[GitHub/mt8127/android_kernel_alcatel_ttab.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/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 = 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 */
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>
1da177e4 LT	15	#include <linux/stat.h>
5a0e3ad6	16	#include <linux/slab.h>
1da177e4 LT	17	#include <linux/param.h>
	18	#include <linux/time.h>
	19	#include <linux/smp_lock.h>
	20	#include "autofs_i.h"
	21
	22	static int autofs_root_readdir(struct file ,void ,filldir_t);
	23	static struct dentry autofs_root_lookup(struct inode ,struct dentry , struct nameidata );
	24	static int autofs_root_symlink(struct inode ,struct dentry ,const char *);
	25	static int autofs_root_unlink(struct inode ,struct dentry );
	26	static int autofs_root_rmdir(struct inode ,struct dentry );
	27	static int autofs_root_mkdir(struct inode ,struct dentry ,int);
	28	static int autofs_root_ioctl(struct inode , struct file ,unsigned int,unsigned long);
	29
4b6f5d20	30	const struct file_operations autofs_root_operations = {
1da177e4 LT	31	.read = generic_read_dir,
	32	.readdir = autofs_root_readdir,
	33	.ioctl = autofs_root_ioctl,
	34	};
	35
754661f1	36	const struct inode_operations autofs_root_inode_operations = {
1da177e4 LT	37	.lookup = autofs_root_lookup,
	38	.unlink = autofs_root_unlink,
	39	.symlink = autofs_root_symlink,
	40	.mkdir = autofs_root_mkdir,
	41	.rmdir = autofs_root_rmdir,
	42	};
	43
	44	static int autofs_root_readdir(struct file filp, void dirent, filldir_t filldir)
	45	{
	46	struct autofs_dir_ent *ent = NULL;
	47	struct autofs_dirhash *dirhash;
	48	struct autofs_sb_info *sbi;
81ed19b0	49	struct inode * inode = filp->f_path.dentry->d_inode;
1da177e4 LT	50	off_t onr, nr;
	51
	52	lock_kernel();
	53
	54	sbi = autofs_sbi(inode->i_sb);
	55	dirhash = &sbi->dirhash;
	56	nr = filp->f_pos;
	57
	58	switch(nr)
	59	{
	60	case 0:
	61	if (filldir(dirent, ".", 1, nr, inode->i_ino, DT_DIR) < 0)
	62	goto out;
	63	filp->f_pos = ++nr;
	64	/* fall through */
	65	case 1:
	66	if (filldir(dirent, "..", 2, nr, inode->i_ino, DT_DIR) < 0)
	67	goto out;
	68	filp->f_pos = ++nr;
	69	/* fall through */
	70	default:
d78e53c8 SB	71	while (onr = nr, ent = autofs_hash_enum(dirhash,&nr,ent)) {
d78e53c8 SB	72	if (!ent->dentry \|\| d_mountpoint(ent->dentry)) {
1da177e4 LT	73	if (filldir(dirent,ent->name,ent->len,onr,ent->ino,DT_UNKNOWN) < 0)
	74	goto out;
	75	filp->f_pos = nr;
	76	}
	77	}
	78	break;
	79	}
	80
	81	out:
	82	unlock_kernel();
	83	return 0;
	84	}
	85
	86	static int try_to_fill_dentry(struct dentry dentry, struct super_block sb, struct autofs_sb_info *sbi)
	87	{
	88	struct inode * inode;
	89	struct autofs_dir_ent *ent;
	90	int status = 0;
	91
d78e53c8	92	if (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name))) {
1da177e4	93	do {
d78e53c8 SB	94	if (status && dentry->d_inode) {
d78e53c8 SB	95	if (status != -ENOENT)
1da177e4 LT	96	printk("autofs warning: lookup failure on positive dentry, status = %d, name = %s\n", status, dentry->d_name.name);
	97	return 0; /* Try to get the kernel to invalidate this dentry */
	98	}
	99
	100	/* Turn this into a real negative dentry? */
	101	if (status == -ENOENT) {
	102	dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
	103	dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
	104	return 1;
	105	} else if (status) {
	106	/* Return a negative dentry, but leave it "pending" */
	107	return 1;
	108	}
	109	status = autofs_wait(sbi, &dentry->d_name);
d78e53c8	110	} while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)));
1da177e4 LT	111	}
	112
	113	/* Abuse this field as a pointer to the directory entry, used to
	114	find the expire list pointers */
	115	dentry->d_time = (unsigned long) ent;
	116
	117	if (!dentry->d_inode) {
62328a02 DH	118	inode = autofs_iget(sb, ent->ino);
62328a02 DH	119	if (IS_ERR(inode)) {
1da177e4 LT	120	/* Failed, but leave pending for next time */
	121	return 1;
	122	}
	123	dentry->d_inode = inode;
	124	}
	125
	126	/* If this is a directory that isn't a mount point, bitch at the
	127	daemon and fix it in user space */
d78e53c8	128	if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
1da177e4 LT	129	return !autofs_wait(sbi, &dentry->d_name);
	130	}
	131
	132	/* We don't update the usages for the autofs daemon itself, this
	133	is necessary for recursive autofs mounts */
d78e53c8	134	if (!autofs_oz_mode(sbi)) {
1da177e4 LT	135	autofs_update_usage(&sbi->dirhash,ent);
	136	}
	137
	138	dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
	139	return 1;
	140	}
	141
	142
	143	/*
	144	* Revalidate is called on every cache lookup. Some of those
	145	* cache lookups may actually happen while the dentry is not
	146	* yet completely filled in, and revalidate has to delay such
	147	* lookups..
	148	*/
	149	static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
	150	{
	151	struct inode * dir;
	152	struct autofs_sb_info *sbi;
	153	struct autofs_dir_ent *ent;
	154	int res;
	155
	156	lock_kernel();
	157	dir = dentry->d_parent->d_inode;
	158	sbi = autofs_sbi(dir->i_sb);
	159
	160	/* Pending dentry */
d78e53c8	161	if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
1da177e4 LT	162	if (autofs_oz_mode(sbi))
	163	res = 1;
	164	else
	165	res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
	166	unlock_kernel();
	167	return res;
	168	}
	169
	170	/* Negative dentry.. invalidate if "old" */
	171	if (!dentry->d_inode) {
	172	unlock_kernel();
	173	return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
	174	}
	175
	176	/* Check for a non-mountpoint directory */
d78e53c8	177	if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
1da177e4 LT	178	if (autofs_oz_mode(sbi))
	179	res = 1;
	180	else
	181	res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
	182	unlock_kernel();
	183	return res;
	184	}
	185
	186	/* Update the usage list */
d78e53c8	187	if (!autofs_oz_mode(sbi)) {
1da177e4	188	ent = (struct autofs_dir_ent *) dentry->d_time;
d78e53c8	189	if (ent)
1da177e4 LT	190	autofs_update_usage(&sbi->dirhash,ent);
	191	}
	192	unlock_kernel();
	193	return 1;
	194	}
	195
08f11513	196	static const struct dentry_operations autofs_dentry_operations = {
1da177e4 LT	197	.d_revalidate = autofs_revalidate,
	198	};
	199
	200	static struct dentry autofs_root_lookup(struct inode dir, struct dentry dentry, struct nameidata nd)
	201	{
	202	struct autofs_sb_info *sbi;
	203	int oz_mode;
	204
	205	DPRINTK(("autofs_root_lookup: name = "));
	206	lock_kernel();
	207	autofs_say(dentry->d_name.name,dentry->d_name.len);
	208
	209	if (dentry->d_name.len > NAME_MAX) {
	210	unlock_kernel();
	211	return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
	212	}
	213
	214	sbi = autofs_sbi(dir->i_sb);
	215
	216	oz_mode = autofs_oz_mode(sbi);
fa0334f1	217	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, "
69cccb88	218	"oz_mode = %d\n", task_pid_nr(current),
a47afb0f	219	task_pgrp_nr(current), sbi->catatonic,
fa0334f1	220	oz_mode));
1da177e4 LT	221
	222	/*
	223	* Mark the dentry incomplete, but add it. This is needed so
	224	* that the VFS layer knows about the dentry, and we can count
	225	* on catching any lookups through the revalidate.
	226	*
	227	* Let all the hard work be done by the revalidate function that
	228	* needs to be able to do this anyway..
	229	*
	230	* We need to do this before we release the directory semaphore.
