+++ /dev/null
-/*
- * Copyright (c) 2016-present, Facebook, Inc.
- * All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License v2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- */
-#include <linux/bio.h>
-#include <linux/err.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/mm.h>
-#include <linux/pagemap.h>
-#include <linux/refcount.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/zstd.h>
-#include "compression.h"
-
-#define ZSTD_BTRFS_MAX_WINDOWLOG 17
-#define ZSTD_BTRFS_MAX_INPUT (1 << ZSTD_BTRFS_MAX_WINDOWLOG)
-#define ZSTD_BTRFS_DEFAULT_LEVEL 3
-
-static ZSTD_parameters zstd_get_btrfs_parameters(size_t src_len)
-{
- ZSTD_parameters params = ZSTD_getParams(ZSTD_BTRFS_DEFAULT_LEVEL,
- src_len, 0);
-
- if (params.cParams.windowLog > ZSTD_BTRFS_MAX_WINDOWLOG)
- params.cParams.windowLog = ZSTD_BTRFS_MAX_WINDOWLOG;
- WARN_ON(src_len > ZSTD_BTRFS_MAX_INPUT);
- return params;
-}
-
-struct workspace {
- void *mem;
- size_t size;
- char *buf;
- struct list_head list;
-};
-
-static void zstd_free_workspace(struct list_head *ws)
-{
- struct workspace *workspace = list_entry(ws, struct workspace, list);
-
- kvfree(workspace->mem);
- kfree(workspace->buf);
- kfree(workspace);
-}
-
-static struct list_head *zstd_alloc_workspace(void)
-{
- ZSTD_parameters params =
- zstd_get_btrfs_parameters(ZSTD_BTRFS_MAX_INPUT);
- struct workspace *workspace;
-
- workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
- if (!workspace)
- return ERR_PTR(-ENOMEM);
-
- workspace->size = max_t(size_t,
- ZSTD_CStreamWorkspaceBound(params.cParams),
- ZSTD_DStreamWorkspaceBound(ZSTD_BTRFS_MAX_INPUT));
- workspace->mem = kvmalloc(workspace->size, GFP_KERNEL);
- workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!workspace->mem || !workspace->buf)
- goto fail;
-
- INIT_LIST_HEAD(&workspace->list);
-
- return &workspace->list;
-fail:
- zstd_free_workspace(&workspace->list);
- return ERR_PTR(-ENOMEM);
-}
-
-static int zstd_compress_pages(struct list_head *ws,
- struct address_space *mapping,
- u64 start,
- struct page **pages,
- unsigned long *out_pages,
- unsigned long *total_in,
- unsigned long *total_out)
-{
- struct workspace *workspace = list_entry(ws, struct workspace, list);
- ZSTD_CStream *stream;
- int ret = 0;
- int nr_pages = 0;
- struct page *in_page = NULL; /* The current page to read */
- struct page *out_page = NULL; /* The current page to write to */
- ZSTD_inBuffer in_buf = { NULL, 0, 0 };
- ZSTD_outBuffer out_buf = { NULL, 0, 0 };
- unsigned long tot_in = 0;
- unsigned long tot_out = 0;
- unsigned long len = *total_out;
- const unsigned long nr_dest_pages = *out_pages;
- unsigned long max_out = nr_dest_pages * PAGE_SIZE;
- ZSTD_parameters params = zstd_get_btrfs_parameters(len);
-
- *out_pages = 0;
- *total_out = 0;
- *total_in = 0;
-
- /* Initialize the stream */
- stream = ZSTD_initCStream(params, len, workspace->mem,
- workspace->size);
- if (!stream) {
- pr_warn("BTRFS: ZSTD_initCStream failed\n");
- ret = -EIO;
- goto out;
- }
-
- /* map in the first page of input data */
- in_page = find_get_page(mapping, start >> PAGE_SHIFT);
- in_buf.src = kmap(in_page);
- in_buf.pos = 0;
- in_buf.size = min_t(size_t, len, PAGE_SIZE);
-
-
- /* Allocate and map in the output buffer */
- out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
- if (out_page == NULL) {
- ret = -ENOMEM;
- goto out;
- }
