From 66d4f4fe2f1c282a34a429f61aa4283e60336500 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Thu, 8 Jun 2023 08:56:33 -0500 Subject: [PATCH] nbd/server: Refactor to pass full request around Part of NBD's 64-bit headers extension involves passing the client's requested offset back as part of the reply header (one reason it stated for this change: converting absolute offsets stored in NBD_REPLY_TYPE_OFFSET_DATA to relative offsets within the buffer is easier if the absolute offset of the buffer is also available). This is a refactoring patch to pass the full request around the reply stack, rather than just the handle, so that later patches can then access request->from when extended headers are active. Meanwhile, this patch enables us to now assert that simple replies are only attempted when appropriate, and otherwise has no semantic change. Signed-off-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy Message-ID: <20230608135653.2918540-5-eblake@redhat.com> --- nbd/server.c | 114 ++++++++++++++++++++++++++------------------------- 1 file changed, 59 insertions(+), 55 deletions(-) diff --git a/nbd/server.c b/nbd/server.c index 6698ab4636..26b27d6920 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1893,7 +1893,7 @@ static inline void set_be_simple_reply(NBDSimpleReply *reply, uint64_t error, } static int coroutine_fn nbd_co_send_simple_reply(NBDClient *client, - uint64_t handle, + NBDRequest *request, uint32_t error, void *data, size_t len, @@ -1907,9 +1907,10 @@ static int coroutine_fn nbd_co_send_simple_reply(NBDClient *client, }; assert(!len || !nbd_err); - trace_nbd_co_send_simple_reply(handle, nbd_err, nbd_err_lookup(nbd_err), - len); - set_be_simple_reply(&reply, nbd_err, handle); + assert(!client->structured_reply || request->type != NBD_CMD_READ); + trace_nbd_co_send_simple_reply(request->handle, nbd_err, + nbd_err_lookup(nbd_err), len); + set_be_simple_reply(&reply, nbd_err, request->handle); return nbd_co_send_iov(client, iov, 2, errp); } @@ -1924,7 +1925,7 @@ static int coroutine_fn nbd_co_send_simple_reply(NBDClient *client, */ static inline void set_be_chunk(NBDClient *client, struct iovec *iov, size_t niov, uint16_t flags, uint16_t type, - uint64_t handle) + NBDRequest *request) { /* TODO - handle structured vs. extended replies */ NBDStructuredReplyChunk *chunk = iov->iov_base; @@ -1939,12 +1940,12 @@ static inline void set_be_chunk(NBDClient *client, struct iovec *iov, stl_be_p(&chunk->magic, NBD_STRUCTURED_REPLY_MAGIC); stw_be_p(&chunk->flags, flags); stw_be_p(&chunk->type, type); - stq_be_p(&chunk->handle, handle); + stq_be_p(&chunk->handle, request->handle); stl_be_p(&chunk->length, length); } static int coroutine_fn nbd_co_send_chunk_done(NBDClient *client, - uint64_t handle, + NBDRequest *request, Error **errp) { NBDReply hdr; @@ -1952,15 +1953,15 @@ static int coroutine_fn nbd_co_send_chunk_done(NBDClient *client, {.iov_base = &hdr}, }; - trace_nbd_co_send_chunk_done(handle); + trace_nbd_co_send_chunk_done(request->handle); set_be_chunk(client, iov, 1, NBD_REPLY_FLAG_DONE, - NBD_REPLY_TYPE_NONE, handle); + NBD_REPLY_TYPE_NONE, request); return nbd_co_send_iov(client, iov, 1, errp); } static int coroutine_fn nbd_co_send_chunk_read(NBDClient *client, - uint64_t handle, + NBDRequest *request, uint64_t offset, void *data, size_t size, @@ -1976,16 +1977,16 @@ static int coroutine_fn nbd_co_send_chunk_read(NBDClient *client, }; assert(size); - trace_nbd_co_send_chunk_read(handle, offset, data, size); + trace_nbd_co_send_chunk_read(request->handle, offset, data, size); set_be_chunk(client, iov, 3, final ? NBD_REPLY_FLAG_DONE : 