[Qemu-devel] [PULL 13/14] blockjobs: split interface into public/private, Part 1

[Jeff Cody]

From: John Snow <address@hidden>

To make it a little more obvious which functions are intended to be
public interface and which are intended to be for use only by jobs
themselves, split the interface into "public" and "private" files.

Convert blockjobs (e.g. block/backup) to using the private interface.
Leave blockdev and others on the public interface.

There are remaining uses of private state by qemu-img, and several
cases in blockdev.c and block/io.c where we grab job->blk for the
purposes of acquiring an AIOContext.

These will be corrected in future patches.

Signed-off-by: John Snow <address@hidden>
Reviewed-by: Kevin Wolf <address@hidden>
Reviewed-by: Jeff Cody <address@hidden>
Message-id: address@hidden
Signed-off-by: Jeff Cody <address@hidden>
---
 block/backup.c               |   2 +-
 block/commit.c               |   2 +-
 block/mirror.c               |   2 +-
 block/stream.c               |   2 +-
 blockjob.c                   |   2 +-
 include/block/block.h        |   3 +-
 include/block/blockjob.h     | 212 +-------------------------------------
 include/block/blockjob_int.h | 239 +++++++++++++++++++++++++++++++++++++++++++
 tests/test-blockjob-txn.c    |   2 +-
 tests/test-blockjob.c        |   2 +-
 10 files changed, 251 insertions(+), 217 deletions(-)
 create mode 100644 include/block/blockjob_int.h

diff --git a/block/backup.c b/block/backup.c
index 3c1114f..deb0909 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -16,7 +16,7 @@
 #include "trace.h"
 #include "block/block.h"
 #include "block/block_int.h"
-#include "block/blockjob.h"
+#include "block/blockjob_int.h"
 #include "block/block_backup.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
diff --git a/block/commit.c b/block/commit.c
index a8e8ed6..33abe05 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -15,7 +15,7 @@
 #include "qemu/osdep.h"
 #include "trace.h"
 #include "block/block_int.h"
-#include "block/blockjob.h"
+#include "block/blockjob_int.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/ratelimit.h"
diff --git a/block/mirror.c b/block/mirror.c
index b7c3080..1ba1c09 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -13,7 +13,7 @@
 
 #include "qemu/osdep.h"
 #include "trace.h"
-#include "block/blockjob.h"
+#include "block/blockjob_int.h"
 #include "block/block_int.h"
 #include "sysemu/block-backend.h"
 #include "qapi/error.h"
diff --git a/block/stream.c b/block/stream.c
index 7d6877d..906f7f3 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -14,7 +14,7 @@
 #include "qemu/osdep.h"
 #include "trace.h"
 #include "block/block_int.h"
-#include "block/blockjob.h"
+#include "block/blockjob_int.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/ratelimit.h"
diff --git a/blockjob.c b/blockjob.c
index 8715e55..6c381d0 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -27,7 +27,7 @@
 #include "qemu-common.h"
 #include "trace.h"
 #include "block/block.h"
-#include "block/blockjob.h"
+#include "block/blockjob_int.h"
 #include "block/block_int.h"
 #include "sysemu/block-backend.h"
 #include "qapi/qmp/qerror.h"
diff --git a/include/block/block.h b/include/block/block.h
index b7dc7d5..6a13a47 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -7,16 +7,15 @@
 #include "qemu/coroutine.h"
 #include "block/accounting.h"
 #include "block/dirty-bitmap.h"
+#include "block/blockjob.h"
 #include "qapi/qmp/qobject.h"
 #include "qapi-types.h"
 #include "qemu/hbitmap.h"
 
 /* block.c */
 typedef struct BlockDriver BlockDriver;
-typedef struct BlockJob BlockJob;
 typedef struct BdrvChild BdrvChild;
 typedef struct BdrvChildRole BdrvChildRole;
-typedef struct BlockJobTxn BlockJobTxn;
 
 typedef struct BlockDriverInfo {
     /* in bytes, 0 if irrelevant */
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index 110a7d1..bfc8233 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -28,85 +28,15 @@
 
 #include "block/block.h"
 
-/**
- * BlockJobDriver:
- *
- * A class type for block job driver.
- */
-typedef struct BlockJobDriver {
-    /** Derived BlockJob struct size */
-    size_t instance_size;
-
-    /** String describing the operation, part of query-block-jobs QMP API */
-    BlockJobType job_type;
-
-    /** Optional callback for job types that support setting a speed limit */
-    void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
-
-    /** Optional callback for job types that need to forward I/O status reset 
*/
-    void (*iostatus_reset)(BlockJob *job);
-
-    /**
-     * Optional callback for job types whose completion must be triggered
-     * manually.
-     */
-    void (*complete)(BlockJob *job, Error **errp);
-
-    /**
-     * 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)(BlockJob *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)(BlockJob *job);
-
-    /**
-     * 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)(BlockJob *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)(BlockJob *job);
-
-    /*
-     * If the callback is not NULL, it will be invoked before the job is
-     * resumed in a new AioContext.  This is the place to move any resources
-     * besides job->blk to the new AioContext.
-     */
-    void (*attached_aio_context)(BlockJob *job, AioContext *new_context);
-
-    /*
-     * If the callback is not NULL, it will be invoked when the job has to be
-     * synchronously cancelled or completed; it should drain BlockDriverStates
-     * as required to ensure progress.
-     */
-    void (*drain)(BlockJob *job);
-} BlockJobDriver;
+typedef struct BlockJobDriver BlockJobDriver;
+typedef struct BlockJobTxn BlockJobTxn;
 
