From: Serge Hallyn <serge.hallyn@ubuntu.com>
Date: Mon, 4 Mar 2013 17:55:16 +0000 (-0600)
Subject: userns: handle delayed write errors at fclose
X-Git-Tag: lxc-0.9.0.rc1~2^2~27
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e4ccd113dce99c9eb0cfba23c09eda4b58234d0d;p=thirdparty%2Flxc.git

userns: handle delayed write errors at fclose

As Kees pointed out, write() errors can be delayed and returned as
close() errors.  So don't ignore error on close when writing the
userns id mapping.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
---

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 04ab8b86d..7d70c97aa 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -2447,7 +2447,7 @@ int lxc_assign_network(struct lxc_list *network, pid_t pid)
 int add_id_mapping(enum idtype idtype, pid_t pid, uid_t host_start, uid_t ns_start, int range)
 {
 	char path[PATH_MAX];
-	int ret;
+	int ret, closeret;
 	FILE *f;
 
 	ret = snprintf(path, PATH_MAX, "/proc/%d/%cid_map", pid, idtype == ID_TYPE_UID ? 'u' : 'g');
@@ -2462,9 +2462,11 @@ int add_id_mapping(enum idtype idtype, pid_t pid, uid_t host_start, uid_t ns_sta
 	}
 	ret = fprintf(f, "%d %d %d", ns_start, host_start, range);
 	if (ret < 0)
-		perror("write");
-	fclose(f);
-	return ret < 0 ? ret : 0;
+		SYSERROR("writing id mapping");
+	closeret = fclose(f);
+	if (closeret)
+		SYSERROR("writing id mapping");
+	return ret < 0 ? ret : closeret;
 }
 
 int lxc_map_ids(struct lxc_list *idmap, pid_t pid)