From: Eric Blake <eblake@redhat.com>
To: qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Max Reitz <mreitz@redhat.com>,
"open list:Network Block Dev..." <qemu-block@nongnu.org>,
libguestfs@redhat.com, nbd@other.debian.org
Subject: [Qemu-devel] [PATCH 3/5] nbd: Implement client use of NBD FAST_ZERO
Date: Fri, 23 Aug 2019 09:37:24 -0500 [thread overview]
Message-ID: <20190823143726.27062-4-eblake@redhat.com> (raw)
In-Reply-To: <20190823143726.27062-1-eblake@redhat.com>
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>
---
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;
--
2.21.0
next prev parent reply other threads:[~2019-08-23 14:49 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 ` Eric Blake [this message]
2019-08-30 18:11 ` [Qemu-devel] [PATCH 3/5] nbd: Implement client use of NBD FAST_ZERO Vladimir Sementsov-Ogievskiy
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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