[PATCH] HFS rewrite

From: Roman Zippel <zippel@linux-m68k.org>

This is a complete rewrite of the HFS driver, it gets rid of a all the
special conversion options, which belong in user space.  The driver uses now
a btree support very similiar to HFS+, so that both could be merged at some
point.

Thanks to Ethan Benson <erbenson@alaska.net> for a number of patches to make
the driver more compliant with the spec and Christoph Hellwig <hch@lst.de>
for fixing up the documentation.

Documentation/filesystems/hfs.txt

+
+Macintosh HFS Filesystem for Linux
+==================================
+
+HFS stands for ``Hierarchical File System'' and is the filesystem used
+by the Mac Plus and all later Macintosh models.  Earlier Macintosh
+models used MFS (``Macintosh File System''), which is not supported,
+MacOS 8.1 and newer support a filesystem called HFS+ that's similar to
+HFS but is extended in various areas.  Use the hfsplus filesystem driver
+to access such filesystems from Linux.
+
+
+Mount options
+=============
+
+When mounting an HFS filesystem, the following options are accepted:
+
+  creator=cccc, type=cccc
+	Specifies the creator/type values as shown by the MacOS finder
+	used for creating new files.  Default values: '????'.
+
+  uid=n, gid=n
+  	Specifies the user/group that owns all files on the filesystems.
+	Default:  user/group id of the mounting process.
+
+  dir_umask=n, file_umask=n, umask=n
+	Specifies the umask used for all files , all directories or all
+	files and directories.  Defaults to the umask of the mounting process.
+
+  session=n
+  	Select the CDROM session to mount as HFS filesystem.  Defaults to
+	leaving that decision to the CDROM driver.  This option will fail
+	with anything but a CDROM as underlying devices.
+
+  part=n
+  	Select partition number n from the devices.  Does only makes
+	sense for CDROMS because they can't be partitioned under Linux.
+	For disk devices the generic partition parsing code does this
+	for us.  Defaults to not parsing the partition table at all.
+
+  quiet
+  	Ignore invalid mount options instead of complaining.
+
+
+Writing to HFS Filesystems
+==========================
+
+HFS is not a UNIX filesystem, thus it does not have the usual features you'd
+expect:
+
+ o You can't modify the set-uid, set-gid, sticky or executable bits or the uid
+   and gid of files.
+ o You can't create hard- or symlinks, device files, sockets or FIFOs.
+
+HFS does on the other have the concepts of multiple forks per file.  These
+non-standard forks are represented as hidden additional files in the normal
+filesystems namespace which is kind of a cludge and makes the semantics for
+the a little strange:
+
+ o You can't create, delete or rename resource forks of files or the
+   Finder's metadata.
+ o They are however created (with default values), deleted and renamed
+   along with the corresponding data fork or directory.
+ o Copying files to a different filesystem will loose those attributes
+   that are essential for MacOS to work.
+
+
+Creating HFS filesystems
+===================================
+
+The hfsutils package from Robert Leslie contains a program called
+hformat that can be used to create HFS filesystem. See
+<http://www.mars.org/home/rob/proj/hfs/> for details.
+
+
+Credits
+=======
+
+The HFS drivers was written by Paul H. Hargrovea (hargrove@sccm.Stanford.EDU)
+and is now maintained by Roman Zippel (roman@ardistech.com) at Ardis
+Technologies.
+Roman rewrote large parts of the code and brought in btree routines derived
+from Brad Boyer's hfsplus driver (also maintained by Roman now).

MAINTAINERS

@@ -862,8 +862,8 @@ W:	http://www.nyx.net/~arobinso
 S:	Maintained
 
 HFS FILESYSTEM
-P:	Oliver Neukum
-M:	oliver@neukum.org
+P:	Roman Zippel
+M:	zippel@linux-m68k.org
 L:	linux-kernel@vger.kernel.org
 S:	Maintained
 

