xl: heal bucket should validate if bucket exists first. (#2953)

Fixes #2944

cmd/xl-v1-healing-common.go

@@ -0,0 +1,135 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 "time"
+
+// commonTime returns a maximally occurring time from a list of time.
+func commonTime(modTimes []time.Time) (modTime time.Time) {
+	var maxima int // Counter for remembering max occurrence of elements.
+	timeOccurenceMap := make(map[time.Time]int)
+	// Ignore the uuid sentinel and count the rest.
+	for _, time := range modTimes {
+		if time == timeSentinel {
+			continue
+		}
+		timeOccurenceMap[time]++
+	}
+	// Find the common cardinality from previously collected
+	// occurrences of elements.
+	for time, count := range timeOccurenceMap {
+		if count > maxima {
+			maxima = count
+			modTime = time
+		}
+	}
+	// Return the collected common uuid.
+	return modTime
+}
+
+// Beginning of unix time is treated as sentinel value here.
+var timeSentinel = time.Unix(0, 0).UTC()
+
+// Boot modTimes up to disk count, setting the value to time sentinel.
+func bootModtimes(diskCount int) []time.Time {
+	modTimes := make([]time.Time, diskCount)
+	// Boots up all the modtimes.
+	for i := range modTimes {
+		modTimes[i] = timeSentinel
+	}
+	return modTimes
+}
+
+// Extracts list of times from xlMetaV1 slice and returns, skips
+// slice elements which have errors. As a special error
+// errFileNotFound is treated as a initial good condition.
+func listObjectModtimes(partsMetadata []xlMetaV1, errs []error) (modTimes []time.Time) {
+	modTimes = bootModtimes(len(partsMetadata))
+	// Set a new time value, specifically set when
+	// error == errFileNotFound (this is needed when this is a
+	// fresh PutObject).
+	timeNow := time.Now().UTC()
+	for index, metadata := range partsMetadata {
+		if errs[index] == nil {
+			// Once the file is found, save the uuid saved on disk.
+			modTimes[index] = metadata.Stat.ModTime
+		} else if errs[index] == errFileNotFound {
+			// Once the file is not found then the epoch is current time.
+			modTimes[index] = timeNow
+		}
+	}
+	return modTimes
+}
+
+// Returns slice of online disks needed.
+// - slice returing readable disks.
+// - modTime of the Object
+func listOnlineDisks(disks []StorageAPI, partsMetadata []xlMetaV1, errs []error) (onlineDisks []StorageAPI, modTime time.Time) {
+	onlineDisks = make([]StorageAPI, len(disks))
+
+	// List all the file commit ids from parts metadata.
+	modTimes := listObjectModtimes(partsMetadata, errs)
+
+	// Reduce list of UUIDs to a single common value.
+	modTime = commonTime(modTimes)
+
+	// Create a new online disks slice, which have common uuid.
+	for index, t := range modTimes {
+		if t == modTime {
+			onlineDisks[index] = disks[index]
+		} else {
+			onlineDisks[index] = nil
+		}
+	}
+	return onlineDisks, modTime
+}
+
+// Return disks with the outdated or missing object.
+func outDatedDisks(disks []StorageAPI, partsMetadata []xlMetaV1, errs []error) (outDatedDisks []StorageAPI) {
+	outDatedDisks = make([]StorageAPI, len(disks))
+	latestDisks, _ := listOnlineDisks(disks, partsMetadata, errs)
+	for index, disk := range latestDisks {
+		if errorCause(errs[index]) == errFileNotFound {
+			outDatedDisks[index] = disks[index]
+			continue
+		}
+		if errs[index] != nil {
+			continue
+		}
+		if disk == nil {
+			outDatedDisks[index] = disks[index]
+		}
+	}
+	return outDatedDisks
+}
+
+// Returns if the object should be healed.
+func xlShouldHeal(partsMetadata []xlMetaV1, errs []error) bool {
+	modTime := commonTime(listObjectModtimes(partsMetadata, errs))
+	for index := range partsMetadata {
+		if errs[index] == errDiskNotFound {
+			continue
+		}
+		if errs[index] != nil {
+			return true
+		}
+		if modTime != partsMetadata[index].Stat.ModTime {
+			return true
+		}
+	}
+	return false
+}

