001-squashfs.patch

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Index: linux-2.6.21.7/fs/Kconfig
===================================================================
--- linux-2.6.21.7.orig/fs/Kconfig
+++ linux-2.6.21.7/fs/Kconfig
@@ -1371,6 +1371,71 @@ config CRAMFS
 
 	  If unsure, say N.
 
+config SQUASHFS
+	tristate "SquashFS 3.0 - Squashed file system support"
+	select ZLIB_INFLATE
+	help
+	  Saying Y here includes support for SquashFS 3.0 (a Compressed Read-Only File
+	  System).  Squashfs is a highly compressed read-only filesystem for Linux.
+	  It uses zlib compression to compress both files, inodes and directories.
+	  Inodes in the system are very small and all blocks are packed to minimise
+	  data overhead. Block sizes greater than 4K are supported up to a maximum of 64K.
+	  SquashFS 3.0 supports 64 bit filesystems and files (larger than 4GB), full
+	  uid/gid information, hard links and timestamps.
+
+	  Squashfs is intended for general read-only filesystem use, for archival
+	  use (i.e. in cases where a .tar.gz file may be used), and in embedded
+	  systems where low overhead is needed.  Further information and filesystem tools
+	  are available from http://squashfs.sourceforge.net.
+
+	  If you want to compile this as a module ( = code which can be
+	  inserted in and removed from the running kernel whenever you want),
+	  say M here and read <file:Documentation/modules.txt>.  The module
+	  will be called squashfs.  Note that the root file system (the one
+	  containing the directory /) cannot be compiled as a module.
+
+	  If unsure, say N.
+
+config SQUASHFS_EMBEDDED
+
+	bool "Additional options for memory-constrained systems"
+	depends on SQUASHFS
+	default n
+	help
+	  Saying Y here allows you to specify cache sizes and how Squashfs
+	  allocates memory.  This is only intended for memory constrained
+	  systems.
+
+	  If unsure, say N.
+
+config SQUASHFS_FRAGMENT_CACHE_SIZE
+	int "Number of fragments cached" if SQUASHFS_EMBEDDED
+	depends on SQUASHFS
+	default "3"
+	help
+	  By default SquashFS caches the last 3 fragments read from
+	  the filesystem.  Increasing this amount may mean SquashFS
+	  has to re-read fragments less often from disk, at the expense
+	  of extra system memory.  Decreasing this amount will mean
+	  SquashFS uses less memory at the expense of extra reads from disk.
+
+	  Note there must be at least one cached fragment.  Anything
+	  much more than three will probably not make much difference.
+
+config SQUASHFS_VMALLOC
+	bool "Use Vmalloc rather than Kmalloc" if SQUASHFS_EMBEDDED
+	depends on SQUASHFS
+	default n
+	help
+	  By default SquashFS uses kmalloc to obtain fragment cache memory.
+	  Kmalloc memory is the standard kernel allocator, but it can fail
+	  on memory constrained systems.  Because of the way Vmalloc works,
+	  Vmalloc can succeed when kmalloc fails.  Specifying this option
+	  will make SquashFS always use Vmalloc to allocate the
+	  fragment cache memory.
+
+	  If unsure, say N.
