[RFC PATCH 0/3] job: split job API in driver and monitor

[RFC PATCH 0/3] job: split job API in driver and monitor

[Emanuele Giuseppe Esposito]

In this series, we split the job API in two headers:
job-driver.h and job-monitor.h.
As explained in job.c, job-monitor are the functions mainly used
by the monitor, and require consistency between the search of
a specific job (job_get) and the actual operation/action on it
(e.g. job_user_cancel). Therefore job-monitor API assume that
the job mutex lock is always held by the caller.

job-driver, on the other side, is the collection of functions
that are used by the job drivers or core block layer. These
functions are not aware of the job mutex, and delegate the
locking to the callee instead.

We also have job-common.h contains the job struct definition
and common functions that are not part of monitor or driver APIs.
job.h is left for legacy and to avoid changing all files that
include it.

RFC: alternative names for the headers: job-locked (was job-monitor)
and job-self-locking (was job-driver). I am open to suggestion for
alternative names.

This serie is based on my previous series "job: replace AioContext
lock with job_mutex".

Based-on: <20211104145334.1346363-1-eesposit@redhat.com>

Emanuele Giuseppe Esposito (3):
  jobs: add job-common.h
  jobs: add job-monitor.h
  jobs: add job-driver.h

 include/qemu/job-common.h  | 336 +++++++++++++++++++
 include/qemu/job-driver.h  | 173 ++++++++++
 include/qemu/job-monitor.h | 282 ++++++++++++++++
 include/qemu/job.h         | 662 +------------------------------------
 job.c                      |   4 +-
 5 files changed, 797 insertions(+), 660 deletions(-)
 create mode 100644 include/qemu/job-common.h
 create mode 100644 include/qemu/job-driver.h
 create mode 100644 include/qemu/job-monitor.h

-- 
2.27.0

[RFC PATCH 1/3] jobs: add job-common.h

[Emanuele Giuseppe Esposito]

job-common.h contains all struct and common function that currently
are in job.h and will be shared by job-monitor and job-driver in
the next commits.

Also move job_type() and job_type_str() there, as they are
common helper functions.

No functional change intended.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 include/qemu/job-common.h | 336 ++++++++++++++++++++++++++++++++++++++
 include/qemu/job.h        | 307 +---------------------------------
 2 files changed, 337 insertions(+), 306 deletions(-)
 create mode 100644 include/qemu/job-common.h

