Commit 007dbc39 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

qcow2: Leave s unchanged on qcow2_update_options() failure 



On return, either all new options should be applied to BDRVQcowState (on
success), or all of the old settings should be preserved (on failure).

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
parent 94edf3fb

block/qcow2.c

+35 −22
Original line number Diff line number Diff line
@@ -597,7 +597,10 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options, 
    const char *opt_overlap_check, *opt_overlap_check_template;

    int overlap_check_template = 0;

    uint64_t l2_cache_size, refcount_cache_size;

    Qcow2Cache *l2_table_cache;

    Qcow2Cache *refcount_block_cache;

    uint64_t cache_clean_interval;

    bool use_lazy_refcounts;

    int i;

    Error *local_err = NULL;

    int ret;
@@ -640,9 +643,9 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options, 
    }



    /* alloc L2 table/refcount block cache */

    s->l2_table_cache = qcow2_cache_create(bs, l2_cache_size);

    s->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size);

    if (s->l2_table_cache == NULL || s->refcount_block_cache == NULL) {

    l2_table_cache = qcow2_cache_create(bs, l2_cache_size);

    refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size);

    if (l2_table_cache == NULL || refcount_block_cache == NULL) {

        error_setg(errp, "Could not allocate metadata caches");

        ret = -ENOMEM;

        goto fail;
@@ -656,23 +659,18 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options, 
        ret = -EINVAL;

        goto fail;

    }

    s->cache_clean_interval = cache_clean_interval;

    cache_clean_timer_init(bs, bdrv_get_aio_context(bs));



    /* Enable lazy_refcounts according to image and command line options */

    s->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS,

    use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS,

        (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS));

    if (use_lazy_refcounts && s->qcow_version < 3) {

        error_setg(errp, "Lazy refcounts require a qcow2 image with at least "

                   "qemu 1.1 compatibility level");

        ret = -EINVAL;

        goto fail;

    }



    s->discard_passthrough[QCOW2_DISCARD_NEVER] = false;

    s->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true;

    s->discard_passthrough[QCOW2_DISCARD_REQUEST] =

        qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST,

                          flags & BDRV_O_UNMAP);

    s->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] =

        qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true);

    s->discard_passthrough[QCOW2_DISCARD_OTHER] =

        qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false);



    /* Overlap check options */

    opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP);

    opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE);

    if (opt_overlap_check_template && opt_overlap_check &&
@@ -704,6 +702,10 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options, 
        goto fail;

    }



    /*

     * Start updating fields in BDRVQcow2State.

     * After this point no failure is allowed any more.

     */

    s->overlap_check = 0;

    for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) {

        /* overlap-check defines a template bitmask, but every flag may be
@@ -713,12 +715,23 @@ static int qcow2_update_options(BlockDriverState *bs, QDict *options, 
                              overlap_check_template & (1 << i)) << i;

    }



    if (s->use_lazy_refcounts && s->qcow_version < 3) {

        error_setg(errp, "Lazy refcounts require a qcow2 image with at least "

                   "qemu 1.1 compatibility level");

        ret = -EINVAL;

        goto fail;

    }

    s->l2_table_cache = l2_table_cache;

    s->refcount_block_cache = refcount_block_cache;



    s->use_lazy_refcounts = use_lazy_refcounts;



    s->discard_passthrough[QCOW2_DISCARD_NEVER] = false;

    s->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true;

    s->discard_passthrough[QCOW2_DISCARD_REQUEST] =

        qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST,

                          flags & BDRV_O_UNMAP);

    s->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] =

        qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true);

    s->discard_passthrough[QCOW2_DISCARD_OTHER] =

        qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false);



    s->cache_clean_interval = cache_clean_interval;

    cache_clean_timer_init(bs, bdrv_get_aio_context(bs));



    ret = 0;

fail: