Example #1
0
// Clean up all state associated with an op to which the user has responded,
// given its underlying bazilfuse request. This must be called before a
// response is sent to the kernel, to avoid a race where the request's ID might
// be reused by osxfuse.
//
// LOCKS_EXCLUDED(c.mu)
func (c *Connection) finishOp(bfReq bazilfuse.Request) {
	c.mu.Lock()
	defer c.mu.Unlock()

	reqID := bfReq.Hdr().ID

	// Even though the op is finished, context.WithCancel requires us to arrange
	// for the cancellation function to be invoked. We also must remove it from
	// our map.
	//
	// Special case: we don't do this for Forget requests. See the note in
	// beginOp above.
	if _, ok := bfReq.(*bazilfuse.ForgetRequest); !ok {
		cancel, ok := c.cancelFuncs[reqID]
		if !ok {
			panic(fmt.Sprintf("Unknown request ID in finishOp: %v", reqID))
		}

		cancel()
		delete(c.cancelFuncs, reqID)
	}
}
Example #2
0
// Set up state for an op that is about to be returned to the user, given its
// underlying bazilfuse request.
//
// Return a context that should be used for the op.
//
// LOCKS_EXCLUDED(c.mu)
func (c *Connection) beginOp(
	bfReq bazilfuse.Request) (ctx context.Context) {
	reqID := bfReq.Hdr().ID

	// Start with the parent context.
	ctx = c.parentCtx

	// Set up a cancellation function.
	//
	// Special case: On Darwin, osxfuse aggressively reuses "unique" request IDs.
	// This matters for Forget requests, which have no reply associated and
	// therefore have IDs that are immediately eligible for reuse. For these, we
	// should not record any state keyed on their ID.
	//
	// Cf. https://github.com/osxfuse/osxfuse/issues/208
	if _, ok := bfReq.(*bazilfuse.ForgetRequest); !ok {
		var cancel func()
		ctx, cancel = context.WithCancel(ctx)
		c.recordCancelFunc(reqID, cancel)
	}

	return
}
Example #3
0
// Record a fuse.Request, after zeroing header fields that are hard to
// reproduce.
//
// Make sure to record a copy, not the original request.
func (r *RequestRecorder) RecordRequest(req fuse.Request) {
	hdr := req.Hdr()
	*hdr = fuse.Header{}
	r.rec.Record(req)
}
Example #4
0
func (c *Server) serve(r fuse.Request) {
	ctx, cancel := context.WithCancel(c.context())
	defer cancel()

	req := &serveRequest{Request: r, cancel: cancel}

	c.debug(request{
		Op:      opName(r),
		Request: r.Hdr(),
		In:      r,
	})
	var node Node
	var snode *serveNode
	c.meta.Lock()
	hdr := r.Hdr()
	if id := hdr.Node; id != 0 {
		if id < fuse.NodeID(len(c.node)) {
			snode = c.node[uint(id)]
		}
		if snode == nil {
			c.meta.Unlock()
			c.debug(response{
				Op:      opName(r),
				Request: logResponseHeader{ID: hdr.ID},
				Error:   fuse.ESTALE.ErrnoName(),
				// this is the only place that sets both Error and
				// Out; not sure if i want to do that; might get rid
				// of len(c.node) things altogether
				Out: logMissingNode{
					MaxNode: fuse.NodeID(len(c.node)),
				},
			})
			r.RespondError(fuse.ESTALE)
			return
		}
		node = snode.node
	}
	if c.req[hdr.ID] != nil {
		// This happens with OSXFUSE.  Assume it's okay and
		// that we'll never see an interrupt for this one.
		// Otherwise everything wedges.  TODO: Report to OSXFUSE?
		//
		// TODO this might have been because of missing done() calls
	} else {
		c.req[hdr.ID] = req
	}
	c.meta.Unlock()

	// Call this before responding.
	// After responding is too late: we might get another request
	// with the same ID and be very confused.
	done := func(resp interface{}) {
		msg := response{
			Op:      opName(r),
			Request: logResponseHeader{ID: hdr.ID},
		}
		if err, ok := resp.(error); ok {
			msg.Error = err.Error()
			if ferr, ok := err.(fuse.ErrorNumber); ok {
				errno := ferr.Errno()
				msg.Errno = errno.ErrnoName()
				if errno == err {
					// it's just a fuse.Errno with no extra detail;
					// skip the textual message for log readability
					msg.Error = ""
				}
			} else {
				msg.Errno = fuse.DefaultErrno.ErrnoName()
			}
		} else {
			msg.Out = resp
		}
		c.debug(msg)

