[PULL 00/19] Block patches

[PULL 00/19] Block patches

[Max Reitz]

The following changes since commit 96662996eda78c48aadddd4e76d8615c7eb72d80:

  Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20210513a' into staging (2021-05-14 12:03:47 +0100)

are available in the Git repository at:

  https://github.com/XanClic/qemu.git tags/pull-block-2021-05-14

for you to fetch changes up to c61ebf362d0abf288ce266845519d5a550a1d89f:

  write-threshold: deal with includes (2021-05-14 16:14:10 +0200)

----------------------------------------------------------------
Block patches:
- drop block/io write notifiers
- qemu-iotests enhancements to make debugging easier
- rbd parsing fix
- HMP qemu-io fix (for iothreads)
- mirror job cancel relaxation (do not cancel in-flight requests when a
  READY mirror job is canceled with force=false)
- document qcow2's data_file and data_file_raw features
- fix iotest 297 for pylint 2.8
- block/copy-on-read refactoring

----------------------------------------------------------------
Connor Kuehl (3):
  iotests/231: Update expected deprecation message
  block/rbd: Add an escape-aware strchr helper
  Document qemu-img options data_file and data_file_raw

Emanuele Giuseppe Esposito (1):
  qemu-iotests: fix pylint 2.8 consider-using-with error

Paolo Bonzini (5):
  qemu-iotests: do not buffer the test output
  qemu-iotests: allow passing unittest.main arguments to the test
    scripts
  qemu-iotests: move command line and environment handling from
    TestRunner to TestEnv
  qemu-iotests: let "check" spawn an arbitrary test command
  qemu-iotests: fix case of SOCK_DIR already in the environment

Vladimir Sementsov-Ogievskiy (10):
  monitor: hmp_qemu_io: acquire aio contex, fix crash
  mirror: stop cancelling in-flight requests on non-force cancel in
    READY
  block/copy-on-read: use bdrv_drop_filter() and drop s->active
  block/write-threshold: don't use write notifiers
  block: drop write notifiers
  test-write-threshold: rewrite test_threshold_(not_)trigger tests
  block/write-threshold: drop extra APIs
  test-write-threshold: drop extra tests
  test-write-threshold: drop extra TestStruct structure
  write-threshold: deal with includes

 docs/tools/qemu-img.rst           |  31 +++++++
 include/block/block_int.h         |  15 +---
 include/block/write-threshold.h   |  27 ++----
 include/qemu/job.h                |   2 +-
 block.c                           |   1 -
 block/backup.c                    |   2 +-
 block/copy-on-read.c              |  33 +------
 block/io.c                        |  11 +--
 block/mirror.c                    |   6 +-
 block/monitor/block-hmp-cmds.c    |  31 ++++---
 block/rbd.c                       |  32 ++++---
 block/write-threshold.c           |  91 ++++---------------
 job.c                             |   2 +-
 qemu-io-cmds.c                    |   8 +-
 qemu-io.c                         |  17 +++-
 tests/unit/test-write-threshold.c |  90 ++-----------------
 tests/qemu-iotests/231            |   4 +
 tests/qemu-iotests/231.out        |   7 +-
 tests/qemu-iotests/240.out        |   8 +-
 tests/qemu-iotests/245.out        |   8 +-
 tests/qemu-iotests/264            |   2 +-
 tests/qemu-iotests/295.out        |   6 +-
 tests/qemu-iotests/296.out        |   8 +-
 tests/qemu-iotests/check          |  19 +++-
 tests/qemu-iotests/iotests.py     | 145 +++++++++++++++++-------------
 tests/qemu-iotests/pylintrc       |   3 +
 tests/qemu-iotests/testenv.py     |  22 ++++-
 tests/qemu-iotests/testrunner.py  |  37 +++-----
 28 files changed, 289 insertions(+), 379 deletions(-)

-- 
2.31.1

[PULL 01/19] iotests/231: Update expected deprecation message

[Max Reitz]

From: Connor Kuehl <ckuehl@redhat.com>

The deprecation message in the expected output has technically been
wrong since the wrong version of a patch was applied to it. Because of
this, the test fails. Correct the expected output so that it passes.

Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20210421212343.85524-2-ckuehl@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/231.out | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/231.out b/tests/qemu-iotests/231.out
index 579ba11c16..747dd221bb 100644
--- a/tests/qemu-iotests/231.out
+++ b/tests/qemu-iotests/231.out
@@ -1,9 +1,7 @@
 QA output created by 231
-qemu-img: RBD options encoded in the filename as keyvalue pairs is deprecated.  Future versions may cease to parse these options in the future.
+qemu-img: warning: RBD options encoded in the filename as keyvalue pairs is deprecated
 unable to get monitor info from DNS SRV with service name: ceph-mon
-no monitors specified to connect to.
 qemu-img: Could not open 'json:{'file.driver':'rbd','file.filename':'rbd:rbd/bogus:conf=BOGUS_CONF'}': error connecting: No such file or directory
 unable to get monitor info from DNS SRV with service name: ceph-mon
-no monitors specified to connect to.
 qemu-img: Could not open 'json:{'file.driver':'rbd','file.pool':'rbd','file.image':'bogus','file.conf':'BOGUS_CONF'}': error connecting: No such file or directory
 *** done
-- 
2.31.1

[PULL 02/19] block/rbd: Add an escape-aware strchr helper

[Max Reitz]

From: Connor Kuehl <ckuehl@redhat.com>

Sometimes the parser needs to further split a token it has collected
from the token input stream. Right now, it does a cursory check to see
if the relevant characters appear in the token to determine if it should
break it down further.

However, qemu_rbd_next_tok() will escape characters as it removes tokens
from the token stream and plain strchr() won't. This can make the
initial strchr() check slightly misleading since it implies
qemu_rbd_next_tok() will find the token and split on it, except the
reality is that qemu_rbd_next_tok() will pass over it if it is escaped.

Use a custom strchr to avoid mixing escaped and unescaped string
operations. Furthermore, this code is identical to how
qemu_rbd_next_tok() seeks its next token, so incorporate this custom
strchr into the body of that function to reduce duplication.

Reported-by: Han Han <hhan@redhat.com>
Fixes: https://bugzilla.redhat.com/1873913
Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Message-Id: <20210421212343.85524-3-ckuehl@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/rbd.c                | 32 +++++++++++++++++++++-----------
 tests/qemu-iotests/231     |  4 ++++
 tests/qemu-iotests/231.out |  3 +++
 3 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/block/rbd.c b/block/rbd.c
index f098a89c7b..26f64cce7c 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -113,21 +113,31 @@ static int qemu_rbd_connect(rados_t *cluster, rados_ioctx_t *io_ctx,
                             const char *keypairs, const char *secretid,
                             Error **errp);
 
+static char *qemu_rbd_strchr(char *src, char delim)
+{
+    char *p;
+
+    for (p = src; *p; ++p) {
+        if (*p == delim) {
+            return p;
+        }
+        if (*p == '\\' && p[1] != '\0') {
+            ++p;
+        }
+    }
+
+    return NULL;
+}
+
+
 static char *qemu_rbd_next_tok(char *src, char delim, char **p)
 {
     char *end;
 
     *p = NULL;
 
-    for (end = src; *end; ++end) {
-        if (*end == delim) {
-            break;
-        }
-        if (*end == '\\' && end[1] != '\0') {
-            end++;
-        }
-    }
-    if (*end == delim) {
+    end = qemu_rbd_strchr(src, delim);
+    if (end) {
         *p = end + 1;
         *end = '\0';
     }
@@ -171,7 +181,7 @@ static void qemu_rbd_parse_filename(const char *filename, QDict *options,
     qemu_rbd_unescape(found_str);
     qdict_put_str(options, "pool", found_str);
 
-    if (strchr(p, '@')) {
+    if (qemu_rbd_strchr(p, '@')) {
         image_name = qemu_rbd_next_tok(p, '@', &p);
 
         found_str = qemu_rbd_next_tok(p, ':', &p);
@@ -181,7 +191,7 @@ static void qemu_rbd_parse_filename(const char *filename, QDict *options,
         image_name = qemu_rbd_next_tok(p, ':', &p);
     }
     /* Check for namespace in the image_name */
-    if (strchr(image_name, '/')) {
+    if (qemu_rbd_strchr(image_name, '/')) {
         found_str = qemu_rbd_next_tok(image_name, '/', &image_name);
         qemu_rbd_unescape(found_str);
         qdict_put_str(options, "namespace", found_str);
diff --git a/tests/qemu-iotests/231 b/tests/qemu-iotests/231
index 0f66d0ca36..8e6c6447c1 100755
--- a/tests/qemu-iotests/231
+++ b/tests/qemu-iotests/231
@@ -55,6 +55,10 @@ _filter_conf()
 $QEMU_IMG info "json:{'file.driver':'rbd','file.filename':'rbd:rbd/bogus:conf=${BOGUS_CONF}'}" 2>&1 | _filter_conf
 $QEMU_IMG info "json:{'file.driver':'rbd','file.pool':'rbd','file.image':'bogus','file.conf':'${BOGUS_CONF}'}" 2>&1 | _filter_conf
 
+# Regression test: the qemu-img invocation is expected to fail, but it should
+# not seg fault the parser.
+$QEMU_IMG create "rbd:rbd/aa\/bb:conf=${BOGUS_CONF}" 1M 2>&1 | _filter_conf
+
 # success, all done
 echo "*** done"
 rm -f $seq.full
diff --git a/tests/qemu-iotests/231.out b/tests/qemu-iotests/231.out
index 747dd221bb..a785a6e859 100644
--- a/tests/qemu-iotests/231.out
+++ b/tests/qemu-iotests/231.out
@@ -4,4 +4,7 @@ unable to get monitor info from DNS SRV with service name: ceph-mon
 qemu-img: Could not open 'json:{'file.driver':'rbd','file.filename':'rbd:rbd/bogus:conf=BOGUS_CONF'}': error connecting: No such file or directory
 unable to get monitor info from DNS SRV with service name: ceph-mon
 qemu-img: Could not open 'json:{'file.driver':'rbd','file.pool':'rbd','file.image':'bogus','file.conf':'BOGUS_CONF'}': error connecting: No such file or directory
+Formatting 'rbd:rbd/aa\/bb:conf=BOGUS_CONF', fmt=raw size=1048576
+unable to get monitor info from DNS SRV with service name: ceph-mon
+qemu-img: rbd:rbd/aa\/bb:conf=BOGUS_CONF: error connecting: No such file or directory
 *** done
-- 
2.31.1

