From c74da4abd20ede6a30c358dc275ba43b1d12e8d5 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Sun, 10 Feb 2019 10:53:06 +0100 Subject: [PATCH] cgfsng: fix cgroup creation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When cgroup creation failed we reset container_cgroup to NULL to avoid issues with __cleanup__. Fix that logic: - add steal_ptr() based on take_ptr() - move stealing the pointer out of the loop lxc ctImport 20190210050705.858 DEBUG network - network.c:instantiate_veth:202 - Instantiated veth "vethGQMH7I/vethSPXNL3", index is "272" lxc ctImport 20190210050705.858 ERROR cgfsng - cgroups/cgfsng.c:mkdir_eexist_on_last:1262 - File exists - Failed to create directory "/sys/fs/cgroup/unified//lxc.payload/ctImport-0" lxc ctImport 20190210050705.858 ERROR cgfsng - cgroups/cgfsng.c:container_create_path_for_hierarchy:1302 - Failed to create cgroup "/sys/fs/cgroup/unified//lxc.payload/ctImport-0" lxc ctImport 20190210050705.858 ERROR cgfsng - cgroups/cgfsng.c:cgfsng_payload_create:1431 - Failed to create cgroup "/sys/fs/cgroup/unified//lxc.payload/ctImport-0" lxc ctImport 20190210050705.858 INFO cgfsng - cgroups/cgfsng.c:cgfsng_payload_create:1441 - The container uses "lxc.payload/ctImport-0" as cgroup lxc ctImport 20190210050705.858 ERROR cgfsng - cgroups/cgfsng.c:mkdir_eexist_on_last:1262 - File exists - Failed to create directory "/sys/fs/cgroup/unified/" lxc ctImport 20190210050705.858 ERROR cgfsng - cgroups/cgfsng.c:container_create_path_for_hierarchy:1302 - Failed to create cgroup "/sys/fs/cgroup/unified/" lxc ctImport 20190210050705.858 ERROR cgfsng - cgroups/cgfsng.c:cgfsng_payload_create:1431 - Failed to create cgroup "/sys/fs/cgroup/unified/" lxc ctImport 20190210050705.858 INFO cgfsng - cgroups/cgfsng.c:cgfsng_payload_create:1441 - The container uses "(null)" as cgroup Fixes: d97919abf22 ("cgroups: partially switch to cleanup macros") Reported-by: Stéphane Graber Signed-off-by: Christian Brauner --- src/lxc/cgroups/cgfsng.c | 15 +++++++-------- src/lxc/macro.h | 7 +++++++ 2 files changed, 14 insertions(+), 8 deletions(-) diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c index 76c7647b5..971c6a523 100644 --- a/src/lxc/cgroups/cgfsng.c +++ b/src/lxc/cgroups/cgfsng.c @@ -1426,9 +1426,11 @@ __cgfsng_ops static inline bool cgfsng_payload_create(struct cgroup_ops *ops, offset = container_cgroup + len - 5; do { - int ret = snprintf(offset, 5, "-%d", idx); - if (ret < 0 || (size_t)ret >= 5) - return false; + if (idx) { + int ret = snprintf(offset, 5, "-%d", idx); + if (ret < 0 || (size_t)ret >= 5) + return false; + } for (i = 0; ops->hierarchies[i]; i++) { if (!container_create_path_for_hierarchy(ops->hierarchies[i], @@ -1443,16 +1445,13 @@ __cgfsng_ops static inline bool cgfsng_payload_create(struct cgroup_ops *ops, break; } } - - ops->container_cgroup = container_cgroup; - container_cgroup = NULL; - INFO("The container uses \"%s\" as cgroup", ops->container_cgroup); } while (ops->hierarchies[i] && idx > 0 && idx < 1000); if (idx == 1000) return false; - INFO("The container process uses \"%s\" as cgroup", ops->container_cgroup); + INFO("The container process uses \"%s\" as cgroup", container_cgroup); + ops->container_cgroup = steal_ptr(container_cgroup); return true; } diff --git a/src/lxc/macro.h b/src/lxc/macro.h index 30aa2a5a5..14e12670e 100644 --- a/src/lxc/macro.h +++ b/src/lxc/macro.h @@ -392,4 +392,11 @@ enum { /* Maximum number of bytes sendfile() is able to send in one go. */ #define LXC_SENDFILE_MAX 0x7ffff000 +#define steal_ptr(ptr) \ + ({ \ + typeof(ptr) _ptr_ = (ptr); \ + (ptr) = NULL; \ + _ptr_; \ + }) + #endif /* __LXC_MACRO_H */