dump: Call fsync only if needed

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

crtools.c

@@ -147,12 +147,6 @@ int prep_cr_fdset_for_dump(struct cr_fdset *cr_fdset,
 
 		magic = cr_fdset->desc[i].tmpl->magic;
 		write_ptr_safe(cr_fdset->desc[i].fd, &magic, err);
-
-		/*
-		 * Make sure it's on disk since we might
-		 * need to re-open files in parasite.
-		 */
-		fsync(cr_fdset->desc[i].fd);
 	}
 	ret = 0;
 err:

parasite-syscall.c

@@ -270,6 +270,12 @@ int parasite_dump_pages_seized(struct parasite_ctl *ctl, struct list_head *vma_a
 		goto chmod_err;
 	}
 
+	/*
+	 * Make sure the data is on disk since we will re-open
+	 * it in another process.
+	 */
+	fsync(cr_fdset->desc[fd_type].fd);
+
 	jerr(ptrace(PTRACE_GETREGS, ctl->pid, NULL, &regs_orig), err);
 
 	parasite_arg.command		= PARASITE_CMD_DUMPPAGES;