	231	*/
	232	dentry->d_op = &autofs_dentry_operations;
	233	dentry->d_flags \|= DCACHE_AUTOFS_PENDING;
	234	d_add(dentry, NULL);
	235
1b1dcc1b	236	mutex_unlock(&dir->i_mutex);
1da177e4	237	autofs_revalidate(dentry, nd);
1b1dcc1b	238	mutex_lock(&dir->i_mutex);
1da177e4 LT	239
	240	/*
	241	* If we are still pending, check if we had to handle
	242	* a signal. If so we can force a restart..
	243	*/
	244	if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
	245	/* See if we were interrupted */
	246	if (signal_pending(current)) {
	247	sigset_t *sigset = &current->pending.signal;
	248	if (sigismember (sigset, SIGKILL) \|\|
	249	sigismember (sigset, SIGQUIT) \|\|
	250	sigismember (sigset, SIGINT)) {
	251	unlock_kernel();
	252	return ERR_PTR(-ERESTARTNOINTR);
	253	}
	254	}
	255	}
	256	unlock_kernel();
	257
	258	/*
	259	* If this dentry is unhashed, then we shouldn't honour this
	260	* lookup even if the dentry is positive. Returning ENOENT here
	261	* doesn't do the right thing for all system calls, but it should
	262	* be OK for the operations we permit from an autofs.
	263	*/
d78e53c8	264	if (dentry->d_inode && d_unhashed(dentry))
1da177e4 LT	265	return ERR_PTR(-ENOENT);
	266
	267	return NULL;
	268	}
	269
	270	static int autofs_root_symlink(struct inode dir, struct dentry dentry, const char *symname)
	271	{
	272	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	273	struct autofs_dirhash *dh = &sbi->dirhash;
	274	struct autofs_dir_ent *ent;
	275	unsigned int n;
	276	int slsize;
	277	struct autofs_symlink *sl;
62328a02	278	struct inode *inode;
1da177e4 LT	279
	280	DPRINTK(("autofs_root_symlink: %s <- ", symname));
	281	autofs_say(dentry->d_name.name,dentry->d_name.len);
	282
	283	lock_kernel();
d78e53c8	284	if (!autofs_oz_mode(sbi)) {
1da177e4 LT	285	unlock_kernel();
	286	return -EACCES;
	287	}
	288
d78e53c8	289	if (autofs_hash_lookup(dh, &dentry->d_name)) {
1da177e4 LT	290	unlock_kernel();
	291	return -EEXIST;
	292	}
	293
	294	n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS);
d78e53c8	295	if (n >= AUTOFS_MAX_SYMLINKS) {
1da177e4 LT	296	unlock_kernel();
	297	return -ENOSPC;
	298	}
	299
	300	set_bit(n,sbi->symlink_bitmap);
	301	sl = &sbi->symlink[n];
	302	sl->len = strlen(symname);
	303	sl->data = kmalloc(slsize = sl->len+1, GFP_KERNEL);
d78e53c8	304	if (!sl->data) {
1da177e4 LT	305	clear_bit(n,sbi->symlink_bitmap);
	306	unlock_kernel();
	307	return -ENOSPC;
	308	}
	309
	310	ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
d78e53c8	311	if (!ent) {
1da177e4 LT	312	kfree(sl->data);
	313	clear_bit(n,sbi->symlink_bitmap);
	314	unlock_kernel();
	315	return -ENOSPC;
	316	}
	317
	318	ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
d78e53c8	319	if (!ent->name) {
1da177e4 LT	320	kfree(sl->data);
	321	kfree(ent);
	322	clear_bit(n,sbi->symlink_bitmap);
	323	unlock_kernel();
	324	return -ENOSPC;
	325	}
	326
	327	memcpy(sl->data,symname,slsize);
	328	sl->mtime = get_seconds();
	329
	330	ent->ino = AUTOFS_FIRST_SYMLINK + n;
	331	ent->hash = dentry->d_name.hash;
	332	memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
	333	ent->dentry = NULL; /* We don't keep the dentry for symlinks */
	334
	335	autofs_hash_insert(dh,ent);
62328a02 DH	336
	337	inode = autofs_iget(dir->i_sb, ent->ino);
	338	if (IS_ERR(inode))
	339	return PTR_ERR(inode);
	340
	341	d_instantiate(dentry, inode);
1da177e4 LT	342	unlock_kernel();
	343	return 0;
	344	}
	345
	346	/*
	347	* NOTE!
