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Message-ID: <Z8kiRym1hS9fB2mE@gondor.apana.org.au>
Date: Thu, 6 Mar 2025 12:19:19 +0800
From: Herbert Xu <herbert@...dor.apana.org.au>
To: Yosry Ahmed <yosry.ahmed@...ux.dev>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
Johannes Weiner <hannes@...xchg.org>, Nhat Pham <nphamcs@...il.com>,
Chengming Zhou <chengming.zhou@...ux.dev>,
Minchan Kim <minchan@...nel.org>,
Sergey Senozhatsky <senozhatsky@...omium.org>,
Thomas Gleixner <tglx@...utronix.de>,
Peter Zijlstra <peterz@...radead.org>, linux-mm@...ck.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH mm-unstable 3/5] mm: zpool: Remove object mapping APIs
On Thu, Mar 06, 2025 at 09:48:58AM +0800, Herbert Xu wrote:
>
> This patch breaks zbud and z3fold because they haven't been converted
> to the new interface.
I've rebased my zswap SG patch on top of your series. I've removed
all the mapping code from zpool/zsmalloc and pushed it out to zram
instead.
This patch depends on a new memcpy_sglist function which I've just
posted a patch for:
https://patchwork.kernel.org/project/linux-crypto/patch/Z8kXhLb681E_FLzs@gondor.apana.org.au/
>From a77ee529b831e7e606ed2a5b723b74ce234a3915 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert@...dor.apana.org.au>
Date: Thu, 6 Mar 2025 12:13:58 +0800
Subject: [PATCH] mm: zswap: Give non-linear objects to Crypto API
Instead of copying non-linear objects into a buffer, use the
scatterlist to give them directly to the Crypto API.
Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>
---
drivers/block/zram/zram_drv.c | 58 ++++++++++++----
include/linux/zpool.h | 26 +++----
include/linux/zsmalloc.h | 11 ++-
mm/z3fold.c | 17 +++--
mm/zbud.c | 45 +++++++------
mm/zpool.c | 54 ++++++---------
mm/zsmalloc.c | 123 +++++++---------------------------
mm/zswap.c | 35 +++-------
8 files changed, 148 insertions(+), 221 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index fda7d8624889..d72becec534d 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -15,6 +15,7 @@
#define KMSG_COMPONENT "zram"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+#include <crypto/scatterwalk.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/bio.h>
@@ -23,6 +24,7 @@
#include <linux/buffer_head.h>
#include <linux/device.h>
#include <linux/highmem.h>
+#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/backing-dev.h>
#include <linux/string.h>
@@ -1559,21 +1561,23 @@ static int read_same_filled_page(struct zram *zram, struct page *page,
static int read_incompressible_page(struct zram *zram, struct page *page,
u32 index)
{
+ struct scatterlist output[1];
+ struct scatterlist input[2];
unsigned long handle;
- void *src, *dst;
+ sg_init_table(output, 1);
+ sg_set_page(output, page, PAGE_SIZE, 0);
handle = zram_get_handle(zram, index);
- src = zs_obj_read_begin(zram->mem_pool, handle, NULL);
- dst = kmap_local_page(page);
- copy_page(dst, src);
- kunmap_local(dst);
- zs_obj_read_end(zram->mem_pool, handle, src);
+ zs_pin_object(zram->mem_pool, handle, input);
+ memcpy_sglist(output, input, PAGE_SIZE);
+ zs_unpin_object(zram->mem_pool, handle);
return 0;
}
static int read_compressed_page(struct zram *zram, struct page *page, u32 index)
{
+ struct scatterlist input[2];
struct zcomp_strm *zstrm;
unsigned long handle;
unsigned int size;
@@ -1585,11 +1589,22 @@ static int read_compressed_page(struct zram *zram, struct page *page, u32 index)
prio = zram_get_priority(zram, index);
zstrm = zcomp_stream_get(zram->comps[prio]);
- src = zs_obj_read_begin(zram->mem_pool, handle, zstrm->local_copy);
+ zs_pin_object(zram->mem_pool, handle, input);
+ if (sg_is_last(input)) {
+ unsigned int offset = input[0].offset;
+