cmd/xl-v1-healing.go

@@ -16,120 +16,211 @@
 
 package cmd
 
-import "time"
-
-// commonTime returns a maximally occurring time from a list of time.
-func commonTime(modTimes []time.Time) (modTime time.Time) {
-	var maxima int // Counter for remembering max occurrence of elements.
-	timeOccurenceMap := make(map[time.Time]int)
-	// Ignore the uuid sentinel and count the rest.
-	for _, time := range modTimes {
-		if time == timeSentinel {
+import "sync"
+
+// Heals a bucket if it doesn't exist on one of the disks.
+func (xl xlObjects) HealBucket(bucket string) error {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return traceError(BucketNameInvalid{Bucket: bucket})
+	}
+
+	// Verify if bucket exists.
+	if !xl.isBucketExist(bucket) {
+		return traceError(BucketNotFound{Bucket: bucket})
+	}
+
+	// Heal bucket - create buckets on disks where it does not exist.
+
+	// get a random ID for lock instrumentation.
+	opsID := getOpsID()
+
+	nsMutex.Lock(bucket, "", opsID)
+	defer nsMutex.Unlock(bucket, "", opsID)
+
+	// Initialize sync waitgroup.
+	var wg = &sync.WaitGroup{}
+
+	// Initialize list of errors.
+	var dErrs = make([]error, len(xl.storageDisks))
+
+	// Make a volume entry on all underlying storage disks.
+	for index, disk := range xl.storageDisks {
+		if disk == nil {
+			dErrs[index] = traceError(errDiskNotFound)
 			continue
 		}
-		timeOccurenceMap[time]++
+		wg.Add(1)
+		// Make a volume inside a go-routine.
+		go func(index int, disk StorageAPI) {
+			defer wg.Done()
+			if _, err := disk.StatVol(bucket); err != nil {
+				if err != errVolumeNotFound {
+					dErrs[index] = traceError(err)
+					return
 				}
-	// Find the common cardinality from previously collected
-	// occurrences of elements.
-	for time, count := range timeOccurenceMap {
-		if count > maxima {
-			maxima = count
-			modTime = time
+				if err = disk.MakeVol(bucket); err != nil {
+					dErrs[index] = traceError(err)
 				}
 			}
-	// Return the collected common uuid.
-	return modTime
-}
+		}(index, disk)
+	}
 
-// Beginning of unix time is treated as sentinel value here.
-var timeSentinel = time.Unix(0, 0).UTC()
+	// Wait for all make vol to finish.
+	wg.Wait()
 
-// Boot modTimes up to disk count, setting the value to time sentinel.
-func bootModtimes(diskCount int) []time.Time {
-	modTimes := make([]time.Time, diskCount)
-	// Boots up all the modtimes.
-	for i := range modTimes {
-		modTimes[i] = timeSentinel
+	// Do we have write quorum?.
+	if !isDiskQuorum(dErrs, xl.writeQuorum) {
+		// Purge successfully created buckets if we don't have writeQuorum.
+		xl.undoMakeBucket(bucket)
+		return toObjectErr(traceError(errXLWriteQuorum), bucket)
 	}
-	return modTimes
-}
 
-// Extracts list of times from xlMetaV1 slice and returns, skips
-// slice elements which have errors. As a special error
-// errFileNotFound is treated as a initial good condition.
-func listObjectModtimes(partsMetadata []xlMetaV1, errs []error) (modTimes []time.Time) {
-	modTimes = bootModtimes(len(partsMetadata))
-	// Set a new time value, specifically set when
-	// error == errFileNotFound (this is needed when this is a
-	// fresh PutObject).
-	timeNow := time.Now().UTC()
-	for index, metadata := range partsMetadata {
-		if errs[index] == nil {
-			// Once the file is found, save the uuid saved on disk.
-			modTimes[index] = metadata.Stat.ModTime
-		} else if errs[index] == errFileNotFound {
-			// Once the file is not found then the epoch is current time.
-			modTimes[index] = timeNow
-		}
-	}
-	return modTimes
+	// Verify we have any other errors which should be returned as failure.
+	if reducedErr := reduceErrs(dErrs, []error{
+		errDiskNotFound,
+		errFaultyDisk,
+		errDiskAccessDenied,
+	}); reducedErr != nil {
+		return toObjectErr(reducedErr, bucket)
+	}
+	return nil
 }
 
