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smb3: do not send compression info by default

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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>
This commit is contained in:
Steve French 2019-06-24 20:39:04 -05:00
parent 412094a8fb
commit 9fe5ff1c5d
3 changed files with 21 additions and 10 deletions
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1
fs/cifs/cifsglob.h
View File

@ -601,6 +601,7 @@ struct smb_vol {
__u64 snapshot_time; /* needed for timewarp tokens */
__u32 handle_timeout; /* persistent and durable handle timeout in ms */
unsigned int max_credits; /* smb3 max_credits 10 < credits < 60000 */
__u16 compression; /* compression algorithm 0xFFFF default 0=disabled */
};
/**

8
fs/cifs/connect.c
View File

@ -97,6 +97,7 @@ enum {
Opt_persistent, Opt_nopersistent,
Opt_resilient, Opt_noresilient,
Opt_domainauto, Opt_rdma, Opt_modesid,
Opt_compress,
/* Mount options which take numeric value */
Opt_backupuid, Opt_backupgid, Opt_uid,
@ -213,6 +214,7 @@ static const match_table_t cifs_mount_option_tokens = {
{ Opt_echo_interval, "echo_interval=%s" },
{ Opt_max_credits, "max_credits=%s" },
{ Opt_snapshot, "snapshot=%s" },
{ Opt_compress, "compress=%s" },
{ Opt_blank_user, "user=" },
{ Opt_blank_user, "username=" },
@ -1915,6 +1917,11 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
case Opt_rdma:
vol->rdma = true;
break;
case Opt_compress:
vol->compression = UNKNOWN_TYPE;
cifs_dbg(VFS,
"SMB3 compression support is experimental\n");
break;
/* Numeric Values */
case Opt_backupuid:
@ -2691,6 +2698,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
tcp_ses->sequence_number = 0;
tcp_ses->reconnect_instance = 1;
tcp_ses->lstrp = jiffies;
tcp_ses->compress_algorithm = cpu_to_le16(volume_info->compression);
spin_lock_init(&tcp_ses->req_lock);
INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
INIT_LIST_HEAD(&tcp_ses->smb_ses_list);

22
fs/cifs/smb2pdu.c
View File

@ -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;