+ src = kmap_local_page(sg_page(input) + (offset >> PAGE_SHIFT));
+ src += offset_in_page(offset);
+ } else {
+ memcpy_from_sglist(zstrm->local_copy, input, 0, size);
+ src = zstrm->local_copy;
+ }
dst = kmap_local_page(page);
ret = zcomp_decompress(zram->comps[prio], zstrm, src, size, dst);
kunmap_local(dst);
- zs_obj_read_end(zram->mem_pool, handle, src);
+ if (sg_is_last(input))
+ kunmap_local(src);
+ zs_unpin_object(zram->mem_pool, handle);
zcomp_stream_put(zstrm);
return ret;
@@ -1684,8 +1699,9 @@ static int write_same_filled_page(struct zram *zram, unsigned long fill,
static int write_incompressible_page(struct zram *zram, struct page *page,
u32 index)
{
+ struct scatterlist output[2];
+ struct scatterlist input[1];
unsigned long handle;
- void *src;
/*
* This function is called from preemptible context so we don't need
@@ -1703,9 +1719,11 @@ static int write_incompressible_page(struct zram *zram, struct page *page,
return -ENOMEM;
}
- src = kmap_local_page(page);
- zs_obj_write(zram->mem_pool, handle, src, PAGE_SIZE);
- kunmap_local(src);
+ sg_init_table(input, 1);
+ sg_set_page(input, page, PAGE_SIZE, 0);
+ zs_pin_object(zram->mem_pool, handle, output);
+ memcpy_sglist(output, input, PAGE_SIZE);
+ zs_unpin_object(zram->mem_pool, handle);
zram_slot_lock(zram, index);
zram_set_flag(zram, index, ZRAM_HUGE);
@@ -1723,6 +1741,8 @@ static int write_incompressible_page(struct zram *zram, struct page *page,
static int zram_write_page(struct zram *zram, struct page *page, u32 index)
{
+ struct scatterlist output[2];
+ struct scatterlist input[1];
int ret = 0;
unsigned long handle;
unsigned int comp_len;
@@ -1773,7 +1793,11 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
return -ENOMEM;
}
- zs_obj_write(zram->mem_pool, handle, zstrm->buffer, comp_len);
+ sg_init_table(input, 1);
+ sg_set_buf(input, zstrm->buffer, comp_len);
+ zs_pin_object(zram->mem_pool, handle, output);
+ memcpy_sglist(output, input, comp_len);
+ zs_unpin_object(zram->mem_pool, handle);
zcomp_stream_put(zstrm);
zram_slot_lock(zram, index);
@@ -1872,6 +1896,8 @@ static int recompress_slot(struct zram *zram, u32 index, struct page *page,
u64 *num_recomp_pages, u32 threshold, u32 prio,
u32 prio_max)
{
+ struct scatterlist output[2];
+ struct scatterlist input[1];
struct zcomp_strm *zstrm = NULL;
unsigned long handle_old;
unsigned long handle_new;
@@ -1990,7 +2016,11 @@ static int recompress_slot(struct zram *zram, u32 index, struct page *page,
return PTR_ERR((void *)handle_new);
}
- zs_obj_write(zram->mem_pool, handle_new, zstrm->buffer, comp_len_new);
+ sg_init_table(input, 1);
+ sg_set_buf(input, zstrm->buffer, comp_len_new);
+ zs_pin_object(zram->mem_pool, handle_new, output);
+ memcpy_sglist(output, input, comp_len_new);
+ zs_unpin_object(zram->mem_pool, handle_new);
zcomp_stream_put(zstrm);
zram_free_page(zram, index);
diff --git a/include/linux/zpool.h b/include/linux/zpool.h
index a976f1962cc7..2beb0b7c82e2 100644
--- a/include/linux/zpool.h
+++ b/include/linux/zpool.h
@@ -12,6 +12,7 @@
#ifndef _ZPOOL_H_
#define _ZPOOL_H_
+struct scatterlist;
struct zpool;
bool zpool_has_pool(char *type);
@@ -27,14 +28,10 @@ int zpool_malloc(struct zpool *pool, size_t size, gfp_t gfp,
void zpool_free(struct zpool *pool, unsigned long handle);
-void *zpool_obj_read_begin(struct zpool *zpool, unsigned long handle,
- void *local_copy);
+void zpool_pin_handle(struct zpool *pool, unsigned long handle,
+ struct scatterlist *sg);
-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);
+void zpool_unpin_handle(struct zpool *pool, unsigned long handle);
u64 zpool_get_total_pages(struct zpool *pool);
@@ -47,9 +44,8 @@ u64 zpool_get_total_pages(struct zpool *pool);
* @destroy: destroy a pool.