fs/hfs/INSTALL.txt

-  Installation instructions for the HFS Filesystem for Linux
-  Paul H. Hargrove, hargrove@sccm.Stanford.EDU
-  version 0.95 28 Apr 1997
-
-  This document explains how to compile and install version 0.95 of
-  hfs_fs, the HFS filesystem for Linux.
-
-  11..  SSyysstteemm RReeqquuiirreemmeennttss
-
-  You will need the following to compile and use this release of hfs_fs:
-
-  +o  Kernel version 2.0.1 or newer compiled with modules enabled
-     (CONFIG_MODULES).
-
-  +o  The kernel sources (or at least the header files) available online.
-
-  +o  The module utilities package current for your kernel version and an
-     understanding of how to use it.
-
-  22..  IInnssttaallllaattiioonn
-
-  This release of the HFS filesystem is not part of the official kernel
-  distribution.  Therefore, it is compiled as a module and then loaded
-  into the kernel using the module utilities.  Therefore, your kernel
-  must be compiled with CONFIG_MODULES enabled.
-
-  22..11..  CCoommppiilliinngg tthhee llooaaddaabbllee mmoodduullee
-
-  To compile hfs.o you should only need to execute ``make'' in the
-  hfs_fs source directory.
-
-  If gcc complains about not finding a large number of header files with
-  names beginning with ``linux/'' then you probably don't have the
-  kernel header files installed correctly.  Either /usr/include/linux,
-  /usr/include/asm and /usr/include/scsi should be symbolic links to
-  include/linux, include/asm and include/scsi in the kernel source tree
-  for the kernel you wish to use hfs_fs with, or else they should be
-  directories containing the header files for the kernel you wish to use
-  hfs_fs with.
-
-  If gcc complains about not finding linux/version.h, then you will need
-  to run ``make dep'' in the kernel source directory to build it.  Under
-  MkLinux, run ``make include/linux/version.h'' instead.
-
-  If gcc complains about not finding the files linux/config.h or
-  linux/autoconf.h, then you will need to run ``make config'' and ``make
-  dep'' in the kernel source directory to build these two files.
-
-  If you are compiling on a DEC Alpha and receive messages saying
-  assignment from incompatible pointer type when compiling files dir_*.c
-  and file_*.c, then you need to change a single line in the file
-  linux/hfs_fs.h.  Remove the text ``&& !defined(__alpha__)'' from the
-  end of line 217.
-
-  22..22..  IInnssttaalllliinngg tthhee mmoodduullee iinn tthhee mmoodduulleess ddiirreeccttoorryy ((ooppttiioonnaall))
-
-  If you plan to use kerneld to automatically load the module or if you
-  wish to use modprobe or insmod without supplying a complete path to
-  hfs.o, then you will need to copy hfs.o into a directory where the
-  module utilities expect to find it.
-
-  The proper directory may depend slightly on your configuration.
-  However, /lib/modules/default/fs/ is a common one for filesystem
-  modules.  Once hfs.o is in the proper directory you should run depmod
-  -a to update the dependency list used by kerneld and modprobe.
-
-  22..33..  LLooaaddiinngg tthhee mmoodduullee iinnttoo tthhee rruunnnniinngg kkeerrnneell
-
-  There are three ways to accomplish this:
-
-  1. If you are running kerneld and have installed hfs.o in the modules
-     directory then you don't need to issue any commands; the module
-     will be loaded when you attempt to mount an HFS filesystem.
-
-  2. If you are _n_o_t running kerneld then you can load hfs.o manually by
-     running modprobe hfs.o.  If you have not installed hfs.o in one of
-     the standard module directories, then you will need provide a full
-     path to the file hfs.o.
-
-  3. If you have been experiencing kernel crashes with hfs_fs, then you
-     should file a bug report including the names of the functions which
-     the EIP and Stack Trace point into.  To help with this you can ask
-     for relocation map for the module when you load it.  To do this
-     load the module with ``insmod -m hfs.o >loadmap''.  Again, you may
-     need a full path to the file hfs.o if you have not placed it in one
-     of the standard module directories.
-
-  22..44..  UUssiinngg tthhee mmoodduullee wwiitthh vveerrssiioonneedd ssyymmbboollss
-
-  All the interface between the module and the kernel take place through
-  very stable (since the mid-1.3.x kernels) parts of the kernel.  If you
-  enabled versioned symbols (CONFIG_MODVERSIONS) when you compiled your
-  kernel you should often be able to compile this module once and then
-  use it with many kernels newer than the one you compiled it for.
-
-  In any case, it is unlikely that this module will need changes with
-  each new kernel patch; simple recompilation should usually suffice.
-
-  33..  LLeeggaall NNoottiicceess
-
-  33..11..  TThhiiss DDooccuummeenntt
-
-  This document is Copyright (c) 1996, 1997 by Paul H. Hargrove.
-
-  Permission is granted to make and distribute verbatim copies of this
-  document provided the copyright notice and this permission notice are
-  preserved on all copies.
-
-  Permission is granted to copy and distribute modified versions of this
-  document under the conditions for verbatim copies above, provided a
-  notice clearly stating that the document is a modified version is also
-  included in the modified document.
-
-  Permission is granted to copy and distribute translations of this
-  document into another language, under the conditions specified above
-  for modified versions.
-
-  Permission is granted to convert this document into another media
-  under the conditions specified above for modified versions provided
-  the requirement to acknowledge the source document is fulfilled by
-  inclusion of an obvious reference to the source document in the new
-  media. Where there is any doubt as to what defines ``obvious'' the
-  copyright owner reserves the right to decide.
-

