Squashfs: add a decompressor framework

This adds a decompressor framework which allows multiple compression algorithms to be cleanly supported. Also update zlib wrapper and other code to use the new framework. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

Squashfs: add a decompressor framework
This adds a decompressor framework which allows multiple compression algorithms to be cleanly supported. Also update zlib wrapper and other code to use the new framework. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Phillip Lougher
1 parent f1a40359f8
Showing 8 changed files with 184 additions and 51 deletions Side-by-side Diff
fs/squashfs/Makefile
fs/squashfs/block.c
fs/squashfs/decompressor.c
fs/squashfs/decompressor.h
fs/squashfs/squashfs.h
fs/squashfs/squashfs_fs_sb.h
fs/squashfs/super.c
fs/squashfs/zlib_wrapper.c
@@ -4,5 +4,5 @@
  
 obj-$(CONFIG_SQUASHFS) += squashfs.o
 squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
-squashfs-y += namei.o super.o symlink.o zlib_wrapper.o
+squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o
@@ -36,6 +36,7 @@
 #include "squashfs_fs_sb.h"
 #include "squashfs_fs_i.h"
 #include "squashfs.h"
+#include "decompressor.h"
  
 /*
  * Read the metadata block length, this is stored in the first two
@@ -151,7 +152,7 @@
 	}
  
 	if (compressed) {
-		length = squashfs_zlib_uncompress(msblk, buffer, bh, b, offset,
+		length = squashfs_decompress(msblk, buffer, bh, b, offset,
 			 length, srclength, pages);
 		if (length < 0)
 			goto read_failure;
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ * Phillip Lougher <phillip@lougher.demon.co.uk>
+ *
+ * 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.
+ *
+ * decompressor.c
+ */
+
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/buffer_head.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "decompressor.h"
+#include "squashfs.h"
+
+/*
+ * This file (and decompressor.h) implements a decompressor framework for
+ * Squashfs, allowing multiple decompressors to be easily supported
+ */
+
+static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
+	NULL, NULL, NULL, 0, "unknown", 0
+};
+
+static const struct squashfs_decompressor *decompressor[] = {
+	&squashfs_zlib_comp_ops,
+	&squashfs_unknown_comp_ops
+};
+
+
+const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
+{
+	int i;
+
+	for (i = 0; decompressor[i]->id; i++)
+		if (id == decompressor[i]->id)
+			break;
+
+	return decompressor[i];
+}
+#ifndef DECOMPRESSOR_H
+#define DECOMPRESSOR_H
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ * Phillip Lougher <phillip@lougher.demon.co.uk>
+ *
+ * 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.
+ *
+ * decompressor.h
+ */
+
+struct squashfs_decompressor {
+	void	*(*init)(struct squashfs_sb_info *);
+	void	(*free)(void *);
+	int	(*decompress)(struct squashfs_sb_info *, void **,
+		struct buffer_head **, int, int, int, int, int);
+	int	id;
+	char	*name;
+	int	supported;
+};
+
+static inline void *squashfs_decompressor_init(struct squashfs_sb_info *msblk)
+{
+	return msblk->decompressor->init(msblk);
+}
+
+static inline void squashfs_decompressor_free(struct squashfs_sb_info *msblk,
+	void *s)
+{
+	if (msblk->decompressor)
+		msblk->decompressor->free(s);
+}
+
+static inline int squashfs_decompress(struct squashfs_sb_info *msblk,
+	void **buffer, struct buffer_head **bh, int b, int offset, int length,
+	int srclength, int pages)
+{
+	return msblk->decompressor->decompress(msblk, buffer, bh, b, offset,
+		length, srclength, pages);
+}
+#endif
@@ -51,6 +51,9 @@
 				u64, int);
 extern int squashfs_read_table(struct super_block *, void *, u64, int);
  
+/* decompressor.c */
+extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int);
+
 /* export.c */
 extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64,
 				unsigned int);
  
@@ -70,14 +73,8 @@
 				unsigned int);
 extern int squashfs_read_inode(struct inode *, long long);
  
-/* zlib_wrapper.c */
-extern void *squashfs_zlib_init(void);
-extern void squashfs_zlib_free(void *);
-extern int squashfs_zlib_uncompress(struct squashfs_sb_info *, void **,
-				struct buffer_head **, int, int, int, int, int);
-
 /*
- * Inodes and files operations
+ * Inodes, files and decompressor operations
  */
  
