On 05/14/2018 08:44 AM, Vladimir Sementsov-Ogievskiy wrote:
> 12.05.2018 04:25, John Snow wrote:
>> Instead of always setting IN_USE, handle whether or not the bitmap
>> is read-only instead of a two-loop pass. This will allow us to show
>> the flags exactly as they appear for bitmaps in `qemu-img info`.
>>
>> Signed-off-by: John Snow <js...@redhat.com>
>> ---
>> block/qcow2-bitmap.c | 48
>> ++++++++++++++++++++----------------------------
>> 1 file changed, 20 insertions(+), 28 deletions(-)
>>
>> diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
>> index d89758f235..fc8d52fc3e 100644
>> --- a/block/qcow2-bitmap.c
>> +++ b/block/qcow2-bitmap.c
>> @@ -942,13 +942,6 @@ fail:
>> return ret;
>> }
>> -/* for g_slist_foreach for GSList of BdrvDirtyBitmap* elements */
>> -static void release_dirty_bitmap_helper(gpointer bitmap,
>> - gpointer bs)
>> -{
>> - bdrv_release_dirty_bitmap(bs, bitmap);
>> -}
>> -
>> /* for g_slist_foreach for GSList of BdrvDirtyBitmap* elements */
>> static void set_readonly_helper(gpointer bitmap, gpointer value)
>> {
>> @@ -967,8 +960,8 @@ bool qcow2_load_dirty_bitmaps(BlockDriverState
>> *bs, Error **errp)
>> BDRVQcow2State *s = bs->opaque;
>> Qcow2BitmapList *bm_list;
>> Qcow2Bitmap *bm;
>> - GSList *created_dirty_bitmaps = NULL;
>> bool header_updated = false;
>> + bool needs_update = false;
>> if (s->nb_bitmaps == 0) {
>> /* No bitmaps - nothing to do */
>> @@ -992,33 +985,32 @@ bool qcow2_load_dirty_bitmaps(BlockDriverState
>> *bs, Error **errp)
>> bdrv_disable_dirty_bitmap(bitmap);
>> }
>> bdrv_dirty_bitmap_set_persistance(bitmap, true);
>> - bm->flags |= BME_FLAG_IN_USE;
>> - created_dirty_bitmaps =
>> - g_slist_append(created_dirty_bitmaps, bitmap);
>> - }
>> - }
>> -
>> - if (created_dirty_bitmaps != NULL) {
>> - if (can_write(bs)) {
>> - /* in_use flags must be updated */
>> - int ret = update_ext_header_and_dir_in_place(bs, bm_list);
>> - if (ret < 0) {
>> - error_setg_errno(errp, -ret, "Can't update bitmap
>> directory");
>> - goto fail;
>> + if (can_write(bs)) {
>> + bm->flags |= BME_FLAG_IN_USE;
>> + needs_update = true;
>> + } else {
>> + bdrv_dirty_bitmap_set_readonly(bitmap, true);
>
> oops. This shows, that patch 01 was incorrect: before this (03) patch,
> in this case we'll have IN_USE set in cache but not in the image.
>
Ah, I can try to order this patch first so that the cache stays
semantically correct.
>> }
>> - header_updated = true;
>> - } else {
>> - g_slist_foreach(created_dirty_bitmaps, set_readonly_helper,
>> - (gpointer)true);
>> }
>> }
>> - g_slist_free(created_dirty_bitmaps);
>> + /* in_use flags must be updated */
>> + if (needs_update) {
>> + int ret = update_ext_header_and_dir_in_place(bs, bm_list);
>> + if (ret < 0) {
>> + error_setg_errno(errp, -ret, "Can't update bitmap
>> directory");
>> + goto fail;
>> + }
>> + header_updated = true;
>> + }
>> return header_updated;
>
> may be safely changed to return needs_update, as if we failed to update,
> we'll go to fail.
>
Ugh, yes.
>> fail:
>> - g_slist_foreach(created_dirty_bitmaps,
>> release_dirty_bitmap_helper, bs);
>> - g_slist_free(created_dirty_bitmaps);
>> + QSIMPLEQ_FOREACH(bm, bm_list, entry) {
>> + if (bm->dirty_bitmap) {
>> + bdrv_release_dirty_bitmap(bs, bm->dirty_bitmap);
>> + }
>> + }
>> del_bitmap_list(bs);
>> return false;
>
> overall looks good, may be worth move it before 01.
>
