[net-next-2.6.git] / fs / autofs / root.c

/* -*- linux-c -*- --------------------------------------------------------- *
 *
 * linux/fs/autofs/root.c
 *
 *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
 *
 * This file is part of the Linux kernel and is made available under
 * the terms of the GNU General Public License, version 2, or at your
 * option, any later version, incorporated herein by reference.
 *
 * ------------------------------------------------------------------------- */

#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/param.h>
#include <linux/time.h>
#include <linux/compat.h>
#include <linux/smp_lock.h>
#include "autofs_i.h"

static int autofs_root_readdir(struct file *,void *,filldir_t);
static struct dentry *autofs_root_lookup(struct inode *,struct dentry *, struct nameidata *);
static int autofs_root_symlink(struct inode *,struct dentry *,const char *);
static int autofs_root_unlink(struct inode *,struct dentry *);
static int autofs_root_rmdir(struct inode *,struct dentry *);
static int autofs_root_mkdir(struct inode *,struct dentry *,int);
static long autofs_root_ioctl(struct file *,unsigned int,unsigned long);
#ifdef CONFIG_COMPAT
static long autofs_root_compat_ioctl(struct file *,unsigned int,unsigned long);
#endif

const struct file_operations autofs_root_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.readdir	= autofs_root_readdir,
	.unlocked_ioctl	= autofs_root_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= autofs_root_compat_ioctl,
#endif
};

const struct inode_operations autofs_root_inode_operations = {
        .lookup		= autofs_root_lookup,
        .unlink		= autofs_root_unlink,
        .symlink	= autofs_root_symlink,
        .mkdir		= autofs_root_mkdir,
        .rmdir		= autofs_root_rmdir,
};

static int autofs_root_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct autofs_dir_ent *ent = NULL;
	struct autofs_dirhash *dirhash;
	struct autofs_sb_info *sbi;
	struct inode * inode = filp->f_path.dentry->d_inode;
	off_t onr, nr;

	lock_kernel();

	sbi = autofs_sbi(inode->i_sb);
	dirhash = &sbi->dirhash;
	nr = filp->f_pos;

	switch(nr)
	{
	case 0:
		if (filldir(dirent, ".", 1, nr, inode->i_ino, DT_DIR) < 0)
			goto out;
		filp->f_pos = ++nr;
		/* fall through */
	case 1:
		if (filldir(dirent, "..", 2, nr, inode->i_ino, DT_DIR) < 0)
			goto out;
		filp->f_pos = ++nr;
		/* fall through */
	default:
		while (onr = nr, ent = autofs_hash_enum(dirhash,&nr,ent)) {
			if (!ent->dentry || d_mountpoint(ent->dentry)) {
				if (filldir(dirent,ent->name,ent->len,onr,ent->ino,DT_UNKNOWN) < 0)
					goto out;
				filp->f_pos = nr;
			}
		}
		break;
	}

out:
	unlock_kernel();
	return 0;
}

static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, struct autofs_sb_info *sbi)
{
	struct inode * inode;
	struct autofs_dir_ent *ent;
	int status = 0;

	if (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name))) {
		do {
			if (status && dentry->d_inode) {
				if (status != -ENOENT)
					printk("autofs warning: lookup failure on positive dentry, status = %d, name = %s\n", status, dentry->d_name.name);
				return 0; /* Try to get the kernel to invalidate this dentry */
			}

			/* Turn this into a real negative dentry? */
			if (status == -ENOENT) {
				dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
				dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
				return 1;
			} else if (status) {
				/* Return a negative dentry, but leave it "pending" */
				return 1;
			}
			status = autofs_wait(sbi, &dentry->d_name);
		} while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)));
	}

	/* Abuse this field as a pointer to the directory entry, used to
	   find the expire list pointers */
	dentry->d_time = (unsigned long) ent;
	
	if (!dentry->d_inode) {
		inode = autofs_iget(sb, ent->ino);
		if (IS_ERR(inode)) {
			/* Failed, but leave pending for next time */
			return 1;
		}
		dentry->d_inode = inode;
	}

	/* If this is a directory that isn't a mount point, bitch at the
	   daemon and fix it in user space */
	if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
		return !autofs_wait(sbi, &dentry->d_name);
	}

	/* We don't update the usages for the autofs daemon itself, this
	   is necessary for recursive autofs mounts */
	if (!autofs_oz_mode(sbi)) {
		autofs_update_usage(&sbi->dirhash,ent);
	}

	dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
	return 1;
}


/*
 * Revalidate is called on every cache lookup.  Some of those
 * cache lookups may actually happen while the dentry is not
 * yet completely filled in, and revalidate has to delay such
 * lookups..
 */
static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
{
	struct inode * dir;
	struct autofs_sb_info *sbi;
	struct autofs_dir_ent *ent;
	int res;

	lock_kernel();
	dir = dentry->d_parent->d_inode;
	sbi = autofs_sbi(dir->i_sb);

	/* Pending dentry */
	if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
		if (autofs_oz_mode(sbi))
			res = 1;
		else
			res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
		unlock_kernel();
		return res;
	}

	/* Negative dentry.. invalidate if "old" */
	if (!dentry->d_inode) {
		unlock_kernel();
		return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
	}
		
