From e86ebe923f1ecc072d8a99949871b46fe8188ac9 Mon Sep 17 00:00:00 2001
From: wujing <wujing50@huawei.com>
Date: Wed, 15 Apr 2020 06:01:36 -0400
Subject: [PATCH 32/49] link proc mounts to etc mtab

Signed-off-by: wujing <wujing50@huawei.com>
---
 src/lxc/conf.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 325e0c2..6856b1d 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -3977,6 +3977,37 @@ struct oci_hook_conf {
 	int which;
 };
 
+static int create_mtab_link()
+{
+	ssize_t ret;
+	int mret;
+	struct stat sbuf;
+	const char *pathname = "/proc/mounts";
+	const char *slink = "/etc/mtab";
+
+	if (file_exists(slink)) {
+		return 0;
+	}
+
+	ret = stat(pathname, &sbuf);
+	if (ret < 0) {
+		SYSERROR("Failed to stat %s: %s", pathname, strerror(errno));
+		return -1;
+	}
+
+	mret = symlink(pathname, slink);
+	if (mret < 0 && errno != EEXIST) {
+		if (errno == EROFS) {
+			WARN("Failed to create link %s for target %s. Read-only filesystem", slink, pathname);
+		} else {
+			SYSERROR("Failed to create \"%s\"", slink);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
 struct wait_conf {
 	pid_t pid;
 	unsigned long long startat;
@@ -4696,6 +4727,12 @@ int lxc_setup(struct lxc_handler *handler)
 			return log_error(-1, "failed to setup readonlypaths");
 		}
 	}
+
+	// isulad: create link /etc/mtab for /proc/mounts
+	if (create_mtab_link() != 0) {
+		ERROR("failed to create link /etc/mtab for target /proc/mounts");
+		goto on_error;
+	}
 #endif
 
 	if (!lxc_list_empty(&lxc_conf->keepcaps)) {
-- 
1.8.3.1