Fixed MTP to work with TWRP

fs/affs/Changes

@@ -0,0 +1,343 @@
+(Note: I consider version numbers as cheap. That means
+that I do not like numbers like 0.1 and the like for
+things that can be used since quite some time. But
+then, 3.1 doesn't mean 'perfectly stable', too.)
+
+Known bugs:
+-----------
+
+- Doesn't work on the alpha. The only 64/32-bit
+  problem that I'm aware of (pointer/int conversion
+  in readdir()) gives compiler warnings but is
+  apparently not causing the failure, as directory
+  reads basically work (but all files are of size 0).
+  Alas, I've got no alpha to debug. :-(
+
+- The partition checker (drivers/block/genhd.c)
+  doesn't work with devices which have 256 byte
+  blocks (some very old SCSI drives). 
+
+- The feature to automatically make the fs clean
+  might leave a trashed file system with the
+  bitmap flag set valid.
+
+- When a file is truncated to a size that is not
+  a multiple of the blocksize, the rest of the
+  last allocated block is not cleared. Well,
+  this fs never claimed to be Posix conformant.
+
+Please direct bug reports to: zippel@linux-m68k.org
+
+Version 3.20
+------------
+- kill kernel lock
+- fix for a possible bitmap corruption
+
+Version 3.19
+------------
+
+- sizeof changes from Kernel Janitor Project
+- several bug fixes found with fsx
+
+Version 3.18
+------------
+
+- change to global min macro + warning fixes
+- add module tags
+
+Version 3.17
+------------
+
+- locking fixes
+- wrong sign in __affs_hash_dentry
+- remove unnecessary check in affs_new_inode
+- enable international mode for dircache fs
+
+Version 3.16
+------------
+
+- use mark_buffer_dirty_inode instead of mark_buffer_dirty.
+- introduce affs_lock_{link|dir|ext}.
+
+Version 3.15
+------------
+
+- disable link to directories until we can properly support them.
+- locking fixes for link creation/removal.
+
+Version 3.14
+------------
+
+- correctly cut off long file names for compares
+- correctly initialize s_last_bmap
+
+Version 3.13
+------------
+
+Major cleanup for 2.4 [Roman Zippel]
+- new extended block handling
+- new bitmap allocation functions
+- locking should be safe for the future
+- cleanup of some interfaces
+
+Version 3.12
+------------
+
+more 2.4 fixes: [Roman Zippel]
+- s_lock changes
+- increased getblock mess
+- clear meta blocks 
+
+Version 3.11
+------------
+
+- Converted to use 2.3.x page cache [Dave Jones]
+- Corruption in truncate() bugfix [Ken Tyler <kent@werple.net.au>]
+
+Version 3.10
+------------
+
+- Changed partition checker to allow devices
+  with physical blocks != 512 bytes.
+
+- The partition checker now also ignores the
+  word at 0xd0 that Windows likes to write to.
+
+Version 3.9
+-----------
+
+- Moved cleanup from release_file() to put_inode().
+  This makes the first one obsolete.
+
+- truncate() zeroes the unused remainder of a
+  partially used last block when a file is truncated.
+  It also marks the inode dirty now (which is not
+  really necessary as notify_change() will do
+  it anyway).
+
+- Added a few comments, fixed some typos (and
+  introduced some new ones), made the debug messages
+  more consistent. Changed a bad example in the
+  doc file (affs.txt).
+
+- Sets the NOEXEC flag in read_super() for old file
+  systems, since you can't run programs on them.
+
+Version 3.8
+-----------
+Bill Hawes kindly reviewed the affs and sent me the
+patches he did. They're marked (BH). Thanks, Bill!
+
+- Cleanup of error handling in read_super().
+  Didn't release all resources in case of an
+  error. (BH)
+
+- put_inode() releases the ext cache only if it's
+  no longer needed. (BH)
+
+- One set of dentry callbacks is enough. (BH)
+
+- Cleanup of error handling in namei.c. (BH)
+
+- Cleanup of error handling in file.c. (BH)
+
+- The original blocksize of the device is
+  restored when the fs is unmounted. (BH)
+
+- getblock() did not invalidate the key cache
+  when it allocated a new block.
+
+- Removed some unnecessary locks as Bill
+  suggested.
+
+- Simplified match_name(), changed all hashing
+  and case insensitive name comparisons to use
+  uppercase. This makes the tolower() routines
+  obsolete.
+
+- Added mount option 'mufs' to force muFS
+  uid/gid interpretation.
+
+- File mode changes were not updated on disk.
+  This was fixed before, but somehow got lost.
+
+Version 3.7
+-----------
+
+- Added dentry callbacks to allow the dcache to
+  operate case insensitive and length ignorant
+  like the affs itself.
+
+- getblock() didn't update the lastblock field in the
+  inode if the fs was not an OFS. This bug only shows
+  up if a file was enlarged via truncate() and there
+  was not enough space.
+
+- Remove some more superfluous code left over from
+  the old link days ...
+
+- Fixed some oversights which were in patch 2.1.78.
+
+- Fixed a few typos.
+
+Version 3.6
+-----------
+
+- dentry changes. (Thanks to Jes Sorensen for his help.)
+
+- Fixed bug in balloc(): Superblock was not set dirty after
+  the bitmap was changed, so the bitmap wasn't sync'd.
+
+- Fixed nasty bug in find_new_zone(): If the current
+  zone number was zero, the loop didn't terminate,
+  causing a solid lock-up.
+
+- Removed support for old-style directory reads.
+
+- Fixed bug in add_entry(): When doing a sorted insert,
+  the pointer to the next entry in the hash chain wasn't
+  correctly byte-swapped. Since most of the users of the
+  affs use it on a 68k, they didn't notice. But why did
+  I not find this during my tests?
+
+- Fixed some oversights (version wasn't updated on some
+  directory changes).
+
+- Handling of hard links rewritten. To the VFS
+  they appear now as normal Unix links. They are
+  now resolved only once in lookup(). The backside
+  is that unlink(), rename() and rmdir() have to
+  be smart about them, but the result is worth the
+  effort. This also led to some code cleanup.
+
+- Changed name type to unsigned char; the test for
+  invalid filenames didn't work correctly.
+  (Thanks to Michael Krause for pointing at this.)
+
+- Changed mapping of executable flag.
+
+- Changed all network byte-order macros to the
+  recommended ones.
+
+- Added a remount function, so attempts to remount
+  a dircache filesystem or one with errors read/write
+  can be trapped. Previously, ro remounts didn't
+  flush the super block, and rw remounts didn't
+  create allocation zones ...
+
+- Call shrink_dcache_parent() in rmdir().
+  (Thanks to Bill Hawes.)
+
+- Permission checks in unlink().
+
+- Allow mounting of volumes with superfluous
+  bitmap pointers read only, also allows them
+  to be remounted read/write.
+
+- Owner/Group defaults now to the fs user (i.e.
+  the one that mounted it) instead of root. This
+  obsoletes the mount options uid and gid.
+
+- Argument to volume option could overflow the
+  name buffer. It is now silently truncated to
+  30 characters. (Damn it! This kind of bug
+  is too embarrassing.)
+
+- Split inode.c into 2 files, the superblock
+  routines desperately wanted their own file.
+
+- truncate() didn't allocate an extension block
+  cache. If a file was extended by means of
+  truncate(), this led to an Oops.
+
+- fsuser is now checked last.
+
+- rename() will not ignore changes in filename
+  casing any more (though mv(1) still won't allow
+  you to do "mv oldname OldName").
+
+Version 3.5
+-----------
+
+- Extension block caches are now allocated on
+  demand instead of when a file is opened, as
+  files can be read and written without opening
+  them (e. g. the loopback device does this).
+
+- Removed an unused function.
+
+Version 3.4
+-----------
+
+- Hash chains are now sorted by block numbers.
+  (Thanks to Kars de Jong for finding this.)
+- Removed all unnecessary external symbols.
+
+Version 3.3
+-----------
+
+- Tried to make all types 'correct' and consistent.
+- Errors and warnings are now reported via a
+  function. They are all prefixed by a severity
+  and have the same appearance:
+    "AFFS: <function>: <error message>"
+  (There's one exception to this, as in that function
+  is no pointer to the super block available.)
+- The filesystem is remounted read-only after an
+  error.
+- The names of newly created filesystem objects are
+  now checked for validity.
+- Minor cleanups in comments.
+- Added this Changes file. At last!
+
+Version 3.2
+-----------
+
+- Extension block cache: Reading/writing of huge files
+  (several MB) is much faster (of course the added
+  overhead slows down opening, but this is hardly
+  noticeable).
+- The same get_block()-routine can now be used for
+  both OFS and FFS.
+- The super block is now searched in the block that
+  was calculated and in the one following. This
+  should remedy the round-off error introduced by
+  the 1-k blocks that Linux uses.
+- Minor changes to adhere to the new VFS interface.
+- The number of used blocks is now also calculated
+  if the filesystem is mounted read-only.
+- Prefixed some constants with AFFS_ to avoid name
+  clashes.
+- Removed 'EXPERIMENTAL' status.
+
+Version 3.1
+-----------
+
+- Fixed a nasty bug which didn't allow read-only
+  mounts.
+- Allow dir-cache filesystems to be mounted
+  read only.
+- OFS support.
+- Several other changes I just cannot remember
+  any more.
+
+Version 3.0
+-----------
+
+- Almost complete rewrite for the new VFS
+  interface in Linux 1.3.
+- Write support.
+- Support for hard and symbolic links.
+- Lots of things I remember even less ...
+
+Version 2.0
+-----------
+
+- Fixed a few things to get it compiled.
+- Automatic root block calculation.
+- Partition checker for genhd.c
+
+========================================
+
+Let's just call Ray Burr's original affs
+'Version 1.0'.

