[Qemu-devel] [RFC PATCH 03/36] block: move job APIs to separate files

[Paolo Bonzini <pbonzini@redhat.com>]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 Makefile.objs       |    5 +-
 block.c             |  128 +----------------------------------
 block.h             |    2 +
 block/Makefile.objs |    3 +-
 block/stream.c      |    1 +
 block_int.h         |  153 ------------------------------------------
 blockdev.c          |    1 +
 blockjob.c          |  164 +++++++++++++++++++++++++++++++++++++++++++++
 blockjob.h          |  184 +++++++++++++++++++++++++++++++++++++++++++++++++++
 9 files changed, 358 insertions(+), 283 deletions(-)
 create mode 100644 blockjob.c
 create mode 100644 blockjob.h

diff --git a/Makefile.objs b/Makefile.objs
index 74110dd..cef9933 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -41,7 +41,8 @@ coroutine-obj-$(CONFIG_WIN32) += coroutine-win32.o
 # block-obj-y is code used by both qemu system emulation and qemu-img
 
 block-obj-y = cutils.o cache-utils.o qemu-option.o module.o async.o
-block-obj-y += nbd.o block.o aio.o aes.o qemu-config.o qemu-progress.o qemu-sockets.o
+block-obj-y += nbd.o block.o blockjob.o aio.o aes.o qemu-config.o
+block-obj-y += qemu-progress.o qemu-sockets.o
 block-obj-y += $(coroutine-obj-y) $(qobject-obj-y) $(version-obj-y)
 block-obj-$(CONFIG_POSIX) += posix-aio-compat.o
 block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
@@ -58,7 +59,7 @@ endif
 # suppress *all* target specific code in case of system emulation, i.e. a
 # single QEMU executable should support all CPUs and machines.
 
-common-obj-y = $(block-obj-y) blockdev.o
+common-obj-y = $(block-obj-y) blockdev.o block/
 common-obj-y += net.o net/
 common-obj-y += qom/
 common-obj-y += readline.o console.o cursor.o
diff --git a/block.c b/block.c
index 29857db..c396d58 100644
--- a/block.c
+++ b/block.c
@@ -26,6 +26,7 @@
 #include "trace.h"
 #include "monitor.h"
 #include "block_int.h"
+#include "blockjob.h"
 #include "module.h"
 #include "qjson.h"
 #include "qemu-coroutine.h"
@@ -4276,130 +4277,3 @@ out:
 
     return ret;
 }
-
-void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
-                       int64_t speed, BlockDriverCompletionFunc *cb,
-                       void *opaque, Error **errp)
-{
-    BlockJob *job;
-
-    if (bs->job || bdrv_in_use(bs)) {
-        error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
-        return NULL;
-    }
-    bdrv_set_in_use(bs, 1);
-
-    job = g_malloc0(job_type->instance_size);
-    job->job_type      = job_type;
-    job->bs            = bs;
-    job->cb            = cb;
-    job->opaque        = opaque;
-    job->busy          = true;
-    bs->job = job;
-
-    /* Only set speed when necessary to avoid NotSupported error */
-    if (speed != 0) {
-        Error *local_err = NULL;
-
-        block_job_set_speed(job, speed, &local_err);
-        if (error_is_set(&local_err)) {
-            bs->job = NULL;
-            g_free(job);
-            bdrv_set_in_use(bs, 0);
-            error_propagate(errp, local_err);
-            return NULL;
-        }
-    }
-    return job;
-}
-
-void block_job_complete(BlockJob *job, int ret)
-{
-    BlockDriverState *bs = job->bs;
-
-    assert(bs->job == job);
-    job->cb(job->opaque, ret);
-    bs->job = NULL;
-    g_free(job);
-    bdrv_set_in_use(bs, 0);
-}
-
-void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
-{
-    Error *local_err = NULL;
-
-    if (!job->job_type->set_speed) {
-        error_set(errp, QERR_NOT_SUPPORTED);
-        return;
-    }
-    job->job_type->set_speed(job, speed, &local_err);
-    if (error_is_set(&local_err)) {
-        error_propagate(errp, local_err);
-        return;
-    }
-
-    job->speed = speed;
-}
-
-void block_job_cancel(BlockJob *job)
-{
-    job->cancelled = true;
-    if (job->co && !job->busy) {
-        qemu_coroutine_enter(job->co, NULL);
-    }
-}
-
-bool block_job_is_cancelled(BlockJob *job)
-{
-    return job->cancelled;
-}
-
-struct BlockCancelData {
-    BlockJob *job;
-    BlockDriverCompletionFunc *cb;
-    void *opaque;
-    bool cancelled;
-    int ret;
-};
-
-static void block_job_cancel_cb(void *opaque, int ret)
-{
-    struct BlockCancelData *data = opaque;
-
-    data->cancelled = block_job_is_cancelled(data->job);
-    data->ret = ret;
-    data->cb(data->opaque, ret);
-}
-
-int block_job_cancel_sync(BlockJob *job)
-{
-    struct BlockCancelData data;
-    BlockDriverState *bs = job->bs;
-
-    assert(bs->job == job);
-
-    /* Set up our own callback to store the result and chain to
-     * the original callback.
-     */
-    data.job = job;
-    data.cb = job->cb;
-    data.opaque = job->opaque;
-    data.ret = -EINPROGRESS;
-    job->cb = block_job_cancel_cb;
-    job->opaque = &data;
-    block_job_cancel(job);
-    while (data.ret == -EINPROGRESS) {
-        qemu_aio_wait();
-    }
-    return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
-}
-
-void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns)
-{
-    /* Check cancellation *before* setting busy = false, too!  */
-    if (!block_job_is_cancelled(job)) {
-        job->busy = false;
-        co_sleep_ns(clock, ns);
-        job->busy = true;
-    }
-}
diff --git a/block.h b/block.h
index 3af93c6..298c616 100644
--- a/block.h
+++ b/block.h
@@ -6,9 +6,11 @@
 #include "qemu-option.h"
 #include "qemu-coroutine.h"
 #include "qobject.h"
+#include "qapi-types.h"
 