-// Returns slice of online disks needed.
-// - slice returing readable disks.
-// - modTime of the Object
-func listOnlineDisks(disks []StorageAPI, partsMetadata []xlMetaV1, errs []error) (onlineDisks []StorageAPI, modTime time.Time) {
-	onlineDisks = make([]StorageAPI, len(disks))
+// HealObject heals a given object for all its missing entries.
+// FIXME: If an object object was deleted and one disk was down, and later the disk comes back
+// up again, heal on the object should delete it.
+func (xl xlObjects) HealObject(bucket, object string) error {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return traceError(BucketNameInvalid{Bucket: bucket})
+	}
+
+	// Verify if object is valid.
+	if !IsValidObjectName(object) {
+		return traceError(ObjectNameInvalid{Bucket: bucket, Object: object})
+	}
 
-	// List all the file commit ids from parts metadata.
-	modTimes := listObjectModtimes(partsMetadata, errs)
+	// get a random ID for lock instrumentation.
+	opsID := getOpsID()
 
-	// Reduce list of UUIDs to a single common value.
-	modTime = commonTime(modTimes)
+	// Lock the object before healing.
+	nsMutex.RLock(bucket, object, opsID)
+	defer nsMutex.RUnlock(bucket, object, opsID)
 
-	// Create a new online disks slice, which have common uuid.
-	for index, t := range modTimes {
-		if t == modTime {
-			onlineDisks[index] = disks[index]
-		} else {
-			onlineDisks[index] = nil
+	partsMetadata, errs := readAllXLMetadata(xl.storageDisks, bucket, object)
+	if err := reduceErrs(errs, nil); err != nil {
+		return toObjectErr(err, bucket, object)
 	}
+
+	if !xlShouldHeal(partsMetadata, errs) {
+		// There is nothing to heal.
+		return nil
 	}
-	return onlineDisks, modTime
-}
 