 /* dir.c */
@@ -94,4 +91,7 @@
  
 /* symlink.c */
 extern const struct address_space_operations squashfs_symlink_aops;
+
+/* zlib_wrapper.c */
+extern const struct squashfs_decompressor squashfs_zlib_comp_ops;
@@ -52,26 +52,27 @@
 };
  
 struct squashfs_sb_info {
-	int			devblksize;
-	int			devblksize_log2;
-	struct squashfs_cache	*block_cache;
-	struct squashfs_cache	*fragment_cache;
-	struct squashfs_cache	*read_page;
-	int			next_meta_index;
-	__le64			*id_table;
-	__le64			*fragment_index;
-	unsigned int		*fragment_index_2;
-	struct mutex		read_data_mutex;
-	struct mutex		meta_index_mutex;
-	struct meta_index	*meta_index;
-	void			*stream;
-	__le64			*inode_lookup_table;
-	u64			inode_table;
-	u64			directory_table;
-	unsigned int		block_size;
-	unsigned short		block_log;
-	long long		bytes_used;
-	unsigned int		inodes;
+	const struct squashfs_decompressor	*decompressor;
+	int					devblksize;
+	int					devblksize_log2;
+	struct squashfs_cache			*block_cache;
+	struct squashfs_cache			*fragment_cache;
+	struct squashfs_cache			*read_page;
+	int					next_meta_index;
+	__le64					*id_table;
+	__le64					*fragment_index;
+	unsigned int				*fragment_index_2;
+	struct mutex				read_data_mutex;
+	struct mutex				meta_index_mutex;
+	struct meta_index			*meta_index;
+	void					*stream;
+	__le64					*inode_lookup_table;
+	u64					inode_table;
+	u64					directory_table;
+	unsigned int				block_size;
+	unsigned short				block_log;
+	long long				bytes_used;
+	unsigned int				inodes;
 };
 #endif
@@ -41,27 +41,35 @@
 #include "squashfs_fs_sb.h"
 #include "squashfs_fs_i.h"
 #include "squashfs.h"
+#include "decompressor.h"
  
 static struct file_system_type squashfs_fs_type;
 static const struct super_operations squashfs_super_ops;
  
-static int supported_squashfs_filesystem(short major, short minor, short comp)
+static const struct squashfs_decompressor *supported_squashfs_filesystem(short
+	major, short minor, short id)
 {
+	const struct squashfs_decompressor *decompressor;
+
 	if (major < SQUASHFS_MAJOR) {
 		ERROR("Major/Minor mismatch, older Squashfs %d.%d "
 			"filesystems are unsupported\n", major, minor);
-		return -EINVAL;
+		return NULL;
 	} else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) {
 		ERROR("Major/Minor mismatch, trying to mount newer "
 			"%d.%d filesystem\n", major, minor);
 		ERROR("Please update your kernel\n");
-		return -EINVAL;
+		return NULL;
 	}
  
-	if (comp != ZLIB_COMPRESSION)
-		return -EINVAL;
+	decompressor = squashfs_lookup_decompressor(id);
+	if (!decompressor->supported) {
+		ERROR("Filesystem uses \"%s\" compression. This is not "
+			"supported\n", decompressor->name);
+		return NULL;
+	}
  
-	return 0;
+	return decompressor;
 }
  
  
@@ -86,10 +94,6 @@
 	}
 	msblk = sb->s_fs_info;
  
-	msblk->stream = squashfs_zlib_init();
-	if (msblk->stream == NULL)
-		goto failure;
-
 	sblk = kzalloc(sizeof(*sblk), GFP_KERNEL);
 	if (sblk == NULL) {
 		ERROR("Failed to allocate squashfs_super_block\n");
  
  
  
  
@@ -116,25 +120,25 @@
 		goto failed_mount;
 	}
  
+	err = -EINVAL;
+
 	/* Check it is a SQUASHFS superblock */
 	sb->s_magic = le32_to_cpu(sblk->s_magic);
 	if (sb->s_magic != SQUASHFS_MAGIC) {
 		if (!silent)
 			ERROR("Can't find a SQUASHFS superblock on %s\n",
 						bdevname(sb->s_bdev, b));
-		err = -EINVAL;
 		goto failed_mount;
 	}
  
-	/* Check the MAJOR & MINOR versions and compression type */
-	err = supported_squashfs_filesystem(le16_to_cpu(sblk->s_major),
+	/* Check the MAJOR & MINOR versions and lookup compression type */
+	msblk->decompressor = supported_squashfs_filesystem(
+			le16_to_cpu(sblk->s_major),
 			le16_to_cpu(sblk->s_minor),
 			le16_to_cpu(sblk->compression));
-	if (err < 0)
+	if (msblk->decompressor == NULL)
 		goto failed_mount;
  