fs/affs/Kconfig

@@ -0,0 +1,21 @@
+config AFFS_FS
+	tristate "Amiga FFS file system support"
+	depends on BLOCK
+	help
+	  The Fast File System (FFS) is the common file system used on hard
+	  disks by Amiga(tm) systems since AmigaOS Version 1.3 (34.20).  Say Y
+	  if you want to be able to read and write files from and to an Amiga
+	  FFS partition on your hard drive.  Amiga floppies however cannot be
+	  read with this driver due to an incompatibility of the floppy
+	  controller used in an Amiga and the standard floppy controller in
+	  PCs and workstations. Read <file:Documentation/filesystems/affs.txt>
+	  and <file:fs/affs/Changes>.
+
+	  With this driver you can also mount disk files used by Bernd
+	  Schmidt's Un*X Amiga Emulator
+	  (<http://www.freiburg.linux.de/~uae/>).
+	  If you want to do this, you will also need to say Y or M to "Loop
+	  device support", above.
+
+	  To compile this file system support as a module, choose M here: the
+	  module will be called affs.  If unsure, say N.

fs/affs/Makefile

@@ -0,0 +1,9 @@
+#
+# Makefile for the Linux affs filesystem routines.
+#
+
+#ccflags-y := -DDEBUG=1
+
+obj-$(CONFIG_AFFS_FS) += affs.o
+
+affs-objs := super.o namei.o inode.o file.o dir.o amigaffs.o bitmap.o symlink.o

