minio/cmd/posix.go
Harshavardhana f44cfb2863
use GlobalContext whenever possible (#9280)
This change is throughout the codebase to
ensure that all codepaths honor GlobalContext
2020-04-09 09:30:02 -07:00

1766 lines
42 KiB
Go

/*
* MinIO Cloud Storage, (C) 2016-2020 MinIO, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cmd
import (
"bufio"
"context"
"crypto/rand"
"encoding/hex"
"errors"
"io"
"io/ioutil"
"os"
slashpath "path"
"path/filepath"
"runtime"
"sort"
"strings"
"sync"
"sync/atomic"
"syscall"
"time"
"bytes"
humanize "github.com/dustin/go-humanize"
jsoniter "github.com/json-iterator/go"
"github.com/klauspost/readahead"
"github.com/minio/minio/cmd/logger"
"github.com/minio/minio/pkg/disk"
xioutil "github.com/minio/minio/pkg/ioutil"
"github.com/minio/minio/pkg/mountinfo"
)
const (
diskMinFreeSpace = 900 * humanize.MiByte // Min 900MiB free space.
diskMinTotalSpace = diskMinFreeSpace // Min 900MiB total space.
readBlockSize = 4 * humanize.MiByte // Default read block size 4MiB.
// On regular files bigger than this;
readAheadSize = 16 << 20
// Read this many buffers ahead.
readAheadBuffers = 4
// Size of each buffer.
readAheadBufSize = 1 << 20
// Wait interval to check if active IO count is low
// to proceed crawling to compute data usage
lowActiveIOWaitTick = 100 * time.Millisecond
)
// isValidVolname verifies a volname name in accordance with object
// layer requirements.
func isValidVolname(volname string) bool {
if len(volname) < 3 {
return false
}
if runtime.GOOS == "windows" {
// Volname shouldn't have reserved characters in Windows.
return !strings.ContainsAny(volname, `\:*?\"<>|`)
}
return true
}
// posix - implements StorageAPI interface.
type posix struct {
// Disk usage metrics
totalUsed uint64 // ref: https://golang.org/pkg/sync/atomic/#pkg-note-BUG
maxActiveIOCount int32
activeIOCount int32
diskPath string
pool sync.Pool
diskMount bool // indicates if the path is an actual mount.
diskID string
formatFileInfo os.FileInfo
formatLastCheck time.Time
// Disk usage metrics
stopUsageCh chan struct{}
sync.RWMutex
}
// checkPathLength - returns error if given path name length more than 255
func checkPathLength(pathName string) error {
// Apple OS X path length is limited to 1016
if runtime.GOOS == "darwin" && len(pathName) > 1016 {
return errFileNameTooLong
}
if runtime.GOOS == "windows" {
// Convert any '\' to '/'.
pathName = filepath.ToSlash(pathName)
}
// Check each path segment length is > 255
for len(pathName) > 0 && pathName != "." && pathName != SlashSeparator {
dir, file := slashpath.Dir(pathName), slashpath.Base(pathName)
if len(file) > 255 {
return errFileNameTooLong
}
pathName = dir
} // Success.
return nil
}
func getValidPath(path string) (string, error) {
if path == "" {
return path, errInvalidArgument
}
var err error
// Disallow relative paths, figure out absolute paths.
path, err = filepath.Abs(path)
if err != nil {
return path, err
}
fi, err := os.Stat(path)
if err != nil && !os.IsNotExist(err) {
return path, err
}
if os.IsNotExist(err) {
// Disk not found create it.
if err = os.MkdirAll(path, 0777); err != nil {
return path, err
}
}
if fi != nil && !fi.IsDir() {
return path, syscall.ENOTDIR
}
di, err := getDiskInfo(path)
if err != nil {
return path, err
}
if err = checkDiskMinTotal(di); err != nil {
return path, err
}
// check if backend is writable.
var rnd [8]byte
_, _ = rand.Read(rnd[:])
fn := pathJoin(path, ".writable-check-"+hex.EncodeToString(rnd[:])+".tmp")
file, err := os.Create(fn)
if err != nil {
return path, err
}
file.Close()
os.Remove(fn)
return path, nil
}
// isDirEmpty - returns whether given directory is empty or not.
func isDirEmpty(dirname string) bool {
f, err := os.Open((dirname))
if err != nil {
if !os.IsNotExist(err) {
logger.LogIf(GlobalContext, err)
}
return false
}
defer f.Close()
// List one entry.
_, err = f.Readdirnames(1)
if err != io.EOF {
if !os.IsNotExist(err) {
logger.LogIf(GlobalContext, err)
}
return false
}
// Returns true if we have reached EOF, directory is indeed empty.
return true
}
// Initialize a new storage disk.
func newPosix(path string) (*posix, error) {
var err error
if path, err = getValidPath(path); err != nil {
return nil, err
}
_, err = os.Stat(path)
if err != nil {
return nil, err
}
p := &posix{
diskPath: path,
pool: sync.Pool{
New: func() interface{} {
b := disk.AlignedBlock(readBlockSize)
return &b
},
},
stopUsageCh: make(chan struct{}),
diskMount: mountinfo.IsLikelyMountPoint(path),
// Allow disk usage crawler to run with up to 2 concurrent
// I/O ops, if and when activeIOCount reaches this
// value disk usage routine suspends the crawler
// and waits until activeIOCount reaches below this threshold.
