[PATCH] merge befs file system from 2.4 (no core changes)

fs/Config.help

@@ -963,6 +963,28 @@ CONFIG_VXFS_FS
   module, say M here and read <file:Documentation/modules.txt>.  If
   unsure, say N.
 
+CONFIG_BEFS_FS
+  The BeOS File System (BeFS) is the native file system of Be, Inc's
+  BeOS. Notable features include support for arbitrary attributes
+  on files and directories, and database-like indices on selected
+  attributes. (Also note that this driver doesn't make those features
+  available at this time). It is a 64 bit filesystem, so it supports
+  extreemly large volumes and files.
+
+  If you use this filesystem, you should also say Y to at least one
+  of the NLS (native language support) options below.
+
+  If you don't know what this is about, say N.
+
+  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 Documentation/modules.txt. The module will be
+  called befs.o.
+
+CONFIG_BEFS_DEBUG
+  If you say Y here, you can use the 'debug' mount option to enable
+  debugging output from the driver. 
+
 CIFS (Common Internet File System) support
 CONFIG_CIFS
   This is the client VFS module for the Common Internet File System

fs/Config.in

@@ -24,6 +24,9 @@ dep_tristate 'Amiga FFS file system support (EXPERIMENTAL)' CONFIG_AFFS_FS $CONF
 
 dep_tristate 'Apple Macintosh file system support (EXPERIMENTAL)' CONFIG_HFS_FS $CONFIG_EXPERIMENTAL
 
+dep_tristate 'BeOS file systemv(BeFS) support (read only) (EXPERIMENTAL)' CONFIG_BEFS_FS $CONFIG_EXPERIMENTAL
+dep_mbool '  Debug BeFS' CONFIG_BEFS_DEBUG $CONFIG_BEFS_FS
+
 dep_tristate 'BFS file system support (EXPERIMENTAL)' CONFIG_BFS_FS $CONFIG_EXPERIMENTAL
 
 tristate 'Ext3 journalling file system support' CONFIG_EXT3_FS

fs/Makefile

@@ -87,5 +87,6 @@ obj-$(CONFIG_SUN_OPENPROMFS)	+= openpromfs/
 obj-$(CONFIG_JFS_FS)		+= jfs/
 obj-$(CONFIG_XFS_FS)		+= xfs/
 obj-$(CONFIG_AFS_FS)		+= afs/
+obj-$(CONFIG_BEFS_FS)		+= befs/
 
 include $(TOPDIR)/Rules.make

fs/befs/ChangeLog

+Version 0.92 (2002-03-29)
+==========
+* Minor cleanup. Ran Lindent on the sources.
+
+Version 0.92 (2002-03-27)
+==========
+* Fixed module makefile problem. It was not compiling all the correct 
+    source files!
+* Removed duplicated function definition
+* Fixed potential null pointer dereference when reporting an error
+
+Version 0.91 (2002-03-26)
+==========
+* Oy! Fixed stupid bug that would cause an unresolved symbol error.
+	Thanks to Laszlo Boszormenyi for pointing this out to me.
+
+Version 0.9 (2002-03-14)
+==========
+* Added Sergey S. Kostyliov's patch to eliminate memcpy() overhead
+	from b+tree operations. Changes the befs_read_datastream() interface.
+
+* Segregated the functions that interface directly with the linux  vfs 
+	interface into their own file called linuxvfs.c. [WD]
+
+Version 0.64 (2002-02-07)
+==========
+* Did the string comparision really right this time (btree.c) [WD]
+
+* Fixed up some places where I assumed that a long int could hold
+	a pointer value. (btree.c) [WD]
+
+* Andrew Farnham <andrewfarnham@uq.net.au> pointed out that the module
+	wouldn't work on older (<2.4.10) kernels due to an unresolved symbol.
+	This is bad, since 2.4.9 is still the current RedHat kernel. I added
+	a workaround for this problem (compatability.h) [WD]
+
+* Sergey S. Kostyliov made befs_find_key() use a binary search to find 
+	keys within btree nodes, rather than the linear search we were using 
+	before. (btree.c) [Sergey S. Kostyliov <rathamahata@php4.ru>]
+
+* Made a debian package of the source for use with kernel-package. [WD]
+
+
+Version 0.63 (2002-01-31)
+==========
+* Fixed bug in befs_find_brun_indirect() that would result in the wrong
+	block being read. It was introduced when adding byteswapping in 
+	0.61. (datastream.c) [WD]
+
+* Fixed a longstanding bug in befs_find_key() that would result in it 
+	finding the first key that is a substring of the string it is searching
+	for. For example, this would cause files in the same directory with 
+	names like file1 and file2 to mysteriously be duplicates of each other 
+	(because they have the same inode number). Many thanks to Pavel Roskin 
+	for reporting this serious bug!!!
+	(btree.c) [WD]
+
+* Added support for long symlinks, after Axel Dorfler explained up how 
+	they work. I had forgotten all about them. (inode.c, symlink.c) [WD]
+
+* Documentation improvements in source. [WD]
+
+* Makefile fix for independant module when CONFIG_MODVERSION is set in 
+	kernel config [Pavel Roskin <proski@gnu.org>]
+
+* Compile warning fix for namei.c. [Sergey S. Kostyliov <rathamahata@php4.ru>]
+
+
+Version 0.62
+==========
+* Fixed makefile for module install [WD]
+
+
+Version 0.61 (2002-01-20)
+==========
+* Made functions in endian.h to do the correct byteswapping, no matter
+	the arch. [WD]
+
+* Abbandoned silly checks for a NULL superblock pointer in debug.c. [WD]
+
+* Misc code cleanups. Also cleanup of this changelog file. [WD]
+
+* Added byteswapping to all metadata reads from disk.
+	Uses the functions from endian.h [WD]
+
+* Remove the typedef of struct super_block to vfs_sb, as it offended
+	certain peoples' aesthetic sense. [WD]
+
+* Ditto with the befs_read_block() interface. [WD]
+ 
+
+Version 0.6 (2001-12-15)
+==========
+* Cleanup of NLS functions (util.c) [WD]
+
+* Make directory lookup/read use the NLS if an iocharset is provided. [WD]
+
+* Fixed stupid bug where specifying the uid or gid mount options as '0' 
+	would result in the filesystem using the on-disk uid and gid. [WD]
+
+* Added mount option to control debug printing. 
+	The option is, simply enough, 'debug'. 
+	(super.c, debug.c) [WD]
+
+* Removed notion of btree handle from btree.c. It was unessisary, as the 
+	linux VFS doesn't allow us to keep any state between calls. Updated 
+	dir.c, namei.c befs_fs.h to account for it. [WD]
+
+* Improved handleing of overflow nodes when listing directories. 
+	Now works for overflow nodes hanging off of nodes other than the root 
+	node. This is the cleaner solution to Brent Miszalaski's problem. [WD]
+
+* Added new debug/warning/error print functions in debug.c. 
+	More flexible. Will soon be controllable at mount time 
+	(see TODO). [WD]
+
+* Rewrote datastream positon lookups.
+	(datastream.c) [WD]
+
+* Moved the TODO list to it's own file.
+
+
+Version 0.50 (2001-11-13)
+==========
+* Added workaround for mis-understanding of the nature of the b+trees used 
+	in directories. A cleaner solution will come after I've thought about it 
+	for a while. Thanks to Brent Miszalaski for finding and reporting this bug. 
+	(btree.c) [WD]
+
+* Minor cleanups
+
+* Added test for "impossible" condition of empty internal nodes in 
+	seekleaf() in btree.c [WD]
+
+* Implemented the abstracted read_block() in io.c [WD]
+
+* Cleaned up the inode validation in inode.c [WD]
+
+* Anton Altaparmakov figured out (by asking Linus :) ) what was causing the 
+ 	hanging disk io problem. It turns out you need to have the sync_pages 
+	callback defined in your address_space_ops, even if it just uses the 
+	default linux-supplied implementation. Fixed. Works now.
+	(file.c) [WD]
+
+* Anton Altaparmakov and Christoph Hellwig alerted me to the fact that 
+	filesystem code should be using GFP_NOFS instead of GFP_KERNEL as the 
+	priority parameter to kmalloc(). Fixed. 
+	(datastream.c, btree.c super.c inode.c) [WD]
+
+* Anton also told me that the blocksize is not allowed to be larger than 
+	the page size in linux, which is 4k i386. Oops. Added a test for 
+	(blocksize > PAGE_SIZE), and refuse to mount in that case. What this 
+	practicaly means is that 8k blocksize volumes won't work without a major
+	restructuring of the driver (or an alpha or other 64bit hardware). [WD]
+
+* Cleaned up the befs_count_blocks() function. Much smarter now. 
+	And somewhat smaller too. [WD]
+
+* Made inode allocations use a slab cache 
+	(super.c inode.c) [WD]
+
+* Moved the freeing of the private inode section from put_inode() to 
+	clear_inode(). This fixes a potential free twice type bug. Put_inode() 
+	can be called multiple times for each inode struct. [WD]
+
+* Converted all non vfs-callback functions to use befs_sb_info as the 
+	superblock type, rather than struct super_block. This is for 
+	portablity. [WD]
+
+* Fixed a couple of compile warnings due to use of malloc.h, when slab.h 
+	is the new way. (inode.c, super.c) [WD]
+
+* Fixed erronous includes of linux/befs_fs_i.h and linux/befs_fs_sb.h 
+	in inode.c [WD]
+
+Version 0.45 (2001-10-29)
+==========
+* Added functions to get the private superblock and inode structures from 
+	their enclosing public structures. Switched all references to the 
+	private portions to use them. (many files) [WD]
+
+* Made read_super and read_inode allocate the private portions of those 
+	structures into the generic pointer fields of the public structures 
+	with kmalloc(). put_super and put_inode free them. This allows us not 
+	to have to touch the definitions of the public structures in 
+	include/linux/fs.h. Also, befs_inode_info is huge (becuase of the 
+	symlink string). (super.c, inode.c, befs_fs.h) [WD]
+
+* Fixed a thinko that was corrupting file reads after the first block_run 
+	is done being read. (datastream.c) [WD]
+
+* Removed fsync() hooks, since a read-only filesystem doesn't need them. 
+	[Christoph Hellwig].
+
+* Fixed befs_readlink() (symlink.c) [Christoph Hellwig].
+
+* Removed all the Read-Write stuff. I'll redo it when it is time to add 
+	write support (various files) [WD].
+
+* Removed prototypes for functions who's definitions have been removed 
+	(befs_fs.h) [WD].
+
+
+Version 0.4 (2001-10-28)
+==========
+* Made it an option to use the old non-pagecache befs_file_read() for 
+	testing purposes. (fs/Config.in)
+
+* Fixed unused variable warnings when compiling without debugging.
+
+* Fixed a bug where the inode and super_block didn't get their blockbits 
+	fields set (inode.c and super.c). 
+
+* Release patch version 11. AKA befs-driver version 0.4.
+
+* Thats right. New versioning scheme. 
+	I've done some serious testing on it now (on my box anyhow), and it 
+	seems stable and not outragously slow. Existing features are more-or-less 
+	correct (see TODO list). But it isn't 1.0 yet. I think 0.4 gives me some 
+	headroom before the big 1.0.
+
+
+2001-10-26
+==========
+* Fixed date format in this file. Was I smoking crack?
+
+* Removed old datastream code from file.c, since it is nolonger used.
+
+* Generic_read_file() is now used to read regular file data. 
+	It doesn't chew up the buffer cache (it does page io instead), and seems 
+	to be about as fast (even though it has to look up each file block 
+	indivdualy). And it knows about doing readahead, which is a major plus. 
+	So it does i/o in much larger chunks. It is the correct linux way. It 
+	uses befs_get_block() by way of befs_readpage() to find the disk offsets 
+	of blocks, which in turn calls befs_fpos2brun() in datastream.c to do 
+	the hard work of finding the disk block number.
+
+* Changed method of checking for a dirty filesystem in befs_read_super 
+	(super.c). Now we check to see if log_start and log_end differ. If so, 
+	the journal needs to be replayed, and the filesystem cannot be mounted.
+
+* Fixed an extra instance of MOD_DEC_USE_COUNT in super.c
+
+* Fixed a problem with reading the superblock on devices with large sector 
+	sizes (such as cdroms) on linux 2.4.10 and up.
+
+2001-10-24
+==========
+* Fix nasty bug in converting block numbers to struct befs_inode_addr. 
+	Subtle, because the old version was only sometimes wrong. 
+	Probably responsible for lots of problems. (inode.c)
+
+* Fix bug with reading an empty directory. (btree.c and dir.c)
+
+* This one looks good. Release patch version 10
+
+2001-10-23
+==========
+* Added btree searching function.
+
+* Use befs_btree_find in befs_lookup (namei.c)
+
+* Additional comments in btree.c
+
+2001-10-22
+==========
+* Added B+tree reading functions (in btree.c). 
+	Made befs_readdir() use them them instead of the cruft in index.c.
+
+2001-09-11
+==========
+* Converted befs_read_file() to use the new datastream code.
+
+* Finally updated the README file.
+
+* Added many comments.
+
+* Posted version 6
+
+* Removed byte-order conversion code. 
+	I have no intention of supporting it, and it was very ugly. 
+	Flow control with #ifdef (ugh). Maybe I'll redo it once 
+	native byteorder works 100%.
+
+2001-09-10
+==========
+* Finished implementing read_datastream()
+
+* made befs_read_brun() more general
+	Supports an offset to start at and a max bytes to read
+	Added a wrapper function to give the old call
+
+2001-09-30
+==========
+* Discovered that the datastream handleing code in file.c is quite deficient 
+	in several respects. For one thing, it doesn't deal with indirect blocks
+
+* Rewrote datastream handleing.
+
+* Created io.c, for io related functions.
+	Previously, the befs_bread() funtions lived in file.c
+	Created the befs_read_brun() function.
+
+
+2001-09-07
+==========
+* Made a function to actually count the number of fs blocks used by a file.
+	And helper functions.
+	(fs/befs/inode.c)
+
+2001-09-05
+==========
+* Fixed a misunderstanding of the inode fields. 
+	This fixed the problmem with wrong file sizes from du and others.
+	The i_blocks field of the inode struct is not the nuber of blocks for the 
+	inode, it is the number of blocks for the file.	Also, i_blksize is not
+	nessisarily the size of the inode, although in  practice it works out.
+	Changed to blocksize of filesystem.
+	(fs/befs/inode.c)
+
+* Permanently removed code that had been provisionally ifdefed out of befs_fs.h
+
+* Since we don't support access time, make that field zero, instead of 
+	copying m_time.
+	(fs/befs/inode.c)
+
+* Added sanity check for inode reading
+	Make sure inode we got was the one we asked for. 
+	(fs/befs/inode.c)
+
+* Code cleanup
+	Local pointers to commonly used structures in inode.c.
+	Got rid of abominations befs_iaddr2inode() and befs_inode2ino(). 
+	Replaced with single function iaddr2blockno().
+	(fs/befs/super.c) (fs/befs/inode.c)
+
+2001-09-01
+==========
+* Fixed the problem with statfs where it would always claim the disk was 
+	half full, due to improper understanding of the statfs fields.
+	(fs/befs/super.c)
+
+* Posted verion 4 of the patch
+
+2001-09-01
+==========
+* Changed the macros in befs_fs.h to inline functions.
+	More readable. Typesafe. Better
+	(include/linux/befs_fs.h)
+
+* Moved type definitions from befs_fs.h to a new file, befs_fs_types.h 
+	Because befs_fs_i.h and befs_fs_sb.h were including befs_fs.h for the 
+	typedefs, and they are inlcuded in <linux/fs.h>, which has definitions 
+	that I want the inline functions in befs_fs.h to be able to see. Nasty
+	circularity.
+	(include/linux/befs_fs.h)
+
+2001-08-30
+==========
+* Cleaned up some wording.
+
+* Added additional consitency checks on mount
+	Check block_size agrees with block_shift
+	Check flags == BEFS_CLEAN
+	(fs/befs/super.c)
+
+* Tell the kernel to only mount befs read-only. 
+	By setting the MS_RDONLY flag in befs_read_super().
+	Not that it was possible to write before. But now the kernel won't even try.
+	(fs/befs/super.c)
+
+* Got rid of kernel warning on mount.
+	The kernel doesn't like it if you call set_blocksize() on a device when 
+	you have some of its blocks open. Moved the second set_blocksize() to the
+	very end of befs_read_super(), after we are done with the disk superblock.
+	(fs/befs/super.c)
+	
+* Fixed wrong number of args bug in befs_dump_inode
+	(fs/befs/debug.c)
+
+* Solved lots of type mismatches in kprint()s
+	(everwhere)
+
+2001-08-27
+==========
+* Cleaned up the fs/Config.in entries a bit, now slightly more descriptive.
+
+* BeFS depends on NLS, so I made activating BeFS enable the NLS questions
+	(fs/nls/Config.in)
+
+* Added Configure.help entries for CONFIG_BEFS_FS and CONFIG_DEBUG_BEFS
+	(Documentation/Configure.help)
+
+2001-08-??
+==========
+* Removed superblock locking calls in befs_read_super(). In 2.4, the VFS 
+	hands us a super_block struct that is already locked.
+
+2001-08-13
+==========
+* Will Dyson <will_dyson@pobox.com> is now attempting to maintain this module
+	Makoto Kato <m_kato@ga2.so-net.ne.jp> is original author.Daniel Berlin 
+	also did some work on it (fixing it up for the later 2.3.x kernels, IIRC).
+
+* Fixed compile errors on 2.4.1 kernel (WD)
+	Resolve rejected patches
+	Accomodate changed NLS interface (util.h)
+	Needed to include <linux/slab.h> in most files
+	Makefile changes
+	fs/Config.in changes
+
+* Tried to niceify the code using the ext2 fs as a guide
+	Declare befs_fs_type using the DECLARE_FSTYPE_DEV() macro
+
+* Made it a configure option to turn on debugging (fs/Config.in)
+
+* Compiles on 2.4.7