fs/affs/affs.h

@@ -0,0 +1,306 @@
+#ifdef pr_fmt
+#undef pr_fmt
+#endif
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/buffer_head.h>
+#include <linux/amigaffs.h>
+#include <linux/mutex.h>
+#include <linux/workqueue.h>
+
+/* Ugly macros make the code more pretty. */
+
+#define GET_END_PTR(st,p,sz)		 ((st *)((char *)(p)+((sz)-sizeof(st))))
+#define AFFS_GET_HASHENTRY(data,hashkey) be32_to_cpu(((struct dir_front *)data)->hashtable[hashkey])
+#define AFFS_BLOCK(sb, bh, blk)		(AFFS_HEAD(bh)->table[AFFS_SB(sb)->s_hashsize-1-(blk)])
+
+#define AFFS_HEAD(bh)		((struct affs_head *)(bh)->b_data)
+#define AFFS_TAIL(sb, bh)	((struct affs_tail *)((bh)->b_data+(sb)->s_blocksize-sizeof(struct affs_tail)))
+#define AFFS_ROOT_HEAD(bh)	((struct affs_root_head *)(bh)->b_data)
+#define AFFS_ROOT_TAIL(sb, bh)	((struct affs_root_tail *)((bh)->b_data+(sb)->s_blocksize-sizeof(struct affs_root_tail)))
+#define AFFS_DATA_HEAD(bh)	((struct affs_data_head *)(bh)->b_data)
+#define AFFS_DATA(bh)		(((struct affs_data_head *)(bh)->b_data)->data)
+
+#define AFFS_CACHE_SIZE		PAGE_SIZE
+
+#define AFFS_LC_SIZE		(AFFS_CACHE_SIZE/sizeof(u32)/2)
+#define AFFS_AC_SIZE		(AFFS_CACHE_SIZE/sizeof(struct affs_ext_key)/2)
+#define AFFS_AC_MASK		(AFFS_AC_SIZE-1)
+
+struct affs_ext_key {
+	u32	ext;				/* idx of the extended block */
+	u32	key;				/* block number */
+};
+
+/*
+ * affs fs inode data in memory
+ */
+struct affs_inode_info {
+	atomic_t i_opencnt;
+	struct semaphore i_link_lock;		/* Protects internal inode access. */
+	struct semaphore i_ext_lock;		/* Protects internal inode access. */
+#define i_hash_lock i_ext_lock
+	u32	 i_blkcnt;			/* block count */
+	u32	 i_extcnt;			/* extended block count */
+	u32	*i_lc;				/* linear cache of extended blocks */
+	u32	 i_lc_size;
+	u32	 i_lc_shift;
+	u32	 i_lc_mask;
+	struct affs_ext_key *i_ac;		/* associative cache of extended blocks */
+	u32	 i_ext_last;			/* last accessed extended block */
+	struct buffer_head *i_ext_bh;		/* bh of last extended block */
+	loff_t	 mmu_private;
+	u32	 i_protect;			/* unused attribute bits */
+	u32	 i_lastalloc;			/* last allocated block */
+	int	 i_pa_cnt;			/* number of preallocated blocks */
+	struct inode vfs_inode;
+};
+
+/* short cut to get to the affs specific inode data */
+static inline struct affs_inode_info *AFFS_I(struct inode *inode)
+{
+	return list_entry(inode, struct affs_inode_info, vfs_inode);
+}
+
+/*
+ * super-block data in memory
+ *
+ * Block numbers are adjusted for their actual size
+ *
+ */
+
+struct affs_bm_info {
+	u32 bm_key;			/* Disk block number */
+	u32 bm_free;			/* Free blocks in here */
+};
+
+struct affs_sb_info {
+	int s_partition_size;		/* Partition size in blocks. */
+	int s_reserved;			/* Number of reserved blocks. */
+	//u32 s_blksize;			/* Initial device blksize */
+	u32 s_data_blksize;		/* size of the data block w/o header */
+	u32 s_root_block;		/* FFS root block number. */
+	int s_hashsize;			/* Size of hash table. */
+	unsigned long s_flags;		/* See below. */
+	kuid_t s_uid;			/* uid to override */
+	kgid_t s_gid;			/* gid to override */
+	umode_t s_mode;			/* mode to override */
+	struct buffer_head *s_root_bh;	/* Cached root block. */
+	struct mutex s_bmlock;		/* Protects bitmap access. */
+	struct affs_bm_info *s_bitmap;	/* Bitmap infos. */
+	u32 s_bmap_count;		/* # of bitmap blocks. */
+	u32 s_bmap_bits;		/* # of bits in one bitmap blocks */
+	u32 s_last_bmap;
+	struct buffer_head *s_bmap_bh;
+	char *s_prefix;			/* Prefix for volumes and assigns. */
+	char s_volume[32];		/* Volume prefix for absolute symlinks. */
+	spinlock_t symlink_lock;	/* protects the previous two */
+	struct super_block *sb;		/* the VFS superblock object */
+	int work_queued;		/* non-zero delayed work is queued */
+	struct delayed_work sb_work;	/* superblock flush delayed work */
+	spinlock_t work_lock;		/* protects sb_work and work_queued */
+};
+
+#define SF_INTL		0x0001		/* International filesystem. */
+#define SF_BM_VALID	0x0002		/* Bitmap is valid. */
+#define SF_IMMUTABLE	0x0004		/* Protection bits cannot be changed */
+#define SF_QUIET	0x0008		/* chmod errors will be not reported */
+#define SF_SETUID	0x0010		/* Ignore Amiga uid */
+#define SF_SETGID	0x0020		/* Ignore Amiga gid */
+#define SF_SETMODE	0x0040		/* Ignore Amiga protection bits */
+#define SF_MUFS		0x0100		/* Use MUFS uid/gid mapping */
+#define SF_OFS		0x0200		/* Old filesystem */
+#define SF_PREFIX	0x0400		/* Buffer for prefix is allocated */
+#define SF_VERBOSE	0x0800		/* Talk about fs when mounting */
+#define SF_NO_TRUNCATE	0x1000		/* Don't truncate filenames */
+
+/* short cut to get to the affs specific sb data */
+static inline struct affs_sb_info *AFFS_SB(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+void affs_mark_sb_dirty(struct super_block *sb);
+
+/* amigaffs.c */
+
+extern int	affs_insert_hash(struct inode *inode, struct buffer_head *bh);
+extern int	affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh);
+extern int	affs_remove_header(struct dentry *dentry);
+extern u32	affs_checksum_block(struct super_block *sb, struct buffer_head *bh);
+extern void	affs_fix_checksum(struct super_block *sb, struct buffer_head *bh);
+extern void	secs_to_datestamp(time_t secs, struct affs_date *ds);
+extern umode_t	prot_to_mode(u32 prot);
+extern void	mode_to_prot(struct inode *inode);
+extern void	affs_error(struct super_block *sb, const char *function,
+			   const char *fmt, ...);
+extern void	affs_warning(struct super_block *sb, const char *function,
+			     const char *fmt, ...);
+extern bool	affs_nofilenametruncate(const struct dentry *dentry);
+extern int	affs_check_name(const unsigned char *name, int len,
+				bool notruncate);
+extern int	affs_copy_name(unsigned char *bstr, struct dentry *dentry);
+
+/* bitmap. c */
+
+extern u32	affs_count_free_blocks(struct super_block *s);
+extern void	affs_free_block(struct super_block *sb, u32 block);
+extern u32	affs_alloc_block(struct inode *inode, u32 goal);
+extern int	affs_init_bitmap(struct super_block *sb, int *flags);
+extern void	affs_free_bitmap(struct super_block *sb);
+
+/* namei.c */
+
+extern int	affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len);
+extern struct dentry *affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int);
+extern int	affs_unlink(struct inode *dir, struct dentry *dentry);
+extern int	affs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool);
+extern int	affs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode);
+extern int	affs_rmdir(struct inode *dir, struct dentry *dentry);
+extern int	affs_link(struct dentry *olddentry, struct inode *dir,
+			  struct dentry *dentry);
+extern int	affs_symlink(struct inode *dir, struct dentry *dentry,
+			     const char *symname);
+extern int	affs_rename(struct inode *old_dir, struct dentry *old_dentry,
+			    struct inode *new_dir, struct dentry *new_dentry);
+
+/* inode.c */
+
+extern unsigned long		 affs_parent_ino(struct inode *dir);
+extern struct inode		*affs_new_inode(struct inode *dir);
+extern int			 affs_notify_change(struct dentry *dentry, struct iattr *attr);
+extern void			 affs_evict_inode(struct inode *inode);
+extern struct inode		*affs_iget(struct super_block *sb,
+					unsigned long ino);
+extern int			 affs_write_inode(struct inode *inode,
+					struct writeback_control *wbc);
+extern int			 affs_add_entry(struct inode *dir, struct inode *inode, struct dentry *dentry, s32 type);
+
+/* file.c */
+
+void		affs_free_prealloc(struct inode *inode);
+extern void	affs_truncate(struct inode *);
+int		affs_file_fsync(struct file *, loff_t, loff_t, int);
+
+/* dir.c */
+
+extern void   affs_dir_truncate(struct inode *);
+
+/* jump tables */
+
+extern const struct inode_operations	 affs_file_inode_operations;
+extern const struct inode_operations	 affs_dir_inode_operations;
+extern const struct inode_operations   affs_symlink_inode_operations;
+extern const struct file_operations	 affs_file_operations;
+extern const struct file_operations	 affs_file_operations_ofs;
+extern const struct file_operations	 affs_dir_operations;
+extern const struct address_space_operations	 affs_symlink_aops;
+extern const struct address_space_operations	 affs_aops;
+extern const struct address_space_operations	 affs_aops_ofs;
+
+extern const struct dentry_operations	 affs_dentry_operations;
+extern const struct dentry_operations	 affs_intl_dentry_operations;
+
+static inline void
+affs_set_blocksize(struct super_block *sb, int size)
+{
+	sb_set_blocksize(sb, size);
+}
+static inline struct buffer_head *
+affs_bread(struct super_block *sb, int block)
+{
+	pr_debug("%s: %d\n", __func__, block);
+	if (block >= AFFS_SB(sb)->s_reserved && block < AFFS_SB(sb)->s_partition_size)
+		return sb_bread(sb, block);
+	return NULL;
+}
+static inline struct buffer_head *
+affs_getblk(struct super_block *sb, int block)
+{
+	pr_debug("%s: %d\n", __func__, block);
+	if (block >= AFFS_SB(sb)->s_reserved && block < AFFS_SB(sb)->s_partition_size)
+		return sb_getblk(sb, block);
+	return NULL;
+}
+static inline struct buffer_head *
+affs_getzeroblk(struct super_block *sb, int block)
+{
+	struct buffer_head *bh;
+	pr_debug("%s: %d\n", __func__, block);
+	if (block >= AFFS_SB(sb)->s_reserved && block < AFFS_SB(sb)->s_partition_size) {
+		bh = sb_getblk(sb, block);
+		lock_buffer(bh);
+		memset(bh->b_data, 0 , sb->s_blocksize);
+		set_buffer_uptodate(bh);
+		unlock_buffer(bh);
+		return bh;
+	}
+	return NULL;
+}
+static inline struct buffer_head *
+affs_getemptyblk(struct super_block *sb, int block)
+{
+	struct buffer_head *bh;
+	pr_debug("%s: %d\n", __func__, block);
+	if (block >= AFFS_SB(sb)->s_reserved && block < AFFS_SB(sb)->s_partition_size) {
+		bh = sb_getblk(sb, block);
+		wait_on_buffer(bh);
+		set_buffer_uptodate(bh);
+		return bh;
+	}
+	return NULL;
+}
+static inline void
+affs_brelse(struct buffer_head *bh)
+{
+	if (bh)
+		pr_debug("%s: %lld\n", __func__, (long long) bh->b_blocknr);
+	brelse(bh);
+}
+
+static inline void
+affs_adjust_checksum(struct buffer_head *bh, u32 val)
+{
+	u32 tmp = be32_to_cpu(((__be32 *)bh->b_data)[5]);
+	((__be32 *)bh->b_data)[5] = cpu_to_be32(tmp - val);
+}
+static inline void
+affs_adjust_bitmapchecksum(struct buffer_head *bh, u32 val)
+{
+	u32 tmp = be32_to_cpu(((__be32 *)bh->b_data)[0]);
+	((__be32 *)bh->b_data)[0] = cpu_to_be32(tmp - val);
+}
+
+static inline void
+affs_lock_link(struct inode *inode)
+{
+	down(&AFFS_I(inode)->i_link_lock);
+}
+static inline void
+affs_unlock_link(struct inode *inode)
+{
+	up(&AFFS_I(inode)->i_link_lock);
+}
+static inline void
+affs_lock_dir(struct inode *inode)
+{
+	down(&AFFS_I(inode)->i_hash_lock);
+}
+static inline void
+affs_unlock_dir(struct inode *inode)
+{
+	up(&AFFS_I(inode)->i_hash_lock);
+}
+static inline void
+affs_lock_ext(struct inode *inode)
+{
+	down(&AFFS_I(inode)->i_ext_lock);
+}
+static inline void
+affs_unlock_ext(struct inode *inode)
+{
+	up(&AFFS_I(inode)->i_ext_lock);
+}

