[Devel] [PATCH 3/3] hooks_ct: fix ub limits setting for upstream containers

[Glauber Costa]

Currently, vps_setup_res() have an explicit test for state != VPS_STARTING
before applying beancounter limits. This means that we can set limits without
further problems when the container is running, but will fail to do so when the
container is starting. In fact, hooks_vz have an explicit call for it in its
startup function.

We should do the same, and call our version of setlimits ourselves when the
container is coming up.

Signed-off-by: Glauber Costa <glommer at openvz.org>
---
 src/lib/hooks_ct.c | 147 +++++++++++++++++++++++++++--------------------------
 1 file changed, 76 insertions(+), 71 deletions(-)

diff --git a/src/lib/hooks_ct.c b/src/lib/hooks_ct.c
index 63af536..3cfb6e9 100644
--- a/src/lib/hooks_ct.c
+++ b/src/lib/hooks_ct.c
@@ -153,6 +153,77 @@ static int _env_create(void *data)
 	return exec_container_init(arg, &create_param);
 }
 
+#define add_value(val, var, mult) do { if (val) { var = *val * mult; } } while (0)
+
+static int ct_setlimits(vps_handler *h, envid_t veid, struct ub_struct *ub)
+{
+	unsigned long tcp = 0;
+	unsigned long kmem = 0;
+	unsigned long kmemall = 0;
+	unsigned long mem = 0;
+	unsigned long swap = 0;
+	int pagesize = sysconf(_SC_PAGESIZE);
+
+	add_value(ub->physpages, mem, pagesize);
+	add_value(ub->tcpsndbuf, tcp, 1);
+	add_value(ub->tcprcvbuf, tcp, 1);
+	add_value(ub->swappages, swap, pagesize);
+
+	/*
+	 * OpenVZ beancounters traditionally acconted objects. Also, we could
+	 * always get a very high granularity about which objects we are
+	 * tracking. Our attempt in this implementation is to translate the
+	 * historical beancounters into something that "makes sense" given the
+	 * underlying Linux infrastructure, and provide something that would
+	 * allow for more or less the kind of protection the user asked for.  A
+	 * 1:1 mapping, however, is not possible - and will never be.
+	 *
+	 * Upstream Linux cgroup controllers went in a very different
+	 * direction. First, resources tend to be viewed in its entirety. We
+	 * have entities like "memory", or "kernel memory", instead of a list
+	 * of all internal structures like dentry, siginfo, etc. For network
+	 * buffers, we can specify the total buffer memory instead of send and
+	 * receive buffers, etc.
+	 *
+	 * Also, all accounting is done in pages, not in objects - which is the
+	 * only thing that makes sense if the accounting is done in an
+	 * aggregate manner.  We don't really know the size of those
+	 * structures, so we use an estimate to get a value in pages. This is
+	 * not a stable API of the kernel, so it is bound to change.
+	 *
+	 * Here is the size in bytes of the following structs, in Linux 3.4:
+	 *
+	 * dcache: 248, siginfo: 128, sock: 1072, task 8128
+	 */
+	#define DCACHE 248
+	#define SIGINFO 128
+	#define SOCK 1072
+
+	add_value(ub->kmemsize, kmem, 1);
+	add_value(ub->dcachesize, kmemall, DCACHE);
+	add_value(ub->numtcpsock, kmemall, SOCK);
+	add_value(ub->numsiginfo, kmemall, SIGINFO);
+	add_value(ub->numothersock, kmemall, SOCK);
+	add_value(ub->othersockbuf, kmemall, 1);
+	add_value(ub->numproc, kmemall, 2 * pagesize);
+	add_value(ub->dgramrcvbuf, kmemall, SOCK);
+
+	if (mem)
+		container_apply_config(veid, MEMORY, &mem);
+	if (tcp)
+		container_apply_config(veid, TCP, &tcp);
+
+	kmem = max_ul(kmem, kmemall);
+	if (kmem)
+		container_apply_config(veid, KMEMORY, &kmem);
+
+	if (swap)
+		container_apply_config(veid, SWAP, &swap);
+
+	return 0;
+}
+#undef add_value
+
 static int ct_env_create(struct arg_start *arg)
 {
 
