[CRIU] Re: [PATCH 07/12] dump: Use parasite file descriptors draining

[Cyrill Gorcunov]

On Tue, Mar 27, 2012 at 04:55:31PM +0400, Pavel Emelyanov wrote:
> > -static int reg_files_fd = -1;
> > +static int collect_fds(pid_t pid, int *fd, int *nr_fd)
> > +{
> > +	struct dirent *d;
> > +	DIR *dir;
> > +	int n;
> > +
> > +	pr_info("\n");
> > +	pr_info("Collecting fds (pid: %d)\n", pid);
> > +	pr_info("----------------------------------------\n");
> > +
> > +	dir = opendir_proc(pid, "fd");
> > +	if (!dir)
> > +		return -1;
> > +
> > +	n = 0;
> > +	while ((d = readdir(dir))) {
> > +		if (d->d_name[0] == '.')
> > +			continue;
> 
> This is wrong.

Why? You can't get file descriptor number started from '.',
this is not arbitrary directory we're scanning but /proc/fd
with predefined structure.
> > +static void fill_fd_params(pid_t pid, int fd, int lfd, struct fd_parms *p)
> >  {
> > -	FILE *file;
> > -	int ret;
> > +	p->fd_name	= fd;
> > +	p->pos		= lseek(lfd, 0, SEEK_CUR);
> > +	p->flags	= fcntl(lfd, F_GETFL);
> > +	p->pid		= pid;
> > +	p->id		= FD_ID_INVALID;
> 
> Stop reformatting the code in one patch with writing new functionality.

Hmm. Wait, the old code had

-static int read_fd_params(pid_t pid, const char *fd, struct fd_parms *p)
 {
	...
-
-	p->pid	= pid;
-	p->id	= FD_ID_INVALID;
-
-	return 0;
}

the new code

+static void fill_fd_params(pid_t pid, int fd, int lfd, struct fd_parms *p)
 {
+	p->fd_name	= fd;
+	p->pos		= lseek(lfd, 0, SEEK_CUR);
+	p->flags	= fcntl(lfd, F_GETFL);
+	p->pid		= pid;
+	p->id		= FD_ID_INVALID;

where is the _reformatting_?

> > +	int nr_fds = PARASITE_MAX_FDS;
> > +	int fds[nr_fds];
> 
> I wouldn't allocate that much space on stack.

It's not that much, but if you prefer, I can use malloc here.