seaweedfs/weed/server/filer_grpc_server.go

package weed_server

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"time"

	"github.com/seaweedfs/seaweedfs/weed/cluster"
	"github.com/seaweedfs/seaweedfs/weed/filer"
	"github.com/seaweedfs/seaweedfs/weed/glog"
	"github.com/seaweedfs/seaweedfs/weed/operation"
	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
	"github.com/seaweedfs/seaweedfs/weed/pb/master_pb"
	"github.com/seaweedfs/seaweedfs/weed/storage/needle"
	"github.com/seaweedfs/seaweedfs/weed/util"
	"github.com/seaweedfs/seaweedfs/weed/wdclient"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

func (fs *FilerServer) LookupDirectoryEntry(ctx context.Context, req *filer_pb.LookupDirectoryEntryRequest) (*filer_pb.LookupDirectoryEntryResponse, error) {

	glog.V(4).InfofCtx(ctx, "LookupDirectoryEntry %s", filepath.Join(req.Directory, req.Name))

	entry, err := fs.filer.FindEntry(ctx, util.JoinPath(req.Directory, req.Name))
	if err == filer_pb.ErrNotFound {
		return &filer_pb.LookupDirectoryEntryResponse{}, err
	}
	if err != nil {
		glog.V(3).InfofCtx(ctx, "LookupDirectoryEntry %s: %+v, ", filepath.Join(req.Directory, req.Name), err)
		return nil, err
	}

	return &filer_pb.LookupDirectoryEntryResponse{
		Entry: entry.ToProtoEntry(),
	}, nil
}

func (fs *FilerServer) ListEntries(req *filer_pb.ListEntriesRequest, stream filer_pb.SeaweedFiler_ListEntriesServer) (err error) {

	glog.V(4).Infof("ListEntries %v", req)

	limit := int(req.Limit)
	if limit == 0 {
		limit = fs.option.DirListingLimit
	}

	paginationLimit := filer.PaginationSize
	if limit < paginationLimit {
		paginationLimit = limit
	}

	lastFileName := req.StartFromFileName
	includeLastFile := req.InclusiveStartFrom
	snapshotTsNs := req.SnapshotTsNs
	if snapshotTsNs == 0 {
		snapshotTsNs = time.Now().UnixNano()
	}
	sentSnapshot := false
	var listErr error
	for limit > 0 {
		var hasEntries bool
		lastFileName, listErr = fs.filer.StreamListDirectoryEntries(stream.Context(), util.FullPath(req.Directory), lastFileName, includeLastFile, int64(paginationLimit), req.Prefix, "", "", func(entry *filer.Entry) (bool, error) {
			hasEntries = true
			resp := &filer_pb.ListEntriesResponse{
				Entry: entry.ToProtoEntry(),
			}
			if !sentSnapshot {
				resp.SnapshotTsNs = snapshotTsNs
				sentSnapshot = true
			}
			if err = stream.Send(resp); err != nil {
				return false, err
			}

			limit--
			if limit == 0 {
				return false, nil
			}
			return true, nil
		})

		if listErr != nil {
			return listErr
		}
		if err != nil {
			return err
		}
		if !hasEntries {
			break
		}

		includeLastFile = false

	}

	// For empty directories we intentionally do NOT send a snapshot-only
	// response (Entry == nil). Many consumers (Java FilerClient, S3 listing,
	// etc.) treat any received response as an entry. The Go client-side
	// DoSeaweedListWithSnapshot generates a client-side cutoff when the
	// server sends no snapshot, so snapshot consistency is preserved
	// without a server-side send.

	return nil
}

func (fs *FilerServer) LookupVolume(ctx context.Context, req *filer_pb.LookupVolumeRequest) (*filer_pb.LookupVolumeResponse, error) {

	resp := &filer_pb.LookupVolumeResponse{
		LocationsMap: make(map[string]*filer_pb.Locations),
	}

	// Use master client's lookup with fallback - it handles cache and master query
	vidLocations, err := fs.filer.MasterClient.LookupVolumeIdsWithFallback(ctx, req.VolumeIds)