@@ -187,6 +258,11 @@ static int ct_env_create(struct arg_start *arg)
 		return VZ_RESOURCE_ERROR;
 	}
 
+	if ((ret = ct_setlimits(arg->h, arg->veid, &arg->res->ub))) {
+		logger(-1, 0, "Could not apply container limits: %s", container_error(ret));
+		return VZ_RESOURCE_ERROR;
+	}
+
 	if ((ret = container_add_task(arg->veid))) {
 		logger(-1, 0, "Can't add task creator to container: %s", container_error(ret));
 		return VZ_RESOURCE_ERROR;
@@ -289,77 +365,6 @@ out:
 	return ret;
 }
 
-#define add_value(val, var, mult) do { if (val) { var = *val * mult; } } while (0)
-
-static int ct_setlimits(vps_handler *h, envid_t veid, struct ub_struct *ub)
-{
-	unsigned long tcp = 0;
-	unsigned long kmem = 0;
-	unsigned long kmemall = 0;
-	unsigned long mem = 0;
-	unsigned long swap = 0;
-	int pagesize = sysconf(_SC_PAGESIZE);
-
-	add_value(ub->physpages, mem, pagesize);
-	add_value(ub->tcpsndbuf, tcp, 1);
-	add_value(ub->tcprcvbuf, tcp, 1);
-	add_value(ub->swappages, swap, pagesize);
-
-	/*
-	 * OpenVZ beancounters traditionally acconted objects. Also, we could
-	 * always get a very high granularity about which objects we are
-	 * tracking. Our attempt in this implementation is to translate the
-	 * historical beancounters into something that "makes sense" given the
-	 * underlying Linux infrastructure, and provide something that would
-	 * allow for more or less the kind of protection the user asked for.  A
-	 * 1:1 mapping, however, is not possible - and will never be.
-	 *
-	 * Upstream Linux cgroup controllers went in a very different
-	 * direction. First, resources tend to be viewed in its entirety. We
-	 * have entities like "memory", or "kernel memory", instead of a list
-	 * of all internal structures like dentry, siginfo, etc. For network
-	 * buffers, we can specify the total buffer memory instead of send and
-	 * receive buffers, etc.
-	 *
-	 * Also, all accounting is done in pages, not in objects - which is the
-	 * only thing that makes sense if the accounting is done in an
-	 * aggregate manner.  We don't really know the size of those
-	 * structures, so we use an estimate to get a value in pages. This is
-	 * not a stable API of the kernel, so it is bound to change.
-	 *
-	 * Here is the size in bytes of the following structs, in Linux 3.4:
-	 *
-	 * dcache: 248, siginfo: 128, sock: 1072, task 8128
-	 */
-	#define DCACHE 248
-	#define SIGINFO 128
-	#define SOCK 1072
-
-	add_value(ub->kmemsize, kmem, 1);
-	add_value(ub->dcachesize, kmemall, DCACHE);
-	add_value(ub->numtcpsock, kmemall, SOCK);
-	add_value(ub->numsiginfo, kmemall, SIGINFO);
-	add_value(ub->numothersock, kmemall, SOCK);
-	add_value(ub->othersockbuf, kmemall, 1);
-	add_value(ub->numproc, kmemall, 2 * pagesize);
-	add_value(ub->dgramrcvbuf, kmemall, SOCK);
-
-	if (mem)
-		container_apply_config(veid, MEMORY, &mem);
-	if (tcp)
-		container_apply_config(veid, TCP, &tcp);
-
-	kmem = max_ul(kmem, kmemall);
-	if (kmem)
-		container_apply_config(veid, KMEMORY, &kmem);
-
-	if (swap)
-		container_apply_config(veid, SWAP, &swap);
-
-	return 0;
-}
-#undef add_value
-
 static int ct_setcpus(vps_handler *h, envid_t veid, struct cpu_param *cpu)
 {
 	int ret = 0;
-- 
1.7.11.7