+
 config VXFS_FS
 	tristate "FreeVxFS file system support (VERITAS VxFS(TM) compatible)"
 	depends on BLOCK
Index: linux-2.6.21.7/fs/Makefile
===================================================================
--- linux-2.6.21.7.orig/fs/Makefile
+++ linux-2.6.21.7/fs/Makefile
@@ -68,6 +68,7 @@ obj-$(CONFIG_JBD)		+= jbd/
 obj-$(CONFIG_JBD2)		+= jbd2/
 obj-$(CONFIG_EXT2_FS)		+= ext2/
 obj-$(CONFIG_CRAMFS)		+= cramfs/
+obj-$(CONFIG_SQUASHFS)		+= squashfs/
 obj-$(CONFIG_RAMFS)		+= ramfs/
 obj-$(CONFIG_HUGETLBFS)		+= hugetlbfs/
 obj-$(CONFIG_CODA_FS)		+= coda/
Index: linux-2.6.21.7/fs/squashfs/inode.c
===================================================================
--- /dev/null
+++ linux-2.6.21.7/fs/squashfs/inode.c
@@ -0,0 +1,2124 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006
+ * Phillip Lougher <[e-mail]>
+ *
+ * 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * inode.c
+ */
+
+#include <linux/types.h>
+#include <linux/squashfs_fs.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/slab.h>
+#include <linux/squashfs_fs_sb.h>
+#include <linux/squashfs_fs_i.h>
+#include <linux/buffer_head.h>
+#include <linux/vfs.h>
+#include <linux/init.h>
+#include <linux/dcache.h>
+#include <linux/wait.h>
+#include <linux/zlib.h>
+#include <linux/blkdev.h>
+#include <linux/vmalloc.h>
+#include <asm/uaccess.h>
+#include <asm/semaphore.h>
+
+#include "squashfs.h"
+
+static void squashfs_put_super(struct super_block *);
+static int squashfs_statfs(struct dentry *, struct kstatfs *);
+static int squashfs_symlink_readpage(struct file *file, struct page *page);
+static int squashfs_readpage(struct file *file, struct page *page);
+static int squashfs_readpage4K(struct file *file, struct page *page);
+static int squashfs_readdir(struct file *, void *, filldir_t);
+static struct inode *squashfs_alloc_inode(struct super_block *sb);
+static void squashfs_destroy_inode(struct inode *inode);
+static int init_inodecache(void);
+static void destroy_inodecache(void);
+static struct dentry *squashfs_lookup(struct inode *, struct dentry *,
+				struct nameidata *);
+static struct inode *squashfs_iget(struct super_block *s, squashfs_inode_t inode);
+static long long read_blocklist(struct inode *inode, int index,
+				int readahead_blks, char *block_list,
+				unsigned short **block_p, unsigned int *bsize);
+static int squashfs_get_sb(struct file_system_type *, int,
+			const char *, void *, struct vfsmount *);
+
+
+static z_stream stream;
+
+static struct file_system_type squashfs_fs_type = {
+	.owner = THIS_MODULE,
+	.name = "squashfs",
+	.get_sb = squashfs_get_sb,
+	.kill_sb = kill_block_super,
+	.fs_flags = FS_REQUIRES_DEV
+};
+
+static unsigned char squashfs_filetype_table[] = {
+	DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_FIFO, DT_SOCK
+};
+
+static struct super_operations squashfs_ops = {
+	.alloc_inode = squashfs_alloc_inode,
+	.destroy_inode = squashfs_destroy_inode,
+	.statfs = squashfs_statfs,
+	.put_super = squashfs_put_super,
+};
+
+SQSH_EXTERN struct address_space_operations squashfs_symlink_aops = {
+	.readpage = squashfs_symlink_readpage
+};
+
+SQSH_EXTERN struct address_space_operations squashfs_aops = {
+	.readpage = squashfs_readpage
+};
+
+SQSH_EXTERN struct address_space_operations squashfs_aops_4K = {
+	.readpage = squashfs_readpage4K
+};
+
+static struct file_operations squashfs_dir_ops = {
+	.read = generic_read_dir,
+	.readdir = squashfs_readdir
+};
+
+SQSH_EXTERN struct inode_operations squashfs_dir_inode_ops = {
+	.lookup = squashfs_lookup
+};
+
+
