storage: Weave end offset into unsealed reader code

lib/readerutil/readerutil.go

@@ -0,0 +1,44 @@
+package readerutil
+
+import (
+	"io"
+	"os"
+)
+
+// NewReadSeekerFromReaderAt returns a new io.ReadSeeker from a io.ReaderAt.
+// The returned io.ReadSeeker will read from the io.ReaderAt starting at the
+// given base offset.
+func NewReadSeekerFromReaderAt(readerAt io.ReaderAt, base int64) io.ReadSeeker {
+	return &readSeekerFromReaderAt{
+		readerAt: readerAt,
+		base:     base,
+		pos:      0,
+	}
+}
+
+type readSeekerFromReaderAt struct {
+	readerAt io.ReaderAt
+	base     int64
+	pos      int64
+}
+
+func (rs *readSeekerFromReaderAt) Read(p []byte) (n int, err error) {
+	n, err = rs.readerAt.ReadAt(p, rs.pos+rs.base)
+	rs.pos += int64(n)
+	return n, err
+}
+
+func (rs *readSeekerFromReaderAt) Seek(offset int64, whence int) (int64, error) {
+	switch whence {
+	case io.SeekStart:
+		rs.pos = offset
+	case io.SeekCurrent:
+		rs.pos += offset
+	case io.SeekEnd:
+		return 0, io.ErrUnexpectedEOF
+	default:
+		return 0, os.ErrInvalid
+	}
+
+	return rs.pos, nil
+}

storage/paths/http_handler.go

@@ -3,6 +3,7 @@ package paths
 import (
 	"bytes"
 	"encoding/json"
+	"io"
 	"net/http"
 	"os"
 	"strconv"
@@ -35,7 +36,7 @@ func (d *DefaultPartialFileHandler) HasAllocated(pf *partialfile.PartialFile, of
 	return pf.HasAllocated(offset, size)
 }
 
-func (d *DefaultPartialFileHandler) Reader(pf *partialfile.PartialFile, offset storiface.PaddedByteIndex, size abi.PaddedPieceSize) (*os.File, error) {
+func (d *DefaultPartialFileHandler) Reader(pf *partialfile.PartialFile, offset storiface.PaddedByteIndex, size abi.PaddedPieceSize) (io.Reader, error) {
 	return pf.Reader(offset, size)
 }
 

storage/paths/interface.go

@@ -2,9 +2,8 @@ package paths
 
 import (
 	"context"
-	"os"
-
 	"github.com/filecoin-project/go-state-types/abi"
+	"io"
 
 	"github.com/filecoin-project/lotus/storage/sealer/fsutil"
 	"github.com/filecoin-project/lotus/storage/sealer/partialfile"
@@ -24,7 +23,7 @@ type PartialFileHandler interface {
 	HasAllocated(pf *partialfile.PartialFile, offset storiface.UnpaddedByteIndex, size abi.UnpaddedPieceSize) (bool, error)
 
 	// Reader returns a file from which we can read the unsealed piece in the partial file.
-	Reader(pf *partialfile.PartialFile, offset storiface.PaddedByteIndex, size abi.PaddedPieceSize) (*os.File, error)
+	Reader(pf *partialfile.PartialFile, offset storiface.PaddedByteIndex, size abi.PaddedPieceSize) (io.Reader, error)
 
 	// Close closes the partial file
 	Close(pf *partialfile.PartialFile) error

storage/paths/remote.go

@@ -559,7 +559,7 @@ func (r *Remote) CheckIsUnsealed(ctx context.Context, s storiface.SectorRef, off
 // 1. no worker(local worker included) has an unsealed file for the given sector OR
 // 2. no worker(local worker included) has the unsealed piece in their unsealed sector file.
 // Will return a nil reader and a nil error in such a case.
-func (r *Remote) Reader(ctx context.Context, s storiface.SectorRef, offset, size abi.PaddedPieceSize) (func(startOffsetAligned storiface.PaddedByteIndex) (io.ReadCloser, error), error) {
+func (r *Remote) Reader(ctx context.Context, s storiface.SectorRef, offset, size abi.PaddedPieceSize) (func(startOffsetAligned, endOffsetAligned storiface.PaddedByteIndex) (io.ReadCloser, error), error) {
 	ft := storiface.FTUnsealed
 
 	// check if we have the unsealed sector file locally
@@ -598,20 +598,8 @@ func (r *Remote) Reader(ctx context.Context, s storiface.SectorRef, offset, size
 		if has {
 			log.Infof("returning piece reader for local unsealed piece sector=%+v, (offset=%d, size=%d)", s.ID, offset, size)
 
