debian/patches/pve/0037-PVE-Add-sequential-job-transaction-support.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Stefan Reiter <s.reiter@proxmox.com>
   3 Date: Thu, 20 Aug 2020 14:31:59 +0200
   4 Subject: [PATCH] PVE: Add sequential job transaction support
   5
   6 Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
   7 Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
   8 ---
   9  include/qemu/job.h | 12 ++++++++++++
  10  job.c              | 31 +++++++++++++++++++++++++++++++
  11  2 files changed, 43 insertions(+)
  12
  13 diff --git a/include/qemu/job.h b/include/qemu/job.h
  14 index c105b31076..5096679571 100644
  15 --- a/include/qemu/job.h
  16 +++ b/include/qemu/job.h
  17 @@ -316,6 +316,18 @@ typedef enum JobCreateFlags {
  18   */
  19  JobTxn *job_txn_new(void);
  20
  21 +/**
  22 + * Create a new transaction and set it to sequential mode, i.e. run all jobs
  23 + * one after the other instead of at the same time.
  24 + */
  25 +JobTxn *job_txn_new_seq(void);
  26 +
  27 +/**
  28 + * Helper method to start the first job in a sequential transaction to kick it
  29 + * off. Other jobs will be run after this one completes.
  30 + */
  31 +void job_txn_start_seq(JobTxn *txn);
  32 +
  33  /**
  34   * Release a reference that was previously acquired with job_txn_add_job or
  35   * job_txn_new. If it's the last reference to the object, it will be freed.
  36 diff --git a/job.c b/job.c
  37 index e5699ad200..34c9758349 100644
  38 --- a/job.c
  39 +++ b/job.c
  40 @@ -72,6 +72,8 @@ struct JobTxn {
  41
  42      /* Reference count */
  43      int refcnt;
  44 +
  45 +    bool sequential;
  46  };
  47
  48  /* Right now, this mutex is only needed to synchronize accesses to job->busy
  49 @@ -102,6 +104,25 @@ JobTxn *job_txn_new(void)
  50      return txn;
  51  }
  52
  53 +JobTxn *job_txn_new_seq(void)
  54 +{
  55 +    JobTxn *txn = job_txn_new();
  56 +    txn->sequential = true;
  57 +    return txn;
  58 +}
  59 +
  60 +void job_txn_start_seq(JobTxn *txn)
  61 +{
  62 +    assert(txn->sequential);
  63 +    assert(!txn->aborting);
  64 +
  65 +    Job *first = QLIST_FIRST(&txn->jobs);
  66 +    assert(first);
  67 +    assert(first->status == JOB_STATUS_CREATED);
  68 +
  69 +    job_start(first);
  70 +}
  71 +
  72  static void job_txn_ref(JobTxn *txn)
  73  {
  74      txn->refcnt++;
  75 @@ -897,6 +918,9 @@ static void job_completed_txn_success(Job *job)
  76       */
  77      QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
  78          if (!job_is_completed(other_job)) {
  79 +            if (txn->sequential) {
  80 +                job_start(other_job);
  81 +            }
  82              return;
  83          }
  84          assert(other_job->ret == 0);
  85 @@ -1093,6 +1117,13 @@ int job_finish_sync(Job *job, void (*finish)(Job *, Error **errp), Error **errp)
  86          return -EBUSY;
  87      }
  88
  89 +    /* in a sequential transaction jobs with status CREATED can appear at time
  90 +     * of cancelling, these have not begun work so job_enter won't do anything,
  91 +     * let's ensure they are marked as ABORTING if required */
  92 +    if (job->status == JOB_STATUS_CREATED && job->txn->sequential) {
  93 +        job_update_rc(job);
  94 +    }
  95 +
  96      AIO_WAIT_WHILE(job->aio_context,
  97                     (job_enter(job), !job_is_completed(job)));
  98