X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/f2426947decc96bde4f9ea50097dac66a0a48acc..f194a1ae530e232b994d23aa8651696dd6664b5d:/blockjob.c

diff --git a/blockjob.c b/blockjob.c
index 0689fdd2b5..9fc37ca965 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -23,26 +23,41 @@
  * THE SOFTWARE.
  */
 
-#include "config-host.h"
+#include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "trace.h"
 #include "block/block.h"
 #include "block/blockjob.h"
 #include "block/block_int.h"
+#include "sysemu/block-backend.h"
+#include "qapi/qmp/qerror.h"
 #include "qapi/qmp/qjson.h"
-#include "block/coroutine.h"
+#include "qemu/coroutine.h"
 #include "qmp-commands.h"
 #include "qemu/timer.h"
 #include "qapi-event.h"
 
+/* Transactional group of block jobs */
+struct BlockJobTxn {
+
+    /* Is this txn being cancelled? */
+    bool aborting;
+
+    /* List of jobs */
+    QLIST_HEAD(, BlockJob) jobs;
+
+    /* Reference count */
+    int refcnt;
+};
+
 void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
-                       int64_t speed, BlockDriverCompletionFunc *cb,
+                       int64_t speed, BlockCompletionFunc *cb,
                        void *opaque, Error **errp)
 {
     BlockJob *job;
 
     if (bs->job) {
-        error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
+        error_setg(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
         return NULL;
     }
     bdrv_ref(bs);
@@ -50,12 +65,15 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
     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->id            = g_strdup(bdrv_get_device_name(bs));
     job->bs            = bs;
     job->cb            = cb;
     job->opaque        = opaque;
     job->busy          = true;
+    job->refcnt        = 1;
     bs->job = job;
 
     /* Only set speed when necessary to avoid NotSupported error */
@@ -64,10 +82,7 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
 
         block_job_set_speed(job, speed, &local_err);
         if (local_err) {
-            bs->job = NULL;
-            bdrv_op_unblock_all(bs, job->blocker);
-            error_free(job->blocker);
-            g_free(job);
+            block_job_unref(job);
             error_propagate(errp, local_err);
             return NULL;
         }
@@ -75,16 +90,118 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
     return job;
 }
 
+void block_job_ref(BlockJob *job)
+{
+    ++job->refcnt;
+}
+
+void block_job_unref(BlockJob *job)
+{
+    if (--job->refcnt == 0) {
+        job->bs->job = NULL;
+        bdrv_op_unblock_all(job->bs, job->blocker);
+        bdrv_unref(job->bs);
+        error_free(job->blocker);
+        g_free(job->id);
+        g_free(job);
+    }
+}
+
+static void block_job_completed_single(BlockJob *job)
+{
+    if (!job->ret) {
+        if (job->driver->commit) {
+            job->driver->commit(job);
+        }
+    } else {
+        if (job->driver->abort) {
+            job->driver->abort(job);
+        }
+    }
+    job->cb(job->opaque, job->ret);
+    if (job->txn) {
+        block_job_txn_unref(job->txn);
+    }
+    block_job_unref(job);
+}
+
+static void block_job_completed_txn_abort(BlockJob *job)
+{
+    AioContext *ctx;
+    BlockJobTxn *txn = job->txn;
+    BlockJob *other_job, *next;
+
+    if (txn->aborting) {
+        /*
+         * We are cancelled by another job, which will handle everything.
+         */
+        return;
+    }
+    txn->aborting = true;
+    /* We are the first failed job. Cancel other jobs. */
+    QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
+        ctx = bdrv_get_aio_context(other_job->bs);
+        aio_context_acquire(ctx);
+    }
+    QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
+        if (other_job == job || other_job->completed) {
+            /* Other jobs are "effectively" cancelled by us, set the status for
+             * them; this job, however, may or may not be cancelled, depending
+             * on the caller, so leave it. */
+            if (other_job != job) {
+                other_job->cancelled = true;
+            }
+            continue;
+        }
+        block_job_cancel_sync(other_job);
+        assert(other_job->completed);
+    }
+    QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) {
+        ctx = bdrv_get_aio_context(other_job->bs);
+        block_job_completed_single(other_job);
+        aio_context_release(ctx);
+    }
+}
+
+static void block_job_completed_txn_success(BlockJob *job)
+{
+    AioContext *ctx;
+    BlockJobTxn *txn = job->txn;
+    BlockJob *other_job, *next;
+    /*
+     * Successful completion, see if there are other running jobs in this
+     * txn.
+     */
+    QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
+        if (!other_job->completed) {
+            return;
+        }
+    }
+    /* We are the last completed job, commit the transaction. */
+    QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) {
+        ctx = bdrv_get_aio_context(other_job->bs);
+        aio_context_acquire(ctx);
+        assert(other_job->ret == 0);
+        block_job_completed_single(other_job);
+        aio_context_release(ctx);
+    }
+}
+
 void block_job_completed(BlockJob *job, int ret)
 {
     BlockDriverState *bs = job->bs;
 
     assert(bs->job == job);
-    job->cb(job->opaque, ret);
-    bs->job = NULL;
-    bdrv_op_unblock_all(bs, job->blocker);
-    error_free(job->blocker);
-    g_free(job);
+    assert(!job->completed);
+    job->completed = true;
+    job->ret = ret;
+    if (!job->txn) {
+        block_job_completed_single(job);
+    } else if (ret < 0 || block_job_is_cancelled(job)) {
+        block_job_completed_txn_abort(job);
+    } else {
+        block_job_completed_txn_success(job);
+    }
 }
 
