freifunkist-firmware/target/linux/generic-2.6/patches-2.6.30/053-squashfs_lzma.patch

--- a/fs/squashfs/Kconfig
+++ b/fs/squashfs/Kconfig
@@ -2,7 +2,6 @@ config SQUASHFS
 	tristate "SquashFS 4.0 - Squashed file system support"
 	depends on BLOCK
 	select CRYPTO
-	select CRYPTO_ZLIB
 	help
 	  Saying Y here includes support for SquashFS 4.0 (a Compressed
 	  Read-Only File System).  Squashfs is a highly compressed read-only
@@ -37,6 +36,26 @@ config SQUASHFS_EMBEDDED
 
 	  If unsure, say N.
 
+config SQUASHFS_SUPPORT_ZLIB
+	bool
+	prompt "Support ZLIB compression" if SQUASHFS_SUPPORT_LZMA
+	depends on SQUASHFS
+	select CRYPTO_ZLIB
+	default y
+	help
+	  ZLIB is the default compression used in squashfs. If you are
+	  using LZMA compression instead, you can remove support for ZLIB
+	  entirely.
+
+config SQUASHFS_SUPPORT_LZMA
+	bool "Support LZMA compression"
+	depends on SQUASHFS
+	select CRYPTO_UNLZMA
+	help
+	  By default SquashFS uses ZLIB compression, however (if your tools
+	  support it, you can use LZMA instead, which saves space.
+
+
 config SQUASHFS_FRAGMENT_CACHE_SIZE
 	int "Number of fragments cached" if SQUASHFS_EMBEDDED
 	depends on SQUASHFS
--- a/fs/squashfs/squashfs_fs.h
+++ b/fs/squashfs/squashfs_fs.h
@@ -212,6 +212,7 @@ struct meta_index {
  * definitions for structures on disk
  */
 #define ZLIB_COMPRESSION	 1
+#define LZMA_COMPRESSION	 2
 
 struct squashfs_super_block {
 	__le32			s_magic;
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -47,13 +47,76 @@
 #include "squashfs.h"
 
 
-#define SQUASHFS_CRYPTO_ALG	"zlib"
+static int squashfs_setup_zlib(struct squashfs_sb_info *msblk)
+{
+	int err = -EOPNOTSUPP;
+
+#ifdef CONFIG_SQUASHFS_SUPPORT_ZLIB
+	struct {
+		struct nlattr nla;
+		int val;
+	} params = {
+		.nla = {
+			.nla_len	= nla_attr_size(sizeof(int)),
+			.nla_type	= ZLIB_DECOMP_WINDOWBITS,
+		},
+		.val			= DEF_WBITS,
+	};
+
+	msblk->tfm = crypto_alloc_pcomp("zlib", 0,
+					CRYPTO_ALG_ASYNC);
+	if (IS_ERR(msblk->tfm)) {
+		ERROR("Failed to load zlib crypto module\n");
+		return PTR_ERR(msblk->tfm);
+	}
+
+	err = crypto_decompress_setup(msblk->tfm, &params, sizeof(params));
+	if (err) {
+		ERROR("Failed to set up decompression parameters\n");
+		crypto_free_pcomp(msblk->tfm);
+	}
+#endif
+
+	return err;
+}
+
+static int squashfs_setup_lzma(struct squashfs_sb_info *msblk)
+{
+	int err = -EOPNOTSUPP;
+
+#ifdef CONFIG_SQUASHFS_SUPPORT_LZMA
+	struct {
+		struct nlattr nla;
+		int val;
+	} params = {
+		.nla = {
+			.nla_len	= nla_attr_size(sizeof(int)),
+			.nla_type	= UNLZMA_DECOMP_OUT_BUFFERS,
+		},
+		.val = (msblk->block_size / PAGE_CACHE_SIZE) + 1
+	};
 
+	msblk->tfm = crypto_alloc_pcomp("lzma", 0,
+					CRYPTO_ALG_ASYNC);
+	if (IS_ERR(msblk->tfm)) {
+		ERROR("Failed to load lzma crypto module\n");
+		return PTR_ERR(msblk->tfm);
+	}
+
+	err = crypto_decompress_setup(msblk->tfm, &params, sizeof(params));
+	if (err) {
+		ERROR("Failed to set up decompression parameters\n");
+		crypto_free_pcomp(msblk->tfm);
+	}
+#endif
+
+	return err;
+}
 
 static struct file_system_type squashfs_fs_type;
 static struct super_operations squashfs_super_ops;
 