maxActiveIOCount: 3,
}
// Success.
return p, nil
}
// getDiskInfo returns given disk information.
func getDiskInfo(diskPath string) (di disk.Info, err error) {
if err = checkPathLength(diskPath); err == nil {
di, err = disk.GetInfo(diskPath)
}
switch {
case os.IsNotExist(err):
err = errDiskNotFound
case isSysErrTooLong(err):
err = errFileNameTooLong
case isSysErrIO(err):
err = errFaultyDisk
}
return di, err
}
// List of operating systems where we ignore disk space
// verification.
var ignoreDiskFreeOS = []string{
globalWindowsOSName,
globalNetBSDOSName,
}
// check if disk total has minimum required size.
func checkDiskMinTotal(di disk.Info) (err error) {
// Remove 5% from total space for cumulative disk space
// used for journalling, inodes etc.
totalDiskSpace := float64(di.Total) * 0.95
if int64(totalDiskSpace) <= diskMinTotalSpace {
return errMinDiskSize
}
return nil
}
// check if disk free has minimum required size.
func checkDiskMinFree(di disk.Info) error {
// Remove 5% from free space for cumulative disk space used for journalling, inodes etc.
availableDiskSpace := float64(di.Free) * 0.95
if int64(availableDiskSpace) <= diskMinFreeSpace {
return errDiskFull
}
// Success.
return nil
}
// checkDiskFree verifies if disk path has sufficient minimum free disk space and files.
func checkDiskFree(diskPath string, neededSpace int64) (err error) {
// We don't validate disk space or inode utilization on windows.
// Each windows call to 'GetVolumeInformationW' takes around
// 3-5seconds. And StatDISK is not supported by Go for solaris
// and netbsd.
if contains(ignoreDiskFreeOS, runtime.GOOS) {
return nil
}
var di disk.Info
di, err = getDiskInfo((diskPath))
if err != nil {
return err
}
if err = checkDiskMinFree(di); err != nil {
return err
}
// Check if we have enough space to store data
if neededSpace > int64(float64(di.Free)*0.95) {
return errDiskFull
}
return nil
}
// Implements stringer compatible interface.
func (s *posix) String() string {
return s.diskPath
}
func (*posix) Hostname() string {
return ""
}
func (s *posix) Close() error {
close(s.stopUsageCh)
return nil
}
func (s *posix) IsOnline() bool {
return true
}
func isQuitting(endCh chan struct{}) bool {
select {
case <-endCh:
return true
default:
return false
}
}
func (s *posix) waitForLowActiveIO() {
for atomic.LoadInt32(&s.activeIOCount) >= s.maxActiveIOCount {
time.Sleep(lowActiveIOWaitTick)
}
}
func (s *posix) CrawlAndGetDataUsage(ctx context.Context, cache dataUsageCache) (dataUsageCache, error) {
dataUsageInfo, err := updateUsage(ctx, s.diskPath, cache, s.waitForLowActiveIO, func(item Item) (int64, error) {
// Look for `xl.json' at the leaf.
if !strings.HasSuffix(item.Path, SlashSeparator+xlMetaJSONFile) {
// if no xl.json found, skip the file.
return 0, errSkipFile
}
xlMetaBuf, err := ioutil.ReadFile(item.Path)
if err != nil {
return 0, errSkipFile
}
meta, err := xlMetaV1UnmarshalJSON(ctx, xlMetaBuf)
if err != nil {
return 0, nil
}
return meta.Stat.Size, nil
})
if err != nil {
return dataUsageInfo, err
}
dataUsageInfo.Info.LastUpdate = time.Now()
total := dataUsageInfo.sizeRecursive(dataUsageInfo.Info.Name)
if total == nil {
total = &dataUsageEntry{}
}
atomic.StoreUint64(&s.totalUsed, uint64(total.Size))
return dataUsageInfo, nil
}
// DiskInfo is an extended type which returns current
// disk usage per path.
type DiskInfo struct {
Total uint64
Free uint64
Used uint64
RootDisk bool
MountPath string
}
// DiskInfo provides current information about disk space usage,
// total free inodes and underlying filesystem.
func (s *posix) DiskInfo() (info DiskInfo, err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
di, err := getDiskInfo(s.diskPath)
if err != nil {
return info, err
}
used := di.Total - di.Free
if !s.diskMount {
used = atomic.LoadUint64(&s.totalUsed)
}
rootDisk, err := disk.IsRootDisk(s.diskPath)
if err != nil {
return info, err
}
return DiskInfo{
Total: di.Total,
Free: di.Free,
Used: used,
RootDisk: rootDisk,
MountPath: s.diskPath,
}, nil
}
// getVolDir - will convert incoming volume names to
// corresponding valid volume names on the backend in a platform
// compatible way for all operating systems. If volume is not found
// an error is generated.
func (s *posix) getVolDir(volume string) (string, error) {
if volume == "" || volume == "." || volume == ".." {
return "", errVolumeNotFound
}
volumeDir := pathJoin(s.diskPath, volume)
return volumeDir, nil
}
// GetDiskID - returns the cached disk uuid
func (s *posix) GetDiskID() (string, error) {
s.RLock()
diskID := s.diskID
fileInfo := s.formatFileInfo
lastCheck := s.formatLastCheck
s.RUnlock()
// check if we have a valid disk ID that is less than 1 second old.
