progressmeter: protect with a mutex

Progressmeter is protected by the AioContext mutex, which
is taken by the block jobs and their caller (like blockdev).

We would like to remove the dependency of block layer code on the
AioContext mutex, since most drivers and the core I/O code are already
not relying on it.

Create a new C file to implement the ProgressMeter API, but keep the
struct as public, to avoid forcing allocation on the heap.

Also add a mutex to be able to provide an accurate snapshot of the
progress values to the caller.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20210614081130.22134-5-eesposit@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

diff --git a/block/meson.build b/block/meson.build
index 01861e154584447bcbbbdd60970e3249c947e638..ef1ba3d9730385cc1bdee0798c47a5248cb6f37c 100644 (file)
--- a/block/meson.build
+++ b/block/meson.build
@@ -13,6 +13,7 @@ block_ss.add(files(
   'commit.c',
   'copy-on-read.c',
   'preallocate.c',
+  'progress_meter.c',
   'create.c',
   'crypto.c',
   'dirty-bitmap.c',

diff --git a/block/progress_meter.c b/block/progress_meter.c
new file mode 100644 (file)
index 0000000..aa2e602
--- /dev/null
+++ b/block/progress_meter.c
@@ -0,0 +1,64 @@
+/*
+ * Helper functionality for some process progress tracking.
+ *
+ * Copyright (c) 2011 IBM Corp.
+ * Copyright (c) 2012, 2018 Red Hat, Inc.
+ * Copyright (c) 2020 Virtuozzo International GmbH
+ *
+ * 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 "qemu/osdep.h"
+#include "qemu/progress_meter.h"
+
+void progress_init(ProgressMeter *pm)
+{
+    qemu_mutex_init(&pm->lock);
+}
+
+void progress_destroy(ProgressMeter *pm)
+{
+    qemu_mutex_destroy(&pm->lock);
+}
+
+void progress_get_snapshot(ProgressMeter *pm, uint64_t *current,
+                           uint64_t *total)
+{
+    QEMU_LOCK_GUARD(&pm->lock);
+
+    *current = pm->current;
+    *total = pm->total;
+}
+
+void progress_work_done(ProgressMeter *pm, uint64_t done)
+{
+    QEMU_LOCK_GUARD(&pm->lock);
+    pm->current += done;
+}
+
+void progress_set_remaining(ProgressMeter *pm, uint64_t remaining)
+{
+    QEMU_LOCK_GUARD(&pm->lock);
+    pm->total = pm->current + remaining;
+}
+
+void progress_increase_remaining(ProgressMeter *pm, uint64_t delta)
+{
+    QEMU_LOCK_GUARD(&pm->lock);
+    pm->total += delta;
+}

diff --git a/blockjob.c b/blockjob.c
index 22e5bb9b1f880518cd1b7eb52c3a3a5c6c6b4bdc..4bad1408cb5b64275ca46f1b3100fc115c0ca21b 100644 (file)
--- a/blockjob.c
+++ b/blockjob.c
@@ -306,18 +306,23 @@ int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n)
 BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
 {
     BlockJobInfo *info;
+    uint64_t progress_current, progress_total;
 
     if (block_job_is_internal(job)) {
         error_setg(errp, "Cannot query QEMU internal jobs");
         return NULL;
     }
+
+    progress_get_snapshot(&job->job.progress, &progress_current,
+                          &progress_total);
+
     info = g_new0(BlockJobInfo, 1);
     info->type      = g_strdup(job_type_str(&job->job));
     info->device    = g_strdup(job->job.id);
     info->busy      = qatomic_read(&job->job.busy);
     info->paused    = job->job.pause_count > 0;
-    info->offset    = job->job.progress.current;
-    info->len       = job->job.progress.total;
+    info->offset    = progress_current;
+    info->len       = progress_total;
     info->speed     = job->speed;
     info->io_status = job->iostatus;
     info->ready     = job_is_ready(&job->job),
@@ -344,15 +349,19 @@ static void block_job_iostatus_set_err(BlockJob *job, int error)
 static void block_job_event_cancelled(Notifier *n, void *opaque)
 {
     BlockJob *job = opaque;
+    uint64_t progress_current, progress_total;
 
     if (block_job_is_internal(job)) {
         return;
     }
 
+    progress_get_snapshot(&job->job.progress, &progress_current,
+                          &progress_total);
+
     qapi_event_send_block_job_cancelled(job_type(&job->job),
                                         job->job.id,
-                                        job->job.progress.total,
-                                        job->job.progress.current,
+                                        progress_total,
+                                        progress_current,
                                         job->speed);
 }
 
@@ -360,6 +369,7 @@ static void block_job_event_completed(Notifier *n, void *opaque)
 {
     BlockJob *job = opaque;
     const char *msg = NULL;
+    uint64_t progress_current, progress_total;
 
     if (block_job_is_internal(job)) {
         return;
@@ -369,10 +379,13 @@ static void block_job_event_completed(Notifier *n, void *opaque)
         msg = error_get_pretty(job->job.err);
     }
 
