qemu/nbd/trace-events

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# See docs/devel/tracing.rst for syntax documentation.
# client.c
nbd_send_option_request(uint32_t opt, const char *name, uint32_t len) "Sending option request %" PRIu32" (%s), len %" PRIu32
nbd_receive_option_reply(uint32_t option, const char *optname, uint32_t type, const char *typename, uint32_t length) "Received option reply %" PRIu32" (%s), type %" PRIu32" (%s), len %" PRIu32
nbd_server_error_msg(uint32_t err, const char *type, const char *msg) "server reported error 0x%" PRIx32 " (%s) with additional message: %s"
nbd_reply_err_ignored(uint32_t option, const char *name, uint32_t reply, const char *reply_name) "server failed request %" PRIu32 " (%s) with error 0x%" PRIx32 " (%s), attempting fallback"
nbd/client: Refactor nbd_receive_list() Right now, nbd_receive_list() is only called by nbd_receive_query_exports(), which in turn is only called if the server lacks NBD_OPT_GO but has working option negotiation, and is merely used as a quality-of-implementation trick since servers can't give decent errors for NBD_OPT_EXPORT_NAME. However, servers that lack NBD_OPT_GO are becoming increasingly rare (nbdkit was a latecomer, in Aug 2018, but qemu has been such a server since commit f37708f6 in July 2017 and released in 2.10), so it no longer makes sense to micro-optimize that function for performance. Furthermore, when debugging a server's implementation, tracing the full reply (both names and descriptions) is useful, not to mention that upcoming patches adding 'qemu-nbd --list' will want to collect that data. And when you consider that a server can send an export name up to the NBD protocol length limit of 4k; but our current NBD_MAX_NAME_SIZE is only 256, we can't trace all valid server names without more storage, but 4k is large enough that the heap is better than the stack for long names. Thus, I'm changing the division of labor, with nbd_receive_list() now always malloc'ing a result on success (the malloc is bounded by the fact that we reject servers with a reply length larger than 32M), and moving the comparison to 'wantname' to the caller. There is a minor change in behavior where a server with 0 exports (an immediate NBD_REP_ACK reply) is now no longer distinguished from a server without LIST support (NBD_REP_ERR_UNSUP); this information could be preserved with a complication to the calling contract to provide a bit more information, but I didn't see the point. After all, the worst that can happen if our guess at a match is wrong is that the caller will get a cryptic disconnect when NBD_OPT_EXPORT_NAME fails (which is no different from what would happen if we had not tried LIST), while treating an empty list as immediate failure would prevent connecting to really old servers that really did lack LIST. Besides, NBD servers with 0 exports are rare (qemu can do it when using QMP nbd-server-start without nbd-server-add - but qemu understands NBD_OPT_GO and thus won't tickle this change in behavior). Fix the spelling of foundExport to match coding standards while in the area. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Richard W.M. Jones <rjones@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20190117193658.16413-9-eblake@redhat.com>
2019-01-17 22:36:45 +03:00
nbd_receive_list(const char *name, const char *desc) "export list includes '%s', description '%s'"
nbd_opt_info_go_start(const char *opt, const char *name) "Attempting %s for export '%s'"
nbd_opt_info_go_success(const char *opt) "Export is ready after %s request"
nbd_opt_info_unknown(int info, const char *name) "Ignoring unknown info %d (%s)"
nbd_opt_info_block_size(uint32_t minimum, uint32_t preferred, uint32_t maximum) "Block sizes are 0x%" PRIx32 ", 0x%" PRIx32 ", 0x%" PRIx32
nbd_receive_query_exports_start(const char *wantname) "Querying export list for '%s'"
nbd_receive_query_exports_success(const char *wantname) "Found desired export name '%s'"
nbd_receive_starttls_new_client(void) "Setting up TLS"
nbd_receive_starttls_tls_handshake(void) "Starting TLS handshake"
nbd_opt_meta_request(const char *optname, const char *context, const char *export) "Requesting %s %s for export %s"