diff --git a/include/qemu/job-common.h b/include/qemu/job-common.h
new file mode 100644
index 0000000000..d2968a848e
--- /dev/null
+++ b/include/qemu/job-common.h
@@ -0,0 +1,336 @@
+/*
+ * Declarations for background jobs
+ *
+ * Copyright (c) 2011 IBM Corp.
+ * Copyright (c) 2012, 2018 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef JOB_COMMON_H
+#define JOB_COMMON_H
+
+#include "qapi/qapi-types-job.h"
+#include "qemu/queue.h"
+#include "qemu/progress_meter.h"
+#include "qemu/coroutine.h"
+#include "block/aio.h"
+
+typedef struct JobDriver JobDriver;
+typedef struct JobTxn JobTxn;
+
+
+/**
+ * Long-running operation.
+ */
+typedef struct Job {
+
+    /* Fields set at initialization (job_create), and never modified */
+
+    /** The ID of the job. May be NULL for internal jobs. */
+    char *id;
+
+    /**
+     * The type of this job.
+     * All callbacks are called with job_mutex *not* held.
+     */
+    const JobDriver *driver;
+
+    /** AioContext to run the job coroutine in */
+    AioContext *aio_context;
+
+    /**
+     * The coroutine that executes the job.  If not NULL, it is reentered when
+     * busy is false and the job is cancelled.
+     * Initialized in job_start()
+     */
+    Coroutine *co;
+
+    /** True if this job should automatically finalize itself */
+    bool auto_finalize;
+
+    /** True if this job should automatically dismiss itself */
+    bool auto_dismiss;
+
+    /** The completion function that will be called when the job completes.  */
+    BlockCompletionFunc *cb;
+
+    /** The opaque value that is passed to the completion function.  */
+    void *opaque;
+
+    /* ProgressMeter API is thread-safe */
+    ProgressMeter progress;
+
+
+    /** Protected by job_mutex */
+
+    /** Reference count of the block job */
+    int refcnt;
+
+    /** Current state; See @JobStatus for details. */
+    JobStatus status;
+
+    /**
+     * Timer that is used by @job_sleep_ns. Accessed under job_mutex (in
+     * job.c).
+     */
+    QEMUTimer sleep_timer;
+
+    /**
+     * Counter for pause request. If non-zero, the block job is either paused,
+     * or if busy == true will pause itself as soon as possible.
+     */
+    int pause_count;
+
+    /**
+     * Set to false by the job while the coroutine has yielded and may be
+     * re-entered by job_enter(). There may still be I/O or event loop activity
+     * pending. Accessed under job_mutex.
+     *
+     * When the job is deferred to the main loop, busy is true as long as the
+     * bottom half is still pending.
+     */
+    bool busy;
+
+    /**
+     * Set to true by the job while it is in a quiescent state, where
+     * no I/O or event loop activity is pending.
+     */
+    bool paused;
+
+    /**
+     * Set to true if the job is paused by user.  Can be unpaused with the
+     * block-job-resume QMP command.
+     */
+    bool user_paused;
+
+    /**
+     * Set to true if the job should cancel itself.  The flag must
+     * always be tested just before toggling the busy flag from false
+     * to true.  After a job has been cancelled, it should only yield
+     * if #aio_poll will ("sooner or later") reenter the coroutine.
+     */
+    bool cancelled;
+
+    /**
+     * Set to true if the job should abort immediately without waiting
+     * for data to be in sync.
+     */
+    bool force_cancel;
+
+    /** Set to true when the job has deferred work to the main loop. */
+    bool deferred_to_main_loop;
+
+    /**
+     * Return code from @run and/or @prepare callback(s).
+     * Not final until the job has reached the CONCLUDED status.
+     * 0 on success, -errno on failure.
+     */
+    int ret;
+
+    /**
+     * Error object for a failed job.
+     * If job->ret is nonzero and an error object was not set, it will be set
+     * to strerror(-job->ret) during job_completed.
+     */
+    Error *err;
+
+    /** Notifiers called when a cancelled job is finalised */
+    NotifierList on_finalize_cancelled;
+
+    /** Notifiers called when a successfully completed job is finalised */
+    NotifierList on_finalize_completed;
+
+    /** Notifiers called when the job transitions to PENDING */
+    NotifierList on_pending;
+
+    /** Notifiers called when the job transitions to READY */
+    NotifierList on_ready;
+
+    /** Notifiers called when the job coroutine yields or terminates */
+    NotifierList on_idle;
+
+    /** Element of the list of jobs */
+    QLIST_ENTRY(Job) job_list;
+
+    /** Transaction this job is part of */
+    JobTxn *txn;
+
+    /** Element of the list of jobs in a job transaction */
+    QLIST_ENTRY(Job) txn_list;
+} Job;
+
+/**
+ * Callbacks and other information about a Job driver.
+ * All callbacks are invoked with job_mutex *not* held.
+ */
+struct JobDriver {
+
+    /* Fields initialized in struct definition and never changed. */
+
+    /** Derived Job struct size */
+    size_t instance_size;
+
+    /** Enum describing the operation */
+    JobType job_type;
+
+    /*
+     * Functions run without regard to the BQL and may run in any
+     * arbitrary thread. These functions do not need to be thread-safe
+     * because the caller ensures that are invoked from one thread at time.
+     */
+
+    /**
+     * Mandatory: Entrypoint for the Coroutine.
+     *
+     * This callback will be invoked when moving from CREATED to RUNNING.
+     *
+     * If this callback returns nonzero, the job transaction it is part of is
+     * aborted. If it returns zero, the job moves into the WAITING state. If it
+     * is the last job to complete in its transaction, all jobs in the
+     * transaction move from WAITING to PENDING.
+     */
+    int coroutine_fn (*run)(Job *job, Error **errp);
+
+    /**
+     * If the callback is not NULL, it will be invoked when the job transitions
+     * into the paused state.  Paused jobs must not perform any asynchronous
+     * I/O or event loop activity.  This callback is used to quiesce jobs.
+     */
+    void coroutine_fn (*pause)(Job *job);
+
+    /**
+     * If the callback is not NULL, it will be invoked when the job transitions
+     * out of the paused state.  Any asynchronous I/O or event loop activity
+     * should be restarted from this callback.
+     */
+    void coroutine_fn (*resume)(Job *job);
+
+    /*
+     * Global state (GS) API. These functions run under the BQL lock.
+     *
+     * See include/block/block-global-state.h for more information about
+     * the GS API.
+     */
+
+    /**
+     * Called when the job is resumed by the user (i.e. user_paused becomes
+     * false). .user_resume is called before .resume.
+     */
+    void (*user_resume)(Job *job);
+
+    /**
+     * Optional callback for job types whose completion must be triggered
+     * manually.
+     */
+    void (*complete)(Job *job, Error **errp);
+
+    /**
+     * If the callback is not NULL, prepare will be invoked when all the jobs
+     * belonging to the same transaction complete; or upon this job's completion
+     * if it is not in a transaction.
+     *
+     * This callback will not be invoked if the job has already failed.
+     * If it fails, abort and then clean will be called.
+     */
+    int (*prepare)(Job *job);
+
+    /**
+     * If the callback is not NULL, it will be invoked when all the jobs
+     * belonging to the same transaction complete; or upon this job's
+     * completion if it is not in a transaction. Skipped if NULL.
+     *
+     * All jobs will complete with a call to either .commit() or .abort() but
+     * never both.
+     */
+    void (*commit)(Job *job);
+
+    /**
+     * If the callback is not NULL, it will be invoked when any job in the
+     * same transaction fails; or upon this job's failure (due to error or
+     * cancellation) if it is not in a transaction. Skipped if NULL.
+     *
+     * All jobs will complete with a call to either .commit() or .abort() but
+     * never both.
+     */
+    void (*abort)(Job *job);
+
+    /**
+     * If the callback is not NULL, it will be invoked after a call to either
+     * .commit() or .abort(). Regardless of which callback is invoked after
+     * completion, .clean() will always be called, even if the job does not
+     * belong to a transaction group.
+     */
+    void (*clean)(Job *job);
+
+    /**
+     * If the callback is not NULL, it will be invoked in job_cancel_async
+     *
+     * This function must return true if the job will be cancelled
+     * immediately without any further I/O (mandatory if @force is
+     * true), and false otherwise.  This lets the generic job layer
+     * know whether a job has been truly (force-)cancelled, or whether
+     * it is just in a special completion mode (like mirror after
+     * READY).
+     * (If the callback is NULL, the job is assumed to terminate
+     * without I/O.)
+     */
+    bool (*cancel)(Job *job, bool force);
+
+
+    /** Called when the job is freed */
+    void (*free)(Job *job);
+};
+
+typedef enum JobCreateFlags {
+    /* Default behavior */
+    JOB_DEFAULT = 0x00,
+    /* Job is not QMP-created and should not send QMP events */
+    JOB_INTERNAL = 0x01,
+    /* Job requires manual finalize step */
+    JOB_MANUAL_FINALIZE = 0x02,
+    /* Job requires manual dismiss step */
+    JOB_MANUAL_DISMISS = 0x04,
+} JobCreateFlags;
+
+/**
+ * job_lock:
+ *
+ * Take the mutex protecting the list of jobs and their status.
+ * Most functions called by the monitor need to call job_lock
+ * and job_unlock manually.  On the other hand, function called
+ * by the block jobs themselves and by the block layer will take the
+ * lock for you.
+ */
+void job_lock(void);
+
+/**
+ * job_unlock:
+ *
+ * Release the mutex protecting the list of jobs and their status.
+ */
+void job_unlock(void);
+
+/** Returns the JobType of a given Job. */
+JobType job_type(const Job *job);
+
+/** Returns the enum string for the JobType of a given Job. */
+const char *job_type_str(const Job *job);
+
+#endif
diff --git a/include/qemu/job.h b/include/qemu/job.h
index d417e1b601..0003b636bc 100644
--- a/include/qemu/job.h
+++ b/include/qemu/job.h
@@ -26,306 +26,7 @@
 #ifndef JOB_H
 #define JOB_H
 
