[CRIU] Re: [PATCH v2 08/11] dump: hide regular file open

[Pavel Emelyanov]

On 03/05/2012 04:38 PM, Kinsbursky Stanislav wrote:

This plus #7 move openat from one function into two sub-functions, don't they?
What for?

> 
> Signed-off-by: Stanislav Kinsbursky <skinsbursky at openvz.org>
> 
> ---
>  cr-dump.c |   44 ++++++++++++++++++++++++++------------------
>  1 files changed, 26 insertions(+), 18 deletions(-)
> 
> diff --git a/cr-dump.c b/cr-dump.c
> index 8494820..03062e5 100644
> --- a/cr-dump.c
> +++ b/cr-dump.c
> @@ -99,20 +99,19 @@ struct fd_parms {
>  	pid_t		pid;
>  };
>  
> -static int dump_one_reg_file(struct fd_parms *p, int lfd,
> -			     struct cr_fdset *cr_fdset,
> -			     bool do_close_lfd)
> +static int dump_one_reg_file_fd(struct fd_parms *p, int lfd,
> +				struct cr_fdset *cr_fdset,
> +				bool do_close_lfd)
>  {
>  	struct fdinfo_entry e;
>  	char fd_str[128];
>  	int len;
> -	int ret = -1;
>  
>  	snprintf(fd_str, sizeof(fd_str), "/proc/self/fd/%d", lfd);
>  	len = readlink(fd_str, big_buffer, sizeof(big_buffer) - 1);
>  	if (len < 0) {
>  		pr_perror("Can't readlink %s", fd_str);
> -		goto err;
> +		return -1;
>  	}
>  
>  	big_buffer[len] = '\0';
> @@ -140,7 +139,7 @@ static int dump_one_reg_file(struct fd_parms *p, int lfd,
>  
>  		entry = fd_id_entry_collect((u32)p->id, p->pid, p->fd_name);
>  		if (!entry)
> -			goto err;
> +			return -1;
>  
>  		/* Now it might have completely new ID here */
>  		e.id	= entry->u.id;
> @@ -150,12 +149,25 @@ static int dump_one_reg_file(struct fd_parms *p, int lfd,
>  		p->type, len, p->flags, p->pos, p->fd_name);
>  
>  	if (write_img(cr_fdset->fds[CR_FD_FDINFO], &e))
> -		goto err;
> +		return -1;
>  	if (write_img_buf(cr_fdset->fds[CR_FD_FDINFO], big_buffer, e.len))
> -		goto err;
> +		return -1;
> +	return 0;
> +}
>  
> -	ret = 0;
> -err:
> +static int dump_one_reg_file(struct fd_parms *p, struct cr_fdset *cr_fdset)
> +{
> +	int ret, lfd;
> +	char d_name[32];
> +
> +	snprintf(d_name, sizeof(d_name), "%ld", p->fd_name);
> +	lfd = openat(p->pid_fd_dir, d_name, O_RDONLY);
> +	if (lfd < 0) {
> +		pr_perror("Failed to open regular file %d/%ld\n", p->pid_fd_dir, p->fd_name);
> +		return -1;
> +	}
> +	ret = dump_one_reg_file_fd(p, lfd, cr_fdset, 0);
> +	close_safe(&lfd);
>  	return ret;
>  }
>  
> @@ -175,7 +187,7 @@ static int dump_task_special_files(pid_t pid, struct cr_fdset *cr_fdset)
>  	fd = open_proc(pid, "cwd");
>  	if (fd < 0)
>  		return -1;
> -	ret = dump_one_reg_file(&params, fd, cr_fdset, 1);
> +	ret = dump_one_reg_file_fd(&params, fd, cr_fdset, 1);
>  	if (ret)
>  		return ret;
>  
> @@ -190,7 +202,7 @@ static int dump_task_special_files(pid_t pid, struct cr_fdset *cr_fdset)
>  	fd = open_proc(pid, "exe");
>  	if (fd < 0)
>  		return -1;
> -	ret = dump_one_reg_file(&params, fd, cr_fdset, 1);
> +	ret = dump_one_reg_file_fd(&params, fd, cr_fdset, 1);
>  
>  	return ret;
>  }
> @@ -338,7 +350,6 @@ static int dump_one_fd(pid_t pid, int pid_fd_dir, char *d_name, struct cr_fdset
>  	struct stat fd_stat;
>  	int err = -1;
>  	struct fd_parms p;
> -	int lfd;
>  
>  	err = fstatat(pid_fd_dir, d_name, &fd_stat, 0);
>  	if (err < 0) {
> @@ -349,8 +360,6 @@ static int dump_one_fd(pid_t pid, int pid_fd_dir, char *d_name, struct cr_fdset
>  	if (read_fd_params(pid, pid_fd_dir, d_name, &fd_stat, &p))
>  		return -1;
>  
> -	lfd = openat(p.pid_fd_dir, d_name, O_RDONLY);
> -
>  	switch (fd_stat.st_mode & S_IFMT) {
>  	case S_IFCHR:
>  		if (major(fd_stat.st_rdev) != MEM_MAJOR) {
> @@ -370,7 +379,7 @@ static int dump_one_fd(pid_t pid, int pid_fd_dir, char *d_name, struct cr_fdset
>  		 * Proceed to dump_one_reg_file().
>  		 */
>  	case S_IFREG:
> -		err = dump_one_reg_file(&p, lfd, cr_fdset, 0);
> +		err = dump_one_reg_file(&p, cr_fdset);
>  		break;
>  	case S_IFIFO:
>  		err = dump_one_pipe(&p, cr_fdset);
> @@ -392,7 +401,6 @@ static int dump_one_fd(pid_t pid, int pid_fd_dir, char *d_name, struct cr_fdset
>  	}
>  	if (err)
>  		pr_err("Can't dump file %ld of that type [%x]\n", p.fd_name, fd_stat.st_mode);
> -	close_safe(&lfd);
>  	return err;
>  }
>  
> @@ -483,7 +491,7 @@ static int dump_task_mappings(pid_t pid, struct list_head *vma_area_list, struct
>  			else
>  				p.flags = O_RDONLY;
>  
> -			ret = dump_one_reg_file(&p, vma_area->vm_file_fd, cr_fdset, 0);
> +			ret = dump_one_reg_file_fd(&p, vma_area->vm_file_fd, cr_fdset, 0);
>  			if (ret)
>  				goto err;
>  		}
>