-// Return disks with the outdated or missing object.
-func outDatedDisks(disks []StorageAPI, partsMetadata []xlMetaV1, errs []error) (outDatedDisks []StorageAPI) {
-	outDatedDisks = make([]StorageAPI, len(disks))
-	latestDisks, _ := listOnlineDisks(disks, partsMetadata, errs)
-	for index, disk := range latestDisks {
-		if errorCause(errs[index]) == errFileNotFound {
-			outDatedDisks[index] = disks[index]
+	// List of disks having latest version of the object.
+	latestDisks, modTime := listOnlineDisks(xl.storageDisks, partsMetadata, errs)
+	// List of disks having outdated version of the object or missing object.
+	outDatedDisks := outDatedDisks(xl.storageDisks, partsMetadata, errs)
+	// Latest xlMetaV1 for reference.
+	latestMeta := pickValidXLMeta(partsMetadata, modTime)
+
+	for index, disk := range outDatedDisks {
+		// Before healing outdated disks, we need to remove xl.json
+		// and part files from "bucket/object/" so that
+		// rename(".minio.sys", "tmp/tmpuuid/", "bucket", "object/") succeeds.
+		if disk == nil {
+			// Not an outdated disk.
 			continue
 		}
 		if errs[index] != nil {
+			// If there was an error (most likely errFileNotFound)
+			continue
+		}
+		// Outdated object with the same name exists that needs to be deleted.
+		outDatedMeta := partsMetadata[index]
+		// Delete all the parts.
+		for partIndex := 0; partIndex < len(outDatedMeta.Parts); partIndex++ {
+			err := disk.DeleteFile(bucket, pathJoin(object, outDatedMeta.Parts[partIndex].Name))
+			if err != nil {
+				return traceError(err)
+			}
+		}
+		// Delete xl.json file.
+		err := disk.DeleteFile(bucket, pathJoin(object, xlMetaJSONFile))
+		if err != nil {
+			return traceError(err)
+		}
+	}
+
+	// Reorder so that we have data disks first and parity disks next.
+	latestDisks = getOrderedDisks(latestMeta.Erasure.Distribution, latestDisks)
+	outDatedDisks = getOrderedDisks(latestMeta.Erasure.Distribution, outDatedDisks)
+	partsMetadata = getOrderedPartsMetadata(latestMeta.Erasure.Distribution, partsMetadata)
+
+	// We write at temporary location and then rename to fianal location.
+	tmpID := getUUID()
+
+	// Checksum of the part files. checkSumInfos[index] will contain checksums
+	// of all the part files in the outDatedDisks[index]
+	checkSumInfos := make([][]checkSumInfo, len(outDatedDisks))
+
+	// Heal each part. erasureHealFile() will write the healed part to
+	// .minio/tmp/uuid/ which needs to be renamed later to the final location.
+	for partIndex := 0; partIndex < len(latestMeta.Parts); partIndex++ {
+		partName := latestMeta.Parts[partIndex].Name
+		partSize := latestMeta.Parts[partIndex].Size
+		erasure := latestMeta.Erasure
+		sumInfo, err := latestMeta.Erasure.GetCheckSumInfo(partName)
+		if err != nil {
+			return err
+		}
+		// Heal the part file.
+		checkSums, err := erasureHealFile(latestDisks, outDatedDisks,
+			bucket, pathJoin(object, partName),
+			minioMetaBucket, pathJoin(tmpMetaPrefix, tmpID, partName),
+			partSize, erasure.BlockSize, erasure.DataBlocks, erasure.ParityBlocks, sumInfo.Algorithm)
+		if err != nil {
+			return err
+		}
+		for index, sum := range checkSums {
+			if outDatedDisks[index] == nil {
 				continue
 			}
+			checkSumInfos[index] = append(checkSumInfos[index], checkSumInfo{partName, sumInfo.Algorithm, sum})
+		}
+	}
+
+	// xl.json should be written to all the healed disks.
+	for index, disk := range outDatedDisks {
 		if disk == nil {
-			outDatedDisks[index] = disks[index]
+			continue
 		}
+		partsMetadata[index] = latestMeta
+		partsMetadata[index].Erasure.Checksum = checkSumInfos[index]
+	}
+
+	// Generate and write `xl.json` generated from other disks.
+	err := writeUniqueXLMetadata(outDatedDisks, minioMetaBucket, pathJoin(tmpMetaPrefix, tmpID), partsMetadata, diskCount(outDatedDisks))
+	if err != nil {
+		return toObjectErr(err, bucket, object)
 	}
-	return outDatedDisks
-}
 
-// Returns if the object should be healed.
-func xlShouldHeal(partsMetadata []xlMetaV1, errs []error) bool {
-	modTime := commonTime(listObjectModtimes(partsMetadata, errs))
-	for index := range partsMetadata {
-		if errs[index] == errDiskNotFound {
+	// Rename from tmp location to the actual location.
+	for _, disk := range outDatedDisks {
+		if disk == nil {
 			continue
 		}
-		if errs[index] != nil {
-			return true
+		// Remove any lingering partial data from current namespace.
+		err = disk.DeleteFile(bucket, retainSlash(object))
+		if err != nil && err != errFileNotFound {
+			return traceError(err)
 		}
-		if modTime != partsMetadata[index].Stat.ModTime {
-			return true
+		// Attempt a rename now from healed data to final location.
+		err = disk.RenameFile(minioMetaBucket, retainSlash(pathJoin(tmpMetaPrefix, tmpID)), bucket, retainSlash(object))
+		if err != nil {
+			return traceError(err)
 		}
 	}
-	return false
+	return nil
 }

cmd/xl-v1-object.go

@@ -218,207 +218,6 @@ func (xl xlObjects) GetObject(bucket, object string, startOffset int64, length i
 	return nil
 }
 
