| Message ID | 1428069921-2957-2-git-send-email-famz@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 03/04/2015 16:05, Fam Zheng wrote: > This patch changes block_job_pause to increase the pause counter and > block_job_resume to decrease it. > > The counter will allow calling block_job_pause/block_job_resume > unconditionally on a job when we need to suspend the IO temporarily. > > From now on, each block_job_resume must be paired with a block_job_pause > to keep the counter balanced. > > The user pause from QMP or HMP will only trigger block_job_pause once > until it's resumed, this is achieved by adding a user_paused flag in > BlockJob. > > One occurrence of block_job_resume in mirror_complete is replaced with > block_job_enter which does what is necessary. > > In block_job_cancel, the cancel flag is good enough to instruct > coroutines to quit loop, so use block_job_enter to replace the unpaired > block_job_resume. > > Upon block job IO error, user is notified about the entering to the > pause state, so this pause belongs to user pause, set the flag > accordingly and expect a matching QMP resume. > > Signed-off-by: Fam Zheng <famz@redhat.com> > --- > block/mirror.c | 2 +- > blockdev.c | 8 +++++--- > blockjob.c | 23 +++++++++++++++++------ > include/block/blockjob.h | 20 ++++++++++++++++---- > 4 files changed, 39 insertions(+), 14 deletions(-) > > diff --git a/block/mirror.c b/block/mirror.c > index 4056164..65b1718 100644 > --- a/block/mirror.c > +++ b/block/mirror.c > @@ -634,7 +634,7 @@ static void mirror_complete(BlockJob *job, Error **errp) > } > > s->should_complete = true; > - block_job_resume(job); > + block_job_enter(&s->common); > } > > static const BlockJobDriver mirror_job_driver = { > diff --git a/blockdev.c b/blockdev.c > index fbb3a79..9132d69 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -2699,7 +2699,7 @@ void qmp_block_job_cancel(const char *device, > force = false; > } > > - if (job->paused && !force) { > + if (job->user_paused && !force) { > error_setg(errp, "The block job for device '%s' is currently paused", > device); > goto out; > @@ -2716,10 +2716,11 @@ void qmp_block_job_pause(const char *device, Error **errp) > AioContext *aio_context; > BlockJob *job = find_block_job(device, &aio_context, errp); > > - if (!job) { > + if (!job || job->user_paused) { > return; > } > > + job->user_paused = true; > trace_qmp_block_job_pause(job); > block_job_pause(job); > aio_context_release(aio_context); > @@ -2730,10 +2731,11 @@ void qmp_block_job_resume(const char *device, Error **errp) > AioContext *aio_context; > BlockJob *job = find_block_job(device, &aio_context, errp); > > - if (!job) { > + if (!job || !job->user_paused) { > return; > } > > + job->user_paused = false; > trace_qmp_block_job_resume(job); > block_job_resume(job); > aio_context_release(aio_context); > diff --git a/blockjob.c b/blockjob.c > index ba2255d..2755465 100644 > --- a/blockjob.c > +++ b/blockjob.c > @@ -107,7 +107,7 @@ void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) > > void block_job_complete(BlockJob *job, Error **errp) > { > - if (job->paused || job->cancelled || !job->driver->complete) { > + if (job->pause_count || job->cancelled || !job->driver->complete) { > error_set(errp, QERR_BLOCK_JOB_NOT_READY, > bdrv_get_device_name(job->bs)); > return; > @@ -118,17 +118,26 @@ void block_job_complete(BlockJob *job, Error **errp) > > void block_job_pause(BlockJob *job) > { > - job->paused = true; > + job->pause_count++; > } > > bool block_job_is_paused(BlockJob *job) > { > - return job->paused; > + return job->pause_count > 0; > } > > void block_job_resume(BlockJob *job) > { > - job->paused = false; > + assert(job->pause_count > 0); > + job->pause_count--; > + if (job->pause_count) { > + return; > + } > + block_job_enter(job); > +} > + > +void block_job_enter(BlockJob *job) > +{ > block_job_iostatus_reset(job); > if (job->co && !job->busy) { > qemu_coroutine_enter(job->co, NULL); > @@ -138,7 +147,7 @@ void block_job_resume(BlockJob *job) > void block_job_cancel(BlockJob *job) > { > job->cancelled = true; > - block_job_resume(job); > + block_job_enter(job); > } > > bool block_job_is_cancelled(BlockJob *job) > @@ -258,7 +267,7 @@ BlockJobInfo *block_job_query(BlockJob *job) > info->device = g_strdup(bdrv_get_device_name(job->bs)); > info->len = job->len; > info->busy = job->busy; > - info->paused = job->paused; > + info->paused = job->pause_count > 0; > info->offset = job->offset; > info->speed = job->speed; > info->io_status = job->iostatus; > @@ -335,6 +344,8 @@ BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs, > IO_OPERATION_TYPE_WRITE, > action, &error_abort); > if (action == BLOCK_ERROR_ACTION_STOP) { > + /* make the pause user visible, which will be resumed from QMP. */ > + job->user_paused = true; > block_job_pause(job); > block_job_iostatus_set_err(job, error); > if (bs != job->bs) { > diff --git a/include/block/blockjob.h b/include/block/blockjob.h > index b6d4ebb..9f4b20d 100644 > --- a/include/block/blockjob.h > +++ b/include/block/blockjob.h > @@ -79,10 +79,14 @@ struct BlockJob { > bool cancelled; > > /** > - * Set to true if the job is either paused, or will pause itself > - * as soon as possible (if busy == true). > + * Counter for pause request. If non-zero, the block job will pause. Why not keep the more complete comment ("If non-zero, the block job is either paused, or if busy == true will pause itself as soon as possible")? > */ > - bool paused; > + int pause_count; > + > + /** > + * Set to true if the job is paused by user. ... and can be unpaused with the block-job-resume QMP command. > + */ > + bool user_paused; > > /** > * Set to false by the job while it is in a quiescent state, where > @@ -225,11 +229,19 @@ void block_job_pause(BlockJob *job); > * block_job_resume: > * @job: The job to be resumed. > * > - * Resume the specified job. > + * Resume the specified job. Must be paired with a preceding block_job_pause. > */ > void block_job_resume(BlockJob *job); > > /** > + * block_job_enter: > + * @job: The job to enter. > + * > + * Continue the specified job by entering the coroutine. > + */ > +void block_job_enter(BlockJob *job); > + > +/** > * block_job_event_cancelled: > * @job: The job whose information is requested. > * > Apart from this, Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
On Fri, Apr 03, 2015 at 10:05:18PM +0800, Fam Zheng wrote: > Signed-off-by: Fam Zheng <famz@redhat.com> > --- > block/mirror.c | 2 +- > blockdev.c | 8 +++++--- > blockjob.c | 23 +++++++++++++++++------ > include/block/blockjob.h | 20 ++++++++++++++++---- > 4 files changed, 39 insertions(+), 14 deletions(-) Reviewed-by: Alberto Garcia <berto@igalia.com> Berto
On Fri, Apr 03, 2015 at 10:05:18PM +0800, Fam Zheng wrote: > This patch changes block_job_pause to increase the pause counter and > block_job_resume to decrease it. > > The counter will allow calling block_job_pause/block_job_resume > unconditionally on a job when we need to suspend the IO temporarily. > > From now on, each block_job_resume must be paired with a block_job_pause > to keep the counter balanced. > > The user pause from QMP or HMP will only trigger block_job_pause once > until it's resumed, this is achieved by adding a user_paused flag in > BlockJob. > > One occurrence of block_job_resume in mirror_complete is replaced with > block_job_enter which does what is necessary. > > In block_job_cancel, the cancel flag is good enough to instruct > coroutines to quit loop, so use block_job_enter to replace the unpaired > block_job_resume. > > Upon block job IO error, user is notified about the entering to the > pause state, so this pause belongs to user pause, set the flag > accordingly and expect a matching QMP resume. > > Signed-off-by: Fam Zheng <famz@redhat.com> > --- > block/mirror.c | 2 +- > blockdev.c | 8 +++++--- > blockjob.c | 23 +++++++++++++++++------ > include/block/blockjob.h | 20 ++++++++++++++++---- > 4 files changed, 39 insertions(+), 14 deletions(-) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
On Fri, Apr 03, 2015 at 04:13:55PM +0200, Paolo Bonzini wrote: > > > On 03/04/2015 16:05, Fam Zheng wrote: > > This patch changes block_job_pause to increase the pause counter and > > block_job_resume to decrease it. > > > > The counter will allow calling block_job_pause/block_job_resume > > unconditionally on a job when we need to suspend the IO temporarily. > > > > From now on, each block_job_resume must be paired with a block_job_pause > > to keep the counter balanced. > > > > The user pause from QMP or HMP will only trigger block_job_pause once > > until it's resumed, this is achieved by adding a user_paused flag in > > BlockJob. > > > > One occurrence of block_job_resume in mirror_complete is replaced with > > block_job_enter which does what is necessary. > > > > In block_job_cancel, the cancel flag is good enough to instruct > > coroutines to quit loop, so use block_job_enter to replace the unpaired > > block_job_resume. > > > > Upon block job IO error, user is notified about the entering to the > > pause state, so this pause belongs to user pause, set the flag > > accordingly and expect a matching QMP resume. > > > > Signed-off-by: Fam Zheng <famz@redhat.com> > > --- > > block/mirror.c | 2 +- > > blockdev.c | 8 +++++--- > > blockjob.c | 23 +++++++++++++++++------ > > include/block/blockjob.h | 20 ++++++++++++++++---- > > 4 files changed, 39 insertions(+), 14 deletions(-) > > > > diff --git a/block/mirror.c b/block/mirror.c > > index 4056164..65b1718 100644 > > --- a/block/mirror.c > > +++ b/block/mirror.c > > @@ -634,7 +634,7 @@ static void mirror_complete(BlockJob *job, Error **errp) > > } > > > > s->should_complete = true; > > - block_job_resume(job); > > + block_job_enter(&s->common); > > } > > > > static const BlockJobDriver mirror_job_driver = { > > diff --git a/blockdev.c b/blockdev.c > > index fbb3a79..9132d69 100644 > > --- a/blockdev.c > > +++ b/blockdev.c > > @@ -2699,7 +2699,7 @@ void qmp_block_job_cancel(const char *device, > > force = false; > > } > > > > - if (job->paused && !force) { > > + if (job->user_paused && !force) { > > error_setg(errp, "The block job for device '%s' is currently paused", > > device); > > goto out; > > @@ -2716,10 +2716,11 @@ void qmp_block_job_pause(const char *device, Error **errp) > > AioContext *aio_context; > > BlockJob *job = find_block_job(device, &aio_context, errp); > > > > - if (!job) { > > + if (!job || job->user_paused) { > > return; > > } > > > > + job->user_paused = true; > > trace_qmp_block_job_pause(job); > > block_job_pause(job); > > aio_context_release(aio_context); > > @@ -2730,10 +2731,11 @@ void qmp_block_job_resume(const char *device, Error **errp) > > AioContext *aio_context; > > BlockJob *job = find_block_job(device, &aio_context, errp); > > > > - if (!job) { > > + if (!job || !job->user_paused) { > > return; > > } > > > > + job->user_paused = false; > > trace_qmp_block_job_resume(job); > > block_job_resume(job); > > aio_context_release(aio_context); > > diff --git a/blockjob.c b/blockjob.c > > index ba2255d..2755465 100644 > > --- a/blockjob.c > > +++ b/blockjob.c > > @@ -107,7 +107,7 @@ void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) > > > > void block_job_complete(BlockJob *job, Error **errp) > > { > > - if (job->paused || job->cancelled || !job->driver->complete) { > > + if (job->pause_count || job->cancelled || !job->driver->complete) { > > error_set(errp, QERR_BLOCK_JOB_NOT_READY, > > bdrv_get_device_name(job->bs)); > > return; > > @@ -118,17 +118,26 @@ void block_job_complete(BlockJob *job, Error **errp) > > > > void block_job_pause(BlockJob *job) > > { > > - job->paused = true; > > + job->pause_count++; > > } > > > > bool