[linux-2.6-block.git] / fs / btrfs / zlib.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2008 Oracle.  All rights reserved.
 *
 * Based on jffs2 zlib code:
 * Copyright © 2001-2007 Red Hat, Inc.
 * Created by David Woodhouse <dwmw2@infradead.org>
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/zlib.h>
#include <linux/zutil.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/sched.h>
#include <linux/pagemap.h>
#include <linux/bio.h>
#include <linux/refcount.h>
#include "btrfs_inode.h"
#include "compression.h"
#include "fs.h"
#include "subpage.h"

/* workspace buffer size for s390 zlib hardware support */
#define ZLIB_DFLTCC_BUF_SIZE    (4 * PAGE_SIZE)

struct workspace {
	z_stream strm;
	char *buf;
	unsigned int buf_size;
	struct list_head list;
	int level;
};

static struct workspace_manager wsm;

struct list_head *zlib_get_workspace(unsigned int level)
{
	struct list_head *ws = btrfs_get_workspace(BTRFS_COMPRESS_ZLIB, level);
	struct workspace *workspace = list_entry(ws, struct workspace, list);

	workspace->level = level;

	return ws;
}

void zlib_free_workspace(struct list_head *ws)
{
	struct workspace *workspace = list_entry(ws, struct workspace, list);

	kvfree(workspace->strm.workspace);
	kfree(workspace->buf);
	kfree(workspace);
}

struct list_head *zlib_alloc_workspace(unsigned int level)
{
	struct workspace *workspace;
	int workspacesize;

	workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
	if (!workspace)
		return ERR_PTR(-ENOMEM);

	workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
			zlib_inflate_workspacesize());
	workspace->strm.workspace = kvzalloc(workspacesize, GFP_KERNEL | __GFP_NOWARN);
	workspace->level = level;
	workspace->buf = NULL;
	/*
	 * In case of s390 zlib hardware support, allocate lager workspace
	 * buffer. If allocator fails, fall back to a single page buffer.
	 */
	if (zlib_deflate_dfltcc_enabled()) {
		workspace->buf = kmalloc(ZLIB_DFLTCC_BUF_SIZE,
					 __GFP_NOMEMALLOC | __GFP_NORETRY |
					 __GFP_NOWARN | GFP_NOIO);
		workspace->buf_size = ZLIB_DFLTCC_BUF_SIZE;
	}
	if (!workspace->buf) {
		workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
		workspace->buf_size = PAGE_SIZE;
	}
	if (!workspace->strm.workspace || !workspace->buf)
		goto fail;

	INIT_LIST_HEAD(&workspace->list);

	return &workspace->list;
fail:
	zlib_free_workspace(&workspace->list);
	return ERR_PTR(-ENOMEM);
}

/*
 * Helper for S390x with hardware zlib compression support.
 *
 * That hardware acceleration requires a buffer size larger than a single page
 * to get ideal performance, thus we need to do the memory copy rather than
 * use the page cache directly as input buffer.
 */
static int copy_data_into_buffer(struct address_space *mapping,
				 struct workspace *workspace, u64 filepos,
				 unsigned long length)
{
	u64 cur = filepos;

	/* It's only for hardware accelerated zlib code. */
	ASSERT(zlib_deflate_dfltcc_enabled());

	while (cur < filepos + length) {
		struct folio *folio;
		void *data_in;
		unsigned int offset;
		unsigned long copy_length;
		int ret;

		ret = btrfs_compress_filemap_get_folio(mapping, cur, &folio);
		if (ret < 0)
			return ret;

		offset = offset_in_folio(folio, cur);
		copy_length = min(folio_size(folio) - offset,
				  filepos + length - cur);

		data_in = kmap_local_folio(folio, offset);
		memcpy(workspace->buf + cur - filepos, data_in, copy_length);
		kunmap_local(data_in);
		cur += copy_length;
	}
	return 0;
}

int zlib_compress_folios(struct list_head *ws, struct address_space *mapping,
			 u64 start, struct folio **folios, unsigned long *out_folios,
			 unsigned long *total_in, unsigned long *total_out)
{
	struct workspace *workspace = list_entry(ws, struct workspace, list);
	int ret;
	char *data_in = NULL;
	char *cfolio_out;
	int nr_folios = 0;
	struct folio *in_folio = NULL;
	struct folio *out_folio = NULL;
	unsigned long len = *total_out;
	unsigned long nr_dest_folios = *out_folios;
	const unsigned long max_out = nr_dest_folios * PAGE_SIZE;
	const u64 orig_end = start + len;

	*out_folios = 0;
	*total_out = 0;
	*total_in = 0;

	ret = zlib_deflateInit(&workspace->strm, workspace->level);
	if (unlikely(ret != Z_OK)) {
		struct btrfs_inode *inode = BTRFS_I(mapping->host);

		btrfs_err(inode->root->fs_info,
	"zlib compression init failed, error %d root %llu inode %llu offset %llu",
			  ret, btrfs_root_id(inode->root), btrfs_ino(inode), start);
		ret = -EIO;
		goto out;
	}

	workspace->strm.total_in = 0;
	workspace->strm.total_out = 0;

	out_folio = btrfs_alloc_compr_folio();
	if (out_folio == NULL) {
		ret = -ENOMEM;
		goto out;
	}
	cfolio_out = folio_address(out_folio);
	folios[0] = out_folio;
	nr_folios = 1;

	workspace->strm.next_in = workspace->buf;
	workspace->strm.avail_in = 0;
	workspace->strm.next_out = cfolio_out;
	workspace->strm.avail_out = PAGE_SIZE;

	while (workspace->strm.total_in < len) {
		/*
		 * Get next input pages and copy the contents to
		 * the workspace buffer if required.
		 */
		if (workspace->strm.avail_in == 0) {
			unsigned long bytes_left = len - workspace->strm.total_in;
			unsigned int copy_length = min(bytes_left, workspace->buf_size);

			/*
			 * This can only happen when hardware zlib compression is
			 * enabled.
			 */
			if (copy_length > PAGE_SIZE) {
				ret = copy_data_into_buffer(mapping, workspace,
							    start, copy_length);
				if (ret < 0)
					goto out;
				start += copy_length;
				workspace->strm.next_in = workspace->buf;
				workspace->strm.avail_in = copy_length;
			} else {
				unsigned int cur_len;

				if (data_in) {
					kunmap_local(data_in);
					folio_put(in_folio);
					data_in = NULL;
				}
				ret = btrfs_compress_filemap_get_folio(mapping,
						start, &in_folio);
				if (ret < 0)
					goto out;
				cur_len = btrfs_calc_input_length(in_folio, orig_end, start);
				data_in = kmap_local_folio(in_folio,
							   offset_in_folio(in_folio, start));
				start += cur_len;
				workspace->strm.next_in = data_in;
				workspace->strm.avail_in = cur_len;
			}
		}

		ret = zlib_deflate(&workspace->strm, Z_SYNC_FLUSH);
		if (unlikely(ret != Z_OK)) {
			struct btrfs_inode *inode = BTRFS_I(mapping->host);

			btrfs_warn(inode->root->fs_info,
		"zlib compression failed, error %d root %llu inode %llu offset %llu",
				   ret, btrfs_root_id(inode->root), btrfs_ino(inode),
				   start);
			zlib_deflateEnd(&workspace->strm);
			ret = -EIO;
			goto out;
		}

		/* we're making it bigger, give up */
		if (workspace->strm.total_in > 8192 &&
		    workspace->strm.total_in <
		    workspace->strm.total_out) {
			ret = -E2BIG;
			goto out;
		}
		/* we need another page for writing out.  Test this
		 * before the total_in so we will pull in a new page for
		 * the stream end if required
		 */
		if (workspace->strm.avail_out == 0) {
			if (nr_folios == nr_dest_folios) {
				ret = -E2BIG;
				goto out;
			}
			out_folio = btrfs_alloc_compr_folio();
			if (out_folio == NULL) {
				ret = -ENOMEM;
				goto out;
			}
			cfolio_out = folio_address(out_folio);
			folios[nr_folios] = out_folio;
			nr_folios++;
			workspace->strm.avail_out = PAGE_SIZE;
			workspace->strm.next_out = cfolio_out;
		}
		/* we're all done */
		if (workspace->strm.total_in >= len)
			break;
		if (workspace->strm.total_out > max_out)
			break;
	}
	workspace->strm.avail_in = 0;
	/*
	 * Call deflate with Z_FINISH flush parameter providing more output
	 * space but no more input data, until it returns with Z_STREAM_END.
	 */
	while (ret != Z_STREAM_END) {
		ret = zlib_deflate(&workspace->strm, Z_FINISH);
		if (ret == Z_STREAM_END)
			break;
		if (ret != Z_OK && ret != Z_BUF_ERROR) {
			zlib_deflateEnd(&workspace->strm);
			ret = -EIO;
			goto out;
		} else if (workspace->strm.avail_out == 0) {
			/* Get another folio for the stream end. */
			if (nr_folios == nr_dest_folios) {
				ret = -E2BIG;
				goto out;
			}
			out_folio = btrfs_alloc_compr_folio();
			if (out_folio == NULL) {
				ret = -ENOMEM;
				goto out;
			}
			cfolio_out = folio_address(out_folio);
			folios[nr_folios] = out_folio;
			nr_folios++;
			workspace->strm.avail_out = PAGE_SIZE;
			workspace->strm.next_out = cfolio_out;
		}
	}
	zlib_deflateEnd(&workspace->strm);

