[ltt-dev] [PATCH v2] LTTNG: Make marker enabled in advance

[Gui Jianfeng]

Mathieu Desnoyers wrote:
...
> Hrm, I did not notice it, but marker_info_read, as it is currently
> implemented in LTTng, should take lock_markers() before iterating on the
> markers. Can you provide a separate patch that fixes this ? (I don't
> want to work under your feet...)
> 
> The same should be done for build_marker_control_files() and
> remove_marker_control_dir().
> 
  Ok, will fix.
 
> The rest looks good. I look forward to see V3.
> 
> Thanks !
> 
> Mathieu
> 
>>  	marker_iter_reset(&iter);
>>  	marker_iter_start(&iter);
>>  	for (; iter.marker != NULL; marker_iter_next(&iter)) {
>> @@ -872,6 +890,7 @@ static ssize_t marker_info_read(struct file *filp, char __user *ubuf,
>>  	}
>>  	marker_iter_stop(&iter);
>>  
>> +out:
>>  	if (len >= PAGE_SIZE) {
>>  		len = PAGE_SIZE;
>>  		buf[PAGE_SIZE] = '\0';
>> @@ -887,6 +906,149 @@ static const struct file_operations info_fops = {
>>  	.read = marker_info_read,
>>  };
>>  
>> +static int marker_mkdir(struct inode *dir, struct dentry *dentry, int mode)
>> +{
>> +	struct dentry *marker_d, *enable_d, *info_d, *channel_d;
>> +	int ret;
>> +
>> +	ret = 0;
>> +	channel_d = (struct dentry *)dir->i_private;
>> +	mutex_unlock(&dir->i_mutex);
>> +
>> +	marker_d = debugfs_create_dir(dentry->d_name.name,
>> +				      channel_d);
>> +	if (IS_ERR(marker_d)) {
>> +		ret = PTR_ERR(marker_d);
>> +		goto out;
>> +	}
>> +
>> +	enable_d = debugfs_create_file("enable", 0644, marker_d,
>> +				       NULL, &enable_fops);
>> +	if (IS_ERR(enable_d) || !enable_d) {
>> +		printk(KERN_ERR
>> +		       "%s: create file of %s failed\n",
>> +		       __func__, "enable");
>> +		ret = -ENOMEM;
>> +		goto remove_marker_dir;
>> +	}
>> +
>> +	info_d = debugfs_create_file("info", 0644, marker_d,
>> +				     NULL, &info_fops);
>> +	if (IS_ERR(info_d) || !info_d) {
>> +		printk(KERN_ERR
>> +		       "%s: create file of %s failed\n",
>> +		       __func__, "info");
>> +		ret = -ENOMEM;
>> +		goto remove_enable_dir;
>> +	}
>> +
>> +	goto out;
>> +
>> +remove_enable_dir:
>> +	debugfs_remove(enable_d);
>> +remove_marker_dir:
>> +	debugfs_remove(marker_d);
>> +out:
>> +	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
>> +	return ret;
>> +}
>> +
>> +static int marker_rmdir(struct inode *dir, struct dentry *dentry)
>> +{
>> +	struct dentry *marker_d, *channel_d;
>> +	const char *channel, *name;
>> +	int ret;
>> +
>> +	ret = 0;
>> +
>> +	channel_d = (struct dentry *)dir->i_private;
>> +	channel = channel_d->d_name.name;
>> +
>> +	marker_d = dir_lookup(channel_d, dentry->d_name.name);
>> +
>> +	if (!marker_d) {
>> +		ret = -ENOENT;
>> +		goto out;
>> +	}
>> +
>> +	name = marker_d->d_name.name;
>> +
>> +	if (is_marker_present(channel, name) ||
>> +	    (!is_marker_present(channel, name) &&
>> +	     is_marker_enabled(channel, name))) {
>> +		ret = -EPERM;
>> +		goto out;
>> +	}
>> +
>> +	mutex_unlock(&dir->i_mutex);
>> +	mutex_unlock(&dentry->d_inode->i_mutex);
>> +	debugfs_remove_recursive(marker_d);
>> +	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
>> +	mutex_lock(&dentry->d_inode->i_mutex);
>> +out:
>> +	return ret;
>> +}
>> +
>> +const struct inode_operations channel_dir_opt = {
>> +	.lookup = simple_lookup,
>> +	.mkdir = marker_mkdir,
>> +	.rmdir = marker_rmdir,
>> +};
>> +
>> +static int channel_mkdir(struct inode *dir, struct dentry *dentry, int mode)
>> +{
>> +	struct dentry *channel_d;
>> +	int ret;
>> +
>> +	ret = 0;
>> +	mutex_unlock(&dir->i_mutex);
>> +
>> +	channel_d = debugfs_create_dir(dentry->d_name.name,
>> +				       markers_control_dir);
>> +	if (IS_ERR(channel_d)) {
>> +		ret = PTR_ERR(channel_d);
>> +		goto out;
>> +	}
>> +
>> +	channel_d->d_inode->i_private = (void *)channel_d;
>> +	init_marker_dir(channel_d, &channel_dir_opt);
>> +out:
>> +	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
>> +	return ret;
>> +}
>> +
>> +static int channel_rmdir(struct inode *dir, struct dentry *dentry)
>> +{
>> +	struct dentry *channel_d;
>> +	int ret;
>> +
>> +	ret = 0;
>> +
>> +	channel_d = dir_lookup(markers_control_dir, dentry->d_name.name);
>> +	if (!channel_d) {
>> +		ret = -ENOENT;
>> +		goto out;
>> +	}
>> +
>> +	if (list_empty(&channel_d->d_subdirs)) {
>> +		mutex_unlock(&dir->i_mutex);
>> +		mutex_unlock(&dentry->d_inode->i_mutex);
>> +		debugfs_remove(channel_d);
>> +		mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
>> +		mutex_lock(&dentry->d_inode->i_mutex);
>> +	} else
>> +		ret = -EPERM;
>> +
>> +out:
>> +	return ret;
>> +}
>> +
>> +const struct inode_operations root_dir_opt = {
>> +	.lookup = simple_lookup,
>> +	.mkdir = channel_mkdir,
>> +	.rmdir = channel_rmdir
>> +};
>> +
>>  static int build_marker_file(struct marker *marker)
>>  {
>>  	struct dentry *channel_d, *marker_d, *enable_d, *info_d;
>> @@ -903,6 +1065,8 @@ static int build_marker_file(struct marker *marker)
>>  			err = -ENOMEM;
>>  			goto err_build_fail;
>>  		}
>> +		channel_d->d_inode->i_private = (void *)channel_d;
>> +		init_marker_dir(channel_d, &channel_dir_opt);
>>  	}
>>  
>>  	marker_d  = dir_lookup(channel_d, marker->name);
>> @@ -1118,6 +1282,8 @@ static int __init ltt_trace_control_init(void)
>>  		goto err_create_marker_control_dir;
>>  	}
>>  
>> +	init_marker_dir(markers_control_dir, &root_dir_opt);
>> +
>>  	if (build_marker_control_files())
>>  		goto err_build_fail;
>>  
>> -- 
>> 1.5.4.rc3
>>
>>
>>
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>>
> 

-- 
Regards
Gui Jianfeng