bzip2/lzma: centralize format detection

Centralize the compression format detection to a common routine in the lib directory, and use it for both initramfs and initrd. Signed-off-by: H. Peter Anvin <hpa@zytor.com>

bzip2/lzma: centralize format detection
Centralize the compression format detection to a common routine in the lib directory, and use it for both initramfs and initrd. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
H. Peter Anvin
1 parent 6c11b12ac6
Showing 5 changed files with 72 additions and 67 deletions Side-by-side Diff
include/linux/decompress/generic.h
init/do_mounts_rd.c
init/initramfs.c
lib/Makefile
lib/decompress.c
@@ -26,6 +26,9 @@
  *fill should be called (repeatedly...) to read data, at most IOBUF_SIZE
  */
  
+/* Utility routine to detect the decompression method */
+decompress_fn decompress_method(const unsigned char *inbuf, int len,
+				const char **name);
  
 #endif
@@ -12,9 +12,6 @@
  
 #include <linux/decompress/generic.h>
  
-#include <linux/decompress/bunzip2.h>
-#include <linux/decompress/unlzma.h>
-#include <linux/decompress/inflate.h>
  
 int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */
  
@@ -49,24 +46,6 @@
  *	cramfs
  *	gzip
  */
-static const struct compress_format {
-	unsigned char magic[2];
-	const char *name;
-	decompress_fn decompressor;
-} compressed_formats[] = {
-#ifdef CONFIG_RD_GZIP
-	{ {037, 0213}, "gzip", gunzip },
-	{ {037, 0236}, "gzip", gunzip },
-#endif
-#ifdef CONFIG_RD_BZIP2
-	{ {0x42, 0x5a}, "bzip2", bunzip2 },
-#endif
-#ifdef CONFIG_RD_LZMA
-	{ {0x5d, 0x00}, "lzma", unlzma },
-#endif
-	{ {0, 0}, NULL, NULL }
-};
-
 static int __init
 identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor)
 {
@@ -77,7 +56,7 @@
 	struct cramfs_super *cramfsb;
 	int nblocks = -1;
 	unsigned char *buf;
-	const struct compress_format *cf;
+	const char *compress_name;
  
 	buf = kmalloc(size, GFP_KERNEL);
 	if (!buf)
@@ -95,15 +74,12 @@
 	sys_lseek(fd, start_block * BLOCK_SIZE, 0);
 	sys_read(fd, buf, size);
  
-	for (cf = compressed_formats; cf->decompressor; cf++) {
-		if (buf[0] == cf->magic[0] && buf[1] == cf->magic[1]) {
-			printk(KERN_NOTICE
-			       "RAMDISK: %s image found at block %d\n",
-			       cf->name, start_block);
-			*decompressor = cf->decompressor;
-			nblocks = 0;
-			goto done;
-		}
+	*decompressor = decompress_method(buf, size, &compress_name);
+	if (*decompressor) {
+		printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
+		       compress_name, start_block);
+		nblocks = 0;
+		goto done;
 	}
  
 	/* romfs is at block zero too */
@@ -416,13 +416,13 @@
  
 static unsigned my_inptr;   /* index of next byte to be processed in inbuf */
  
-#include <linux/decompress/bunzip2.h>
-#include <linux/decompress/unlzma.h>
-#include <linux/decompress/inflate.h>
+#include <linux/decompress/generic.h>
  