	if (workspace->strm.total_out >= workspace->strm.total_in) {
		ret = -E2BIG;
		goto out;
	}

	ret = 0;
	*total_out = workspace->strm.total_out;
	*total_in = workspace->strm.total_in;
out:
	*out_folios = nr_folios;
	if (data_in) {
		kunmap_local(data_in);
		folio_put(in_folio);
	}

	return ret;
}

int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
{
	struct workspace *workspace = list_entry(ws, struct workspace, list);
	int ret = 0, ret2;
	int wbits = MAX_WBITS;
	char *data_in;
	size_t total_out = 0;
	unsigned long folio_in_index = 0;
	size_t srclen = cb->compressed_len;
	unsigned long total_folios_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
	unsigned long buf_start;
	struct folio **folios_in = cb->compressed_folios;

	data_in = kmap_local_folio(folios_in[folio_in_index], 0);
	workspace->strm.next_in = data_in;
	workspace->strm.avail_in = min_t(size_t, srclen, PAGE_SIZE);
	workspace->strm.total_in = 0;

	workspace->strm.total_out = 0;
	workspace->strm.next_out = workspace->buf;
	workspace->strm.avail_out = workspace->buf_size;

	/* If it's deflate, and it's got no preset dictionary, then
	   we can tell zlib to skip the adler32 check. */
	if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
	    ((data_in[0] & 0x0f) == Z_DEFLATED) &&
	    !(((data_in[0]<<8) + data_in[1]) % 31)) {

		wbits = -((data_in[0] >> 4) + 8);
		workspace->strm.next_in += 2;
		workspace->strm.avail_in -= 2;
	}

	ret = zlib_inflateInit2(&workspace->strm, wbits);
	if (unlikely(ret != Z_OK)) {
		struct btrfs_inode *inode = cb->bbio.inode;

		kunmap_local(data_in);
		btrfs_err(inode->root->fs_info,
	"zlib decompression init failed, error %d root %llu inode %llu offset %llu",
			  ret, btrfs_root_id(inode->root), btrfs_ino(inode), cb->start);
		return -EIO;
	}
	while (workspace->strm.total_in < srclen) {
		ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
		if (ret != Z_OK && ret != Z_STREAM_END)
			break;

		buf_start = total_out;
		total_out = workspace->strm.total_out;

		/* we didn't make progress in this inflate call, we're done */
		if (buf_start == total_out)
			break;

		ret2 = btrfs_decompress_buf2page(workspace->buf,
				total_out - buf_start, cb, buf_start);
		if (ret2 == 0) {
			ret = 0;
			goto done;
		}

		workspace->strm.next_out = workspace->buf;
		workspace->strm.avail_out = workspace->buf_size;

		if (workspace->strm.avail_in == 0) {
			unsigned long tmp;
			kunmap_local(data_in);
			folio_in_index++;
			if (folio_in_index >= total_folios_in) {
				data_in = NULL;
				break;
			}
			data_in = kmap_local_folio(folios_in[folio_in_index], 0);
			workspace->strm.next_in = data_in;
			tmp = srclen - workspace->strm.total_in;
			workspace->strm.avail_in = min(tmp, PAGE_SIZE);
		}
	}
	if (unlikely(ret != Z_STREAM_END)) {
		btrfs_err(cb->bbio.inode->root->fs_info,
		"zlib decompression failed, error %d root %llu inode %llu offset %llu",
			  ret, btrfs_root_id(cb->bbio.inode->root),
			  btrfs_ino(cb->bbio.inode), cb->start);
		ret = -EIO;
	} else {
		ret = 0;
	}
done:
	zlib_inflateEnd(&workspace->strm);
	if (data_in)
		kunmap_local(data_in);
	return ret;
}