0, - NBD_REPLY_TYPE_OFFSET_DATA, handle); + NBD_REPLY_TYPE_OFFSET_DATA, request); stq_be_p(&chunk.offset, offset); return nbd_co_send_iov(client, iov, 3, errp); } - +/*ebb*/ static int coroutine_fn nbd_co_send_chunk_error(NBDClient *client, - uint64_t handle, + NBDRequest *request, uint32_t error, const char *msg, Error **errp) @@ -2000,10 +2001,10 @@ static int coroutine_fn nbd_co_send_chunk_error(NBDClient *client, }; assert(nbd_err); - trace_nbd_co_send_chunk_error(handle, nbd_err, + trace_nbd_co_send_chunk_error(request->handle, nbd_err, nbd_err_lookup(nbd_err), msg ? msg : ""); set_be_chunk(client, iov, 3, NBD_REPLY_FLAG_DONE, - NBD_REPLY_TYPE_ERROR, handle); + NBD_REPLY_TYPE_ERROR, request); stl_be_p(&chunk.error, nbd_err); stw_be_p(&chunk.message_length, iov[2].iov_len); @@ -2015,7 +2016,7 @@ static int coroutine_fn nbd_co_send_chunk_error(NBDClient *client, * reported to the client, at which point this function succeeds. */ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, - uint64_t handle, + NBDRequest *request, uint64_t offset, uint8_t *data, size_t size, @@ -2037,7 +2038,7 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, char *msg = g_strdup_printf("unable to check for holes: %s", strerror(-status)); - ret = nbd_co_send_chunk_error(client, handle, -status, msg, errp); + ret = nbd_co_send_chunk_error(client, request, -status, msg, errp); g_free(msg); return ret; } @@ -2051,10 +2052,11 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, {.iov_base = &chunk, .iov_len = sizeof(chunk)}, }; - trace_nbd_co_send_chunk_read_hole(handle, offset + progress, pnum); + trace_nbd_co_send_chunk_read_hole(request->handle, + offset + progress, pnum); set_be_chunk(client, iov, 2, final ? NBD_REPLY_FLAG_DONE : 0, - NBD_REPLY_TYPE_OFFSET_HOLE, handle); + NBD_REPLY_TYPE_OFFSET_HOLE, request); stq_be_p(&chunk.offset, offset + progress); stl_be_p(&chunk.length, pnum); ret = nbd_co_send_iov(client, iov, 2, errp); @@ -2065,7 +2067,7 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, error_setg_errno(errp, -ret, "reading from file failed"); break; } - ret = nbd_co_send_chunk_read(client, handle, offset + progress, + ret = nbd_co_send_chunk_read(client, request, offset + progress, data + progress, pnum, final, errp); } @@ -2219,7 +2221,7 @@ static int coroutine_fn blockalloc_to_extents(BlockBackend *blk, * @last controls whether NBD_REPLY_FLAG_DONE is sent. */ static int coroutine_fn -nbd_co_send_extents(NBDClient *client, uint64_t handle, NBDExtentArray *ea, +nbd_co_send_extents(NBDClient *client, NBDRequest *request, NBDExtentArray *ea, bool last, uint32_t context_id, Error **errp) { NBDReply hdr; @@ -2232,10 +2234,10 @@ nbd_co_send_extents(NBDClient *client, uint64_t handle, NBDExtentArray *ea, nbd_extent_array_convert_to_be(ea); - trace_nbd_co_send_extents(handle, ea->count, context_id, ea->total_length, - last); + trace_nbd_co_send_extents(request->handle, ea->count, context_id, + ea->total_length, last); set_be_chunk(client, iov, 3, last ? NBD_REPLY_FLAG_DONE : 0, - NBD_REPLY_TYPE_BLOCK_STATUS, handle); + NBD_REPLY_TYPE_BLOCK_STATUS, request); stl_be_p(&chunk.context_id, context_id); return nbd_co_send_iov(client, iov, 3, errp); @@ -2243,7 +2245,7 @@ nbd_co_send_extents(NBDClient *client, uint64_t handle, NBDExtentArray *ea, /* Get block status from the exported device and send it to the client */ static int -coroutine_fn nbd_co_send_block_status(NBDClient *client, uint64_t handle, +coroutine_fn nbd_co_send_block_status(NBDClient *client, NBDRequest *request, BlockBackend *blk, uint64_t offset, uint32_t length, bool dont_fragment, bool last, uint32_t