diff options
| -rw-r--r-- | nbd/server.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/nbd/server.c b/nbd/server.c index 280bdbb104..cea158913b 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -22,6 +22,8 @@ #include "trace.h" #include "nbd-internal.h" +#define NBD_META_ID_BASE_ALLOCATION 0 + static int system_errno_to_nbd_errno(int err) { switch (err) { @@ -82,6 +84,16 @@ struct NBDExport { static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports); +/* 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 +114,7 @@ struct NBDClient { bool closing; bool structured_reply; + NBDExportMetaContexts export_meta; uint32_t opt; /* Current option being negotiated */ uint32_t optlen; /* remaining length of data in ioc for the option being @@ -273,6 +286,20 @@ static int nbd_opt_read(NBDClient *client, void *buffer, size_t size, return qio_channel_read_all(client->ioc, buffer, size, errp) < 0 ? -EIO : 1; } +/* 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 -= size; + return nbd_drop(client->ioc, size, errp) < 0 ? -EIO : 1; +} + /* nbd_opt_read_name * * Read a string with the format: @@ -372,6 +399,12 @@ static int nbd_negotiate_handle_list(NBDClient *client, Error **errp) return nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); } +static void nbd_check_meta_export_name(NBDClient *client) +{ + client->export_meta.valid &= !strcmp(client->exp->name, + client->export_meta.export_name); +} + /* Send a reply to NBD_OPT_EXPORT_NAME. * Return -errno on error, 0 on success. */ static int nbd_negotiate_handle_export_name(NBDClient *client, @@ -423,6 +456,7 @@ static int nbd_negotiate_handle_export_name(NBDClient *client, QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); nbd_export_get(client->exp); + nbd_check_meta_export_name(client); return 0; } @@ -616,6 +650,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags, client->exp = exp; QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); nbd_export_get(client->exp); + nbd_check_meta_export_name(client); rc = 1; } return rc; @@ -670,6 +705,189 @@ static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client, return QIO_CHANNEL(tioc); } +/* 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[] = { + {.iov_base = &opt, .iov_len = sizeof(opt)}, + {.iov_base = (void *)context, .iov_len = strlen(context)} + }; + + if (client->opt == NBD_OPT_LIST_META_CONTEXT) { + context_id = 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. 'len' is the amount of text remaining to be read from + * the current name, after the 'base:' portion has been stripped. + * + * 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 *meta, + uint32_t len, Error **errp) +{ + int ret; + char query[sizeof("allocation") - 1]; + size_t alen = strlen("allocation"); + + if (len == 0) { + if (client->opt == NBD_OPT_LIST_META_CONTEXT) { + meta->base_allocation = true; + } + return 1; + } + + if (len != alen) { + return nbd_opt_skip(client, len, errp); + } + + ret = nbd_opt_read(client, query, len, errp); + if (ret <= 0) { + return ret; + } + + if (strncmp(query, "allocation", alen) == 0) { + meta->base_allocation = true; + } + + return 1; +} + +/* nbd_negotiate_meta_query + * + * Parse namespace name and call corresponding function to parse body of the + * query. + * + * The only supported namespace now is 'base'. + * + * The function aims not wasting time and memory to read long unknown namespace + * 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 **errp) +{ + int ret; + char query[sizeof("base:") - 1]; + size_t baselen = strlen("base:"); + uint32_t len; + + ret = nbd_opt_read(client, &len, sizeof(len), errp); + if (ret <= 0) { + return ret; + } + cpu_to_be32s(&len); + + /* The only supported namespace for now is 'base'. So query should start + * with 'base:'. Otherwise, we can ignore it and skip the remainder. */ + if (len < baselen) { + return nbd_opt_skip(client, len, errp); + } + + len -= baselen; + ret = nbd_opt_read(client, query, baselen, errp); + if (ret <= 0) { + return ret; + } + if (strncmp(query, "base:", baselen) != 