fs: dlm: constify receive buffer

The dlm receive buffer should be never manipulated as DLM is the last
instance of parsing layer. This patch constify the whole receive buffer
so we are sure it never gets manipulated when it's being parsed.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/dir.c

@@ -196,7 +196,8 @@ int dlm_recover_directory(struct dlm_ls *ls, uint64_t seq)
 	return error;
 }
 
-static struct dlm_rsb *find_rsb_root(struct dlm_ls *ls, char *name, int len)
+static struct dlm_rsb *find_rsb_root(struct dlm_ls *ls, const char *name,
+				     int len)
 {
 	struct dlm_rsb *r;
 	uint32_t hash, bucket;
@@ -232,7 +233,7 @@ static struct dlm_rsb *find_rsb_root(struct dlm_ls *ls, char *name, int len)
    for rsb's we're master of and whose directory node matches the requesting
    node.  inbuf is the rsb name last sent, inlen is the name's length */
 
-void dlm_copy_master_names(struct dlm_ls *ls, char *inbuf, int inlen,
+void dlm_copy_master_names(struct dlm_ls *ls, const char *inbuf, int inlen,
  			   char *outbuf, int outlen, int nodeid)
 {
 	struct list_head *list;

fs/dlm/dir.h

@@ -16,7 +16,7 @@ int dlm_dir_nodeid(struct dlm_rsb *rsb);
 int dlm_hash2nodeid(struct dlm_ls *ls, uint32_t hash);
 void dlm_recover_dir_nodeid(struct dlm_ls *ls);
 int dlm_recover_directory(struct dlm_ls *ls, uint64_t seq);
-void dlm_copy_master_names(struct dlm_ls *ls, char *inbuf, int inlen,
+void dlm_copy_master_names(struct dlm_ls *ls, const char *inbuf, int inlen,
 			   char *outbuf, int outlen, int nodeid);
 
 #endif				/* __DIR_DOT_H__ */

fs/dlm/lock.h

@@ -12,11 +12,11 @@
 #define __LOCK_DOT_H__
 
 void dlm_dump_rsb(struct dlm_rsb *r);
-void dlm_dump_rsb_name(struct dlm_ls *ls, char *name, int len);
+void dlm_dump_rsb_name(struct dlm_ls *ls, const char *name, int len);
 void dlm_print_lkb(struct dlm_lkb *lkb);
-void dlm_receive_message_saved(struct dlm_ls *ls, struct dlm_message *ms,
+void dlm_receive_message_saved(struct dlm_ls *ls, const struct dlm_message *ms,
 			       uint32_t saved_seq);
-void dlm_receive_buffer(union dlm_packet *p, int nodeid);
+void dlm_receive_buffer(const union dlm_packet *p, int nodeid);
 int dlm_modes_compat(int mode1, int mode2);
 void dlm_put_rsb(struct dlm_rsb *r);
 void dlm_hold_rsb(struct dlm_rsb *r);
@@ -25,8 +25,8 @@ void dlm_scan_rsbs(struct dlm_ls *ls);
 int dlm_lock_recovery_try(struct dlm_ls *ls);
 void dlm_unlock_recovery(struct dlm_ls *ls);
 
-int dlm_master_lookup(struct dlm_ls *ls, int nodeid, char *name, int len,
-		      unsigned int flags, int *r_nodeid, int *result);
+int dlm_master_lookup(struct dlm_ls *ls, int from_nodeid, const char *name,
+		      int len, unsigned int flags, int *r_nodeid, int *result);
 
 int dlm_search_rsb_tree(struct rb_root *tree, const void *name, int len,
 			struct dlm_rsb **r_ret);
@@ -36,9 +36,9 @@ void dlm_purge_mstcpy_locks(struct dlm_rsb *r);
 void dlm_recover_grant(struct dlm_ls *ls);
 int dlm_recover_waiters_post(struct dlm_ls *ls);
 void dlm_recover_waiters_pre(struct dlm_ls *ls);
-int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc,
+int dlm_recover_master_copy(struct dlm_ls *ls, const struct dlm_rcom *rc,
 			    __le32 *rl_remid, __le32 *rl_result);
-int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc,
+int dlm_recover_process_copy(struct dlm_ls *ls, const struct dlm_rcom *rc,
 			     uint64_t seq);
 
 int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua, int mode,

fs/dlm/member.c

@@ -18,7 +18,7 @@
 #include "midcomms.h"
 #include "lowcomms.h"
 