	// Convert wdclient.Location to filer_pb.Location
	// Return partial results even if there was an error
	for vidString, locations := range vidLocations {
		resp.LocationsMap[vidString] = &filer_pb.Locations{
			Locations: wdclientLocationsToPb(locations),
		}
	}

	return resp, err
}

func wdclientLocationsToPb(locations []wdclient.Location) []*filer_pb.Location {
	locs := make([]*filer_pb.Location, 0, len(locations))
	for _, loc := range locations {
		locs = append(locs, &filer_pb.Location{
			Url:        loc.Url,
			PublicUrl:  loc.PublicUrl,
			GrpcPort:   uint32(loc.GrpcPort),
			DataCenter: loc.DataCenter,
		})
	}
	return locs
}

func (fs *FilerServer) lookupFileId(ctx context.Context, fileId string) (targetUrls []string, err error) {
	fid, err := needle.ParseFileIdFromString(fileId)
	if err != nil {
		return nil, err
	}
	locations, found := fs.filer.MasterClient.GetLocations(uint32(fid.VolumeId))
	if !found || len(locations) == 0 {
		return nil, fmt.Errorf("not found volume %d in %s", fid.VolumeId, fileId)
	}
	for _, loc := range locations {
		targetUrls = append(targetUrls, fmt.Sprintf("http://%s/%s", loc.Url, fileId))
	}
	return
}

func (fs *FilerServer) CreateEntry(ctx context.Context, req *filer_pb.CreateEntryRequest) (resp *filer_pb.CreateEntryResponse, err error) {

	glog.V(4).InfofCtx(ctx, "CreateEntry %v/%v", req.Directory, req.Entry.Name)
	if len(req.Entry.HardLinkId) > 0 {
		glog.V(4).InfofCtx(ctx, "CreateEntry %s/%s with HardLinkId %x counter=%d", req.Directory, req.Entry.Name, req.Entry.HardLinkId, req.Entry.HardLinkCounter)
	}

	resp = &filer_pb.CreateEntryResponse{}

	chunks, garbage, err2 := fs.cleanupChunks(ctx, util.Join(req.Directory, req.Entry.Name), nil, req.Entry)
	if err2 != nil {
		return &filer_pb.CreateEntryResponse{}, fmt.Errorf("CreateEntry cleanupChunks %s %s: %v", req.Directory, req.Entry.Name, err2)
	}

	so, err := fs.detectStorageOption(ctx, string(util.NewFullPath(req.Directory, req.Entry.Name)), "", "", 0, "", "", "", "")
	if err != nil {
		return nil, err
	}
	newEntry := filer.FromPbEntry(req.Directory, req.Entry)
	newEntry.Chunks = chunks
	// Don't apply TTL to remote entries - they're managed by remote storage
	if newEntry.Remote == nil {
		if newEntry.TtlSec == 0 {
			newEntry.TtlSec = so.TtlSeconds
		}
	} else {
		newEntry.TtlSec = 0
	}

	// Serialize concurrent mutations to the same path on this filer so the
	// read (existence/condition) and the write are atomic. Callers route a
	// key's writes to this owner filer, making this local lock sufficient.
	fullpath := newEntry.FullPath
	pathLock := fs.entryLockTable.AcquireLock("CreateEntry", fullpath, util.ExclusiveLock)
	defer fs.entryLockTable.ReleaseLock(fullpath, pathLock)

	// Evaluate the optional precondition against the current entry while the
	// path lock is held, so the check and the write are atomic on this filer.
	if conditionIsSet(req.Condition) {
		current, findErr := fs.filer.FindEntry(ctx, fullpath)
		if findErr != nil && findErr != filer_pb.ErrNotFound {
			return &filer_pb.CreateEntryResponse{}, fmt.Errorf("CreateEntry condition check %s: %w", fullpath, findErr)
		}
		if findErr == filer_pb.ErrNotFound {
			current = nil
		}
		if !writeConditionSatisfied(req.Condition, current) {
			glog.V(3).InfofCtx(ctx, "CreateEntry %s: precondition failed: %v", fullpath, req.Condition)
			return &filer_pb.CreateEntryResponse{
				Error:     "precondition failed",
				ErrorCode: filer_pb.FilerError_PRECONDITION_FAILED,
			}, nil
		}
	}

	ctx, eventSink := filer.WithMetadataEventSink(ctx)
	createErr := fs.filer.CreateEntry(ctx, newEntry, req.OExcl, req.IsFromOtherCluster, req.Signatures, req.SkipCheckParentDirectory, so.MaxFileNameLength)

