rlimit: Restore rlimist from Core data

To save backward compatibility try to read
data from old image if Core entry doesn't
has rlimits bound.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-restore.c

@@ -86,7 +86,7 @@ static struct pstree_item *current;
 static int restore_task_with_children(void *);
 static int sigreturn_restore(pid_t pid, CoreEntry *core);
 static int prepare_restorer_blob(void);
-static int prepare_rlimits(int pid);
+static int prepare_rlimits(int pid, CoreEntry *core);
 static int prepare_posix_timers(int pid);
 static int prepare_signals(int pid);
 
@@ -717,7 +717,7 @@ static int restore_one_alive_task(int pid, CoreEntry *core)
 	if (prepare_posix_timers(pid))
 		return -1;
 
-	if (prepare_rlimits(pid) < 0)
+	if (prepare_rlimits(pid, core) < 0)
 		return -1;
 
 	return sigreturn_restore(pid, core);
@@ -2034,13 +2034,42 @@ static unsigned long decode_rlim(u_int64_t ival)
 static unsigned long rlims_cpos;
 static unsigned int rlims_nr;
 
-static int prepare_rlimits(int pid)
+static int prepare_rlimits(int pid, CoreEntry *core)
 {
 	struct rlimit *r;
 	int fd, ret;
 
 	rlims_cpos = rst_mem_cpos(RM_PRIVATE);
 
+	/*
+	 * New image format: rlimits are bound to the core entry.
+	 */
+	if (core->rlimits) {
+		TaskRlimitsEntry *rls = core->rlimits;
+		int i;
+
+		for (i = 0; i < rls->n_rlimits; i++) {
+			r = rst_mem_alloc(sizeof(*r), RM_PRIVATE);
+			if (!r) {
+				pr_err("Can't allocate memory for resource %d\n", i);
+				return -1;
+			}
+
+			r->rlim_cur = decode_rlim(rls->rlimits[i]->cur);
+			r->rlim_max = decode_rlim(rls->rlimits[i]->max);
+
+			if (r->rlim_cur > r->rlim_max) {
+				pr_warn("Can't restore cur > max for %d.%d\n", pid, i);
+				r->rlim_cur = r->rlim_max;
+			}
+		}
+		rlims_nr = rls->n_rlimits;
+		return 0;
+	}
+
+	/*
+	 * Old image -- read from the file.
+	 */
 	fd = open_image(CR_FD_RLIMIT, O_RSTR, pid);
 	if (fd < 0) {
 		if (errno == ENOENT) {