* @malloc: allocate mem from a pool.
* @free: free mem from a pool.
- * @sleep_mapped: whether zpool driver can sleep during map.
- * @map: map a handle.
- * @unmap: unmap a handle.
+ * @pin: pin a handle and write it into a two-entry SG list.
+ * @unpin: unpin a handle.
* @total_size: get total size of a pool.
*
* This is created by a zpool implementation and registered
@@ -68,12 +64,8 @@ struct zpool_driver {
unsigned long *handle);
void (*free)(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);
+ void (*pin)(void *pool, unsigned long handle, struct scatterlist *sg);
+ void (*unpin)(void *pool, unsigned long handle);
u64 (*total_pages)(void *pool);
};
@@ -82,6 +74,4 @@ void zpool_register_driver(struct zpool_driver *driver);
int zpool_unregister_driver(struct zpool_driver *driver);
-bool zpool_can_sleep_mapped(struct zpool *pool);
-
#endif
diff --git a/include/linux/zsmalloc.h b/include/linux/zsmalloc.h
index c26baf9fb331..fba57a792153 100644
--- a/include/linux/zsmalloc.h
+++ b/include/linux/zsmalloc.h
@@ -16,6 +16,8 @@
#include <linux/types.h>
+struct scatterlist;
+
struct zs_pool_stats {
/* How many pages were migrated (freed) */
atomic_long_t pages_compacted;
@@ -38,11 +40,8 @@ unsigned int zs_lookup_class_index(struct zs_pool *pool, unsigned int size);
void zs_pool_stats(struct zs_pool *pool, struct zs_pool_stats *stats);
-void *zs_obj_read_begin(struct zs_pool *pool, unsigned long handle,
- void *local_copy);
-void zs_obj_read_end(struct zs_pool *pool, unsigned long handle,
- void *handle_mem);
-void zs_obj_write(struct zs_pool *pool, unsigned long handle,
- void *handle_mem, size_t mem_len);
+void zs_pin_object(struct zs_pool *pool, unsigned long handle,
+ struct scatterlist *sg);
+void zs_unpin_object(struct zs_pool *pool, unsigned long handle);
#endif
diff --git a/mm/z3fold.c b/mm/z3fold.c
index 379d24b4fef9..eab5c81fa7ad 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -36,6 +36,7 @@
#include <linux/percpu.h>
#include <linux/preempt.h>
#include <linux/workqueue.h>
+#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/zpool.h>
@@ -1392,12 +1393,15 @@ static void z3fold_zpool_free(void *pool, unsigned long handle)
z3fold_free(pool, handle);
}
-static void *z3fold_zpool_map(void *pool, unsigned long handle,
- enum zpool_mapmode mm)
+static void z3fold_zpool_pin(void *pool, unsigned long handle,
+ struct scatterlist sg[2])
{
- return z3fold_map(pool, handle);
+ void *buf = z3fold_map(pool, handle);
+
+ sg_init_one(sg, buf, PAGE_SIZE - offset_in_page(buf));
}
-static void z3fold_zpool_unmap(void *pool, unsigned long handle)
+
+static void z3fold_zpool_unpin(void *pool, unsigned long handle)
{
z3fold_unmap(pool, handle);
}
@@ -1409,14 +1413,13 @@ static u64 z3fold_zpool_total_pages(void *pool)
static struct zpool_driver z3fold_zpool_driver = {
.type = "z3fold",
- .sleep_mapped = true,
.owner = THIS_MODULE,
.create = z3fold_zpool_create,
.destroy = z3fold_zpool_destroy,
.malloc = z3fold_zpool_malloc,
.free = z3fold_zpool_free,
- .map = z3fold_zpool_map,
- .unmap = z3fold_zpool_unmap,
+ .pin = z3fold_zpool_pin,
+ .unpin = z3fold_zpool_unpin,
.total_pages = z3fold_zpool_total_pages,
};
diff --git a/mm/zbud.c b/mm/zbud.c
index e9836fff9438..3132a7c6f926 100644
--- a/mm/zbud.c
+++ b/mm/zbud.c
@@ -36,10 +36,9 @@
*
* The zbud API differs from that of conventional allocators in that the
* allocation function, zbud_alloc(), returns an opaque handle to the user,
- * not a dereferenceable pointer. The user must map the handle using
- * zbud_map() in order to get a usable pointer by which to access the
- * allocation data and unmap the handle with zbud_unmap() when operations
- * on the allocation data are complete.
