Commit 178e08a5 authored by Anthony Liguori's avatar Anthony Liguori
Browse files

Fix savevm after BDRV_FILE size enforcement 



We now enforce that you cannot write beyond the end of a non-growable file.
qcow2 files are not growable but we rely on them being growable to do
savevm/loadvm.  Temporarily allow them to be growable by introducing a new
API specifically for savevm read/write operations.

Reported-by: malc
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6994 c046a42c-6fe2-441c-8c8c-71466251a162
parent 8185d2c9

block-qcow2.c

+28 −0
Original line number Diff line number Diff line
@@ -2721,6 +2721,31 @@ static void dump_refcounts(BlockDriverState *bs) 
#endif

#endif



static int qcow_put_buffer(BlockDriverState *bs, const uint8_t *buf,

                           int64_t pos, int size)

{

    int growable = bs->growable;



    bs->growable = 1;

    bdrv_pwrite(bs, pos, buf, size);

    bs->growable = growable;



    return size;

}



static int qcow_get_buffer(BlockDriverState *bs, uint8_t *buf,

                           int64_t pos, int size)

{

    int growable = bs->growable;

    int ret;



    bs->growable = 1;

    ret = bdrv_pread(bs, pos, buf, size);

    bs->growable = growable;



    return ret;

}



BlockDriver bdrv_qcow2 = {

    .format_name	= "qcow2",

    .instance_size	= sizeof(BDRVQcowState),
@@ -2745,5 +2770,8 @@ BlockDriver bdrv_qcow2 = { 
    .bdrv_snapshot_list	= qcow_snapshot_list,

    .bdrv_get_info	= qcow_get_info,



    .bdrv_put_buffer    = qcow_put_buffer,

    .bdrv_get_buffer    = qcow_get_buffer,



    .bdrv_create2 = qcow_create2,

};

block.c

+20 −0
Original line number Diff line number Diff line
@@ -1146,6 +1146,26 @@ int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 
    return drv->bdrv_get_info(bs, bdi);

}



int bdrv_put_buffer(BlockDriverState *bs, const uint8_t *buf, int64_t pos, int size)

{

    BlockDriver *drv = bs->drv;

    if (!drv)

        return -ENOMEDIUM;

    if (!drv->bdrv_put_buffer)

        return -ENOTSUP;

    return drv->bdrv_put_buffer(bs, buf, pos, size);

}



int bdrv_get_buffer(BlockDriverState *bs, uint8_t *buf, int64_t pos, int size)

{

    BlockDriver *drv = bs->drv;

    if (!drv)

        return -ENOMEDIUM;

    if (!drv->bdrv_get_buffer)

        return -ENOTSUP;

    return drv->bdrv_get_buffer(bs, buf, pos, size);

}



/**************************************************************/

/* handling of snapshots */

block.h

+5 −0
Original line number Diff line number Diff line
@@ -178,4 +178,9 @@ void path_combine(char *dest, int dest_size, 
                  const char *base_path,

                  const char *filename);



int bdrv_put_buffer(BlockDriverState *bs, const uint8_t *buf,

                    int64_t pos, int size);



int bdrv_get_buffer(BlockDriverState *bs, uint8_t *buf, int64_t pos, int size);



#endif

block_int.h

+5 −0
Original line number Diff line number Diff line
@@ -78,6 +78,11 @@ struct BlockDriver { 
                              QEMUSnapshotInfo **psn_info);

    int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);



    int (*bdrv_put_buffer)(BlockDriverState *bs, const uint8_t *buf,

                           int64_t pos, int size);

    int (*bdrv_get_buffer)(BlockDriverState *bs, uint8_t *buf,

                           int64_t pos, int size);



    /* removable device specific */

    int (*bdrv_is_inserted)(BlockDriverState *bs);

    int (*bdrv_media_changed)(BlockDriverState *bs);

savevm.c

+6 −6
Original line number Diff line number Diff line
@@ -310,18 +310,18 @@ typedef struct QEMUFileBdrv 
    int64_t base_offset;

} QEMUFileBdrv;



static int bdrv_put_buffer(void *opaque, const uint8_t *buf,

static int block_put_buffer(void *opaque, const uint8_t *buf,

                           int64_t pos, int size)

{

    QEMUFileBdrv *s = opaque;

    bdrv_pwrite(s->bs, s->base_offset + pos, buf, size);

    bdrv_put_buffer(s->bs, buf, s->base_offset + pos, size);

    return size;

}



static int bdrv_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)

static int block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)

{

    QEMUFileBdrv *s = opaque;

    return bdrv_pread(s->bs, s->base_offset + pos, buf, size);

    return bdrv_get_buffer(s->bs, buf, s->base_offset + pos, size);

}



static int bdrv_fclose(void *opaque)
@@ -341,9 +341,9 @@ static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int64_t offset, int is_wr 
    s->base_offset = offset;



    if (is_writable)

        return qemu_fopen_ops(s, bdrv_put_buffer, NULL, bdrv_fclose, NULL);

        return qemu_fopen_ops(s, block_put_buffer, NULL, bdrv_fclose, NULL);



    return qemu_fopen_ops(s, NULL, bdrv_get_buffer, bdrv_fclose, NULL);

    return qemu_fopen_ops(s, NULL, block_get_buffer, bdrv_fclose, NULL);

}



QEMUFile *qemu_fopen_ops(void *opaque, QEMUFilePutBufferFunc *put_buffer,