int zlib_decompress(struct list_head *ws, const u8 *data_in,
		struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
		size_t destlen)
{
	struct workspace *workspace = list_entry(ws, struct workspace, list);
	int ret = 0;
	int wbits = MAX_WBITS;
	unsigned long to_copy;

	workspace->strm.next_in = data_in;
	workspace->strm.avail_in = srclen;
	workspace->strm.total_in = 0;

	workspace->strm.next_out = workspace->buf;
	workspace->strm.avail_out = workspace->buf_size;
	workspace->strm.total_out = 0;
	/* If it's deflate, and it's got no preset dictionary, then
	   we can tell zlib to skip the adler32 check. */
	if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
	    ((data_in[0] & 0x0f) == Z_DEFLATED) &&
	    !(((data_in[0]<<8) + data_in[1]) % 31)) {

		wbits = -((data_in[0] >> 4) + 8);
		workspace->strm.next_in += 2;
		workspace->strm.avail_in -= 2;
	}

	ret = zlib_inflateInit2(&workspace->strm, wbits);
	if (unlikely(ret != Z_OK)) {
		struct btrfs_inode *inode = folio_to_inode(dest_folio);

		btrfs_err(inode->root->fs_info,
		"zlib decompression init failed, error %d root %llu inode %llu offset %llu",
			  ret, btrfs_root_id(inode->root), btrfs_ino(inode),
			  folio_pos(dest_folio));
		return -EIO;
	}

	/*
	 * Everything (in/out buf) should be at most one sector, there should
	 * be no need to switch any input/output buffer.
	 */
	ret = zlib_inflate(&workspace->strm, Z_FINISH);
	to_copy = min(workspace->strm.total_out, destlen);
	if (ret != Z_STREAM_END)
		goto out;

	memcpy_to_folio(dest_folio, dest_pgoff, workspace->buf, to_copy);

out:
	if (unlikely(to_copy != destlen)) {
		struct btrfs_inode *inode = folio_to_inode(dest_folio);

		btrfs_err(inode->root->fs_info,
"zlib decompression failed, error %d root %llu inode %llu offset %llu decompressed %lu expected %zu",
			  ret, btrfs_root_id(inode->root), btrfs_ino(inode),
			  folio_pos(dest_folio), to_copy, destlen);
		ret = -EIO;
	} else {
		ret = 0;
	}

	zlib_inflateEnd(&workspace->strm);

	if (unlikely(to_copy < destlen))
		folio_zero_range(dest_folio, dest_pgoff + to_copy, destlen - to_copy);
	return ret;
}

