From: John Snow <jsnow@redhat.com>
To: Eric Blake <eblake@redhat.com>,
qemu-block@nongnu.org, qemu-devel@nongnu.org
Cc: Fam Zheng <fam@euphon.net>, Kevin Wolf <kwolf@redhat.com>,
vsementsov@virtuozzo.com, Markus Armbruster <armbru@redhat.com>,
Max Reitz <mreitz@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 4/5] block/qcow2-bitmap: Count queued bitmaps towards nb_bitmaps
Date: Fri, 7 Jun 2019 14:04:05 -0400 [thread overview]
Message-ID: <35ec49d9-0000-f7f2-a3ae-7ac19787f54d@redhat.com> (raw)
In-Reply-To: <0d0c47ea-20ce-ba00-0ffd-df35975b71ea@redhat.com>
On 6/6/19 10:27 PM, Eric Blake wrote:
> On 6/6/19 1:41 PM, John Snow wrote:
>> When we check to see if we can store a bitmap, we don't check how many
>> we've queued up. This can cause a problem saving bitmaps on close
>> instead of when we request them to be added. With the stricter add
>> interface, prohibit these bitmaps specifically.
>>
>> To match, make the remove interface more strict as well; now rejecting
>> any requests to remove bitmaps that were never queued for storage.
>>
>> We don't need to "find" the bitmap when the interface has been given the
>> bitmap explicitly, but this is done to make sure that the bitmap given
>> actually does belong to the bs we were passed as a paranoia check to
>> enforce consistency.
>>
>> ---
>
> Oops - that marker...
>
>>
>> "What about directory size?" Please see the following patch.
>>
>> Signed-off-by: John Snow <jsnow@redhat.com>
>
> ...renders the S-o-b invisible.
>
>> +++ b/block/qcow2-bitmap.c
>> @@ -1402,6 +1402,23 @@ static Qcow2Bitmap *find_bitmap_by_name(Qcow2BitmapList *bm_list,
>> return NULL;
>> }
>>
>> +static int qcow2_remove_queued_dirty_bitmap(
>> + BlockDriverState *bs, const char *name, Error **errp)
>> +{
>> + BDRVQcow2State *s = bs->opaque;
>> + BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(bs, name);
>> + if (!bitmap) {
>> + error_setg(errp, "Node '%s' has no stored or enqueued bitmap '%s'",
>> + bdrv_get_node_name(bs), name);
>> + return -ENOENT;
>> + }
>> + assert(s->nb_queued_bitmaps > 0);
>> + assert(bdrv_dirty_bitmap_get_persistence(bitmap));
>> + s->nb_queued_bitmaps -= 1;
>
> I tend to use -- over -= 1.
>
>> @@ -1667,6 +1686,8 @@ int qcow2_add_persistent_dirty_bitmap(BlockDriverState *bs,
>> goto fail;
>> }
>>
>> + s->nb_queued_bitmaps += 1;
>
> And again, for ++
>
> Reviewed-by: Eric Blake <eblake@redhat.com>
>
Wow, sorry, lots of Python lately!
next prev parent reply other threads:[~2019-06-07 19:48 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-06 18:41 [Qemu-devel] [PATCH 0/5] block/dirty-bitmap: check number and size constraints against queued bitmaps John Snow
2019-06-06 18:41 ` [Qemu-devel] [PATCH 1/5] block/qcow2-bitmap: allow bitmap_list_load to return an error code John Snow
2019-06-07 2:07 ` Eric Blake
2019-06-07 12:36 ` Vladimir Sementsov-Ogievskiy
2019-06-06 18:41 ` [Qemu-devel] [PATCH 2/5] block/dirty-bitmap: Refactor bdrv_can_store_new_bitmap John Snow
2019-06-07 2:16 ` Eric Blake
2019-06-07 14:29 ` Vladimir Sementsov-Ogievskiy
2019-06-07 18:10 ` John Snow
2019-06-07 18:15 ` Eric Blake
2019-06-07 18:17 ` Vladimir Sementsov-Ogievskiy
2019-06-07 18:23 ` Vladimir Sementsov-Ogievskiy
2019-06-07 22:08 ` John Snow
2019-06-10 9:29 ` Vladimir Sementsov-Ogievskiy
2019-06-06 18:41 ` [Qemu-devel] [PATCH 3/5] block/dirty-bitmap: rework bdrv_remove_persistent_dirty_bitmap John Snow
2019-06-07 2:24 ` Eric Blake
2019-06-07 14:41 ` Vladimir Sementsov-Ogievskiy
2019-06-07 18:16 ` John Snow
2019-06-06 18:41 ` [Qemu-devel] [PATCH 4/5] block/qcow2-bitmap: Count queued bitmaps towards nb_bitmaps John Snow
2019-06-07 2:27 ` Eric Blake
2019-06-07 18:04 ` John Snow [this message]
2019-06-07 14:58 ` Vladimir Sementsov-Ogievskiy
2019-06-07 18:24 ` John Snow
2019-06-06 18:41 ` [Qemu-devel] [PATCH 5/5] block/qcow2-bitmap: Count queued bitmaps towards directory_size John Snow
2019-06-07 2:30 ` Eric Blake
2019-06-07 19:24 ` John Snow
2019-06-06 21:54 ` [Qemu-devel] [PATCH 0/5] block/dirty-bitmap: check number and size constraints against queued bitmaps no-reply
2019-06-06 22:26 ` John Snow
2019-10-09 18:57 ` Eric Blake
2019-10-09 20:44 ` John Snow
2019-10-10 6:23 ` Vladimir Sementsov-Ogievskiy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=35ec49d9-0000-f7f2-a3ae-7ac19787f54d@redhat.com \
--to=jsnow@redhat.com \
--cc=armbru@redhat.com \
--cc=eblake@redhat.com \
--cc=fam@euphon.net \
--cc=kwolf@redhat.com \
--cc=mreitz@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=vsementsov@virtuozzo.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).