if fileInfo != nil && diskID != "" && time.Now().Before(lastCheck.Add(time.Second)) {
return diskID, nil
}
s.Lock()
defer s.Unlock()
// If somebody else updated the disk ID and changed the time, return what they got.
if !lastCheck.IsZero() && !s.formatLastCheck.Equal(lastCheck) && diskID != "" {
// Somebody else got the lock first.
return diskID, nil
}
formatFile := pathJoin(s.diskPath, minioMetaBucket, formatConfigFile)
fi, err := os.Stat(formatFile)
if err != nil {
// If the disk is still not initialized.
if os.IsNotExist(err) {
return "", errUnformattedDisk
}
return "", errCorruptedFormat
}
if xioutil.SameFile(fi, fileInfo) && diskID != "" {
// If the file has not changed, just return the cached diskID information.
s.formatLastCheck = time.Now()
return diskID, nil
}
b, err := ioutil.ReadFile(formatFile)
if err != nil {
return "", errCorruptedFormat
}
format := &formatXLV3{}
var json = jsoniter.ConfigCompatibleWithStandardLibrary
if err = json.Unmarshal(b, &format); err != nil {
return "", errCorruptedFormat
}
s.diskID = format.XL.This
s.formatFileInfo = fi
s.formatLastCheck = time.Now()
return s.diskID, nil
}
// Make a volume entry.
func (s *posix) SetDiskID(id string) {
// NO-OP for posix as it is handled either by posixDiskIDCheck{} for local disks or
// storage rest server for remote disks.
}
func (s *posix) MakeVolBulk(volumes ...string) (err error) {
for _, volume := range volumes {
if err = s.MakeVol(volume); err != nil {
if err != errVolumeExists {
return err
}
}
}
return nil
}
// Make a volume entry.
func (s *posix) MakeVol(volume string) (err error) {
if !isValidVolname(volume) {
return errInvalidArgument
}
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
volumeDir, err := s.getVolDir(volume)
if err != nil {
return err
}
if _, err := os.Stat(volumeDir); err != nil {
// Volume does not exist we proceed to create.
if os.IsNotExist(err) {
// Make a volume entry, with mode 0777 mkdir honors system umask.
err = os.MkdirAll(volumeDir, 0777)
}
if os.IsPermission(err) {
return errDiskAccessDenied
} else if isSysErrIO(err) {
return errFaultyDisk
}
return err
}
// Stat succeeds we return errVolumeExists.
return errVolumeExists
}
// ListVols - list volumes.
func (s *posix) ListVols() (volsInfo []VolInfo, err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
volsInfo, err = listVols(s.diskPath)
if err != nil {
if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
for i, vol := range volsInfo {
volInfo := VolInfo{
Name: vol.Name,
Created: vol.Created,
}
volsInfo[i] = volInfo
}
return volsInfo, nil
}
// List all the volumes from diskPath.
func listVols(dirPath string) ([]VolInfo, error) {
if err := checkPathLength(dirPath); err != nil {
return nil, err
}
entries, err := readDir(dirPath)
if err != nil {
return nil, errDiskNotFound
}
var volsInfo []VolInfo
for _, entry := range entries {
if !HasSuffix(entry, SlashSeparator) || !isValidVolname(slashpath.Clean(entry)) {
// Skip if entry is neither a directory not a valid volume name.
continue
}
var fi os.FileInfo
fi, err = os.Stat(pathJoin(dirPath, entry))
if err != nil {
// If the file does not exist, skip the entry.
if os.IsNotExist(err) {
continue
} else if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
volsInfo = append(volsInfo, VolInfo{
Name: fi.Name(),
// As os.Stat() doesn't carry other than ModTime(), use
// ModTime() as CreatedTime.
Created: fi.ModTime(),
})
}
return volsInfo, nil
}
// StatVol - get volume info.
func (s *posix) StatVol(volume string) (volInfo VolInfo, err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
// Verify if volume is valid and it exists.
volumeDir, err := s.getVolDir(volume)
if err != nil {
return VolInfo{}, err
}
// Stat a volume entry.
var st os.FileInfo
st, err = os.Stat(volumeDir)
if err != nil {
if os.IsNotExist(err) {
return VolInfo{}, errVolumeNotFound
} else if isSysErrIO(err) {
return VolInfo{}, errFaultyDisk
}
return VolInfo{}, err
}
// As os.Stat() doesn't carry other than ModTime(), use ModTime()
// as CreatedTime.
createdTime := st.ModTime()
return VolInfo{
Name: volume,
Created: createdTime,
}, nil
}
// DeleteVol - delete a volume.
func (s *posix) DeleteVol(volume string, forceDelete bool) (err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
// Verify if volume is valid and it exists.
volumeDir, err := s.getVolDir(volume)
if err != nil {
return err
}
if forceDelete {
err = os.RemoveAll(volumeDir)
} else {
err = os.Remove(volumeDir)
}
if err != nil {
switch {
case os.IsNotExist(err):
return errVolumeNotFound
case isSysErrNotEmpty(err):
return errVolumeNotEmpty
case os.IsPermission(err):
return errDiskAccessDenied
case isSysErrIO(err):
return errFaultyDisk
default:
return err
}
}
return nil
}
const guidSplunk = "guidSplunk"
// ListDirSplunk - return all the entries at the given directory path.
