Merge "mm: zbud: fix the locking scenarios with zcache" (23b1223c) · Commits · e / devices / android_kernel_xiaomi_markw

mm/zbud.c

+16 −13

Original line number	Diff line number	Diff line
		@@ -342,6 +342,7 @@ int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
		struct zbud_header *zhdr = NULL;
		enum buddy bud;
		struct page *page;
		unsigned long flags;
		int found = 0;

		if (!size \|\| (gfp & __GFP_HIGHMEM))
		@@ -349,7 +350,7 @@ int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
		if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED - CHUNK_SIZE)
		return -ENOSPC;
		chunks = size_to_chunks(size);
		spin_lock_bh(&pool->lock);
		spin_lock_irqsave(&pool->lock, flags);

		/* First, try to find an unbuddied zbud page. */
		zhdr = NULL;
		@@ -368,11 +369,11 @@ int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
		}

		/* Couldn't find unbuddied zbud page, create new one */
		spin_unlock_bh(&pool->lock);
		spin_unlock_irqrestore(&pool->lock, flags);
		page = alloc_page(gfp);
		if (!page)
		return -ENOMEM;
		spin_lock_bh(&pool->lock);
		spin_lock_irqsave(&pool->lock, flags);
		pool->pages_nr++;
		zhdr = init_zbud_page(page);
		bud = FIRST;
		@@ -400,7 +401,7 @@ found:
		*handle = encode_handle(zhdr, bud);
		if ((gfp & __GFP_ZERO) && found)
		memset((void )handle, 0, size);
		spin_unlock_bh(&pool->lock);
		spin_unlock_irqrestore(&pool->lock, flags);

		return 0;
		}
		@@ -419,8 +420,9 @@ void zbud_free(struct zbud_pool *pool, unsigned long handle)
		{
		struct zbud_header *zhdr;
		int freechunks;
		unsigned long flags;

		spin_lock_bh(&pool->lock);
		spin_lock_irqsave(&pool->lock, flags);
		zhdr = handle_to_zbud_header(handle);

		/* If first buddy, handle will be page aligned */
		@@ -431,7 +433,7 @@ void zbud_free(struct zbud_pool *pool, unsigned long handle)

		if (zhdr->under_reclaim) {
		/* zbud page is under reclaim, reclaim will free */
		spin_unlock_bh(&pool->lock);
		spin_unlock_irqrestore(&pool->lock, flags);
		return;
		}

		@@ -449,7 +451,7 @@ void zbud_free(struct zbud_pool *pool, unsigned long handle)
		list_add(&zhdr->buddy, &pool->unbuddied[freechunks]);
		}

		spin_unlock_bh(&pool->lock);
		spin_unlock_irqrestore(&pool->lock, flags);
		}

		#define list_tail_entry(ptr, type, member) \
		@@ -494,12 +496,13 @@ int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)
		{
		int i, ret, freechunks;
		struct zbud_header *zhdr;
		unsigned long flags;
		unsigned long first_handle = 0, last_handle = 0;

		spin_lock_bh(&pool->lock);
		spin_lock_irqsave(&pool->lock, flags);
		if (!pool->ops \|\| !pool->ops->evict \|\| list_empty(&pool->lru) \|\|
		retries == 0) {
		spin_unlock_bh(&pool->lock);
		spin_unlock_irqrestore(&pool->lock, flags);
		return -EINVAL;
		}
		for (i = 0; i < retries; i++) {
		@@ -518,7 +521,7 @@ int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)
		first_handle = encode_handle(zhdr, FIRST);
		if (zhdr->last_chunks)
		last_handle = encode_handle(zhdr, LAST);
		spin_unlock_bh(&pool->lock);
		spin_unlock_irqrestore(&pool->lock, flags);

		/* Issue the eviction callback(s) */
		if (first_handle) {
		@@ -532,7 +535,7 @@ int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)
		goto next;
		}
		next:
		spin_lock_bh(&pool->lock);
		spin_lock_irqsave(&pool->lock, flags);
		zhdr->under_reclaim = false;
		if (zhdr->first_chunks == 0 && zhdr->last_chunks == 0) {
		/*
		@@ -541,7 +544,7 @@ next:
		*/
		free_zbud_page(zhdr);
		pool->pages_nr--;
		spin_unlock_bh(&pool->lock);
		spin_unlock_irqrestore(&pool->lock, flags);
		return 0;
		} else if (zhdr->first_chunks == 0 \|\|
		zhdr->last_chunks == 0) {
		@@ -556,7 +559,7 @@ next:
		/* add to beginning of LRU */
		list_add(&zhdr->lru, &pool->lru);
		}
		spin_unlock_bh(&pool->lock);
		spin_unlock_irqrestore(&pool->lock, flags);
		return -EAGAIN;
		}