int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
		enum autofs_notify notify)
{
	struct autofs_wait_queue *wq;
	struct qstr qstr;
	char *name;
	int status, ret, type;

	/* In catatonic mode, we don't wait for nobody */
	if (sbi->catatonic)
		return -ENOENT;

	if (!dentry->d_inode) {
		/*
		 * A wait for a negative dentry is invalid for certain
		 * cases. A direct or offset mount "always" has its mount
		 * point directory created and so the request dentry must
		 * be positive or the map key doesn't exist. The situation
		 * is very similar for indirect mounts except only dentrys
		 * in the root of the autofs file system may be negative.
		 */
		if (autofs_type_trigger(sbi->type))
			return -ENOENT;
		else if (!IS_ROOT(dentry->d_parent))
			return -ENOENT;
	}

	name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
	if (!name)
		return -ENOMEM;

	/* If this is a direct mount request create a dummy name */
	if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type))
		qstr.len = sprintf(name, "%p", dentry);
	else {
		qstr.len = autofs4_getpath(sbi, dentry, &name);
		if (!qstr.len) {
			kfree(name);
			return -ENOENT;
		}
	}
	qstr.name = name;
	qstr.hash = full_name_hash(name, qstr.len);

	if (mutex_lock_interruptible(&sbi->wq_mutex)) {
		kfree(qstr.name);
		return -EINTR;
	}

	ret = validate_request(&wq, sbi, &qstr, dentry, notify);
	if (ret <= 0) {
		if (ret == 0)
			mutex_unlock(&sbi->wq_mutex);
		kfree(qstr.name);
		return ret;
	}

	if (!wq) {
		/* Create a new wait queue */
		wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
		if (!wq) {
			kfree(qstr.name);
			mutex_unlock(&sbi->wq_mutex);
			return -ENOMEM;
		}

		wq->wait_queue_token = autofs4_next_wait_queue;
		if (++autofs4_next_wait_queue == 0)
			autofs4_next_wait_queue = 1;
		wq->next = sbi->queues;
		sbi->queues = wq;
		init_waitqueue_head(&wq->queue);
		memcpy(&wq->name, &qstr, sizeof(struct qstr));
		wq->dev = autofs4_get_dev(sbi);
		wq->ino = autofs4_get_ino(sbi);
		wq->uid = current_uid();
		wq->gid = current_gid();
		wq->pid = current->pid;
		wq->tgid = current->tgid;
		wq->status = -EINTR; /* Status return if interrupted */
		wq->wait_ctr = 2;
		mutex_unlock(&sbi->wq_mutex);

		if (sbi->version < 5) {
			if (notify == NFY_MOUNT)
				type = autofs_ptype_missing;
			else
				type = autofs_ptype_expire_multi;
		} else {
			if (notify == NFY_MOUNT)
				type = autofs_type_trigger(sbi->type) ?
					autofs_ptype_missing_direct :
					 autofs_ptype_missing_indirect;
			else
				type = autofs_type_trigger(sbi->type) ?
					autofs_ptype_expire_direct :
					autofs_ptype_expire_indirect;
		}

		DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
			(unsigned long) wq->wait_queue_token, wq->name.len,
			wq->name.name, notify);

		/* autofs4_notify_daemon() may block */
		autofs4_notify_daemon(sbi, wq, type);
	} else {
		wq->wait_ctr++;
		mutex_unlock(&sbi->wq_mutex);
		kfree(qstr.name);
		DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
			(unsigned long) wq->wait_queue_token, wq->name.len,
			wq->name.name, notify);
	}

	/*
	 * wq->name.name is NULL iff the lock is already released
	 * or the mount has been made catatonic.
	 */
	if (wq->name.name) {
		/* Block all but "shutdown" signals while waiting */
		sigset_t oldset;
		unsigned long irqflags;

		spin_lock_irqsave(&current->sighand->siglock, irqflags);
		oldset = current->blocked;
		siginitsetinv(&current->blocked, SHUTDOWN_SIGS & ~oldset.sig[0]);
		recalc_sigpending();
		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);

		wait_event_interruptible(wq->queue, wq->name.name == NULL);

		spin_lock_irqsave(&current->sighand->siglock, irqflags);
		current->blocked = oldset;
		recalc_sigpending();
		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
	} else {
		DPRINTK("skipped sleeping");
	}

	status = wq->status;

	/*
	 * For direct and offset mounts we need to track the requester's
	 * uid and gid in the dentry info struct. This is so it can be
	 * supplied, on request, by the misc device ioctl interface.
	 * This is needed during daemon resatart when reconnecting
	 * to existing, active, autofs mounts. The uid and gid (and
	 * related string values) may be used for macro substitution
	 * in autofs mount maps.
	 */
	if (!status) {
		struct autofs_info *ino;
		struct dentry *de = NULL;

