[merged mm-stable] mm-damon-core-document-damos_commit_dests-failure-semantics.patch removed from -mm tree

[merged mm-stable] mm-damon-core-document-damos_commit_dests-failure-semantics.patch removed from -mm tree

[Andrew Morton]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 2742 bytes --]


The quilt patch titled
     Subject: mm/damon/core: document damos_commit_dests() failure semantics
has been removed from the -mm tree.  Its filename was
     mm-damon-core-document-damos_commit_dests-failure-semantics.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Josh Law <objecting@objecting.org>
Subject: mm/damon/core: document damos_commit_dests() failure semantics
Date: Fri, 20 Mar 2026 07:36:45 -0700

Add a kernel-doc-like comment to damos_commit_dests() documenting its
allocation failure contract: on -ENOMEM, the destination structure is left
in a partially torn-down state that is safe to deallocate via
damon_destroy_scheme(), but must not be reused for further commits.

This was unclear from the code alone and led to a separate patch [1]
attempting to reset nr_dests on failure.  Make the intended usage explicit
so future readers do not repeat the confusion.

Link: https://lkml.kernel.org/r/20260320143648.91673-1-sj@kernel.org
Link: https://lore.kernel.org/20260318214939.36100-1-objecting@objecting.org [1]
Signed-off-by: Josh Law <objecting@objecting.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/damon/core.c |   17 +++++++++++++++++
 1 file changed, 17 insertions(+)

--- a/mm/damon/core.c~mm-damon-core-document-damos_commit_dests-failure-semantics
+++ a/mm/damon/core.c
@@ -1060,6 +1060,23 @@ static void damos_set_filters_default_re
 		damos_filters_default_reject(&s->ops_filters);
 }
 
+/*
+ * damos_commit_dests() - Copy migration destinations from @src to @dst.
+ * @dst:	Destination structure to update.
+ * @src:	Source structure to copy from.
+ *
+ * If the number of destinations has changed, the old arrays in @dst are freed
+ * and new ones are allocated.  On success, @dst contains a full copy of
+ * @src's arrays and count.
+ *
+ * On allocation failure, @dst is left in a partially torn-down state: its
+ * arrays may be NULL and @nr_dests may not reflect the actual allocation
+ * sizes.  The structure remains safe to deallocate via damon_destroy_scheme(),
+ * but callers must not reuse @dst for further commits — it should be
+ * discarded.
+ *
+ * Return: 0 on success, -ENOMEM on allocation failure.
+ */
 static int damos_commit_dests(struct damos_migrate_dests *dst,
 		struct damos_migrate_dests *src)
 {
_

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

lib-maple_tree-fix-swapped-arguments-in-mas_safe_pivot-call.patch
lib-idr-fix-ida_find_first_range-missing-ids-across-chunk-boundaries.patch