fs/befs/Makefile

+#
+# Makefile for the linux BeOS filesystem routines.
+#
+# Note! Dependencies are done automagically by 'make dep', which also
+# removes any old dependencies. DON'T put your own dependencies here
+# unless it's something special (ie not a .c file).
+#
+# Note 2! The CFLAGS definitions are now in the main makefile...
+
+ 
+obj-$(CONFIG_BEFS_FS) += befs.o
+
+befs-objs := datastream.o btree.o super.o inode.o debug.o io.o linuxvfs.o
+
+include $(TOPDIR)/Rules.make

fs/befs/TODO

+TODO
+==========
+
+* Convert comments to the Kernel-Doc format.
+
+* Befs_fs.h has gotten big and messy. No reason not to break it up into 
+	smaller peices.
+
+* See if Alexander Viro's option parser made it into the kernel tree. 
+	Use that if we can. (include/linux/parser.h)
+
+* See if we really need separate types for on-disk and in-memory 
+	representations of the superblock and inode.
+

fs/befs/attribute.c

+/*
+ * linux/fs/befs/attribute.c
+ *
+ * Copyright (C) 2002 Will Dyson <will_dyson@pobox.com>
+ *
+ * Many thanks to Dominic Giampaolo, author of "Practical File System
+ * Design with the Be File System", for such a helpful book.
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+
+#include "befs.h"
+#include "endian.h"
+
+#define SD_DATA(sd)\
+	(void*)((char*)sd + sizeof(*sd) + (sd->name_size - sizeof(sd->name)))
+
+#define SD_NEXT(sd)\
+	(befs_small_data*)((char*)sd + sizeof(*sd) + (sd->name_size - \
+	sizeof(sd->name) + sd->data_size))
+
+int
+list_small_data(struct super_block *sb, befs_inode * inode, filldir_t filldir);
+
+befs_small_data *
+find_small_data(struct super_block *sb, befs_inode * inode,
+				 const char *name);
+int
+read_small_data(struct super_block *sb, befs_inode * inode,
+		 befs_small_data * sdata, void *buf, size_t bufsize);
+
+/**
+ *
+ *
+ *
+ *
+ *
+ */
+befs_small_data *
+find_small_data(struct super_block *sb, befs_inode * inode, const char *name)
+{
+	befs_small_data *sdata = inode->small_data;
+
+	while (sdata->type != 0) {
+		if (strcmp(name, sdata->name) != 0) {
+			return sdata;
+		}
+		sdata = SD_NEXT(sdata);
+	}
+	return NULL;
+}
+
+/**
+ *
+ *
+ *
+ *
+ *
+ */
+int
+read_small_data(struct super_block *sb, befs_inode * inode,
+		const char *name, void *buf, size_t bufsize)
+{
+	befs_small_data *sdata;
+
+	sdata = find_small_data(sb, inode, name);
+	if (sdata == NULL)
+		return BEFS_ERR;
+	else if (sdata->data_size > bufsize)
+		return BEFS_ERR;
+
+	memcpy(buf, SD_DATA(sdata), sdata->data_size);
+
+	return BEFS_OK;
+}
+
+/**
+ *
+ *
+ *
+ *
+ *
+ */
+int
+list_small_data(struct super_block *sb, befs_inode * inode)
+{
+
+}
+
+/**
+ *
+ *
+ *
+ *
+ *
+ */
+int
+list_attr(struct super_block *sb, befs_inode * inode)
+{
+
+}
+
+/**
+ *
+ *
+ *
+ *
+ *
+ */
+int
+read_attr(struct super_block *sb, befs_inode * inode)
+{
+
+}

fs/befs/befs.h

+/*
+ * befs.h
+ *
+ * Copyright (C) 2001-2002 Will Dyson <will_dyson@pobox.com>
+ * Copyright (C) 1999 Makoto Kato (m_kato@ga2.so-net.ne.jp)
+ */
+
+#ifndef _LINUX_BEFS_H
+#define _LINUX_BEFS_H
+
+#include "befs_fs_types.h"
+
+/* used in debug.c */
+#define BEFS_VERSION "0.9.3"
+
+
+/* Sector_t makes this sillyness obsolete */
+typedef u64 befs_blocknr_t;
+typedef u32 vfs_blocknr_t;
+
+/*
+ * BeFS in memory structures
+ */
+
+typedef struct befs_mount_options {
+	gid_t gid;
+	uid_t uid;
+	int use_gid;
+	int use_uid;
+	int debug;
+	char *iocharset;
+} befs_mount_options;
+
+typedef struct befs_sb_info {
+	u32 magic1;
+	u32 block_size;
+	u32 block_shift;
+	int byte_order;
+	befs_off_t num_blocks;
+	befs_off_t used_blocks;
+	u32 inode_size;
+	u32 magic2;
+
+	/* Allocation group information */
+	u32 blocks_per_ag;
+	u32 ag_shift;
+	u32 num_ags;
+
+	/* jornal log entry */
+	befs_block_run log_blocks;
+	befs_off_t log_start;
+	befs_off_t log_end;
+
+	befs_inode_addr root_dir;
+	befs_inode_addr indices;
+	u32 magic3;
+
+	befs_mount_options mount_opts;
+	struct nls_table *nls;
+
+} befs_sb_info;
+
+typedef struct befs_inode_info {
+	u32 i_flags;
+	u32 i_type;
+
+	befs_inode_addr i_inode_num;
+	befs_inode_addr i_parent;
+	befs_inode_addr i_attribute;
+
+	union {
+		befs_data_stream ds;
+		char symlink[BEFS_SYMLINK_LEN];
+	} i_data;
+
+	struct inode vfs_inode;
+
+} befs_inode_info;
+
+enum befs_err {
+	BEFS_OK,
+	BEFS_ERR,
+	BEFS_BAD_INODE,
+	BEFS_BT_END,
+	BEFS_BT_EMPTY,
+	BEFS_BT_MATCH,
+	BEFS_BT_PARMATCH,
+	BEFS_BT_NOT_FOUND
+};
+
+
+/****************************/
+/* debug.c */
+void befs_error(const struct super_block *sb, const char *fmt, ...);
+void befs_warning(const struct super_block *sb, const char *fmt, ...);
+void befs_debug(const struct super_block *sb, const char *fmt, ...);
+
+void befs_dump_super_block(const struct super_block *sb, befs_super_block *);
+void befs_dump_inode(const struct super_block *sb, befs_inode *);
+void befs_dump_index_entry(const struct super_block *sb, befs_btree_super *);
+void befs_dump_index_node(const struct super_block *sb, befs_btree_nodehead *);
+void befs_dump_inode_addr(const struct super_block *sb, befs_inode_addr);
+/****************************/
+
+
+/* Gets a pointer to the private portion of the super_block
+ * structure from the public part
+ */
+static inline befs_sb_info *
+BEFS_SB(const struct super_block *super)
+{
+	return (befs_sb_info *) super->s_fs_info;
+}
+
+static inline befs_inode_info *
+BEFS_I(const struct inode *inode)
+{
+	return list_entry(inode, struct befs_inode_info, vfs_inode);
+}
+
+static inline befs_blocknr_t
+iaddr2blockno(struct super_block *sb, befs_inode_addr * iaddr)
+{
+	return ((iaddr->allocation_group << BEFS_SB(sb)->ag_shift) +
+		iaddr->start);
+}
+
+static inline befs_inode_addr
+blockno2iaddr(struct super_block *sb, befs_blocknr_t blockno)
+{
+	befs_inode_addr iaddr;
+	iaddr.allocation_group = blockno >> BEFS_SB(sb)->ag_shift;
+	iaddr.start =
+	    blockno - (iaddr.allocation_group << BEFS_SB(sb)->ag_shift);
+	iaddr.len = 1;
+
+	return iaddr;
+}
+
+static inline unsigned int
+befs_iaddrs_per_block(struct super_block *sb)
+{
+	return BEFS_SB(sb)->block_size / sizeof (befs_inode_addr);
+}
+
+static inline int
+befs_iaddr_is_empty(befs_inode_addr * iaddr)
+{
+	return (!iaddr->allocation_group) && (!iaddr->start) && (!iaddr->len);
+}
+
+static inline size_t
+befs_brun_size(struct super_block *sb, befs_block_run run)
+{
+	return BEFS_SB(sb)->block_size * run.len;
+}
+
+#endif				/* _LINUX_BEFS_H */

fs/befs/befs_fs_types.h

+/*
+ * include/linux/befs_fs_types.h
+ *
+ * Copyright (C) 2001 Will Dyson (will@cs.earlham.edu)
+ *
+ *
+ *
+ * from linux/include/linux/befs_fs.h
+ *
+ * Copyright (C) 1999 Makoto Kato (m_kato@ga2.so-net.ne.jp)
+ *
+ */
+
+#ifndef _LINUX_BEFS_FS_TYPES
+#define _LINUX_BEFS_FS_TYPES
+
+#ifdef __KERNEL__
+#include <linux/types.h>
+#endif /*__KERNEL__*/
+
+#define PACKED __attribute__ ((__packed__))
+
+/*
+ * Max name lengths of BFS
+ */
+
+#define BEFS_NAME_LEN 255
+
+#define BEFS_SYMLINK_LEN 144
+#define BEFS_NUM_DIRECT_BLOCKS 12
+#define B_OS_NAME_LENGTH 32
+
+/* The datastream blocks mapped by the double-indirect
+ * block are always 4 fs blocks long.
+ * This eliminates the need for linear searches among
+ * the potentially huge number of indirect blocks
+ *
+ * Err. Should that be 4 fs blocks or 4k???
+ * It matters on large blocksize volumes
+ */
+#define BEFS_DBLINDIR_BRUN_LEN 4
+
+/*
+ * Flags of superblock
+ */
+
+enum super_flags {
+	BEFS_BYTESEX_BE,
+	BEFS_BYTESEX_LE,
+	BEFS_CLEAN = 0x434c454e,
+	BEFS_DIRTY = 0x44495254,
+	BEFS_SUPER_MAGIC1 = 0x42465331,	/* BFS1 */
+	BEFS_SUPER_MAGIC2 = 0xdd121031,
+	BEFS_SUPER_MAGIC3 = 0x15b6830e,
+};
+
+#define BEFS_BYTEORDER_NATIVE 0x42494745
+
+#define BEFS_SUPER_MAGIC BEFS_SUPER_MAGIC1
+
+/*
+ * Flags of inode
+ */
+
+#define BEFS_INODE_MAGIC1 0x3bbe0ad9
+
+enum inode_flags {
+	BEFS_INODE_IN_USE = 0x00000001,
+	BEFS_ATTR_INODE = 0x00000004,
+	BEFS_INODE_LOGGED = 0x00000008,
+	BEFS_INODE_DELETED = 0x00000010,
+	BEFS_LONG_SYMLINK = 0x00000040,
+	BEFS_PERMANENT_FLAG = 0x0000ffff,
+	BEFS_INODE_NO_CREATE = 0x00010000,
+	BEFS_INODE_WAS_WRITTEN = 0x00020000,
+	BEFS_NO_TRANSACTION = 0x00040000,
+};
+/* 
+ * On-Disk datastructures of BeFS
+ */
+
+typedef u64 befs_off_t;
+typedef u64 befs_time_t;
+typedef void befs_binode_etc;
+
+/* Block runs */
+typedef struct {
+	u32 allocation_group;
+	u16 start;
+	u16 len;
+} PACKED befs_block_run;
+
+typedef befs_block_run befs_inode_addr;
+
+/*
+ * The Superblock Structure
+ */
+typedef struct {
+	char name[B_OS_NAME_LENGTH];
+	u32 magic1;
+	u32 fs_byte_order;
+
+	u32 block_size;
+	u32 block_shift;
+
+	befs_off_t num_blocks;
+	befs_off_t used_blocks;
+
+	u32 inode_size;
+
+	u32 magic2;
+	u32 blocks_per_ag;
+	u32 ag_shift;
+	u32 num_ags;
+
+	u32 flags;
+
+	befs_block_run log_blocks;
+	befs_off_t log_start;
+	befs_off_t log_end;
+
+	u32 magic3;
+	befs_inode_addr root_dir;
+	befs_inode_addr indices;
+
+} PACKED befs_super_block;
+
+/* 
+ * Note: the indirect and dbl_indir block_runs may
+ * be longer than one block!
+ */
+typedef struct {
+	befs_block_run direct[BEFS_NUM_DIRECT_BLOCKS];
+	befs_off_t max_direct_range;
+	befs_block_run indirect;
+	befs_off_t max_indirect_range;
+	befs_block_run double_indirect;
+	befs_off_t max_double_indirect_range;
+	befs_off_t size;
+} PACKED befs_data_stream;
+
+/* Attribute */
+typedef struct {
+	u32 type;
+	u16 name_size;
+	u16 data_size;
+	char name[1];
+} PACKED befs_small_data;
+
+/* Inode structure */
+typedef struct {
+	u32 magic1;
+	befs_inode_addr inode_num;
+	u32 uid;
+	u32 gid;
+	u32 mode;
+	u32 flags;
+	befs_time_t create_time;
+	befs_time_t last_modified_time;
+	befs_inode_addr parent;
+	befs_inode_addr attributes;
+	u32 type;
+
+	u32 inode_size;
+	u32 etc;		/* not use */
+
+	union {
+		befs_data_stream datastream;
+		char symlink[BEFS_SYMLINK_LEN];
+	} data;
+
+	u32 pad[4];		/* not use */
+	befs_small_data small_data[1];
+} PACKED befs_inode;
+
+/*
+ * B+tree superblock
+ */
+
+#define BEFS_BTREE_MAGIC 0x69f6c2e8
+
+enum btree_types {
+	BTREE_STRING_TYPE = 0,
+	BTREE_INT32_TYPE = 1,
+	BTREE_UINT32_TYPE = 2,
+	BTREE_INT64_TYPE = 3,
+	BTREE_UINT64_TYPE = 4,
+	BTREE_FLOAT_TYPE = 5,
+	BTREE_DOUBLE_TYPE = 6
+};
+
+typedef struct {
+	u32 magic;
+	u32 node_size;
+	u32 max_depth;
+	u32 data_type;
+	befs_off_t root_node_ptr;
+	befs_off_t free_node_ptr;
+	befs_off_t max_size;
+} PACKED befs_btree_super;
+
+/*
+ * Header stucture of each btree node
+ */
+typedef struct {
+	befs_off_t left;
+	befs_off_t right;
+	befs_off_t overflow;
+	u16 all_key_count;
+	u16 all_key_length;
+} PACKED befs_btree_nodehead;
+
+#endif				/* _LINUX_BEFS_FS_TYPES */

