fdset: Introduce glbal fdset

This contains reg-files and sk-queues images, as they contain data
which is potentially generated by every task, so keep it open all
the time dump goes.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-dump.c

@@ -87,8 +87,7 @@ err:
 	return ret;
 }
 
-static int reg_files_fd = -1;
-int sk_queues_fd = -1;
+struct cr_fdset *glob_fdset;
 
 struct fd_parms {
 	unsigned long	fd_name;
@@ -103,7 +102,7 @@ struct fd_parms {
 static int dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p)
 {
 	char fd_str[128];
-	int len;
+	int len, rfd;
 	struct reg_file_entry rfe;
 
 	snprintf(fd_str, sizeof(fd_str), "/proc/self/fd/%d", lfd);
@@ -122,9 +121,11 @@ static int dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p)
 	rfe.pos = p->pos;
 	rfe.id = id;
 
-	if (write_img(reg_files_fd, &rfe))
+	rfd = fdset_fd(glob_fdset, CR_FD_REG_FILES);
+
+	if (write_img(rfd, &rfe))
 		return -1;
-	if (write_img_buf(reg_files_fd, big_buffer, len))
+	if (write_img_buf(rfd, big_buffer, len))
 		return -1;
 
 	return 0;
@@ -1494,12 +1495,8 @@ 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;
-
-	sk_queues_fd = open_image(CR_FD_SK_QUEUES, O_RDWR | O_CREAT | O_EXCL);
-	if (sk_queues_fd < 0)
+	glob_fdset = cr_glob_fdset_open(O_DUMP);
+	if (!glob_fdset)
 		goto err;
 
 	nr_shmems = 0;
@@ -1520,8 +1517,7 @@ int cr_dump_tasks(pid_t pid, const struct cr_options *opts)
 
 	fd_id_show_tree();
 err:
-	close(sk_queues_fd);
-	close(reg_files_fd);
+	close_cr_fdset(&glob_fdset);
 	pstree_switch_state(&pstree_list, opts);
 	free_pstree(&pstree_list);
 

crtools.c

@@ -233,6 +233,11 @@ struct cr_fdset *cr_ns_fdset_open(int pid, int mode)
 	return cr_fdset_open(pid, _CR_FD_NS_FROM, _CR_FD_NS_TO, mode);
 }
 
+struct cr_fdset *cr_glob_fdset_open(int mode)
+{
+	return cr_fdset_open(-1 /* ignored */, _CR_FD_GLOB_FROM, _CR_FD_GLOB_TO, mode);
+}
+
 static int parse_ns_string(const char *ptr, unsigned int *flags)
 {
 	const char *end = ptr + strlen(ptr);

include/crtools.h

@@ -47,8 +47,10 @@ enum {
 	CR_FD_PSTREE,
 	CR_FD_SHMEM_PAGES,
 
+	_CR_FD_GLOB_FROM,
 	CR_FD_SK_QUEUES,
 	CR_FD_REG_FILES,
+	_CR_FD_GLOB_TO,
 
 	CR_FD_MAX
 };
@@ -129,6 +131,8 @@ static inline int fdset_fd(const struct cr_fdset *fdset, int type)
 	return fdset->_fds[idx];
 }
 
+extern struct cr_fdset *glob_fdset;
+
 int cr_dump_tasks(pid_t pid, const struct cr_options *opts);
 int cr_restore_tasks(pid_t pid, struct cr_options *opts);
 int cr_show(unsigned long pid, struct cr_options *opts);
@@ -140,6 +144,8 @@ int cr_check(void);
 
 struct cr_fdset *cr_task_fdset_open(int pid, int mode);
 struct cr_fdset *cr_ns_fdset_open(int pid, int mode);
+struct cr_fdset *cr_glob_fdset_open(int mode);
+
 void close_cr_fdset(struct cr_fdset **cr_fdset);
 
 void free_mappings(struct list_head *vma_area_list);

include/sockets.h

@@ -30,6 +30,5 @@ extern int prepare_sockets(int pid);
 extern void show_unixsk(int fd);
 extern void show_inetsk(int fd);
 extern int show_sk_queues(int fd);
-extern int sk_queues_fd;
 
 #endif /* CR_SOCKETS_H__ */

parasite-syscall.c

@@ -499,7 +499,7 @@ int parasite_dump_socket_info(struct parasite_ctl *ctl, struct cr_fdset *fdset,
 		xfree(tmp);
 	}
 
-	ret = parasite_prep_file(sk_queues_fd, ctl);
+	ret = parasite_prep_file(fdset_fd(glob_fdset, CR_FD_SK_QUEUES), ctl);
 	if (ret < 0)
 		goto err_prepf;