Squashfs: extend decompressor framework to handle compression options

Extend decompressor framework to handle compression options stored in the filesystem. These options can be used by the relevant decompressor at initialisation time to over-ride defaults. The presence of compression options in the filesystem is indicated by the COMP_OPT filesystem flag. If present the data is read from the filesystem and passed to the decompressor init function. The decompressor init function signature has been extended to take this data. Also update the init function signature in the glib, lzo and xz decompressor wrappers. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

Squashfs: extend decompressor framework to handle compression options
Extend decompressor framework to handle compression options stored in the filesystem. These options can be used by the relevant decompressor at initialisation time to over-ride defaults. The presence of compression options in the filesystem is indicated by the COMP_OPT filesystem flag. If present the data is read from the filesystem and passed to the decompressor init function. The decompressor init function signature has been extended to take this data. Also update the init function signature in the glib, lzo and xz decompressor wrappers. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Phillip Lougher
1 parent 100b33c8bd
Showing 8 changed files with 54 additions and 16 deletions Side-by-side Diff
fs/squashfs/decompressor.c
fs/squashfs/decompressor.h
fs/squashfs/lzo_wrapper.c
fs/squashfs/squashfs.h
fs/squashfs/squashfs_fs.h
fs/squashfs/super.c
fs/squashfs/xz_wrapper.c
fs/squashfs/zlib_wrapper.c
@@ -23,6 +23,7 @@
  
 #include <linux/types.h>
 #include <linux/mutex.h>
+#include <linux/slab.h>
 #include <linux/buffer_head.h>
  
 #include "squashfs_fs.h"
@@ -73,5 +74,38 @@
 			break;
  
 	return decompressor[i];
+}
+
+
+void *squashfs_decompressor_init(struct super_block *sb, unsigned short flags)
+{
+	struct squashfs_sb_info *msblk = sb->s_fs_info;
+	void *strm, *buffer = NULL;
+	int length = 0;
+
+	/*
+	 * Read decompressor specific options from file system if present
+	 */
+	if (SQUASHFS_COMP_OPTS(flags)) {
+		buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
+		if (buffer == NULL)
+			return ERR_PTR(-ENOMEM);
+
+		length = squashfs_read_data(sb, &buffer,
+			sizeof(struct squashfs_super_block), 0, NULL,
+			PAGE_CACHE_SIZE, 1);
+
+		if (length < 0) {
+			strm = ERR_PTR(length);
+			goto finished;
+		}
+	}
+
+	strm = msblk->decompressor->init(msblk, buffer, length);
+
+finished:
+	kfree(buffer);
+
+	return strm;
 }
@@ -24,7 +24,7 @@
  */
  
 struct squashfs_decompressor {
-	void	*(*init)(struct squashfs_sb_info *);
+	void	*(*init)(struct squashfs_sb_info *, void *, int);
 	void	(*free)(void *);
 	int	(*decompress)(struct squashfs_sb_info *, void **,
 		struct buffer_head **, int, int, int, int, int);
@@ -32,11 +32,6 @@
 	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)
@@ -37,7 +37,7 @@
 	void	*output;
 };
  
-static void *lzo_init(struct squashfs_sb_info *msblk)
+static void *lzo_init(struct squashfs_sb_info *msblk, void *buff, int len)
 {
 	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
  
@@ -58,7 +58,7 @@
 failed:
 	ERROR("Failed to allocate lzo workspace\n");
 	kfree(stream);
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }
  
  
@@ -48,6 +48,7 @@
  
 /* decompressor.c */
 extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int);
+extern void *squashfs_decompressor_init(struct super_block *, unsigned short);
  
 /* export.c */
 extern __le64 *squashfs_read_inode_lookup_table(struct super_block *, u64,
@@ -57,6 +57,7 @@
 #define SQUASHFS_ALWAYS_FRAG		5
 #define SQUASHFS_DUPLICATE		6
 #define SQUASHFS_EXPORT			7
+#define SQUASHFS_COMP_OPT		10
  
 #define SQUASHFS_BIT(flag, bit)		((flag >> bit) & 1)
  
