From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Tue, 14 Aug 2018 22:37:05 +0000 (+0200)
Subject: lxccontainer: improve file locking
X-Git-Tag: lxc-3.1.0~163^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d1bc8d484caa7b3157aa76da346badabf2a64d12;p=thirdparty%2Flxc.git

lxccontainer: improve file locking

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 04c2f672b..5f1e7330c 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -155,12 +155,13 @@ static int ongoing_create(struct lxc_container *c)
 	if (ret < 0 || (size_t)ret >= len)
 		return -1;
 
-	if (!file_exists(path))
-		return 0;
+	fd = open(path, O_RDWR | O_CLOEXEC);
+	if (fd < 0) {
+		if (errno != ENOENT)
+			return -1;
 
-	fd = open(path, O_RDWR);
-	if (fd < 0)
 		return 0;
+	}
 
 	lk.l_type = F_WRLCK;
 	lk.l_whence = SEEK_SET;
@@ -170,8 +171,11 @@ static int ongoing_create(struct lxc_container *c)
 	lk.l_pid = 0;
 
 	ret = fcntl(fd, F_OFD_GETLK, &lk);
-	if (ret < 0 && errno == EINVAL)
+	if (ret < 0 && errno == EINVAL) {
 		ret = flock(fd, LOCK_EX | LOCK_NB);
+		if (ret < 0 && errno == EWOULDBLOCK)
+			ret = 0;
+	}
 
 	close(fd);
 
@@ -198,7 +202,7 @@ static int create_partial(struct lxc_container *c)
 	if (ret < 0 || (size_t)ret >= len)
 		return -1;
 
-	fd = open(path, O_RDWR | O_CREAT | O_EXCL, 0755);
+	fd = open(path, O_RDWR | O_CREAT | O_EXCL | O_CLOEXEC, 0000);
 	if (fd < 0)
 		return -1;