[PULL 03/19] monitor: hmp_qemu_io: acquire aio contex, fix crash

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Max reported the following bug:

$ ./qemu-img create -f raw src.img 1G
$ ./qemu-img create -f raw dst.img 1G

$ (echo '
   {"execute":"qmp_capabilities"}
   {"execute":"blockdev-mirror",
    "arguments":{"job-id":"mirror",
                 "device":"source",
                 "target":"target",
                 "sync":"full",
                 "filter-node-name":"mirror-top"}}
'; sleep 3; echo '
   {"execute":"human-monitor-command",
    "arguments":{"command-line":
                 "qemu-io mirror-top \"write 0 1G\""}}') \
| x86_64-softmmu/qemu-system-x86_64 \
   -qmp stdio \
   -blockdev file,node-name=source,filename=src.img \
   -blockdev file,node-name=target,filename=dst.img \
   -object iothread,id=iothr0 \
   -device virtio-blk,drive=source,iothread=iothr0

crashes:

0  raise () at /usr/lib/libc.so.6
1  abort () at /usr/lib/libc.so.6
2  error_exit
   (err=<optimized out>,
   msg=msg@entry=0x55fbb1634790 <__func__.27> "qemu_mutex_unlock_impl")
   at ../util/qemu-thread-posix.c:37
3  qemu_mutex_unlock_impl
   (mutex=mutex@entry=0x55fbb25ab6e0,
   file=file@entry=0x55fbb1636957 "../util/async.c",
   line=line@entry=650)
   at ../util/qemu-thread-posix.c:109
4  aio_context_release (ctx=ctx@entry=0x55fbb25ab680) at ../util/async.c:650
5  bdrv_do_drained_begin
   (bs=bs@entry=0x55fbb3a87000, recursive=recursive@entry=false,
   parent=parent@entry=0x0,
   ignore_bds_parents=ignore_bds_parents@entry=false,
   poll=poll@entry=true) at ../block/io.c:441
6  bdrv_do_drained_begin
   (poll=true, ignore_bds_parents=false, parent=0x0, recursive=false,
   bs=0x55fbb3a87000) at ../block/io.c:448
7  blk_drain (blk=0x55fbb26c5a00) at ../block/block-backend.c:1718
8  blk_unref (blk=0x55fbb26c5a00) at ../block/block-backend.c:498
9  blk_unref (blk=0x55fbb26c5a00) at ../block/block-backend.c:491
10 hmp_qemu_io (mon=0x7fffaf3fc7d0, qdict=<optimized out>)
   at ../block/monitor/block-hmp-cmds.c:628

man pthread_mutex_unlock
...
    EPERM  The  mutex type is PTHREAD_MUTEX_ERRORCHECK or
    PTHREAD_MUTEX_RECURSIVE, or the mutex is a robust mutex, and the
    current thread does not own the mutex.

So, thread doesn't own the mutex. And we have iothread here.

Next, note that AIO_WAIT_WHILE() documents that ctx must be acquired
exactly once by caller. But where is it acquired in the call stack?
Seems nowhere.

qemuio_command do acquire aio context.. But we need context acquired
around blk_unref() as well and actually around blk_insert_bs() too.

Let's refactor qemuio_command so that it doesn't acquire aio context
but callers do that instead. This way we can cleanly acquire aio
context in hmp_qemu_io() around all three calls.

Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210423134233.51495-1-vsementsov@virtuozzo.com>
[mreitz: Fixed comment]
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/monitor/block-hmp-cmds.c | 31 +++++++++++++++++++++----------
 qemu-io-cmds.c                 |  8 ++++----
 qemu-io.c                      | 17 +++++++++++++++--
 3 files changed, 40 insertions(+), 16 deletions(-)

diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
index ebf1033f31..3e6670c963 100644
--- a/block/monitor/block-hmp-cmds.c
+++ b/block/monitor/block-hmp-cmds.c
@@ -557,8 +557,10 @@ void hmp_eject(Monitor *mon, const QDict *qdict)
 
 void hmp_qemu_io(Monitor *mon, const QDict *qdict)
 {
-    BlockBackend *blk;
+    BlockBackend *blk = NULL;
+    BlockDriverState *bs = NULL;
     BlockBackend *local_blk = NULL;
+    AioContext *ctx = NULL;
     bool qdev = qdict_get_try_bool(qdict, "qdev", false);
     const char *device = qdict_get_str(qdict, "device");
     const char *command = qdict_get_str(qdict, "command");
@@ -573,20 +575,24 @@ void hmp_qemu_io(Monitor *mon, const QDict *qdict)
     } else {
         blk = blk_by_name(device);
         if (!blk) {
-            BlockDriverState *bs = bdrv_lookup_bs(NULL, device, &err);
-            if (bs) {
-                blk = local_blk = blk_new(bdrv_get_aio_context(bs),
-                                          0, BLK_PERM_ALL);
-                ret = blk_insert_bs(blk, bs, &err);
-                if (ret < 0) {
-                    goto fail;
-                }
-            } else {
+            bs = bdrv_lookup_bs(NULL, device, &err);
+            if (!bs) {
                 goto fail;
             }
         }
     }
 
+    ctx = blk ? blk_get_aio_context(blk) : bdrv_get_aio_context(bs);
+    aio_context_acquire(ctx);
+
+    if (bs) {
+        blk = local_blk = blk_new(bdrv_get_aio_context(bs), 0, BLK_PERM_ALL);
+        ret = blk_insert_bs(blk, bs, &err);
+        if (ret < 0) {
+            goto fail;
+        }
+    }
+
     /*
      * Notably absent: Proper permission management. This is sad, but it seems
      * almost impossible to achieve without changing the semantics and thereby
@@ -616,6 +622,11 @@ void hmp_qemu_io(Monitor *mon, const QDict *qdict)
 
 fail:
     blk_unref(local_blk);
+
+    if (ctx) {
+        aio_context_release(ctx);
+    }
+
     hmp_handle_error(mon, err);
 }
 
diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 97611969cb..998b67186d 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -2457,9 +2457,12 @@ static const cmdinfo_t help_cmd = {
     .oneline    = "help for one or all commands",
 };
 
+/*
+ * Called with aio context of blk acquired. Or with qemu_get_aio_context()
+ * context acquired if blk is NULL.
+ */
 int qemuio_command(BlockBackend *blk, const char *cmd)
 {
-    AioContext *ctx;
     char *input;
     const cmdinfo_t *ct;
     char **v;
@@ -2471,10 +2474,7 @@ int qemuio_command(BlockBackend *blk, const char *cmd)
     if (c) {
         ct = find_command(v[0]);
         if (ct) {
-            ctx = blk ? blk_get_aio_context(blk) : qemu_get_aio_context();
-            aio_context_acquire(ctx);
             ret = command(blk, ct, c, v);
-            aio_context_release(ctx);
         } else {
             fprintf(stderr, "command \"%s\" not found\n", v[0]);
             ret = -EINVAL;
diff --git a/qemu-io.c b/qemu-io.c
index bf902302e9..57f07501df 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -411,6 +411,19 @@ static void prep_fetchline(void *opaque)
     *fetchable= 1;
 }
 
+static int do_qemuio_command(const char *cmd)
+{
+    int ret;
+    AioContext *ctx =
+        qemuio_blk ? blk_get_aio_context(qemuio_blk) : qemu_get_aio_context();
+
+    aio_context_acquire(ctx);
+    ret = qemuio_command(qemuio_blk, cmd);
+    aio_context_release(ctx);
+
+    return ret;
+}
+
 static int command_loop(void)
 {
     int i, fetchable = 0, prompted = 0;
@@ -418,7 +431,7 @@ static int command_loop(void)
     char *input;
 
     for (i = 0; !quit_qemu_io && i < ncmdline; i++) {
-        ret = qemuio_command(qemuio_blk, cmdline[i]);
+        ret = do_qemuio_command(cmdline[i]);
         if (ret < 0) {
             last_error = ret;
         }
@@ -446,7 +459,7 @@ static int command_loop(void)
         if (input == NULL) {
             break;
         }
-        ret = qemuio_command(qemuio_blk, input);
+        ret = do_qemuio_command(input);
         g_free(input);
 
         if (ret < 0) {
-- 
2.31.1

[PULL 04/19] mirror: stop cancelling in-flight requests on non-force cancel in READY

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

If mirror is READY than cancel operation is not discarding the whole
result of the operation, but instead it's a documented way get a
point-in-time snapshot of source disk.

So, we should not cancel any requests if mirror is READ and
force=false. Let's fix that case.

Note, that bug that we have before this commit is not critical, as the
only .bdrv_cancel_in_flight implementation is nbd_cancel_in_flight()
and it cancels only requests waiting for reconnection, so it should be
rare case.

