In the future, we may choose to support these, but it poses some challenges. In order to create a disconnected dentry/inode, we'll need to encode the mountpoint and bpf into the file_handle, which means we'd need a stable representation of them. This also won't hold up to cases where the bpf is not stateless. One possibility is registering bpf programs and mounts in a specific order, so they can be assigned consistent ids we can use in the file_handle. We can defer to the lower filesystem for the lower inode's representation in the file_handle. Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx> --- fs/fuse/inode.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index b71e8758fab5..fe80984f099a 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1107,6 +1107,14 @@ static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len, nodeid = get_fuse_inode(inode)->nodeid; generation = inode->i_generation; +#ifdef CONFIG_FUSE_BPF + /* TODO: Does it make sense to support this in some cases? */ + if (!nodeid && get_fuse_inode(inode)->backing_inode) { + *max_len = 0; + return FILEID_INVALID; + } +#endif + fh[0] = (u32)(nodeid >> 32); fh[1] = (u32)(nodeid & 0xffffffff); fh[2] = generation; -- 2.40.0.634.g4ca3ef3211-goog