+static struct buffer_head *get_block_length(struct super_block *s,
+				int *cur_index, int *offset, int *c_byte)
+{
+	struct squashfs_sb_info *msblk = s->s_fs_info;
+	unsigned short temp;
+	struct buffer_head *bh;
+
+	if (!(bh = sb_bread(s, *cur_index)))
+		goto out;
+
+	if (msblk->devblksize - *offset == 1) {
+		if (msblk->swap)
+			((unsigned char *) &temp)[1] = *((unsigned char *)
+				(bh->b_data + *offset));
+		else
+			((unsigned char *) &temp)[0] = *((unsigned char *)
+				(bh->b_data + *offset));
+		brelse(bh);
+		if (!(bh = sb_bread(s, ++(*cur_index))))
+			goto out;
+		if (msblk->swap)
+			((unsigned char *) &temp)[0] = *((unsigned char *)
+				bh->b_data);
+		else
+			((unsigned char *) &temp)[1] = *((unsigned char *)
+				bh->b_data);
+		*c_byte = temp;
+		*offset = 1;
+	} else {
+		if (msblk->swap) {
+			((unsigned char *) &temp)[1] = *((unsigned char *)
+				(bh->b_data + *offset));
+			((unsigned char *) &temp)[0] = *((unsigned char *)
+				(bh->b_data + *offset + 1));
+		} else {
+			((unsigned char *) &temp)[0] = *((unsigned char *)
+				(bh->b_data + *offset));
+			((unsigned char *) &temp)[1] = *((unsigned char *)
+				(bh->b_data + *offset + 1));
+		}
+		*c_byte = temp;
+		*offset += 2;
+	}
+
+	if (SQUASHFS_CHECK_DATA(msblk->sblk.flags)) {
+		if (*offset == msblk->devblksize) {
+			brelse(bh);
+			if (!(bh = sb_bread(s, ++(*cur_index))))
+				goto out;
+			*offset = 0;
+		}
+		if (*((unsigned char *) (bh->b_data + *offset)) !=
+						SQUASHFS_MARKER_BYTE) {
+			ERROR("Metadata block marker corrupt @ %x\n",
+						*cur_index);
+			brelse(bh);
+			goto out;
+		}
+		(*offset)++;
+	}
+	return bh;
+
+out:
+	return NULL;
+}
+
+
+SQSH_EXTERN unsigned int squashfs_read_data(struct super_block *s, char *buffer,
+			long long index, unsigned int length,
+			long long *next_index)
+{
+	struct squashfs_sb_info *msblk = s->s_fs_info;
+	struct buffer_head *bh[((SQUASHFS_FILE_MAX_SIZE - 1) >>
+			msblk->devblksize_log2) + 2];
+	unsigned int offset = index & ((1 << msblk->devblksize_log2) - 1);
+	unsigned int cur_index = index >> msblk->devblksize_log2;
+	int bytes, avail_bytes, b = 0, k;
+	char *c_buffer;
+	unsigned int compressed;
+	unsigned int c_byte = length;
+
+	if (c_byte) {
+		bytes = msblk->devblksize - offset;
+		compressed = SQUASHFS_COMPRESSED_BLOCK(c_byte);
+		c_buffer = compressed ? msblk->read_data : buffer;
+		c_byte = SQUASHFS_COMPRESSED_SIZE_BLOCK(c_byte);
+
+		TRACE("Block @ 0x%llx, %scompressed size %d\n", index, compressed
+					? "" : "un", (unsigned int) c_byte);
+
+		if (!(bh[0] = sb_getblk(s, cur_index)))
+			goto block_release;
+
+		for (b = 1; bytes < c_byte; b++) {
+			if (!(bh[b] = sb_getblk(s, ++cur_index)))
+				goto block_release;
+			bytes += msblk->devblksize;
+		}
+		ll_rw_block(READ, b, bh);
+	} else {
+		if (!(bh[0] = get_block_length(s, &cur_index, &offset,
+								&c_byte)))
+			goto read_failure;
+
+		bytes = msblk->devblksize - offset;
+		compressed = SQUASHFS_COMPRESSED(c_byte);
+		c_buffer = compressed ? msblk->read_data : buffer;
+		c_byte = SQUASHFS_COMPRESSED_SIZE(c_byte);
+
+		TRACE("Block @ 0x%llx, %scompressed size %d\n", index, compressed
+					? "" : "un", (unsigned int) c_byte);
+
+		for (b = 1; bytes < c_byte; b++) {
+			if (!(bh[b] = sb_getblk(s, ++cur_index)))
+				goto block_release;
+			bytes += msblk->devblksize;
+		}
+		ll_rw_block(READ, b - 1, bh + 1);
+	}
+
+	if (compressed)
+		down(&msblk->read_data_mutex);
+
+	for (bytes = 0, k = 0; k < b; k++) {
+		avail_bytes = (c_byte - bytes) > (msblk->devblksize - offset) ?