	/* Check for a non-mountpoint directory */
	if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
		if (autofs_oz_mode(sbi))
			res = 1;
		else
			res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
		unlock_kernel();
		return res;
	}

	/* Update the usage list */
	if (!autofs_oz_mode(sbi)) {
		ent = (struct autofs_dir_ent *) dentry->d_time;
		if (ent)
			autofs_update_usage(&sbi->dirhash,ent);
	}
	unlock_kernel();
	return 1;
}

static const struct dentry_operations autofs_dentry_operations = {
	.d_revalidate	= autofs_revalidate,
};

static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
	struct autofs_sb_info *sbi;
	int oz_mode;

	DPRINTK(("autofs_root_lookup: name = "));
	lock_kernel();
	autofs_say(dentry->d_name.name,dentry->d_name.len);

	if (dentry->d_name.len > NAME_MAX) {
		unlock_kernel();
		return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
	}

	sbi = autofs_sbi(dir->i_sb);

	oz_mode = autofs_oz_mode(sbi);
	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, "
				"oz_mode = %d\n", task_pid_nr(current),
				task_pgrp_nr(current), sbi->catatonic,
				oz_mode));

	/*
	 * Mark the dentry incomplete, but add it. This is needed so
	 * that the VFS layer knows about the dentry, and we can count
	 * on catching any lookups through the revalidate.
	 *
	 * Let all the hard work be done by the revalidate function that
	 * needs to be able to do this anyway..
	 *
	 * We need to do this before we release the directory semaphore.
	 */
	dentry->d_op = &autofs_dentry_operations;
	dentry->d_flags |= DCACHE_AUTOFS_PENDING;
	d_add(dentry, NULL);

	mutex_unlock(&dir->i_mutex);
	autofs_revalidate(dentry, nd);
	mutex_lock(&dir->i_mutex);

	/*
	 * If we are still pending, check if we had to handle
	 * a signal. If so we can force a restart..
	 */
	if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
		/* See if we were interrupted */
		if (signal_pending(current)) {
			sigset_t *sigset = &current->pending.signal;
			if (sigismember (sigset, SIGKILL) ||
			    sigismember (sigset, SIGQUIT) ||
			    sigismember (sigset, SIGINT)) {
				unlock_kernel();
				return ERR_PTR(-ERESTARTNOINTR);
			}
		}
	}
	unlock_kernel();

	/*
	 * If this dentry is unhashed, then we shouldn't honour this
	 * lookup even if the dentry is positive.  Returning ENOENT here
	 * doesn't do the right thing for all system calls, but it should
	 * be OK for the operations we permit from an autofs.
	 */
	if (dentry->d_inode && d_unhashed(dentry))
		return ERR_PTR(-ENOENT);

	return NULL;
}

static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	struct autofs_dirhash *dh = &sbi->dirhash;
	struct autofs_dir_ent *ent;
	unsigned int n;
	int slsize;
	struct autofs_symlink *sl;
	struct inode *inode;

	DPRINTK(("autofs_root_symlink: %s <- ", symname));
	autofs_say(dentry->d_name.name,dentry->d_name.len);

	lock_kernel();
	if (!autofs_oz_mode(sbi)) {
		unlock_kernel();
		return -EACCES;
	}

	if (autofs_hash_lookup(dh, &dentry->d_name)) {
		unlock_kernel();
		return -EEXIST;
	}

	n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS);
	if (n >= AUTOFS_MAX_SYMLINKS) {
		unlock_kernel();
		return -ENOSPC;
	}

	set_bit(n,sbi->symlink_bitmap);
	sl = &sbi->symlink[n];
	sl->len = strlen(symname);
	sl->data = kmalloc(slsize = sl->len+1, GFP_KERNEL);
	if (!sl->data) {
		clear_bit(n,sbi->symlink_bitmap);
		unlock_kernel();
		return -ENOSPC;
	}

	ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
	if (!ent) {
		kfree(sl->data);
		clear_bit(n,sbi->symlink_bitmap);
		unlock_kernel();
		return -ENOSPC;
	}

	ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
	if (!ent->name) {
		kfree(sl->data);
		kfree(ent);
		clear_bit(n,sbi->symlink_bitmap);
		unlock_kernel();
		return -ENOSPC;
	}

	memcpy(sl->data,symname,slsize);
	sl->mtime = get_seconds();

	ent->ino = AUTOFS_FIRST_SYMLINK + n;
	ent->hash = dentry->d_name.hash;
	memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
	ent->dentry = NULL;	/* We don't keep the dentry for symlinks */

	autofs_hash_insert(dh,ent);

	inode = autofs_iget(dir->i_sb, ent->ino);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	d_instantiate(dentry, inode);
	unlock_kernel();
	return 0;
}

/*
 * NOTE!
 *
 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
 * that the file no longer exists. However, doing that means that the
 * VFS layer can turn the dentry into a negative dentry, which we
 * obviously do not want (we're dropping the entry not because it
 * doesn't exist, but because it has timed out).
 *
 * Also see autofs_root_rmdir()..
 */
static int autofs_root_unlink(struct inode *dir, struct dentry *dentry)
{
	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	struct autofs_dirhash *dh = &sbi->dirhash;
	struct autofs_dir_ent *ent;
	unsigned int n;

