Merge pull request #2177 from k8s-infra-cherrypick-robot/cherry-pick-2176-to-release-1.21

[release-1.21] Fix partial cache tail latency by correcting the cache chunk size calc

Author: k8s-ci-robot

pkg/gce-pd-csi-driver/cache.go

@@ -573,9 +573,11 @@ func isCachingSetup(mainLvName string) (error, bool) {
 	return nil, false
 }
 
+// cacheSize is always in GiB
 func fetchChunkSizeKiB(cacheSize string) (string, error) {
 	var chunkSize float64
 
+	cacheSize = strings.TrimSuffix(cacheSize, "GiB")
 	cacheSizeInt, err := strconv.ParseInt(cacheSize, 10, 64)
 	if err != nil {
 		return "0", err
@@ -691,10 +693,8 @@ func addRaidedLSSDToVg(vgName, lssdPath string) error {
 
 func fetchPvSizeGiB() (string, error) {
 	args := []string{
-		"--select",
-		"-o",
+		"-o", "pv_name,pv_size",
 		"--noheadings",
-		"pv_size",
 		"--units=b",
 	}
 	// RAIDed device is always registered with its /dev/md127 equivalent in VG so cannot check it directly based on the RAIDed LSSD path which could be /dev/md/csi-driver-data-cache

pkg/gce-pd-csi-driver/cache_test.go

@@ -13,24 +13,29 @@ func TestFetchChunkSizeKiB(t *testing.T) {
 	}{
 		{
 			name:         "chunk size is in the allowed range",
-			cacheSize:    "500",
+			cacheSize:    "500GiB",
 			expChunkSize: "512KiB", //range defined in fetchChunkSizeKiB
 		},
 		{
 			name:         "chunk size is set to the range ceil",
-			cacheSize:    "30000000",
+			cacheSize:    "30000000GiB",
 			expChunkSize: "1048576KiB", //range defined in fetchChunkSizeKiB - max 1GiB
 		},
 		{
 			name:         "chunk size is set to the allowed range floor",
-			cacheSize:    "100",
+			cacheSize:    "100GiB",
 			expChunkSize: "160KiB", //range defined in fetchChunkSizeKiB - min 160 KiB
 		},
 		{
 			name:         "cacheSize set to KiB also sets the chunk size to range floor",
-			cacheSize:    "1",
+			cacheSize:    "1GiB",
 			expChunkSize: "160KiB", //range defined in fetchChunkSizeKiB - min 160 KiB
 		},
+		{
+			name:         "chunk size with GiB string parses correctly",
+			cacheSize:    "375GiB",
+			expChunkSize: "384KiB",
+		},
 		{
 			name:         "invalid cacheSize",
 			cacheSize:    "fdfsdKi",