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From: Logan Gunthorpe <logang@deltatee.com>
To: Max Gurtovoy <maxg@mellanox.com>,
	linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
	linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
	Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@fb.com>,
	Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
	Stephen Bates <sbates@raithlin.com>
Subject: Re: [PATCH v7 07/14] nvmet-passthru: add enable/disable helpers
Date: Thu, 15 Aug 2019 10:02:47 -0600
Message-ID: <90e7402f-bd2b-1e3b-1f15-53eff50a1abd@deltatee.com> (raw)
In-Reply-To: <e0323600-c4e8-00e7-d8cc-ff8d31b4ed10@mellanox.com>



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@wdc.com: this patch is very roughly based
>>   on a similar one by Chaitanya]
>> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
>> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
>> ---
>>   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

  reply index

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path() Logan Gunthorpe
2019-08-14 14:20   ` Max Gurtovoy
2019-08-15 11:46   ` Max Gurtovoy
2019-08-15 15:59     ` Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 02/14] nvme-core: export existing ctrl and ns interfaces Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 03/14] nvmet: add return value to nvmet_add_async_event() Logan Gunthorpe
2019-08-14 14:26   ` Max Gurtovoy
2019-08-14 16:59     ` Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 04/14] nvmet: make nvmet_copy_ns_identifier() non-static Logan Gunthorpe
2019-08-14 14:29   ` Max Gurtovoy
2019-08-15  7:15     ` Chaitanya Kulkarni
2019-08-01 23:45 ` [PATCH v7 05/14] nvmet-passthru: update KConfig with config passthru option Logan Gunthorpe
2019-08-14 14:31   ` Max Gurtovoy
2019-08-01 23:45 ` [PATCH v7 06/14] nvmet-passthru: add passthru code to process commands Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 07/14] nvmet-passthru: add enable/disable helpers Logan Gunthorpe
2019-08-15 12:20   ` Max Gurtovoy
2019-08-15 16:02     ` Logan Gunthorpe [this message]
2019-08-01 23:45 ` [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl Logan Gunthorpe
2019-08-15 12:36   ` Max Gurtovoy
2019-08-15 16:06     ` Logan Gunthorpe
2019-08-18 10:33       ` Max Gurtovoy
2019-08-22  0:09         ` Sagi Grimberg
2019-08-22  8:50           ` Max Gurtovoy
2019-08-22 17:41             ` Sagi Grimberg
2019-08-22 19:17               ` Sagi Grimberg
2019-08-22 19:41                 ` Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 09/14] nvmet-core: don't check the data len for pt-ctrl Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 10/14] nvmet-tcp: don't check data_len in nvmet_tcp_map_data() Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 11/14] nvmet-configfs: introduce passthru configfs interface Logan Gunthorpe
2019-08-15 12:46   ` Max Gurtovoy
2019-08-01 23:45 ` [PATCH v7 12/14] block: don't check blk_rq_is_passthrough() in blk_do_io_stat() Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 13/14] block: call blk_account_io_start() in blk_execute_rq_nowait() Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 14/14] nvmet-passthru: support block accounting Logan Gunthorpe

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