The patch titled
Subject: mm: zpool: add interfaces for object read/write APIs
has been added to the -mm mm-unstable branch. Its filename is
mm-zpool-add-interfaces-for-object-read-write-apis.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zpool-add-interfaces-for-object-read-write-apis.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: Yosry Ahmed <yosry.ahmed@xxxxxxxxx>
Subject: mm: zpool: add interfaces for object read/write APIs
Date: Wed, 5 Mar 2025 06:11:29 +0000
Patch series "Switch zswap to object read/write APIs".
This patch series updates zswap to use the new object read/write APIs
defined by zsmalloc in [1], and remove the old object mapping APIs and the
related code from zpool and zsmalloc.
This patch (of 5):
Zsmalloc introduced new APIs to read/write objects besides mapping them.
Add the necessary zpool interfaces.
Link: https://lkml.kernel.org/r/20250305061134.4105762-1-yosry.ahmed@xxxxxxxxx
Link: https://lkml.kernel.org/r/20250305061134.4105762-2-yosry.ahmed@xxxxxxxxx
Signed-off-by: Yosry Ahmed <yosry.ahmed@xxxxxxxxx>
Reviewed-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Nhat Pham <nphamcs@xxxxxxxxx>
Cc: Chengming Zhou <chengming.zhou@xxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/zpool.h | 17 ++++++++++++++
mm/zpool.c | 48 ++++++++++++++++++++++++++++++++++++++++
mm/zsmalloc.c | 21 +++++++++++++++++
3 files changed, 86 insertions(+)
--- a/include/linux/zpool.h~mm-zpool-add-interfaces-for-object-read-write-apis
+++ a/include/linux/zpool.h
@@ -52,6 +52,16 @@ void *zpool_map_handle(struct zpool *poo
void zpool_unmap_handle(struct zpool *pool, unsigned long handle);
+
+void *zpool_obj_read_begin(struct zpool *zpool, unsigned long handle,
+ void *local_copy);
+
+void zpool_obj_read_end(struct zpool *zpool, unsigned long handle,
+ void *handle_mem);
+
+void zpool_obj_write(struct zpool *zpool, unsigned long handle,
+ void *handle_mem, size_t mem_len);
+
u64 zpool_get_total_pages(struct zpool *pool);
@@ -90,6 +100,13 @@ struct zpool_driver {
enum zpool_mapmode mm);
void (*unmap)(void *pool, unsigned long handle);
+ void *(*obj_read_begin)(void *pool, unsigned long handle,
+ void *local_copy);
+ void (*obj_read_end)(void *pool, unsigned long handle,
+ void *handle_mem);
+ void (*obj_write)(void *pool, unsigned long handle,
+ void *handle_mem, size_t mem_len);
+
u64 (*total_pages)(void *pool);
};
--- a/mm/zpool.c~mm-zpool-add-interfaces-for-object-read-write-apis
+++ a/mm/zpool.c
@@ -321,6 +321,54 @@ void zpool_unmap_handle(struct zpool *zp
}
/**
+ * zpool_obj_read_begin() - Start reading from a previously allocated handle.
+ * @zpool: The zpool that the handle was allocated from
+ * @handle: The handle to read from
+ * @local_copy: A local buffer to use if needed.
+ *
+ * This starts a read operation of a previously allocated handle. The passed
+ * @local_copy buffer may be used if needed by copying the memory into.
+ * zpool_obj_read_end() MUST be called after the read is completed to undo any
+ * actions taken (e.g. release locks).
+ *
+ * Returns: A pointer to the handle memory to be read, if @local_copy is used,
+ * the returned pointer is @local_copy.
+ */
+void *zpool_obj_read_begin(struct zpool *zpool, unsigned long handle,
+ void *local_copy)
+{
+ return zpool->driver->obj_read_begin(zpool->pool, handle, local_copy);
+}
+
+/**
+ * zpool_obj_read_end() - Finish reading from a previously allocated handle.
+ * @zpool: The zpool that the handle was allocated from
+ * @handle: The handle to read from
+ * @handle_mem: The pointer returned by zpool_obj_read_begin()
+ *
+ * Finishes a read operation previously started by zpool_obj_read_begin().
+ */
+void zpool_obj_read_end(struct zpool *zpool, unsigned long handle,
+ void *handle_mem)
+{
+ zpool->driver->obj_read_end(zpool->pool, handle, handle_mem);
+}
+
+/**
+ * zpool_obj_write() - Write to a previously allocated handle.
+ * @zpool: The zpool that the handle was allocated from
+ * @handle: The handle to read from
+ * @handle_mem: The memory to copy from into the handle.
+ * @mem_len: The length of memory to be written.
+ *
+ */
+void zpool_obj_write(struct zpool *zpool, unsigned long handle,
+ void *handle_mem, size_t mem_len)
+{
+ zpool->driver->obj_write(zpool->pool, handle, handle_mem, mem_len);
+}
+
+/**
* zpool_get_total_pages() - The total size of the pool
* @zpool: The zpool to check
*
--- a/mm/zsmalloc.c~mm-zpool-add-interfaces-for-object-read-write-apis
+++ a/mm/zsmalloc.c
@@ -507,6 +507,24 @@ static void zs_zpool_unmap(void *pool, u
zs_unmap_object(pool, handle);
}
+static void *zs_zpool_obj_read_begin(void *pool, unsigned long handle,
+ void *local_copy)
+{
+ return zs_obj_read_begin(pool, handle, local_copy);
+}
+
+static void zs_zpool_obj_read_end(void *pool, unsigned long handle,
+ void *handle_mem)
+{
+ zs_obj_read_end(pool, handle, handle_mem);
+}
+
+static void zs_zpool_obj_write(void *pool, unsigned long handle,
+ void *handle_mem, size_t mem_len)
+{
+ zs_obj_write(pool, handle, handle_mem, mem_len);
+}
+
static u64 zs_zpool_total_pages(void *pool)
{
return zs_get_total_pages(pool);
@@ -522,6 +540,9 @@ static struct zpool_driver zs_zpool_driv
.free = zs_zpool_free,
.map = zs_zpool_map,
.unmap = zs_zpool_unmap,
+ .obj_read_begin = zs_zpool_obj_read_begin,
+ .obj_read_end = zs_zpool_obj_read_end,
+ .obj_write = zs_zpool_obj_write,
.total_pages = zs_zpool_total_pages,
};
_
Patches currently in -mm which might be from yosry.ahmed@xxxxxxxxx are
mm-z3fold-remove-z3fold.patch
mm-zbud-remove-zbud.patch
mm-zpool-add-interfaces-for-object-read-write-apis.patch
mm-zswap-use-object-read-write-apis-instead-of-object-mapping-apis.patch
mm-zpool-remove-object-mapping-apis.patch
mm-zsmalloc-remove-object-mapping-apis-and-per-cpu-map-areas.patch
mm-zsmalloc-remove-object-mapping-apis-and-per-cpu-map-areas-fix.patch
mm-zpool-remove-zpool_malloc_support_movable.patch
