smb3: do not send compression info by default
Since in theory a server could respond with compressed read
responses even if not requested on read request (assuming that
a compression negcontext is sent in negotiate protocol) - do
not send compression information during negotiate protocol
unless the user asks for compression explicitly (compression
is experimental), and add a mount warning that compression
is experimental.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index ab3300a..8e28940 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -521,7 +521,7 @@ build_posix_ctxt(struct smb2_posix_neg_context *pneg_ctxt)
static void
assemble_neg_contexts(struct smb2_negotiate_req *req,
- unsigned int *total_len)
+ struct TCP_Server_Info *server, unsigned int *total_len)
{
char *pneg_ctxt = (char *)req;
unsigned int ctxt_len;
@@ -551,17 +551,19 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
*total_len += ctxt_len;
pneg_ctxt += ctxt_len;
- build_compression_ctxt((struct smb2_compression_capabilities_context *)
+ if (server->compress_algorithm) {
+ build_compression_ctxt((struct smb2_compression_capabilities_context *)
pneg_ctxt);
- ctxt_len = DIV_ROUND_UP(
- sizeof(struct smb2_compression_capabilities_context), 8) * 8;
- *total_len += ctxt_len;
- pneg_ctxt += ctxt_len;
-
+ ctxt_len = DIV_ROUND_UP(
+ sizeof(struct smb2_compression_capabilities_context),
+ 8) * 8;
+ *total_len += ctxt_len;
+ pneg_ctxt += ctxt_len;
+ req->NegotiateContextCount = cpu_to_le16(4);
+ } else
+ req->NegotiateContextCount = cpu_to_le16(3);
build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
*total_len += sizeof(struct smb2_posix_neg_context);
-
- req->NegotiateContextCount = cpu_to_le16(4);
}
static void decode_preauth_context(struct smb2_preauth_neg_context *ctxt)
@@ -829,7 +831,7 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
(strcmp(ses->server->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0))
- assemble_neg_contexts(req, &total_len);
+ assemble_neg_contexts(req, server, &total_len);
}
iov[0].iov_base = (char *)req;
iov[0].iov_len = total_len;