		c.meta.Lock()
		delete(c.req, hdr.ID)
		c.meta.Unlock()
	}

	defer func() {
		if rec := recover(); rec != nil {
			const size = 1 << 16
			buf := make([]byte, size)
			n := runtime.Stack(buf, false)
			buf = buf[:n]
			log.Printf("fuse: panic in handler for %v: %v\n%s", r, rec, buf)
			err := handlerPanickedError{
				Request: r,
				Err:     rec,
			}
			done(err)
			r.RespondError(err)
		}
	}()

	switch r := r.(type) {
	default:
		// Note: To FUSE, ENOSYS means "this server never implements this request."
		// It would be inappropriate to return ENOSYS for other operations in this
		// switch that might only be unavailable in some contexts, not all.
		done(fuse.ENOSYS)
		r.RespondError(fuse.ENOSYS)

	case *fuse.StatfsRequest:
		s := &fuse.StatfsResponse{}
		if fs, ok := c.fs.(FSStatfser); ok {
			if err := fs.Statfs(ctx, r, s); err != nil {
				done(err)
				r.RespondError(err)
				break
			}
		}
		done(s)
		r.Respond(s)

	// Node operations.
	case *fuse.GetattrRequest:
		s := &fuse.GetattrResponse{}
		if n, ok := node.(NodeGetattrer); ok {
			if err := n.Getattr(ctx, r, s); err != nil {
				done(err)
				r.RespondError(err)
				break
			}
		} else {
			if err := snode.attr(ctx, &s.Attr); err != nil {
				done(err)
				r.RespondError(err)
				break
			}
		}
		done(s)
		r.Respond(s)

	case *fuse.SetattrRequest:
		s := &fuse.SetattrResponse{}
		if n, ok := node.(NodeSetattrer); ok {
			if err := n.Setattr(ctx, r, s); err != nil {
				done(err)
				r.RespondError(err)
				break
			}
			done(s)
			r.Respond(s)
			break
		}

		if err := snode.attr(ctx, &s.Attr); err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(s)
		r.Respond(s)

	case *fuse.SymlinkRequest:
		s := &fuse.SymlinkResponse{}
		initLookupResponse(&s.LookupResponse)
		n, ok := node.(NodeSymlinker)
		if !ok {
			done(fuse.EIO) // XXX or EPERM like Mkdir?
			r.RespondError(fuse.EIO)
			break
		}
		n2, err := n.Symlink(ctx, r)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		if err := c.saveLookup(ctx, &s.LookupResponse, snode, r.NewName, n2); err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(s)
		r.Respond(s)

	case *fuse.ReadlinkRequest:
		n, ok := node.(NodeReadlinker)
		if !ok {
			done(fuse.EIO) /// XXX or EPERM?
			r.RespondError(fuse.EIO)
			break
		}
		target, err := n.Readlink(ctx, r)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(target)
		r.Respond(target)

	case *fuse.LinkRequest:
		n, ok := node.(NodeLinker)
		if !ok {
			done(fuse.EIO) /// XXX or EPERM?
			r.RespondError(fuse.EIO)
			break
		}
		c.meta.Lock()
		var oldNode *serveNode
		if int(r.OldNode) < len(c.node) {
			oldNode = c.node[r.OldNode]
		}
		c.meta.Unlock()
		if oldNode == nil {
			c.debug(logLinkRequestOldNodeNotFound{
				Request: r.Hdr(),
				In:      r,
			})
			done(fuse.EIO)
			r.RespondError(fuse.EIO)
			break
		}
		n2, err := n.Link(ctx, r, oldNode.node)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		s := &fuse.LookupResponse{}
		initLookupResponse(s)
		if err := c.saveLookup(ctx, s, snode, r.NewName, n2); err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(s)
		r.Respond(s)

	case *fuse.RemoveRequest:
		n, ok := node.(NodeRemover)
		if !ok {
			done(fuse.EIO) /// XXX or EPERM?
			r.RespondError(fuse.EIO)
			break
		}
		err := n.Remove(ctx, r)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(nil)
		r.Respond()

	case *fuse.AccessRequest:
		if n, ok := node.(NodeAccesser); ok {
			if err := n.Access(ctx, r); err != nil {
				done(err)
				r.RespondError(err)
				break
			}
		}
		done(nil)
		r.Respond()

	case *fuse.LookupRequest:
		var n2 Node
		var err error
		s := &fuse.LookupResponse{}
		initLookupResponse(s)
		if n, ok := node.(NodeStringLookuper); ok {
			n2, err = n.Lookup(ctx, r.Name)
		} else if n, ok := node.(NodeRequestLookuper); ok {
			n2, err = n.Lookup(ctx, r, s)
		} else {
			done(fuse.ENOENT)
			r.RespondError(fuse.ENOENT)
			break
		}
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		if err := c.saveLookup(ctx, s, snode, r.Name, n2); err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(s)
		r.Respond(s)