 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
@@ -92,7 +209,7 @@ void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
     Error *local_err = NULL;
 
     if (!job->driver->set_speed) {
-        error_set(errp, QERR_UNSUPPORTED);
+        error_setg(errp, QERR_UNSUPPORTED);
         return;
     }
     job->driver->set_speed(job, speed, &local_err);
@@ -106,8 +223,8 @@ void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
 
 void block_job_complete(BlockJob *job, Error **errp)
 {
-    if (job->paused || job->cancelled || !job->driver->complete) {
-        error_set(errp, QERR_BLOCK_JOB_NOT_READY, job->bs->device_name);
+    if (job->pause_count || job->cancelled || !job->driver->complete) {
+        error_setg(errp, QERR_BLOCK_JOB_NOT_READY, job->id);
         return;
     }
 
@@ -116,17 +233,26 @@ void block_job_complete(BlockJob *job, Error **errp)
 
 void block_job_pause(BlockJob *job)
 {
-    job->paused = true;
+    job->pause_count++;
 }
 
 bool block_job_is_paused(BlockJob *job)
 {
-    return job->paused;
+    return job->pause_count > 0;
 }
 
 void block_job_resume(BlockJob *job)
 {
-    job->paused = false;
+    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);
@@ -136,7 +262,7 @@ void block_job_resume(BlockJob *job)
 void block_job_cancel(BlockJob *job)
 {
     job->cancelled = true;
-    block_job_resume(job);
+    block_job_enter(job);
 }
 
 bool block_job_is_cancelled(BlockJob *job)
@@ -152,44 +278,49 @@ void block_job_iostatus_reset(BlockJob *job)
     }
 }
 
-struct BlockCancelData {
-    BlockJob *job;
-    BlockDriverCompletionFunc *cb;
-    void *opaque;
-    bool cancelled;
+static int block_job_finish_sync(BlockJob *job,
+                                 void (*finish)(BlockJob *, Error **errp),
+                                 Error **errp)
+{
+    BlockDriverState *bs = job->bs;
+    Error *local_err = NULL;
     int ret;
-};
 
-static void block_job_cancel_cb(void *opaque, int ret)
-{
-    struct BlockCancelData *data = opaque;
+    assert(bs->job == job);
 
-    data->cancelled = block_job_is_cancelled(data->job);
-    data->ret = ret;
-    data->cb(data->opaque, ret);
+    block_job_ref(job);
+    finish(job, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        block_job_unref(job);
+        return -EBUSY;
+    }
+    while (!job->completed) {
+        aio_poll(job->deferred_to_main_loop ? qemu_get_aio_context() :
+                                              bdrv_get_aio_context(bs),
+                 true);
+    }
+    ret = (job->cancelled && job->ret == 0) ? -ECANCELED : job->ret;
+    block_job_unref(job);
+    return ret;
 }
 
-int block_job_cancel_sync(BlockJob *job)
+/* 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)
 {
-    struct BlockCancelData data;
-    BlockDriverState *bs = job->bs;
+    block_job_cancel(job);
+}
 
-    assert(bs->job == job);
+int block_job_cancel_sync(BlockJob *job)
+{
+    return block_job_finish_sync(job, &block_job_cancel_err, NULL);
+}
 
-    /* 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) {
-        aio_poll(bdrv_get_aio_context(bs), true);
-    }
-    return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
+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)
@@ -228,13 +359,14 @@ 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->device    = g_strdup(job->id);
     info->len       = job->len;
     info->busy      = job->busy;
-    info->paused    = job->paused;
+    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;
 }
 
@@ -249,7 +381,7 @@ static void block_job_iostatus_set_err(BlockJob *job, int error)
 void block_job_event_cancelled(BlockJob *job)
 {
     qapi_event_send_block_job_cancelled(job->driver->job_type,
-                                        bdrv_get_device_name(job->bs),
+                                        job->id,
                                         job->len,
                                         job->offset,
                                         job->speed,
@@ -259,7 +391,7 @@ void block_job_event_cancelled(BlockJob *job)
 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->id,
                                         job->len,
                                         job->offset,
                                         job->speed,
@@ -270,8 +402,10 @@ void block_job_event_completed(BlockJob *job, const char *msg)
 
 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->id,
                                     job->len,
                                     job->offset,
                                     job->speed, &error_abort);
@@ -300,16 +434,98 @@ BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs,
     default:
         abort();
     }
-    qapi_event_send_block_job_error(bdrv_get_device_name(job->bs),
+    qapi_event_send_block_job_error(job->id,
                                     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);
+        if (bs->blk && bs != job->bs) {
+            blk_iostatus_set_err(bs->blk, 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->job->deferred_to_main_loop = false;
+    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;
+    job->deferred_to_main_loop = true;
+
+    qemu_bh_schedule(data->bh);
+}
+
+BlockJobTxn *block_job_txn_new(void)
+{
+    BlockJobTxn *txn = g_new0(BlockJobTxn, 1);
+    QLIST_INIT(&txn->jobs);
+    txn->refcnt = 1;
+    return txn;
+}
+
+static void block_job_txn_ref(BlockJobTxn *txn)
+{
+    txn->refcnt++;
+}
+
+void block_job_txn_unref(BlockJobTxn *txn)
+{
+    if (txn && --txn->refcnt == 0) {
+        g_free(txn);
+    }
+}
+
+void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job)
+{
+    if (!txn) {
+        return;
+    }
+
+    assert(!job->txn);
+    job->txn = txn;
+
+    QLIST_INSERT_HEAD(&txn->jobs, job, txn_list);
+    block_job_txn_ref(txn);
+}