Fixes: 521ff8b779b11c394dbdc43f02e158dd99df308a
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210421075858.40197-1-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 include/block/block_int.h | 2 +-
 include/qemu/job.h        | 2 +-
 block/backup.c            | 2 +-
 block/mirror.c            | 6 ++++--
 job.c                     | 2 +-
 tests/qemu-iotests/264    | 2 +-
 6 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/include/block/block_int.h b/include/block/block_int.h
index c823f5b1b3..731ffedb27 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -357,7 +357,7 @@ struct BlockDriver {
      * of in-flight requests, so don't waste the time if possible.
      *
      * One example usage is to avoid waiting for an nbd target node reconnect
-     * timeout during job-cancel.
+     * timeout during job-cancel with force=true.
      */
     void (*bdrv_cancel_in_flight)(BlockDriverState *bs);
 
diff --git a/include/qemu/job.h b/include/qemu/job.h
index efc6fa7544..41162ed494 100644
--- a/include/qemu/job.h
+++ b/include/qemu/job.h
@@ -254,7 +254,7 @@ struct JobDriver {
     /**
      * If the callback is not NULL, it will be invoked in job_cancel_async
      */
-    void (*cancel)(Job *job);
+    void (*cancel)(Job *job, bool force);
 
 
     /** Called when the job is freed */
diff --git a/block/backup.c b/block/backup.c
index 6cf2f974aa..bd3614ce70 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -331,7 +331,7 @@ static void coroutine_fn backup_set_speed(BlockJob *job, int64_t speed)
     }
 }
 
-static void backup_cancel(Job *job)
+static void backup_cancel(Job *job, bool force)
 {
     BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
 
diff --git a/block/mirror.c b/block/mirror.c
index 840b8e8c15..019f6deaa5 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1178,12 +1178,14 @@ static bool mirror_drained_poll(BlockJob *job)
     return !!s->in_flight;
 }
 
-static void mirror_cancel(Job *job)
+static void mirror_cancel(Job *job, bool force)
 {
     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);
     BlockDriverState *target = blk_bs(s->target);
 
-    bdrv_cancel_in_flight(target);
+    if (force || !job_is_ready(job)) {
+        bdrv_cancel_in_flight(target);
+    }
 }
 
 static const BlockJobDriver mirror_job_driver = {
diff --git a/job.c b/job.c
index 4aff13d95a..8775c1803b 100644
--- a/job.c
+++ b/job.c
@@ -716,7 +716,7 @@ static int job_finalize_single(Job *job)
 static void job_cancel_async(Job *job, bool force)
 {
     if (job->driver->cancel) {
-        job->driver->cancel(job);
+        job->driver->cancel(job, force);
     }
     if (job->user_paused) {
         /* Do not call job_enter here, the caller will handle it.  */
diff --git a/tests/qemu-iotests/264 b/tests/qemu-iotests/264
index 4f96825a22..bc431d1a19 100755
--- a/tests/qemu-iotests/264
+++ b/tests/qemu-iotests/264
@@ -95,7 +95,7 @@ class TestNbdReconnect(iotests.QMPTestCase):
             self.assert_qmp(result, 'return', {})
 
     def cancel_job(self):
-        result = self.vm.qmp('block-job-cancel', device='drive0')
+        result = self.vm.qmp('block-job-cancel', device='drive0', force=True)
         self.assert_qmp(result, 'return', {})
 
         start_t = time.time()
-- 
2.31.1

[PULL 05/19] qemu-iotests: do not buffer the test output

[Max Reitz]

From: Paolo Bonzini <pbonzini@redhat.com>

Instead of buffering the test output into a StringIO, patch it on
the fly by wrapping sys.stdout's write method.  This can be
done unconditionally, even if using -d, which makes execute_unittest
a bit simpler.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210323181928.311862-2-pbonzini@redhat.com>
Message-Id: <20210503110110.476887-2-pbonzini@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/240.out    |  8 ++--
 tests/qemu-iotests/245.out    |  8 ++--
 tests/qemu-iotests/295.out    |  6 +--
 tests/qemu-iotests/296.out    |  8 ++--
 tests/qemu-iotests/iotests.py | 70 ++++++++++++++++++++---------------
 5 files changed, 56 insertions(+), 44 deletions(-)

diff --git a/tests/qemu-iotests/240.out b/tests/qemu-iotests/240.out
index e0982831ae..89ed25e506 100644
--- a/tests/qemu-iotests/240.out
+++ b/tests/qemu-iotests/240.out
@@ -15,7 +15,7 @@
 {"return": {}}
 {"execute": "blockdev-del", "arguments": {"node-name": "hd0"}}
 {"return": {}}
-==Attach two SCSI disks using the same block device and the same iothread==
+.==Attach two SCSI disks using the same block device and the same iothread==
 {"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "hd0", "read-only": true, "read-zeroes": true}}
 {"return": {}}
 {"execute": "object-add", "arguments": {"id": "iothread0", "qom-type": "iothread"}}
@@ -32,7 +32,7 @@
 {"return": {}}
 {"execute": "blockdev-del", "arguments": {"node-name": "hd0"}}
 {"return": {}}
-==Attach two SCSI disks using the same block device but different iothreads==
+.==Attach two SCSI disks using the same block device but different iothreads==
 {"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "hd0", "read-only": true, "read-zeroes": true}}
 {"return": {}}
 {"execute": "object-add", "arguments": {"id": "iothread0", "qom-type": "iothread"}}
@@ -55,7 +55,7 @@
 {"return": {}}
 {"execute": "blockdev-del", "arguments": {"node-name": "hd0"}}
 {"return": {}}
-==Attach a SCSI disks using the same block device as a NBD server==
+.==Attach a SCSI disks using the same block device as a NBD server==
 {"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "hd0", "read-only": true, "read-zeroes": true}}
 {"return": {}}
 {"execute": "nbd-server-start", "arguments": {"addr": {"data": {"path": "SOCK_DIR/PID-nbd.sock"}, "type": "unix"}}}
@@ -68,7 +68,7 @@
 {"return": {}}
 {"execute": "device_add", "arguments": {"drive": "hd0", "driver": "scsi-hd", "id": "scsi-hd0"}}
 {"return": {}}
-....
+.
 ----------------------------------------------------------------------
 Ran 4 tests
 
diff --git a/tests/qemu-iotests/245.out b/tests/qemu-iotests/245.out
index 4b33dcaf5c..99c12f4f98 100644
--- a/tests/qemu-iotests/245.out
+++ b/tests/qemu-iotests/245.out
@@ -1,16 +1,16 @@
-{"execute": "job-finalize", "arguments": {"id": "commit0"}}
+..{"execute": "job-finalize", "arguments": {"id": "commit0"}}
 {"return": {}}
 {"data": {"id": "commit0", "type": "commit"}, "event": "BLOCK_JOB_PENDING", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"device": "commit0", "len": 3145728, "offset": 3145728, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
-{"execute": "job-finalize", "arguments": {"id": "stream0"}}
+...{"execute": "job-finalize", "arguments": {"id": "stream0"}}
 {"return": {}}
 {"data": {"id": "stream0", "type": "stream"}, "event": "BLOCK_JOB_PENDING", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"device": "stream0", "len": 3145728, "offset": 3145728, "speed": 0, "type": "stream"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
-{"execute": "job-finalize", "arguments": {"id": "stream0"}}
+.{"execute": "job-finalize", "arguments": {"id": "stream0"}}
 {"return": {}}
 {"data": {"id": "stream0", "type": "stream"}, "event": "BLOCK_JOB_PENDING", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"device": "stream0", "len": 3145728, "offset": 3145728, "speed": 0, "type": "stream"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
-.....................
+...............
 ----------------------------------------------------------------------
 Ran 21 tests
 
diff --git a/tests/qemu-iotests/295.out b/tests/qemu-iotests/295.out
index ad34b2ca2c..5ff91f116c 100644
--- a/tests/qemu-iotests/295.out
+++ b/tests/qemu-iotests/295.out
@@ -4,7 +4,7 @@
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job_erase_key"}}
 {"return": {}}
-{"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
+.{"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job_erase_key"}}
 {"return": {}}
@@ -13,7 +13,7 @@ Job failed: Invalid password, cannot unlock any keyslot
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
 {"return": {}}
-{"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
+.{"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job_add_key"}}
 {"return": {}}
@@ -33,7 +33,7 @@ Job failed: All the active keyslots match the (old) password that was given and
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job_erase_key"}}
 {"return": {}}
-...
+.
 ----------------------------------------------------------------------
 Ran 3 tests
 
diff --git a/tests/qemu-iotests/296.out b/tests/qemu-iotests/296.out
index cb2859a15c..6c69735604 100644
--- a/tests/qemu-iotests/296.out
+++ b/tests/qemu-iotests/296.out
@@ -13,7 +13,7 @@ Job failed: Failed to get shared "consistent read" lock
 qemu-img: Failed to get shared "consistent read" lock
 Is another process using the image [TEST_DIR/test.img]?
 
-Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
+.Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
 
 Job failed: Block node is read-only
 {"execute": "job-dismiss", "arguments": {"id": "job0"}}
@@ -26,15 +26,15 @@ Job failed: Failed to get shared "consistent read" lock
 {"return": {}}
 {"execute": "job-dismiss", "arguments": {"id": "job0"}}
 {"return": {}}
-Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
+.Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
 
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "Failed to get \"write\" lock"}}
-Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
+.Formatting 'TEST_DIR/test.img', fmt=luks size=1048576 key-secret=keysec0 iter-time=10
 
 {"return": {}}
 {"return": {}}
-....
+.
 ----------------------------------------------------------------------
 Ran 4 tests
 
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 5af0182895..55a017577f 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -20,7 +20,6 @@
 import bz2
 from collections import OrderedDict
 import faulthandler
-import io
 import json
 import logging
 import os
@@ -32,7 +31,7 @@
 import sys
 import time
 from typing import (Any, Callable, Dict, Iterable,
-                    List, Optional, Sequence, Tuple, TypeVar)
+                    List, Optional, Sequence, TextIO, Tuple, Type, TypeVar)
 import unittest
 
 from contextlib import contextmanager
@@ -1271,37 +1270,50 @@ def func_wrapper(*args, **kwargs):
             return func(*args, **kwargs)
     return func_wrapper
 
