Commit e7368187 authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: get rid of `z_pagemap_global' 



In order to introduce multi-reference pclusters for compressed data
deduplication, let's get rid of the global page array for now since
it needs to be re-designed then at least.

Acked-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220715154203.48093-12-hsiangkao@linux.alibaba.com
parent db166fc2

fs/erofs/zdata.c

+4 −24
Original line number Diff line number Diff line
@@ -291,9 +291,6 @@ struct z_erofs_decompress_frontend { 
	.inode = __i, .owned_head = Z_EROFS_PCLUSTER_TAIL, \

	.mode = Z_EROFS_PCLUSTER_FOLLOWED, .backmost = true }



static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES];

static DEFINE_MUTEX(z_pagemap_global_lock);



static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe,

			       enum z_erofs_cache_alloctype type,

			       struct page **pagepool)
@@ -966,26 +963,11 @@ static int z_erofs_decompress_pcluster(struct super_block *sb, 
	mutex_lock(&pcl->lock);

	nr_pages = pcl->nr_pages;



	if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES) {

	if (nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES)

		pages = pages_onstack;

	} else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES &&

		   mutex_trylock(&z_pagemap_global_lock)) {

		pages = z_pagemap_global;

	} else {

		gfp_t gfp_flags = GFP_KERNEL;



		if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES)

			gfp_flags |= __GFP_NOFAIL;



	else

		pages = kvmalloc_array(nr_pages, sizeof(struct page *),

				       gfp_flags);



		/* fallback to global pagemap for the lowmem scenario */

		if (!pages) {

			mutex_lock(&z_pagemap_global_lock);

			pages = z_pagemap_global;

		}

	}

				       GFP_KERNEL | __GFP_NOFAIL);



	for (i = 0; i < nr_pages; ++i)

		pages[i] = NULL;
@@ -1065,9 +1047,7 @@ static int z_erofs_decompress_pcluster(struct super_block *sb, 
		z_erofs_onlinepage_endio(page);

	}



	if (pages == z_pagemap_global)

		mutex_unlock(&z_pagemap_global_lock);

	else if (pages != pages_onstack)

	if (pages != pages_onstack)

		kvfree(pages);



	pcl->nr_pages = 0;

fs/erofs/zdata.h

+0 −1
Original line number Diff line number Diff line
@@ -175,6 +175,5 @@ static inline void z_erofs_onlinepage_endio(struct page *page) 


#define Z_EROFS_VMAP_ONSTACK_PAGES	\

	min_t(unsigned int, THREAD_SIZE / 8 / sizeof(struct page *), 96U)

#define Z_EROFS_VMAP_GLOBAL_PAGES	2048



#endif