Initial import of qemu-2.4.1HEADmaster

1 files changed, 406 insertions, 0 deletions

diff --git a/blockjob.c b/blockjob.c
new file mode 100644
index 00000000..62bb9066
--- /dev/null
+++ b/blockjob.c
@@ -0,0 +1,406 @@
+/*
+ * 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 "block/block.h"
+#include "block/blockjob.h"
+#include "block/block_int.h"
+#include "qapi/qmp/qerror.h"
+#include "qapi/qmp/qjson.h"
+#include "block/coroutine.h"
+#include "qmp-commands.h"
+#include "qemu/timer.h"
+#include "qapi-event.h"
+
+void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
+                       int64_t speed, BlockCompletionFunc *cb,
+                       void *opaque, Error **errp)
+{
+    BlockJob *job;
+
+    if (bs->job) {
+        error_setg(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
+        return NULL;
+    }
+    bdrv_ref(bs);
+    job = g_malloc0(driver->instance_size);
+    error_setg(&job->blocker, "block device is in use by block job: %s",
+               BlockJobType_lookup[driver->job_type]);
+    bdrv_op_block_all(bs, job->blocker);
+    bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
+
+    job->driver        = driver;
+    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 (local_err) {
+            block_job_release(bs);
+            error_propagate(errp, local_err);
+            return NULL;
+        }
+    }
+    return job;
+}
+
+void block_job_release(BlockDriverState *bs)
+{
+    BlockJob *job = bs->job;
+
+    bs->job = NULL;
+    bdrv_op_unblock_all(bs, job->blocker);
+    error_free(job->blocker);
+    g_free(job);
+}
+
+void block_job_completed(BlockJob *job, int ret)
+{
+    BlockDriverState *bs = job->bs;
+
+    assert(bs->job == job);
+    job->cb(job->opaque, ret);
+    block_job_release(bs);
+}
+
+void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
+{
+    Error *local_err = NULL;
+
+    if (!job->driver->set_speed) {
+        error_setg(errp, QERR_UNSUPPORTED);
+        return;
+    }
+    job->driver->set_speed(job, speed, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    job->speed = speed;
+}
+
+void block_job_complete(BlockJob *job, Error **errp)
+{
+    if (job->pause_count || job->cancelled || !job->driver->complete) {
+        error_setg(errp, QERR_BLOCK_JOB_NOT_READY,
+                   bdrv_get_device_name(job->bs));
+        return;
+    }
+
+    job->driver->complete(job, errp);
+}
+
+void block_job_pause(BlockJob *job)
+{
+    job->pause_count++;
+}
+
+bool block_job_is_paused(BlockJob *job)
+{
+    return job->pause_count > 0;
+}
+
+void block_job_resume(BlockJob *job)
+{
+    assert(job->pause_count > 0);
+    job->pause_count--;
+    if (job->pause_count) {
+        return;
+    }
+    block_job_enter(job);
+}
+
+void block_job_enter(BlockJob *job)
+{
+    block_job_iostatus_reset(job);
+    if (job->co && !job->busy) {
+        qemu_coroutine_enter(job->co, NULL);
+    }
+}
+
+void block_job_cancel(BlockJob *job)
+{
+    job->cancelled = true;
+    block_job_enter(job);
+}
+
+bool block_job_is_cancelled(BlockJob *job)
+{
+    return job->cancelled;
+}
+
+void block_job_iostatus_reset(BlockJob *job)
+{
+    job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
+    if (job->driver->iostatus_reset) {
+        job->driver->iostatus_reset(job);
+    }
+}
+
+struct BlockFinishData {
+    BlockJob *job;
+    BlockCompletionFunc *cb;
+    void *opaque;
+    bool cancelled;
+    int ret;
+};
+
+static void block_job_finish_cb(void *opaque, int ret)
+{
+    struct BlockFinishData *data = opaque;
+
+    data->cancelled = block_job_is_cancelled(data->job);
+    data->ret = ret;
+    data->cb(data->opaque, ret);
+}
+
+static int block_job_finish_sync(BlockJob *job,
+                                 void (*finish)(BlockJob *, Error **errp),
+                                 Error **errp)
+{
+    struct BlockFinishData data;
+    BlockDriverState *bs = job->bs;
+    Error *local_err = NULL;
+
+    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_finish_cb;
+    job->opaque = &data;
+    finish(job, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return -EBUSY;
+    }
+    while (data.ret == -EINPROGRESS) {
+        aio_poll(bdrv_get_aio_context(bs), true);
+    }
+    return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
+}
+
+/* A wrapper around block_job_cancel() taking an Error ** parameter so it may be
+ * used with block_job_finish_sync() without the need for (rather nasty)
+ * function pointer casts there. */
+static void block_job_cancel_err(BlockJob *job, Error **errp)
+{
+    block_job_cancel(job);
+}
+
+int block_job_cancel_sync(BlockJob *job)
+{
+    return block_job_finish_sync(job, &block_job_cancel_err, NULL);
+}
+
+int block_job_complete_sync(BlockJob *job, Error **errp)
+{
+    return block_job_finish_sync(job, &block_job_complete, errp);
+}
+
+void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns)
+{
+    assert(job->busy);
+
+    /* Check cancellation *before* setting busy = false, too!  */
+    if (block_job_is_cancelled(job)) {
+        return;
+    }
+
+    job->busy = false;
+    if (block_job_is_paused(job)) {