		/* direct mount or browsable map */
		ino = autofs4_dentry_ino(dentry);
		if (!ino) {
			/* If not lookup actual dentry used */
			de = d_lookup(dentry->d_parent, &dentry->d_name);
			if (de)
				ino = autofs4_dentry_ino(de);
		}

		/* Set mount requester */
		if (ino) {
			spin_lock(&sbi->fs_lock);
			ino->uid = wq->uid;
			ino->gid = wq->gid;
			spin_unlock(&sbi->fs_lock);
		}

		if (de)
			dput(de);
	}

	/* Are we the last process to need status? */
	mutex_lock(&sbi->wq_mutex);
	if (!--wq->wait_ctr)
		kfree(wq);
	mutex_unlock(&sbi->wq_mutex);

	return status;
}
Beispiel #2
0
int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
		enum autofs_notify notify)
{
	struct autofs_wait_queue *wq;
	char *name;
	int len, status;

	/* In catatonic mode, we don't wait for nobody */
	if (sbi->catatonic)
		return -ENOENT;

	name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
	if (!name)
		return -ENOMEM;

	len = autofs4_getpath(sbi, dentry, &name);
	if (!len) {
		kfree(name);
		return -ENOENT;
	}

	if (down_interruptible(&sbi->wq_sem)) {
		kfree(name);
		return -EINTR;
	}

	for ( wq = sbi->queues ; wq ; wq = wq->next ) {
		if ( wq->hash == dentry->d_name.hash &&
		     wq->len == len &&
		     wq->name && !memcmp(wq->name, name, len) )
			break;
	}
	
	if ( !wq ) {
		/* Can't wait for an expire if there's no mount */
		if (notify == NFY_NONE && !d_mountpoint(dentry)) {
			kfree(name);
			up(&sbi->wq_sem);
			return -ENOENT;
		}

		/* Create a new wait queue */
		wq = kmalloc(sizeof(struct autofs_wait_queue), GFP_KERNEL);
		if ( !wq ) {
			kfree(name);
			up(&sbi->wq_sem);
			return -ENOMEM;
		}

		wq->wait_queue_token = autofs4_next_wait_queue;
		if (++autofs4_next_wait_queue == 0)
			autofs4_next_wait_queue = 1;
		wq->next = sbi->queues;
		sbi->queues = wq;
		init_waitqueue_head(&wq->queue);
		wq->hash = dentry->d_name.hash;
		wq->name = name;
		wq->len = len;
		wq->status = -EINTR; /* Status return if interrupted */
		atomic_set(&wq->wait_ctr, 2);
		up(&sbi->wq_sem);

		DPRINTK(("autofs4_wait: new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
			(unsigned long) wq->wait_queue_token, wq->len, wq->name, notify));
		/* autofs4_notify_daemon() may block */
		if (notify != NFY_NONE) {
			autofs4_notify_daemon(sbi,wq, 
				notify == NFY_MOUNT ? 
					autofs_ptype_missing :
				       	autofs_ptype_expire_multi);
		}
	} else {
		atomic_inc(&wq->wait_ctr);
		up(&sbi->wq_sem);
		kfree(name);
		DPRINTK(("autofs4_wait: existing wait id = 0x%08lx, name = %.*s, nfy=%d\n",
			(unsigned long) wq->wait_queue_token, wq->len, wq->name, notify));
	}

	/* wq->name is NULL if and only if the lock is already released */

	if ( sbi->catatonic ) {
		/* We might have slept, so check again for catatonic mode */
		wq->status = -ENOENT;
		if ( wq->name ) {
			kfree(wq->name);
			wq->name = NULL;
		}
	}

	if ( wq->name ) {
		/* Block all but "shutdown" signals while waiting */
		sigset_t oldset;
		unsigned long irqflags;

		spin_lock_irqsave(&current->sighand->siglock, irqflags);
		oldset = current->blocked;
		siginitsetinv(&current->blocked, SHUTDOWN_SIGS & ~oldset.sig[0]);
		recalc_sigpending();
		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);

		wait_event_interruptible(wq->queue, wq->name == NULL);

		spin_lock_irqsave(&current->sighand->siglock, irqflags);
		current->blocked = oldset;
		recalc_sigpending();
		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
	} else {
		DPRINTK(("autofs_wait: skipped sleeping\n"));
	}

	status = wq->status;

	/* Are we the last process to need status? */
	if (atomic_dec_and_test(&wq->wait_ctr))
		kfree(wq);

	return status;
}
Beispiel #3
0
int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
		enum autofs_notify notify)
{
	struct autofs_info *ino;
	struct autofs_wait_queue *wq;
	char *name;
	unsigned int len = 0;
	unsigned int hash = 0;
	int status, type;

