Description: Reduce the timeout to zero seconds when running in a container (LP: #1760173)
 When inside a lxd container with zfs storage, zfs list or zpool status
 appears to hang, no output for 10 seconds. Check if we are inside a
 container and set the timeout to zero in this specific case.
Origin: ubuntu
Forwarded: not-needed
Bug: https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1760173
--- a/lib/libzfs/os/linux/libzfs_util_os.c
+++ b/lib/libzfs/os/linux/libzfs_util_os.c
@@ -110,6 +110,16 @@
 
 	const char *timeout_str = getenv("ZFS_MODULE_TIMEOUT");
 	int seconds = 10;
+
+	/*
+	 * If inside a container, set the timeout to zero (LP: #1760173),
+	 * however, this can be over-ridden by ZFS_MODULE_TIMEOUT just
+	 * in case the user explicitly wants to set the timeout for some
+	 * reason just for backward compatibilty
+	 */
+	if (access("/run/systemd/container", R_OK) == 0)
+		seconds = 0;
+
 	if (timeout_str)
 		seconds = MIN(strtol(timeout_str, NULL, 0), 600);
 	struct itimerspec timeout = {.it_value.tv_sec = MAX(seconds, 0)};