Reduced control channel code duplication.

2009-02-17  David Smith  <dsmith@redhat.com>

	* control.c: Contains generic control channel functions.
	* procfs.c: Specific procfs control channel functions.  All generic
	control channel functions moved to control.c.
	* debugfs.c: New file containing debugfs specific control channel
	functions.
	* control.h: New file.
	* transport.c: Updated file inclusion.

1 files changed, 10 insertions, 233 deletions

diff --git a/runtime/transport/procfs.c b/runtime/transport/procfs.c
index 0c31ae3c..5a8e4238 100644
--- a/runtime/transport/procfs.c
+++ b/runtime/transport/procfs.c
@@ -1,7 +1,7 @@
 /* -*- linux-c -*-
  *
  * /proc transport and control
- * Copyright (C) 2005-2008 Red Hat Inc.
+ * Copyright (C) 2005-2009 Red Hat Inc.
  *
  * This file is part of systemtap, and is free software.  You can
  * redistribute it and/or modify it under the terms of the GNU General
@@ -12,11 +12,6 @@
 #include "../procfs.c"		   // for _stp_mkdir_proc_module()
 
 #define STP_DEFAULT_BUFFERS 256
-static int _stp_current_buffers = STP_DEFAULT_BUFFERS;
-
-static _stp_mempool_t *_stp_pool_q;
-static struct list_head _stp_ctl_ready_q;
-DEFINE_SPINLOCK(_stp_ctl_ready_lock);
 
 #ifdef STP_BULKMODE
 extern int _stp_relay_flushing;
@@ -62,112 +57,19 @@ static struct file_operations _stp_proc_fops = {
 };
 #endif /* STP_BULKMODE */
 
-
-static ssize_t _stp_ctl_write_cmd(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
-{
-	int type;
-	static int started = 0;
-
-	if (count < sizeof(int))
-		return 0;
-
-	if (get_user(type, (int __user *)buf))
-		return -EFAULT;
-
-#if DEBUG_TRANS
-	if (type < STP_MAX_CMD)
-		_dbug("Got %s. len=%d\n", _stp_command_name[type], (int)count);
-#endif
-
-	count -= sizeof(int);
-	buf += sizeof(int);
-
-	switch (type) {
-	case STP_START:
-		if (started == 0) {
-			struct _stp_msg_start st;
-			if (count < sizeof(st))
-				return 0;
-			if (copy_from_user(&st, buf, sizeof(st)))
-				return -EFAULT;
-			_stp_handle_start(&st);
-			started = 1;
-		}
-		break;
-
-	case STP_EXIT:
-		_stp_exit_flag = 1;
-		break;
-
-	case STP_RELOCATION:
-          	_stp_do_relocation (buf, count);
-          	break;
-
-	case STP_READY:
-		break;
-
-	default:
-		errk("invalid command type %d\n", type);
-		return -EINVAL;
-	}
-
-	return count;
-}
-
-struct _stp_buffer {
-	struct list_head list;
-	int len;
-	int type;
-	char buf[STP_CTL_BUFFER_SIZE];
-};
-
-static DECLARE_WAIT_QUEUE_HEAD(_stp_ctl_wq);
-
-#if DEBUG_TRANS
-static void _stp_ctl_write_dbug(int type, void *data, int len)
-{
-	char buf[64];
-	switch (type) {
-	case STP_START:
-		_dbug("sending STP_START\n");
-		break;
-	case STP_EXIT:
-		_dbug("sending STP_EXIT\n");
-		break;
-	case STP_OOB_DATA:
-		snprintf(buf, sizeof(buf), "%s", (char *)data);
-		_dbug("sending %d bytes of STP_OOB_DATA: %s\n", len, buf);
-		break;
-	case STP_SYSTEM:
-		snprintf(buf, sizeof(buf), "%s", (char *)data);
-		_dbug("sending STP_SYSTEM: %s\n", buf);
-		break;
-	case STP_TRANSPORT:
-		_dbug("sending STP_TRANSPORT\n");
-		break;
-	default:
-		_dbug("ERROR: unknown message type: %d\n", type);
-		break;
-	}
-}
-#endif
-
-static int _stp_ctl_write(int type, void *data, int len)
+inline static int _stp_ctl_write_fs(int type, void *data, unsigned len)
 {
 	struct _stp_buffer *bptr;
 	unsigned long flags;
 
