Re: [PATCH v3 3/3] nbd/server: Allow MULTI_CONN for shared writable exports

From: "Richard W.M. Jones" <rjones@redhat.com>
To: Eric Blake <eblake@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
	Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
	qemu-block@nongnu.org, qemu-devel@nongnu.org,
	Markus Armbruster <armbru@redhat.com>,
	nsoffer@redhat.com, Hanna Reitz <hreitz@redhat.com>,
	v.sementsov-og@ya.ru
Subject: Re: [PATCH v3 3/3] nbd/server: Allow MULTI_CONN for shared writable exports
Date: Tue, 15 Mar 2022 13:14:41 +0000	[thread overview]
Message-ID: <20220315131441.GD1127@redhat.com> (raw)
In-Reply-To: <20220314203818.3681277-4-eblake@redhat.com>

The patches seem OK to me, but I don't really know enough about the
internals of qemu-nbd to give a line-by-line review.  I did however
build and test qemu-nbd with the patches:

  $ ./build/qemu-nbd /var/tmp/test.qcow2 
  $ nbdinfo nbd://localhost
  ...
	can_multi_conn: false

  $ ./build/qemu-nbd -e 2 /var/tmp/test.qcow2 
  $ nbdinfo nbd://localhost
  ...
	can_multi_conn: false

^^^ Is this expected?  It also happens with -e 0.

  $ ./build/qemu-nbd -e 2 -m on /var/tmp/test.qcow2 
  $ nbdinfo nbd://localhost
  ...
	can_multi_conn: true

  $ ./build/qemu-nbd -e 2 -m off /var/tmp/test.qcow2 
  $ nbdinfo nbd://localhost
  ...
	can_multi_conn: false

Rich.

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