-			return func(startOffsetAligned storiface.PaddedByteIndex) (io.ReadCloser, error) {
+			return func(startOffsetAligned, endOffsetAligned storiface.PaddedByteIndex) (io.ReadCloser, error) {
-				// don't reuse between readers unless closed
+				r, err := r.pfHandler.Reader(pf, storiface.PaddedByteIndex(offset)+startOffsetAligned, abi.PaddedPieceSize(endOffsetAligned-startOffsetAligned))
-				f := pf
-				pf = nil
-
-				if f == nil {
-					f, err = r.pfHandler.OpenPartialFile(abi.PaddedPieceSize(ssize), path)
-					if err != nil {
-						return nil, xerrors.Errorf("opening partial file: %w", err)
-					}
-					log.Debugf("local partial file (re)opened %s (+%d,%d)", path, offset, size)
-				}
-
-				r, err := r.pfHandler.Reader(f, storiface.PaddedByteIndex(offset)+startOffsetAligned, size-abi.PaddedPieceSize(startOffsetAligned))
 				if err != nil {
 					return nil, err
 				}
@@ -622,22 +610,7 @@ func (r *Remote) Reader(ctx context.Context, s storiface.SectorRef, offset, size
 				}{
 					Reader: r,
 					Closer: funcCloser(func() error {
-						// if we already have a reader cached, close this one
+						// todo keep some refcount, close pf (or push to some lru) when it hits 0
-						if pf != nil {
-							if f == nil {
-								return nil
-							}
-							if pf == f {
-								pf = nil
-							}
-
-							tmp := f
-							f = nil
-							return tmp.Close()
-						}
-
-						// otherwise stash it away for reuse
-						pf = f
 						return nil
 					}),
 				}, nil
@@ -685,10 +658,10 @@ func (r *Remote) Reader(ctx context.Context, s storiface.SectorRef, offset, size
 				continue
 			}
 
-			return func(startOffsetAligned storiface.PaddedByteIndex) (io.ReadCloser, error) {
+			return func(startOffsetAligned, endOffsetAligned storiface.PaddedByteIndex) (io.ReadCloser, error) {
 				// readRemote fetches a reader that we can use to read the unsealed piece from the remote worker.
 				// It uses a ranged HTTP query to ensure we ONLY read the unsealed piece and not the entire unsealed file.
-				rd, err := r.readRemote(ctx, url, offset+abi.PaddedPieceSize(startOffsetAligned), size)
+				rd, err := r.readRemote(ctx, url, offset+abi.PaddedPieceSize(startOffsetAligned), offset+abi.PaddedPieceSize(endOffsetAligned))
 				if err != nil {
 					log.Warnw("reading from remote", "url", url, "error", err)
 					return nil, err

storage/sealer/partialfile/partialfile.go

@@ -2,6 +2,7 @@ package partialfile
 
 import (
 	"encoding/binary"
+	"github.com/filecoin-project/lotus/lib/readerutil"
 	"io"
 	"os"
 	"syscall"
@@ -249,7 +250,10 @@ func (pf *PartialFile) Free(offset storiface.PaddedByteIndex, size abi.PaddedPie
 	return nil
 }
 
-func (pf *PartialFile) Reader(offset storiface.PaddedByteIndex, size abi.PaddedPieceSize) (*os.File, error) {
+// Reader forks off a new reader from the underlying file, and returns a reader
+// starting at the given offset and reading the given size. Safe for concurrent
+// use.
+func (pf *PartialFile) Reader(offset storiface.PaddedByteIndex, size abi.PaddedPieceSize) (io.Reader, error) {
 	if _, err := pf.file.Seek(int64(offset), io.SeekStart); err != nil {
 		return nil, xerrors.Errorf("seek piece start: %w", err)
 	}
@@ -275,7 +279,7 @@ func (pf *PartialFile) Reader(offset storiface.PaddedByteIndex, size abi.PaddedP
 		}
 	}
 
-	return pf.file, nil
+	return io.LimitReader(readerutil.NewReadSeekerFromReaderAt(pf.file, int64(offset)), int64(size)), nil
 }
 
