[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);
static long autofs_root_compat_ioctl(struct file *,unsigned int,unsigned long);

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