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.

Link: https://lkml.kernel.org/r/20250221222958.2225035-14-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index cfdde2e0748a91cccb9fdca7e16c5253809c2eb8..a1d627054bb15f3304ccdd323d2d169662a5f6a4 100644 (file)
--- 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 *zstrm)
 {
        comp->ops->destroy_ctx(&zstrm->ctx);
+       vfree(zstrm->local_copy);
        vfree(zstrm->buffer);
        zstrm->buffer = NULL;
 }
@@ -57,12 +58,13 @@ static int zcomp_strm_init(struct zcomp *comp, struct zcomp_strm *zstrm)
        if (ret)
                return ret;
 
+       zstrm->local_copy = vzalloc(PAGE_SIZE);
        /*
         * allocate 2 pages. 1 for compressed data, plus 1 extra for the
         * case when compressed size is larger than the original one
         */
        zstrm->buffer = vzalloc(2 * PAGE_SIZE);
-       if (!zstrm->buffer) {
+       if (!zstrm->buffer || !zstrm->local_copy) {
                zcomp_strm_free(comp, zstrm);
                return -ENOMEM;
        }

diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index 23b8236b9090922efabd63de22c6adb4fe81e868..25339ed1e07ec05f04f231aef86339d172e28193 100644 (file)
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -34,6 +34,8 @@ struct zcomp_strm {
        struct mutex lock;
        /* 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 b96be8576cbc280aa597ddb01c65c411fd3a7733..1ce981ce6f48ddf0f431c0b547b5568b998a00bd 100644 (file)
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1566,11 +1566,11 @@ 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;
 }
@@ -1588,11 +1588,11 @@ 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(zstrm);
 
        return ret;
@@ -1688,7 +1688,7 @@ 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
@@ -1705,11 +1705,9 @@ 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_lock(zram, index);
        zram_set_flag(zram, index, ZRAM_HUGE);
@@ -1730,7 +1728,7 @@ 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;
@@ -1776,11 +1774,8 @@ 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(zstrm);
-       zs_unmap_object(zram->mem_pool, handle);
 
        zram_slot_lock(zram, index);
        zram_set_handle(zram, index, handle);
@@ -1892,7 +1887,7 @@ static int recompress_slot(struct zram *zram, u32 index, struct page *page,
        unsigned int comp_len_new;
        unsigned int class_index_old;
        unsigned int class_index_new;
-       void *src, *dst;
+       void *src;
        int ret = 0;
 
        handle_old = zram_get_handle(zram, index);
@@ -2002,12 +1997,9 @@ static int recompress_slot(struct zram *zram, u32 index, struct page *page,
                return PTR_ERR((void *)handle_new);
        }
 
-       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(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);