-	err = -EINVAL;
-
 	/*
 	 * Check if there's xattrs in the filesystem.  These are not
 	 * supported in this version, so warn that they will be ignored.
@@ -201,6 +205,10 @@
  
 	err = -ENOMEM;
  
+	msblk->stream = squashfs_decompressor_init(msblk);
+	if (msblk->stream == NULL)
+		goto failed_mount;
+
 	msblk->block_cache = squashfs_cache_init("metadata",
 			SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
 	if (msblk->block_cache == NULL)
@@ -288,7 +296,7 @@
 	squashfs_cache_delete(msblk->block_cache);
 	squashfs_cache_delete(msblk->fragment_cache);
 	squashfs_cache_delete(msblk->read_page);
-	squashfs_zlib_free(msblk->stream);
+	squashfs_decompressor_free(msblk, msblk->stream);
 	kfree(msblk->inode_lookup_table);
 	kfree(msblk->fragment_index);
 	kfree(msblk->id_table);
@@ -298,7 +306,6 @@
 	return err;
  
 failure:
-	squashfs_zlib_free(msblk->stream);
 	kfree(sb->s_fs_info);
 	sb->s_fs_info = NULL;
 	return -ENOMEM;
@@ -342,7 +349,7 @@
 		squashfs_cache_delete(sbi->block_cache);
 		squashfs_cache_delete(sbi->fragment_cache);
 		squashfs_cache_delete(sbi->read_page);
-		squashfs_zlib_free(sbi->stream);
+		squashfs_decompressor_free(sbi, sbi->stream);
 		kfree(sbi->id_table);
 		kfree(sbi->fragment_index);
 		kfree(sbi->meta_index);
@@ -30,8 +30,9 @@
 #include "squashfs_fs_sb.h"
 #include "squashfs_fs_i.h"
 #include "squashfs.h"
+#include "decompressor.h"
  
-void *squashfs_zlib_init()
+static void *zlib_init(struct squashfs_sb_info *dummy)
 {
 	z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
 	if (stream == NULL)
@@ -50,7 +51,7 @@
 }
  
  
-void squashfs_zlib_free(void *strm)
+static void zlib_free(void *strm)
 {
 	z_stream *stream = strm;
  
@@ -60,7 +61,7 @@
 }
  
  
-int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
+static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
 	struct buffer_head **bh, int b, int offset, int length, int srclength,
 	int pages)
 {
@@ -137,4 +138,13 @@
  