fs/befs/btree.c

+/*
+ * linux/fs/befs/btree.c
+ *
+ * Copyright (C) 2001-2002 Will Dyson <will_dyson@pobox.com>
+ *
+ * Licensed under the GNU GPL. See the file COPYING for details.
+ *
+ * 2002-02-05: Sergey S. Kostyliov added binary search withing
+ * 		btree nodes.
+ *
+ * Many thanks to:
+ *
+ * Dominic Giampaolo, author of "Practical File System
+ * Design with the Be File System", for such a helpful book.
+ * 
+ * Marcus J. Ranum, author of the b+tree package in 
+ * comp.sources.misc volume 10. This code is not copied from that
+ * work, but it is partially based on it.
+ *
+ * Makoto Kato, author of the original BeFS for linux filesystem
+ * driver.
+ */
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/buffer_head.h>
+
+#include "befs.h"
+#include "btree.h"
+#include "datastream.h"
+#include "endian.h"
+
+/*
+ * The btree functions in this file are built on top of the
+ * datastream.c interface, which is in turn built on top of the
+ * io.c interface.
+ */
+
+/* Befs B+tree structure:
+ * 
+ * The first thing in the tree is the tree superblock. It tells you
+ * all kinds of usefull things about the tree, like where the rootnode
+ * is located, and the size of the nodes (always 1024 with current version
+ * of BeOS).
+ *
+ * The rest of the tree consists of a series of nodes. Nodes contain a header
+ * (struct befs_btree_nodehead), the packed key data, an array of shorts 
+ * containing the ending offsets for each of the keys, and an array of
+ * befs_off_t values. In interior nodes, the keys are the ending keys for 
+ * the childnode they point to, and the values are offsets into the 
+ * datastream containing the tree. 
+ */
+
+/* Note:
+ * 
+ * The book states 2 confusing things about befs b+trees. First, 
+ * it states that the overflow feild of node headers is used by internal nodes 
+ * to point to another node that "effectivly continues this one". Here is what 
+ * I belive that means. Each key in internal nodes points to another node that
+ * contains key values less than itself. Inspection reveals that the last key 
+ * in the internal node is not the last key in the index. Keys that are 
+ * greater than the last key in the internal node go into the overflow node. 
+ * I imagine there is a performance reason for this.
+ *
+ * Second, it states that the header of a btree node is sufficient to 
+ * distinguish internal nodes from leaf nodes. Without saying exactly how. 
+ * After figuring out the first, it becomes obvious that internal nodes have
+ * overflow nodes and leafnodes do not.
+ */
+
+/* 
+ * Currently, this code is only good for directory B+trees.
+ * In order to be used for other BFS indexes, it needs to be extended to handle
+ * duplicate keys and non-string keytypes (int32, int64, float, double).
+ */
+
+/*
+ * In memory structure of each btree node
+ */
+typedef struct {
+	befs_btree_nodehead head;	/* head of node converted to cpu byteorder */
+	struct buffer_head *bh;
+	befs_btree_nodehead *od_node;	/* on disk node */
+} befs_btree_node;
+
+/* local constants */
+const static befs_off_t befs_bt_inval = 0xffffffffffffffff;
+
+/* local functions */
+static int befs_btree_seekleaf(struct super_block *sb, befs_data_stream * ds,
+			       befs_btree_super * bt_super,
+			       befs_btree_node * this_node,
+			       befs_off_t * node_off);
+
+static int befs_bt_read_super(struct super_block *sb, befs_data_stream * ds,
+			      befs_btree_super * sup);
+
+static int befs_bt_read_node(struct super_block *sb, befs_data_stream * ds,
+			     befs_btree_node * node, befs_off_t node_off);
+
+static int befs_leafnode(befs_btree_node * node);
+
+static u16 *befs_bt_keylen_index(befs_btree_node * node);
+
+static befs_off_t *befs_bt_valarray(befs_btree_node * node);
+
+static char *befs_bt_keydata(befs_btree_node * node);
+
+static int befs_find_key(struct super_block *sb, befs_btree_node * node,
+			 const char *findkey, befs_off_t * value);
+
+static char *befs_bt_get_key(struct super_block *sb, befs_btree_node * node,
+			     int index, u16 * keylen);
+
+static int befs_compare_strings(const void *key1, int keylen1,
+				const void *key2, int keylen2);
+
+/**
+ * befs_bt_read_super - read in btree superblock convert to cpu byteorder
+ * @sb: Filesystem superblock
+ * @ds: Datastream to read from
+ * @sup: Buffer in which to place the btree superblock
+ *
+ * Calls befs_read_datastream to read in the btree superblock and
+ * makes sure it is in cpu byteorder, byteswapping if nessisary.
+ *
+ * On success, returns BEFS_OK and *@sup contains the btree superblock,
+ * in cpu byte order.
+ *
+ * On failure, BEFS_ERR is returned.
+ */
+static int
+befs_bt_read_super(struct super_block *sb, befs_data_stream * ds,
+		   befs_btree_super * sup)
+{
+	struct buffer_head *bh = NULL;
+	befs_btree_super *od_sup = NULL;
+
+	befs_debug(sb, "---> befs_btree_read_super()");
+
+	bh = befs_read_datastream(sb, ds, 0, NULL);
+
+	if (!bh) {
+		befs_error(sb, "Couldn't read index header.");
+		goto error;
+	}
+	od_sup = (befs_btree_super *) bh->b_data;
+	befs_dump_index_entry(sb, od_sup);
+
+	sup->magic = fs32_to_cpu(sb, od_sup->magic);
+	sup->node_size = fs32_to_cpu(sb, od_sup->node_size);
+	sup->max_depth = fs32_to_cpu(sb, od_sup->max_depth);
+	sup->data_type = fs32_to_cpu(sb, od_sup->data_type);
+	sup->root_node_ptr = fs64_to_cpu(sb, od_sup->root_node_ptr);
+	sup->free_node_ptr = fs64_to_cpu(sb, od_sup->free_node_ptr);
+	sup->max_size = fs64_to_cpu(sb, od_sup->max_size);
+
+	brelse(bh);
+	if (sup->magic != BEFS_BTREE_MAGIC) {
+		befs_error(sb, "Index header has bad magic.");
+		goto error;
+	}
+
+	befs_debug(sb, "<--- befs_btree_read_super()");
+	return BEFS_OK;
+
+      error:
+	befs_debug(sb, "<--- befs_btree_read_super() ERROR");
+	return BEFS_ERR;
+}
+
+/**
+ * befs_bt_read_node - read in btree node and convert to cpu byteorder
+ * @sb: Filesystem superblock
+ * @ds: Datastream to read from
+ * @node: Buffer in which to place the btree node
+ * @node_off: Starting offset (in bytes) of the node in @ds
+ *
+ * Calls befs_read_datastream to read in the indicated btree node and
+ * makes sure its header feilds are in cpu byteorder, byteswapping if 
+ * nessisary.
+ * Note: node->bh must be NULL when this function called first
+ * time. Don't forget brelse(node->bh) after last call.
+ *
+ * On success, returns BEFS_OK and *@node contains the btree node that
+ * starts at @node_off, with the node->head fields in cpu byte order.
+ *
+ * On failure, BEFS_ERR is returned.
+ */
+
+static int
+befs_bt_read_node(struct super_block *sb, befs_data_stream * ds,
+		  befs_btree_node * node, befs_off_t node_off)
+{
+	uint off = 0;
+
+	befs_debug(sb, "---> befs_bt_read_node()");
+
+	if (node->bh)
+		brelse(node->bh);
+
+	node->bh = befs_read_datastream(sb, ds, node_off, &off);
+	if (!node->bh) {
+		befs_error(sb, "befs_bt_read_node() failed to read "
+			   "node at %Lu", node_off);
+		befs_debug(sb, "<--- befs_bt_read_node() ERROR");
+
+		return BEFS_ERR;
+	}
+	node->od_node =
+	    (befs_btree_nodehead *) ((void *) node->bh->b_data + off);
+
+	befs_dump_index_node(sb, node->od_node);
+
+	node->head.left = fs64_to_cpu(sb, node->od_node->left);
+	node->head.right = fs64_to_cpu(sb, node->od_node->right);
+	node->head.overflow = fs64_to_cpu(sb, node->od_node->overflow);
+	node->head.all_key_count =
+	    fs16_to_cpu(sb, node->od_node->all_key_count);
+	node->head.all_key_length =
+	    fs16_to_cpu(sb, node->od_node->all_key_length);
+
+	befs_debug(sb, "<--- befs_btree_read_node()");
+	return BEFS_OK;
+}
+
+/**
+ * befs_btree_find - Find a key in a befs B+tree
+ * @sb: Filesystem superblock
+ * @ds: Datastream containing btree
+ * @key: Key string to lookup in btree
+ * @value: Value stored with @key
+ *
+ * On sucess, returns BEFS_OK and sets *@value to the value stored
+ * with @key (usually the disk block number of an inode).
+ *
+ * On failure, returns BEFS_ERR or BEFS_BT_NOT_FOUND.
+ * 
+ * Algorithm: 
+ *   Read the superblock and rootnode of the b+tree.
+ *   Drill down through the interior nodes using befs_find_key().
+ *   Once at the correct leaf node, use befs_find_key() again to get the
+ *   actuall value stored with the key.
+ */
+int
+befs_btree_find(struct super_block *sb, befs_data_stream * ds,
+		const char *key, befs_off_t * value)
+{
+	befs_btree_node *this_node = NULL;
+	befs_btree_super bt_super;
+	befs_off_t node_off;
+	int res;
+
+	befs_debug(sb, "---> befs_btree_find() Key: %s", key);
+
+	if (befs_bt_read_super(sb, ds, &bt_super) != BEFS_OK) {
+		befs_error(sb,
+			   "befs_btree_find() failed to read index superblock");
+		goto error;
+	}
+
+	this_node = (befs_btree_node *) kmalloc(sizeof (befs_btree_node),
+						GFP_NOFS);
+	if (!this_node) {
+		befs_error(sb, "befs_btree_find() failed to allocate %u "
+			   "bytes of memory", sizeof (befs_btree_node));
+		goto error;
+	}
+
+	this_node->bh = NULL;
+
+	/* read in root node */
+	node_off = bt_super.root_node_ptr;
+	if (befs_bt_read_node(sb, ds, this_node, node_off) != BEFS_OK) {
+		befs_error(sb, "befs_btree_find() failed to read "
+			   "node at %Lu", node_off);
+		goto error_alloc;
+	}
+
+	while (!befs_leafnode(this_node)) {
+		res = befs_find_key(sb, this_node, key, &node_off);
+		if (res == BEFS_BT_NOT_FOUND)
+			node_off = this_node->head.overflow;
+		/* if no match, go to overflow node */
+		if (befs_bt_read_node(sb, ds, this_node, node_off) != BEFS_OK) {
+			befs_error(sb, "befs_btree_find() failed to read "
+				   "node at %Lu", node_off);
+			goto error_alloc;
+		}
+	}
+
+	/* at the correct leaf node now */
+
+	res = befs_find_key(sb, this_node, key, value);
+
+	brelse(this_node->bh);
+	kfree(this_node);
+
+	if (res != BEFS_BT_MATCH) {
+		befs_debug(sb, "<--- befs_btree_find() Key %s not found", key);
+		*value = 0;
+		return BEFS_BT_NOT_FOUND;
+	}
+	befs_debug(sb, "<--- befs_btree_find() Found key %s, value %Lu",
+		   key, *value);
+	return BEFS_OK;
+
+      error_alloc:
+	kfree(this_node);
+      error:
+	*value = 0;
+	befs_debug(sb, "<--- befs_btree_find() ERROR");
+	return BEFS_ERR;
+}
+
+/**
+ * befs_find_key - Search for a key within a node
+ * @sb: Filesystem superblock
+ * @node: Node to find the key within
+ * @key: Keystring to search for
+ * @value: If key is found, the value stored with the key is put here
+ *
+ * finds exact match if one exists, and returns BEFS_BT_MATCH
+ * If no exact match, finds first key in node that is greater
+ * (alpabeticly) than the search key and returns BEFS_BT_PARMATCH
+ * (for partial match, I guess). Can you think of something better to
+ * call it?
+ *
+ * If no key was a match or greater than the search key, return
+ * BEFS_BT_NOT_FOUND.
+ *
+ * Use binary search instead of a linear.
+ */
+static int
+befs_find_key(struct super_block *sb, befs_btree_node * node,
+	      const char *findkey, befs_off_t * value)
+{
+	int first, last, mid;
+	int eq;
+	u16 keylen;
+	int findkey_len;
+	char *thiskey;
+	befs_off_t *valarray;
+
+	befs_debug(sb, "---> befs_find_key() %s", findkey);
+
+	*value = 0;
+
+	findkey_len = strlen(findkey);
+
+	/* if node can not contain key, just skeep this node */
+	last = node->head.all_key_count - 1;
+	thiskey = befs_bt_get_key(sb, node, last, &keylen);
+
+	eq = befs_compare_strings(thiskey, keylen, findkey, findkey_len);
+	if (eq < 0) {
+		befs_debug(sb, "<--- befs_find_key() %s not found", findkey);
+		return BEFS_BT_NOT_FOUND;
+	}
+
+	valarray = befs_bt_valarray(node);
+
+	/* simple binary search */
+	first = 0;
+	mid = 0;
+	while (last >= first) {
+		mid = (last + first) / 2;
+		befs_debug(sb, "first: %d, last: %d, mid: %d", first, last,
+			   mid);
+		thiskey = befs_bt_get_key(sb, node, mid, &keylen);
+		eq = befs_compare_strings(thiskey, keylen, findkey,
+					  findkey_len);
+		*value = fs64_to_cpu(sb, valarray[mid]);
+
+		if (eq == 0) {
+			befs_debug(sb, "<--- befs_find_key() found %s at %d",
+				   thiskey, mid);
+
+			return BEFS_BT_MATCH;
+		}
+		if (eq > 0)
+			last = mid - 1;
+		else
+			first = mid + 1;
+	}
+	if (eq < 0)
+		*value = fs64_to_cpu(sb, valarray[mid + 1]);
+	befs_debug(sb, "<--- befs_find_key() found %s at %d", thiskey, mid);
+	return BEFS_BT_PARMATCH;
+}
+
+/**
+ * befs_btree_read - Traverse leafnodes of a btree
+ * @sb: Filesystem superblock
+ * @ds: Datastream containing btree
+ * @key_no: Key number (alphabetical order) of key to read
+ * @bufsize: Size of the buffer to return key in
+ * @keybuf: Pointer to a buffer to put the key in
+ * @keysize: Length of the returned key
+ * @value: Value stored with the returned key
+ *
+ * Heres how it works: Key_no is the index of the key/value pair to 
+ * retun in keybuf/value.
+ * Bufsize is the size of keybuf (BEFS_NAME_LEN+1 is a good size). Keysize is 
+ * the number of charecters in the key (just a convience).
+ *
+ * Algorithm:
+ *   Get the first leafnode of the tree. See if the requested key is in that
+ *   node. If not, follow the node->right link to the next leafnode. Repeat 
+ *   until the (key_no)th key is found or the tree is out of keys.
+ */
+int
+befs_btree_read(struct super_block *sb, befs_data_stream * ds,
+		loff_t key_no, size_t bufsize, char *keybuf, size_t * keysize,
+		befs_off_t * value)
+{
+	befs_btree_node *this_node;
+	befs_btree_super bt_super;
+	befs_off_t node_off = 0;
+	int cur_key;
+	befs_off_t *valarray;
+	char *keystart;
+	u16 keylen;
+	int res;
+
+	uint key_sum = 0;
+
+	befs_debug(sb, "---> befs_btree_read()");
+
+	if (befs_bt_read_super(sb, ds, &bt_super) != BEFS_OK) {
+		befs_error(sb,
+			   "befs_btree_read() failed to read index superblock");
+		goto error;
+	}
+
+	if ((this_node = (befs_btree_node *)
+	     kmalloc(sizeof (befs_btree_node), GFP_NOFS)) == NULL) {
+		befs_error(sb, "befs_btree_read() failed to allocate %u "
+			   "bytes of memory", sizeof (befs_btree_node));
+		goto error;
+	}
+
+	node_off = bt_super.root_node_ptr;
+	this_node->bh = NULL;
+
+	/* seeks down to first leafnode, reads it into this_node */
+	res = befs_btree_seekleaf(sb, ds, &bt_super, this_node, &node_off);
+	if (res == BEFS_BT_EMPTY) {
+		brelse(this_node->bh);
+		kfree(this_node);
+		*value = 0;
+		*keysize = 0;
+		befs_debug(sb, "<--- befs_btree_read() Tree is EMPTY");
+		return BEFS_BT_EMPTY;
+	} else if (res == BEFS_ERR) {
+		goto error_alloc;
+	}
+
+	/* find the leaf node containing the key_no key */
+
+	while (key_sum + this_node->head.all_key_count <= key_no) {
+
+		/* no more nodes to look in: key_no is too large */
+		if (this_node->head.right == befs_bt_inval) {
+			*keysize = 0;
+			*value = 0;
+			befs_debug(sb,
+				   "<--- befs_btree_read() END of keys at %Lu",
+				   key_sum + this_node->head.all_key_count);
+			brelse(this_node->bh);
+			kfree(this_node);
+			return BEFS_BT_END;
+		}
+
+		key_sum += this_node->head.all_key_count;
+		node_off = this_node->head.right;
+
+		if (befs_bt_read_node(sb, ds, this_node, node_off) != BEFS_OK) {
+			befs_error(sb, "befs_btree_read() failed to read "
+				   "node at %Lu", node_off);
+			goto error_alloc;
+		}
+	}
+
+	/* how many keys into this_node is key_no */
+	cur_key = key_no - key_sum;
+
+	/* get pointers to datastructures within the node body */
+	valarray = befs_bt_valarray(this_node);
+
+	keystart = befs_bt_get_key(sb, this_node, cur_key, &keylen);
+
+	befs_debug(sb, "Read [%Lu,%d]: keysize %d", node_off, cur_key, keylen);
+
+	if (bufsize < keylen + 1) {
+		befs_error(sb, "befs_btree_read() keybuf too small (%u) "
+			   "for key of size %d", bufsize, keylen);
+		brelse(this_node->bh);
+		goto error_alloc;
+	};
+
+	strncpy(keybuf, keystart, keylen);
+	*value = fs64_to_cpu(sb, valarray[cur_key]);
+	*keysize = keylen;
+	keybuf[keylen] = '\0';
+
+	befs_debug(sb, "Read [%Lu,%d]: Key \"%.*s\", Value %Lu", node_off,
+		   cur_key, keylen, keybuf, *value);
+
+	brelse(this_node->bh);
+	kfree(this_node);
+
+	befs_debug(sb, "<--- befs_btree_read()");
+
+	return BEFS_OK;
+
+      error_alloc:
+	kfree(this_node);
+
+      error:
+	*keysize = 0;
+	*value = 0;
+	befs_debug(sb, "<--- befs_btree_read() ERROR");
+	return BEFS_ERR;
+}
+
+/**
+ * befs_btree_seekleaf - Find the first leafnode in the btree
+ * @sb: Filesystem superblock
+ * @ds: Datastream containing btree
+ * @bt_super: Pointer to the uperblock of the btree
+ * @this_node: Buffer to return the leafnode in
+ * @node_off: Pointer to offset of current node within datastream. Modified
+ * 		by the function.
+ *
+ *
+ * Helper function for btree traverse. Moves the current position to the 
+ * start of the first leaf node.
+ *
+ * Also checks for an empty tree. If there are no keys, returns BEFS_BT_EMPTY.
+ */
+static int
+befs_btree_seekleaf(struct super_block *sb, befs_data_stream * ds,
+		    befs_btree_super * bt_super, befs_btree_node * this_node,
+		    befs_off_t * node_off)
+{
+
+	befs_debug(sb, "---> befs_btree_seekleaf()");
+
+	if (befs_bt_read_node(sb, ds, this_node, *node_off) != BEFS_OK) {
+		befs_error(sb, "befs_btree_seekleaf() failed to read "
+			   "node at %Lu", *node_off);
+		goto error;
+	}
+	befs_debug(sb, "Seekleaf to root node %Lu", *node_off);
+
+	if (this_node->head.all_key_count == 0 && befs_leafnode(this_node)) {
+		befs_debug(sb, "<--- befs_btree_seekleaf() Tree is EMPTY");
+		return BEFS_BT_EMPTY;
+	}
+
+	while (!befs_leafnode(this_node)) {
+
+		if (this_node->head.all_key_count == 0) {
+			befs_debug(sb, "befs_btree_seekleaf() encountered "
+				   "an empty interior node: %Lu. Using Overflow "
+				   "node: %Lu", *node_off,
+				   this_node->head.overflow);
+			*node_off = this_node->head.overflow;
+		} else {
+			befs_off_t *valarray = befs_bt_valarray(this_node);
+			*node_off = fs64_to_cpu(sb, valarray[0]);
+		}
+		if (befs_bt_read_node(sb, ds, this_node, *node_off) != BEFS_OK) {
+			befs_error(sb, "befs_btree_seekleaf() failed to read "
+				   "node at %Lu", *node_off);
+			goto error;
+		}
+
+		befs_debug(sb, "Seekleaf to child node %Lu", *node_off);
+	}
+	befs_debug(sb, "Node %Lu is a leaf node", *node_off);
+
+	return BEFS_OK;
+
+      error:
+	befs_debug(sb, "<--- befs_btree_seekleaf() ERROR");
+	return BEFS_ERR;
+}
+
+/**
+ * befs_leafnode - Determine if the btree node is a leaf node or an 
+ * interior node
+ * @node: Pointer to node structure to test
+ * 
+ * Return 1 if leaf, 0 if interior
+ */
+static int
+befs_leafnode(befs_btree_node * node)
+{
+	/* all interior nodes (and only interior nodes) have an overflow node */
+	if (node->head.overflow == befs_bt_inval)
+		return 1;
+	else
+		return 0;
+}
+
+/**
+ * befs_bt_keylen_index - Finds start of keylen index in a node
+ * @node: Pointer to the node structure to find the keylen index within
+ *
+ * Returns a pointer to the start of the key length index array
+ * of the B+tree node *@node
+ *
+ * "The length of all the keys in the node is added to the size of the
+ * header and then rounded up to a multiple of four to get the begining
+ * of the key length index" (p.88, practical filesystem design).
+ *
+ * Exept that rounding up to 8 works, and rounding up to 4 doesn't.
+ */
+static u16 *
+befs_bt_keylen_index(befs_btree_node * node)
+{
+	const int keylen_align = 8;
+	unsigned long int off =
+	    (sizeof (befs_btree_nodehead) + node->head.all_key_length);
+	ulong tmp = off % keylen_align;
+
+	if (tmp)
+		off += keylen_align - tmp;
+
+	return (u16 *) ((void *) node->od_node + off);
+}
+
+/**
+ * befs_bt_valarray - Finds the start of value array in a node
+ * @node: Pointer to the node structure to find the value array within
+ *
+ * Returns a pointer to the start of the value array
+ * of the node pointed to by the node header
+ */
+static befs_off_t *
+befs_bt_valarray(befs_btree_node * node)
+{
+	void *keylen_index_start = (void *) befs_bt_keylen_index(node);
+	size_t keylen_index_size = node->head.all_key_count * sizeof (u16);
+
+	return (befs_off_t *) (keylen_index_start + keylen_index_size);
+}
+
+/**
+ * befs_bt_keydata - Finds start of keydata array in a node
+ * @node: Pointer to the node structure to find the keydata array within
+ *
+ * Returns a pointer to the start of the keydata array
+ * of the node pointed to by the node header 
+ */
+static char *
+befs_bt_keydata(befs_btree_node * node)
+{
+	return (char *) ((void *) node->od_node + sizeof (befs_btree_nodehead));
+}
+
+/**
+ * befs_bt_get_key - returns a pointer to the start of a key
+ * @sb: filesystem superblock
+ * @node: node in which to look for the key
+ * @index: the index of the key to get
+ * @keylen: modified to be the length of the key at @index
+ *
+ * Returns a valid pointer into @node on success.
+ * Returns NULL on failure (bad input) and sets *@keylen = 0
+ */
+static char *
+befs_bt_get_key(struct super_block *sb, befs_btree_node * node,
+		int index, u16 * keylen)
+{
+	int prev_key_end;
+	char *keystart;
+	u16 *keylen_index;
+
+	if (index < 0 || index > node->head.all_key_count) {
+		*keylen = 0;
+		return NULL;
+	}
+
+	keystart = befs_bt_keydata(node);
+	keylen_index = befs_bt_keylen_index(node);
+
+	if (index == 0)
+		prev_key_end = 0;
+	else
+		prev_key_end = fs16_to_cpu(sb, keylen_index[index - 1]);
+
+	*keylen = fs16_to_cpu(sb, keylen_index[index]) - prev_key_end;
+
+	return keystart + prev_key_end;
+}
+
+/**
+ * befs_compare_strings - compare two strings
+ * @key1: pointer to the first key to be compared 
+ * @keylen1: length in bytes of key1
+ * @key2: pointer to the second key to be compared
+ * @kelen2: lenght in bytes of key2
+ *
+ * Returns 0 if @key1 and @key2 are equal.
+ * Returns >0 if @key1 is greater.
+ * Returns <0 if @key2 is greater..
+ */
+static int
+befs_compare_strings(const void *key1, int keylen1,
+		     const void *key2, int keylen2)
+{
+	int len = min_t(int, keylen1, keylen2);
+	int result = strncmp(key1, key2, len);
+	if (result == 0)
+		result = keylen1 - keylen2;
+	return result;
+}
+
+/* These will be used for non-string keyed btrees */
+#if 0
+static int
+btree_compare_int32(cont void *key1, int keylen1, const void *key2, int keylen2)
+{
+	return *(int32_t *) key1 - *(int32_t *) key2;
+}
+
+static int
+btree_compare_uint32(cont void *key1, int keylen1,
+		     const void *key2, int keylen2)
+{
+	if (*(u_int32_t *) key1 == *(u_int32_t *) key2)
+		return 0;
+	else if (*(u_int32_t *) key1 > *(u_int32_t *) key2)
+		return 1;
+
+	return -1;
+}
+static int
+btree_compare_int64(cont void *key1, int keylen1, const void *key2, int keylen2)
+{
+	if (*(int64_t *) key1 == *(int64_t *) key2)
+		return 0;
+	else if (*(int64_t *) key1 > *(int64_t *) key2)
+		return 1;
+
+	return -1;
+}
+
+static int
+btree_compare_uint64(cont void *key1, int keylen1,
+		     const void *key2, int keylen2)
+{
+	if (*(u_int64_t *) key1 == *(u_int64_t *) key2)
+		return 0;
+	else if (*(u_int64_t *) key1 > *(u_int64_t *) key2)
+		return 1;
+
+	return -1;
+}
+
+static int
+btree_compare_float(cont void *key1, int keylen1, const void *key2, int keylen2)
+{
+	float result = *(float *) key1 - *(float *) key2;
+	if (result == 0.0f)
+		return 0;
+
+	return (result < 0.0f) ? -1 : 1;
+}
+
+static int
+btree_compare_double(cont void *key1, int keylen1,
+		     const void *key2, int keylen2)
+{
+	double result = *(double *) key1 - *(double *) key2;
+	if (result == 0.0)
+		return 0;
+
+	return (result < 0.0) ? -1 : 1;
+}
+#endif				//0

