Fixes #1636 New format now generates a UUID and includes it along with the order of disks. So that UUID is the real order of disks and on command line user is able to specify disks in any order. This pre-dominantly solves our dilemma. ``` { "format" : "xl", "xl" : { "version" : "1", "disk": "00e4cf06-5bf5-4bb5-b885-4b2fff4a7959", "jbod" : [ "00e4cf06-5bf5-4bb5-b885-4b2fff4a7959", .... "c47d2608-5067-4ed7-b1e4-fb81bdbb549f", "a543293e-99f1-4310-b540-1e450878e844", "18f97cbe-529a-456a-b6d4-0feacf64534d" ] }, "version" : "1" } ```
590 lines
15 KiB
Go
590 lines
15 KiB
Go
/*
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* Minio Cloud Storage, (C) 2016 Minio, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package main
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import (
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"errors"
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"fmt"
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"math/rand"
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"os"
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slashpath "path"
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"strings"
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"path"
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"sync"
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"github.com/klauspost/reedsolomon"
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)
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const (
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// XL erasure metadata file.
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xlMetaV1File = "file.json"
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)
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// XL layer structure.
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type XL struct {
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ReedSolomon reedsolomon.Encoder // Erasure encoder/decoder.
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DataBlocks int
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ParityBlocks int
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storageDisks []StorageAPI
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readQuorum int
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writeQuorum int
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}
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// errUnexpected - returned for any unexpected error.
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var errUnexpected = errors.New("Unexpected error - please report at https://github.com/minio/minio/issues")
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// newXL instantiate a new XL.
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func newXL(disks []StorageAPI) (StorageAPI, error) {
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// Initialize XL.
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xl := &XL{}
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// Calculate data and parity blocks.
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dataBlocks, parityBlocks := len(disks)/2, len(disks)/2
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// Initialize reed solomon encoding.
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rs, err := reedsolomon.New(dataBlocks, parityBlocks)
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if err != nil {
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return nil, err
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}
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// Save the reedsolomon.
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xl.DataBlocks = dataBlocks
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xl.ParityBlocks = parityBlocks
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xl.ReedSolomon = rs
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// Save all the initialized storage disks.
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xl.storageDisks = disks
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// Figure out read and write quorum based on number of storage disks.
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// Read quorum should be always N/2 + 1 (due to Vandermonde matrix
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// erasure requirements)
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xl.readQuorum = len(xl.storageDisks)/2 + 1
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// Write quorum is assumed if we have total disks + 3
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// parity. (Need to discuss this again)
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xl.writeQuorum = len(xl.storageDisks)/2 + 3
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if xl.writeQuorum > len(xl.storageDisks) {
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xl.writeQuorum = len(xl.storageDisks)
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}
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// Return successfully initialized.
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return xl, nil
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}
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// MakeVol - make a volume.
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func (xl XL) MakeVol(volume string) error {
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if !isValidVolname(volume) {
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return errInvalidArgument
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}
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// Err counters.
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createVolErr := 0 // Count generic create vol errs.
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volumeExistsErrCnt := 0 // Count all errVolumeExists errs.
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// Initialize sync waitgroup.
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var wg = &sync.WaitGroup{}
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// Initialize list of errors.
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var dErrs = make([]error, len(xl.storageDisks))
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// Make a volume entry on all underlying storage disks.
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for index, disk := range xl.storageDisks {
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wg.Add(1)
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// Make a volume inside a go-routine.
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go func(index int, disk StorageAPI) {
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defer wg.Done()
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if disk == nil {
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return
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}
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dErrs[index] = disk.MakeVol(volume)
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}(index, disk)
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}
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// Wait for all make vol to finish.
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wg.Wait()
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// Loop through all the concocted errors.
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for _, err := range dErrs {
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if err == nil {
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continue
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}
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// if volume already exists, count them.
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if err == errVolumeExists {
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volumeExistsErrCnt++
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continue
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}
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// Update error counter separately.
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createVolErr++
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}
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// Return err if all disks report volume exists.
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if volumeExistsErrCnt == len(xl.storageDisks) {
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return errVolumeExists
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} else if createVolErr > len(xl.storageDisks)-xl.writeQuorum {
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// Return errWriteQuorum if errors were more than
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// allowed write quorum.
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return errWriteQuorum
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}
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return nil
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}
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// DeleteVol - delete a volume.
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func (xl XL) DeleteVol(volume string) error {
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if !isValidVolname(volume) {
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return errInvalidArgument
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}
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// Collect if all disks report volume not found.