	/* This allows root to remove symlinks */
	lock_kernel();
	if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) {
		unlock_kernel();
		return -EACCES;
	}

	ent = autofs_hash_lookup(dh, &dentry->d_name);
	if (!ent) {
		unlock_kernel();
		return -ENOENT;
	}

	n = ent->ino - AUTOFS_FIRST_SYMLINK;
	if (n >= AUTOFS_MAX_SYMLINKS) {
		unlock_kernel();
		return -EISDIR;	/* It's a directory, dummy */
	}
	if (!test_bit(n,sbi->symlink_bitmap)) {
		unlock_kernel();
		return -EINVAL;	/* Nonexistent symlink?  Shouldn't happen */
	}
	
	dentry->d_time = (unsigned long)(struct autofs_dirhash *)NULL;
	autofs_hash_delete(ent);
	clear_bit(n,sbi->symlink_bitmap);
	kfree(sbi->symlink[n].data);
	d_drop(dentry);
	
	unlock_kernel();
	return 0;
}

static int autofs_root_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	struct autofs_dirhash *dh = &sbi->dirhash;
	struct autofs_dir_ent *ent;

	lock_kernel();
	if (!autofs_oz_mode(sbi)) {
		unlock_kernel();
		return -EACCES;
	}

	ent = autofs_hash_lookup(dh, &dentry->d_name);
	if (!ent) {
		unlock_kernel();
		return -ENOENT;
	}

	if ((unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO) {
		unlock_kernel();
		return -ENOTDIR; /* Not a directory */
	}

	if (ent->dentry != dentry) {
		printk("autofs_rmdir: odentry != dentry for entry %s\n", dentry->d_name.name);
	}

	dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL;
	autofs_hash_delete(ent);
	drop_nlink(dir);
	d_drop(dentry);
	unlock_kernel();

	return 0;
}

static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	struct autofs_dirhash *dh = &sbi->dirhash;
	struct autofs_dir_ent *ent;
	struct inode *inode;
	ino_t ino;

	lock_kernel();
	if (!autofs_oz_mode(sbi)) {
		unlock_kernel();
		return -EACCES;
	}

	ent = autofs_hash_lookup(dh, &dentry->d_name);
	if (ent) {
		unlock_kernel();
		return -EEXIST;
	}

	if (sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO) {
		printk("autofs: Out of inode numbers -- what the heck did you do??\n");
		unlock_kernel();
		return -ENOSPC;
	}
	ino = sbi->next_dir_ino++;

	ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
	if (!ent) {
		unlock_kernel();
		return -ENOSPC;
	}

	ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
	if (!ent->name) {
		kfree(ent);
		unlock_kernel();
		return -ENOSPC;
	}

	ent->hash = dentry->d_name.hash;
	memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
	ent->ino = ino;
	ent->dentry = dentry;
	autofs_hash_insert(dh,ent);

	inc_nlink(dir);

	inode = autofs_iget(dir->i_sb, ino);
	if (IS_ERR(inode)) {
		drop_nlink(dir);
		return PTR_ERR(inode);
	}

	d_instantiate(dentry, inode);
	unlock_kernel();

	return 0;
}

/* Get/set timeout ioctl() operation */
#ifdef CONFIG_COMPAT
static inline int autofs_compat_get_set_timeout(struct autofs_sb_info *sbi,
					 unsigned int __user *p)
{
	unsigned long ntimeout;

	if (get_user(ntimeout, p) ||
	    put_user(sbi->exp_timeout / HZ, p))
		return -EFAULT;

	if (ntimeout > UINT_MAX/HZ)
		sbi->exp_timeout = 0;
	else
		sbi->exp_timeout = ntimeout * HZ;

	return 0;
}
#endif

static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
					 unsigned long __user *p)
{
	unsigned long ntimeout;

	if (get_user(ntimeout, p) ||
	    put_user(sbi->exp_timeout / HZ, p))
		return -EFAULT;

	if (ntimeout > ULONG_MAX/HZ)
		sbi->exp_timeout = 0;
	else
		sbi->exp_timeout = ntimeout * HZ;

	return 0;
}

/* Return protocol version */
static inline int autofs_get_protover(int __user *p)
{
	return put_user(AUTOFS_PROTO_VERSION, p);
}

/* Perform an expiry operation */
static inline int autofs_expire_run(struct super_block *sb,
				    struct autofs_sb_info *sbi,
				    struct vfsmount *mnt,
				    struct autofs_packet_expire __user *pkt_p)
{
	struct autofs_dir_ent *ent;
	struct autofs_packet_expire pkt;

	memset(&pkt,0,sizeof pkt);

	pkt.hdr.proto_version = AUTOFS_PROTO_VERSION;
	pkt.hdr.type = autofs_ptype_expire;

	if (!sbi->exp_timeout || !(ent = autofs_expire(sb,sbi,mnt)))
		return -EAGAIN;

	pkt.len = ent->len;
	memcpy(pkt.name, ent->name, pkt.len);
	pkt.name[pkt.len] = '\0';

	if (copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)))
		return -EFAULT;

	return 0;
}

/*
 * ioctl()'s on the root directory is the chief method for the daemon to
 * generate kernel reactions
 */
static int autofs_do_root_ioctl(struct inode *inode, struct file *filp,
			     unsigned int cmd, unsigned long arg)
{
	struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
	void __user *argp = (void __user *)arg;

