From nobody Mon Feb 9 12:43:10 2026 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 1520868246806169.13051185620157; Mon, 12 Mar 2018 08:24:06 -0700 (PDT) Received: from localhost ([::1]:59511 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1evPIz-0002Xh-Rw for importer@patchew.org; Mon, 12 Mar 2018 11:24:05 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52210) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1evPGY-0000sV-Hp for qemu-devel@nongnu.org; Mon, 12 Mar 2018 11:21:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1evPGV-0006dD-35 for qemu-devel@nongnu.org; Mon, 12 Mar 2018 11:21:34 -0400 Received: from relay.sw.ru ([185.231.240.75]:55736) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1evPGU-0006ZW-Km; Mon, 12 Mar 2018 11:21:31 -0400 Received: from msk-vpn.virtuozzo.com ([195.214.232.6] helo=kvm.sw.ru) by relay.sw.ru with esmtp (Exim 4.89) (envelope-from ) id 1evPGR-0005yw-8y; Mon, 12 Mar 2018 18:21:27 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Mon, 12 Mar 2018 18:21:21 +0300 Message-Id: <20180312152126.286890-4-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.11.1 In-Reply-To: <20180312152126.286890-1-vsementsov@virtuozzo.com> References: <20180312152126.286890-1-vsementsov@virtuozzo.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 185.231.240.75 Subject: [Qemu-devel] [PATCH v2 3/8] nbd: BLOCK_STATUS for standard get_block_status function: server part 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, den@openvz.org, pbonzini@redhat.com 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" Minimal realization: only one extent in server answer is supported. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Eric Blake --- v2: - constants and type defs were splitted out by Eric, except for=20 NBD_META_ID_BASE_ALLOCATION - add nbd_opt_skip, to skip meta query remainder, if we are already sur= e, that the query selects nothing - check meta export name in OPT_EXPORT_NAME and OPT_GO - always set context_id =3D 0 for NBD_OPT_LIST_META_CONTEXT - negotiation rewritten to avoid wasting time and memory on reading lon= g, obviously invalid meta queries - fixed ERR_INVALID->ERR_UNKNOWN if export not found in nbd_negotiate_m= eta_queries - check client->export_meta.valid in "case NBD_CMD_BLOCK_STATUS" include/block/nbd.h | 2 + nbd/server.c | 310 ++++++++++++++++++++++++++++++++++++++++++++++++= ++++ 2 files changed, 312 insertions(+) diff --git a/include/block/nbd.h b/include/block/nbd.h index 2285637e67..9f2be18186 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -188,6 +188,8 @@ typedef struct NBDExtent { #define NBD_CMD_FLAG_REQ_ONE (1 << 3) /* only one extent in BLOCK_STATUS * reply chunk */ =20 +#define NBD_META_ID_BASE_ALLOCATION 0 + /* Supported request types */ enum { NBD_CMD_READ =3D 0, diff --git a/nbd/server.c b/nbd/server.c index 085e14afbf..16d7388085 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -82,6 +82,16 @@ struct NBDExport { =20 static QTAILQ_HEAD(, NBDExport) exports =3D QTAILQ_HEAD_INITIALIZER(export= s); =20 +/* NBDExportMetaContexts represents a list of contexts to be exported, + * as selected by NBD_OPT_SET_META_CONTEXT. Also used for + * NBD_OPT_LIST_META_CONTEXT. */ +typedef struct NBDExportMetaContexts { + char export_name[NBD_MAX_NAME_SIZE + 1]; + bool valid; /* means that negotiation of the option finished without + errors */ + bool base_allocation; /* export base:allocation context (block status)= */ +} NBDExportMetaContexts; + struct NBDClient { int refcount; void (*close_fn)(NBDClient *client, bool negotiated); @@ -102,6 +112,7 @@ struct NBDClient { bool closing; =20 bool structured_reply; + NBDExportMetaContexts export_meta; =20 uint32_t opt; /* Current option being negotiated */ uint32_t optlen; /* remaining length of data in ioc for the option bei= ng @@ -273,6 +284,20 @@ static int nbd_opt_read(NBDClient *client, void *buffe= r, size_t size, return qio_channel_read_all(client->ioc, buffer, size, errp) < 0 ? -EI= O : 1; } =20 +/* Drop size bytes from the unparsed payload of the current option. + * Return -errno on I/O error, 0 if option was completely handled by + * sending a reply about inconsistent lengths, or 1 on success. */ +static int nbd_opt_skip(NBDClient *client, size_t size, Error **errp) +{ + if (size > client->optlen) { + return nbd_opt_invalid(client, errp, + "Inconsistent lengths in option %s", + nbd_opt_lookup(client->opt)); + } + client->optlen -=3D size; + return nbd_drop(client->ioc, size, errp) < 0 ? -EIO : 1; +} + /* nbd_opt_read_name * * Read string in format: @@ -371,6 +396,12 @@ static int nbd_negotiate_handle_list(NBDClient *client= , Error **errp) return nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); } =20 +static void nbd_check_meta_export_name(NBDClient *client) +{ + client->export_meta.valid =3D client->export_meta.valid && + strcmp(client->exp->name, client->export_meta.export_name) =3D=3D = 0; +} + /* Send a reply to NBD_OPT_EXPORT_NAME. * Return -errno on error, 0 on success. */ static int nbd_negotiate_handle_export_name(NBDClient *client, @@ -422,6 +453,7 @@ static int nbd_negotiate_handle_export_name(NBDClient *= client, =20 QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); nbd_export_get(client->exp); + nbd_check_meta_export_name(client); =20 return 0; } @@ -612,6 +644,7 @@ static int nbd_negotiate_handle_info(NBDClient *client,= uint16_t myflags, client->exp =3D exp; QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); nbd_export_get(client->exp); + nbd_check_meta_export_name(client); rc =3D 1; } return rc; @@ -666,6 +699,181 @@ static QIOChannel *nbd_negotiate_handle_starttls(NBDC= lient *client, return QIO_CHANNEL(tioc); } =20 +/* nbd_negotiate_send_meta_context + * + * Send one chunk of reply to NBD_OPT_{LIST,SET}_META_CONTEXT + * + * For NBD_OPT_LIST_META_CONTEXT @context_id is ignored, 0 is used instead. + */ +static int nbd_negotiate_send_meta_context(NBDClient *client, + const char *context, + uint32_t context_id, + Error **errp) +{ + NBDOptionReplyMetaContext opt; + struct iovec iov[] =3D { + {.iov_base =3D &opt, .iov_len =3D sizeof(opt)}, + {.iov_base =3D (void *)context, .iov_len =3D strlen(context)} + }; + + if (client->opt =3D=3D NBD_OPT_LIST_META_CONTEXT) { + context_id =3D 0; + } + + set_be_option_rep(&opt.h, client->opt, NBD_REP_META_CONTEXT, + sizeof(opt) - sizeof(opt.h) + iov[1].iov_len); + stl_be_p(&opt.context_id, context_id); + + return qio_channel_writev_all(client->ioc, iov, 2, errp) < 0 ? -EIO : = 0; +} + +/* nbd_meta_base_query + * + * Handle query to 'base' namespace. For now, only base:allocation context= is + * available in it. + * + * Return -errno on I/O error, 0 if option was completely handled by + * sending a reply about inconsistent lengths, or 1 on success. */ +static int nbd_meta_base_query(NBDClient *client, NBDExportMetaContexts *m= eta, + uint32_t len, Error **errp) +{ + int ret; + char query[sizeof("allocation") - 1]; + size_t alen =3D strlen("allocation"); + + if (len =3D=3D 0) { + if (client->opt =3D=3D NBD_OPT_LIST_META_CONTEXT) { + meta->base_allocation =3D true; + } + return 1; + } + + if (len !