+# We need to filter out the time taken from the output so that
+# qemu-iotest can reliably diff the results against master output,
+# and hide skipped tests from the reference output.
+
+class ReproducibleTestResult(unittest.TextTestResult):
+    def addSkip(self, test, reason):
+        # Same as TextTestResult, but print dot instead of "s"
+        unittest.TestResult.addSkip(self, test, reason)
+        if self.showAll:
+            self.stream.writeln("skipped {0!r}".format(reason))
+        elif self.dots:
+            self.stream.write(".")
+            self.stream.flush()
+
+class ReproducibleStreamWrapper:
+    def __init__(self, stream: TextIO):
+        self.stream = stream
+
+    def __getattr__(self, attr):
+        if attr in ('stream', '__getstate__'):
+            raise AttributeError(attr)
+        return getattr(self.stream, attr)
+
+    def write(self, arg=None):
+        arg = re.sub(r'Ran (\d+) tests? in [\d.]+s', r'Ran \1 tests', arg)
+        arg = re.sub(r' \(skipped=\d+\)', r'', arg)
+        self.stream.write(arg)
+
+class ReproducibleTestRunner(unittest.TextTestRunner):
+    def __init__(self, stream: Optional[TextIO] = None,
+             resultclass: Type[unittest.TestResult] = ReproducibleTestResult,
+             **kwargs: Any) -> None:
+        rstream = ReproducibleStreamWrapper(stream or sys.stdout)
+        super().__init__(stream=rstream,           # type: ignore
+                         descriptions=True,
+                         resultclass=resultclass,
+                         **kwargs)
+
 def execute_unittest(debug=False):
     """Executes unittests within the calling module."""
 
     verbosity = 2 if debug else 1
-
-    if debug:
-        output = sys.stdout
-    else:
-        # We need to filter out the time taken from the output so that
-        # qemu-iotest can reliably diff the results against master output.
-        output = io.StringIO()
-
-    runner = unittest.TextTestRunner(stream=output, descriptions=True,
-                                     verbosity=verbosity)
-    try:
-        # unittest.main() will use sys.exit(); so expect a SystemExit
-        # exception
-        unittest.main(testRunner=runner)
-    finally:
-        # We need to filter out the time taken from the output so that
-        # qemu-iotest can reliably diff the results against master output.
-        if not debug:
-            out = output.getvalue()
-            out = re.sub(r'Ran (\d+) tests? in [\d.]+s', r'Ran \1 tests', out)
-
-            # Hide skipped tests from the reference output
-            out = re.sub(r'OK \(skipped=\d+\)', 'OK', out)
-            out_first_line, out_rest = out.split('\n', 1)
-            out = out_first_line.replace('s', '.') + '\n' + out_rest
-
-            sys.stderr.write(out)
+    runner = ReproducibleTestRunner(verbosity=verbosity)
+    unittest.main(testRunner=runner)
 
 def execute_setup_common(supported_fmts: Sequence[str] = (),
                          supported_platforms: Sequence[str] = (),
-- 
2.31.1

[PULL 06/19] qemu-iotests: allow passing unittest.main arguments to the test scripts

[Max Reitz]

From: Paolo Bonzini <pbonzini@redhat.com>

Python test scripts that use unittest consist of multiple tests.
unittest.main allows selecting which tests to run, but currently this
is not possible because the iotests wrapper ignores sys.argv.

unittest.main command line options also allow the user to pick the
desired options for verbosity, failfast mode, etc.  While "-d" is
currently translated to "-v", it also enables extra debug output,
and other options are not available at all.

These command line options only work if the unittest.main testRunner
argument is a type, rather than a TestRunner instance.  Therefore, pass
the class name and "verbosity" argument to unittest.main, and adjust for
the different default warnings between TextTestRunner and unittest.main.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210323181928.311862-3-pbonzini@redhat.com>
Message-Id: <20210503110110.476887-3-pbonzini@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/iotests.py | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 55a017577f..5ead94229f 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -1308,12 +1308,16 @@ def __init__(self, stream: Optional[TextIO] = None,
                          resultclass=resultclass,
                          **kwargs)
 
-def execute_unittest(debug=False):
+def execute_unittest(argv: List[str], debug: bool = False) -> None:
     """Executes unittests within the calling module."""
 
-    verbosity = 2 if debug else 1
-    runner = ReproducibleTestRunner(verbosity=verbosity)
-    unittest.main(testRunner=runner)
+    # Some tests have warnings, especially ResourceWarnings for unclosed
+    # files and sockets.  Ignore them for now to ensure reproducibility of
+    # the test output.
+    unittest.main(argv=argv,
+                  testRunner=ReproducibleTestRunner,
+                  verbosity=2 if debug else 1,
+                  warnings=None if sys.warnoptions else 'ignore')
 
 def execute_setup_common(supported_fmts: Sequence[str] = (),
                          supported_platforms: Sequence[str] = (),
@@ -1350,7 +1354,7 @@ def execute_test(*args, test_function=None, **kwargs):
 
     debug = execute_setup_common(*args, **kwargs)
     if not test_function:
-        execute_unittest(debug)
+        execute_unittest(sys.argv, debug)
     else:
         test_function()
 
-- 
2.31.1

[PULL 07/19] qemu-iotests: move command line and environment handling from TestRunner to TestEnv

[Max Reitz]

From: Paolo Bonzini <pbonzini@redhat.com>

In the next patch, "check" will learn how to execute a test script without
going through TestRunner.  To enable this, keep only the text output
and subprocess handling in the TestRunner; move into TestEnv the logic
to prepare for running a subprocess.

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210323181928.311862-4-pbonzini@redhat.com>
Message-Id: <20210503110110.476887-4-pbonzini@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/testenv.py    | 17 ++++++++++++++++-
 tests/qemu-iotests/testrunner.py | 14 +-------------
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/tests/qemu-iotests/testenv.py b/tests/qemu-iotests/testenv.py
index 6d27712617..fca3a609e0 100644
--- a/tests/qemu-iotests/testenv.py
+++ b/tests/qemu-iotests/testenv.py
@@ -25,7 +25,7 @@
 import random
 import subprocess
 import glob
-from typing import Dict, Any, Optional, ContextManager
+from typing import List, Dict, Any, Optional, ContextManager
 
 
 def isxfile(path: str) -> bool:
@@ -74,6 +74,21 @@ class TestEnv(ContextManager['TestEnv']):
                      'CACHEMODE_IS_DEFAULT', 'IMGFMT_GENERIC', 'IMGOPTSSYNTAX',
                      'IMGKEYSECRET', 'QEMU_DEFAULT_MACHINE', 'MALLOC_PERTURB_']
 
+    def prepare_subprocess(self, args: List[str]) -> Dict[str, str]:
+        if self.debug:
+            args.append('-d')
+
+        with open(args[0], encoding="utf-8") as f:
+            try:
+                if f.readline().rstrip() == '#!/usr/bin/env python3':
+                    args.insert(0, self.python)
+            except UnicodeDecodeError:  # binary test? for future.
+                pass
+
+        os_env = os.environ.copy()
+        os_env.update(self.get_env())
+        return os_env
+
     def get_env(self) -> Dict[str, str]:
         env = {}
         for v in self.env_variables:
diff --git a/tests/qemu-iotests/testrunner.py b/tests/qemu-iotests/testrunner.py
index 1fc61fcaa3..519924dc81 100644
--- a/tests/qemu-iotests/testrunner.py
+++ b/tests/qemu-iotests/testrunner.py
@@ -129,7 +129,6 @@ class TestRunner(ContextManager['TestRunner']):
     def __init__(self, env: TestEnv, makecheck: bool = False,
                  color: str = 'auto') -> None:
         self.env = env
-        self.test_run_env = self.env.get_env()
         self.makecheck = makecheck
         self.last_elapsed = LastElapsedTime('.last-elapsed-cache', env)
 
@@ -243,18 +242,7 @@ def do_run_test(self, test: str) -> TestResult:
             silent_unlink(p)
 
         args = [str(f_test.resolve())]
-        if self.env.debug:
-            args.append('-d')
-
-        with f_test.open(encoding="utf-8") as f:
-            try:
-                if f.readline().rstrip() == '#!/usr/bin/env python3':
-                    args.insert(0, self.env.python)
-            except UnicodeDecodeError:  # binary test? for future.
-                pass
-
-        env = os.environ.copy()
-        env.update(self.test_run_env)
+        env = self.env.prepare_subprocess(args)
 
         t0 = time.time()
         with f_bad.open('w', encoding="utf-8") as f:
-- 
2.31.1

[PULL 08/19] qemu-iotests: let "check" spawn an arbitrary test command

[Max Reitz]

From: Paolo Bonzini <pbonzini@redhat.com>

Right now there is no easy way for "check" to print a reproducer command.
Because such a reproducer command line would be huge, we can instead teach
check to start a command of our choice.  This can be for example a Python
unit test with arguments to only run a specific subtest.

