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SquashFS linux kernel patch

dev
Sean Purcell 2017-04-27 15:04:31 -07:00
parent 89df466b2f
commit 32c658a289
2 changed files with 388 additions and 0 deletions
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146
contrib/linux-kernel/fs/squashfs/zstd_wrapper.c Normal file
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@ -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
};

242
contrib/linux-kernel/squashfs.diff Normal file
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@ -0,0 +1,242 @@
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
+};