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 + * + * Return -errno on I/O error, or 0 if option was completely handled. */ +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; + + if (!client->structured_reply) { + return nbd_opt_invalid(client, errp, + "request option '%s' when structured reply " + "is not negotiated", + nbd_opt_lookup(client->opt)); + } + + if (client->opt == NBD_OPT_LIST_META_CONTEXT) { + /* Only change the caller's meta on SET. */ + meta = &local_meta; + } + + memset(meta, 0, sizeof(*meta)); + + ret = nbd_opt_read_name(client, meta->export_name, NULL, errp); + if (ret <= 0) { + return ret; + } + + exp = nbd_export_find(meta->export_name); + if (exp == NULL) { + return nbd_opt_drop(client, NBD_REP_ERR_UNKNOWN, errp, + "export '%s' not present", meta->export_name); + } + + ret = nbd_opt_read(client, &nb_queries, sizeof(nb_queries), errp); + if (ret <= 0) { + return ret; + } + cpu_to_be32s(&nb_queries); + + if (client->opt == NBD_OPT_LIST_META_CONTEXT && !nb_queries) { + /* enable all known contexts */ + meta->base_allocation = true; + } else { + for (i = 0; i < nb_queries; ++i) { + ret = nbd_negotiate_meta_query(client, meta, errp); + if (ret <= 0) { + return ret; + } + } + } + + if (meta->base_allocation) { + ret = nbd_negotiate_send_meta_context(client, "base:allocation", + NBD_META_ID_BASE_ALLOCATION, + errp); + if (ret < 0) { + return ret; + } + } + + ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp); + if (ret == 0) { + meta->valid = true; + } + + return ret; +} + /* nbd_negotiate_options * Process all NBD_OPT_* client option commands, during fixed newstyle * negotiation. @@ -860,6 +1078,12 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags, } break; + case NBD_OPT_LIST_META_CONTEXT: + case NBD_OPT_SET_META_CONTEXT: + ret = nbd_negotiate_meta_queries(client, &client->export_meta, + errp); + break; + default: ret = nbd_opt_drop(client, NBD_REP_ERR_UNSUP, errp, "Unsupported option %" PRIu32 " (%s)", @@ -1489,6 +1713,79 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, return ret; } +static int blockstatus_to_extent_be(BlockDriverState *bs, uint64_t offset, + uint64_t bytes, NBDExtent *extent) +{ + uint64_t remaining_bytes = bytes; + + while (remaining_bytes) { + uint32_t flags; + int64_t num; + int ret = bdrv_block_status_above(bs, NULL, offset, remaining_bytes, + &num, NULL, NULL); + if (ret < 0) { + return ret; + } + + flags = (ret & BDRV_BLOCK_ALLOCATED ? 0 : NBD_STATE_HOLE) | + (ret & BDRV_BLOCK_ZERO ? NBD_STATE_ZERO : 0); + + if (remaining_bytes == bytes) { + extent->flags = flags; + } + + if (flags != extent->flags) { + break; + } + + offset += num; + remaining_bytes -= num; + } + + cpu_to_be32s(&extent->flags); + extent->length = 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[] = { + {.iov_base = &chunk, .iov_len = sizeof(chunk)}, + {.iov_base = extents, .iov_len = nb_extents * sizeof(extents[0])} + }; + + set_be_chunk(&chunk.h, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_BLOCK_STATUS, + 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 = 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, errp); +} + /* 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 @@ -1566,6 +1863,8 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, valid_flags |= NBD_CMD_FLAG_DF; } else if (request->type == NBD_CMD_WRITE_ZEROES) { valid_flags |= NBD_CMD_FLAG_NO_HOLE; + } else if (request->type == NBD_CMD_BLOCK_STATUS) { + valid_flags |= NBD_CMD_FLAG_REQ_ONE; } if (request->flags & ~valid_flags) { error_setg(errp, "unsupported flags for command %s (got 0x%x)", @@ -1699,6 +1998,18 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, 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_allocation) { + return nbd_co_send_block_status(client, request->handle, + blk_bs(exp->blk), request->from, + request->len, + NBD_META_ID_BASE_ALLOCATION, errp); + } else { + return nbd_send_generic_reply(client, request->handle, -EINVAL, + "CMD_BLOCK_STATUS not negotiated", + errp); + } + default: msg = g_strdup_printf("invalid request type (%" PRIu32 ") received", request->type); |