files: Split regfiles info into separate file

Since now on the fdinfo image only contains plain fdinfo_entry-es.
The tpye == FDINFO_REG files are described by regfiles.img entries
and are matched by te ID in both.

At dump stage each new ID generated results in a new entry in the
regfiles.img. At restore stage open_fe_fd should open a regfile by
the fdinfo's ID. Now this is done in suboptimal way, need to improve.

Show shows both images separately.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-dump.c

@@ -87,6 +87,8 @@ err:
 	return ret;
 }
 
+static int reg_files_fd = -1;
+
 struct fd_parms {
 	unsigned long	fd_name;
 	unsigned long	pos;
@@ -102,24 +104,8 @@ static int dump_one_reg_file(const struct fd_parms *p, int lfd,
 			     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;
-	}
-
-	big_buffer[len] = '\0';
-	pr_info("Dumping path for %lx fd via self %d [%s]\n",
-		p->fd_name, lfd, big_buffer);
-
-	if (do_close_lfd)
-		close(lfd);
-
 	e.type	= p->type;
 	e.addr	= p->fd_name;
 	e.id	= p->id;
@@ -128,18 +114,41 @@ static int dump_one_reg_file(const struct fd_parms *p, int lfd,
 	if (ret < 0)
 		goto err;
 
-	e.rfe.len = len;
-	e.rfe.flags = p->flags;
-	e.rfe.pos = p->pos;
-	e.rfe.id = e.id;
+	if (ret) { /* new ID generated */
+		char fd_str[128];
+		int len;
+		struct reg_file_entry rfe;
+
+		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;
+		}
+
+		big_buffer[len] = '\0';
+		pr_info("Dumping path for %lx fd via self %d [%s]\n",
+				p->fd_name, lfd, big_buffer);
 
-	pr_info("fdinfo: type: %2x len: %2x flags: %4x pos: %8lx addr: %16lx\n",
-		p->type, len, p->flags, p->pos, p->fd_name);
+		rfe.len = len;
+		rfe.flags = p->flags;
+		rfe.pos = p->pos;
+		rfe.id = e.id;
+
+		if (write_img(reg_files_fd, &rfe))
+			goto err;
+		if (write_img_buf(reg_files_fd, big_buffer, len))
+			goto err;
+	}
+
+	if (do_close_lfd)
+		close(lfd);
+
+	pr_info("fdinfo: type: %2x flags: %4x pos: %8lx addr: %16lx\n",
+		p->type, p->flags, p->pos, p->fd_name);
 
 	if (write_img(cr_fdset->fds[CR_FD_FDINFO], &e))
 		goto err;
-	if (write_img_buf(cr_fdset->fds[CR_FD_FDINFO], big_buffer, e.rfe.len))
-		goto err;
 
 	ret = 0;
 err:
@@ -1478,6 +1487,10 @@ int cr_dump_tasks(pid_t pid, const struct cr_options *opts)
 
 	collect_sockets();
 
+	reg_files_fd = open_image(CR_FD_REG_FILES, O_RDWR | O_CREAT | O_EXCL);
+	if (reg_files_fd < 0)
+		goto err;
+
 	nr_shmems = 0;
 	shmems = xmalloc(SHMEMS_SIZE);
 	if (!shmems)
@@ -1514,6 +1527,7 @@ int cr_dump_tasks(pid_t pid, const struct cr_options *opts)
 
 	fd_id_show_tree();
 err:
+	close(reg_files_fd);
 	pstree_switch_state(&pstree_list, opts);
 	free_pstree(&pstree_list);
 

cr-show.c

@@ -83,17 +83,38 @@ static void show_files(int fd_files)
 		if (ret <= 0)
 			goto out;
 
-		pr_msg("type: %s flags: %4x pos: %lx "
-		       "addr: %16lx id: %8x",
-		       fdtype2s(e.type), e.rfe.flags, e.rfe.pos, e.addr, e.id);
-
-		if (e.rfe.len) {
-			int ret = read(fd_files, local_buf, e.rfe.len);
-			if (ret != e.rfe.len) {
-				pr_perror("Can't read %d bytes", e.rfe.len);
+		pr_msg("type: %s addr: %16lx id: %8x",
+		       fdtype2s(e.type), e.addr, e.id);
+
+		pr_msg("\n");
+	}
+
+out:
+	pr_img_tail(CR_FD_FDINFO);
+}
+
+static void show_reg_files(int fd_reg_files)
+{
+	struct reg_file_entry rfe;
+
+	pr_img_head(CR_FD_REG_FILES);
+
+	while (1) {
+		int ret;
+
+		ret = read_img_eof(fd_reg_files, &rfe);
+		if (ret <= 0)
+			goto out;
+
+		pr_msg("id: %8x flags: %4x pos: %lx", rfe.id, rfe.flags, rfe.pos);
+
+		if (rfe.len) {
+			int ret = read(fd_reg_files, local_buf, rfe.len);
+			if (ret != rfe.len) {
+				pr_perror("Can't read %d bytes", rfe.len);
 				goto out;
 			}
-			local_buf[e.rfe.len] = 0;
+			local_buf[rfe.len] = 0;
 			pr_msg(" --> %s", local_buf);
 		}
 