@@ -80,6 +81,9 @@
  
 #define SQUASHFS_EXPORTABLE(flags)		SQUASHFS_BIT(flags, \
 						SQUASHFS_EXPORT)
+
+#define SQUASHFS_COMP_OPTS(flags)		SQUASHFS_BIT(flags, \
+						SQUASHFS_COMP_OPT)
  
 /* Max number of types and file types */
 #define SQUASHFS_DIR_TYPE		1
@@ -199,10 +199,6 @@
  
 	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)
@@ -212,6 +208,13 @@
 	msblk->read_page = squashfs_cache_init("data", 1, msblk->block_size);
 	if (msblk->read_page == NULL) {
 		ERROR("Failed to allocate read_page block\n");
+		goto failed_mount;
+	}
+
+	msblk->stream = squashfs_decompressor_init(sb, flags);
+	if (IS_ERR(msblk->stream)) {
+		err = PTR_ERR(msblk->stream);
+		msblk->stream = NULL;
 		goto failed_mount;
 	}
  
@@ -38,7 +38,8 @@
 	struct xz_buf buf;
 };
  
-static void *squashfs_xz_init(struct squashfs_sb_info *msblk)
+static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff,
+	int len)
 {
 	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
  
@@ -55,7 +56,7 @@
 failed:
 	ERROR("Failed to allocate xz workspace\n");
 	kfree(stream);
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }
  
  
@@ -32,7 +32,7 @@
 #include "squashfs.h"
 #include "decompressor.h"
  
