staging: erofs: add a generic z_erofs VLE decompressor (0d40d6e3) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/staging/erofs/Kconfig

+14 −0

Original line number	Diff line number	Diff line
		@@ -87,3 +87,17 @@ config EROFS_FS_ZIP

		If you don't want to use compression feature, say N.

		config EROFS_FS_CLUSTER_PAGE_LIMIT
		int "EROFS Cluster Pages Hard Limit"
		depends on EROFS_FS_ZIP
		range 1 256
		default "1"
		help
		Indicates VLE compressed pages hard limit of a
		compressed cluster.

		For example, if files of a image are compressed
		into 8k-unit, the hard limit should not be less
		than 2. Otherwise, the image cannot be mounted
		correctly on this kernel.

drivers/staging/erofs/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -9,5 +9,5 @@ obj-$(CONFIG_EROFS_FS) += erofs.o
		ccflags-y += -I$(src)/include
		erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
		erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
		erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o unzip_lz4.o
		erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o unzip_lz4.o unzip_vle_lz4.o

drivers/staging/erofs/internal.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -161,6 +161,11 @@ static inline void erofs_kmalloc(struct erofs_sb_info sbi,

		#define ROOT_NID(sb) ((sb)->root_nid)

		#ifdef CONFIG_EROFS_FS_ZIP
		/* hard limit of pages per compressed cluster */
		#define Z_EROFS_CLUSTER_MAX_PAGES (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT)
		#endif

		typedef u64 erofs_off_t;

		/* data type for filesystem-wide blocks number */

drivers/staging/erofs/unzip_vle.h

0 → 100644

+35 −0

Original line number	Diff line number	Diff line
		/* SPDX-License-Identifier: GPL-2.0
		*
		* linux/drivers/staging/erofs/unzip_vle.h
		*
		* Copyright (C) 2018 HUAWEI, Inc.
		* http://www.huawei.com/
		* Created by Gao Xiang <gaoxiang25@huawei.com>
		*
		* This file is subject to the terms and conditions of the GNU General Public
		* License. See the file COPYING in the main directory of the Linux
		* distribution for more details.
		*/
		#ifndef __EROFS_FS_UNZIP_VLE_H
		#define __EROFS_FS_UNZIP_VLE_H

		#include "internal.h"

		#define Z_EROFS_VLE_INLINE_PAGEVECS 3

		/* unzip_vle_lz4.c */
		extern int z_erofs_vle_plain_copy(struct page **compressed_pages,
		unsigned clusterpages, struct page **pages,
		unsigned nr_pages, unsigned short pageofs);

		extern int z_erofs_vle_unzip_fast_percpu(struct page **compressed_pages,
		unsigned clusterpages, struct page **pages,
		unsigned outlen, unsigned short pageofs,
		void (endio)(struct page ));

		extern int z_erofs_vle_unzip_vmap(struct page **compressed_pages,
		unsigned clusterpages, void *vaddr, unsigned llen,
		unsigned short pageofs, bool overlapped);

		#endif

drivers/staging/erofs/unzip_vle_lz4.c

0 → 100644

+209 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* linux/drivers/staging/erofs/unzip_vle_lz4.c
		*
		* Copyright (C) 2018 HUAWEI, Inc.
		* http://www.huawei.com/
		* Created by Gao Xiang <gaoxiang25@huawei.com>
		*
		* This file is subject to the terms and conditions of the GNU General Public
		* License. See the file COPYING in the main directory of the Linux
		* distribution for more details.
		*/
		#include "unzip_vle.h"

		#if Z_EROFS_CLUSTER_MAX_PAGES > Z_EROFS_VLE_INLINE_PAGEVECS
		#define EROFS_PERCPU_NR_PAGES Z_EROFS_CLUSTER_MAX_PAGES
		#else
		#define EROFS_PERCPU_NR_PAGES Z_EROFS_VLE_INLINE_PAGEVECS
		#endif

		static struct {
		char data[PAGE_SIZE * EROFS_PERCPU_NR_PAGES];
		} erofs_pcpubuf[NR_CPUS];

		int z_erofs_vle_plain_copy(struct page **compressed_pages,
		unsigned clusterpages,
		struct page **pages,
		unsigned nr_pages,
		unsigned short pageofs)
		{
		unsigned i, j;
		void *src = NULL;
		const unsigned righthalf = PAGE_SIZE - pageofs;
		char *percpu_data;
		bool mirrored[Z_EROFS_CLUSTER_MAX_PAGES] = { 0 };

		preempt_disable();
		percpu_data = erofs_pcpubuf[smp_processor_id()].data;

		j = 0;
		for (i = 0; i < nr_pages; j = i++) {
		struct page *page = pages[i];
		void *dst;

		if (page == NULL) {
		if (src != NULL) {
		if (!mirrored[j])
		kunmap_atomic(src);
		src = NULL;
		}
		continue;
		}

		dst = kmap_atomic(page);

		for (; j < clusterpages; ++j) {
		if (compressed_pages[j] != page)
		continue;

