[Qemu-devel] [PULL 00/20] NBD patches through 2019-01-14

[Qemu-devel] [PULL 00/20] NBD patches through 2019-01-14

[Eric Blake]

The following changes since commit 7260438b7056469610ee166f7abe9ff8a26b8b16:

  Merge remote-tracking branch 'remotes/palmer/tags/riscv-for-master-3.2-part2' into staging (2019-01-14 11:41:43 +0000)

are available in the Git repository at:

  https://repo.or.cz/qemu/ericb.git tags/pull-nbd-2019-01-14

for you to fetch changes up to 636192c4b6052820ea126a5287c58a8f53f3c84f:

  qemu-nbd: Add --bitmap=NAME option (2019-01-14 10:09:46 -0600)

----------------------------------------------------------------
nbd patches for 2019-01-14

Promote bitmap/NBD interfaces to stable for use in incremental
backups. Add 'qemu-nbd --bitmap'.

- John Snow: 0/11 bitmaps: remove x- prefix from QMP api
- Philippe Mathieu-Daudé: qemu-nbd: Rename 'exp' variable clashing with math::exp() symbol
- Eric Blake: 0/8 Promote x-nbd-server-add-bitmap to stable

----------------------------------------------------------------
Eric Blake (8):
      nbd: Add some error case testing to iotests 223
      nbd: Forbid nbd-server-stop when server is not running
      nbd: Only require disabled bitmap for read-only exports
      nbd: Merge nbd_export_set_name into nbd_export_new
      nbd: Allow bitmap export during QMP nbd-server-add
      nbd: Remove x-nbd-server-add-bitmap
      nbd: Merge nbd_export_bitmap into nbd_export_new
      qemu-nbd: Add --bitmap=NAME option

John Snow (11):
      blockdev: abort transactions in reverse order
      block/dirty-bitmap: remove assertion from restore
      blockdev: n-ary bitmap merge
      block: remove 'x' prefix from experimental bitmap APIs
      iotests.py: don't abort if IMGKEYSECRET is undefined
      iotests: add filter_generated_node_ids
      iotests: add qmp recursive sorting function
      iotests: remove default filters from qmp_log
      iotests: change qmp_log filters to expect QMP objects only
      iotests: implement pretty-print for log and qmp_log
      iotests: add iotest 236 for testing bitmap merge

Philippe Mathieu-Daudé (1):
      qemu-nbd: Rename 'exp' variable clashing with math::exp() symbol

 qemu-nbd.texi                 |   4 +
 qapi/block-core.json          |  56 +++----
 qapi/block.json               |  30 +---
 qapi/transaction.json         |  12 +-
 include/block/nbd.h           |  12 +-
 block/dirty-bitmap.c          |   1 -
 blockdev-nbd.c                |  36 ++---
 blockdev.c                    | 107 ++++++++-----
 hmp.c                         |   5 +-
 nbd/server.c                  | 136 ++++++++--------
 qemu-nbd.c                    |  26 ++--
 tests/qemu-iotests/206        |   8 +-
 tests/qemu-iotests/223        |  52 +++++--
 tests/qemu-iotests/223.out    |  23 ++-
 tests/qemu-iotests/236        | 161 +++++++++++++++++++
 tests/qemu-iotests/236.out    | 351 ++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/group      |   1 +
 tests/qemu-iotests/iotests.py |  64 ++++++--
 18 files changed, 841 insertions(+), 244 deletions(-)
 create mode 100755 tests/qemu-iotests/236
 create mode 100644 tests/qemu-iotests/236.out

-- 
2.20.1

[Qemu-devel] [PULL 01/20] blockdev: abort transactions in reverse order

[Eric Blake]

From: John Snow <jsnow@redhat.com>

Presently, we abort transactions in the same order they were processed in.
Bitmap commands, though, attempt to restore backup data structures on abort.

That's not valid, they need to be aborted in reverse chronological order.

Replace the QSIMPLEQ data structure with a QTAILQ one, so we can iterate
in reverse for the abort phase of the transaction.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-2-jsnow@redhat.com>
[eblake: rebase]
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 blockdev.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 1cc893fe617..3d46f8191f5 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1339,7 +1339,7 @@ struct BlkActionState {
     const BlkActionOps *ops;
     JobTxn *block_job_txn;
     TransactionProperties *txn_props;
-    QSIMPLEQ_ENTRY(BlkActionState) entry;
+    QTAILQ_ENTRY(BlkActionState) entry;
 };

 /* internal snapshot private data */
@@ -2266,8 +2266,8 @@ void qmp_transaction(TransactionActionList *dev_list,
     BlkActionState *state, *next;
     Error *local_err = NULL;

-    QSIMPLEQ_HEAD(, BlkActionState) snap_bdrv_states;
-    QSIMPLEQ_INIT(&snap_bdrv_states);
+    QTAILQ_HEAD(, BlkActionState) snap_bdrv_states;
+    QTAILQ_INIT(&snap_bdrv_states);

     /* Does this transaction get canceled as a group on failure?
      * If not, we don't really need to make a JobTxn.
@@ -2298,7 +2298,7 @@ void qmp_transaction(TransactionActionList *dev_list,
         state->action = dev_info;
         state->block_job_txn = block_job_txn;
         state->txn_props = props;
-        QSIMPLEQ_INSERT_TAIL(&snap_bdrv_states, state, entry);
+        QTAILQ_INSERT_TAIL(&snap_bdrv_states, state, entry);

         state->ops->prepare(state, &local_err);
         if (local_err) {
@@ -2307,7 +2307,7 @@ void qmp_transaction(TransactionActionList *dev_list,
         }
     }

-    QSIMPLEQ_FOREACH(state, &snap_bdrv_states, entry) {
+    QTAILQ_FOREACH(state, &snap_bdrv_states, entry) {
         if (state->ops->commit) {
             state->ops->commit(state);
         }
@@ -2318,13 +2318,13 @@ void qmp_transaction(TransactionActionList *dev_list,

 delete_and_fail:
     /* failure, and it is all-or-none; roll back all operations */
-    QSIMPLEQ_FOREACH(state, &snap_bdrv_states, entry) {
+    QTAILQ_FOREACH_REVERSE(state, &snap_bdrv_states, entry) {
         if (state->ops->abort) {
             state->ops->abort(state);
         }
     }
 exit:
-    QSIMPLEQ_FOREACH_SAFE(state, &snap_bdrv_states, entry, next) {
+    QTAILQ_FOREACH_SAFE(state, &snap_bdrv_states, entry, next) {
         if (state->ops->clean) {
             state->ops->clean(state);
         }
-- 
2.20.1

[Qemu-devel] [PULL 02/20] block/dirty-bitmap: remove assertion from restore

[Eric Blake]

From: John Snow <jsnow@redhat.com>

When making a backup of a dirty bitmap (for transactions), we want to
restore that backup whether or not the bitmap is enabled.

It is perfectly valid to write into bitmaps that are disabled. It is
only illegitimate for the guest to have done so.

Remove this assertion.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20181221093529.23855-3-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 block/dirty-bitmap.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 89fd1d7f8ba..6b688394e4e 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -625,7 +625,6 @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
 void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup)
 {
     HBitmap *tmp = bitmap->bitmap;
-    assert(bdrv_dirty_bitmap_enabled(bitmap));
     assert(!bdrv_dirty_bitmap_readonly(bitmap));
     bitmap->bitmap = backup;
     hbitmap_free(tmp);
-- 
2.20.1

[Qemu-devel] [PULL 03/20] blockdev: n-ary bitmap merge

[Eric Blake]

From: John Snow <jsnow@redhat.com>

Especially outside of transactions, it is helpful to provide
all-or-nothing semantics for bitmap merges. This facilitates
the coalescing of multiple bitmaps into a single target for
the "checkpoint" interpretation when assembling bitmaps that
represent arbitrary points in time from component bitmaps.

This is an incompatible change from the preliminary version
of the API.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-4-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 qapi/block-core.json | 22 ++++++-------
 blockdev.c           | 75 ++++++++++++++++++++++++++++++--------------
 2 files changed, 62 insertions(+), 35 deletions(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index 762000f31f0..a153ea44203 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1821,14 +1821,14 @@
 #
 # @node: name of device/node which the bitmap is tracking
 #
-# @dst_name: name of the destination dirty bitmap
+# @target: name of the destination dirty bitmap
 #
-# @src_name: name of the source dirty bitmap
+# @bitmaps: name(s) of the source dirty bitmap(s)
 #
 # Since: 3.0
 ##
 { 'struct': 'BlockDirtyBitmapMerge',
-  'data': { 'node': 'str', 'dst_name': 'str', 'src_name': 'str' } }
+  'data': { 'node': 'str', 'target': 'str', 'bitmaps': ['str'] } }

 ##
 # @block-dirty-bitmap-add:
@@ -1943,23 +1943,23 @@
 ##
 # @x-block-dirty-bitmap-merge:
 #
-# FIXME: Rename @src_name and @dst_name to src-name and dst-name.
-#
-# Merge @src_name dirty bitmap to @dst_name dirty bitmap. @src_name dirty
-# bitmap is unchanged. On error, @dst_name is unchanged.
+# Merge dirty bitmaps listed in @bitmaps to the @target dirty bitmap.
+# The @bitmaps dirty bitmaps are unchanged.
+# On error, @target is unchanged.
 #
 # Returns: nothing on success
 #          If @node is not a valid block device, DeviceNotFound
-#          If @dst_name or @src_name is not found, GenericError
-#          If bitmaps has different sizes or granularities, GenericError
+#          If any bitmap in @bitmaps or @target is not found, GenericError
+#          If any of the bitmaps have different sizes or granularities,
+#              GenericError
 #
 # Since: 3.0
 #
 # Example:
 #
 # -> { "execute": "x-block-dirty-bitmap-merge",
-#      "arguments": { "node": "drive0", "dst_name": "bitmap0",
-#                     "src_name": "bitmap1" } }
+#      "arguments": { "node": "drive0", "target": "bitmap0",
+#                     "bitmaps": ["bitmap1"] } }
 # <- { "return": {} }
 #
 ##
diff --git a/blockdev.c b/blockdev.c
index 3d46f8191f5..f7bf48dfe71 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2119,33 +2119,28 @@ static void block_dirty_bitmap_disable_abort(BlkActionState *common)
     }
 }

+static BdrvDirtyBitmap *do_block_dirty_bitmap_merge(const char *node,
+                                                    const char *target,
+                                                    strList *bitmaps,
+                                                    HBitmap **backup,
+                                                    Error **errp);
+
 static void block_dirty_bitmap_merge_prepare(BlkActionState *common,
                                              Error **errp)
 {
     BlockDirtyBitmapMerge *action;
     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
                                              common, common);
-    BdrvDirtyBitmap *merge_source;

     if (action_check_completion_mode(common, errp) < 0) {
         return;
     }

     action = common->action->u.x_block_dirty_bitmap_merge.data;
-    state->bitmap = block_dirty_bitmap_lookup(action->node,
-                                              action->dst_name,
-                                              &state->bs,
-                                              errp);
-    if (!state->bitmap) {
-        return;
-    }

-    merge_source = bdrv_find_dirty_bitmap(state->bs, action->src_name);
-    if (!merge_source) {
-        return;
-    }
-
-    bdrv_merge_dirty_bitmap(state->bitmap, merge_source, &state->backup, errp);
+    state->bitmap = do_block_dirty_bitmap_merge(action->node, action->target,
+                                                action->bitmaps, &state->backup,
+                                                errp);
 }

 static void abort_prepare(BlkActionState *common, Error **errp)
@@ -2977,24 +2972,56 @@ void qmp_x_block_dirty_bitmap_disable(const char *node, const char *name,
     bdrv_disable_dirty_bitmap(bitmap);
 }

-void qmp_x_block_dirty_bitmap_merge(const char *node, const char *dst_name,
-                                    const char *src_name, Error **errp)
+static BdrvDirtyBitmap *do_block_dirty_bitmap_merge(const char *node,
+                                                    const char *target,
+                                                    strList *bitmaps,
+                                                    HBitmap **backup,
+                                                    Error **errp)
 {
     BlockDriverState *bs;
-    BdrvDirtyBitmap *dst, *src;
+    BdrvDirtyBitmap *dst, *src, *anon;
+    strList *lst;
+    Error *local_err = NULL;

-    dst = block_dirty_bitmap_lookup(node, dst_name, &bs, errp);
+    dst = block_dirty_bitmap_lookup(node, target, &bs, errp);
     if (!dst) {
-        return;
+        return NULL;
     }

-    src = bdrv_find_dirty_bitmap(bs, src_name);
-    if (!src) {
-        error_setg(errp, "Dirty bitmap '%s' not found", src_name);
-        return;
+    anon = bdrv_create_dirty_bitmap(bs, bdrv_dirty_bitmap_granularity(dst),
+                                    NULL, errp);
+    if (!anon) {
+        return NULL;
     }

-    bdrv_merge_dirty_bitmap(dst, src, NULL, errp);
+    for (lst = bitmaps; lst; lst = lst->next) {
+        src = bdrv_find_dirty_bitmap(bs, lst->value);
+        if (!src) {
+            error_setg(errp, "Dirty bitmap '%s' not found", lst->value);
+            dst = NULL;
+            goto out;
+        }
+
+        bdrv_merge_dirty_bitmap(anon, src, NULL, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            dst = NULL;
+            goto out;
+        }
+    }
+
+    /* Merge into dst; dst is unchanged on failure. */
+    bdrv_merge_dirty_bitmap(dst, anon, backup, errp);
+
+ out:
+    bdrv_release_dirty_bitmap(bs, anon);
+    return dst;
+}
+
+void qmp_x_block_dirty_bitmap_merge(const char *node, const char *target,
+                                    strList *bitmaps, Error **errp)
+{
+    do_block_dirty_bitmap_merge(node, target, bitmaps, NULL, errp);
 }

 BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char *node,
-- 
2.20.1

[Qemu-devel] [PULL 04/20] block: remove 'x' prefix from experimental bitmap APIs

[Eric Blake]

