Re: [PATCH v3 16/16] nvmet-fc: take ref count on tgtport before delete assoc

Hannes Reinecke
2023-12-19T11:47:19Z

On 12/18/23 16:31, Daniel Wagner wrote:
> We have to ensure that the tgtport is not going away
> before be have remove all the associations.

before we have removed all the associations.

>
> Signed-off-by: Daniel Wagner <dwagner@suse.de>
> ---
> drivers/nvme/target/fc.c | 31 +++++++++++++++++++++++--------
> 1 file changed, 23 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
> index 30ba4ede333f..455d35ef97eb 100644
> --- a/drivers/nvme/target/fc.c
> +++ b/drivers/nvme/target/fc.c
> @@ -1092,13 +1092,28 @@ nvmet_fc_alloc_hostport(struct nvmet_fc_tgtport *tgtport, void *hosthandle)
> }
>
> static void
> -nvmet_fc_delete_assoc(struct work_struct *work)
> +nvmet_fc_delete_assoc(struct nvmet_fc_tgt_assoc *assoc)
> +{
> + nvmet_fc_delete_target_assoc(assoc);
> + nvmet_fc_tgt_a_put(assoc);
> +}
> +
> +static void
> +nvmet_fc_delete_assoc_work(struct work_struct *work)
> {
> struct nvmet_fc_tgt_assoc *assoc =
> container_of(work, struct nvmet_fc_tgt_assoc, del_work);
> + struct nvmet_fc_tgtport *tgtport = assoc->tgtport;
>
> - nvmet_fc_delete_target_assoc(assoc);
> - nvmet_fc_tgt_a_put(assoc);
> + nvmet_fc_delete_assoc(assoc);
> + nvmet_fc_tgtport_put(tgtport);
> +}
> +
> +static void
> +nvmet_fc_schedule_delete_assoc(struct nvmet_fc_tgt_assoc *assoc)
> +{
> + nvmet_fc_tgtport_get(assoc->tgtport);
> + queue_work(nvmet_wq, &assoc->del_work);

Errm.
That is dangerous, as it will leak a reference if 'del_work' is already
queued.
And we already took a reference from the caller. Why do we need two
references here?

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@suse.de +49 911 74053 688
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