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154 lines
3.2 KiB
154 lines
3.2 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Squashfs - a compressed read only filesystem for Linux |
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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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* zstd_wrapper.c |
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*/ |
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#include <linux/mutex.h> |
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#include <linux/bio.h> |
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#include <linux/slab.h> |
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#include <linux/zstd.h> |
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#include <linux/vmalloc.h> |
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#include "squashfs_fs.h" |
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#include "squashfs_fs_sb.h" |
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#include "squashfs.h" |
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#include "decompressor.h" |
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#include "page_actor.h" |
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struct workspace { |
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void *mem; |
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size_t mem_size; |
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size_t window_size; |
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}; |
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static void *zstd_init(struct squashfs_sb_info *msblk, void *buff) |
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{ |
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struct workspace *wksp = kmalloc(sizeof(*wksp), GFP_KERNEL); |
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if (wksp == NULL) |
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goto failed; |
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wksp->window_size = max_t(size_t, |
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msblk->block_size, SQUASHFS_METADATA_SIZE); |
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wksp->mem_size = zstd_dstream_workspace_bound(wksp->window_size); |
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wksp->mem = vmalloc(wksp->mem_size); |
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if (wksp->mem == NULL) |
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goto failed; |
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return wksp; |
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failed: |
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ERROR("Failed to allocate zstd workspace\n"); |
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kfree(wksp); |
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return ERR_PTR(-ENOMEM); |
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} |
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static void zstd_free(void *strm) |
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{ |
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struct workspace *wksp = strm; |
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if (wksp) |
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vfree(wksp->mem); |
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kfree(wksp); |
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} |
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static int zstd_uncompress(struct squashfs_sb_info *msblk, void *strm, |
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struct bio *bio, int offset, int length, |
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struct squashfs_page_actor *output) |
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{ |
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struct workspace *wksp = strm; |
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zstd_dstream *stream; |
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size_t total_out = 0; |
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int error = 0; |
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zstd_in_buffer in_buf = { NULL, 0, 0 }; |
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zstd_out_buffer out_buf = { NULL, 0, 0 }; |
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struct bvec_iter_all iter_all = {}; |
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struct bio_vec *bvec = bvec_init_iter_all(&iter_all); |
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stream = zstd_init_dstream(wksp->window_size, wksp->mem, wksp->mem_size); |
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if (!stream) { |
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ERROR("Failed to initialize zstd decompressor\n"); |
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return -EIO; |
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} |
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out_buf.size = PAGE_SIZE; |
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out_buf.dst = squashfs_first_page(output); |
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if (IS_ERR(out_buf.dst)) { |
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error = PTR_ERR(out_buf.dst); |
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goto finish; |
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} |
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for (;;) { |
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size_t zstd_err; |
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if (in_buf.pos == in_buf.size) { |
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const void *data; |
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int avail; |
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if (!bio_next_segment(bio, &iter_all)) { |
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error = -EIO; |
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break; |
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} |
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avail = min(length, ((int)bvec->bv_len) - offset); |
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data = bvec_virt(bvec); |
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length -= avail; |
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in_buf.src = data + offset; |
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in_buf.size = avail; |
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in_buf.pos = 0; |
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offset = 0; |
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} |
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if (out_buf.pos == out_buf.size) { |
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out_buf.dst = squashfs_next_page(output); |
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if (IS_ERR(out_buf.dst)) { |
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error = PTR_ERR(out_buf.dst); |
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break; |
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} else if (out_buf.dst == NULL) { |
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/* Shouldn't run out of pages |
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* before stream is done. |
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*/ |
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error = -EIO; |
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break; |
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} |
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out_buf.pos = 0; |
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out_buf.size = PAGE_SIZE; |
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} |
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total_out -= out_buf.pos; |
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zstd_err = zstd_decompress_stream(stream, &out_buf, &in_buf); |
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total_out += out_buf.pos; /* add the additional data produced */ |
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if (zstd_err == 0) |
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break; |
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if (zstd_is_error(zstd_err)) { |
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ERROR("zstd decompression error: %d\n", |
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(int)zstd_get_error_code(zstd_err)); |
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error = -EIO; |
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break; |
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} |
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} |
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finish: |
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squashfs_finish_page(output); |
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return error ? error : total_out; |
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} |
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const struct squashfs_decompressor squashfs_zstd_comp_ops = { |
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.init = zstd_init, |
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.free = zstd_free, |
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.decompress = zstd_uncompress, |
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.id = ZSTD_COMPRESSION, |
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.name = "zstd", |
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.alloc_buffer = 1, |
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.supported = 1 |
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};
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