From: John Snow <jsnow@redhat.com>

The 'x' prefix was added because I was uncertain of the direction we'd
take for the libvirt API. With the general approach solidified, I feel
comfortable committing to this API for 4.0.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-5-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 qapi/block-core.json   | 34 +++++++++++++++++-----------------
 qapi/transaction.json  | 12 ++++++------
 blockdev.c             | 22 +++++++++++-----------
 tests/qemu-iotests/223 |  4 ++--
 4 files changed, 36 insertions(+), 36 deletions(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index a153ea44203..91685be6c29 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1806,15 +1806,15 @@
 #            Currently, all dirty tracking bitmaps are loaded from Qcow2 on
 #            open.
 #
-# @x-disabled: the bitmap is created in the disabled state, which means that
-#              it will not track drive changes. The bitmap may be enabled with
-#              x-block-dirty-bitmap-enable. Default is false. (Since: 3.0)
+# @disabled: the bitmap is created in the disabled state, which means that
+#            it will not track drive changes. The bitmap may be enabled with
+#            block-dirty-bitmap-enable. Default is false. (Since: 4.0)
 #
 # Since: 2.4
 ##
 { 'struct': 'BlockDirtyBitmapAdd',
   'data': { 'node': 'str', 'name': 'str', '*granularity': 'uint32',
-            '*persistent': 'bool', '*autoload': 'bool', '*x-disabled': 'bool' } }
+            '*persistent': 'bool', '*autoload': 'bool', '*disabled': 'bool' } }

 ##
 # @BlockDirtyBitmapMerge:
@@ -1825,7 +1825,7 @@
 #
 # @bitmaps: name(s) of the source dirty bitmap(s)
 #
-# Since: 3.0
+# Since: 4.0
 ##
 { 'struct': 'BlockDirtyBitmapMerge',
   'data': { 'node': 'str', 'target': 'str', 'bitmaps': ['str'] } }
@@ -1899,7 +1899,7 @@
   'data': 'BlockDirtyBitmap' }

 ##
-# @x-block-dirty-bitmap-enable:
+# @block-dirty-bitmap-enable:
 #
 # Enables a dirty bitmap so that it will begin tracking disk changes.
 #
@@ -1907,20 +1907,20 @@
 #          If @node is not a valid block device, DeviceNotFound
 #          If @name is not found, GenericError with an explanation
 #
-# Since: 3.0
+# Since: 4.0
 #
 # Example:
 #
-# -> { "execute": "x-block-dirty-bitmap-enable",
+# -> { "execute": "block-dirty-bitmap-enable",
 #      "arguments": { "node": "drive0", "name": "bitmap0" } }
 # <- { "return": {} }
 #
 ##
-  { 'command': 'x-block-dirty-bitmap-enable',
+  { 'command': 'block-dirty-bitmap-enable',
     'data': 'BlockDirtyBitmap' }

 ##
-# @x-block-dirty-bitmap-disable:
+# @block-dirty-bitmap-disable:
 #
 # Disables a dirty bitmap so that it will stop tracking disk changes.
 #
@@ -1928,20 +1928,20 @@
 #          If @node is not a valid block device, DeviceNotFound
 #          If @name is not found, GenericError with an explanation
 #
-# Since: 3.0
+# Since: 4.0
 #
 # Example:
 #
-# -> { "execute": "x-block-dirty-bitmap-disable",
+# -> { "execute": "block-dirty-bitmap-disable",
 #      "arguments": { "node": "drive0", "name": "bitmap0" } }
 # <- { "return": {} }
 #
 ##
-    { 'command': 'x-block-dirty-bitmap-disable',
+    { 'command': 'block-dirty-bitmap-disable',
       'data': 'BlockDirtyBitmap' }

 ##
-# @x-block-dirty-bitmap-merge:
+# @block-dirty-bitmap-merge:
 #
 # Merge dirty bitmaps listed in @bitmaps to the @target dirty bitmap.
 # The @bitmaps dirty bitmaps are unchanged.
@@ -1953,17 +1953,17 @@
 #          If any of the bitmaps have different sizes or granularities,
 #              GenericError
 #
-# Since: 3.0
+# Since: 4.0
 #
 # Example:
 #
-# -> { "execute": "x-block-dirty-bitmap-merge",
+# -> { "execute": "block-dirty-bitmap-merge",
 #      "arguments": { "node": "drive0", "target": "bitmap0",
 #                     "bitmaps": ["bitmap1"] } }
 # <- { "return": {} }
 #
 ##
-      { 'command': 'x-block-dirty-bitmap-merge',
+      { 'command': 'block-dirty-bitmap-merge',
         'data': 'BlockDirtyBitmapMerge' }

 ##
diff --git a/qapi/transaction.json b/qapi/transaction.json
index 5875cdb16c5..95edb782278 100644
--- a/qapi/transaction.json
+++ b/qapi/transaction.json
@@ -46,9 +46,9 @@
 # - @abort: since 1.6
 # - @block-dirty-bitmap-add: since 2.5
 # - @block-dirty-bitmap-clear: since 2.5
-# - @x-block-dirty-bitmap-enable: since 3.0
-# - @x-block-dirty-bitmap-disable: since 3.0
-# - @x-block-dirty-bitmap-merge: since 3.1
+# - @block-dirty-bitmap-enable: since 4.0
+# - @block-dirty-bitmap-disable: since 4.0
+# - @block-dirty-bitmap-merge: since 4.0
 # - @blockdev-backup: since 2.3
 # - @blockdev-snapshot: since 2.5
 # - @blockdev-snapshot-internal-sync: since 1.7
@@ -62,9 +62,9 @@
        'abort': 'Abort',
        'block-dirty-bitmap-add': 'BlockDirtyBitmapAdd',
        'block-dirty-bitmap-clear': 'BlockDirtyBitmap',
-       'x-block-dirty-bitmap-enable': 'BlockDirtyBitmap',
-       'x-block-dirty-bitmap-disable': 'BlockDirtyBitmap',
-       'x-block-dirty-bitmap-merge': 'BlockDirtyBitmapMerge',
+       'block-dirty-bitmap-enable': 'BlockDirtyBitmap',
+       'block-dirty-bitmap-disable': 'BlockDirtyBitmap',
+       'block-dirty-bitmap-merge': 'BlockDirtyBitmapMerge',
        'blockdev-backup': 'BlockdevBackup',
        'blockdev-snapshot': 'BlockdevSnapshot',
        'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal',
diff --git a/blockdev.c b/blockdev.c
index f7bf48dfe71..a8fa8748a9c 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1963,7 +1963,7 @@ static void block_dirty_bitmap_add_prepare(BlkActionState *common,
                                action->has_granularity, action->granularity,
                                action->has_persistent, action->persistent,
                                action->has_autoload, action->autoload,
-                               action->has_x_disabled, action->x_disabled,
+                               action->has_disabled, action->disabled,
                                &local_err);

     if (!local_err) {
@@ -2048,7 +2048,7 @@ static void block_dirty_bitmap_enable_prepare(BlkActionState *common,
         return;
     }

-    action = common->action->u.x_block_dirty_bitmap_enable.data;
+    action = common->action->u.block_dirty_bitmap_enable.data;
     state->bitmap = block_dirty_bitmap_lookup(action->node,
                                               action->name,
                                               NULL,
@@ -2089,7 +2089,7 @@ static void block_dirty_bitmap_disable_prepare(BlkActionState *common,
         return;
     }

-    action = common->action->u.x_block_dirty_bitmap_disable.data;
+    action = common->action->u.block_dirty_bitmap_disable.data;
     state->bitmap = block_dirty_bitmap_lookup(action->node,
                                               action->name,
                                               NULL,
@@ -2136,7 +2136,7 @@ static void block_dirty_bitmap_merge_prepare(BlkActionState *common,
         return;
     }

-    action = common->action->u.x_block_dirty_bitmap_merge.data;
+    action = common->action->u.block_dirty_bitmap_merge.data;

     state->bitmap = do_block_dirty_bitmap_merge(action->node, action->target,
                                                 action->bitmaps, &state->backup,
@@ -2204,17 +2204,17 @@ static const BlkActionOps actions[] = {
         .commit = block_dirty_bitmap_free_backup,
         .abort = block_dirty_bitmap_restore,
     },
-    [TRANSACTION_ACTION_KIND_X_BLOCK_DIRTY_BITMAP_ENABLE] = {
+    [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ENABLE] = {
         .instance_size = sizeof(BlockDirtyBitmapState),
         .prepare = block_dirty_bitmap_enable_prepare,
         .abort = block_dirty_bitmap_enable_abort,
     },
-    [TRANSACTION_ACTION_KIND_X_BLOCK_DIRTY_BITMAP_DISABLE] = {
+    [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_DISABLE] = {
         .instance_size = sizeof(BlockDirtyBitmapState),
         .prepare = block_dirty_bitmap_disable_prepare,
         .abort = block_dirty_bitmap_disable_abort,
     },
-    [TRANSACTION_ACTION_KIND_X_BLOCK_DIRTY_BITMAP_MERGE] = {
+    [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_MERGE] = {
         .instance_size = sizeof(BlockDirtyBitmapState),
         .prepare = block_dirty_bitmap_merge_prepare,
         .commit = block_dirty_bitmap_free_backup,
@@ -2930,7 +2930,7 @@ void qmp_block_dirty_bitmap_clear(const char *node, const char *name,
     bdrv_clear_dirty_bitmap(bitmap, NULL);
 }

-void qmp_x_block_dirty_bitmap_enable(const char *node, const char *name,
+void qmp_block_dirty_bitmap_enable(const char *node, const char *name,
                                    Error **errp)
 {
     BlockDriverState *bs;
@@ -2951,7 +2951,7 @@ void qmp_x_block_dirty_bitmap_enable(const char *node, const char *name,
     bdrv_enable_dirty_bitmap(bitmap);
 }

-void qmp_x_block_dirty_bitmap_disable(const char *node, const char *name,
+void qmp_block_dirty_bitmap_disable(const char *node, const char *name,
                                     Error **errp)
 {
     BlockDriverState *bs;
@@ -3018,8 +3018,8 @@ static BdrvDirtyBitmap *do_block_dirty_bitmap_merge(const char *node,
     return dst;
 }

-void qmp_x_block_dirty_bitmap_merge(const char *node, const char *target,
-                                    strList *bitmaps, Error **errp)
+void qmp_block_dirty_bitmap_merge(const char *node, const char *target,
+                                  strList *bitmaps, Error **errp)
 {
     do_block_dirty_bitmap_merge(node, target, bitmaps, NULL, errp);
 }
diff --git a/tests/qemu-iotests/223 b/tests/qemu-iotests/223
index 397b865d347..5513dc62159 100755
--- a/tests/qemu-iotests/223
+++ b/tests/qemu-iotests/223
@@ -112,9 +112,9 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"qmp_capabilities"}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"blockdev-add",
   "arguments":{"driver":"qcow2", "node-name":"n",
     "file":{"driver":"file", "filename":"'"$TEST_IMG"'"}}}' "return"
-_send_qemu_cmd $QEMU_HANDLE '{"execute":"x-block-dirty-bitmap-disable",
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"block-dirty-bitmap-disable",
   "arguments":{"node":"n", "name":"b"}}' "return"
-_send_qemu_cmd $QEMU_HANDLE '{"execute":"x-block-dirty-bitmap-disable",
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"block-dirty-bitmap-disable",
   "arguments":{"node":"n", "name":"b2"}}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-start",
   "arguments":{"addr":{"type":"unix",
-- 
2.20.1

[Qemu-devel] [PULL 05/20] iotests.py: don't abort if IMGKEYSECRET is undefined

[Eric Blake]

From: John Snow <jsnow@redhat.com>

Instead of using os.environ[], use .get with a default of empty string
to match the setup in check to allow us to import the iotests module
(for debugging, say) without needing a crafted environment just to
import the module.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-6-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/iotests.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index d537538ba02..a34e66813a3 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -63,7 +63,7 @@ socket_scm_helper = os.environ.get('SOCKET_SCM_HELPER', 'socket_scm_helper')
 debug = False

 luks_default_secret_object = 'secret,id=keysec0,data=' + \
-                             os.environ['IMGKEYSECRET']
+                             os.environ.get('IMGKEYSECRET', '')
 luks_default_key_secret_opt = 'key-secret=keysec0'


-- 
2.20.1

[Qemu-devel] [PULL 06/20] iotests: add filter_generated_node_ids

[Eric Blake]

From: John Snow <jsnow@redhat.com>

To mimic the common filter of the same name, but for the python tests.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-7-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/iotests.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index a34e66813a3..9595429fea2 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -239,6 +239,9 @@ def filter_testfiles(msg):
     prefix = os.path.join(test_dir, "%s-" % (os.getpid()))
     return msg.replace(prefix, 'TEST_DIR/PID-')

+def filter_generated_node_ids(msg):
+    return re.sub("#block[0-9]+", "NODE_NAME", msg)
+
 def filter_img_info(output, filename):
     lines = []
     for line in output.split('\n'):
-- 
2.20.1

[Qemu-devel] [PULL 07/20] iotests: add qmp recursive sorting function

[Eric Blake]

From: John Snow <jsnow@redhat.com>

Python before 3.6 does not sort dictionaries (including kwargs).
Therefore, printing QMP objects involves sorting the keys to have
a predictable ordering in the iotests output. This means that
iotests output will sometimes show arguments in an order not
specified by the test author.

Presently, we accomplish this by using json.dumps' sort_keys argument,
where we only serialize the arguments dictionary, but not the command.

However, if we want to pretty-print QMP objects being sent to the
QEMU process, we need to build the entire command before logging it.
Ordinarily, this would then involve "arguments" being sorted above
"execute", which would necessitate a rather ugly and harder-to-read
change to many iotests outputs.

To facilitate pretty-printing AND maintaining predictable output AND
having "arguments" sort after "execute", add a custom sort function
that takes a dictionary and recursively builds an OrderedDict that
maintains the specific key order we wish to see in iotests output.

