Commit 281d22d8 authored by Max Reitz's avatar Max Reitz Committed by Kevin Wolf
Browse files

block: Add BlockBackendRootState 



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: default avatarMax Reitz <mreitz@redhat.com>
Reviewed-by: default avatarKevin Wolf <kwolf@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 973f2ddf

block/block-backend.c

+40 −0
Original line number Diff line number Diff line
@@ -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 +166,10 @@ static void blk_delete(BlockBackend *blk) 
        bdrv_unref(blk->bs);

        blk->bs = NULL;

    }

    if (blk->root_state.throttle_state) {

        g_free(blk->root_state.throttle_group);

        throttle_group_unref(blk->root_state.throttle_state);

    }

    /* Avoid double-remove after blk_hide_on_behalf_of_hmp_drive_del() */

    if (blk->name[0]) {

        QTAILQ_REMOVE(&blk_backends, blk, link);
@@ -1067,3 +1076,34 @@ 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;



    if (blk->root_state.throttle_group) {

        g_free(blk->root_state.throttle_group);

        throttle_group_unref(blk->root_state.throttle_state);

    }

    if (blk->bs->throttle_state) {

        const char *name = throttle_group_get_name(blk->bs);

        blk->root_state.throttle_group = g_strdup(name);

        blk->root_state.throttle_state = throttle_group_incref(name);

    } else {

        blk->root_state.throttle_group = NULL;

        blk->root_state.throttle_state = NULL;

    }

}



BlockBackendRootState *blk_get_root_state(BlockBackend *blk)

{

    return &blk->root_state;

}

include/block/block_int.h

+10 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 


#include "block/accounting.h"

#include "block/block.h"

#include "block/throttle-groups.h"

#include "qemu/option.h"

#include "qemu/queue.h"

#include "qemu/coroutine.h"
@@ -449,6 +450,15 @@ struct BlockDriverState { 
    NotifierWithReturn write_threshold_notifier;

};



struct BlockBackendRootState {

    int open_flags;

    bool read_only;

    BlockdevDetectZeroesOptions detect_zeroes;



    char *throttle_group;

    ThrottleState *throttle_state;

};



static inline BlockDriverState *backing_bs(BlockDriverState *bs)

{

    return bs->backing ? bs->backing->bs : NULL;

include/qemu/typedefs.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

include/sysemu/block-backend.h

+2 −0
Original line number Diff line number Diff line
@@ -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);