-#if DEBUG_TRANS
-	_stp_ctl_write_dbug(type, data, len);
-#endif
-
 #define WRITE_AGG
 #ifdef WRITE_AGG
-
 	spin_lock_irqsave(&_stp_ctl_ready_lock, flags);
 	if (!list_empty(&_stp_ctl_ready_q)) {
 		bptr = (struct _stp_buffer *)_stp_ctl_ready_q.prev;
-		if (bptr->len + len <= STP_BUFFER_SIZE && type == STP_REALTIME_DATA && bptr->type == STP_REALTIME_DATA) {
+		if ((bptr->len + len) <= STP_CTL_BUFFER_SIZE
+		    && type == STP_REALTIME_DATA
+		    && bptr->type == STP_REALTIME_DATA) {
 			memcpy(bptr->buf + bptr->len, data, len);
 			bptr->len += len;
 			spin_unlock_irqrestore(&_stp_ctl_ready_lock, flags);
@@ -176,114 +78,9 @@ static int _stp_ctl_write(int type, void *data, int len)
 	}
 	spin_unlock_irqrestore(&_stp_ctl_ready_lock, flags);
 #endif
-
-	/* make sure we won't overflow the buffer */
-	if (unlikely(len > STP_BUFFER_SIZE))
-		return 0;
-
-	/* get a buffer from the free pool */
-	bptr = _stp_mempool_alloc(_stp_pool_q);
-	if (unlikely(bptr == NULL))
-		return -1;
-
-	bptr->type = type;
-	memcpy(bptr->buf, data, len);
-	bptr->len = len;
-
-	/* put it on the pool of ready buffers */
-	spin_lock_irqsave(&_stp_ctl_ready_lock, flags);
-	list_add_tail(&bptr->list, &_stp_ctl_ready_q);
-	spin_unlock_irqrestore(&_stp_ctl_ready_lock, flags);
-
-	return len;
-}
-
-
-/* send commands with timeout and retry */
-static int _stp_ctl_send(int type, void *data, int len)
-{
-	int err, trylimit = 50;
-	dbug_trans(1, "ctl_send: type=%d len=%d\n", type, len);
-        while ((err = _stp_ctl_write(type, data, len)) < 0 && trylimit--)
-          msleep(5);
-        if (err > 0)
-          wake_up_interruptible(&_stp_ctl_wq);
-	dbug_trans(1, "returning %d\n", err);
-	return err;
-}
-
-
-static ssize_t _stp_ctl_read_cmd(struct file *file, char __user *buf, size_t count, loff_t *ppos)
-{
-	struct _stp_buffer *bptr;
-	int len;
-	unsigned long flags;
-
-	/* wait for nonempty ready queue */
-	spin_lock_irqsave(&_stp_ctl_ready_lock, flags);
-	while (list_empty(&_stp_ctl_ready_q)) {
-		spin_unlock_irqrestore(&_stp_ctl_ready_lock, flags);
-		if (file->f_flags & O_NONBLOCK)
-			return -EAGAIN;
-		if (wait_event_interruptible(_stp_ctl_wq, !list_empty(&_stp_ctl_ready_q)))
-			return -ERESTARTSYS;
-		spin_lock_irqsave(&_stp_ctl_ready_lock, flags);
-	}
-
-	/* get the next buffer off the ready list */
-	bptr = (struct _stp_buffer *)_stp_ctl_ready_q.next;
-	list_del_init(&bptr->list);
-	spin_unlock_irqrestore(&_stp_ctl_ready_lock, flags);
-
-	/* write it out */
-	len = bptr->len + 4;
-	if (len > count || copy_to_user(buf, &bptr->type, len)) {
-		/* now what?  We took it off the queue then failed to send it */
-		/* we can't put it back on the queue because it will likely be out-of-order */
-		/* fortunately this should never happen */
-		/* FIXME need to mark this as a transport failure */
-		errk("Supplied buffer too small. count:%d len:%d\n", (int)count, len);
-		return -EFAULT;
-	}
-
-	/* put it on the pool of free buffers */
-	_stp_mempool_free(bptr);
-
-	return len;
-}
-
-static int _stp_ctl_open_cmd(struct inode *inode, struct file *file)
-{
-	if (_stp_attached)
-		return -1;
-
-	_stp_attach();
-	return 0;
-}
-
-static int _stp_ctl_close_cmd(struct inode *inode, struct file *file)
-{
-	if (_stp_attached)
-		_stp_detach();
 	return 0;
 }
 