// If an entry is a directory it will be returned with a trailing SlashSeparator.
func (s *posix) ListDirSplunk(volume, dirPath string, count int) (entries []string, err error) {
guidIndex := strings.Index(dirPath, guidSplunk)
if guidIndex != -1 {
return nil, nil
}
const receiptJSON = "receipt.json"
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
// Verify if volume is valid and it exists.
volumeDir, err := s.getVolDir(volume)
if err != nil {
return nil, err
}
if _, err = os.Stat(volumeDir); err != nil {
if os.IsNotExist(err) {
return nil, errVolumeNotFound
} else if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
dirPath = pathJoin(volumeDir, dirPath)
if count > 0 {
entries, err = readDirN(dirPath, count)
} else {
entries, err = readDir(dirPath)
}
if err != nil {
return nil, err
}
for i, entry := range entries {
if entry != receiptJSON {
continue
}
if _, serr := os.Stat(pathJoin(dirPath, entry, xlMetaJSONFile)); serr == nil {
entries[i] = strings.TrimSuffix(entry, SlashSeparator)
}
}
return entries, nil
}
// WalkSplunk - is a sorted walker which returns file entries in lexically
// sorted order, additionally along with metadata about each of those entries.
// Implemented specifically for Splunk backend structure and List call with
// delimiter as "guidSplunk"
func (s *posix) WalkSplunk(volume, dirPath, marker string, endWalkCh <-chan struct{}) (ch chan FileInfo, err error) {
// Verify if volume is valid and it exists.
volumeDir, err := s.getVolDir(volume)
if err != nil {
return nil, err
}
// Stat a volume entry.
_, err = os.Stat(volumeDir)
if err != nil {
if os.IsNotExist(err) {
return nil, errVolumeNotFound
} else if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
ch = make(chan FileInfo)
go func() {
defer close(ch)
listDir := func(volume, dirPath, dirEntry string) (bool, []string) {
entries, err := s.ListDirSplunk(volume, dirPath, -1)
if err != nil {
return false, nil
}
if len(entries) == 0 {
return true, nil
}
sort.Strings(entries)
return false, filterMatchingPrefix(entries, dirEntry)
}
walkResultCh := startTreeWalk(GlobalContext, volume, dirPath, marker, true, listDir, endWalkCh)
for {
walkResult, ok := <-walkResultCh
if !ok {
return
}
var fi FileInfo
if HasSuffix(walkResult.entry, SlashSeparator) {
fi = FileInfo{
Volume: volume,
Name: walkResult.entry,
Mode: os.ModeDir,
}
} else {
xlMetaBuf, err := ioutil.ReadFile(pathJoin(volumeDir, walkResult.entry, xlMetaJSONFile))
if err != nil {
continue
}
fi = readMetadata(xlMetaBuf, volume, walkResult.entry)
}
select {
case ch <- fi:
case <-endWalkCh:
return
}
}
}()
return ch, nil
}
// Walk - is a sorted walker which returns file entries in lexically
// sorted order, additionally along with metadata about each of those entries.
func (s *posix) Walk(volume, dirPath, marker string, recursive bool, leafFile string,
readMetadataFn readMetadataFunc, endWalkCh <-chan struct{}) (ch chan FileInfo, err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
// Verify if volume is valid and it exists.
volumeDir, err := s.getVolDir(volume)
if err != nil {
return nil, err
}
// Stat a volume entry.
_, err = os.Stat(volumeDir)
if err != nil {
if os.IsNotExist(err) {
return nil, errVolumeNotFound
} else if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
// buffer channel matches the S3 ListObjects implementation
ch = make(chan FileInfo, maxObjectList)
go func() {
defer close(ch)
listDir := func(volume, dirPath, dirEntry string) (bool, []string) {
entries, err := s.ListDir(volume, dirPath, -1, leafFile)
if err != nil {
return false, nil
}
if len(entries) == 0 {
return true, nil
}
sort.Strings(entries)
return false, filterMatchingPrefix(entries, dirEntry)
}
walkResultCh := startTreeWalk(GlobalContext, volume, dirPath, marker, recursive, listDir, endWalkCh)
for {
walkResult, ok := <-walkResultCh
if !ok {
return
}
var fi FileInfo
if HasSuffix(walkResult.entry, SlashSeparator) {
fi = FileInfo{
Volume: volume,
Name: walkResult.entry,
Mode: os.ModeDir,
}
} else {
xlMetaBuf, err := ioutil.ReadFile(pathJoin(volumeDir, walkResult.entry, leafFile))
if err != nil {
continue
}
fi = readMetadataFn(xlMetaBuf, volume, walkResult.entry)
}
select {
case ch <- fi:
case <-endWalkCh:
return
}
}
}()
return ch, nil
}
// ListDir - return all the entries at the given directory path.
// If an entry is a directory it will be returned with a trailing SlashSeparator.
func (s *posix) ListDir(volume, dirPath string, count int, leafFile string) (entries []string, err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
// Verify if volume is valid and it exists.
volumeDir, err := s.getVolDir(volume)
if err != nil {
return nil, err
}
if _, err = os.Stat(volumeDir); err != nil {
if os.IsNotExist(err) {
return nil, errVolumeNotFound
} else if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
dirPath = pathJoin(volumeDir, dirPath)
if count > 0 {
entries, err = readDirN(dirPath, count)
} else {
entries, err = readDir(dirPath)
}
if err != nil {
return nil, err
}
// If leaf file is specified, filter out the entries.
if leafFile != "" {
for i, entry := range entries {
if _, serr := os.Stat(pathJoin(dirPath, entry, leafFile)); serr == nil {
entries[i] = strings.TrimSuffix(entry, SlashSeparator)
}
}
}
return entries, err
}
// ReadAll reads from r until an error or EOF and returns the data it read.
