Merge tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next

Pull squashfs update from Phillip Lougher: "These patches optionally add LZ4 compression support to Squashfs. LZ4 is a lightweight compression algorithm which can be used on embedded systems to reduce CPU and memory overhead (in comparison to the standard zlib compression). These patches add the wrapper code to allow Squashfs to use the existing LZ4 decompression code, and the necessary configuration option" * tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next: Squashfs: Add LZ4 compression configuration option Squashfs: add LZ4 compression support

Merge tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next
Pull squashfs update from Phillip Lougher: "These patches optionally add LZ4 compression support to Squashfs. LZ4 is a lightweight compression algorithm which can be used on embedded systems to reduce CPU and memory overhead (in comparison to the standard zlib compression). These patches add the wrapper code to allow Squashfs to use the existing LZ4 decompression code, and the necessary configuration option" * tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next: Squashfs: Add LZ4 compression configuration option Squashfs: add LZ4 compression support
Linus Torvalds
2 parents 980f3c344f 62421645bb
Showing 7 changed files Side-by-side Diff
Documentation/filesystems/squashfs.txt
fs/squashfs/Kconfig
fs/squashfs/Makefile
fs/squashfs/decompressor.c
fs/squashfs/decompressor.h
fs/squashfs/lz4_wrapper.c
fs/squashfs/squashfs_fs.h
@@ -2,10 +2,10 @@
 =======================
  
 Squashfs is a compressed read-only filesystem for Linux.
-It uses zlib/lzo/xz compression to compress files, inodes and directories.
-Inodes in the system are very small and all blocks are packed to minimise
-data overhead. Block sizes greater than 4K are supported up to a maximum
-of 1Mbytes (default block size 128K).
+It uses zlib, lz4, lzo, or xz compression to compress files, inodes and
+directories.  Inodes in the system are very small and all blocks are packed to
+minimise data overhead. Block sizes greater than 4K are supported up to a
+maximum of 1Mbytes (default block size 128K).
  
 Squashfs is intended for general read-only filesystem use, for archival
 use (i.e. in cases where a .tar.gz file may be used), and in constrained
@@ -120,6 +120,21 @@
  
 	  If unsure, say Y.
  
+config SQUASHFS_LZ4
+	bool "Include support for LZ4 compressed file systems"
+	depends on SQUASHFS
+	select LZ4_DECOMPRESS
+	help
+	  Saying Y here includes support for reading Squashfs file systems
+	  compressed with LZ4 compression.  LZ4 compression is mainly
+	  aimed at embedded systems with slower CPUs where the overheads
+	  of zlib are too high.
+
+	  LZ4 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_LZO
 	bool "Include support for LZO compressed file systems"
 	depends on SQUASHFS
@@ -11,6 +11,7 @@
 squashfs-$(CONFIG_SQUASHFS_DECOMP_MULTI) += decompressor_multi.o
 squashfs-$(CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU) += decompressor_multi_percpu.o
 squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o
+squashfs-$(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
@@ -41,6 +41,12 @@
 	NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
 };
  
+#ifndef CONFIG_SQUASHFS_LZ4
+static const struct squashfs_decompressor squashfs_lz4_comp_ops = {
+	NULL, NULL, NULL, NULL, LZ4_COMPRESSION, "lz4", 0
+};
+#endif
+
 #ifndef CONFIG_SQUASHFS_LZO
 static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
 	NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
@@ -65,6 +71,7 @@
  
 static const struct squashfs_decompressor *decompressor[] = {
 	&squashfs_zlib_comp_ops,
+	&squashfs_lz4_comp_ops,
 	&squashfs_lzo_comp_ops,
 	&squashfs_xz_comp_ops,
 	&squashfs_lzma_unsupported_comp_ops,
@@ -46,6 +46,10 @@
 extern const struct squashfs_decompressor squashfs_xz_comp_ops;
 #endif
  