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var volumeNotFoundErrCnt int
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var wg = &sync.WaitGroup{}
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var dErrs = make([]error, len(xl.storageDisks))
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// Remove a volume entry on all underlying storage disks.
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for index, disk := range xl.storageDisks {
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wg.Add(1)
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// Delete volume inside a go-routine.
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go func(index int, disk StorageAPI) {
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defer wg.Done()
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dErrs[index] = disk.DeleteVol(volume)
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}(index, disk)
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}
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// Wait for all the delete vols to finish.
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wg.Wait()
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// Loop through concocted errors and return anything unusual.
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for _, err := range dErrs {
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if err != nil {
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// We ignore error if errVolumeNotFound or errDiskNotFound
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if err == errVolumeNotFound || err == errDiskNotFound {
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volumeNotFoundErrCnt++
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continue
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}
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return err
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}
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}
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// Return err if all disks report volume not found.
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if volumeNotFoundErrCnt == len(xl.storageDisks) {
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return errVolumeNotFound
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}
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return nil
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}
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// ListVols - list volumes.
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func (xl XL) ListVols() (volsInfo []VolInfo, err error) {
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emptyCount := 0
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// Initialize sync waitgroup.
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var wg = &sync.WaitGroup{}
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// Success vols map carries successful results of ListVols from each disks.
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var successVols = make([][]VolInfo, len(xl.storageDisks))
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for index, disk := range xl.storageDisks {
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wg.Add(1) // Add each go-routine to wait for.
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go func(index int, disk StorageAPI) {
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// Indicate wait group as finished.
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defer wg.Done()
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// Initiate listing.
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vlsInfo, lErr := disk.ListVols()
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if lErr == nil {
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if len(vlsInfo) == 0 {
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emptyCount++ // Calculate empty count specially.
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} else {
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successVols[index] = vlsInfo
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}
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}
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}(index, disk)
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}
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// For all the list volumes running in parallel to finish.
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wg.Wait()
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// If all list operations resulted in an empty count which is same
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// as your total storage disks, then it is a valid case return
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// success with empty vols.
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if emptyCount == len(xl.storageDisks) {
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return []VolInfo{}, nil
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} else if len(successVols) < xl.readQuorum {
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// If there is data and not empty, then we attempt quorum verification.
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// Verify if we have enough quorum to list vols.
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return nil, errReadQuorum
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}
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var total, free int64
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// Loop through success vols and get aggregated usage values.
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for _, vlsInfo := range successVols {
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if len(vlsInfo) == 0 {
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continue
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}
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free += vlsInfo[0].Free
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total += vlsInfo[0].Total
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}
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// Save the updated usage values back into the vols.
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for _, volInfo := range successVols[0] {
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volInfo.Free = free
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volInfo.Total = total
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volsInfo = append(volsInfo, volInfo)
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}
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// NOTE: The assumption here is that volumes across all disks in
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// readQuorum have consistent view i.e they all have same number
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// of buckets. This is essentially not verified since healing
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// should take care of this.
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return volsInfo, nil
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}
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// getAllVolInfo - list bucket volume info from all disks.
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// Returns error slice indicating the failed volume stat operations.
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func (xl XL) getAllVolInfo(volume string) (volsInfo []VolInfo, errs []error) {
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// Create errs and volInfo slices of storageDisks size.
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errs = make([]error, len(xl.storageDisks))
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volsInfo = make([]VolInfo, len(xl.storageDisks))
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// Allocate a new waitgroup.
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var wg = &sync.WaitGroup{}
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for index, disk := range xl.storageDisks {
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wg.Add(1)
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// Stat volume on all the disks in a routine.
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go func(index int, disk StorageAPI) {
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defer wg.Done()
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volInfo, err := disk.StatVol(volume)
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if err != nil {
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errs[index] = err
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return
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}
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volsInfo[index] = volInfo
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}(index, disk)
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}
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// Wait for all the Stat operations to finish.
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wg.Wait()
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// Return the concocted values.
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return volsInfo, errs
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}
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// listAllVolInfo - list all stat volume info from all disks.
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// Returns
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// - stat volume info for all online disks.
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// - boolean to indicate if healing is necessary.
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// - error if any.
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func (xl XL) listAllVolInfo(volume string) ([]VolInfo, bool, error) {
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volsInfo, errs := xl.getAllVolInfo(volume)
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volsInfo = removeDuplicateVols(volsInfo)
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notFoundCount := 0
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for _, err := range errs {
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if err == errVolumeNotFound {
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notFoundCount++
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// If we have errors with file not found greater than allowed read
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// quorum we return err as errFileNotFound.