-#include "qapi/qapi-types-job.h"
-#include "qemu/queue.h"
-#include "qemu/progress_meter.h"
-#include "qemu/coroutine.h"
-#include "block/aio.h"
-
-typedef struct JobDriver JobDriver;
-typedef struct JobTxn JobTxn;
-
-
-/**
- * Long-running operation.
- */
-typedef struct Job {
-
-    /* Fields set at initialization (job_create), and never modified */
-
-    /** The ID of the job. May be NULL for internal jobs. */
-    char *id;
-
-    /**
-     * The type of this job.
-     * All callbacks are called with job_mutex *not* held.
-     */
-    const JobDriver *driver;
-
-    /** AioContext to run the job coroutine in */
-    AioContext *aio_context;
-
-    /**
-     * The coroutine that executes the job.  If not NULL, it is reentered when
-     * busy is false and the job is cancelled.
-     * Initialized in job_start()
-     */
-    Coroutine *co;
-
-    /** True if this job should automatically finalize itself */
-    bool auto_finalize;
-
-    /** True if this job should automatically dismiss itself */
-    bool auto_dismiss;
-
-    /** The completion function that will be called when the job completes.  */
-    BlockCompletionFunc *cb;
-
-    /** The opaque value that is passed to the completion function.  */
-    void *opaque;
-
-    /* ProgressMeter API is thread-safe */
-    ProgressMeter progress;
-
-
-    /** Protected by job_mutex */
-
-    /** Reference count of the block job */
-    int refcnt;
-
-    /** Current state; See @JobStatus for details. */
-    JobStatus status;
-
-    /**
-     * Timer that is used by @job_sleep_ns. Accessed under job_mutex (in
-     * job.c).
-     */
-    QEMUTimer sleep_timer;
-
-    /**
-     * Counter for pause request. If non-zero, the block job is either paused,
-     * or if busy == true will pause itself as soon as possible.
-     */
-    int pause_count;
-
-    /**
-     * Set to false by the job while the coroutine has yielded and may be
-     * re-entered by job_enter(). There may still be I/O or event loop activity
-     * pending. Accessed under job_mutex.
-     *
-     * When the job is deferred to the main loop, busy is true as long as the
-     * bottom half is still pending.
-     */
-    bool busy;
-
-    /**
-     * Set to true by the job while it is in a quiescent state, where
-     * no I/O or event loop activity is pending.
-     */
-    bool paused;
-
-    /**
-     * Set to true if the job is paused by user.  Can be unpaused with the
-     * block-job-resume QMP command.
-     */
-    bool user_paused;
-
-    /**
-     * Set to true if the job should cancel itself.  The flag must
-     * always be tested just before toggling the busy flag from false
-     * to true.  After a job has been cancelled, it should only yield
-     * if #aio_poll will ("sooner or later") reenter the coroutine.
-     */
-    bool cancelled;
-
-    /**
-     * Set to true if the job should abort immediately without waiting
-     * for data to be in sync.
-     */
-    bool force_cancel;
-
-    /** Set to true when the job has deferred work to the main loop. */
-    bool deferred_to_main_loop;
-
-    /**
-     * Return code from @run and/or @prepare callback(s).
-     * Not final until the job has reached the CONCLUDED status.
-     * 0 on success, -errno on failure.
-     */
-    int ret;
-
-    /**
-     * Error object for a failed job.
-     * If job->ret is nonzero and an error object was not set, it will be set
-     * to strerror(-job->ret) during job_completed.
-     */
-    Error *err;
-
-    /** Notifiers called when a cancelled job is finalised */
-    NotifierList on_finalize_cancelled;
-
-    /** Notifiers called when a successfully completed job is finalised */
-    NotifierList on_finalize_completed;
-
-    /** Notifiers called when the job transitions to PENDING */
-    NotifierList on_pending;
-
-    /** Notifiers called when the job transitions to READY */
-    NotifierList on_ready;
-
-    /** Notifiers called when the job coroutine yields or terminates */
-    NotifierList on_idle;
-
-    /** Element of the list of jobs */
-    QLIST_ENTRY(Job) job_list;
-
-    /** Transaction this job is part of */
-    JobTxn *txn;
-
-    /** Element of the list of jobs in a job transaction */
-    QLIST_ENTRY(Job) txn_list;
-} Job;
-
-/**
- * Callbacks and other information about a Job driver.
- * All callbacks are invoked with job_mutex *not* held.
- */
-struct JobDriver {
-
-    /* Fields initialized in struct definition and never changed. */
-
-    /** Derived Job struct size */
-    size_t instance_size;
-
-    /** Enum describing the operation */
-    JobType job_type;
-
-    /*
-     * Functions run without regard to the BQL and may run in any
-     * arbitrary thread. These functions do not need to be thread-safe
-     * because the caller ensures that are invoked from one thread at time.
-     */
-
-    /**
-     * Mandatory: Entrypoint for the Coroutine.
-     *
-     * This callback will be invoked when moving from CREATED to RUNNING.
-     *
-     * If this callback returns nonzero, the job transaction it is part of is
-     * aborted. If it returns zero, the job moves into the WAITING state. If it
-     * is the last job to complete in its transaction, all jobs in the
-     * transaction move from WAITING to PENDING.
-     */
-    int coroutine_fn (*run)(Job *job, Error **errp);
-
-    /**
-     * If the callback is not NULL, it will be invoked when the job transitions
-     * into the paused state.  Paused jobs must not perform any asynchronous
-     * I/O or event loop activity.  This callback is used to quiesce jobs.
-     */
-    void coroutine_fn (*pause)(Job *job);
-
-    /**
-     * If the callback is not NULL, it will be invoked when the job transitions
-     * out of the paused state.  Any asynchronous I/O or event loop activity
-     * should be restarted from this callback.
-     */
-    void coroutine_fn (*resume)(Job *job);
-
-    /*
-     * Global state (GS) API. These functions run under the BQL lock.
-     *
-     * See include/block/block-global-state.h for more information about
-     * the GS API.
-     */
-
-    /**
-     * Called when the job is resumed by the user (i.e. user_paused becomes
-     * false). .user_resume is called before .resume.
-     */
-    void (*user_resume)(Job *job);
-
-    /**
-     * Optional callback for job types whose completion must be triggered
-     * manually.
-     */
-    void (*complete)(Job *job, Error **errp);
-
-    /**
-     * If the callback is not NULL, prepare will be invoked when all the jobs
-     * belonging to the same transaction complete; or upon this job's completion
-     * if it is not in a transaction.
-     *
-     * This callback will not be invoked if the job has already failed.
-     * If it fails, abort and then clean will be called.
-     */
-    int (*prepare)(Job *job);
-
-    /**
-     * If the callback is not NULL, it will be invoked when all the jobs
-     * belonging to the same transaction complete; or upon this job's
-     * completion if it is not in a transaction. Skipped if NULL.
-     *
-     * All jobs will complete with a call to either .commit() or .abort() but
-     * never both.
-     */
-    void (*commit)(Job *job);
-
-    /**
-     * If the callback is not NULL, it will be invoked when any job in the
-     * same transaction fails; or upon this job's failure (due to error or
-     * cancellation) if it is not in a transaction. Skipped if NULL.
-     *
-     * All jobs will complete with a call to either .commit() or .abort() but
-     * never both.
-     */
-    void (*abort)(Job *job);
-
-    /**
-     * If the callback is not NULL, it will be invoked after a call to either
-     * .commit() or .abort(). Regardless of which callback is invoked after
-     * completion, .clean() will always be called, even if the job does not
-     * belong to a transaction group.
-     */
-    void (*clean)(Job *job);
-
-    /**
-     * If the callback is not NULL, it will be invoked in job_cancel_async
-     *
-     * This function must return true if the job will be cancelled
-     * immediately without any further I/O (mandatory if @force is
-     * true), and false otherwise.  This lets the generic job layer
-     * know whether a job has been truly (force-)cancelled, or whether
-     * it is just in a special completion mode (like mirror after
-     * READY).
-     * (If the callback is NULL, the job is assumed to terminate
-     * without I/O.)
-     */
-    bool (*cancel)(Job *job, bool force);
-
-
-    /** Called when the job is freed */
-    void (*free)(Job *job);
-};
-
-typedef enum JobCreateFlags {
-    /* Default behavior */
-    JOB_DEFAULT = 0x00,
-    /* Job is not QMP-created and should not send QMP events */
-    JOB_INTERNAL = 0x01,
-    /* Job requires manual finalize step */
-    JOB_MANUAL_FINALIZE = 0x02,
-    /* Job requires manual dismiss step */
-    JOB_MANUAL_DISMISS = 0x04,
-} JobCreateFlags;
-
-/**
- * job_lock:
- *
- * Take the mutex protecting the list of jobs and their status.
- * Most functions called by the monitor need to call job_lock
- * and job_unlock manually.  On the other hand, function called
- * by the block jobs themselves and by the block layer will take the
- * lock for you.
- */
-void job_lock(void);
-
-/**
- * job_unlock:
- *
- * Release the mutex protecting the list of jobs and their status.
- */
-void job_unlock(void);
+#include "job-common.h"
 
