parasite: transfer image fd in parasite

Don't open image files from parasite.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

include/parasite.h

@@ -68,16 +68,8 @@ struct parasite_init_args {
 	struct sockaddr_un saddr;
 };
 
-struct parasite_dump_file_args {
-	parasite_status_t	status;
-	unsigned long		open_mode;
-	unsigned long		open_flags;
-	char			open_path[PATH_MAX];
-};
-
 struct parasite_dump_pages_args {
-	struct parasite_dump_file_args fa;
-
+	parasite_status_t       status;
 	struct vma_entry	vma_entry;
 	unsigned long		nrpages_dumped;	/* how many pages are dumped */
 	unsigned long		fd;

parasite-syscall.c

@@ -383,34 +383,34 @@ out:
 	return ret;
 }
 
-static int parasite_prep_file(int type, struct parasite_dump_file_args *fa,
+static int parasite_prep_file(int type,
 		struct parasite_ctl *ctl, struct cr_fdset *fdset)
 {
-	if (get_image_path(fa->open_path, sizeof(fa->open_path),
-				fdset_template[type].fmt, ctl->pid))
-		return -1;
+	int ret;
 
 	if (fchmod(fdset->fds[type], CR_FD_PERM_DUMP)) {
 		pr_perror("Can't change permissions on %d file", type);
 		return -1;
 	}
 
-	fa->open_flags	= O_WRONLY;
-	fa->open_mode	= CR_FD_PERM_DUMP;
+	ret = parasite_send_fd(ctl, fdset->fds[type]);
+	if (ret)
+		return ret;
+
 	return 0;
 }
 
 static int parasite_file_cmd(int cmd, int type,
 		struct parasite_ctl *ctl, struct cr_fdset *cr_fdset)
 {
-	struct parasite_dump_file_args args = { };
+	parasite_status_t args = { };
 	int status, ret = -1;
 
 	pr_info("\n");
 	pr_info("Dumping sigactions (pid: %d)\n", ctl->pid);
 	pr_info("----------------------------------------\n");
 
-	ret = parasite_prep_file(type, &args, ctl, cr_fdset);
+	ret = parasite_prep_file(type, ctl, cr_fdset);
 	if (ret < 0)
 		goto out;
 
@@ -488,7 +488,7 @@ int parasite_dump_pages_seized(struct parasite_ctl *ctl, struct list_head *vma_a
 	pr_info("Dumping pages (type: %d pid: %d)\n", CR_FD_PAGES, ctl->pid);
 	pr_info("----------------------------------------\n");
 
-	ret = parasite_prep_file(CR_FD_PAGES, &parasite_dumppages.fa, ctl, cr_fdset);
+	ret = parasite_prep_file(CR_FD_PAGES, ctl, cr_fdset);
 	if (ret < 0)
 		goto out;
 
@@ -519,9 +519,9 @@ int parasite_dump_pages_seized(struct parasite_ctl *ctl, struct list_head *vma_a
 					sizeof(parasite_dumppages));
 		if (ret) {
 			pr_panic("Dumping pages failed with %li (%li) at %li\n",
-				 parasite_dumppages.fa.status.ret,
-				 parasite_dumppages.fa.status.sys_ret,
-				 parasite_dumppages.fa.status.line);
+				 parasite_dumppages.status.ret,
+				 parasite_dumppages.status.sys_ret,
+				 parasite_dumppages.status.line);
 
 			goto err_restore;
 		}

parasite.c

@@ -94,27 +94,13 @@ static inline int should_dump_page(struct vma_entry *vmae, unsigned char mincore
 #endif
 }
 
-static int parasite_open_file(struct parasite_dump_file_args *fa)
-{
-	int fd;
-
-	fd = sys_open(fa->open_path, fa->open_flags, fa->open_mode);
-	if (fd < 0) {
-		sys_write_msg("sys_open failed\n");
-		SET_PARASITE_STATUS(&fa->status, PARASITE_ERR_OPEN, fd);
-		fd = fa->status.ret;
-	}
-
-	return fd;
-}
-
 /*
  * This is the main page dumping routine, it's executed
  * inside a victim process space.
  */
 static int dump_pages(struct parasite_dump_pages_args *args)
 {
-	parasite_status_t *st = &args->fa.status;
+	parasite_status_t *st = &args->status;
 	unsigned long nrpages, pfn, length;
 	unsigned long prot_old, prot_new;
 	unsigned char *map_brk = NULL;
@@ -126,7 +112,7 @@ static int dump_pages(struct parasite_dump_pages_args *args)
 	prot_old = prot_new = 0;
 
 	if (args->fd == -1UL) {
-		ret = parasite_open_file(&args->fa);
+		ret = recv_fd(tsock);
 		if (ret < 0)
 			goto err;
 
@@ -241,16 +227,15 @@ err:
 	return ret;
 }
 
-static int dump_sigact(struct parasite_dump_file_args *args)
+static int dump_sigact(parasite_status_t *st)
 {
-	parasite_status_t *st = &args->status;
 	rt_sigaction_t act;
 	struct sa_entry e;
 	int fd, sig;
 
 	int ret = PARASITE_ERR_FAIL;
 
-	fd = parasite_open_file(args);
+	fd = recv_fd(tsock);
 	if (fd < 0)
 		return fd;
 
@@ -318,16 +303,15 @@ static int dump_itimer(int which, int fd, parasite_status_t *st)
 	return 0;
 }
 
-static int dump_itimers(struct parasite_dump_file_args *args)
+static int dump_itimers(parasite_status_t *st)
 {
-	parasite_status_t *st = &args->status;
 	rt_sigaction_t act;
 	struct sa_entry e;
 	int fd, sig;
 
 	int ret = PARASITE_ERR_FAIL;
 
-	fd = parasite_open_file(args);
+	fd = recv_fd(tsock);
 	if (fd < 0)
 		return fd;
 
@@ -398,7 +382,6 @@ static int __used parasite_service(unsigned long cmd, void *args, void *brk)
 	brk_init(brk);
 
 	BUILD_BUG_ON(sizeof(struct parasite_dump_pages_args) > PARASITE_ARG_SIZE);
-	BUILD_BUG_ON(sizeof(struct parasite_dump_file_args) > PARASITE_ARG_SIZE);
 
 	switch (cmd) {
 	case PARASITE_CMD_PINGME:
@@ -412,9 +395,9 @@ static int __used parasite_service(unsigned long cmd, void *args, void *brk)
 	case PARASITE_CMD_DUMPPAGES:
 		return dump_pages((struct parasite_dump_pages_args *)args);
 	case PARASITE_CMD_DUMP_SIGACTS:
-		return dump_sigact((struct parasite_dump_file_args *)args);
+		return dump_sigact((parasite_status_t *)args);
 	case PARASITE_CMD_DUMP_ITIMERS:
-		return dump_itimers((struct parasite_dump_file_args *)args);
+		return dump_itimers((parasite_status_t *)args);
 	case PARASITE_CMD_DUMP_MISC:
 		return dump_misc((struct parasite_dump_misc *)args);
 	default: