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	Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Signed-off-by: David Sterba <dsterba@suse.com>
		
			
				
	
	
		
			433 lines
		
	
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			433 lines
		
	
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/*
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 * Copyright (c) 2016-present, Facebook, Inc.
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 * All rights reserved.
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 *
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 */
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#include <linux/bio.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/refcount.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/zstd.h>
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#include "compression.h"
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#define ZSTD_BTRFS_MAX_WINDOWLOG 17
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#define ZSTD_BTRFS_MAX_INPUT (1 << ZSTD_BTRFS_MAX_WINDOWLOG)
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#define ZSTD_BTRFS_DEFAULT_LEVEL 3
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static ZSTD_parameters zstd_get_btrfs_parameters(size_t src_len)
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{
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	ZSTD_parameters params = ZSTD_getParams(ZSTD_BTRFS_DEFAULT_LEVEL,
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						src_len, 0);
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	if (params.cParams.windowLog > ZSTD_BTRFS_MAX_WINDOWLOG)
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		params.cParams.windowLog = ZSTD_BTRFS_MAX_WINDOWLOG;
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	WARN_ON(src_len > ZSTD_BTRFS_MAX_INPUT);
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	return params;
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}
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struct workspace {
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	void *mem;
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	size_t size;
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	char *buf;
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	struct list_head list;
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	ZSTD_inBuffer in_buf;
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	ZSTD_outBuffer out_buf;
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};
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static void zstd_free_workspace(struct list_head *ws)
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{
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	struct workspace *workspace = list_entry(ws, struct workspace, list);
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	kvfree(workspace->mem);
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	kfree(workspace->buf);
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	kfree(workspace);
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}
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static struct list_head *zstd_alloc_workspace(void)
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{
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	ZSTD_parameters params =
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			zstd_get_btrfs_parameters(ZSTD_BTRFS_MAX_INPUT);
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	struct workspace *workspace;
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	workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
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	if (!workspace)
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		return ERR_PTR(-ENOMEM);
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	workspace->size = max_t(size_t,
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			ZSTD_CStreamWorkspaceBound(params.cParams),
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			ZSTD_DStreamWorkspaceBound(ZSTD_BTRFS_MAX_INPUT));
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	workspace->mem = kvmalloc(workspace->size, GFP_KERNEL);
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	workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
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	if (!workspace->mem || !workspace->buf)
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		goto fail;
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	INIT_LIST_HEAD(&workspace->list);
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	return &workspace->list;
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fail:
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	zstd_free_workspace(&workspace->list);
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	return ERR_PTR(-ENOMEM);
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}
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static int zstd_compress_pages(struct list_head *ws,
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		struct address_space *mapping,
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		u64 start,
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		struct page **pages,
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		unsigned long *out_pages,
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		unsigned long *total_in,
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		unsigned long *total_out)
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{
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	struct workspace *workspace = list_entry(ws, struct workspace, list);
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	ZSTD_CStream *stream;
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	int ret = 0;
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	int nr_pages = 0;
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	struct page *in_page = NULL;  /* The current page to read */
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	struct page *out_page = NULL; /* The current page to write to */
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	unsigned long tot_in = 0;
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	unsigned long tot_out = 0;
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	unsigned long len = *total_out;
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	const unsigned long nr_dest_pages = *out_pages;
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	unsigned long max_out = nr_dest_pages * PAGE_SIZE;
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	ZSTD_parameters params = zstd_get_btrfs_parameters(len);
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	*out_pages = 0;
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	*total_out = 0;
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	*total_in = 0;
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	/* Initialize the stream */
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	stream = ZSTD_initCStream(params, len, workspace->mem,
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			workspace->size);
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	if (!stream) {
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		pr_warn("BTRFS: ZSTD_initCStream failed\n");
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		ret = -EIO;
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		goto out;
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	}
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	/* map in the first page of input data */
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	in_page = find_get_page(mapping, start >> PAGE_SHIFT);
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	workspace->in_buf.src = kmap(in_page);
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	workspace->in_buf.pos = 0;
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	workspace->in_buf.size = min_t(size_t, len, PAGE_SIZE);
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	/* Allocate and map in the output buffer */
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	out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
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	if (out_page == NULL) {
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		ret = -ENOMEM;
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		goto out;
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	}
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	pages[nr_pages++] = out_page;
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	workspace->out_buf.dst = kmap(out_page);
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	workspace->out_buf.pos = 0;
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	workspace->out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
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	while (1) {
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		size_t ret2;
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		ret2 = ZSTD_compressStream(stream, &workspace->out_buf,
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				&workspace->in_buf);
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		if (ZSTD_isError(ret2)) {
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			pr_debug("BTRFS: ZSTD_compressStream returned %d\n",
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					ZSTD_getErrorCode(ret2));
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			ret = -EIO;
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			goto out;
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		}
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		/* Check to see if we are making it bigger */
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		if (tot_in + workspace->in_buf.pos > 8192 &&
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				tot_in + workspace->in_buf.pos <
