diff options
| -rw-r--r-- | fs/squashfs/Kconfig | 14 | ||||
| -rw-r--r-- | fs/squashfs/Makefile | 1 | ||||
| -rw-r--r-- | fs/squashfs/decompressor.c | 7 | ||||
| -rw-r--r-- | fs/squashfs/decompressor.h | 4 | ||||
| -rw-r--r-- | fs/squashfs/squashfs_fs.h | 1 | ||||
| -rw-r--r-- | fs/squashfs/zstd_wrapper.c | 151 |
6 files changed, 178 insertions, 0 deletions
diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig index ffb093e72b6c..1adb3346b9d6 100644 --- a/fs/squashfs/Kconfig +++ b/fs/squashfs/Kconfig @@ -165,6 +165,20 @@ config SQUASHFS_XZ If unsure, say N. +config SQUASHFS_ZSTD + bool "Include support for ZSTD compressed file systems" + depends on SQUASHFS + select ZSTD_DECOMPRESS + help + Saying Y here includes support for reading Squashfs file systems + compressed with ZSTD compression. ZSTD gives better compression than + the default ZLIB compression, while using less CPU. + + ZSTD is not the standard compression used in Squashfs and so most + file systems will be readable without selecting this option. + + If unsure, say N. + config SQUASHFS_4K_DEVBLK_SIZE bool "Use 4K device block size?" depends on SQUASHFS diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile index 246a6f329d89..6655631c53ae 100644 --- a/fs/squashfs/Makefile +++ b/fs/squashfs/Makefile @@ -15,3 +15,4 @@ squashfs-$(CONFIG_SQUASHFS_LZ4) += lz4_wrapper.o squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o squashfs-$(CONFIG_SQUASHFS_ZLIB) += zlib_wrapper.o +squashfs-$(CONFIG_SQUASHFS_ZSTD) += zstd_wrapper.o diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c index d2bc13636f79..836639810ea0 100644 --- a/fs/squashfs/decompressor.c +++ b/fs/squashfs/decompressor.c @@ -65,6 +65,12 @@ static const struct squashfs_decompressor squashfs_zlib_comp_ops = { }; #endif +#ifndef CONFIG_SQUASHFS_ZSTD +static const struct squashfs_decompressor squashfs_zstd_comp_ops = { + NULL, NULL, NULL, NULL, ZSTD_COMPRESSION, "zstd", 0 +}; +#endif + static const struct squashfs_decompressor squashfs_unknown_comp_ops = { NULL, NULL, NULL, NULL, 0, "unknown", 0 }; @@ -75,6 +81,7 @@ static const struct squashfs_decompressor *decompressor[] = { &squashfs_lzo_comp_ops, &squashfs_xz_comp_ops, &squashfs_lzma_unsupported_comp_ops, + &squashfs_zstd_comp_ops, &squashfs_unknown_comp_ops }; diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h index a25713c031a5..0f5a8e4e58da 100644 --- a/fs/squashfs/decompressor.h +++ b/fs/squashfs/decompressor.h @@ -58,4 +58,8 @@ extern const struct squashfs_decompressor squashfs_lzo_comp_ops; extern const struct squashfs_decompressor squashfs_zlib_comp_ops; #endif +#ifdef CONFIG_SQUASHFS_ZSTD +extern const struct squashfs_decompressor squashfs_zstd_comp_ops; +#endif + #endif diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h index 506f4ba5b983..24d12fd14177 100644 --- a/fs/squashfs/squashfs_fs.h +++ b/fs/squashfs/squashfs_fs.h @@ -241,6 +241,7 @@ struct meta_index { #define LZO_COMPRESSION 3 #define XZ_COMPRESSION 4 #define LZ4_COMPRESSION 5 +#define ZSTD_COMPRESSION 6 struct squashfs_super_block { __le32 s_magic; diff --git a/fs/squashfs/zstd_wrapper.c b/fs/squashfs/zstd_wrapper.c new file mode 100644 index 000000000000..eeaabf881159 --- /dev/null +++ b/fs/squashfs/zstd_wrapper.c @@ -0,0 +1,151 @@ +/* + * Squashfs - a compressed read only filesystem for Linux + * + * 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 + * as published by the Free Software Foundation; either version 2, + * or (at your option) any later version. + * + * 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. + * + * zstd_wrapper.c + */ + +#include <linux/mutex.h> +#include <linux/buffer_head.h> +#include <linux/slab.h> +#include <linux/zstd.h> +#include <linux/vmalloc.h> + +#include "squashfs_fs.h" +#include "squashfs_fs_sb.h" +#include "squashfs.h" +#include "decompressor.h" +#include "page_actor.h" + +struct workspace { + void *mem; + size_t mem_size; + size_t window_size; +}; + +static void *zstd_init(struct squashfs_sb_info *msblk, void *buff) +{ + struct workspace *wksp = kmalloc(sizeof(*wksp), GFP_KERNEL); + + if (wksp == NULL) + goto failed; + wksp->window_size = max_t(size_t, + msblk->block_size, SQUASHFS_METADATA_SIZE); + wksp->mem_size = ZSTD_DStreamWorkspaceBound(wksp->window_size); + wksp->mem = vmalloc(wksp->mem_size); + if (wksp->mem == NULL) + goto failed; + + return wksp; + +failed: + ERROR("Failed to allocate zstd workspace\n"); + kfree(wksp); + return ERR_PTR(-ENOMEM); +} + + +static void zstd_free(void *strm) +{ + struct workspace *wksp = strm; + + if (wksp) + vfree(wksp->mem); + kfree(wksp); +} + + +static int zstd_uncompress(struct squashfs_sb_info *msblk, void *strm, + struct buffer_head **bh, int b, int offset, int length, + struct squashfs_page_actor *output) +{ + struct workspace *wksp = strm; + ZSTD_DStream *stream; + size_t total_out = 0; + size_t zstd_err; + int k = 0; + ZSTD_inBuffer in_buf = { NULL, 0, 0 }; + ZSTD_outBuffer out_buf = { NULL, 0, 0 }; + + stream = ZSTD_initDStream(wksp->window_size, wksp->mem, wksp->mem_size); + + if (!stream) { + ERROR("Failed to initialize zstd decompressor\n"); + goto out; + } + + out_buf.size = PAGE_SIZE; + out_buf.dst = squashfs_first_page(output); + + do { + if (in_buf.pos == in_buf.size && k < b) { + int avail = min(length, msblk->devblksize - offset); + + length -= avail; + in_buf.src = bh[k]->b_data + offset; + in_buf.size = avail; + in_buf.pos = 0; + offset = 0; + } + + if (out_buf.pos == out_buf.size) { + out_buf.dst = squashfs_next_page(output); + if (out_buf.dst == NULL) { + /* Shouldn't run out of pages + * before stream is done. + */ + squashfs_finish_page(output); + goto out; + } + out_buf.pos = 0; + out_buf.size = PAGE_SIZE; + } + + total_out -= out_buf.pos; + zstd_err = ZSTD_decompressStream(stream, &out_buf, &in_buf); + total_out += out_buf.pos; /* add the additional data produced */ + + if (in_buf.pos == in_buf.size && k < b) + put_bh(bh[k++]); + } while (zstd_err != 0 && !ZSTD_isError(zstd_err)); + + squashfs_finish_page(output); + + if (ZSTD_isError(zstd_err)) { + ERROR("zstd decompression error: %d\n", + (int)ZSTD_getErrorCode(zstd_err)); + goto out; + } + + if (k < b) + goto out; + + return (int)total_out; + +out: + for (; k < b; k++) + put_bh(bh[k]); + + return -EIO; +} + +const struct squashfs_decompressor squashfs_zstd_comp_ops = { + .init = zstd_init, + .free = zstd_free, + .decompress = zstd_uncompress, + .id = ZSTD_COMPRESSION, + .name = "zstd", + .supported = 1 +}; |