-func (xl xlObjects) HealBucket(bucket string) error {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return traceError(BucketNameInvalid{Bucket: bucket})
-	}
-
-	// Heal bucket - create buckets on disks where it does not exist.
-
-	// get a random ID for lock instrumentation.
-	opsID := getOpsID()
-
-	nsMutex.Lock(bucket, "", opsID)
-	defer nsMutex.Unlock(bucket, "", opsID)
-
-	// Initialize sync waitgroup.
-	var wg = &sync.WaitGroup{}
-
-	// Initialize list of errors.
-	var dErrs = make([]error, len(xl.storageDisks))
-
-	// Make a volume entry on all underlying storage disks.
-	for index, disk := range xl.storageDisks {
-		if disk == nil {
-			dErrs[index] = traceError(errDiskNotFound)
-			continue
-		}
-		wg.Add(1)
-		// Make a volume inside a go-routine.
-		go func(index int, disk StorageAPI) {
-			defer wg.Done()
-			if _, err := disk.StatVol(bucket); err != nil {
-				if err != errVolumeNotFound {
-					dErrs[index] = traceError(err)
-					return
-				}
-				if err = disk.MakeVol(bucket); err != nil {
-					dErrs[index] = traceError(err)
-				}
-			}
-		}(index, disk)
-	}
-
-	// Wait for all make vol to finish.
-	wg.Wait()
-
-	// Do we have write quorum?.
-	if !isDiskQuorum(dErrs, xl.writeQuorum) {
-		// Purge successfully created buckets if we don't have writeQuorum.
-		xl.undoMakeBucket(bucket)
-		return toObjectErr(traceError(errXLWriteQuorum), bucket)
-	}
-
-	// Verify we have any other errors which should be returned as failure.
-	if reducedErr := reduceErrs(dErrs, []error{
-		errDiskNotFound,
-		errFaultyDisk,
-		errDiskAccessDenied,
-	}); reducedErr != nil {
-		return toObjectErr(reducedErr, bucket)
-	}
-	return nil
-}
-
-// HealObject heals a given object for all its missing entries.
-// FIXME: If an object object was deleted and one disk was down, and later the disk comes back
-// up again, heal on the object should delete it.
-func (xl xlObjects) HealObject(bucket, object string) error {
-	// Verify if bucket is valid.
-	if !IsValidBucketName(bucket) {
-		return traceError(BucketNameInvalid{Bucket: bucket})
-	}
-
-	// Verify if object is valid.
-	if !IsValidObjectName(object) {
-		return traceError(ObjectNameInvalid{Bucket: bucket, Object: object})
-	}
-
-	// get a random ID for lock instrumentation.
-	opsID := getOpsID()
-
-	// Lock the object before healing.
-	nsMutex.RLock(bucket, object, opsID)
-	defer nsMutex.RUnlock(bucket, object, opsID)
-
-	partsMetadata, errs := readAllXLMetadata(xl.storageDisks, bucket, object)
-	if err := reduceErrs(errs, nil); err != nil {
-		return toObjectErr(err, bucket, object)
-	}
-
-	if !xlShouldHeal(partsMetadata, errs) {
-		// There is nothing to heal.
-		return nil
-	}
-
-	// List of disks having latest version of the object.
-	latestDisks, modTime := listOnlineDisks(xl.storageDisks, partsMetadata, errs)
-	// List of disks having outdated version of the object or missing object.
-	outDatedDisks := outDatedDisks(xl.storageDisks, partsMetadata, errs)
-	// Latest xlMetaV1 for reference.
-	latestMeta := pickValidXLMeta(partsMetadata, modTime)
-
-	for index, disk := range outDatedDisks {
-		// Before healing outdated disks, we need to remove xl.json
-		// and part files from "bucket/object/" so that
-		// rename(".minio.sys", "tmp/tmpuuid/", "bucket", "object/") succeeds.
-		if disk == nil {
-			// Not an outdated disk.
-			continue
-		}
-		if errs[index] != nil {
-			// If there was an error (most likely errFileNotFound)