=3D alen) { + return nbd_opt_skip(client, len, errp); + } + + ret =3D nbd_opt_read(client, query, len, errp); + if (ret <=3D 0) { + return ret; + } + + if (strncmp(query, "allocation", alen) =3D=3D 0) { + meta->base_allocation =3D true; + } + + return 1; +} + +/* nbd_negotiate_meta_query + * + * Parse namespace name and call corresponding function to parse body of t= he + * query. + * + * The only supported namespace now is 'base'. + * + * The function aims not wasting time and memory to read long unknown name= space + * names. + * + * Return -errno on I/O error, 0 if option was completely handled by + * sending a reply about inconsistent lengths, or 1 on success. */ +static int nbd_negotiate_meta_query(NBDClient *client, + NBDExportMetaContexts *meta, Error **e= rrp) +{ + int ret; + char query[sizeof("base:") - 1]; + size_t baselen =3D strlen("base:"); + uint32_t len; + + ret =3D nbd_opt_read(client, &len, sizeof(len), errp); + if (ret <=3D 0) { + return ret; + } + cpu_to_be32s(&len); + + /* The only supported namespace for now is 'base'. So query should sta= rt + * with 'base:'. Otherwise, we can ignore it and skip the remainder. */ + if (len < baselen) { + return nbd_opt_skip(client, len, errp); + } + + len -=3D baselen; + ret =3D nbd_opt_read(client, query, baselen, errp); + if (ret <=3D 0) { + return ret; + } + if (strncmp(query, "base:", baselen) !=3D 0) { + return nbd_opt_skip(client, len, errp); + } + + return nbd_meta_base_query(client, meta, len, errp); +} + +/* nbd_negotiate_meta_queries + * Handle NBD_OPT_LIST_META_CONTEXT and NBD_OPT_SET_META_CONTEXT + * + * @meta may be NULL, if caller isn't interested in selected contexts (for + * NBD_OPT_LIST_META_CONTEXT) + * + * Return -errno on I/O error, 0 if option was completely handled by + * sending a reply about inconsistent lengths, or 1 on success. */ +static int nbd_negotiate_meta_queries(NBDClient *client, + NBDExportMetaContexts *meta, Error *= *errp) +{ + int ret; + NBDExport *exp; + NBDExportMetaContexts local_meta; + uint32_t nb_queries; + int i; + + assert(client->structured_reply); + + if (!meta) { + meta =3D &local_meta; + } + + memset(meta, 0, sizeof(*meta)); + + ret =3D nbd_opt_read_name(client, meta->export_name, NULL, errp); + if (ret <=3D 0) { + return ret; + } + + exp =3D nbd_export_find(meta->export_name); + if (exp =3D=3D NULL) { + return nbd_opt_drop(client, NBD_REP_ERR_UNKNOWN, errp, + "export '%s' not present", meta->export_name); + } + + ret =3D nbd_opt_read(client, &nb_queries, sizeof(nb_queries), errp); + if (ret <=3D 0) { + return ret; + } + cpu_to_be32s(&nb_queries); + + for (i =3D 0; i < nb_queries; ++i) { + ret =3D nbd_negotiate_meta_query(client, meta, errp); + if (ret <=3D 0) { + return ret; + } + } + + if (meta->base_allocation) { + ret =3D nbd_negotiate_send_meta_context(client, "base:allocation", + NBD_META_ID_BASE_ALLOCATION, + errp); + if (ret < 0) { + return ret; + } + } + + ret =3D nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); + if (ret =3D=3D 0) { + meta->valid =3D true; + } + + return ret; +} + /* nbd_negotiate_options * Process all NBD_OPT_* client option commands, during fixed newstyle * negotiation. @@ -856,6 +1064,22 @@ static int nbd_negotiate_options(NBDClient *client, u= int16_t myflags, } break; =20 + case NBD_OPT_LIST_META_CONTEXT: + case NBD_OPT_SET_META_CONTEXT: + if (!client->structured_reply) { + ret =3D nbd_opt_invalid( + client, errp, + "request option '%s' when structured reply " + "is not negotiated", nbd_opt_lookup(option)); + } else if (option =3D=3D NBD_OPT_LIST_META_CONTEXT) { + ret =3D