 static char * __init unpack_to_rootfs(char *buf, unsigned len, int check_only)
 {
 	int written;
+	decompress_fn decompress;
+
 	dry_run = check_only;
 	header_buf = kmalloc(110, GFP_KERNEL);
 	symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
@@ -450,35 +450,10 @@
 			continue;
 		}
 		this_header = 0;
-#ifdef CONFIG_RD_GZIP
-		if (!gunzip(buf, len, NULL, flush_buffer, NULL,
-			    &my_inptr, error) &&
-		    message == NULL)
-			goto ok;
-#endif
-
-#ifdef CONFIG_RD_BZIP2
-		message = NULL; /* Zero out message, or else cpio will
-				   think an error has already occured */
-		if (!bunzip2(buf, len, NULL, flush_buffer, NULL,
-			     &my_inptr, error) &&
-		    message == NULL) {
-			goto ok;
-		}
-#endif
-
-#ifdef CONFIG_RD_LZMA
-		message = NULL; /* Zero out message, or else cpio will
-				   think an error has already occured */
-		if (!unlzma(buf, len, NULL, flush_buffer, NULL,
-			    &my_inptr, error) &&
-		    message == NULL) {
-			goto ok;
-		}
-#endif
-#if defined CONFIG_RD_GZIP || defined CONFIG_RD_BZIP2 || defined CONFIG_RD_LZMA
-ok:
-#endif
+		decompress = decompress_method(buf, len, NULL);
+		if (decompress)
+			decompress(buf, len, NULL, flush_buffer, NULL,
+				   &my_inptr, error);
 		if (state != Reset)
 			error("junk in compressed archive");
 		this_header = saved_offset + my_inptr;
@@ -11,7 +11,8 @@
 	 rbtree.o radix-tree.o dump_stack.o \
 	 idr.o int_sqrt.o extable.o prio_tree.o \
 	 sha1.o irq_regs.o reciprocal_div.o argv_split.o \
-	 proportions.o prio_heap.o ratelimit.o show_mem.o is_single_threaded.o
+	 proportions.o prio_heap.o ratelimit.o show_mem.o \
+	 is_single_threaded.o decompress.o
  
 lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
@@ -65,9 +66,9 @@
 obj-$(CONFIG_LZO_COMPRESS) += lzo/
 obj-$(CONFIG_LZO_DECOMPRESS) += lzo/
  
-obj-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
-obj-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
-obj-$(CONFIG_DECOMPRESS_LZMA) += decompress_unlzma.o
+lib-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
+lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
+lib-$(CONFIG_DECOMPRESS_LZMA) += decompress_unlzma.o
  