 /* block.c */
 typedef struct BlockDriver BlockDriver;
+typedef struct BlockJob BlockJob;
 
 typedef struct BlockDriverInfo {
     /* in bytes, 0 if irrelevant */
diff --git a/block/Makefile.objs b/block/Makefile.objs
index b5754d3..c45affc 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -3,9 +3,10 @@ block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-c
 block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o
 block-obj-y += qed-check.o
 block-obj-y += parallels.o nbd.o blkdebug.o sheepdog.o blkverify.o
-block-obj-y += stream.o
 block-obj-$(CONFIG_WIN32) += raw-win32.o
 block-obj-$(CONFIG_POSIX) += raw-posix.o
 block-obj-$(CONFIG_LIBISCSI) += iscsi.o
 block-obj-$(CONFIG_CURL) += curl.o
 block-obj-$(CONFIG_RBD) += rbd.o
+
+common-obj-y += stream.o
diff --git a/block/stream.c b/block/stream.c
index 37c4652..5b801b4 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -13,6 +13,7 @@
 
 #include "trace.h"
 #include "block_int.h"
+#include "blockjob.h"
 #include "qemu/ratelimit.h"
 
 enum {
diff --git a/block_int.h b/block_int.h
index 1fb5352..4fef4f3 100644
--- a/block_int.h
+++ b/block_int.h
@@ -64,73 +64,6 @@ typedef struct BlockIOBaseValue {
     uint64_t ios[2];
 } BlockIOBaseValue;
 
-typedef struct BlockJob BlockJob;
-
-/**
- * BlockJobType:
- *
- * A class type for block job objects.
- */
-typedef struct BlockJobType {
-    /** Derived BlockJob struct size */
-    size_t instance_size;
-
-    /** String describing the operation, part of query-block-jobs QMP API */
-    const char *job_type;
-
-    /** Optional callback for job types that support setting a speed limit */
-    void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
-} BlockJobType;
-
-/**
- * BlockJob:
- *
- * Long-running operation on a BlockDriverState.
- */
-struct BlockJob {
-    /** The job type, including the job vtable.  */
-    const BlockJobType *job_type;
-
-    /** The block device on which the job is operating.  */
-    BlockDriverState *bs;
-
-    /**
-     * The coroutine that executes the job.  If not NULL, it is
-     * reentered when busy is false and the job is cancelled.
-     */
-    Coroutine *co;
-
-    /**
-     * 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 #qemu_aio_wait will ("sooner or later") reenter the coroutine.
-     */
-    bool cancelled;
-
-    /**
-     * Set to false by the job while it is in a quiescent state, where
-     * no I/O is pending and the job has yielded on any condition
-     * that is not detected by #qemu_aio_wait, such as a timer.
-     */
-    bool busy;
-
-    /** Offset that is published by the query-block-jobs QMP API */
-    int64_t offset;
-
-    /** Length that is published by the query-block-jobs QMP API */
-    int64_t len;
-
-    /** Speed that was set with @block_job_set_speed.  */
-    int64_t speed;
-
-    /** The completion function that will be called when the job completes.  */
-    BlockDriverCompletionFunc *cb;
-
-    /** The opaque value that is passed to the completion function.  */
-    void *opaque;
-};
-
 struct BlockDriver {
     const char *format_name;
     int instance_size;
@@ -346,92 +279,6 @@ int is_windows_drive(const char *filename);
 #endif
 