const struct btrfs_compress_op btrfs_zlib_compress = {
	.workspace_manager	= &wsm,
	.min_level		= 1,
	.max_level		= 9,
	.default_level		= BTRFS_ZLIB_DEFAULT_LEVEL,
};
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Copyright (C) 2008 Oracle. All rights reserved.
	4	*
	5	* Based on jffs2 zlib code:
	6	* Copyright © 2001-2007 Red Hat, Inc.
	7	* Created by David Woodhouse <dwmw2@infradead.org>
	8	*/
	9
	10	#include <linux/kernel.h>
	11	#include <linux/slab.h>
	12	#include <linux/zlib.h>
	13	#include <linux/zutil.h>
	14	#include <linux/mm.h>
	15	#include <linux/init.h>
	16	#include <linux/err.h>
	17	#include <linux/sched.h>
	18	#include <linux/pagemap.h>
	19	#include <linux/bio.h>
	20	#include <linux/refcount.h>
	21	#include "btrfs_inode.h"
	22	#include "compression.h"
	23	#include "fs.h"
	24	#include "subpage.h"
	25
	26	/* workspace buffer size for s390 zlib hardware support */
	27	#define ZLIB_DFLTCC_BUF_SIZE (4 * PAGE_SIZE)
	28
	29	struct workspace {
	30	z_stream strm;
	31	char *buf;
	32	unsigned int buf_size;
	33	struct list_head list;
	34	int level;
	35	};
	36
	37	static struct workspace_manager wsm;
	38
	39	struct list_head *zlib_get_workspace(unsigned int level)
	40	{
	41	struct list_head *ws = btrfs_get_workspace(BTRFS_COMPRESS_ZLIB, level);
	42	struct workspace *workspace = list_entry(ws, struct workspace, list);
	43
	44	workspace->level = level;
	45
	46	return ws;
	47	}
	48
	49	void zlib_free_workspace(struct list_head *ws)
	50	{
	51	struct workspace *workspace = list_entry(ws, struct workspace, list);
	52
	53	kvfree(workspace->strm.workspace);
	54	kfree(workspace->buf);
	55	kfree(workspace);
	56	}
	57
	58	struct list_head *zlib_alloc_workspace(unsigned int level)
	59	{
	60	struct workspace *workspace;
	61	int workspacesize;
	62
	63	workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
	64	if (!workspace)
	65	return ERR_PTR(-ENOMEM);
	66
	67	workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
	68	zlib_inflate_workspacesize());
	69	workspace->strm.workspace = kvzalloc(workspacesize, GFP_KERNEL \| __GFP_NOWARN);
	70	workspace->level = level;
	71	workspace->buf = NULL;
	72	/*
	73	* In case of s390 zlib hardware support, allocate lager workspace
	74	* buffer. If allocator fails, fall back to a single page buffer.
	75	*/
	76	if (zlib_deflate_dfltcc_enabled()) {
	77	workspace->buf = kmalloc(ZLIB_DFLTCC_BUF_SIZE,
	78	__GFP_NOMEMALLOC \| __GFP_NORETRY \|
	79	__GFP_NOWARN \| GFP_NOIO);
	80	workspace->buf_size = ZLIB_DFLTCC_BUF_SIZE;
	81	}
	82	if (!workspace->buf) {
	83	workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
	84	workspace->buf_size = PAGE_SIZE;
	85	}
	86	if (!workspace->strm.workspace \|\| !workspace->buf)
	87	goto fail;
	88
	89	INIT_LIST_HEAD(&workspace->list);
	90
	91	return &workspace->list;
	92	fail:
	93	zlib_free_workspace(&workspace->list);
	94	return ERR_PTR(-ENOMEM);
	95	}
	96
	97	/*
	98	* Helper for S390x with hardware zlib compression support.
	99	*
	100	* That hardware acceleration requires a buffer size larger than a single page
	101	* to get ideal performance, thus we need to do the memory copy rather than
	102	* use the page cache directly as input buffer.
	103	*/
	104	static int copy_data_into_buffer(struct address_space *mapping,
	105	struct workspace *workspace, u64 filepos,
	106	unsigned long length)
	107	{
	108	u64 cur = filepos;
	109
	110	/* It's only for hardware accelerated zlib code. */
	111	ASSERT(zlib_deflate_dfltcc_enabled());
	112
	113	while (cur < filepos + length) {
	114	struct folio *folio;
	115	void *data_in;
	116	unsigned int offset;
	117	unsigned long copy_length;
	118	int ret;
	119
	120	ret = btrfs_compress_filemap_get_folio(mapping, cur, &folio);
	121	if (ret < 0)
	122	return ret;
	123
	124	offset = offset_in_folio(folio, cur);
	125	copy_length = min(folio_size(folio) - offset,
