[PATCH dlm/next 2/3] dlm: add grmode sanity checks and debug info

[Alexander Aring <aahringo@redhat.com>]

We had earlier issues regarding to look for invalid cases when DLM
conversions were called in a invalid lkb state or if recovery handling
set lkb states. Cover those cases and let the user warn them about that
we were running into those. While on it add more debugging information
for the kernel logger when we run into those cases if rqmode or grmode
is in some invalid state.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
 fs/dlm/lock.c    | 15 +++++++++++----
 fs/dlm/recover.c |  2 ++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 966a926c301b..b883bb94e3e8 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -2830,6 +2830,11 @@ static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
 		if (test_bit(DLM_IFL_MSTCPY_BIT, &lkb->lkb_iflags))
 			goto out;
 
+		/* sanity check to do a conversion on a invalid lkb state */
+		if (lkb->lkb_grmode == DLM_LOCK_IV ||
+		    lkb->lkb_status != DLM_LKSTS_GRANTED)
+			goto out;
+
 		if (args->flags & DLM_LKF_QUECVT &&
 		    !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
 			goto out;
@@ -2852,14 +2857,16 @@ static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
 	case -EINVAL:
 		/* annoy the user because dlm usage is wrong */
 		WARN_ON(1);
-		log_error(ls, "%s %d %x %x %x %d %d", __func__,
+		log_error(ls, "%s %d %x %x %x %d %d %d %d", __func__,
 			  rv, lkb->lkb_id, dlm_iflags_val(lkb), args->flags,
-			  lkb->lkb_status, lkb->lkb_wait_type);
+			  lkb->lkb_status, lkb->lkb_wait_type,
+			  lkb->lkb_rqmode, lkb->lkb_grmode);
 		break;
 	default:
-		log_debug(ls, "%s %d %x %x %x %d %d", __func__,
+		log_debug(ls, "%s %d %x %x %x %d %d %d %d", __func__,
 			  rv, lkb->lkb_id, dlm_iflags_val(lkb), args->flags,
-			  lkb->lkb_status, lkb->lkb_wait_type);
+			  lkb->lkb_status, lkb->lkb_wait_type,
+			  lkb->lkb_rqmode, lkb->lkb_grmode);
 		break;
 	}
 
diff --git a/fs/dlm/recover.c b/fs/dlm/recover.c
index 7f748b21f1fb..011153fcb84f 100644
--- a/fs/dlm/recover.c
+++ b/fs/dlm/recover.c
@@ -855,6 +855,8 @@ static void recover_conversion(struct dlm_rsb *r)
 			log_debug(ls, "%s %x set gr to rq %d", __func__,
 				  lkb->lkb_id, lkb->lkb_rqmode);
 		} else {
+			WARN_ON(grmode == lkb->lkb_rqmode);
+
 			log_debug(ls, "%s %x set gr %d", __func__,
 				  lkb->lkb_id, grmode);
 			lkb->lkb_grmode = grmode;
-- 
2.43.0