOENT;

  	spin_lock(&proc_subdir_lock);

  	for (de = de->subdir; de ; de = de->next) {
  		if (de->namelen != dentry->d_name.len)
  			continue;
  		if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {

  			pde_get(de);

  			spin_unlock(&proc_subdir_lock);
  			error = -EINVAL;

  			inode = proc_get_inode(dir->i_sb, de);

  			goto out_unlock;

  		}
  	}

  	spin_unlock(&proc_subdir_lock);

  out_unlock:

  
  	if (inode) {

  		d_set_d_op(dentry, &proc_dentry_operations);

  		d_add(dentry, inode);
  		return NULL;
  	}

  	if (de)

  		pde_put(de);

  	return ERR_PTR(error);
  }

  struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
  		struct nameidata *nd)
  {
  	return proc_lookup_de(PDE(dir), dir, dentry);
  }

  /*
   * This returns non-zero if at EOF, so that the /proc
   * root directory can use this and check if it should
   * continue with the <pid> entries..
   *
   * Note that the VFS-layer doesn't care about the return
   * value of the readdir() call, as long as it's non-negative
   * for success..
   */

  int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent,
  		filldir_t filldir)

  {

  	unsigned int ino;
  	int i;

  	struct inode *inode = filp->f_path.dentry->d_inode;

  	int ret = 0;

  	ino = inode->i_ino;

  	i = filp->f_pos;
  	switch (i) {
  		case 0:
  			if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
  				goto out;
  			i++;
  			filp->f_pos++;
  			/* fall through */
  		case 1:
  			if (filldir(dirent, "..", 2, i,

  				    parent_ino(filp->f_path.dentry),

  				    DT_DIR) < 0)
  				goto out;
  			i++;
  			filp->f_pos++;
  			/* fall through */
  		default:

  			spin_lock(&proc_subdir_lock);

  			de = de->subdir;
  			i -= 2;
  			for (;;) {
  				if (!de) {
  					ret = 1;

  					spin_unlock(&proc_subdir_lock);

  					goto out;
  				}
  				if (!i)
  					break;
  				de = de->next;
  				i--;
  			}
  
  			do {

  				struct proc_dir_entry *next;

  				/* filldir passes info to user space */

  				pde_get(de);

  				spin_unlock(&proc_subdir_lock);

  				if (filldir(dirent, de->name, de->namelen, filp->f_pos,

  					    de->low_ino, de->mode >> 12) < 0) {

  					pde_put(de);

  					goto out;

  				}

  				spin_lock(&proc_subdir_lock);

  				filp->f_pos++;

  				next = de->next;

  				pde_put(de);

  				de = next;

  			} while (de);

  			spin_unlock(&proc_subdir_lock);

  	}
  	ret = 1;

  out:

  	return ret;	
  }

  int proc_readdir(struct file *filp, void *dirent, filldir_t filldir)
  {
  	struct inode *inode = filp->f_path.dentry->d_inode;
  
  	return proc_readdir_de(PDE(inode), filp, dirent, filldir);
  }

  /*
   * These are the generic /proc directory operations. They
   * use the in-memory "struct proc_dir_entry" tree to parse
   * the /proc directory.
   */

  static const struct file_operations proc_dir_operations = {

  	.llseek			= generic_file_llseek,

  	.read			= generic_read_dir,
  	.readdir		= proc_readdir,
  };
  
  /*
   * proc directories can do almost nothing..
   */

  static const struct inode_operations proc_dir_inode_operations = {

  	.lookup		= proc_lookup,

  	.getattr	= proc_getattr,

  	.setattr	= proc_notify_change,
  };
  
  static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
  {
  	unsigned int i;

  	struct proc_dir_entry *tmp;

  	
  	i = get_inode_number();
  	if (i == 0)
  		return -EAGAIN;
  	dp->low_ino = i;

  	if (S_ISDIR(dp->mode)) {
  		if (dp->proc_iops == NULL) {
  			dp->proc_fops = &proc_dir_operations;
  			dp->proc_iops = &proc_dir_inode_operations;
  		}
  		dir->nlink++;
  	} else if (S_ISLNK(dp->mode)) {
  		if (dp->proc_iops == NULL)
  			dp->proc_iops = &proc_link_inode_operations;
  	} else if (S_ISREG(dp->mode)) {
  		if (dp->proc_fops == NULL)
  			dp->proc_fops = &proc_file_operations;
  		if (dp->proc_iops == NULL)
  			dp->proc_iops = &proc_file_inode_operations;
  	}

  
  	spin_lock(&proc_subdir_lock);

  
  	for (tmp = dir->subdir; tmp; tmp = tmp->next)
  		if (strcmp(tmp->name, dp->name) == 0) {

