linux-nvme.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: James Smart <jsmart2021@gmail.com>
To: linux-nvme@lists.infradead.org
Cc: James Smart <jsmart2021@gmail.com>
Subject: [PATCH v2] nvme: Treat discovery subsystems as unique subsystems
Date: Tue,  3 Sep 2019 14:20:37 -0700	[thread overview]
Message-ID: <20190903212037.29705-1-jsmart2021@gmail.com> (raw)

Current code matches subnqn and collapses all controllers to the
same subnqn to a single subsystem structure. This is good for
recognizing multiple controllers for the same subsystem. But with
the well-known discovery subnqn, the subsystems aren't truly the
same subsystem. As such, subsystem specific rules, such as no
overlap of controller id, do not apply. With today's behavior, the
check for overlap of controller id can fail, preventing the new
discovery controller from being created.

When searching for like subsystem nqn, exclude the discovery nqn
from matching. This will result in each discovery controller being
attached to a unique subsystem structure.

Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>

---
v2: add comment
---
 drivers/nvme/host/core.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 4660505eded9..6960781a514e 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2358,6 +2358,17 @@ static struct nvme_subsystem *__nvme_find_get_subsystem(const char *subsysnqn)
 
 	lockdep_assert_held(&nvme_subsystems_lock);
 
+	/*
+	 * Fail matches for discovery subsystems. This results
+	 * in each discovery controller bound to a unique subsystem.
+	 * This avoids issues with validating controller values
+	 * that can only be true when there is a single unique subsystem.
+	 * There may be multiple and completely independent entities
+	 * that provide discovery controllers.
+	 */
+	if (!strcmp(subsysnqn, NVME_DISC_SUBSYS_NAME))
+		return NULL;
+
 	list_for_each_entry(subsys, &nvme_subsystems, entry) {
 		if (strcmp(subsys->subnqn, subsysnqn))
 			continue;
-- 
2.13.7


_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme

             reply	other threads:[~2019-09-03 21:20 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-03 21:20 James Smart [this message]
2019-09-04 12:46 ` [PATCH v2] nvme: Treat discovery subsystems as unique subsystems Christoph Hellwig
2019-09-04 14:08 ` Max Gurtovoy

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190903212037.29705-1-jsmart2021@gmail.com \
    --to=jsmart2021@gmail.com \
    --cc=linux-nvme@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).