fs/affs/amigaffs.c

@@ -0,0 +1,518 @@
+/*
+ *  linux/fs/affs/amigaffs.c
+ *
+ *  (c) 1996  Hans-Joachim Widmaier - Rewritten
+ *
+ *  (C) 1993  Ray Burr - Amiga FFS filesystem.
+ *
+ *  Please send bug reports to: hjw@zvw.de
+ */
+
+#include "affs.h"
+
+static char ErrorBuffer[256];
+
+/*
+ * Functions for accessing Amiga-FFS structures.
+ */
+
+
+/* Insert a header block bh into the directory dir
+ * caller must hold AFFS_DIR->i_hash_lock!
+ */
+
+int
+affs_insert_hash(struct inode *dir, struct buffer_head *bh)
+{
+	struct super_block *sb = dir->i_sb;
+	struct buffer_head *dir_bh;
+	u32 ino, hash_ino;
+	int offset;
+
+	ino = bh->b_blocknr;
+	offset = affs_hash_name(sb, AFFS_TAIL(sb, bh)->name + 1, AFFS_TAIL(sb, bh)->name[0]);
+
+	pr_debug("%s(dir=%u, ino=%d)\n", __func__, (u32)dir->i_ino, ino);
+
+	dir_bh = affs_bread(sb, dir->i_ino);
+	if (!dir_bh)
+		return -EIO;
+
+	hash_ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[offset]);
+	while (hash_ino) {
+		affs_brelse(dir_bh);
+		dir_bh = affs_bread(sb, hash_ino);
+		if (!dir_bh)
+			return -EIO;
+		hash_ino = be32_to_cpu(AFFS_TAIL(sb, dir_bh)->hash_chain);
+	}
+	AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);
+	AFFS_TAIL(sb, bh)->hash_chain = 0;
+	affs_fix_checksum(sb, bh);
+
+	if (dir->i_ino == dir_bh->b_blocknr)
+		AFFS_HEAD(dir_bh)->table[offset] = cpu_to_be32(ino);
+	else
+		AFFS_TAIL(sb, dir_bh)->hash_chain = cpu_to_be32(ino);
+
+	affs_adjust_checksum(dir_bh, ino);
+	mark_buffer_dirty_inode(dir_bh, dir);
+	affs_brelse(dir_bh);
+
+	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+	dir->i_version++;
+	mark_inode_dirty(dir);
+
+	return 0;
+}
+
+/* Remove a header block from its directory.
+ * caller must hold AFFS_DIR->i_hash_lock!
+ */
+
+int
+affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh)
+{
+	struct super_block *sb;
+	struct buffer_head *bh;
+	u32 rem_ino, hash_ino;
+	__be32 ino;
+	int offset, retval;
+
+	sb = dir->i_sb;
+	rem_ino = rem_bh->b_blocknr;
+	offset = affs_hash_name(sb, AFFS_TAIL(sb, rem_bh)->name+1, AFFS_TAIL(sb, rem_bh)->name[0]);
+	pr_debug("%s(dir=%d, ino=%d, hashval=%d)\n",
+		 __func__, (u32)dir->i_ino, rem_ino, offset);
+
+	bh = affs_bread(sb, dir->i_ino);
+	if (!bh)
+		return -EIO;
+
+	retval = -ENOENT;
+	hash_ino = be32_to_cpu(AFFS_HEAD(bh)->table[offset]);
+	while (hash_ino) {
+		if (hash_ino == rem_ino) {
+			ino = AFFS_TAIL(sb, rem_bh)->hash_chain;
+			if (dir->i_ino == bh->b_blocknr)
+				AFFS_HEAD(bh)->table[offset] = ino;
+			else
+				AFFS_TAIL(sb, bh)->hash_chain = ino;
+			affs_adjust_checksum(bh, be32_to_cpu(ino) - hash_ino);
+			mark_buffer_dirty_inode(bh, dir);
+			AFFS_TAIL(sb, rem_bh)->parent = 0;
+			retval = 0;
+			break;
+		}
+		affs_brelse(bh);
+		bh = affs_bread(sb, hash_ino);
+		if (!bh)
+			return -EIO;
+		hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
+	}
+
+	affs_brelse(bh);
+
+	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+	dir->i_version++;
+	mark_inode_dirty(dir);
+
+	return retval;
+}
+
+static void
+affs_fix_dcache(struct inode *inode, u32 entry_ino)
+{
+	struct dentry *dentry;
+	spin_lock(&inode->i_lock);
+	hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {
+		if (entry_ino == (u32)(long)dentry->d_fsdata) {
+			dentry->d_fsdata = (void *)inode->i_ino;
+			break;
+		}
+	}
+	spin_unlock(&inode->i_lock);
+}
+
+
+/* Remove header from link chain */
+
+static int
+affs_remove_link(struct dentry *dentry)
+{
+	struct inode *dir, *inode = dentry->d_inode;
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *bh = NULL, *link_bh = NULL;
+	u32 link_ino, ino;
+	int retval;
+
+	pr_debug("%s(key=%ld)\n", __func__, inode->i_ino);
+	retval = -EIO;
+	bh = affs_bread(sb, inode->i_ino);
+	if (!bh)
+		goto done;
+
+	link_ino = (u32)(long)dentry->d_fsdata;
+	if (inode->i_ino == link_ino) {
+		/* we can't remove the head of the link, as its blocknr is still used as ino,
+		 * so we remove the block of the first link instead.
+		 */ 
+		link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain);
+		link_bh = affs_bread(sb, link_ino);
+		if (!link_bh)
+			goto done;
+
+		dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));
+		if (IS_ERR(dir)) {
+			retval = PTR_ERR(dir);
+			goto done;
+		}
+
+		affs_lock_dir(dir);
+		/*
+		 * if there's a dentry for that block, make it
+		 * refer to inode itself.
+		 */
+		affs_fix_dcache(inode, link_ino);
+		retval = affs_remove_hash(dir, link_bh);
+		if (retval) {
+			affs_unlock_dir(dir);
+			goto done;
+		}
+		mark_buffer_dirty_inode(link_bh, inode);
+
+		memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32);
+		retval = affs_insert_hash(dir, bh);
+		if (retval) {
+			affs_unlock_dir(dir);
+			goto done;
+		}
+		mark_buffer_dirty_inode(bh, inode);
+
+		affs_unlock_dir(dir);
+		iput(dir);
+	} else {
+		link_bh = affs_bread(sb, link_ino);
+		if (!link_bh)
+			goto done;
+	}
+
+	while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) {
+		if (ino == link_ino) {
+			__be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain;
+			AFFS_TAIL(sb, bh)->link_chain = ino2;
+			affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino);
+			mark_buffer_dirty_inode(bh, inode);
+			retval = 0;
+			/* Fix the link count, if bh is a normal header block without links */
+			switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
+			case ST_LINKDIR:
+			case ST_LINKFILE:
+				break;
+			default:
+				if (!AFFS_TAIL(sb, bh)->link_chain)
+					set_nlink(inode, 1);
+			}
+			affs_free_block(sb, link_ino);
+			goto done;
+		}
+		affs_brelse(bh);
+		bh = affs_bread(sb, ino);
+		if (!bh)
+			goto done;
+	}
+	retval = -ENOENT;
+done:
+	affs_brelse(link_bh);
+	affs_brelse(bh);
+	return retval;
+}
+
+
+static int
+affs_empty_dir(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *bh;
+	int retval, size;
+
+	retval = -EIO;
+	bh = affs_bread(sb, inode->i_ino);
+	if (!bh)
+		goto done;
+
+	retval = -ENOTEMPTY;
+	for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--)
+		if (AFFS_HEAD(bh)->table[size])
+			goto not_empty;
+	retval = 0;
+not_empty:
+	affs_brelse(bh);
+done:
