From 2bbc5b0726611d0faf7895ec01a42286e26c8ca4 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Thu, 5 Jan 2017 16:22:22 -0800 Subject: [PATCH] ip vrf: Improve cgroup2 error messages Currently, if a non-root user attempts to run ip vrf exec a non-helpful error is returned: $ ip vrf exec mgmt bash Failed to mount cgroup2. Are CGROUPS enabled in your kernel? Only show the CGROUPS kernel hint for the ENODEV error and for the rest show the strerror for the errno. So now: $ ip/ip vrf exec mgmt bash Failed to mount cgroup2: Operation not permitted Signed-off-by: David Ahern --- lib/fs.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/lib/fs.c b/lib/fs.c index 644bb486..12a4657a 100644 --- a/lib/fs.c +++ b/lib/fs.c @@ -80,13 +80,21 @@ char *find_cgroup2_mount(void) if (mount("none", mnt, CGROUP2_FS_NAME, 0, NULL)) { /* EBUSY means already mounted */ - if (errno != EBUSY) { + if (errno == EBUSY) + goto out; + + if (errno == ENODEV) { fprintf(stderr, "Failed to mount cgroup2. Are CGROUPS enabled in your kernel?\n"); - free(mnt); - return NULL; + } else { + fprintf(stderr, + "Failed to mount cgroup2: %s\n", + strerror(errno)); } + free(mnt); + return NULL; } +out: return mnt; }