+#ifdef CONFIG_SQUASHFS_LZ4
+extern const struct squashfs_decompressor squashfs_lz4_comp_ops;
+#endif
+
 #ifdef CONFIG_SQUASHFS_LZO
 extern const struct squashfs_decompressor squashfs_lzo_comp_ops;
 #endif
+/*
+ * Copyright (c) 2013, 2014
+ * Phillip Lougher <phillip@squashfs.org.uk>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+
+#include <linux/buffer_head.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/lz4.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs.h"
+#include "decompressor.h"
+#include "page_actor.h"
+
+#define LZ4_LEGACY	1
+
+struct lz4_comp_opts {
+	__le32 version;
+	__le32 flags;
+};
+
+struct squashfs_lz4 {
+	void *input;
+	void *output;
+};
+
+
+static void *lz4_comp_opts(struct squashfs_sb_info *msblk,
+	void *buff, int len)
+{
+	struct lz4_comp_opts *comp_opts = buff;
+
+	/* LZ4 compressed filesystems always have compression options */
+	if (comp_opts == NULL || len < sizeof(*comp_opts))
+		return ERR_PTR(-EIO);
+
+	if (le32_to_cpu(comp_opts->version) != LZ4_LEGACY) {
+		/* LZ4 format currently used by the kernel is the 'legacy'
+		 * format */
+		ERROR("Unknown LZ4 version\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	return NULL;
+}
+
+
+static void *lz4_init(struct squashfs_sb_info *msblk, void *buff)
+{
+	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
+	struct squashfs_lz4 *stream;
+
+	stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+	if (stream == NULL)
+		goto failed;
+	stream->input = vmalloc(block_size);
+	if (stream->input == NULL)
+		goto failed2;
+	stream->output = vmalloc(block_size);
+	if (stream->output == NULL)
+		goto failed3;
+
+	return stream;
+
+failed3:
+	vfree(stream->input);
+failed2:
+	kfree(stream);
+failed:
+	ERROR("Failed to initialise LZ4 decompressor\n");
+	return ERR_PTR(-ENOMEM);
+}
+
+
+static void lz4_free(void *strm)
+{
+	struct squashfs_lz4 *stream = strm;
+
+	if (stream) {
+		vfree(stream->input);
+		vfree(stream->output);
+	}
+	kfree(stream);
+}
+
+
+static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm,
+	struct buffer_head **bh, int b, int offset, int length,
+	struct squashfs_page_actor *output)
+{
+	struct squashfs_lz4 *stream = strm;
+	void *buff = stream->input, *data;
+	int avail, i, bytes = length, res;
+	size_t dest_len = output->length;
+
+	for (i = 0; i < b; i++) {
+		avail = min(bytes, msblk->devblksize - offset);
+		memcpy(buff, bh[i]->b_data + offset, avail);
+		buff += avail;
+		bytes -= avail;
+		offset = 0;
+		put_bh(bh[i]);
+	}
+
+	res = lz4_decompress_unknownoutputsize(stream->input, length,
+					stream->output, &dest_len);
+	if (res)
+		return -EIO;
+
+	bytes = dest_len;
+	data = squashfs_first_page(output);
+	buff = stream->output;
+	while (data) {
+		if (bytes <= PAGE_CACHE_SIZE) {
+			memcpy(data, buff, bytes);
+			break;
+		}
+		memcpy(data, buff, PAGE_CACHE_SIZE);
+		buff += PAGE_CACHE_SIZE;
+		bytes -= PAGE_CACHE_SIZE;
+		data = squashfs_next_page(output);
+	}
+	squashfs_finish_page(output);
+
+	return dest_len;
+}
+
+const struct squashfs_decompressor squashfs_lz4_comp_ops = {
+	.init = lz4_init,
+	.comp_opts = lz4_comp_opts,
+	.free = lz4_free,
+	.decompress = lz4_uncompress,
+	.id = LZ4_COMPRESSION,
+	.name = "lz4",
+	.supported = 1
+};
@@ -240,6 +240,7 @@
 #define LZMA_COMPRESSION	2
 #define LZO_COMPRESSION		3
 #define XZ_COMPRESSION		4
+#define LZ4_COMPRESSION		5
  