	126	filepos + length - cur);
	127
	128	data_in = kmap_local_folio(folio, offset);
	129	memcpy(workspace->buf + cur - filepos, data_in, copy_length);
	130	kunmap_local(data_in);
	131	cur += copy_length;
	132	}
	133	return 0;
	134	}
	135
	136	int zlib_compress_folios(struct list_head ws, struct address_space mapping,
	137	u64 start, struct folio *folios, unsigned long out_folios,
	138	unsigned long total_in, unsigned long total_out)
	139	{
	140	struct workspace *workspace = list_entry(ws, struct workspace, list);
	141	int ret;
	142	char *data_in = NULL;
	143	char *cfolio_out;
	144	int nr_folios = 0;
	145	struct folio *in_folio = NULL;
	146	struct folio *out_folio = NULL;
	147	unsigned long len = *total_out;
	148	unsigned long nr_dest_folios = *out_folios;
	149	const unsigned long max_out = nr_dest_folios * PAGE_SIZE;
	150	const u64 orig_end = start + len;
	151
	152	*out_folios = 0;
	153	*total_out = 0;
	154	*total_in = 0;
	155
	156	ret = zlib_deflateInit(&workspace->strm, workspace->level);
	157	if (unlikely(ret != Z_OK)) {
	158	struct btrfs_inode *inode = BTRFS_I(mapping->host);
	159
	160	btrfs_err(inode->root->fs_info,
	161	"zlib compression init failed, error %d root %llu inode %llu offset %llu",
	162	ret, btrfs_root_id(inode->root), btrfs_ino(inode), start);
	163	ret = -EIO;
	164	goto out;
	165	}
	166
	167	workspace->strm.total_in = 0;
	168	workspace->strm.total_out = 0;
	169
	170	out_folio = btrfs_alloc_compr_folio();
	171	if (out_folio == NULL) {
	172	ret = -ENOMEM;
	173	goto out;
	174	}
	175	cfolio_out = folio_address(out_folio);
	176	folios[0] = out_folio;
	177	nr_folios = 1;
	178
	179	workspace->strm.next_in = workspace->buf;
	180	workspace->strm.avail_in = 0;
	181	workspace->strm.next_out = cfolio_out;
	182	workspace->strm.avail_out = PAGE_SIZE;
	183
	184	while (workspace->strm.total_in < len) {
	185	/*
	186	* Get next input pages and copy the contents to
	187	* the workspace buffer if required.
	188	*/
	189	if (workspace->strm.avail_in == 0) {
	190	unsigned long bytes_left = len - workspace->strm.total_in;
	191	unsigned int copy_length = min(bytes_left, workspace->buf_size);
	192
	193	/*
	194	* This can only happen when hardware zlib compression is
	195	* enabled.
	196	*/
	197	if (copy_length > PAGE_SIZE) {
	198	ret = copy_data_into_buffer(mapping, workspace,
	199	start, copy_length);
	200	if (ret < 0)
	201	goto out;
	202	start += copy_length;
	203	workspace->strm.next_in = workspace->buf;
	204	workspace->strm.avail_in = copy_length;
	205	} else {
	206	unsigned int cur_len;
	207
	208	if (data_in) {
	209	kunmap_local(data_in);
	210	folio_put(in_folio);
	211	data_in = NULL;
	212	}
	213	ret = btrfs_compress_filemap_get_folio(mapping,
	214	start, &in_folio);
	215	if (ret < 0)
	216	goto out;
	217	cur_len = btrfs_calc_input_length(in_folio, orig_end, start);
	218	data_in = kmap_local_folio(in_folio,
	219	offset_in_folio(in_folio, start));
	220	start += cur_len;
	221	workspace->strm.next_in = data_in;
	222	workspace->strm.avail_in = cur_len;
	223	}
	224	}
	225
	226	ret = zlib_deflate(&workspace->strm, Z_SYNC_FLUSH);
	227	if (unlikely(ret != Z_OK)) {
	228	struct btrfs_inode *inode = BTRFS_I(mapping->host);
	229
	230	btrfs_warn(inode->root->fs_info,
	231	"zlib compression failed, error %d root %llu inode %llu offset %llu",
	232	ret, btrfs_root_id(inode->root), btrfs_ino(inode),
	233	start);
	234	zlib_deflateEnd(&workspace->strm);
	235	ret = -EIO;
	236	goto out;
	237	}
	238
	239	/* we're making it bigger, give up */
	240	if (workspace->strm.total_in > 8192 &&
	241	workspace->strm.total_in <
	242	workspace->strm.total_out) {
	243	ret = -E2BIG;
	244	goto out;
	245	}
	246	/* we need another page for writing out. Test this
	247	* before the total_in so we will pull in a new page for
	248	* the stream end if required