Move the trailing empty line to print_env(), since it always looks better
and one caller was not adding it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210323181928.311862-5-pbonzini@redhat.com>
Message-Id: <20210503110110.476887-5-pbonzini@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/check         | 19 ++++++++++++++++++-
 tests/qemu-iotests/testenv.py    |  3 ++-
 tests/qemu-iotests/testrunner.py |  1 -
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index 08f51366f1..2dd529eb75 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -19,6 +19,9 @@
 import os
 import sys
 import argparse
+import shutil
+from pathlib import Path
+
 from findtests import TestFinder
 from testenv import TestEnv
 from testrunner import TestRunner
@@ -100,7 +103,7 @@ def make_argparser() -> argparse.ArgumentParser:
                        'rerun failed ./check command, starting from the '
                        'middle of the process.')
     g_sel.add_argument('tests', metavar='TEST_FILES', nargs='*',
-                       help='tests to run')
+                       help='tests to run, or "--" followed by a command')
 
     return p
 
@@ -113,6 +116,20 @@ if __name__ == '__main__':
                   imgopts=args.imgopts, misalign=args.misalign,
                   debug=args.debug, valgrind=args.valgrind)
 
+    if len(sys.argv) > 1 and sys.argv[-len(args.tests)-1] == '--':
+        if not args.tests:
+            sys.exit("missing command after '--'")
+        cmd = args.tests
+        env.print_env()
+        exec_pathstr = shutil.which(cmd[0])
+        if exec_pathstr is None:
+            sys.exit('command not found: ' + cmd[0])
+        exec_path = Path(exec_pathstr).resolve()
+        cmd[0] = str(exec_path)
+        full_env = env.prepare_subprocess(cmd)
+        os.chdir(exec_path.parent)
+        os.execve(cmd[0], cmd, full_env)
+
     testfinder = TestFinder(test_dir=env.source_iotests)
 
     groups = args.groups.split(',') if args.groups else None
diff --git a/tests/qemu-iotests/testenv.py b/tests/qemu-iotests/testenv.py
index fca3a609e0..cd0e39b789 100644
--- a/tests/qemu-iotests/testenv.py
+++ b/tests/qemu-iotests/testenv.py
@@ -284,7 +284,8 @@ def print_env(self) -> None:
 PLATFORM      -- {platform}
 TEST_DIR      -- {TEST_DIR}
 SOCK_DIR      -- {SOCK_DIR}
-SOCKET_SCM_HELPER -- {SOCKET_SCM_HELPER}"""
+SOCKET_SCM_HELPER -- {SOCKET_SCM_HELPER}
+"""
 
         args = collections.defaultdict(str, self.get_env())
 
diff --git a/tests/qemu-iotests/testrunner.py b/tests/qemu-iotests/testrunner.py
index 519924dc81..2f56ac545d 100644
--- a/tests/qemu-iotests/testrunner.py
+++ b/tests/qemu-iotests/testrunner.py
@@ -316,7 +316,6 @@ def run_tests(self, tests: List[str]) -> bool:
 
         if not self.makecheck:
             self.env.print_env()
-            print()
 
         test_field_width = max(len(os.path.basename(t)) for t in tests) + 2
 
-- 
2.31.1

[PULL 09/19] qemu-iotests: fix case of SOCK_DIR already in the environment

[Max Reitz]

From: Paolo Bonzini <pbonzini@redhat.com>

Due to a typo, in this case the SOCK_DIR was not being created.

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210323181928.311862-6-pbonzini@redhat.com>
Message-Id: <20210503110110.476887-6-pbonzini@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/testenv.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/qemu-iotests/testenv.py b/tests/qemu-iotests/testenv.py
index cd0e39b789..0c3fe75636 100644
--- a/tests/qemu-iotests/testenv.py
+++ b/tests/qemu-iotests/testenv.py
@@ -120,7 +120,7 @@ def init_directories(self) -> None:
         try:
             self.sock_dir = os.environ['SOCK_DIR']
             self.tmp_sock_dir = False
-            Path(self.test_dir).mkdir(parents=True, exist_ok=True)
+            Path(self.sock_dir).mkdir(parents=True, exist_ok=True)
         except KeyError:
             self.sock_dir = tempfile.mkdtemp()
             self.tmp_sock_dir = True
-- 
2.31.1

[PULL 10/19] Document qemu-img options data_file and data_file_raw

[Max Reitz]

From: Connor Kuehl <ckuehl@redhat.com>

The contents of this patch were initially developed and posted by Han
Han[1], however, it appears the original patch was not applied. Since
then, the relevant documentation has been moved and adapted to a new
format.

I've taken most of the original wording and tweaked it according to
some of the feedback from the original patch submission. I've also
adapted it to restructured text, which is the format the documentation
currently uses.

[1] https://lists.nongnu.org/archive/html/qemu-block/2019-10/msg01253.html

Fixes: https://bugzilla.redhat.com/1763105
Signed-off-by: Han Han <hhan@redhat.com>
Suggested-by: Max Reitz <mreitz@redhat.com>
[ Max: provided description of data_file_raw behavior ]
Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Message-Id: <20210505195512.391128-1-ckuehl@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 docs/tools/qemu-img.rst | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/docs/tools/qemu-img.rst b/docs/tools/qemu-img.rst
index c9efcfaefc..cfe1147879 100644
--- a/docs/tools/qemu-img.rst
+++ b/docs/tools/qemu-img.rst
@@ -866,6 +866,37 @@ Supported image file formats:
     issue ``lsattr filename`` to check if the NOCOW flag is set or not
     (Capital 'C' is NOCOW flag).
 
+  ``data_file``
+    Filename where all guest data will be stored. If this option is used,
+    the qcow2 file will only contain the image's metadata.
+
+    Note: Data loss will occur if the given filename already exists when
+    using this option with ``qemu-img create`` since ``qemu-img`` will create
+    the data file anew, overwriting the file's original contents. To simply
+    update the reference to point to the given pre-existing file, use
+    ``qemu-img amend``.
+
+  ``data_file_raw``
+    If this option is set to ``on``, QEMU will always keep the external data
+    file consistent as a standalone read-only raw image.
+
+    It does this by forwarding all write accesses to the qcow2 file through to
+    the raw data file, including their offsets. Therefore, data that is visible
+    on the qcow2 node (i.e., to the guest) at some offset is visible at the same
+    offset in the raw data file. This results in a read-only raw image. Writes
+    that bypass the qcow2 metadata may corrupt the qcow2 metadata because the
+    out-of-band writes may result in the metadata falling out of sync with the
+    raw image.
+
+    If this option is ``off``, QEMU will use the data file to store data in an
+    arbitrary manner. The file’s content will not make sense without the
+    accompanying qcow2 metadata. Where data is written will have no relation to
+    its offset as seen by the guest, and some writes (specifically zero writes)
+    may not be forwarded to the data file at all, but will only be handled by
+    modifying qcow2 metadata.
+
+    This option can only be enabled if ``data_file`` is set.
+
 ``Other``
 
   QEMU also supports various other image file formats for
-- 
2.31.1

[PULL 11/19] block/copy-on-read: use bdrv_drop_filter() and drop s->active

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Now, after huge update of block graph permission update algorithm, we
don't need this workaround with active state of the filter. Drop it and
use new smart bdrv_drop_filter() function.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210506194143.394141-1-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/copy-on-read.c | 33 +--------------------------------
 1 file changed, 1 insertion(+), 32 deletions(-)

diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index 9cad9e1b8c..c428682272 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -29,7 +29,6 @@
 
 
 typedef struct BDRVStateCOR {
-    bool active;
     BlockDriverState *bottom_bs;
     bool chain_frozen;
 } BDRVStateCOR;
@@ -89,7 +88,6 @@ static int cor_open(BlockDriverState *bs, QDict *options, int flags,
          */
         bdrv_ref(bottom_bs);
     }
-    state->active = true;
     state->bottom_bs = bottom_bs;
 
     /*
@@ -112,17 +110,6 @@ static void cor_child_perm(BlockDriverState *bs, BdrvChild *c,
                            uint64_t perm, uint64_t shared,
                            uint64_t *nperm, uint64_t *nshared)
 {
-    BDRVStateCOR *s = bs->opaque;
-
-    if (!s->active) {
-        /*
-         * While the filter is being removed
-         */
-        *nperm = 0;
-        *nshared = BLK_PERM_ALL;
-        return;
-    }
-
     *nperm = perm & PERM_PASSTHROUGH;
     *nshared = (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED;
 
@@ -280,32 +267,14 @@ static BlockDriver bdrv_copy_on_read = {
 
 void bdrv_cor_filter_drop(BlockDriverState *cor_filter_bs)
 {
-    BdrvChild *child;
-    BlockDriverState *bs;
     BDRVStateCOR *s = cor_filter_bs->opaque;
 
-    child = bdrv_filter_child(cor_filter_bs);
-    if (!child) {
-        return;
-    }
-    bs = child->bs;
-
-    /* Retain the BDS until we complete the graph change. */
-    bdrv_ref(bs);
-    /* Hold a guest back from writing while permissions are being reset. */
-    bdrv_drained_begin(bs);
-    /* Drop permissions before the graph change. */
-    s->active = false;
     /* unfreeze, as otherwise bdrv_replace_node() will fail */
     if (s->chain_frozen) {
         s->chain_frozen = false;
         bdrv_unfreeze_backing_chain(cor_filter_bs, s->bottom_bs);
     }
-    bdrv_child_refresh_perms(cor_filter_bs, child, &error_abort);
-    bdrv_replace_node(cor_filter_bs, bs, &error_abort);
-
-    bdrv_drained_end(bs);
-    bdrv_unref(bs);
+    bdrv_drop_filter(cor_filter_bs, &error_abort);
     bdrv_unref(cor_filter_bs);
 }
 
-- 
2.31.1

[PULL 12/19] qemu-iotests: fix pylint 2.8 consider-using-with error

[Max Reitz]

From: Emanuele Giuseppe Esposito <eesposit@redhat.com>

pylint 2.8 introduces consider-using-with error, suggesting
to use the 'with' block statement when possible.