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				tot_out + workspace->out_buf.pos) {
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			ret = -E2BIG;
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			goto out;
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		}
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		/* We've reached the end of our output range */
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		if (workspace->out_buf.pos >= max_out) {
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			tot_out += workspace->out_buf.pos;
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			ret = -E2BIG;
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			goto out;
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		}
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		/* Check if we need more output space */
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		if (workspace->out_buf.pos == workspace->out_buf.size) {
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			tot_out += PAGE_SIZE;
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			max_out -= PAGE_SIZE;
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			kunmap(out_page);
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			if (nr_pages == nr_dest_pages) {
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				out_page = NULL;
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				ret = -E2BIG;
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				goto out;
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			}
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			out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
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			if (out_page == NULL) {
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				ret = -ENOMEM;
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				goto out;
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			}
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			pages[nr_pages++] = out_page;
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			workspace->out_buf.dst = kmap(out_page);
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			workspace->out_buf.pos = 0;
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			workspace->out_buf.size = min_t(size_t, max_out,
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							PAGE_SIZE);
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		}
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		/* We've reached the end of the input */
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		if (workspace->in_buf.pos >= len) {
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			tot_in += workspace->in_buf.pos;
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			break;
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		}
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		/* Check if we need more input */
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		if (workspace->in_buf.pos == workspace->in_buf.size) {
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			tot_in += PAGE_SIZE;
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			kunmap(in_page);
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			put_page(in_page);
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			start += PAGE_SIZE;
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			len -= PAGE_SIZE;
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			in_page = find_get_page(mapping, start >> PAGE_SHIFT);
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			workspace->in_buf.src = kmap(in_page);
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			workspace->in_buf.pos = 0;
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			workspace->in_buf.size = min_t(size_t, len, PAGE_SIZE);
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		}
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	}
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	while (1) {
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		size_t ret2;
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		ret2 = ZSTD_endStream(stream, &workspace->out_buf);
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		if (ZSTD_isError(ret2)) {
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			pr_debug("BTRFS: ZSTD_endStream returned %d\n",
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					ZSTD_getErrorCode(ret2));
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			ret = -EIO;
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			goto out;
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		}
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		if (ret2 == 0) {
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			tot_out += workspace->out_buf.pos;
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			break;
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		}
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		if (workspace->out_buf.pos >= max_out) {
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			tot_out += workspace->out_buf.pos;
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			ret = -E2BIG;
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			goto out;
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		}
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		tot_out += PAGE_SIZE;
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		max_out -= PAGE_SIZE;
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		kunmap(out_page);
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		if (nr_pages == nr_dest_pages) {
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			out_page = NULL;
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			ret = -E2BIG;
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			goto out;
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		}
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		out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
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		if (out_page == NULL) {
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			ret = -ENOMEM;
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			goto out;
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		}
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		pages[nr_pages++] = out_page;
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		workspace->out_buf.dst = kmap(out_page);
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		workspace->out_buf.pos = 0;
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		workspace->out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
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	}
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	if (tot_out >= tot_in) {
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		ret = -E2BIG;
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		goto out;
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	}
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	ret = 0;
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	*total_in = tot_in;
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	*total_out = tot_out;
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out:
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	*out_pages = nr_pages;
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	/* Cleanup */
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	if (in_page) {
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		kunmap(in_page);
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		put_page(in_page);
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	}
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	if (out_page)
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		kunmap(out_page);
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	return ret;
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}
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static int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
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{
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	struct workspace *workspace = list_entry(ws, struct workspace, list);
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	struct page **pages_in = cb->compressed_pages;
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	u64 disk_start = cb->start;
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	struct bio *orig_bio = cb->orig_bio;
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	size_t srclen = cb->compressed_len;
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	ZSTD_DStream *stream;
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	int ret = 0;
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	unsigned long page_in_index = 0;
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	unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
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	unsigned long buf_start;
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	unsigned long total_out = 0;
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	stream = ZSTD_initDStream(
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			ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size);
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	if (!stream) {
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		pr_debug("BTRFS: ZSTD_initDStream failed\n");
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		ret = -EIO;
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		goto done;
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	}
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	workspace->in_buf.src = kmap(pages_in[page_in_index]);
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	workspace->in_buf.pos = 0;
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	workspace->in_buf.size = min_t(size_t, srclen, PAGE_SIZE);
