X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fautofs4%2Fwaitq.c;h=1e4a539f4417c3c94a38c844c6a419dea606d709;hb=refs%2Fheads%2Fvserver;hp=c1b7279cae81738f773de69f9bd30c716ab2b042;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git

diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index c1b7279ca..1e4a539f4 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -3,6 +3,7 @@
  * linux/fs/autofs/waitq.c
  *
  *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *  Copyright 2001-2006 Ian Kent <raven@themaw.net>
  *
  * 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
@@ -27,25 +28,21 @@ void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
 {
 	struct autofs_wait_queue *wq, *nwq;
 
-	DPRINTK(("autofs: entering catatonic mode\n"));
+	DPRINTK("entering catatonic mode");
 
 	sbi->catatonic = 1;
 	wq = sbi->queues;
 	sbi->queues = NULL;	/* Erase all wait queues */
-	while ( wq ) {
+	while (wq) {
 		nwq = wq->next;
 		wq->status = -ENOENT; /* Magic is gone - report failure */
 		kfree(wq->name);
 		wq->name = NULL;
-		wake_up(&wq->queue);
+		wake_up_interruptible(&wq->queue);
 		wq = nwq;
 	}
-	if (sbi->pipe) {
-		fput(sbi->pipe);	/* Close the pipe */
-		sbi->pipe = NULL;
-	}
-
-	shrink_dcache_sb(sbi->sb);
+	fput(sbi->pipe);	/* Close the pipe */
+	sbi->pipe = NULL;
 }
 
 static int autofs4_write(struct file *file, const void *addr, int bytes)
@@ -90,14 +87,17 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 	union autofs_packet_union pkt;
 	size_t pktsz;
 
-	DPRINTK(("autofs_notify: wait id = 0x%08lx, name = %.*s, type=%d\n",
-		 wq->wait_queue_token, wq->len, wq->name, type));
+	DPRINTK("wait id = 0x%08lx, name = %.*s, type=%d",
+		wq->wait_queue_token, wq->len, wq->name, type);
 
 	memset(&pkt,0,sizeof pkt); /* For security reasons */
 
 	pkt.hdr.proto_version = sbi->version;
 	pkt.hdr.type = type;
-	if (type == autofs_ptype_missing) {
+	switch (type) {
+	/* Kernel protocol v4 missing and expire packets */
+	case autofs_ptype_missing:
+	{
 		struct autofs_packet_missing *mp = &pkt.missing;
 
 		pktsz = sizeof(*mp);
@@ -106,7 +106,10 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 		mp->len = wq->len;
 		memcpy(mp->name, wq->name, wq->len);
 		mp->name[wq->len] = '\0';
-	} else if (type == autofs_ptype_expire_multi) {
+		break;
+	}
+	case autofs_ptype_expire_multi:
+	{
 		struct autofs_packet_expire_multi *ep = &pkt.expire_multi;
 
 		pktsz = sizeof(*ep);
@@ -115,8 +118,35 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 		ep->len = wq->len;
 		memcpy(ep->name, wq->name, wq->len);
 		ep->name[wq->len] = '\0';
-	} else {
-		printk("autofs_notify_daemon: bad type %d!\n", type);
+		break;
+	}
+	/*
+	 * Kernel protocol v5 packet for handling indirect and direct
+	 * mount missing and expire requests
+	 */
+	case autofs_ptype_missing_indirect:
+	case autofs_ptype_expire_indirect:
+	case autofs_ptype_missing_direct:
+	case autofs_ptype_expire_direct:
+	{
+		struct autofs_v5_packet *packet = &pkt.v5_packet;
+
+		pktsz = sizeof(*packet);
+
+		packet->wait_queue_token = wq->wait_queue_token;
+		packet->len = wq->len;
+		memcpy(packet->name, wq->name, wq->len);
+		packet->name[wq->len] = '\0';
+		packet->dev = wq->dev;
+		packet->ino = wq->ino;
+		packet->uid = wq->uid;
+		packet->gid = wq->gid;
+		packet->pid = wq->pid;
+		packet->tgid = wq->tgid;
+		break;
+	}
+	default:
+		printk("autofs4_notify_daemon: bad type %d!\n", type);
 		return;
 	}
 
@@ -124,76 +154,189 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 		autofs4_catatonic_mode(sbi);
 }
 