+	return retval;
+}
+
+
+/* Remove a filesystem object. If the object to be removed has
+ * links to it, one of the links must be changed to inherit
+ * the file or directory. As above, any inode will do.
+ * The buffer will not be freed. If the header is a link, the
+ * block will be marked as free.
+ * This function returns a negative error number in case of
+ * an error, else 0 if the inode is to be deleted or 1 if not.
+ */
+
+int
+affs_remove_header(struct dentry *dentry)
+{
+	struct super_block *sb;
+	struct inode *inode, *dir;
+	struct buffer_head *bh = NULL;
+	int retval;
+
+	dir = dentry->d_parent->d_inode;
+	sb = dir->i_sb;
+
+	retval = -ENOENT;
+	inode = dentry->d_inode;
+	if (!inode)
+		goto done;
+
+	pr_debug("%s(key=%ld)\n", __func__, inode->i_ino);
+	retval = -EIO;
+	bh = affs_bread(sb, (u32)(long)dentry->d_fsdata);
+	if (!bh)
+		goto done;
+
+	affs_lock_link(inode);
+	affs_lock_dir(dir);
+	switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
+	case ST_USERDIR:
+		/* if we ever want to support links to dirs
+		 * i_hash_lock of the inode must only be
+		 * taken after some checks
+		 */
+		affs_lock_dir(inode);
+		retval = affs_empty_dir(inode);
+		affs_unlock_dir(inode);
+		if (retval)
+			goto done_unlock;
+		break;
+	default:
+		break;
+	}
+
+	retval = affs_remove_hash(dir, bh);
+	if (retval)
+		goto done_unlock;
+	mark_buffer_dirty_inode(bh, inode);
+
+	affs_unlock_dir(dir);
+
+	if (inode->i_nlink > 1)
+		retval = affs_remove_link(dentry);
+	else
+		clear_nlink(inode);
+	affs_unlock_link(inode);
+	inode->i_ctime = CURRENT_TIME_SEC;
+	mark_inode_dirty(inode);
+
+done:
+	affs_brelse(bh);
+	return retval;
+
+done_unlock:
+	affs_unlock_dir(dir);
+	affs_unlock_link(inode);
+	goto done;
+}
+
+/* Checksum a block, do various consistency checks and optionally return
+   the blocks type number.  DATA points to the block.  If their pointers
+   are non-null, *PTYPE and *STYPE are set to the primary and secondary
+   block types respectively, *HASHSIZE is set to the size of the hashtable
+   (which lets us calculate the block size).
+   Returns non-zero if the block is not consistent. */
+
+u32
+affs_checksum_block(struct super_block *sb, struct buffer_head *bh)
+{
+	__be32 *ptr = (__be32 *)bh->b_data;
+	u32 sum;
+	int bsize;
+
+	sum = 0;
+	for (bsize = sb->s_blocksize / sizeof(__be32); bsize > 0; bsize--)
+		sum += be32_to_cpu(*ptr++);
+	return sum;
+}
+
+/*
+ * Calculate the checksum of a disk block and store it
+ * at the indicated position.
+ */
+
+void
+affs_fix_checksum(struct super_block *sb, struct buffer_head *bh)
+{
+	int cnt = sb->s_blocksize / sizeof(__be32);
+	__be32 *ptr = (__be32 *)bh->b_data;
+	u32 checksum;
+	__be32 *checksumptr;
+
+	checksumptr = ptr + 5;
+	*checksumptr = 0;
+	for (checksum = 0; cnt > 0; ptr++, cnt--)
+		checksum += be32_to_cpu(*ptr);
+	*checksumptr = cpu_to_be32(-checksum);
+}
+
+void
+secs_to_datestamp(time_t secs, struct affs_date *ds)
+{
+	u32	 days;
+	u32	 minute;
+
+	secs -= sys_tz.tz_minuteswest * 60 + ((8 * 365 + 2) * 24 * 60 * 60);
+	if (secs < 0)
+		secs = 0;
+	days    = secs / 86400;
+	secs   -= days * 86400;
+	minute  = secs / 60;
+	secs   -= minute * 60;
+
+	ds->days = cpu_to_be32(days);
+	ds->mins = cpu_to_be32(minute);
+	ds->ticks = cpu_to_be32(secs * 50);
+}
+
+umode_t
+prot_to_mode(u32 prot)
+{
+	umode_t mode = 0;
+
+	if (!(prot & FIBF_NOWRITE))
+		mode |= S_IWUSR;
+	if (!(prot & FIBF_NOREAD))
+		mode |= S_IRUSR;
+	if (!(prot & FIBF_NOEXECUTE))
+		mode |= S_IXUSR;
+	if (prot & FIBF_GRP_WRITE)
+		mode |= S_IWGRP;
+	if (prot & FIBF_GRP_READ)
+		mode |= S_IRGRP;
+	if (prot & FIBF_GRP_EXECUTE)
+		mode |= S_IXGRP;
+	if (prot & FIBF_OTR_WRITE)
+		mode |= S_IWOTH;
+	if (prot & FIBF_OTR_READ)
+		mode |= S_IROTH;
+	if (prot & FIBF_OTR_EXECUTE)
+		mode |= S_IXOTH;
+
+	return mode;
+}
+
+void
+mode_to_prot(struct inode *inode)
+{
+	u32 prot = AFFS_I(inode)->i_protect;
+	umode_t mode = inode->i_mode;
+
+	if (!(mode & S_IXUSR))
+		prot |= FIBF_NOEXECUTE;
+	if (!(mode & S_IRUSR))
+		prot |= FIBF_NOREAD;
+	if (!(mode & S_IWUSR))
+		prot |= FIBF_NOWRITE;
+	if (mode & S_IXGRP)
+		prot |= FIBF_GRP_EXECUTE;
+	if (mode & S_IRGRP)
+		prot |= FIBF_GRP_READ;
+	if (mode & S_IWGRP)
+		prot |= FIBF_GRP_WRITE;
+	if (mode & S_IXOTH)
+		prot |= FIBF_OTR_EXECUTE;
+	if (mode & S_IROTH)
+		prot |= FIBF_OTR_READ;
+	if (mode & S_IWOTH)
+		prot |= FIBF_OTR_WRITE;
+
+	AFFS_I(inode)->i_protect = prot;
+}
+
+void
+affs_error(struct super_block *sb, const char *function, const char *fmt, ...)
+{
+	va_list	 args;
+
+	va_start(args,fmt);
+	vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args);
+	va_end(args);
+
+	pr_crit("error (device %s): %s(): %s\n", sb->s_id,
+		function,ErrorBuffer);
+	if (!(sb->s_flags & MS_RDONLY))
+		pr_warn("Remounting filesystem read-only\n");
+	sb->s_flags |= MS_RDONLY;
+}
+
+void
+affs_warning(struct super_block *sb, const char *function, const char *fmt, ...)
+{
+	va_list	 args;
+
+	va_start(args,fmt);
+	vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args);
+	va_end(args);
+
+	pr_warn("(device %s): %s(): %s\n", sb->s_id,
+		function,ErrorBuffer);
+}
+
+bool
+affs_nofilenametruncate(const struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	return AFFS_SB(inode->i_sb)->s_flags & SF_NO_TRUNCATE;
+
+}
+
+/* Check if the name is valid for a affs object. */
+
+int
+affs_check_name(const unsigned char *name, int len, bool notruncate)
+{
+	int	 i;
+
+	if (len > 30) {
+		if (notruncate)
+			return -ENAMETOOLONG;
+		else
+			len = 30;
+	}
+	for (i = 0; i < len; i++) {
+		if (name[i] < ' ' || name[i] == ':'
+		    || (name[i] > 0x7e && name[i] < 0xa0))
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* This function copies name to bstr, with at most 30
+ * characters length. The bstr will be prepended by
+ * a length byte.
+ * NOTE: The name will must be already checked by
+ *       affs_check_name()!
+ */
+
+int
+affs_copy_name(unsigned char *bstr, struct dentry *dentry)
+{
+	int len = min(dentry->d_name.len, 30u);
+
+	*bstr++ = len;
+	memcpy(bstr, dentry->d_name.name, len);
+	return len;
+}

