--- /dev/null
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2017 Facebook
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * 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;
+};
+
+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->mem_size = ZSTD_DStreamWorkspaceBound(max_t(size_t,
+ msblk->block_size, SQUASHFS_METADATA_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->mem_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);
+ out_buf.pos = 0;
+ if (out_buf.dst != NULL) {
+ out_buf.size = PAGE_SIZE;
+ } else {
+ out_buf.size = 0;
+ }
+ }
+
+ 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));
+
+ if (ZSTD_isError(zstd_err)) {
+ ERROR("zstd decompression error: %d\n",
+ (int)ZSTD_getErrorCode(zstd_err));
+ }
+
+ squashfs_finish_page(output);
+
+ if (k < b)
+ goto out;
+
+ return 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
+};
--- /dev/null
+commit 7289653483a0579c3b63a06abf008210c8cc6c8b
+Author: Sean Purcell <me@seanp.xyz>
+Date: Thu Apr 27 14:56:25 2017 -0700
+
+ Add zstd support to kernel squashfs
+
+diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig
+index ffb093e..1adb334 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 246a6f3..6655631 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 d2bc136..8366398 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 a25713c..0f5a8e4 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 506f4ba..24d12fd 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 0000000..81f4b5a
+--- /dev/null
++++ b/fs/squashfs/zstd_wrapper.c
+@@ -0,0 +1,146 @@
++/*
++ * Squashfs - a compressed read only filesystem for Linux
++ *
++ * Copyright (c) 2017 Facebook
++ *
++ * 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.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
++ *
++ * 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;
++};
++
++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->mem_size = ZSTD_DStreamWorkspaceBound(max_t(size_t,
++ msblk->block_size, SQUASHFS_METADATA_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->mem_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);
++ out_buf.pos = 0;
++ if (out_buf.dst != NULL) {
++ out_buf.size = PAGE_SIZE;
++ } else {
++ out_buf.size = 0;
++ }
++ }
++
++ 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));
++
++ if (ZSTD_isError(zstd_err)) {
++ ERROR("zstd decompression error: %d\n",
++ (int)ZSTD_getErrorCode(zstd_err));
++ }
++
++ squashfs_finish_page(output);
++
++ if (k < b)
++ goto out;
++
++ return 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
++};
projects / thirdparty / zstd.git / commitdiff