 /**
- * block_job_create:
- * @job_type: The class object for the newly-created job.
- * @bs: The block
- * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
- * @cb: Completion function for the job.
- * @opaque: Opaque pointer value passed to @cb.
- * @errp: Error object.
- *
- * Create a new long-running block device job and return it.  The job
- * will call @cb asynchronously when the job completes.  Note that
- * @bs may have been closed at the time the @cb it is called.  If
- * this is the case, the job may be reported as either cancelled or
- * completed.
- *
- * This function is not part of the public job interface; it should be
- * called from a wrapper that is specific to the job type.
- */
-void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
-                       int64_t speed, BlockDriverCompletionFunc *cb,
-                       void *opaque, Error **errp);
-
-/**
- * block_job_sleep_ns:
- * @job: The job that calls the function.
- * @clock: The clock to sleep on.
- * @ns: How many nanoseconds to stop for.
- *
- * Put the job to sleep (assuming that it wasn't canceled) for @ns
- * nanoseconds.  Canceling the job will interrupt the wait immediately.
- */
-void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns);
-
-/**
- * block_job_complete:
- * @job: The job being completed.
- * @ret: The status code.
- *
- * Call the completion function that was registered at creation time, and
- * free @job.
- */
-void block_job_complete(BlockJob *job, int ret);
-
-/**
- * block_job_set_speed:
- * @job: The job to set the speed for.
- * @speed: The new value
- * @errp: Error object.
- *
- * Set a rate-limiting parameter for the job; the actual meaning may
- * vary depending on the job type.
- */
-void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
-
-/**
- * block_job_cancel:
- * @job: The job to be canceled.
- *
- * Asynchronously cancel the specified job.
- */
-void block_job_cancel(BlockJob *job);
-
-/**
- * block_job_is_cancelled:
- * @job: The job being queried.
- *
- * Returns whether the job is scheduled for cancellation.
- */
-bool block_job_is_cancelled(BlockJob *job);
-
-/**
- * block_job_cancel:
- * @job: The job to be canceled.
- *
- * Asynchronously cancel the job and wait for it to reach a quiescent
- * state.  Note that the completion callback will still be called
- * asynchronously, hence it is *not* valid to call #bdrv_delete
- * immediately after #block_job_cancel_sync.  Users of block jobs
- * will usually protect the BlockDriverState objects with a reference
- * count, should this be a concern.
- *
- * Returns the return value from the job if the job actually completed
- * during the call, or -ECANCELED if it was canceled.
- */
-int block_job_cancel_sync(BlockJob *job);
-
-/**
  * stream_start:
  * @bs: Block device to operate on.
  * @base: Block device that will become the new base, or %NULL to
diff --git a/blockdev.c b/blockdev.c
index a3518f0..fe270cd 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -9,6 +9,7 @@
 
