From: Christoph Hellwig <hch@lst.de>
To: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: linux-nvme@lists.infradead.org, linux-block@vger.kernel.org,
Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@fb.com>
Subject: Re: [PATCH 4/4] block: expose devt for GENHD_FL_HIDDEN disks
Date: Thu, 6 Dec 2018 21:22:00 +0100 [thread overview]
Message-ID: <20181206202200.GA32080@lst.de> (raw)
In-Reply-To: <20181206164812.30925-5-cascardo@canonical.com>
On Thu, Dec 06, 2018 at 02:48:12PM -0200, Thadeu Lima de Souza Cascardo wrote:
> Without this exposure, lsblk will fail as it tries to find out the
> device's dev_t numbers. This causes a real problem for nvme multipath
> devices, as their slaves are hidden.
>
> Exposing them fixes the problem, even though trying to open the devices
> returns an error in the case of nvme multipath. So, right now, it's the
> driver's responsibility to return a failure to open hidden devices.
So the problem with this is that it will cause udev to actually create
the /dev/nvmeXcYnZ nodes, which due to the previous patch will always
fail to open, which is a bit confusing. I guess we could live with this
if we add udev rules to supress the creation or something, but in general
it is a bit ugly.
WARNING: multiple messages have this Message-ID (diff)
From: hch@lst.de (Christoph Hellwig)
Subject: [PATCH 4/4] block: expose devt for GENHD_FL_HIDDEN disks
Date: Thu, 6 Dec 2018 21:22:00 +0100 [thread overview]
Message-ID: <20181206202200.GA32080@lst.de> (raw)
In-Reply-To: <20181206164812.30925-5-cascardo@canonical.com>
On Thu, Dec 06, 2018@02:48:12PM -0200, Thadeu Lima de Souza Cascardo wrote:
> Without this exposure, lsblk will fail as it tries to find out the
> device's dev_t numbers. This causes a real problem for nvme multipath
> devices, as their slaves are hidden.
>
> Exposing them fixes the problem, even though trying to open the devices
> returns an error in the case of nvme multipath. So, right now, it's the
> driver's responsibility to return a failure to open hidden devices.
So the problem with this is that it will cause udev to actually create
the /dev/nvmeXcYnZ nodes, which due to the previous patch will always
fail to open, which is a bit confusing. I guess we could live with this
if we add udev rules to supress the creation or something, but in general
it is a bit ugly.
next prev parent reply other threads:[~2018-12-06 20:22 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-06 16:48 [PATCH 0/4] nvme multipath: expose slaves/holders Thadeu Lima de Souza Cascardo
2018-12-06 16:48 ` Thadeu Lima de Souza Cascardo
2018-12-06 16:48 ` [PATCH 1/4] block: move holder tracking from struct block_device to hd_struct Thadeu Lima de Souza Cascardo
2018-12-06 16:48 ` Thadeu Lima de Souza Cascardo
2018-12-13 9:14 ` Hannes Reinecke
2018-12-13 9:14 ` Hannes Reinecke
2018-12-06 16:48 ` [PATCH 2/4] nvme: create slaves/holder entries for multipath devices Thadeu Lima de Souza Cascardo
2018-12-06 16:48 ` Thadeu Lima de Souza Cascardo
2018-12-13 9:15 ` Hannes Reinecke
2018-12-13 9:15 ` Hannes Reinecke
2018-12-06 16:48 ` [PATCH 3/4] nvme: Should not warn when a disk path is opened Thadeu Lima de Souza Cascardo
2018-12-06 16:48 ` Thadeu Lima de Souza Cascardo
2018-12-13 9:16 ` Hannes Reinecke
2018-12-13 9:16 ` Hannes Reinecke
2018-12-06 16:48 ` [PATCH 4/4] block: expose devt for GENHD_FL_HIDDEN disks Thadeu Lima de Souza Cascardo
2018-12-06 16:48 ` Thadeu Lima de Souza Cascardo
2018-12-06 20:22 ` Christoph Hellwig [this message]
2018-12-06 20:22 ` Christoph Hellwig
2018-12-12 8:32 ` Christoph Hellwig
2018-12-12 8:32 ` Christoph Hellwig
2018-12-12 12:39 ` Thadeu Lima de Souza Cascardo
2018-12-12 12:39 ` Thadeu Lima de Souza Cascardo
2018-12-13 9:18 ` Hannes Reinecke
2018-12-13 9:18 ` Hannes Reinecke
2018-12-13 11:41 ` Thadeu Lima de Souza Cascardo
2018-12-13 11:41 ` Thadeu Lima de Souza Cascardo
2018-12-13 12:19 ` Hannes Reinecke
2018-12-13 12:19 ` Hannes Reinecke
2018-12-13 16:08 ` Thadeu Lima de Souza Cascardo
2018-12-13 16:08 ` Thadeu Lima de Souza Cascardo
2018-12-13 14:32 ` Christoph Hellwig
2018-12-13 14:32 ` Christoph Hellwig
2018-12-13 15:25 ` Thadeu Lima de Souza Cascardo
2018-12-13 15:25 ` Thadeu Lima de Souza Cascardo
2018-12-13 20:20 ` Christoph Hellwig
2018-12-13 20:20 ` Christoph Hellwig
2018-12-13 21:00 ` Thadeu Lima de Souza Cascardo
2018-12-13 21:00 ` Thadeu Lima de Souza Cascardo
2018-12-14 7:47 ` Hannes Reinecke
2018-12-14 7:47 ` Hannes Reinecke
2018-12-14 8:56 ` Thadeu Lima de Souza Cascardo
2018-12-14 8:56 ` Thadeu Lima de Souza Cascardo
2018-12-14 9:06 ` Thadeu Lima de Souza Cascardo
2018-12-14 9:06 ` Thadeu Lima de Souza Cascardo
2018-12-14 9:54 ` Hannes Reinecke
2018-12-14 9:54 ` Hannes Reinecke
2018-12-14 10:18 ` Hannes Reinecke
2018-12-14 10:18 ` Hannes Reinecke
2018-12-14 11:09 ` Thadeu Lima de Souza Cascardo
2018-12-14 11:09 ` Thadeu Lima de Souza Cascardo
2018-12-14 9:44 ` Hannes Reinecke
2018-12-14 9:44 ` Hannes Reinecke
2018-12-13 9:33 ` [PATCH 0/4] nvme multipath: expose slaves/holders Johannes Thumshirn
2018-12-13 9:33 ` Johannes Thumshirn
2018-12-13 11:35 ` Thadeu Lima de Souza Cascardo
2018-12-13 11:35 ` Thadeu Lima de Souza Cascardo
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