diff options
| author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2018-04-13 17:31:56 +0300 |
|---|---|---|
| committer | Eric Blake <eblake@redhat.com> | 2018-06-21 09:41:39 -0500 |
| commit | bc37b06a5cde24fb24c2a2cc44dd86756034ba9d (patch) | |
| tree | 9d3f3a1819a76c79d048858072ab3d0ce66be975 /nbd | |
| parent | 3229a835a3c574a8ebc605e007785c4e01c61623 (diff) | |
nbd/server: introduce NBD_CMD_CACHE
Handle nbd CACHE command. Just do read, without sending read data back.
Cache mechanism should be done by exported node driver chain.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180413143156.11409-1-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: fix two missing case labels in switch statements]
Signed-off-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'nbd')
| -rw-r--r-- | nbd/common.c | 2 | ||||
| -rw-r--r-- | nbd/server.c | 11 |
2 files changed, 9 insertions, 4 deletions
diff --git a/nbd/common.c b/nbd/common.c index 8c95c1d606..41f5ed8d9f 100644 --- a/nbd/common.c +++ b/nbd/common.c @@ -148,6 +148,8 @@ const char *nbd_cmd_lookup(uint16_t cmd) return "flush"; case NBD_CMD_TRIM: return "trim"; + case NBD_CMD_CACHE: + return "cache"; case NBD_CMD_WRITE_ZEROES: return "write zeroes"; case NBD_CMD_BLOCK_STATUS: diff --git a/nbd/server.c b/nbd/server.c index 2c2d62c636..274604609f 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1252,7 +1252,7 @@ static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp) int ret; const uint16_t myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA | - NBD_FLAG_SEND_WRITE_ZEROES); + NBD_FLAG_SEND_WRITE_ZEROES | NBD_FLAG_SEND_CACHE); bool oldStyle; /* Old style negotiation header, no room for options @@ -2034,7 +2034,9 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, return -EIO; } - if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE) { + if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE || + request->type == NBD_CMD_CACHE) + { if (request->len > NBD_MAX_BUFFER_SIZE) { error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)", request->len, NBD_MAX_BUFFER_SIZE); @@ -2119,7 +2121,7 @@ static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, int ret; NBDExport *exp = client->exp; - assert(request->type == NBD_CMD_READ); + assert(request->type == NBD_CMD_READ || request->type == NBD_CMD_CACHE); /* XXX: NBD Protocol only documents use of FUA with WRITE */ if (request->flags & NBD_CMD_FLAG_FUA) { @@ -2138,7 +2140,7 @@ static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request, ret = blk_pread(exp->blk, request->from + exp->dev_offset, data, request->len); - if (ret < 0) { + if (ret < 0 || request->type == NBD_CMD_CACHE) { return nbd_send_generic_reply(client, request->handle, ret, "reading from file failed", errp); } @@ -2171,6 +2173,7 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, switch (request->type) { case NBD_CMD_READ: + case NBD_CMD_CACHE: return nbd_do_cmd_read(client, request, data, errp); case NBD_CMD_WRITE: |