	case *fuse.MkdirRequest:
		s := &fuse.MkdirResponse{}
		initLookupResponse(&s.LookupResponse)
		n, ok := node.(NodeMkdirer)
		if !ok {
			done(fuse.EPERM)
			r.RespondError(fuse.EPERM)
			break
		}
		n2, err := n.Mkdir(ctx, r)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		if err := c.saveLookup(ctx, &s.LookupResponse, snode, r.Name, n2); err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(s)
		r.Respond(s)

	case *fuse.OpenRequest:
		s := &fuse.OpenResponse{}
		var h2 Handle
		if n, ok := node.(NodeOpener); ok {
			hh, err := n.Open(ctx, r, s)
			if err != nil {
				done(err)
				r.RespondError(err)
				break
			}
			h2 = hh
		} else {
			h2 = node
		}
		s.Handle = c.saveHandle(h2, hdr.Node)
		done(s)
		r.Respond(s)

	case *fuse.CreateRequest:
		n, ok := node.(NodeCreater)
		if !ok {
			// If we send back ENOSYS, FUSE will try mknod+open.
			done(fuse.EPERM)
			r.RespondError(fuse.EPERM)
			break
		}
		s := &fuse.CreateResponse{OpenResponse: fuse.OpenResponse{}}
		initLookupResponse(&s.LookupResponse)
		n2, h2, err := n.Create(ctx, r, s)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		if err := c.saveLookup(ctx, &s.LookupResponse, snode, r.Name, n2); err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		s.Handle = c.saveHandle(h2, hdr.Node)
		done(s)
		r.Respond(s)

	case *fuse.GetxattrRequest:
		n, ok := node.(NodeGetxattrer)
		if !ok {
			done(fuse.ENOTSUP)
			r.RespondError(fuse.ENOTSUP)
			break
		}
		s := &fuse.GetxattrResponse{}
		err := n.Getxattr(ctx, r, s)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		if r.Size != 0 && uint64(len(s.Xattr)) > uint64(r.Size) {
			done(fuse.ERANGE)
			r.RespondError(fuse.ERANGE)
			break
		}
		done(s)
		r.Respond(s)

	case *fuse.ListxattrRequest:
		n, ok := node.(NodeListxattrer)
		if !ok {
			done(fuse.ENOTSUP)
			r.RespondError(fuse.ENOTSUP)
			break
		}
		s := &fuse.ListxattrResponse{}
		err := n.Listxattr(ctx, r, s)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		if r.Size != 0 && uint64(len(s.Xattr)) > uint64(r.Size) {
			done(fuse.ERANGE)
			r.RespondError(fuse.ERANGE)
			break
		}
		done(s)
		r.Respond(s)

	case *fuse.SetxattrRequest:
		n, ok := node.(NodeSetxattrer)
		if !ok {
			done(fuse.ENOTSUP)
			r.RespondError(fuse.ENOTSUP)
			break
		}
		err := n.Setxattr(ctx, r)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(nil)
		r.Respond()

	case *fuse.RemovexattrRequest:
		n, ok := node.(NodeRemovexattrer)
		if !ok {
			done(fuse.ENOTSUP)
			r.RespondError(fuse.ENOTSUP)
			break
		}
		err := n.Removexattr(ctx, r)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(nil)
		r.Respond()

	case *fuse.ForgetRequest:
		forget := c.dropNode(hdr.Node, r.N)
		if forget {
			n, ok := node.(NodeForgetter)
			if ok {
				n.Forget()
			}
		}
		done(nil)
		r.Respond()

	// Handle operations.
	case *fuse.ReadRequest:
		shandle := c.getHandle(r.Handle)
		if shandle == nil {
			done(fuse.ESTALE)
			r.RespondError(fuse.ESTALE)
			return
		}
		handle := shandle.handle

		s := &fuse.ReadResponse{Data: make([]byte, 0, r.Size)}
		if r.Dir {
			if h, ok := handle.(HandleReadDirAller); ok {
				if shandle.readData == nil {
					dirs, err := h.ReadDirAll(ctx)
					if err != nil {
						done(err)
						r.RespondError(err)
						break
					}
					var data []byte
					for _, dir := range dirs {
						if dir.Inode == 0 {
							dir.Inode = c.dynamicInode(snode.inode, dir.Name)
						}
						data = fuse.AppendDirent(data, dir)
					}
					shandle.readData = data
				}
				fuseutil.HandleRead(r, s, shandle.readData)
				done(s)
				r.Respond(s)
				break
			}
		} else {
			if h, ok := handle.(HandleReadAller); ok {
				if shandle.readData == nil {
					data, err := h.ReadAll(ctx)
					if err != nil {
						done(err)
						r.RespondError(err)
						break
					}
					if data == nil {
						data = []byte{}
					}
					shandle.readData = data
				}
				fuseutil.HandleRead(r, s, shandle.readData)
				done(s)
				r.Respond(s)
				break
			}
			h, ok := handle.(HandleReader)
			if !ok {
				fmt.Printf("NO READ FOR %T\n", handle)
				done(fuse.EIO)
				r.RespondError(fuse.EIO)
				break
			}
			if err := h.Read(ctx, r, s); err != nil {
				done(err)
				r.RespondError(err)
				break
			}
		}
		done(s)
		r.Respond(s)

