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>

1 files changed, 11 insertions, 9 deletions

diff --git a/fs/dlm/rcom.c b/fs/dlm/rcom.c
index 0946431e370a..6ab029149a1d 100644
--- a/fs/dlm/rcom.c
+++ b/fs/dlm/rcom.c
@@ -221,7 +221,8 @@ retry:
 	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 @@ retry:
 	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;