From patchwork Tue Mar 13 16:17:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 885252 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4010mv6Bxgz9sQx for ; Wed, 14 Mar 2018 03:34:23 +1100 (AEDT) Received: from localhost ([::1]:41086 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1evmsX-0006SC-ER for incoming@patchwork.ozlabs.org; Tue, 13 Mar 2018 12:34:21 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59287) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1evmd8-0001MN-3L for qemu-devel@nongnu.org; Tue, 13 Mar 2018 12:18:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1evmd3-0004XA-7T for qemu-devel@nongnu.org; Tue, 13 Mar 2018 12:18:26 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:52378 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1evmcv-0004Qp-0Y; Tue, 13 Mar 2018 12:18:13 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9D9CC7B4C8; Tue, 13 Mar 2018 16:18:12 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-117-214.ams2.redhat.com [10.36.117.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id CDE57215CDA7; Tue, 13 Mar 2018 16:18:11 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Tue, 13 Mar 2018 17:17:27 +0100 Message-Id: <20180313161803.1814-6-kwolf@redhat.com> In-Reply-To: <20180313161803.1814-1-kwolf@redhat.com> References: <20180313161803.1814-1-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 13 Mar 2018 16:18:12 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 13 Mar 2018 16:18:12 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'kwolf@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PULL 05/41] blockjobs: add state transition table 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, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: John Snow The state transition table has mostly been implied. We're about to make it a bit more complex, so let's make the STM explicit instead. Perform state transitions with a function that for now just asserts the transition is appropriate. Transitions: Undefined -> Created: During job initialization. Created -> Running: Once the job is started. Jobs cannot transition from "Created" to "Paused" directly, but will instead synchronously transition to running to paused immediately. Running -> Paused: Normal workflow for pauses. Running -> Ready: Normal workflow for jobs reaching their sync point. (e.g. mirror) Ready -> Standby: Normal workflow for pausing ready jobs. Paused -> Running: Normal resume. Standby -> Ready: Resume of a Standby job. +---------+ |UNDEFINED| +--+------+ | +--v----+ |CREATED| +--+----+ | +--v----+ +------+ |RUNNING<----->PAUSED| +--+----+ +------+ | +--v--+ +-------+ |READY<------->STANDBY| +-----+ +-------+ Notably, there is no state presently defined as of this commit that deals with a job after the "running" or "ready" states, so this table will be adjusted alongside the commits that introduce those states. Signed-off-by: John Snow Signed-off-by: Kevin Wolf --- blockjob.c | 40 +++++++++++++++++++++++++++++++++------- block/trace-events | 3 +++ 2 files changed, 36 insertions(+), 7 deletions(-) diff --git a/blockjob.c b/blockjob.c index 719169cccd..442426e27b 100644 --- a/blockjob.c +++ b/blockjob.c @@ -28,6 +28,7 @@ #include "block/block.h" #include "block/blockjob_int.h" #include "block/block_int.h" +#include "block/trace.h" #include "sysemu/block-backend.h" #include "qapi/error.h" #include "qapi/qapi-events-block-core.h" @@ -41,6 +42,31 @@ * block_job_enter. */ static QemuMutex block_job_mutex; +/* BlockJob State Transition Table */ +bool BlockJobSTT[BLOCK_JOB_STATUS__MAX][BLOCK_JOB_STATUS__MAX] = { + /* U, C, R, P, Y, S */ + /* U: */ [BLOCK_JOB_STATUS_UNDEFINED] = {0, 1, 0, 0, 0, 0}, + /* C: */ [BLOCK_JOB_STATUS_CREATED] = {0, 0, 1, 0, 0, 0}, + /* R: */ [BLOCK_JOB_STATUS_RUNNING] = {0, 0, 0, 1, 1, 0}, + /* P: */ [BLOCK_JOB_STATUS_PAUSED] = {0, 0, 1, 0, 0, 0}, + /* Y: */ [BLOCK_JOB_STATUS_READY] = {0, 0, 0, 0, 0, 1}, + /* S: */ [BLOCK_JOB_STATUS_STANDBY] = {0, 0, 0, 0, 1, 0}, +}; + +static void block_job_state_transition(BlockJob *job, BlockJobStatus s1) +{ + BlockJobStatus s0 = job->status; + assert(s1 >= 0 && s1 <= BLOCK_JOB_STATUS__MAX); + trace_block_job_state_transition(job, job->ret, BlockJobSTT[s0][s1] ? + "allowed" : "disallowed", + qapi_enum_lookup(&BlockJobStatus_lookup, + s0), + qapi_enum_lookup(&BlockJobStatus_lookup, + s1)); + assert(BlockJobSTT[s0][s1]); + job->status = s1; +} + static void block_job_lock(void) { qemu_mutex_lock(&block_job_mutex); @@ -320,7 +346,7 @@ void block_job_start(BlockJob *job) job->pause_count--; job->busy = true; job->paused = false; - job->status = BLOCK_JOB_STATUS_RUNNING; + block_job_state_transition(job, BLOCK_JOB_STATUS_RUNNING); bdrv_coroutine_enter(blk_bs(job->blk), job->co); } @@ -702,7 +728,7 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver, job->paused = true; job->pause_count = 1; job->refcnt = 1; - job->status = BLOCK_JOB_STATUS_CREATED; + block_job_state_transition(job, BLOCK_JOB_STATUS_CREATED); aio_timer_init(qemu_get_aio_context(), &job->sleep_timer, QEMU_CLOCK_REALTIME, SCALE_NS, block_job_sleep_timer_cb, job); @@ -817,13 +843,13 @@ void coroutine_fn block_job_pause_point(BlockJob *job) if (block_job_should_pause(job) && !block_job_is_cancelled(job)) { BlockJobStatus status = job->status; - job->status = status == BLOCK_JOB_STATUS_READY ? \ - BLOCK_JOB_STATUS_STANDBY : \ - BLOCK_JOB_STATUS_PAUSED; + block_job_state_transition(job, status == BLOCK_JOB_STATUS_READY ? \ + BLOCK_JOB_STATUS_STANDBY : \ + BLOCK_JOB_STATUS_PAUSED); job->paused = true; block_job_do_yield(job, -1); job->paused = false; - job->status = status; + block_job_state_transition(job, status); } if (job->driver->resume) { @@ -929,7 +955,7 @@ void block_job_iostatus_reset(BlockJob *job) void block_job_event_ready(BlockJob *job) { - job->status = BLOCK_JOB_STATUS_READY; + block_job_state_transition(job, BLOCK_JOB_STATUS_READY); job->ready = true; if (block_job_is_internal(job)) { diff --git a/block/trace-events b/block/trace-events index 02dd80ff0c..b75a0c8409 100644 --- a/block/trace-events +++ b/block/trace-events @@ -4,6 +4,9 @@ bdrv_open_common(void *bs, const char *filename, int flags, const char *format_name) "bs %p filename \"%s\" flags 0x%x format_name \"%s\"" bdrv_lock_medium(void *bs, bool locked) "bs %p locked %d" +# blockjob.c +block_job_state_transition(void *job, int ret, const char *legal, const char *s0, const char *s1) "job %p (ret: %d) attempting %s transition (%s-->%s)" + # block/block-backend.c blk_co_preadv(void *blk, void *bs, int64_t offset, unsigned int bytes, int flags) "blk %p bs %p offset %"PRId64" bytes %u flags 0x%x" blk_co_pwritev(void *blk, void *bs, int64_t offset, unsigned int bytes, int flags) "blk %p bs %p offset %"PRId64" bytes %u flags 0x%x"