+					msblk->devblksize - offset :
+					c_byte - bytes;
+		wait_on_buffer(bh[k]);
+		if (!buffer_uptodate(bh[k]))
+			goto block_release;
+		memcpy(c_buffer + bytes, bh[k]->b_data + offset, avail_bytes);
+		bytes += avail_bytes;
+		offset = 0;
+		brelse(bh[k]);
+	}
+
+	/*
+	 * uncompress block
+	 */
+	if (compressed) {
+		int zlib_err;
+
+		stream.next_in = c_buffer;
+		stream.avail_in = c_byte;
+		stream.next_out = buffer;
+		stream.avail_out = msblk->read_size;
+
+		if (((zlib_err = zlib_inflateInit(&stream)) != Z_OK) ||
+				((zlib_err = zlib_inflate(&stream, Z_FINISH))
+				 != Z_STREAM_END) || ((zlib_err =
+				zlib_inflateEnd(&stream)) != Z_OK)) {
+			ERROR("zlib_fs returned unexpected result 0x%x\n",
+				zlib_err);
+			bytes = 0;
+		} else
+			bytes = stream.total_out;
+
+		up(&msblk->read_data_mutex);
+	}
+
+	if (next_index)
+		*next_index = index + c_byte + (length ? 0 :
+				(SQUASHFS_CHECK_DATA(msblk->sblk.flags)
+				 ? 3 : 2));
+	return bytes;
+
+block_release:
+	while (--b >= 0)
+		brelse(bh[b]);
+
+read_failure:
+	ERROR("sb_bread failed reading block 0x%x\n", cur_index);
+	return 0;
+}
+
+
+SQSH_EXTERN int squashfs_get_cached_block(struct super_block *s, char *buffer,
+				long long block, unsigned int offset,
+				int length, long long *next_block,
+				unsigned int *next_offset)
+{
+	struct squashfs_sb_info *msblk = s->s_fs_info;
+	int n, i, bytes, return_length = length;
+	long long next_index;
+
+	TRACE("Entered squashfs_get_cached_block [%llx:%x]\n", block, offset);
+
+	while ( 1 ) {
+		for (i = 0; i < SQUASHFS_CACHED_BLKS; i++)
+			if (msblk->block_cache[i].block == block)
+				break;
+
+		down(&msblk->block_cache_mutex);
+
+		if (i == SQUASHFS_CACHED_BLKS) {
+			/* read inode header block */
+			for (i = msblk->next_cache, n = SQUASHFS_CACHED_BLKS;
+					n ; n --, i = (i + 1) %
+					SQUASHFS_CACHED_BLKS)
+				if (msblk->block_cache[i].block !=
+							SQUASHFS_USED_BLK)
+					break;
+
+			if (n == 0) {
+				wait_queue_t wait;
+
+				init_waitqueue_entry(&wait, current);
+				add_wait_queue(&msblk->waitq, &wait);
+				set_current_state(TASK_UNINTERRUPTIBLE);
+ 				up(&msblk->block_cache_mutex);
+				schedule();
+				set_current_state(TASK_RUNNING);
+				remove_wait_queue(&msblk->waitq, &wait);
+				continue;
+			}
+			msblk->next_cache = (i + 1) % SQUASHFS_CACHED_BLKS;
+
+			if (msblk->block_cache[i].block ==
+							SQUASHFS_INVALID_BLK) {
+				if (!(msblk->block_cache[i].data =
+						kmalloc(SQUASHFS_METADATA_SIZE,
+						GFP_KERNEL))) {
+					ERROR("Failed to allocate cache"
+							"block\n");
+					up(&msblk->block_cache_mutex);
+					goto out;
+				}
+			}
+
+			msblk->block_cache[i].block = SQUASHFS_USED_BLK;
+			up(&msblk->block_cache_mutex);
+
+			if (!(msblk->block_cache[i].length =
+						squashfs_read_data(s,
+						msblk->block_cache[i].data,
+						block, 0, &next_index))) {
+				ERROR("Unable to read cache block [%llx:%x]\n",
+						block, offset);
+				goto out;
+			}
+
+			down(&msblk->block_cache_mutex);
+			wake_up(&msblk->waitq);
+			msblk->block_cache[i].block = block;
+			msblk->block_cache[i].next_index = next_index;
+			TRACE("Read cache block [%llx:%x]\n", block, offset);
+		}
+
+		if (msblk->block_cache[i].block != block) {