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| author | Eric Blake <eblake@redhat.com> | 2016-05-11 16:39:34 -0600 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-06-16 18:39:04 +0200 |
| commit | a0c303693ead8236a55a59097d75bd521f8212e2 (patch) | |
| tree | cf5e0e2311a9db129e90f2b1c765cc62696917b0 | |
| parent | 37146e7eafafd121d80d68455b8f4bc9043a9f4f (diff) | |
| download | qemu-a0c303693ead8236a55a59097d75bd521f8212e2.zip qemu-a0c303693ead8236a55a59097d75bd521f8212e2.tar.gz qemu-a0c303693ead8236a55a59097d75bd521f8212e2.tar.bz2 | |
nbd: Use BDRV_REQ_FUA for better FUA where supported
Rather than always flushing ourselves, let the block layer
forward the FUA on to the underlying device - where all
underlying layers also understand FUA, we are now more
efficient; and where any underlying layer doesn't understand
it, now the block layer takes care of the full flush fallback
on our behalf.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1463006384-7734-2-git-send-email-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | nbd/server.c | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/nbd/server.c b/nbd/server.c index 91471f1..7063edb 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1038,6 +1038,7 @@ static void nbd_trip(void *opaque) struct nbd_reply reply; ssize_t ret; uint32_t command; + int flags; TRACE("Reading request."); if (client->closing) { @@ -1114,23 +1115,18 @@ static void nbd_trip(void *opaque) TRACE("Writing to device"); + flags = 0; + if (request.type & NBD_CMD_FLAG_FUA) { + flags |= BDRV_REQ_FUA; + } ret = blk_pwrite(exp->blk, request.from + exp->dev_offset, - req->data, request.len, 0); + req->data, request.len, flags); if (ret < 0) { LOG("writing to file failed"); reply.error = -ret; goto error_reply; } - if (request.type & NBD_CMD_FLAG_FUA) { - ret = blk_co_flush(exp->blk); - if (ret < 0) { - LOG("flush failed"); - reply.error = -ret; - goto error_reply; - } - } - if (nbd_co_send_reply(req, &reply, 0) < 0) { goto out; } |