search for: cmd_issu

...to_issue = cmd; /* This will leave the command on the in-flight list. Is this a * problem? Probably it isn't. If it is, we could add a flag to * the command struct to tell SEND_REQUEST not to add it to the * in-flight list. */ - return nbd_internal_run (conn->h, conn, cmd_issue); + return 0; } diff --git a/lib/internal.h b/lib/internal.h index 3f2b729..67bd52a 100644 --- a/lib/internal.h +++ b/lib/internal.h @@ -265,6 +265,12 @@ extern void nbd_internal_set_last_error (int errnum, char *error); extern int nbd_internal_errno_of_nbd_error (uint32_t error); extern const...

Our construction of struct command_in_flight was ad hoc; most parameters were set in command_common(), but extent callbacks were done after the fact, and NBD_CMD_DISC was open-coding things. Furthermore, every caller was triggering nbd_internal_run() for the cmd_issue event; doing that in a central place makes it easier for the next patch to improve that logic without duplicating the fix at each caller. Fix these things by renaming the function to nbd_internal_command_common, which is necessary for exporting it, and by adding parameters and an updated return t...

On v1, we discussed whether cmds_to_issue needed to be a list, since it never had more than one element. I played with the idea of making it a list, and allowing the client to queue up new commands regardless of whether the state machine is currently in READY. I also polished up the tmp demo into a bit more full-fledged example file, worth including since it also let me discover a hard-to-hit race

...is is not as friendly on the client - once we are in transmission phase, a client may want to queue up another command whether or not the state machine is still tied up in processing a previous command. We still want to reject commands sent before the first time we reach READY, as well as keep the cmd_issue event for kicking the state machine into action when there is no previous command being worked on, but otherwise, the state machine itself can recognize when the command queue needs draining. --- generator/states.c | 5 +++++ lib/rw.c | 32 +++++++++++++++++++++++++++----- 2 files chan...

...y on the client - once we are in > transmission phase, a client may want to queue up another command > whether or not the state machine is still tied up in processing a > previous command. We still want to reject commands sent before the > first time we reach READY, as well as keep the cmd_issue event for > kicking the state machine into action when there is no previous > command being worked on, but otherwise, the state machine itself can > recognize when the command queue needs draining. I have a queued series which adds some new calls that may make this patch simpler: int...

Since v2: - rebase to Rich's new API calls - more refactoring in patch 1 (retitled) - new patches 3 and 4 - fix data corruption in patch 6 (was 4) - more tweaks to the reproducer example (including using new API from 3) Eric Blake (7): lib: Refactor command_common() to do more common work commands: Allow for a command queue commands: Expose FIFO ordering of server completions

...is is not as friendly on the client - once we are in transmission phase, a client may want to queue up another command whether or not the state machine is still tied up in processing a previous command. We still want to reject commands sent before the first time we reach READY, as well as keep the cmd_issue event for kicking the state machine into action when there is no previous command being worked on, but otherwise, the state machine itself can recognize when the command queue needs draining. Signed-off-by: Eric Blake <eblake@redhat.com> --- generator/states.c | 6 ++++++ lib/internal.h...

Although rare, it is possible that nbd_internal_run(cmd_issue) will report failure (perhaps because the server disconnected at the wrong time), even though we have queued the user's command. If we have a valid cookie, we MUST return it for the sake of users that will be calling nbd_aio_command_complete, as otherwise the user has no idea what cookie to w...

As promised in my earlier thread on libnbd completion callback question. Eric Blake (2): generator: Refactor handling of closures in unlocked functions generator: Free closures on failure docs/libnbd.pod | 2 +- generator/C.ml | 48 +++++++++++------ generator/C.mli | 1 + lib/debug.c | 7 +-- lib/opt.c | 31 ++++++-----

...LBACK_TO_NULL (*list); if (wait_for_option (h) == -1) return -1; if (s.err) { @@ -172,6 +173,7 @@ nbd_unlocked_aio_opt_go (struct nbd_handle *h, { h->opt_current = NBD_OPT_GO; h->opt_cb.completion = *complete; + SET_CALLBACK_TO_NULL (*complete); if (nbd_internal_run (h, cmd_issue) == -1) debug (h, "option queued, ignoring state machine failure"); @@ -190,6 +192,7 @@ nbd_unlocked_aio_opt_info (struct nbd_handle *h, h->opt_current = NBD_OPT_INFO; h->opt_cb.completion = *complete; + SET_CALLBACK_TO_NULL (*complete); if (nbd_internal_run (h, cm...