	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,task_pgrp_nr(current)));

	if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
	     _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
		return -ENOTTY;
	
	if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
		return -EPERM;
	
	switch(cmd) {
	case AUTOFS_IOC_READY:	/* Wait queue: go ahead and retry */
		return autofs_wait_release(sbi,(autofs_wqt_t)arg,0);
	case AUTOFS_IOC_FAIL:	/* Wait queue: fail with ENOENT */
		return autofs_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
	case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
		autofs_catatonic_mode(sbi);
		return 0;
	case AUTOFS_IOC_PROTOVER: /* Get protocol version */
		return autofs_get_protover(argp);
#ifdef CONFIG_COMPAT
	case AUTOFS_IOC_SETTIMEOUT32:
		return autofs_compat_get_set_timeout(sbi, argp);
#endif
	case AUTOFS_IOC_SETTIMEOUT:
		return autofs_get_set_timeout(sbi, argp);
	case AUTOFS_IOC_EXPIRE:
		return autofs_expire_run(inode->i_sb, sbi, filp->f_path.mnt,
					 argp);
	default:
		return -ENOSYS;
	}

}

static long autofs_root_ioctl(struct file *filp,
			     unsigned int cmd, unsigned long arg)
{
	int ret;

	lock_kernel();
	ret = autofs_do_root_ioctl(filp->f_path.dentry->d_inode,
				   filp, cmd, arg);
	unlock_kernel();

	return ret;
}

#ifdef CONFIG_COMPAT
static long autofs_root_compat_ioctl(struct file *filp,
			     unsigned int cmd, unsigned long arg)
{
	struct inode *inode = filp->f_path.dentry->d_inode;
	int ret;

	lock_kernel();
	if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL)
		ret = autofs_do_root_ioctl(inode, filp, cmd, arg);
	else
		ret = autofs_do_root_ioctl(inode, filp, cmd,
			(unsigned long)compat_ptr(arg));
	unlock_kernel();