	if createErr == nil {
		fs.filer.DeleteChunksNotRecursive(garbage)
		resp.MetadataEvent = eventSink.Last()
	} else {
		glog.V(3).InfofCtx(ctx, "CreateEntry %s: %v", filepath.Join(req.Directory, req.Entry.Name), createErr)
		resp.Error = createErr.Error()
		switch {
		case errors.Is(createErr, filer_pb.ErrEntryNameTooLong):
			resp.ErrorCode = filer_pb.FilerError_ENTRY_NAME_TOO_LONG
		case errors.Is(createErr, filer_pb.ErrParentIsFile):
			resp.ErrorCode = filer_pb.FilerError_PARENT_IS_FILE
		case errors.Is(createErr, filer_pb.ErrExistingIsDirectory):
			resp.ErrorCode = filer_pb.FilerError_EXISTING_IS_DIRECTORY
		case errors.Is(createErr, filer_pb.ErrExistingIsFile):
			resp.ErrorCode = filer_pb.FilerError_EXISTING_IS_FILE
		case errors.Is(createErr, filer_pb.ErrEntryAlreadyExists):
			resp.ErrorCode = filer_pb.FilerError_ENTRY_ALREADY_EXISTS
		}
	}

	return
}

// ObjectTransaction applies an ordered list of entry mutations atomically with
// respect to other writers of the same object, by holding the per-path lock on
// lock_key for the whole call. The optional condition is checked first, against
// the entry at lock_key. This lets a caller describe a multi-entry object
// operation (e.g. delete the null version + write a delete marker + flip the
// latest pointer) as one request, replacing a distributed lock held across
// several RPCs. Callers must route the object's writes to its owner filer for
// the lock to be authoritative.
func (fs *FilerServer) ObjectTransaction(ctx context.Context, req *filer_pb.ObjectTransactionRequest) (*filer_pb.ObjectTransactionResponse, error) {
	if req.LockKey == "" {
		return &filer_pb.ObjectTransactionResponse{Error: "lock_key is required"}, nil
	}

	lockPath := util.FullPath(req.LockKey)
	pathLock := fs.entryLockTable.AcquireLock("ObjectTransaction", lockPath, util.ExclusiveLock)
	defer fs.entryLockTable.ReleaseLock(lockPath, pathLock)

	if conditionIsSet(req.Condition) {
		current, findErr := fs.filer.FindEntry(ctx, lockPath)
		if findErr != nil && findErr != filer_pb.ErrNotFound {
			return &filer_pb.ObjectTransactionResponse{}, fmt.Errorf("ObjectTransaction condition %s: %w", lockPath, findErr)
		}
		if findErr == filer_pb.ErrNotFound {
			current = nil
		}
		if !writeConditionSatisfied(req.Condition, current) {
			glog.V(3).InfofCtx(ctx, "ObjectTransaction %s: precondition failed", lockPath)
			return &filer_pb.ObjectTransactionResponse{
				Error:     "precondition failed",
				ErrorCode: filer_pb.FilerError_PRECONDITION_FAILED,
			}, nil
		}
	}

	for i, m := range req.Mutations {
		if err := fs.applyObjectMutation(ctx, m, req.IsFromOtherCluster, req.Signatures); err != nil {
			glog.V(2).InfofCtx(ctx, "ObjectTransaction %s mutation %d (%v): %v", lockPath, i, m.Type, err)
			return &filer_pb.ObjectTransactionResponse{Error: fmt.Sprintf("mutation %d: %v", i, err)}, nil
		}
	}

	return &filer_pb.ObjectTransactionResponse{}, nil
}

// applyObjectMutation applies a single mutation while the transaction's path
// lock is held. PUT entries are expected to be fully prepared by the caller
// (chunks resolved); mutations here are metadata-scoped. A DELETE of an absent
// entry and a PATCH of an absent entry are no-ops, so transactions are
// idempotent on replay.
func (fs *FilerServer) applyObjectMutation(ctx context.Context, m *filer_pb.ObjectMutation, fromOtherCluster bool, signatures []int32) error {
	switch m.Type {
	case filer_pb.ObjectMutation_PUT:
		if m.Entry == nil {
			return fmt.Errorf("PUT requires an entry")
		}
		newEntry := filer.FromPbEntry(m.Directory, m.Entry)
		return fs.filer.CreateEntry(ctx, newEntry, false, fromOtherCluster, signatures, false, fs.filer.MaxFilenameLength)