 	return -EIO;
 }
+
+const struct squashfs_decompressor squashfs_zlib_comp_ops = {
+	.init = zlib_init,
+	.free = zlib_free,
+	.decompress = zlib_uncompress,
+	.id = ZLIB_COMPRESSION,
+	.name = "zlib",
+	.supported = 1
+};
...	...	@@ -4,5 +4,5 @@
4	4
5	5	obj-$(CONFIG_SQUASHFS) += squashfs.o
6	6	squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
7		-squashfs-y += namei.o super.o symlink.o zlib_wrapper.o
	7	+squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o
...	...	@@ -36,6 +36,7 @@
36	36	#include "squashfs_fs_sb.h"
37	37	#include "squashfs_fs_i.h"
38	38	#include "squashfs.h"
	39	+#include "decompressor.h"
39	40
40	41	/*
41	42	* Read the metadata block length, this is stored in the first two
...	...	@@ -151,7 +152,7 @@
151	152	}
152	153
153	154	if (compressed) {
154		- length = squashfs_zlib_uncompress(msblk, buffer, bh, b, offset,
	155	+ length = squashfs_decompress(msblk, buffer, bh, b, offset,
155	156	length, srclength, pages);
156	157	if (length < 0)
157	158	goto read_failure;
	1	+/*
	2	+ * Squashfs - a compressed read only filesystem for Linux
	3	+ *
	4	+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
	5	+ * Phillip Lougher <phillip@lougher.demon.co.uk>
	6	+ *
	7	+ * This program is free software; you can redistribute it and/or
	8	+ * modify it under the terms of the GNU General Public License
	9	+ * as published by the Free Software Foundation; either version 2,
	10	+ * or (at your option) any later version.
	11	+ *
	12	+ * This program is distributed in the hope that it will be useful,
	13	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	+ * GNU General Public License for more details.
	16	+ *
	17	+ * You should have received a copy of the GNU General Public License
	18	+ * along with this program; if not, write to the Free Software
	19	+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	20	+ *
	21	+ * decompressor.c
	22	+ */
	23	+
	24	+#include <linux/types.h>
	25	+#include <linux/mutex.h>
	26	+#include <linux/buffer_head.h>
	27	+
	28	+#include "squashfs_fs.h"
	29	+#include "squashfs_fs_sb.h"
	30	+#include "squashfs_fs_i.h"
	31	+#include "decompressor.h"
	32	+#include "squashfs.h"
	33	+
	34	+/*
	35	+ * This file (and decompressor.h) implements a decompressor framework for
	36	+ * Squashfs, allowing multiple decompressors to be easily supported
	37	+ */
	38	+
	39	+static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
	40	+ NULL, NULL, NULL, 0, "unknown", 0
	41	+};
	42	+
	43	+static const struct squashfs_decompressor *decompressor[] = {
	44	+ &squashfs_zlib_comp_ops,
	45	+ &squashfs_unknown_comp_ops
	46	+};
	47	+
	48	+
	49	+const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
	50	+{
	51	+ int i;
	52	+
	53	+ for (i = 0; decompressor[i]->id; i++)
	54	+ if (id == decompressor[i]->id)
	55	+ break;
	56	+
	57	+ return decompressor[i];
	58	+}
	1	+#ifndef DECOMPRESSOR_H
	2	+#define DECOMPRESSOR_H
	3	+/*
	4	+ * Squashfs - a compressed read only filesystem for Linux
	5	+ *
	6	+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
	7	+ * Phillip Lougher <phillip@lougher.demon.co.uk>
	8	+ *
	9	+ * This program is free software; you can redistribute it and/or
	10	+ * modify it under the terms of the GNU General Public License
	11	+ * as published by the Free Software Foundation; either version 2,
	12	+ * or (at your option) any later version.
	13	+ *
	14	+ * This program is distributed in the hope that it will be useful,
	15	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	+ * GNU General Public License for more details.
	18	+ *
	19	+ * You should have received a copy of the GNU General Public License
	20	+ * along with this program; if not, write to the Free Software
	21	+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	22	+ *
	23	+ * decompressor.h
	24	+ */
	25	+
	26	+struct squashfs_decompressor {
	27	+ void (init)(struct squashfs_sb_info *);
	28	+ void (free)(void );
	29	+ int (decompress)(struct squashfs_sb_info , void **,
	30	+ struct buffer_head **, int, int, int, int, int);
	31	+ int id;
	32	+ char *name;
	33	+ int supported;
	34	+};
	35	+
	36	+static inline void squashfs_decompressor_init(struct squashfs_sb_info msblk)