	return ret;
}
#endif
Commit	Line	Data
1da177e4 LT	1	/* -- linux-c -- --------------------------------------------------------- *
	2	*
	3	* linux/fs/autofs/root.c
	4	*
	5	* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
	6	*
	7	* This file is part of the Linux kernel and is made available under
	8	* the terms of the GNU General Public License, version 2, or at your
	9	* option, any later version, incorporated herein by reference.
	10	*
	11	* ------------------------------------------------------------------------- */
	12
16f7e0fe	13	#include <linux/capability.h>
1da177e4 LT	14	#include <linux/errno.h>
1da177e4 LT	15	#include <linux/stat.h>
5a0e3ad6	16	#include <linux/slab.h>
1da177e4 LT	17	#include <linux/param.h>
1da177e4 LT	18	#include <linux/time.h>
c9243f5b	19	#include <linux/compat.h>
1da177e4 LT	20	#include <linux/smp_lock.h>
	21	#include "autofs_i.h"
	22
	23	static int autofs_root_readdir(struct file ,void ,filldir_t);
	24	static struct dentry autofs_root_lookup(struct inode ,struct dentry , struct nameidata );
	25	static int autofs_root_symlink(struct inode ,struct dentry ,const char *);
	26	static int autofs_root_unlink(struct inode ,struct dentry );
	27	static int autofs_root_rmdir(struct inode ,struct dentry );
	28	static int autofs_root_mkdir(struct inode ,struct dentry ,int);
c9243f5b	29	static long autofs_root_ioctl(struct file *,unsigned int,unsigned long);
26daad80	30	#ifdef CONFIG_COMPAT
c9243f5b	31	static long autofs_root_compat_ioctl(struct file *,unsigned int,unsigned long);
26daad80	32	#endif
1da177e4	33
4b6f5d20	34	const struct file_operations autofs_root_operations = {
ca572727	35	.llseek = generic_file_llseek,
1da177e4 LT	36	.read = generic_read_dir,
1da177e4 LT	37	.readdir = autofs_root_readdir,
c9243f5b AB	38	.unlocked_ioctl = autofs_root_ioctl,
	39	#ifdef CONFIG_COMPAT
	40	.compat_ioctl = autofs_root_compat_ioctl,
	41	#endif
1da177e4 LT	42	};
1da177e4 LT	43
754661f1	44	const struct inode_operations autofs_root_inode_operations = {
1da177e4 LT	45	.lookup = autofs_root_lookup,
	46	.unlink = autofs_root_unlink,
	47	.symlink = autofs_root_symlink,
	48	.mkdir = autofs_root_mkdir,
	49	.rmdir = autofs_root_rmdir,
	50	};
	51
	52	static int autofs_root_readdir(struct file filp, void dirent, filldir_t filldir)
	53	{
	54	struct autofs_dir_ent *ent = NULL;
	55	struct autofs_dirhash *dirhash;
	56	struct autofs_sb_info *sbi;
81ed19b0	57	struct inode * inode = filp->f_path.dentry->d_inode;
1da177e4 LT	58	off_t onr, nr;
	59
	60	lock_kernel();
	61
	62	sbi = autofs_sbi(inode->i_sb);
	63	dirhash = &sbi->dirhash;
	64	nr = filp->f_pos;
	65
	66	switch(nr)
	67	{
	68	case 0:
	69	if (filldir(dirent, ".", 1, nr, inode->i_ino, DT_DIR) < 0)
	70	goto out;
	71	filp->f_pos = ++nr;
	72	/* fall through */
	73	case 1:
	74	if (filldir(dirent, "..", 2, nr, inode->i_ino, DT_DIR) < 0)
	75	goto out;
	76	filp->f_pos = ++nr;
	77	/* fall through */
	78	default:
d78e53c8 SB	79	while (onr = nr, ent = autofs_hash_enum(dirhash,&nr,ent)) {
d78e53c8 SB	80	if (!ent->dentry \|\| d_mountpoint(ent->dentry)) {
1da177e4 LT	81	if (filldir(dirent,ent->name,ent->len,onr,ent->ino,DT_UNKNOWN) < 0)
	82	goto out;
	83	filp->f_pos = nr;
	84	}
	85	}
	86	break;
	87	}
	88
	89	out:
	90	unlock_kernel();
	91	return 0;
	92	}
	93
	94	static int try_to_fill_dentry(struct dentry dentry, struct super_block sb, struct autofs_sb_info *sbi)
	95	{
	96	struct inode * inode;
	97	struct autofs_dir_ent *ent;
	98	int status = 0;
	99
d78e53c8	100	if (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name))) {
1da177e4	101	do {
d78e53c8 SB	102	if (status && dentry->d_inode) {
d78e53c8 SB	103	if (status != -ENOENT)
1da177e4 LT	104	printk("autofs warning: lookup failure on positive dentry, status = %d, name = %s\n", status, dentry->d_name.name);
	105	return 0; /* Try to get the kernel to invalidate this dentry */
	106	}
	107
	108	/* Turn this into a real negative dentry? */
	109	if (status == -ENOENT) {
	110	dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
	111	dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
	112	return 1;
	113	} else if (status) {
	114	/* Return a negative dentry, but leave it "pending" */
	115	return 1;
	116	}
	117	status = autofs_wait(sbi, &dentry->d_name);
d78e53c8	118	} while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)));
1da177e4 LT	119	}
	120
	121	/* Abuse this field as a pointer to the directory entry, used to
	122	find the expire list pointers */
	123	dentry->d_time = (unsigned long) ent;
	124
	125	if (!dentry->d_inode) {
62328a02 DH	126	inode = autofs_iget(sb, ent->ino);
62328a02 DH	127	if (IS_ERR(inode)) {
1da177e4 LT	128	/* Failed, but leave pending for next time */
	129	return 1;
	130	}
	131	dentry->d_inode = inode;
	132	}
	133
	134	/* If this is a directory that isn't a mount point, bitch at the
	135	daemon and fix it in user space */
d78e53c8	136	if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
1da177e4 LT	137	return !autofs_wait(sbi, &dentry->d_name);
	138	}
	139
	140	/* We don't update the usages for the autofs daemon itself, this
