minio/cmd/disk-cache-utils.go
Andreas Auernhammer d8eb7d3e15
kms: replace KES client implementation with minio/kes (#12207)
This commit replaces the custom KES client implementation
with the KES SDK from https://github.com/minio/kes

The SDK supports multi-server client load-balancing and
requests retry out of the box. Therefore, this change reduces
the overall complexity within the MinIO server and there
is no need to maintain two separate client implementations.

Signed-off-by: Andreas Auernhammer <aead@mail.de>
2021-05-10 18:15:11 -07:00

509 lines
12 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package cmd
import (
"container/list"
"encoding/hex"
"errors"
"fmt"
"io"
"math"
"os"
"path"
"strconv"
"strings"
"time"
"github.com/minio/minio/cmd/crypto"
"github.com/minio/minio/pkg/kms"
)
// CacheStatusType - whether the request was served from cache.
type CacheStatusType string
const (
// CacheHit - whether object was served from cache.
CacheHit CacheStatusType = "HIT"
// CacheMiss - object served from backend.
CacheMiss CacheStatusType = "MISS"
)
func (c CacheStatusType) String() string {
if c != "" {
return string(c)
}
return string(CacheMiss)
}
type cacheControl struct {
expiry time.Time
maxAge int
sMaxAge int
minFresh int
maxStale int
noStore bool
onlyIfCached bool
noCache bool
}
func (c *cacheControl) isStale(modTime time.Time) bool {
if c == nil {
return false
}
// response will never be stale if only-if-cached is set
if c.onlyIfCached {
return false
}
// Cache-Control value no-store indicates never cache
if c.noStore {
return true
}
// Cache-Control value no-cache indicates cache entry needs to be revalidated before
// serving from cache
if c.noCache {
return true
}
now := time.Now()
if c.sMaxAge > 0 && c.sMaxAge < int(now.Sub(modTime).Seconds()) {
return true
}
if c.maxAge > 0 && c.maxAge < int(now.Sub(modTime).Seconds()) {
return true
}
if !c.expiry.Equal(time.Time{}) && c.expiry.Before(time.Now().Add(time.Duration(c.maxStale))) {
return true
}
if c.minFresh > 0 && c.minFresh <= int(now.Sub(modTime).Seconds()) {
return true
}
return false
}
// returns struct with cache-control settings from user metadata.
func cacheControlOpts(o ObjectInfo) *cacheControl {
c := cacheControl{}
m := o.UserDefined
if !o.Expires.Equal(timeSentinel) {
c.expiry = o.Expires
}
var headerVal string
for k, v := range m {
if strings.ToLower(k) == "cache-control" {
headerVal = v
}
}
if headerVal == "" {
return nil
}
headerVal = strings.ToLower(headerVal)
headerVal = strings.TrimSpace(headerVal)
vals := strings.Split(headerVal, ",")
for _, val := range vals {
val = strings.TrimSpace(val)
if val == "no-store" {
c.noStore = true
continue
}
if val == "only-if-cached" {
c.onlyIfCached = true
continue
}
if val == "no-cache" {
c.noCache = true
continue
}
p := strings.Split(val, "=")
if len(p) != 2 {
continue
}
if p[0] == "max-age" ||
p[0] == "s-maxage" ||
p[0] == "min-fresh" ||
p[0] == "max-stale" {
i, err := strconv.Atoi(p[1])
if err != nil {
return nil
}
if p[0] == "max-age" {
c.maxAge = i
}
if p[0] == "s-maxage" {
c.sMaxAge = i
}
if p[0] == "min-fresh" {
c.minFresh = i
}
if p[0] == "max-stale" {
c.maxStale = i
}
}
}
return &c
}
// backendDownError returns true if err is due to backend failure or faulty disk if in server mode
func backendDownError(err error) bool {
_, backendDown := err.(BackendDown)
return backendDown || IsErr(err, baseErrs...)
