From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: Eric Blake <eblake@redhat.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Cc: Kevin Wolf <kwolf@redhat.com>,
"nbd@other.debian.org" <nbd@other.debian.org>,
"libguestfs@redhat.com" <libguestfs@redhat.com>,
"open list:Network Block Dev..." <qemu-block@nongnu.org>,
Max Reitz <mreitz@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 3/5] nbd: Implement client use of NBD FAST_ZERO
Date: Fri, 30 Aug 2019 18:11:03 +0000 [thread overview]
Message-ID: <8dc987a5-ec87-faa6-1e86-d7c3573694f7@virtuozzo.com> (raw)
In-Reply-To: <20190823143726.27062-4-eblake@redhat.com>
23.08.2019 17:37, Eric Blake wrote:
> The client side is fairly straightforward: if the server advertised
> fast zero support, then we can map that to BDRV_REQ_NO_FALLBACK
> support. A server that advertises FAST_ZERO but not WRITE_ZEROES
> is technically broken, but we can ignore that situation as it does
> not change our behavior.
>
> Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>
> ---
>
> Perhaps this is worth merging with the previous patch.
> ---
> block/nbd.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/block/nbd.c b/block/nbd.c
> index beed46fb3414..8339d7106366 100644
> --- a/block/nbd.c
> +++ b/block/nbd.c
> @@ -1044,6 +1044,10 @@ static int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
> if (!(flags & BDRV_REQ_MAY_UNMAP)) {
> request.flags |= NBD_CMD_FLAG_NO_HOLE;
> }
> + if (flags & BDRV_REQ_NO_FALLBACK) {
> + assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO);
> + request.flags |= NBD_CMD_FLAG_FAST_ZERO;
> + }
>
> if (!bytes) {
> return 0;
> @@ -1239,6 +1243,9 @@ static int nbd_client_connect(BlockDriverState *bs, Error **errp)
> }
> if (s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) {
> bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP;
> + if (s->info.flags & NBD_FLAG_SEND_FAST_ZERO) {
> + bs->supported_zero_flags |= BDRV_REQ_NO_FALLBACK;
> + }
> }
>
> s->sioc = sioc;
>
--
Best regards,
Vladimir
next prev parent reply other threads:[~2019-08-30 18:15 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-23 14:30 [Qemu-devel] cross-project patches: Add NBD Fast Zero support Eric Blake
2019-08-23 14:34 ` [Qemu-devel] [PATCH 0/1] NBD protocol change to add fast zero support Eric Blake
2019-08-23 14:34 ` [Qemu-devel] [PATCH 1/1] protocol: Add NBD_CMD_FLAG_FAST_ZERO Eric Blake
2019-08-23 18:48 ` Wouter Verhelst
2019-08-23 18:58 ` Eric Blake
2019-08-24 6:44 ` Wouter Verhelst
2019-08-28 9:57 ` Vladimir Sementsov-Ogievskiy
2019-08-28 13:04 ` Eric Blake
2019-08-28 13:45 ` Vladimir Sementsov-Ogievskiy
2019-09-03 20:53 ` [Qemu-devel] [Libguestfs] [PATCH 0/1] NBD protocol change to add fast zero support Eric Blake
2019-08-23 14:37 ` [Qemu-devel] [PATCH 0/5] Add NBD fast zero support to qemu client and server Eric Blake
2019-08-23 14:37 ` [Qemu-devel] [PATCH 1/5] nbd: Improve per-export flag handling in server Eric Blake
2019-08-30 18:00 ` Vladimir Sementsov-Ogievskiy
2019-08-30 23:10 ` Eric Blake
2019-08-30 23:32 ` Eric Blake
2019-09-03 16:39 ` Eric Blake
2019-09-04 17:08 ` Vladimir Sementsov-Ogievskiy
2019-08-23 14:37 ` [Qemu-devel] [PATCH 2/5] nbd: Prepare for NBD_CMD_FLAG_FAST_ZERO Eric Blake
2019-08-30 18:07 ` Vladimir Sementsov-Ogievskiy
2019-08-30 23:37 ` Eric Blake
2019-08-31 8:11 ` Vladimir Sementsov-Ogievskiy
2019-09-03 18:49 ` Eric Blake
2019-08-31 8:20 ` Vladimir Sementsov-Ogievskiy
2019-08-23 14:37 ` [Qemu-devel] [PATCH 3/5] nbd: Implement client use of NBD FAST_ZERO Eric Blake
2019-08-30 18:11 ` Vladimir Sementsov-Ogievskiy [this message]
2019-08-23 14:37 ` [Qemu-devel] [PATCH 4/5] nbd: Implement server " Eric Blake
2019-08-30 18:40 ` Vladimir Sementsov-Ogievskiy
2019-08-23 14:37 ` [Qemu-devel] [PATCH 5/5] nbd: Tolerate more errors to structured reply request Eric Blake
2019-08-23 16:41 ` Eric Blake
2019-08-28 13:55 ` [Qemu-devel] [PATCH 0/5] Add NBD fast zero support to qemu client and server Vladimir Sementsov-Ogievskiy
2019-08-28 14:05 ` Eric Blake
2019-08-23 14:38 ` [Qemu-devel] [libnbd PATCH 0/1] libnbd support for new fast zero Eric Blake
2019-08-23 14:38 ` [Qemu-devel] [libnbd PATCH 1/1] api: Add support for FAST_ZERO flag Eric Blake
2019-08-27 12:25 ` [Qemu-devel] [Libguestfs] " Richard W.M. Jones
2019-08-23 14:40 ` [Qemu-devel] [nbdkit PATCH 0/3] nbdkit support for new NBD fast zero Eric Blake
2019-08-23 14:40 ` [Qemu-devel] [nbdkit PATCH 1/3] server: Add internal support for NBDKIT_FLAG_FAST_ZERO Eric Blake
2019-08-23 14:40 ` [Qemu-devel] [nbdkit PATCH 2/3] filters: Add .can_fast_zero hook Eric Blake
2019-08-23 14:40 ` [Qemu-devel] [nbdkit PATCH 3/3] plugins: " Eric Blake
2019-08-23 21:16 ` [Qemu-devel] [Libguestfs] " Eric Blake
2019-08-27 15:43 ` Richard W.M. Jones
2019-08-23 15:05 ` [Qemu-devel] cross-project patches: Add NBD Fast Zero support Vladimir Sementsov-Ogievskiy
2019-08-27 12:14 ` [Qemu-devel] [Libguestfs] " Richard W.M. Jones
2019-08-27 13:23 ` Eric Blake
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