fs/befs/btree.h

+/*
+ * btree.h
+ * 
+ */
+
+
+int befs_btree_find(struct super_block *sb, befs_data_stream * ds,
+		    const char *key, befs_off_t * value);
+
+int befs_btree_read(struct super_block *sb, befs_data_stream * ds,
+		    loff_t key_no, size_t bufsize, char *keybuf,
+		    size_t * keysize, befs_off_t * value);
+

fs/befs/datastream.c

+/*
+ * linux/fs/befs/datastream.c
+ *
+ * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com>
+ *
+ * Based on portions of file.c by Makoto Kato <m_kato@ga2.so-net.ne.jp>
+ *
+ * Many thanks to Dominic Giampaolo, author of "Practical File System
+ * Design with the Be File System", for such a helpful book.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+
+#include "befs.h"
+#include "datastream.h"
+#include "io.h"
+#include "endian.h"
+
+const befs_inode_addr BAD_IADDR = { 0, 0, 0 };
+
+static int befs_find_brun_direct(struct super_block *sb,
+				 befs_data_stream * data,
+				 befs_blocknr_t blockno, befs_block_run * run);
+
+static int befs_find_brun_indirect(struct super_block *sb,
+				   befs_data_stream * data,
+				   befs_blocknr_t blockno,
+				   befs_block_run * run);
+
+static int befs_find_brun_dblindirect(struct super_block *sb,
+				      befs_data_stream * data,
+				      befs_blocknr_t blockno,
+				      befs_block_run * run);
+
+/**
+ * befs_read_datastream - get buffer_head containing data, starting from pos.
+ * @sb: Filesystem superblock
+ * @ds: datastrem to find data with
+ * @pos: start of data
+ * @off: offset of data in buffer_head->b_data
+ *
+ * Returns pointer to buffer_head containing data starting with offset @off,
+ * if you don't need to know offset just set @off = NULL.
+ */
+struct buffer_head *
+befs_read_datastream(struct super_block *sb, befs_data_stream * ds,
+		     befs_off_t pos, uint * off)
+{
+	struct buffer_head *bh = NULL;
+	befs_block_run run;
+	befs_blocknr_t block;	/* block coresponding to pos */
+
+	befs_debug(sb, "---> befs_read_datastream() %Lu", pos);
+	block = pos >> BEFS_SB(sb)->block_shift;
+	if (off)
+		*off = pos - (block << BEFS_SB(sb)->block_shift);
+
+	if (befs_fblock2brun(sb, ds, block, &run) != BEFS_OK) {
+		befs_error(sb, "BeFS: Error finding disk addr of block %lu",
+			   block);
+		befs_debug(sb, "<--- befs_read_datastream() ERROR");
+		return NULL;
+	}
+	bh = befs_bread_iaddr(sb, run);
+	if (!bh) {
+		befs_error(sb, "BeFS: Error reading block %lu from datastream",
+			   block);
+		return NULL;
+	}
+
+	befs_debug(sb, "<--- befs_read_datastream() read data, starting at %Lu",
+		   pos);
+
+	return bh;
+}
+
+/*
+ * Takes a file position and gives back a brun who's starting block
+ * is block number fblock of the file.
+ * 
+ * Returns BEFS_OK or BEFS_ERR.
+ * 
+ * Calls specialized functions for each of the three possible
+ * datastream regions.
+ *
+ * 2001-11-15 Will Dyson
+ */
+int
+befs_fblock2brun(struct super_block *sb, befs_data_stream * data,
+		 befs_blocknr_t fblock, befs_block_run * run)
+{
+	int err;
+	befs_off_t pos = fblock << BEFS_SB(sb)->block_shift;
+
+	if (pos < data->max_direct_range) {
+		err = befs_find_brun_direct(sb, data, fblock, run);
+
+	} else if (pos < data->max_indirect_range) {
+		err = befs_find_brun_indirect(sb, data, fblock, run);
+
+	} else if (pos < data->max_double_indirect_range) {
+		err = befs_find_brun_dblindirect(sb, data, fblock, run);
+
+	} else {
+		befs_error(sb,
+			   "befs_fblock2brun() was asked to find block %lu, "
+			   "which is not mapped by the datastream\n", fblock);
+		err = BEFS_ERR;
+	}
+	return err;
+}
+
+/**
+ * befs_read_lsmylink - read long symlink from datastream.
+ * @sb: Filesystem superblock 
+ * @ds: Datastrem to read from
+ * @buf: Buffer in wich to place long symlink data
+ * @len: Length of the long symlink in bytes
+ *
+ * Returns the number of bytes read
+ */
+size_t
+befs_read_lsymlink(struct super_block * sb, befs_data_stream * ds, void *buff,
+		   befs_off_t len)
+{
+	befs_off_t bytes_read = 0;	/* bytes readed */
+	u16 plen;
+	struct buffer_head *bh = NULL;
+	befs_debug(sb, "---> befs_read_lsymlink() length: %Lu", len);
+
+	while (bytes_read < len) {
+		bh = befs_read_datastream(sb, ds, bytes_read, NULL);
+		if (!bh) {
+			befs_error(sb, "BeFS: Error reading datastream block "
+				   "starting from %Lu", bytes_read);
+			befs_debug(sb, "<--- befs_read_lsymlink() ERROR");
+			return bytes_read;
+
+		}
+		plen = ((bytes_read + BEFS_SB(sb)->block_size) < len) ?
+		    BEFS_SB(sb)->block_size : len - bytes_read;
+		memcpy(buff + bytes_read, bh->b_data, plen);
+		brelse(bh);
+		bytes_read += plen;
+	}
+
+	befs_debug(sb, "<--- befs_read_lsymlink() read %u bytes", bytes_read);
+	return bytes_read;
+}
+
+/**
+ * befs_count_blocks - blocks used by a file
+ * @sb: Filesystem superblock
+ * @ds: Datastream of the file
+ *
+ * Counts the number of fs blocks that the file represented by
+ * inode occupies on the filesystem, counting both regular file
+ * data and filesystem metadata (and eventually attribute data
+ * when we support attributes)
+*/
+
+befs_blocknr_t
+befs_count_blocks(struct super_block * sb, befs_data_stream * ds)
+{
+	befs_blocknr_t blocks;
+	befs_blocknr_t datablocks;	/* File data blocks */
+	befs_blocknr_t metablocks;	/* FS metadata blocks */
+	befs_sb_info *befs_sb = BEFS_SB(sb);
+
+	befs_debug(sb, "---> befs_count_blocks()");
+
+	datablocks = ds->size >> befs_sb->block_shift;
+	if (ds->size & (befs_sb->block_size - 1))
+		datablocks += 1;
+
+	metablocks = 1;		/* Start with 1 block for inode */
+
+	/* Size of indirect block */
+	if (ds->size > ds->max_direct_range)
+		metablocks += ds->indirect.len;
+
+	/*
+	   Double indir block, plus all the indirect blocks it mapps
+	   In the double-indirect range, all block runs of data are
+	   BEFS_DBLINDIR_BRUN_LEN blocks long. Therefore, we know 
+	   how many data block runs are in the double-indirect region,
+	   and from that we know how many indirect blocks it takes to
+	   map them. We assume that the indirect blocks are also
+	   BEFS_DBLINDIR_BRUN_LEN blocks long.
+	 */
+	if (ds->size > ds->max_indirect_range && ds->max_indirect_range != 0) {
+		uint dbl_bytes;
+		uint dbl_bruns;
+		uint indirblocks;
+
+		dbl_bytes =
+		    ds->max_double_indirect_range - ds->max_indirect_range;
+		dbl_bruns =
+		    dbl_bytes / (befs_sb->block_size * BEFS_DBLINDIR_BRUN_LEN);
+		indirblocks = dbl_bruns / befs_iaddrs_per_block(sb);
+
+		metablocks += ds->double_indirect.len;
+		metablocks += indirblocks;
+	}
+
+	blocks = datablocks + metablocks;
+	befs_debug(sb, "<--- befs_count_blocks() %u blocks", blocks);
+
+	return blocks;
+}
+
+/*
+	Finds the block run that starts at file block number blockno
+	in the file represented by the datastream data, if that 
+	blockno is in the direct region of the datastream.
+	
+	sb: the superblock
+	data: the datastream
+	blockno: the blocknumber to find
+	run: The found run is passed back through this pointer
+	
+	Return value is BEFS_OK if the blockrun is found, BEFS_ERR
+	otherwise.
+	
+	Algorithm:
+	Linear search. Checks each element of array[] to see if it
+	contains the blockno-th filesystem block. This is nessisary
+	because the block runs map variable amounts of data. Simply
+	keeps a count of the number of blocks searched so far (sum),
+	incrementing this by the length of each block run as we come
+	across it. Adds sum to *count before returning (this is so
+	you can search multiple arrays that are logicaly one array,
+	as in the indirect region code).
+	
+	When/if blockno is found, if blockno is inside of a block 
+	run as stored on disk, we offset the start and lenght members 
+	of the block run, so that blockno is the start and len is
+	still valid (the run ends in the same place).
+	
+	2001-11-15 Will Dyson
+*/
+static int
+befs_find_brun_direct(struct super_block *sb, befs_data_stream * data,
+		      befs_blocknr_t blockno, befs_block_run * run)
+{
+	int i;
+	befs_block_run *array = data->direct;
+	befs_blocknr_t sum;
+	befs_blocknr_t max_block =
+	    data->max_direct_range >> BEFS_SB(sb)->block_shift;
+
+	befs_debug(sb, "---> befs_find_brun_direct(), find %lu", blockno);
+
+	if (blockno > max_block) {
+		befs_error(sb, "befs_find_brun_direct() passed block outside of"
+			   "direct region");
+		return BEFS_ERR;
+	}
+
+	for (i = 0, sum = 0; i < BEFS_NUM_DIRECT_BLOCKS;
+	     sum += array[i].len, i++) {
+		if (blockno >= sum && blockno < sum + (array[i].len)) {
+			int offset = blockno - sum;
+			run->allocation_group = array[i].allocation_group;
+			run->start = array[i].start + offset;
+			run->len = array[i].len - offset;
+
+			befs_debug(sb, "---> befs_find_brun_direct(), "
+				   "found %lu at direct[%d]", blockno, i);
+			return BEFS_OK;
+		}
+	}
+
+	befs_debug(sb, "---> befs_find_brun_direct() ERROR");
+	return BEFS_ERR;
+}
+
+/*
+	Finds the block run that starts at file block number blockno
+	in the file represented by the datastream data, if that 
+	blockno is in the indirect region of the datastream.
+	
+	sb: the superblock
+	data: the datastream
+	blockno: the blocknumber to find
+	run: The found run is passed back through this pointer
+	
+	Return value is BEFS_OK if the blockrun is found, BEFS_ERR
+	otherwise.
+	
+	Algorithm:
+	For each block in the indirect run of the datastream, read
+	it in and search through it for	search_blk.
+	
+	XXX:
+	Really should check to make sure blockno is inside indirect
+	region.
+	
+	2001-11-15 Will Dyson
+*/
+static int
+befs_find_brun_indirect(struct super_block *sb,
+			befs_data_stream * data, befs_blocknr_t blockno,
+			befs_block_run * run)
+{
+	int i, j;
+	befs_blocknr_t sum = 0;
+	befs_blocknr_t indir_start_blk;
+	befs_blocknr_t search_blk;
+	struct buffer_head *indirblock;
+	befs_block_run *array;
+
+	befs_block_run indirect = data->indirect;
+	befs_blocknr_t indirblockno = iaddr2blockno(sb, &indirect);
+	int arraylen = befs_iaddrs_per_block(sb);
+
+	befs_debug(sb, "---> befs_find_brun_indirect(), find %lu", blockno);
+
+	indir_start_blk = data->max_direct_range >> BEFS_SB(sb)->block_shift;
+	search_blk = blockno - indir_start_blk;
+
+	/* Examine blocks of the indirect run one at a time */
+	for (i = 0; i < indirect.len; i++) {
+		indirblock = befs_bread(sb, indirblockno + i);
+		if (indirblock == NULL) {
+			befs_debug(sb,
+				   "---> befs_find_brun_indirect() failed to "
+				   "read disk block %lu from the indirect brun",
+				   indirblockno + i);
+			return BEFS_ERR;
+		}
+
+		array = (befs_block_run *) indirblock->b_data;
+
+		for (j = 0; j < arraylen; ++j) {
+			int len = fs16_to_cpu(sb, array[j].len);
+
+			if (search_blk >= sum && search_blk < sum + len) {
+				int offset = search_blk - sum;
+				run->allocation_group =
+				    fs32_to_cpu(sb, array[j].allocation_group);
+				run->start =
+				    fs16_to_cpu(sb, array[j].start) + offset;
+				run->len =
+				    fs16_to_cpu(sb, array[j].len) - offset;
+
+				brelse(indirblock);
+				befs_debug(sb,
+					   "<--- befs_find_brun_indirect() found "
+					   "file block %lu at indirect[%d]",
+					   blockno, j + (i * arraylen));
+				return BEFS_OK;
+			}
+			sum += len;
+		}
+
+		brelse(indirblock);
+	}
+
+	/* Only fallthrough is an error */
+	befs_error(sb, "BeFS: befs_find_brun_indirect() failed to find "
+		   "file block %lu", blockno);
+
+	befs_debug(sb, "<--- befs_find_brun_indirect() ERROR");
+	return BEFS_ERR;
+}
+
+/*
+	Finds the block run that starts at file block number blockno
+	in the file represented by the datastream data, if that 
+	blockno is in the double-indirect region of the datastream.
+	
+	sb: the superblock
+	data: the datastream
+	blockno: the blocknumber to find
+	run: The found run is passed back through this pointer
+	
+	Return value is BEFS_OK if the blockrun is found, BEFS_ERR
+	otherwise.
+	
+	Algorithm:
+	The block runs in the double-indirect region are different.
+	They are always allocated 4 fs blocks at a time, so each
+	block run maps a constant amount of file data. This means
+	that we can directly calculate how many block runs into the
+	double-indirect region we need to go to get to the one that
+	maps a particular filesystem block.
+	
+	We do this in two stages. First we calculate which of the
+	inode addresses in the double-indirect block will point us
+	to the indirect block that contains the mapping for the data,
+	then we calculate which of the inode addresses in that 
+	indirect block maps the data block we are after.
+	
+	Oh, and once we've done that, we actually read in the blocks 
+	that contain the inode addresses we calculated above. Even 
+	though the double-indirect run may be several blocks long, 
+	we can calculate which of those blocks will contain the index
+	we are after and only read that one. We then follow it to 
+	the indirect block and perform a  similar process to find
+	the actual block run that maps the data block we are interested
+	in.
+	
+	Then we offset the run as in befs_find_brun_array() and we are 
+	done.
+	
+	2001-11-15 Will Dyson
+*/
+static int
+befs_find_brun_dblindirect(struct super_block *sb,
+			   befs_data_stream * data, befs_blocknr_t blockno,
+			   befs_block_run * run)
+{
+	int dblindir_indx;
+	int indir_indx;
+	int offset;
+	int dbl_which_block;
+	int which_block;
+	int dbl_block_indx;
+	int block_indx;
+	off_t dblindir_leftover;
+	befs_blocknr_t blockno_at_run_start;
+	struct buffer_head *dbl_indir_block;
+	struct buffer_head *indir_block;
+	befs_block_run indir_run;
+	befs_inode_addr *iaddr_array = NULL;
+	befs_sb_info *befs_sb = BEFS_SB(sb);
+
+	befs_blocknr_t indir_start_blk =
+	    data->max_indirect_range >> befs_sb->block_shift;
+
+	off_t dbl_indir_off = blockno - indir_start_blk;
+
+	/* number of data blocks mapped by each of the iaddrs in
+	 * the indirect block pointed to by the double indirect block
+	 */
+	size_t iblklen = BEFS_DBLINDIR_BRUN_LEN;
+
+	/* number of data blocks mapped by each of the iaddrs in
+	 * the double indirect block
+	 */
+	size_t diblklen = iblklen * befs_iaddrs_per_block(sb)
+	    * BEFS_DBLINDIR_BRUN_LEN;
+
+	befs_debug(sb, "---> befs_find_brun_dblindirect() find %lu", blockno);
+
+	/* First, discover which of the double_indir->indir blocks
+	 * contains pos. Then figure out how much of pos that
+	 * accounted for. Then discover which of the iaddrs in
+	 * the indirect block contains pos.
+	 */
+
+	dblindir_indx = dbl_indir_off / diblklen;
+	dblindir_leftover = dbl_indir_off % diblklen;
+	indir_indx = dblindir_leftover / diblklen;
+
+	/* Read double indirect block */
+	dbl_which_block = dblindir_indx / befs_iaddrs_per_block(sb);
+	if (dbl_which_block > data->double_indirect.len) {
+		befs_error(sb, "The double-indirect index calculated by "
+			   "befs_read_brun_dblindirect(), %d, is outside the range "
+			   "of the double-indirect block", dblindir_indx);
+		return BEFS_ERR;
+	}
+
+	dbl_indir_block =
+	    befs_bread(sb, iaddr2blockno(sb, &data->double_indirect) +
+					dbl_which_block);
+	if (dbl_indir_block == NULL) {
+		befs_error(sb, "befs_read_brun_dblindirect() couldn't read the "
+			   "double-indirect block at blockno %lu",
+			   iaddr2blockno(sb,
+					 &data->double_indirect) +
+			   dbl_which_block);
+		brelse(dbl_indir_block);
+		return BEFS_ERR;
+	}
+
+	dbl_block_indx =
+	    dblindir_indx - (dbl_which_block * befs_iaddrs_per_block(sb));
+	iaddr_array = (befs_inode_addr *) dbl_indir_block->b_data;
+	indir_run = fsrun_to_cpu(sb, iaddr_array[dbl_block_indx]);
+	brelse(dbl_indir_block);
+	iaddr_array = NULL;
+
+	/* Read indirect block */
+	which_block = indir_indx / befs_iaddrs_per_block(sb);
+	if (which_block > indir_run.len) {
+		befs_error(sb, "The indirect index calculated by "
+			   "befs_read_brun_dblindirect(), %d, is outside the range "
+			   "of the indirect block", indir_indx);
+		return BEFS_ERR;
+	}
+
+	indir_block =
+	    befs_bread(sb, iaddr2blockno(sb, &indir_run) + which_block);
+	if (indir_block == NULL) {
+		befs_error(sb, "befs_read_brun_dblindirect() couldn't read the "
+			   "indirect block at blockno %lu",
+			   iaddr2blockno(sb, &indir_run) + which_block);
+		brelse(indir_block);
+		return BEFS_ERR;
+	}
+
+	block_indx = indir_indx - (which_block * befs_iaddrs_per_block(sb));
+	iaddr_array = (befs_inode_addr *) indir_block->b_data;
+	*run = fsrun_to_cpu(sb, iaddr_array[block_indx]);
+	brelse(indir_block);
+	iaddr_array = NULL;
+
+	blockno_at_run_start = indir_start_blk;
+	blockno_at_run_start += diblklen * dblindir_indx;
+	blockno_at_run_start += iblklen * indir_indx;
+	offset = blockno - blockno_at_run_start;
+
+	run->start += offset;
+	run->len -= offset;
+
+	befs_debug(sb, "Found file block %lu in double_indirect[%d][%d],"
+		   " double_indirect_leftover = %lu",
+		   blockno, dblindir_indx, indir_indx, dblindir_leftover);
+
+	return BEFS_OK;
+}

fs/befs/datastream.h

+/*
+ * datastream.h
+ *
+ */
+
+struct buffer_head *befs_read_datastream(struct super_block *sb,
+					 befs_data_stream * ds, befs_off_t pos,
+					 uint * off);
+
+int befs_fblock2brun(struct super_block *sb, befs_data_stream * data,
+		     befs_blocknr_t fblock, befs_block_run * run);
+
+size_t befs_read_lsymlink(struct super_block *sb, befs_data_stream * data,
+			  void *buff, befs_off_t len);
+
+befs_blocknr_t befs_count_blocks(struct super_block *sb, befs_data_stream * ds);
+
+extern const befs_inode_addr BAD_IADDR;
+