-			continue
-		}
-		// Outdated object with the same name exists that needs to be deleted.
-		outDatedMeta := partsMetadata[index]
-		// Delete all the parts.
-		for partIndex := 0; partIndex < len(outDatedMeta.Parts); partIndex++ {
-			err := disk.DeleteFile(bucket, pathJoin(object, outDatedMeta.Parts[partIndex].Name))
-			if err != nil {
-				return traceError(err)
-			}
-		}
-		// Delete xl.json file.
-		err := disk.DeleteFile(bucket, pathJoin(object, xlMetaJSONFile))
-		if err != nil {
-			return traceError(err)
-		}
-	}
-
-	// Reorder so that we have data disks first and parity disks next.
-	latestDisks = getOrderedDisks(latestMeta.Erasure.Distribution, latestDisks)
-	outDatedDisks = getOrderedDisks(latestMeta.Erasure.Distribution, outDatedDisks)
-	partsMetadata = getOrderedPartsMetadata(latestMeta.Erasure.Distribution, partsMetadata)
-
-	// We write at temporary location and then rename to fianal location.
-	tmpID := getUUID()
-
-	// Checksum of the part files. checkSumInfos[index] will contain checksums
-	// of all the part files in the outDatedDisks[index]
-	checkSumInfos := make([][]checkSumInfo, len(outDatedDisks))
-
-	// Heal each part. erasureHealFile() will write the healed part to
-	// .minio/tmp/uuid/ which needs to be renamed later to the final location.
-	for partIndex := 0; partIndex < len(latestMeta.Parts); partIndex++ {
-		partName := latestMeta.Parts[partIndex].Name
-		partSize := latestMeta.Parts[partIndex].Size
-		erasure := latestMeta.Erasure
-		sumInfo, err := latestMeta.Erasure.GetCheckSumInfo(partName)
-		if err != nil {
-			return err
-		}
-		// Heal the part file.
-		checkSums, err := erasureHealFile(latestDisks, outDatedDisks,
-			bucket, pathJoin(object, partName),
-			minioMetaBucket, pathJoin(tmpMetaPrefix, tmpID, partName),
-			partSize, erasure.BlockSize, erasure.DataBlocks, erasure.ParityBlocks, sumInfo.Algorithm)
-		if err != nil {
-			return err
-		}
-		for index, sum := range checkSums {
-			if outDatedDisks[index] == nil {
-				continue
-			}
-			checkSumInfos[index] = append(checkSumInfos[index], checkSumInfo{partName, sumInfo.Algorithm, sum})
-		}
-	}
-
-	// xl.json should be written to all the healed disks.
-	for index, disk := range outDatedDisks {
-		if disk == nil {
-			continue
-		}
-		partsMetadata[index] = latestMeta
-		partsMetadata[index].Erasure.Checksum = checkSumInfos[index]
-	}
-
-	// Generate and write `xl.json` generated from other disks.
-	err := writeUniqueXLMetadata(outDatedDisks, minioMetaBucket, pathJoin(tmpMetaPrefix, tmpID), partsMetadata, diskCount(outDatedDisks))
-	if err != nil {
-		return toObjectErr(err, bucket, object)
-	}
-
-	// Rename from tmp location to the actual location.
-	for _, disk := range outDatedDisks {
-		if disk == nil {
-			continue
-		}
-		// Remove any lingering partial data from current namespace.
-		err = disk.DeleteFile(bucket, retainSlash(object))
-		if err != nil && err != errFileNotFound {
-			return traceError(err)
-		}
-		// Attempt a rename now from healed data to final location.
-		err = disk.RenameFile(minioMetaBucket, retainSlash(pathJoin(tmpMetaPrefix, tmpID)), bucket, retainSlash(object))
-		if err != nil {
-			return traceError(err)
-		}
-	}
-	return nil
-}
-
 // GetObjectInfo - reads object metadata and replies back ObjectInfo.
 func (xl xlObjects) GetObjectInfo(bucket, object string) (ObjectInfo, error) {
 	// Verify if bucket is valid.