Re: [PATCH v4 4/6] block: Support multiple reopening with x-blockdev-reopen
05.05.2021 19:18, Kevin Wolf wrote: And then, bdrv_reopen_multiple() is called with no aio context acquired, and no drained section.. And it shoud be refactored to properly operate with acquiring and realeasing the contexts and drained sections when needed... The drained section shouldn't be a problem, we can keep this. In fact, we need this, it is a documented requirement of bdrv_reopen_multiple(). We just need to drop the AioContext lock after drained_begin. bdrv_reopen_multiple() should really document its requirements regarding AioContext locks. It probably doesn't really care, but requires that it be called from the main thread. (note preexisting problem of reopen, that during reopen the whole tree may be moved to another aio context, but we continue operations with acquired old aio context which is wrong). Do we even acquire the old AioContext? I think, I mean aio_context_acquire(ctx); in current qmp_x_blockdev_reopen().. And I remember, that you said about that problem. Still, may be I misunderstood (or misremember). Doesn't worth digging, I'd prefer just review v5 with a fresh eye when it comes. -- Best regards, Vladimir
Re: [PATCH v4 4/6] block: Support multiple reopening with x-blockdev-reopen
Am 18.03.2021 um 15:45 hat Vladimir Sementsov-Ogievskiy geschrieben:
> 17.03.2021 20:15, Alberto Garcia wrote:
> > Signed-off-by: Alberto Garcia
> > ---
> > qapi/block-core.json | 18 +
> > blockdev.c | 78 +++---
> > tests/qemu-iotests/155 | 9 +++--
> > tests/qemu-iotests/165 | 4 +-
> > tests/qemu-iotests/245 | 27 +++--
> > tests/qemu-iotests/248 | 2 +-
> > tests/qemu-iotests/248.out | 2 +-
> > tests/qemu-iotests/296 | 9 +++--
> > tests/qemu-iotests/298 | 4 +-
> > 9 files changed, 92 insertions(+), 61 deletions(-)
> >
> > diff --git a/qapi/block-core.json b/qapi/block-core.json
> > index 9f555d5c1d..9150f765da 100644
> > --- a/qapi/block-core.json
> > +++ b/qapi/block-core.json
> > @@ -4181,13 +4181,15 @@
> > ##
> > # @x-blockdev-reopen:
> > #
> > -# Reopens a block device using the given set of options. Any option
> > -# not specified will be reset to its default value regardless of its
> > -# previous status. If an option cannot be changed or a particular
> > +# Reopens one or more block devices using the given set of options.
> > +# Any option not specified will be reset to its default value regardless
> > +# of its previous status. If an option cannot be changed or a particular
> > # driver does not support reopening then the command will return an
> > -# error.
> > +# error. All devices in the list are reopened in one transaction, so
> > +# if one of them fails then the whole transaction is cancelled.
> > #
> > -# The top-level @node-name option (from BlockdevOptions) must be
> > +# The command receives a list of block devices to reopen. For each one
> > +# of them, the top-level @node-name option (from BlockdevOptions) must be
> > # specified and is used to select the block device to be reopened.
> > # Other @node-name options must be either omitted or set to the
> > # current name of the appropriate node. This command won't change any
> > @@ -4207,8 +4209,8 @@
> > #
> > # 4) NULL: the current child (if any) is detached.
> > #
> > -# Options (1) and (2) are supported in all cases, but at the moment
> > -# only @backing allows replacing or detaching an existing child.
> > +# Options (1) and (2) are supported in all cases. Option (3) is
> > +# supported for @file and @backing, and option (4) for @backing only.
