This structure will store some of the state of the root BDS if the BDS
tree is removed, so that state can be restored once a new BDS tree is
inserted.
Signed-off-by: Max Reitz <mre...@redhat.com>
---
block/block-backend.c | 37 +++++++++++++++++++++++++++++++++++++
include/block/block_int.h | 10 ++++++++++
include/qemu/typedefs.h | 1 +
include/sysemu/block-backend.h | 2 ++
4 files changed, 50 insertions(+)
diff --git a/block/block-backend.c b/block/block-backend.c
index 0672ce7..b4a158d 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -13,6 +13,7 @@
#include "sysemu/block-backend.h"
#include "block/block_int.h"
#include "block/blockjob.h"
+#include "block/throttle-groups.h"
#include "sysemu/blockdev.h"
#include "sysemu/sysemu.h"
#include "qapi-event.h"
@@ -37,6 +38,10 @@ struct BlockBackend {
/* the block size for which the guest device expects atomicity */
int guest_block_size;
+ /* If the BDS tree is removed, some of its options are stored here (which
+ * can be used to restore those options in the new BDS on insert) */
+ BlockBackendRootState root_state;
+
/* I/O stats (display with "info blockstats"). */
BlockAcctStats stats;
@@ -161,6 +166,7 @@ static void blk_delete(BlockBackend *blk)
bdrv_unref(blk->bs);
blk->bs = NULL;
}
+ g_free(blk->root_state.throttle_group_name);
/* Avoid double-remove after blk_hide_on_behalf_of_hmp_drive_del() */
if (blk->name[0]) {
QTAILQ_REMOVE(&blk_backends, blk, link);
@@ -1050,3 +1056,34 @@ int blk_probe_geometry(BlockBackend *blk, HDGeometry
*geo)
{
return bdrv_probe_geometry(blk->bs, geo);
}
+
+/*
+ * Updates the BlockBackendRootState object with data from the currently
+ * attached BlockDriverState.
+ */
+void blk_update_root_state(BlockBackend *blk)
+{
+ assert(blk->bs);
+
+ blk->root_state.open_flags = blk->bs->open_flags;
+ blk->root_state.read_only = blk->bs->read_only;
+ blk->root_state.detect_zeroes = blk->bs->detect_zeroes;
+
+ blk->root_state.io_limits_enabled = blk->bs->io_limits_enabled;
+
+ g_free(blk->root_state.throttle_group_name);
+ if (blk->bs->throttle_state) {
+ throttle_get_config(blk->bs->throttle_state,
+ &blk->root_state.throttle_config);
+ blk->root_state.throttle_group_name =
+ g_strdup(throttle_group_get_name(blk->bs));
+ } else {
+ blk->root_state.throttle_config = (ThrottleConfig){};
+ blk->root_state.throttle_group_name = NULL;
+ }
+}
+
+BlockBackendRootState *blk_get_root_state(BlockBackend *blk)
+{
+ return &blk->root_state;
+}
diff --git a/include/block/block_int.h b/include/block/block_int.h
index bd35570..ca1eefa 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -449,6 +449,16 @@ struct BlockDriverState {
NotifierWithReturn write_threshold_notifier;
};
+struct BlockBackendRootState {
+ int open_flags;
+ bool read_only;
+ BlockdevDetectZeroesOptions detect_zeroes;
+
+ bool io_limits_enabled;
+ ThrottleConfig throttle_config;
+ char *throttle_group_name;
+};
+
/* Essential block drivers which must always be statically linked into qemu,
and
* which therefore can be accessed without using bdrv_find_format() */
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index 6fdcbcd..413ac6e 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -11,6 +11,7 @@ typedef struct AddressSpace AddressSpace;
typedef struct AioContext AioContext;
typedef struct AudioState AudioState;
typedef struct BlockBackend BlockBackend;
+typedef struct BlockBackendRootState BlockBackendRootState;
typedef struct BlockDriverState BlockDriverState;
typedef struct BusClass BusClass;
typedef struct BusState BusState;
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index eafcef0..52e35a1 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -163,6 +163,8 @@ void blk_add_close_notifier(BlockBackend *blk, Notifier
*notify);
void blk_io_plug(BlockBackend *blk);
void blk_io_unplug(BlockBackend *blk);
BlockAcctStats *blk_get_stats(BlockBackend *blk);
+BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
+void blk_update_root_state(BlockBackend *blk);
void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
BlockCompletionFunc *cb, void *opaque);
--
2.4.6