-static void *zlib_init(struct squashfs_sb_info *dummy)
+static void *zlib_init(struct squashfs_sb_info *dummy, void *buff, int len)
 {
 	z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
 	if (stream == NULL)
@@ -47,7 +47,7 @@
 failed:
 	ERROR("Failed to allocate zlib workspace\n");
 	kfree(stream);
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }
...	...	@@ -23,6 +23,7 @@
23	23
24	24	#include <linux/types.h>
25	25	#include <linux/mutex.h>
	26	+#include <linux/slab.h>
26	27	#include <linux/buffer_head.h>
27	28
28	29	#include "squashfs_fs.h"
...	...	@@ -73,5 +74,38 @@
73	74	break;
74	75
75	76	return decompressor[i];
	77	+}
	78	+
	79	+
	80	+void squashfs_decompressor_init(struct super_block sb, unsigned short flags)
	81	+{
	82	+ struct squashfs_sb_info *msblk = sb->s_fs_info;
	83	+ void strm, buffer = NULL;
	84	+ int length = 0;
	85	+
	86	+ /*
	87	+ * Read decompressor specific options from file system if present
	88	+ */
	89	+ if (SQUASHFS_COMP_OPTS(flags)) {
	90	+ buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
	91	+ if (buffer == NULL)
	92	+ return ERR_PTR(-ENOMEM);
	93	+
	94	+ length = squashfs_read_data(sb, &buffer,
	95	+ sizeof(struct squashfs_super_block), 0, NULL,
	96	+ PAGE_CACHE_SIZE, 1);
	97	+
	98	+ if (length < 0) {
	99	+ strm = ERR_PTR(length);
	100	+ goto finished;
	101	+ }
	102	+ }
	103	+
	104	+ strm = msblk->decompressor->init(msblk, buffer, length);
	105	+
	106	+finished:
	107	+ kfree(buffer);
	108	+
	109	+ return strm;
76	110	}
...	...	@@ -24,7 +24,7 @@
24	24	*/
25	25
26	26	struct squashfs_decompressor {
27		- void (init)(struct squashfs_sb_info *);
	27	+ void (init)(struct squashfs_sb_info , void , int);
28	28	void (free)(void );
29	29	int (decompress)(struct squashfs_sb_info , void **,
30	30	struct buffer_head **, int, int, int, int, int);
...	...	@@ -32,11 +32,6 @@
32	32	char *name;
33	33	int supported;
34	34	};
35		-
36		-static inline void squashfs_decompressor_init(struct squashfs_sb_info msblk)
37		-{
38		- return msblk->decompressor->init(msblk);
39		-}
40	35
41	36	static inline void squashfs_decompressor_free(struct squashfs_sb_info *msblk,
42	37	void *s)
...	...	@@ -37,7 +37,7 @@
37	37	void *output;
38	38	};
39	39
40		-static void lzo_init(struct squashfs_sb_info msblk)
	40	+static void lzo_init(struct squashfs_sb_info msblk, void *buff, int len)
41	41	{
42	42	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
43	43
...	...	@@ -58,7 +58,7 @@
58	58	failed:
59	59	ERROR("Failed to allocate lzo workspace\n");
60	60	kfree(stream);
61		- return NULL;
	61	+ return ERR_PTR(-ENOMEM);
62	62	}
63	63
64	64
...	...	@@ -48,6 +48,7 @@
48	48
49	49	/* decompressor.c */
50	50	extern const struct squashfs_decompressor *squashfs_lookup_decompressor(int);
	51	+extern void squashfs_decompressor_init(struct super_block , unsigned short);
51	52
52	53	/* export.c */
53	54	extern __le64 squashfs_read_inode_lookup_table(struct super_block , u64,
...	...	@@ -57,6 +57,7 @@
57	57	#define SQUASHFS_ALWAYS_FRAG 5
58	58	#define SQUASHFS_DUPLICATE 6
59	59	#define SQUASHFS_EXPORT 7
	60	+#define SQUASHFS_COMP_OPT 10
60	61
61	62	#define SQUASHFS_BIT(flag, bit) ((flag >> bit) & 1)
62	63
...	...	@@ -80,6 +81,9 @@
80	81
81	82	#define SQUASHFS_EXPORTABLE(flags) SQUASHFS_BIT(flags, \
82	83	SQUASHFS_EXPORT)
	84	+
	85	+#define SQUASHFS_COMP_OPTS(flags) SQUASHFS_BIT(flags, \
	86	+ SQUASHFS_COMP_OPT)
83	87
84	88	/* Max number of types and file types */
85	89	#define SQUASHFS_DIR_TYPE 1
...	...	@@ -199,10 +199,6 @@
199	199
200	200	err = -ENOMEM;
201	201
202		- msblk->stream = squashfs_decompressor_init(msblk);
203		- if (msblk->stream == NULL)
204		- goto failed_mount;
205		-
206	202	msblk->block_cache = squashfs_cache_init("metadata",
207	203	SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
208	204	if (msblk->block_cache == NULL)
...	...	@@ -212,6 +208,13 @@
212	208	msblk->read_page = squashfs_cache_init("data", 1, msblk->block_size);
213	209	if (msblk->read_page == NULL) {
214	210	ERROR("Failed to allocate read_page block\n");
	211	+ goto failed_mount;
	212	+ }
	213	+
	214	+ msblk->stream = squashfs_decompressor_init(sb, flags);
	215	+ if (IS_ERR(msblk->stream)) {
	216	+ err = PTR_ERR(msblk->stream);
	217	+ msblk->stream = NULL;
215	218	goto failed_mount;
216	219	}
217	220
...	...	@@ -38,7 +38,8 @@
38	38	struct xz_buf buf;
39	39	};
40	40
41		-static void squashfs_xz_init(struct squashfs_sb_info msblk)
	41	+static void squashfs_xz_init(struct squashfs_sb_info msblk, void *buff,
	42	+ int len)
42	43	{
43	44	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
44	45
...	...	@@ -55,7 +56,7 @@
55	56	failed:
56	57	ERROR("Failed to allocate xz workspace\n");
57	58	kfree(stream);
58		- return NULL;
	59	+ return ERR_PTR(-ENOMEM);
59	60	}
60	61
61	62
...	...	@@ -32,7 +32,7 @@
32	32	#include "squashfs.h"
33	33	#include "decompressor.h"
34	34
35		-static void zlib_init(struct squashfs_sb_info dummy)
	35	+static void zlib_init(struct squashfs_sb_info dummy, void *buff, int len)
36	36	{
37	37	z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
38	38	if (stream == NULL)
...	...	@@ -47,7 +47,7 @@
47	47	failed:
48	48	ERROR("Failed to allocate zlib workspace\n");
49	49	kfree(stream);
50		- return NULL;
	50	+ return ERR_PTR(-ENOMEM);
51	51	}
52	52
53	53