[libvirt] [PATCH] Fix cgroups when all are mounted on /sys/fs/cgroup
Daniel P. Berrange
berrange at redhat.com
Tue Sep 10 13:35:22 UTC 2013
From: "Daniel P. Berrange" <berrange at redhat.com>
Some users in Ubuntu/Debian seem to have a setup where all the
cgroup controllers are mounted on /sys/fs/cgroup rather than
any /sys/fs/cgroup/<controller> name. In the loop which detects
which controllers are present for a mount point we were modifying
'mnt_dir' field in the 'struct mntent' var, but not always restoring
the original value. This caused detection to break in the all-in-one
mount setup.
Fix that logic bug and add test case coverage for this mount
setup.
Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
---
src/util/vircgroup.c | 3 ++-
tests/vircgroupmock.c | 42 ++++++++++++++++++++++++++++++++++++---
tests/vircgrouptest.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 96 insertions(+), 4 deletions(-)
diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c
index 16458a3..a260356 100644
--- a/src/util/vircgroup.c
+++ b/src/util/vircgroup.c
@@ -342,10 +342,11 @@ virCgroupDetectMounts(virCgroupPtr group)
entry.mnt_dir);
goto error;
}
- *tmp2 = '\0';
+
/* If it is a co-mount it has a filename like "cpu,cpuacct"
* and we must identify the symlink path */
if (strchr(tmp2 + 1, ',')) {
+ *tmp2 = '\0';
if (virAsprintf(&linksrc, "%s/%s",
entry.mnt_dir, typestr) < 0)
goto error;
diff --git a/tests/vircgroupmock.c b/tests/vircgroupmock.c
index f1a5700..bf52843 100644
--- a/tests/vircgroupmock.c
+++ b/tests/vircgroupmock.c
@@ -103,6 +103,27 @@ const char *proccgroups =
"blkio 8 4 1\n";
+const char *procmountsallinone =
+ "rootfs / rootfs rw 0 0\n"
+ "sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0\n"
+ "proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0\n"
+ "udev /dev devtmpfs rw,relatime,size=16458560k,nr_inodes=4114640,mode=755 0 0\n"
+ "devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0\n"
+ "nfsd /proc/fs/nfsd nfsd rw,relatime 0 0\n"
+ "cgroup /not/really/sys/fs/cgroup cgroup rw,relatime,blkio,devices,memory,cpuacct,cpu,cpuset 0 0\n";
+
+const char *procselfcgroupsallinone =
+ "6:blkio,devices,memory,cpuacct,cpu,cpuset:/";
+
+const char *proccgroupsallinone =
+ "#subsys_name hierarchy num_cgroups enabled\n"
+ "cpuset 6 1 1\n"
+ "cpu 6 1 1\n"
+ "cpuacct 6 1 1\n"
+ "memory 6 1 1\n"
+ "devices 6 1 1\n"
+ "blkio 6 1 1\n";
+
static int make_file(const char *path,
const char *name,
const char *value)
@@ -378,11 +399,20 @@ static void init_sysfs(void)
FILE *fopen(const char *path, const char *mode)
{
+ const char *mock;
+ bool allinone = false;
init_syms();
+ mock = getenv("VIR_CGROUP_MOCK_MODE");
+ if (mock && STREQ(mock, "allinone"))
+ allinone = true;
+
if (STREQ(path, "/proc/mounts")) {
if (STREQ(mode, "r")) {
- return fmemopen((void *)procmounts, strlen(procmounts), mode);
+ if (allinone)
+ return fmemopen((void *)procmountsallinone, strlen(procmountsallinone), mode);
+ else
+ return fmemopen((void *)procmounts, strlen(procmounts), mode);
} else {
errno = EACCES;
return NULL;
@@ -390,7 +420,10 @@ FILE *fopen(const char *path, const char *mode)
}
if (STREQ(path, "/proc/cgroups")) {
if (STREQ(mode, "r")) {
- return fmemopen((void *)proccgroups, strlen(proccgroups), mode);
+ if (allinone)
+ return fmemopen((void *)proccgroupsallinone, strlen(proccgroupsallinone), mode);
+ else
+ return fmemopen((void *)proccgroups, strlen(proccgroups), mode);
} else {