nbd_opt_meta_reply(const char *optname, const char *context, uint32_t id) "Received %s mapping of %s to id %" PRIu32
nbd_start_negotiate(void *tlscreds, const char *hostname) "Receiving negotiation tlscreds=%p hostname=%s"
nbd_receive_negotiate_magic(uint64_t magic) "Magic is 0x%" PRIx64
nbd_receive_negotiate_server_flags(uint32_t globalflags) "Global flags are 0x%" PRIx32
nbd_receive_negotiate_name(const char *name) "Requesting NBD export name '%s'"
nbd_receive_negotiate_size_flags(uint64_t size, uint16_t flags) "Size is %" PRIu64 ", export flags 0x%" PRIx16
nbd_init_set_socket(void) "Setting NBD socket"
nbd_init_set_block_size(unsigned long block_size) "Setting block size to %lu"
nbd_init_set_size(unsigned long sectors) "Setting size to %lu block(s)"
nbd_init_trailing_bytes(int ignored_bytes) "Ignoring trailing %d bytes of export"
nbd_init_set_readonly(void) "Setting readonly attribute"
nbd_init_finish(void) "Negotiation ended"
nbd_client_loop(void) "Doing NBD loop"
nbd_client_loop_ret(int ret, const char *error) "NBD loop returned %d: %s"
nbd_client_clear_queue(void) "Clearing NBD queue"
nbd_client_clear_socket(void) "Clearing NBD socket"
nbd_send_request(uint64_t from, uint32_t len, uint64_t handle, uint16_t flags, uint16_t type, const char *name) "Sending request to server: { .from = %" PRIu64", .len = %" PRIu32 ", .handle = %" PRIu64 ", .flags = 0x%" PRIx16 ", .type = %" PRIu16 " (%s) }"
nbd_receive_simple_reply(int32_t error, const char *errname, uint64_t handle) "Got simple reply: { .error = %" PRId32 " (%s), handle = %" PRIu64" }"
nbd_receive_structured_reply_chunk(uint16_t flags, uint16_t type, const char *name, uint64_t handle, uint32_t length) "Got structured reply chunk: { flags = 0x%" PRIx16 ", type = %d (%s), handle = %" PRIu64 ", length = %" PRIu32 " }"
# common.c
nbd_unknown_error(int err) "Squashing unexpected error %d to EINVAL"
# server.c
nbd_negotiate_send_rep_len(uint32_t opt, const char *optname, uint32_t type, const char *typename, uint32_t len) "Reply opt=%" PRIu32 " (%s), type=%" PRIu32 " (%s), len=%" PRIu32
nbd_negotiate_send_rep_err(const char *msg) "sending error message \"%s\""
nbd_negotiate_send_rep_list(const char *name, const char *desc) "Advertising export name '%s' description '%s'"
nbd_negotiate_handle_export_name(void) "Checking length"
nbd_negotiate_handle_export_name_request(const char *name) "Client requested export '%s'"
nbd_negotiate_send_info(int info, const char *name, uint32_t length) "Sending NBD_REP_INFO type %d (%s) with remaining length %" PRIu32
nbd_negotiate_handle_info_requests(int requests) "Client requested %d items of info"
nbd_negotiate_handle_info_request(int request, const char *name) "Client requested info %d (%s)"
nbd_negotiate_handle_info_block_size(uint32_t minimum, uint32_t preferred, uint32_t maximum) "advertising minimum 0x%" PRIx32 ", preferred 0x%" PRIx32 ", maximum 0x%" PRIx32
nbd_negotiate_handle_starttls(void) "Setting up TLS"
nbd_negotiate_handle_starttls_handshake(void) "Starting TLS handshake"
nbd_negotiate_meta_context(const char *optname, const char *export, uint32_t queries) "Client requested %s for export %s, with %" PRIu32 " queries"
nbd_negotiate_meta_query_skip(const char *reason) "Skipping meta query: %s"
nbd_negotiate_meta_query_parse(const char *query) "Parsed meta query '%s'"
nbd_negotiate_meta_query_reply(const char *context, uint32_t id) "Replying with meta context '%s' id %" PRIu32
nbd_negotiate_options_flags(uint32_t flags) "Received client flags 0x%" PRIx32
nbd_negotiate_options_check_magic(uint64_t magic) "Checking opts magic 0x%" PRIx64
nbd_negotiate_options_check_option(uint32_t option, const char *name) "Checking option %" PRIu32 " (%s)"
nbd_negotiate_begin(void) "Beginning negotiation"
nbd_negotiate_new_style_size_flags(uint64_t size, unsigned flags) "advertising size %" PRIu64 " and flags 0x%x"
nbd_negotiate_success(void) "Negotiation succeeded"
nbd_receive_request(uint32_t magic, uint16_t flags, uint16_t type, uint64_t from, uint32_t len) "Got request: { magic = 0x%" PRIx32 ", .flags = 0x%" PRIx16 ", .type = 0x%" PRIx16 ", from = %" PRIu64 ", len = %" PRIu32 " }"
