diff mbox series

[v12,02/14] block: add insert/remove node functions

Message ID 1603390423-980205-3-git-send-email-andrey.shinkevich@virtuozzo.com
State New
Headers show
Series Apply COR-filter to the block-stream permanently | expand

Commit Message

Zhijian Li (Fujitsu)" via Oct. 22, 2020, 6:13 p.m. UTC
Provide API for a node insertion to and removal from a backing chain.

Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 block.c               | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/block/block.h |  3 +++
 2 files changed, 52 insertions(+)

Comments

Vladimir Sementsov-Ogievskiy Oct. 23, 2020, 2:24 p.m. UTC | #1
22.10.2020 21:13, Andrey Shinkevich wrote:
> Provide API for a node insertion to and removal from a backing chain.

> 

> Suggested-by: Max Reitz <mreitz@redhat.com>

> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>

> ---

>   block.c               | 49 +++++++++++++++++++++++++++++++++++++++++++++++++

>   include/block/block.h |  3 +++

>   2 files changed, 52 insertions(+)

> 

> diff --git a/block.c b/block.c

> index 430edf7..502b483 100644

> --- a/block.c

> +++ b/block.c

> @@ -4670,6 +4670,55 @@ static void bdrv_delete(BlockDriverState *bs)

>       g_free(bs);

>   }

>   

> +BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,

> +                                   int flags, Error **errp)

> +{

> +    BlockDriverState *new_node_bs;

> +    Error *local_err = NULL;

> +

> +    new_node_bs =  bdrv_open(NULL, NULL, node_options, flags, errp);

> +    if (new_node_bs == NULL) {

> +        error_prepend(errp, "Could not create node: ");

> +        return NULL;

> +    }

> +

> +    bdrv_drained_begin(bs);

> +    bdrv_replace_node(bs, new_node_bs, &local_err);

> +    bdrv_drained_end(bs);

> +

> +    if (local_err) {

> +        bdrv_unref(new_node_bs);

> +        error_propagate(errp, local_err);

> +        return NULL;

> +    }

> +

> +    return new_node_bs;

> +}

> +

> +void bdrv_remove_node(BlockDriverState *bs)

> +{

> +    BdrvChild *child;

> +    BlockDriverState *inferior_bs;

> +

> +    child = bdrv_filter_or_cow_child(bs);

> +    if (!child) {

> +        return;

> +    }

> +    inferior_bs = child->bs;

> +

> +    /* Retain the BDS until we complete the graph change. */

> +    bdrv_ref(inferior_bs);

> +    /* Hold a guest back from writing while permissions are being reset. */

> +    bdrv_drained_begin(inferior_bs);

> +    /* Refresh permissions before the graph change. */

> +    bdrv_child_refresh_perms(bs, child, &error_abort);

> +    bdrv_replace_node(bs, inferior_bs, &error_abort);

> +

> +    bdrv_drained_end(inferior_bs);

> +    bdrv_unref(inferior_bs);

> +    bdrv_unref(bs);

> +}


The function is unused, and as I understand can't work as intended without s->active handling. I think it should be dropped

> +

>   /*

>    * Run consistency checks on an image

>    *

> diff --git a/include/block/block.h b/include/block/block.h

> index d16c401..ae7612f 100644

> --- a/include/block/block.h

> +++ b/include/block/block.h

> @@ -350,6 +350,9 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,

>                    Error **errp);

>   void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,

>                          Error **errp);

> +BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,

> +                                   int flags, Error **errp);

> +void bdrv_remove_node(BlockDriverState *bs);

>   

>   int bdrv_parse_aio(const char *mode, int *flags);

>   int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);

> 



-- 
Best regards,
Vladimir
Vladimir Sementsov-Ogievskiy Oct. 23, 2020, 2:32 p.m. UTC | #2
23.10.2020 17:24, Vladimir Sementsov-Ogievskiy wrote:
> 22.10.2020 21:13, Andrey Shinkevich wrote:

>> Provide API for a node insertion to and removal from a backing chain.

>>

>> Suggested-by: Max Reitz <mreitz@redhat.com>

>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>

>> ---

>>   block.c               | 49 +++++++++++++++++++++++++++++++++++++++++++++++++

>>   include/block/block.h |  3 +++

>>   2 files changed, 52 insertions(+)

>>

>> diff --git a/block.c b/block.c

>> index 430edf7..502b483 100644

>> --- a/block.c

>> +++ b/block.c

>> @@ -4670,6 +4670,55 @@ static void bdrv_delete(BlockDriverState *bs)

>>       g_free(bs);

>>   }

>> +BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,

>> +                                   int flags, Error **errp)

>> +{

>> +    BlockDriverState *new_node_bs;

