On Sat, Feb 02, 2019 at 01:42:46PM +0200, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
>
> Add new general helper to get restrack entry given by ID and
> their respective type.
>
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> drivers/infiniband/core/restrack.c | 22 ++++++++++++++++++++++
> include/rdma/restrack.h | 3 +++
> 2 files changed, 25 insertions(+)
>
> diff --git a/drivers/infiniband/core/restrack.c b/drivers/infiniband/core/restrack.c
> index ef5f16669262..b10b9c3cbb06 100644
> +++ b/drivers/infiniband/core/restrack.c
> @@ -256,6 +256,28 @@ int __must_check rdma_restrack_get(struct rdma_restrack_entry *res)
> }
> EXPORT_SYMBOL(rdma_restrack_get);
>
> +/**
> + * rdma_restrack_get_byid() - translate from ID to restrack object
> + * @dev: IB device
> + * @type: resource track type
> + * @id: ID to take a look
> + *
> + * Return: Pointer to restrack entry or -ENOENT in case of error.
> + */
> +struct rdma_restrack_entry *
> +rdma_restrack_get_byid(struct ib_device *dev,
> + enum rdma_restrack_type type, u32 id)
> +{
> + struct rdma_restrack_root *rt = &dev->res;
> + struct rdma_restrack_entry *res;
> +
> + res = xa_load(&rt->xa[type], id);
> + if (!res || !rdma_restrack_get(res))
> + return ERR_PTR(-ENOENT);
> + return res;
This is missing holding the read side of the rwsem
And the order of xa_erase should be changed:
void rdma_restrack_del(struct rdma_restrack_entry *res)
{
[..]
down_write(&rt->rwsem);
xa_erase(xa, res->id);
up_write(&rt->rwsem);
rdma_restrack_put(res);
wait_for_completion(&res->comp);
I'd also get rid of valid during the xarray conversion.
The only place that sets it to true is after rt_xa_alloc_cyclic, so
write it as:
down_write(&rt->rwsem);
add_has_been_done = xa_cmpxchg(xa, res->id, res, NULL, GFP_KERNEL) == res;
up_write(&rt->rwsem);
Ie if the entry was stored in it's own ID in the xarray then it is
'valid'.
Jason