 /**
  * Allocate and return a new job transaction. Jobs can be added to the
@@ -474,12 +175,6 @@ void job_yield(Job *job);
  */
 void coroutine_fn job_sleep_ns(Job *job, int64_t ns);
 
-/** Returns the JobType of a given Job. */
-JobType job_type(const Job *job);
-
-/** Returns the enum string for the JobType of a given Job. */
-const char *job_type_str(const Job *job);
-
 /** Returns true if the job should not be visible to the management layer. */
 bool job_is_internal(Job *job);
 
-- 
2.27.0

[RFC PATCH 2/3] jobs: add job-monitor.h

[Emanuele Giuseppe Esposito]

job-monitor.h contains all functions of job.h that are used by the
monitor and essentially all functions that do not define a
JobDriver/Blockdriver.

No functional change intended.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 include/qemu/job-monitor.h | 282 +++++++++++++++++++++++++++++++++++++
 include/qemu/job.h         | 228 +-----------------------------
 job.c                      |   1 +
 3 files changed, 284 insertions(+), 227 deletions(-)
 create mode 100644 include/qemu/job-monitor.h

diff --git a/include/qemu/job-monitor.h b/include/qemu/job-monitor.h
new file mode 100644
index 0000000000..7189cdafef
--- /dev/null
+++ b/include/qemu/job-monitor.h
@@ -0,0 +1,282 @@
+/*
+ * Declarations for background jobs
+ *
+ * Copyright (c) 2011 IBM Corp.
+ * Copyright (c) 2012, 2018 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef JOB_MONITOR_H
+#define JOB_MONITOR_H
+
+#include "job-common.h"
+
+/*
+ * Job monitor API.
+ *
+ * These functions use are used by the QEMU monitor, for example
+ * to execute QMP commands. The monitor is aware of the job_mutex
+ * presence, so these functions assume it is held by the caller
+ * to protect job fields (see job-common.h).
+ * This prevents TOC/TOU bugs, allowing the caller to hold the
+ * lock between a check in the job state and the actual action.
+ *
+ * Therefore, each function in this API that needs protection
+ * must have the comment
+ * "Called between job_lock and job_unlock."
+ */
+
+/**
+ * Allocate and return a new job transaction. Jobs can be added to the
+ * transaction using job_txn_add_job().
+ *
+ * The transaction is automatically freed when the last job completes or is
+ * cancelled.
+ *
+ * All jobs in the transaction either complete successfully or fail/cancel as a
+ * group.  Jobs wait for each other before completing.  Cancelling one job
+ * cancels all jobs in the transaction.
+ */
+JobTxn *job_txn_new(void);
+
+/**
+ * Release a reference that was previously acquired with job_txn_add_job or
+ * job_txn_new. If it's the last reference to the object, it will be freed.
+ */
+void job_txn_unref(JobTxn *txn);
+
+/**
+ * @txn: The transaction (may be NULL)
+ * @job: Job to add to the transaction
+ *
+ * Add @job to the transaction.  The @job must not already be in a transaction.
+ * The caller must call either job_txn_unref() or job_completed() to release
+ * the reference that is automatically grabbed here.
+ *
+ * If @txn is NULL, the function does nothing.
+ *
+ * Called between job_lock and job_unlock.
+ */
+void job_txn_add_job(JobTxn *txn, Job *job);
+
+/**
+ * Add a reference to Job refcnt, it will be decreased with job_unref, and then
+ * be freed if it comes to be the last reference.
+ *
+ * Called between job_lock and job_unlock.
+ */
+void job_ref(Job *job);
+
+/**
+ * Release a reference that was previously acquired with job_ref() or
+ * job_create(). If it's the last reference to the object, it will be freed.
+ *
+ * Called between job_lock and job_unlock.
+ */
+void job_unref(Job *job);
+
+/**
+ * Conditionally enter the job coroutine if the job is ready to run, not
+ * already busy and fn() returns true. fn() is called while under the job_lock
+ * critical section.
+ *
+ * Called between job_lock and job_unlock, but it releases the lock temporarly.
+ */
+void job_enter_cond(Job *job, bool(*fn)(Job *job));
+
+/**
+ * Returns true if the job should not be visible to the management layer.
+ */
+bool job_is_internal(Job *job);
+
+/**
+ * Returns whether the job is in a completed state.
+ * Called between job_lock and job_unlock.
+ */
+bool job_is_completed(Job *job);
+
+/**
+ * Request @job to pause at the next pause point. Must be paired with
+ * job_resume(). If the job is supposed to be resumed by user action, call
+ * job_user_pause() instead.
+ *
+ * Called between job_lock and job_unlock.
+ */
+void job_pause(Job *job);
+
+/**
+ * Resumes a @job paused with job_pause.
+ * Called between job_lock and job_unlock.
+ */
+void job_resume(Job *job);
+
+/**
+ * Asynchronously pause the specified @job.
+ * Do not allow a resume until a matching call to job_user_resume.
+ *
+ * Called between job_lock and job_unlock.
+ */
+void job_user_pause(Job *job, Error **errp);
+
+/**
+ * Returns true if the job is user-paused.
+ * Called between job_lock and job_unlock.
+ */
+bool job_user_paused(Job *job);
+
+/**
+ * Resume the specified @job.
+ * Must be paired with a preceding job_user_pause.
+ *
+ * Called between job_lock and job_unlock.
+ */
+void job_user_resume(Job *job, Error **errp);
+
+/**
+ * Get the next element from the list of block jobs after @job, or the
+ * first one if @job is %NULL.
+ *
+ * Returns the requested job, or %NULL if there are no more jobs left.
+ *
+ * Called between job_lock and job_unlock.
+ */
+Job *job_next(Job *job);
+
+/**