fs/befs/debug.c

+/*
+ *  linux/fs/befs/debug.c
+ * 
+ * Copyright (C) 2001 Will Dyson (will_dyson at pobox.com)
+ *
+ * With help from the ntfs-tng driver by Anton Altparmakov
+ *
+ * Copyright (C) 1999  Makoto Kato (m_kato@ga2.so-net.ne.jp)
+ *
+ * debug functions
+ */
+
+#ifdef __KERNEL__
+
+#include <stdarg.h>
+#include <linux/string.h>
+#include <linux/spinlock.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+
+#endif				/* __KERNEL__ */
+
+#include "befs.h"
+#include "endian.h"
+
+#define ERRBUFSIZE 1024
+
+void
+befs_error(const struct super_block *sb, const char *fmt, ...)
+{
+	va_list args;
+	char err_buf[ERRBUFSIZE];
+
+	va_start(args, fmt);
+	vsnprintf(err_buf, ERRBUFSIZE, fmt, args);
+	va_end(args);
+
+	printk(KERN_ERR "BeFS(%s): %s\n", sb->s_id, err_buf);
+
+	befs_debug(sb, err_buf);
+}
+
+void
+befs_warning(const struct super_block *sb, const char *fmt, ...)
+{
+	va_list args;
+	char err_buf[ERRBUFSIZE];
+
+	va_start(args, fmt);
+	vsnprintf(err_buf, ERRBUFSIZE, fmt, args);
+	va_end(args);
+
+	printk(KERN_WARNING "BeFS(%s): %s\n", sb->s_id, err_buf);
+
+	befs_debug(sb, err_buf);
+}
+
+void
+befs_debug(const struct super_block *sb, const char *fmt, ...)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	va_list args;
+	char err_buf[ERRBUFSIZE];
+
+	if (BEFS_SB(sb)->mount_opts.debug) {
+		va_start(args, fmt);
+		vsnprintf(err_buf, ERRBUFSIZE, fmt, args);
+		va_end(args);
+
+		printk(KERN_DEBUG "BeFS(%s): %s\n", sb->s_id, err_buf);
+	}
+#endif				//CONFIG_BEFS_DEBUG
+}
+
+void
+befs_dump_inode(const struct super_block *sb, befs_inode * inode)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	befs_block_run tmp_run;
+
+	befs_debug(sb, "befs_inode infomation");
+
+	befs_debug(sb, "  magic1 %08x", fs32_to_cpu(sb, inode->magic1));
+
+	tmp_run = fsrun_to_cpu(sb, inode->inode_num);
+	befs_debug(sb, "  inode_num %u, %hu, %hu",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+	befs_debug(sb, "  uid %u", fs32_to_cpu(sb, inode->uid));
+	befs_debug(sb, "  gid %u", fs32_to_cpu(sb, inode->gid));
+	befs_debug(sb, "  mode %08x", fs32_to_cpu(sb, inode->mode));
+	befs_debug(sb, "  flags %08x", fs32_to_cpu(sb, inode->flags));
+	befs_debug(sb, "  create_time %Lu",
+		   fs64_to_cpu(sb, inode->create_time));
+	befs_debug(sb, "  last_modified_time %Lu",
+		   fs64_to_cpu(sb, inode->last_modified_time));
+
+	tmp_run = fsrun_to_cpu(sb, inode->parent);
+	befs_debug(sb, "  parent [%u, %hu, %hu]",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+	tmp_run = fsrun_to_cpu(sb, inode->attributes);
+	befs_debug(sb, "  attributes [%u, %hu, %hu]",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+	befs_debug(sb, "  type %08x", fs32_to_cpu(sb, inode->type));
+	befs_debug(sb, "  inode_size %u", fs32_to_cpu(sb, inode->inode_size));
+
+	if (S_ISLNK(inode->mode)) {
+		befs_debug(sb, "  Symbolic link [%s]", inode->data.symlink);
+	} else {
+		int i;
+
+		for (i = 0; i < BEFS_NUM_DIRECT_BLOCKS; i++) {
+			tmp_run =
+			    fsrun_to_cpu(sb, inode->data.datastream.direct[i]);
+			befs_debug(sb, "  direct %d [%u, %hu, %hu]", i,
+				   tmp_run.allocation_group, tmp_run.start,
+				   tmp_run.len);
+		}
+		befs_debug(sb, "  max_direct_range %Lu",
+			   fs64_to_cpu(sb,
+				       inode->data.datastream.
+				       max_direct_range));
+
+		tmp_run = fsrun_to_cpu(sb, inode->data.datastream.indirect);
+		befs_debug(sb, "  indirect [%u, %hu, %hu]",
+			   tmp_run.allocation_group,
+			   tmp_run.start, tmp_run.len);
+
+		befs_debug(sb, "  max_indirect_range %Lu",
+			   fs64_to_cpu(sb,
+				       inode->data.datastream.
+				       max_indirect_range));
+
+		tmp_run =
+		    fsrun_to_cpu(sb, inode->data.datastream.double_indirect);
+		befs_debug(sb, "  double indirect [%u, %hu, %hu]",
+			   tmp_run.allocation_group, tmp_run.start,
+			   tmp_run.len);
+
+		befs_debug(sb, "  max_double_indirect_range %Lu",
+			   fs64_to_cpu(sb,
+				       inode->data.datastream.
+				       max_double_indirect_range));
+
+		befs_debug(sb, "  size %Lu",
+			   fs64_to_cpu(sb, inode->data.datastream.size));
+	}
+
+#endif				//CONFIG_BEFS_DEBUG
+}
+
+/*
+ * Display super block structure for debug.
+ */
+
+void
+befs_dump_super_block(const struct super_block *sb, befs_super_block * sup)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	befs_block_run tmp_run;
+
+	befs_debug(sb, "befs_super_block information");
+
+	befs_debug(sb, "  name %s", sup->name);
+	befs_debug(sb, "  magic1 %08x", fs32_to_cpu(sb, sup->magic1));
+	befs_debug(sb, "  fs_byte_order %08x",
+		   fs32_to_cpu(sb, sup->fs_byte_order));
+
+	befs_debug(sb, "  block_size %u", fs32_to_cpu(sb, sup->block_size));
+	befs_debug(sb, "  block_shift %u", fs32_to_cpu(sb, sup->block_shift));
+
+	befs_debug(sb, "  num_blocks %Lu", fs64_to_cpu(sb, sup->num_blocks));
+	befs_debug(sb, "  used_blocks %Lu", fs64_to_cpu(sb, sup->used_blocks));
+
+	befs_debug(sb, "  magic2 %08x", fs32_to_cpu(sb, sup->magic2));
+	befs_debug(sb, "  blocks_per_ag %u",
+		   fs32_to_cpu(sb, sup->blocks_per_ag));
+	befs_debug(sb, "  ag_shift %u", fs32_to_cpu(sb, sup->ag_shift));
+	befs_debug(sb, "  num_ags %u", fs32_to_cpu(sb, sup->num_ags));
+
+	befs_debug(sb, "  flags %08x", fs32_to_cpu(sb, sup->flags));
+
+	tmp_run = fsrun_to_cpu(sb, sup->log_blocks);
+	befs_debug(sb, "  log_blocks %u, %hu, %hu",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+	befs_debug(sb, "  log_start %Ld", fs64_to_cpu(sb, sup->log_start));
+	befs_debug(sb, "  log_end %Ld", fs64_to_cpu(sb, sup->log_end));
+
+	befs_debug(sb, "  magic3 %08x", fs32_to_cpu(sb, sup->magic3));
+
+	tmp_run = fsrun_to_cpu(sb, sup->root_dir);
+	befs_debug(sb, "  root_dir %u, %hu, %hu",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+	tmp_run = fsrun_to_cpu(sb, sup->indices);
+	befs_debug(sb, "  indices %u, %hu, %hu",
+		   tmp_run.allocation_group, tmp_run.start, tmp_run.len);
+
+#endif				//CONFIG_BEFS_DEBUG
+}
+
+void
+befs_dump_small_data(const struct super_block *sb, befs_small_data * sd)
+{
+}
+
+void
+befs_dump_run(const struct super_block *sb, befs_block_run run)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	run = fsrun_to_cpu(sb, run);
+
+	befs_debug(sb, "[%u, %hu, %hu]",
+		   run.allocation_group, run.start, run.len);
+
+#endif				//CONFIG_BEFS_DEBUG
+}
+
+void
+befs_dump_index_entry(const struct super_block *sb, befs_btree_super * super)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	befs_debug(sb, "Btree super structure");
+	befs_debug(sb, "  magic %08x", fs32_to_cpu(sb, super->magic));
+	befs_debug(sb, "  node_size %u", fs32_to_cpu(sb, super->node_size));
+	befs_debug(sb, "  max_depth %08x", fs32_to_cpu(sb, super->max_depth));
+
+	befs_debug(sb, "  data_type %08x", fs32_to_cpu(sb, super->data_type));
+	befs_debug(sb, "  root_node_pointer %016LX",
+		   fs64_to_cpu(sb, super->root_node_ptr));
+	befs_debug(sb, "  free_node_pointer %016LX",
+		   fs64_to_cpu(sb, super->free_node_ptr));
+	befs_debug(sb, "  maximum size %016LX",
+		   fs64_to_cpu(sb, super->max_size));
+
+#endif				//CONFIG_BEFS_DEBUG
+}
+
+void
+befs_dump_index_node(const struct super_block *sb, befs_btree_nodehead * node)
+{
+#ifdef CONFIG_BEFS_DEBUG
+
+	befs_debug(sb, "Btree node structure");
+	befs_debug(sb, "  left %016LX", fs64_to_cpu(sb, node->left));
+	befs_debug(sb, "  right %016LX", fs64_to_cpu(sb, node->right));
+	befs_debug(sb, "  overflow %016LX", fs64_to_cpu(sb, node->overflow));
+	befs_debug(sb, "  all_key_count %hu",
+		   fs16_to_cpu(sb, node->all_key_count));
+	befs_debug(sb, "  all_key_length %hu",
+		   fs16_to_cpu(sb, node->all_key_length));
+
+#endif				//CONFIG_BEFS_DEBUG
+}

fs/befs/endian.h

+/*
+ * linux/fs/befs/endian.h
+ *
+ * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com>
+ *
+ * Partially based on similar funtions in the sysv driver.
+ */
+
+#ifndef LINUX_BEFS_ENDIAN
+#define LINUX_BEFS_ENDIAN
+
+#include <linux/byteorder/generic.h>
+#include "befs.h"
+
+static inline u64
+fs64_to_cpu(const struct super_block *sb, u64 n)
+{
+	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
+		return le64_to_cpu(n);
+	else
+		return be64_to_cpu(n);
+}
+
+static inline u64
+cpu_to_fs64(const struct super_block *sb, u64 n)
+{
+	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
+		return cpu_to_le64(n);
+	else
+		return cpu_to_be64(n);
+}
+
+static inline u32
+fs32_to_cpu(const struct super_block *sb, u32 n)
+{
+	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
+		return le32_to_cpu(n);
+	else
+		return be32_to_cpu(n);
+}
+
+static inline u32
+cpu_to_fs32(const struct super_block *sb, u32 n)
+{
+	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
+		return cpu_to_le32(n);
+	else
+		return cpu_to_be32(n);
+}
+
+static inline u16
+fs16_to_cpu(const struct super_block *sb, u16 n)
+{
+	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
+		return le16_to_cpu(n);
+	else
+		return be16_to_cpu(n);
+}
+
+static inline u16
+cpu_to_fs16(const struct super_block *sb, u16 n)
+{
+	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE)
+		return cpu_to_le16(n);
+	else
+		return cpu_to_be16(n);
+}
+
+/* Composite types below here */
+
+static inline befs_block_run
+fsrun_to_cpu(const struct super_block *sb, befs_block_run n)
+{
+	befs_block_run run;
+
+	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE) {
+		run.allocation_group = le32_to_cpu(n.allocation_group);
+		run.start = le16_to_cpu(n.start);
+		run.len = le16_to_cpu(n.len);
+	} else {
+		run.allocation_group = be32_to_cpu(n.allocation_group);
+		run.start = be16_to_cpu(n.start);
+		run.len = be16_to_cpu(n.len);
+	}
+	return run;
+}
+
+static inline befs_block_run
+cpu_to_fsrun(const struct super_block *sb, befs_block_run n)
+{
+	befs_block_run run;
+
+	if (BEFS_SB(sb)->byte_order == BEFS_BYTESEX_LE) {
+		run.allocation_group = cpu_to_le32(n.allocation_group);
+		run.start = cpu_to_le16(n.start);
+		run.len = cpu_to_le16(n.len);
+	} else {
+		run.allocation_group = cpu_to_be32(n.allocation_group);
+		run.start = cpu_to_be16(n.start);
+		run.len = cpu_to_be16(n.len);
+	}
+	return run;
+}
+
+static inline befs_data_stream
+fsds_to_cpu(const struct super_block *sb, befs_data_stream n)
+{
+	befs_data_stream data;
+	int i;
+
+	for (i = 0; i < BEFS_NUM_DIRECT_BLOCKS; ++i)
+		data.direct[i] = fsrun_to_cpu(sb, n.direct[i]);
+
+	data.max_direct_range = fs64_to_cpu(sb, n.max_direct_range);
+	data.indirect = fsrun_to_cpu(sb, n.indirect);
+	data.max_indirect_range = fs64_to_cpu(sb, n.max_indirect_range);
+	data.double_indirect = fsrun_to_cpu(sb, n.double_indirect);
+	data.max_double_indirect_range = fs64_to_cpu(sb,
+						     n.
+						     max_double_indirect_range);
+	data.size = fs64_to_cpu(sb, n.size);
+
+	return data;
+}
+
+#endif				//LINUX_BEFS_ENDIAN

fs/befs/inode.c

+/*
+ * inode.c
+ * 
+ * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com>
+ */
+
+#include <linux/fs.h>
+
+#include "befs.h"
+#include "inode.h"
+#include "endian.h"
+
+/*
+	Validates the correctness of the befs inode
+	Returns BEFS_OK if the inode should be used, otherwise
+	returns BEFS_BAD_INODE
+*/
+int
+befs_check_inode(struct super_block *sb, befs_inode * raw_inode,
+		 befs_blocknr_t inode)
+{
+	u32 magic1 = fs32_to_cpu(sb, raw_inode->magic1);
+	befs_inode_addr ino_num = fsrun_to_cpu(sb, raw_inode->inode_num);
+	u32 flags = fs32_to_cpu(sb, raw_inode->flags);
+
+	/* check magic header. */
+	if (magic1 != BEFS_INODE_MAGIC1) {
+		befs_error(sb,
+			   "Inode has a bad magic header - inode = %lu", inode);
+		return BEFS_BAD_INODE;
+	}
+
+	/*
+	 * Sanity check2: inodes store their own block address. Check it.
+	 */
+	if (inode != iaddr2blockno(sb, &ino_num)) {
+		befs_error(sb, "inode blocknr field disagrees with vfs "
+			   "VFS: %lu, Inode %lu",
+			   inode, iaddr2blockno(sb, &ino_num));
+		return BEFS_BAD_INODE;
+	}
+
+	/*
+	 * check flag
+	 */
+
+	if (!(flags & BEFS_INODE_IN_USE)) {
+		befs_error(sb, "inode is not used - inode = %lu", inode);
+		return BEFS_BAD_INODE;
+	}
+
+	return BEFS_OK;
+}

fs/befs/inode.h

+/*
+ * inode.h
+ * 
+ */
+
+int befs_check_inode(struct super_block *sb, befs_inode * raw_inode,
+		     befs_blocknr_t inode);
+

fs/befs/io.c

+/*
+ * linux/fs/befs/io.c
+ *
+ * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
+ *
+ * Based on portions of file.c and inode.c 
+ * by Makoto Kato (m_kato@ga2.so-net.ne.jp)
+ *
+ * Many thanks to Dominic Giampaolo, author of Practical File System
+ * Design with the Be File System, for such a helpful book.
+ *
+ */
+
+#include <linux/buffer_head.h>
+
+#include "befs.h"
+#include "io.h"
+
+/*
+ * Converts befs notion of disk addr to a disk offset and uses
+ * linux kernel function sb_bread() to get the buffer containing
+ * the offset. -Will Dyson
+ *
+ */
+
+struct buffer_head *
+befs_bread_iaddr(struct super_block *sb, befs_inode_addr iaddr)
+{
+	struct buffer_head *bh = NULL;
+	befs_blocknr_t block = 0;
+	vfs_blocknr_t vfs_block = 0;
+	befs_sb_info *befs_sb = BEFS_SB(sb);
+
+	befs_debug(sb, "---> Enter befs_read_iaddr() "
+		   "[%u, %hu, %hu]",
+		   iaddr.allocation_group, iaddr.start, iaddr.len);
+
+	if (iaddr.allocation_group > befs_sb->num_ags) {
+		befs_error(sb, "BEFS: Invalid allocation group %u, max is %u",
+			   iaddr.allocation_group, befs_sb->num_ags);
+		goto error;
+	}
+
+	block = iaddr2blockno(sb, &iaddr);
+	vfs_block = (vfs_blocknr_t) block;
+
+	if (vfs_block != block) {
+		befs_error(sb, "Error converting to host blocknr_t. %Lu "
+			   "is larger than the host can use", block);
+		goto error;
+	}
+
+	befs_debug(sb, "befs_read_iaddr: offset = %lu", block);
+
+	bh = sb_bread(sb, vfs_block);
+
+	if (bh == NULL) {
+		befs_error(sb, "Failed to read block %lu", block);
+		goto error;
+	}
+
+	befs_debug(sb, "<--- befs_read_iaddr()");
+	return bh;
+
+      error:
+	befs_debug(sb, "<--- befs_read_iaddr() ERROR");
+	return NULL;
+}
+
+struct buffer_head *
+befs_bread(struct super_block *sb, befs_blocknr_t block)
+{
+	struct buffer_head *bh = NULL;
+	vfs_blocknr_t vfs_block = (vfs_blocknr_t) block;
+
+	befs_debug(sb, "---> Enter befs_read() %Lu", block);
+
+	if (vfs_block != block) {
+		befs_error(sb, "Error converting to host blocknr_t. %Lu "
+			   "is larger than the host can use", block);
+		goto error;
+	}
+
+	bh = sb_bread(sb, vfs_block);
+
+	if (bh == NULL) {
+		befs_error(sb, "Failed to read block %lu", vfs_block);
+		goto error;
+	}
+
+	befs_debug(sb, "<--- befs_read()");
+
+	return bh;
+
+      error:
+	befs_debug(sb, "<--- befs_read() ERROR");
+	return NULL;
+}

fs/befs/io.h

+/*
+ * io.h
+ */
+
+struct buffer_head *befs_bread_iaddr(struct super_block *sb,
+				     befs_inode_addr iaddr);
+
+struct buffer_head *befs_bread(struct super_block *sb, befs_blocknr_t block);
+

