From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45811) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cFPWC-0002Qu-GQ for qemu-devel@nongnu.org; Fri, 09 Dec 2016 13:03:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cFPW8-0005LG-Gi for qemu-devel@nongnu.org; Fri, 09 Dec 2016 13:03:36 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:8229 helo=relay.sw.ru) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cFPW8-0005KI-6j for qemu-devel@nongnu.org; Fri, 09 Dec 2016 13:03:32 -0500 References: <1479835586-74394-1-git-send-email-vsementsov@virtuozzo.com> <1479835586-74394-16-git-send-email-vsementsov@virtuozzo.com> From: Vladimir Sementsov-Ogievskiy Message-ID: <8d6d6ad4-ab85-e45d-7d53-d03c595ff3f3@virtuozzo.com> Date: Fri, 9 Dec 2016 21:03:15 +0300 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 15/21] qcow2: add .bdrv_can_store_dirty_bitmap List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz , qemu-block@nongnu.org, qemu-devel@nongnu.org Cc: kwolf@redhat.com, armbru@redhat.com, eblake@redhat.com, jsnow@redhat.com, famz@redhat.com, den@openvz.org, stefanha@redhat.com, pbonzini@redhat.com 09.12.2016 20:28, Max Reitz wrote: > On 22.11.2016 18:26, Vladimir Sementsov-Ogievskiy wrote: >> Realize .bdrv_can_store_dirty_bitmap interface. >> >> Signed-off-by: Vladimir Sementsov-Ogievskiy >> --- >> block/qcow2-bitmap.c | 40 ++++++++++++++++++++++++++++++++++++++++ >> block/qcow2.c | 1 + >> block/qcow2.h | 4 ++++ >> 3 files changed, 45 insertions(+) >> >> diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c >> index a975388..55b1112 100644 >> --- a/block/qcow2-bitmap.c >> +++ b/block/qcow2-bitmap.c >> @@ -1115,3 +1115,43 @@ fail: >> >> bitmap_list_free(bm_list); >> } >> + >> +bool qcow2_can_store_dirty_bitmap(BlockDriverState *bs, >> + const char *name, >> + uint32_t granularity, >> + Error **errp) >> +{ >> + BDRVQcow2State *s = bs->opaque; >> + const char *reason = NULL; >> + bool found; >> + Qcow2BitmapList *bm_list; >> + >> + if (check_constraints_on_bitmap(bs, name, granularity) != 0) { >> + reason = "it doesn't satisfy the constraints"; >> + goto common_errp; >> + } >> + >> + if (s->nb_bitmaps == 0) { >> + return true; >> + } >> + >> + bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, >> + s->bitmap_directory_size, errp); > Maybe it would make sense to keep the bitmap list in memory... > >> + if (bm_list == NULL) { >> + return false; >> + } >> + >> + found = !!find_bitmap_by_name(bm_list, name); > You can omit the !!, storing it in a bool will do that for you. > >> + bitmap_list_free(bm_list); >> + if (found) { >> + reason = "bitmap with the same name is already stored"; >> + goto common_errp; >> + } >> + >> + return true; >> + >> +common_errp: >> + error_setg(errp, "Can't make bitmap '%s' persistent in '%s', as %s.", >> + name, bdrv_get_device_or_node_name(bs), reason); > Hm, so this function isn't for checking whether a bitmap can be stored, > but whether it can be made persistent. That's a difference; you can > store a bitmap of the same name in the file if you want to overwrite it > (i.e. it's an auto-load bitmap), but you cannot create a new bitmap with > the same name. > > Maybe rename it from bdrv_can_store_dirty_bitmap to > bdrv_can_store_new_dirty_bitmap? Yes, I'll rename it. > > Max > >> + return false; >> +} >> diff --git a/block/qcow2.c b/block/qcow2.c >> index 66c7f74..cb9c2a2 100644 >> --- a/block/qcow2.c >> +++ b/block/qcow2.c >> @@ -3516,6 +3516,7 @@ BlockDriver bdrv_qcow2 = { >> >> .bdrv_load_autoloading_dirty_bitmaps = qcow2_load_autoloading_dirty_bitmaps, >> .bdrv_store_persistent_dirty_bitmaps = qcow2_store_persistent_dirty_bitmaps, >> + .bdrv_can_store_dirty_bitmap = qcow2_can_store_dirty_bitmap, >> }; >> >> static void bdrv_qcow2_init(void) >> diff --git a/block/qcow2.h b/block/qcow2.h >> index d9a7643..e7a44a1 100644 >> --- a/block/qcow2.h >> +++ b/block/qcow2.h >> @@ -616,5 +616,9 @@ void qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); >> /* qcow2-bitmap.c functions */ >> void qcow2_load_autoloading_dirty_bitmaps(BlockDriverState *bs, Error **errp); >> void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp); >> +bool qcow2_can_store_dirty_bitmap(BlockDriverState *bs, >> + const char *name, >> + uint32_t granularity, >> + Error **errp); >> >> #endif >> > -- Best regards, Vladimir