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if notFoundCount > len(xl.storageDisks)-xl.readQuorum {
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return nil, false, errVolumeNotFound
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}
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}
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}
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// Calculate online disk count.
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onlineDiskCount := 0
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for index := range errs {
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if errs[index] == nil {
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onlineDiskCount++
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}
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}
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var heal bool
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// If online disks count is lesser than configured disks, most
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// probably we need to heal the file, additionally verify if the
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// count is lesser than readQuorum, if not we throw an error.
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if onlineDiskCount < len(xl.storageDisks) {
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// Online disks lesser than total storage disks, needs to be
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// healed. unless we do not have readQuorum.
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heal = true
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// Verify if online disks count are lesser than readQuorum
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// threshold, return an error if yes.
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if onlineDiskCount < xl.readQuorum {
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return nil, false, errReadQuorum
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}
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}
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// Return success.
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return volsInfo, heal, nil
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}
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// healVolume - heals any missing volumes.
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func (xl XL) healVolume(volume string) error {
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// Lists volume info for all online disks.
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volsInfo, heal, err := xl.listAllVolInfo(volume)
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if err != nil {
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return err
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}
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if !heal {
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return nil
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}
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// Create volume if missing on online disks.
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for index, volInfo := range volsInfo {
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if volInfo.Name != "" {
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continue
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}
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// Volinfo name would be an empty string, create it.
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if err = xl.storageDisks[index].MakeVol(volume); err != nil {
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continue
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}
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}
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return nil
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}
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// Removes any duplicate vols.
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func removeDuplicateVols(volsInfo []VolInfo) []VolInfo {
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// Use map to record duplicates as we find them.
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result := []VolInfo{}
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m := make(map[string]VolInfo)
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for _, v := range volsInfo {
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if _, found := m[v.Name]; !found {
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m[v.Name] = v
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}
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}
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result = make([]VolInfo, 0, len(m))
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for _, v := range m {
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result = append(result, v)
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}
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// Return the new slice.
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return result
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}
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// StatVol - get volume stat info.
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func (xl XL) StatVol(volume string) (volInfo VolInfo, err error) {
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if !isValidVolname(volume) {
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return VolInfo{}, errInvalidArgument
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}
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volsInfo, heal, err := xl.listAllVolInfo(volume)
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if err != nil {
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return VolInfo{}, err
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}
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if heal {
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go func() {
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hErr := xl.healVolume(volume)
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errorIf(hErr, "Unable to heal volume "+volume+".")
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}()
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}
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// Loop through all statVols, calculate the actual usage values.
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var total, free int64
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for _, volInfo := range volsInfo {
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free += volInfo.Free
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total += volInfo.Total
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}
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// Filter volsInfo and update the volInfo.
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volInfo = volsInfo[0]
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volInfo.Free = free
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volInfo.Total = total
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return volInfo, nil
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}
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// isLeafDirectoryXL - check if a given path is leaf directory. i.e
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// if it contains file xlMetaV1File
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func isLeafDirectoryXL(disk StorageAPI, volume, leafPath string) (isLeaf bool) {
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_, err := disk.StatFile(volume, path.Join(leafPath, xlMetaV1File))
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return err == nil
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}
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// ListDir - return all the entries at the given directory path.
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// If an entry is a directory it will be returned with a trailing "/".
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func (xl XL) ListDir(volume, dirPath string) (entries []string, err error) {
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if !isValidVolname(volume) {
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return nil, errInvalidArgument
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}
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// Count for list errors encountered.
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var listErrCount = 0
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// Loop through and return the first success entry based on the
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// selected random disk.
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for listErrCount < len(xl.storageDisks) {
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// Choose a random disk on each attempt, do not hit the same disk all the time.
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randIndex := rand.Intn(len(xl.storageDisks) - 1)
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disk := xl.storageDisks[randIndex] // Pick a random disk.
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// Initiate a list operation, if successful filter and return quickly.
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if entries, err = disk.ListDir(volume, dirPath); err == nil {
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for i, entry := range entries {
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isLeaf := isLeafDirectoryXL(disk, volume, path.Join(dirPath, entry))
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isDir := strings.HasSuffix(entry, slashSeparator)
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if isDir && isLeaf {
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entries[i] = strings.TrimSuffix(entry, slashSeparator)
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}
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}
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// We got the entries successfully return.
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return entries, nil
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}
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listErrCount++ // Update list error count.
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}
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// Return error at the end.
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return nil, err
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}
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// Object API.