// A successful call returns err == nil, not err == EOF. Because ReadAll is
// defined to read from src until EOF, it does not treat an EOF from Read
// as an error to be reported.
// This API is meant to be used on files which have small memory footprint, do
// not use this on large files as it would cause server to crash.
func (s *posix) ReadAll(volume, path string) (buf []byte, err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
volumeDir, err := s.getVolDir(volume)
if err != nil {
return nil, err
}
// Stat a volume entry.
_, err = os.Stat((volumeDir))
if err != nil {
if os.IsNotExist(err) {
return nil, errVolumeNotFound
} else if isSysErrIO(err) {
return nil, errFaultyDisk
} else if isSysErrTooManyFiles(err) {
return nil, errTooManyOpenFiles
}
return nil, err
}
// Validate file path length, before reading.
filePath := pathJoin(volumeDir, path)
if err = checkPathLength((filePath)); err != nil {
return nil, err
}
// Open the file for reading.
buf, err = ioutil.ReadFile((filePath))
if err != nil {
if os.IsNotExist(err) {
return nil, errFileNotFound
} else if os.IsPermission(err) {
return nil, errFileAccessDenied
} else if errors.Is(err, syscall.ENOTDIR) || errors.Is(err, syscall.EISDIR) {
return nil, errFileNotFound
} else if isSysErrHandleInvalid(err) {
// This case is special and needs to be handled for windows.
return nil, errFileNotFound
} else if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
return buf, nil
}
// ReadFile reads exactly len(buf) bytes into buf. It returns the
// number of bytes copied. The error is EOF only if no bytes were
// read. On return, n == len(buf) if and only if err == nil. n == 0
// for io.EOF.
//
// If an EOF happens after reading some but not all the bytes,
// ReadFile returns ErrUnexpectedEOF.
//
// If the BitrotVerifier is not nil or not verified ReadFile
// tries to verify whether the disk has bitrot.
//
// Additionally ReadFile also starts reading from an offset. ReadFile
// semantics are same as io.ReadFull.
func (s *posix) ReadFile(volume, path string, offset int64, buffer []byte, verifier *BitrotVerifier) (int64, error) {
if offset < 0 {
return 0, errInvalidArgument
}
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
volumeDir, err := s.getVolDir(volume)
if err != nil {
return 0, err
}
var n int
// Stat a volume entry.
_, err = os.Stat((volumeDir))
if err != nil {
if os.IsNotExist(err) {
return 0, errVolumeNotFound
} else if isSysErrIO(err) {
return 0, errFaultyDisk
}
return 0, err
}
// Validate effective path length before reading.
filePath := pathJoin(volumeDir, path)
if err = checkPathLength((filePath)); err != nil {
return 0, err
}
// Open the file for reading.
file, err := os.Open((filePath))
if err != nil {
switch {
case os.IsNotExist(err):
return 0, errFileNotFound
case os.IsPermission(err):
return 0, errFileAccessDenied
case isSysErrNotDir(err):
return 0, errFileAccessDenied
case isSysErrIO(err):
return 0, errFaultyDisk
case isSysErrTooManyFiles(err):
return 0, errTooManyOpenFiles
default:
return 0, err
}
}
// Close the file descriptor.
defer file.Close()
st, err := file.Stat()
if err != nil {
return 0, err
}
// Verify it is a regular file, otherwise subsequent Seek is
// undefined.
if !st.Mode().IsRegular() {
return 0, errIsNotRegular
}
if verifier == nil {
n, err = file.ReadAt(buffer, offset)
return int64(n), err
}
bufp := s.pool.Get().(*[]byte)
defer s.pool.Put(bufp)
h := verifier.algorithm.New()
if _, err = io.CopyBuffer(h, io.LimitReader(file, offset), *bufp); err != nil {
return 0, err
}
if n, err = io.ReadFull(file, buffer); err != nil {
return int64(n), err
}
if _, err = h.Write(buffer); err != nil {
return 0, err
}
if _, err = io.CopyBuffer(h, file, *bufp); err != nil {
return 0, err
}
if !bytes.Equal(h.Sum(nil), verifier.sum) {
return 0, errFileCorrupt
}
return int64(len(buffer)), nil
}
func (s *posix) openFile(volume, path string, mode int) (f *os.File, err error) {
volumeDir, err := s.getVolDir(volume)
if err != nil {
return nil, err
}
// Stat a volume entry.
_, err = os.Stat((volumeDir))
if err != nil {
if os.IsNotExist(err) {
return nil, errVolumeNotFound
} else if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
filePath := pathJoin(volumeDir, path)
if err = checkPathLength((filePath)); err != nil {
return nil, err
}
// Verify if the file already exists and is not of regular type.
var st os.FileInfo
if st, err = os.Stat(filePath); err == nil {
if !st.Mode().IsRegular() {
return nil, errIsNotRegular
}
} else {
// Create top level directories if they don't exist.