	case filer_pb.ObjectMutation_DELETE:
		fullpath := util.NewFullPath(m.Directory, m.Name)
		err := fs.filer.DeleteEntryMetaAndData(ctx, fullpath, m.IsRecursive, false, m.IsDeleteData, fromOtherCluster, signatures, 0)
		if err == filer_pb.ErrNotFound {
			return nil
		}
		return err

	case filer_pb.ObjectMutation_PATCH_EXTENDED:
		fullpath := util.NewFullPath(m.Directory, m.Name)
		oldEntry, err := fs.filer.FindEntry(ctx, fullpath)
		if err == filer_pb.ErrNotFound {
			return nil
		}
		if err != nil {
			return err
		}
		// Patch a copy so oldEntry still reflects the pre-update state for the
		// metadata notification's diff.
		newEntry := oldEntry.ShallowClone()
		newEntry.Extended = make(map[string][]byte, len(oldEntry.Extended))
		for k, v := range oldEntry.Extended {
			newEntry.Extended[k] = v
		}
		for k, v := range m.SetExtended {
			newEntry.Extended[k] = v
		}
		for _, k := range m.DeleteExtended {
			delete(newEntry.Extended, k)
		}
		if err := fs.filer.UpdateEntry(ctx, oldEntry, newEntry); err != nil {
			return err
		}
		// Emit the metadata event so the update replicates and subscribers see it,
		// matching the UpdateEntry handler.
		fs.filer.NotifyUpdateEvent(ctx, oldEntry, newEntry, true, fromOtherCluster, signatures)
		return nil

	default:
		return fmt.Errorf("unknown mutation type %v", m.Type)
	}
}

func (fs *FilerServer) UpdateEntry(ctx context.Context, req *filer_pb.UpdateEntryRequest) (*filer_pb.UpdateEntryResponse, error) {

	glog.V(4).InfofCtx(ctx, "UpdateEntry %v", req)
	if len(req.Entry.HardLinkId) > 0 {
		glog.V(4).InfofCtx(ctx, "UpdateEntry %s/%s with HardLinkId %x counter=%d", req.Directory, req.Entry.Name, req.Entry.HardLinkId, req.Entry.HardLinkCounter)
	}

	fullpath := util.Join(req.Directory, req.Entry.Name)
	entry, err := fs.filer.FindEntry(ctx, util.FullPath(fullpath))
	if err != nil {
		return &filer_pb.UpdateEntryResponse{}, fmt.Errorf("not found %s: %v", fullpath, err)
	}
	if err := validateUpdateEntryPreconditions(entry, req.ExpectedExtended); err != nil {
		return &filer_pb.UpdateEntryResponse{}, err
	}

	chunks, garbage, err2 := fs.cleanupChunks(ctx, fullpath, entry, req.Entry)
	if err2 != nil {
		return &filer_pb.UpdateEntryResponse{}, fmt.Errorf("UpdateEntry cleanupChunks %s: %v", fullpath, err2)
	}

	newEntry := filer.FromPbEntry(req.Directory, req.Entry)
	newEntry.Chunks = chunks

	// Don't apply TTL to remote entries - they're managed by remote storage
	if newEntry.Remote != nil {
		newEntry.TtlSec = 0
	}

	if filer.EqualEntry(entry, newEntry) {
		return &filer_pb.UpdateEntryResponse{}, err
	}

	ctx, eventSink := filer.WithMetadataEventSink(ctx)
	resp := &filer_pb.UpdateEntryResponse{}
	if err = fs.filer.UpdateEntry(ctx, entry, newEntry); err == nil {
		fs.filer.DeleteChunksNotRecursive(garbage)

		fs.filer.NotifyUpdateEvent(ctx, entry, newEntry, true, req.IsFromOtherCluster, req.Signatures)
		resp.MetadataEvent = eventSink.Last()

