zram: inline zram_compress

zram_compress does several things, compress, entry alloc and check
limitation.  I did for just readbility but it hurts modulization.:(

So this patch removes zram_compress functions and inline it in
__zram_bvec_write for upcoming patches.

Link: http://lkml.kernel.org/r/1498459987-24562-3-git-send-email-minchan@kernel.orgSigned-off-by: Minchan Kim <minchan@kernel.org>
Cc: Juneho Choi <juno.choi@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/block/zram/zram_drv.c

@@ -589,25 +589,38 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
 	return ret;
 }
 
-static int zram_compress(struct zram *zram, struct zcomp_strm **zstrm,
-			struct page *page,
-			unsigned long *out_handle, unsigned int *out_comp_len)
+static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
 {
 	int ret;
-	unsigned int comp_len;
-	void *src;
 	unsigned long alloced_pages;
 	unsigned long handle = 0;
+	unsigned int comp_len = 0;
+	void *src, *dst, *mem;
+	struct zcomp_strm *zstrm;
+	struct page *page = bvec->bv_page;
+	unsigned long element = 0;
+	enum zram_pageflags flags = 0;
+
+	mem = kmap_atomic(page);
+	if (page_same_filled(mem, &element)) {
+		kunmap_atomic(mem);
+		/* Free memory associated with this sector now. */
+		flags = ZRAM_SAME;
+		atomic64_inc(&zram->stats.same_pages);
+		goto out;
+	}
+	kunmap_atomic(mem);
 
 compress_again:
+	zstrm = zcomp_stream_get(zram->comp);
 	src = kmap_atomic(page);
-	ret = zcomp_compress(*zstrm, src, &comp_len);
+	ret = zcomp_compress(zstrm, src, &comp_len);
 	kunmap_atomic(src);
 
 	if (unlikely(ret)) {
+		zcomp_stream_put(zram->comp);
 		pr_err("Compression failed! err=%d\n", ret);
-		if (handle)
-			zs_free(zram->mem_pool, handle);
+		zs_free(zram->mem_pool, handle);
 		return ret;
 	}
 
@@ -639,7 +652,6 @@ static int zram_compress(struct zram *zram, struct zcomp_strm **zstrm,
 		handle = zs_malloc(zram->mem_pool, comp_len,
 				GFP_NOIO | __GFP_HIGHMEM |
 				__GFP_MOVABLE);
-		*zstrm = zcomp_stream_get(zram->comp);
 		if (handle)
 			goto compress_again;
 		return -ENOMEM;
@@ -649,43 +661,11 @@ static int zram_compress(struct zram *zram, struct zcomp_strm **zstrm,
 	update_used_max(zram, alloced_pages);
 
 	if (zram->limit_pages && alloced_pages > zram->limit_pages) {
+		zcomp_stream_put(zram->comp);
 		zs_free(zram->mem_pool, handle);
 		return -ENOMEM;
 	}
 
-	*out_handle = handle;
-	*out_comp_len = comp_len;
-	return 0;
-}
-
-static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
-{
-	int ret;
-	unsigned long handle = 0;
-	unsigned int comp_len = 0;
-	void *src, *dst, *mem;
-	struct zcomp_strm *zstrm;
-	struct page *page = bvec->bv_page;
-	unsigned long element = 0;
-	enum zram_pageflags flags = 0;
-
-	mem = kmap_atomic(page);
-	if (page_same_filled(mem, &element)) {
-		kunmap_atomic(mem);
-		/* Free memory associated with this sector now */
-		atomic64_inc(&zram->stats.same_pages);
-		flags = ZRAM_SAME;
-		goto out;
-	}
-	kunmap_atomic(mem);
-
-	zstrm = zcomp_stream_get(zram->comp);
-	ret = zram_compress(zram, &zstrm, page, &handle, &comp_len);
-	if (ret) {
-		zcomp_stream_put(zram->comp);
-		return ret;
-	}
-
 	dst = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
 
 	src = zstrm->buffer;