From 3d9074ead33a5c27dc20bb49457c69c6d2ae6b57 Mon Sep 17 00:00:00 2001
From: Justin Cormack <justin.cormack@docker.com>
Date: Fri, 23 Jun 2017 17:17:00 -0700
Subject: [PATCH 3/3] Update memory specs to use int64 not uint64

replace #1492 #1494
fix #1422

Since https://github.com/opencontainers/runtime-spec/pull/876 the memory
specifications are now `int64`, as that better matches the visible interface where
`-1` is a valid value. Otherwise finding the correct value was difficult as it
was kernel dependent.

Signed-off-by: Justin Cormack <justin.cormack@docker.com>
---
 libcontainer/cgroups/fs/memory.go    | 36 +++++++++++++++++-------------------
 libcontainer/configs/cgroup_linux.go | 10 +++++-----
 update.go                            | 14 +++++++-------
 3 files changed, 29 insertions(+), 31 deletions(-)

diff --git a/libcontainer/cgroups/fs/memory.go b/libcontainer/cgroups/fs/memory.go
index da2cc9f8..b739c631 100644
--- a/src/import/libcontainer/cgroups/fs/memory.go
+++ b/src/import/libcontainer/cgroups/fs/memory.go
@@ -73,14 +73,14 @@ func EnableKernelMemoryAccounting(path string) error {
 	// until a limit is set on the cgroup and limit cannot be set once the
 	// cgroup has children, or if there are already tasks in the cgroup.
 	for _, i := range []int64{1, -1} {
-		if err := setKernelMemory(path, uint64(i)); err != nil {
+		if err := setKernelMemory(path, i); err != nil {
 			return err
 		}
 	}
 	return nil
 }
 
-func setKernelMemory(path string, kernelMemoryLimit uint64) error {
+func setKernelMemory(path string, kernelMemoryLimit int64) error {
 	if path == "" {
 		return fmt.Errorf("no such directory for %s", cgroupKernelMemoryLimit)
 	}
@@ -88,7 +88,7 @@ func setKernelMemory(path string, kernelMemoryLimit uint64) error {
 		// kernel memory is not enabled on the system so we should do nothing
 		return nil
 	}
-	if err := ioutil.WriteFile(filepath.Join(path, cgroupKernelMemoryLimit), []byte(strconv.FormatUint(kernelMemoryLimit, 10)), 0700); err != nil {
+	if err := ioutil.WriteFile(filepath.Join(path, cgroupKernelMemoryLimit), []byte(strconv.FormatInt(kernelMemoryLimit, 10)), 0700); err != nil {
 		// Check if the error number returned by the syscall is "EBUSY"
 		// The EBUSY signal is returned on attempts to write to the
 		// memory.kmem.limit_in_bytes file if the cgroup has children or
@@ -106,14 +106,12 @@ func setKernelMemory(path string, kernelMemoryLimit uint64) error {
 }
 
 func setMemoryAndSwap(path string, cgroup *configs.Cgroup) error {
-	ulimited := -1
-
-	// If the memory update is set to uint64(-1) we should also
-	// set swap to uint64(-1), it means unlimited memory.
-	if cgroup.Resources.Memory == uint64(ulimited) {
-		// Only set swap if it's enbled in kernel
+	// If the memory update is set to -1 we should also
+	// set swap to -1, it means unlimited memory.
+	if cgroup.Resources.Memory == -1 {
+		// Only set swap if it's enabled in kernel
 		if cgroups.PathExists(filepath.Join(path, cgroupMemorySwapLimit)) {
-			cgroup.Resources.MemorySwap = uint64(ulimited)
+			cgroup.Resources.MemorySwap = -1
 		}
 	}
 
@@ -128,29 +126,29 @@ func setMemoryAndSwap(path string, cgroup *configs.Cgroup) error {
 		// When update memory limit, we should adapt the write sequence
 		// for memory and swap memory, so it won't fail because the new
 		// value and the old value don't fit kernel's validation.
-		if cgroup.Resources.MemorySwap == uint64(ulimited) || memoryUsage.Limit < cgroup.Resources.MemorySwap {
-			if err := writeFile(path, cgroupMemorySwapLimit, strconv.FormatUint(cgroup.Resources.MemorySwap, 10)); err != nil {
+		if cgroup.Resources.MemorySwap == -1 || memoryUsage.Limit < uint64(cgroup.Resources.MemorySwap) {
+			if err := writeFile(path, cgroupMemorySwapLimit, strconv.FormatInt(cgroup.Resources.MemorySwap, 10)); err != nil {
 				return err
 			}
-			if err := writeFile(path, cgroupMemoryLimit, strconv.FormatUint(cgroup.Resources.Memory, 10)); err != nil {
+			if err := writeFile(path, cgroupMemoryLimit, strconv.FormatInt(cgroup.Resources.Memory, 10)); err != nil {
 				return err
 			}
 		} else {
-			if err := writeFile(path, cgroupMemoryLimit, strconv.FormatUint(cgroup.Resources.Memory, 10)); err != nil {
+			if err := writeFile(path, cgroupMemoryLimit, strconv.FormatInt(cgroup.Resources.Memory, 10)); err != nil {
 				return err
 			}
-			if err := writeFile(path, cgroupMemorySwapLimit, strconv.FormatUint(cgroup.Resources.MemorySwap, 10)); err != nil {
+			if err := writeFile(path, cgroupMemorySwapLimit, strconv.FormatInt(cgroup.Resources.MemorySwap, 10)); err != nil {
 				return err
 			}
 		}
 	} else {
 		if cgroup.Resources.Memory != 0 {
-			if err := writeFile(path, cgroupMemoryLimit, strconv.FormatUint(cgroup.Resources.Memory, 10)); err != nil {
+			if err := writeFile(path, cgroupMemoryLimit, strconv.FormatInt(cgroup.Resources.Memory, 10)); err != nil {
 				return err
 			}
 		}
 		if cgroup.Resources.MemorySwap != 0 {
-			if err := writeFile(path, cgroupMemorySwapLimit, strconv.FormatUint(cgroup.Resources.MemorySwap, 10)); err != nil {
+			if err := writeFile(path, cgroupMemorySwapLimit, strconv.FormatInt(cgroup.Resources.MemorySwap, 10)); err != nil {
 				return err
 			}
 		}
@@ -171,13 +169,13 @@ func (s *MemoryGroup) Set(path string, cgroup *configs.Cgroup) error {
 	}
 
