func (c *serveConn) dropNode(id fuse.NodeID, n uint64) (forget bool) {
c.meta.Lock()
defer c.meta.Unlock()
snode := c.node[id]
if snode == nil {
// this should only happen if refcounts kernel<->us disagree
// *and* two ForgetRequests for the same node race each other;
// this indicates a bug somewhere
fuse.Debug(nodeRefcountDropBug{N: n, Node: id})
// we may end up triggering Forget twice, but that's better
// than not even once, and that's the best we can do
return true
}
if n > snode.refs {
fuse.Debug(nodeRefcountDropBug{N: n, Refs: snode.refs, Node: id})
n = snode.refs
}
snode.refs -= n
if snode.refs == 0 {
c.node[id] = nil
if nodeRef, ok := snode.node.(nodeRef); ok {
ref := nodeRef.nodeRef()
*ref = NodeRef{}
}
c.freeNode = append(c.freeNode, id)
return true
}
return false
}
// Returns nil for invalid handles.
func (c *serveConn) getHandle(id fuse.HandleID) (shandle *serveHandle) {
c.meta.Lock()
defer c.meta.Unlock()
if id < fuse.HandleID(len(c.handle)) {
shandle = c.handle[uint(id)]
}
if shandle == nil {
fuse.Debug(missingHandle{
Handle: id,
MaxHandle: fuse.HandleID(len(c.handle)),
})
}
return
}
func (c *serveConn) serve(fs FS, r fuse.Request) {
intr := make(Intr)
req := &serveRequest{Request: r, Intr: intr}
fuse.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()
fuse.Debug(response{
Op: opName(r),
Request: logResponseHeader{ID: hdr.ID},
Error: fuse.ESTALE,
// 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
intr = nil
} 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.(fuse.Error); ok {
msg.Error = err
} else {
msg.Out = resp
}
fuse.Debug(msg)
c.meta.Lock()
delete(c.req, hdr.ID)
c.meta.Unlock()
}
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)
// FS operations.
case *fuse.InitRequest:
s := &fuse.InitResponse{
MaxWrite: 4096,
}
if fs, ok := fs.(FSIniter); ok {
if err := fs.Init(r, s, intr); err != nil {
done(err)
r.RespondError(err)
break
}
}
done(s)
r.Respond(s)
case *fuse.StatfsRequest:
s := &fuse.StatfsResponse{}
if fs, ok := fs.(FSStatfser); ok {
if err := fs.Statfs(r, s, intr); 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(r, s, intr); err != nil {
done(err)
r.RespondError(err)
break
}
} else {
s.AttrValid = attrValidTime
s.Attr = snode.attr()
}
done(s)
r.Respond(s)
case *fuse.SetattrRequest:
s := &fuse.SetattrResponse{}
if n, ok := node.(NodeSetattrer); ok {
if err := n.Setattr(r, s, intr); err != nil {
done(err)
r.RespondError(err)
break
}
done(s)
r.Respond(s)
break
}
if s.AttrValid == 0 {
s.AttrValid = attrValidTime
}
s.Attr = snode.attr()
done(s)
r.Respond(s)
case *fuse.SymlinkRequest:
s := &fuse.SymlinkResponse{}
n, ok := node.(NodeSymlinker)
if !ok {
done(fuse.EIO) // XXX or EPERM like Mkdir?
r.RespondError(fuse.EIO)
break
}
n2, err := n.Symlink(r, intr)
if err != nil {
done(err)
r.RespondError(err)
break
}
c.saveLookup(&s.LookupResponse, snode, r.NewName, n2)
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(r, intr)
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 {
fuse.Debug(logLinkRequestOldNodeNotFound{
Request: r.Hdr(),
In: r,
})
done(fuse.EIO)
r.RespondError(fuse.EIO)
break
}
n2, err := n.Link(r, oldNode.node, intr)
if err != nil {
done(err)
r.RespondError(err)
break
}
s := &fuse.LookupResponse{}
c.saveLookup(s, snode, r.NewName, n2)
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(r, intr)
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(r, intr); err != nil {
done(err)
r.RespondError(err)
break
}
}
done(nil)
r.Respond()
case *fuse.LookupRequest:
var n2 Node
var err fuse.Error
s := &fuse.LookupResponse{}
if n, ok := node.(NodeStringLookuper); ok {
n2, err = n.Lookup(r.Name, intr)
} else if n, ok := node.(NodeRequestLookuper); ok {
n2, err = n.Lookup(r, s, intr)
} else {
done(fuse.ENOENT)
r.RespondError(fuse.ENOENT)
break
}
if err != nil {
done(err)
r.RespondError(err)
break
}
c.saveLookup(s, snode, r.Name, n2)
done(s)
r.Respond(s)
case *fuse.MkdirRequest:
s := &fuse.MkdirResponse{}
n, ok := node.(NodeMkdirer)
if !ok {
done(fuse.EPERM)
r.RespondError(fuse.EPERM)
break
}
n2, err := n.Mkdir(r, intr)
if err != nil {
done(err)
r.RespondError(err)
break
}
c.saveLookup(&s.LookupResponse, snode, r.Name, n2)
done(s)
r.Respond(s)
case *fuse.OpenRequest:
s := &fuse.OpenResponse{Flags: fuse.OpenDirectIO}
var h2 Handle
if n, ok := node.(NodeOpener); ok {
hh, err := n.Open(r, s, intr)
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{Flags: fuse.OpenDirectIO}}
n2, h2, err := n.Create(r, s, intr)
if err != nil {
done(err)
r.RespondError(err)
break
}
c.saveLookup(&s.LookupResponse, snode, r.Name, n2)
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(r, s, intr)
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(r, s, intr)
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(r, intr)
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(r, intr)
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.(HandleReadDirer); ok {
if shandle.readData == nil {
dirs, err := h.ReadDir(intr)
if err != nil {
done(err)
r.RespondError(err)
break
}
var data []byte
for _, dir := range dirs {
if dir.Inode == 0 {
dir.Inode = hash(path.Join(snode.name, 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(intr)
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(r, s, intr); 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(r, s, intr); 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(r, intr); 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(r, intr); err != nil {
done(err)
r.RespondError(err)
break
}
}
done(nil)
r.Respond()
case *fuse.DestroyRequest:
if fs, ok := 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 {
fuse.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(r, newDirNode.node, intr)
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(r, intr)
if err != nil {
done(err)
r.RespondError(err)
break
}
s := &fuse.LookupResponse{}
c.saveLookup(s, snode, r.Name, n2)
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(r, intr)
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.Intr != nil {
close(ireq.Intr)
ireq.Intr = 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)
*/
}
}