+ * not a dereferenceable pointer. The user must pin the handle using
+ * zbud_pin() in order to access the allocation data and unpin the handle
+ * with zbud_unpin() when operations on the allocation data are complete.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -49,6 +48,7 @@
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/preempt.h>
+#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/zpool.h>
@@ -339,28 +339,30 @@ static void zbud_free(struct zbud_pool *pool, unsigned long handle)
}
/**
- * zbud_map() - maps the allocation associated with the given handle
+ * zbud_pin() - pins the allocation associated with the given handle
* @pool: pool in which the allocation resides
- * @handle: handle associated with the allocation to be mapped
+ * @handle: handle associated with the allocation to be pinned
+ * @sg: 2-entry scatter list to store the memory pointers
*
- * While trivial for zbud, the mapping functions for others allocators
+ * While trivial for zbud, the pinning functions for others allocators
* implementing this allocation API could have more complex information encoded
* in the handle and could create temporary mappings to make the data
* accessible to the user.
- *
- * Returns: a pointer to the mapped allocation
*/
-static void *zbud_map(struct zbud_pool *pool, unsigned long handle)
+static void zbud_pin(struct zbud_pool *pool, unsigned long handle,
+ struct scatterlist sg[2])
{
- return (void *)(handle);
+ void *buf = (void *)handle;
+
+ sg_init_one(sg, buf, PAGE_SIZE - offset_in_page(buf));
}
/**
- * zbud_unmap() - maps the allocation associated with the given handle
+ * zbud_unpin() - unpins the allocation associated with the given handle
* @pool: pool in which the allocation resides
- * @handle: handle associated with the allocation to be unmapped
+ * @handle: handle associated with the allocation to be unpinned
*/
-static void zbud_unmap(struct zbud_pool *pool, unsigned long handle)
+static void zbud_unpin(struct zbud_pool *pool, unsigned long handle)
{
}
@@ -400,14 +402,14 @@ static void zbud_zpool_free(void *pool, unsigned long handle)
zbud_free(pool, handle);
}
-static void *zbud_zpool_map(void *pool, unsigned long handle,
- enum zpool_mapmode mm)
+static void zbud_zpool_pin(void *pool, unsigned long handle,
+ struct scatterlist sg[2])
{
- return zbud_map(pool, handle);
+ zbud_pin(pool, handle, sg);
}
-static void zbud_zpool_unmap(void *pool, unsigned long handle)
+static void zbud_zpool_unpin(void *pool, unsigned long handle)
{
- zbud_unmap(pool, handle);
+ zbud_unpin(pool, handle);
}
static u64 zbud_zpool_total_pages(void *pool)
@@ -417,14 +419,13 @@ static u64 zbud_zpool_total_pages(void *pool)
static struct zpool_driver zbud_zpool_driver = {
.type = "zbud",
- .sleep_mapped = true,
.owner = THIS_MODULE,
.create = zbud_zpool_create,
.destroy = zbud_zpool_destroy,
.malloc = zbud_zpool_malloc,
.free = zbud_zpool_free,
- .map = zbud_zpool_map,
- .unmap = zbud_zpool_unmap,
+ .pin = zbud_zpool_pin,
+ .unpin = zbud_zpool_unpin,
.total_pages = zbud_zpool_total_pages,
};
diff --git a/mm/zpool.c b/mm/zpool.c
index 0931b8135d72..3355b57ec7ee 100644
--- a/mm/zpool.c
+++ b/mm/zpool.c
@@ -13,6 +13,7 @@
#include <linux/list.h>
#include <linux/types.h>
#include <linux/mm.h>
+#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/module.h>
@@ -262,51 +263,38 @@ void zpool_free(struct zpool *zpool, unsigned long handle)
}
/**
- * zpool_obj_read_begin() - Start reading from a previously allocated handle.
