[to-be-updated] maple_tree-drop-dead-code-from-mas_extend_spanning_null.patch removed from -mm tree

[to-be-updated] maple_tree-drop-dead-code-from-mas_extend_spanning_null.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: maple_tree: drop dead code from mas_extend_spanning_null()
has been removed from the -mm tree.  Its filename was
     maple_tree-drop-dead-code-from-mas_extend_spanning_null.patch

This patch was dropped because an updated version will be issued

------------------------------------------------------
From: "Liam R. Howlett (Oracle)" <liam@infradead.org>
Subject: maple_tree: drop dead code from mas_extend_spanning_null()
Date: Tue, 30 Jun 2026 15:08:29 -0400

mas_extend_spanning_null() had a clause if the end of the range being
written (mas->last) is the same as the end of the existing range it is
overwriting (wr_mas->r_max), action will be taken.

This code path is not possible because the only calling function
increments mas->last (unless it's ULONG_MAX) to walk to one beyond the
write and then resets the value back to the initial value.

In the case of mas->last == ULONG_MAX, then the second part of the
statement will always be false - mas->last cannot be less than the node
max.

This code never executed and is flawed anyways (the arguments are
incorrectly ordered), so removing it is the safest action.  Since the code
never executes, it is not fixing any issue so Fixes tag is not given.

Link: https://lore.kernel.org/20260630190843.3563858-6-liam@infradead.org
Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Chris Mason <clm@meta.com>
Cc: Chuck Lever <cel@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joe Perches <joe@perches.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/maple_tree.c |    7 -------
 1 file changed, 7 deletions(-)

--- a/lib/maple_tree.c~maple_tree-drop-dead-code-from-mas_extend_spanning_null
+++ a/lib/maple_tree.c
@@ -2997,13 +2997,6 @@ static inline void mas_extend_spanning_n
 		if (r_mas->last < r_wr_mas->r_max)
 			r_mas->last = r_wr_mas->r_max;
 		r_mas->offset++;
-	} else if ((r_mas->last == r_wr_mas->r_max) &&
-	    (r_mas->last < r_mas->max) &&
-	    !mas_slot_locked(r_mas, r_wr_mas->slots, r_mas->offset + 1)) {
-		r_mas->last = mas_safe_pivot(r_mas, r_wr_mas->pivots,
-					     r_wr_mas->type, r_mas->offset + 1);
-		r_mas->offset++;
-		r_wr_mas->r_max = r_mas->last;
 	}
 }
 
_

Patches currently in -mm which might be from liam@infradead.org are

maple_tree-drop-maple_alloc_slots.patch
maple_tree-clarify-comments-on-mas_nomem.patch
maple_tree-use-prefetched-value-in-mas_wr_store_type.patch
maple_tree-optimise-mas_wr_node_store-when-not-in-rcu-mode.patch
maple_tree-micro-optimisation-of-mas_wr_store_type.patch
maple_tree-add-bulk-parent-set-helper.patch
maple_tree-catch-race-in-mas_alloc_cyclic.patch
maple_tree-document-that-erase-may-use-gfp_kernel-for-allocations.patch
maple_tree-warn_on_once-when-allocations-fail.patch
maple_tree-document-erase-and-allocations-better.patch
maple_tree-change-two-gfp-flags-in-tests.patch
maple_tree-fix-argument-name-in-header.patch
maple_tree-avoid-extra-gap-calculation.patch
maple_tree-add-helper-mas_make_walkable.patch