 	if cgroup.Resources.MemoryReservation != 0 {
-		if err := writeFile(path, "memory.soft_limit_in_bytes", strconv.FormatUint(cgroup.Resources.MemoryReservation, 10)); err != nil {
+		if err := writeFile(path, "memory.soft_limit_in_bytes", strconv.FormatInt(cgroup.Resources.MemoryReservation, 10)); err != nil {
 			return err
 		}
 	}
 
 	if cgroup.Resources.KernelMemoryTCP != 0 {
-		if err := writeFile(path, "memory.kmem.tcp.limit_in_bytes", strconv.FormatUint(cgroup.Resources.KernelMemoryTCP, 10)); err != nil {
+		if err := writeFile(path, "memory.kmem.tcp.limit_in_bytes", strconv.FormatInt(cgroup.Resources.KernelMemoryTCP, 10)); err != nil {
 			return err
 		}
 	}
diff --git a/libcontainer/configs/cgroup_linux.go b/libcontainer/configs/cgroup_linux.go
index 3e0509de..e15a662f 100644
--- a/src/import/libcontainer/configs/cgroup_linux.go
+++ b/src/import/libcontainer/configs/cgroup_linux.go
@@ -43,19 +43,19 @@ type Resources struct {
 	Devices []*Device `json:"devices"`
 
 	// Memory limit (in bytes)
-	Memory uint64 `json:"memory"`
+	Memory int64 `json:"memory"`
 
 	// Memory reservation or soft_limit (in bytes)
-	MemoryReservation uint64 `json:"memory_reservation"`
+	MemoryReservation int64 `json:"memory_reservation"`
 
 	// Total memory usage (memory + swap); set `-1` to enable unlimited swap
-	MemorySwap uint64 `json:"memory_swap"`
+	MemorySwap int64 `json:"memory_swap"`
 
 	// Kernel memory limit (in bytes)
-	KernelMemory uint64 `json:"kernel_memory"`
+	KernelMemory int64 `json:"kernel_memory"`
 
 	// Kernel memory limit for TCP use (in bytes)
-	KernelMemoryTCP uint64 `json:"kernel_memory_tcp"`
+	KernelMemoryTCP int64 `json:"kernel_memory_tcp"`
 
 	// CPU shares (relative weight vs. other containers)
 	CpuShares uint64 `json:"cpu_shares"`
diff --git a/update.go b/update.go
index 0ea90d60..133be999 100644
--- a/src/import/update.go
+++ b/src/import/update.go
@@ -124,11 +124,11 @@ other options are ignored.
 
 		r := specs.LinuxResources{
 			Memory: &specs.LinuxMemory{
-				Limit:       u64Ptr(0),
-				Reservation: u64Ptr(0),
-				Swap:        u64Ptr(0),
-				Kernel:      u64Ptr(0),
-				KernelTCP:   u64Ptr(0),
+				Limit:       i64Ptr(0),
+				Reservation: i64Ptr(0),
+				Swap:        i64Ptr(0),
+				Kernel:      i64Ptr(0),
+				KernelTCP:   i64Ptr(0),
 			},
 			CPU: &specs.LinuxCPU{
 				Shares:          u64Ptr(0),
@@ -213,7 +213,7 @@ other options are ignored.
 			}
 			for _, pair := range []struct {
 				opt  string
-				dest *uint64
+				dest *int64
 			}{
 				{"memory", r.Memory.Limit},
 				{"memory-swap", r.Memory.Swap},
@@ -232,7 +232,7 @@ other options are ignored.
 					} else {
 						v = -1
 					}
-					*pair.dest = uint64(v)
+					*pair.dest = v
 				}
 			}
 			r.Pids.Limit = int64(context.Int("pids-limit"))
-- 
2.11.0