// 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)
}
}
// 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
}
// 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)
}
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)
*/
}
}