From: Pavel Shilovsky <pavel.shilovsky@gmail.com>
To: Steve French <smfrench@gmail.com>
Cc: CIFS <linux-cifs@vger.kernel.org>,
samba-technical <samba-technical@lists.samba.org>
Subject: Re: [PATCH] Improve performance of POSIX open - request query disk id open context
Date: Sat, 6 Jul 2019 09:34:41 -0700 [thread overview]
Message-ID: <CAKywueQu8idf6120LybjsNwHqy7MOnXMcm=e8ug=UtiU4u0zWA@mail.gmail.com> (raw)
In-Reply-To: <CAH2r5mtb_g1Hx4UPB+5XpSY3Ew_fn=bdjLnpRD=ZQymJxrUw0g@mail.gmail.com>
Good idea! See some comments below.
When adding new context, the following defines need to be changed:
689 /*
690 * Maximum size of a SMB2_CREATE response is 64 (smb2 header) +
691 * 88 (fixed part of create response) + 520 (path) + 150 (contexts) +
692 * 2 bytes of padding.
693 */
694 #define MAX_SMB2_CREATE_RESPONSE_SIZE 824
and
657 /*
658 * Maximum number of iovs we need for an open/create request.
659 * [0] : struct smb2_create_req
660 * [1] : path
661 * [2] : lease context
662 * [3] : durable context
663 * [4] : posix context
664 * [5] : time warp context
665 * [6] : compound padding
666 */
667 #define SMB2_CREATE_IOV_SIZE 7
+ if (n_iov > 2) {
+ struct create_context *ccontext =
+ (struct create_context *)iov[n_iov-1].iov_base;
+ ccontext->Next = cpu_to_le32(iov[n_iov-1].iov_len);
+ }
+ add_query_id_context(iov, &n_iov);
I think we should add a check if iov has enough capacity to keep all
the contexts. Right now it will oops if it wasn't allocated right in
the upper layer.
In general, I think having a complete patch that adds the whole
functionality is better for future git bisect and looks more logical
instead of breaking such small features into parts.
Best regards,
Pavel Shilovskiy
пт, 5 июл. 2019 г. в 23:14, Steve French via samba-technical
<samba-technical@lists.samba.org>:
>
> We can cut the number of roundtrips on open (may also
> help some rename cases as well) by returning the inode
> number in the SMB2 open request itself instead of
> querying it afterwards via a query FILE_INTERNAL_INFO.
> This should significantly improve the performance of
> posix open.
>
> Add SMB2_CREATE_QUERY_ON_DISK_ID create context request
> on open calls so that when server supports this we
> can save a roundtrip for QUERY_INFO on every open.
>
> Follow on patch will add the response processing for
> SMB2_CREATE_QUERY_ON_DISK_ID context and optimize
> smb2_open_file to avoid the extra network roundtrip
> on every posix open. This patch adds the context on
> SMB2/SMB3 open requests.
>
> --
> Thanks,
>
> Steve
next prev parent reply other threads:[~2019-07-06 16:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-06 6:13 [PATCH] Improve performance of POSIX open - request query disk id open context Steve French
2019-07-06 16:34 ` Pavel Shilovsky [this message]
2019-07-06 19:43 ` Steve French
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