Modify all subprocess.Popen call to use the 'with' statement,
except the one in __init__ of QemuIoInteractive class, since
it is assigned to a class field and used in other methods.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210510190449.65948-1-eesposit@redhat.com>
[mreitz: Disable bad-option-value warning in the iotests' pylintrc, so
         that disabling consider-using-with in QemuIoInteractive will
         not produce a warning in pre-2.8 pylint versions]
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/iotests.py    | 65 ++++++++++++++++----------------
 tests/qemu-iotests/pylintrc      |  3 ++
 tests/qemu-iotests/testrunner.py | 22 +++++------
 3 files changed, 47 insertions(+), 43 deletions(-)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 5ead94229f..777fa2ec0e 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -112,15 +112,14 @@ def qemu_tool_pipe_and_status(tool: str, args: Sequence[str],
     Run a tool and return both its output and its exit code
     """
     stderr = subprocess.STDOUT if connect_stderr else None
-    subp = subprocess.Popen(args,
-                            stdout=subprocess.PIPE,
-                            stderr=stderr,
-                            universal_newlines=True)
-    output = subp.communicate()[0]
-    if subp.returncode < 0:
-        cmd = ' '.join(args)
-        sys.stderr.write(f'{tool} received signal {-subp.returncode}: {cmd}\n')
-    return (output, subp.returncode)
+    with subprocess.Popen(args, stdout=subprocess.PIPE,
+                          stderr=stderr, universal_newlines=True) as subp:
+        output = subp.communicate()[0]
+        if subp.returncode < 0:
+            cmd = ' '.join(args)
+            sys.stderr.write(f'{tool} received signal \
+                               {-subp.returncode}: {cmd}\n')
+        return (output, subp.returncode)
 
 def qemu_img_pipe_and_status(*args: str) -> Tuple[str, int]:
     """
@@ -236,6 +235,9 @@ def qemu_io_silent_check(*args):
 class QemuIoInteractive:
     def __init__(self, *args):
         self.args = qemu_io_args_no_fmt + list(args)
+        # We need to keep the Popen objext around, and not
+        # close it immediately. Therefore, disable the pylint check:
+        # pylint: disable=consider-using-with
         self._p = subprocess.Popen(self.args, stdin=subprocess.PIPE,
                                    stdout=subprocess.PIPE,
                                    stderr=subprocess.STDOUT,
@@ -309,22 +311,22 @@ def qemu_nbd_popen(*args):
     cmd.extend(args)
 
     log('Start NBD server')
-    p = subprocess.Popen(cmd)
-    try:
-        while not os.path.exists(pid_file):
-            if p.poll() is not None:
-                raise RuntimeError(
-                    "qemu-nbd terminated with exit code {}: {}"
-                    .format(p.returncode, ' '.join(cmd)))
-
-            time.sleep(0.01)
-        yield
-    finally:
-        if os.path.exists(pid_file):
-            os.remove(pid_file)
-        log('Kill NBD server')
-        p.kill()
-        p.wait()
+    with subprocess.Popen(cmd) as p:
+        try:
+            while not os.path.exists(pid_file):
+                if p.poll() is not None:
+                    raise RuntimeError(
+                        "qemu-nbd terminated with exit code {}: {}"
+                        .format(p.returncode, ' '.join(cmd)))
+
+                time.sleep(0.01)
+            yield
+        finally:
+            if os.path.exists(pid_file):
+                os.remove(pid_file)
+            log('Kill NBD server')
+            p.kill()
+            p.wait()
 
 def compare_images(img1, img2, fmt1=imgfmt, fmt2=imgfmt):
     '''Return True if two image files are identical'''
@@ -333,13 +335,12 @@ def compare_images(img1, img2, fmt1=imgfmt, fmt2=imgfmt):
 
 def create_image(name, size):
     '''Create a fully-allocated raw image with sector markers'''
-    file = open(name, 'wb')
-    i = 0
-    while i < size:
-        sector = struct.pack('>l504xl', i // 512, i // 512)
-        file.write(sector)
-        i = i + 512
-    file.close()
+    with open(name, 'wb') as file:
+        i = 0
+        while i < size:
+            sector = struct.pack('>l504xl', i // 512, i // 512)
+            file.write(sector)
+            i = i + 512
 
 def image_size(img):
     '''Return image's virtual size'''
diff --git a/tests/qemu-iotests/pylintrc b/tests/qemu-iotests/pylintrc
index 7a6c0a9474..f2c0b522ac 100644
--- a/tests/qemu-iotests/pylintrc
+++ b/tests/qemu-iotests/pylintrc
@@ -19,6 +19,9 @@ disable=invalid-name,
         too-many-public-methods,
         # pylint warns about Optional[] etc. as unsubscriptable in 3.9
         unsubscriptable-object,
+        # Sometimes we need to disable a newly introduced pylint warning.
+        # Doing so should not produce a warning in older versions of pylint.
+        bad-option-value,
         # These are temporary, and should be removed:
         missing-docstring,
         too-many-return-statements,
diff --git a/tests/qemu-iotests/testrunner.py b/tests/qemu-iotests/testrunner.py
index 2f56ac545d..4a6ec421ed 100644
--- a/tests/qemu-iotests/testrunner.py
+++ b/tests/qemu-iotests/testrunner.py
@@ -246,17 +246,17 @@ def do_run_test(self, test: str) -> TestResult:
 
         t0 = time.time()
         with f_bad.open('w', encoding="utf-8") as f:
-            proc = subprocess.Popen(args, cwd=str(f_test.parent), env=env,
-                                    stdout=f, stderr=subprocess.STDOUT)
-            try:
-                proc.wait()
-            except KeyboardInterrupt:
-                proc.terminate()
-                proc.wait()
-                return TestResult(status='not run',
-                                  description='Interrupted by user',
-                                  interrupted=True)
-            ret = proc.returncode
+            with subprocess.Popen(args, cwd=str(f_test.parent), env=env,
+                                  stdout=f, stderr=subprocess.STDOUT) as proc:
+                try:
+                    proc.wait()
+                except KeyboardInterrupt:
+                    proc.terminate()
+                    proc.wait()
+                    return TestResult(status='not run',
+                                      description='Interrupted by user',
+                                      interrupted=True)
+                ret = proc.returncode
 
         elapsed = round(time.time() - t0, 1)
 
-- 
2.31.1

[PULL 13/19] block/write-threshold: don't use write notifiers

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

write-notifiers are used only for write-threshold. New code for such
purpose should create filters.

Let's better special-case write-threshold and drop write notifiers at
all. (Actually, write-threshold is special-cased anyway, as the only
user of write-notifiers)

So, create a new direct interface for bdrv_co_write_req_prepare() and
drop all write-notifier related logic from write-threshold.c.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[mreitz: Adjusted comment as per Eric's suggestion]
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 include/block/block_int.h       |  1 -
 include/block/write-threshold.h |  9 +++++
 block/io.c                      |  5 ++-
 block/write-threshold.c         | 70 +++++++--------------------------
 4 files changed, 27 insertions(+), 58 deletions(-)

diff --git a/include/block/block_int.h b/include/block/block_int.h
index 731ffedb27..aff948fb63 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -959,7 +959,6 @@ struct BlockDriverState {
 
     /* threshold limit for writes, in bytes. "High water mark". */
     uint64_t write_threshold_offset;
-    NotifierWithReturn write_threshold_notifier;
 
     /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
      * Reading from the list can be done with either the BQL or the
diff --git a/include/block/write-threshold.h b/include/block/write-threshold.h
index c646f267a4..848a5dde85 100644
--- a/include/block/write-threshold.h
+++ b/include/block/write-threshold.h
@@ -59,4 +59,13 @@ bool bdrv_write_threshold_is_set(const BlockDriverState *bs);
 uint64_t bdrv_write_threshold_exceeded(const BlockDriverState *bs,
                                        const BdrvTrackedRequest *req);
 
+/*
+ * bdrv_write_threshold_check_write
+ *
+ * Check whether the specified request exceeds the write threshold.
+ * If so, send a corresponding event and disable write threshold checking.
+ */
+void bdrv_write_threshold_check_write(BlockDriverState *bs, int64_t offset,
+                                      int64_t bytes);
+
 #endif
diff --git a/block/io.c b/block/io.c
index 35b6c56efc..3520de51bb 100644
--- a/block/io.c
+++ b/block/io.c
@@ -30,6 +30,7 @@
 #include "block/blockjob_int.h"
 #include "block/block_int.h"
 #include "block/coroutines.h"
+#include "block/write-threshold.h"
 #include "qemu/cutils.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
@@ -2008,8 +2009,8 @@ bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, int64_t bytes,
         } else {
             assert(child->perm & BLK_PERM_WRITE);
         }
-        return notifier_with_return_list_notify(&bs->before_write_notifiers,
-                                                req);
+        bdrv_write_threshold_check_write(bs, offset, bytes);
+        return 0;
     case BDRV_TRACKED_TRUNCATE:
         assert(child->perm & BLK_PERM_RESIZE);
         return 0;
diff --git a/block/write-threshold.c b/block/write-threshold.c
index 85b78dc2a9..71df3c434f 100644
--- a/block/write-threshold.c
+++ b/block/write-threshold.c
@@ -29,14 +29,6 @@ bool bdrv_write_threshold_is_set(const BlockDriverState *bs)
     return bs->write_threshold_offset > 0;
 }
 
-static void write_threshold_disable(BlockDriverState *bs)
-{
-    if (bdrv_write_threshold_is_set(bs)) {
-        notifier_with_return_remove(&bs->write_threshold_notifier);
-        bs->write_threshold_offset = 0;
-    }
-}
-
 uint64_t bdrv_write_threshold_exceeded(const BlockDriverState *bs,
                                        const BdrvTrackedRequest *req)
 {
@@ -51,55 +43,9 @@ uint64_t bdrv_write_threshold_exceeded(const BlockDriverState *bs,
     return 0;
 }
 
