smb: client: set 'server->primary_server = server'

Make server->primary_server always point to the primary server, even if
it's itself.

By making it directly accessible, this also removes possible branch
mispredictions in runtime.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>

8 files changed, 34 insertions, 71 deletions

diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 9958748b9f28..75cd0f8d095d 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -835,8 +835,10 @@ struct TCP_Server_Info {
 	 * If this is a session channel,
 	 * primary_server holds the ref-counted
 	 * pointer to primary channel connection for the session.
+	 *
+	 * If this is a primary channel, primary_server points to itself.
 	 */
-#define SERVER_IS_CHAN(server)	(!!(server)->primary_server)
+#define SERVER_IS_CHAN(server)	((server)->primary_server != (server))
 	struct TCP_Server_Info *primary_server;
 	__u16 channel_sequence_num;  /* incremented on primary channel on each chan reconnect */
 
diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 0454e96f1573..c66bd630b769 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -121,13 +121,9 @@ void
 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 				bool all_channels)
 {
-	struct TCP_Server_Info *pserver;
 	struct cifs_ses *ses;
 	int i;
 
-	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
-
 	/* if we need to signal just this channel */
 	if (!all_channels) {
 		spin_lock(&server->srv_lock);
@@ -138,7 +134,7 @@ cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 	}
 
 	spin_lock(&cifs_tcp_ses_lock);
-	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+	list_for_each_entry(ses, &server->primary_server->smb_ses_list, smb_ses_list) {
 		if (cifs_ses_exiting(ses))
 			continue;
 		spin_lock(&ses->chan_lock);
@@ -181,7 +177,7 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 	cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
 
 	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
+	pserver = server->primary_server;
 
 	/*
 	 * if the server has been marked for termination, there is a
@@ -1828,8 +1824,10 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
 		spin_lock(&cifs_tcp_ses_lock);
 		++primary_server->srv_count;
 		spin_unlock(&cifs_tcp_ses_lock);
-		tcp_ses->primary_server = primary_server;
+	} else {
+		primary_server = tcp_ses;
 	}
+	tcp_ses->primary_server = primary_server;
 	spin_lock_init(&tcp_ses->iface_lock);
 	INIT_LIST_HEAD(&tcp_ses->iface_list);
 	init_waitqueue_head(&tcp_ses->response_q);
@@ -4267,7 +4265,7 @@ cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
 		   struct nls_table *nls_info)
 {
 	int rc = 0;
-	struct TCP_Server_Info *pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
+	struct TCP_Server_Info *pserver = server->primary_server;
 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&pserver->dstaddr;
 	struct sockaddr_in *addr = (struct sockaddr_in *)&pserver->dstaddr;
 	bool is_binding = false;
@@ -4302,7 +4300,7 @@ cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
 	spin_unlock(&ses->ses_lock);
 
 	/* update ses ip_addr only for primary chan */
-	if (server == pserver) {
+	if (!SERVER_IS_CHAN(server)) {
 		spin_lock(&server->srv_lock);
 		/* force iface_list refresh */
 		server->iface_last_update = 0;
diff --git a/fs/smb/client/misc.c b/fs/smb/client/misc.c
index 608b75c10926..fce0650a762e 100644
--- a/fs/smb/client/misc.c
+++ b/fs/smb/client/misc.c
@@ -489,7 +489,7 @@ is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
 		return false;
 
 	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv;
+	pserver = srv->primary_server;
 
 	/* look up tcon based on tid & uid */
 	spin_lock(&cifs_tcp_ses_lock);
diff --git a/fs/smb/client/smb1ops.c b/fs/smb/client/smb1ops.c
index b27a182629ec..157ddbe66c69 100644
--- a/fs/smb/client/smb1ops.c
+++ b/fs/smb/client/smb1ops.c
@@ -1280,7 +1280,6 @@ static bool
 cifs_is_network_name_deleted(char *buf, struct TCP_Server_Info *server)
 {
 	struct smb_hdr *shdr = (struct smb_hdr *)buf;
-	struct TCP_Server_Info *pserver;
 	struct cifs_ses *ses;
 	struct cifs_tcon *tcon;
 
@@ -1293,11 +1292,8 @@ cifs_is_network_name_deleted(char *buf, struct TCP_Server_Info *server)
 			return false;
 	}
 
