[CRIU] [PATCH 2/5] pipes: do not restore file flags via set_fd_flags()

[Stanislav Kinsburskiу]

15 дек. 2015 г. 12:17 PM пользователь Andrew Vagin <avagin at virtuozzo.com> написал:
>
> On Tue, Dec 15, 2015 at 01:57:50PM +0300, Stanislav Kinsburskiy wrote: 
> > It doesn't work for pipes with O_DIRECT. System call sys_pipe2() can be used 
> > instead to create pipe with desired flags. 
>
> Is it possiable to set O_NONBLOCK only for one end of a pipe? Does this 
> code handle this case? 

Yes, it's possible.
No, it doesn't handle.
This is a big problem with two piles per pipe...
Probably, kernel have to fixed to be able to set O_DIRECT on pipe via fcntl().
I'll check it.


> > 
> > Signed-off-by: Stanislav Kinsburskiy <skinsbursky at virtuozzo.com> 
> > --- 
> >  pipes.c |    6 +++--- 
> >  1 file changed, 3 insertions(+), 3 deletions(-) 
> > 
> > diff --git a/pipes.c b/pipes.c 
> > index dfba12d..532ff7e 100644 
> > --- a/pipes.c 
> > +++ b/pipes.c 
> > @@ -273,7 +273,7 @@ static int recv_pipe_fd(struct pipe_info *pi) 
> >  else 
> >  fd = tmp; 
> >  if (fd >= 0) { 
> > - if (rst_file_params(fd, pi->pe->fown, pi->pe->flags)) { 
> > + if (restore_fown(fd, pi->pe->fown) < 0) { 
> >  close(fd); 
> >  return -1; 
> >  } 
> > @@ -316,7 +316,7 @@ static int open_pipe(struct file_desc *d) 
> >  if (!pi->create) 
> >  return recv_pipe_fd(pi); 
> >  
> > - if (pipe(pfd) < 0) { 
> > + if (pipe2(pfd, pi->pe->flags & (O_NONBLOCK | O_DIRECT | O_CLOEXEC)) < 0) { 
> >  pr_perror("Can't create pipe"); 
> >  return -1; 
> >  } 
> > @@ -355,7 +355,7 @@ out: 
> >  tmp = reopen_pipe(tmp, pi->pe->flags); 
> >  
> >  if (tmp >= 0) 
> > - if (rst_file_params(tmp, pi->pe->fown, pi->pe->flags)) 
> > + if (restore_fown(tmp, pi->pe->fown) < 0) 
> >  return -1; 
> >  
> >  return tmp; 
> > 
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