-static int coroutine_fn before_write_notify(NotifierWithReturn *notifier,
-                                            void *opaque)
-{
-    BdrvTrackedRequest *req = opaque;
-    BlockDriverState *bs = req->bs;
-    uint64_t amount = 0;
-
-    amount = bdrv_write_threshold_exceeded(bs, req);
-    if (amount > 0) {
-        qapi_event_send_block_write_threshold(
-            bs->node_name,
-            amount,
-            bs->write_threshold_offset);
-
-        /* autodisable to avoid flooding the monitor */
-        write_threshold_disable(bs);
-    }
-
-    return 0; /* should always let other notifiers run */
-}
-
-static void write_threshold_register_notifier(BlockDriverState *bs)
-{
-    bs->write_threshold_notifier.notify = before_write_notify;
-    bdrv_add_before_write_notifier(bs, &bs->write_threshold_notifier);
-}
-
-static void write_threshold_update(BlockDriverState *bs,
-                                   int64_t threshold_bytes)
-{
-    bs->write_threshold_offset = threshold_bytes;
-}
-
 void bdrv_write_threshold_set(BlockDriverState *bs, uint64_t threshold_bytes)
 {
-    if (bdrv_write_threshold_is_set(bs)) {
-        if (threshold_bytes > 0) {
-            write_threshold_update(bs, threshold_bytes);
-        } else {
-            write_threshold_disable(bs);
-        }
-    } else {
-        if (threshold_bytes > 0) {
-            /* avoid multiple registration */
-            write_threshold_register_notifier(bs);
-            write_threshold_update(bs, threshold_bytes);
-        }
-        /* discard bogus disable request */
-    }
+    bs->write_threshold_offset = threshold_bytes;
 }
 
 void qmp_block_set_write_threshold(const char *node_name,
@@ -122,3 +68,17 @@ void qmp_block_set_write_threshold(const char *node_name,
 
     aio_context_release(aio_context);
 }
+
+void bdrv_write_threshold_check_write(BlockDriverState *bs, int64_t offset,
+                                      int64_t bytes)
+{
+    int64_t end = offset + bytes;
+    uint64_t wtr = bs->write_threshold_offset;
+
+    if (wtr > 0 && end > wtr) {
+        qapi_event_send_block_write_threshold(bs->node_name, end - wtr, wtr);
+
+        /* autodisable to avoid flooding the monitor */
+        bdrv_write_threshold_set(bs, 0);
+    }
+}
-- 
2.31.1

[PULL 14/19] block: drop write notifiers

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

They are unused now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-3-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 include/block/block_int.h | 12 ------------
 block.c                   |  1 -
 block/io.c                |  6 ------
 3 files changed, 19 deletions(-)

diff --git a/include/block/block_int.h b/include/block/block_int.h
index aff948fb63..b2c8b09d0f 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -954,9 +954,6 @@ struct BlockDriverState {
      */
     int64_t total_sectors;
 
-    /* Callback before write request is processed */
-    NotifierWithReturnList before_write_notifiers;
-
     /* threshold limit for writes, in bytes. "High water mark". */
     uint64_t write_threshold_offset;
 
@@ -1083,15 +1080,6 @@ void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
 bool bdrv_backing_overridden(BlockDriverState *bs);
 
 
-/**
- * bdrv_add_before_write_notifier:
- *
- * Register a callback that is invoked before write requests are processed but
- * after any throttling or waiting for overlapping requests.
- */
-void bdrv_add_before_write_notifier(BlockDriverState *bs,
-                                    NotifierWithReturn *notifier);
-
 /**
  * bdrv_add_aio_context_notifier:
  *
diff --git a/block.c b/block.c
index 9ad725d205..75a82af641 100644
--- a/block.c
+++ b/block.c
@@ -400,7 +400,6 @@ BlockDriverState *bdrv_new(void)
     for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
         QLIST_INIT(&bs->op_blockers[i]);
     }
-    notifier_with_return_list_init(&bs->before_write_notifiers);
     qemu_co_mutex_init(&bs->reqs_lock);
     qemu_mutex_init(&bs->dirty_bitmap_mutex);
     bs->refcnt = 1;
diff --git a/block/io.c b/block/io.c
index 3520de51bb..1e826ba9e8 100644
--- a/block/io.c
+++ b/block/io.c
@@ -3165,12 +3165,6 @@ bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
     return true;
 }
 
-void bdrv_add_before_write_notifier(BlockDriverState *bs,
-                                    NotifierWithReturn *notifier)
-{
-    notifier_with_return_list_add(&bs->before_write_notifiers, notifier);
-}
-
 void bdrv_io_plug(BlockDriverState *bs)
 {
     BdrvChild *child;
-- 
2.31.1

[PULL 15/19] test-write-threshold: rewrite test_threshold_(not_)trigger tests

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

These tests use bdrv_write_threshold_exceeded() API, which is used only
for test (since pre-previous commit). Better is testing real API, which
is used in block.c as well.

So, let's call bdrv_write_threshold_check_write(), and check is
bs->write_threshold_offset cleared or not (it's cleared iff threshold
triggered).

Also we get rid of BdrvTrackedRequest use here. Note, that paranoiac
bdrv_check_request() calls were added in 8b1170012b1 to protect
BdrvTrackedRequest. Drop them now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-4-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/unit/test-write-threshold.c | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/tests/unit/test-write-threshold.c b/tests/unit/test-write-threshold.c
index fc1c45a2eb..fd40a815b8 100644
--- a/tests/unit/test-write-threshold.c
+++ b/tests/unit/test-write-threshold.c
@@ -55,41 +55,27 @@ static void test_threshold_multi_set_get(void)
 
 static void test_threshold_not_trigger(void)
 {
-    uint64_t amount = 0;
     uint64_t threshold = 4 * 1024 * 1024;
     BlockDriverState bs;
-    BdrvTrackedRequest req;
 
     memset(&bs, 0, sizeof(bs));
-    memset(&req, 0, sizeof(req));
-    req.offset = 1024;
-    req.bytes = 1024;
-
-    bdrv_check_request(req.offset, req.bytes, &error_abort);
 
     bdrv_write_threshold_set(&bs, threshold);
-    amount = bdrv_write_threshold_exceeded(&bs, &req);
-    g_assert_cmpuint(amount, ==, 0);
+    bdrv_write_threshold_check_write(&bs, 1024, 1024);
+    g_assert_cmpuint(bdrv_write_threshold_get(&bs), ==, threshold);
 }
 
 
 static void test_threshold_trigger(void)
 {
-    uint64_t amount = 0;
     uint64_t threshold = 4 * 1024 * 1024;
     BlockDriverState bs;
-    BdrvTrackedRequest req;
 
     memset(&bs, 0, sizeof(bs));
-    memset(&req, 0, sizeof(req));
-    req.offset = (4 * 1024 * 1024) - 1024;
-    req.bytes = 2 * 1024;
-
-    bdrv_check_request(req.offset, req.bytes, &error_abort);
 
     bdrv_write_threshold_set(&bs, threshold);
-    amount = bdrv_write_threshold_exceeded(&bs, &req);
-    g_assert_cmpuint(amount, >=, 1024);
+    bdrv_write_threshold_check_write(&bs, threshold - 1024, 2 * 1024);
+    g_assert_cmpuint(bdrv_write_threshold_get(&bs), ==, 0);
 }
 
 typedef struct TestStruct {
-- 
2.31.1

[PULL 16/19] block/write-threshold: drop extra APIs

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

bdrv_write_threshold_exceeded() is unused.

bdrv_write_threshold_is_set() is used only to double check the value of
bs->write_threshold_offset in tests. No real sense in it (both tests do
check real value with help of bdrv_write_threshold_get())

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-5-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[mreitz: Adjusted commit message as per Eric's suggestion]
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 include/block/write-threshold.h   | 24 ------------------------
 block/write-threshold.c           | 19 -------------------
 tests/unit/test-write-threshold.c |  4 ----
 3 files changed, 47 deletions(-)

diff --git a/include/block/write-threshold.h b/include/block/write-threshold.h
index 848a5dde85..a03ee1cacd 100644
--- a/include/block/write-threshold.h
+++ b/include/block/write-threshold.h
@@ -35,30 +35,6 @@ void bdrv_write_threshold_set(BlockDriverState *bs, uint64_t threshold_bytes);
  */
 uint64_t bdrv_write_threshold_get(const BlockDriverState *bs);
 
-/*
- * bdrv_write_threshold_is_set
- *
- * Tell if a write threshold is set for a given BDS.
- */
-bool bdrv_write_threshold_is_set(const BlockDriverState *bs);
-
-/*
- * bdrv_write_threshold_exceeded
- *
- * Return the extent of a write request that exceeded the threshold,
- * or zero if the request is below the threshold.
- * Return zero also if the threshold was not set.
- *
- * NOTE: here we assume the following holds for each request this code
- * deals with:
- *
- * assert((req->offset + req->bytes) <= UINT64_MAX)
- *
- * Please not there is *not* an actual C assert().
- */
-uint64_t bdrv_write_threshold_exceeded(const BlockDriverState *bs,
-                                       const BdrvTrackedRequest *req);
-
 /*
  * bdrv_write_threshold_check_write
  *
diff --git a/block/write-threshold.c b/block/write-threshold.c
index 71df3c434f..65a6acd142 100644
--- a/block/write-threshold.c
+++ b/block/write-threshold.c
@@ -24,25 +24,6 @@ uint64_t bdrv_write_threshold_get(const BlockDriverState *bs)
     return bs->write_threshold_offset;
 }
 
-bool bdrv_write_threshold_is_set(const BlockDriverState *bs)
-{
-    return bs->write_threshold_offset > 0;
-}
-
-uint64_t bdrv_write_threshold_exceeded(const BlockDriverState *bs,
-                                       const BdrvTrackedRequest *req)
-{
-    if (bdrv_write_threshold_is_set(bs)) {
-        if (req->offset > bs->write_threshold_offset) {
-            return (req->offset - bs->write_threshold_offset) + req->bytes;
-        }
-        if ((req->offset + req->bytes) > bs->write_threshold_offset) {
-            return (req->offset + req->bytes) - bs->write_threshold_offset;
-        }
-    }
-    return 0;
-}
-
 void bdrv_write_threshold_set(BlockDriverState *bs, uint64_t threshold_bytes)
 {
     bs->write_threshold_offset = threshold_bytes;
diff --git a/tests/unit/test-write-threshold.c b/tests/unit/test-write-threshold.c
index fd40a815b8..bb5c1a5217 100644
--- a/tests/unit/test-write-threshold.c
+++ b/tests/unit/test-write-threshold.c
@@ -18,8 +18,6 @@ static void test_threshold_not_set_on_init(void)
     BlockDriverState bs;
     memset(&bs, 0, sizeof(bs));
 
-    g_assert(!bdrv_write_threshold_is_set(&bs));
-
     res = bdrv_write_threshold_get(&bs);
     g_assert_cmpint(res, ==, 0);
 }
@@ -33,8 +31,6 @@ static void test_threshold_set_get(void)
 
     bdrv_write_threshold_set(&bs, threshold);
 