-	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
-
 	spin_lock(&cifs_tcp_ses_lock);
-	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+	list_for_each_entry(ses, &server->primary_server->smb_ses_list, smb_ses_list) {
 		if (cifs_ses_exiting(ses))
 			continue;
 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
diff --git a/fs/smb/client/smb2misc.c b/fs/smb/client/smb2misc.c
index cddf273c14ae..cf644b3c1d1a 100644
--- a/fs/smb/client/smb2misc.c
+++ b/fs/smb/client/smb2misc.c
@@ -135,7 +135,6 @@ static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len,
 int
 smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server)
 {
-	struct TCP_Server_Info *pserver;
 	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
 	struct smb2_pdu *pdu = (struct smb2_pdu *)shdr;
 	int hdr_size = sizeof(struct smb2_hdr);
@@ -144,8 +143,7 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server)
 	__u32 calc_len; /* calculated length */
 	__u64 mid;
 
-	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
+	server = server->primary_server;
 
 	/*
 	 * Add function to do table lookup of StructureSize by command
@@ -159,7 +157,7 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server)
 
 		/* decrypt frame now that it is completely read in */
 		spin_lock(&cifs_tcp_ses_lock);
-		list_for_each_entry(iter, &pserver->smb_ses_list, smb_ses_list) {
+		list_for_each_entry(iter, &server->smb_ses_list, smb_ses_list) {
 			if (iter->Suid == le64_to_cpu(thdr->SessionId)) {
 				ses = iter;
 				break;
@@ -609,19 +607,15 @@ static bool
 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
 {
 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
-	struct TCP_Server_Info *pserver;
 	struct cifs_ses *ses;
 	struct cifs_tcon *tcon;
 	struct cifs_pending_open *open;
 
 	cifs_dbg(FYI, "Checking for lease break\n");
 
-	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
-
 	/* look up tcon based on tid & uid */
 	spin_lock(&cifs_tcp_ses_lock);
-	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
 		if (cifs_ses_exiting(ses))
 			continue;
 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
@@ -672,7 +666,6 @@ bool
 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 {
 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
-	struct TCP_Server_Info *pserver;
 	struct cifs_ses *ses;
 	struct cifs_tcon *tcon;
 	struct cifsInodeInfo *cinode;
@@ -683,22 +676,19 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
 		return false;
 
-	if (rsp->StructureSize !=
-				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
+	server = server->primary_server;
+
+	if (rsp->StructureSize != smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
 		if (le16_to_cpu(rsp->StructureSize) == 44)
 			return smb2_is_valid_lease_break(buffer, server);
-		else
-			return false;
+		return false;
 	}
 
 	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
 
-	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
-
 	/* look up tcon based on tid & uid */
 	spin_lock(&cifs_tcp_ses_lock);
-	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
 		if (cifs_ses_exiting(ses))
 			continue;
 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index f27da2612327..4d431f0d136a 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -195,10 +195,7 @@ smb2_set_credits(struct TCP_Server_Info *server, const int val)
 		 * ChannelSequence updated for all channels in primary channel so that consistent
 		 * across SMB3 requests sent on any channel. See MS-SMB2 3.2.4.1 and 3.2.7.1
 		 */
-		if (SERVER_IS_CHAN(server))
-			server->primary_server->channel_sequence_num++;
-		else
-			server->channel_sequence_num++;
+		server->primary_server->channel_sequence_num++;
 	}
 	scredits = server->credits;
 	in_flight = server->in_flight;
@@ -2594,7 +2591,6 @@ static bool
 smb2_is_network_name_deleted(char *buf, struct TCP_Server_Info *server)
 {
 	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
-	struct TCP_Server_Info *pserver;
 	struct cifs_ses *ses;
 	struct cifs_tcon *tcon;
 
@@ -2602,10 +2598,10 @@ smb2_is_network_name_deleted(char *buf, struct TCP_Server_Info *server)
 		return false;
 
 	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
+	server = server->primary_server;
 
 	spin_lock(&cifs_tcp_ses_lock);
-	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
 		if (cifs_ses_exiting(ses))
 			continue;
 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
@@ -4324,15 +4320,11 @@ static void *smb2_get_aead_req(struct crypto_aead *tfm, struct smb_rqst *rqst,
 static int
 smb2_get_enc_key(struct TCP_Server_Info *server, __u64 ses_id, int enc, u8 *key)
 {
-	struct TCP_Server_Info *pserver;
 	struct cifs_ses *ses;
 	u8 *ses_enc_key;
 
