From 8acc72a4d20910d522516dab31272fe66da8da28 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 28 Sep 2012 17:22:50 +0200 Subject: block: add support for job pause/resume Job pausing reuses the existing support for cancellable sleeps. A pause happens at the next sleeping point and lasts until the coroutine is re-entered explicitly. Cancellation was already doing a forced resume, so implement it explicitly in terms of resume. Paused jobs cannot be canceled without first resuming them. This ensures that I/O errors are never missed by management. Signed-off-by: Paolo Bonzini Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- blockjob.c | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-) (limited to 'blockjob.c') diff --git a/blockjob.c b/blockjob.c index 64c9d2dda1..8219f73979 100644 --- a/blockjob.c +++ b/blockjob.c @@ -99,14 +99,30 @@ void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) job->speed = speed; } -void block_job_cancel(BlockJob *job) +void block_job_pause(BlockJob *job) { - job->cancelled = true; + job->paused = true; +} + +bool block_job_is_paused(BlockJob *job) +{ + return job->paused; +} + +void block_job_resume(BlockJob *job) +{ + job->paused = false; if (job->co && !job->busy) { qemu_coroutine_enter(job->co, NULL); } } +void block_job_cancel(BlockJob *job) +{ + job->cancelled = true; + block_job_resume(job); +} + bool block_job_is_cancelled(BlockJob *job) { return job->cancelled; @@ -154,12 +170,20 @@ int block_job_cancel_sync(BlockJob *job) void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns) { + assert(job->busy); + /* Check cancellation *before* setting busy = false, too! */ - if (!block_job_is_cancelled(job)) { - job->busy = false; + if (block_job_is_cancelled(job)) { + return; + } + + job->busy = false; + if (block_job_is_paused(job)) { + qemu_coroutine_yield(); + } else { co_sleep_ns(clock, ns); - job->busy = true; } + job->busy = true; } BlockJobInfo *block_job_query(BlockJob *job) @@ -169,6 +193,7 @@ 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->offset = job->offset; info->speed = job->speed; return info; -- cgit v1.2.1