	37	+{
	38	+ return msblk->decompressor->init(msblk);
	39	+}
	40	+
	41	+static inline void squashfs_decompressor_free(struct squashfs_sb_info *msblk,
	42	+ void *s)
	43	+{
	44	+ if (msblk->decompressor)
	45	+ msblk->decompressor->free(s);
	46	+}
	47	+
	48	+static inline int squashfs_decompress(struct squashfs_sb_info *msblk,
	49	+ void buffer, struct buffer_head bh, int b, int offset, int length,
	50	+ int srclength, int pages)
	51	+{
	52	+ return msblk->decompressor->decompress(msblk, buffer, bh, b, offset,
	53	+ length, srclength, pages);
	54	+}
	55	+#endif
...	...	@@ -51,6 +51,9 @@
51	51	u64, int);
52	52	extern int squashfs_read_table(struct super_block , void , u64, int);
53	53
	54	+/* decompressor.c */
	55	+extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int);
	56	+
54	57	/* export.c */
55	58	extern __le64 squashfs_read_inode_lookup_table(struct super_block , u64,
56	59	unsigned int);
57	60
...	...	@@ -70,14 +73,8 @@
70	73	unsigned int);
71	74	extern int squashfs_read_inode(struct inode *, long long);
72	75
73		-/* zlib_wrapper.c */
74		-extern void *squashfs_zlib_init(void);
75		-extern void squashfs_zlib_free(void *);
76		-extern int squashfs_zlib_uncompress(struct squashfs_sb_info , void *,
77		- struct buffer_head **, int, int, int, int, int);
78		-
79	76	/*
80		- * Inodes and files operations
	77	+ * Inodes, files and decompressor operations
81	78	*/
82	79
83	80	/* dir.c */
...	...	@@ -94,4 +91,7 @@
94	91
95	92	/* symlink.c */
96	93	extern const struct address_space_operations squashfs_symlink_aops;
	94	+
	95	+/* zlib_wrapper.c */
	96	+extern const struct squashfs_decompressor squashfs_zlib_comp_ops;
...	...	@@ -52,26 +52,27 @@
52	52	};
53	53
54	54	struct squashfs_sb_info {
55		- int devblksize;
56		- int devblksize_log2;
57		- struct squashfs_cache *block_cache;
58		- struct squashfs_cache *fragment_cache;
59		- struct squashfs_cache *read_page;
60		- int next_meta_index;
61		- __le64 *id_table;
62		- __le64 *fragment_index;
63		- unsigned int *fragment_index_2;
64		- struct mutex read_data_mutex;
65		- struct mutex meta_index_mutex;
66		- struct meta_index *meta_index;
67		- void *stream;
68		- __le64 *inode_lookup_table;
69		- u64 inode_table;
70		- u64 directory_table;
71		- unsigned int block_size;
72		- unsigned short block_log;
73		- long long bytes_used;
74		- unsigned int inodes;
	55	+ const struct squashfs_decompressor *decompressor;
	56	+ int devblksize;
	57	+ int devblksize_log2;
	58	+ struct squashfs_cache *block_cache;
	59	+ struct squashfs_cache *fragment_cache;
	60	+ struct squashfs_cache *read_page;
	61	+ int next_meta_index;
	62	+ __le64 *id_table;
	63	+ __le64 *fragment_index;
	64	+ unsigned int *fragment_index_2;
	65	+ struct mutex read_data_mutex;
	66	+ struct mutex meta_index_mutex;
	67	+ struct meta_index *meta_index;
	68	+ void *stream;
	69	+ __le64 *inode_lookup_table;
	70	+ u64 inode_table;
	71	+ u64 directory_table;
	72	+ unsigned int block_size;
	73	+ unsigned short block_log;
	74	+ long long bytes_used;
	75	+ unsigned int inodes;
75	76	};
76	77	#endif
...	...	@@ -41,27 +41,35 @@
41	41	#include "squashfs_fs_sb.h"
42	42	#include "squashfs_fs_i.h"
43	43	#include "squashfs.h"
	44	+#include "decompressor.h"
44	45
45	46	static struct file_system_type squashfs_fs_type;
46	47	static const struct super_operations squashfs_super_ops;
47	48
48		-static int supported_squashfs_filesystem(short major, short minor, short comp)
	49	+static const struct squashfs_decompressor *supported_squashfs_filesystem(short
	50	+ major, short minor, short id)
49	51	{
	52	+ const struct squashfs_decompressor *decompressor;
	53	+
50	54	if (major < SQUASHFS_MAJOR) {
51	55	ERROR("Major/Minor mismatch, older Squashfs %d.%d "
52	56	"filesystems are unsupported\n", major, minor);
53		- return -EINVAL;
	57	+ return NULL;
54	58	} else if (major > SQUASHFS_MAJOR \|\| minor > SQUASHFS_MINOR) {
55	59	ERROR("Major/Minor mismatch, trying to mount newer "
56	60	"%d.%d filesystem\n", major, minor);
57	61	ERROR("Please update your kernel\n");
58		- return -EINVAL;
	62	+ return NULL;
59	63	}
60	64
61		- if (comp != ZLIB_COMPRESSION)
62		- return -EINVAL;