	249	*/
	250	if (workspace->strm.avail_out == 0) {
	251	if (nr_folios == nr_dest_folios) {
	252	ret = -E2BIG;
	253	goto out;
	254	}
	255	out_folio = btrfs_alloc_compr_folio();
	256	if (out_folio == NULL) {
	257	ret = -ENOMEM;
	258	goto out;
	259	}
	260	cfolio_out = folio_address(out_folio);
	261	folios[nr_folios] = out_folio;
	262	nr_folios++;
	263	workspace->strm.avail_out = PAGE_SIZE;
	264	workspace->strm.next_out = cfolio_out;
	265	}
	266	/* we're all done */
	267	if (workspace->strm.total_in >= len)
	268	break;
	269	if (workspace->strm.total_out > max_out)
	270	break;
	271	}
	272	workspace->strm.avail_in = 0;
	273	/*
	274	* Call deflate with Z_FINISH flush parameter providing more output
	275	* space but no more input data, until it returns with Z_STREAM_END.
	276	*/
	277	while (ret != Z_STREAM_END) {
	278	ret = zlib_deflate(&workspace->strm, Z_FINISH);
	279	if (ret == Z_STREAM_END)
	280	break;
	281	if (ret != Z_OK && ret != Z_BUF_ERROR) {
	282	zlib_deflateEnd(&workspace->strm);
	283	ret = -EIO;
	284	goto out;
	285	} else if (workspace->strm.avail_out == 0) {
	286	/* Get another folio for the stream end. */
	287	if (nr_folios == nr_dest_folios) {
	288	ret = -E2BIG;
	289	goto out;
	290	}
	291	out_folio = btrfs_alloc_compr_folio();
	292	if (out_folio == NULL) {
	293	ret = -ENOMEM;
	294	goto out;
	295	}
	296	cfolio_out = folio_address(out_folio);
	297	folios[nr_folios] = out_folio;
	298	nr_folios++;
	299	workspace->strm.avail_out = PAGE_SIZE;
	300	workspace->strm.next_out = cfolio_out;
	301	}
	302	}
	303	zlib_deflateEnd(&workspace->strm);
	304
	305	if (workspace->strm.total_out >= workspace->strm.total_in) {
	306	ret = -E2BIG;
	307	goto out;
	308	}
	309
	310	ret = 0;
	311	*total_out = workspace->strm.total_out;
	312	*total_in = workspace->strm.total_in;
	313	out:
	314	*out_folios = nr_folios;
	315	if (data_in) {
	316	kunmap_local(data_in);
	317	folio_put(in_folio);
	318	}
	319
	320	return ret;
	321	}
	322
	323	int zlib_decompress_bio(struct list_head ws, struct compressed_bio cb)
	324	{
	325	struct workspace *workspace = list_entry(ws, struct workspace, list);
	326	int ret = 0, ret2;
	327	int wbits = MAX_WBITS;
	328	char *data_in;
	329	size_t total_out = 0;
	330	unsigned long folio_in_index = 0;
	331	size_t srclen = cb->compressed_len;
	332	unsigned long total_folios_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
	333	unsigned long buf_start;
	334	struct folio **folios_in = cb->compressed_folios;
	335
	336	data_in = kmap_local_folio(folios_in[folio_in_index], 0);
	337	workspace->strm.next_in = data_in;
	338	workspace->strm.avail_in = min_t(size_t, srclen, PAGE_SIZE);
	339	workspace->strm.total_in = 0;
	340
	341	workspace->strm.total_out = 0;
	342	workspace->strm.next_out = workspace->buf;
	343	workspace->strm.avail_out = workspace->buf_size;
	344
	345	/* If it's deflate, and it's got no preset dictionary, then
	346	we can tell zlib to skip the adler32 check. */
	347	if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
	348	((data_in[0] & 0x0f) == Z_DEFLATED) &&
	349	!(((data_in[0]<<8) + data_in[1]) % 31)) {
	350
	351	wbits = -((data_in[0] >> 4) + 8);
	352	workspace->strm.next_in += 2;
	353	workspace->strm.avail_in -= 2;
	354	}
	355
	356	ret = zlib_inflateInit2(&workspace->strm, wbits);
	357	if (unlikely(ret != Z_OK)) {
	358	struct btrfs_inode *inode = cb->bbio.inode;
	359
	360	kunmap_local(data_in);
	361	btrfs_err(inode->root->fs_info,
	362	"zlib decompression init failed, error %d root %llu inode %llu offset %llu",
	363	ret, btrfs_root_id(inode->root), btrfs_ino(inode), cb->start);
	364	return -EIO;
	365	}
	366	while (workspace->strm.total_in < srclen) {
	367	ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
	368	if (ret != Z_OK && ret != Z_STREAM_END)
	369	break;
	370
	371	buf_start = total_out;