-int dlm_slots_version(struct dlm_header *h)
+int dlm_slots_version(const struct dlm_header *h)
 {
 	if ((le32_to_cpu(h->h_version) & 0x0000FFFF) < DLM_HEADER_SLOTS)
 		return 0;

fs/dlm/member.h

@@ -18,7 +18,7 @@ void dlm_clear_members_gone(struct dlm_ls *ls);
 int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv,int *neg_out);
 int dlm_is_removed(struct dlm_ls *ls, int nodeid);
 int dlm_is_member(struct dlm_ls *ls, int nodeid);
-int dlm_slots_version(struct dlm_header *h);
+int dlm_slots_version(const struct dlm_header *h);
 void dlm_slot_save(struct dlm_ls *ls, struct dlm_rcom *rc,
 		   struct dlm_member *memb);
 void dlm_slots_copy_out(struct dlm_ls *ls, struct dlm_rcom *rc);

fs/dlm/midcomms.c

@@ -499,7 +499,8 @@ static void dlm_pas_fin_ack_rcv(struct midcomms_node *node)
 	spin_unlock(&node->state_lock);
 }
 
-static void dlm_receive_buffer_3_2_trace(uint32_t seq, union dlm_packet *p)
+static void dlm_receive_buffer_3_2_trace(uint32_t seq,
+					 const union dlm_packet *p)
 {
 	switch (p->header.h_cmd) {
 	case DLM_MSG:
@@ -513,7 +514,7 @@ static void dlm_receive_buffer_3_2_trace(uint32_t seq, union dlm_packet *p)
 	}
 }
 
-static void dlm_midcomms_receive_buffer(union dlm_packet *p,
+static void dlm_midcomms_receive_buffer(const union dlm_packet *p,
 					struct midcomms_node *node,
 					uint32_t seq)
 {
@@ -708,7 +709,8 @@ static int dlm_midcomms_version_check_3_2(struct midcomms_node *node)
 	return 0;
 }
 
-static int dlm_opts_check_msglen(union dlm_packet *p, uint16_t msglen, int nodeid)
+static int dlm_opts_check_msglen(const union dlm_packet *p, uint16_t msglen,
+				 int nodeid)
 {
 	int len = msglen;
 
@@ -757,7 +759,7 @@ static int dlm_opts_check_msglen(union dlm_packet *p, uint16_t msglen, int nodei
 	return 0;
 }
 
-static void dlm_midcomms_receive_buffer_3_2(union dlm_packet *p, int nodeid)
+static void dlm_midcomms_receive_buffer_3_2(const union dlm_packet *p, int nodeid)
 {
 	uint16_t msglen = le16_to_cpu(p->header.h_length);
 	struct midcomms_node *node;
@@ -878,7 +880,7 @@ static int dlm_midcomms_version_check_3_1(struct midcomms_node *node)
 	return 0;
 }
 
-static void dlm_midcomms_receive_buffer_3_1(union dlm_packet *p, int nodeid)
+static void dlm_midcomms_receive_buffer_3_1(const union dlm_packet *p, int nodeid)
 {
 	uint16_t msglen = le16_to_cpu(p->header.h_length);
 	struct midcomms_node *node;
@@ -977,10 +979,10 @@ int dlm_process_incoming_buffer(int nodeid, unsigned char *buf, int len)
 
 		switch (hd->h_version) {
 		case cpu_to_le32(DLM_VERSION_3_1):
-			dlm_midcomms_receive_buffer_3_1((union dlm_packet *)ptr, nodeid);
+			dlm_midcomms_receive_buffer_3_1((const union dlm_packet *)ptr, nodeid);
 			break;
 		case cpu_to_le32(DLM_VERSION_3_2):
-			dlm_midcomms_receive_buffer_3_2((union dlm_packet *)ptr, nodeid);
+			dlm_midcomms_receive_buffer_3_2((const union dlm_packet *)ptr, nodeid);
 			break;
 		default:
 			log_print("received invalid version header: %u from node %d, will skip this message",

fs/dlm/rcom.c

@@ -221,7 +221,8 @@ int dlm_rcom_status(struct dlm_ls *ls, int nodeid, uint32_t status_flags,
 	return error;
 }
 
-static void receive_rcom_status(struct dlm_ls *ls, struct dlm_rcom *rc_in,
+static void receive_rcom_status(struct dlm_ls *ls,
+				const struct dlm_rcom *rc_in,
 				uint64_t seq)
 {
 	struct dlm_rcom *rc;
@@ -283,7 +284,7 @@ static void receive_rcom_status(struct dlm_ls *ls, struct dlm_rcom *rc_in,
 	send_rcom_stateless(msg, rc);
 }
 
-static void receive_sync_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
+static void receive_sync_reply(struct dlm_ls *ls, const struct dlm_rcom *rc_in)
 {
 	spin_lock(&ls->ls_rcom_spin);
 	if (!test_bit(LSFL_RCOM_WAIT, &ls->ls_flags) ||
@@ -333,7 +334,7 @@ int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name,
 	return error;
 }
 
-static void receive_rcom_names(struct dlm_ls *ls, struct dlm_rcom *rc_in,
+static void receive_rcom_names(struct dlm_ls *ls, const struct dlm_rcom *rc_in,
 			       uint64_t seq)
 {
 	struct dlm_rcom *rc;
@@ -376,8 +377,8 @@ int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid, uint64_t seq)
 	return error;
 }
 