		BUG_ON(mirrored[j]);
		memcpy(percpu_data + j * PAGE_SIZE, dst, PAGE_SIZE);
		mirrored[j] = true;
		break;
		}

		if (i) {
		if (src == NULL)
		src = mirrored[i-1] ?
		percpu_data + (i-1) * PAGE_SIZE :
		kmap_atomic(compressed_pages[i-1]);

		memcpy(dst, src + righthalf, pageofs);

		if (!mirrored[i-1])
		kunmap_atomic(src);

		if (unlikely(i >= clusterpages)) {
		kunmap_atomic(dst);
		break;
		}
		}

		if (!righthalf)
		src = NULL;
		else {
		src = mirrored[i] ? percpu_data + i * PAGE_SIZE :
		kmap_atomic(compressed_pages[i]);

		memcpy(dst + pageofs, src, righthalf);
		}

		kunmap_atomic(dst);
		}

		if (src != NULL && !mirrored[j])
		kunmap_atomic(src);

		preempt_enable();
		return 0;
		}

		extern int z_erofs_unzip_lz4(void in, void out, size_t inlen, size_t outlen);

		int z_erofs_vle_unzip_fast_percpu(struct page **compressed_pages,
		unsigned clusterpages,
		struct page **pages,
		unsigned outlen,
		unsigned short pageofs,
		void (endio)(struct page ))
		{
		void vin, vout;
		unsigned nr_pages, i, j;
		int ret;

		if (outlen + pageofs > EROFS_PERCPU_NR_PAGES * PAGE_SIZE)
		return -ENOTSUPP;

		nr_pages = DIV_ROUND_UP(outlen + pageofs, PAGE_SIZE);

		if (clusterpages == 1)
		vin = kmap_atomic(compressed_pages[0]);
		else
		vin = erofs_vmap(compressed_pages, clusterpages);

		preempt_disable();
		vout = erofs_pcpubuf[smp_processor_id()].data;

		ret = z_erofs_unzip_lz4(vin, vout + pageofs,
		clusterpages * PAGE_SIZE, outlen);

		if (ret >= 0) {
		outlen = ret;
		ret = 0;
		}

		for (i = 0; i < nr_pages; ++i) {
		j = min((unsigned)PAGE_SIZE - pageofs, outlen);

		if (pages[i] != NULL) {
		if (ret < 0)
		SetPageError(pages[i]);
		else if (clusterpages == 1 && pages[i] == compressed_pages[0])
		memcpy(vin + pageofs, vout + pageofs, j);
		else {
		void *dst = kmap_atomic(pages[i]);

		memcpy(dst + pageofs, vout + pageofs, j);
		kunmap_atomic(dst);
		}
		endio(pages[i]);
		}
		vout += PAGE_SIZE;
		outlen -= j;
		pageofs = 0;
		}
		preempt_enable();

		if (clusterpages == 1)
		kunmap_atomic(vin);
		else
		erofs_vunmap(vin, clusterpages);

		return ret;
		}

		int z_erofs_vle_unzip_vmap(struct page **compressed_pages,
		unsigned clusterpages,
		void *vout,
		unsigned llen,
		unsigned short pageofs,
		bool overlapped)
		{
		void *vin;
		unsigned i;
		int ret;

		if (overlapped) {
		preempt_disable();
		vin = erofs_pcpubuf[smp_processor_id()].data;

		for (i = 0; i < clusterpages; ++i) {
		void *t = kmap_atomic(compressed_pages[i]);

		memcpy(vin + PAGE_SIZE *i, t, PAGE_SIZE);
		kunmap_atomic(t);
		}
		} else if (clusterpages == 1)
		vin = kmap_atomic(compressed_pages[0]);
		else {
		vin = erofs_vmap(compressed_pages, clusterpages);
		}

		ret = z_erofs_unzip_lz4(vin, vout + pageofs,
		clusterpages * PAGE_SIZE, llen);
		if (ret > 0)
		ret = 0;

		if (!overlapped) {
		if (clusterpages == 1)
		kunmap_atomic(vin);
		else {
		erofs_vunmap(vin, clusterpages);
		}
		} else
		preempt_enable();

		return ret;
		}