The qmp_log function uses this to build a QMP object that keeps
"execute" above "arguments", but sorts all keys and keys in any
subdicts in "arguments" lexicographically to maintain consistent
iotests output, with no incompatible changes to any current test.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-8-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/iotests.py | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 9595429fea2..565eebb1ab5 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -30,6 +30,7 @@ import signal
 import logging
 import atexit
 import io
+from collections import OrderedDict

 sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'scripts'))
 import qtest
@@ -75,6 +76,16 @@ def qemu_img(*args):
         sys.stderr.write('qemu-img received signal %i: %s\n' % (-exitcode, ' '.join(qemu_img_args + list(args))))
     return exitcode

+def ordered_kwargs(kwargs):
+    # kwargs prior to 3.6 are not ordered, so:
+    od = OrderedDict()
+    for k, v in sorted(kwargs.items()):
+        if isinstance(v, dict):
+            od[k] = ordered_kwargs(v)
+        else:
+            od[k] = v
+    return od
+
 def qemu_img_create(*args):
     args = list(args)

@@ -257,8 +268,10 @@ def filter_img_info(output, filename):
 def log(msg, filters=[]):
     for flt in filters:
         msg = flt(msg)
-    if type(msg) is dict or type(msg) is list:
-        print(json.dumps(msg, sort_keys=True))
+    if isinstance(msg, dict) or isinstance(msg, list):
+        # Don't sort if it's already sorted
+        do_sort = not isinstance(msg, OrderedDict)
+        print(json.dumps(msg, sort_keys=do_sort))
     else:
         print(msg)

@@ -448,8 +461,11 @@ class VM(qtest.QEMUQtestMachine):
         return result

     def qmp_log(self, cmd, filters=[filter_testfiles], **kwargs):
-        logmsg = '{"execute": "%s", "arguments": %s}' % \
-            (cmd, json.dumps(kwargs, sort_keys=True))
+        full_cmd = OrderedDict((
+            ("execute", cmd),
+            ("arguments", ordered_kwargs(kwargs))
+        ))
+        logmsg = json.dumps(full_cmd)
         log(logmsg, filters)
         result = self.qmp(cmd, **kwargs)
         log(json.dumps(result, sort_keys=True), filters)
-- 
2.20.1

[Qemu-devel] [PULL 08/20] iotests: remove default filters from qmp_log

[Eric Blake]

From: John Snow <jsnow@redhat.com>

Several places in iotests deal with serializing objects into JSON
strings, but to add pretty-printing it seems desirable to localize
all of those cases.

log() seems like a good candidate for that centralized behavior.
log() can already serialize json objects, but when it does so,
it assumes filters=[] operates on QMP objects, not strings.

qmp_log currently operates by dumping outgoing and incoming QMP
objects into strings and filtering them assuming that filters=[]
are string filters.

To have qmp_log use log's serialization, qmp_log will need to
accept only qmp filters, not text filters.

However, only a single caller of qmp_log actually requires any
filters at all. I remove the default filter and add it explicitly
to the caller in preparation for refactoring qmp_log to use rich
filters instead.

test 206 is amended to name the filter explicitly and the default
is removed.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-9-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/206        | 8 ++++++--
 tests/qemu-iotests/iotests.py | 2 +-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/206 b/tests/qemu-iotests/206
index 128c334c7c5..e92550fa59f 100755
--- a/tests/qemu-iotests/206
+++ b/tests/qemu-iotests/206
@@ -26,7 +26,9 @@ from iotests import imgfmt
 iotests.verify_image_format(supported_fmts=['qcow2'])

 def blockdev_create(vm, options):
-    result = vm.qmp_log('blockdev-create', job_id='job0', options=options)
+    result = vm.qmp_log('blockdev-create',
+                        filters=[iotests.filter_testfiles],
+                        job_id='job0', options=options)

     if 'return' in result:
         assert result['return'] == {}
@@ -52,7 +54,9 @@ with iotests.FilePath('t.qcow2') as disk_path, \
                           'filename': disk_path,
                           'size': 0 })

-    vm.qmp_log('blockdev-add', driver='file', filename=disk_path,
+    vm.qmp_log('blockdev-add',
+               filters=[iotests.filter_testfiles],
+               driver='file', filename=disk_path,
                node_name='imgfile')

     blockdev_create(vm, { 'driver': imgfmt,
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 565eebb1ab5..57fe20db45a 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -460,7 +460,7 @@ class VM(qtest.QEMUQtestMachine):
             result.append(filter_qmp_event(ev))
         return result

-    def qmp_log(self, cmd, filters=[filter_testfiles], **kwargs):
+    def qmp_log(self, cmd, filters=[], **kwargs):
         full_cmd = OrderedDict((
             ("execute", cmd),
             ("arguments", ordered_kwargs(kwargs))
-- 
2.20.1

[Qemu-devel] [PULL 09/20] iotests: change qmp_log filters to expect QMP objects only

[Eric Blake]

From: John Snow <jsnow@redhat.com>

As laid out in the previous commit's message:

```
Several places in iotests deal with serializing objects into JSON
strings, but to add pretty-printing it seems desirable to localize
all of those cases.

log() seems like a good candidate for that centralized behavior.
log() can already serialize json objects, but when it does so,
it assumes filters=[] operates on QMP objects, not strings.

qmp_log currently operates by dumping outgoing and incoming QMP
objects into strings and filtering them assuming that filters=[]
are string filters.
```

Therefore:

Change qmp_log to treat filters as if they're always qmp object filters,
then change the logging call to rely on log()'s ability to serialize QMP
objects, so we're not duplicating that effort.

Add a qmp version of filter_testfiles and adjust the only caller using
it for qmp_log to use the qmp version.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20181221093529.23855-10-jsnow@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/206        |  4 ++--
 tests/qemu-iotests/iotests.py | 28 +++++++++++++++++++++++++---
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/tests/qemu-iotests/206 b/tests/qemu-iotests/206
index e92550fa59f..5bb738bf23c 100755
--- a/tests/qemu-iotests/206
+++ b/tests/qemu-iotests/206
@@ -27,7 +27,7 @@ iotests.verify_image_format(supported_fmts=['qcow2'])

 def blockdev_create(vm, options):
     result = vm.qmp_log('blockdev-create',
-                        filters=[iotests.filter_testfiles],
+                        filters=[iotests.filter_qmp_testfiles],
                         job_id='job0', options=options)

     if 'return' in result:
@@ -55,7 +55,7 @@ with iotests.FilePath('t.qcow2') as disk_path, \
                           'size': 0 })

     vm.qmp_log('blockdev-add',
-               filters=[iotests.filter_testfiles],
+               filters=[iotests.filter_qmp_testfiles],
                driver='file', filename=disk_path,
                node_name='imgfile')

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 57fe20db45a..a96a7010d49 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -246,10 +246,33 @@ def filter_qmp_event(event):
         event['timestamp']['microseconds'] = 'USECS'
     return event

+def filter_qmp(qmsg, filter_fn):
+    '''Given a string filter, filter a QMP object's values.
+    filter_fn takes a (key, value) pair.'''
+    # Iterate through either lists or dicts;
+    if isinstance(qmsg, list):
+        items = enumerate(qmsg)
+    else:
+        items = qmsg.items()
+
+    for k, v in items:
+        if isinstance(v, list) or isinstance(v, dict):
+            qmsg[k] = filter_qmp(v, filter_fn)
+        else:
+            qmsg[k] = filter_fn(k, v)
+    return qmsg
+
 def filter_testfiles(msg):
     prefix = os.path.join(test_dir, "%s-" % (os.getpid()))
     return msg.replace(prefix, 'TEST_DIR/PID-')

+def filter_qmp_testfiles(qmsg):
+    def _filter(key, value):
+        if key == 'filename' or key == 'backing-file':
+            return filter_testfiles(value)
+        return value
+    return filter_qmp(qmsg, _filter)
+
 def filter_generated_node_ids(msg):
     return re.sub("#block[0-9]+", "NODE_NAME", msg)

@@ -465,10 +488,9 @@ class VM(qtest.QEMUQtestMachine):
             ("execute", cmd),
             ("arguments", ordered_kwargs(kwargs))
         ))
-        logmsg = json.dumps(full_cmd)
-        log(logmsg, filters)
+        log(full_cmd, filters)
         result = self.qmp(cmd, **kwargs)
-        log(json.dumps(result, sort_keys=True), filters)
+        log(result, filters)
         return result

     def run_job(self, job, auto_finalize=True, auto_dismiss=False):
-- 
2.20.1

[Qemu-devel] [PULL 10/20] iotests: implement pretty-print for log and qmp_log

[Eric Blake]

From: John Snow <jsnow@redhat.com>

If iotests have lines exceeding >998 characters long, git doesn't
want to send it plaintext to the list. We can solve this by allowing
the iotests to use pretty printed QMP output that we can match against
instead.

As a bonus, it's much nicer for human eyes too.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-11-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/iotests.py | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index a96a7010d49..cbedfaf1df6 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -288,13 +288,18 @@ def filter_img_info(output, filename):
         lines.append(line)
     return '\n'.join(lines)

-def log(msg, filters=[]):
+def log(msg, filters=[], indent=None):
+    '''Logs either a string message or a JSON serializable message (like QMP).
+    If indent is provided, JSON serializable messages are pretty-printed.'''
     for flt in filters:
         msg = flt(msg)
     if isinstance(msg, dict) or isinstance(msg, list):
+        # Python < 3.4 needs to know not to add whitespace when pretty-printing:
+        separators = (', ', ': ') if indent is None else (',', ': ')
         # Don't sort if it's already sorted
         do_sort = not isinstance(msg, OrderedDict)
-        print(json.dumps(msg, sort_keys=do_sort))
+        print(json.dumps(msg, sort_keys=do_sort,
+                         indent=indent, separators=separators))
     else:
         print(msg)

@@ -483,14 +488,14 @@ class VM(qtest.QEMUQtestMachine):
             result.append(filter_qmp_event(ev))
         return result

-    def qmp_log(self, cmd, filters=[], **kwargs):
+    def qmp_log(self, cmd, filters=[], indent=None, **kwargs):
         full_cmd = OrderedDict((
             ("execute", cmd),
             ("arguments", ordered_kwargs(kwargs))
         ))
-        log(full_cmd, filters)
+        log(full_cmd, filters, indent=indent)
         result = self.qmp(cmd, **kwargs)
-        log(result, filters)
+        log(result, filters, indent=indent)
         return result

     def run_job(self, job, auto_finalize=True, auto_dismiss=False):
-- 
2.20.1

[Qemu-devel] [PULL 11/20] iotests: add iotest 236 for testing bitmap merge

[Eric Blake]

From: John Snow <jsnow@redhat.com>

New interface, new smoke test.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20181221093529.23855-12-jsnow@redhat.com>
[eblake: fix last-minute change to echo text]
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/236     | 161 +++++++++++++++++
 tests/qemu-iotests/236.out | 351 +++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/group   |   1 +
 3 files changed, 513 insertions(+)
 create mode 100755 tests/qemu-iotests/236
 create mode 100644 tests/qemu-iotests/236.out

