From nobody Wed Apr 24 15:08:20 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=virtuozzo.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1523630032166800.1937414031481; Fri, 13 Apr 2018 07:33:52 -0700 (PDT) Received: from localhost ([::1]:57882 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f6zlv-00014y-E2 for importer@patchew.org; Fri, 13 Apr 2018 10:33:51 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36309) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f6zkE-00007f-RT for qemu-devel@nongnu.org; Fri, 13 Apr 2018 10:32:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f6zk9-0001g7-RN for qemu-devel@nongnu.org; Fri, 13 Apr 2018 10:32:06 -0400 Received: from relay.sw.ru ([185.231.240.75]:53936) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f6zk9-0001cV-JL; Fri, 13 Apr 2018 10:32:01 -0400 Received: from msk-vpn.virtuozzo.com ([195.214.232.6] helo=kvm.sw.ru) by relay.sw.ru with esmtp (Exim 4.90_1) (envelope-from ) id 1f6zk5-0002sv-83; Fri, 13 Apr 2018 17:31:57 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Fri, 13 Apr 2018 17:31:56 +0300 Message-Id: <20180413143156.11409-1-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.11.1 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 185.231.240.75 Subject: [Qemu-devel] [PATCH] nbd/server: introduce NBD_CMD_CACHE X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, mreitz@redhat.com, pbonzini@redhat.com, den@openvz.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Handle nbd CACHE command. Just do read, without sending read data back. Cache mechanism should be done by exported node driver chain. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Eric Blake --- include/block/nbd.h | 3 ++- nbd/server.c | 10 ++++++---- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/include/block/nbd.h b/include/block/nbd.h index fcdcd54502..b4793d0a29 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -135,6 +135,7 @@ typedef struct NBDExtent { #define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */ #define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* Send WRITE_ZEROES */ #define NBD_FLAG_SEND_DF (1 << 7) /* Send DF (Do not Fragment) */ +#define NBD_FLAG_SEND_CACHE (1 << 8) /* Send CACHE (prefetch) */ =20 /* New-style handshake (global) flags, sent from server to client, and control what will happen during handshake phase. */ @@ -195,7 +196,7 @@ enum { NBD_CMD_DISC =3D 2, NBD_CMD_FLUSH =3D 3, NBD_CMD_TRIM =3D 4, - /* 5 reserved for failed experiment NBD_CMD_CACHE */ + NBD_CMD_CACHE =3D 5, NBD_CMD_WRITE_ZEROES =3D 6, NBD_CMD_BLOCK_STATUS =3D 7, }; diff --git a/nbd/server.c b/nbd/server.c index 9e1f227178..30d7d3f444 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1134,7 +1134,7 @@ static coroutine_fn int nbd_negotiate(NBDClient *clie= nt, Error **errp) int ret; const uint16_t myflags =3D (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA | - NBD_FLAG_SEND_WRITE_ZEROES); + NBD_FLAG_SEND_WRITE_ZEROES | NBD_FLAG_SEND_C= ACHE); bool oldStyle; =20 /* Old style negotiation header, no room for options @@ -1826,7 +1826,9 @@ static int nbd_co_receive_request(NBDRequestData *req= , NBDRequest *request, return -EIO; } =20 - if (request->type =3D=3D NBD_CMD_READ || request->type =3D=3D NBD_CMD_= WRITE) { + if (request->type =3D=3D NBD_CMD_READ || request->type =3D=3D NBD_CMD_= WRITE || + request->type =3D=3D NBD_CMD_CACHE) + { if (request->len > NBD_MAX_BUFFER_SIZE) { error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u= )", request->len, NBD_MAX_BUFFER_SIZE); @@ -1911,7 +1913,7 @@ static coroutine_fn int nbd_do_cmd_read(NBDClient *cl= ient, NBDRequest *request, int ret; NBDExport *exp =3D client->exp; =20 - assert(request->type =3D=3D NBD_CMD_READ); + assert(request->type =3D=3D NBD_CMD_READ || request->type =3D=3D NBD_C= MD_CACHE); =20 /* XXX: NBD Protocol only documents use of FUA with WRITE */ if (request->flags & NBD_CMD_FLAG_FUA) { @@ -1930,7 +1932,7 @@ static coroutine_fn int nbd_do_cmd_read(NBDClient *cl= ient, NBDRequest *request, =20 ret =3D blk_pread(exp->blk, request->from + exp->dev_offset, data, request->len); - if (ret < 0) { + if (ret < 0 || request->type =3D=3D NBD_CMD_CACHE) { return nbd_send_generic_reply(client, request->handle, ret, "reading from file failed", errp); } --=20 2.11.1