	} else {
		glog.V(3).InfofCtx(ctx, "UpdateEntry %s: %v", filepath.Join(req.Directory, req.Entry.Name), err)
	}

	return resp, err
}

func validateUpdateEntryPreconditions(entry *filer.Entry, expectedExtended map[string][]byte) error {
	if len(expectedExtended) == 0 {
		return nil
	}

	for key, expectedValue := range expectedExtended {
		var actualValue []byte
		var ok bool
		if entry != nil {
			actualValue, ok = entry.Extended[key]
		}
		if ok {
			if !bytes.Equal(actualValue, expectedValue) {
				return status.Errorf(codes.FailedPrecondition, "extended attribute %q changed", key)
			}
			continue
		}
		if len(expectedValue) > 0 {
			return status.Errorf(codes.FailedPrecondition, "extended attribute %q changed", key)
		}
	}

	return nil
}

func (fs *FilerServer) cleanupChunks(ctx context.Context, fullpath string, existingEntry *filer.Entry, newEntry *filer_pb.Entry) (chunks, garbage []*filer_pb.FileChunk, err error) {

	// remove old chunks if not included in the new ones
	if existingEntry != nil {
		garbage, err = filer.MinusChunks(ctx, fs.lookupFileId, existingEntry.GetChunks(), newEntry.GetChunks())
		if err != nil {
			return newEntry.GetChunks(), nil, fmt.Errorf("MinusChunks: %w", err)
		}
	}

	// files with manifest chunks are usually large and append only, skip calculating covered chunks
	manifestChunks, nonManifestChunks := filer.SeparateManifestChunks(newEntry.GetChunks())

	chunks, coveredChunks := filer.CompactFileChunks(ctx, fs.lookupFileId, nonManifestChunks)
	garbage = append(garbage, coveredChunks...)

	if newEntry.Attributes != nil {
		so, _ := fs.detectStorageOption(ctx, fullpath,
			"",
			"",
			newEntry.Attributes.TtlSec,
			"",
			"",
			"",
			"",
		) // ignore readonly error for capacity needed to manifestize
		chunks, err = filer.MaybeManifestize(fs.saveAsChunk(ctx, so), chunks)
		if err != nil {
			// not good, but should be ok
			glog.V(0).InfofCtx(ctx, "MaybeManifestize: %v", err)
		}
	}

	chunks = append(manifestChunks, chunks...)

	return
}

func (fs *FilerServer) AppendToEntry(ctx context.Context, req *filer_pb.AppendToEntryRequest) (*filer_pb.AppendToEntryResponse, error) {

	glog.V(4).InfofCtx(ctx, "AppendToEntry %v", req)
	fullpath := util.NewFullPath(req.Directory, req.EntryName)

	lockClient := cluster.NewLockClient(fs.grpcDialOption, fs.option.Host)
	lock := lockClient.NewShortLivedLock(string(fullpath), string(fs.option.Host))
	defer lock.StopShortLivedLock()

	var offset int64 = 0
	entry, err := fs.filer.FindEntry(ctx, fullpath)
	if err == filer_pb.ErrNotFound {
		entry = &filer.Entry{
			FullPath: fullpath,
			Attr: filer.Attr{
				Crtime: time.Now(),
				Mtime:  time.Now(),
				Mode:   os.FileMode(0644),
				Uid:    OS_UID,
				Gid:    OS_GID,
			},
		}
	} else {
		offset = int64(filer.TotalSize(entry.GetChunks()))
	}

	for _, chunk := range req.Chunks {
		chunk.Offset = offset
		offset += int64(chunk.Size)
	}

	entry.Chunks = append(entry.GetChunks(), req.Chunks...)
	so, err := fs.detectStorageOption(ctx, string(fullpath), "", "", entry.TtlSec, "", "", "", "")
	if err != nil {
		glog.WarningfCtx(ctx, "detectStorageOption: %v", err)
		return &filer_pb.AppendToEntryResponse{}, err
	}
	entry.Chunks, err = filer.MaybeManifestize(fs.saveAsChunk(ctx, so), entry.GetChunks())
	if err != nil {
		// not good, but should be ok
		glog.V(0).InfofCtx(ctx, "MaybeManifestize: %v", err)
	}

	err = fs.filer.CreateEntry(context.Background(), entry, false, false, nil, false, fs.filer.MaxFilenameLength)

	return &filer_pb.AppendToEntryResponse{}, err
}

func (fs *FilerServer) DeleteEntry(ctx context.Context, req *filer_pb.DeleteEntryRequest) (resp *filer_pb.DeleteEntryResponse, err error) {

	glog.V(4).InfofCtx(ctx, "DeleteEntry %v", req)