fs/hfs/Makefile

@@ -4,7 +4,7 @@
 
 obj-$(CONFIG_HFS_FS) += hfs.o
 
-hfs-objs := balloc.o bdelete.o bfind.o bins_del.o binsert.o bitmap.o bitops.o \
-	    bnode.o brec.o btree.o catalog.o dir.o dir_cap.o dir_dbl.o \
-	    dir_nat.o extent.o file.o file_cap.o file_hdr.o inode.o mdb.o \
-            part_tbl.o string.o super.o sysdep.o trans.o version.o
+hfs-objs := bitmap.o bfind.o bnode.o brec.o btree.o \
+	    catalog.o dir.o extent.o inode.o mdb.o \
+            part_tbl.o string.o super.o sysdep.o trans.o
+

fs/hfs/TODO

-The hfs_fs "to do" list.
-------------------------
-Items are broken down into groups and the groups are listed in order
-from most important to least important.  The items within each group
-are not placed in any particular order.  The order in which items are
-listed probably doesn't correlate well with the order they will be
-addressed.
-
-Genuine bugs:
-1.	Header files have compiled-in limit (currently 10) on descriptors.
-
-Missing features:
-1.	1k block support is needed for some devices.
-2.	An ioctl()-based interface is needed to provide a consistent way
-	to do things under all of the representations of forked files.
-
-Possible additional "fork" mount options:
-1.	AppleSingle.
-2.	The scheme MacOS uses on FAT disks (PC Exchange).
-3.	"Flat" (no resource forks or metadata).
-
-Performance issues:
-1.	Use drAllocPtr to speed block allocations.
-2.	Keep a real cache of bnodes, rather than just a hash table of
-	the ones that are currently in use.
-3.	Keep a real cache of extent records, rather than just a linked
-	list of the ones that are currently in use and the one most
-	recently used.  This is particularly needed to get acceptable
-	performance with multiple readers on a file.  Perhaps simply
-	keep them in memory once they've been read until the file is
-	closed.
-
-Implementation details:
-1.	Allocation scheme could/should be closer to that used by Apple.
-2.	B*-tree insertion could/should be closer to that used by Apple.
-3.	Magic-number checks on data structures are rarely done.
-4.	Error recovery is needed for failed binsert(), bdelete() and rename().
-5.	Deadlock detection is needed to make insert_empty_bnode() and
-	bdelete() less likely to hang on a corrupted B-tree.
-6.	Metadata for covered directories shouldn't appear in the filesystem.
-	Under CAP and AppleDouble it currently does.  However, the obvious
-	solution is a real performance killer and is not worth implementing.
-
-Fantasy features:
-1.	Access Desktop file/database for comment and icon.
-2.	Implement mmap() for AppleDouble header files and CAP info files.
-3.	Implement AppleShare client support.
-
-Suggestions/comments/questions are welcome.
-Code addressing any of the issues listed above is especially welcome.
-Paul H. Hargrove
-hargrove@sccm.Stanford.EDU

