Commit 9bbe033c authored by Yosry Ahmed's avatar Yosry Ahmed Committed by Andrew Morton
Browse files

mm: zpool: add interfaces for object read/write APIs 

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@linux.dev
Link: https://lkml.kernel.org/r/20250305061134.4105762-2-yosry.ahmed@linux.dev


Signed-off-by: default avatarYosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarNhat Pham <nphamcs@gmail.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent ac55b38f

include/linux/zpool.h

+17 −0
Original line number Diff line number Diff line
@@ -52,6 +52,16 @@ void *zpool_map_handle(struct zpool *pool, unsigned long handle, 


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);

};

mm/zpool.c

+48 −0
Original line number Diff line number Diff line
@@ -320,6 +320,54 @@ void zpool_unmap_handle(struct zpool *zpool, unsigned long handle) 
	zpool->driver->unmap(zpool->pool, handle);

}



/**

 * 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

mm/zsmalloc.c

+21 −0
Original line number Diff line number Diff line
@@ -507,6 +507,24 @@ static void zs_zpool_unmap(void *pool, unsigned long handle) 
	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_driver = { 
	.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,

};