fs/affs/bitmap.c

@@ -0,0 +1,365 @@
+/*
+ *  linux/fs/affs/bitmap.c
+ *
+ *  (c) 1996 Hans-Joachim Widmaier
+ *
+ *  bitmap.c contains the code that handles all bitmap related stuff -
+ *  block allocation, deallocation, calculation of free space.
+ */
+
+#include <linux/slab.h>
+#include "affs.h"
+
+u32
+affs_count_free_blocks(struct super_block *sb)
+{
+	struct affs_bm_info *bm;
+	u32 free;
+	int i;
+
+	pr_debug("%s()\n", __func__);
+
+	if (sb->s_flags & MS_RDONLY)
+		return 0;
+
+	mutex_lock(&AFFS_SB(sb)->s_bmlock);
+
+	bm = AFFS_SB(sb)->s_bitmap;
+	free = 0;
+	for (i = AFFS_SB(sb)->s_bmap_count; i > 0; bm++, i--)
+		free += bm->bm_free;
+
+	mutex_unlock(&AFFS_SB(sb)->s_bmlock);
+
+	return free;
+}
+
+void
+affs_free_block(struct super_block *sb, u32 block)
+{
+	struct affs_sb_info *sbi = AFFS_SB(sb);
+	struct affs_bm_info *bm;
+	struct buffer_head *bh;
+	u32 blk, bmap, bit, mask, tmp;
+	__be32 *data;
+
+	pr_debug("%s(%u)\n", __func__, block);
+
+	if (block > sbi->s_partition_size)
+		goto err_range;
+
+	blk     = block - sbi->s_reserved;
+	bmap    = blk / sbi->s_bmap_bits;
+	bit     = blk % sbi->s_bmap_bits;
+	bm      = &sbi->s_bitmap[bmap];
+
+	mutex_lock(&sbi->s_bmlock);
+
+	bh = sbi->s_bmap_bh;
+	if (sbi->s_last_bmap != bmap) {
+		affs_brelse(bh);
+		bh = affs_bread(sb, bm->bm_key);
+		if (!bh)
+			goto err_bh_read;
+		sbi->s_bmap_bh = bh;
+		sbi->s_last_bmap = bmap;
+	}
+
+	mask = 1 << (bit & 31);
+	data = (__be32 *)bh->b_data + bit / 32 + 1;
+
+	/* mark block free */
+	tmp = be32_to_cpu(*data);
+	if (tmp & mask)
+		goto err_free;
+	*data = cpu_to_be32(tmp | mask);
+
+	/* fix checksum */
+	tmp = be32_to_cpu(*(__be32 *)bh->b_data);
+	*(__be32 *)bh->b_data = cpu_to_be32(tmp - mask);
+
+	mark_buffer_dirty(bh);
+	affs_mark_sb_dirty(sb);
+	bm->bm_free++;
+
+	mutex_unlock(&sbi->s_bmlock);
+	return;
+
+err_free:
+	affs_warning(sb,"affs_free_block","Trying to free block %u which is already free", block);
+	mutex_unlock(&sbi->s_bmlock);
+	return;
+
+err_bh_read:
+	affs_error(sb,"affs_free_block","Cannot read bitmap block %u", bm->bm_key);
+	sbi->s_bmap_bh = NULL;
+	sbi->s_last_bmap = ~0;
+	mutex_unlock(&sbi->s_bmlock);
+	return;
+
+err_range:
+	affs_error(sb, "affs_free_block","Block %u outside partition", block);
+	return;
+}
+
+/*
+ * Allocate a block in the given allocation zone.
+ * Since we have to byte-swap the bitmap on little-endian
+ * machines, this is rather expensive. Therefore we will
+ * preallocate up to 16 blocks from the same word, if
+ * possible. We are not doing preallocations in the
+ * header zone, though.
+ */
+
+u32
+affs_alloc_block(struct inode *inode, u32 goal)
+{
+	struct super_block *sb;
+	struct affs_sb_info *sbi;
+	struct affs_bm_info *bm;
+	struct buffer_head *bh;
+	__be32 *data, *enddata;
+	u32 blk, bmap, bit, mask, mask2, tmp;
+	int i;
+
+	sb = inode->i_sb;
+	sbi = AFFS_SB(sb);
+
+	pr_debug("balloc(inode=%lu,goal=%u): ", inode->i_ino, goal);
+
+	if (AFFS_I(inode)->i_pa_cnt) {
+		pr_debug("%d\n", AFFS_I(inode)->i_lastalloc+1);
+		AFFS_I(inode)->i_pa_cnt--;
+		return ++AFFS_I(inode)->i_lastalloc;
+	}
+
+	if (!goal || goal > sbi->s_partition_size) {
+		if (goal)
+			affs_warning(sb, "affs_balloc", "invalid goal %d", goal);
+		//if (!AFFS_I(inode)->i_last_block)
+		//	affs_warning(sb, "affs_balloc", "no last alloc block");
+		goal = sbi->s_reserved;
+	}
+
+	blk = goal - sbi->s_reserved;
+	bmap = blk / sbi->s_bmap_bits;
+	bm = &sbi->s_bitmap[bmap];
+
+	mutex_lock(&sbi->s_bmlock);
+
+	if (bm->bm_free)
+		goto find_bmap_bit;
+
+find_bmap:
+	/* search for the next bmap buffer with free bits */
+	i = sbi->s_bmap_count;
+	do {
+		if (--i < 0)
+			goto err_full;
+		bmap++;
+		bm++;
+		if (bmap < sbi->s_bmap_count)
+			continue;
+		/* restart search at zero */
+		bmap = 0;
+		bm = sbi->s_bitmap;
+	} while (!bm->bm_free);
+	blk = bmap * sbi->s_bmap_bits;
+
+find_bmap_bit:
+
+	bh = sbi->s_bmap_bh;
+	if (sbi->s_last_bmap != bmap) {
+		affs_brelse(bh);
+		bh = affs_bread(sb, bm->bm_key);
+		if (!bh)
+			goto err_bh_read;
+		sbi->s_bmap_bh = bh;
+		sbi->s_last_bmap = bmap;
+	}
+
+	/* find an unused block in this bitmap block */
+	bit = blk % sbi->s_bmap_bits;
+	data = (__be32 *)bh->b_data + bit / 32 + 1;
+	enddata = (__be32 *)((u8 *)bh->b_data + sb->s_blocksize);
+	mask = ~0UL << (bit & 31);
+	blk &= ~31UL;
+
+	tmp = be32_to_cpu(*data);
+	if (tmp & mask)
+		goto find_bit;
+
+	/* scan the rest of the buffer */
+	do {
+		blk += 32;
+		if (++data >= enddata)
+			/* didn't find something, can only happen
+			 * if scan didn't start at 0, try next bmap
+			 */
+			goto find_bmap;
+	} while (!*data);
+	tmp = be32_to_cpu(*data);
+	mask = ~0;
+
+find_bit:
+	/* finally look for a free bit in the word */
+	bit = ffs(tmp & mask) - 1;
+	blk += bit + sbi->s_reserved;
+	mask2 = mask = 1 << (bit & 31);
+	AFFS_I(inode)->i_lastalloc = blk;
+
+	/* prealloc as much as possible within this word */
+	while ((mask2 <<= 1)) {
+		if (!(tmp & mask2))
+			break;
+		AFFS_I(inode)->i_pa_cnt++;
+		mask |= mask2;
+	}
+	bm->bm_free -= AFFS_I(inode)->i_pa_cnt + 1;
+
+	*data = cpu_to_be32(tmp & ~mask);
+
+	/* fix checksum */
+	tmp = be32_to_cpu(*(__be32 *)bh->b_data);
+	*(__be32 *)bh->b_data = cpu_to_be32(tmp + mask);
+
+	mark_buffer_dirty(bh);
+	affs_mark_sb_dirty(sb);
+
+	mutex_unlock(&sbi->s_bmlock);
+
+	pr_debug("%d\n", blk);
+	return blk;
+
+err_bh_read:
+	affs_error(sb,"affs_read_block","Cannot read bitmap block %u", bm->bm_key);
+	sbi->s_bmap_bh = NULL;
+	sbi->s_last_bmap = ~0;
+err_full:
+	mutex_unlock(&sbi->s_bmlock);
+	pr_debug("failed\n");
+	return 0;
+}
+
+int affs_init_bitmap(struct super_block *sb, int *flags)
+{
+	struct affs_bm_info *bm;
+	struct buffer_head *bmap_bh = NULL, *bh = NULL;
+	__be32 *bmap_blk;
+	u32 size, blk, end, offset, mask;
+	int i, res = 0;
+	struct affs_sb_info *sbi = AFFS_SB(sb);
+
+	if (*flags & MS_RDONLY)
+		return 0;
+
+	if (!AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag) {
+		pr_notice("Bitmap invalid - mounting %s read only\n", sb->s_id);
+		*flags |= MS_RDONLY;
+		return 0;
+	}
+
+	sbi->s_last_bmap = ~0;
+	sbi->s_bmap_bh = NULL;
+	sbi->s_bmap_bits = sb->s_blocksize * 8 - 32;
+	sbi->s_bmap_count = (sbi->s_partition_size - sbi->s_reserved +
+				 sbi->s_bmap_bits - 1) / sbi->s_bmap_bits;
+	size = sbi->s_bmap_count * sizeof(*bm);
+	bm = sbi->s_bitmap = kzalloc(size, GFP_KERNEL);
+	if (!sbi->s_bitmap) {
+		pr_err("Bitmap allocation failed\n");
+		return -ENOMEM;
+	}
+
+	bmap_blk = (__be32 *)sbi->s_root_bh->b_data;
+	blk = sb->s_blocksize / 4 - 49;
+	end = blk + 25;
+
+	for (i = sbi->s_bmap_count; i > 0; bm++, i--) {
+		affs_brelse(bh);
+
+		bm->bm_key = be32_to_cpu(bmap_blk[blk]);
+		bh = affs_bread(sb, bm->bm_key);
+		if (!bh) {
+			pr_err("Cannot read bitmap\n");
+			res = -EIO;
+			goto out;
+		}
+		if (affs_checksum_block(sb, bh)) {
+			pr_warn("Bitmap %u invalid - mounting %s read only.\n",
+				bm->bm_key, sb->s_id);
+			*flags |= MS_RDONLY;
+			goto out;
+		}
+		pr_debug("read bitmap block %d: %d\n", blk, bm->bm_key);
+		bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);
+
+		/* Don't try read the extension if this is the last block,
+		 * but we also need the right bm pointer below
+		 */
+		if (++blk < end || i == 1)
+			continue;
+		if (bmap_bh)
+			affs_brelse(bmap_bh);
+		bmap_bh = affs_bread(sb, be32_to_cpu(bmap_blk[blk]));
+		if (!bmap_bh) {
+			pr_err("Cannot read bitmap extension\n");
+			res = -EIO;
+			goto out;
+		}
+		bmap_blk = (__be32 *)bmap_bh->b_data;
+		blk = 0;
+		end = sb->s_blocksize / 4 - 1;
+	}
+
+	offset = (sbi->s_partition_size - sbi->s_reserved) % sbi->s_bmap_bits;
+	mask = ~(0xFFFFFFFFU << (offset & 31));
+	pr_debug("last word: %d %d %d\n", offset, offset / 32 + 1, mask);
+	offset = offset / 32 + 1;
+
+	if (mask) {
+		u32 old, new;
+
+		/* Mark unused bits in the last word as allocated */
+		old = be32_to_cpu(((__be32 *)bh->b_data)[offset]);
+		new = old & mask;
+		//if (old != new) {
+			((__be32 *)bh->b_data)[offset] = cpu_to_be32(new);
+			/* fix checksum */
+			//new -= old;
+			//old = be32_to_cpu(*(__be32 *)bh->b_data);
+			//*(__be32 *)bh->b_data = cpu_to_be32(old - new);
+			//mark_buffer_dirty(bh);
+		//}
+		/* correct offset for the bitmap count below */
+		//offset++;
+	}
+	while (++offset < sb->s_blocksize / 4)
+		((__be32 *)bh->b_data)[offset] = 0;
+	((__be32 *)bh->b_data)[0] = 0;
+	((__be32 *)bh->b_data)[0] = cpu_to_be32(-affs_checksum_block(sb, bh));
+	mark_buffer_dirty(bh);
+
+	/* recalculate bitmap count for last block */
+	bm--;
+	bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);
+
+out:
+	affs_brelse(bh);
+	affs_brelse(bmap_bh);
+	return res;
+}
+
+void affs_free_bitmap(struct super_block *sb)
+{
+	struct affs_sb_info *sbi = AFFS_SB(sb);
+
+	if (!sbi->s_bitmap)
+		return;
+
+	affs_brelse(sbi->s_bmap_bh);
+	sbi->s_bmap_bh = NULL;
+	sbi->s_last_bmap = ~0;
+	kfree(sbi->s_bitmap);
+	sbi->s_bitmap = NULL;
+}

