[linux.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/param.h>
#include <linux/time.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 int autofs_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);

const struct file_operations autofs_root_operations = {
	.read		= generic_read_dir,
	.readdir	= autofs_root_readdir,
	.ioctl		= autofs_root_ioctl,
};

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 = iget(sb, ent->ino);
		if (!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 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", pid_nr(task_pid(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;

	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);
	d_instantiate(dentry, iget(dir->i_sb,ent->ino));
	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;
	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);
	d_instantiate(dentry, iget(dir->i_sb,ino));
	unlock_kernel();

	return 0;
}

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