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authorEric Blake <eblake@redhat.com>2016-05-11 16:39:34 -0600
committerPaolo Bonzini <pbonzini@redhat.com>2016-06-16 18:39:04 +0200
commita0c303693ead8236a55a59097d75bd521f8212e2 (patch)
treecf5e0e2311a9db129e90f2b1c765cc62696917b0 /nbd/server.c
parent37146e7eafafd121d80d68455b8f4bc9043a9f4f (diff)
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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>
Diffstat (limited to 'nbd/server.c')
-rw-r--r--nbd/server.c16
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;
}