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// StatFile - stat a file
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func (xl XL) StatFile(volume, path string) (FileInfo, error) {
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if !isValidVolname(volume) {
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return FileInfo{}, errInvalidArgument
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}
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if !isValidPath(path) {
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return FileInfo{}, errInvalidArgument
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}
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_, metadata, heal, err := xl.listOnlineDisks(volume, path)
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if err != nil {
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return FileInfo{}, err
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}
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if heal {
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// Heal in background safely, since we already have read quorum disks.
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go func() {
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hErr := xl.healFile(volume, path)
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errorIf(hErr, "Unable to heal file "+volume+"/"+path+".")
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}()
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}
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// Return file info.
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return FileInfo{
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Volume: volume,
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Name: path,
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Size: metadata.Stat.Size,
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ModTime: metadata.Stat.ModTime,
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Mode: os.FileMode(0644),
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}, nil
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}
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// deleteXLFiles - delete all XL backend files.
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func (xl XL) deleteXLFiles(volume, path string) error {
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errCount := 0
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// Update meta data file and remove part file
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for index, disk := range xl.storageDisks {
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erasureFilePart := slashpath.Join(path, fmt.Sprintf("file.%d", index))
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err := disk.DeleteFile(volume, erasureFilePart)
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if err != nil {
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errCount++
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// We can safely allow DeleteFile errors up to len(xl.storageDisks) - xl.writeQuorum
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// otherwise return failure.
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if errCount <= len(xl.storageDisks)-xl.writeQuorum {
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continue
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}
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return err
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}
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xlMetaV1FilePath := slashpath.Join(path, "file.json")
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err = disk.DeleteFile(volume, xlMetaV1FilePath)
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if err != nil {
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errCount++
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// We can safely allow DeleteFile errors up to len(xl.storageDisks) - xl.writeQuorum
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// otherwise return failure.
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if errCount <= len(xl.storageDisks)-xl.writeQuorum {
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continue
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}
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return err
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}
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}
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// Return success.
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return nil
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}
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// DeleteFile - delete a file
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func (xl XL) DeleteFile(volume, path string) error {
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if !isValidVolname(volume) {
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return errInvalidArgument
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}
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if !isValidPath(path) {
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return errInvalidArgument
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}
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// Delete all XL files.
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return xl.deleteXLFiles(volume, path)
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}
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// RenameFile - rename file.
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func (xl XL) RenameFile(srcVolume, srcPath, dstVolume, dstPath string) error {
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// Validate inputs.
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if !isValidVolname(srcVolume) {
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return errInvalidArgument
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}
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if !isValidPath(srcPath) {
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return errInvalidArgument
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}
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if !isValidVolname(dstVolume) {
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return errInvalidArgument
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}
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if !isValidPath(dstPath) {
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return errInvalidArgument
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}
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|
|
// Initialize sync waitgroup.
|
|
var wg = &sync.WaitGroup{}
|
|
|
|
// Initialize list of errors.
|
|
var errs = make([]error, len(xl.storageDisks))
|
|
|
|
// Rename file on all underlying storage disks.
|
|
for index, disk := range xl.storageDisks {
|
|
// Append "/" as srcPath and dstPath are either leaf-dirs or non-leaf-dris.
|
|
// If srcPath is an object instead of prefix we just rename the leaf-dir and
|
|
// not rename the part and metadata files separately.
|
|
wg.Add(1)
|
|
go func(index int, disk StorageAPI) {
|
|
defer wg.Done()
|
|
err := disk.RenameFile(srcVolume, retainSlash(srcPath), dstVolume, retainSlash(dstPath))
|
|
if err != nil {
|
|
errs[index] = err
|
|
}
|
|
errs[index] = nil
|
|
}(index, disk)
|
|
}
|
|
|
|
// Wait for all RenameFile to finish.
|
|
wg.Wait()
|
|
|
|
// Gather err count.
|
|
var errCount = 0
|
|
for _, err := range errs {
|
|
if err == nil {
|
|
continue
|
|
}
|
|
errCount++
|
|
}
|
|
// We can safely allow RenameFile errors up to len(xl.storageDisks) - xl.writeQuorum
|
|
// otherwise return failure. Cleanup successful renames.
|
|
if errCount > len(xl.storageDisks)-xl.writeQuorum {
|
|
// Special condition if readQuorum exists, then return success.
|
|
if errCount <= len(xl.storageDisks)-xl.readQuorum {
|
|
return nil
|
|
}
|
|
// Ignore errors here, delete all successfully written files.
|
|
xl.deleteXLFiles(dstVolume, dstPath)
|
|
return errWriteQuorum
|
|
}
|
|
return nil
|
|
}
|