1 files changed, 41 insertions, 2 deletions

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 5fa4faaa9d81..5d77b6123918 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -53,6 +53,40 @@ static size_t huge_class_size;
 
 static void zram_free_page(struct zram *zram, size_t index);
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages)
+{
+	size_t index;
+
+	for (index = 0; index < num_pages; index++)
+		spin_lock_init(&zram->table[index].lock);
+}
+
+static int zram_slot_trylock(struct zram *zram, u32 index)
+{
+	int ret;
+
+	ret = spin_trylock(&zram->table[index].lock);
+	if (ret)
+		__set_bit(ZRAM_LOCK, &zram->table[index].value);
+	return ret;
+}
+
+static void zram_slot_lock(struct zram *zram, u32 index)
+{
+	spin_lock(&zram->table[index].lock);
+	__set_bit(ZRAM_LOCK, &zram->table[index].value);
+}
+
+static void zram_slot_unlock(struct zram *zram, u32 index)
+{
+	__clear_bit(ZRAM_LOCK, &zram->table[index].value);
+	spin_unlock(&zram->table[index].lock);
+}
+
+#else
+static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages) { }
+
 static int zram_slot_trylock(struct zram *zram, u32 index)
 {
 	return bit_spin_trylock(ZRAM_LOCK, &zram->table[index].value);
@@ -67,6 +101,7 @@ static void zram_slot_unlock(struct zram *zram, u32 index)
 {
 	bit_spin_unlock(ZRAM_LOCK, &zram->table[index].value);
 }
+#endif
 
 static inline bool init_done(struct zram *zram)
 {
@@ -901,6 +936,8 @@ static DEVICE_ATTR_RO(io_stat);
 static DEVICE_ATTR_RO(mm_stat);
 static DEVICE_ATTR_RO(debug_stat);
 
+
+
 static void zram_meta_free(struct zram *zram, u64 disksize)
 {
 	size_t num_pages = disksize >> PAGE_SHIFT;
@@ -931,6 +968,7 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize)
 
 	if (!huge_class_size)
 		huge_class_size = zs_huge_class_size(zram->mem_pool);
+	zram_meta_init_table_locks(zram, num_pages);
 	return true;
 }
 
@@ -989,6 +1027,7 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
 	unsigned long handle;
 	unsigned int size;
 	void *src, *dst;
+	struct zcomp_strm *zstrm;
 
 	if (zram_wb_enabled(zram)) {
 		zram_slot_lock(zram, index);
@@ -1023,6 +1062,7 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
 
 	size = zram_get_obj_size(zram, index);
 
+	zstrm = zcomp_stream_get(zram->comp);
 	src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
 	if (size == PAGE_SIZE) {
 		dst = kmap_atomic(page);
@@ -1030,14 +1070,13 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
 		kunmap_atomic(dst);
 		ret = 0;
 	} else {
-		struct zcomp_strm *zstrm = zcomp_stream_get(zram->comp);
 
 		dst = kmap_atomic(page);
 		ret = zcomp_decompress(zstrm, src, size, dst);
 		kunmap_atomic(dst);
-		zcomp_stream_put(zram->comp);
 	}
 	zs_unmap_object(zram->mem_pool, handle);
+	zcomp_stream_put(zram->comp);
 	zram_slot_unlock(zram, index);
 
 	/* Should NEVER happen. Return bio error if it does. */