	372	total_out = workspace->strm.total_out;
	373
	374	/* we didn't make progress in this inflate call, we're done */
	375	if (buf_start == total_out)
	376	break;
	377
	378	ret2 = btrfs_decompress_buf2page(workspace->buf,
	379	total_out - buf_start, cb, buf_start);
	380	if (ret2 == 0) {
	381	ret = 0;
	382	goto done;
	383	}
	384
	385	workspace->strm.next_out = workspace->buf;
	386	workspace->strm.avail_out = workspace->buf_size;
	387
	388	if (workspace->strm.avail_in == 0) {
	389	unsigned long tmp;
	390	kunmap_local(data_in);
	391	folio_in_index++;
	392	if (folio_in_index >= total_folios_in) {
	393	data_in = NULL;
	394	break;
	395	}
	396	data_in = kmap_local_folio(folios_in[folio_in_index], 0);
	397	workspace->strm.next_in = data_in;
	398	tmp = srclen - workspace->strm.total_in;
	399	workspace->strm.avail_in = min(tmp, PAGE_SIZE);
	400	}
	401	}
	402	if (unlikely(ret != Z_STREAM_END)) {
	403	btrfs_err(cb->bbio.inode->root->fs_info,
	404	"zlib decompression failed, error %d root %llu inode %llu offset %llu",
	405	ret, btrfs_root_id(cb->bbio.inode->root),
	406	btrfs_ino(cb->bbio.inode), cb->start);
	407	ret = -EIO;
	408	} else {
	409	ret = 0;
	410	}
	411	done:
	412	zlib_inflateEnd(&workspace->strm);
	413	if (data_in)
	414	kunmap_local(data_in);
	415	return ret;
	416	}
	417
	418	int zlib_decompress(struct list_head ws, const u8 data_in,
	419	struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
	420	size_t destlen)
	421	{
	422	struct workspace *workspace = list_entry(ws, struct workspace, list);
	423	int ret = 0;
	424	int wbits = MAX_WBITS;
	425	unsigned long to_copy;
	426
	427	workspace->strm.next_in = data_in;
	428	workspace->strm.avail_in = srclen;
	429	workspace->strm.total_in = 0;
	430
	431	workspace->strm.next_out = workspace->buf;
	432	workspace->strm.avail_out = workspace->buf_size;
	433	workspace->strm.total_out = 0;
	434	/* If it's deflate, and it's got no preset dictionary, then
	435	we can tell zlib to skip the adler32 check. */
	436	if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
	437	((data_in[0] & 0x0f) == Z_DEFLATED) &&
	438	!(((data_in[0]<<8) + data_in[1]) % 31)) {
	439
	440	wbits = -((data_in[0] >> 4) + 8);
	441	workspace->strm.next_in += 2;
	442	workspace->strm.avail_in -= 2;
	443	}
	444
	445	ret = zlib_inflateInit2(&workspace->strm, wbits);
	446	if (unlikely(ret != Z_OK)) {
	447	struct btrfs_inode *inode = folio_to_inode(dest_folio);
	448
	449	btrfs_err(inode->root->fs_info,
	450	"zlib decompression init failed, error %d root %llu inode %llu offset %llu",
	451	ret, btrfs_root_id(inode->root), btrfs_ino(inode),
	452	folio_pos(dest_folio));
	453	return -EIO;
	454	}
	455
	456	/*
	457	* Everything (in/out buf) should be at most one sector, there should
	458	* be no need to switch any input/output buffer.
	459	*/
	460	ret = zlib_inflate(&workspace->strm, Z_FINISH);
	461	to_copy = min(workspace->strm.total_out, destlen);
	462	if (ret != Z_STREAM_END)
	463	goto out;
	464
	465	memcpy_to_folio(dest_folio, dest_pgoff, workspace->buf, to_copy);
	466
	467	out:
	468	if (unlikely(to_copy != destlen)) {
	469	struct btrfs_inode *inode = folio_to_inode(dest_folio);
	470
	471	btrfs_err(inode->root->fs_info,
	472	"zlib decompression failed, error %d root %llu inode %llu offset %llu decompressed %lu expected %zu",
	473	ret, btrfs_root_id(inode->root), btrfs_ino(inode),
	474	folio_pos(dest_folio), to_copy, destlen);
	475	ret = -EIO;
	476	} else {
	477	ret = 0;
	478	}
	479
	480	zlib_inflateEnd(&workspace->strm);
	481
	482	if (unlikely(to_copy < destlen))
	483	folio_zero_range(dest_folio, dest_pgoff + to_copy, destlen - to_copy);
	484	return ret;
	485	}
	486
	487	const struct btrfs_compress_op btrfs_zlib_compress = {
	488	.workspace_manager = &wsm,
	489	.min_level = 1,
	490	.max_level = 9,
	491	.default_level = BTRFS_ZLIB_DEFAULT_LEVEL,
	492	};