fs/hfs/bins_del.c

-/*
- * linux/fs/hfs/bins_del.c
- *
- * Copyright (C) 1995-1997  Paul H. Hargrove
- * This file may be distributed under the terms of the GNU General Public License.
- *
- * This file contains the code common to inserting and deleting records
- * in a B-tree.
- *
- * "XXX" in a comment is a note to myself to consider changing something.
- *
- * In function preconditions the term "valid" applied to a pointer to
- * a structure means that the pointer is non-NULL and the structure it
- * points to has all fields initialized to consistent values.
- */
-
-#include "hfs_btree.h"
-
-/*================ File-local functions ================*/
-
-/*
- * hfs_bnode_update_key()
- *
- * Description:
- *   Updates the key for a bnode in its parent.
- *   The key change is propagated up the tree as necessary.
- * Input Variable(s):
- *   struct hfs_brec *brec: the search path to update keys in
- *   struct hfs_belem *belem: the search path element with the changed key
- *   struct hfs_bnode *bnode: the bnode with the changed key
- *   int offset: the "distance" from 'belem->bn' to 'bnode':
- *    0 if the change is in 'belem->bn',
- *    1 if the change is in its right sibling, etc.
- * Output Variable(s):
- *   NONE
- * Returns:
- *   void
- * Preconditions:
- *   'brec' points to a valid (struct hfs_brec)
- *   'belem' points to a valid (struct hfs_belem) in 'brec'.
- *   'bnode' points to a valid (struct hfs_bnode) which is non-empty
- *    and is 'belem->bn' or one of its siblings.
- *   'offset' is as described above.
- * Postconditions:
- *   The key change is propagated up the tree as necessary.
- */
-void hfs_bnode_update_key(struct hfs_brec *brec, struct hfs_belem *belem,
-			  struct hfs_bnode *bnode, int offset)
-{
-	int record = (--belem)->record + offset;
-	void *key = bnode_datastart(bnode) + 1;
-	int keysize = brec->tree->bthKeyLen;
-	struct hfs_belem *limit;
-
-  	memcpy(1+bnode_key(belem->bnr.bn, record), key, keysize);
-
-	/* don't trash the header */
-	if (brec->top > &brec->elem[1]) {
-		limit = brec->top;
-	} else {
-		limit = &brec->elem[1];
-	}
-
-	while ((belem > limit) && (record == 1)) {
-		record = (--belem)->record;
-		memcpy(1+belem_key(belem), key, keysize);
-	}
-}
-
-/*
- * hfs_bnode_shift_right()
- *
- * Description:
- *   Shifts some records from a node to its right neighbor.
- * Input Variable(s):
- *   struct hfs_bnode* left: the node to shift records from
- *   struct hfs_bnode* right: the node to shift records to
- *   hfs_u16 first: the number of the first record in 'left' to move to 'right'
- * Output Variable(s):
- *   NONE
- * Returns:
- *   void
- * Preconditions:
- *   'left' and 'right' point to valid (struct hfs_bnode)s.
- *   'left' contains at least 'first' records.
- *   'right' has enough free space to hold the records to be moved from 'left'
- * Postconditions:
- *   The record numbered 'first' and all records after it in 'left' are
- *   placed at the beginning of 'right'.
- *   The key corresponding to 'right' in its parent is NOT updated.
- */
-void hfs_bnode_shift_right(struct hfs_bnode *left, struct hfs_bnode *right,
-			   int first)
-{
-	int i, adjust, nrecs;
-	unsigned size;
-	hfs_u16 *to, *from;
-
-	if ((first <= 0) || (first > left->ndNRecs)) {
-		hfs_warn("bad argument to shift_right: first=%d, nrecs=%d\n",
-		       first, left->ndNRecs);
-		return;
-	}
-
-	/* initialize variables */
-	nrecs = left->ndNRecs + 1 - first;
-	size = bnode_end(left) - bnode_offset(left, first);
-