+ * Get the job identified by @id (which must not be %NULL).
+ *
+ * Returns the requested job, or %NULL if it doesn't exist.
+ *
+ * Called between job_lock and job_unlock.
+ */
+Job *job_get(const char *id);
+
+/**
+ * Check whether the verb @verb can be applied to @job in its current state.
+ * Returns 0 if the verb can be applied; otherwise errp is set and -EPERM
+ * returned.
+ *
+ * Called between job_lock and job_unlock.
+ */
+int job_apply_verb(Job *job, JobVerb verb, Error **errp);
+
+/**
+ * Asynchronously complete the specified @job.
+ * Called between job_lock and job_unlock, but it releases the lock temporarly.
+ */
+void job_complete(Job *job, Error **errp);
+
+/**
+ * Asynchronously cancel the specified @job. If @force is true, the job should
+ * be cancelled immediately without waiting for a consistent state.
+ *
+ * Called between job_lock and job_unlock.
+ */
+void job_cancel(Job *job, bool force);
+
+/**
+ * Cancels the specified job like job_cancel(), but may refuse to do so if the
+ * operation isn't meaningful in the current state of the job.
+ *
+ * Called between job_lock and job_unlock.
+ */
+void job_user_cancel(Job *job, bool force, Error **errp);
+
+/**
+ * Synchronously cancel the @job.  The completion callback is called
+ * before the function returns.  If @force is false, the job may
+ * actually complete instead of canceling itself; the circumstances
+ * under which this happens depend on the kind of job that is active.
+ *
+ * Returns the return value from the job if the job actually completed
+ * during the call, or -ECANCELED if it was canceled.
+ *
+ * Callers must hold the AioContext lock of job->aio_context.
+ */
+int job_cancel_sync(Job *job, bool force);
+
+/**
+ * Synchronously force-cancels all jobs using job_cancel_sync().
+ *
+ * Called with job_lock *not* held, unlike most other APIs consumed
+ * by the monitor! This is primarly to avoid adding unnecessary lock-unlock
+ * patterns in the caller.
+ */
+void job_cancel_sync_all(void);
+
+/**
+ * @job: The job to be completed.
+ * @errp: Error object which may be set by job_complete(); this is not
+ *        necessarily set on every error, the job return value has to be
+ *        checked as well.
+ *
+ * Synchronously complete the job.  The completion callback is called before the
+ * function returns, unless it is NULL (which is permissible when using this
+ * function).
+ *
+ * Returns the return value from the job.
+ *
+ * Callers must hold the AioContext lock of job->aio_context.
+ *
+ * Called between job_lock and job_unlock.
+ */
+int job_complete_sync(Job *job, Error **errp);
+
+/**
+ * For a @job that has finished its work and is pending awaiting explicit
+ * acknowledgement to commit its work, this will commit that work.
+ *
+ * FIXME: Make the below statement universally true:
+ * For jobs that support the manual workflow mode, all graph changes that occur
+ * as a result will occur after this command and before a successful reply.
+ *
+ * Called between job_lock and job_unlock.
+ */
+void job_finalize(Job *job, Error **errp);
+
+/**
+ * Remove the concluded @job from the query list and resets the passed pointer
+ * to %NULL. Returns an error if the job is not actually concluded.
+ *
+ * Called between job_lock and job_unlock.
+ */
+void job_dismiss(Job **job, Error **errp);
+
+/**
+ * Synchronously finishes the given @job. If @finish is given, it is called to
+ * trigger completion or cancellation of the job.
+ *
+ * Returns 0 if the job is successfully completed, -ECANCELED if the job was
+ * cancelled before completing, and -errno in other error cases.
+ *
+ * Callers must hold the AioContext lock of job->aio_context.
+ *
+ * Called between job_lock and job_unlock, but it releases the lock temporarly.
+ */
+int job_finish_sync(Job *job, void (*finish)(Job *, Error **errp),
+                    Error **errp);
+
+/** Same as job_is_ready(), but assumes job_lock is held. */
+bool job_is_ready_locked(Job *job);
+
+/** Same as job_early_fail(), but assumes job_lock is held. */
+void job_early_fail_locked(Job *job);
+
+#endif
diff --git a/include/qemu/job.h b/include/qemu/job.h
index 0003b636bc..79f5367f3d 100644
--- a/include/qemu/job.h
+++ b/include/qemu/job.h
@@ -26,40 +26,7 @@
 #ifndef JOB_H
 #define JOB_H
 
-#include "job-common.h"
-
-/**
- * Allocate and return a new job transaction. Jobs can be added to the
- * transaction using job_txn_add_job().
- *
- * The transaction is automatically freed when the last job completes or is
- * cancelled.
- *
- * All jobs in the transaction either complete successfully or fail/cancel as a
- * group.  Jobs wait for each other before completing.  Cancelling one job
- * cancels all jobs in the transaction.
- */
-JobTxn *job_txn_new(void);
-
-/**
- * Release a reference that was previously acquired with job_txn_add_job or
- * job_txn_new. If it's the last reference to the object, it will be freed.
- */
-void job_txn_unref(JobTxn *txn);
-
-/**
- * @txn: The transaction (may be NULL)
- * @job: Job to add to the transaction
- *
- * Add @job to the transaction.  The @job must not already be in a transaction.
- * The caller must call either job_txn_unref() or job_completed() to release
- * the reference that is automatically grabbed here.
- *
- * If @txn is NULL, the function does nothing.
- *
- * Called between job_lock and job_unlock.
- */
-void job_txn_add_job(JobTxn *txn, Job *job);
+#include "job-monitor.h"
 