	348	*
	349	* Normal filesystems would do a "d_delete()" to tell the VFS dcache
	350	* that the file no longer exists. However, doing that means that the
	351	* VFS layer can turn the dentry into a negative dentry, which we
	352	* obviously do not want (we're dropping the entry not because it
	353	* doesn't exist, but because it has timed out).
	354	*
	355	* Also see autofs_root_rmdir()..
	356	*/
	357	static int autofs_root_unlink(struct inode dir, struct dentry dentry)
	358	{
	359	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	360	struct autofs_dirhash *dh = &sbi->dirhash;
	361	struct autofs_dir_ent *ent;
	362	unsigned int n;
	363
	364	/* This allows root to remove symlinks */
	365	lock_kernel();
d78e53c8	366	if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) {
1da177e4 LT	367	unlock_kernel();
	368	return -EACCES;
	369	}
	370
	371	ent = autofs_hash_lookup(dh, &dentry->d_name);
d78e53c8	372	if (!ent) {
1da177e4 LT	373	unlock_kernel();
	374	return -ENOENT;
	375	}
	376
	377	n = ent->ino - AUTOFS_FIRST_SYMLINK;
d78e53c8	378	if (n >= AUTOFS_MAX_SYMLINKS) {
1da177e4 LT	379	unlock_kernel();
	380	return -EISDIR; /* It's a directory, dummy */
	381	}
d78e53c8	382	if (!test_bit(n,sbi->symlink_bitmap)) {
1da177e4 LT	383	unlock_kernel();
	384	return -EINVAL; /* Nonexistent symlink? Shouldn't happen */
	385	}
	386
	387	dentry->d_time = (unsigned long)(struct autofs_dirhash *)NULL;
	388	autofs_hash_delete(ent);
	389	clear_bit(n,sbi->symlink_bitmap);
	390	kfree(sbi->symlink[n].data);
	391	d_drop(dentry);
	392
	393	unlock_kernel();
	394	return 0;
	395	}
	396
	397	static int autofs_root_rmdir(struct inode dir, struct dentry dentry)
	398	{
	399	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	400	struct autofs_dirhash *dh = &sbi->dirhash;
	401	struct autofs_dir_ent *ent;
	402
	403	lock_kernel();
d78e53c8	404	if (!autofs_oz_mode(sbi)) {
1da177e4 LT	405	unlock_kernel();
	406	return -EACCES;
	407	}
	408
	409	ent = autofs_hash_lookup(dh, &dentry->d_name);
d78e53c8	410	if (!ent) {
1da177e4 LT	411	unlock_kernel();
	412	return -ENOENT;
	413	}
	414
d78e53c8	415	if ((unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO) {
1da177e4 LT	416	unlock_kernel();
	417	return -ENOTDIR; /* Not a directory */
	418	}
	419
d78e53c8	420	if (ent->dentry != dentry) {
1da177e4 LT	421	printk("autofs_rmdir: odentry != dentry for entry %s\n", dentry->d_name.name);
	422	}
	423
	424	dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL;
	425	autofs_hash_delete(ent);
9a53c3a7	426	drop_nlink(dir);
1da177e4 LT	427	d_drop(dentry);
	428	unlock_kernel();
	429
	430	return 0;
	431	}
	432
	433	static int autofs_root_mkdir(struct inode dir, struct dentry dentry, int mode)
	434	{
	435	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
	436	struct autofs_dirhash *dh = &sbi->dirhash;
	437	struct autofs_dir_ent *ent;
62328a02	438	struct inode *inode;
1da177e4 LT	439	ino_t ino;
	440
	441	lock_kernel();
d78e53c8	442	if (!autofs_oz_mode(sbi)) {
1da177e4 LT	443	unlock_kernel();
	444	return -EACCES;
	445	}
	446
	447	ent = autofs_hash_lookup(dh, &dentry->d_name);
d78e53c8	448	if (ent) {
1da177e4 LT	449	unlock_kernel();
	450	return -EEXIST;
	451	}
	452
d78e53c8	453	if (sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO) {
1da177e4 LT	454	printk("autofs: Out of inode numbers -- what the heck did you do??\n");
	455	unlock_kernel();
	456	return -ENOSPC;
	457	}
	458	ino = sbi->next_dir_ino++;
	459
	460	ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
d78e53c8	461	if (!ent) {
1da177e4 LT	462	unlock_kernel();
	463	return -ENOSPC;