>
> A bit of it should be already updated in "[PATCH v4 2/6] block: Allow
> changing bs->file on reopen"
>
> > #
> > # Unlike with blockdev-add, the @backing option must always be present
> > # unless the node being reopened does not have a backing file and its
> > @@ -4218,7 +4220,7 @@
> > # Since: 4.0
> > ##
> > { 'command': 'x-blockdev-reopen',
> > - 'data': 'BlockdevOptions', 'boxed': true }
> > + 'data': { 'options': ['BlockdevOptions'] } }
> > ##
> > # @blockdev-del:
> > diff --git a/blockdev.c b/blockdev.c
> > index 825d40aa11..7019397b05 100644
> > --- a/blockdev.c
> > +++ b/blockdev.c
> > @@ -3580,46 +3580,64 @@ fail:
> > visit_free(v);
> > }
> > -void qmp_x_blockdev_reopen(BlockdevOptions *options, Error **errp)
> > +void qmp_x_blockdev_reopen(BlockdevOptionsList *reopen_list, Error **errp)
> > {
> > -BlockDriverState *bs;
> > -AioContext *ctx;
> > -QObject *obj;
> > -Visitor *v = qobject_output_visitor_new(&obj);
> > -BlockReopenQueue *queue;
> > -QDict *qdict;
> > +BlockReopenQueue *queue = NULL;
> > +GSList *aio_ctxs = NULL;
> > +GSList *visitors = NULL;
> > +GSList *drained = NULL;
> > -/* Check for the selected node name */
> > -if (!options->has_node_name) {
> > -error_setg(errp, "node-name not specified");
> > -goto fail;
> > -}
> > +/* Add each one of the BDS that we want to reopen to the queue */
> > +for (; reopen_list != NULL; reopen_list = reopen_list->next) {
> > +BlockdevOptions *options = reopen_list->value;
> > +BlockDriverState *bs;
> > +AioContext *ctx;
> > +QObject *obj;
> > +Visitor *v;
> > +QDict *qdict;
> > -bs = bdrv_find_node(options->node_name);
> > -if (!bs) {
> > -error_setg(errp, "Failed to find node with node-name='%s'",
> > +/* Check for the selected node name */
> > +if (!options->has_node_name) {
> > +error_setg(errp, "node-name not specified");
> > +goto fail;
> > +}
> > +
> > +bs = bdrv_find_node(options->node_name);
> > +if (!bs) {
> > +error_setg(errp, "Failed to find node with node-name='%s'",
> > options->node_name);
> > -goto fail;
> > +goto fail;
> > +}
> > +
> > +v = qobject_output_visitor_new(&obj);
> > +visitors = g_slist_prepend(visitors, v);
>
> I'd better just call visit_free inside the block instead of putting v
> to list be freed later after the block..
Yes, I had the same thought.
> > +
>
Re: [PATCH v4 4/6] block: Support multiple reopening with x-blockdev-reopen
17.03.2021 20:15, Alberto Garcia wrote:
Signed-off-by: Alberto Garcia
---
qapi/block-core.json | 18 +
blockdev.c | 78 +++---
tests/qemu-iotests/155 | 9 +++--
tests/qemu-iotests/165 | 4 +-
tests/qemu-iotests/245 | 27 +++--
tests/qemu-iotests/248 | 2 +-
tests/qemu-iotests/248.out | 2 +-
tests/qemu-iotests/296 | 9 +++--
tests/qemu-iotests/298 | 4 +-
9 files changed, 92 insertions(+), 61 deletions(-)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 9f555d5c1d..9150f765da 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -4181,13 +4181,15 @@
##
# @x-blockdev-reopen:
#
-# Reopens a block device using the given set of options. Any option
-# not specified will be reset to its default value regardless of its
-# previous status. If an option cannot be changed or a particular
+# Reopens one or more block devices using the given set of options.
+# Any option not specified will be reset to its default value regardless
+# of its previous status. If an option cannot be changed or a particular
# driver does not support reopening then the command will return an
-# error.
+# error. All devices in the list are reopened in one transaction, so
+# if one of them fails then the whole transaction is cancelled.
#
-# The top-level @node-name option (from BlockdevOptions) must be
+# The command receives a list of block devices to reopen. For each one
+# of them, the top-level @node-name option (from BlockdevOptions) must be
# specified and is used to select the block device to be reopened.
# Other @node-name options must be either omitted or set to the
# current name of the appropriate node. This command won't change any
@@ -4207,8 +4209,8 @@
#
# 4) NULL: the current child (if any) is detached.
#
-# Options (1) and (2) are supported in all cases, but at the moment
-# only @backing allows replacing or detaching an existing child.