+    progress_get_snapshot(&job->job.progress, &progress_current,
+                          &progress_total);
+
     qapi_event_send_block_job_completed(job_type(&job->job),
                                         job->job.id,
-                                        job->job.progress.total,
-                                        job->job.progress.current,
+                                        progress_total,
+                                        progress_current,
                                         job->speed,
                                         !!msg,
                                         msg);
@@ -393,15 +406,19 @@ static void block_job_event_pending(Notifier *n, void *opaque)
 static void block_job_event_ready(Notifier *n, void *opaque)
 {
     BlockJob *job = opaque;
+    uint64_t progress_current, progress_total;
 
     if (block_job_is_internal(job)) {
         return;
     }
 
+    progress_get_snapshot(&job->job.progress, &progress_current,
+                          &progress_total);
+
     qapi_event_send_block_job_ready(job_type(&job->job),
                                     job->job.id,
-                                    job->job.progress.total,
-                                    job->job.progress.current,
+                                    progress_total,
+                                    progress_current,
                                     job->speed);
 }
 

diff --git a/include/qemu/progress_meter.h b/include/qemu/progress_meter.h
index 9a23ff071c4c327c099eb5b4ec3e9d6505b298ef..dadf822bbf805be1a560b287e23d21cb35db8cab 100644 (file)
--- a/include/qemu/progress_meter.h
+++ b/include/qemu/progress_meter.h
@@ -27,6 +27,8 @@
 #ifndef QEMU_PROGRESS_METER_H
 #define QEMU_PROGRESS_METER_H
 
+#include "qemu/lockable.h"
+
 typedef struct ProgressMeter {
     /**
      * Current progress. The unit is arbitrary as long as the ratio between
@@ -37,22 +39,24 @@ typedef struct ProgressMeter {
 
     /** Estimated current value at the completion of the process */
     uint64_t total;
+
+    QemuMutex lock; /* protects concurrent access to above fields */
 } ProgressMeter;
 
-static inline void progress_work_done(ProgressMeter *pm, uint64_t done)
-{
-    pm->current += done;
-}
-
-static inline void progress_set_remaining(ProgressMeter *pm, uint64_t remaining)
-{
-    pm->total = pm->current + remaining;
-}
-
-static inline void progress_increase_remaining(ProgressMeter *pm,
-                                               uint64_t delta)
-{
-    pm->total += delta;
-}
+void progress_init(ProgressMeter *pm);
+void progress_destroy(ProgressMeter *pm);
+
+/* Get a snapshot of internal current and total values  */
+void progress_get_snapshot(ProgressMeter *pm, uint64_t *current,
+                           uint64_t *total);
+
+/* Increases the amount of work done so far by @done */
+void progress_work_done(ProgressMeter *pm, uint64_t done);
+
+/* Sets how much work has to be done to complete to @remaining */
+void progress_set_remaining(ProgressMeter *pm, uint64_t remaining);
+
+/* Increases the total work to do by @delta */
+void progress_increase_remaining(ProgressMeter *pm, uint64_t delta);
 
 #endif /* QEMU_PROGRESS_METER_H */

diff --git a/job-qmp.c b/job-qmp.c
index 34c4da094f22a8828c32416e509bfd7b34f92126..829a28aa70e3e0a880fe2007ba8ca75a9fc4cbeb 100644 (file)
--- a/job-qmp.c
+++ b/job-qmp.c
@@ -144,16 +144,20 @@ void qmp_job_dismiss(const char *id, Error **errp)
 static JobInfo *job_query_single(Job *job, Error **errp)
 {
     JobInfo *info;
+    uint64_t progress_current;
+    uint64_t progress_total;
 
     assert(!job_is_internal(job));
+    progress_get_snapshot(&job->progress, &progress_current,
+                          &progress_total);
 
     info = g_new(JobInfo, 1);
     *info = (JobInfo) {
         .id                 = g_strdup(job->id),
         .type               = job_type(job),
         .status             = job->status,
-        .current_progress   = job->progress.current,
-        .total_progress     = job->progress.total,
+        .current_progress   = progress_current,
+        .total_progress     = progress_total,
         .has_error          = !!job->err,
         .error              = job->err ? \
                               g_strdup(error_get_pretty(job->err)) : NULL,

diff --git a/job.c b/job.c
index 8775c1803b1b3e9d720e68c11b2e8b210b422ea9..e7a5d288546416e5973d1e8ea326475ddea61e40 100644 (file)
--- a/job.c
+++ b/job.c
@@ -339,6 +339,8 @@ void *job_create(const char *job_id, const JobDriver *driver, JobTxn *txn,
     job->cb            = cb;
     job->opaque        = opaque;
 
+    progress_init(&job->progress);
+
     notifier_list_init(&job->on_finalize_cancelled);
     notifier_list_init(&job->on_finalize_completed);
     notifier_list_init(&job->on_pending);
@@ -382,6 +384,7 @@ void job_unref(Job *job)
 
         QLIST_REMOVE(job, job_list);
 
+        progress_destroy(&job->progress);
         error_free(job->err);
         g_free(job->id);
         g_free(job);

diff --git a/qemu-img.c b/qemu-img.c
index a5993682aad40b3dc55ee5c13b512bc8b16077a8..7956a8996512412ed70477ff5016cdad0adfe65c 100644 (file)
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -900,6 +900,7 @@ static void common_block_job_cb(void *opaque, int ret)
 
 static void run_block_job(BlockJob *job, Error **errp)
 {
+    uint64_t progress_current, progress_total;
     AioContext *aio_context = blk_get_aio_context(job->blk);
     int ret = 0;
 
@@ -908,9 +909,11 @@ static void run_block_job(BlockJob *job, Error **errp)
     do {
         float progress = 0.0f;
         aio_poll(aio_context, true);
-        if (job->job.progress.total) {
-            progress = (float)job->job.progress.current /
-                       job->job.progress.total * 100.f;
+
+        progress_get_snapshot(&job->job.progress, &progress_current,
+                              &progress_total);
+        if (progress_total) {
+            progress = (float)progress_current / progress_total * 100.f;
         }
         qemu_progress_print(progress, 0);
     } while (!job_is_ready(&job->job) && !job_is_completed(&job->job));