diff --git a/tests/qemu-iotests/236 b/tests/qemu-iotests/236
new file mode 100755
index 00000000000..79a6381f8e8
--- /dev/null
+++ b/tests/qemu-iotests/236
@@ -0,0 +1,161 @@
+#!/usr/bin/env python
+#
+# Test bitmap merges.
+#
+# Copyright (c) 2018 John Snow for Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# owner=jsnow@redhat.com
+
+import iotests
+from iotests import log
+
+iotests.verify_image_format(supported_fmts=['generic'])
+size = 64 * 1024 * 1024
+granularity = 64 * 1024
+
+patterns = [("0x5d", "0",         "64k"),
+            ("0xd5", "1M",        "64k"),
+            ("0xdc", "32M",       "64k"),
+            ("0xcd", "0x3ff0000", "64k")]  # 64M - 64K
+
+overwrite = [("0xab", "0",         "64k"), # Full overwrite
+             ("0xad", "0x00f8000", "64k"), # Partial-left (1M-32K)
+             ("0x1d", "0x2008000", "64k"), # Partial-right (32M+32K)
+             ("0xea", "0x3fe0000", "64k")] # Adjacent-left (64M - 128K)
+
+def query_bitmaps(vm):
+    res = vm.qmp("query-block")
+    return { "bitmaps": { device['device']: device.get('dirty-bitmaps', []) for
+                          device in res['return'] } }
+
+with iotests.FilePath('img') as img_path, \
+     iotests.VM() as vm:
+
+    log('--- Preparing image & VM ---\n')
+    iotests.qemu_img_create('-f', iotests.imgfmt, img_path, str(size))
+    vm.add_drive(img_path)
+    vm.launch()
+
+    log('\n--- Adding preliminary bitmaps A & B ---\n')
+    vm.qmp_log("block-dirty-bitmap-add", node="drive0",
+               name="bitmapA", granularity=granularity)
+    vm.qmp_log("block-dirty-bitmap-add", node="drive0",
+               name="bitmapB", granularity=granularity)
+
+    # Dirties 4 clusters. count=262144
+    log('\n--- Emulating writes ---\n')
+    for p in patterns:
+        cmd = "write -P%s %s %s" % p
+        log(cmd)
+        log(vm.hmp_qemu_io("drive0", cmd))
+
+    log(query_bitmaps(vm), indent=2)
+
+    log('\n--- Submitting & Aborting Transaction ---\n')
+    vm.qmp_log("transaction", indent=2, actions=[
+        { "type": "block-dirty-bitmap-disable",
+          "data": { "node": "drive0", "name": "bitmapB" }},
+        { "type": "block-dirty-bitmap-add",
+          "data": { "node": "drive0", "name": "bitmapC",
+                    "granularity": granularity }},
+        { "type": "block-dirty-bitmap-clear",
+          "data": { "node": "drive0", "name": "bitmapA" }},
+        { "type": "abort", "data": {}}
+    ])
+    log(query_bitmaps(vm), indent=2)
+
+    log('\n--- Disabling B & Adding C ---\n')
+    vm.qmp_log("transaction", indent=2, actions=[
+        { "type": "block-dirty-bitmap-disable",
+          "data": { "node": "drive0", "name": "bitmapB" }},
+        { "type": "block-dirty-bitmap-add",
+          "data": { "node": "drive0", "name": "bitmapC",
+                    "granularity": granularity }},
+        # Purely extraneous, but test that it works:
+        { "type": "block-dirty-bitmap-disable",
+          "data": { "node": "drive0", "name": "bitmapC" }},
+        { "type": "block-dirty-bitmap-enable",
+          "data": { "node": "drive0", "name": "bitmapC" }},
+    ])
+
+    log('\n--- Emulating further writes ---\n')
+    # Dirties 6 clusters, 3 of which are new in contrast to "A".
+    # A = 64 * 1024 * (4 + 3) = 458752
+    # C = 64 * 1024 * 6       = 393216
+    for p in overwrite:
+        cmd = "write -P%s %s %s" % p
+        log(cmd)
+        log(vm.hmp_qemu_io("drive0", cmd))
+
+    log('\n--- Disabling A & C ---\n')
+    vm.qmp_log("transaction", indent=2, actions=[
+        { "type": "block-dirty-bitmap-disable",
+          "data": { "node": "drive0", "name": "bitmapA" }},
+        { "type": "block-dirty-bitmap-disable",
+          "data": { "node": "drive0", "name": "bitmapC" }}
+    ])
+
+    # A: 7 clusters
+    # B: 4 clusters
+    # C: 6 clusters
+    log(query_bitmaps(vm), indent=2)
+
+    log('\n--- Submitting & Aborting Merge Transaction ---\n')
+    vm.qmp_log("transaction", indent=2, actions=[
+        { "type": "block-dirty-bitmap-add",
+          "data": { "node": "drive0", "name": "bitmapD",
+                    "disabled": True, "granularity": granularity }},
+        { "type": "block-dirty-bitmap-merge",
+          "data": { "node": "drive0", "target": "bitmapD",
+                    "bitmaps": ["bitmapB", "bitmapC"] }},
+        { "type": "abort", "data": {}}
+    ])
+    log(query_bitmaps(vm), indent=2)
+
+    log('\n--- Creating D as a merge of B & C ---\n')
+    # Good hygiene: create a disabled bitmap as a merge target.
+    vm.qmp_log("transaction", indent=2, actions=[
+        { "type": "block-dirty-bitmap-add",
+          "data": { "node": "drive0", "name": "bitmapD",
+                    "disabled": True, "granularity": granularity }},
+        { "type": "block-dirty-bitmap-merge",
+          "data": { "node": "drive0", "target": "bitmapD",
+                    "bitmaps": ["bitmapB", "bitmapC"] }}
+    ])
+
+    # A and D should now both have 7 clusters apiece.
+    # B and C remain unchanged with 4 and 6 respectively.
+    log(query_bitmaps(vm), indent=2)
+
+    # A and D should be equivalent.
+    # Some formats round the size of the disk, so don't print the checksums.
+    check_a = vm.qmp('x-debug-block-dirty-bitmap-sha256',
+                     node="drive0", name="bitmapA")['return']['sha256']
+    check_d = vm.qmp('x-debug-block-dirty-bitmap-sha256',
+                     node="drive0", name="bitmapD")['return']['sha256']
+    assert(check_a == check_d)
+
+    log('\n--- Removing bitmaps A, B, C, and D ---\n')
+    vm.qmp_log("block-dirty-bitmap-remove", node="drive0", name="bitmapA")
+    vm.qmp_log("block-dirty-bitmap-remove", node="drive0", name="bitmapB")
+    vm.qmp_log("block-dirty-bitmap-remove", node="drive0", name="bitmapC")
+    vm.qmp_log("block-dirty-bitmap-remove", node="drive0", name="bitmapD")
+
+    log('\n--- Final Query ---\n')
+    log(query_bitmaps(vm), indent=2)
+
+    log('\n--- Done ---\n')
+    vm.shutdown()
diff --git a/tests/qemu-iotests/236.out b/tests/qemu-iotests/236.out
new file mode 100644
index 00000000000..1dad24db0de
--- /dev/null
+++ b/tests/qemu-iotests/236.out
@@ -0,0 +1,351 @@
+--- Preparing image & VM ---
+
+
+--- Adding preliminary bitmaps A & B ---
+
+{"execute": "block-dirty-bitmap-add", "arguments": {"granularity": 65536, "name": "bitmapA", "node": "drive0"}}
+{"return": {}}
+{"execute": "block-dirty-bitmap-add", "arguments": {"granularity": 65536, "name": "bitmapB", "node": "drive0"}}
+{"return": {}}
+
+--- Emulating writes ---
+
+write -P0x5d 0 64k
+{"return": ""}
+write -P0xd5 1M 64k
+{"return": ""}
+write -P0xdc 32M 64k
+{"return": ""}
+write -P0xcd 0x3ff0000 64k
+{"return": ""}
+{
+  "bitmaps": {
+    "drive0": [
+      {
+        "count": 262144,
+        "granularity": 65536,
+        "name": "bitmapB",
+        "status": "active"
+      },
+      {
+        "count": 262144,
+        "granularity": 65536,
+        "name": "bitmapA",
+        "status": "active"
+      }
+    ]
+  }
+}
+
+--- Submitting & Aborting Transaction ---
+
+{
+  "execute": "transaction",
+  "arguments": {
+    "actions": [
+      {
+        "data": {
+          "node": "drive0",
+          "name": "bitmapB"
+        },
+        "type": "block-dirty-bitmap-disable"
+      },
+      {
+        "data": {
+          "node": "drive0",
+          "name": "bitmapC",
+          "granularity": 65536
+        },
+        "type": "block-dirty-bitmap-add"
+      },
+      {
+        "data": {
+          "node": "drive0",
+          "name": "bitmapA"
+        },
+        "type": "block-dirty-bitmap-clear"
+      },
+      {
+        "data": {},
+        "type": "abort"
+      }
+    ]
+  }
+}
+{
+  "error": {
+    "class": "GenericError",
+    "desc": "Transaction aborted using Abort action"
+  }
+}
+{
+  "bitmaps": {
+    "drive0": [
+      {
+        "count": 262144,
+        "granularity": 65536,
+        "name": "bitmapB",
+        "status": "active"
+      },
+      {
+        "count": 262144,
+        "granularity": 65536,
+        "name": "bitmapA",
+        "status": "active"
+      }
+    ]
+  }
+}
+
+--- Disabling B & Adding C ---
+
+{
+  "execute": "transaction",
+  "arguments": {
+    "actions": [
+      {
+        "data": {
+          "node": "drive0",
+          "name": "bitmapB"
+        },
+        "type": "block-dirty-bitmap-disable"
+      },
+      {
+        "data": {
+          "node": "drive0",
+          "name": "bitmapC",
+          "granularity": 65536
+        },
+        "type": "block-dirty-bitmap-add"
+      },
+      {
+        "data": {
+          "node": "drive0",
+          "name": "bitmapC"
+        },
+        "type": "block-dirty-bitmap-disable"
+      },
+      {
+        "data": {
+          "node": "drive0",
+          "name": "bitmapC"
+        },
+        "type": "block-dirty-bitmap-enable"
+      }
+    ]
+  }
+}
+{
+  "return": {}
+}
+
+--- Emulating further writes ---
+
+write -P0xab 0 64k
+{"return": ""}
+write -P0xad 0x00f8000 64k
+{"return": ""}
+write -P0x1d 0x2008000 64k
+{"return": ""}
+write -P0xea 0x3fe0000 64k
+{"return": ""}
+
+--- Disabling A & C ---
+
+{
+  "execute": "transaction",
+  "arguments": {
+    "actions": [
+      {
+        "data": {
+          "node": "drive0",
+          "name": "bitmapA"
+        },
+        "type": "block-dirty-bitmap-disable"
+      },
+      {
+        "data": {
+          "node": "drive0",
+          "name": "bitmapC"
+        },
+        "type": "block-dirty-bitmap-disable"
+      }
+    ]
+  }
+}
+{
+  "return": {}
+}
+{
+  "bitmaps": {
+    "drive0": [
+      {
+        "count": 393216,
+        "granularity": 65536,
+        "name": "bitmapC",
+        "status": "disabled"
+      },
+      {
+        "count": 262144,
+        "granularity": 65536,
+        "name": "bitmapB",
+        "status": "disabled"
+      },
+      {
+        "count": 458752,
+        "granularity": 65536,
+        "name": "bitmapA",
+        "status": "disabled"
+      }
+    ]
+  }
+}
+
+--- Submitting & Aborting Merge Transaction ---
+
+{
+  "execute": "transaction",
+  "arguments": {
+    "actions": [
+      {
+        "data": {
+          "node": "drive0",
+          "disabled": true,
+          "name": "bitmapD",
+          "granularity": 65536
+        },
+        "type": "block-dirty-bitmap-add"
+      },
+      {
+        "data": {
+          "node": "drive0",
+          "target": "bitmapD",
+          "bitmaps": [
+            "bitmapB",
+            "bitmapC"
+          ]
+        },
+        "type": "block-dirty-bitmap-merge"
+      },
+      {
+        "data": {},
+        "type": "abort"
+      }
+    ]
+  }
+}
+{
+  "error": {
+    "class": "GenericError",
+    "desc": "Transaction aborted using Abort action"
+  }
+}
+{
+  "bitmaps": {
+    "drive0": [
+      {
+        "count": 393216,
+        "granularity": 65536,
+        "name": "bitmapC",
+        "status": "disabled"
+      },
+      {
+        "count": 262144,
+        "granularity": 65536,
+        "name": "bitmapB",
+        "status": "disabled"
+      },
+      {
+        "count": 458752,
+        "granularity": 65536,
+        "name": "bitmapA",
+        "status": "disabled"
+      }
+    ]
+  }
+}
+
+--- Creating D as a merge of B & C ---
+
+{
+  "execute": "transaction",
+  "arguments": {
+    "actions": [
+      {
+        "data": {
+          "node": "drive0",
+          "disabled": true,
+          "name": "bitmapD",
+          "granularity": 65536
+        },
+        "type": "block-dirty-bitmap-add"
+      },
+      {
+        "data": {
+          "node": "drive0",
+          "target": "bitmapD",
+          "bitmaps": [
+            "bitmapB",
+            "bitmapC"
+          ]
+        },
+        "type": "block-dirty-bitmap-merge"
+      }
+    ]
+  }
+}
+{
+  "return": {}
+}
+{
+  "bitmaps": {
+    "drive0": [
+      {
+        "count": 458752,
+        "granularity": 65536,
+        "name": "bitmapD",
+        "status": "disabled"
+      },
+      {
+        "count": 393216,
+        "granularity": 65536,
+        "name": "bitmapC",
+        "status": "disabled"
+      },
+      {
+        "count": 262144,
+        "granularity": 65536,
+        "name": "bitmapB",
+        "status": "disabled"
+      },
+      {
+        "count": 458752,
+        "granularity": 65536,
+        "name": "bitmapA",
+        "status": "disabled"
+      }
+    ]
+  }
+}
+
+--- Removing bitmaps A, B, C, and D ---
+
+{"execute": "block-dirty-bitmap-remove", "arguments": {"name": "bitmapA", "node": "drive0"}}
+{"return": {}}
+{"execute": "block-dirty-bitmap-remove", "arguments": {"name": "bitmapB", "node": "drive0"}}
+{"return": {}}
+{"execute": "block-dirty-bitmap-remove", "arguments": {"name": "bitmapC", "node": "drive0"}}
+{"return": {}}
+{"execute": "block-dirty-bitmap-remove", "arguments": {"name": "bitmapD", "node": "drive0"}}
+{"return": {}}
+
+--- Final Query ---
+
+{
+  "bitmaps": {
+    "drive0": []
+  }
+}
+
+--- Done ---
+
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 61a6d98ebd3..f6b245917ab 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -233,3 +233,4 @@
 233 auto quick
 234 auto quick migration
 235 auto quick
+236 auto quick
-- 
2.20.1

Re: [Qemu-devel] [PULL 11/20] iotests: add iotest 236 for testing bitmap merge

[Kevin Wolf]

Am 14.01.2019 um 17:25 hat Eric Blake geschrieben:
> From: John Snow <jsnow@redhat.com>
> 
> New interface, new smoke test.
> 
> Signed-off-by: John Snow <jsnow@redhat.com>
> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Message-Id: <20181221093529.23855-12-jsnow@redhat.com>
> [eblake: fix last-minute change to echo text]
> Signed-off-by: Eric Blake <eblake@redhat.com>

This test fails for me (with Python 3) because I get a different dict
order.

Probably related to the OrderedDict that qmp_log() uses, so log() uses
sort_keys=False and the unordered dicts that are contained in the outer
OrderedDict stay unordered.

Kevin

Re: [Qemu-devel] [PULL 11/20] iotests: add iotest 236 for testing bitmap merge

[John Snow]

On 1/30/19 12:27 PM, Kevin Wolf wrote:
> Am 14.01.2019 um 17:25 hat Eric Blake geschrieben:
>> From: John Snow <jsnow@redhat.com>
>>
>> New interface, new smoke test.
>>
>> Signed-off-by: John Snow <jsnow@redhat.com>
>> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>> Message-Id: <20181221093529.23855-12-jsnow@redhat.com>
>> [eblake: fix last-minute change to echo text]
>> Signed-off-by: Eric Blake <eblake@redhat.com>
> 
> This test fails for me (with Python 3) because I get a different dict
> order.
> 
> Probably related to the OrderedDict that qmp_log() uses, so log() uses
> sort_keys=False and the unordered dicts that are contained in the outer
> OrderedDict stay unordered.
> 
> Kevin
> 

Gurg. Sorry, apparently Python is hard. Will fix.

Re: [Qemu-devel] [PULL 11/20] iotests: add iotest 236 for testing bitmap merge

[John Snow]

On 1/30/19 12:27 PM, Kevin Wolf wrote:
> Am 14.01.2019 um 17:25 hat Eric Blake geschrieben:
>> From: John Snow <jsnow@redhat.com>
>>
>> New interface, new smoke test.
>>
>> Signed-off-by: John Snow <jsnow@redhat.com>
>> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>> Message-Id: <20181221093529.23855-12-jsnow@redhat.com>
>> [eblake: fix last-minute change to echo text]
>> Signed-off-by: Eric Blake <eblake@redhat.com>
> 
> This test fails for me (with Python 3) because I get a different dict
> order.
> 
> Probably related to the OrderedDict that qmp_log() uses, so log() uses
> sort_keys=False and the unordered dicts that are contained in the outer
> OrderedDict stay unordered.
> 
> Kevin
> 

OK, the problem is that ordered_kwargs() is not recursively ordering
those kwargs beneath list entries, so transactions are avoiding the sort.

