pipes: Make dump_one_pipe to use dump_one_pipe_data

xemul: Why we haven't done this earlier? Because the pe entry contained the
amount of bytes in the pipe and this value had to be calculated before we
wrote this entry into the image. Now the pipe data is stored in another img
file and we can happily split pe dump and pde dump into two calls.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

pipes.c

@@ -304,7 +304,6 @@ static int open_pipe(struct file_desc *d)
 static u32 *pipes_with_data;	/* pipes for which data already dumped */
 static int nr_pipes = 0;
 
-#if 0
 static int dump_one_pipe_data(int lfd, u32 id, const struct fd_parms *p)
 {
 	int pipe_size, i, bytes;
@@ -394,111 +393,22 @@ err_close:
 err:
 	return ret;
 }
-#endif
 
 static int dump_one_pipe(int lfd, u32 id, const struct fd_parms *p)
 {
 	struct pipe_entry pe;
-	int fd_pipes;
-	int steal_pipe[2];
-	int pipe_size;
-	int has_bytes = 0;
-	int ret = -1;
-	int i = 0;
 
 	pr_info("Dumping pipe %d with id %#x pipe_id %#x\n", lfd, id, p->id);
 
-	fd_pipes = fdset_fd(glob_fdset, CR_FD_PIPES);
-
-	if (p->flags & O_WRONLY)
-		goto dump;
+	pe.id		= id;
+	pe.pipe_id	= p->id;
+	pe.flags	= p->flags;
+	pe.fown		= p->fown;
 
-	for (i = 0; i < nr_pipes; i++)
-		if (pipes_with_data[i] == p->id)
-			goto dump; /* data was dumped already */
-
-	nr_pipes++;
-	if (nr_pipes > PIPES_SIZE) {
-		pr_err("OOM storing pipe\n");
+	if (write_img(fdset_fd(glob_fdset, CR_FD_PIPES), &pe))
 		return -1;
-	}
-
-	pr_info("Dumping data from pipe %#x fd %d\n", id, lfd);
-
-	pipes_with_data[nr_pipes - 1] = p->id;
-
-	pipe_size = fcntl(lfd, F_GETPIPE_SZ);
-	if (pipe_size < 0) {
-		pr_err("Can't obtain piped data size\n");
-		goto err;
-	}
-
-	if (pipe(steal_pipe) < 0) {
-		pr_perror("Can't create pipe for stealing data");
-		goto err;
-	}
-
-	has_bytes = tee(lfd, steal_pipe[1], pipe_size, SPLICE_F_NONBLOCK);
-	if (has_bytes < 0) {
-		if (errno != EAGAIN) {
-			pr_perror("Can't pick pipe data");
-			goto err_close;
-		} else
-			has_bytes = 0;
-	}
-dump:
-	pe.id = id;
-	pe.pipe_id = p->id;
-	pe.flags = p->flags;
-	pe.fown = p->fown;
-
-	if (write_img(fd_pipes, &pe))
-		goto err_close;
-
-	if (has_bytes) {
-		off_t off;
-		struct pipe_data_entry pde;
-
-		fd_pipes = fdset_fd(glob_fdset, CR_FD_PIPES_DATA);
-
-		pde.pipe_id = p->id;
-		pde.bytes = has_bytes;
-		pde.off = 0;
-
-		if (has_bytes > PIPE_MAX_NONALIG_SIZE) {
-			off = lseek(fd_pipes, 0, SEEK_CUR);
-			off += sizeof(pde);
-			off &= PAGE_SIZE -1;
-			if (off)
-				pde.off = PAGE_SIZE - off;
-			pr_info("off 0x%lx %#x\n", off, pde.off);
-		}
 
-		if (write_img(fd_pipes, &pde))
-			goto err_close;
-
-		if (pde.off) {
-			off = lseek(fd_pipes, pde.off, SEEK_CUR);
-			pr_info("off 0x%lx\n", off);
-		}
-
-		ret = splice(steal_pipe[0], NULL, fd_pipes,
-			     NULL, has_bytes, 0);
-		if (ret < 0) {
-			pr_perror("Can't push pipe data");
-			goto err_close;
-		}
-	}
-
-	ret = 0;
-
-err_close:
-	if (has_bytes) {
-		close(steal_pipe[0]);
-		close(steal_pipe[1]);
-	}
-err:
-	return ret;
+	return dump_one_pipe_data(lfd, id, p);
 }
 
 static const struct fdtype_ops pipe_ops = {