1 files changed, 44 insertions, 18 deletions

diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index e1fbdeef85db..9c098db43344 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -56,26 +56,27 @@ void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
 	mutex_unlock(&sbi->wq_mutex);
 }
 
-static int autofs4_write(struct file *file, const void *addr, int bytes)
+static int autofs4_write(struct autofs_sb_info *sbi,
+			 struct file *file, const void *addr, int bytes)
 {
 	unsigned long sigpipe, flags;
 	mm_segment_t fs;
 	const char *data = (const char *)addr;
 	ssize_t wr = 0;
 
-	/** WARNING: this is not safe for writing more than PIPE_BUF bytes! **/
-
 	sigpipe = sigismember(&current->pending.signal, SIGPIPE);
 
 	/* Save pointer to user space and point back to kernel space */
 	fs = get_fs();
 	set_fs(KERNEL_DS);
 
+	mutex_lock(&sbi->pipe_mutex);
 	while (bytes &&
 	       (wr = file->f_op->write(file,data,bytes,&file->f_pos)) > 0) {
 		data += wr;
 		bytes -= wr;
 	}
+	mutex_unlock(&sbi->pipe_mutex);
 
 	set_fs(fs);
 
@@ -90,7 +91,24 @@ static int autofs4_write(struct file *file, const void *addr, int bytes)
 
 	return (bytes > 0);
 }
-	
+
+/*
+ * The autofs_v5 packet was misdesigned.
+ *
+ * The packets are identical on x86-32 and x86-64, but have different
+ * alignment. Which means that 'sizeof()' will give different results.
+ * Fix it up for the case of running 32-bit user mode on a 64-bit kernel.
+ */
+static noinline size_t autofs_v5_packet_size(struct autofs_sb_info *sbi)
+{
+	size_t pktsz = sizeof(struct autofs_v5_packet);
+#if defined(CONFIG_X86_64) && defined(CONFIG_COMPAT)
+	if (sbi->compat_daemon > 0)
+		pktsz -= 4;
+#endif
+	return pktsz;
+}
+
 static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 				 struct autofs_wait_queue *wq,
 				 int type)
@@ -110,6 +128,13 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 
 	pkt.hdr.proto_version = sbi->version;
 	pkt.hdr.type = type;
+	mutex_lock(&sbi->wq_mutex);
+
+	/* Check if we have become catatonic */
+	if (sbi->catatonic) {
+		mutex_unlock(&sbi->wq_mutex);
+		return;
+	}
 	switch (type) {
 	/* Kernel protocol v4 missing and expire packets */
 	case autofs_ptype_missing:
@@ -147,8 +172,7 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 	{
 		struct autofs_v5_packet *packet = &pkt.v5_pkt.v5_packet;
 
-		pktsz = sizeof(*packet);
-
+		pktsz = autofs_v5_packet_size(sbi);
 		packet->wait_queue_token = wq->wait_queue_token;
 		packet->len = wq->name.len;
 		memcpy(packet->name, wq->name.name, wq->name.len);
@@ -163,22 +187,18 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 	}
 	default:
 		printk("autofs4_notify_daemon: bad type %d!\n", type);
+		mutex_unlock(&sbi->wq_mutex);
 		return;
 	}
 
-	/* Check if we have become catatonic */
-	mutex_lock(&sbi->wq_mutex);
-	if (!sbi->catatonic) {
-		pipe = sbi->pipe;
-		get_file(pipe);
-	}
+	pipe = sbi->pipe;
+	get_file(pipe);
+
 	mutex_unlock(&sbi->wq_mutex);
 
-	if (pipe) {
-		if (autofs4_write(pipe, &pkt, pktsz))
-			autofs4_catatonic_mode(sbi);
-		fput(pipe);
-	}
+	if (autofs4_write(sbi, pipe, &pkt, pktsz))
+		autofs4_catatonic_mode(sbi);
+	fput(pipe);
 }
 
 static int autofs4_getpath(struct autofs_sb_info *sbi,
@@ -257,6 +277,9 @@ static int validate_request(struct autofs_wait_queue **wait,
 	struct autofs_wait_queue *wq;
 	struct autofs_info *ino;
 
+	if (sbi->catatonic)
+		return -ENOENT;
+
 	/* Wait in progress, continue; */
 	wq = autofs4_find_wait(sbi, qstr);
 	if (wq) {
@@ -289,6 +312,9 @@ static int validate_request(struct autofs_wait_queue **wait,
 			if (mutex_lock_interruptible(&sbi->wq_mutex))
 				return -EINTR;
 
+			if (sbi->catatonic)
+				return -ENOENT;
+
 			wq = autofs4_find_wait(sbi, qstr);
 			if (wq) {
 				*wait = wq;
@@ -389,7 +415,7 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
 
 	ret = validate_request(&wq, sbi, &qstr, dentry, notify);
 	if (ret <= 0) {
-		if (ret == 0)
+		if (ret != -EINTR)
 			mutex_unlock(&sbi->wq_mutex);
 		kfree(qstr.name);
 		return ret;