lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20250130044455.2642465-7-senozhatsky@chromium.org>
Date: Thu, 30 Jan 2025 13:42:49 +0900
From: Sergey Senozhatsky <senozhatsky@...omium.org>
To: Andrew Morton <akpm@...ux-foundation.org>,
	Yosry Ahmed <yosry.ahmed@...ux.dev>
Cc: Minchan Kim <minchan@...nel.org>,
	Johannes Weiner <hannes@...xchg.org>,
	Nhat Pham <nphamcs@...il.com>,
	Uros Bizjak <ubizjak@...il.com>,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: [PATCHv2 6/7] zram: switch to new zsmalloc object mapping API

Use new read/write zsmalloc object API.  For cases when RO mapped
object spans two physical pages (requires temp buffer) compression
streams now carry around one extra physical page.

Signed-off-by: Sergey Senozhatsky <senozhatsky@...omium.org>
---
 drivers/block/zram/zcomp.c    |  4 +++-
 drivers/block/zram/zcomp.h    |  2 ++
 drivers/block/zram/zram_drv.c | 28 ++++++++++------------------
 3 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index efd5919808d9..675f2a51ad5f 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -45,6 +45,7 @@ static const struct zcomp_ops *backends[] = {
 static void zcomp_strm_free(struct zcomp *comp, struct zcomp_strm *strm)
 {
 	comp->ops->destroy_ctx(&strm->ctx);
+	vfree(strm->local_copy);
 	vfree(strm->buffer);
 	kfree(strm);
 }
@@ -66,12 +67,13 @@ static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp)
 		return NULL;
 	}
 
+	strm->local_copy = vzalloc(PAGE_SIZE);
 	/*
 	 * allocate 2 pages. 1 for compressed data, plus 1 extra in case if
 	 * compressed data is larger than the original one.
 	 */
 	strm->buffer = vzalloc(2 * PAGE_SIZE);
-	if (!strm->buffer) {
+	if (!strm->buffer || !strm->local_copy) {
 		zcomp_strm_free(comp, strm);
 		return NULL;
 	}
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index 62330829db3f..9683d4aa822d 100644
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -34,6 +34,8 @@ struct zcomp_strm {
 	struct list_head entry;
 	/* compression buffer */
 	void *buffer;
+	/* local copy of handle memory */
+	void *local_copy;
 	struct zcomp_ctx ctx;
 };
 
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index ad3e8885b0d2..d73e8374e9cc 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1562,11 +1562,11 @@ static int read_incompressible_page(struct zram *zram, struct page *page,
 	void *src, *dst;
 
 	handle = zram_get_handle(zram, index);
-	src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
+	src = zs_obj_read_begin(zram->mem_pool, handle, NULL);
 	dst = kmap_local_page(page);
 	copy_page(dst, src);
 	kunmap_local(dst);
-	zs_unmap_object(zram->mem_pool, handle);
+	zs_obj_read_end(zram->mem_pool, handle, src);
 
 	return 0;
 }
@@ -1584,11 +1584,11 @@ 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_map_object(zram->mem_pool, handle, ZS_MM_RO);
+	src = zs_obj_read_begin(zram->mem_pool, handle, zstrm->local_copy);
 	dst = kmap_local_page(page);
 	ret = zcomp_decompress(zram->comps[prio], zstrm, src, size, dst);
 	kunmap_local(dst);
-	zs_unmap_object(zram->mem_pool, handle);
+	zs_obj_read_end(zram->mem_pool, handle, src);
 	zcomp_stream_put(zram->comps[prio], zstrm);
 
 	return ret;
@@ -1684,7 +1684,7 @@ static int write_incompressible_page(struct zram *zram, struct page *page,
 				     u32 index)
 {
 	unsigned long handle;
-	void *src, *dst;
+	void *src;
 
 	/*
 	 * This function is called from preemptible context so we don't need
@@ -1701,11 +1701,9 @@ static int write_incompressible_page(struct zram *zram, struct page *page,
 		return -ENOMEM;
 	}
 
-	dst = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
 	src = kmap_local_page(page);
-	memcpy(dst, src, PAGE_SIZE);
+	zs_obj_write(zram->mem_pool, handle, src, PAGE_SIZE);
 	kunmap_local(src);
-	zs_unmap_object(zram->mem_pool, handle);
 
 	zram_slot_write_lock(zram, index);
 	zram_set_flag(zram, index, ZRAM_HUGE);
@@ -1726,7 +1724,7 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
 	int ret = 0;
 	unsigned long handle;
 	unsigned int comp_len;
-	void *dst, *mem;
+	void *mem;
 	struct zcomp_strm *zstrm;
 	unsigned long element;
 	bool same_filled;
@@ -1769,11 +1767,8 @@ static int zram_write_page(struct zram *zram, struct page *page, u32 index)
 		return -ENOMEM;
 	}
 
-	dst = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
-
-	memcpy(dst, zstrm->buffer, comp_len);
+	zs_obj_write(zram->mem_pool, handle, zstrm->buffer, comp_len);
 	zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP], zstrm);
-	zs_unmap_object(zram->mem_pool, handle);
 
 	zram_slot_write_lock(zram, index);
 	zram_set_handle(zram, index, handle);
@@ -1882,7 +1877,7 @@ static int recompress_slot(struct zram *zram, u32 index, struct page *page,
 	unsigned int class_index_old;
 	unsigned int class_index_new;
 	u32 num_recomps = 0;
-	void *src, *dst;
+	void *src;
 	int ret;
 
 	handle_old = zram_get_handle(zram, index);
@@ -2020,12 +2015,9 @@ static int recompress_slot(struct zram *zram, u32 index, struct page *page,
 		return 0;
 	}
 
-	dst = zs_map_object(zram->mem_pool, handle_new, ZS_MM_WO);
-	memcpy(dst, zstrm->buffer, comp_len_new);
+	zs_obj_write(zram->mem_pool, handle_new, zstrm->buffer, comp_len_new);
 	zcomp_stream_put(zram->comps[prio], zstrm);
 
-	zs_unmap_object(zram->mem_pool, handle_new);
-
 	zram_free_page(zram, index);
 	zram_set_handle(zram, index, handle_new);
 	zram_set_obj_size(zram, index, comp_len_new);
-- 
2.48.1.262.g85cc9f2d1e-goog


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