From: Christoph Hellwig <hch@lst.de>
To: Daniel Wagner <dwagner@suse.de>
Cc: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
Keith Busch <kbusch@kernel.org>, Christoph Hellwig <hch@lst.de>,
Sagi Grimberg <sagi@grimberg.me>, Hannes Reinecke <hare@suse.de>
Subject: Re: [RFC v1] nvme: add cse, ds, ms, nsze and nuse to sysfs
Date: Mon, 27 Nov 2023 15:18:57 +0100 [thread overview]
Message-ID: <20231127141857.GA25833@lst.de> (raw)
In-Reply-To: <20231127103208.25748-1-dwagner@suse.de>
On Mon, Nov 27, 2023 at 11:32:08AM +0100, Daniel Wagner wrote:
> Also getting a pointer to the nvme_ns data structure is a bit strange
> (dev_to_nvme_ns).
> This stip is necessary as many of the ns attributes are in
> nvme_ns. Shouldn't these per path values not all be the same and thus couldn't
> these be in nvme_ns_head? Anyway, just not sure who to deal with this. So any
> pointers highly welcomed!
Yes, they probably should be in the ns_head.
> + list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
> + down_read(&ctrl->namespaces_rwsem);
> + list_for_each_entry(ns, &ctrl->namespaces, list) {
> + ret = ns;
> + break;
> + }
> + up_read(&ctrl->namespaces_rwsem);
> + }
> + return ret;
> + }
.. I also don't think this would even be safe as-is as we dont hold
a reference to the ns after dropping the lock.
> +static ssize_t csi_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + return sysfs_emit(buf, "%d\n", dev_to_ns_head(dev)->ids.csi);
> +}
> +static DEVICE_ATTR_RO(csi);
> +
> +static ssize_t lba_ds_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct nvme_ns *ns = dev_to_nvme_ns(dev);
> +
> + return sysfs_emit(buf, "%d\n", ns->lba_shift);
lba_ds is a bit of an odd name. And I also don't think we even need
this, because it really is just a weird enconding for the logical block
size already exposed by the block layer.
> +static ssize_t lba_ms_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct nvme_ns *ns = dev_to_nvme_ns(dev);
> +
> + return sysfs_emit(buf, "%d\n", ns->ms);
> +}
> +static DEVICE_ATTR_RO(lba_ms);
I'd probably spell out metadata_size, or probably even better
metadata_bytes to match the unit postfixes elsewhere in the block code.
> +
> +static ssize_t nsze_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct nvme_ns *ns = dev_to_nvme_ns(dev);
> +
> + return sysfs_emit(buf, "%llu\n", ns->nsze);
> +}
> +static DEVICE_ATTR_RO(nsze);
This is just the normal size of the block device we already export.
next prev parent reply other threads:[~2023-11-27 14:19 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-27 10:32 [RFC v1] nvme: add cse, ds, ms, nsze and nuse to sysfs Daniel Wagner
2023-11-27 10:44 ` Keith Busch
2023-11-27 12:07 ` Daniel Wagner
2023-11-27 13:57 ` Christoph Hellwig
2023-11-27 14:18 ` Christoph Hellwig [this message]
2023-11-27 15:44 ` Keith Busch
2023-11-27 15:56 ` Christoph Hellwig
2023-11-27 16:30 ` Keith Busch
2023-11-27 16:33 ` Christoph Hellwig
2023-11-27 16:46 ` Keith Busch
2023-11-28 8:21 ` Daniel Wagner
2023-11-28 10:06 ` Sagi Grimberg
2023-11-28 13:05 ` Christoph Hellwig
2023-11-28 19:02 ` Keith Busch
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