-	/* move (possibly empty) contents of right node forward */
-	memmove(bnode_datastart(right) + size,
-		bnode_datastart(right), 
-		bnode_end(right) - sizeof(struct NodeDescriptor));
-
-	/* copy in new records */
-	memcpy(bnode_datastart(right), bnode_key(left,first), size);
-
-	/* fix up offsets in right node */
-	i = right->ndNRecs + 1;
-	from = RECTBL(right, i);
-	to = from - nrecs;
-	while (i--) {
-		hfs_put_hs(hfs_get_hs(from++) + size, to++);
-	}
-	adjust = sizeof(struct NodeDescriptor) - bnode_offset(left, first);
-	i = nrecs-1;
-	from = RECTBL(left, first+i);
-	while (i--) {
-		hfs_put_hs(hfs_get_hs(from++) + adjust, to++);
-	}
-
-	/* fix record counts */
-	left->ndNRecs -= nrecs;
-	right->ndNRecs += nrecs;
-}
-
-/*
- * hfs_bnode_shift_left()
- *
- * Description:
- *   Shifts some records from a node to its left neighbor.
- * Input Variable(s):
- *   struct hfs_bnode* left: the node to shift records to
- *   struct hfs_bnode* right: the node to shift records from
- *   hfs_u16 last: the number of the last record in 'right' to move to 'left'
- * Output Variable(s):
- *   NONE
- * Returns:
- *   void
- * Preconditions:
- *   'left' and 'right' point to valid (struct hfs_bnode)s.
- *   'right' contains at least 'last' records.
- *   'left' has enough free space to hold the records to be moved from 'right'
- * Postconditions:
- *   The record numbered 'last' and all records before it in 'right' are
- *   placed at the end of 'left'.
- *   The key corresponding to 'right' in its parent is NOT updated.
- */
-void hfs_bnode_shift_left(struct hfs_bnode *left, struct hfs_bnode *right,
-			  int last)
-{
-	int i, adjust, nrecs;
-	unsigned size;
-	hfs_u16 *to, *from;
-
-	if ((last <= 0) || (last > right->ndNRecs)) {
-		hfs_warn("bad argument to shift_left: last=%d, nrecs=%d\n",
-		       last, right->ndNRecs);
-		return;
-	}
-
-	/* initialize variables */
-	size = bnode_offset(right, last + 1) - sizeof(struct NodeDescriptor);
-
-	/* copy records to left node */
-	memcpy(bnode_dataend(left), bnode_datastart(right), size);
-
-	/* move (possibly empty) remainder of right node backward */
-	memmove(bnode_datastart(right), bnode_datastart(right) + size, 
-			bnode_end(right) - bnode_offset(right, last + 1));
-
-	/* fix up offsets */
-	nrecs = left->ndNRecs;
-	i = last;
-	from = RECTBL(right, 2);
-	to = RECTBL(left, nrecs + 2);
-	adjust = bnode_offset(left, nrecs + 1) - sizeof(struct NodeDescriptor);
-	while (i--) {
-		hfs_put_hs(hfs_get_hs(from--) + adjust, to--);
-	}
-	i = right->ndNRecs + 1 - last;
-	++from;
-	to = RECTBL(right, 1);
-	while (i--) {
-		hfs_put_hs(hfs_get_hs(from--) - size, to--);
-	}
-
-	/* fix record counts */
-	left->ndNRecs += last;
-	right->ndNRecs -= last;
-}
-
-/*
- * hfs_bnode_in_brec()
- *
- * Description:
- *   Determines whethet a given bnode is part of a given brec.
- *   This is used to avoid deadlock in the case of a corrupted b-tree.
- * Input Variable(s):
- *   hfs_u32 node: the number of the node to check for.
- *   struct hfs_brec* brec: the brec to check in.
- * Output Variable(s):
- *   NONE
- * Returns:
- *   int: 1 it found, 0 if not
- * Preconditions:
- *   'brec' points to a valid struct hfs_brec.
- * Postconditions:
- *   'brec' is unchanged.
- */
-int hfs_bnode_in_brec(hfs_u32 node, const struct hfs_brec *brec)
-{
-	const struct hfs_belem *belem = brec->bottom;
-
-	while (belem && (belem >= brec->top)) {
-		if (belem->bnr.bn && (belem->bnr.bn->node == node)) {
-			return 1;
-		}
-		--belem;
-	}
-	return 0;
-}