 obj-$(CONFIG_TEXTSEARCH) += textsearch.o
 obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o
+/*
+ * decompress.c
+ *
+ * Detect the decompression method based on magic number
+ */
+
+#include <linux/decompress/generic.h>
+
+#include <linux/decompress/bunzip2.h>
+#include <linux/decompress/unlzma.h>
+#include <linux/decompress/inflate.h>
+
+#include <linux/types.h>
+#include <linux/string.h>
+
+static const struct compress_format {
+	unsigned char magic[2];
+	const char *name;
+	decompress_fn decompressor;
+} compressed_formats[] = {
+#ifdef CONFIG_DECOMPRESS_GZIP
+	{ {037, 0213}, "gzip", gunzip },
+	{ {037, 0236}, "gzip", gunzip },
+#endif
+#ifdef CONFIG_DECOMPRESS_BZIP2
+	{ {0x42, 0x5a}, "bzip2", bunzip2 },
+#endif
+#ifdef CONFIG_DECOMPRESS_LZMA
+	{ {0x5d, 0x00}, "lzma", unlzma },
+#endif
+	{ {0, 0}, NULL, NULL }
+};
+
+decompress_fn decompress_method(const unsigned char *inbuf, int len,
+				const char **name)
+{
+	const struct compress_format *cf;
+
+	if (len < 2)
+		return NULL;	/* Need at least this much... */
+
+	for (cf = compressed_formats; cf->decompressor; cf++) {
+		if (!memcmp(inbuf, cf->magic, 2))
+			break;
+
+	}
+	if (name)
+		*name = cf->name;
+	return cf->decompressor;
+}
...	...	@@ -26,6 +26,9 @@
26	26	*fill should be called (repeatedly...) to read data, at most IOBUF_SIZE
27	27	*/
28	28
	29	+/* Utility routine to detect the decompression method */
	30	+decompress_fn decompress_method(const unsigned char *inbuf, int len,
	31	+ const char **name);
29	32
30	33	#endif
...	...	@@ -12,9 +12,6 @@
12	12
13	13	#include <linux/decompress/generic.h>
14	14
15		-#include <linux/decompress/bunzip2.h>
16		-#include <linux/decompress/unlzma.h>
17		-#include <linux/decompress/inflate.h>
18	15
19	16	int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */
20	17
...	...	@@ -49,24 +46,6 @@
49	46	* cramfs
50	47	* gzip
51	48	*/
52		-static const struct compress_format {
53		- unsigned char magic[2];
54		- const char *name;
55		- decompress_fn decompressor;
56		-} compressed_formats[] = {
57		-#ifdef CONFIG_RD_GZIP
58		- { {037, 0213}, "gzip", gunzip },
59		- { {037, 0236}, "gzip", gunzip },
60		-#endif
61		-#ifdef CONFIG_RD_BZIP2
62		- { {0x42, 0x5a}, "bzip2", bunzip2 },
63		-#endif
64		-#ifdef CONFIG_RD_LZMA
65		- { {0x5d, 0x00}, "lzma", unlzma },
66		-#endif
67		- { {0, 0}, NULL, NULL }
68		-};
69		-
70	49	static int __init
71	50	identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor)
72	51	{
...	...	@@ -77,7 +56,7 @@
77	56	struct cramfs_super *cramfsb;
78	57	int nblocks = -1;
79	58	unsigned char *buf;
80		- const struct compress_format *cf;
	59	+ const char *compress_name;
81	60
82	61	buf = kmalloc(size, GFP_KERNEL);
83	62	if (!buf)
...	...	@@ -95,15 +74,12 @@
95	74	sys_lseek(fd, start_block * BLOCK_SIZE, 0);
96	75	sys_read(fd, buf, size);
97	76
98		- for (cf = compressed_formats; cf->decompressor; cf++) {
99		- if (buf[0] == cf->magic[0] && buf[1] == cf->magic[1]) {
100		- printk(KERN_NOTICE
101		- "RAMDISK: %s image found at block %d\n",
102		- cf->name, start_block);
103		- *decompressor = cf->decompressor;
104		- nblocks = 0;
105		- goto done;
106		- }
	77	+ *decompressor = decompress_method(buf, size, &compress_name);
	78	+ if (*decompressor) {
	79	+ printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
	80	+ compress_name, start_block);
	81	+ nblocks = 0;
	82	+ goto done;
107	83	}
108	84
109	85	/* romfs is at block zero too */
...	...	@@ -416,13 +416,13 @@
416	416
417	417	static unsigned my_inptr; /* index of next byte to be processed in inbuf */
418	418
419		-#include <linux/decompress/bunzip2.h>
420		-#include <linux/decompress/unlzma.h>
421		-#include <linux/decompress/inflate.h>
	419	+#include <linux/decompress/generic.h>
422	420
423	421	static char * __init unpack_to_rootfs(char *buf, unsigned len, int check_only)
