Commit e023b2e2 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Kevin Wolf
Browse files

block: fix snapshot on QED 



QED's opaque data includes a pointer back to the BlockDriverState.
This breaks when bdrv_append shuffles data between bs_new and bs_top.
To avoid this, add a "rebind" function that tells the driver about
the new relationship between the BlockDriverState and its opaque.

The patch also adds rebind to VVFAT for completeness, even though
it is not used with live snapshots.

Reviewed-by: default avatarStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: default avatarKevin Wolf <kwolf@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 93e9eb68

block.c

+10 −0
Original line number Diff line number Diff line
@@ -949,6 +949,13 @@ void bdrv_make_anon(BlockDriverState *bs) 
    bs->device_name[0] = '\0';

}



static void bdrv_rebind(BlockDriverState *bs)

{

    if (bs->drv && bs->drv->bdrv_rebind) {

        bs->drv->bdrv_rebind(bs);

    }

}



/*

 * Add new bs contents at the top of an image chain while the chain is

 * live, while keeping required fields on the top layer.
@@ -1037,6 +1044,9 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) 
    bs_new->slice_time        = 0;

    bs_new->slice_start       = 0;

    bs_new->slice_end         = 0;



    bdrv_rebind(bs_new);

    bdrv_rebind(bs_top);

}



void bdrv_delete(BlockDriverState *bs)

block/qed.c

+7 −0
Original line number Diff line number Diff line
@@ -367,6 +367,12 @@ static void qed_cancel_need_check_timer(BDRVQEDState *s) 
    qemu_del_timer(s->need_check_timer);

}



static void bdrv_qed_rebind(BlockDriverState *bs)

{

    BDRVQEDState *s = bs->opaque;

    s->bs = bs;

}



static int bdrv_qed_open(BlockDriverState *bs, int flags)

{

    BDRVQEDState *s = bs->opaque;
@@ -1550,6 +1556,7 @@ static BlockDriver bdrv_qed = { 
    .create_options           = qed_create_options,



    .bdrv_probe               = bdrv_qed_probe,

    .bdrv_rebind              = bdrv_qed_rebind,

    .bdrv_open                = bdrv_qed_open,

    .bdrv_close               = bdrv_qed_close,

    .bdrv_create              = bdrv_qed_create,

block/vvfat.c

+7 −0
Original line number Diff line number Diff line
@@ -982,6 +982,12 @@ static BDRVVVFATState *vvv = NULL; 
static int enable_write_target(BDRVVVFATState *s);

static int is_consistent(BDRVVVFATState *s);



static void vvfat_rebind(BlockDriverState *bs)

{

    BDRVVVFATState *s = bs->opaque;

    s->bs = bs;

}



static int vvfat_open(BlockDriverState *bs, const char* dirname, int flags)

{

    BDRVVVFATState *s = bs->opaque;
@@ -2855,6 +2861,7 @@ static BlockDriver bdrv_vvfat = { 
    .format_name	= "vvfat",

    .instance_size	= sizeof(BDRVVVFATState),

    .bdrv_file_open	= vvfat_open,

    .bdrv_rebind	= vvfat_rebind,

    .bdrv_read          = vvfat_co_read,

    .bdrv_write         = vvfat_co_write,

    .bdrv_close		= vvfat_close,

block_int.h

+1 −0
Original line number Diff line number Diff line
@@ -140,6 +140,7 @@ struct BlockDriver { 
    int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,

                      const uint8_t *buf, int nb_sectors);

    void (*bdrv_close)(BlockDriverState *bs);

    void (*bdrv_rebind)(BlockDriverState *bs);

    int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);

    int (*bdrv_set_key)(BlockDriverState *bs, const char *key);

    int (*bdrv_make_empty)(BlockDriverState *bs);