	case *fuse.WriteRequest:
		shandle := c.getHandle(r.Handle)
		if shandle == nil {
			done(fuse.ESTALE)
			r.RespondError(fuse.ESTALE)
			return
		}

		s := &fuse.WriteResponse{}
		if h, ok := shandle.handle.(HandleWriter); ok {
			if err := h.Write(ctx, r, s); err != nil {
				done(err)
				r.RespondError(err)
				break
			}
			done(s)
			r.Respond(s)
			break
		}
		done(fuse.EIO)
		r.RespondError(fuse.EIO)

	case *fuse.FlushRequest:
		shandle := c.getHandle(r.Handle)
		if shandle == nil {
			done(fuse.ESTALE)
			r.RespondError(fuse.ESTALE)
			return
		}
		handle := shandle.handle

		if h, ok := handle.(HandleFlusher); ok {
			if err := h.Flush(ctx, r); err != nil {
				done(err)
				r.RespondError(err)
				break
			}
		}
		done(nil)
		r.Respond()

	case *fuse.ReleaseRequest:
		shandle := c.getHandle(r.Handle)
		if shandle == nil {
			done(fuse.ESTALE)
			r.RespondError(fuse.ESTALE)
			return
		}
		handle := shandle.handle

		// No matter what, release the handle.
		c.dropHandle(r.Handle)

		if h, ok := handle.(HandleReleaser); ok {
			if err := h.Release(ctx, r); err != nil {
				done(err)
				r.RespondError(err)
				break
			}
		}
		done(nil)
		r.Respond()

	case *fuse.DestroyRequest:
		if fs, ok := c.fs.(FSDestroyer); ok {
			fs.Destroy()
		}
		done(nil)
		r.Respond()

	case *fuse.RenameRequest:
		c.meta.Lock()
		var newDirNode *serveNode
		if int(r.NewDir) < len(c.node) {
			newDirNode = c.node[r.NewDir]
		}
		c.meta.Unlock()
		if newDirNode == nil {
			c.debug(renameNewDirNodeNotFound{
				Request: r.Hdr(),
				In:      r,
			})
			done(fuse.EIO)
			r.RespondError(fuse.EIO)
			break
		}
		n, ok := node.(NodeRenamer)
		if !ok {
			done(fuse.EIO) // XXX or EPERM like Mkdir?
			r.RespondError(fuse.EIO)
			break
		}
		err := n.Rename(ctx, r, newDirNode.node)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(nil)
		r.Respond()

	case *fuse.MknodRequest:
		n, ok := node.(NodeMknoder)
		if !ok {
			done(fuse.EIO)
			r.RespondError(fuse.EIO)
			break
		}
		n2, err := n.Mknod(ctx, r)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		s := &fuse.LookupResponse{}
		initLookupResponse(s)
		if err := c.saveLookup(ctx, s, snode, r.Name, n2); err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(s)
		r.Respond(s)

	case *fuse.FsyncRequest:
		n, ok := node.(NodeFsyncer)
		if !ok {
			done(fuse.EIO)
			r.RespondError(fuse.EIO)
			break
		}
		err := n.Fsync(ctx, r)
		if err != nil {
			done(err)
			r.RespondError(err)
			break
		}
		done(nil)
		r.Respond()

	case *fuse.InterruptRequest:
		c.meta.Lock()
		ireq := c.req[r.IntrID]
		if ireq != nil && ireq.cancel != nil {
			ireq.cancel()
			ireq.cancel = nil
		}
		c.meta.Unlock()
		done(nil)
		r.Respond()

		/*	case *FsyncdirRequest:
				done(ENOSYS)
				r.RespondError(ENOSYS)

			case *GetlkRequest, *SetlkRequest, *SetlkwRequest:
				done(ENOSYS)
				r.RespondError(ENOSYS)

			case *BmapRequest:
				done(ENOSYS)
				r.RespondError(ENOSYS)

			case *SetvolnameRequest, *GetxtimesRequest, *ExchangeRequest:
				done(ENOSYS)
				r.RespondError(ENOSYS)
		*/
	}
}