Patch coming up, thank you for the report and my apologies for breaking
iotests so often this cycle.

(While I'm here, how do you configure iotests to use your python3
binary? I tried at configure time but that breaks the build for me with
some "magic number" errors. I could toy with it after by editing
common.env, but should the build work with python3?)

Re: [Qemu-devel] [PULL 11/20] iotests: add iotest 236 for testing bitmap merge

[Kevin Wolf]

Am 31.01.2019 um 03:03 hat John Snow geschrieben:
> On 1/30/19 12:27 PM, Kevin Wolf wrote:
> > Am 14.01.2019 um 17:25 hat Eric Blake geschrieben:
> >> From: John Snow <jsnow@redhat.com>
> >>
> >> New interface, new smoke test.
> >>
> >> Signed-off-by: John Snow <jsnow@redhat.com>
> >> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> >> Reviewed-by: Eric Blake <eblake@redhat.com>
> >> Message-Id: <20181221093529.23855-12-jsnow@redhat.com>
> >> [eblake: fix last-minute change to echo text]
> >> Signed-off-by: Eric Blake <eblake@redhat.com>
> > 
> > This test fails for me (with Python 3) because I get a different dict
> > order.
> > 
> > Probably related to the OrderedDict that qmp_log() uses, so log() uses
> > sort_keys=False and the unordered dicts that are contained in the outer
> > OrderedDict stay unordered.
> > 
> > Kevin
> > 
> 
> OK, the problem is that ordered_kwargs() is not recursively ordering
> those kwargs beneath list entries, so transactions are avoiding the sort.
> 
> Patch coming up, thank you for the report and my apologies for breaking
> iotests so often this cycle.
> 
> (While I'm here, how do you configure iotests to use your python3
> binary? I tried at configure time but that breaks the build for me with
> some "magic number" errors. I could toy with it after by editing
> common.env, but should the build work with python3?)

Yes, just at configure time:

    ./configure --target-list=x86_64-softmmu --python=/usr/bin/python3

I'm building and running tests in-tree, if that makes a difference.

But maybe it's actually not so bad if at least one of us still tests
with Python 2 as long as we haven't officially removed support for
that...

Kevin

Re: [Qemu-devel] [PULL 11/20] iotests: add iotest 236 for testing bitmap merge

[John Snow]

On 1/31/19 3:55 AM, Kevin Wolf wrote:
> Am 31.01.2019 um 03:03 hat John Snow geschrieben:
>> On 1/30/19 12:27 PM, Kevin Wolf wrote:
>>> Am 14.01.2019 um 17:25 hat Eric Blake geschrieben:
>>>> From: John Snow <jsnow@redhat.com>
>>>>
>>>> New interface, new smoke test.
>>>>
>>>> Signed-off-by: John Snow <jsnow@redhat.com>
>>>> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>>>> Reviewed-by: Eric Blake <eblake@redhat.com>
>>>> Message-Id: <20181221093529.23855-12-jsnow@redhat.com>
>>>> [eblake: fix last-minute change to echo text]
>>>> Signed-off-by: Eric Blake <eblake@redhat.com>
>>>
>>> This test fails for me (with Python 3) because I get a different dict
>>> order.
>>>
>>> Probably related to the OrderedDict that qmp_log() uses, so log() uses
>>> sort_keys=False and the unordered dicts that are contained in the outer
>>> OrderedDict stay unordered.
>>>
>>> Kevin
>>>
>>
>> OK, the problem is that ordered_kwargs() is not recursively ordering
>> those kwargs beneath list entries, so transactions are avoiding the sort.
>>
>> Patch coming up, thank you for the report and my apologies for breaking
>> iotests so often this cycle.
>>
>> (While I'm here, how do you configure iotests to use your python3
>> binary? I tried at configure time but that breaks the build for me with
>> some "magic number" errors. I could toy with it after by editing
>> common.env, but should the build work with python3?)
> 
> Yes, just at configure time:
> 
>     ./configure --target-list=x86_64-softmmu --python=/usr/bin/python3
> 
> I'm building and running tests in-tree, if that makes a difference.
> 
> But maybe it's actually not so bad if at least one of us still tests
> with Python 2 as long as we haven't officially removed support for
> that...
> 
> Kevin
> 

jhuston@probe (master) ~/s/q/b/git> make
  GEN     qapi-gen
Traceback (most recent call last):
  File "/home/bos/jhuston/src/qemu/scripts/qapi-gen.py", line 8, in <module>
    import argparse
ImportError: bad magic number in 'argparse': b'\x03\xf3\r\n'
make: *** [Makefile:540: qapi-gen-timestamp] Error 1

Ah, I see ... there are stale .pyc and __pycache__ files hiding around
that break things when you switch from 2 to 3 and `make distclean`
doesn't clear those out.

Probably ought to.

[Qemu-devel] [PULL 12/20] qemu-nbd: Rename 'exp' variable clashing with math::exp() symbol

[Eric Blake]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

The use of a variable named 'exp' prevents includes to import <math.h>.

Rename it to avoid:

  qemu-nbd.c:64:19: error: ‘exp’ redeclared as different kind of symbol
   static NBDExport *exp;
                     ^~~
  In file included from /usr/include/features.h:428,
                   from /usr/include/bits/libc-header-start.h:33,
                   from /usr/include/stdint.h:26,
                   from /usr/lib/gcc/x86_64-redhat-linux/8/include/stdint.h:9,
                   from /source/qemu/include/qemu/osdep.h:80,
                   from /source/qemu/qemu-nbd.c:19:
  /usr/include/bits/mathcalls.h:95:1: note: previous declaration of ‘exp’ was here
    __MATHCALL_VEC (exp,, (_Mdouble_ __x));
    ^~~~~~~~~~~~~~

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190111163519.11457-1-philmd@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 qemu-nbd.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/qemu-nbd.c b/qemu-nbd.c
index 2807e132396..6ca02b6d87b 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -61,7 +61,7 @@

 #define MBR_SIZE 512

-static NBDExport *exp;
+static NBDExport *export;
 static int verbose;
 static char *srcpath;
 static SocketAddress *saddr;
@@ -335,7 +335,7 @@ static int nbd_can_accept(void)
     return state == RUNNING && nb_fds < shared;
 }

-static void nbd_export_closed(NBDExport *exp)
+static void nbd_export_closed(NBDExport *export)
 {
     assert(state == TERMINATING);
     state = TERMINATED;
@@ -1015,10 +1015,11 @@ int main(int argc, char **argv)
         }
     }

-    exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags, nbd_export_closed,
-                         writethrough, NULL, &error_fatal);
-    nbd_export_set_name(exp, export_name);
-    nbd_export_set_description(exp, export_description);
+    export = nbd_export_new(bs, dev_offset, fd_size, nbdflags,
+                            nbd_export_closed, writethrough,
+                            NULL, &error_fatal);
+    nbd_export_set_name(export, export_name);
+    nbd_export_set_description(export, export_description);

     if (device) {
 #if HAVE_NBD_DEVICE
@@ -1055,9 +1056,9 @@ int main(int argc, char **argv)
         main_loop_wait(false);
         if (state == TERMINATE) {
             state = TERMINATING;
-            nbd_export_close(exp);
-            nbd_export_put(exp);
-            exp = NULL;
+            nbd_export_close(export);
+            nbd_export_put(export);
+            export = NULL;
         }
     } while (state != TERMINATED);

-- 
2.20.1

[Qemu-devel] [PULL 13/20] nbd: Add some error case testing to iotests 223

[Eric Blake]

Testing success paths is important, but it's also nice to highlight
expected failure handling, to show that we don't crash, and so that
upcoming tests that change behavior can demonstrate the resulting
effects on error paths.

Add the following errors:
Attempting to export without a running server
Attempting to start a second server
Attempting to export a bad node name
Attempting to export a name that is already exported
Attempting to export an enabled bitmap
Attempting to remove an already removed export
Attempting to quit server a second time

All of these properly complain except for a second server-stop,
which will be fixed next.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190111194720.15671-2-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/223     | 19 +++++++++++++++++--
 tests/qemu-iotests/223.out |  7 +++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/tests/qemu-iotests/223 b/tests/qemu-iotests/223
index 5513dc62159..61b46a2f066 100755
--- a/tests/qemu-iotests/223
+++ b/tests/qemu-iotests/223
@@ -107,6 +107,7 @@ echo

 _launch_qemu 2> >(_filter_nbd)

+# Intentionally provoke some errors as well, to check error handling
 silent=
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"qmp_capabilities"}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"blockdev-add",
@@ -114,17 +115,28 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"blockdev-add",
     "file":{"driver":"file", "filename":"'"$TEST_IMG"'"}}}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"block-dirty-bitmap-disable",
   "arguments":{"node":"n", "name":"b"}}' "return"
-_send_qemu_cmd $QEMU_HANDLE '{"execute":"block-dirty-bitmap-disable",
-  "arguments":{"node":"n", "name":"b2"}}' "return"
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
+  "arguments":{"device":"n"}}' "error" # Attempt add without server
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-start",
   "arguments":{"addr":{"type":"unix",
     "data":{"path":"'"$TEST_DIR/nbd"'"}}}}' "return"
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-start",
+  "arguments":{"addr":{"type":"unix",
+    "data":{"path":"'"$TEST_DIR/nbd"1'"}}}}' "error" # Attempt second server
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
   "arguments":{"device":"n"}}' "return"
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
+  "arguments":{"device":"nosuch"}}' "error" # Attempt to export missing node
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
+  "arguments":{"device":"n"}}' "error" # Attempt to export same name twice
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"x-nbd-server-add-bitmap",
   "arguments":{"name":"n", "bitmap":"b"}}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
   "arguments":{"device":"n", "name":"n2"}}' "return"
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"x-nbd-server-add-bitmap",
+  "arguments":{"name":"n2", "bitmap":"b2"}}' "error" # Attempt enabled bitmap
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"block-dirty-bitmap-disable",
+  "arguments":{"node":"n", "name":"b2"}}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"x-nbd-server-add-bitmap",
   "arguments":{"name":"n2", "bitmap":"b2"}}' "return"

@@ -157,7 +169,10 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-remove",
   "arguments":{"name":"n"}}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-remove",
   "arguments":{"name":"n2"}}' "return"
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-remove",
+  "arguments":{"name":"n2"}}' "error" # Attempt duplicate clean
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-stop"}' "return"
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-stop"}' "return" # Oops
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"quit"}' "return"

 # success, all done
diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out
index 99ca172fbb8..e6ede0591cd 100644
--- a/tests/qemu-iotests/223.out
+++ b/tests/qemu-iotests/223.out
@@ -27,10 +27,15 @@ wrote 2097152/2097152 bytes at offset 2097152
 {"return": {}}
 {"return": {}}
 {"return": {}}
+{"error": {"class": "GenericError", "desc": "NBD server not running"}}
 {"return": {}}
+{"error": {"class": "GenericError", "desc": "NBD server already running"}}
 {"return": {}}
+{"error": {"class": "GenericError", "desc": "Cannot find device=nosuch nor node_name=nosuch"}}
+{"error": {"class": "GenericError", "desc": "NBD server already has export named 'n'"}}
 {"return": {}}
 {"return": {}}
+{"error": {"class": "GenericError", "desc": "Bitmap 'b2' is enabled"}}
 {"return": {}}
 {"return": {}}

@@ -62,6 +67,8 @@ read 2097152/2097152 bytes at offset 2097152

 {"return": {}}
 {"return": {}}
+{"error": {"class": "GenericError", "desc": "Export 'n2' is not found"}}
+{"return": {}}
 {"return": {}}
 {"return": {}}
 *** done
-- 
2.20.1

[Qemu-devel] [PULL 14/20] nbd: Forbid nbd-server-stop when server is not running

[Eric Blake]

Since we already forbid other nbd-server commands when not
in the right state, it is unlikely that any caller was relying
on a second stop to behave as a silent no-op.  Update iotest
223 to show the improved behavior.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190111194720.15671-3-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 blockdev-nbd.c             | 5 +++++
 tests/qemu-iotests/223     | 2 +-
 tests/qemu-iotests/223.out | 2 +-
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index 1d170c80b82..ca584919194 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -214,6 +214,11 @@ void qmp_nbd_server_remove(const char *name,

 void qmp_nbd_server_stop(Error **errp)
 {
+    if (!nbd_server) {
+        error_setg(errp, "NBD server not running");
+        return;
+    }
+
     nbd_export_close_all();

     nbd_server_free(nbd_server);
diff --git a/tests/qemu-iotests/223 b/tests/qemu-iotests/223
index 61b46a2f066..a4016091b21 100755
--- a/tests/qemu-iotests/223
+++ b/tests/qemu-iotests/223
@@ -172,7 +172,7 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-remove",
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-remove",
   "arguments":{"name":"n2"}}' "error" # Attempt duplicate clean
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-stop"}' "return"
-_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-stop"}' "return" # Oops
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-stop"}' "error" # Again
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"quit"}' "return"

 # success, all done
diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out
index e6ede0591cd..8a4d63a4fc2 100644
--- a/tests/qemu-iotests/223.out
+++ b/tests/qemu-iotests/223.out
@@ -69,6 +69,6 @@ read 2097152/2097152 bytes at offset 2097152
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "Export 'n2' is not found"}}
 {"return": {}}
-{"return": {}}
+{"error": {"class": "GenericError", "desc": "NBD server not running"}}
 {"return": {}}
 *** done
-- 
2.20.1

[Qemu-devel] [PULL 15/20] nbd: Only require disabled bitmap for read-only exports

[Eric Blake]

Our initial implementation of x-nbd-server-add-bitmap put
in a restriction because of incremental backups: in that
usage, we are exporting one qcow2 file (the temporary overlay
target of a blockdev-backup sync:none job) and a dirty bitmap
owned by a second qcow2 file (the source of the
blockdev-backup, which is the backing file of the temporary).
While both qcow2 files are still writable (the target in
order to capture copy-on-write of old contents, and the
source in order to track live guest writes in the meantime),
the NBD client expects to see constant data, including the
dirty bitmap.  An enabled bitmap in the source would be
modified by guest writes, which is at odds with the NBD
export being a read-only constant view, hence the initial
code choice of enforcing a disabled bitmap (the intent is
that the exposed bitmap was disabled in the same transaction
that started the blockdev-backup job, although we don't want
to track enough state to actually enforce that).