 /**
  * BlockJob:
  *
  * Long-running operation on a BlockDriverState.
  */
-struct BlockJob {
+typedef struct BlockJob {
     /** The job type, including the job vtable.  */
     const BlockJobDriver *driver;
 
@@ -205,7 +135,7 @@ struct BlockJob {
     /** Non-NULL if this job is part of a transaction */
     BlockJobTxn *txn;
     QLIST_ENTRY(BlockJob) txn_list;
-};
+} BlockJob;
 
 typedef enum BlockJobCreateFlags {
     BLOCK_JOB_DEFAULT = 0x00,
@@ -234,76 +164,6 @@ BlockJob *block_job_next(BlockJob *job);
 BlockJob *block_job_get(const char *id);
 
 /**
- * block_job_create:
- * @job_id: The id of the newly-created job, or %NULL to have one
- * generated automatically.
- * @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 char *job_id, const BlockJobDriver *driver,
-                       BlockDriverState *bs, int64_t speed, int flags,
-                       BlockCompletionFunc *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, QEMUClockType type, int64_t ns);
-
-/**
- * block_job_yield:
- * @job: The job that calls the function.
- *
- * Yield the block job coroutine.
- */
-void block_job_yield(BlockJob *job);
-
-/**
- * block_job_ref:
- * @bs: The block device.
- *
- * Grab a reference to the block job. Should be paired with block_job_unref.
- */
-void block_job_ref(BlockJob *job);
-
-/**
- * block_job_unref:
- * @bs: The block device.
- *
- * Release reference to the block job and release resources if it is the last
- * reference.
- */
-void block_job_unref(BlockJob *job);
-
-/**
- * block_job_completed:
- * @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_completed(BlockJob *job, int ret);
-
-/**
  * block_job_set_speed:
  * @job: The job to set the speed for.
  * @speed: The new value
@@ -332,14 +192,6 @@ void block_job_cancel(BlockJob *job);
 void block_job_complete(BlockJob *job, Error **errp);
 
 /**
- * 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_query:
  * @job: The job to get information about.
  *
@@ -348,15 +200,6 @@ bool block_job_is_cancelled(BlockJob *job);
 BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
 
 /**
- * block_job_pause_point:
- * @job: The job that is ready to pause.
- *
- * Pause now if block_job_pause() has been called.  Block jobs that perform
- * lots of I/O must call this between requests so that the job can be paused.
- */
-void coroutine_fn block_job_pause_point(BlockJob *job);
-
-/**
  * block_job_pause:
  * @job: The job to be paused.
  *
@@ -399,22 +242,6 @@ void block_job_resume(BlockJob *job);
 void block_job_user_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_ready:
- * @job: The job which is now ready to complete.
- *
- * Send a BLOCK_JOB_READY event for the specified job.
- */
-void block_job_event_ready(BlockJob *job);
-
-/**
  * block_job_cancel_sync:
  * @job: The job to be canceled.
  *
@@ -460,37 +287,6 @@ int block_job_complete_sync(BlockJob *job, Error **errp);
 void block_job_iostatus_reset(BlockJob *job);
 