-int autofs4_wait(struct autofs_sb_info *sbi, struct qstr *name,
+static int autofs4_getpath(struct autofs_sb_info *sbi,
+			   struct dentry *dentry, char **name)
+{
+	struct dentry *root = sbi->sb->s_root;
+	struct dentry *tmp;
+	char *buf = *name;
+	char *p;
+	int len = 0;
+
+	spin_lock(&dcache_lock);
+	for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
+		len += tmp->d_name.len + 1;
+
+	if (--len > NAME_MAX) {
+		spin_unlock(&dcache_lock);
+		return 0;
+	}
+
+	*(buf + len) = '\0';
+	p = buf + len - dentry->d_name.len;
+	strncpy(p, dentry->d_name.name, dentry->d_name.len);
+
+	for (tmp = dentry->d_parent; tmp != root ; tmp = tmp->d_parent) {
+		*(--p) = '/';
+		p -= tmp->d_name.len;
+		strncpy(p, tmp->d_name.name, tmp->d_name.len);
+	}
+	spin_unlock(&dcache_lock);
+
+	return len;
+}
+
+static struct autofs_wait_queue *
+autofs4_find_wait(struct autofs_sb_info *sbi,
+		  char *name, unsigned int hash, unsigned int len)
+{
+	struct autofs_wait_queue *wq;
+
+	for (wq = sbi->queues; wq; wq = wq->next) {
+		if (wq->hash == hash &&
+		    wq->len == len &&
+		    wq->name && !memcmp(wq->name, name, len))
+			break;
+	}
+	return wq;
+}
+
+int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
 		enum autofs_notify notify)
 {
+	struct autofs_info *ino;
 	struct autofs_wait_queue *wq;
-	int status;
+	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 )
+	if (sbi->catatonic)
 		return -ENOENT;
 	
-	/* We shouldn't be able to get here, but just in case */
-	if ( name->len > NAME_MAX )
-		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) && (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);
 
-	for ( wq = sbi->queues ; wq ; wq = wq->next ) {
-		if ( wq->hash == name->hash &&
-		     wq->len == name->len &&
-		     wq->name && !memcmp(wq->name,name->name,name->len) )
-			break;
+	if (mutex_lock_interruptible(&sbi->wq_mutex)) {
+		kfree(name);
+		return -EINTR;
 	}
-	
-	if ( !wq ) {
+
+	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 )
-			return -ENOMEM;
-
-		wq->name = kmalloc(name->len,GFP_KERNEL);
-		if ( !wq->name ) {
-			kfree(wq);
+		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;
-		init_waitqueue_head(&wq->queue);
-		wq->hash = name->hash;
-		wq->len = name->len;
-		wq->status = -EINTR; /* Status return if interrupted */
-		memcpy(wq->name, name->name, name->len);
 		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);
 
-		DPRINTK(("autofs_wait: new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
-			 wq->wait_queue_token, wq->len, wq->name, notify));
 		/* autofs4_notify_daemon() may block */
-		wq->wait_ctr = 2;
-		if (notify != NFY_NONE) {
-			autofs4_notify_daemon(sbi,wq, 
-					      notify == NFY_MOUNT ? autofs_ptype_missing :
-								    autofs_ptype_expire_multi);
-		}
+		autofs4_notify_daemon(sbi, wq, type);
 	} else {
-		wq->wait_ctr++;
-		DPRINTK(("autofs_wait: existing wait id = 0x%08lx, name = %.*s, nfy=%d\n",
-			 wq->wait_queue_token, wq->len, wq->name, notify));
+		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 ) {
+	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;
-		}
+		kfree(wq->name);
+		wq->name = NULL;
 	}
 
-	if ( wq->name ) {
+	if (wq->name) {
 		/* Block all but "shutdown" signals while waiting */
 		sigset_t oldset;
 		unsigned long irqflags;
@@ -204,19 +347,20 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct qstr *name,
 		recalc_sigpending();
 		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 
-		interruptible_sleep_on(&wq->queue);
+		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"));
+		DPRINTK("skipped sleeping");
 	}
 
 	status = wq->status;
 
-	if (--wq->wait_ctr == 0)	/* Are we the last process to need status? */
+	/* Are we the last process to need status? */
+	if (atomic_dec_and_test(&wq->wait_ctr))
 		kfree(wq);
 
 	return status;
@@ -227,23 +371,28 @@ int autofs4_wait_release(struct autofs_sb_info *sbi, autofs_wqt_t wait_queue_tok
 {
 	struct autofs_wait_queue *wq, **wql;
 
-	for ( wql = &sbi->queues ; (wq = *wql) ; wql = &wq->next ) {
-		if ( wq->wait_queue_token == wait_queue_token )
+	mutex_lock(&sbi->wq_mutex);
+	for (wql = &sbi->queues ; (wq = *wql) != 0 ; wql = &wq->next) {
+		if (wq->wait_queue_token == wait_queue_token)
 			break;
 	}
-	if ( !wq )
+
+	if (!wq) {
+		mutex_unlock(&sbi->wq_mutex);
 		return -EINVAL;
+	}
 
 	*wql = wq->next;	/* Unlink from chain */
+	mutex_unlock(&sbi->wq_mutex);
 	kfree(wq->name);
 	wq->name = NULL;	/* Do not wait on this queue */
 
 	wq->status = status;
 
-	if (--wq->wait_ctr == 0)	/* Is anyone still waiting for this guy? */
+	if (atomic_dec_and_test(&wq->wait_ctr))	/* Is anyone still waiting for this guy? */
 		kfree(wq);
 	else
-		wake_up(&wq->queue);
+		wake_up_interruptible(&wq->queue);
 
 	return 0;
 }