fs/affs/dir.c

@@ -0,0 +1,143 @@
+/*
+ *  linux/fs/affs/dir.c
+ *
+ *  (c) 1996  Hans-Joachim Widmaier - Rewritten
+ *
+ *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
+ *
+ *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ *
+ *  affs directory handling functions
+ *
+ */
+
+#include "affs.h"
+
+static int affs_readdir(struct file *, struct dir_context *);
+
+const struct file_operations affs_dir_operations = {
+	.read		= generic_read_dir,
+	.llseek		= generic_file_llseek,
+	.iterate	= affs_readdir,
+	.fsync		= affs_file_fsync,
+};
+
+/*
+ * directories can handle most operations...
+ */
+const struct inode_operations affs_dir_inode_operations = {
+	.create		= affs_create,
+	.lookup		= affs_lookup,
+	.link		= affs_link,
+	.unlink		= affs_unlink,
+	.symlink	= affs_symlink,
+	.mkdir		= affs_mkdir,
+	.rmdir		= affs_rmdir,
+	.rename		= affs_rename,
+	.setattr	= affs_notify_change,
+};
+
+static int
+affs_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct inode		*inode = file_inode(file);
+	struct super_block	*sb = inode->i_sb;
+	struct buffer_head	*dir_bh = NULL;
+	struct buffer_head	*fh_bh = NULL;
+	unsigned char		*name;
+	int			 namelen;
+	u32			 i;
+	int			 hash_pos;
+	int			 chain_pos;
+	u32			 ino;
+	int			 error = 0;
+
+	pr_debug("%s(ino=%lu,f_pos=%lx)\n",
+		 __func__, inode->i_ino, (unsigned long)ctx->pos);
+
+	if (ctx->pos < 2) {
+		file->private_data = (void *)0;
+		if (!dir_emit_dots(file, ctx))
+			return 0;
+	}
+
+	affs_lock_dir(inode);
+	chain_pos = (ctx->pos - 2) & 0xffff;
+	hash_pos  = (ctx->pos - 2) >> 16;
+	if (chain_pos == 0xffff) {
+		affs_warning(sb, "readdir", "More than 65535 entries in chain");
+		chain_pos = 0;
+		hash_pos++;
+		ctx->pos = ((hash_pos << 16) | chain_pos) + 2;
+	}
+	dir_bh = affs_bread(sb, inode->i_ino);
+	if (!dir_bh)
+		goto out_unlock_dir;
+
+	/* If the directory hasn't changed since the last call to readdir(),
+	 * we can jump directly to where we left off.
+	 */
+	ino = (u32)(long)file->private_data;
+	if (ino && file->f_version == inode->i_version) {
+		pr_debug("readdir() left off=%d\n", ino);
+		goto inside;
+	}
+
+	ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
+	for (i = 0; ino && i < chain_pos; i++) {
+		fh_bh = affs_bread(sb, ino);
+		if (!fh_bh) {
+			affs_error(sb, "readdir","Cannot read block %d", i);
+			error = -EIO;
+			goto out_brelse_dir;
+		}
+		ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
+		affs_brelse(fh_bh);
+		fh_bh = NULL;
+	}
+	if (ino)
+		goto inside;
+	hash_pos++;
+
+	for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
+		ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
+		if (!ino)
+			continue;
+		ctx->pos = (hash_pos << 16) + 2;
+inside:
+		do {
+			fh_bh = affs_bread(sb, ino);
+			if (!fh_bh) {
+				affs_error(sb, "readdir",
+					   "Cannot read block %d", ino);
+				break;
+			}
+
+			namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], (u8)30);
+			name = AFFS_TAIL(sb, fh_bh)->name + 1;
+			pr_debug("readdir(): dir_emit(\"%.*s\", "
+				 "ino=%u), hash=%d, f_pos=%x\n",
+				 namelen, name, ino, hash_pos, (u32)ctx->pos);
+
+			if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN))
+				goto done;
+			ctx->pos++;
+			ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
+			affs_brelse(fh_bh);
+			fh_bh = NULL;
+		} while (ino);
+	}
+done:
+	file->f_version = inode->i_version;
+	file->private_data = (void *)(long)ino;
+	affs_brelse(fh_bh);
+
+out_brelse_dir:
+	affs_brelse(dir_bh);
+
+out_unlock_dir:
+	affs_unlock_dir(inode);
+	return error;
+}

