vfs_fsadd() returns EINVAL

#sudo kextutil -s fsd/symdir fsd/fsd.kext

Notice: Using running kernel architecture x86_64 to generate symbols.

(kernel) Kext com.company.kext.fsd start failed (result 0x5).

(kernel) Kext com.company.kext.fsd failed to load (0xdc008017).

(kernel) Failed to load kext com.company.kext.fsd (error 0xdc008017).

Failed to load fsd/fsd.kext - (libkern/kext) kext (kmod) start/stop routine failed.

From /var/log/kernel.log:

Nov 4 13:38:09 Xserve1 kernel[0]: fsd_module_start: returned failure, error 22

Nov 4 13:38:09 Xserve1 kernel[0]: Kext com.company.kext.fsd start failed (result 0x5).

I have added all checks that I found in vfs_fsadd() in opensource, and I do not trip them.

Here are the relevant portions:

* vfs operations.

struct vfsops fsd_vfsops = {

fsd_mount,

fsd_vfsstart,

fsd_unmount,

fsd_root,

NULL, /* quotactl */

fsd_vfs_getattr,

fsd_sync,

fsd_vget,

NULL,

fsd_init,

NULL /*sysctl */

};

struct vnodeopv_desc * fsd_vnodeop_opv_desc_list[] =

{

&fsd_vnodeop_opv_desc,

NULL

};

struct vfs_fsentry fsd_fsentry = {

&fsd_vfsops,

fsd_vnodeop_opv_desc_list,

FSD_FS_NAME,

VFS_TBLTHREADSAFE | VFS_TBLFSNODELOCK | VFS_TBLNOTYPENUM | VFS_TBL64BITREADY,

{ NULL, NULL }

};

static kern_return_t

fsd_module_start(struct kmod_info *ki, void *data)

{

int desccount;

errno_t error = 0;

struct vfs_fsentry *vfe = &fsd_fsentry;

desccount = vfe->vfe_vopcnt;

IOLog("%s: %d, %p, %p, %d\n", __FUNCTION__, desccount,

vfe->vfe_vfsops, vfe->vfe_opvdescs, vfe->vfe_flags);

if ((desccount <=0) || ((desccount > 8)) ||

(vfe->vfe_vfsops == (struct vfsops *)NULL) ||

(vfe->vfe_opvdescs == (struct vnodeopv_desc **)NULL)) {

IOLog("%s: returning failure, %d\n", __FUNCTION__, __LINE__);

return KMOD_RETURN_FAILURE;

}

if ((vfe->vfe_flags & (VFS_TBLTHREADSAFE | VFS_TBLFSNODELOCK)) == 0) {

IOLog("%s: returning failure, %d\n", __FUNCTION__, __LINE__);

return KMOD_RETURN_FAILURE;

}

error = vfs_fsadd(vfe, &fsd_vfsconf);

IOLog("%s: returned %s, %d, %d\n", __FUNCTION__,

error ? "failure" : "success", __LINE__, error);

return error ? KMOD_RETURN_FAILURE : KMOD_RETURN_SUCCESS;

}

Any help is greatly appreciated. Thanks!