 /**
  * Create a new long-running job and return it.
@@ -77,22 +44,6 @@ void *job_create(const char *job_id, const JobDriver *driver, JobTxn *txn,
                  AioContext *ctx, int flags, BlockCompletionFunc *cb,
                  void *opaque, Error **errp);
 
-/**
- * Add a reference to Job refcnt, it will be decreased with job_unref, and then
- * be freed if it comes to be the last reference.
- *
- * Called between job_lock and job_unlock.
- */
-void job_ref(Job *job);
-
-/**
- * Release a reference that was previously acquired with job_ref() or
- * job_create(). If it's the last reference to the object, it will be freed.
- *
- * Called between job_lock and job_unlock.
- */
-void job_unref(Job *job);
-
 /**
  * @job: The job that has made progress
  * @done: How much progress the job made since the last call
@@ -126,15 +77,6 @@ void job_progress_set_remaining(Job *job, uint64_t remaining);
  */
 void job_progress_increase_remaining(Job *job, uint64_t delta);
 
-/**
- * Conditionally enter the job coroutine if the job is ready to run, not
- * already busy and fn() returns true. fn() is called while under the job_lock
- * critical section.
- *
- * Called between job_lock and job_unlock, but it releases the lock temporarly.
- */
-void job_enter_cond(Job *job, bool(*fn)(Job *job));
-
 /**
  * @job: A job that has not yet been started.
  *
@@ -175,9 +117,6 @@ void job_yield(Job *job);
  */
 void coroutine_fn job_sleep_ns(Job *job, int64_t ns);
 
-/** Returns true if the job should not be visible to the management layer. */
-bool job_is_internal(Job *job);
-
 /** Returns whether the job is being cancelled. */
 bool job_is_cancelled(Job *job);
 
@@ -187,180 +126,15 @@ bool job_is_cancelled(Job *job);
  */
 bool job_cancel_requested(Job *job);
 
-/**
- * Returns whether the job is in a completed state.
- * Called between job_lock and job_unlock.
- */
-bool job_is_completed(Job *job);
-
 /** Returns whether the job is ready to be completed. */
 bool job_is_ready(Job *job);
 
-/** Same as job_is_ready(), but assumes job_lock is held. */
-bool job_is_ready_locked(Job *job);
-
-/**
- * Request @job to pause at the next pause point. Must be paired with
- * job_resume(). If the job is supposed to be resumed by user action, call
- * job_user_pause() instead.
- *
- * Called between job_lock and job_unlock.
- */
-void job_pause(Job *job);
-
-/**
- * Resumes a @job paused with job_pause.
- * Called between job_lock and job_unlock.
- */
-void job_resume(Job *job);
-
-/**
- * Asynchronously pause the specified @job.
- * Do not allow a resume until a matching call to job_user_resume.
- *
- * Called between job_lock and job_unlock.
- */
-void job_user_pause(Job *job, Error **errp);
-
-/**
- * Returns true if the job is user-paused.
- * Called between job_lock and job_unlock.
- */
-bool job_user_paused(Job *job);
-
-/**
- * Resume the specified @job.
- * Must be paired with a preceding job_user_pause.
- *
- * Called between job_lock and job_unlock.
- */
-void job_user_resume(Job *job, Error **errp);
-
-/**
- * Get the next element from the list of block jobs after @job, or the
- * first one if @job is %NULL.
- *
- * Returns the requested job, or %NULL if there are no more jobs left.
- *
- * Called between job_lock and job_unlock.
- */
-Job *job_next(Job *job);
-
-/**
- * Get the job identified by @id (which must not be %NULL).
- *
- * Returns the requested job, or %NULL if it doesn't exist.
- *
- * Called between job_lock and job_unlock.
- */
-Job *job_get(const char *id);
-
-/**
- * Check whether the verb @verb can be applied to @job in its current state.
- * Returns 0 if the verb can be applied; otherwise errp is set and -EPERM
- * returned.
- *
- * Called between job_lock and job_unlock.
- */
-int job_apply_verb(Job *job, JobVerb verb, Error **errp);
-
 /** The @job could not be started, free it. */
 void job_early_fail(Job *job);
 
-/** Same as job_early_fail(), but assumes job_lock is held. */
-void job_early_fail_locked(Job *job);
-
 /** Moves the @job from RUNNING to READY */
 void job_transition_to_ready(Job *job);
 
-/**
- * Asynchronously complete the specified @job.
- * Called between job_lock and job_unlock, but it releases the lock temporarly.
- */
-void job_complete(Job *job, Error **errp);
-
-/**
- * Asynchronously cancel the specified @job. If @force is true, the job should
- * be cancelled immediately without waiting for a consistent state.
- *
- * Called between job_lock and job_unlock.
- */
-void job_cancel(Job *job, bool force);
-
-/**
- * Cancels the specified job like job_cancel(), but may refuse to do so if the
- * operation isn't meaningful in the current state of the job.
- *
- * Called between job_lock and job_unlock.
- */
-void job_user_cancel(Job *job, bool force, Error **errp);
-
-/**
- * Synchronously cancel the @job.  The completion callback is called
- * before the function returns.  If @force is false, the job may
- * actually complete instead of canceling itself; the circumstances
- * under which this happens depend on the kind of job that is active.
- *
- * Returns the return value from the job if the job actually completed
- * during the call, or -ECANCELED if it was canceled.
- */
-int job_cancel_sync(Job *job, bool force);
-
-/**
- * Synchronously force-cancels all jobs using job_cancel_sync().
- *
- * Called with job_lock *not* held, unlike most other APIs consumed
- * by the monitor! This is primarly to avoid adding unnecessary lock-unlock
- * patterns in the caller.
- */
-void job_cancel_sync_all(void);
-
-/**
- * @job: The job to be completed.
- * @errp: Error object which may be set by job_complete(); this is not
- *        necessarily set on every error, the job return value has to be
- *        checked as well.
- *
- * Synchronously complete the job.  The completion callback is called before the
- * function returns, unless it is NULL (which is permissible when using this
- * function).
- *
- * Returns the return value from the job.
- * Called between job_lock and job_unlock.
- */
-int job_complete_sync(Job *job, Error **errp);
-
-/**
- * For a @job that has finished its work and is pending awaiting explicit
- * acknowledgement to commit its work, this will commit that work.
- *
- * FIXME: Make the below statement universally true:
- * For jobs that support the manual workflow mode, all graph changes that occur
- * as a result will occur after this command and before a successful reply.
- *
- * Called between job_lock and job_unlock.
- */
-void job_finalize(Job *job, Error **errp);
-
-/**
- * Remove the concluded @job from the query list and resets the passed pointer
- * to %NULL. Returns an error if the job is not actually concluded.
- *
- * Called between job_lock and job_unlock.
- */
-void job_dismiss(Job **job, Error **errp);
-
-/**
- * Synchronously finishes the given @job. If @finish is given, it is called to
- * trigger completion or cancellation of the job.
- *
- * Returns 0 if the job is successfully completed, -ECANCELED if the job was
- * cancelled before completing, and -errno in other error cases.
- *
- * Called between job_lock and job_unlock.
- */
-int job_finish_sync(Job *job, void (*finish)(Job *, Error **errp), Error **errp);
-
 /** Enters the @job if it is not paused */
 void job_enter_not_paused(Job *job);
 
