Le Tuesday 04 Feb 2014 à 16:49:22 (+0100), Kevin Wolf a écrit :
> Am 03.02.2014 um 22:51 hat Benoît Canet geschrieben:
> > From: Benoît Canet <[email protected]>
> >
> > Signed-off-by: Benoit Canet <[email protected]>
> > Reviewed-by: Max Reitz <[email protected]>
> > ---
> > block/quorum.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 51 insertions(+)
> >
> > diff --git a/block/quorum.c b/block/quorum.c
> > index cef4424..677a96d 100644
> > --- a/block/quorum.c
> > +++ b/block/quorum.c
> > @@ -619,6 +619,56 @@ static void quorum_invalidate_cache(BlockDriverState
> > *bs)
> > }
> > }
> >
> > +static int64_t coroutine_fn quorum_co_get_block_status(BlockDriverState
> > *bs,
> > + int64_t sector_num,
> > + int nb_sectors,
> > + int *pnum)
> > +{
> > + BDRVQuorumState *s = bs->opaque;
> > + QuorumVoteVersion *winner = NULL;
> > + QuorumVotes result_votes, num_votes;
> > + QuorumVoteValue result_value, num_value;
> > + int i, num;
> > + int64_t result = 0;
> > +
> > + QLIST_INIT(&result_votes.vote_list);
> > + QLIST_INIT(&num_votes.vote_list);
> > + result_votes.compare = quorum_64bits_compare;
> > + num_votes.compare = quorum_64bits_compare;
> > +
> > + for (i = 0; i < s->total; i++) {
> > + result = bdrv_get_block_status(s->bs[i], sector_num, nb_sectors,
> > &num);
> > + /* skip failed requests */
> > + if (result < 0) {
> > + continue;
> > + }
> > + result_value.l = result & BDRV_BLOCK_DATA;
> > + num_value.l = num;
> > + quorum_count_vote(&result_votes, &result_value, i);
> > + quorum_count_vote(&num_votes, &num_value, i);
> > + }
>
> This doesn't work. bdrv_get_block_status() doesn't guarantee that it
> returns all consecutive blocks with the same status. You need to call it
> in a loop here, or change bdrv_get_block_status() so that it loops
> itself.
I don't see what can be done with the results generated by the loop.
Does quorum really need this function ?
Best regards
Benoît
>
> > + winner = quorum_get_vote_winner(&result_votes);
> > + if (winner->vote_count < s->threshold) {
> > + result = -EIO;
> > + goto free_exit;
> > + }
> > + result = winner->value.l;
> > +
> > + winner = quorum_get_vote_winner(&num_votes);
> > + if (winner->vote_count < s->threshold) {
> > + result = -EIO;
> > + goto free_exit;
> > + }
> > + *pnum = winner->value.l;
>
> You can take the status from one group of devices and the number of
> blocks that share this state from another group?!
>
> > +
> > +free_exit:
> > + quorum_free_vote_list(&result_votes);
> > + quorum_free_vote_list(&num_votes);
> > +
> > + return result;
> > +}
> > +
> > static BlockDriver bdrv_quorum = {
> > .format_name = "quorum",
> > .protocol_name = "quorum",
> > @@ -630,6 +680,7 @@ static BlockDriver bdrv_quorum = {
> > .bdrv_aio_readv = quorum_aio_readv,
> > .bdrv_aio_writev = quorum_aio_writev,
> > .bdrv_invalidate_cache = quorum_invalidate_cache,
> > + .bdrv_co_get_block_status = quorum_co_get_block_status,
> > };
> >
> > static void bdrv_quorum_init(void)
>
> Kevin