- pages[nr_pages++] = out_page;
- out_buf.dst = kmap(out_page);
- out_buf.pos = 0;
- out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
-
- while (1) {
- size_t ret2;
-
- ret2 = ZSTD_compressStream(stream, &out_buf, &in_buf);
- if (ZSTD_isError(ret2)) {
- pr_debug("BTRFS: ZSTD_compressStream returned %d\n",
- ZSTD_getErrorCode(ret2));
- ret = -EIO;
- goto out;
- }
-
- /* Check to see if we are making it bigger */
- if (tot_in + in_buf.pos > 8192 &&
- tot_in + in_buf.pos <
- tot_out + out_buf.pos) {
- ret = -E2BIG;
- goto out;
- }
-
- /* We've reached the end of our output range */
- if (out_buf.pos >= max_out) {
- tot_out += out_buf.pos;
- ret = -E2BIG;
- goto out;
- }
-
- /* Check if we need more output space */
- if (out_buf.pos == out_buf.size) {
- tot_out += PAGE_SIZE;
- max_out -= PAGE_SIZE;
- kunmap(out_page);
- if (nr_pages == nr_dest_pages) {
- out_page = NULL;
- ret = -E2BIG;
- goto out;
- }
- out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
- if (out_page == NULL) {
- ret = -ENOMEM;
- goto out;
- }
- pages[nr_pages++] = out_page;
- out_buf.dst = kmap(out_page);
- out_buf.pos = 0;
- out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
- }
-
- /* We've reached the end of the input */
- if (in_buf.pos >= len) {
- tot_in += in_buf.pos;
- break;
- }
-
- /* Check if we need more input */
- if (in_buf.pos == in_buf.size) {
- tot_in += PAGE_SIZE;
- kunmap(in_page);
- put_page(in_page);
-
- start += PAGE_SIZE;
- len -= PAGE_SIZE;
- in_page = find_get_page(mapping, start >> PAGE_SHIFT);
- in_buf.src = kmap(in_page);
- in_buf.pos = 0;
- in_buf.size = min_t(size_t, len, PAGE_SIZE);
- }
- }
- while (1) {
- size_t ret2;
-
- ret2 = ZSTD_endStream(stream, &out_buf);
- if (ZSTD_isError(ret2)) {
- pr_debug("BTRFS: ZSTD_endStream returned %d\n",
- ZSTD_getErrorCode(ret2));
- ret = -EIO;
- goto out;
- }
- if (ret2 == 0) {
- tot_out += out_buf.pos;
- break;
- }
- if (out_buf.pos >= max_out) {
- tot_out += out_buf.pos;
- ret = -E2BIG;
- goto out;
- }
-
- tot_out += PAGE_SIZE;
- max_out -= PAGE_SIZE;
- kunmap(out_page);
- if (nr_pages == nr_dest_pages) {
- out_page = NULL;
- ret = -E2BIG;
- goto out;
- }
- out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
- if (out_page == NULL) {
- ret = -ENOMEM;
- goto out;
- }
- pages[nr_pages++] = out_page;
- out_buf.dst = kmap(out_page);
- out_buf.pos = 0;
- out_buf.size = min_t(size_t, max_out, PAGE_SIZE);
- }
-
- if (tot_out >= tot_in) {
- ret = -E2BIG;
- goto out;
- }
-
- ret = 0;
- *total_in = tot_in;
- *total_out = tot_out;
-out:
- *out_pages = nr_pages;
- /* Cleanup */
- if (in_page) {
- kunmap(in_page);
- put_page(in_page);
- }
- if (out_page)
- kunmap(out_page);
- return ret;
-}
-
-static int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
-{
- struct workspace *workspace = list_entry(ws, struct workspace, list);
- struct page **pages_in = cb->compressed_pages;
- u64 disk_start = cb->start;
- struct bio *orig_bio = cb->orig_bio;
- size_t srclen = cb->compressed_len;
- ZSTD_DStream *stream;
- int ret = 0;
- unsigned long page_in_index = 0;
- unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE);
- unsigned long buf_start;
- unsigned long total_out = 0;
- ZSTD_inBuffer in_buf = { NULL, 0, 0 };
- ZSTD_outBuffer out_buf = { NULL, 0, 0 };
-
- stream = ZSTD_initDStream(
- ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size);
- if (!stream) {
