From b8395c8a835e4101333210cafb88671fbc898d96 Mon Sep 17 00:00:00 2001
From: Tom Marshall <tdm.code@gmail.com>
Date: Sun, 3 Nov 2019 09:00:28 -0800
Subject: [PATCH] Alloc compress state using vmalloc

---
 dm-compress/lbd.c           | 20 +++++++++-----------
 dm-compress/util.c          | 12 ------------
 include/linux/dm-compress.h |  4 ----
 3 files changed, 9 insertions(+), 27 deletions(-)

diff --git a/dm-compress/lbd.c b/dm-compress/lbd.c
index cdc6e97..8f47fdf 100644
--- a/dm-compress/lbd.c
+++ b/dm-compress/lbd.c
@@ -65,7 +65,6 @@ lblk_is_zeros(struct cbd_params* params, struct lbd* lbd)
 }
 
 struct lblk_compress_state {
-    struct page*        pages;
     u8*                 buf;
 #ifdef COMPRESS_HAVE_LZ4
     u8*                 lz4_workmem;
@@ -571,21 +570,20 @@ lbdcache_alloc_compress_state(void* percpu, const struct cbd_params* params, int
     }
     statep = per_cpu_ptr(percpu, cpu);
     *statep = state;
-    state->pages = cbd_alloc_pages_nowait(lblk_per_pblk(params));
-    if (!state->pages) {
+    state->buf = vmalloc(PBLK_SIZE * lblk_per_pblk(params));
+    if (!state->buf) {
         return false;
     }
-    state->buf = page_address(state->pages);
 #ifdef COMPRESS_HAVE_LZ4
     workmem_len = LZ4_compressBound(PBLK_SIZE * lblk_per_pblk(params));
-    state->lz4_workmem = kzalloc(workmem_len, GFP_NOWAIT);
+    state->lz4_workmem = vzalloc(workmem_len);
     if (!state->lz4_workmem) {
         return false;
     }
 #endif
 #ifdef COMPRESS_HAVE_ZLIB
     workmem_len = zlib_deflate_workspacesize(MAX_WBITS, DEF_MEM_LEVEL);
-    state->zlib_cstream.workspace = kzalloc(workmem_len, GFP_NOWAIT);
+    state->zlib_cstream.workspace = vzalloc(workmem_len);
     if (!state->zlib_cstream.workspace) {
         return false;
     }
@@ -594,7 +592,7 @@ lbdcache_alloc_compress_state(void* percpu, const struct cbd_params* params, int
                             Z_DEFAULT_STRATEGY);
     BUG_ON(ret != Z_OK);
     workmem_len = zlib_inflate_workspacesize();
-    state->zlib_dstream.workspace = kzalloc(workmem_len, GFP_NOWAIT);
+    state->zlib_dstream.workspace = vzalloc(workmem_len);
     if (!state->zlib_dstream.workspace) {
         return false;
     }
@@ -617,13 +615,13 @@ lbdcache_free_compress_state(void* percpu, const struct cbd_params* params, int
         return;
     }
 #ifdef COMPRESS_HAVE_ZLIB
-    kfree(state->zlib_dstream.workspace);
-    kfree(state->zlib_cstream.workspace);
+    vfree(state->zlib_dstream.workspace);
+    vfree(state->zlib_cstream.workspace);
 #endif
 #ifdef COMPRESS_HAVE_LZ4
-    kfree(state->lz4_workmem);
+    vfree(state->lz4_workmem);
 #endif
-    cbd_free_pages(state->pages, lblk_per_pblk(params));
+    vfree(state->buf);
     kfree(state);
 }
 
diff --git a/dm-compress/util.c b/dm-compress/util.c
index b384ec5..df940ea 100644
--- a/dm-compress/util.c
+++ b/dm-compress/util.c
@@ -39,12 +39,6 @@ cbd_alloc_page(void)
     return alloc_page(GFP_KERNEL);
 }
 
-struct page*
-cbd_alloc_page_nowait(void)
-{
-    return alloc_page(GFP_NOWAIT);
-}
-
 void
 cbd_free_page(struct page* page)
 {
@@ -57,12 +51,6 @@ cbd_alloc_pages(size_t len)
     return alloc_pages(GFP_KERNEL, get_order(len * PAGE_SIZE));
 }
 
-struct page*
-cbd_alloc_pages_nowait(size_t len)
-{
-    return alloc_pages(GFP_NOWAIT, get_order(len * PAGE_SIZE));
-}
-
 void
 cbd_free_pages(struct page* pages, size_t len)
 {
diff --git a/include/linux/dm-compress.h b/include/linux/dm-compress.h
index 3ca2669..f653d65 100644
--- a/include/linux/dm-compress.h
+++ b/include/linux/dm-compress.h
@@ -456,14 +456,10 @@ typedef void (*pblk_endio_t)(struct bio*);
 /* Single page allocator */
 struct page*
        cbd_alloc_page(void);
-struct page*
-       cbd_alloc_page_nowait(void);
 void   cbd_free_page(struct page* page);
 /* Multiple page allocator */
 struct page*
        cbd_alloc_pages(size_t len);
-struct page*
-       cbd_alloc_pages_nowait(size_t len);
 void   cbd_free_pages(struct page* pages, size_t len);
 /* Vector page allocator */
 bool   cbd_alloc_pagev(struct page** pagev, size_t len);