However, consider the case of a bitmap contained in a read-only
node (including when the bitmap is found in a backing layer of
the active image).  Because the node can't be modified, the
bitmap won't change due to writes, regardless of whether it is
still enabled.  Forbidding the export unless the bitmap is
disabled is awkward, paritcularly since we can't change the
bitmap to be disabled (because the node is read-only).

Alternatively, consider the case of live storage migration,
where management directs the destination to create a writable
NBD server, then performs a drive-mirror from the source to
the target, prior to doing the rest of the live migration.
Since storage migration can be time-consuming, it may be wise
to let the destination include a dirty bitmap to track which
portions it has already received, where even if the migration
is interrupted and restarted, the source can query the
destination block status in order to potentially minimize
re-sending data that has not changed in the meantime on a
second attempt. Such code has not been written, and might not
be trivial (after all, a cluster being marked dirty in the
bitmap does not necessarily guarantee it has the desired
contents), but it makes sense that letting an active dirty
bitmap be exposed and changing alongside writes may prove
useful in the future.

Solve both issues by gating the restriction against a
disabled bitmap to only happen when the caller has requested
a read-only export, and where the BDS that owns the bitmap
(whether or not it is the BDS handed to nbd_export_new() or
from its backing chain) is still writable.  We could drop
the check altogether (if management apps are prepared to
deal with a changing bitmap even on a read-only image), but
for now keeping a check for the read-only case still stands
a chance of preventing management errors.

Update iotest 223 to show the looser behavior by leaving
a bitmap enabled the whole run; note that we have to tear
down and re-export a node when handling an error.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190111194720.15671-4-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 nbd/server.c               |  7 +++++--
 tests/qemu-iotests/223     | 10 +++++++---
 tests/qemu-iotests/223.out |  3 ++-
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/nbd/server.c b/nbd/server.c
index 7af0ddffb20..98327088cb4 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -2456,8 +2456,11 @@ void nbd_export_bitmap(NBDExport *exp, const char *bitmap,
         return;
     }

-    if (bdrv_dirty_bitmap_enabled(bm)) {
-        error_setg(errp, "Bitmap '%s' is enabled", bitmap);
+    if ((exp->nbdflags & NBD_FLAG_READ_ONLY) && bdrv_is_writable(bs) &&
+        bdrv_dirty_bitmap_enabled(bm)) {
+        error_setg(errp,
+                   "Enabled bitmap '%s' incompatible with readonly export",
+                   bitmap);
         return;
     }

diff --git a/tests/qemu-iotests/223 b/tests/qemu-iotests/223
index a4016091b21..f200e313c06 100755
--- a/tests/qemu-iotests/223
+++ b/tests/qemu-iotests/223
@@ -61,6 +61,8 @@ echo "=== Create partially sparse image, then add dirty bitmaps ==="
 echo

 # Two bitmaps, to contrast granularity issues
+# Also note that b will be disabled, while b2 is left enabled, to
+# check for read-only interactions
 _make_test_img -o cluster_size=4k 4M
 $QEMU_IO -c 'w -P 0x11 1M 2M' "$TEST_IMG" | _filter_qemu_io
 run_qemu <<EOF
@@ -134,9 +136,11 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"x-nbd-server-add-bitmap",
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
   "arguments":{"device":"n", "name":"n2"}}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"x-nbd-server-add-bitmap",
-  "arguments":{"name":"n2", "bitmap":"b2"}}' "error" # Attempt enabled bitmap
-_send_qemu_cmd $QEMU_HANDLE '{"execute":"block-dirty-bitmap-disable",
-  "arguments":{"node":"n", "name":"b2"}}' "return"
+  "arguments":{"name":"n2", "bitmap":"b2"}}' "error" # Enabled vs. read-only
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-remove",
+  "arguments":{"name":"n2"}}' "return"
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
+  "arguments":{"device":"n", "name":"n2", "writable":true}}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"x-nbd-server-add-bitmap",
   "arguments":{"name":"n2", "bitmap":"b2"}}' "return"

diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out
index 8a4d63a4fc2..7d147291d48 100644
--- a/tests/qemu-iotests/223.out
+++ b/tests/qemu-iotests/223.out
@@ -35,7 +35,8 @@ wrote 2097152/2097152 bytes at offset 2097152
 {"error": {"class": "GenericError", "desc": "NBD server already has export named 'n'"}}
 {"return": {}}
 {"return": {}}
-{"error": {"class": "GenericError", "desc": "Bitmap 'b2' is enabled"}}
+{"error": {"class": "GenericError", "desc": "Enabled bitmap 'b2' incompatible with readonly export"}}
+{"return": {}}
 {"return": {}}
 {"return": {}}

-- 
2.20.1

[Qemu-devel] [PULL 16/20] nbd: Merge nbd_export_set_name into nbd_export_new

[Eric Blake]

The existing NBD code had a weird split where nbd_export_new()
created an export but did not add it to the list of exported
names until a later nbd_export_set_name() came along and grabbed
a second reference on the object; later, the first call to
nbd_export_close() drops the second reference while removing
the export from the list.  This is in part because the QAPI
NbdServerRemoveNode enum documents the possibility of adding a
mode where we could do a soft disconnect: preventing new clients,
but waiting for existing clients to gracefully quit, based on
the mode used when calling nbd_export_close().

But in spite of all that, note that we never change the name of
an NBD export while it is exposed, which means it is easier to
just inline the process of setting the name as part of creating
the export.

Inline the contents of nbd_export_set_name() and
nbd_export_set_description() into the two points in an export
lifecycle where they matter, then adjust both callers to pass
the name up front.  Note that for creation, all callers pass a
non-NULL name, (passing NULL at creation was for old style
servers, but we removed support for that in commit 7f7dfe2a),
so we can add an assert and do things unconditionally; but for
cleanup, because of the dual nature of nbd_export_close(), we
still have to be careful to avoid use-after-free.  Along the
way, add a comment reminding ourselves of the potential of
adding a middle mode disconnect.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190111194720.15671-5-eblake@redhat.com>
---
 include/block/nbd.h |  3 +--
 blockdev-nbd.c      |  5 ++---
 nbd/server.c        | 52 ++++++++++++++++++++-------------------------
 qemu-nbd.c          |  8 +++----
 4 files changed, 29 insertions(+), 39 deletions(-)

diff --git a/include/block/nbd.h b/include/block/nbd.h
index 65402d33964..2f9a2aeb73c 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -295,6 +295,7 @@ typedef struct NBDExport NBDExport;
 typedef struct NBDClient NBDClient;

 NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
+                          const char *name, const char *description,
                           uint16_t nbdflags, void (*close)(NBDExport *),
                           bool writethrough, BlockBackend *on_eject_blk,
                           Error **errp);
@@ -306,8 +307,6 @@ void nbd_export_put(NBDExport *exp);
 BlockBackend *nbd_export_get_blockdev(NBDExport *exp);

 NBDExport *nbd_export_find(const char *name);
-void nbd_export_set_name(NBDExport *exp, const char *name);
-void nbd_export_set_description(NBDExport *exp, const char *description);
 void nbd_export_close_all(void);

 void nbd_client_new(QIOChannelSocket *sioc,
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index ca584919194..582ffded77f 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -174,14 +174,13 @@ void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
         writable = false;
     }

-    exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY,
+    exp = nbd_export_new(bs, 0, -1, name, NULL,
+                         writable ? 0 : NBD_FLAG_READ_ONLY,
                          NULL, false, on_eject_blk, errp);
     if (!exp) {
         return;
     }

-    nbd_export_set_name(exp, name);
-
     /* The list of named exports has a strong reference to this export now and
      * our only way of accessing it is through nbd_export_find(), so we can drop
      * the strong reference that is @exp. */
diff --git a/nbd/server.c b/nbd/server.c
index 98327088cb4..bb5438c448b 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1456,6 +1456,7 @@ static void nbd_eject_notifier(Notifier *n, void *data)
 }

 NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
+                          const char *name, const char *description,
                           uint16_t nbdflags, void (*close)(NBDExport *),
                           bool writethrough, BlockBackend *on_eject_blk,
                           Error **errp)
@@ -1471,6 +1472,7 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
      * that BDRV_O_INACTIVE is cleared and the image is ready for write
      * access since the export could be available before migration handover.
      */
+    assert(name);
     ctx = bdrv_get_aio_context(bs);
     aio_context_acquire(ctx);
     bdrv_invalidate_cache(bs, NULL);
@@ -1494,6 +1496,8 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
     QTAILQ_INIT(&exp->clients);
     exp->blk = blk;
     exp->dev_offset = dev_offset;
+    exp->name = g_strdup(name);
+    exp->description = g_strdup(description);
     exp->nbdflags = nbdflags;
     exp->size = size < 0 ? blk_getlength(blk) : size;
     if (exp->size < 0) {
@@ -1513,10 +1517,14 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
         exp->eject_notifier.notify = nbd_eject_notifier;
         blk_add_remove_bs_notifier(on_eject_blk, &exp->eject_notifier);
     }
+    QTAILQ_INSERT_TAIL(&exports, exp, next);
+    nbd_export_get(exp);
     return exp;

 fail:
     blk_unref(blk);
+    g_free(exp->name);
+    g_free(exp->description);
     g_free(exp);
     return NULL;
 }
@@ -1533,43 +1541,29 @@ NBDExport *nbd_export_find(const char *name)
     return NULL;
 }

-void nbd_export_set_name(NBDExport *exp, const char *name)
-{
-    if (exp->name == name) {
-        return;
-    }
-
-    nbd_export_get(exp);
-    if (exp->name != NULL) {
-        g_free(exp->name);
-        exp->name = NULL;
-        QTAILQ_REMOVE(&exports, exp, next);
-        nbd_export_put(exp);
-    }
-    if (name != NULL) {
-        nbd_export_get(exp);
-        exp->name = g_strdup(name);
-        QTAILQ_INSERT_TAIL(&exports, exp, next);
-    }
-    nbd_export_put(exp);
-}
-
-void nbd_export_set_description(NBDExport *exp, const char *description)
-{
-    g_free(exp->description);
-    exp->description = g_strdup(description);
-}
-
 void nbd_export_close(NBDExport *exp)
 {
     NBDClient *client, *next;

     nbd_export_get(exp);
+    /*
+     * TODO: Should we expand QMP NbdServerRemoveNode enum to allow a
+     * close mode that stops advertising the export to new clients but
+     * still permits existing clients to run to completion? Because of
+     * that possibility, nbd_export_close() can be called more than
+     * once on an export.
+     */
     QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) {
         client_close(client, true);
     }
-    nbd_export_set_name(exp, NULL);
-    nbd_export_set_description(exp, NULL);
+    if (exp->name) {
+        nbd_export_put(exp);
+        g_free(exp->name);
+        exp->name = NULL;
+        QTAILQ_REMOVE(&exports, exp, next);
+    }
+    g_free(exp->description);
+    exp->description = NULL;
     nbd_export_put(exp);
 }

diff --git a/qemu-nbd.c b/qemu-nbd.c
index 6ca02b6d87b..b93fa196dac 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -1015,11 +1015,9 @@ int main(int argc, char **argv)
         }
     }

-    export = nbd_export_new(bs, dev_offset, fd_size, nbdflags,
-                            nbd_export_closed, writethrough,
-                            NULL, &error_fatal);
-    nbd_export_set_name(export, export_name);
-    nbd_export_set_description(export, export_description);
+    export = nbd_export_new(bs, dev_offset, fd_size, export_name,
+                            export_description, nbdflags, nbd_export_closed,
+                            writethrough, NULL, &error_fatal);

     if (device) {
 #if HAVE_NBD_DEVICE
-- 
2.20.1

[Qemu-devel] [PULL 17/20] nbd: Allow bitmap export during QMP nbd-server-add

[Eric Blake]

With the experimental x-nbd-server-add-bitmap command, there was
a window of time where an NBD client could see the export but not
the associated dirty bitmap, which can cause a client that planned
on using the dirty bitmap to be forced to treat the entire image
as dirty as a safety fallback.  Furthermore, if the QMP client
successfully exports a disk but then fails to add the bitmap, it
has to take on the burden of removing the export.  Since we don't
allow changing the exposed dirty bitmap (whether to a different
bitmap, or removing advertisement of the bitmap), it is nicer to
make the bitmap tied to the export at the time the export is
created, with automatic failure to export if the bitmap is not
available.

The experimental command included an optional 'bitmap-export-name'
field for remapping the name exposed over NBD to be different from
the bitmap name stored on disk.  However, my libvirt demo code
for implementing differential backups on top of persistent bitmaps
did not need to take advantage of that feature (it is instead
possible to create a new temporary bitmap with the desired name,
use block-dirty-bitmap-merge to merge one or more persistent
bitmaps into the temporary, then associate the temporary with the
NBD export, if control is needed over the exported bitmap name).
Hence, I'm not copying that part of the experiment over to the
stable addition. For more details on the libvirt demo, see
https://www.redhat.com/archives/libvir-list/2018-October/msg01254.html,
https://kvmforum2018.sched.com/event/FzuB/facilitating-incremental-backup-eric-blake-red-hat

This patch focuses on the user interface, and reduces (but does
not completely eliminate) the window where an NBD client can see
the export but not the dirty bitmap, with less work to clean up
after errors.  Later patches will add further cleanups now that
this interface is declared stable via a single QMP command,
including removing the race window.