diff --git a/job.c b/job.c
index 53c64fcde1..aa8c4fe1b6 100644
--- a/job.c
+++ b/job.c
@@ -40,6 +40,7 @@
  * therefore needs consistency across job_get and the actual operation
  * (e.g. job_user_cancel). To achieve this consistency, the caller
  * calls job_lock/job_unlock itself around the whole operation.
+ * These functions are declared in job-monitor.h.
  *
  *
  * The second includes functions used by the block job drivers and sometimes
-- 
2.27.0

[RFC PATCH 3/3] jobs: add job-driver.h

[Emanuele Giuseppe Esposito]

job-driver.h contains all functions of job.h that are used by
the drivers (JobDriver, BlockJobDriver).

These functions are unaware of the job_mutex,
so they all take and release the lock internally.

No functional change intended.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 include/qemu/job-driver.h  | 173 +++++++++++++++++++++++++++++++++++++
 include/qemu/job-monitor.h |   4 +-
 include/qemu/job.h         | 129 +--------------------------
 job.c                      |   3 +-
 4 files changed, 179 insertions(+), 130 deletions(-)
 create mode 100644 include/qemu/job-driver.h

diff --git a/include/qemu/job-driver.h b/include/qemu/job-driver.h
new file mode 100644
index 0000000000..19ae5ce8f0
--- /dev/null
+++ b/include/qemu/job-driver.h
@@ -0,0 +1,173 @@
+/*
+ * Declarations for background jobs
+ *
+ * Copyright (c) 2011 IBM Corp.
+ * Copyright (c) 2012, 2018 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef JOB_DRIVER_H
+#define JOB_DRIVER_H
+
+#include "job-common.h"
+
+/*
+ * Job driver API.
+ *
+ * These functions use are used by job drivers like mirror,
+ * stream, commit etc. The driver is not aware of the job_mutex
+ * presence, so these functions use it internally to protect
+ * job fields (see job-common.h).
+ *
+ * Therefore, each function in this API that requires protection
+ * must have the comment
+ * "Called with job_mutext *not* held"
+ * in job.c
+ */
+
+/**
+ * Create a new long-running job and return it.
+ *
+ * @job_id: The id of the newly-created job, or %NULL for internal jobs
+ * @driver: The class object for the newly-created job.
+ * @txn: The transaction this job belongs to, if any. %NULL otherwise.
+ * @ctx: The AioContext to run the job coroutine in.
+ * @flags: Creation flags for the job. See @JobCreateFlags.
+ * @cb: Completion function for the job.
+ * @opaque: Opaque pointer value passed to @cb.
+ * @errp: Error object.
+ */
+void *job_create(const char *job_id, const JobDriver *driver, JobTxn *txn,
+                 AioContext *ctx, int flags, BlockCompletionFunc *cb,
+                 void *opaque, Error **errp);
+
+/**
+ * @job: The job that has made progress
+ * @done: How much progress the job made since the last call
+ *
+ * Updates the progress counter of the job.
+ */
+void job_progress_update(Job *job, uint64_t done);
+
+/**
+ * @job: The job whose expected progress end value is set
+ * @remaining: Missing progress (on top of the current progress counter value)
+ *             until the new expected end value is reached
+ *
+ * Sets the expected end value of the progress counter of a job so that a
+ * completion percentage can be calculated when the progress is updated.
+ */
+void job_progress_set_remaining(Job *job, uint64_t remaining);
+
+/**
+ * @job: The job whose expected progress end value is updated
+ * @delta: Value which is to be added to the current expected end
+ *         value
+ *
+ * Increases the expected end value of the progress counter of a job.
+ * This is useful for parenthesis operations: If a job has to
+ * conditionally perform a high-priority operation as part of its
+ * progress, it calls this function with the expected operation's
+ * length before, and job_progress_update() afterwards.
+ * (So the operation acts as a parenthesis in regards to the main job
+ * operation running in background.)
+ */
+void job_progress_increase_remaining(Job *job, uint64_t delta);
+
+/**
+ * @job: A job that has not yet been started.
+ *
+ * Begins execution of a job.
+ * Takes ownership of one reference to the job object.
+ */
+void job_start(Job *job);
+
+/**
+ * @job: The job to enter.
+ *
+ * Continue the specified job by entering the coroutine.
+ */
+void job_enter(Job *job);
+
+/**
+ * @job: The job that is ready to pause.
+ *
+ * Pause now if job_pause() has been called. Jobs that perform lots of I/O
+ * must call this between requests so that the job can be paused.
+ */
+void coroutine_fn job_pause_point(Job *job);
+
+/**
+ * @job: The job that calls the function.
+ *
+ * Yield the job coroutine.
+ */
+void job_yield(Job *job);
+
+/**
+ * @job: The job that calls the function.
+ * @ns: How many nanoseconds to stop for.
+ *
+ * Put the job to sleep (assuming that it wasn't canceled) for @ns
+ * %QEMU_CLOCK_REALTIME nanoseconds.  Canceling the job will immediately
+ * interrupt the wait.
+ */
+void coroutine_fn job_sleep_ns(Job *job, int64_t ns);
+
+/**
+ * Returns whether the job is scheduled for cancellation (at an
+ * indefinite point).
+ */
+bool job_cancel_requested(Job *job);
+
+/** Returns whether the job is scheduled for cancellation. */
+bool job_is_cancelled(Job *job);
+
+/** Returns whether the job is ready to be completed. */
+bool job_is_ready(Job *job);
+
+/** The @job could not be started, free it. */
+void job_early_fail(Job *job);
+
+/** Moves the @job from RUNNING to READY */
+void job_transition_to_ready(Job *job);
+
+/** Enters the @job if it is not paused */
+void job_enter_not_paused(Job *job);
+
+/** returns @job->ret */
+bool job_has_failed(Job *job);
+
+/** Returns the @job->status */
+JobStatus job_get_status(Job *job);
+
+/** Returns the @job->pause_count */
+int job_get_pause_count(Job *job);
+
+/** Returns @job->paused */
+bool job_get_paused(Job *job);
+
+/** Returns @job->busy */
+bool job_get_busy(Job *job);
+
+/** Return true if @job not paused and not cancelled */
+bool job_not_paused_nor_cancelled(Job *job);
+
+#endif /* JOB_DRIVER_H */
diff --git a/include/qemu/job-monitor.h b/include/qemu/job-monitor.h
index 7189cdafef..edcdb1575f 100644
--- a/include/qemu/job-monitor.h
+++ b/include/qemu/job-monitor.h
@@ -273,10 +273,10 @@ void job_dismiss(Job **job, Error **errp);
 int job_finish_sync(Job *job, void (*finish)(Job *, Error **errp),
                     Error **errp);
 