}
// IsCacheable returns if the object should be saved in the cache.
func (o ObjectInfo) IsCacheable() bool {
if globalCacheKMS != nil {
return true
}
_, ok := crypto.IsEncrypted(o.UserDefined)
return !ok
}
// reads file cached on disk from offset upto length
func readCacheFileStream(filePath string, offset, length int64) (io.ReadCloser, error) {
if filePath == "" || offset < 0 {
return nil, errInvalidArgument
}
if err := checkPathLength(filePath); err != nil {
return nil, err
}
fr, err := os.Open(filePath)
if err != nil {
return nil, osErrToFileErr(err)
}
// Stat to get the size of the file at path.
st, err := fr.Stat()
if err != nil {
err = osErrToFileErr(err)
return nil, err
}
if err = os.Chtimes(filePath, time.Now(), st.ModTime()); err != nil {
return nil, err
}
// Verify if its not a regular file, since subsequent Seek is undefined.
if !st.Mode().IsRegular() {
return nil, errIsNotRegular
}
if err = os.Chtimes(filePath, time.Now(), st.ModTime()); err != nil {
return nil, err
}
// Seek to the requested offset.
if offset > 0 {
_, err = fr.Seek(offset, io.SeekStart)
if err != nil {
return nil, err
}
}
return struct {
io.Reader
io.Closer
}{Reader: io.LimitReader(fr, length), Closer: fr}, nil
}
func isCacheEncrypted(meta map[string]string) bool {
_, ok := meta[SSECacheEncrypted]
return ok
}
// decryptCacheObjectETag tries to decrypt the ETag saved in encrypted format using the cache KMS
func decryptCacheObjectETag(info *ObjectInfo) error {
// Directories are never encrypted.
if info.IsDir {
return nil
}
encrypted := crypto.S3.IsEncrypted(info.UserDefined) && isCacheEncrypted(info.UserDefined)
switch {
case encrypted:
if globalCacheKMS == nil {
return errKMSNotConfigured
}
keyID, kmsKey, sealedKey, err := crypto.S3.ParseMetadata(info.UserDefined)
if err != nil {
return err
}
extKey, err := globalCacheKMS.DecryptKey(keyID, kmsKey, kms.Context{info.Bucket: path.Join(info.Bucket, info.Name)})
if err != nil {
return err
}
var objectKey crypto.ObjectKey
if err = objectKey.Unseal(extKey, sealedKey, crypto.S3.String(), info.Bucket, info.Name); err != nil {
return err
}
etagStr := tryDecryptETag(objectKey[:], info.ETag, false)
// backend ETag was hex encoded before encrypting, so hex decode to get actual ETag
etag, err := hex.DecodeString(etagStr)
if err != nil {
return err
}
info.ETag = string(etag)
return nil
}
return nil
}
func isMetadataSame(m1, m2 map[string]string) bool {
if m1 == nil && m2 == nil {
return true
}
if (m1 == nil && m2 != nil) || (m2 == nil && m1 != nil) {
return false
}
if len(m1) != len(m2) {
return false
}
for k1, v1 := range m1 {
if v2, ok := m2[k1]; !ok || (v1 != v2) {
return false
}
}
return true
}
type fileScorer struct {
saveBytes uint64
now int64
maxHits int
// 1/size for consistent score.
sizeMult float64
// queue is a linked list of files we want to delete.
// The list is kept sorted according to score, highest at top, lowest at bottom.
queue list.List
queuedBytes uint64
seenBytes uint64
}
type queuedFile struct {
name string
versionID string
size uint64
score float64
}
// newFileScorer allows to collect files to save a specific number of bytes.
// Each file is assigned a score based on its age, size and number of hits.
// A list of files is maintained
func newFileScorer(saveBytes uint64, now int64, maxHits int) (*fileScorer, error) {
if saveBytes == 0 {
return nil, errors.New("newFileScorer: saveBytes = 0")
}
if now < 0 {
return nil, errors.New("newFileScorer: now < 0")
}
if maxHits <= 0 {
return nil, errors.New("newFileScorer: maxHits <= 0")
}
f := fileScorer{saveBytes: saveBytes, maxHits: maxHits, now: now, sizeMult: 1 / float64(saveBytes)}
f.queue.Init()
return &f, nil
}
func (f *fileScorer) addFile(name string, accTime time.Time, size int64, hits int) {
f.addFileWithObjInfo(ObjectInfo{
Name: name,
AccTime: accTime,
Size: size,
}, hits)
}
func (f *fileScorer) addFileWithObjInfo(objInfo ObjectInfo, hits int) {
// Calculate how much we want to delete this object.
file := queuedFile{
name: objInfo.Name,
versionID: objInfo.VersionID,
size: uint64(objInfo.Size),
}
f.seenBytes += uint64(objInfo.Size)
var score float64
if objInfo.ModTime.IsZero() {
// Mod time is not available with disk cache use atime.
score = float64(f.now - objInfo.AccTime.Unix())
} else {
// if not used mod time when mod time is available.