 #include "block.h"
 #include "blockdev.h"
+#include "blockjob.h"
 #include "monitor.h"
 #include "qerror.h"
 #include "qemu-option.h"
diff --git a/blockjob.c b/blockjob.c
new file mode 100644
index 0000000..accd646
--- /dev/null
+++ b/blockjob.c
@@ -0,0 +1,164 @@
+/*
+ * QEMU System Emulator block driver
+ *
+ * Copyright (c) 2011 IBM Corp.
+ * Copyright (c) 2012 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.
+ */
+
+#include "config-host.h"
+#include "qemu-common.h"
+#include "trace.h"
+#include "monitor.h"
+#include "block.h"
+#include "blockjob.h"
+#include "block_int.h"
+#include "qjson.h"
+#include "qemu-coroutine.h"
+#include "qmp-commands.h"
+#include "qemu-timer.h"
+
+void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
+                       int64_t speed, BlockDriverCompletionFunc *cb,
+                       void *opaque, Error **errp)
+{
+    BlockJob *job;
+
+    if (bs->job || bdrv_in_use(bs)) {
+        error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
+        return NULL;
+    }
+    bdrv_set_in_use(bs, 1);
+
+    job = g_malloc0(job_type->instance_size);
+    job->job_type      = job_type;
+    job->bs            = bs;
+    job->cb            = cb;
+    job->opaque        = opaque;
+    job->busy          = true;
+    bs->job = job;
+
+    /* Only set speed when necessary to avoid NotSupported error */
+    if (speed != 0) {
+        Error *local_err = NULL;
+
+        block_job_set_speed(job, speed, &local_err);
+        if (error_is_set(&local_err)) {
+            bs->job = NULL;
+            g_free(job);
+            bdrv_set_in_use(bs, 0);
+            error_propagate(errp, local_err);
+            return NULL;
+        }
+    }
+    return job;
+}
+
+void block_job_complete(BlockJob *job, int ret)
+{
+    BlockDriverState *bs = job->bs;
+
+    assert(bs->job == job);
+    job->cb(job->opaque, ret);
+    bs->job = NULL;
+    g_free(job);
+    bdrv_set_in_use(bs, 0);
+}
+
+void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
+{
+    Error *local_err = NULL;
+
+    if (!job->job_type->set_speed) {
+        error_set(errp, QERR_NOT_SUPPORTED);
+        return;
+    }
+    job->job_type->set_speed(job, speed, &local_err);
+    if (error_is_set(&local_err)) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    job->speed = speed;
+}
+
+void block_job_cancel(BlockJob *job)
+{
+    job->cancelled = true;
+    if (job->co && !job->busy) {
+        qemu_coroutine_enter(job->co, NULL);
+    }
+}
+
+bool block_job_is_cancelled(BlockJob *job)
+{
+    return job->cancelled;
+}
+
+struct BlockCancelData {
+    BlockJob *job;
+    BlockDriverCompletionFunc *cb;
+    void *opaque;
+    bool cancelled;
+    int ret;
+};
+
+static void block_job_cancel_cb(void *opaque, int ret)
+{
+    struct BlockCancelData *data = opaque;
+
+    data->cancelled = block_job_is_cancelled(data->job);
+    data->ret = ret;
+    data->cb(data->opaque, ret);
+}
+
+int block_job_cancel_sync(BlockJob *job)
+{
+    struct BlockCancelData data;
+    BlockDriverState *bs = job->bs;
+
+    assert(bs->job == job);
+
+    /* Set up our own callback to store the result and chain to
+     * the original callback.
+     */
+    data.job = job;
+    data.cb = job->cb;
+    data.opaque = job->opaque;
+    data.ret = -EINPROGRESS;
+    job->cb = block_job_cancel_cb;
+    job->opaque = &data;
+    block_job_cancel(job);
+    while (data.ret == -EINPROGRESS) {
+        qemu_aio_wait();
+    }
+    return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
+}
+
+void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns)
+{
+    /* Check cancellation *before* setting busy = false, too!  */
+    if (!block_job_is_cancelled(job)) {
+        job->busy = false;
+        co_sleep_ns(clock, ns);
+        job->busy = true;
+    }
+}
+
diff --git a/blockjob.h b/blockjob.h
new file mode 100644
index 0000000..abcb2ee
--- /dev/null
+++ b/blockjob.h
@@ -0,0 +1,184 @@
+/*
+ * Declarations for long-running block device operations
+ *
+ * Copyright (c) 2011 IBM Corp.
+ * Copyright (c) 2012 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 BLOCKJOB_H
+#define BLOCKJOB_H 1
+
+#include "block.h"
+
+typedef struct BlockJob BlockJob;
+
+/**
+ * BlockJobType:
+ *
+ * A class type for block job objects.
+ */
+typedef struct BlockJobType {
+    /** Derived BlockJob struct size */
+    size_t instance_size;
+