	65	+ decompressor = squashfs_lookup_decompressor(id);
	66	+ if (!decompressor->supported) {
	67	+ ERROR("Filesystem uses \"%s\" compression. This is not "
	68	+ "supported\n", decompressor->name);
	69	+ return NULL;
	70	+ }
63	71
64		- return 0;
	72	+ return decompressor;
65	73	}
66	74
67	75
...	...	@@ -86,10 +94,6 @@
86	94	}
87	95	msblk = sb->s_fs_info;
88	96
89		- msblk->stream = squashfs_zlib_init();
90		- if (msblk->stream == NULL)
91		- goto failure;
92		-
93	97	sblk = kzalloc(sizeof(*sblk), GFP_KERNEL);
94	98	if (sblk == NULL) {
95	99	ERROR("Failed to allocate squashfs_super_block\n");
96	100
97	101
98	102
99	103
...	...	@@ -116,25 +120,25 @@
116	120	goto failed_mount;
117	121	}
118	122
	123	+ err = -EINVAL;
	124	+
119	125	/* Check it is a SQUASHFS superblock */
120	126	sb->s_magic = le32_to_cpu(sblk->s_magic);
121	127	if (sb->s_magic != SQUASHFS_MAGIC) {
122	128	if (!silent)
123	129	ERROR("Can't find a SQUASHFS superblock on %s\n",
124	130	bdevname(sb->s_bdev, b));
125		- err = -EINVAL;
126	131	goto failed_mount;
127	132	}
128	133
129		- /* Check the MAJOR & MINOR versions and compression type */
130		- err = supported_squashfs_filesystem(le16_to_cpu(sblk->s_major),
	134	+ /* Check the MAJOR & MINOR versions and lookup compression type */
	135	+ msblk->decompressor = supported_squashfs_filesystem(
	136	+ le16_to_cpu(sblk->s_major),
131	137	le16_to_cpu(sblk->s_minor),
132	138	le16_to_cpu(sblk->compression));
133		- if (err < 0)
	139	+ if (msblk->decompressor == NULL)
134	140	goto failed_mount;
135	141
136		- err = -EINVAL;
137		-
138	142	/*
139	143	* Check if there's xattrs in the filesystem. These are not
140	144	* supported in this version, so warn that they will be ignored.
...	...	@@ -201,6 +205,10 @@
201	205
202	206	err = -ENOMEM;
203	207
	208	+ msblk->stream = squashfs_decompressor_init(msblk);
	209	+ if (msblk->stream == NULL)
	210	+ goto failed_mount;
	211	+
204	212	msblk->block_cache = squashfs_cache_init("metadata",
205	213	SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
206	214	if (msblk->block_cache == NULL)
...	...	@@ -288,7 +296,7 @@
288	296	squashfs_cache_delete(msblk->block_cache);
289	297	squashfs_cache_delete(msblk->fragment_cache);
290	298	squashfs_cache_delete(msblk->read_page);
291		- squashfs_zlib_free(msblk->stream);
	299	+ squashfs_decompressor_free(msblk, msblk->stream);
292	300	kfree(msblk->inode_lookup_table);
293	301	kfree(msblk->fragment_index);
294	302	kfree(msblk->id_table);
...	...	@@ -298,7 +306,6 @@
298	306	return err;
299	307
300	308	failure:
301		- squashfs_zlib_free(msblk->stream);
302	309	kfree(sb->s_fs_info);
303	310	sb->s_fs_info = NULL;
304	311	return -ENOMEM;
...	...	@@ -342,7 +349,7 @@
342	349	squashfs_cache_delete(sbi->block_cache);
343	350	squashfs_cache_delete(sbi->fragment_cache);
344	351	squashfs_cache_delete(sbi->read_page);
345		- squashfs_zlib_free(sbi->stream);
	352	+ squashfs_decompressor_free(sbi, sbi->stream);
346	353	kfree(sbi->id_table);
347	354	kfree(sbi->fragment_index);
348	355	kfree(sbi->meta_index);
...	...	@@ -30,8 +30,9 @@
30	30	#include "squashfs_fs_sb.h"
31	31	#include "squashfs_fs_i.h"
32	32	#include "squashfs.h"
	33	+#include "decompressor.h"
33	34
34		-void *squashfs_zlib_init()
	35	+static void zlib_init(struct squashfs_sb_info dummy)
35	36	{
36	37	z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
37	38	if (stream == NULL)
...	...	@@ -50,7 +51,7 @@
50	51	}
51	52
52	53
53		-void squashfs_zlib_free(void *strm)
	54	+static void zlib_free(void *strm)
54	55	{
55	56	z_stream *stream = strm;
56	57
...	...	@@ -60,7 +61,7 @@
60	61	}
61	62
62	63
63		-int squashfs_zlib_uncompress(struct squashfs_sb_info msblk, void *buffer,
	64	+static int zlib_uncompress(struct squashfs_sb_info msblk, void *buffer,
64	65	struct buffer_head **bh, int b, int offset, int length, int srclength,
65	66	int pages)
66	67	{
...	...	@@ -137,4 +138,13 @@
137	138
138	139	return -EIO;
139	140	}
	141	+
	142	+const struct squashfs_decompressor squashfs_zlib_comp_ops = {
	143	+ .init = zlib_init,
	144	+ .free = zlib_free,
	145	+ .decompress = zlib_uncompress,
	146	+ .id = ZLIB_COMPRESSION,
	147	+ .name = "zlib",
	148	+ .supported = 1
	149	+};