score = float64(f.now - objInfo.ModTime.Unix())
}
// Size as fraction of how much we want to save, 0->1.
szWeight := math.Max(0, (math.Min(1, float64(file.size)*f.sizeMult)))
// 0 at f.maxHits, 1 at 0.
hitsWeight := (1.0 - math.Max(0, math.Min(1.0, float64(hits)/float64(f.maxHits))))
file.score = score * (1 + 0.25*szWeight + 0.25*hitsWeight)
// If we still haven't saved enough, just add the file
if f.queuedBytes < f.saveBytes {
f.insertFile(file)
f.trimQueue()
return
}
// If we score less than the worst, don't insert.
worstE := f.queue.Back()
if worstE != nil && file.score < worstE.Value.(queuedFile).score {
return
}
f.insertFile(file)
f.trimQueue()
}
// adjustSaveBytes allows to adjust the number of bytes to save.
// This can be used to adjust the count on the fly.
// Returns true if there still is a need to delete files (n+saveBytes >0),
// false if no more bytes needs to be saved.
func (f *fileScorer) adjustSaveBytes(n int64) bool {
if int64(f.saveBytes)+n <= 0 {
f.saveBytes = 0
f.trimQueue()
return false
}
if n < 0 {
f.saveBytes -= ^uint64(n - 1)
} else {
f.saveBytes += uint64(n)
}
if f.saveBytes == 0 {
f.queue.Init()
f.saveBytes = 0
return false
}
if n < 0 {
f.trimQueue()
}
return true
}
// insertFile will insert a file into the list, sorted by its score.
func (f *fileScorer) insertFile(file queuedFile) {
e := f.queue.Front()
for e != nil {
v := e.Value.(queuedFile)
if v.score < file.score {
break
}
e = e.Next()
}
f.queuedBytes += file.size
// We reached the end.
if e == nil {
f.queue.PushBack(file)
return
}
f.queue.InsertBefore(file, e)
}
// trimQueue will trim the back of queue and still keep below wantSave.
func (f *fileScorer) trimQueue() {
for {
e := f.queue.Back()
if e == nil {
return
}
v := e.Value.(queuedFile)
if f.queuedBytes-v.size < f.saveBytes {
return
}
f.queue.Remove(e)
f.queuedBytes -= v.size
}
}
// fileObjInfos returns all queued file object infos
func (f *fileScorer) fileObjInfos() []ObjectInfo {
res := make([]ObjectInfo, 0, f.queue.Len())
e := f.queue.Front()
for e != nil {
qfile := e.Value.(queuedFile)
res = append(res, ObjectInfo{
Name: qfile.name,
Size: int64(qfile.size),
VersionID: qfile.versionID,
})
e = e.Next()
}
return res
}
func (f *fileScorer) purgeFunc(p func(qfile queuedFile)) {
e := f.queue.Front()
for e != nil {
p(e.Value.(queuedFile))
e = e.Next()
}
}
// fileNames returns all queued file names.
func (f *fileScorer) fileNames() []string {
res := make([]string, 0, f.queue.Len())
e := f.queue.Front()
for e != nil {
res = append(res, e.Value.(queuedFile).name)
e = e.Next()
}
return res
}
func (f *fileScorer) reset() {
f.queue.Init()
f.queuedBytes = 0
}
func (f *fileScorer) queueString() string {
var res strings.Builder
e := f.queue.Front()
i := 0
for e != nil {
v := e.Value.(queuedFile)
if i > 0 {
res.WriteByte('\n')
}
res.WriteString(fmt.Sprintf("%03d: %s (score: %.3f, bytes: %d)", i, v.name, v.score, v.size))
i++
e = e.Next()
}
return res.String()
}
// bytesToClear() returns the number of bytes to clear to reach low watermark
// w.r.t quota given disk total and free space, quota in % allocated to cache
// and low watermark % w.r.t allowed quota.
// If the high watermark hasn't been reached 0 will be returned.
func bytesToClear(total, free int64, quotaPct, lowWatermark, highWatermark uint64) uint64 {
used := total - free
quotaAllowed := total * (int64)(quotaPct) / 100
highWMUsage := total * (int64)(highWatermark*quotaPct) / (100 * 100)
if used < highWMUsage {
return 0
}
// Return bytes needed to reach low watermark.
lowWMUsage := total * (int64)(lowWatermark*quotaPct) / (100 * 100)
return (uint64)(math.Min(float64(quotaAllowed), math.Max(0.0, float64(used-lowWMUsage))))
}