1 //go:build linux 2 // +build linux 3 4 /* 5 Copyright 2016 The Kubernetes Authors. 6 7 Licensed under the Apache License, Version 2.0 (the "License"); 8 you may not use this file except in compliance with the License. 9 You may obtain a copy of the License at 10 11 http://www.apache.org/licenses/LICENSE-2.0 12 13 Unless required by applicable law or agreed to in writing, software 14 distributed under the License is distributed on an "AS IS" BASIS, 15 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 See the License for the specific language governing permissions and 17 limitations under the License. 18 */ 19 20 package e2enode 21 22 import ( 23 "path/filepath" 24 "syscall" 25 26 "k8s.io/mount-utils" 27 ) 28 29 func detectMountpoint(m mount.Interface, path string) string { 30 path, err := filepath.Abs(path) 31 if err == nil { 32 path, err = filepath.EvalSymlinks(path) 33 } 34 if err != nil { 35 return "" 36 } 37 for path != "" && path != "/" { 38 isNotMount, err := m.IsLikelyNotMountPoint(path) 39 if err != nil { 40 return "" 41 } 42 if !isNotMount { 43 return path 44 } 45 path = filepath.Dir(path) 46 } 47 return "/" 48 } 49 50 const ( 51 xfsMagic = 0x58465342 52 ) 53 54 // XFS over-allocates and then eventually removes that excess allocation. 55 // That can lead to a file growing beyond its eventual size, causing 56 // an unnecessary eviction: 57 // 58 // % ls -ls 59 // total 32704 60 // 32704 -rw-r--r-- 1 rkrawitz rkrawitz 20971520 Jan 15 13:16 foo.bin 61 // 62 // This issue can be hit regardless of the means used to count storage. 63 // It is not present in ext4fs. 64 func isXfs(dir string) bool { 65 mountpoint := detectMountpoint(mount.New(""), dir) 66 if mountpoint == "" { 67 return false 68 } 69 var buf syscall.Statfs_t 70 err := syscall.Statfs(mountpoint, &buf) 71 if err != nil { 72 return false 73 } 74 return buf.Type == xfsMagic 75 } 76