.

wcfs/misc.go

@@ -22,13 +22,74 @@ package main
 
 import (
 	"context"
+	"fmt"
+	"syscall"
+
+	log "github.com/golang/glog"
 
 	"github.com/hanwen/go-fuse/fuse"
 	"github.com/hanwen/go-fuse/fuse/nodefs"
+	"github.com/pkg/errors"
 
 	"lab.nexedi.com/kirr/neo/go/zodb"
 )
 
+// // errors as fuse.Status (not already exposed by fuse iteself)
+// const (
+// 	fEEXIST = fuse.Status(syscall.EEXIST)
+// )
+
+// eInvalError is the error wrapper signifying that underlying error is about "invalid argument".
+type eInvalError struct {
+	err error
+}
+
+func (e *eInvalError) Error() string {
+	return "invalid argument: " + e.err.Error()
+}
+
+// don't propagate eInvalError.Cause -> e.err
+
+func eINVAL(err error) *eInvalError {
+	return &eInvalError{err}
+}
+
+func eINVALf(format string, argv ...interface{}) *eInvalError {
+	return eINVAL(fmt.Errorf(format, argv...))
+}
+
+// err2LogStatus converts an error into FUSE status code and logs it appropriately.
+//
+// the error is logged because otherwise, if e.g. returning EINVAL or EIO
+// codes, there is no more detail except the error code itself.
+func err2LogStatus(err error) fuse.Status {
+	// no error
+	if err == nil {
+		return fuse.OK
+	}
+
+	// direct usage of error code - don't log
+	ecode, iscode := err.(syscall.Errno)
+	if iscode {
+		return fuse.Status(ecode)
+	}
+
+	// otherwise log as warnings EINVAL and as errors everything else
+	var st fuse.Status
+	switch errors.Cause(err).(type) {
+	case *eInvalError:
+		st = fuse.EINVAL
+		log.Warning(err)
+
+	default:
+		st = fuse.EIO
+		log.Error(err)
+	}
+
+	return st
+}
+
+
 // asctx represents fuse context as context.Context ready for interrupt handling.
 //
 // XXX temp. only after proper interrupt handling is not yet merged into go-fuse.

wcfs/wcfs.go

@@ -257,6 +257,7 @@ import (
 	"flag"
 	stdlog "log"
 	"os"
+	"strings"
 	"sync"
 	"syscall"
 
@@ -264,6 +265,7 @@ import (
 	"golang.org/x/sync/errgroup"
 
 	"lab.nexedi.com/kirr/go123/xcontext"
+	"lab.nexedi.com/kirr/go123/xerr"
 
 	"lab.nexedi.com/kirr/neo/go/transaction"
 	"lab.nexedi.com/kirr/neo/go/zodb"
@@ -288,12 +290,16 @@ type BigFileRoot struct {
 // /bigfile/<bigfileX>/	- served by BigFileDir.
 type BigFileDir struct {
 	nodefs.Node
+	oid zodb.Oid // oid of ZBigFile
+
+	// ZODB DB handle for this bigfile.
+	// keeps cache of connections for both head/ and @<rev>/ accesses.
 	zdb *zodb.DB
 
 	// head/ is implicitly linked to by fs
 
 	// {} rev -> @<rev>/ bigfile snapshot
-	revMu  sync.Mutex
+	mu     sync.Mutex
 	revTab map[zodb.Tid]*BigFileRev
 }
 
@@ -350,30 +356,7 @@ type blkLoadState struct {
 
 // ----------------------------------------
 
-
-// /bigfile -> Mkdir receives client request to create /bigfile/<bigfileX>.
-//
-// It creates <bigfileX>/head/* along the way.
-func (bfroot *BigFileRoot) Mkdir(name string, mode uint32, fctx *fuse.Context) (_ *nodefs.Inode, status fuse.Status) {
-	oid, err := zodb.ParseOid(name)
-	if err != nil {
-		log.Warningf("/bigfile: mkdir %q: not-oid", name)
-		return nil, fuse.EINVAL
-	}
-
-	// XXX ok to ignore mode?
-
-	// check to see if dir(oid) is already there
-	bfroot.mu.Lock()
-	_, already := bfroot.tab[oid]
-	bfroot.mu.Unlock()
-
-	if already {
-		return nil, fuse.Status(syscall.EEXIST)
-	}
-
-	// not there - without bfroot lock proceed to load corresponding objects from ZODB:
-
+/*
 	// create new read-only transaction for this bigfile
 	txn, txnCtx := transaction.New(context.Background())
 	defer func() {
@@ -432,6 +415,48 @@ func (bfroot *BigFileRoot) Mkdir(name string, mode uint32, fctx *fuse.Context) (
 		log.Errorf("/bigfile: mkdir %q: %s", name, err)
 		return nil, fuse.EIO
 	}
+*/
+
+
+// /bigfile -> Mkdir receives client request to create /bigfile/<bigfileX>.
+//
+// It creates <bigfileX>/head/* along the way.
+func (bfroot *BigFileRoot) Mkdir(name string, mode uint32, fctx *fuse.Context) (_ *nodefs.Inode, status fuse.Status) {
+	// XXX ok to ignore mode?
+	inode, err := bfroot.mkdir(name, fctx)
+	return inode, err2LogStatus(err)
+
+}
+
+func (bfroot *BigFileRoot) mkdir(name string, fctx *fuse.Context) (_ *nodefs.Inode, err error) {
+	defer xerr.Contextf(&err, "/bigfile: mkdir %q", name)
+
+	oid, err := zodb.ParseOid(name)
+	if err != nil {
+		return nil, eINVALf("not oid")
+	}
+
+
+	// check to see if dir(oid) is already there
+	bfroot.mu.Lock()
+	_, already := bfroot.tab[oid]
+	bfroot.mu.Unlock()
+
+	if already {
+		return nil, syscall.EEXIST
+	}
+
+	// not there - without bfroot lock proceed to load corresponding objects from ZODB
+	zdb := zodb.NewDB(bfroot.zstor)
+	bf, err := bigopen(asctx(fctx), zdb, oid, &zodb.ConnOptions{})
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			bf.Close()
+		}
+	}()
 
