C++ (Cpp) blk_create_tree Examples

Example #1

File: blktrace.c Project: FatSunHYS/OSCourseDesign

/*
 * Setup everything required to start tracing
 */
static int blk_trace_setup(request_queue_t *q, struct block_device *bdev,
			   char __user *arg)
{
	struct blk_user_trace_setup buts;
	struct blk_trace *old_bt, *bt = NULL;
	struct dentry *dir = NULL;
	char b[BDEVNAME_SIZE];
	int ret, i;

	if (copy_from_user(&buts, arg, sizeof(buts)))
		return -EFAULT;

	if (!buts.buf_size || !buts.buf_nr)
		return -EINVAL;

	strcpy(buts.name, bdevname(bdev, b));

	/*
	 * some device names have larger paths - convert the slashes
	 * to underscores for this to work as expected
	 */
	for (i = 0; i < strlen(buts.name); i++)
		if (buts.name[i] == '/')
			buts.name[i] = '_';

	if (copy_to_user(arg, &buts, sizeof(buts)))
		return -EFAULT;

	ret = -ENOMEM;
	bt = kzalloc(sizeof(*bt), GFP_KERNEL);
	if (!bt)
		goto err;

	bt->sequence = alloc_percpu(unsigned long);
	if (!bt->sequence)
		goto err;

	ret = -ENOENT;
	dir = blk_create_tree(buts.name);
	if (!dir)
		goto err;

	bt->dir = dir;
	bt->dev = bdev->bd_dev;
	atomic_set(&bt->dropped, 0);

	ret = -EIO;
	bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops);
	if (!bt->dropped_file)
		goto err;

	bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, &blk_relay_callbacks);
	if (!bt->rchan)
		goto err;
	bt->rchan->private_data = bt;

	bt->act_mask = buts.act_mask;
	if (!bt->act_mask)
		bt->act_mask = (u16) -1;

	bt->start_lba = buts.start_lba;
	bt->end_lba = buts.end_lba;
	if (!bt->end_lba)
		bt->end_lba = -1ULL;

	bt->pid = buts.pid;
	bt->trace_state = Blktrace_setup;

	ret = -EBUSY;
	old_bt = xchg(&q->blk_trace, bt);
	if (old_bt) {
		(void) xchg(&q->blk_trace, old_bt);
		goto err;
	}

	return 0;
err:
	if (dir)
		blk_remove_tree(dir);
	if (bt) {
		if (bt->dropped_file)
			debugfs_remove(bt->dropped_file);
		if (bt->sequence)
			free_percpu(bt->sequence);
		if (bt->rchan)
			relay_close(bt->rchan);
		kfree(bt);
	}
	return ret;
}

Example #2

File: blktrace.c Project: Tigrouzen/k1099

/*
 * Setup everything required to start tracing
 */
int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
			struct blk_user_trace_setup *buts)
{
	struct blk_trace *old_bt, *bt = NULL;
	struct dentry *dir = NULL;
	int ret, i;

	if (!buts->buf_size || !buts->buf_nr)
		return -EINVAL;

	strcpy(buts->name, name);

	/*
	 * some device names have larger paths - convert the slashes
	 * to underscores for this to work as expected
	 */
	for (i = 0; i < strlen(buts->name); i++)
		if (buts->name[i] == '/')
			buts->name[i] = '_';

	ret = -ENOMEM;
	bt = kzalloc(sizeof(*bt), GFP_KERNEL);
	if (!bt)
		goto err;

	bt->sequence = alloc_percpu(unsigned long);
	if (!bt->sequence)
		goto err;

	ret = -ENOENT;
	dir = blk_create_tree(buts->name);
	if (!dir)
		goto err;

	bt->dir = dir;
	bt->dev = dev;
	atomic_set(&bt->dropped, 0);

	ret = -EIO;
	bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops);
	if (!bt->dropped_file)
		goto err;

	bt->rchan = relay_open("trace", dir, buts->buf_size,
				buts->buf_nr, &blk_relay_callbacks, bt);
	if (!bt->rchan)
		goto err;

	bt->act_mask = buts->act_mask;
	if (!bt->act_mask)
		bt->act_mask = (u16) -1;

	bt->start_lba = buts->start_lba;
	bt->end_lba = buts->end_lba;
	if (!bt->end_lba)
		bt->end_lba = -1ULL;

	bt->pid = buts->pid;
	bt->trace_state = Blktrace_setup;

	ret = -EBUSY;
	old_bt = xchg(&q->blk_trace, bt);
	if (old_bt) {
		(void) xchg(&q->blk_trace, old_bt);
		goto err;
	}

	return 0;
err:
	if (dir)
		blk_remove_tree(dir);
	if (bt) {
		if (bt->dropped_file)
			debugfs_remove(bt->dropped_file);
		free_percpu(bt->sequence);
		if (bt->rchan)
			relay_close(bt->rchan);
		kfree(bt);
	}
	return ret;
}