block_job_is_paused(BlockJob *job) > > { > > - return job->paused; > > + return job->pause_count > 0; > > } > > > > void block_job_resume(BlockJob *job) > > { > > - job->paused = false; > > + assert(job->pause_count > 0); > > + job->pause_count--; > > + if (job->pause_count) { > > + return; > > + } > > + block_job_enter(job); > > +} > > + > > +void block_job_enter(BlockJob *job) > > +{ > > block_job_iostatus_reset(job); > > if (job->co && !job->busy) { > > qemu_coroutine_enter(job->co, NULL); > > @@ -138,7 +147,7 @@ void block_job_resume(BlockJob *job) > > void block_job_cancel(BlockJob *job) > > { > > job->cancelled = true; > > - block_job_resume(job); > > + block_job_enter(job); > > } > > > > bool block_job_is_cancelled(BlockJob *job) > > @@ -258,7 +267,7 @@ BlockJobInfo *block_job_query(BlockJob *job) > > info->device = g_strdup(bdrv_get_device_name(job->bs)); > > info->len = job->len; > > info->busy = job->busy; > > - info->paused = job->paused; > > + info->paused = job->pause_count > 0; > > info->offset = job->offset; > > info->speed = job->speed; > > info->io_status = job->iostatus; > > @@ -335,6 +344,8 @@ BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs, > > IO_OPERATION_TYPE_WRITE, > > action, &error_abort); > > if (action == BLOCK_ERROR_ACTION_STOP) { > > + /* make the pause user visible, which will be resumed from QMP. */ > > + job->user_paused = true; > > block_job_pause(job); > > block_job_iostatus_set_err(job, error); > > if (bs != job->bs) { > > diff --git a/include/block/blockjob.h b/include/block/blockjob.h > > index b6d4ebb..9f4b20d 100644 > > --- a/include/block/blockjob.h > > +++ b/include/block/blockjob.h > > @@ -79,10 +79,14 @@ struct BlockJob { > > bool cancelled; > > > > /** > > - * Set to true if the job is either paused, or will pause itself > > - * as soon as possible (if busy == true). > > + * Counter for pause request. If non-zero, the block job will pause. > > Why not keep the more complete comment ("If non-zero, the block job is > either paused, or if busy == true will pause itself as soon as possible")? > > > */ > > - bool paused; > > + int pause_count; > > + > > + /** > > + * Set to true if the job is paused by user. > > ... and can be unpaused with the block-job-resume QMP command. I squashed in your suggestions.
diff --git a/block/mirror.c b/block/mirror.c index 4056164..65b1718 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -634,7 +634,7 @@ static void mirror_complete(BlockJob *job, Error **errp) } s->should_complete = true; - block_job_resume(job); + block_job_enter(&s->common); } static const BlockJobDriver mirror_job_driver = { diff --git a/blockdev.c b/blockdev.c index fbb3a79..9132d69 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2699,7 +2699,7 @@ void qmp_block_job_cancel(const char *device, force = false; } - if (job->paused && !force) { + if (job->user_paused && !force) { error_setg(errp, "The block job for device '%s' is currently paused", device); goto out; @@ -2716,10 +2716,11 @@ void qmp_block_job_pause(const char *device, Error **errp) AioContext *aio_context; BlockJob *job = find_block_job(device, &aio_context, errp); - if (!job) { + if (!job || job->user_paused) { return; } + job->user_paused = true; trace_qmp_block_job_pause(job); block_job_pause(job); aio_context_release(aio_context); @@ -2730,10 +2731,11 @@ void qmp_block_job_resume(const char *device, Error **errp) AioContext *aio_context; BlockJob *job = find_block_job(device, &aio_context, errp); - if (!job) { + if (!job || !job->user_paused) { return; } + job->user_paused = false; trace_qmp_block_job_resume(job); block_job_resume(job); aio_context_release(aio_context); diff --git a/blockjob.c b/blockjob.c index ba2255d..2755465 100644 --- a/blockjob.c +++ b/blockjob.c @@ -107,7 +107,7 @@ void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) void block_job_complete(BlockJob *job, Error **errp) { - if (job->paused || job->cancelled || !job->driver->complete) { + if (job->pause_count || job->cancelled || !job->driver->complete) { error_set(errp, QERR_BLOCK_JOB_NOT_READY, bdrv_get_device_name(job->bs)); return; @@ -118,17 +118,26 @@ void block_job_complete(BlockJob *job, Error **errp) void block_job_pause(BlockJob *job) { - job->paused = true; + job->pause_count++; } bool block_job_is_paused(BlockJob *job) { - return job->paused; + return job->pause_count > 0; } void block_job_resume(BlockJob *job) { - job->paused = false; + assert(job->pause_count > 0); + job->pause_count--; + if (job->pause_count) { + return; + } + block_job_enter(job); +} + +void block_job_enter(BlockJob *job) +{ block_job_iostatus_reset(job); if (job->co && !job->busy) { qemu_coroutine_enter(job->co, NULL); @@ -138,7 +147,7 @@ void block_job_resume(BlockJob *job) void block_job_cancel(BlockJob *job) { job->cancelled = true; - block_job_resume(job); + block_job_enter(job); } bool block_job_is_cancelled(BlockJob *job) @@ -258,7 +267,7 @@ BlockJobInfo *block_job_query(BlockJob *job) info->device = g_strdup(bdrv_get_device_name(job->bs)); info->len = job->len; info->busy = job->busy; - info->paused = job->paused; + info->paused = job->pause_count > 0; info->offset = job->offset; info->speed = job->speed; info->io_status = job->iostatus; @@ -335,6 +344,8 @@ BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs, IO_OPERATION_TYPE_WRITE, action, &error_abort); if (action == BLOCK_ERROR_ACTION_STOP) { + /* make the pause user visible, which will be resumed from QMP. */ + job->user_paused = true; block_job_pause(job); block_job_iostatus_set_err(job, error); if (bs != job->bs) { diff --git a/include/block/blockjob.h b/include/block/blockjob.h index b6d4ebb..9f4b20d 100644 --- a/include/block/blockjob.h +++ b/include/block/blockjob.h @@ -79,10 +79,14 @@ struct BlockJob { bool cancelled; /** - * Set to true if the job is either paused, or will pause itself - * as soon as possible (if busy == true). + * Counter for pause request. If non-zero, the block job will pause. */ - bool paused; + int pause_count; + + /** + * Set to true if the job is paused by user. + */ + bool user_paused; /** * Set to false by the job while it is in a quiescent state, where @@ -225,11 +229,19 @@ void block_job_pause(BlockJob *job); * block_job_resume: * @job: The job to be resumed. * - * Resume the specified job. + * Resume the specified job. Must be paired with a preceding block_job_pause. */ void block_job_resume(BlockJob *job); /** + * block_job_enter: + * @job: The job to enter. + * + * Continue the specified job by entering the coroutine. + */ +void block_job_enter(BlockJob *job); + +/** * block_job_event_cancelled: * @job: The job whose information is requested. *
This patch changes block_job_pause to increase the pause counter and block_job_resume to decrease it. The counter will allow calling block_job_pause/block_job_resume unconditionally on a job when we need to suspend the IO temporarily. From now on, each block_job_resume must be paired with a block_job_pause to keep the counter balanced. The user pause from QMP or HMP will only trigger block_job_pause once until it's resumed, this is achieved by adding a user_paused flag in BlockJob. One occurrence of block_job_resume in mirror_complete is replaced with block_job_enter which does what is necessary. In block_job_cancel, the cancel flag is good enough to instruct coroutines to quit loop, so use block_job_enter to replace the unpaired block_job_resume. Upon block job IO error, user is notified about the entering to the pause state, so this pause belongs to user pause, set the flag accordingly and expect a matching QMP resume. Signed-off-by: Fam Zheng <famz@redhat.com> --- block/mirror.c | 2 +- blockdev.c | 8 +++++--- blockjob.c | 23 +++++++++++++++++------ include/block/blockjob.h | 20 ++++++++++++++++---- 4 files changed, 39 insertions(+), 14 deletions(-)