 	// relock bfroot and either mkdir or EEXIST if the directory was maybe
 	// simultanously created while we were not holding bfroot.mu
@@ -439,11 +464,12 @@ func (bfroot *BigFileRoot) Mkdir(name string, mode uint32, fctx *fuse.Context) (
 	_, already = bfroot.tab[oid]
 	if already {
 		bfroot.mu.Unlock()
-		return nil, fuse.Status(syscall.EEXIST)
+		return nil, syscall.EEXIST
 	}
 
 	bfdir := &BigFileDir{
 		Node: nodefs.NewDefaultNode(),
+		oid:  oid,
 		zdb:  zdb,
 	}
 
@@ -451,13 +477,6 @@ func (bfroot *BigFileRoot) Mkdir(name string, mode uint32, fctx *fuse.Context) (
 		Node: nodefs.NewDefaultNode(),
 	}
 
-	bf := &BigFile{
-		txnCtx:  txnCtx,
-		zconn:   zconn,
-		zbf:     zbf,
-		zbfSize: zbfSize,
-	}
-
 	bfdata := &BigFileData{
 		Node:    nodefs.NewDefaultNode(),
 		bigfile: bf,
@@ -474,16 +493,22 @@ func (bfroot *BigFileRoot) Mkdir(name string, mode uint32, fctx *fuse.Context) (
 	mkfile(bfhead, "at", NewSmallFile(bf.readAt))	// TODO mtime(at) = tidtime(at)
 	// XXX mkfile(bh, "invalidations", bh.inv)
 
-	return bfdir.Inode(), fuse.OK
+	return bfdir.Inode(), nil
 }
 
 // XXX do we need to support rmdir? (probably no)
 
-/*
-// /bigfile/<bigfileX> -> Mkdir receives client request to create @<tid>.
+// /bigfile/<bigfileX> -> Mkdir receives client request to create @<tid>/.
 func (bfdir *BigFileDir) Mkdir(name string, mode uint32, fctx *fuse.Context) (*nodefs.Inode, fuse.Status) {
+	// XXX ok to ignore mode?
+	inode, err := bfdir.mkdir(name, fctx)
+	return inode, err2LogStatus(err)
+}
+
+func (bfdir *BigFileDir) mkdir(name string, fctx *fuse.Context) (_ *nodefs.Inode, err error) {
+	defer xerr.Contextf(&err, "/bigfile/%s: mkdir %q", bfdir.oid, name)
+
 	var tid zodb.Tid
-	var err error
 	ok := false
 
 	if strings.HasPrefix(name, "@") {
@@ -491,13 +516,9 @@ func (bfdir *BigFileDir) Mkdir(name string, mode uint32, fctx *fuse.Context) (*n
 		ok = (err == nil)
 	}
 	if !ok {
-		log.Warning("/bigfile/XXX: mkdir %q: not-@tid", name)
-		return nil, fuse.EINVAL
+		return nil, eINVALf("not @tid")
 	}
 
-	// XXX ok to ignore mode?
-
-	// XXX vvv dups BigFileRoot.Mkdir ?
 