fs/hfs/bitops.c

-/*
- * linux/fs/hfs/bitops.c
- *
- * Copyright (C) 1996  Paul H. Hargrove
- * This file may be distributed under the terms of the GNU General Public License.
- *
- * This file contains functions to handle bitmaps in "left-to-right"
- * bit-order such that the MSB of a 32-bit big-endian word is bit 0.
- * (This corresponds to bit 7 of a 32-bit little-endian word.)
- *
- * I have tested and confirmed that the results are identical on the
- * Intel x86, PowerPC and DEC Alpha processors.
- *
- * "XXX" in a comment is a note to myself to consider changing something.
- */
-
-#include "hfs.h"
-
-/*================ Global functions ================*/
-
-/*
- * hfs_find_zero_bit()
- *
- * Description:
- *  Given a block of memory, its length in bits, and a starting bit number,
- *  determine the number of the first zero bits (in left-to-right ordering)
- *  in that range.
- *
- *  Returns >= 'size' if no zero bits are found in the range.
- *
- *  Accesses memory in 32-bit aligned chunks of 32-bits and thus
- *  may read beyond the 'size'th bit.
- */
-hfs_u32 hfs_find_zero_bit(const hfs_u32 *start, hfs_u32 size, hfs_u32 offset)
-{
-	const hfs_u32 *end   = start + ((size + 31) >> 5);
-	const hfs_u32 *curr  = start + (offset >> 5);
-	int bit = offset % 32;
-	
-	if (offset < size) {
-		/* scan the first partial hfs_u32 for zero bits */
-		if (bit != 0) {
-			do {
-				if (!hfs_test_bit(bit, curr)) {
-					goto done;
-				}
-				++bit;
-			} while (bit < 32);
-			bit = 0;
-			++curr;
-		}
-	
-		/* scan complete hfs_u32s for the first zero bit */
-		while (curr < end) {
-			if (*curr == ~((hfs_u32)0)) {
-				++curr;
-			} else {
-				while (hfs_test_bit(bit, curr)) {
-					++bit;
-				}
-				break;
-			}
-		}
-
-done:
-		bit |= (curr - start) << 5;
-		return bit;
-	} else {
-		return size;
-	}
-}
-
-/*
- * hfs_count_zero_bits()
- *
- * Description:
- *  Given a block of memory, its length in bits, and a starting bit number,
- *  determine the number of consecutive zero bits (in left-to-right ordering)
- *  in that range.
- *
- *  Accesses memory in 32-bit aligned chunks of 32-bits and thus
- *  may read beyond the 'size'th bit.
- */
-hfs_u32 hfs_count_zero_bits(const hfs_u32 *start, hfs_u32 size, hfs_u32 offset)
-{
-	const hfs_u32 *end   = start + ((size + 31) >> 5);
-	const hfs_u32 *curr  = start + (offset >> 5);
-	int bit = offset % 32;
-
-	if (offset < size) {
-		/* scan the first partial hfs_u32 for one bits */
-		if (bit != 0) {
-			do {
-				if (hfs_test_bit(bit, curr)) {
-					goto done;
-				}
-				++bit;
-			} while (bit < 32);
-			bit = 0;
-			++curr;
-		}
-	
-		/* scan complete hfs_u32s for the first one bit */
-		while (curr < end) {
-			if (*curr == ((hfs_u32)0)) {
-				++curr;
-			} else {
-				while (!hfs_test_bit(bit, curr)) {
-					++bit;
-				}
-				break;
-			}
-		}
-
-done:
-		bit |= (curr - start) << 5;
-		if (bit > size) {
-			bit = size;
-		}
-		return bit - offset;
-	} else {
-		return 0;
-	}
-}

fs/hfs/version.c

-/*
- * linux/fs/hfs/version.c
- *
- * Copyright (C) 1995-1997  Paul H. Hargrove
- * This file may be distributed under the terms of the GNU General Public License.
- *
- * This file contains the version string for this release.
- */
-
-const char hfs_version[]="0.96";