fs/befs/linuxvfs.c

+/*
+ * linux/fs/befs/linuxvfs.c
+ *
+ * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/nls.h>
+#include <linux/buffer_head.h>
+
+#include "befs.h"
+#include "btree.h"
+#include "inode.h"
+#include "datastream.h"
+#include "super.h"
+#include "io.h"
+#include "endian.h"
+
+EXPORT_NO_SYMBOLS;
+MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
+MODULE_AUTHOR("Will Dyson");
+MODULE_LICENSE("GPL");
+
+/* The units the vfs expects inode->i_blocks to be in */
+#define VFS_BLOCK_SIZE 512
+
+static int befs_readdir(struct file *, void *, filldir_t);
+static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
+static int befs_readpage(struct file *file, struct page *page);
+static sector_t befs_bmap(struct address_space *mapping, sector_t block);
+static struct dentry *befs_lookup(struct inode *, struct dentry *);
+static void befs_read_inode(struct inode *ino);
+static struct inode *befs_alloc_inode(struct super_block *sb);
+static void befs_destroy_inode(struct inode *inode);
+static int befs_init_inodecache(void);
+static void befs_destroy_inodecache(void);
+static int befs_readlink(struct dentry *, char *, int);
+static int befs_follow_link(struct dentry *, struct nameidata *nd);
+static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
+			char **out, int *out_len);
+static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
+			char **out, int *out_len);
+static void befs_put_super(struct super_block *);
+static int befs_remount(struct super_block *, int *, char *);
+static int befs_statfs(struct super_block *, struct statfs *);
+static int parse_options(char *, befs_mount_options *);
+
+static const struct super_operations befs_sops = {
+	.read_inode	= befs_read_inode,	/* initialize & read inode */
+	.alloc_inode	= befs_alloc_inode,	/* allocate a new inode */
+	.destroy_inode	= befs_destroy_inode, /* deallocate an inode */
+	.put_super	= befs_put_super,	/* uninit super */
+	.statfs		= befs_statfs,	/* statfs */
+	.remount_fs	= befs_remount,
+};
+
+/* slab cache for befs_inode_info objects */
+static kmem_cache_t *befs_inode_cachep;
+
+struct file_operations befs_dir_operations = {
+	.read		= generic_read_dir,
+	.readdir	= befs_readdir,
+};
+
+struct inode_operations befs_dir_inode_operations = {
+	.lookup		= befs_lookup,
+};
+
+struct file_operations befs_file_operations = {
+	.llseek		= default_llseek,
+	.read		= generic_file_read,
+	.mmap		= generic_file_mmap,
+};
+
+struct address_space_operations befs_aops = {
+	.readpage	= befs_readpage,
+	.sync_page	= block_sync_page,
+	.bmap		= befs_bmap,
+};
+
+static struct inode_operations befs_symlink_inode_operations = {
+	.readlink	= befs_readlink,
+	.follow_link	= befs_follow_link,
+};
+
+/* 
+ * Called by generic_file_read() to read a page of data
+ * 
+ * In turn, simply calls a generic block read function and
+ * passes it the address of befs_get_block, for mapping file
+ * positions to disk blocks.
+ */
+static int
+befs_readpage(struct file *file, struct page *page)
+{
+	return block_read_full_page(page, befs_get_block);
+}
+
+static sector_t
+befs_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping, block, befs_get_block);
+}
+
+/* 
+ * Generic function to map a file position (block) to a 
+ * disk offset (passed back in bh_result).
+ *
+ * Used by many higher level functions.
+ *
+ * Calls befs_fblock2brun() in datastream.c to do the real work.
+ *
+ * -WD 10-26-01
+ */
+
+static int
+befs_get_block(struct inode *inode, sector_t block,
+	       struct buffer_head *bh_result, int create)
+{
+	struct super_block *sb = inode->i_sb;
+	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
+	befs_block_run run = BAD_IADDR;
+	int res = 0;
+	ulong disk_off;
+
+	befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
+		   inode->i_ino, block);
+
+	if (block < 0) {
+		befs_error(sb, "befs_get_block() was asked for a block "
+			   "number less than zero: block %ld in inode %lu",
+			   block, inode->i_ino);
+		return -EIO;
+	}
+
+	if (create) {
+		befs_error(sb, "befs_get_block() was asked to write to "
+			   "block %ld in inode %lu", block, inode->i_ino);
+		return -EPERM;
+	}
+
+	res = befs_fblock2brun(sb, ds, block, &run);
+	if (res != BEFS_OK) {
+		befs_error(sb,
+			   "<--- befs_get_block() for inode %lu, block "
+			   "%ld ERROR", inode->i_ino, block);
+		return -EFBIG;
+	}
+
+	disk_off = (ulong) iaddr2blockno(sb, &run);
+
+	map_bh(bh_result, inode->i_sb, disk_off);
+
+	befs_debug(sb, "<--- befs_get_block() for inode %lu, block %ld, "
+		   "disk address %lu", inode->i_ino, block, disk_off);
+
+	return 0;
+}
+
+static struct dentry *
+befs_lookup(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = NULL;
+	struct super_block *sb = dir->i_sb;
+	befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
+	befs_off_t offset;
+	int ret;
+	int utfnamelen;
+	char *utfname;
+	const char *name = dentry->d_name.name;
+
+	befs_debug(sb, "---> befs_lookup() "
+		   "name %s inode %ld", dentry->d_name.name, dir->i_ino);
+
+	/* Convert to UTF-8 */
+	if (BEFS_SB(sb)->nls) {
+		ret =
+		    befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
+		if (ret < 0) {
+			befs_debug(sb, "<--- befs_lookup() ERROR");
+			return ERR_PTR(ret);
+		}
+		ret = befs_btree_find(sb, ds, utfname, &offset);
+		kfree(utfname);
+
+	} else {
+		ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
+	}
+
+	if (ret == BEFS_BT_NOT_FOUND) {
+		befs_debug(sb, "<--- befs_lookup() %s not found",
+			   dentry->d_name.name);
+		return ERR_PTR(-ENOENT);
+
+	} else if (ret != BEFS_OK || offset == 0) {
+		befs_warning(sb, "<--- befs_lookup() Error");
+		return ERR_PTR(-ENODATA);
+	}
+
+	inode = iget(dir->i_sb, (ino_t) offset);
+	if (!inode)
+		return ERR_PTR(-EACCES);
+
+	d_add(dentry, inode);
+
+	befs_debug(sb, "<--- befs_lookup()");
+
+	return NULL;
+}
+
+static int
+befs_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+	struct inode *inode = filp->f_dentry->d_inode;
+	struct super_block *sb = inode->i_sb;
+	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
+	befs_off_t value;
+	int result;
+	size_t keysize;
+	unsigned char d_type;
+	char keybuf[BEFS_NAME_LEN + 1];
+	char *nlsname;
+	int nlsnamelen;
+	const char *dirname = filp->f_dentry->d_name.name;
+
+	befs_debug(sb, "---> befs_readdir() "
+		   "name %s, inode %ld, filp->f_pos %Ld",
+		   dirname, inode->i_ino, filp->f_pos);
+
+	result = befs_btree_read(sb, ds, filp->f_pos, BEFS_NAME_LEN + 1,
+				 keybuf, &keysize, &value);
+
+	if (result == BEFS_ERR) {
+		befs_debug(sb, "<--- befs_readdir() ERROR");
+		befs_error(sb, "IO error reading %s (inode %lu)",
+			   dirname, inode->i_ino);
+		return -EIO;
+
+	} else if (result == BEFS_BT_END) {
+		befs_debug(sb, "<--- befs_readdir() END");
+		return 0;
+
+	} else if (result == BEFS_BT_EMPTY) {
+		befs_debug(sb, "<--- befs_readdir() Empty directory");
+		return 0;
+	}
+
+	d_type = DT_UNKNOWN;
+
+	/* Convert to NLS */
+	if (BEFS_SB(sb)->nls) {
+		result =
+		    befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
+		if (result < 0) {
+			befs_debug(sb, "<--- befs_readdir() ERROR");
+			return result;
+		}
+		result = filldir(dirent, nlsname, nlsnamelen, filp->f_pos,
+				 (ino_t) value, d_type);
+		kfree(nlsname);
+
+	} else {
+		result = filldir(dirent, keybuf, keysize, filp->f_pos,
+				 (ino_t) value, d_type);
+	}
+
+	filp->f_pos++;
+
+	befs_debug(sb, "<--- befs_readdir() filp->f_pos %Ld", filp->f_pos);
+
+	return 0;
+}
+
+static struct inode *
+befs_alloc_inode(struct super_block *sb)
+{
+        struct befs_inode_info *bi;
+        bi = (struct befs_inode_info *)kmem_cache_alloc(befs_inode_cachep,
+							SLAB_KERNEL);
+        if (!bi)
+                return NULL;
+        return &bi->vfs_inode;
+}
+
+static void
+befs_destroy_inode(struct inode *inode)
+{
+        kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
+}
+
+static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
+{
+        struct befs_inode_info *bi = (struct befs_inode_info *) foo;
+	
+	        if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+		            SLAB_CTOR_CONSTRUCTOR) {
+			inode_init_once(&bi->vfs_inode);
+		}
+}
+
+static void
+befs_read_inode(struct inode *inode)
+{
+	struct buffer_head *bh = NULL;
+	befs_inode *raw_inode = NULL;
+
+	struct super_block *sb = inode->i_sb;
+	befs_sb_info *befs_sb = BEFS_SB(sb);
+	befs_inode_info *befs_ino = NULL;
+
+	befs_debug(sb, "---> befs_read_inode() " "inode = %lu", inode->i_ino);
+
+	befs_ino = BEFS_I(inode);
+
+	/* convert from vfs's inode number to befs's inode number */
+	befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
+
+	befs_debug(sb, "  real inode number [%u, %hu, %hu]",
+		   befs_ino->i_inode_num.allocation_group,
+		   befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
+
+	bh = befs_bread_iaddr(sb, befs_ino->i_inode_num);
+	if (!bh) {
+		befs_error(sb, "unable to read inode block - "
+			   "inode = %lu", inode->i_ino);
+		goto unaquire_none;
+	}
+
+	raw_inode = (befs_inode *) bh->b_data;
+
+	befs_dump_inode(sb, raw_inode);
+
+	if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
+		befs_error(sb, "Bad inode: %lu", inode->i_ino);
+		goto unaquire_bh;
+	}
+
+	inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
+
+	/*
+	 * set uid and gid.  But since current BeOS is single user OS, so
+	 * you can change by "uid" or "gid" options.
+	 */
+
+	inode->i_uid = befs_sb->mount_opts.use_uid ?
+	    befs_sb->mount_opts.uid : (uid_t) fs32_to_cpu(sb, raw_inode->uid);
+	inode->i_gid = befs_sb->mount_opts.use_gid ?
+	    befs_sb->mount_opts.gid : (gid_t) fs32_to_cpu(sb, raw_inode->gid);
+
+	inode->i_nlink = 1;
+
+	/*
+	 * BEFS's time is 64 bits, but current VFS is 32 bits...
+	 * BEFS don't have access time. Nor inode change time. VFS
+	 * doesn't have creation time.
+	 */
+
+	inode->i_mtime =
+	    (time_t) (fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16);
+	inode->i_ctime = inode->i_mtime;
+	inode->i_atime = inode->i_mtime;
+	inode->i_blksize = befs_sb->block_size;
+
+	befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
+	befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
+	befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
+	befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
+
+	if (S_ISLNK(inode->i_mode) && !(inode->i_flags & BEFS_LONG_SYMLINK)) {
+		inode->i_size = 0;
+		inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
+		strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
+			BEFS_SYMLINK_LEN);
+	} else {
+		int num_blks;
+
+		befs_ino->i_data.ds =
+		    fsds_to_cpu(sb, raw_inode->data.datastream);
+
+		num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
+		inode->i_blocks =
+		    num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
+		inode->i_size = befs_ino->i_data.ds.size;
+	}
+
+	inode->i_mapping->a_ops = &befs_aops;
+
+	if (S_ISREG(inode->i_mode)) {
+		inode->i_fop = &befs_file_operations;
+	} else if (S_ISDIR(inode->i_mode)) {
+		inode->i_op = &befs_dir_inode_operations;
+		inode->i_fop = &befs_dir_operations;
+	} else if (S_ISLNK(inode->i_mode)) {
+		inode->i_op = &befs_symlink_inode_operations;
+	} else {
+		befs_error(sb, "Inode %lu is not a regular file, "
+			   "directory or symlink. THAT IS WRONG! BeFS has no "
+			   "on disk special files", inode->i_ino);
+		goto unaquire_bh;
+	}
+
+	brelse(bh);
+	befs_debug(sb, "<--- befs_read_inode()");
+	return;
+
+      unaquire_bh:
+	brelse(bh);
+
+      unaquire_none:
+	make_bad_inode(inode);
+	befs_debug(sb, "<--- befs_read_inode() - Bad inode");
+	return;
+}
+
+/* Initialize the inode cache. Called at fs setup.
+ * 
+ * Taken from NFS implementation by Al Viro.
+ */
+static int
+befs_init_inodecache(void)
+{
+	befs_inode_cachep = kmem_cache_create("befs_inode_cache",
+					      sizeof (struct befs_inode_info),
+					      0, SLAB_HWCACHE_ALIGN,
+					      init_once, NULL);
+	if (befs_inode_cachep == NULL) {
+		printk(KERN_ERR "befs_init_inodecache: "
+		       "Couldn't initalize inode slabcache\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/* Called at fs teardown.
+ * 
+ * Taken from NFS implementation by Al Viro.
+ */
+static void
+befs_destroy_inodecache(void)
+{
+	if (kmem_cache_destroy(befs_inode_cachep))
