initramfs: support initramfs that is bigger than 2GiB

Now with 64bit bzImage and kexec tools, we support ramdisk that size is
bigger than 2g, as we could put it above 4G.

Found compressed initramfs image could not be decompressed properly.  It
turns out that image length is int during decompress detection, and it
will become < 0 when length is more than 2G.  Furthermore, during
decompressing len as int is used for inbuf count, that has problem too.

Change len to long, that should be ok as on 32 bit platform long is
32bits.

Tested with following compressed initramfs image as root with kexec.
	gzip, bzip2, xz, lzma, lzop, lz4.
run time for populate_rootfs():
   size        name       Nehalem-EX  Westmere-EX  Ivybridge-EX
 9034400256 root_img     :   26s           24s          30s
 3561095057 root_img.lz4 :   28s           27s          27s
 3459554629 root_img.lzo :   29s           29s          28s
 3219399480 root_img.gz  :   64s           62s          49s
 2251594592 root_img.xz  :  262s          260s         183s
 2226366598 root_img.lzma:  386s          376s         277s
 2901482513 root_img.bz2 :  635s          599s

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rashika Kheria <rashika.kheria@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: P J P <ppandit@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: "Daniel M. Weeks" <dan@danweeks.net>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 11 deletions

diff --git a/init/initramfs.c b/init/initramfs.c
index 4f276b6a167b..a7566031242e 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -197,7 +197,7 @@ static __initdata enum state {
 } state, next_state;
 
 static __initdata char *victim;
-static __initdata unsigned count;
+static unsigned long count __initdata;
 static __initdata loff_t this_header, next_header;
 
 static inline void __init eat(unsigned n)
@@ -209,7 +209,7 @@ static inline void __init eat(unsigned n)
 
 static __initdata char *vcollected;
 static __initdata char *collected;
-static __initdata int remains;
+static long remains __initdata;
 static __initdata char *collect;
 
 static void __init read_into(char *buf, unsigned size, enum state next)
@@ -236,7 +236,7 @@ static int __init do_start(void)
 
 static int __init do_collect(void)
 {
-	unsigned n = remains;
+	unsigned long n = remains;
 	if (count < n)
 		n = count;
 	memcpy(collect, victim, n);
@@ -407,7 +407,7 @@ static __initdata int (*actions[])(void) = {
 	[Reset]		= do_reset,
 };
 
-static int __init write_buffer(char *buf, unsigned len)
+static long __init write_buffer(char *buf, unsigned long len)
 {
 	count = len;
 	victim = buf;
@@ -417,11 +417,11 @@ static int __init write_buffer(char *buf, unsigned len)
 	return len - count;
 }
 
-static int __init flush_buffer(void *bufv, unsigned len)
+static long __init flush_buffer(void *bufv, unsigned long len)
 {
 	char *buf = (char *) bufv;
-	int written;
-	int origLen = len;
+	long written;
+	long origLen = len;
 	if (message)
 		return -1;
 	while ((written = write_buffer(buf, len)) < len && !message) {
@@ -440,13 +440,13 @@ static int __init flush_buffer(void *bufv, unsigned len)
 	return origLen;
 }
 
-static unsigned my_inptr;   /* index of next byte to be processed in inbuf */
+static unsigned long my_inptr; /* index of next byte to be processed in inbuf */
 
 #include <linux/decompress/generic.h>
 
-static char * __init unpack_to_rootfs(char *buf, unsigned len)
+static char * __init unpack_to_rootfs(char *buf, unsigned long len)
 {
-	int written, res;
+	long written;
 	decompress_fn decompress;
 	const char *compress_name;
 	static __initdata char msg_buf[64];
@@ -480,7 +480,7 @@ static char * __init unpack_to_rootfs(char *buf, unsigned len)
 		decompress = decompress_method(buf, len, &compress_name);
 		pr_debug("Detected %s compressed data\n", compress_name);
 		if (decompress) {
-			res = decompress(buf, len, NULL, flush_buffer, NULL,
+			int res = decompress(buf, len, NULL, flush_buffer, NULL,
 				   &my_inptr, error);
 			if (res)
 				error("decompressor failed");