>> +    Error *local_err = NULL;

>> +

>> +    new_node_bs =  bdrv_open(NULL, NULL, node_options, flags, errp);

>> +    if (new_node_bs == NULL) {

>> +        error_prepend(errp, "Could not create node: ");

>> +        return NULL;

>> +    }

>> +

>> +    bdrv_drained_begin(bs);

>> +    bdrv_replace_node(bs, new_node_bs, &local_err);

>> +    bdrv_drained_end(bs);

>> +

>> +    if (local_err) {

>> +        bdrv_unref(new_node_bs);

>> +        error_propagate(errp, local_err);

>> +        return NULL;

>> +    }

>> +

>> +    return new_node_bs;

>> +}

>> +

>> +void bdrv_remove_node(BlockDriverState *bs)

>> +{

>> +    BdrvChild *child;

>> +    BlockDriverState *inferior_bs;

>> +

>> +    child = bdrv_filter_or_cow_child(bs);

>> +    if (!child) {

>> +        return;

>> +    }

>> +    inferior_bs = child->bs;

>> +

>> +    /* Retain the BDS until we complete the graph change. */

>> +    bdrv_ref(inferior_bs);

>> +    /* Hold a guest back from writing while permissions are being reset. */

>> +    bdrv_drained_begin(inferior_bs);

>> +    /* Refresh permissions before the graph change. */

>> +    bdrv_child_refresh_perms(bs, child, &error_abort);

>> +    bdrv_replace_node(bs, inferior_bs, &error_abort);

>> +

>> +    bdrv_drained_end(inferior_bs);

>> +    bdrv_unref(inferior_bs);

>> +    bdrv_unref(bs);

>> +}

> 

> The function is unused, and as I understand can't work as intended without s->active handling. I think it should be dropped


with bdrv_remove_node dropped:

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


> 

>> +

>>   /*

>>    * Run consistency checks on an image

>>    *

>> diff --git a/include/block/block.h b/include/block/block.h

>> index d16c401..ae7612f 100644

>> --- a/include/block/block.h

>> +++ b/include/block/block.h

>> @@ -350,6 +350,9 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,

>>                    Error **errp);

>>   void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,

>>                          Error **errp);

>> +BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,

>> +                                   int flags, Error **errp);

>> +void bdrv_remove_node(BlockDriverState *bs);

>>   int bdrv_parse_aio(const char *mode, int *flags);

>>   int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);

>>

> 

> 



-- 
Best regards,
Vladimir
diff mbox series

Patch

diff --git a/block.c b/block.c
index 430edf7..502b483 100644
--- a/block.c
+++ b/block.c
@@ -4670,6 +4670,55 @@  static void bdrv_delete(BlockDriverState *bs)
     g_free(bs);
 }
 
+BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
+                                   int flags, Error **errp)
+{
+    BlockDriverState *new_node_bs;
+    Error *local_err = NULL;
+
+    new_node_bs =  bdrv_open(NULL, NULL, node_options, flags, errp);
+    if (new_node_bs == NULL) {
+        error_prepend(errp, "Could not create node: ");
+        return NULL;
+    }
+
+    bdrv_drained_begin(bs);
+    bdrv_replace_node(bs, new_node_bs, &local_err);
+    bdrv_drained_end(bs);
+
+    if (local_err) {
+        bdrv_unref(new_node_bs);
+        error_propagate(errp, local_err);
+        return NULL;
+    }
+
+    return new_node_bs;
+}
+
+void bdrv_remove_node(BlockDriverState *bs)
+{
+    BdrvChild *child;
+    BlockDriverState *inferior_bs;
+
+    child = bdrv_filter_or_cow_child(bs);
+    if (!child) {
+        return;
+    }
+    inferior_bs = child->bs;
+
+    /* Retain the BDS until we complete the graph change. */
+    bdrv_ref(inferior_bs);
+    /* Hold a guest back from writing while permissions are being reset. */
+    bdrv_drained_begin(inferior_bs);
+    /* Refresh permissions before the graph change. */
+    bdrv_child_refresh_perms(bs, child, &error_abort);
+    bdrv_replace_node(bs, inferior_bs, &error_abort);
+
+    bdrv_drained_end(inferior_bs);
+    bdrv_unref(inferior_bs);
+    bdrv_unref(bs);
+}
+
 /*
  * Run consistency checks on an image
  *
diff --git a/include/block/block.h b/include/block/block.h
index d16c401..ae7612f 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -350,6 +350,9 @@  void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
                  Error **errp);
 void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
                        Error **errp);
+BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
+                                   int flags, Error **errp);
+void bdrv_remove_node(BlockDriverState *bs);
 
 int bdrv_parse_aio(const char *mode, int *flags);
 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);