On 2019-08-15 6:20 a.m., Max Gurtovoy wrote:
>
> On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
>> This patch adds helper functions which are used in the NVMeOF configfs
>> when the user is configuring the passthru subsystem. Here we ensure
>> that only one subsys is assigned to each nvme_ctrl by using an xarray
>> on the cntlid.
>>
>> [chaitanya.kulkarni@xxxxxxx: this patch is very roughly based
>> on a similar one by Chaitanya]
>> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
>> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
>> ---
>> drivers/nvme/target/core.c | 8 +++
>> drivers/nvme/target/io-cmd-passthru.c | 77 +++++++++++++++++++++++++++
>> drivers/nvme/target/nvmet.h | 10 ++++
>> 3 files changed, 95 insertions(+)
>>
>> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
>> index 50c01b2da568..2e75968af7f4 100644
>> --- a/drivers/nvme/target/core.c
>> +++ b/drivers/nvme/target/core.c
>> @@ -519,6 +519,12 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
>> mutex_lock(&subsys->lock);
>> ret = 0;
>> +
>> + if (nvmet_passthru_ctrl(subsys)) {
>> + pr_info("cannot enable both passthru and regular namespaces
>> for a single subsystem");
>> + goto out_unlock;
>> + }
>> +
>> if (ns->enabled)
>> goto out_unlock;
>> @@ -1439,6 +1445,8 @@ static void nvmet_subsys_free(struct kref *ref)
>> WARN_ON_ONCE(!list_empty(&subsys->namespaces));
>> + nvmet_passthru_subsys_free(subsys);
>> +
>> kfree(subsys->subsysnqn);
>> kfree(subsys);
>> }
>> diff --git a/drivers/nvme/target/io-cmd-passthru.c
>> b/drivers/nvme/target/io-cmd-passthru.c
>> index 46c58fec5608..b199785500ad 100644
>> --- a/drivers/nvme/target/io-cmd-passthru.c
>> +++ b/drivers/nvme/target/io-cmd-passthru.c
>> @@ -11,6 +11,11 @@
>> #include "../host/nvme.h"
>> #include "nvmet.h"
>> +/*
>> + * xarray to maintain one passthru subsystem per nvme controller.
>> + */
>> +static DEFINE_XARRAY(passthru_subsystems);
>> +
>> static struct workqueue_struct *passthru_wq;
>> int nvmet_passthru_init(void)
>> @@ -27,6 +32,78 @@ void nvmet_passthru_destroy(void)
>> destroy_workqueue(passthru_wq);
>> }
>> +int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys)
>> +{
>> + struct nvme_ctrl *ctrl;
>> + int ret = -EINVAL;
>> + void *old;
>> +
>> + mutex_lock(&subsys->lock);
>> + if (!subsys->passthru_ctrl_path)
>> + goto out_unlock;
>> + if (subsys->passthru_ctrl)
>> + goto out_unlock;
>> +
>> + if (subsys->nr_namespaces) {
>> + pr_info("cannot enable both passthru and regular namespaces
>> for a single subsystem");
>> + goto out_unlock;
>> + }
>> +
>> + ctrl = nvme_ctrl_get_by_path(subsys->passthru_ctrl_path);
>> + if (IS_ERR(ctrl)) {
>> + ret = PTR_ERR(ctrl);
>> + pr_err("failed to open nvme controller %s\n",
>> + subsys->passthru_ctrl_path);
>> +
>> + goto out_unlock;
>> + }
>> +
>> + old = xa_cmpxchg(&passthru_subsystems, ctrl->cntlid, NULL,
>> + subsys, GFP_KERNEL);
>> + if (xa_is_err(old)) {
>> + ret = xa_err(old);
>> + goto out_put_ctrl;
>> + }
>> +
>> + if (old)
>> + goto out_put_ctrl;
>> +
>> + subsys->passthru_ctrl = ctrl;
>> + ret = 0;
>> +
>> + goto out_unlock;
>
> can we re-arrange the code here ?
>
> it's not so common to see goto in a good flow.
>
> maybe have 1 good flow the goto's will go bellow it as we usually do in
> this subsystem.
OK, queued up for v8.
Thanks,
Logan