+        qemu_coroutine_yield();
+    } else {
+        co_aio_sleep_ns(bdrv_get_aio_context(job->bs), type, ns);
+    }
+    job->busy = true;
+}
+
+void block_job_yield(BlockJob *job)
+{
+    assert(job->busy);
+
+    /* Check cancellation *before* setting busy = false, too!  */
+    if (block_job_is_cancelled(job)) {
+        return;
+    }
+
+    job->busy = false;
+    qemu_coroutine_yield();
+    job->busy = true;
+}
+
+BlockJobInfo *block_job_query(BlockJob *job)
+{
+    BlockJobInfo *info = g_new0(BlockJobInfo, 1);
+    info->type      = g_strdup(BlockJobType_lookup[job->driver->job_type]);
+    info->device    = g_strdup(bdrv_get_device_name(job->bs));
+    info->len       = job->len;
+    info->busy      = job->busy;
+    info->paused    = job->pause_count > 0;
+    info->offset    = job->offset;
+    info->speed     = job->speed;
+    info->io_status = job->iostatus;
+    info->ready     = job->ready;
+    return info;
+}
+
+static void block_job_iostatus_set_err(BlockJob *job, int error)
+{
+    if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
+        job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
+                                          BLOCK_DEVICE_IO_STATUS_FAILED;
+    }
+}
+
+void block_job_event_cancelled(BlockJob *job)
+{
+    qapi_event_send_block_job_cancelled(job->driver->job_type,
+                                        bdrv_get_device_name(job->bs),
+                                        job->len,
+                                        job->offset,
+                                        job->speed,
+                                        &error_abort);
+}
+
+void block_job_event_completed(BlockJob *job, const char *msg)
+{
+    qapi_event_send_block_job_completed(job->driver->job_type,
+                                        bdrv_get_device_name(job->bs),
+                                        job->len,
+                                        job->offset,
+                                        job->speed,
+                                        !!msg,
+                                        msg,
+                                        &error_abort);
+}
+
+void block_job_event_ready(BlockJob *job)
+{
+    job->ready = true;
+
+    qapi_event_send_block_job_ready(job->driver->job_type,
+                                    bdrv_get_device_name(job->bs),
+                                    job->len,
+                                    job->offset,
+                                    job->speed, &error_abort);
+}
+
+BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs,
+                                        BlockdevOnError on_err,
+                                        int is_read, int error)
+{
+    BlockErrorAction action;
+
+    switch (on_err) {
+    case BLOCKDEV_ON_ERROR_ENOSPC:
+        action = (error == ENOSPC) ?
+                 BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
+        break;
+    case BLOCKDEV_ON_ERROR_STOP:
+        action = BLOCK_ERROR_ACTION_STOP;
+        break;
+    case BLOCKDEV_ON_ERROR_REPORT:
+        action = BLOCK_ERROR_ACTION_REPORT;
+        break;
+    case BLOCKDEV_ON_ERROR_IGNORE:
+        action = BLOCK_ERROR_ACTION_IGNORE;
+        break;
+    default:
+        abort();
+    }
+    qapi_event_send_block_job_error(bdrv_get_device_name(job->bs),
+                                    is_read ? IO_OPERATION_TYPE_READ :
+                                    IO_OPERATION_TYPE_WRITE,
+                                    action, &error_abort);
+    if (action == BLOCK_ERROR_ACTION_STOP) {
+        /* make the pause user visible, which will be resumed from QMP. */
+        job->user_paused = true;
+        block_job_pause(job);
+        block_job_iostatus_set_err(job, error);
+        if (bs != job->bs) {
+            bdrv_iostatus_set_err(bs, error);
+        }
+    }
+    return action;
+}
+
+typedef struct {
+    BlockJob *job;
+    QEMUBH *bh;
+    AioContext *aio_context;
+    BlockJobDeferToMainLoopFn *fn;
+    void *opaque;
+} BlockJobDeferToMainLoopData;
+
+static void block_job_defer_to_main_loop_bh(void *opaque)
+{
+    BlockJobDeferToMainLoopData *data = opaque;
+    AioContext *aio_context;
+
+    qemu_bh_delete(data->bh);
+
+    /* Prevent race with block_job_defer_to_main_loop() */
+    aio_context_acquire(data->aio_context);
+
+    /* Fetch BDS AioContext again, in case it has changed */
+    aio_context = bdrv_get_aio_context(data->job->bs);
+    aio_context_acquire(aio_context);
+
+    data->fn(data->job, data->opaque);
+
+    aio_context_release(aio_context);
+
+    aio_context_release(data->aio_context);
+
+    g_free(data);
+}
+
+void block_job_defer_to_main_loop(BlockJob *job,
+                                  BlockJobDeferToMainLoopFn *fn,
+                                  void *opaque)
+{
+    BlockJobDeferToMainLoopData *data = g_malloc(sizeof(*data));
+    data->job = job;
+    data->bh = qemu_bh_new(block_job_defer_to_main_loop_bh, data);
+    data->aio_context = bdrv_get_aio_context(job->bs);
+    data->fn = fn;
+    data->opaque = opaque;
+
+    qemu_bh_schedule(data->bh);
+}