Update test 223 to use the new interface.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190111194720.15671-6-eblake@redhat.com>
---
 qapi/block.json            |  7 ++++++-
 blockdev-nbd.c             | 12 +++++++++++-
 hmp.c                      |  5 +++--
 tests/qemu-iotests/223     | 19 ++++++++-----------
 tests/qemu-iotests/223.out |  5 +----
 5 files changed, 29 insertions(+), 19 deletions(-)

diff --git a/qapi/block.json b/qapi/block.json
index 11f01f28efe..3d70420f763 100644
--- a/qapi/block.json
+++ b/qapi/block.json
@@ -246,6 +246,10 @@
 #
 # @writable: Whether clients should be able to write to the device via the
 #     NBD connection (default false).
+
+# @bitmap: Also export the dirty bitmap reachable from @device, so the
+#          NBD client can use NBD_OPT_SET_META_CONTEXT with
+#          "qemu:dirty-bitmap:NAME" to inspect the bitmap. (since 4.0)
 #
 # Returns: error if the server is not running, or export with the same name
 #          already exists.
@@ -253,7 +257,8 @@
 # Since: 1.3.0
 ##
 { 'command': 'nbd-server-add',
-  'data': {'device': 'str', '*name': 'str', '*writable': 'bool'} }
+  'data': {'device': 'str', '*name': 'str', '*writable': 'bool',
+           '*bitmap': 'str' } }

 ##
 # @NbdServerRemoveMode:
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index 582ffded77f..ec8cf0ab8c3 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -140,7 +140,8 @@ void qmp_nbd_server_start(SocketAddressLegacy *addr,
 }

 void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
-                        bool has_writable, bool writable, Error **errp)
+                        bool has_writable, bool writable,
+                        bool has_bitmap, const char *bitmap, Error **errp)
 {
     BlockDriverState *bs = NULL;
     BlockBackend *on_eject_blk;
@@ -185,6 +186,15 @@ void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
      * our only way of accessing it is through nbd_export_find(), so we can drop
      * the strong reference that is @exp. */
     nbd_export_put(exp);
+
+    if (has_bitmap) {
+        Error *err = NULL;
+        nbd_export_bitmap(exp, bitmap, bitmap, &err);
+        if (err) {
+            error_propagate(errp, err);
+            nbd_export_remove(exp, NBD_SERVER_REMOVE_MODE_HARD, NULL);
+        }
+    }
 }

 void qmp_nbd_server_remove(const char *name,
diff --git a/hmp.c b/hmp.c
index 80aa5ab504b..8da5fd8760a 100644
--- a/hmp.c
+++ b/hmp.c
@@ -2326,7 +2326,7 @@ void hmp_nbd_server_start(Monitor *mon, const QDict *qdict)
         }

         qmp_nbd_server_add(info->value->device, false, NULL,
-                           true, writable, &local_err);
+                           true, writable, false, NULL, &local_err);

         if (local_err != NULL) {
             qmp_nbd_server_stop(NULL);
@@ -2347,7 +2347,8 @@ void hmp_nbd_server_add(Monitor *mon, const QDict *qdict)
     bool writable = qdict_get_try_bool(qdict, "writable", false);
     Error *local_err = NULL;

-    qmp_nbd_server_add(device, !!name, name, true, writable, &local_err);
+    qmp_nbd_server_add(device, !!name, name, true, writable,
+                       false, NULL, &local_err);
     hmp_handle_error(mon, &local_err);
 }

diff --git a/tests/qemu-iotests/223 b/tests/qemu-iotests/223
index f200e313c06..0bcc98a8677 100755
--- a/tests/qemu-iotests/223
+++ b/tests/qemu-iotests/223
@@ -126,23 +126,20 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-start",
   "arguments":{"addr":{"type":"unix",
     "data":{"path":"'"$TEST_DIR/nbd"1'"}}}}' "error" # Attempt second server
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
-  "arguments":{"device":"n"}}' "return"
+  "arguments":{"device":"n", "bitmap":"b"}}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
   "arguments":{"device":"nosuch"}}' "error" # Attempt to export missing node
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
   "arguments":{"device":"n"}}' "error" # Attempt to export same name twice
-_send_qemu_cmd $QEMU_HANDLE '{"execute":"x-nbd-server-add-bitmap",
-  "arguments":{"name":"n", "bitmap":"b"}}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
-  "arguments":{"device":"n", "name":"n2"}}' "return"
-_send_qemu_cmd $QEMU_HANDLE '{"execute":"x-nbd-server-add-bitmap",
-  "arguments":{"name":"n2", "bitmap":"b2"}}' "error" # Enabled vs. read-only
-_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-remove",
-  "arguments":{"name":"n2"}}' "return"
+  "arguments":{"device":"n", "name":"n2",
+  "bitmap":"b2"}}' "error" # enabled vs. read-only
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
-  "arguments":{"device":"n", "name":"n2", "writable":true}}' "return"
-_send_qemu_cmd $QEMU_HANDLE '{"execute":"x-nbd-server-add-bitmap",
-  "arguments":{"name":"n2", "bitmap":"b2"}}' "return"
+  "arguments":{"device":"n", "name":"n2",
+  "bitmap":"b3"}}' "error" # Missing bitmap
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
+  "arguments":{"device":"n", "name":"n2", "writable":true,
+  "bitmap":"b2"}}' "return"

 echo
 echo "=== Contrast normal status to large granularity dirty-bitmap ==="
diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out
index 7d147291d48..ebd3935c974 100644
--- a/tests/qemu-iotests/223.out
+++ b/tests/qemu-iotests/223.out
@@ -33,11 +33,8 @@ wrote 2097152/2097152 bytes at offset 2097152
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "Cannot find device=nosuch nor node_name=nosuch"}}
 {"error": {"class": "GenericError", "desc": "NBD server already has export named 'n'"}}
-{"return": {}}
-{"return": {}}
 {"error": {"class": "GenericError", "desc": "Enabled bitmap 'b2' incompatible with readonly export"}}
-{"return": {}}
-{"return": {}}
+{"error": {"class": "GenericError", "desc": "Bitmap 'b3' is not found"}}
 {"return": {}}

 === Contrast normal status to large granularity dirty-bitmap ===
-- 
2.20.1

[Qemu-devel] [PULL 18/20] nbd: Remove x-nbd-server-add-bitmap

[Eric Blake]

Now that nbd-server-add can do the same functionality (well, other
than making the exported bitmap name different than the underlying
bitamp - but we argued that was not essential, since it is just as
easy to create a new non-persistent bitmap with the desired name),
we no longer need the experimental separate command.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190111194720.15671-7-eblake@redhat.com>
---
 qapi/block.json | 23 -----------------------
 blockdev-nbd.c  | 23 -----------------------
 2 files changed, 46 deletions(-)

diff --git a/qapi/block.json b/qapi/block.json
index 3d70420f763..5a79d639e8c 100644
--- a/qapi/block.json
+++ b/qapi/block.json
@@ -301,29 +301,6 @@
 { 'command': 'nbd-server-remove',
   'data': {'name': 'str', '*mode': 'NbdServerRemoveMode'} }

-##
-# @x-nbd-server-add-bitmap:
-#
-# Expose a dirty bitmap associated with the selected export. The bitmap search
-# starts at the device attached to the export, and includes all backing files.
-# The exported bitmap is then locked until the NBD export is removed.
-#
-# @name: Export name.
-#
-# @bitmap: Bitmap name to search for.
-#
-# @bitmap-export-name: How the bitmap will be seen by nbd clients
-#                      (default @bitmap)
-#
-# Note: the client must use NBD_OPT_SET_META_CONTEXT with a query of
-# "qemu:dirty-bitmap:NAME" (where NAME matches @bitmap-export-name) to access
-# the exposed bitmap.
-#
-# Since: 3.0
-##
-  { 'command': 'x-nbd-server-add-bitmap',
-    'data': {'name': 'str', 'bitmap': 'str', '*bitmap-export-name': 'str'} }
-
 ##
 # @nbd-server-stop:
 #
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index ec8cf0ab8c3..cd86b38cdaa 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -233,26 +233,3 @@ void qmp_nbd_server_stop(Error **errp)
     nbd_server_free(nbd_server);
     nbd_server = NULL;
 }
-
-void qmp_x_nbd_server_add_bitmap(const char *name, const char *bitmap,
-                                 bool has_bitmap_export_name,
-                                 const char *bitmap_export_name,
-                                 Error **errp)
-{
-    NBDExport *exp;
-
-    if (!nbd_server) {
-        error_setg(errp, "NBD server not running");
-        return;
-    }
-
-    exp = nbd_export_find(name);
-    if (exp == NULL) {
-        error_setg(errp, "Export '%s' is not found", name);
-        return;
-    }
-
-    nbd_export_bitmap(exp, bitmap,
-                      has_bitmap_export_name ? bitmap_export_name : bitmap,
-                      errp);
-}
-- 
2.20.1

[Qemu-devel] [PULL 19/20] nbd: Merge nbd_export_bitmap into nbd_export_new

[Eric Blake]

We only have one caller that wants to export a bitmap name,
which it does right after creation of the export. But there is
still a brief window of time where an NBD client could see the
export but not the dirty bitmap, which a robust client would
have to interpret as meaning the entire image should be treated
as dirty.  Better is to eliminate the window entirely, by
inlining nbd_export_bitmap() into nbd_export_new(), and refusing
to create the bitmap in the first place if the requested bitmap
can't be located.

We also no longer need logic for setting a different bitmap
name compared to the bitmap being exported.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190111194720.15671-8-eblake@redhat.com>
---
 include/block/nbd.h |  9 ++---
 blockdev-nbd.c      | 11 +-----
 nbd/server.c        | 87 +++++++++++++++++++++------------------------
 qemu-nbd.c          |  5 +--
 4 files changed, 47 insertions(+), 65 deletions(-)

diff --git a/include/block/nbd.h b/include/block/nbd.h
index 2f9a2aeb73c..1971b557896 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -296,9 +296,9 @@ typedef struct NBDClient NBDClient;

 NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
                           const char *name, const char *description,
-                          uint16_t nbdflags, void (*close)(NBDExport *),
-                          bool writethrough, BlockBackend *on_eject_blk,
-                          Error **errp);
+                          const char *bitmap, uint16_t nbdflags,
+                          void (*close)(NBDExport *), bool writethrough,
+                          BlockBackend *on_eject_blk, Error **errp);
 void nbd_export_close(NBDExport *exp);
 void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp);
 void nbd_export_get(NBDExport *exp);
@@ -319,9 +319,6 @@ void nbd_client_put(NBDClient *client);
 void nbd_server_start(SocketAddress *addr, const char *tls_creds,
                       Error **errp);

-void nbd_export_bitmap(NBDExport *exp, const char *bitmap,
-                       const char *bitmap_export_name, Error **errp);
-
 /* nbd_read
  * Reads @size bytes from @ioc. Returns 0 on success.
  */
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index cd86b38cdaa..c76d5416b90 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -175,7 +175,7 @@ void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
         writable = false;
     }

-    exp = nbd_export_new(bs, 0, -1, name, NULL,
+    exp = nbd_export_new(bs, 0, -1, name, NULL, bitmap,
                          writable ? 0 : NBD_FLAG_READ_ONLY,
                          NULL, false, on_eject_blk, errp);
     if (!exp) {
@@ -186,15 +186,6 @@ void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
      * our only way of accessing it is through nbd_export_find(), so we can drop
      * the strong reference that is @exp. */
     nbd_export_put(exp);
-
-    if (has_bitmap) {
-        Error *err = NULL;
-        nbd_export_bitmap(exp, bitmap, bitmap, &err);
-        if (err) {
-            error_propagate(errp, err);
-            nbd_export_remove(exp, NBD_SERVER_REMOVE_MODE_HARD, NULL);
-        }
-    }
 }

 void qmp_nbd_server_remove(const char *name,
diff --git a/nbd/server.c b/nbd/server.c
index bb5438c448b..e8c56607eff 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1457,9 +1457,9 @@ static void nbd_eject_notifier(Notifier *n, void *data)

 NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
                           const char *name, const char *description,
-                          uint16_t nbdflags, void (*close)(NBDExport *),
-                          bool writethrough, BlockBackend *on_eject_blk,
-                          Error **errp)
+                          const char *bitmap, uint16_t nbdflags,
+                          void (*close)(NBDExport *), bool writethrough,
+                          BlockBackend *on_eject_blk, Error **errp)
 {
     AioContext *ctx;
     BlockBackend *blk;
@@ -1507,6 +1507,43 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
     }
     exp->size -= exp->size % BDRV_SECTOR_SIZE;

+    if (bitmap) {
+        BdrvDirtyBitmap *bm = NULL;
+        BlockDriverState *bs = blk_bs(blk);
+
+        while (true) {
+            bm = bdrv_find_dirty_bitmap(bs, bitmap);
+            if (bm != NULL || bs->backing == NULL) {
+                break;
+            }
+
+            bs = bs->backing->bs;
+        }
+
+        if (bm == NULL) {
+            error_setg(errp, "Bitmap '%s' is not found", bitmap);
+            goto fail;
+        }
+
+        if ((nbdflags & NBD_FLAG_READ_ONLY) && bdrv_is_writable(bs) &&
+            bdrv_dirty_bitmap_enabled(bm)) {
+            error_setg(errp,
+                       "Enabled bitmap '%s' incompatible with readonly export",
+                       bitmap);
+            goto fail;
+        }
+
+        if (bdrv_dirty_bitmap_user_locked(bm)) {
+            error_setg(errp, "Bitmap '%s' is in use", bitmap);
+            goto fail;
+        }
+
+        bdrv_dirty_bitmap_set_qmp_locked(bm, true);
+        exp->export_bitmap = bm;
+        exp->export_bitmap_context = g_strdup_printf("qemu:dirty-bitmap:%s",
+                                                     bitmap);
+    }
+
     exp->close = close;
     exp->ctx = blk_get_aio_context(blk);
     blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp);
@@ -2424,47 +2461,3 @@ void nbd_client_new(QIOChannelSocket *sioc,
     co = qemu_coroutine_create(nbd_co_client_start, client);
     qemu_coroutine_enter(co);
 }
-
-void nbd_export_bitmap(NBDExport *exp, const char *bitmap,
-                       const char *bitmap_export_name, Error **errp)
-{
-    BdrvDirtyBitmap *bm = NULL;
-    BlockDriverState *bs = blk_bs(exp->blk);
-
-    if (exp->export_bitmap) {
-        error_setg(errp, "Export bitmap is already set");
-        return;
-    }
-
-    while (true) {
-        bm = bdrv_find_dirty_bitmap(bs, bitmap);
-        if (bm != NULL || bs->backing == NULL) {
-            break;
-        }
-
-        bs = bs->backing->bs;
-    }
-
-    if (bm == NULL) {
-        error_setg(errp, "Bitmap '%s' is not found", bitmap);
-        return;
-    }
-
-    if ((exp->nbdflags & NBD_FLAG_READ_ONLY) && bdrv_is_writable(bs) &&
-        bdrv_dirty_bitmap_enabled(bm)) {
-        error_setg(errp,
-                   "Enabled bitmap '%s' incompatible with readonly export",
-                   bitmap);
-        return;
-    }
-
-    if (bdrv_dirty_bitmap_user_locked(bm)) {
-        error_setg(errp, "Bitmap '%s' is in use", bitmap);
-        return;
-    }
-
-    bdrv_dirty_bitmap_set_qmp_locked(bm, true);
-    exp->export_bitmap = bm;
-    exp->export_bitmap_context =
-            g_strdup_printf("qemu:dirty-bitmap:%s", bitmap_export_name);
-}
diff --git a/qemu-nbd.c b/qemu-nbd.c
index b93fa196dac..1552274c189 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -1016,8 +1016,9 @@ int main(int argc, char **argv)
     }

     export = nbd_export_new(bs, dev_offset, fd_size, export_name,
-                            export_description, nbdflags, nbd_export_closed,
-                            writethrough, NULL, &error_fatal);
+                            export_description, NULL, nbdflags,
+                            nbd_export_closed, writethrough, NULL,
+                            &error_fatal);

     if (device) {
 #if HAVE_NBD_DEVICE
-- 
2.20.1

Re: [Qemu-devel] [PULL 19/20] nbd: Merge nbd_export_bitmap into nbd_export_new

[Peter Maydell]