+		printk(KERN_ERR "befs_destroy_inodecache: "
+		       "not all structures were freed\n");
+}
+
+/*
+ * The inode of symbolic link is different to data stream.
+ * The data stream become link name. Unless the LONG_SYMLINK
+ * flag is set.
+ */
+static int
+befs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	struct super_block *sb = dentry->d_sb;
+	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
+	char *link;
+	int res;
+
+	if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
+		befs_data_stream *data = &befs_ino->i_data.ds;
+		befs_off_t linklen = data->size;
+
+		befs_debug(sb, "Follow long symlink");
+
+		link = kmalloc(linklen, GFP_NOFS);
+		if (link == NULL)
+			return -ENOMEM;
+
+		if (befs_read_lsymlink(sb, data, link, linklen) != linklen) {
+			kfree(link);
+			befs_error(sb, "Failed to read entire long symlink");
+			return -EIO;
+		}
+
+		res = vfs_follow_link(nd, link);
+
+		kfree(link);
+	} else {
+		link = befs_ino->i_data.symlink;
+		res = vfs_follow_link(nd, link);
+	}
+
+	return res;
+}
+
+static int
+befs_readlink(struct dentry *dentry, char *buffer, int buflen)
+{
+	struct super_block *sb = dentry->d_sb;
+	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
+	char *link;
+	int res;
+
+	if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
+		befs_data_stream *data = &befs_ino->i_data.ds;
+		befs_off_t linklen = data->size;
+
+		befs_debug(sb, "Read long symlink");
+
+		link = kmalloc(linklen, GFP_NOFS);
+		if (link == NULL)
+			return -ENOMEM;
+
+		if (befs_read_lsymlink(sb, data, link, linklen) != linklen) {
+			kfree(link);
+			befs_error(sb, "Failed to read entire long symlink");
+			return -EIO;
+		}
+
+		res = vfs_readlink(dentry, buffer, buflen, link);
+
+		kfree(link);
+	} else {
+		link = befs_ino->i_data.symlink;
+		res = vfs_readlink(dentry, buffer, buflen, link);
+	}
+
+	return res;
+}
+
+/*
+ * UTF-8 to NLS charset  convert routine
+ *
+ * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
+ * the nls tables directly
+ */
+
+static int
+befs_utf2nls(struct super_block *sb, const char *in,
+	     int in_len, char **out, int *out_len)
+{
+	struct nls_table *nls = BEFS_SB(sb)->nls;
+	int i, o;
+	wchar_t uni;
+	int unilen, utflen;
+	char *result;
+	int maxlen = in_len; /* The utf8->nls conversion cant make more chars */
+
+	befs_debug(sb, "---> utf2nls()");
+
+	if (!nls) {
+		befs_error(sb, "befs_utf2nls called with no NLS table loaded");
+		return -EINVAL;
+	}
+
+	*out = result = kmalloc(maxlen, GFP_NOFS);
+	if (!*out) {
+		befs_error(sb, "befs_utf2nls() cannot allocate memory");
+		*out_len = 0;
+		return -ENOMEM;
+	}
+
+	for (i = o = 0; i < in_len; i += utflen, o += unilen) {
+
+		/* convert from UTF-8 to Unicode */
+		utflen = utf8_mbtowc(&uni, &in[i], in_len - i);
+		if (utflen < 0) {
+			goto conv_err;
+		}
+
+		/* convert from Unicode to nls */
+		unilen = nls->uni2char(uni, &result[o], 1);
+		if (unilen < 0) {
+			goto conv_err;
+		}
+	}
+	result[o] = '\0';
+
+	befs_debug(sb, "<--- utf2nls()");
+
+	return o;
+	*out_len = o;
+
+      conv_err:
+	befs_error(sb, "Name using charecter set %s contains a charecter that "
+		   "cannot be converted to unicode.", nls->charset);
+	befs_debug(sb, "<--- utf2nls()");
+	kfree(result);
+	return -EILSEQ;
+}
+
+/**
+ * befs_nls2utf - Convert NLS string to utf8 encodeing
+ * @sb: Superblock
+ * @src: Input string buffer in NLS format
+ * @srclen: Length of input string in bytes
+ * @dest: The output string in UTF8 format
+ * @destlen: Length of the output buffer
+ * 
+ * Converts input string @src, which is in the format of the loaded NLS map,
+ * into a utf8 string.
+ * 
+ * The destination string @dest is allocated by this function and the caller is
+ * responsible for freeing it with kfree()
+ * 
+ * On return, *@destlen is the length of @dest in bytes.
+ *
+ * On success, the return value is the number of utf8 charecters written to
+ * the ouput buffer @dest.
+ *  
+ * On Failure, a negative number coresponding to the error code is returned.
+ */
+
+static int
+befs_nls2utf(struct super_block *sb, const char *in,
+	     int in_len, char **out, int *out_len)
+{
+	struct nls_table *nls = BEFS_SB(sb)->nls;
+	int i, o;
+	wchar_t uni;
+	int unilen, utflen;
+	char *result;
+	int maxlen = 3 * in_len;
+
+	befs_debug(sb, "---> nls2utf()\n");
+
+	if (!nls) {
+		befs_error(sb, "befs_nls2utf called with no NLS table loaded.");
+		return -EINVAL;
+	}
+
+	*out = result = kmalloc(maxlen, GFP_NOFS);
+	if (!*out) {
+		befs_error(sb, "befs_nls2utf() cannot allocate memory");
+		*out_len = 0;
+		return -ENOMEM;
+	}
+
+	for (i = o = 0; i < in_len; i += unilen, o += utflen) {
+
+		/* convert from nls to unicode */
+		unilen = nls->char2uni(&in[i], in_len - i, &uni);
+		if (unilen < 0) {
+			goto conv_err;
+		}
+
+		/* convert from unicode to UTF-8 */
+		utflen = utf8_wctomb(&result[o], uni, 3);
+		if (utflen <= 0) {
+			goto conv_err;
+		}
+	}
+
+	result[o] = '\0';
+	*out_len = o;
+
+	befs_debug(sb, "<--- nls2utf()");
+
+	return i;
+
+      conv_err:
+	befs_error(sb, "Name using charecter set %s contains a charecter that "
+		   "cannot be converted to unicode.", nls->charset);
+	befs_debug(sb, "<--- nls2utf()");
+	kfree(result);
+	return -EILSEQ;
+}
+
+static int
+parse_options(char *options, befs_mount_options * opts)
+{
+	char *this_char;
+	char *value;
+	int ret = 1;
+
+	/* Initialize options */
+	opts->uid = 0;
+	opts->gid = 0;
+	opts->use_uid = 0;
+	opts->use_gid = 0;
+	opts->iocharset = NULL;
+	opts->debug = 0;
+
+	if (!options)
+		return ret;
+
+	while ((this_char = strsep(&options, ",")) != NULL) {
+
+		if ((value = strchr(this_char, '=')) != NULL)
+			*value++ = 0;
+
+		if (!strcmp(this_char, "uid")) {
+			if (!value || !*value) {
+				ret = 0;
+			} else {
+				opts->uid = simple_strtoul(value, &value, 0);
+				opts->use_uid = 1;
+				if (*value) {
+					printk(KERN_ERR "BEFS: Invalid uid "
+					       "option: %s\n", value);
+					ret = 0;
+				}
+			}
+		} else if (!strcmp(this_char, "gid")) {
+			if (!value || !*value)
+				ret = 0;
+			else {
+				opts->gid = simple_strtoul(value, &value, 0);
+				opts->use_gid = 1;
+				if (*value) {
+					printk(KERN_ERR
+					       "BEFS: Invalid gid option: "
+					       "%s\n", value);
+					ret = 0;
+				}
+			}
+		} else if (!strcmp(this_char, "iocharset") && value) {
+			char *p = value;
+			int len;
+
+			while (*value && *value != ',')
+				value++;
+			len = value - p;
+			if (len) {
+				char *buffer = kmalloc(len + 1, GFP_NOFS);
+				if (buffer) {
+					opts->iocharset = buffer;
+					memcpy(buffer, p, len);
+					buffer[len] = 0;
+
+				} else {
+					printk(KERN_ERR "BEFS: "
+					       "cannot allocate memory\n");
+					ret = 0;
+				}
+			}
+		} else if (!strcmp(this_char, "debug")) {
+			opts->debug = 1;
+		}
+	}
+
+	return ret;
+}
+
+/* This function has the responsibiltiy of getting the
+ * filesystem ready for unmounting. 
+ * Basicly, we free everything that we allocated in
+ * befs_read_inode
+ */
+static void
+befs_put_super(struct super_block *sb)
+{
+	if (BEFS_SB(sb)->mount_opts.iocharset) {
+		kfree(BEFS_SB(sb)->mount_opts.iocharset);
+		BEFS_SB(sb)->mount_opts.iocharset = NULL;
+	}
+
+	if (BEFS_SB(sb)->nls) {
+		unload_nls(BEFS_SB(sb)->nls);
+		BEFS_SB(sb)->nls = NULL;
+	}
+
+	if (sb->s_fs_info) {
+		kfree(sb->s_fs_info);
+		sb->s_fs_info = NULL;
+	}
+	return;
+}
+
+/* Allocate private field of the superblock, fill it.
+ *
+ * Finish filling the public superblock fields
+ * Make the root directory
+ * Load a set of NLS translations if needed.
+ */
+static int
+befs_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct buffer_head *bh;
+	befs_sb_info *befs_sb;
+	befs_super_block *disk_sb;
+
+	const unsigned long sb_block = 0;
+	const off_t x86_sb_off = 512;
+
+	sb->s_fs_info = kmalloc(sizeof (*befs_sb), GFP_KERNEL);
+	if (sb->s_fs_info == NULL) {
+		printk(KERN_ERR
+		       "BeFS(%s): Unable to allocate memory for private "
+		       "portion of superblock. Bailing.\n", sb->s_id);
+		goto unaquire_none;
+	}
+	befs_sb = BEFS_SB(sb);
+	memset(befs_sb, 0, sizeof(befs_sb_info));
+
+	if (!parse_options((char *) data, &befs_sb->mount_opts)) {
+		befs_error(sb, "cannot parse mount options");
+		goto unaquire_priv_sbp;
+	}
+
+	befs_debug(sb, "---> befs_fill_super()");
+
+#ifndef CONFIG_BEFS_RW
+	if (!(sb->s_flags & MS_RDONLY)) {
+		befs_warning(sb,
+			     "No write support. Marking filesystem read-only");
+		sb->s_flags |= MS_RDONLY;
+	}
+#endif				/* CONFIG_BEFS_RW */
+
+	/*
+	 * Set dummy blocksize to read super block.
+	 * Will be set to real fs blocksize later.
+	 *
+	 * Linux 2.4.10 and later refuse to read blocks smaller than
+	 * the hardsect size for the device. But we also need to read at 
+	 * least 1k to get the second 512 bytes of the volume.
+	 * -WD 10-26-01
+	 */ 
+	sb_min_blocksize(sb, 1024);
+
+	if (!(bh = sb_bread(sb, sb_block))) {
+		befs_error(sb, "unable to read superblock");
+		goto unaquire_priv_sbp;
+	}
+
+	/* account for offset of super block on x86 */
+	disk_sb = (befs_super_block *) bh->b_data;
+	if ((le32_to_cpu(disk_sb->magic1) == BEFS_SUPER_MAGIC1) ||
+	    (be32_to_cpu(disk_sb->magic1) == BEFS_SUPER_MAGIC1)) {
+		befs_debug(sb, "Using PPC superblock location");
+	} else {
+		befs_debug(sb, "Using x86 superblock location");
+		disk_sb =
+		    (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
+	}
+
+	if (befs_load_sb(sb, disk_sb) != BEFS_OK)
+		goto unaquire_bh;
+
+	befs_dump_super_block(sb, disk_sb);
+
+	brelse(bh);
+
+	if (befs_check_sb(sb) != BEFS_OK)
+		goto unaquire_priv_sbp;
+
+	/*
+	 * set up enough so that it can read an inode
+	 * Fill in kernel superblock fields from private sb
+	 */
+	sb->s_magic = BEFS_SUPER_MAGIC;
+	/* Set real blocksize of fs */
+	sb_set_blocksize(sb, (ulong) befs_sb->block_size);
+	sb->s_op = (struct super_operations *) &befs_sops;
+	sb->s_root =
+	    d_alloc_root(iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir))));
+	if (!sb->s_root) {
+		befs_error(sb, "get root inode failed");
+		goto unaquire_priv_sbp;
+	}
+
+	/* load nls library */
+	if (befs_sb->mount_opts.iocharset) {
+		befs_debug(sb, "Loading nls: %s",
+			   befs_sb->mount_opts.iocharset);
+		befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
+		if (!befs_sb->nls) {
+			befs_warning(sb, "Cannot load nls %s"
+				     "loding default nls",
+				     befs_sb->mount_opts.iocharset);
+			befs_sb->nls = load_nls_default();
+		}
+	}
+
+	return 0;
+/*****************/
+      unaquire_bh:
+	brelse(bh);
+
+      unaquire_priv_sbp:
+	kfree(sb->s_fs_info);
+
+      unaquire_none:
+	sb->s_fs_info = NULL;
+	return -EINVAL;
+}
+
+static int
+befs_remount(struct super_block *sb, int *flags, char *data)
+{
+	if (!(*flags & MS_RDONLY))
+		return -EINVAL;
+	return 0;
+}
+
+static int
+befs_statfs(struct super_block *sb, struct statfs *buf)
+{
+
+	befs_debug(sb, "---> befs_statfs()");
+
+	buf->f_type = BEFS_SUPER_MAGIC;
+	buf->f_bsize = sb->s_blocksize;
+	buf->f_blocks = BEFS_SB(sb)->num_blocks;
+	buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
+	buf->f_bavail = buf->f_bfree;
+	buf->f_files = 0;	/* UNKNOWN */
+	buf->f_ffree = 0;	/* UNKNOWN */
+	buf->f_namelen = BEFS_NAME_LEN;
+
+	befs_debug(sb, "<--- befs_statfs()");
+
+	return 0;
+}
+
+static struct super_block *
+befs_get_sb(struct file_system_type *fs_type, int flags, char *dev_name,
+		void *data)
+{
+	return get_sb_bdev(fs_type, flags, dev_name, data, befs_fill_super);
+}
+
+static struct file_system_type befs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "befs",
+	.get_sb		= befs_get_sb,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,	
+};
+
+static int __init
+init_befs_fs(void)
+{
+	int err;
+
+	printk(KERN_INFO "BeFS version: %s\n", BEFS_VERSION);
+
+	err = befs_init_inodecache();
+	if (err)
+		return err;
+
+	return register_filesystem(&befs_fs_type);
+}
+
+static void __exit
+exit_befs_fs(void)
+{
+	befs_destroy_inodecache();
+
+	unregister_filesystem(&befs_fs_type);
+}
+
+/*
+Macros that typecheck the init and exit functions,
+ensures that they are called at init and cleanup,
+and eliminates warnings about unused functions.
+*/
+module_init(init_befs_fs)
+module_exit(exit_befs_fs)