+# Options (1) and (2) are supported in all cases. Option (3) is
+# supported for @file and @backing, and option (4) for @backing only.
A bit of it should be already updated in "[PATCH v4 2/6] block: Allow changing
bs->file on reopen"
#
# Unlike with blockdev-add, the @backing option must always be present
# unless the node being reopened does not have a backing file and its
@@ -4218,7 +4220,7 @@
# Since: 4.0
##
{ 'command': 'x-blockdev-reopen',
- 'data': 'BlockdevOptions', 'boxed': true }
+ 'data': { 'options': ['BlockdevOptions'] } }
##
# @blockdev-del:
diff --git a/blockdev.c b/blockdev.c
index 825d40aa11..7019397b05 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3580,46 +3580,64 @@ fail:
visit_free(v);
}
-void qmp_x_blockdev_reopen(BlockdevOptions *options, Error **errp)
+void qmp_x_blockdev_reopen(BlockdevOptionsList *reopen_list, Error **errp)
{
-BlockDriverState *bs;
-AioContext *ctx;
-QObject *obj;
-Visitor *v = qobject_output_visitor_new(&obj);
-BlockReopenQueue *queue;
-QDict *qdict;
+BlockReopenQueue *queue = NULL;
+GSList *aio_ctxs = NULL;
+GSList *visitors = NULL;
+GSList *drained = NULL;
-/* Check for the selected node name */
-if (!options->has_node_name) {
-error_setg(errp, "node-name not specified");
-goto fail;
-}
+/* Add each one of the BDS that we want to reopen to the queue */
+for (; reopen_list != NULL; reopen_list = reopen_list->next) {
+BlockdevOptions *options = reopen_list->value;
+BlockDriverState *bs;
+AioContext *ctx;
+QObject *obj;
+Visitor *v;
+QDict *qdict;
-bs = bdrv_find_node(options->node_name);
-if (!bs) {
-error_setg(errp, "Failed to find node with node-name='%s'",
+/* Check for the selected node name */
+if (!options->has_node_name) {
+error_setg(errp, "node-name not specified");
+goto fail;
+}
+
+bs = bdrv_find_node(options->node_name);
+if (!bs) {
+error_setg(errp, "Failed to find node with node-name='%s'",
options->node_name);
-goto fail;
+goto fail;
+}
+
+v = qobject_output_visitor_new(&obj);
+visitors = g_slist_prepend(visitors, v);
I'd better just call visit_free inside the block instead of putting v to list
be freed later after the block..
+
+/* Put all options in a QDict and flatten it */
+visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
+visit_complete(v, &obj);
+qdict = qobject_to(QDict, obj);
+
+qdict_flatten(qdict);
+
+ctx = bdrv_get_aio_context(bs);
+if (!g_slist_find(aio_ctxs, ctx)) {
+aio_ctxs = g_slist_prepend(aio_ctxs, ctx);
+aio_context_acquire(ctx);
+}
+bdrv_subtree_drained_begin(bs);
I expect Kevin will complain that aquiring several context an
[PATCH v4 4/6] block: Support multiple reopening with x-blockdev-reopen
Signed-off-by: Alberto Garcia
---
qapi/block-core.json | 18 +
blockdev.c | 78 +++---
tests/qemu-iotests/155 | 9 +++--
tests/qemu-iotests/165 | 4 +-
tests/qemu-iotests/245 | 27 +++--
tests/qemu-iotests/248 | 2 +-
tests/qemu-iotests/248.out | 2 +-
tests/qemu-iotests/296 | 9 +++--
tests/qemu-iotests/298 | 4 +-
9 files changed, 92 insertions(+), 61 deletions(-)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 9f555d5c1d..9150f765da 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -4181,13 +4181,15 @@
##
# @x-blockdev-reopen:
#
-# Reopens a block device using the given set of options. Any option
-# not specified will be reset to its default value regardless of its
-# previous status. If an option cannot be changed or a particular
+# Reopens one or more block devices using the given set of options.