nbd_negotiate_meta_queries(client, NULL, errp); + } else { + ret =3D nbd_negotiate_meta_queries(client, + &client->export_meta, + errp); + } + break; + default: ret =3D nbd_opt_drop(client, NBD_REP_ERR_UNSUP, errp, "Unsupported option %" PRIu32 " (%s)", @@ -1485,6 +1709,79 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDC= lient *client, return ret; } =20 +static int blockstatus_to_extent_be(BlockDriverState *bs, uint64_t offset, + uint64_t bytes, NBDExtent *extent) +{ + uint64_t remaining_bytes =3D bytes; + + while (remaining_bytes) { + uint32_t flags; + int64_t num; + int ret =3D bdrv_block_status_above(bs, NULL, offset, remaining_by= tes, + &num, NULL, NULL); + if (ret < 0) { + return ret; + } + + flags =3D (ret & BDRV_BLOCK_ALLOCATED ? 0 : NBD_STATE_HOLE) | + (ret & BDRV_BLOCK_ZERO ? NBD_STATE_ZERO : 0); + + if (remaining_bytes =3D=3D bytes) { + extent->flags =3D flags; + } + + if (flags !=3D extent->flags) { + break; + } + + offset +=3D num; + remaining_bytes -=3D num; + } + + cpu_to_be32s(&extent->flags); + extent->length =3D cpu_to_be32(bytes - remaining_bytes); + + return 0; +} + +/* nbd_co_send_extents + * @extents should be in big-endian */ +static int nbd_co_send_extents(NBDClient *client, uint64_t handle, + NBDExtent *extents, unsigned nb_extents, + uint32_t context_id, Error **errp) +{ + NBDStructuredMeta chunk; + + struct iovec iov[] =3D { + {.iov_base =3D &chunk, .iov_len =3D sizeof(chunk)}, + {.iov_base =3D extents, .iov_len =3D nb_extents * sizeof(extents[0= ])} + }; + + set_be_chunk(&chunk.h, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_BLOCK_STATU= S, + handle, sizeof(chunk) - sizeof(chunk.h) + iov[1].iov_len); + stl_be_p(&chunk.context_id, context_id); + + return nbd_co_send_iov(client, iov, 2, errp); +} + +/* Get block status from the exported device and send it to the client */ +static int nbd_co_send_block_status(NBDClient *client, uint64_t handle, + BlockDriverState *bs, uint64_t offset, + uint64_t length, uint32_t context_id, + Error **errp) +{ + int ret; + NBDExtent extent; + + ret =3D blockstatus_to_extent_be(bs, offset, length, &extent); + if (ret < 0) { + return nbd_co_send_structured_error( + client, handle, -ret, "can't get block status", errp); + } + + return nbd_co_send_extents(client, handle, &extent, 1, context_id, err= p); +} + /* nbd_co_receive_request * Collect a client request. Return 0 if request looks valid, -EIO to drop * connection right away, and any other negative value to report an error = to @@ -1562,6 +1859,8 @@ static int nbd_co_receive_request(NBDRequestData *req= , NBDRequest *request, valid_flags |=3D NBD_CMD_FLAG_DF; } else if (request->type =3D=3D NBD_CMD_WRITE_ZEROES) { valid_flags |=3D NBD_CMD_FLAG_NO_HOLE; + } else if (request->type =3D=3D NBD_CMD_BLOCK_STATUS) { + valid_flags |=3D NBD_CMD_FLAG_REQ_ONE; } if (request->flags & ~valid_flags) { error_setg(errp, "unsupported flags for command %s (got 0x%x)", @@ -1690,6 +1989,17 @@ static coroutine_fn int nbd_handle_request(NBDClient= *client, =20 return nbd_send_generic_reply(client, request->handle, ret, "discard failed", errp); + case NBD_CMD_BLOCK_STATUS: + if (client->export_meta.valid && client->export_meta.base_allocati= on) { + return nbd_co_send_block_status(client, request->handle, + blk_bs(exp->blk), request->fro= m, + request->len, + NBD_META_ID_BASE_ALLOCATION, e= rrp); + } else { + return nbd_send_generic_reply(client, request->handle, -EINVAL, + "CMD_BLOCK_STATUS not negotiated= ", + errp); + } default: msg =3D g_strdup_printf("invalid request type (%" PRIu32 ") receiv= ed", request->type); --=20 2.11.1