-static struct file_operations _stp_proc_fops_cmd = {
-	.owner = THIS_MODULE,
-	.read = _stp_ctl_read_cmd,
-	.write = _stp_ctl_write_cmd,
-	.open = _stp_ctl_open_cmd,
-	.release = _stp_ctl_close_cmd,
-};
-
-/* copy since proc_match is not MODULE_EXPORT'd */
-static int my_proc_match(int len, const char *name, struct proc_dir_entry *de)
-{
-	if (de->namelen != len)
-		return 0;
-	return !memcmp(name, de->name, len);
-}
-
 /* set the number of buffers to use to 'num' */
 static int _stp_set_buffers(int num)
 {
@@ -305,7 +102,7 @@ static int _stp_ctl_read_bufsize(char *page, char **start, off_t off, int count,
 	return len;
 }
 
-static int _stp_register_ctl_channel(void)
+static int _stp_register_ctl_channel_fs(void)
 {
 	int i;
 	const char *dirname = "systemtap";
@@ -313,17 +110,7 @@ static int _stp_register_ctl_channel(void)
 #ifdef STP_BULKMODE
 	int j;
 #endif
-
 	struct proc_dir_entry *de, *bs = NULL;
-	struct list_head *p, *tmp;
-
-	INIT_LIST_HEAD(&_stp_ctl_ready_q);
-
-	/* allocate buffers */
-	_stp_pool_q = _stp_mempool_init(sizeof(struct _stp_buffer), STP_DEFAULT_BUFFERS);
-	if (unlikely(_stp_pool_q == NULL))
-		goto err0;
-	_stp_allocated_net_memory += sizeof(struct _stp_buffer) * STP_DEFAULT_BUFFERS;
 
 	if (!_stp_mkdir_proc_module())
 		goto err0;
@@ -354,7 +141,7 @@ static int _stp_register_ctl_channel(void)
 		goto err1;
 	de->uid = _stp_uid;
 	de->gid = _stp_gid;
-	de->proc_fops = &_stp_proc_fops_cmd;
+	de->proc_fops = &_stp_ctl_fops_cmd;
 
 	return 0;
 err2:
@@ -375,18 +162,16 @@ err1:
 #endif /* STP_BULKMODE */
 	_stp_rmdir_proc_module();
 err0:
-	_stp_mempool_destroy(_stp_pool_q);
-	errk("Error creating systemtap /proc entries.\n");
 	return -1;
 }
 
-static void _stp_unregister_ctl_channel(void)
+static void _stp_unregister_ctl_channel_fs(void)
 {
-	struct list_head *p, *tmp;
-	char buf[32];
 #ifdef STP_BULKMODE
+	char buf[32];
 	int i;
 	struct proc_dir_entry *de;
+
 	dbug_trans(1, "unregistering procfs\n");
 	for (de = _stp_proc_root->subdir; de; de = de->next)
 		_stp_kfree(de->data);
@@ -398,14 +183,6 @@ static void _stp_unregister_ctl_channel(void)
 	remove_proc_entry("bufsize", _stp_proc_root);
 #endif /* STP_BULKMODE */
 
-	remove_proc_entry(".symbols", _stp_proc_root);
 	remove_proc_entry(".cmd", _stp_proc_root);
 	_stp_rmdir_proc_module();
-
-	/* Return memory to pool and free it. */
-	list_for_each_safe(p, tmp, &_stp_ctl_ready_q) {
-		list_del(p);
-		_stp_mempool_free(p);
-	}
-	_stp_mempool_destroy(_stp_pool_q);	
 }