 struct squashfs_super_block {
 	__le32			s_magic;
...	...	@@ -2,10 +2,10 @@
2	2	=======================
3	3
4	4	Squashfs is a compressed read-only filesystem for Linux.
5		-It uses zlib/lzo/xz compression to compress files, inodes and directories.
6		-Inodes in the system are very small and all blocks are packed to minimise
7		-data overhead. Block sizes greater than 4K are supported up to a maximum
8		-of 1Mbytes (default block size 128K).
	5	+It uses zlib, lz4, lzo, or xz compression to compress files, inodes and
	6	+directories. Inodes in the system are very small and all blocks are packed to
	7	+minimise data overhead. Block sizes greater than 4K are supported up to a
	8	+maximum of 1Mbytes (default block size 128K).
9	9
10	10	Squashfs is intended for general read-only filesystem use, for archival
11	11	use (i.e. in cases where a .tar.gz file may be used), and in constrained
...	...	@@ -120,6 +120,21 @@
120	120
121	121	If unsure, say Y.
122	122
	123	+config SQUASHFS_LZ4
	124	+ bool "Include support for LZ4 compressed file systems"
	125	+ depends on SQUASHFS
	126	+ select LZ4_DECOMPRESS
	127	+ help
	128	+ Saying Y here includes support for reading Squashfs file systems
	129	+ compressed with LZ4 compression. LZ4 compression is mainly
	130	+ aimed at embedded systems with slower CPUs where the overheads
	131	+ of zlib are too high.
	132	+
	133	+ LZ4 is not the standard compression used in Squashfs and so most
	134	+ file systems will be readable without selecting this option.
	135	+
	136	+ If unsure, say N.
	137	+
123	138	config SQUASHFS_LZO
124	139	bool "Include support for LZO compressed file systems"
125	140	depends on SQUASHFS
...	...	@@ -11,6 +11,7 @@
11	11	squashfs-$(CONFIG_SQUASHFS_DECOMP_MULTI) += decompressor_multi.o
12	12	squashfs-$(CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU) += decompressor_multi_percpu.o
13	13	squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o
	14	+squashfs-$(CONFIG_SQUASHFS_LZ4) += lz4_wrapper.o
14	15	squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o
15	16	squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o
16	17	squashfs-$(CONFIG_SQUASHFS_ZLIB) += zlib_wrapper.o
...	...	@@ -41,6 +41,12 @@
41	41	NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
42	42	};
43	43
	44	+#ifndef CONFIG_SQUASHFS_LZ4
	45	+static const struct squashfs_decompressor squashfs_lz4_comp_ops = {
	46	+ NULL, NULL, NULL, NULL, LZ4_COMPRESSION, "lz4", 0
	47	+};
	48	+#endif
	49	+
44	50	#ifndef CONFIG_SQUASHFS_LZO
45	51	static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
46	52	NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
...	...	@@ -65,6 +71,7 @@
65	71
66	72	static const struct squashfs_decompressor *decompressor[] = {
67	73	&squashfs_zlib_comp_ops,
	74	+ &squashfs_lz4_comp_ops,
68	75	&squashfs_lzo_comp_ops,
69	76	&squashfs_xz_comp_ops,
70	77	&squashfs_lzma_unsupported_comp_ops,
...	...	@@ -46,6 +46,10 @@
46	46	extern const struct squashfs_decompressor squashfs_xz_comp_ops;
47	47	#endif
48	48
	49	+#ifdef CONFIG_SQUASHFS_LZ4
	50	+extern const struct squashfs_decompressor squashfs_lz4_comp_ops;
	51	+#endif
	52	+
49	53	#ifdef CONFIG_SQUASHFS_LZO
50	54	extern const struct squashfs_decompressor squashfs_lzo_comp_ops;
51	55	#endif
	1	+/*
	2	+ * Copyright (c) 2013, 2014
	3	+ * Phillip Lougher <phillip@squashfs.org.uk>
	4	+ *
	5	+ * This work is licensed under the terms of the GNU GPL, version 2. See
	6	+ * the COPYING file in the top-level directory.
	7	+ */
	8	+
	9	+#include <linux/buffer_head.h>
	10	+#include <linux/mutex.h>
	11	+#include <linux/slab.h>
	12	+#include <linux/vmalloc.h>