errno = EACCES;
return NULL;
@@ -398,7 +431,10 @@ FILE *fopen(const char *path, const char *mode)
}
if (STREQ(path, "/proc/self/cgroup")) {
if (STREQ(mode, "r")) {
- return fmemopen((void *)procselfcgroups, strlen(procselfcgroups), mode);
+ if (allinone)
+ return fmemopen((void *)procselfcgroupsallinone, strlen(procselfcgroupsallinone), mode);
+ else
+ return fmemopen((void *)procselfcgroups, strlen(procselfcgroups), mode);
} else {
errno = EACCES;
return NULL;
diff --git a/tests/vircgrouptest.c b/tests/vircgrouptest.c
index 4bdd4c9..f12587c 100644
--- a/tests/vircgrouptest.c
+++ b/tests/vircgrouptest.c
@@ -99,6 +99,16 @@ const char *mountsFull[VIR_CGROUP_CONTROLLER_LAST] = {
[VIR_CGROUP_CONTROLLER_BLKIO] = "/not/really/sys/fs/cgroup/blkio",
[VIR_CGROUP_CONTROLLER_SYSTEMD] = "/not/really/sys/fs/cgroup/systemd",
};
+const char *mountsAllInOne[VIR_CGROUP_CONTROLLER_LAST] = {
+ [VIR_CGROUP_CONTROLLER_CPU] = "/not/really/sys/fs/cgroup",
+ [VIR_CGROUP_CONTROLLER_CPUACCT] = "/not/really/sys/fs/cgroup",
+ [VIR_CGROUP_CONTROLLER_CPUSET] = "/not/really/sys/fs/cgroup",
+ [VIR_CGROUP_CONTROLLER_MEMORY] = "/not/really/sys/fs/cgroup",
+ [VIR_CGROUP_CONTROLLER_DEVICES] = "/not/really/sys/fs/cgroup",
+ [VIR_CGROUP_CONTROLLER_FREEZER] = NULL,
+ [VIR_CGROUP_CONTROLLER_BLKIO] = "/not/really/sys/fs/cgroup",
+ [VIR_CGROUP_CONTROLLER_SYSTEMD] = NULL,
+};
const char *links[VIR_CGROUP_CONTROLLER_LAST] = {
[VIR_CGROUP_CONTROLLER_CPU] = "/not/really/sys/fs/cgroup/cpu",
@@ -108,6 +118,18 @@ const char *links[VIR_CGROUP_CONTROLLER_LAST] = {
[VIR_CGROUP_CONTROLLER_DEVICES] = NULL,
[VIR_CGROUP_CONTROLLER_FREEZER] = NULL,
[VIR_CGROUP_CONTROLLER_BLKIO] = NULL,
+ [VIR_CGROUP_CONTROLLER_SYSTEMD] = NULL,
+};
+
+const char *linksAllInOne[VIR_CGROUP_CONTROLLER_LAST] = {
+ [VIR_CGROUP_CONTROLLER_CPU] = NULL,
+ [VIR_CGROUP_CONTROLLER_CPUACCT] = NULL,
+ [VIR_CGROUP_CONTROLLER_CPUSET] = NULL,
+ [VIR_CGROUP_CONTROLLER_MEMORY] = NULL,
+ [VIR_CGROUP_CONTROLLER_DEVICES] = NULL,
+ [VIR_CGROUP_CONTROLLER_FREEZER] = NULL,
+ [VIR_CGROUP_CONTROLLER_BLKIO] = NULL,
+ [VIR_CGROUP_CONTROLLER_SYSTEMD] = NULL,
};
@@ -417,6 +439,34 @@ cleanup:
return ret;
}
+static int testCgroupNewForSelfAllInOne(const void *args ATTRIBUTE_UNUSED)
+{
+ virCgroupPtr cgroup = NULL;
+ int ret = -1;
+ const char *placement[VIR_CGROUP_CONTROLLER_LAST] = {
+ [VIR_CGROUP_CONTROLLER_CPU] = "/",
+ [VIR_CGROUP_CONTROLLER_CPUACCT] = "/",
+ [VIR_CGROUP_CONTROLLER_CPUSET] = "/",
+ [VIR_CGROUP_CONTROLLER_MEMORY] = "/",
+ [VIR_CGROUP_CONTROLLER_DEVICES] = "/",
+ [VIR_CGROUP_CONTROLLER_FREEZER] = NULL,
+ [VIR_CGROUP_CONTROLLER_BLKIO] = "/",
+ };
+
+ if (virCgroupNewSelf(&cgroup) < 0) {
+ fprintf(stderr, "Cannot create cgroup for self\n");
+ goto cleanup;
+ }
+
+ ret = validateCgroup(cgroup, "", mountsAllInOne, linksAllInOne, placement);
+
+cleanup:
+ virCgroupFree(&cgroup);
+ return ret;
+}
+
+
+
# define FAKESYSFSDIRTEMPLATE abs_builddir "/fakesysfsdir-XXXXXX"
static int
@@ -455,6 +505,11 @@ mymain(void)
if (virtTestRun("New cgroup for domain partition escaped", 1, testCgroupNewForPartitionDomainEscaped, NULL) < 0)
ret = -1;
+ setenv("VIR_CGROUP_MOCK_MODE", "allinone", 1);
+ if (virtTestRun("New cgroup for self (allinone)", 1, testCgroupNewForSelfAllInOne, NULL) < 0)
+ ret = -1;
+ unsetenv("VIR_CGROUP_MOCK_MODE");
+
if (getenv("LIBVIRT_SKIP_CLEANUP") == NULL)
virFileDeleteTree(fakesysfsdir);
--
1.8.3.1
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