zram/zcomp: do not zero out zcomp private pages

Do not __GFP_ZERO allocated zcomp ->private pages.  We keep allocated
streams around and use them for read/write requests, so we supply a
zeroed out ->private to compression algorithm as a scratch buffer only
once -- the first time we use that stream.  For the rest of IO requests
served by this stream ->private usually contains some temporarily data
from the previous requests.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/block/zram/zcomp_lz4.c

@@ -19,10 +19,10 @@ static void *zcomp_lz4_create(gfp_t flags)
 {
 	void *ret;
 
-	ret = kzalloc(LZ4_MEM_COMPRESS, flags);
+	ret = kmalloc(LZ4_MEM_COMPRESS, flags);
 	if (!ret)
 		ret = __vmalloc(LZ4_MEM_COMPRESS,
-				flags | __GFP_ZERO | __GFP_HIGHMEM,
+				flags | __GFP_HIGHMEM,
 				PAGE_KERNEL);
 	return ret;
 }

drivers/block/zram/zcomp_lzo.c

@@ -19,10 +19,10 @@ static void *lzo_create(gfp_t flags)
 {
 	void *ret;
 
-	ret = kzalloc(LZO1X_MEM_COMPRESS, flags);
+	ret = kmalloc(LZO1X_MEM_COMPRESS, flags);
 	if (!ret)
 		ret = __vmalloc(LZO1X_MEM_COMPRESS,
-				flags | __GFP_ZERO | __GFP_HIGHMEM,
+				flags | __GFP_HIGHMEM,
 				PAGE_KERNEL);
 	return ret;
 }