+ * zpool_pin_handle() - Pin a previously allocated handle into memory
* @zpool: The zpool that the handle was allocated from
- * @handle: The handle to read from
- * @local_copy: A local buffer to use if needed.
+ * @handle: The handle to pin
+ * @sg: 2-entry scatterlist to store pointers to the memmory
*
- * 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).
+ * This pins a previously allocated handle into memory.
*
- * Returns: A pointer to the handle memory to be read, if @local_copy is used,
- * the returned pointer is @local_copy.
+ * This may hold locks, disable interrupts, and/or preemption,
+ * and the zpool_unpin_handle() must be called to undo those
+ * actions. The code that uses the pinned handle should complete
+ * its operations on the pinned handle memory quickly and unpin
+ * as soon as possible.
*/
-void *zpool_obj_read_begin(struct zpool *zpool, unsigned long handle,
- void *local_copy)
+void zpool_pin_handle(struct zpool *zpool, unsigned long handle,
+ struct scatterlist *sg)
{
- return zpool->driver->obj_read_begin(zpool->pool, handle, local_copy);
+ zpool->driver->pin(zpool->pool, handle, sg);
}
/**
- * zpool_obj_read_end() - Finish reading from a previously allocated handle.
+ * zpool_unpin_handle() - Unpin a previously pinned 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()
+ * @handle: The handle to unpin
*
- * Finishes a read operation previously started by zpool_obj_read_begin().
+ * This unpins a previously pinned handle. Any locks or other
+ * actions that the implementation took in zpool_pin_handle()
+ * will be undone here. The memory area returned from
+ * zpool_pin_handle() should no longer be used after this.
*/
-void zpool_obj_read_end(struct zpool *zpool, unsigned long handle,
- void *handle_mem)
+void zpool_unpin_handle(struct zpool *zpool, unsigned long handle)
{
- 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->driver->unpin(zpool->pool, handle);
}
/**
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 961b270f023c..90ce09bc4d0a 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -23,6 +23,7 @@
* zspage->lock
*/
+#include <crypto/scatterwalk.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
@@ -49,6 +50,7 @@
#include <linux/pagemap.h>
#include <linux/fs.h>
#include <linux/local_lock.h>
+#include <linux/scatterlist.h>
#include "zpdesc.h"
#define ZSPAGE_MAGIC 0x58
@@ -445,7 +447,6 @@ static void record_obj(unsigned long handle, unsigned long obj)
/* zpool driver */
#ifdef CONFIG_ZPOOL
-
static void *zs_zpool_create(const char *name, gfp_t gfp)
{
/*
@@ -475,22 +476,15 @@ static void zs_zpool_free(void *pool, unsigned long handle)
zs_free(pool, handle);
}
-static void *zs_zpool_obj_read_begin(void *pool, unsigned long handle,
- void *local_copy)
+static void zs_zpool_pin(void *pool, unsigned long handle,
+ struct scatterlist sg[2])
{
- return zs_obj_read_begin(pool, handle, local_copy);
+ zs_pin_object(pool, handle, sg);
}
-static void zs_zpool_obj_read_end(void *pool, unsigned long handle,
- void *handle_mem)
+static void zs_zpool_unpin(void *pool, unsigned long handle)
{
- 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);
+ zs_unpin_object(pool, handle);
}
static u64 zs_zpool_total_pages(void *pool)
@@ -505,9 +499,8 @@ static struct zpool_driver zs_zpool_driver = {
.destroy = zs_zpool_destroy,
.malloc = zs_zpool_malloc,
.free = zs_zpool_free,
- .obj_read_begin = zs_zpool_obj_read_begin,
- .obj_read_end = zs_zpool_obj_read_end,
- .obj_write = zs_zpool_obj_write,
+ .pin = zs_zpool_pin,
+ .unpin = zs_zpool_unpin,
.total_pages = zs_zpool_total_pages,
};
@@ -1145,15 +1138,15 @@ unsigned long zs_get_total_pages(struct zs_pool *pool)
}
EXPORT_SYMBOL_GPL(zs_get_total_pages);
-void *zs_obj_read_begin(struct zs_pool *pool, unsigned long handle,
- void *local_copy)
+void zs_pin_object(struct zs_pool *pool, unsigned long handle,
+ struct scatterlist *sg)
{
+ int handle_size = ZS_HANDLE_SIZE;
struct zspage *zspage;
struct zpdesc *zpdesc;
unsigned long obj, off;
unsigned int obj_idx;
struct size_class *class;
- void *addr;
/* Guarantee we can get zspage from handle safely */
read_lock(&pool->lock);
@@ -1168,107 +1161,43 @@ void *zs_obj_read_begin(struct zs_pool *pool, unsigned long handle,
class = zspage_class(pool, zspage);
off = offset_in_page(class->size * obj_idx);
+ if (ZsHugePage(zspage))
+ handle_size = 0;
+
if (off + class->size <= PAGE_SIZE) {
/* this object is contained entirely within a page */
- addr = kmap_local_zpdesc(zpdesc);
- addr += off;
+ sg_init_table(sg, 1);
+ sg_set_page(sg, zpdesc_page(zpdesc),
+ class->size - handle_size, off + handle_size);
} else {
size_t sizes[2];
/* this object spans two pages */
sizes[0] = PAGE_SIZE - off;
sizes[1] = class->size - sizes[0];
- addr = local_copy;
- memcpy_from_page(addr, zpdesc_page(zpdesc),
- off, sizes[0]);
+ sg_init_table(sg, 2);
+ sg_set_page(sg, zpdesc_page(zpdesc), sizes[0] - handle_size,
+ off + handle_size);
zpdesc = get_next_zpdesc(zpdesc);
- memcpy_from_page(addr + sizes[0],
- zpdesc_page(zpdesc),
- 0, sizes[1]);
+ sg_set_page(&sg[1], zpdesc_page(zpdesc), sizes[1], 0);
}
-
- if (!ZsHugePage(zspage))
- addr += ZS_HANDLE_SIZE;
-
- return addr;
}
-EXPORT_SYMBOL_GPL(zs_obj_read_begin);
+EXPORT_SYMBOL_GPL(zs_pin_object);
-void zs_obj_read_end(struct zs_pool *pool, unsigned long handle,
- void *handle_mem)
+void zs_unpin_object(struct zs_pool *pool, unsigned long handle)
{
struct zspage *zspage;
struct zpdesc *zpdesc;
- unsigned long obj, off;
unsigned int obj_idx;
- struct size_class *class;
+ unsigned long obj;
obj = handle_to_obj(handle);
obj_to_location(obj, &zpdesc, &obj_idx);
zspage = get_zspage(zpdesc);
- class = zspage_class(pool, zspage);
- off = offset_in_page(class->size * obj_idx);
-
- if (off + class->size <= PAGE_SIZE) {
- if (!ZsHugePage(zspage))
- off += ZS_HANDLE_SIZE;
- handle_mem -= off;
- kunmap_local(handle_mem);
- }
-
zspage_read_unlock(zspage);
}
-EXPORT_SYMBOL_GPL(zs_obj_read_end);
-
-void zs_obj_write(struct zs_pool *pool, unsigned long handle,
- void *handle_mem, size_t mem_len)
-{
- struct zspage *zspage;
- struct zpdesc *zpdesc;
- unsigned long obj, off;
- unsigned int obj_idx;
- struct size_class *class;
-
- /* Guarantee we can get zspage from handle safely */
- read_lock(&pool->lock);
- obj = handle_to_obj(handle);
- obj_to_location(obj, &zpdesc, &obj_idx);
- zspage = get_zspage(zpdesc);
-
- /* Make sure migration doesn't move any pages in this zspage */
- zspage_read_lock(zspage);
- read_unlock(&pool->lock);
-
- class = zspage_class(pool, zspage);
- off = offset_in_page(class->size * obj_idx);
-
- if (off + class->size <= PAGE_SIZE) {
- /* this object is contained entirely within a page */
- void *dst = kmap_local_zpdesc(zpdesc);
-
- if (!ZsHugePage(zspage))
- off += ZS_HANDLE_SIZE;
- memcpy(dst + off, handle_mem, mem_len);
- kunmap_local(dst);
- } else {
- /* this object spans two pages */
- size_t sizes[2];
-
- off += ZS_HANDLE_SIZE;
- sizes[0] = PAGE_SIZE - off;
- sizes[1] = mem_len - sizes[0];
-
- memcpy_to_page(zpdesc_page(zpdesc), off,
- handle_mem, sizes[0]);
- zpdesc = get_next_zpdesc(zpdesc);
- memcpy_to_page(zpdesc_page(zpdesc), 0,
- handle_mem + sizes[0], sizes[1]);
- }
-
- zspage_read_unlock(zspage);
-}
-EXPORT_SYMBOL_GPL(zs_obj_write);
+EXPORT_SYMBOL_GPL(zs_unpin_object);
/**
* zs_huge_class_size() - Returns the size (in bytes) of the first huge
diff --git a/mm/zswap.c b/mm/zswap.c
index 8b086740698a..42b5fbeea477 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -13,6 +13,8 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <crypto/acompress.h>
+#include <crypto/scatterwalk.h>
#include <linux/module.h>
#include <linux/cpu.h>
#include <linux/highmem.h>
@@ -26,7 +28,6 @@
#include <linux/mempolicy.h>
#include <linux/mempool.h>
#include <linux/zpool.h>
-#include <crypto/acompress.h>
#include <linux/zswap.h>
#include <linux/mm_types.h>
#include <linux/page-flags.h>
@@ -147,7 +148,6 @@ struct crypto_acomp_ctx {
struct crypto_wait wait;
u8 *buffer;
struct mutex mutex;
- bool is_sleepable;
};
/*
@@ -865,7 +865,6 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node)
acomp_ctx->buffer = buffer;
acomp_ctx->acomp = acomp;
- acomp_ctx->is_sleepable = acomp_is_async(acomp);
acomp_ctx->req = req;
mutex_unlock(&acomp_ctx->mutex);
return 0;
@@ -928,6 +927,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry,
struct scatterlist input, output;
int comp_ret = 0, alloc_ret = 0;
unsigned int dlen = PAGE_SIZE;
+ struct scatterlist sg[2];
unsigned long handle;
struct zpool *zpool;
gfp_t gfp;
@@ -969,7 +969,9 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry,
if (alloc_ret)
goto unlock;
- zpool_obj_write(zpool, handle, dst, dlen);
+ zpool_pin_handle(zpool, handle, sg);
+ memcpy_to_sglist(sg, 0, dst, dlen);
+ zpool_unpin_handle(zpool, handle);
entry->handle = handle;
entry->length = dlen;
@@ -988,34 +990,19 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry,
static void zswap_decompress(struct zswap_entry *entry, struct folio *folio)
{
struct zpool *zpool = entry->pool->zpool;
- struct scatterlist input, output;
struct crypto_acomp_ctx *acomp_ctx;
- u8 *src, *obj;
+ struct scatterlist input[2];
+ struct scatterlist output;
acomp_ctx = acomp_ctx_get_cpu_lock(entry->pool);
- obj = zpool_obj_read_begin(zpool, entry->handle, acomp_ctx->buffer);
-
- /*
- * zpool_obj_read_begin() might return a kmap address of highmem when
- * acomp_ctx->buffer is not used. However, sg_init_one() does not
- * handle highmem addresses, so copy the object to acomp_ctx->buffer.
- */
- if (virt_addr_valid(obj)) {
- src = obj;
- } else {
- WARN_ON_ONCE(obj == acomp_ctx->buffer);
- memcpy(acomp_ctx->buffer, obj, entry->length);
- src = acomp_ctx->buffer;
- }
-
- sg_init_one(&input, src, entry->length);
+ zpool_pin_handle(zpool, entry->handle, input);
sg_init_table(&output, 1);
sg_set_folio(&output, folio, PAGE_SIZE, 0);
- acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, PAGE_SIZE);
+ acomp_request_set_params(acomp_ctx->req, input, &output, entry->length, PAGE_SIZE);
BUG_ON(crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait));
BUG_ON(acomp_ctx->req->dlen != PAGE_SIZE);
- zpool_obj_read_end(zpool, entry->handle, obj);
+ zpool_unpin_handle(zpool, entry->handle);
acomp_ctx_put_unlock(acomp_ctx);
}
--
2.39.5
Cheers,
--
Email: Herbert Xu <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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