+    /** String describing the operation, part of query-block-jobs QMP API */
+    const char *job_type;
+
+    /** Optional callback for job types that support setting a speed limit */
+    void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
+} BlockJobType;
+
+/**
+ * BlockJob:
+ *
+ * Long-running operation on a BlockDriverState.
+ */
+struct BlockJob {
+    /** The job type, including the job vtable.  */
+    const BlockJobType *job_type;
+
+    /** The block device on which the job is operating.  */
+    BlockDriverState *bs;
+
+    /**
+     * The coroutine that executes the job.  If not NULL, it is
+     * reentered when busy is false and the job is cancelled.
+     */
+    Coroutine *co;
+
+    /**
+     * 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 #qemu_aio_wait will ("sooner or later") reenter the coroutine.
+     */
+    bool cancelled;
+
+    /**
+     * Set to false by the job while it is in a quiescent state, where
+     * no I/O is pending and the job has yielded on any condition
+     * that is not detected by #qemu_aio_wait, such as a timer.
+     */
+    bool busy;
+
+    /** Offset that is published by the query-block-jobs QMP API */
+    int64_t offset;
+
+    /** Length that is published by the query-block-jobs QMP API */
+    int64_t len;
+
+    /** Speed that was set with @block_job_set_speed.  */
+    int64_t speed;
+
+    /** The completion function that will be called when the job completes.  */
+    BlockDriverCompletionFunc *cb;
+
+    /** The opaque value that is passed to the completion function.  */
+    void *opaque;
+};
+
+/**
+ * block_job_create:
+ * @job_type: The class object for the newly-created job.
+ * @bs: The block
+ * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
+ * @cb: Completion function for the job.
+ * @opaque: Opaque pointer value passed to @cb.
+ * @errp: Error object.
+ *
+ * Create a new long-running block device job and return it.  The job
+ * will call @cb asynchronously when the job completes.  Note that
+ * @bs may have been closed at the time the @cb it is called.  If
+ * this is the case, the job may be reported as either cancelled or
+ * completed.
+ *
+ * This function is not part of the public job interface; it should be
+ * called from a wrapper that is specific to the job type.
+ */
+void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
+                       int64_t speed, BlockDriverCompletionFunc *cb,
+                       void *opaque, Error **errp);
+
+/**
+ * block_job_sleep_ns:
+ * @job: The job that calls the function.
+ * @clock: The clock to sleep on.
+ * @ns: How many nanoseconds to stop for.
+ *
+ * Put the job to sleep (assuming that it wasn't canceled) for @ns
+ * nanoseconds.  Canceling the job will interrupt the wait immediately.
+ */
+void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns);
+
+/**
+ * block_job_complete:
+ * @job: The job being completed.
+ * @ret: The status code.
+ *
+ * Call the completion function that was registered at creation time, and
+ * free @job.
+ */
+void block_job_complete(BlockJob *job, int ret);
+
+/**
+ * block_job_set_speed:
+ * @job: The job to set the speed for.
+ * @speed: The new value
+ * @errp: Error object.
+ *
+ * Set a rate-limiting parameter for the job; the actual meaning may
+ * vary depending on the job type.
+ */
+void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
+
+/**
+ * block_job_cancel:
+ * @job: The job to be canceled.
+ *
+ * Asynchronously cancel the specified job.
+ */
+void block_job_cancel(BlockJob *job);
+
+/**
+ * block_job_is_cancelled:
+ * @job: The job being queried.
+ *
+ * Returns whether the job is scheduled for cancellation.
+ */
+bool block_job_is_cancelled(BlockJob *job);
+
+/**
+ * block_job_cancel_sync:
+ * @job: The job to be canceled.
+ *
+ * Synchronously cancel the job and wait for it to reach a quiescent
+ * state.  Note that the completion callback will still be called
+ * asynchronously, hence it is *not* valid to call #bdrv_delete
+ * immediately after #block_job_cancel_sync.  Users of block jobs
+ * will usually protect the BlockDriverState objects with a reference
+ * count, should this be a concern.
+ *
+ * Returns the return value from the job if the job actually completed
+ * during the call, or -ECANCELED if it was canceled.
+ */
+int block_job_cancel_sync(BlockJob *job);
+
+#endif
+
-- 
1.7.10.2