+ zsmalloc-return-handle-from-obj_allocated.patch added to mm-unstable branch

+ zsmalloc-return-handle-from-obj_allocated.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: zsmalloc: return handle from obj_allocated()
has been added to the -mm mm-unstable branch.  Its filename is
     zsmalloc-return-handle-from-obj_allocated.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zsmalloc-return-handle-from-obj_allocated.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: zsmalloc: return handle from obj_allocated()
Date: Wed, 11 Nov 2026 15:46:26 +0900

Allocated handles are valid kernel addresses and never 0, so let
obj_allocated() return the handle directly (or 0 if unallocated) instead
of returning a bool.

No functional change.

Link: https://lore.kernel.org/20261111064707.2568433-4-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Yosry Ahmed <yosry@kernel.org>
Reviewed-by: Yosry Ahmed <yosry@kernel.org>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Richard Chang <richardycc@google.com>
---

 mm/zsmalloc.c |   15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

--- a/mm/zsmalloc.c~zsmalloc-return-handle-from-obj_allocated
+++ a/mm/zsmalloc.c
@@ -822,8 +822,7 @@ static unsigned long handle_to_obj(unsig
 	return READ_ONCE(*(unsigned long *)handle);
 }
 
-static inline bool obj_allocated(struct zpdesc *zpdesc, void *obj,
-				 unsigned long *phandle)
+static inline unsigned long obj_allocated(struct zpdesc *zpdesc, void *obj)
 {
 	unsigned long handle;
 	struct zspage *zspage = get_zspage(zpdesc);
@@ -836,11 +835,10 @@ static inline bool obj_allocated(struct
 		handle = *(unsigned long *)obj;
 
 	if (!(handle & OBJ_ALLOCATED_TAG))
-		return false;
+		return 0;
 
 	/* Clear all tags before returning the handle */
-	*phandle = handle & ~OBJ_TAG_MASK;
-	return true;
+	return handle & ~OBJ_TAG_MASK;
 }
 
 static void reset_zpdesc(struct zpdesc *zpdesc)
@@ -1571,7 +1569,8 @@ static unsigned long find_alloced_obj(st
 	offset += class->size * index;
 
 	while (offset < PAGE_SIZE) {
-		if (obj_allocated(zpdesc, addr + offset, &handle))
+		handle = obj_allocated(zpdesc, addr + offset);
+		if (handle)
 			break;
 
 		offset += class->size;
@@ -1824,8 +1823,8 @@ static int zs_page_migrate(struct page *
 
 	for (addr = s_addr + offset; addr < s_addr + PAGE_SIZE;
 					addr += class->size) {
-		if (obj_allocated(zpdesc, addr, &handle)) {
-
+		handle = obj_allocated(zpdesc, addr);
+		if (handle) {
 			old_obj = handle_to_obj(handle);
 			obj_to_location(old_obj, &dummy, &obj_idx);
 			new_obj = location_to_obj(newzpdesc, obj_idx,
_

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

zram-prefix-backends-printk-s.patch
zram-remove-debugfs-entry-on-init-failure.patch
zram-reset-writeback-state-in-zram_reset_device.patch
zram-move-mark_slot_accessed-under-existing-slot-lock-sections.patch
zram-remove-stale-warn_on-from-zram_read_page.patch
zram-zstd-do-not-allocate-empty-c-d-dictionaries.patch
zram-lz4hc-pre-initialize-dictionary-stream-in-setup_params.patch
zram-lz4-use-lz4_decompress_safe_usingdict.patch
zram-lz4hc-use-lz4_decompress_safe_usingdict.patch
zram-zstd-do-not-use-kvzalloc-for-zstd-allocations.patch
zram-split-zcomp-into-separate-r-w-streams.patch
zram-introduce-shared-decompression-streams.patch
zram-allocate-bounce-buffer-for-spanning-objects.patch
zram-borrow-idle-decompression-streams-in-exclusive-mode.patch
zram-use-a-singleton-compression-context-for-recompression.patch
zram-drop-stale-comment-in-write_incompressible_page.patch
zram-drop-get_slot_handle-and-set_slot_handle.patch
zsmalloc-return-handle-from-obj_allocated.patch
zsmalloc-switch-handle-type-to-struct-zs_handle.patch
zram-check-mem_limit-before-allocating-zsmalloc-object.patch
zram-allocate-zsmalloc-object-under-slot-lock.patch
zswap-do-not-free-the-entry-if-its-pool-is-null.patch
zsmalloc-encode-1-based-obj_idx-so-valid-obj-is-never-0.patch
zsmalloc-embed-struct-zs_handle-into-zram-and-zswap-entries.patch
zsmalloc-fold-zs_obj_write-into-zs_store.patch
zsmalloc-populate-new-zspage-outside-class-lock-in-zs_store.patch
zram-fix-quadratic-writeback-bitmap-search.patch