-/** Same as job_is_ready(), but assumes job_lock is held. */
+/** Same as job_is_ready() in job-driver.h, but assumes job_lock is held. */
 bool job_is_ready_locked(Job *job);
 
-/** Same as job_early_fail(), but assumes job_lock is held. */
+/** Same as job_early_fail() in job-driver.h, but assumes job_lock is held. */
 void job_early_fail_locked(Job *job);
 
 #endif
diff --git a/include/qemu/job.h b/include/qemu/job.h
index 79f5367f3d..4a0b01dd1d 100644
--- a/include/qemu/job.h
+++ b/include/qemu/job.h
@@ -27,133 +27,8 @@
 #define JOB_H
 
 #include "job-monitor.h"
+#include "job-driver.h"
 
-/**
- * Create a new long-running job and return it.
- *
- * @job_id: The id of the newly-created job, or %NULL for internal jobs
- * @driver: The class object for the newly-created job.
- * @txn: The transaction this job belongs to, if any. %NULL otherwise.
- * @ctx: The AioContext to run the job coroutine in.
- * @flags: Creation flags for the job. See @JobCreateFlags.
- * @cb: Completion function for the job.
- * @opaque: Opaque pointer value passed to @cb.
- * @errp: Error object.
- */
-void *job_create(const char *job_id, const JobDriver *driver, JobTxn *txn,
-                 AioContext *ctx, int flags, BlockCompletionFunc *cb,
-                 void *opaque, Error **errp);
-
-/**
- * @job: The job that has made progress
- * @done: How much progress the job made since the last call
- *
- * Updates the progress counter of the job.
- */
-void job_progress_update(Job *job, uint64_t done);
-
-/**
- * @job: The job whose expected progress end value is set
- * @remaining: Missing progress (on top of the current progress counter value)
- *             until the new expected end value is reached
- *
- * Sets the expected end value of the progress counter of a job so that a
- * completion percentage can be calculated when the progress is updated.
- */
-void job_progress_set_remaining(Job *job, uint64_t remaining);
-
-/**
- * @job: The job whose expected progress end value is updated
- * @delta: Value which is to be added to the current expected end
- *         value
- *
- * Increases the expected end value of the progress counter of a job.
- * This is useful for parenthesis operations: If a job has to
- * conditionally perform a high-priority operation as part of its
- * progress, it calls this function with the expected operation's
- * length before, and job_progress_update() afterwards.
- * (So the operation acts as a parenthesis in regards to the main job
- * operation running in background.)
- */
-void job_progress_increase_remaining(Job *job, uint64_t delta);
-
-/**
- * @job: A job that has not yet been started.
- *
- * Begins execution of a job.
- * Takes ownership of one reference to the job object.
- */
-void job_start(Job *job);
-
-/**
- * @job: The job to enter.
- *
- * Continue the specified job by entering the coroutine.
- */
-void job_enter(Job *job);
-
-/**
- * @job: The job that is ready to pause.
- *
- * Pause now if job_pause() has been called. Jobs that perform lots of I/O
- * must call this between requests so that the job can be paused.
- */
-void coroutine_fn job_pause_point(Job *job);
-
-/**
- * @job: The job that calls the function.
- *
- * Yield the job coroutine.
- */
-void job_yield(Job *job);
-
-/**
- * @job: The job that calls the function.
- * @ns: How many nanoseconds to stop for.
- *
- * Put the job to sleep (assuming that it wasn't canceled) for @ns
- * %QEMU_CLOCK_REALTIME nanoseconds.  Canceling the job will immediately
- * interrupt the wait.
- */
-void coroutine_fn job_sleep_ns(Job *job, int64_t ns);
-
-/** Returns whether the job is being cancelled. */
-bool job_is_cancelled(Job *job);
-
-/**
- * Returns whether the job is scheduled for cancellation (at an
- * indefinite point).
- */
-bool job_cancel_requested(Job *job);
-
-/** Returns whether the job is ready to be completed. */
-bool job_is_ready(Job *job);
-
-/** The @job could not be started, free it. */
-void job_early_fail(Job *job);
-
-/** Moves the @job from RUNNING to READY */
-void job_transition_to_ready(Job *job);
-
-/** Enters the @job if it is not paused */
-void job_enter_not_paused(Job *job);
-
-/** returns @job->ret */
-bool job_has_failed(Job *job);
-
-/** Returns the @job->status */
-JobStatus job_get_status(Job *job);
-
-/** Returns the @job->pause_count */
-int job_get_pause_count(Job *job);
-
-/** Returns @job->paused */
-bool job_get_paused(Job *job);
-
-/** Returns @job->busy */
-bool job_get_busy(Job *job);
-
-/** Return true if @job not paused and not cancelled */
-bool job_not_paused_nor_cancelled(Job *job);
+/* DO NOT ADD ANYTHING IN HERE. USE ONE OF THE HEADERS INCLUDED ABOVE */
 
 #endif
diff --git a/job.c b/job.c
index aa8c4fe1b6..f225e770f5 100644
--- a/job.c
+++ b/job.c
@@ -44,7 +44,8 @@
  *
  *
  * The second includes functions used by the block job drivers and sometimes
- * by the core block layer. These delegate the locking to the callee instead.
+ * by the core block layer. These delegate the locking to the callee instead,
+ * and are declared in job-driver.h.
  */
 
 
-- 
2.27.0