-static int supported_squashfs_filesystem(short major, short minor, short comp)
+static int supported_squashfs_filesystem(short major, short minor)
 {
 	if (major < SQUASHFS_MAJOR) {
 		ERROR("Major/Minor mismatch, older Squashfs %d.%d "
@@ -66,9 +129,6 @@ static int supported_squashfs_filesystem
 		return -EINVAL;
 	}
 
-	if (comp != ZLIB_COMPRESSION)
-		return -EINVAL;
-
 	return 0;
 }
 
@@ -83,16 +143,6 @@ static int squashfs_fill_super(struct su
 	unsigned short flags;
 	unsigned int fragments;
 	u64 lookup_table_start;
-	struct {
-		struct nlattr nla;
-		int val;
-	} params = {
-		.nla = {
-			.nla_len	= nla_attr_size(sizeof(int)),
-			.nla_type	= ZLIB_DECOMP_WINDOWBITS,
-		},
-		.val			= DEF_WBITS,
-	};
 	int err;
 
 	TRACE("Entered squashfs_fill_superblock\n");
@@ -104,21 +154,6 @@ static int squashfs_fill_super(struct su
 	}
 	msblk = sb->s_fs_info;
 
-	msblk->tfm = crypto_alloc_pcomp(SQUASHFS_CRYPTO_ALG, 0,
-					CRYPTO_ALG_ASYNC);
-	if (IS_ERR(msblk->tfm)) {
-		ERROR("Failed to load %s crypto module\n",
-		      SQUASHFS_CRYPTO_ALG);
-		err = PTR_ERR(msblk->tfm);
-		goto failed_pcomp;
-	}
-
-	err = crypto_decompress_setup(msblk->tfm, &params, sizeof(params));
-	if (err) {
-		ERROR("Failed to set up decompression parameters\n");
-		goto failure;
-	}
-
 	sblk = kzalloc(sizeof(*sblk), GFP_KERNEL);
 	if (sblk == NULL) {
 		ERROR("Failed to allocate squashfs_super_block\n");
@@ -156,10 +191,28 @@ static int squashfs_fill_super(struct su
 		goto failed_mount;
 	}
 
+	/* Check block size for sanity */
+	msblk->block_size = le32_to_cpu(sblk->block_size);
+	if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE)
+		goto failed_mount;
+
 	/* Check the MAJOR & MINOR versions and compression type */
 	err = supported_squashfs_filesystem(le16_to_cpu(sblk->s_major),
-			le16_to_cpu(sblk->s_minor),
-			le16_to_cpu(sblk->compression));
+			le16_to_cpu(sblk->s_minor));
+	if (err < 0)
+		goto failed_mount;
+
+	switch(le16_to_cpu(sblk->compression)) {
+	case ZLIB_COMPRESSION:
+		err = squashfs_setup_zlib(msblk);
+		break;
+	case LZMA_COMPRESSION:
+		err = squashfs_setup_lzma(msblk);
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
 	if (err < 0)
 		goto failed_mount;
 
@@ -179,11 +232,6 @@ static int squashfs_fill_super(struct su
 			i_size_read(sb->s_bdev->bd_inode))
 		goto failed_mount;
 
-	/* Check block size for sanity */
-	msblk->block_size = le32_to_cpu(sblk->block_size);
-	if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE)
-		goto failed_mount;
-
 	/*
 	 * Check the system page size is not larger than the filesystem
 	 * block size (by default 128K).  This is currently not supported.
@@ -315,21 +363,16 @@ allocate_root:
 	return 0;
 
 failed_mount:
+	if (msblk->tfm)
+		crypto_free_pcomp(msblk->tfm);
 	squashfs_cache_delete(msblk->block_cache);
 	squashfs_cache_delete(msblk->fragment_cache);
 	squashfs_cache_delete(msblk->read_page);
 	kfree(msblk->inode_lookup_table);
 	kfree(msblk->fragment_index);
 	kfree(msblk->id_table);
-	crypto_free_pcomp(msblk->tfm);
-	kfree(sb->s_fs_info);
-	sb->s_fs_info = NULL;
 	kfree(sblk);
-	return err;
-
 failure:
-	crypto_free_pcomp(msblk->tfm);
-failed_pcomp:
 	kfree(sb->s_fs_info);
 	sb->s_fs_info = NULL;
 	return err;