k3s/vendor/github.com/hanwen/go-fuse/v2/fuse/poll.go
Kohei Tokunaga 8b857eef9c
Ship Stargz Snapshotter (#2936)
* Ship Stargz Snapshotter

Signed-off-by: ktock <ktokunaga.mail@gmail.com>

* Bump github.com/containerd/stargz-snapshotter to v0.8.0

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
2021-09-01 16:27:42 -07:00

50 lines
1.3 KiB
Go

package fuse
// Go 1.9 introduces polling for file I/O. The implementation causes
// the runtime's epoll to take up the last GOMAXPROCS slot, and if
// that happens, we won't have any threads left to service FUSE's
// _OP_POLL request. Prevent this by forcing _OP_POLL to happen, so we
// can say ENOSYS and prevent further _OP_POLL requests.
const pollHackName = ".go-fuse-epoll-hack"
const pollHackInode = ^uint64(0)
func doPollHackLookup(ms *Server, req *request) {
attr := Attr{
Ino: pollHackInode,
Mode: S_IFREG | 0644,
Nlink: 1,
}
switch req.inHeader.Opcode {
case _OP_LOOKUP:
out := (*EntryOut)(req.outData())
*out = EntryOut{
NodeId: pollHackInode,
Attr: attr,
}
req.status = OK
case _OP_OPEN:
out := (*OpenOut)(req.outData())
*out = OpenOut{
Fh: pollHackInode,
}
req.status = OK
case _OP_GETATTR, _OP_SETATTR:
out := (*AttrOut)(req.outData())
out.Attr = attr
req.status = OK
case _OP_POLL:
req.status = ENOSYS
case _OP_ACCESS, _OP_FLUSH, _OP_RELEASE:
// Avoid upsetting the OSX mount process.
req.status = OK
default:
// We want to avoid switching off features through our
// poll hack, so don't use ENOSYS. It would be nice if
// we could transmit no error code at all, but for
// some opcodes, we'd have to invent credible data to
// return as well.
req.status = ERANGE
}
}