Re: [PATCH] 9p/xen: Use flexible array for data rings

Jürgen Groß <[email protected]> Wed, 27 May 2026 12:07:08 +0200

Newsgroups	dev.linux.lists.v9fs,org.kernel.vger.linux-kernel
Message-ID	<[email protected]>

On 27.05.26 08:38, Rosen Penev wrote:
> On Tue, May 26, 2026 at 10:39 PM Jürgen Groß <[email protected]> wrote:
>>
>> On 19.05.26 03:57, Rosen Penev wrote:
>>> Store the fixed set of Xen 9p data rings in the frontend private
>>> allocation instead of allocating a separate rings array.
>>>
>>> This keeps the data ring storage tied to the frontend lifetime and
>>> simplifies the allocation and cleanup paths.
>>>
>>> Assisted-by: Codex:GPT-5.5
>>> Signed-off-by: Rosen Penev <[email protected]>
>>> ---
>>>    net/9p/trans_xen.c | 68 ++++++++++++++++++++--------------------------
>>>    1 file changed, 30 insertions(+), 38 deletions(-)
>>>
>>> diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
>>> index f9fb2db7a066..5a110d71d18c 100644
>>> --- a/net/9p/trans_xen.c
>>> +++ b/net/9p/trans_xen.c
>>> @@ -55,7 +55,7 @@ struct xen_9pfs_front_priv {
>>>        char *tag;
>>>        struct p9_client *client;
>>>
>>> -     struct xen_9pfs_dataring *rings;
>>> +     struct xen_9pfs_dataring rings[];
>>
>> Any reason not to use rings[XEN_9PFS_NUM_RINGS] instead of a flex array?
>>
>> The number of rings is a compile time constant, after all!
> flexibility really. I don't know if this will ever change.

If it ever changes we can still switch to a flex array.


Juergen

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