From ee4e3175c888135f143ad1b0c54768459c9d88b4 Mon Sep 17 00:00:00 2001
From: Andrea Mazzoleni <amadvance@gmail.com>
Date: Thu, 20 Aug 2026 01:22:31 +0200
Subject: [PATCH] Enforce mode parity limits

---
 raid/check.c  |  5 ++++-
 raid/module.c | 23 +++++++++++++++++++----
 raid/raid.c   |  3 +++
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/raid/check.c b/raid/check.c
index 5f11008c..a2aa6308 100644
--- a/raid/check.c
+++ b/raid/check.c
@@ -115,7 +115,10 @@ int raid_check(int nr, int *ir, int nd, int np, size_t size, void **v)
 
 	/* enforce limit on number of failures */
 	BUG_ON(nr >= np); /* >= because we check with extra parity */
-	BUG_ON(np > RAID_PARITY_MAX);
+	if (raid_mode(RAID_MODE_GET) == RAID_MODE_VANDERMONDE_RAID)
+		BUG_ON(np > 3);
+	else
+		BUG_ON(np > RAID_PARITY_MAX);
 
 	/* enforce order in index vector */
 	BUG_ON(nr >= 2 && ir[0] >= ir[1]);
diff --git a/raid/module.c b/raid/module.c
index 9a8da20e..7043838d 100644
--- a/raid/module.c
+++ b/raid/module.c
@@ -80,8 +80,12 @@ void raid_gen(int nd, int np, size_t size, void **v)
 
 	/* enforce limit on number of failures */
 	BUG_ON(np < 1);
-	BUG_ON(np > RAID_PARITY_MAX);
+	if (raid_mode_active == RAID_MODE_VANDERMONDE_RAID)
+		BUG_ON(np > 3);
+	else
+		BUG_ON(np > RAID_PARITY_MAX);
 
+	BUG_ON(raid_gen_ptr[np - 1] == 0);
 	raid_gen_ptr[np - 1](nd, size, v);
 }
 
@@ -104,7 +108,10 @@ void raid_rec(int nr, int *ir, int nd, int np, size_t size, void **v)
 
 	/* enforce limit on number of failures */
 	BUG_ON(nr > np);
-	BUG_ON(np > RAID_PARITY_MAX);
+	if (raid_mode_active == RAID_MODE_VANDERMONDE_RAID)
+		BUG_ON(np > 3);
+	else
+		BUG_ON(np > RAID_PARITY_MAX);
 
 	/* enforce order in index vector */
 	BUG_ON(nr >= 2 && ir[0] >= ir[1]);
@@ -183,9 +190,17 @@ void raid_data(int nr, int *id, int *ip, int nd, size_t size, void **v)
 	BUG_ON(nr >= 5 && ip[3] >= ip[4]);
 	BUG_ON(nr >= 6 && ip[4] >= ip[5]);
 
+	/* enforce limit on index vector for parity */
+	if (raid_mode_active == RAID_MODE_VANDERMONDE_RAID)
+		BUG_ON(nr > 0 && ip[nr - 1] >= 3);
+	else
+		BUG_ON(nr > 0 && ip[nr - 1] >= RAID_PARITY_MAX);
+
 	/* if failed data is present */
-	if (nr != 0)
-		raid_rec_algo[nr - 1].rec(nr, id, ip, nd, size, v);
+	if (nr != 0) {
+		BUG_ON(raid_rec_ptr[nr - 1] == 0);
+		raid_rec_ptr[nr - 1](nr, id, ip, nd, size, v);
+	}
 }
 
 const char * raid_gen_tag(int na)
diff --git a/raid/raid.c b/raid/raid.c
index f752518c..b5d07407 100644
--- a/raid/raid.c
+++ b/raid/raid.c
@@ -295,6 +295,9 @@ void raid_delta_gen(int nr, int *id, int *ip, int nd, size_t size, void **v)
 	int np;
 	void *latest;
 
+	/* zero buffer must be initialized prior to delta recovery */
+	BUG_ON(raid_zero_block == 0);
+
 	/*
 	 * Total number of parities we are going to process
 	 * they are both the used and the unused ones