+# Any option not specified will be reset to its default value regardless
+# of its previous status. If an option cannot be changed or a particular
# driver does not support reopening then the command will return an
-# error.
+# error. All devices in the list are reopened in one transaction, so
+# if one of them fails then the whole transaction is cancelled.
#
-# The top-level @node-name option (from BlockdevOptions) must be
+# The command receives a list of block devices to reopen. For each one
+# of them, the top-level @node-name option (from BlockdevOptions) must be
# specified and is used to select the block device to be reopened.
# Other @node-name options must be either omitted or set to the
# current name of the appropriate node. This command won't change any
@@ -4207,8 +4209,8 @@
#
# 4) NULL: the current child (if any) is detached.
#
-# Options (1) and (2) are supported in all cases, but at the moment
-# only @backing allows replacing or detaching an existing child.
+# Options (1) and (2) are supported in all cases. Option (3) is
+# supported for @file and @backing, and option (4) for @backing only.
#
# Unlike with blockdev-add, the @backing option must always be present
# unless the node being reopened does not have a backing file and its
@@ -4218,7 +4220,7 @@
# Since: 4.0
##
{ 'command': 'x-blockdev-reopen',
- 'data': 'BlockdevOptions', 'boxed': true }
+ 'data': { 'options': ['BlockdevOptions'] } }
##
# @blockdev-del:
diff --git a/blockdev.c b/blockdev.c
index 825d40aa11..7019397b05 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3580,46 +3580,64 @@ fail:
visit_free(v);
}
-void qmp_x_blockdev_reopen(BlockdevOptions *options, Error **errp)
+void qmp_x_blockdev_reopen(BlockdevOptionsList *reopen_list, Error **errp)
{
-BlockDriverState *bs;
-AioContext *ctx;
-QObject *obj;
-Visitor *v = qobject_output_visitor_new(&obj);
-BlockReopenQueue *queue;
-QDict *qdict;
+BlockReopenQueue *queue = NULL;
+GSList *aio_ctxs = NULL;
+GSList *visitors = NULL;
+GSList *drained = NULL;
-/* Check for the selected node name */
-if (!options->has_node_name) {
-error_setg(errp, "node-name not specified");
-goto fail;
-}
+/* Add each one of the BDS that we want to reopen to the queue */
+for (; reopen_list != NULL; reopen_list = reopen_list->next) {
+BlockdevOptions *options = reopen_list->value;
+BlockDriverState *bs;
+AioContext *ctx;
+QObject *obj;
+Visitor *v;
+QDict *qdict;
-bs = bdrv_find_node(options->node_name);
-if (!bs) {
-error_setg(errp, "Failed to find node with node-name='%s'",
+/* Check for the selected node name */
+if (!options->has_node_name) {
+error_setg(errp, "node-name not specified");
+goto fail;
+}
+
+bs = bdrv_find_node(options->node_name);
+if (!bs) {
+error_setg(errp, "Failed to find node with node-name='%s'",
options->node_name);
-goto fail;
+goto fail;
+}
+
+v = qobject_output_visitor_new(&obj);
+visitors = g_slist_prepend(visitors, v);
+
+/* Put all options in a QDict and flatten it */
+visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
+visit_complete(v, &obj);
+qdict = qobject_to(QDict, obj);
+
+qdict_flatten(qdict);
+
+ctx = bdrv_get_aio_context(bs);
+if (!g_slist_find(aio_ctxs, ctx)) {
+aio_ctxs = g_slist_prepend(aio_ctxs, ctx);
+aio_context_acquire(ctx);
+}
+bdrv_subtree_drained_begin(bs);
+queue = bdrv_reopen_queue(queue, bs, qdict, false);
+drained = g_slist_prepend(drained, bs);
}
-/* Put all options in a QDict and flatten it */
-visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
-visit_complete(v, &obj);
-qdict = qobject_to(QDict, obj);
-
-qdict_flatten(qdict);
-
/* Perform the reopen ope