	141	is necessary for recursive autofs mounts */
d78e53c8	142	if (!autofs_oz_mode(sbi)) {
1da177e4 LT	143	autofs_update_usage(&sbi->dirhash,ent);
	144	}
	145
	146	dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
	147	return 1;
	148	}
	149
	150
	151	/*
	152	* Revalidate is called on every cache lookup. Some of those
	153	* cache lookups may actually happen while the dentry is not
	154	* yet completely filled in, and revalidate has to delay such
	155	* lookups..
	156	*/
	157	static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
	158	{
	159	struct inode * dir;
	160	struct autofs_sb_info *sbi;
	161	struct autofs_dir_ent *ent;
	162	int res;
	163
	164	lock_kernel();
	165	dir = dentry->d_parent->d_inode;
	166	sbi = autofs_sbi(dir->i_sb);
	167
	168	/* Pending dentry */
d78e53c8	169	if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
1da177e4 LT	170	if (autofs_oz_mode(sbi))
	171	res = 1;
	172	else
	173	res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
	174	unlock_kernel();
	175	return res;
	176	}
	177
	178	/* Negative dentry.. invalidate if "old" */
	179	if (!dentry->d_inode) {
	180	unlock_kernel();
	181	return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
	182	}
	183
	184	/* Check for a non-mountpoint directory */
d78e53c8	185	if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
1da177e4 LT	186	if (autofs_oz_mode(sbi))
	187	res = 1;
	188	else
	189	res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
	190	unlock_kernel();
	191	return res;
	192	}
	193
	194	/* Update the usage list */
d78e53c8	195	if (!autofs_oz_mode(sbi)) {
1da177e4	196	ent = (struct autofs_dir_ent *) dentry->d_time;
d78e53c8	197	if (ent)
1da177e4 LT	198	autofs_update_usage(&sbi->dirhash,ent);
	199	}
	200	unlock_kernel();
	201	return 1;
	202	}
	203
08f11513	204	static const struct dentry_operations autofs_dentry_operations = {
1da177e4 LT	205	.d_revalidate = autofs_revalidate,
	206	};
	207
	208	static struct dentry autofs_root_lookup(struct inode dir, struct dentry dentry, struct nameidata nd)
	209	{
	210	struct autofs_sb_info *sbi;
	211	int oz_mode;
	212
	213	DPRINTK(("autofs_root_lookup: name = "));
	214	lock_kernel();
	215	autofs_say(dentry->d_name.name,dentry->d_name.len);
	216
	217	if (dentry->d_name.len > NAME_MAX) {
	218	unlock_kernel();
	219	return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
	220	}
	221
	222	sbi = autofs_sbi(dir->i_sb);
	223
	224	oz_mode = autofs_oz_mode(sbi);
fa0334f1	225	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, "
69cccb88	226	"oz_mode = %d\n", task_pid_nr(current),
a47afb0f	227	task_pgrp_nr(current), sbi->catatonic,
fa0334f1	228	oz_mode));
1da177e4 LT	229
	230	/*
	231	* Mark the dentry incomplete, but add it. This is needed so
	232	* that the VFS layer knows about the dentry, and we can count
	233	* on catching any lookups through the revalidate.
	234	*
	235	* Let all the hard work be done by the revalidate function that
	236	* needs to be able to do this anyway..
	237	*
	238	* We need to do this before we release the directory semaphore.
	239	*/
	240	dentry->d_op = &autofs_dentry_operations;
	241	dentry->d_flags \|= DCACHE_AUTOFS_PENDING;
	242	d_add(dentry, NULL);
	243
1b1dcc1b	244	mutex_unlock(&dir->i_mutex);
1da177e4	245	autofs_revalidate(dentry, nd);
1b1dcc1b	246	mutex_lock(&dir->i_mutex);
1da177e4 LT	247
	248	/*
	249	* If we are still pending, check if we had to handle
	250	* a signal. If so we can force a restart..
	251	*/
	252	if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
	253	/* See if we were interrupted */
	254	if (signal_pending(current)) {
	255	sigset_t *sigset = &current->pending.signal;
	256	if (sigismember (sigset, SIGKILL) \|\|
	257	sigismember (sigset, SIGQUIT) \|\|
	258	sigismember (sigset, SIGINT)) {
	259	unlock_kernel();
	260	return ERR_PTR(-ERESTARTNOINTR);
	261	}
	262	}
	263	}
	264	unlock_kernel();
	265
	266	/*
	267	* If this dentry is unhashed, then we shouldn't honour this
	268	* lookup even if the dentry is positive. Returning ENOENT here
	269	* doesn't do the right thing for all system calls, but it should
	270	* be OK for the operations we permit from an autofs.
	271	*/
d78e53c8	272	if (dentry->d_inode && d_unhashed(dentry))
1da177e4 LT	273	return ERR_PTR(-ENOENT);
	274
	275	return NULL;
	276	}
	277
	278	static int autofs_root_symlink(struct inode dir, struct dentry dentry, const char *symname)
	279	{
	280	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	281	struct autofs_dirhash *dh = &sbi->dirhash;
	282	struct autofs_dir_ent *ent;
	283	unsigned int n;
	284	int slsize;
	285	struct autofs_symlink *sl;
62328a02	286	struct inode *inode;
1da177e4 LT	287
	288	DPRINTK(("autofs_root_symlink: %s <- ", symname));
	289	autofs_say(dentry->d_name.name,dentry->d_name.len);
	290
	291	lock_kernel();
d78e53c8	292	if (!autofs_oz_mode(sbi)) {
1da177e4 LT	293	unlock_kernel();
	294	return -EACCES;
	295	}
	296
d78e53c8	297	if (autofs_hash_lookup(dh, &dentry->d_name)) {
1da177e4 LT	298	unlock_kernel();
	299	return -EEXIST;
	300	}