	ctx, eventSink := filer.WithMetadataEventSink(ctx)
	err = fs.filer.DeleteEntryMetaAndData(ctx, util.JoinPath(req.Directory, req.Name), req.IsRecursive, req.IgnoreRecursiveError, req.IsDeleteData, req.IsFromOtherCluster, req.Signatures, req.IfNotModifiedAfter)
	resp = &filer_pb.DeleteEntryResponse{}
	if err != nil && err != filer_pb.ErrNotFound {
		resp.Error = err.Error()
	} else {
		resp.MetadataEvent = eventSink.Last()
	}
	return resp, nil
}

func (fs *FilerServer) AssignVolume(ctx context.Context, req *filer_pb.AssignVolumeRequest) (resp *filer_pb.AssignVolumeResponse, err error) {

	so, err := fs.resolveAssignStorageOption(ctx, req)
	if err != nil {
		glog.V(3).InfofCtx(ctx, "AssignVolume: %v", err)
		return &filer_pb.AssignVolumeResponse{Error: fmt.Sprintf("assign volume: %v", err)}, nil
	}

	assignRequest, altRequest := so.ToAssignRequests(int(req.Count))
	assignRequest.ExpectedDataSize = req.ExpectedDataSize
	if altRequest != nil {
		altRequest.ExpectedDataSize = req.ExpectedDataSize
	}

	assignResult, err := operation.Assign(ctx, fs.filer.GetMaster, fs.grpcDialOption, assignRequest, altRequest)
	if err != nil {
		glog.V(3).InfofCtx(ctx, "AssignVolume: %v", err)
		return &filer_pb.AssignVolumeResponse{Error: fmt.Sprintf("assign volume: %v", err)}, nil
	}
	if assignResult.Error != "" {
		glog.V(3).InfofCtx(ctx, "AssignVolume error: %v", assignResult.Error)
		return &filer_pb.AssignVolumeResponse{Error: fmt.Sprintf("assign volume result: %v", assignResult.Error)}, nil
	}

	return &filer_pb.AssignVolumeResponse{
		FileId: assignResult.Fid,
		Count:  int32(assignResult.Count),
		Location: &filer_pb.Location{
			Url:       assignResult.Url,
			PublicUrl: assignResult.PublicUrl,
			GrpcPort:  uint32(assignResult.GrpcPort),
		},
		Auth:        string(assignResult.Auth),
		Collection:  so.Collection,
		Replication: so.Replication,
	}, nil
}

func (fs *FilerServer) resolveAssignStorageOption(ctx context.Context, req *filer_pb.AssignVolumeRequest) (*operation.StorageOption, error) {
	so, err := fs.detectStorageOption(ctx, req.Path, req.Collection, req.Replication, req.TtlSec, req.DiskType, req.DataCenter, req.Rack, req.DataNode)
	if err != nil {
		return nil, err
	}

	// Mirror the HTTP write path: only apply the filer's default disk when the
	// matched locationPrefix rule did not already select one.
	if so.DiskType == "" {
		so.DiskType = fs.option.DiskType
	}

	return so, nil
}

func (fs *FilerServer) CollectionList(ctx context.Context, req *filer_pb.CollectionListRequest) (resp *filer_pb.CollectionListResponse, err error) {

	glog.V(4).InfofCtx(ctx, "CollectionList %v", req)
	resp = &filer_pb.CollectionListResponse{}

	err = fs.filer.MasterClient.WithClient(false, func(client master_pb.SeaweedClient) error {
		masterResp, err := client.CollectionList(context.Background(), &master_pb.CollectionListRequest{
			IncludeNormalVolumes: req.IncludeNormalVolumes,
			IncludeEcVolumes:     req.IncludeEcVolumes,
		})
		if err != nil {
			return err
		}
		for _, c := range masterResp.Collections {
			resp.Collections = append(resp.Collections, &filer_pb.Collection{Name: c.Name})
		}
		return nil
	})

	return
}

func (fs *FilerServer) DeleteCollection(ctx context.Context, req *filer_pb.DeleteCollectionRequest) (resp *filer_pb.DeleteCollectionResponse, err error) {

	glog.V(4).InfofCtx(ctx, "DeleteCollection %v", req)

	err = fs.filer.DoDeleteCollection(req.GetCollection())

	return &filer_pb.DeleteCollectionResponse{}, err
}