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

[Kirill Tkhai]

On 18.01.2017 12:12, Pavel Emelyanov wrote:
> 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? ;)

Yes, it will be OK
 
>>>
>>>> +		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 */
>>>>
>>>> .
>>>>
>>>
>> .
>>
>