fs/befs/super.c

+/*
+ * super.c
+ *
+ * Copyright (C) 2001-2002 Will Dyson <will_dyson@pobox.com>
+ *
+ * Licensed under the GNU GPL. See the file COPYING for details.
+ *
+ */
+
+#include <linux/fs.h>
+
+#include "befs.h"
+#include "super.h"
+#include "endian.h"
+
+/**
+ * load_befs_sb -- Read from disk and properly byteswap all the fields
+ * of the befs superblock
+ *
+ *
+ *
+ *
+ */
+int
+befs_load_sb(struct super_block *sb, befs_super_block * disk_sb)
+{
+	befs_sb_info *befs_sb = BEFS_SB(sb);
+
+	/* Check the byte order of the filesystem */
+	if (le32_to_cpu(disk_sb->fs_byte_order) == BEFS_BYTEORDER_NATIVE)
+	    befs_sb->byte_order = BEFS_BYTESEX_LE;
+	else if (be32_to_cpu(disk_sb->fs_byte_order) == BEFS_BYTEORDER_NATIVE)
+	    befs_sb->byte_order = BEFS_BYTESEX_BE;	
+
+	befs_sb->magic1 = fs32_to_cpu(sb, disk_sb->magic1);
+	befs_sb->magic2 = fs32_to_cpu(sb, disk_sb->magic2);
+	befs_sb->magic3 = fs32_to_cpu(sb, disk_sb->magic3);
+	befs_sb->block_size = fs32_to_cpu(sb, disk_sb->block_size);
+	befs_sb->block_shift = fs32_to_cpu(sb, disk_sb->block_shift);
+	befs_sb->num_blocks = fs64_to_cpu(sb, disk_sb->num_blocks);
+	befs_sb->used_blocks = fs64_to_cpu(sb, disk_sb->used_blocks);
+	befs_sb->inode_size = fs32_to_cpu(sb, disk_sb->inode_size);
+
+	befs_sb->blocks_per_ag = fs32_to_cpu(sb, disk_sb->blocks_per_ag);
+	befs_sb->ag_shift = fs32_to_cpu(sb, disk_sb->ag_shift);
+	befs_sb->num_ags = fs32_to_cpu(sb, disk_sb->num_ags);
+
+	befs_sb->log_blocks = fsrun_to_cpu(sb, disk_sb->log_blocks);
+	befs_sb->log_start = fs64_to_cpu(sb, disk_sb->log_start);
+	befs_sb->log_end = fs64_to_cpu(sb, disk_sb->log_end);
+
+	befs_sb->root_dir = fsrun_to_cpu(sb, disk_sb->root_dir);
+	befs_sb->indices = fsrun_to_cpu(sb, disk_sb->indices);
+	befs_sb->nls = NULL;
+
+	return BEFS_OK;
+}
+
+int
+befs_check_sb(struct super_block *sb)
+{
+	befs_sb_info *befs_sb = BEFS_SB(sb);
+
+	/* Check magic headers of super block */
+	if ((befs_sb->magic1 != BEFS_SUPER_MAGIC1)
+	    || (befs_sb->magic2 != BEFS_SUPER_MAGIC2)
+	    || (befs_sb->magic3 != BEFS_SUPER_MAGIC3)) {
+		befs_error(sb, "invalid magic header");
+		return BEFS_ERR;
+	}
+
+	/*
+	 * Check blocksize of BEFS.
+	 *
+	 * Blocksize of BEFS is 1024, 2048, 4096 or 8192.
+	 */
+
+	if ((befs_sb->block_size != 1024)
+	    && (befs_sb->block_size != 2048)
+	    && (befs_sb->block_size != 4096)
+	    && (befs_sb->block_size != 8192)) {
+		befs_error(sb, "invalid blocksize: %u", befs_sb->block_size);
+		return BEFS_ERR;
+	}
+
+	if (befs_sb->block_size > PAGE_SIZE) {
+		befs_error(sb, "blocksize(%u) cannot be larger"
+			   "than system pagesize(%lu)", befs_sb->block_size,
+			   PAGE_SIZE);
+		return BEFS_ERR;
+	}
+
+	/*
+	   * block_shift and block_size encode the same information
+	   * in different ways as a consistency check.
+	 */
+
+	if ((1 << befs_sb->block_shift) != befs_sb->block_size) {
+		befs_error(sb, "block_shift disagrees with block_size. "
+			   "Corruption likely.");
+		return BEFS_ERR;
+	}
+
+	if (befs_sb->log_start != befs_sb->log_end) {
+		befs_error(sb, "Filesystem not clean! There are blocks in the "
+			   "journal. You must boot into BeOS and mount this volume "
+			   "to make it clean.");
+		return BEFS_ERR;
+	}
+
+	return BEFS_OK;
+}

fs/befs/super.h

+/*
+ * super.h
+ */
+
+int befs_load_sb(struct super_block *sb, befs_super_block * disk_sb);
+
+int befs_check_sb(struct super_block *sb);
+

fs/nls/Config.in

@@ -12,7 +12,8 @@ fi
 # msdos and Joliet want NLS
 if [ "$CONFIG_JOLIET" = "y" -o "$CONFIG_FAT_FS" != "n" \
 	-o "$CONFIG_NTFS_FS" != "n" -o "$CONFIG_NCPFS_NLS" = "y" \
-	-o "$CONFIG_SMB_NLS" = "y" -o "$CONFIG_JFS_FS" != "n" -o "$CONFIG_CIFS" != "n" ]; then
+	-o "$CONFIG_SMB_NLS" = "y" -o "$CONFIG_JFS_FS" != "n" \
+	-o "$CONFIG_CIFS" != "n" -o "$CONFIG_BEFS_FS" != "n" ]; then
   define_bool CONFIG_NLS y
 else
   define_bool CONFIG_NLS n