 func (pf *PartialFile) Allocated() (rlepluslazy.RunIterator, error) {

storage/sealer/piece_provider.go

@@ -71,7 +71,7 @@ func (p *pieceProvider) IsUnsealed(ctx context.Context, sector storiface.SectorR
 // It will NOT try to schedule an Unseal of a sealed sector file for the read.
 //
 // Returns a nil reader if the piece does NOT exist in any unsealed file or there is no unsealed file for the given sector on any of the workers.
-func (p *pieceProvider) tryReadUnsealedPiece(ctx context.Context, pc cid.Cid, sector storiface.SectorRef, pieceOffset storiface.UnpaddedByteIndex, size abi.UnpaddedPieceSize) (mount.Reader, error) {
+func (p *pieceProvider) tryReadUnsealedPiece(ctx context.Context, pc cid.Cid, sector storiface.SectorRef, pieceOffset storiface.UnpaddedByteIndex, pieceSize abi.UnpaddedPieceSize) (mount.Reader, error) {
 	// acquire a lock purely for reading unsealed sectors
 	ctx, cancel := context.WithCancel(ctx)
 	if err := p.index.StorageLock(ctx, sector.ID, storiface.FTUnsealed, storiface.FTNone); err != nil {
@@ -82,7 +82,7 @@ func (p *pieceProvider) tryReadUnsealedPiece(ctx context.Context, pc cid.Cid, se
 	// Reader returns a reader getter for an unsealed piece at the given offset in the given sector.
 	// The returned reader will be nil if none of the workers has an unsealed sector file containing
 	// the unsealed piece.
-	rg, err := p.storage.Reader(ctx, sector, abi.PaddedPieceSize(pieceOffset.Padded()), size.Padded())
+	rg, err := p.storage.Reader(ctx, sector, abi.PaddedPieceSize(pieceOffset.Padded()), pieceSize.Padded())
 	if err != nil {
 		cancel()
 		log.Debugf("did not get storage reader;sector=%+v, err:%s", sector.ID, err)
@@ -93,19 +93,23 @@ func (p *pieceProvider) tryReadUnsealedPiece(ctx context.Context, pc cid.Cid, se
 		return nil, nil
 	}
 
-	buf := make([]byte, fr32.BufSize(size.Padded()))
+	buf := make([]byte, fr32.BufSize(pieceSize.Padded()))
 
 	pr, err := (&pieceReader{
 		ctx: ctx,
-		getReader: func(ctx context.Context, startOffset uint64) (io.ReadCloser, error) {
+		getReader: func(ctx context.Context, startOffset, readSize uint64) (io.ReadCloser, error) {
 			startOffsetAligned := storiface.UnpaddedByteIndex(startOffset / 127 * 127) // floor to multiple of 127
+			startOffsetDiff := int(startOffset - uint64(startOffsetAligned))
 
-			r, err := rg(startOffsetAligned.Padded())
+			endOffset := startOffset + readSize
+			endOffsetAligned := storiface.UnpaddedByteIndex((endOffset + 126) / 127 * 127) // ceil to multiple of 127
+
+			r, err := rg(startOffsetAligned.Padded(), endOffsetAligned.Padded())
 			if err != nil {
 				return nil, xerrors.Errorf("getting reader at +%d: %w", startOffsetAligned, err)
 			}
 
-			upr, err := fr32.NewUnpadReaderBuf(r, size.Padded(), buf)
+			upr, err := fr32.NewUnpadReaderBuf(r, pieceSize.Padded(), buf)
 			if err != nil {
 				r.Close() // nolint
 				return nil, xerrors.Errorf("creating unpadded reader: %w", err)
@@ -113,7 +117,7 @@ func (p *pieceProvider) tryReadUnsealedPiece(ctx context.Context, pc cid.Cid, se
 
 			bir := bufio.NewReaderSize(upr, 127)
 			if startOffset > uint64(startOffsetAligned) {
-				if _, err := bir.Discard(int(startOffset - uint64(startOffsetAligned))); err != nil {
+				if _, err := bir.Discard(startOffsetDiff); err != nil {
 					r.Close() // nolint
 					return nil, xerrors.Errorf("discarding bytes for startOffset: %w", err)
 				}
@@ -129,7 +133,7 @@ func (p *pieceProvider) tryReadUnsealedPiece(ctx context.Context, pc cid.Cid, se
 				}),
 			}, nil
 		},
-		len:      size,
+		len:      pieceSize,
 		onClose:  cancel,
 		pieceCid: pc,
 	}).init()

storage/sealer/piece_reader.go

@@ -21,7 +21,7 @@ import (
 var MaxPieceReaderBurnBytes int64 = 1 << 20 // 1M
 var ReadBuf = 128 * (127 * 8)               // unpadded(128k)
 
-type pieceGetter func(ctx context.Context, offset uint64) (io.ReadCloser, error)
+type pieceGetter func(ctx context.Context, offset, size uint64) (io.ReadCloser, error)
 
 type pieceReader struct {
 	ctx       context.Context
@@ -43,7 +43,7 @@ func (p *pieceReader) init() (_ *pieceReader, err error) {
 	stats.Record(p.ctx, metrics.DagStorePRInitCount.M(1))
 
 	p.rAt = 0
-	p.r, err = p.getReader(p.ctx, uint64(p.rAt))
+	p.r, err = p.getReader(p.ctx, uint64(p.rAt), uint64(p.len))
 	if err != nil {
 		return nil, err
 	}
@@ -160,7 +160,7 @@ func (p *pieceReader) readAtUnlocked(b []byte, off int64) (n int, err error) {
 		}
 
 		p.rAt = off
-		p.r, err = p.getReader(p.ctx, uint64(p.rAt))
+		p.r, err = p.getReader(p.ctx, uint64(p.rAt), uint64(p.len))
 		p.br = bufio.NewReaderSize(p.r, ReadBuf)
 		if err != nil {
 			return 0, xerrors.Errorf("getting backing reader: %w", err)