 /**
- * block_job_error_action:
- * @job: The job to signal an error for.
- * @on_err: The error action setting.
- * @is_read: Whether the operation was a read.
- * @error: The error that was reported.
- *
- * Report an I/O error for a block job and possibly stop the VM.  Return the
- * action that was selected based on @on_err and @error.
- */
-BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
-                                        int is_read, int error);
-
-typedef void BlockJobDeferToMainLoopFn(BlockJob *job, void *opaque);
-
-/**
- * block_job_defer_to_main_loop:
- * @job: The job
- * @fn: The function to run in the main loop
- * @opaque: The opaque value that is passed to @fn
- *
- * Execute a given function in the main loop with the BlockDriverState
- * AioContext acquired.  Block jobs must call bdrv_unref(), bdrv_close(), and
- * anything that uses bdrv_drain_all() in the main loop.
- *
- * The @job AioContext is held while @fn executes.
- */
-void block_job_defer_to_main_loop(BlockJob *job,
-                                  BlockJobDeferToMainLoopFn *fn,
-                                  void *opaque);
-
-/**
  * block_job_txn_new:
  *
  * Allocate and return a new block job transaction.  Jobs can be added to the
diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
new file mode 100644
index 0000000..2b1e859
--- /dev/null
+++ b/include/block/blockjob_int.h
@@ -0,0 +1,239 @@
+/*
+ * 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_INT_H
+#define BLOCKJOB_INT_H
+
+#include "block/blockjob.h"
+#include "block/block.h"
+
+/**
+ * BlockJobDriver:
+ *
+ * A class type for block job driver.
+ */
+struct BlockJobDriver {
+    /** Derived BlockJob struct size */
+    size_t instance_size;
+
+    /** String describing the operation, part of query-block-jobs QMP API */
+    BlockJobType job_type;
+
+    /** Optional callback for job types that support setting a speed limit */
+    void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
+
+    /** Optional callback for job types that need to forward I/O status reset 
*/
+    void (*iostatus_reset)(BlockJob *job);
+
+    /**
+     * Optional callback for job types whose completion must be triggered
+     * manually.
+     */
+    void (*complete)(BlockJob *job, Error **errp);
+
+    /**
+     * 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)(BlockJob *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)(BlockJob *job);
+
+    /**
+     * 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)(BlockJob *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)(BlockJob *job);
+
+    /*
+     * If the callback is not NULL, it will be invoked before the job is
+     * resumed in a new AioContext.  This is the place to move any resources
+     * besides job->blk to the new AioContext.
+     */
+    void (*attached_aio_context)(BlockJob *job, AioContext *new_context);
+
+    /*
+     * If the callback is not NULL, it will be invoked when the job has to be
+     * synchronously cancelled or completed; it should drain BlockDriverStates
+     * as required to ensure progress.
+     */
+    void (*drain)(BlockJob *job);
+};
+
+/**
+ * block_job_create:
+ * @job_id: The id of the newly-created job, or %NULL to have one
+ * generated automatically.
+ * @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 char *job_id, const BlockJobDriver *driver,
+                       BlockDriverState *bs, int64_t speed, int flags,
+                       BlockCompletionFunc *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, QEMUClockType type, int64_t ns);
+
+/**
+ * block_job_yield:
+ * @job: The job that calls the function.
+ *
+ * Yield the block job coroutine.
+ */
+void block_job_yield(BlockJob *job);
+
+/**
+ * block_job_ref:
+ * @bs: The block device.
+ *
+ * Grab a reference to the block job. Should be paired with block_job_unref.
+ */
+void block_job_ref(BlockJob *job);
+
+/**
+ * block_job_unref:
+ * @bs: The block device.
+ *
+ * Release reference to the block job and release resources if it is the last
+ * reference.
+ */
+void block_job_unref(BlockJob *job);
+
+/**
+ * block_job_completed:
+ * @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_completed(BlockJob *job, int ret);
+
+/**
+ * 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_pause_point:
+ * @job: The job that is ready to pause.
+ *
+ * Pause now if block_job_pause() has been called.  Block jobs that perform
+ * lots of I/O must call this between requests so that the job can be paused.
+ */
+void coroutine_fn block_job_pause_point(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_ready:
+ * @job: The job which is now ready to complete.
+ *
+ * Send a BLOCK_JOB_READY event for the specified job.
+ */
+void block_job_event_ready(BlockJob *job);
+
+/**
+ * block_job_error_action:
+ * @job: The job to signal an error for.
+ * @on_err: The error action setting.
+ * @is_read: Whether the operation was a read.
+ * @error: The error that was reported.
+ *
+ * Report an I/O error for a block job and possibly stop the VM.  Return the
+ * action that was selected based on @on_err and @error.
+ */
+BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err,
+                                        int is_read, int error);
+
+typedef void BlockJobDeferToMainLoopFn(BlockJob *job, void *opaque);
+
+/**
+ * block_job_defer_to_main_loop:
+ * @job: The job
+ * @fn: The function to run in the main loop
+ * @opaque: The opaque value that is passed to @fn
+ *
+ * Execute a given function in the main loop with the BlockDriverState
+ * AioContext acquired.  Block jobs must call bdrv_unref(), bdrv_close(), and
+ * anything that uses bdrv_drain_all() in the main loop.
+ *
+ * The @job AioContext is held while @fn executes.
+ */
+void block_job_defer_to_main_loop(BlockJob *job,
+                                  BlockJobDeferToMainLoopFn *fn,
+                                  void *opaque);
+
+#endif
diff --git a/tests/test-blockjob-txn.c b/tests/test-blockjob-txn.c
index b79e0c6..f9afc3b 100644
--- a/tests/test-blockjob-txn.c
+++ b/tests/test-blockjob-txn.c
@@ -13,7 +13,7 @@
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qemu/main-loop.h"
-#include "block/blockjob.h"
+#include "block/blockjob_int.h"
 #include "sysemu/block-backend.h"
 
 typedef struct {
diff --git a/tests/test-blockjob.c b/tests/test-blockjob.c
index 18bf850..60b78a3 100644
--- a/tests/test-blockjob.c
+++ b/tests/test-blockjob.c
@@ -13,7 +13,7 @@
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qemu/main-loop.h"
-#include "block/blockjob.h"
+#include "block/blockjob_int.h"
 #include "sysemu/block-backend.h"
 
 static const BlockJobDriver test_block_job_driver = {
-- 
2.7.4