424	422	{
425	423	int written;
	424	+ decompress_fn decompress;
	425	+
426	426	dry_run = check_only;
427	427	header_buf = kmalloc(110, GFP_KERNEL);
428	428	symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
...	...	@@ -450,35 +450,10 @@
450	450	continue;
451	451	}
452	452	this_header = 0;
453		-#ifdef CONFIG_RD_GZIP
454		- if (!gunzip(buf, len, NULL, flush_buffer, NULL,
455		- &my_inptr, error) &&
456		- message == NULL)
457		- goto ok;
458		-#endif
459		-
460		-#ifdef CONFIG_RD_BZIP2
461		- message = NULL; /* Zero out message, or else cpio will
462		- think an error has already occured */
463		- if (!bunzip2(buf, len, NULL, flush_buffer, NULL,
464		- &my_inptr, error) &&
465		- message == NULL) {
466		- goto ok;
467		- }
468		-#endif
469		-
470		-#ifdef CONFIG_RD_LZMA
471		- message = NULL; /* Zero out message, or else cpio will
472		- think an error has already occured */
473		- if (!unlzma(buf, len, NULL, flush_buffer, NULL,
474		- &my_inptr, error) &&
475		- message == NULL) {
476		- goto ok;
477		- }
478		-#endif
479		-#if defined CONFIG_RD_GZIP \|\| defined CONFIG_RD_BZIP2 \|\| defined CONFIG_RD_LZMA
480		-ok:
481		-#endif
	453	+ decompress = decompress_method(buf, len, NULL);
	454	+ if (decompress)
	455	+ decompress(buf, len, NULL, flush_buffer, NULL,
	456	+ &my_inptr, error);
482	457	if (state != Reset)
483	458	error("junk in compressed archive");
484	459	this_header = saved_offset + my_inptr;
...	...	@@ -11,7 +11,8 @@
11	11	rbtree.o radix-tree.o dump_stack.o \
12	12	idr.o int_sqrt.o extable.o prio_tree.o \
13	13	sha1.o irq_regs.o reciprocal_div.o argv_split.o \
14		- proportions.o prio_heap.o ratelimit.o show_mem.o is_single_threaded.o
	14	+ proportions.o prio_heap.o ratelimit.o show_mem.o \
	15	+ is_single_threaded.o decompress.o
15	16
16	17	lib-$(CONFIG_MMU) += ioremap.o
17	18	lib-$(CONFIG_SMP) += cpumask.o
...	...	@@ -65,9 +66,9 @@
65	66	obj-$(CONFIG_LZO_COMPRESS) += lzo/
66	67	obj-$(CONFIG_LZO_DECOMPRESS) += lzo/
67	68
68		-obj-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
69		-obj-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
70		-obj-$(CONFIG_DECOMPRESS_LZMA) += decompress_unlzma.o
	69	+lib-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
	70	+lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
	71	+lib-$(CONFIG_DECOMPRESS_LZMA) += decompress_unlzma.o
71	72
72	73	obj-$(CONFIG_TEXTSEARCH) += textsearch.o
73	74	obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o
	1	+/*
	2	+ * decompress.c
	3	+ *
	4	+ * Detect the decompression method based on magic number
	5	+ */
	6	+
	7	+#include <linux/decompress/generic.h>
	8	+
	9	+#include <linux/decompress/bunzip2.h>
	10	+#include <linux/decompress/unlzma.h>
	11	+#include <linux/decompress/inflate.h>
	12	+
	13	+#include <linux/types.h>
	14	+#include <linux/string.h>
	15	+
	16	+static const struct compress_format {
	17	+ unsigned char magic[2];
	18	+ const char *name;
	19	+ decompress_fn decompressor;
	20	+} compressed_formats[] = {
	21	+#ifdef CONFIG_DECOMPRESS_GZIP
	22	+ { {037, 0213}, "gzip", gunzip },
	23	+ { {037, 0236}, "gzip", gunzip },
	24	+#endif
	25	+#ifdef CONFIG_DECOMPRESS_BZIP2
	26	+ { {0x42, 0x5a}, "bzip2", bunzip2 },
	27	+#endif
	28	+#ifdef CONFIG_DECOMPRESS_LZMA
	29	+ { {0x5d, 0x00}, "lzma", unlzma },
	30	+#endif
	31	+ { {0, 0}, NULL, NULL }
	32	+};
	33	+
	34	+decompress_fn decompress_method(const unsigned char *inbuf, int len,
	35	+ const char **name)
	36	+{
	37	+ const struct compress_format *cf;
	38	+
	39	+ if (len < 2)
	40	+ return NULL; /* Need at least this much... */
	41	+
	42	+ for (cf = compressed_formats; cf->decompressor; cf++) {
	43	+ if (!memcmp(inbuf, cf->magic, 2))
	44	+ break;
	45	+
	46	+ }
	47	+ if (name)
	48	+ *name = cf->name;
	49	+ return cf->decompressor;
	50	+}