	301
	302	n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS);
d78e53c8	303	if (n >= AUTOFS_MAX_SYMLINKS) {
1da177e4 LT	304	unlock_kernel();
	305	return -ENOSPC;
	306	}
	307
	308	set_bit(n,sbi->symlink_bitmap);
	309	sl = &sbi->symlink[n];
	310	sl->len = strlen(symname);
	311	sl->data = kmalloc(slsize = sl->len+1, GFP_KERNEL);
d78e53c8	312	if (!sl->data) {
1da177e4 LT	313	clear_bit(n,sbi->symlink_bitmap);
	314	unlock_kernel();
	315	return -ENOSPC;
	316	}
	317
	318	ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
d78e53c8	319	if (!ent) {
1da177e4 LT	320	kfree(sl->data);
	321	clear_bit(n,sbi->symlink_bitmap);
	322	unlock_kernel();
	323	return -ENOSPC;
	324	}
	325
	326	ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
d78e53c8	327	if (!ent->name) {
1da177e4 LT	328	kfree(sl->data);
	329	kfree(ent);
	330	clear_bit(n,sbi->symlink_bitmap);
	331	unlock_kernel();
	332	return -ENOSPC;
	333	}
	334
	335	memcpy(sl->data,symname,slsize);
	336	sl->mtime = get_seconds();
	337
	338	ent->ino = AUTOFS_FIRST_SYMLINK + n;
	339	ent->hash = dentry->d_name.hash;
	340	memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
	341	ent->dentry = NULL; /* We don't keep the dentry for symlinks */
	342
	343	autofs_hash_insert(dh,ent);
62328a02 DH	344
	345	inode = autofs_iget(dir->i_sb, ent->ino);
	346	if (IS_ERR(inode))
	347	return PTR_ERR(inode);
	348
	349	d_instantiate(dentry, inode);
1da177e4 LT	350	unlock_kernel();
	351	return 0;
	352	}
	353
	354	/*
	355	* NOTE!
	356	*
	357	* Normal filesystems would do a "d_delete()" to tell the VFS dcache
	358	* that the file no longer exists. However, doing that means that the
	359	* VFS layer can turn the dentry into a negative dentry, which we
	360	* obviously do not want (we're dropping the entry not because it
	361	* doesn't exist, but because it has timed out).
	362	*
	363	* Also see autofs_root_rmdir()..
	364	*/
	365	static int autofs_root_unlink(struct inode dir, struct dentry dentry)
	366	{
	367	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	368	struct autofs_dirhash *dh = &sbi->dirhash;
	369	struct autofs_dir_ent *ent;
	370	unsigned int n;
	371
	372	/* This allows root to remove symlinks */
	373	lock_kernel();
d78e53c8	374	if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) {
1da177e4 LT	375	unlock_kernel();
	376	return -EACCES;
	377	}
	378
	379	ent = autofs_hash_lookup(dh, &dentry->d_name);
d78e53c8	380	if (!ent) {
1da177e4 LT	381	unlock_kernel();
	382	return -ENOENT;
	383	}
	384
	385	n = ent->ino - AUTOFS_FIRST_SYMLINK;
d78e53c8	386	if (n >= AUTOFS_MAX_SYMLINKS) {
1da177e4 LT	387	unlock_kernel();
	388	return -EISDIR; /* It's a directory, dummy */
	389	}
d78e53c8	390	if (!test_bit(n,sbi->symlink_bitmap)) {
1da177e4 LT	391	unlock_kernel();
	392	return -EINVAL; /* Nonexistent symlink? Shouldn't happen */
	393	}
	394
	395	dentry->d_time = (unsigned long)(struct autofs_dirhash *)NULL;
	396	autofs_hash_delete(ent);
	397	clear_bit(n,sbi->symlink_bitmap);
	398	kfree(sbi->symlink[n].data);
	399	d_drop(dentry);
	400
	401	unlock_kernel();
	402	return 0;
	403	}
	404
	405	static int autofs_root_rmdir(struct inode dir, struct dentry dentry)
	406	{
	407	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	408	struct autofs_dirhash *dh = &sbi->dirhash;
	409	struct autofs_dir_ent *ent;
	410
	411	lock_kernel();
d78e53c8	412	if (!autofs_oz_mode(sbi)) {
1da177e4 LT	413	unlock_kernel();
	414	return -EACCES;
	415	}
	416
	417	ent = autofs_hash_lookup(dh, &dentry->d_name);
d78e53c8	418	if (!ent) {
1da177e4 LT	419	unlock_kernel();
	420	return -ENOENT;
	421	}
	422
d78e53c8	423	if ((unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO) {
1da177e4 LT	424	unlock_kernel();
	425	return -ENOTDIR; /* Not a directory */
	426	}
	427
d78e53c8	428	if (ent->dentry != dentry) {
1da177e4 LT	429	printk("autofs_rmdir: odentry != dentry for entry %s\n", dentry->d_name.name);
	430	}
	431
	432	dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL;
	433	autofs_hash_delete(ent);
9a53c3a7	434	drop_nlink(dir);
1da177e4 LT	435	d_drop(dentry);
	436	unlock_kernel();
	437
	438	return 0;
	439	}
	440
	441	static int autofs_root_mkdir(struct inode dir, struct dentry dentry, int mode)
	442	{
	443	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	444	struct autofs_dirhash *dh = &sbi->dirhash;
	445	struct autofs_dir_ent *ent;
62328a02	446	struct inode *inode;
1da177e4 LT	447	ino_t ino;
	448
	449	lock_kernel();
d78e53c8	450	if (!autofs_oz_mode(sbi)) {
1da177e4 LT	451	unlock_kernel();
	452	return -EACCES;
	453	}
	454
	455	ent = autofs_hash_lookup(dh, &dentry->d_name);
d78e53c8	456	if (ent) {
1da177e4 LT	457	unlock_kernel();
	458	return -EEXIST;
	459	}
	460
d78e53c8	461	if (sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO) {
1da177e4 LT	462	printk("autofs: Out of inode numbers -- what the heck did you do??\n");
	463	unlock_kernel();
	464	return -ENOSPC;
	465	}
	466	ino = sbi->next_dir_ino++;
	467
	468	ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
d78e53c8	469	if (!ent) {
1da177e4 LT	470	unlock_kernel();