...io_opt_go (struct nbd_handle *h, - nbd_completion_callback complete) + nbd_completion_callback *complete) { h->opt_current = NBD_OPT_GO; - h->opt_cb.completion = complete; + h->opt_cb.completion = *complete; if (nbd_internal_run (h, cmd_issue) == -1) debug (h, "option queued, ignoring state machine failure"); @@ -181,7 +181,7 @@ nbd_unlocked_aio_opt_go (struct nbd_handle *h, /* Issue NBD_OPT_INFO without waiting. */ int nbd_unlocked_aio_opt_info (struct nbd_handle *h, - nbd_completion_callbac...

...EXPORT_NAME) without waiting. */ int -nbd_unlocked_aio_opt_go (struct nbd_handle *h) +nbd_unlocked_aio_opt_go (struct nbd_handle *h, + nbd_completion_callback complete) { h->current_opt = NBD_OPT_GO; + h->opt_cb.completion = complete; if (nbd_internal_run (h, cmd_issue) == -1) debug (h, "option queued, ignoring state machine failure"); -- 2.28.0

...ail = h->cmds_to_issue_tail->next = cmd; } else { - h->cmds_to_issue = cmd; + assert (h->cmds_to_issue_tail == NULL); + h->cmds_to_issue = h->cmds_to_issue_tail = cmd; if (nbd_internal_is_state_ready (get_next_state (h)) && nbd_internal_run (h, cmd_issue) == -1) return -1; -- 2.20.1

..._cmd = prev_cmd->next; @@ -209,7 +209,7 @@ nbd_internal_command_common (struct nbd_handle *h, } else { h->cmds_to_issue = cmd; - if (nbd_internal_is_state_ready (h->state) && + if (nbd_internal_is_state_ready (get_state (h)) && nbd_internal_run (h, cmd_issue) == -1) return -1; } -- 2.21.0

...t) prev_cmd = prev_cmd->next; @@ -209,7 +209,7 @@ nbd_internal_command_common (struct nbd_handle *h, } else { h->cmds_to_issue = cmd; - if (nbd_unlocked_aio_is_ready (h) && + if (nbd_internal_is_state_ready (h->state) && nbd_internal_run (h, cmd_issue) == -1) return -1; } -- 2.21.0

...prev_cmd->next; @@ -209,7 +209,7 @@ nbd_internal_command_common (struct nbd_handle *h, } else { h->cmds_to_issue = cmd; - if (nbd_internal_is_state_ready (get_state (h)) && + if (nbd_internal_is_state_ready (get_next_state (h)) && nbd_internal_run (h, cmd_issue) == -1) return -1; } -- 2.21.0

I need to think about this patch series a bit more, but it does at least pass the tests. Rich.

Noticed while thinking about the recent threads wondering if we need a more efficient lookup from cookie back to command. Both of these fix bugs, but are tricky enough that I'm posting for review. Eric Blake (2): lib: Decrement in_flight at response, not retirement lib: Do O(1) rather than O(n) queue insertion generator/states-issue-command.c | 2 ++ generator/states-reply.c |

...set_error (errno, "malloc"); - return -1; - } + if (wait_for_option (h) == -1) + return -1; + if (s.err) { + set_error (s.err, "server replied with error to list request"); + return -1; } - - h->current_opt = NBD_OPT_LIST; - if (nbd_internal_run (h, cmd_issue) == -1) - debug (h, "option queued, ignoring state machine failure"); - return wait_for_option (h); + return s.count; } /* Issue NBD_OPT_GO (or NBD_OPT_EXPORT_NAME) without waiting. */ @@ -132,3 +151,22 @@ nbd_unlocked_aio_opt_abort (struct nbd_handle *h) debug (h, "opt...

...76,7 @@ let c_string_of_external_event = function | CmdConnectTCP -> "cmd_connect_tcp" | CmdConnectCommand -> "cmd_connect_command" | CmdConnectSA -> "cmd_connect_sa" + | CmdConnectSocket -> "cmd_connect_socket" | CmdIssue -> "cmd_issue" (* Find a state in the state machine hierarchy by path. The [path] @@ -3588,7 +3625,7 @@ let generate_lib_states_run_c () = | CmdCreate | CmdConnectSockAddr | CmdConnectUnix | CmdConnectTCP - | CmdConnectCommand | CmdConnectSA + | CmdCon...