nbd_blk_aio_attached(const char *name, void *ctx) "Export %s: Attaching clients to AIO context %p"
nbd_blk_aio_detach(const char *name, void *ctx) "Export %s: Detaching clients from AIO context %p"
nbd_co_send_simple_reply(uint64_t handle, uint32_t error, const char *errname, int len) "Send simple reply: handle = %" PRIu64 ", error = %" PRIu32 " (%s), len = %d"
nbd_co_send_structured_done(uint64_t handle) "Send structured reply done: handle = %" PRIu64
nbd_co_send_structured_read(uint64_t handle, uint64_t offset, void *data, size_t size) "Send structured read data reply: handle = %" PRIu64 ", offset = %" PRIu64 ", data = %p, len = %zu"
nbd_co_send_structured_read_hole(uint64_t handle, uint64_t offset, size_t size) "Send structured read hole reply: handle = %" PRIu64 ", offset = %" PRIu64 ", len = %zu"
nbd_co_send_extents(uint64_t handle, unsigned int extents, uint32_t id, uint64_t length, int last) "Send block status reply: handle = %" PRIu64 ", extents = %u, context = %d (extents cover %" PRIu64 " bytes, last chunk = %d)"
nbd_co_send_structured_error(uint64_t handle, int err, const char *errname, const char *msg) "Send structured error reply: handle = %" PRIu64 ", error = %d (%s), msg = '%s'"
nbd_co_receive_request_decode_type(uint64_t handle, uint16_t type, const char *name) "Decoding type: handle = %" PRIu64 ", type = %" PRIu16 " (%s)"
nbd_co_receive_request_payload_received(uint64_t handle, uint32_t len) "Payload received: handle = %" PRIu64 ", len = %" PRIu32
nbd/server: Trace client noncompliance on unaligned requests We've recently added traces for clients to flag server non-compliance; let's do the same for servers to flag client non-compliance. According to the spec, if the client requests NBD_INFO_BLOCK_SIZE, it is promising to send all requests aligned to those boundaries. Of course, if the client does not request NBD_INFO_BLOCK_SIZE, then it made no promises so we shouldn't flag anything; and because we are willing to handle clients that made no promises (the spec allows us to use NBD_REP_ERR_BLOCK_SIZE_REQD if we had been unwilling), we already have to handle unaligned requests (which the block layer already does on our behalf). So even though the spec allows us to return EINVAL for clients that promised to behave, it's easier to always answer unaligned requests. Still, flagging non-compliance can be useful in debugging a client that is trying to be maximally portable. Qemu as client used to have one spot where it sent non-compliant requests: if the server sends an unaligned reply to NBD_CMD_BLOCK_STATUS, and the client was iterating over the entire disk, the next request would start at that unaligned point; this was fixed in commit a39286dd when the client was taught to work around server non-compliance; but is equally fixed if the server is patched to not send unaligned replies in the first place (yes, qemu 4.0 as server still has few such bugs, although they will be patched in 4.1). Fortunately, I did not find any more spots where qemu as client was non-compliant. I was able to test the patch by using the following hack to convince qemu-io to run various unaligned commands, coupled with serving 512-byte alignment by intentionally omitting '-f raw' on the server while viewing server traces. | diff --git i/nbd/client.c w/nbd/client.c | index 427980bdd22..1858b2aac35 100644 | --- i/nbd/client.c | +++ w/nbd/client.c | @@ -449,6 +449,7 @@ static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt, | nbd_send_opt_abort(ioc); | return -1; | } | + info->min_block = 1;//hack | if (!is_power_of_2(info->min_block)) { | error_setg(errp, "server minimum block size %" PRIu32 | " is not a power of two", info->min_block); Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20190403030526.12258-3-eblake@redhat.com> [eblake: address minor review nits] Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-04-03 06:05:21 +03:00
nbd_co_receive_align_compliance(const char *op, uint64_t from, uint32_t len, uint32_t align) "client sent non-compliant unaligned %s request: from=0x%" PRIx64 ", len=0x%" PRIx32 ", align=0x%" PRIx32
nbd_trip(void) "Reading request"