-    g_assert(bdrv_write_threshold_is_set(&bs));
-
     res = bdrv_write_threshold_get(&bs);
     g_assert_cmpint(res, ==, threshold);
 }
-- 
2.31.1

[PULL 17/19] test-write-threshold: drop extra tests

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Testing set/get of one 64bit variable doesn't seem necessary. We have a
lot of such variables. Also remaining tests do test set/get anyway.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-7-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/unit/test-write-threshold.c | 43 -------------------------------
 1 file changed, 43 deletions(-)

diff --git a/tests/unit/test-write-threshold.c b/tests/unit/test-write-threshold.c
index bb5c1a5217..9e9986aefc 100644
--- a/tests/unit/test-write-threshold.c
+++ b/tests/unit/test-write-threshold.c
@@ -12,43 +12,6 @@
 #include "block/write-threshold.h"
 
 
-static void test_threshold_not_set_on_init(void)
-{
-    uint64_t res;
-    BlockDriverState bs;
-    memset(&bs, 0, sizeof(bs));
-
-    res = bdrv_write_threshold_get(&bs);
-    g_assert_cmpint(res, ==, 0);
-}
-
-static void test_threshold_set_get(void)
-{
-    uint64_t threshold = 4 * 1024 * 1024;
-    uint64_t res;
-    BlockDriverState bs;
-    memset(&bs, 0, sizeof(bs));
-
-    bdrv_write_threshold_set(&bs, threshold);
-
-    res = bdrv_write_threshold_get(&bs);
-    g_assert_cmpint(res, ==, threshold);
-}
-
-static void test_threshold_multi_set_get(void)
-{
-    uint64_t threshold1 = 4 * 1024 * 1024;
-    uint64_t threshold2 = 15 * 1024 * 1024;
-    uint64_t res;
-    BlockDriverState bs;
-    memset(&bs, 0, sizeof(bs));
-
-    bdrv_write_threshold_set(&bs, threshold1);
-    bdrv_write_threshold_set(&bs, threshold2);
-    res = bdrv_write_threshold_get(&bs);
-    g_assert_cmpint(res, ==, threshold2);
-}
-
 static void test_threshold_not_trigger(void)
 {
     uint64_t threshold = 4 * 1024 * 1024;
@@ -84,12 +47,6 @@ int main(int argc, char **argv)
 {
     size_t i;
     TestStruct tests[] = {
-        { "/write-threshold/not-set-on-init",
-          test_threshold_not_set_on_init },
-        { "/write-threshold/set-get",
-          test_threshold_set_get },
-        { "/write-threshold/multi-set-get",
-          test_threshold_multi_set_get },
         { "/write-threshold/not-trigger",
           test_threshold_not_trigger },
         { "/write-threshold/trigger",
-- 
2.31.1

[PULL 18/19] test-write-threshold: drop extra TestStruct structure

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

We don't need this extra logic: it doesn't make code simpler.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210506090621.11848-8-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/unit/test-write-threshold.c | 20 +++-----------------
 1 file changed, 3 insertions(+), 17 deletions(-)

diff --git a/tests/unit/test-write-threshold.c b/tests/unit/test-write-threshold.c
index 9e9986aefc..49b1ef7a20 100644
--- a/tests/unit/test-write-threshold.c
+++ b/tests/unit/test-write-threshold.c
@@ -37,26 +37,12 @@ static void test_threshold_trigger(void)
     g_assert_cmpuint(bdrv_write_threshold_get(&bs), ==, 0);
 }
 
-typedef struct TestStruct {
-    const char *name;
-    void (*func)(void);
-} TestStruct;
-
 
 int main(int argc, char **argv)
 {
-    size_t i;
-    TestStruct tests[] = {
-        { "/write-threshold/not-trigger",
-          test_threshold_not_trigger },
-        { "/write-threshold/trigger",
-          test_threshold_trigger },
-        { NULL, NULL }
-    };
-
     g_test_init(&argc, &argv, NULL);
-    for (i = 0; tests[i].name != NULL; i++) {
-        g_test_add_func(tests[i].name, tests[i].func);
-    }
+    g_test_add_func("/write-threshold/not-trigger", test_threshold_not_trigger);
+    g_test_add_func("/write-threshold/trigger", test_threshold_trigger);
+
     return g_test_run();
 }
-- 
2.31.1

[PULL 19/19] write-threshold: deal with includes

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

"qemu/typedefs.h" is enough for include/block/write-threshold.h header
with forward declaration of BlockDriverState. Also drop extra includes
from block/write-threshold.c and tests/unit/test-write-threshold.c

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210506090621.11848-9-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 include/block/write-threshold.h   | 2 +-
 block/write-threshold.c           | 2 --
 tests/unit/test-write-threshold.c | 1 -
 3 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/include/block/write-threshold.h b/include/block/write-threshold.h
index a03ee1cacd..f50f923e7e 100644
--- a/include/block/write-threshold.h
+++ b/include/block/write-threshold.h
@@ -13,7 +13,7 @@
 #ifndef BLOCK_WRITE_THRESHOLD_H
 #define BLOCK_WRITE_THRESHOLD_H
 
-#include "block/block_int.h"
+#include "qemu/typedefs.h"
 
 /*
  * bdrv_write_threshold_set:
diff --git a/block/write-threshold.c b/block/write-threshold.c
index 65a6acd142..35cafbc22d 100644
--- a/block/write-threshold.c
+++ b/block/write-threshold.c
@@ -12,9 +12,7 @@
 
 #include "qemu/osdep.h"
 #include "block/block_int.h"
-#include "qemu/coroutine.h"
 #include "block/write-threshold.h"
-#include "qemu/notify.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-block-core.h"
 #include "qapi/qapi-events-block-core.h"
diff --git a/tests/unit/test-write-threshold.c b/tests/unit/test-write-threshold.c
index 49b1ef7a20..0158e4637a 100644
--- a/tests/unit/test-write-threshold.c
+++ b/tests/unit/test-write-threshold.c
@@ -7,7 +7,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qapi/error.h"
 #include "block/block_int.h"
 #include "block/write-threshold.h"
 
-- 
2.31.1

Re: [PULL 00/19] Block patches

[Peter Maydell]

On Fri, 14 May 2021 at 17:45, Max Reitz <mreitz@redhat.com> wrote:
>
> The following changes since commit 96662996eda78c48aadddd4e76d8615c7eb72d80:
>
>   Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20210513a' into staging (2021-05-14 12:03:47 +0100)
>
> are available in the Git repository at:
>
>   https://github.com/XanClic/qemu.git tags/pull-block-2021-05-14
>
> for you to fetch changes up to c61ebf362d0abf288ce266845519d5a550a1d89f:
>
>   write-threshold: deal with includes (2021-05-14 16:14:10 +0200)
>
> ----------------------------------------------------------------
> Block patches:
> - drop block/io write notifiers
> - qemu-iotests enhancements to make debugging easier
> - rbd parsing fix
> - HMP qemu-io fix (for iothreads)
> - mirror job cancel relaxation (do not cancel in-flight requests when a
>   READY mirror job is canceled with force=false)
> - document qcow2's data_file and data_file_raw features
> - fix iotest 297 for pylint 2.8
> - block/copy-on-read refactoring
>
> ----------------------------------------------------------------


Applied, thanks.

Please update the changelog at https://wiki.qemu.org/ChangeLog/6.1
for any user-visible changes.

-- PMM

Re: [PULL 03/19] monitor: hmp_qemu_io: acquire aio contex, fix crash

[Peter Maydell]

On Fri, 14 May 2021 at 17:45, Max Reitz <mreitz@redhat.com> wrote:
>
> From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Hi; Coverity complains about this code (CID 1453194):

> diff --git a/qemu-io.c b/qemu-io.c
> index bf902302e9..57f07501df 100644
> --- a/qemu-io.c
> +++ b/qemu-io.c
> @@ -411,6 +411,19 @@ static void prep_fetchline(void *opaque)
>      *fetchable= 1;
>  }
>
> +static int do_qemuio_command(const char *cmd)
> +{
> +    int ret;
> +    AioContext *ctx =
> +        qemuio_blk ? blk_get_aio_context(qemuio_blk) : qemu_get_aio_context();

Here we check whether qemuio_blk is NULL...

> +
> +    aio_context_acquire(ctx);
> +    ret = qemuio_command(qemuio_blk, cmd);

...but here we pass it to qemuio_command(), which assumes it must
be non-NULL (via calling command() which calls blk_is_available()).

Bug, or false positive ?

thanks
-- PMM

Re: [PULL 03/19] monitor: hmp_qemu_io: acquire aio contex, fix crash

[Max Reitz]

On 20.05.21 15:44, Peter Maydell wrote:
> On Fri, 14 May 2021 at 17:45, Max Reitz <mreitz@redhat.com> wrote:
>>
>> From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> 
> Hi; Coverity complains about this code (CID 1453194):
> 
>> diff --git a/qemu-io.c b/qemu-io.c
>> index bf902302e9..57f07501df 100644
>> --- a/qemu-io.c
>> +++ b/qemu-io.c
>> @@ -411,6 +411,19 @@ static void prep_fetchline(void *opaque)
>>       *fetchable= 1;
>>   }
>>
>> +static int do_qemuio_command(const char *cmd)
>> +{
>> +    int ret;
>> +    AioContext *ctx =
>> +        qemuio_blk ? blk_get_aio_context(qemuio_blk) : qemu_get_aio_context();
> 
> Here we check whether qemuio_blk is NULL...
> 
>> +
>> +    aio_context_acquire(ctx);
>> +    ret = qemuio_command(qemuio_blk, cmd);
> 
> ...but here we pass it to qemuio_command(), which assumes it must
> be non-NULL (via calling command() which calls blk_is_available()).
> 
> Bug, or false positive ?

It’s a false positive, Vladimir has sent a patch to silence Coverity:

https://lists.nongnu.org/archive/html/qemu-block/2021-05/msg00853.html

Max