	13	+#include <linux/lz4.h>
	14	+
	15	+#include "squashfs_fs.h"
	16	+#include "squashfs_fs_sb.h"
	17	+#include "squashfs.h"
	18	+#include "decompressor.h"
	19	+#include "page_actor.h"
	20	+
	21	+#define LZ4_LEGACY 1
	22	+
	23	+struct lz4_comp_opts {
	24	+ __le32 version;
	25	+ __le32 flags;
	26	+};
	27	+
	28	+struct squashfs_lz4 {
	29	+ void *input;
	30	+ void *output;
	31	+};
	32	+
	33	+
	34	+static void lz4_comp_opts(struct squashfs_sb_info msblk,
	35	+ void *buff, int len)
	36	+{
	37	+ struct lz4_comp_opts *comp_opts = buff;
	38	+
	39	+ /* LZ4 compressed filesystems always have compression options */
	40	+ if (comp_opts == NULL \|\| len < sizeof(*comp_opts))
	41	+ return ERR_PTR(-EIO);
	42	+
	43	+ if (le32_to_cpu(comp_opts->version) != LZ4_LEGACY) {
	44	+ /* LZ4 format currently used by the kernel is the 'legacy'
	45	+ * format */
	46	+ ERROR("Unknown LZ4 version\n");
	47	+ return ERR_PTR(-EINVAL);
	48	+ }
	49	+
	50	+ return NULL;
	51	+}
	52	+
	53	+
	54	+static void lz4_init(struct squashfs_sb_info msblk, void *buff)
	55	+{
	56	+ int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
	57	+ struct squashfs_lz4 *stream;
	58	+
	59	+ stream = kzalloc(sizeof(*stream), GFP_KERNEL);
	60	+ if (stream == NULL)
	61	+ goto failed;
	62	+ stream->input = vmalloc(block_size);
	63	+ if (stream->input == NULL)
	64	+ goto failed2;
	65	+ stream->output = vmalloc(block_size);
	66	+ if (stream->output == NULL)
	67	+ goto failed3;
	68	+
	69	+ return stream;
	70	+
	71	+failed3:
	72	+ vfree(stream->input);
	73	+failed2:
	74	+ kfree(stream);
	75	+failed:
	76	+ ERROR("Failed to initialise LZ4 decompressor\n");
	77	+ return ERR_PTR(-ENOMEM);
	78	+}
	79	+
	80	+
	81	+static void lz4_free(void *strm)
	82	+{
	83	+ struct squashfs_lz4 *stream = strm;
	84	+
	85	+ if (stream) {
	86	+ vfree(stream->input);
	87	+ vfree(stream->output);
	88	+ }
	89	+ kfree(stream);
	90	+}
	91	+
	92	+
	93	+static int lz4_uncompress(struct squashfs_sb_info msblk, void strm,
	94	+ struct buffer_head **bh, int b, int offset, int length,
	95	+ struct squashfs_page_actor *output)
	96	+{
	97	+ struct squashfs_lz4 *stream = strm;
	98	+ void buff = stream->input, data;
	99	+ int avail, i, bytes = length, res;
	100	+ size_t dest_len = output->length;
	101	+
	102	+ for (i = 0; i < b; i++) {
	103	+ avail = min(bytes, msblk->devblksize - offset);
	104	+ memcpy(buff, bh[i]->b_data + offset, avail);
	105	+ buff += avail;
	106	+ bytes -= avail;
	107	+ offset = 0;
	108	+ put_bh(bh[i]);
	109	+ }
	110	+
	111	+ res = lz4_decompress_unknownoutputsize(stream->input, length,
	112	+ stream->output, &dest_len);
	113	+ if (res)
	114	+ return -EIO;
	115	+
	116	+ bytes = dest_len;
	117	+ data = squashfs_first_page(output);
	118	+ buff = stream->output;
	119	+ while (data) {
	120	+ if (bytes <= PAGE_CACHE_SIZE) {
	121	+ memcpy(data, buff, bytes);
	122	+ break;
	123	+ }
	124	+ memcpy(data, buff, PAGE_CACHE_SIZE);
	125	+ buff += PAGE_CACHE_SIZE;
	126	+ bytes -= PAGE_CACHE_SIZE;
	127	+ data = squashfs_next_page(output);
	128	+ }
	129	+ squashfs_finish_page(output);
	130	+
	131	+ return dest_len;
	132	+}
	133	+
	134	+const struct squashfs_decompressor squashfs_lz4_comp_ops = {
	135	+ .init = lz4_init,
	136	+ .comp_opts = lz4_comp_opts,
	137	+ .free = lz4_free,
	138	+ .decompress = lz4_uncompress,
	139	+ .id = LZ4_COMPRESSION,
	140	+ .name = "lz4",
	141	+ .supported = 1
	142	+};
...	...	@@ -240,6 +240,7 @@
240	240	#define LZMA_COMPRESSION 2
241	241	#define LZO_COMPRESSION 3
242	242	#define XZ_COMPRESSION 4
	243	+#define LZ4_COMPRESSION 5
243	244
244	245	struct squashfs_super_block {
245	246	__le32 s_magic;