[PATCH 1/2] zram: pass gfp from zcomp frontend to backend

[Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>]

From: Minchan Kim <minchan@kernel.org>

Each zcomp backend uses own gfp flag but it's pointless
because the context they could be called is driven by upper
layer(ie, zcomp frontend). As well, zcomp frondend could
call them in different context. One context(ie, zram init part)
is it should be better to make sure successful allocation
other context(ie, further stream allocation part for accelarating
I/O speed) is just optional so let's pass gfp down from driver
(ie, zcomp frontend) like normal MM convention.

[sergey: add missing __vmalloc zero and highmem gfps]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
 drivers/block/zram/zcomp.c     | 24 ++++++++++++++++--------
 drivers/block/zram/zcomp.h     |  2 +-
 drivers/block/zram/zcomp_lz4.c | 16 +++-------------
 drivers/block/zram/zcomp_lzo.c | 16 +++-------------
 4 files changed, 23 insertions(+), 35 deletions(-)

diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index c536177..2bc4aea 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -74,18 +74,18 @@ static void zcomp_strm_free(struct zcomp *comp, struct zcomp_strm *zstrm)
  * allocate new zcomp_strm structure with ->private initialized by
  * backend, return NULL on error
  */
-static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp)
+static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp, gfp_t flags)
 {
-	struct zcomp_strm *zstrm = kmalloc(sizeof(*zstrm), GFP_NOIO);
+	struct zcomp_strm *zstrm = kmalloc(sizeof(*zstrm), flags);
 	if (!zstrm)
 		return NULL;
 
-	zstrm->private = comp->backend->create();
+	zstrm->private = comp->backend->create(flags);
 	/*
 	 * allocate 2 pages. 1 for compressed data, plus 1 extra for the
 	 * case when compressed size is larger than the original one
 	 */
-	zstrm->buffer = (void *)__get_free_pages(GFP_NOIO | __GFP_ZERO, 1);
+	zstrm->buffer = (void *)__get_free_pages(flags | __GFP_ZERO, 1);
 	if (!zstrm->private || !zstrm->buffer) {
 		zcomp_strm_free(comp, zstrm);
 		zstrm = NULL;
@@ -120,8 +120,16 @@ static struct zcomp_strm *zcomp_strm_multi_find(struct zcomp *comp)
 		/* allocate new zstrm stream */
 		zs->avail_strm++;
 		spin_unlock(&zs->strm_lock);
-
-		zstrm = zcomp_strm_alloc(comp);
+		/*
+		 * This function can be called in swapout/fs write path
+		 * so we can't use GFP_FS|IO. And it assumes we already
+		 * have at least one stream in zram initialization so we
+		 * don't do best effort to allocate more stream in here.
+		 * A default stream will work well without further multiple
+		 * streams. That's why we use NORETRY | NOWARN | NOMEMALLOC.
+		 */
+		zstrm = zcomp_strm_alloc(comp, GFP_NOIO | __GFP_NORETRY |
+					__GFP_NOWARN | __GFP_NOMEMALLOC);
 		if (!zstrm) {
 			spin_lock(&zs->strm_lock);
 			zs->avail_strm--;
@@ -209,7 +217,7 @@ static int zcomp_strm_multi_create(struct zcomp *comp, int max_strm)
 	zs->max_strm = max_strm;
 	zs->avail_strm = 1;
 
-	zstrm = zcomp_strm_alloc(comp);
+	zstrm = zcomp_strm_alloc(comp, GFP_KERNEL);
 	if (!zstrm) {
 		kfree(zs);
 		return -ENOMEM;
@@ -259,7 +267,7 @@ static int zcomp_strm_single_create(struct zcomp *comp)
 
 	comp->stream = zs;
 	mutex_init(&zs->strm_lock);
-	zs->zstrm = zcomp_strm_alloc(comp);
+	zs->zstrm = zcomp_strm_alloc(comp, GFP_KERNEL);
 	if (!zs->zstrm) {
 		kfree(zs);
 		return -ENOMEM;
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index 46e2b9f..b7d2a4b 100644
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -33,7 +33,7 @@ struct zcomp_backend {
 	int (*decompress)(const unsigned char *src, size_t src_len,
 			unsigned char *dst);
 
-	void *(*create)(void);
+	void *(*create)(gfp_t flags);
 	void (*destroy)(void *private);
 
 	const char *name;
diff --git a/drivers/block/zram/zcomp_lz4.c b/drivers/block/zram/zcomp_lz4.c
index f2bfced..dc2338d 100644
--- a/drivers/block/zram/zcomp_lz4.c
+++ b/drivers/block/zram/zcomp_lz4.c
@@ -15,24 +15,14 @@
 
 #include "zcomp_lz4.h"
 
-static void *zcomp_lz4_create(void)
+static void *zcomp_lz4_create(gfp_t flags)
 {
 	void *ret;
 
-	/*
-	 * This function can be called in swapout/fs write path
-	 * so we can't use GFP_FS|IO. And it assumes we already
-	 * have at least one stream in zram initialization so we
-	 * don't do best effort to allocate more stream in here.
-	 * A default stream will work well without further multiple
-	 * streams. That's why we use NORETRY | NOWARN | NOMEMALLOC.
-	 */
-	ret = kzalloc(LZ4_MEM_COMPRESS, GFP_NOIO | __GFP_NORETRY |
-					__GFP_NOWARN | __GFP_NOMEMALLOC);
+	ret = kzalloc(LZ4_MEM_COMPRESS, flags);
 	if (!ret)
 		ret = __vmalloc(LZ4_MEM_COMPRESS,
-				GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN |
-				__GFP_NOMEMALLOC | __GFP_ZERO | __GFP_HIGHMEM,
+				flags | __GFP_ZERO | __GFP_HIGHMEM,
 				PAGE_KERNEL);
 	return ret;
 }
diff --git a/drivers/block/zram/zcomp_lzo.c b/drivers/block/zram/zcomp_lzo.c
index 7fbb4a3..0ab6fce 100644
--- a/drivers/block/zram/zcomp_lzo.c
+++ b/drivers/block/zram/zcomp_lzo.c
@@ -15,24 +15,14 @@
 
 #include "zcomp_lzo.h"
 
-static void *lzo_create(void)
+static void *lzo_create(gfp_t flags)
 {
 	void *ret;
 
-	/*
-	 * This function can be called in swapout/fs write path
-	 * so we can't use GFP_FS|IO. And it assumes we already
-	 * have at least one stream in zram initialization so we
-	 * don't do best effort to allocate more stream in here.
-	 * A default stream will work well without further multiple
-	 * streams. That's why we use NORETRY | NOWARN | NOMEMALLOC.
-	 */
-	ret = kzalloc(LZO1X_MEM_COMPRESS, GFP_NOIO | __GFP_NORETRY |
-					__GFP_NOWARN | __GFP_NOMEMALLOC);
+	ret = kzalloc(LZO1X_MEM_COMPRESS, flags);
 	if (!ret)
 		ret = __vmalloc(LZO1X_MEM_COMPRESS,
-				GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN |
-				__GFP_NOMEMALLOC | __GFP_ZERO | __GFP_HIGHMEM,
+				flags | __GFP_ZERO | __GFP_HIGHMEM,
 				PAGE_KERNEL);
 	return ret;
 }
-- 
2.6.3.368.gf34be46