	/* In catatonic mode, we don't wait for nobody */
	if (sbi->catatonic)
		return -ENOENT;
	
	name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
	if (!name)
		return -ENOMEM;

	/* If this is a direct mount request create a dummy name */
	if (IS_ROOT(tx_cache_get_dentry(dentry)) && (sbi->type & AUTOFS_TYPE_DIRECT))
		len = sprintf(name, "%p", dentry);
	else {
		len = autofs4_getpath(sbi, dentry, &name);
		if (!len) {
			kfree(name);
			return -ENOENT;
		}
	}
	hash = full_name_hash(name, len);

	if (mutex_lock_interruptible(&sbi->wq_mutex)) {
		kfree(name);
		return -EINTR;
	}

	wq = autofs4_find_wait(sbi, name, hash, len);
	ino = autofs4_dentry_ino(dentry);
	if (!wq && ino && notify == NFY_NONE) {
		/*
		 * Either we've betean the pending expire to post it's
		 * wait or it finished while we waited on the mutex.
		 * So we need to wait till either, the wait appears
		 * or the expire finishes.
		 */

		while (ino->flags & AUTOFS_INF_EXPIRING) {
			mutex_unlock(&sbi->wq_mutex);
			schedule_timeout_interruptible(HZ/10);
			if (mutex_lock_interruptible(&sbi->wq_mutex)) {
				kfree(name);
				return -EINTR;
			}
			wq = autofs4_find_wait(sbi, name, hash, len);
			if (wq)
				break;
		}

		/*
		 * Not ideal but the status has already gone. Of the two
		 * cases where we wait on NFY_NONE neither depend on the
		 * return status of the wait.
		 */
		if (!wq) {
			kfree(name);
			mutex_unlock(&sbi->wq_mutex);
			return 0;
		}
	}

	if (!wq) {
		/* Create a new wait queue */
		wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
		if (!wq) {
			kfree(name);
			mutex_unlock(&sbi->wq_mutex);
			return -ENOMEM;
		}

		wq->wait_queue_token = autofs4_next_wait_queue;
		if (++autofs4_next_wait_queue == 0)
			autofs4_next_wait_queue = 1;
		wq->next = sbi->queues;
		sbi->queues = wq;
		init_waitqueue_head(&wq->queue);
		wq->hash = hash;
		wq->name = name;
		wq->len = len;
		wq->dev = autofs4_get_dev(sbi);
		wq->ino = autofs4_get_ino(sbi);
		wq->uid = current->uid;
		wq->gid = current->gid;
		wq->pid = current->pid;
		wq->tgid = current->tgid;
		wq->status = -EINTR; /* Status return if interrupted */
		atomic_set(&wq->wait_ctr, 2);
		mutex_unlock(&sbi->wq_mutex);

		if (sbi->version < 5) {
			if (notify == NFY_MOUNT)
				type = autofs_ptype_missing;
			else
				type = autofs_ptype_expire_multi;
		} else {
			if (notify == NFY_MOUNT)
				type = (sbi->type & AUTOFS_TYPE_DIRECT) ?
					autofs_ptype_missing_direct :
					 autofs_ptype_missing_indirect;
			else
				type = (sbi->type & AUTOFS_TYPE_DIRECT) ?
					autofs_ptype_expire_direct :
					autofs_ptype_expire_indirect;
		}

		DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
			(unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);

		/* autofs4_notify_daemon() may block */
		autofs4_notify_daemon(sbi, wq, type);
	} else {
		atomic_inc(&wq->wait_ctr);
		mutex_unlock(&sbi->wq_mutex);
		kfree(name);
		DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
			(unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
	}

	/* wq->name is NULL if and only if the lock is already released */

	if (sbi->catatonic) {
		/* We might have slept, so check again for catatonic mode */
		wq->status = -ENOENT;
		kfree(wq->name);
		wq->name = NULL;
	}

	if (wq->name) {
		/* Block all but "shutdown" signals while waiting */
		sigset_t oldset;
		unsigned long irqflags;

		spin_lock_irqsave(&current->sighand->siglock, irqflags);
		oldset = current->blocked;
		siginitsetinv(&current->blocked, SHUTDOWN_SIGS & ~oldset.sig[0]);
		recalc_sigpending();
		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);

		wait_event_interruptible(wq->queue, wq->name == NULL);

		spin_lock_irqsave(&current->sighand->siglock, irqflags);
		current->blocked = oldset;
		recalc_sigpending();
		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
	} else {
		DPRINTK("skipped sleeping");
	}

	status = wq->status;

	/* Are we the last process to need status? */
	if (atomic_dec_and_test(&wq->wait_ctr))
		kfree(wq);

	return status;
}