@@ -101,7 +122,7 @@ static void show_files(int fd_files)
 	}
 
 out:
-	pr_img_tail(CR_FD_FDINFO);
+	pr_img_tail(CR_FD_REG_FILES);
 }
 
 static void show_pipes(int fd_pipes)
@@ -521,6 +542,9 @@ static int cr_parse_file(struct cr_options *opts)
 	case IPCNS_SEM_MAGIC:
 		show_ipc_sem(fd);
 		break;
+	case REG_FILES_MAGIC:
+		show_reg_files(fd);
+		break;
 	default:
 		pr_err("Unknown magic %x on %s\n", magic, opts->show_dump_file);
 		goto err;

files.c

@@ -58,18 +58,6 @@ static struct fdinfo_desc *find_fd(u64 id)
 	return NULL;
 }
 
-static int get_file_path(char *path, struct fdinfo_entry *fe, int fd)
-{
-	if (read(fd, path, fe->rfe.len) != fe->rfe.len) {
-		pr_perror("Error reading path");
-		return -1;
-	}
-
-	path[fe->rfe.len] = '\0';
-
-	return 0;
-}
-
 static int collect_fd(int pid, struct fdinfo_entry *e)
 {
 	int i;
@@ -147,9 +135,6 @@ int prepare_fd_pid(int pid)
 		if (ret <= 0)
 			break;
 
-		if (e.rfe.len)
-			lseek(fdinfo_fd, e.rfe.len, SEEK_CUR);
-
 		if (fd_is_special(&e))
 			continue;
 
@@ -164,19 +149,49 @@ int prepare_fd_pid(int pid)
 
 static int open_fe_fd(struct fdinfo_entry *fe, int fd)
 {
+	struct reg_file_entry rfe;
 	char path[PATH_MAX];
 	int tmp;
 
-	if (get_file_path(path, fe, fd))
+	/* FIXME This should be made in more optimal way */
+
+	tmp = open_image_ro(CR_FD_REG_FILES);
+	if (tmp < 0)
 		return -1;
 
-	tmp = open(path, fe->rfe.flags);
+	while (1) {
+		int ret;
+
+		ret = read_img_eof(tmp, &rfe);
+		if (ret < 0)
+			return -1;
+
+		if (!ret) {
+			pr_err("Can't find file id %x\n", fe->id);
+			return -1;
+		}
+
+		if (rfe.id == fe->id)
+			break;
+
+		lseek(tmp, rfe.len, SEEK_CUR);
+	}
+
+	if (read(tmp, path, rfe.len) != rfe.len) {
+		pr_perror("Error reading path");
+		return -1;
+	}
+
+	close(tmp);
+	path[rfe.len] = '\0';
+
+	tmp = open(path, rfe.flags);
 	if (tmp < 0) {
 		pr_perror("Can't open file %s", path);
 		return -1;
 	}
 
-	lseek(tmp, fe->rfe.pos, SEEK_SET);
+	lseek(tmp, rfe.pos, SEEK_SET);
 
 	return tmp;
 }
@@ -434,10 +449,8 @@ static int open_fdinfo(int pid, struct fdinfo_entry *fe, int *fdinfo_fd, int sta
 static int open_special_fdinfo(int pid, struct fdinfo_entry *fe,
 		int fdinfo_fd, int state)
 {
-	if (state != FD_STATE_RECV) {
-		lseek(fdinfo_fd, fe->rfe.len, SEEK_CUR);
+	if (state != FD_STATE_RECV)
 		return 0;
-	}
 
 	if (fe->type == FDINFO_MAP)
 		return open_fmap(pid, fe, fdinfo_fd);
@@ -482,11 +495,8 @@ int prepare_fds(int pid)
 			if (fd_is_special(&fe))
 				ret = open_special_fdinfo(pid, &fe,
 						fdinfo_fd, state);
-			else {
-				offset = lseek(fdinfo_fd, 0, SEEK_CUR);
+			else
 				ret = open_fdinfo(pid, &fe, &fdinfo_fd, state);
-				lseek(fdinfo_fd, offset + fe.rfe.len, SEEK_SET);
-			}
 
 			if (ret)
 				break;

include/image.h

@@ -57,7 +57,6 @@ struct fdinfo_entry {
 	u64	addr;
 	u8	type;
 	u32	id;
-	struct reg_file_entry rfe;
 } __packed;
 
 #define fd_is_special(fe)		\