- pr_debug("BTRFS: ZSTD_initDStream failed\n");
- ret = -EIO;
- goto done;
- }
-
- in_buf.src = kmap(pages_in[page_in_index]);
- in_buf.pos = 0;
- in_buf.size = min_t(size_t, srclen, PAGE_SIZE);
-
- out_buf.dst = workspace->buf;
- out_buf.pos = 0;
- out_buf.size = PAGE_SIZE;
-
- while (1) {
- size_t ret2;
-
- ret2 = ZSTD_decompressStream(stream, &out_buf, &in_buf);
- if (ZSTD_isError(ret2)) {
- pr_debug("BTRFS: ZSTD_decompressStream returned %d\n",
- ZSTD_getErrorCode(ret2));
- ret = -EIO;
- goto done;
- }
- buf_start = total_out;
- total_out += out_buf.pos;
- out_buf.pos = 0;
-
- ret = btrfs_decompress_buf2page(out_buf.dst, buf_start,
- total_out, disk_start, orig_bio);
- if (ret == 0)
- break;
-
- if (in_buf.pos >= srclen)
- break;
-
- /* Check if we've hit the end of a frame */
- if (ret2 == 0)
- break;
-
- if (in_buf.pos == in_buf.size) {
- kunmap(pages_in[page_in_index++]);
- if (page_in_index >= total_pages_in) {
- in_buf.src = NULL;
- ret = -EIO;
- goto done;
- }
- srclen -= PAGE_SIZE;
- in_buf.src = kmap(pages_in[page_in_index]);
- in_buf.pos = 0;
- in_buf.size = min_t(size_t, srclen, PAGE_SIZE);
- }
- }
- ret = 0;
- zero_fill_bio(orig_bio);
-done:
- if (in_buf.src)
- kunmap(pages_in[page_in_index]);
- return ret;
-}
-
-static int zstd_decompress(struct list_head *ws, unsigned char *data_in,
- struct page *dest_page,
- unsigned long start_byte,
- size_t srclen, size_t destlen)
-{
- struct workspace *workspace = list_entry(ws, struct workspace, list);
- ZSTD_DStream *stream;
- int ret = 0;
- size_t ret2;
- ZSTD_inBuffer in_buf = { NULL, 0, 0 };
- ZSTD_outBuffer out_buf = { NULL, 0, 0 };
- unsigned long total_out = 0;
- unsigned long pg_offset = 0;
- char *kaddr;
-
- stream = ZSTD_initDStream(
- ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size);
- if (!stream) {
- pr_warn("BTRFS: ZSTD_initDStream failed\n");
- ret = -EIO;
- goto finish;
- }
-
- destlen = min_t(size_t, destlen, PAGE_SIZE);
-
- in_buf.src = data_in;
- in_buf.pos = 0;
- in_buf.size = srclen;
-
- out_buf.dst = workspace->buf;
- out_buf.pos = 0;
- out_buf.size = PAGE_SIZE;
-
- ret2 = 1;
- while (pg_offset < destlen && in_buf.pos < in_buf.size) {
- unsigned long buf_start;
- unsigned long buf_offset;
- unsigned long bytes;
-
- /* Check if the frame is over and we still need more input */
- if (ret2 == 0) {
- pr_debug("BTRFS: ZSTD_decompressStream ended early\n");
- ret = -EIO;
- goto finish;
- }
- ret2 = ZSTD_decompressStream(stream, &out_buf, &in_buf);
- if (ZSTD_isError(ret2)) {
- pr_debug("BTRFS: ZSTD_decompressStream returned %d\n",
- ZSTD_getErrorCode(ret2));
- ret = -EIO;
- goto finish;
- }
-
- buf_start = total_out;
- total_out += out_buf.pos;
- out_buf.pos = 0;
-
- if (total_out <= start_byte)
- continue;
-
- if (total_out > start_byte && buf_start < start_byte)
- buf_offset = start_byte - buf_start;
- else
- buf_offset = 0;
-
- bytes = min_t(unsigned long, destlen - pg_offset,
- out_buf.size - buf_offset);
-
- kaddr = kmap_atomic(dest_page);
- memcpy(kaddr + pg_offset, out_buf.dst + buf_offset, bytes);
- kunmap_atomic(kaddr);
-
- pg_offset += bytes;
- }
- ret = 0;
-finish:
- if (pg_offset < destlen) {
- kaddr = kmap_atomic(dest_page);
- memset(kaddr + pg_offset, 0, destlen - pg_offset);
- kunmap_atomic(kaddr);
- }
- return ret;
-}
-
-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,
-};
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