 	// check to see if dir(tid) is already
 	bfdir.mu.Lock()
@@ -505,47 +526,67 @@ func (bfdir *BigFileDir) Mkdir(name string, mode uint32, fctx *fuse.Context) (*n
 	bfdir.mu.Unlock()
 
 	if already {
-		return nil, fuse.Status(syscall.EEXIST)
+		return nil, syscall.EEXIST
 	}
 
 	// not there - without bfdir lock proceed to create @tid historical connection
 
-	// create new read-only transaction for this bigfile conn
-	txn, txnCtx := transaction.New(context.Background())
+	bf, err := bigopen(asctx(fctx), bfdir.zdb, bfdir.oid, &zodb.ConnOptions{
+		At: tid,
+	})
+	if err != nil {
+		return nil, err
+	}
 	defer func() {
-		if status != fuse.OK {
-			txn.Abort()
+		if err != nil {
+			bf.Close()
 		}
-	}
+	}()
 
-	// create new DB/Connection for this @tid
+	// relock bfdir and either mkdir or EEXIST if the directory was maybe
+	// simultanously created while we were not holding bfroot.mu
+	bfdir.mu.Lock()
+	_, already = bfdir.revTab[tid]
+	if already {
+		bfdir.mu.Unlock()
+		return nil, syscall.EEXIST
+	}
 
-	// XXX better ctx = transaction.PutIntoContext(ctx, txn)
-	ctx, cancel := xcontext.Merge(asctx(fctx), txnCtx)
-	defer cancel()
+	bfrev := &BigFileRev{
+		Node: nodefs.NewDefaultNode(),
+	}
 
-	// XXX ok to reuse bfdir.zdb? (or better keep that only for head?)
-	zconn, err := bfdir.zdb.Open(ctx, &zodb.ConnOptions{
-		At: tid,
-	})
+	revdata := &BigFileData{
+		Node:    nodefs.NewDefaultNode(),
+		bigfile: bf,
+		loading: make(map[int64]*blkLoadState),
+	}
 
-	...
+	bfdir.revTab[tid] = bfrev
+	bfdir.mu.Unlock()
 
+	// mkdir takes filesystem treeLock - do it outside bfroot.mu
+	mkdir(bfdir, name, bfrev)
 	mkfile(bfrev, "data", revdata)
 
-	return bfrev.Inode(), fuse.OK
+	return bfrev.Inode(), nil
 }
 
 
-// XXX -> zopen ?
-func openBigFile(zopt *zodb.ConnOptions) (, err error) {
-	// XXX errctx
-	defer xerr.Contextf(&err, "XXX")
+// bigopen opens BigFile corresponding to oid and zopt.
+//
+// A new read-only transaction is opened.
+// A new ZODB connection is opened via zdb.
+// A ZBigFile corresponding to oid is activated and statted.
+//
+// The whole result is returned as BigFile.
+func bigopen(ctx context.Context, zdb *zodb.DB, oid zodb.Oid, zopt *zodb.ConnOptions) (_ *BigFile, err error) {
+	defer xerr.Contextf(&err, "bigopen %s %s", oid, zopt)
 
 	// create new read-only transaction for this bigfile
 	txn, txnCtx := transaction.New(context.Background())
 	defer func() {
-		if status != fuse.OK {
+		if err != nil {
 			txn.Abort()
 		}
 	}()
@@ -554,18 +595,65 @@ func openBigFile(zopt *zodb.ConnOptions) (, err error) {
 	// create new DB/Connection for this bigfile open
 
 	// XXX better ctx = transaction.PutIntoContext(ctx, txn)
-	ctx, cancel := xcontext.Merge(asctx(fctx), txnCtx)
+	ctx, cancel := xcontext.Merge(ctx, txnCtx)
 	defer cancel()
 
-	zconn, err := zdb.Open(ctx, zope)
+	zconn, err := zdb.Open(ctx, zopt)
 	if err != nil {
-		return err
-		//log.Errorf("/bigfile: mkdir %q: %s", name, err)
-		//return nil, fuse.EIO
+		return nil, err
 	}
+
+	xzbf, err := zconn.Get(ctx, oid)
+	if err != nil {
+		switch errors.Cause(err).(type) {
+		case *zodb.NoObjectError:
+			return nil, eINVAL(err)
+		case *zodb.NoDataError:
+			return nil, eINVAL(err) // XXX what to do if it was existing and got deleted?
+		default:
+			return nil, err
+		}
+	}
+
+	zbf, ok := xzbf.(*ZBigFile)
+	if !ok {
+		return nil, eINVALf("%s is not a ZBigFile", typeOf(xzbf))
+	}
+
+	// activate ZBigFile and keep it this way
+	err = zbf.PActivate(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			zbf.PDeactivate()
+		}
+	}()
+
+	zbfSize, err := zbf.Size(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	return &BigFile{
+		txnCtx:  txnCtx,
+		zconn:   zconn,
+		zbf:     zbf,
+		zbfSize: zbfSize,
+	}, nil
 }
-*/
 
+// Close release all resources of BigFile.
+func (bf *BigFile) Close() error {
+	bf.zbf.PDeactivate()
+	bf.zbf = nil
+
+	transaction.Current(bf.txnCtx).Abort()
+	bf.zconn = nil
+
+	return nil
+}
 
 // /bigfile/<bigfileX>/head/data -> Getattr serves stat.
 func (bfdata *BigFileData) GetAttr(out *fuse.Attr, _ nodefs.File, fctx *fuse.Context) fuse.Status {