	471	return -ENOSPC;
	472	}
	473
	474	ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
d78e53c8	475	if (!ent->name) {
1da177e4 LT	476	kfree(ent);
	477	unlock_kernel();
	478	return -ENOSPC;
	479	}
	480
	481	ent->hash = dentry->d_name.hash;
	482	memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
	483	ent->ino = ino;
	484	ent->dentry = dentry;
	485	autofs_hash_insert(dh,ent);
	486
d8c76e6f	487	inc_nlink(dir);
62328a02 DH	488
	489	inode = autofs_iget(dir->i_sb, ino);
	490	if (IS_ERR(inode)) {
	491	drop_nlink(dir);
	492	return PTR_ERR(inode);
	493	}
	494
	495	d_instantiate(dentry, inode);
1da177e4 LT	496	unlock_kernel();
	497
	498	return 0;
	499	}
	500
	501	/* Get/set timeout ioctl() operation */
c9243f5b AB	502	#ifdef CONFIG_COMPAT
	503	static inline int autofs_compat_get_set_timeout(struct autofs_sb_info *sbi,
	504	unsigned int __user *p)
	505	{
	506	unsigned long ntimeout;
	507
	508	if (get_user(ntimeout, p) \|\|
	509	put_user(sbi->exp_timeout / HZ, p))
	510	return -EFAULT;
	511
	512	if (ntimeout > UINT_MAX/HZ)
	513	sbi->exp_timeout = 0;
	514	else
	515	sbi->exp_timeout = ntimeout * HZ;
	516
	517	return 0;
	518	}
	519	#endif
	520
1da177e4 LT	521	static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
	522	unsigned long __user *p)
	523	{
	524	unsigned long ntimeout;
	525
	526	if (get_user(ntimeout, p) \|\|
	527	put_user(sbi->exp_timeout / HZ, p))
	528	return -EFAULT;
	529
d78e53c8	530	if (ntimeout > ULONG_MAX/HZ)
1da177e4 LT	531	sbi->exp_timeout = 0;
	532	else
	533	sbi->exp_timeout = ntimeout * HZ;
	534
	535	return 0;
	536	}
	537
	538	/* Return protocol version */
	539	static inline int autofs_get_protover(int __user *p)
	540	{
	541	return put_user(AUTOFS_PROTO_VERSION, p);
	542	}
	543
	544	/* Perform an expiry operation */
	545	static inline int autofs_expire_run(struct super_block *sb,
	546	struct autofs_sb_info *sbi,
	547	struct vfsmount *mnt,
	548	struct autofs_packet_expire __user *pkt_p)
	549	{
	550	struct autofs_dir_ent *ent;
	551	struct autofs_packet_expire pkt;
	552
	553	memset(&pkt,0,sizeof pkt);
	554
	555	pkt.hdr.proto_version = AUTOFS_PROTO_VERSION;
	556	pkt.hdr.type = autofs_ptype_expire;
	557
d78e53c8	558	if (!sbi->exp_timeout \|\| !(ent = autofs_expire(sb,sbi,mnt)))
1da177e4 LT	559	return -EAGAIN;
	560
	561	pkt.len = ent->len;
	562	memcpy(pkt.name, ent->name, pkt.len);
	563	pkt.name[pkt.len] = '\0';
	564
d78e53c8	565	if (copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)))
1da177e4 LT	566	return -EFAULT;
	567
	568	return 0;
	569	}
	570
	571	/*
	572	* ioctl()'s on the root directory is the chief method for the daemon to
	573	* generate kernel reactions
	574	*/
c9243f5b	575	static int autofs_do_root_ioctl(struct inode inode, struct file filp,
1da177e4 LT	576	unsigned int cmd, unsigned long arg)
	577	{
	578	struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
	579	void __user argp = (void __user )arg;
	580
a47afb0f	581	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,task_pgrp_nr(current)));
1da177e4	582
d78e53c8 SB	583	if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) \|\|
d78e53c8 SB	584	_IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
1da177e4 LT	585	return -ENOTTY;
1da177e4 LT	586
d78e53c8	587	if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
1da177e4 LT	588	return -EPERM;
	589
	590	switch(cmd) {
	591	case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
	592	return autofs_wait_release(sbi,(autofs_wqt_t)arg,0);
	593	case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
	594	return autofs_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
	595	case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
	596	autofs_catatonic_mode(sbi);
	597	return 0;
	598	case AUTOFS_IOC_PROTOVER: /* Get protocol version */
	599	return autofs_get_protover(argp);
c9243f5b AB	600	#ifdef CONFIG_COMPAT
	601	case AUTOFS_IOC_SETTIMEOUT32:
	602	return autofs_compat_get_set_timeout(sbi, argp);
	603	#endif
1da177e4 LT	604	case AUTOFS_IOC_SETTIMEOUT:
	605	return autofs_get_set_timeout(sbi, argp);
	606	case AUTOFS_IOC_EXPIRE:
81ed19b0	607	return autofs_expire_run(inode->i_sb, sbi, filp->f_path.mnt,
1da177e4 LT	608	argp);
	609	default:
	610	return -ENOSYS;
	611	}
c9243f5b AB	612
	613	}
	614
	615	static long autofs_root_ioctl(struct file *filp,
	616	unsigned int cmd, unsigned long arg)
	617	{
	618	int ret;
	619
	620	lock_kernel();
	621	ret = autofs_do_root_ioctl(filp->f_path.dentry->d_inode,
	622	filp, cmd, arg);
	623	unlock_kernel();
	624
	625	return ret;
	626	}
	627
	628	#ifdef CONFIG_COMPAT
	629	static long autofs_root_compat_ioctl(struct file *filp,
	630	unsigned int cmd, unsigned long arg)
	631	{
	632	struct inode *inode = filp->f_path.dentry->d_inode;
	633	int ret;
	634
	635	lock_kernel();
	636	if (cmd == AUTOFS_IOC_READY \|\| cmd == AUTOFS_IOC_FAIL)
	637	ret = autofs_do_root_ioctl(inode, filp, cmd, arg);
	638	else
	639	ret = autofs_do_root_ioctl(inode, filp, cmd,
	640	(unsigned long)compat_ptr(arg));
	641	unlock_kernel();
	642
	643	return ret;
1da177e4	644	}
c9243f5b	645	#endif