-	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
-
 	spin_lock(&cifs_tcp_ses_lock);
-	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+	list_for_each_entry(ses, &server->primary_server->smb_ses_list, smb_ses_list) {
 		if (ses->Suid == ses_id) {
 			spin_lock(&ses->ses_lock);
 			ses_enc_key = enc ? ses->smb3encryptionkey :
diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index f8755f111be4..605dd04469da 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -110,12 +110,8 @@ smb2_hdr_assemble(struct smb2_hdr *shdr, __le16 smb2_cmd,
 			 * if primary channel is not set yet, use default
 			 * channel for chan sequence num
 			 */
-			if (SERVER_IS_CHAN(server))
-				smb3_hdr->ChannelSequence =
-					cpu_to_le16(server->primary_server->channel_sequence_num);
-			else
-				smb3_hdr->ChannelSequence =
-					cpu_to_le16(server->channel_sequence_num);
+			smb3_hdr->ChannelSequence =
+				cpu_to_le16(server->primary_server->channel_sequence_num);
 		}
 		spin_lock(&server->req_lock);
 		/* Request up to 10 credits but don't go over the limit. */
@@ -659,7 +655,6 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 		      struct TCP_Server_Info *server, unsigned int *total_len)
 {
 	unsigned int ctxt_len, neg_context_count;
-	struct TCP_Server_Info *pserver;
 	char *pneg_ctxt;
 	char *hostname;
 
@@ -692,9 +687,9 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 	 * secondary channels don't have the hostname field populated
 	 * use the hostname field in the primary channel instead
 	 */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
-	cifs_server_lock(pserver);
-	hostname = pserver->hostname;
+	server = server->primary_server;
+	cifs_server_lock(server);
+	hostname = server->hostname;
 	if (hostname && (hostname[0] != 0)) {
 		ctxt_len = build_netname_ctxt((struct smb2_netname_neg_context *)pneg_ctxt,
 					      hostname);
@@ -703,7 +698,7 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 		neg_context_count = 3;
 	} else
 		neg_context_count = 2;
-	cifs_server_unlock(pserver);
+	cifs_server_unlock(server);
 
 	build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
 	*total_len += sizeof(struct smb2_posix_neg_context);
@@ -4106,7 +4101,7 @@ void smb2_reconnect_server(struct work_struct *work)
 	spin_unlock(&cifs_tcp_ses_lock);
 
 	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
+	pserver = server->primary_server;
 
 	/* Prevent simultaneous reconnects that can corrupt tcon->rlist list */
 	mutex_lock(&pserver->reconnect_mutex);
diff --git a/fs/smb/client/smb2transport.c b/fs/smb/client/smb2transport.c
index 475b36c27f65..7db158f926bc 100644
--- a/fs/smb/client/smb2transport.c
+++ b/fs/smb/client/smb2transport.c
@@ -77,18 +77,13 @@ static
 int smb3_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
 {
 	struct cifs_chan *chan;
-	struct TCP_Server_Info *pserver;
 	struct cifs_ses *ses = NULL;
 	int i;
 	int rc = 0;
 	bool is_binding = false;
 
 	spin_lock(&cifs_tcp_ses_lock);
-
-	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
-
-	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+	list_for_each_entry(ses, &server->primary_server->smb_ses_list, smb_ses_list) {
 		if (ses->Suid == ses_id)
 			goto found;
 	}
@@ -145,13 +140,9 @@ out:
 static struct cifs_ses *
 smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
 {
-	struct TCP_Server_Info *pserver;
 	struct cifs_ses *ses;
 
-	/* If server is a channel, select the primary channel */
-	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
-
-	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+	list_for_each_entry(ses, &server->primary_server->smb_ses_list, smb_ses_list) {
 		if (ses->Suid != ses_id)
 			continue;
 
@@ -174,8 +165,7 @@ static int smb2_get_sign_key(struct TCP_Server_Info *server,
 	struct cifs_ses *ses;
 	int rc = -ENOENT;
 
-	if (SERVER_IS_CHAN(server))
-		server = server->primary_server;
+	server = server->primary_server;
 
 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {