mm/zswap: refactor out __zswap_load()

zswap_load() and zswap_writeback_entry() have the same part that
decompress the data from zswap_entry to page, so refactor out the common
part as __zswap_load(entry, page).

Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-2-9382162bbf05@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Chris Li <chrisl@kernel.org> (Google)
Cc: Barry Song <21cnbao@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/zswap.c b/mm/zswap.c
index 8dc0d2a8f0480987aaf5674e1299f987ac493720..801c25d939f2505fb37485d87dfcbe0a0649dd26 100644 (file)
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1383,6 +1383,35 @@ static int zswap_enabled_param_set(const char *val,
        return ret;
 }
 
+static void __zswap_load(struct zswap_entry *entry, struct page *page)
+{
+       struct zpool *zpool = zswap_find_zpool(entry);
+       struct scatterlist input, output;
+       struct crypto_acomp_ctx *acomp_ctx;
+       u8 *src;
+
+       acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
+       mutex_lock(acomp_ctx->mutex);
+
+       src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO);
+       if (!zpool_can_sleep_mapped(zpool)) {
+               memcpy(acomp_ctx->dstmem, src, entry->length);
+               src = acomp_ctx->dstmem;
+               zpool_unmap_handle(zpool, entry->handle);
+       }
+
+       sg_init_one(&input, src, entry->length);
+       sg_init_table(&output, 1);
+       sg_set_page(&output, page, PAGE_SIZE, 0);
+       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);
+       mutex_unlock(acomp_ctx->mutex);
+
+       if (zpool_can_sleep_mapped(zpool))
+               zpool_unmap_handle(zpool, entry->handle);
+}
+
 /*********************************
 * writeback code
 **********************************/
@@ -1404,12 +1433,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
        swp_entry_t swpentry = entry->swpentry;
        struct page *page;
        struct mempolicy *mpol;
-       struct scatterlist input, output;
-       struct crypto_acomp_ctx *acomp_ctx;
-       struct zpool *pool = zswap_find_zpool(entry);
        bool page_was_allocated;
-       u8 *src;
-       unsigned int dlen;
        int ret;
        struct writeback_control wbc = {
                .sync_mode = WB_SYNC_NONE,
@@ -1447,31 +1471,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
        }
        spin_unlock(&tree->lock);
 
-       /* decompress */
-       acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
-       dlen = PAGE_SIZE;
-       mutex_lock(acomp_ctx->mutex);
-
-       src = zpool_map_handle(pool, entry->handle, ZPOOL_MM_RO);
-       if (!zpool_can_sleep_mapped(pool)) {
-               memcpy(acomp_ctx->dstmem, src, entry->length);
-               src = acomp_ctx->dstmem;
-               zpool_unmap_handle(pool, entry->handle);
-       }
-
-       sg_init_one(&input, src, entry->length);
-       sg_init_table(&output, 1);
-       sg_set_page(&output, page, PAGE_SIZE, 0);
-       acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, dlen);
-       ret = crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait);
-       dlen = acomp_ctx->req->dlen;
-       mutex_unlock(acomp_ctx->mutex);
-
-       if (zpool_can_sleep_mapped(pool))
-               zpool_unmap_handle(pool, entry->handle);
-
-       BUG_ON(ret);
-       BUG_ON(dlen != PAGE_SIZE);
+       __zswap_load(entry, page);
 
        /* page is up to date */
        SetPageUptodate(page);
@@ -1745,11 +1745,7 @@ bool zswap_load(struct folio *folio)
        struct page *page = &folio->page;
        struct zswap_tree *tree = zswap_trees[type];
        struct zswap_entry *entry;
-       struct scatterlist input, output;
-       struct crypto_acomp_ctx *acomp_ctx;
-       u8 *src, *dst;
-       struct zpool *zpool;
-       unsigned int dlen;
+       u8 *dst;
        bool ret;
 
        VM_WARN_ON_ONCE(!folio_test_locked(folio));
@@ -1771,31 +1767,7 @@ bool zswap_load(struct folio *folio)
                goto stats;
        }
 
-       zpool = zswap_find_zpool(entry);
-
-       /* decompress */
-       dlen = PAGE_SIZE;
-       acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
-       mutex_lock(acomp_ctx->mutex);
-
-       src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO);
-       if (!zpool_can_sleep_mapped(zpool)) {
-               memcpy(acomp_ctx->dstmem, src, entry->length);
-               src = acomp_ctx->dstmem;
-               zpool_unmap_handle(zpool, entry->handle);
-       }
-
-       sg_init_one(&input, src, entry->length);
-       sg_init_table(&output, 1);
-       sg_set_page(&output, page, PAGE_SIZE, 0);
-       acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, dlen);
-       if (crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait))
-               WARN_ON(1);
-       mutex_unlock(acomp_ctx->mutex);
-
-       if (zpool_can_sleep_mapped(zpool))
-               zpool_unmap_handle(zpool, entry->handle);
-
+       __zswap_load(entry, page);
        ret = true;
 stats:
        count_vm_event(ZSWPIN);