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	workspace->out_buf.dst = workspace->buf;
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	workspace->out_buf.pos = 0;
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	workspace->out_buf.size = PAGE_SIZE;
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	while (1) {
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		size_t ret2;
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		ret2 = ZSTD_decompressStream(stream, &workspace->out_buf,
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				&workspace->in_buf);
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		if (ZSTD_isError(ret2)) {
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			pr_debug("BTRFS: ZSTD_decompressStream returned %d\n",
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					ZSTD_getErrorCode(ret2));
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			ret = -EIO;
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			goto done;
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		}
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		buf_start = total_out;
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		total_out += workspace->out_buf.pos;
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		workspace->out_buf.pos = 0;
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		ret = btrfs_decompress_buf2page(workspace->out_buf.dst,
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				buf_start, total_out, disk_start, orig_bio);
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		if (ret == 0)
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			break;
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		if (workspace->in_buf.pos >= srclen)
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			break;
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		/* Check if we've hit the end of a frame */
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		if (ret2 == 0)
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			break;
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		if (workspace->in_buf.pos == workspace->in_buf.size) {
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			kunmap(pages_in[page_in_index++]);
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			if (page_in_index >= total_pages_in) {
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				workspace->in_buf.src = NULL;
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				ret = -EIO;
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				goto done;
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			}
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			srclen -= PAGE_SIZE;
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			workspace->in_buf.src = kmap(pages_in[page_in_index]);
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			workspace->in_buf.pos = 0;
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			workspace->in_buf.size = min_t(size_t, srclen, PAGE_SIZE);
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		}
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	}
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	ret = 0;
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	zero_fill_bio(orig_bio);
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done:
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	if (workspace->in_buf.src)
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		kunmap(pages_in[page_in_index]);
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	return ret;
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}
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static int zstd_decompress(struct list_head *ws, unsigned char *data_in,
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		struct page *dest_page,
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		unsigned long start_byte,
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		size_t srclen, size_t destlen)
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{
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	struct workspace *workspace = list_entry(ws, struct workspace, list);
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	ZSTD_DStream *stream;
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	int ret = 0;
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	size_t ret2;
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	unsigned long total_out = 0;
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	unsigned long pg_offset = 0;
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	char *kaddr;
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	stream = ZSTD_initDStream(
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			ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size);
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	if (!stream) {
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		pr_warn("BTRFS: ZSTD_initDStream failed\n");
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		ret = -EIO;
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		goto finish;
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	}
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	destlen = min_t(size_t, destlen, PAGE_SIZE);
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	workspace->in_buf.src = data_in;
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	workspace->in_buf.pos = 0;
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	workspace->in_buf.size = srclen;
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	workspace->out_buf.dst = workspace->buf;
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	workspace->out_buf.pos = 0;
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	workspace->out_buf.size = PAGE_SIZE;
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	ret2 = 1;
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	while (pg_offset < destlen
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	       && workspace->in_buf.pos < workspace->in_buf.size) {
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		unsigned long buf_start;
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		unsigned long buf_offset;
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		unsigned long bytes;
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		/* Check if the frame is over and we still need more input */
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		if (ret2 == 0) {
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			pr_debug("BTRFS: ZSTD_decompressStream ended early\n");
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			ret = -EIO;
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			goto finish;
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		}
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		ret2 = ZSTD_decompressStream(stream, &workspace->out_buf,
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				&workspace->in_buf);
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		if (ZSTD_isError(ret2)) {
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			pr_debug("BTRFS: ZSTD_decompressStream returned %d\n",
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					ZSTD_getErrorCode(ret2));
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			ret = -EIO;
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			goto finish;
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		}
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		buf_start = total_out;
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		total_out += workspace->out_buf.pos;
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		workspace->out_buf.pos = 0;
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		if (total_out <= start_byte)
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			continue;
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		if (total_out > start_byte && buf_start < start_byte)
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			buf_offset = start_byte - buf_start;
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		else
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			buf_offset = 0;
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		bytes = min_t(unsigned long, destlen - pg_offset,
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				workspace->out_buf.size - buf_offset);
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		kaddr = kmap_atomic(dest_page);
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		memcpy(kaddr + pg_offset, workspace->out_buf.dst + buf_offset,
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				bytes);
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		kunmap_atomic(kaddr);
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		pg_offset += bytes;
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	}
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	ret = 0;
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finish:
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	if (pg_offset < destlen) {
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		kaddr = kmap_atomic(dest_page);
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		memset(kaddr + pg_offset, 0, destlen - pg_offset);
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		kunmap_atomic(kaddr);
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						|
	}
 | 
						|
	return ret;
 | 
						|
}
 | 
						|
 | 
						|
static void zstd_set_level(struct list_head *ws, unsigned int type)
 | 
						|
{
 | 
						|
}
 | 
						|
 | 
						|
const struct btrfs_compress_op btrfs_zstd_compress = {
 | 
						|
	.alloc_workspace = zstd_alloc_workspace,
 | 
						|
	.free_workspace = zstd_free_workspace,
 | 
						|
	.compress_pages = zstd_compress_pages,
 | 
						|
	.decompress_bio = zstd_decompress_bio,
 | 
						|
	.decompress = zstd_decompress,
 | 
						|
	.set_level = zstd_set_level,
 | 
						|
};
 |