context_id, @@ -2259,11 +2261,11 @@ coroutine_fn nbd_co_send_block_status(NBDClient *client, uint64_t handle, ret = blockalloc_to_extents(blk, offset, length, ea); } if (ret < 0) { - return nbd_co_send_chunk_error(client, handle, -ret, + return nbd_co_send_chunk_error(client, request, -ret, "can't get block status", errp); } - return nbd_co_send_extents(client, handle, ea, last, context_id, errp); + return nbd_co_send_extents(client, request, ea, last, context_id, errp); } /* Populate @ea from a dirty bitmap. */ @@ -2298,17 +2300,20 @@ static void bitmap_to_extents(BdrvDirtyBitmap *bitmap, bdrv_dirty_bitmap_unlock(bitmap); } -static int coroutine_fn nbd_co_send_bitmap(NBDClient *client, uint64_t handle, - BdrvDirtyBitmap *bitmap, uint64_t offset, - uint32_t length, bool dont_fragment, bool last, - uint32_t context_id, Error **errp) +static int coroutine_fn nbd_co_send_bitmap(NBDClient *client, + NBDRequest *request, + BdrvDirtyBitmap *bitmap, + uint64_t offset, + uint32_t length, bool dont_fragment, + bool last, uint32_t context_id, + Error **errp) { unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS; g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents); bitmap_to_extents(bitmap, offset, length, ea); - return nbd_co_send_extents(client, handle, ea, last, context_id, errp); + return nbd_co_send_extents(client, request, ea, last, context_id, errp); } /* nbd_co_receive_request @@ -2426,15 +2431,15 @@ static int coroutine_fn nbd_co_receive_request(NBDRequestData *req, NBDRequest * * Returns 0 if connection is still live, -errno on failure to talk to client */ static coroutine_fn int nbd_send_generic_reply(NBDClient *client, - uint64_t handle, + NBDRequest *request, int ret, const char *error_msg, Error **errp) { if (client->structured_reply && ret < 0) { - return nbd_co_send_chunk_error(client, handle, -ret, error_msg, errp); + return nbd_co_send_chunk_error(client, request, -ret, error_msg, errp); } else { - return nbd_co_send_simple_reply(client, handle, ret < 0 ? -ret : 0, + return nbd_co_send_simple_reply(client, request, ret < 0 ? -ret : 0, NULL, 0, errp); } } @@ -2454,7 +2459,7 @@ static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, if (request->flags & NBD_CMD_FLAG_FUA) { ret = blk_co_flush(exp->common.blk); if (ret < 0) { - return nbd_send_generic_reply(client, request->handle, ret, + return nbd_send_generic_reply(client, request, ret, "flush failed", errp); } } @@ -2462,26 +2467,25 @@ static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, if (client->structured_reply && !(request->flags & NBD_CMD_FLAG_DF) && request->len) { - return nbd_co_send_sparse_read(client, request->handle, request->from, + return nbd_co_send_sparse_read(client, request, request->from, data, request->len, errp); } ret = blk_co_pread(exp->common.blk, request->from, request->len, data, 0); if (ret < 0) { - return nbd_send_generic_reply(client, request->handle, ret, + return nbd_send_generic_reply(client, request, ret, "reading from file failed", errp); } if (client->structured_reply) { if (request->len) { - return nbd_co_send_chunk_read(client, request->handle, - request->from, data, + return nbd_co_send_chunk_read(client, request, request->from, data, request->len, true, errp); } else { - return nbd_co_send_chunk_done(client, request->handle, errp); + return nbd_co_send_chunk_done(client, request, errp); } } else { - return nbd_co_send_simple_reply(client, request->handle, 0, + return nbd_co_send_simple_reply(client, request, 0, data, request->len, errp); } } @@ -2504,7 +2508,7 @@ static coroutine_fn int nbd_do_cmd_cache(NBDClient *client, NBDRequest *request, ret = blk_co_preadv(exp->common.blk, request->from, request->len, NULL, BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH); - return nbd_send_generic_reply(client, request->handle, ret, + return nbd_send_generic_reply(client, request, ret, "caching data failed", errp); } @@ -2535,7 +2539,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, } ret = blk_co_pwrite(exp->common.blk, request->from, request->len, data, flags); - return nbd_send_generic_reply(client, request->handle, ret, + return nbd_send_generic_reply(client, request, ret, "writing to file failed", errp); case NBD_CMD_WRITE_ZEROES: @@ -2551,7 +2555,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, } ret = blk_co_pwrite_zeroes(exp->common.blk, request->from, request->len, flags); - return nbd_send_generic_reply(client, request->handle, ret, + return nbd_send_generic_reply(client, request, ret, "writing to file failed", errp); case NBD_CMD_DISC: @@ -2560,7 +2564,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, case NBD_CMD_FLUSH: ret = blk_co_flush(exp->common.blk); - return nbd_send_generic_reply(client, request->handle, ret, + return nbd_send_generic_reply(client, request, ret, "flush failed", errp); case NBD_CMD_TRIM: @@ -2568,12 +2572,12 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, if (ret >= 0 && request->flags & NBD_CMD_FLAG_FUA) { ret = blk_co_flush(exp->common.blk); } - return nbd_send_generic_reply(client, request->handle, ret, + return nbd_send_generic_reply(client, request, ret, "discard failed", errp); case NBD_CMD_BLOCK_STATUS: if (!request->len) { - return nbd_send_generic_reply(client, request->handle, -EINVAL, + return nbd_send_generic_reply(client, request, -EINVAL, "need non-zero length", errp); } if (client->export_meta.count) { @@ -2581,7 +2585,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, int contexts_remaining = client->export_meta.count; if (client->export_meta.base_allocation) { - ret = nbd_co_send_block_status(client, request->handle, + ret = nbd_co_send_block_status(client, request, exp->common.blk, request->from, request->len, dont_fragment, @@ -2594,7 +2598,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, } if (client->export_meta.allocation_depth) { - ret = nbd_co_send_block_status(client, request->handle, + ret = nbd_co_send_block_status(client, request, exp->common.blk, request->from, request->len, dont_fragment, @@ -2610,7 +2614,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, if (!client->export_meta.bitmaps[i]) { continue; } - ret = nbd_co_send_bitmap(client, request->handle, + ret = nbd_co_send_bitmap(client, request, client->exp->export_bitmaps[i], request->from, request->len, dont_fragment, !--contexts_remaining, @@ -2624,7 +2628,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, return 0; } else { - return nbd_send_generic_reply(client, request->handle, -EINVAL, + return nbd_send_generic_reply(client, request, -EINVAL, "CMD_BLOCK_STATUS not negotiated", errp); } @@ -2632,7 +2636,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, default: msg = g_strdup_printf("invalid request type (%" PRIu32 ") received", request->type); - ret = nbd_send_generic_reply(client, request->handle, -EINVAL, msg, + ret = nbd_send_generic_reply(client, request, -EINVAL, msg, errp); g_free(msg); return ret; @@ -2695,7 +2699,7 @@ static coroutine_fn void nbd_trip(void *opaque) Error *export_err = local_err; local_err = NULL; - ret = nbd_send_generic_reply(client, request.handle, -EINVAL, + ret = nbd_send_generic_reply(client, &request, -EINVAL, error_get_pretty(export_err), &local_err); error_free(export_err); } else {