[CRIU] [PATCH v5 16/33] files: Add fdinfo_list_entry::stage

[Pavel Emelyanov]

On 01/18/2017 11:57 AM, Kirill Tkhai wrote:
> 
> 
> On 18.01.2017 11:43, Pavel Emelyanov wrote:
>> On 12/26/2016 05:27 PM, Kirill Tkhai wrote:
>>> Add fle open stages. Set a stage after every operation.
>>>
>>> v2: Do not merge filetype specific state with generic.
>>>
>>> Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
>>> ---
>>>  criu/files.c         |   13 ++++++++++---
>>>  criu/include/files.h |    9 +++++++++
>>>  2 files changed, 19 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/criu/files.c b/criu/files.c
>>> index 87d8fc655..8e04309b6 100644
>>> --- a/criu/files.c
>>> +++ b/criu/files.c
>>> @@ -1005,12 +1005,16 @@ static int post_open_fd(int pid, struct fdinfo_list_entry *fle)
>>>  			return -1;
>>>  		}
>>>  		if (!is_service_fd(fle->fe->fd, CTL_TTY_OFF))
>>> -			return 0;
>>> +			goto out;
>>>  	}
>>>  
>>>  	if (!d->ops->post_open)
>>> -		return 0;
>>> -	return d->ops->post_open(d, fle->fe->fd);
>>> +		goto out;
>>> +	if (d->ops->post_open(d, fle->fe->fd))
>>> +		return -1;
>>> +out:
>>> +	fle->stage = FLE_RESTORED;
>>> +	return 0;
>>>  }
>>>  
>>>  
>>> @@ -1058,6 +1062,9 @@ static int open_fd(int pid, struct fdinfo_list_entry *fle)
>>>  		return -1;
>>>  	}
>>>  
>>> +	if (fle->stage < FLE_OPEN)
>>
>> Why is this if here?
> 
> I supposed, there may be file types, which would need to advance their state
> more, that to FLE_OPEN. But there is no one no.
> 
> If you want, I may do patch, which will delete this and below, on top of the series.

If I just remove this if from the patch, will it still work? ;)

>>
>>> +		fle->stage = FLE_OPEN;
>>> +
>>>  	return serve_out_fd(pid, fle->fe->fd, d);
>>>  }
>>>  
>>> diff --git a/criu/include/files.h b/criu/include/files.h
>>> index 1b44960de..5fffed6a8 100644
>>> --- a/criu/include/files.h
>>> +++ b/criu/include/files.h
>>> @@ -64,6 +64,13 @@ extern int fill_fdlink(int lfd, const struct fd_parms *p, struct fd_link *link);
>>>  
>>>  struct file_desc;
>>>  
>>> +enum {
>>> +	FLE_INITIALIZED,
>>> +	FLE_OPEN,
>>> +	FLE_RESTORING,
>>
>> State not used in this set.
> 
> It's aimed for the future using for file types, which need a intermediate state. But, correctly,
> it's not used in this set.
> 
> 
>>> +	FLE_RESTORED,
>>> +};
>>> +
>>>  struct fdinfo_list_entry {
>>>  	struct list_head	desc_list;	/* To chain on  @fd_info_head */
>>>  	struct file_desc	*desc;		/* Associated file descriptor */
>>> @@ -72,6 +79,7 @@ struct fdinfo_list_entry {
>>>  	int			pid;
>>>  	FdinfoEntry		*fe;
>>>  	u8			received:1;
>>> +	u8			stage:3;
>>>  };
>>>  
>>>  static inline void fle_init(struct fdinfo_list_entry *fle, int pid, FdinfoEntry *fe)
>>> @@ -79,6 +87,7 @@ static inline void fle_init(struct fdinfo_list_entry *fle, int pid, FdinfoEntry
>>>  	fle->pid = pid;
>>>  	fle->fe = fe;
>>>  	fle->received = 0;
>>> +	fle->stage = FLE_INITIALIZED;
>>>  }
>>>  
>>>  /* reports whether fd_a takes prio over fd_b */
>>>
>>> .
>>>
>>
> .
>