From 0616172bdffee9e1c3a508be3091c59bf0d686bb Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Thu, 16 May 2013 18:47:07 +0100 Subject: [PATCH] Fix failure to detect missing cgroup partitions Change bbe97ae968eba60b71e0066d49f9fc909966d9d6 caused the QEMU driver to ignore ENOENT errors from cgroups, in order to cope with missing /proc/cgroups. This is not good though because many other things can cause ENOENT and should not be ignored. The callers expect to see ENXIO when cgroups are not present, so adjust the code to report that errno when /proc/cgroups is missing Signed-off-by: Daniel P. Berrange (cherry picked from commit c2cf5f1c2abc81d607abe34bf5dc4c615a9b8b4d) --- src/qemu/qemu_cgroup.c | 3 +-- src/util/vircgroup.c | 7 ++++++- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c index 5745085c76..400a2b39b8 100644 --- a/src/qemu/qemu_cgroup.c +++ b/src/qemu/qemu_cgroup.c @@ -415,8 +415,7 @@ int qemuInitCgroup(virQEMUDriverPtr driver, if (rc != 0) { if (rc == -ENXIO || rc == -EPERM || - rc == -EACCES || - rc == -ENOENT) { /* No cgroups mounts == success */ + rc == -EACCES) { /* No cgroups mounts == success */ VIR_DEBUG("No cgroups present/configured/accessible, ignoring error"); goto done; } diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c index 4abe1b17c7..ad5da0271b 100644 --- a/src/util/vircgroup.c +++ b/src/util/vircgroup.c @@ -1122,8 +1122,13 @@ static int virCgroupPartitionNeedsEscaping(const char *path) path[0] == '.') return 1; - if (!(fp = fopen("/proc/cgroups", "r"))) + if (!(fp = fopen("/proc/cgroups", "r"))) { + /* The API contract is that we return ENXIO + * if cgroups are not available on a host */ + if (errno == ENOENT) + errno = ENXIO; return -errno; + } /* * Data looks like this: -- 2.47.2