-static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in,
-				uint64_t seq)
+static void receive_rcom_lookup(struct dlm_ls *ls,
+				const struct dlm_rcom *rc_in, uint64_t seq)
 {
 	struct dlm_rcom *rc;
 	struct dlm_mhandle *mh;
@@ -408,7 +409,8 @@ static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in,
 	send_rcom(mh, rc);
 }
 
-static void receive_rcom_lookup_reply(struct dlm_ls *ls, struct dlm_rcom *rc_in)
+static void receive_rcom_lookup_reply(struct dlm_ls *ls,
+				      const struct dlm_rcom *rc_in)
 {
 	dlm_recover_master_reply(ls, rc_in);
 }
@@ -469,7 +471,7 @@ int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb, uint64_t seq)
 }
 
 /* needs at least dlm_rcom + rcom_lock */
-static void receive_rcom_lock(struct dlm_ls *ls, struct dlm_rcom *rc_in,
+static void receive_rcom_lock(struct dlm_ls *ls, const struct dlm_rcom *rc_in,
 			      uint64_t seq)
 {
 	__le32 rl_remid, rl_result;
@@ -500,7 +502,7 @@ static void receive_rcom_lock(struct dlm_ls *ls, struct dlm_rcom *rc_in,
 /* If the lockspace doesn't exist then still send a status message
    back; it's possible that it just doesn't have its global_id yet. */
 
-int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
+int dlm_send_ls_not_ready(int nodeid, const struct dlm_rcom *rc_in)
 {
 	struct dlm_rcom *rc;
 	struct rcom_config *rf;
@@ -578,7 +580,7 @@ int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in)
 /* Called by dlm_recv; corresponds to dlm_receive_message() but special
    recovery-only comms are sent through here. */
 
-void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
+void dlm_receive_rcom(struct dlm_ls *ls, const struct dlm_rcom *rc, int nodeid)
 {
 	int lock_size = sizeof(struct dlm_rcom) + sizeof(struct rcom_lock);
 	int stop, reply = 0, names = 0, lookup = 0, lock = 0;

fs/dlm/rcom.h

@@ -18,8 +18,9 @@ int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name,
 		   int last_len, uint64_t seq);
 int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid, uint64_t seq);
 int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb, uint64_t seq);
-void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid);
-int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in);
+void dlm_receive_rcom(struct dlm_ls *ls, const struct dlm_rcom *rc,
+		      int nodeid);
+int dlm_send_ls_not_ready(int nodeid, const struct dlm_rcom *rc_in);
 
 #endif
 

fs/dlm/recover.c

@@ -564,7 +564,7 @@ int dlm_recover_masters(struct dlm_ls *ls, uint64_t seq)
 	return error;
 }
 
-int dlm_recover_master_reply(struct dlm_ls *ls, struct dlm_rcom *rc)
+int dlm_recover_master_reply(struct dlm_ls *ls, const struct dlm_rcom *rc)
 {
 	struct dlm_rsb *r;
 	int ret_nodeid, new_master;

fs/dlm/recover.h

@@ -20,7 +20,7 @@ int dlm_recover_directory_wait(struct dlm_ls *ls, uint64_t seq);
 int dlm_recover_locks_wait(struct dlm_ls *ls, uint64_t seq);
 int dlm_recover_done_wait(struct dlm_ls *ls, uint64_t seq);
 int dlm_recover_masters(struct dlm_ls *ls, uint64_t seq);
-int dlm_recover_master_reply(struct dlm_ls *ls, struct dlm_rcom *rc);
+int dlm_recover_master_reply(struct dlm_ls *ls, const struct dlm_rcom *rc);
 int dlm_recover_locks(struct dlm_ls *ls, uint64_t seq);
 void dlm_recovered_lock(struct dlm_rsb *r);
 int dlm_create_root_list(struct dlm_ls *ls);

fs/dlm/requestqueue.c

@@ -30,7 +30,8 @@ struct rq_entry {
  * lockspace is enabled on some while still suspended on others.
  */
 
-void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid, struct dlm_message *ms)
+void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid,
+			  const struct dlm_message *ms)
 {
 	struct rq_entry *e;
 	int length = le16_to_cpu(ms->m_header.h_length) -

fs/dlm/requestqueue.h

@@ -11,7 +11,8 @@
 #ifndef __REQUESTQUEUE_DOT_H__
 #define __REQUESTQUEUE_DOT_H__
 
-void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid, struct dlm_message *ms);
+void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid,
+			  const struct dlm_message *ms);
 int dlm_process_requestqueue(struct dlm_ls *ls);
 void dlm_wait_requestqueue(struct dlm_ls *ls);
 void dlm_purge_requestqueue(struct dlm_ls *ls);