  			WARN(1, KERN_WARNING "proc_dir_entry '%s/%s' already registered
  ",

  				dir->name, dp->name);

  			break;
  		}

  	dp->next = dir->subdir;
  	dp->parent = dir;
  	dir->subdir = dp;
  	spin_unlock(&proc_subdir_lock);

  	return 0;
  }

  static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,

  					  const char *name,
  					  mode_t mode,
  					  nlink_t nlink)
  {
  	struct proc_dir_entry *ent = NULL;
  	const char *fn = name;

  	unsigned int len;

  
  	/* make sure name is valid */
  	if (!name || !strlen(name)) goto out;

  	if (xlate_proc_name(name, parent, &fn) != 0)

  		goto out;
  
  	/* At this point there must not be any '/' characters beyond *fn */
  	if (strchr(fn, '/'))
  		goto out;
  
  	len = strlen(fn);
  
  	ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
  	if (!ent) goto out;
  
  	memset(ent, 0, sizeof(struct proc_dir_entry));

  	memcpy(ent->name, fn, len + 1);

  	ent->namelen = len;
  	ent->mode = mode;
  	ent->nlink = nlink;

  	atomic_set(&ent->count, 1);

  	ent->pde_users = 0;
  	spin_lock_init(&ent->pde_unload_lock);
  	ent->pde_unload_completion = NULL;

  	INIT_LIST_HEAD(&ent->pde_openers);

   out:
  	return ent;
  }
  
  struct proc_dir_entry *proc_symlink(const char *name,
  		struct proc_dir_entry *parent, const char *dest)
  {
  	struct proc_dir_entry *ent;

  	ent = __proc_create(&parent, name,

  			  (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
  
  	if (ent) {
  		ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
  		if (ent->data) {
  			strcpy((char*)ent->data,dest);
  			if (proc_register(parent, ent) < 0) {
  				kfree(ent->data);
  				kfree(ent);
  				ent = NULL;
  			}
  		} else {
  			kfree(ent);
  			ent = NULL;
  		}
  	}
  	return ent;
  }

  EXPORT_SYMBOL(proc_symlink);

  
  struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode,
  		struct proc_dir_entry *parent)
  {
  	struct proc_dir_entry *ent;

  	ent = __proc_create(&parent, name, S_IFDIR | mode, 2);

  	if (ent) {

  		if (proc_register(parent, ent) < 0) {
  			kfree(ent);
  			ent = NULL;
  		}
  	}
  	return ent;
  }

  EXPORT_SYMBOL(proc_mkdir_mode);

  struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
  		struct proc_dir_entry *parent)
  {
  	struct proc_dir_entry *ent;
  
  	ent = __proc_create(&parent, name, S_IFDIR | S_IRUGO | S_IXUGO, 2);
  	if (ent) {
  		ent->data = net;
  		if (proc_register(parent, ent) < 0) {
  			kfree(ent);
  			ent = NULL;
  		}
  	}
  	return ent;
  }
  EXPORT_SYMBOL_GPL(proc_net_mkdir);

  struct proc_dir_entry *proc_mkdir(const char *name,
  		struct proc_dir_entry *parent)
  {
  	return proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent);
  }

  EXPORT_SYMBOL(proc_mkdir);

  
  struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
  					 struct proc_dir_entry *parent)
  {
  	struct proc_dir_entry *ent;
  	nlink_t nlink;
  
  	if (S_ISDIR(mode)) {
  		if ((mode & S_IALLUGO) == 0)
  			mode |= S_IRUGO | S_IXUGO;
  		nlink = 2;
  	} else {
  		if ((mode & S_IFMT) == 0)
  			mode |= S_IFREG;
  		if ((mode & S_IALLUGO) == 0)
  			mode |= S_IRUGO;
  		nlink = 1;
  	}

  	ent = __proc_create(&parent, name, mode, nlink);

  	if (ent) {

  		if (proc_register(parent, ent) < 0) {
  			kfree(ent);
  			ent = NULL;
  		}
  	}
  	return ent;
  }