// with mode 0777 mkdir honors system umask.
if err = mkdirAll(slashpath.Dir(filePath), 0777); err != nil {
return nil, err
}
}
w, err := os.OpenFile(filePath, mode, 0666)
if err != nil {
// File path cannot be verified since one of the parents is a file.
switch {
case isSysErrNotDir(err):
return nil, errFileAccessDenied
case os.IsPermission(err):
return nil, errFileAccessDenied
case isSysErrIO(err):
return nil, errFaultyDisk
case isSysErrTooManyFiles(err):
return nil, errTooManyOpenFiles
default:
return nil, err
}
}
return w, nil
}
// ReadFileStream - Returns the read stream of the file.
func (s *posix) ReadFileStream(volume, path string, offset, length int64) (io.ReadCloser, error) {
if offset < 0 {
return nil, errInvalidArgument
}
volumeDir, err := s.getVolDir(volume)
if err != nil {
return nil, err
}
// Stat a volume entry.
_, err = os.Stat((volumeDir))
if err != nil {
if os.IsNotExist(err) {
return nil, errVolumeNotFound
} else if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
// Validate effective path length before reading.
filePath := pathJoin(volumeDir, path)
if err = checkPathLength((filePath)); err != nil {
return nil, err
}
// Open the file for reading.
file, err := os.Open((filePath))
if err != nil {
switch {
case os.IsNotExist(err):
return nil, errFileNotFound
case os.IsPermission(err):
return nil, errFileAccessDenied
case isSysErrNotDir(err):
return nil, errFileAccessDenied
case isSysErrIO(err):
return nil, errFaultyDisk
case isSysErrTooManyFiles(err):
return nil, errTooManyOpenFiles
default:
return nil, err
}
}
st, err := file.Stat()
if err != nil {
return nil, err
}
// Verify it is a regular file, otherwise subsequent Seek is
// undefined.
if !st.Mode().IsRegular() {
return nil, errIsNotRegular
}
if _, err = file.Seek(offset, io.SeekStart); err != nil {
return nil, err
}
atomic.AddInt32(&s.activeIOCount, 1)
r := struct {
io.Reader
io.Closer
}{Reader: io.LimitReader(file, length), Closer: closeWrapper(func() error {
atomic.AddInt32(&s.activeIOCount, -1)
return file.Close()
})}
// Add readahead to big reads
if length >= readAheadSize {
rc, err := readahead.NewReadCloserSize(r, readAheadBuffers, readAheadBufSize)
if err != nil {
r.Close()
return nil, err
}
return rc, nil
}
// Just add a small 64k buffer.
r.Reader = bufio.NewReaderSize(r.Reader, 64<<10)
return r, nil
}
// closeWrapper converts a function to an io.Closer
type closeWrapper func() error
// Close calls the wrapped function.
func (c closeWrapper) Close() error {
return c()
}
// CreateFile - creates the file.
func (s *posix) CreateFile(volume, path string, fileSize int64, r io.Reader) (err error) {
if fileSize < -1 {
return errInvalidArgument
}
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
// Validate if disk is indeed free.
if err = checkDiskFree(s.diskPath, fileSize); err != nil {
if isSysErrIO(err) {
return errFaultyDisk
}
return err
}
volumeDir, err := s.getVolDir(volume)
if err != nil {
return err
}
// Stat a volume entry.
_, err = os.Stat((volumeDir))
if err != nil {
if os.IsNotExist(err) {
return errVolumeNotFound
} else if isSysErrIO(err) {
return errFaultyDisk
}
return err
}
filePath := pathJoin(volumeDir, path)
if err = checkPathLength((filePath)); err != nil {
return err
}
// Create top level directories if they don't exist.
// with mode 0777 mkdir honors system umask.
if err = mkdirAll(slashpath.Dir(filePath), 0777); err != nil {
return err
}
w, err := disk.OpenFileDirectIO(filePath, os.O_CREATE|os.O_WRONLY|os.O_EXCL, 0666)
if err != nil {
switch {
case os.IsPermission(err):
return errFileAccessDenied
case os.IsExist(err):
return errFileAccessDenied
case isSysErrIO(err):
return errFaultyDisk
default:
return err
}
}
var e error
if fileSize > 0 {
// Allocate needed disk space to append data
e = Fallocate(int(w.Fd()), 0, fileSize)
}
// Ignore errors when Fallocate is not supported in the current system
if e != nil && !isSysErrNoSys(e) && !isSysErrOpNotSupported(e) {
switch {
case isSysErrNoSpace(e):
err = errDiskFull
case isSysErrIO(e):
err = errFaultyDisk
default:
// For errors: EBADF, EINTR, EINVAL, ENODEV, EPERM, ESPIPE and ETXTBSY
// Appending was failed anyway, returns unexpected error
err = errUnexpected
}
return err
}
defer w.Close()
bufp := s.pool.Get().(*[]byte)
defer s.pool.Put(bufp)
written, err := xioutil.CopyAligned(w, r, *bufp, fileSize)
if err != nil {
return err
}
if written < fileSize {
return errLessData
} else if written > fileSize {
return errMoreData
}
return nil
}
func (s *posix) WriteAll(volume, path string, reader io.Reader) (err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
// Create file if not found. Note that it is created with os.O_EXCL flag as the file
// always is supposed to be created in the tmp directory with a unique file name.
w, err := s.openFile(volume, path, os.O_CREATE|os.O_SYNC|os.O_WRONLY|os.O_EXCL)
if err != nil {
return err
}
defer w.Close()
bufp := s.pool.Get().(*[]byte)
defer s.pool.Put(bufp)
_, err = io.CopyBuffer(w, reader, *bufp)
return err
}
// AppendFile - append a byte array at path, if file doesn't exist at
// path this call explicitly creates it.
func (s *posix) AppendFile(volume, path string, buf []byte) (err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
var w *os.File
// Create file if not found. Not doing O_DIRECT here to avoid the code that does buffer aligned writes.