	464	}
	465
	466	ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
d78e53c8	467	if (!ent->name) {
1da177e4 LT	468	kfree(ent);
	469	unlock_kernel();
	470	return -ENOSPC;
	471	}
	472
	473	ent->hash = dentry->d_name.hash;
	474	memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
	475	ent->ino = ino;
	476	ent->dentry = dentry;
	477	autofs_hash_insert(dh,ent);
	478
d8c76e6f	479	inc_nlink(dir);
62328a02 DH	480
	481	inode = autofs_iget(dir->i_sb, ino);
	482	if (IS_ERR(inode)) {
	483	drop_nlink(dir);
	484	return PTR_ERR(inode);
	485	}
	486
	487	d_instantiate(dentry, inode);
1da177e4 LT	488	unlock_kernel();
	489
	490	return 0;
	491	}
	492
	493	/* Get/set timeout ioctl() operation */
	494	static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
	495	unsigned long __user *p)
	496	{
	497	unsigned long ntimeout;
	498
	499	if (get_user(ntimeout, p) \|\|
	500	put_user(sbi->exp_timeout / HZ, p))
	501	return -EFAULT;
	502
d78e53c8	503	if (ntimeout > ULONG_MAX/HZ)
1da177e4 LT	504	sbi->exp_timeout = 0;
	505	else
	506	sbi->exp_timeout = ntimeout * HZ;
	507
	508	return 0;
	509	}
	510
	511	/* Return protocol version */
	512	static inline int autofs_get_protover(int __user *p)
	513	{
	514	return put_user(AUTOFS_PROTO_VERSION, p);
	515	}
	516
	517	/* Perform an expiry operation */
	518	static inline int autofs_expire_run(struct super_block *sb,
	519	struct autofs_sb_info *sbi,
	520	struct vfsmount *mnt,
	521	struct autofs_packet_expire __user *pkt_p)
	522	{
	523	struct autofs_dir_ent *ent;
	524	struct autofs_packet_expire pkt;
	525
	526	memset(&pkt,0,sizeof pkt);
	527
	528	pkt.hdr.proto_version = AUTOFS_PROTO_VERSION;
	529	pkt.hdr.type = autofs_ptype_expire;
	530
d78e53c8	531	if (!sbi->exp_timeout \|\| !(ent = autofs_expire(sb,sbi,mnt)))
1da177e4 LT	532	return -EAGAIN;
	533
	534	pkt.len = ent->len;
	535	memcpy(pkt.name, ent->name, pkt.len);
	536	pkt.name[pkt.len] = '\0';
	537
d78e53c8	538	if (copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)))
1da177e4 LT	539	return -EFAULT;
	540
	541	return 0;
	542	}
	543
	544	/*
	545	* ioctl()'s on the root directory is the chief method for the daemon to
	546	* generate kernel reactions
	547	*/
	548	static int autofs_root_ioctl(struct inode inode, struct file filp,
	549	unsigned int cmd, unsigned long arg)
	550	{
	551	struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
	552	void __user argp = (void __user )arg;
	553
a47afb0f	554	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,task_pgrp_nr(current)));
1da177e4	555
d78e53c8 SB	556	if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) \|\|
d78e53c8 SB	557	_IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
1da177e4 LT	558	return -ENOTTY;
1da177e4 LT	559
d78e53c8	560	if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
1da177e4 LT	561	return -EPERM;
	562
	563	switch(cmd) {
	564	case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
	565	return autofs_wait_release(sbi,(autofs_wqt_t)arg,0);
	566	case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
	567	return autofs_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
	568	case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
	569	autofs_catatonic_mode(sbi);
	570	return 0;
	571	case AUTOFS_IOC_PROTOVER: /* Get protocol version */
	572	return autofs_get_protover(argp);
	573	case AUTOFS_IOC_SETTIMEOUT:
	574	return autofs_get_set_timeout(sbi, argp);
	575	case AUTOFS_IOC_EXPIRE:
81ed19b0	576	return autofs_expire_run(inode->i_sb, sbi, filp->f_path.mnt,
1da177e4 LT	577	argp);
	578	default:
	579	return -ENOSYS;
	580	}
	581	}