Commit e5e3abba authored by Gao Xiang's avatar Gao Xiang Committed by Greg Kroah-Hartman
Browse files

staging: erofs: drop multiref support temporarily 



Multiref support means that a compressed page could have
more than one reference, which is designed for on-disk data
deduplication. However, mkfs doesn't support this mode
at this moment, and the kernel implementation is also broken.

Let's drop multiref support. If it is fully implemented
in the future, it can be reverted later.

Signed-off-by: default avatarGao Xiang <gaoxiang25@huawei.com>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b27661cf

drivers/staging/erofs/unzip_vle.c

+5 −31
Original line number Diff line number Diff line
@@ -301,12 +301,9 @@ z_erofs_vle_work_lookup(const struct z_erofs_vle_work_finder *f) 
	grp = container_of(egrp, struct z_erofs_vle_workgroup, obj);

	*f->grp_ret = grp;



#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF

	work = z_erofs_vle_grab_work(grp, f->pageofs);

	/* if multiref is disabled, `primary' is always true */

	primary = true;

#else

	BUG();

#endif



	DBG_BUGON(work->pageofs != f->pageofs);
@@ -368,12 +365,9 @@ z_erofs_vle_work_register(const struct z_erofs_vle_work_finder *f, 
	struct z_erofs_vle_workgroup *grp = *f->grp_ret;

	struct z_erofs_vle_work *work;



#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF

	/* if multiref is disabled, grp should never be nullptr */

	BUG_ON(grp != NULL);

#else

	if (grp != NULL)

		goto skip;

#endif



	/* no available workgroup, let's allocate one */

	grp = kmem_cache_zalloc(z_erofs_workgroup_cachep, GFP_NOFS);

	if (unlikely(grp == NULL))
@@ -396,13 +390,7 @@ z_erofs_vle_work_register(const struct z_erofs_vle_work_finder *f, 
	*f->hosted = true;



	gnew = true;

#ifdef CONFIG_EROFS_FS_ZIP_MULTIREF

skip:

	/* currently unimplemented */

	BUG();

#else

	work = z_erofs_vle_grab_primary_work(grp);

#endif

	work->pageofs = f->pageofs;



	mutex_init(&work->lock);
@@ -797,9 +785,7 @@ static int z_erofs_vle_unzip(struct super_block *sb, 


	struct z_erofs_pagevec_ctor ctor;

	unsigned int nr_pages;

#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF

	unsigned int sparsemem_pages = 0;

#endif

	struct page *pages_onstack[Z_EROFS_VLE_VMAP_ONSTACK_PAGES];

	struct page **pages, **compressed_pages, *page;

	unsigned int i, llen;
@@ -811,11 +797,7 @@ static int z_erofs_vle_unzip(struct super_block *sb, 
	int err;



	might_sleep();

#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF

	work = z_erofs_vle_grab_primary_work(grp);

#else

	BUG();

#endif

	BUG_ON(!READ_ONCE(work->nr_pages));



	mutex_lock(&work->lock);
@@ -866,13 +848,11 @@ repeat: 
			pagenr = z_erofs_onlinepage_index(page);



		BUG_ON(pagenr >= nr_pages);



#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF

		BUG_ON(pages[pagenr] != NULL);

		++sparsemem_pages;

#endif



		pages[pagenr] = page;

	}

	sparsemem_pages = i;



	z_erofs_pagevec_ctor_exit(&ctor, true);
@@ -902,10 +882,8 @@ repeat: 
		pagenr = z_erofs_onlinepage_index(page);



		BUG_ON(pagenr >= nr_pages);

#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF

		BUG_ON(pages[pagenr] != NULL);

		++sparsemem_pages;

#endif

		pages[pagenr] = page;



		overlapped = true;
@@ -931,12 +909,10 @@ repeat: 
	if (err != -ENOTSUPP)

		goto out_percpu;



#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF

	if (sparsemem_pages >= nr_pages) {

		BUG_ON(sparsemem_pages > nr_pages);

		goto skip_allocpage;

	}

#endif



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

		if (pages[i] != NULL)
@@ -945,9 +921,7 @@ repeat: 
		pages[i] = __stagingpage_alloc(page_pool, GFP_NOFS);

	}



#ifndef CONFIG_EROFS_FS_ZIP_MULTIREF

skip_allocpage:

#endif

	vout = erofs_vmap(pages, nr_pages);



	err = z_erofs_vle_unzip_vmap(compressed_pages,

drivers/staging/erofs/unzip_vle.h

+1 −11
Original line number Diff line number Diff line
@@ -47,13 +47,6 @@ static inline bool z_erofs_gather_if_stagingpage(struct list_head *page_pool, 
#define Z_EROFS_VLE_INLINE_PAGEVECS     3



struct z_erofs_vle_work {

	/* struct z_erofs_vle_work *left, *right; */



#ifdef CONFIG_EROFS_FS_ZIP_MULTIREF

	struct list_head list;



	atomic_t refcount;

#endif

	struct mutex lock;



	/* I: decompression offset in page */
@@ -107,10 +100,8 @@ static inline void z_erofs_vle_set_workgrp_fmt( 
	grp->flags = fmt | (grp->flags & ~Z_EROFS_VLE_WORKGRP_FMT_MASK);

}



#ifdef CONFIG_EROFS_FS_ZIP_MULTIREF

#error multiref decompression is unimplemented yet

#else



/* definitions if multiref is disabled */

#define z_erofs_vle_grab_primary_work(grp)	(&(grp)->work)

#define z_erofs_vle_grab_work(grp, pageofs)	(&(grp)->work)

#define z_erofs_vle_work_workgroup(wrk, primary)	\
@@ -118,7 +109,6 @@ static inline void z_erofs_vle_set_workgrp_fmt( 
		struct z_erofs_vle_workgroup, work) : \

		({ BUG(); (void *)NULL; }))



#endif



#define Z_EROFS_WORKGROUP_SIZE       sizeof(struct z_erofs_vle_workgroup)

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