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| author | Eric Blake <eblake@redhat.com> | 2019-08-23 09:37:25 -0500 |
|---|---|---|
| committer | Eric Blake <eblake@redhat.com> | 2019-09-05 16:04:53 -0500 |
| commit | b491dbb7f8e09ef864770c205a3b5bce6c5c1881 (patch) | |
| tree | 8d9bdb3c13e3e7849c739a2faec6490f522394cb /nbd | |
| parent | f061656cc355161f9984237298c45762ce5187d3 (diff) | |
| download | qemu-b491dbb7f8e09ef864770c205a3b5bce6c5c1881.zip | |
nbd: Implement server use of NBD FAST_ZERO
The server side is fairly straightforward: we can always advertise
support for detection of fast zero, and implement it by mapping the
request to the block layer BDRV_REQ_NO_FALLBACK.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190823143726.27062-5-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[eblake: update iotests 223, 233]
Diffstat (limited to 'nbd')
| -rw-r--r-- | nbd/server.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/nbd/server.c b/nbd/server.c index 4992148de1..28c3c8be85 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1513,7 +1513,8 @@ NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset, exp->nbdflags |= NBD_FLAG_CAN_MULTI_CONN; } } else { - exp->nbdflags |= NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_WRITE_ZEROES; + exp->nbdflags |= (NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_WRITE_ZEROES | + NBD_FLAG_SEND_FAST_ZERO); } assert(size <= INT64_MAX - dev_offset); exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE); @@ -2166,7 +2167,7 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, if (request->type == NBD_CMD_READ && client->structured_reply) { valid_flags |= NBD_CMD_FLAG_DF; } else if (request->type == NBD_CMD_WRITE_ZEROES) { - valid_flags |= NBD_CMD_FLAG_NO_HOLE; + valid_flags |= NBD_CMD_FLAG_NO_HOLE | NBD_CMD_FLAG_FAST_ZERO; } else if (request->type == NBD_CMD_BLOCK_STATUS) { valid_flags |= NBD_CMD_FLAG_REQ_ONE; } @@ -2305,6 +2306,9 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, if (!(request->flags & NBD_CMD_FLAG_NO_HOLE)) { flags |= BDRV_REQ_MAY_UNMAP; } + if (request->flags & NBD_CMD_FLAG_FAST_ZERO) { + flags |= BDRV_REQ_NO_FALLBACK; + } ret = blk_pwrite_zeroes(exp->blk, request->from + exp->dev_offset, request->len, flags); return nbd_send_generic_reply(client, request->handle, ret, |