// AppendFile() is only used by healing code to heal objects written in old format.
w, err = s.openFile(volume, path, os.O_CREATE|os.O_SYNC|os.O_APPEND|os.O_WRONLY)
if err != nil {
return err
}
if _, err = w.Write(buf); err != nil {
return err
}
return w.Close()
}
// StatFile - get file info.
func (s *posix) StatFile(volume, path string) (file FileInfo, err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
volumeDir, err := s.getVolDir(volume)
if err != nil {
return FileInfo{}, err
}
// Stat a volume entry.
_, err = os.Stat((volumeDir))
if err != nil {
if os.IsNotExist(err) {
return FileInfo{}, errVolumeNotFound
}
return FileInfo{}, err
}
filePath := slashpath.Join(volumeDir, path)
if err = checkPathLength((filePath)); err != nil {
return FileInfo{}, err
}
st, err := os.Stat((filePath))
if err != nil {
switch {
case os.IsNotExist(err):
// File is really not found.
return FileInfo{}, errFileNotFound
case isSysErrIO(err):
return FileInfo{}, errFaultyDisk
case isSysErrNotDir(err):
// File path cannot be verified since one of the parents is a file.
return FileInfo{}, errFileNotFound
default:
// Return all errors here.
return FileInfo{}, err
}
}
// If its a directory its not a regular file.
if st.Mode().IsDir() {
return FileInfo{}, errFileNotFound
}
return FileInfo{
Volume: volume,
Name: path,
ModTime: st.ModTime(),
Size: st.Size(),
Mode: st.Mode(),
}, nil
}
// deleteFile deletes a file or a directory if its empty unless recursive
// is set to true. If the target is successfully deleted, it will recursively
// move up the tree, deleting empty parent directories until it finds one
// with files in it. Returns nil for a non-empty directory even when
// recursive is set to false.
func deleteFile(basePath, deletePath string, recursive bool) error {
if basePath == "" || deletePath == "" {
return nil
}
basePath = filepath.Clean(basePath)
deletePath = filepath.Clean(deletePath)
if !strings.HasPrefix(deletePath, basePath) || deletePath == basePath {
return nil
}
var err error
if recursive {
err = os.RemoveAll(deletePath)
} else {
err = os.Remove(deletePath)
}
if err != nil {
switch {
case isSysErrNotEmpty(err):
// Ignore errors if the directory is not empty. The server relies on
// this functionality, and sometimes uses recursion that should not
// error on parent directories.
return nil
case os.IsNotExist(err):
return errFileNotFound
case os.IsPermission(err):
return errFileAccessDenied
case isSysErrIO(err):
return errFaultyDisk
default:
return err
}
}
deletePath = filepath.Dir(deletePath)
// Delete parent directory obviously not recursively. Errors for
// parent directories shouldn't trickle down.
deleteFile(basePath, deletePath, false)
return nil
}
// DeletePrefixes forcibly deletes all the contents of a set of specified paths.
// Parent directories are automatically removed if they become empty. err can
// bil nil while errs can contain some errors for corresponding objects. No error
// is set if a specified prefix path does not exist.
func (s *posix) DeletePrefixes(volume string, paths []string) (errs []error, err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
volumeDir, err := s.getVolDir(volume)
if err != nil {
return nil, err
}
// Stat a volume entry.
_, err = os.Stat(volumeDir)
if err != nil {
if os.IsNotExist(err) {
return nil, errVolumeNotFound
} else if os.IsPermission(err) {
return nil, errVolumeAccessDenied
} else if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
errs = make([]error, len(paths))
// Following code is needed so that we retain SlashSeparator
// suffix if any in path argument.
for idx, path := range paths {
filePath := pathJoin(volumeDir, path)
errs[idx] = checkPathLength(filePath)
if errs[idx] != nil {
continue
}
// Delete file or a directory recursively, delete parent
// directory as well if its empty.
errs[idx] = deleteFile(volumeDir, filePath, true)
}
return
}
// DeleteFile - delete a file at path.
func (s *posix) DeleteFile(volume, path string) (err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
volumeDir, err := s.getVolDir(volume)
if err != nil {
return err
}
// Stat a volume entry.
_, err = os.Stat(volumeDir)
if err != nil {
if os.IsNotExist(err) {
return errVolumeNotFound
} else if os.IsPermission(err) {
return errVolumeAccessDenied
} else if isSysErrIO(err) {
return errFaultyDisk
}
return err
}
// Following code is needed so that we retain SlashSeparator suffix if any in
// path argument.
filePath := pathJoin(volumeDir, path)
if err = checkPathLength(filePath); err != nil {
return err
}
// Delete file and delete parent directory as well if its empty.
return deleteFile(volumeDir, filePath, false)
}
func (s *posix) DeleteFileBulk(volume string, paths []string) (errs []error, err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
volumeDir, err := s.getVolDir(volume)
if err != nil {
return nil, err
}
// Stat a volume entry.
_, err = os.Stat(volumeDir)
if err != nil {
if os.IsNotExist(err) {
return nil, errVolumeNotFound
} else if os.IsPermission(err) {
return nil, errVolumeAccessDenied
} else if isSysErrIO(err) {
return nil, errFaultyDisk
}
return nil, err
}
errs = make([]error, len(paths))
// Following code is needed so that we retain SlashSeparator
// suffix if any in path argument.
for idx, path := range paths {
filePath := pathJoin(volumeDir, path)
errs[idx] = checkPathLength(filePath)
if errs[idx] != nil {
continue
}
// Delete file and delete parent directory as well if its empty.
errs[idx] = deleteFile(volumeDir, filePath, false)
}
return
}
// RenameFile - rename source path to destination path atomically.
func (s *posix) RenameFile(srcVolume, srcPath, dstVolume, dstPath string) (err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
srcVolumeDir, err := s.getVolDir(srcVolume)
if err != nil {
return err
}
dstVolumeDir, err := s.getVolDir(dstVolume)
if err != nil {
return err
}
// Stat a volume entry.
_, err = os.Stat(srcVolumeDir)
if err != nil {
if os.IsNotExist(err) {
return errVolumeNotFound
} else if isSysErrIO(err) {
return errFaultyDisk
}
return err
}
_, err = os.Stat(dstVolumeDir)
if err != nil {
if os.IsNotExist(err) {
return errVolumeNotFound
} else if isSysErrIO(err) {
return errFaultyDisk
}
}
srcIsDir := HasSuffix(srcPath, SlashSeparator)
dstIsDir := HasSuffix(dstPath, SlashSeparator)
// Either src and dst have to be directories or files, else return error.
if !(srcIsDir && dstIsDir || !srcIsDir && !dstIsDir) {
return errFileAccessDenied
}
srcFilePath := slashpath.Join(srcVolumeDir, srcPath)
if err = checkPathLength(srcFilePath); err != nil {
return err
}
dstFilePath := slashpath.Join(dstVolumeDir, dstPath)
if err = checkPathLength(dstFilePath); err != nil {
return err
}
if srcIsDir {
// If source is a directory, we expect the destination to be non-existent but we
// we still need to allow overwriting an empty directory since it represents
// an object empty directory.
_, err = os.Stat(dstFilePath)
if isSysErrIO(err) {
return errFaultyDisk
}
if err == nil && !isDirEmpty(dstFilePath) {
return errFileAccessDenied
}
if err != nil && !os.IsNotExist(err) {
return err
}
// Empty destination remove it before rename.
if isDirEmpty(dstFilePath) {
if err = os.Remove(dstFilePath); err != nil {
if isSysErrNotEmpty(err) {
return errFileAccessDenied
}
return err
}
}
}
if err = renameAll(srcFilePath, dstFilePath); err != nil {
if isSysErrIO(err) {
return errFaultyDisk
}
return err
}
// Remove parent dir of the source file if empty
if parentDir := slashpath.Dir(srcFilePath); isDirEmpty(parentDir) {
deleteFile(srcVolumeDir, parentDir, false)
}
return nil
}
func (s *posix) VerifyFile(volume, path string, fileSize int64, algo BitrotAlgorithm, sum []byte, shardSize int64) (err error) {
atomic.AddInt32(&s.activeIOCount, 1)
defer func() {
atomic.AddInt32(&s.activeIOCount, -1)
}()
volumeDir, err := s.getVolDir(volume)
if err != nil {
return err
}
// Stat a volume entry.
_, err = os.Stat(volumeDir)
if err != nil {
if os.IsNotExist(err) {
return errVolumeNotFound
} else if isSysErrIO(err) {
return errFaultyDisk
} else if os.IsPermission(err) {
return errVolumeAccessDenied
}
return err
}
// Validate effective path length before reading.
filePath := pathJoin(volumeDir, path)
if err = checkPathLength(filePath); err != nil {
return err
}
// Open the file for reading.
file, err := os.Open(filePath)
if err != nil {
return osErrToFSFileErr(err)
}
// Close the file descriptor.
defer file.Close()
if algo != HighwayHash256S {
bufp := s.pool.Get().(*[]byte)
defer s.pool.Put(bufp)
h := algo.New()
if _, err = io.CopyBuffer(h, file, *bufp); err != nil {
// Premature failure in reading the object,file is corrupt.
return errFileCorrupt
}
if !bytes.Equal(h.Sum(nil), sum) {
return errFileCorrupt
}
return nil
}
buf := make([]byte, shardSize)
h := algo.New()
hashBuf := make([]byte, h.Size())
fi, err := file.Stat()
if err != nil {
// Unable to stat on the file, return an expected error
// for healing code to fix this file.
return err
}
size := fi.Size()
// Calculate the size of the bitrot file and compare
// it with the actual file size.
if size != bitrotShardFileSize(fileSize, shardSize, algo) {
return errFileCorrupt
}
var n int
for {
if size == 0 {
return nil
}
h.Reset()
n, err = file.Read(hashBuf)
if err != nil {
// Read's failed for object with right size, file is corrupt.
return err
}
size -= int64(n)
if size < int64(len(buf)) {
buf = buf[:size]
}
n, err = file.Read(buf)
if err != nil {
// Read's failed for object with right size, at different offsets.
return err
}
size -= int64(n)
h.Write(buf)
if !bytes.Equal(h.Sum(nil), hashBuf) {
return errFileCorrupt
}
}
}