  EXPORT_SYMBOL(create_proc_entry);

  struct proc_dir_entry *proc_create_data(const char *name, mode_t mode,
  					struct proc_dir_entry *parent,
  					const struct file_operations *proc_fops,
  					void *data)

  {
  	struct proc_dir_entry *pde;
  	nlink_t nlink;
  
  	if (S_ISDIR(mode)) {
  		if ((mode & S_IALLUGO) == 0)
  			mode |= S_IRUGO | S_IXUGO;
  		nlink = 2;
  	} else {
  		if ((mode & S_IFMT) == 0)
  			mode |= S_IFREG;
  		if ((mode & S_IALLUGO) == 0)
  			mode |= S_IRUGO;
  		nlink = 1;
  	}
  
  	pde = __proc_create(&parent, name, mode, nlink);
  	if (!pde)
  		goto out;
  	pde->proc_fops = proc_fops;

  	pde->data = data;

  	if (proc_register(parent, pde) < 0)
  		goto out_free;
  	return pde;
  out_free:
  	kfree(pde);
  out:
  	return NULL;
  }

  EXPORT_SYMBOL(proc_create_data);

  static void free_proc_entry(struct proc_dir_entry *de)

  {

  	release_inode_number(de->low_ino);

  	if (S_ISLNK(de->mode))

  		kfree(de->data);
  	kfree(de);
  }

  void pde_put(struct proc_dir_entry *pde)
  {
  	if (atomic_dec_and_test(&pde->count))
  		free_proc_entry(pde);
  }

  /*
   * Remove a /proc entry and free it if it's not currently in use.

   */
  void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
  {
  	struct proc_dir_entry **p;

  	struct proc_dir_entry *de = NULL;

  	const char *fn = name;

  	unsigned int len;

  	spin_lock(&proc_subdir_lock);
  	if (__xlate_proc_name(name, &parent, &fn) != 0) {
  		spin_unlock(&proc_subdir_lock);

  		return;

  	}

  	len = strlen(fn);

  	for (p = &parent->subdir; *p; p=&(*p)->next ) {

  		if (proc_match(len, fn, *p)) {
  			de = *p;
  			*p = de->next;
  			de->next = NULL;
  			break;
  		}
  	}
  	spin_unlock(&proc_subdir_lock);

  	if (!de) {
  		WARN(1, "name '%s'
  ", name);

  		return;

  	}

  	spin_lock(&de->pde_unload_lock);
  	/*
  	 * Stop accepting new callers into module. If you're
  	 * dynamically allocating ->proc_fops, save a pointer somewhere.
  	 */
  	de->proc_fops = NULL;
  	/* Wait until all existing callers into module are done. */
  	if (de->pde_users > 0) {
  		DECLARE_COMPLETION_ONSTACK(c);
  
  		if (!de->pde_unload_completion)
  			de->pde_unload_completion = &c;

  		spin_unlock(&de->pde_unload_lock);

  		wait_for_completion(de->pde_unload_completion);

  		spin_lock(&de->pde_unload_lock);

  	}

  	while (!list_empty(&de->pde_openers)) {
  		struct pde_opener *pdeo;
  
  		pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
  		list_del(&pdeo->lh);
  		spin_unlock(&de->pde_unload_lock);
  		pdeo->release(pdeo->inode, pdeo->file);
  		kfree(pdeo);
  		spin_lock(&de->pde_unload_lock);
  	}
  	spin_unlock(&de->pde_unload_lock);

  	if (S_ISDIR(de->mode))
  		parent->nlink--;
  	de->nlink = 0;

  	WARN(de->subdir, KERN_WARNING "%s: removing non-empty directory "

  			"'%s/%s', leaking at least '%s'
  ", __func__,
  			de->parent->name, de->name, de->subdir->name);

  	pde_put(de);

  }

  EXPORT_SYMBOL(remove_proc_entry);