On Mon, 14 Jan 2019 at 16:47, Eric Blake <eblake@redhat.com> wrote:
>
> We only have one caller that wants to export a bitmap name,
> which it does right after creation of the export. But there is
> still a brief window of time where an NBD client could see the
> export but not the dirty bitmap, which a robust client would
> have to interpret as meaning the entire image should be treated
> as dirty.  Better is to eliminate the window entirely, by
> inlining nbd_export_bitmap() into nbd_export_new(), and refusing
> to create the bitmap in the first place if the requested bitmap
> can't be located.


>  NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
>                            const char *name, const char *description,
> -                          uint16_t nbdflags, void (*close)(NBDExport *),
> -                          bool writethrough, BlockBackend *on_eject_blk,
> -                          Error **errp)
> +                          const char *bitmap, uint16_t nbdflags,
> +                          void (*close)(NBDExport *), bool writethrough,
> +                          BlockBackend *on_eject_blk, Error **errp)
>  {
>      AioContext *ctx;
>      BlockBackend *blk;
> @@ -1507,6 +1507,43 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
>      }
>      exp->size -= exp->size % BDRV_SECTOR_SIZE;
>
> +    if (bitmap) {
> +        BdrvDirtyBitmap *bm = NULL;
> +        BlockDriverState *bs = blk_bs(blk);

lgtm.com points out that this local variable 'bs' shadows
the 'bs' argument to the function. Is this intentional?
I think that the two can't ever be different, in which case
you could just delete the variable declaration here, but
I'm not an expert on the block layer APIs.

thanks
-- PMM

Re: [Qemu-devel] [PULL 19/20] nbd: Merge nbd_export_bitmap into nbd_export_new

[Eric Blake]

[-- Attachment #1: Type: text/plain, Size: 1619 bytes --]

On 2/7/19 12:40 PM, Peter Maydell wrote:

> 
>>  NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
>>                            const char *name, const char *description,
>> -                          uint16_t nbdflags, void (*close)(NBDExport *),
>> -                          bool writethrough, BlockBackend *on_eject_blk,
>> -                          Error **errp)
>> +                          const char *bitmap, uint16_t nbdflags,
>> +                          void (*close)(NBDExport *), bool writethrough,
>> +                          BlockBackend *on_eject_blk, Error **errp)
>>  {
>>      AioContext *ctx;
>>      BlockBackend *blk;
>> @@ -1507,6 +1507,43 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
>>      }
>>      exp->size -= exp->size % BDRV_SECTOR_SIZE;
>>
>> +    if (bitmap) {
>> +        BdrvDirtyBitmap *bm = NULL;
>> +        BlockDriverState *bs = blk_bs(blk);
> 
> lgtm.com points out that this local variable 'bs' shadows
> the 'bs' argument to the function. Is this intentional?

No, I will fix.

> I think that the two can't ever be different, in which case
> you could just delete the variable declaration here, but
> I'm not an expert on the block layer APIs.

Yes, that looks right to me as well, since we just barely called
blk_insert_bs(blk, bs, errp) a few lines above.  (Someday, it would be
nice to turn -Wshadow on, to catch stuff like this sooner)

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [Qemu-devel] [PULL 19/20] nbd: Merge nbd_export_bitmap into nbd_export_new

[Peter Maydell]

On Thu, 7 Feb 2019 at 19:00, Eric Blake <eblake@redhat.com> wrote:
> (Someday, it would be
> nice to turn -Wshadow on, to catch stuff like this sooner)

Yes; unfortunately -Wshadow currently generates a ton of
warnings in existing code which we'd need to fix to get
the noise level down...

thanks
-- PMM

Re: [Qemu-devel] [PULL 19/20] nbd: Merge nbd_export_bitmap into nbd_export_new

[Eric Blake]

[-- Attachment #1: Type: text/plain, Size: 545 bytes --]

On 2/7/19 1:05 PM, Peter Maydell wrote:
> On Thu, 7 Feb 2019 at 19:00, Eric Blake <eblake@redhat.com> wrote:
>> (Someday, it would be
>> nice to turn -Wshadow on, to catch stuff like this sooner)
> 
> Yes; unfortunately -Wshadow currently generates a ton of
> warnings in existing code which we'd need to fix to get
> the noise level down...

I've added the wish to https://wiki.qemu.org/BiteSizedTasks

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

[Qemu-devel] [PULL 20/20] qemu-nbd: Add --bitmap=NAME option

[Eric Blake]

Having to fire up qemu, then use QMP commands for nbd-server-start
and nbd-server-add, just to expose a persistent dirty bitmap, is
rather tedious.  Make it possible to expose a dirty bitmap using
just qemu-nbd (of course, for now this only works when qemu-nbd is
visiting a BDS formatted as qcow2).

Of course, any good feature also needs unit testing, so expand
iotest 223 to cover it.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190111194720.15671-9-eblake@redhat.com>
---
 qemu-nbd.texi              |  4 ++++
 qemu-nbd.c                 | 10 ++++++++--
 tests/qemu-iotests/223     | 18 +++++++++++++++++-
 tests/qemu-iotests/223.out | 12 +++++++++++-
 4 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 9a84e81eed9..96b1546006a 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -45,6 +45,10 @@ auto-detecting
 Export the disk as read-only
 @item -P, --partition=@var{num}
 Only expose partition @var{num}
+@item -B, --bitmap=@var{name}
+If @var{filename} has a qcow2 persistent bitmap @var{name}, expose
+that bitmap via the ``qemu:dirty-bitmap:@var{name}'' context
+accessible through NBD_OPT_SET_META_CONTEXT.
 @item -s, --snapshot
 Use @var{filename} as an external snapshot, create a temporary
 file with backing_file=@var{filename}, redirect the write to
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 1552274c189..51b55f2e066 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -95,6 +95,7 @@ static void usage(const char *name)
 "Exposing part of the image:\n"
 "  -o, --offset=OFFSET       offset into the image\n"
 "  -P, --partition=NUM       only expose partition NUM\n"
+"  -B, --bitmap=NAME         expose a persistent dirty bitmap\n"
 "\n"
 "General purpose options:\n"
 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"
@@ -509,7 +510,7 @@ int main(int argc, char **argv)
     off_t fd_size;
     QemuOpts *sn_opts = NULL;
     const char *sn_id_or_name = NULL;
-    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:";
+    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:";
     struct option lopt[] = {
         { "help", no_argument, NULL, 'h' },
         { "version", no_argument, NULL, 'V' },
@@ -519,6 +520,7 @@ int main(int argc, char **argv)
         { "offset", required_argument, NULL, 'o' },
         { "read-only", no_argument, NULL, 'r' },
         { "partition", required_argument, NULL, 'P' },
+        { "bitmap", required_argument, NULL, 'B' },
         { "connect", required_argument, NULL, 'c' },
         { "disconnect", no_argument, NULL, 'd' },
         { "snapshot", no_argument, NULL, 's' },
@@ -558,6 +560,7 @@ int main(int argc, char **argv)
     QDict *options = NULL;
     const char *export_name = ""; /* Default export name */
     const char *export_description = NULL;
+    const char *bitmap = NULL;
     const char *tlscredsid = NULL;
     bool imageOpts = false;
     bool writethrough = true;
@@ -695,6 +698,9 @@ int main(int argc, char **argv)
                 exit(EXIT_FAILURE);
             }
             break;
+        case 'B':
+            bitmap = optarg;
+            break;
         case 'k':
             sockpath = optarg;
             if (sockpath[0] != '/') {
@@ -1016,7 +1022,7 @@ int main(int argc, char **argv)
     }

     export = nbd_export_new(bs, dev_offset, fd_size, export_name,
-                            export_description, NULL, nbdflags,
+                            export_description, bitmap, nbdflags,
                             nbd_export_closed, writethrough, NULL,
                             &error_fatal);

diff --git a/tests/qemu-iotests/223 b/tests/qemu-iotests/223
index 0bcc98a8677..773892dbe60 100755
--- a/tests/qemu-iotests/223
+++ b/tests/qemu-iotests/223
@@ -25,6 +25,7 @@ status=1 # failure is the default!

 _cleanup()
 {
+    nbd_server_stop
     _cleanup_test_img
     _cleanup_qemu
     rm -f "$TEST_DIR/nbd"
@@ -35,6 +36,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 . ./common.rc
 . ./common.filter
 . ./common.qemu
+. ./common.nbd

 _supported_fmt qcow2
 _supported_proto file # uses NBD as well
@@ -163,7 +165,7 @@ $QEMU_IMG map --output=json --image-opts \
   "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b2" | _filter_qemu_img_map

 echo
-echo "=== End NBD server ==="
+echo "=== End qemu NBD server ==="
 echo

 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-remove",
@@ -176,6 +178,20 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-stop"}' "return"
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-stop"}' "error" # Again
 _send_qemu_cmd $QEMU_HANDLE '{"execute":"quit"}' "return"

+echo
+echo "=== Use qemu-nbd as server ==="
+echo
+
+nbd_server_start_unix_socket -r -f $IMGFMT -B b "$TEST_IMG"
+IMG="driver=nbd,server.type=unix,server.path=$nbd_unix_socket"
+$QEMU_IMG map --output=json --image-opts \
+  "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b" | _filter_qemu_img_map
+
+nbd_server_start_unix_socket -f $IMGFMT -B b2 "$TEST_IMG"
+IMG="driver=nbd,server.type=unix,server.path=$nbd_unix_socket"
+$QEMU_IMG map --output=json --image-opts \
+  "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b2" | _filter_qemu_img_map
+
 # success, all done
 echo '*** done'
 rm -f $seq.full
diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out
index ebd3935c974..0de5240a75e 100644
--- a/tests/qemu-iotests/223.out
+++ b/tests/qemu-iotests/223.out
@@ -61,7 +61,7 @@ read 2097152/2097152 bytes at offset 2097152
 { "start": 1024, "length": 2096128, "depth": 0, "zero": false, "data": true},
 { "start": 2097152, "length": 2097152, "depth": 0, "zero": false, "data": false}]

-=== End NBD server ===
+=== End qemu NBD server ===

 {"return": {}}
 {"return": {}}
@@ -69,4 +69,14 @@ read 2097152/2097152 bytes at offset 2097152
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "NBD server not running"}}
 {"return": {}}
+
+=== Use qemu-nbd as server ===
+
+[{ "start": 0, "length": 65536, "depth": 0, "zero": false, "data": false},
+{ "start": 65536, "length": 2031616, "depth": 0, "zero": false, "data": true},
+{ "start": 2097152, "length": 2097152, "depth": 0, "zero": false, "data": false}]
+[{ "start": 0, "length": 512, "depth": 0, "zero": false, "data": true},
+{ "start": 512, "length": 512, "depth": 0, "zero": false, "data": false},
+{ "start": 1024, "length": 2096128, "depth": 0, "zero": false, "data": true},
+{ "start": 2097152, "length": 2097152, "depth": 0, "zero": false, "data": false}]
 *** done
-- 
2.20.1

Re: [Qemu-devel] [PULL 00/20] NBD patches through 2019-01-14

[Peter Maydell]

On Mon, 14 Jan 2019 at 16:28, Eric Blake <eblake@redhat.com> wrote:
>
> The following changes since commit 7260438b7056469610ee166f7abe9ff8a26b8b16:
>
>   Merge remote-tracking branch 'remotes/palmer/tags/riscv-for-master-3.2-part2' into staging (2019-01-14 11:41:43 +0000)
>
> are available in the Git repository at:
>
>   https://repo.or.cz/qemu/ericb.git tags/pull-nbd-2019-01-14
>
> for you to fetch changes up to 636192c4b6052820ea126a5287c58a8f53f3c84f:
>
>   qemu-nbd: Add --bitmap=NAME option (2019-01-14 10:09:46 -0600)
>
> ----------------------------------------------------------------
> nbd patches for 2019-01-14
>
> Promote bitmap/NBD interfaces to stable for use in incremental
> backups. Add 'qemu-nbd --bitmap'.
>
> - John Snow: 0/11 bitmaps: remove x- prefix from QMP api
> - Philippe Mathieu-Daudé: qemu-nbd: Rename 'exp' variable clashing with math::exp() symbol
> - Eric Blake: 0/8 Promote x-nbd-server-add-bitmap to stable
>

Applied, thanks.

Please update the changelog at https://wiki.qemu.org/ChangeLog/4.0
for any user-visible changes.

-- PMM