fs/affs/file.c

@@ -0,0 +1,963 @@
+/*
+ *  linux/fs/affs/file.c
+ *
+ *  (c) 1996  Hans-Joachim Widmaier - Rewritten
+ *
+ *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
+ *
+ *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ *
+ *  affs regular file handling primitives
+ */
+
+#include "affs.h"
+
+#if PAGE_SIZE < 4096
+#error PAGE_SIZE must be at least 4096
+#endif
+
+static int affs_grow_extcache(struct inode *inode, u32 lc_idx);
+static struct buffer_head *affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext);
+static inline struct buffer_head *affs_get_extblock(struct inode *inode, u32 ext);
+static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
+static int affs_file_open(struct inode *inode, struct file *filp);
+static int affs_file_release(struct inode *inode, struct file *filp);
+
+const struct file_operations affs_file_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= new_sync_read,
+	.read_iter	= generic_file_read_iter,
+	.write		= new_sync_write,
+	.write_iter	= generic_file_write_iter,
+	.mmap		= generic_file_mmap,
+	.open		= affs_file_open,
+	.release	= affs_file_release,
+	.fsync		= affs_file_fsync,
+	.splice_read	= generic_file_splice_read,
+};
+
+const struct inode_operations affs_file_inode_operations = {
+	.setattr	= affs_notify_change,
+};
+
+static int
+affs_file_open(struct inode *inode, struct file *filp)
+{
+	pr_debug("open(%lu,%d)\n",
+		 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
+	atomic_inc(&AFFS_I(inode)->i_opencnt);
+	return 0;
+}
+
+static int
+affs_file_release(struct inode *inode, struct file *filp)
+{
+	pr_debug("release(%lu, %d)\n",
+		 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
+
+	if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
+		mutex_lock(&inode->i_mutex);
+		if (inode->i_size != AFFS_I(inode)->mmu_private)
+			affs_truncate(inode);
+		affs_free_prealloc(inode);
+		mutex_unlock(&inode->i_mutex);
+	}
+
+	return 0;
+}
+
+static int
+affs_grow_extcache(struct inode *inode, u32 lc_idx)
+{
+	struct super_block	*sb = inode->i_sb;
+	struct buffer_head	*bh;
+	u32 lc_max;
+	int i, j, key;
+
+	if (!AFFS_I(inode)->i_lc) {
+		char *ptr = (char *)get_zeroed_page(GFP_NOFS);
+		if (!ptr)
+			return -ENOMEM;
+		AFFS_I(inode)->i_lc = (u32 *)ptr;
+		AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
+	}
+
+	lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
+
+	if (AFFS_I(inode)->i_extcnt > lc_max) {
+		u32 lc_shift, lc_mask, tmp, off;
+
+		/* need to recalculate linear cache, start from old size */
+		lc_shift = AFFS_I(inode)->i_lc_shift;
+		tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
+		for (; tmp; tmp >>= 1)
+			lc_shift++;
+		lc_mask = (1 << lc_shift) - 1;
+
+		/* fix idx and old size to new shift */
+		lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
+		AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
+
+		/* first shrink old cache to make more space */
+		off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
+		for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
+			AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
+
+		AFFS_I(inode)->i_lc_shift = lc_shift;
+		AFFS_I(inode)->i_lc_mask = lc_mask;
+	}
+
+	/* fill cache to the needed index */
+	i = AFFS_I(inode)->i_lc_size;
+	AFFS_I(inode)->i_lc_size = lc_idx + 1;
+	for (; i <= lc_idx; i++) {
+		if (!i) {
+			AFFS_I(inode)->i_lc[0] = inode->i_ino;
+			continue;
+		}
+		key = AFFS_I(inode)->i_lc[i - 1];
+		j = AFFS_I(inode)->i_lc_mask + 1;
+		// unlock cache
+		for (; j > 0; j--) {
+			bh = affs_bread(sb, key);
+			if (!bh)
+				goto err;
+			key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+			affs_brelse(bh);
+		}
+		// lock cache
+		AFFS_I(inode)->i_lc[i] = key;
+	}
+
+	return 0;
+
+err:
+	// lock cache
+	return -EIO;
+}
+
+static struct buffer_head *
+affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
+{
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *new_bh;
+	u32 blocknr, tmp;
+
+	blocknr = affs_alloc_block(inode, bh->b_blocknr);
+	if (!blocknr)
+		return ERR_PTR(-ENOSPC);
+
+	new_bh = affs_getzeroblk(sb, blocknr);
+	if (!new_bh) {
+		affs_free_block(sb, blocknr);
+		return ERR_PTR(-EIO);
+	}
+
+	AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
+	AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
+	AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
+	AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
+	affs_fix_checksum(sb, new_bh);
+
+	mark_buffer_dirty_inode(new_bh, inode);
+
+	tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+	if (tmp)
+		affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
+	AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
+	affs_adjust_checksum(bh, blocknr - tmp);
+	mark_buffer_dirty_inode(bh, inode);
+
+	AFFS_I(inode)->i_extcnt++;
+	mark_inode_dirty(inode);
+
+	return new_bh;
+}
+
+static inline struct buffer_head *
+affs_get_extblock(struct inode *inode, u32 ext)
+{
+	/* inline the simplest case: same extended block as last time */
+	struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
+	if (ext == AFFS_I(inode)->i_ext_last)
+		get_bh(bh);
+	else
+		/* we have to do more (not inlined) */
+		bh = affs_get_extblock_slow(inode, ext);
+
+	return bh;
+}
+
+static struct buffer_head *
+affs_get_extblock_slow(struct inode *inode, u32 ext)
+{
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *bh;
+	u32 ext_key;
+	u32 lc_idx, lc_off, ac_idx;
+	u32 tmp, idx;
+
+	if (ext == AFFS_I(inode)->i_ext_last + 1) {
+		/* read the next extended block from the current one */
+		bh = AFFS_I(inode)->i_ext_bh;
+		ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+		if (ext < AFFS_I(inode)->i_extcnt)
+			goto read_ext;
+		if (ext > AFFS_I(inode)->i_extcnt)
+			BUG();
+		bh = affs_alloc_extblock(inode, bh, ext);
+		if (IS_ERR(bh))
+			return bh;
+		goto store_ext;
+	}
+
+	if (ext == 0) {
+		/* we seek back to the file header block */
+		ext_key = inode->i_ino;
+		goto read_ext;
+	}
+
+	if (ext >= AFFS_I(inode)->i_extcnt) {
+		struct buffer_head *prev_bh;
+
+		/* allocate a new extended block */
+		if (ext > AFFS_I(inode)->i_extcnt)
+			BUG();
+
+		/* get previous extended block */
+		prev_bh = affs_get_extblock(inode, ext - 1);
+		if (IS_ERR(prev_bh))
+			return prev_bh;
+		bh = affs_alloc_extblock(inode, prev_bh, ext);
+		affs_brelse(prev_bh);
+		if (IS_ERR(bh))
+			return bh;
+		goto store_ext;
+	}
+
+again:
+	/* check if there is an extended cache and whether it's large enough */
+	lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
+	lc_off = ext & AFFS_I(inode)->i_lc_mask;
+
+	if (lc_idx >= AFFS_I(inode)->i_lc_size) {
+		int err;
+
+		err = affs_grow_extcache(inode, lc_idx);
+		if (err)
+			return ERR_PTR(err);
+		goto again;
+	}
+
+	/* every n'th key we find in the linear cache */
+	if (!lc_off) {
+		ext_key = AFFS_I(inode)->i_lc[lc_idx];
+		goto read_ext;
+	}
+
+	/* maybe it's still in the associative cache */
+	ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
+	if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
+		ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
+		goto read_ext;
+	}
+
+	/* try to find one of the previous extended blocks */
+	tmp = ext;
+	idx = ac_idx;
+	while (--tmp, --lc_off > 0) {
+		idx = (idx - 1) & AFFS_AC_MASK;
+		if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
+			ext_key = AFFS_I(inode)->i_ac[idx].key;
+			goto find_ext;
+		}
+	}
+
+	/* fall back to the linear cache */
+	ext_key = AFFS_I(inode)->i_lc[lc_idx];
+find_ext:
+	/* read all extended blocks until we find the one we need */
+	//unlock cache
+	do {
+		bh = affs_bread(sb, ext_key);
+		if (!bh)
+			goto err_bread;
+		ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+		affs_brelse(bh);
+		tmp++;
+	} while (tmp < ext);
+	//lock cache
+
+	/* store it in the associative cache */
+	// recalculate ac_idx?
+	AFFS_I(inode)->i_ac[ac_idx].ext = ext;
+	AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
+
+read_ext:
+	/* finally read the right extended block */
+	//unlock cache
+	bh = affs_bread(sb, ext_key);
+	if (!bh)
+		goto err_bread;
+	//lock cache
+
+store_ext:
+	/* release old cached extended block and store the new one */
+	affs_brelse(AFFS_I(inode)->i_ext_bh);
+	AFFS_I(inode)->i_ext_last = ext;
+	AFFS_I(inode)->i_ext_bh = bh;
+	get_bh(bh);
+
+	return bh;
+
+err_bread:
+	affs_brelse(bh);
+	return ERR_PTR(-EIO);
+}
+
+static int
+affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
+{
+	struct super_block	*sb = inode->i_sb;
+	struct buffer_head	*ext_bh;
+	u32			 ext;
+
+	pr_debug("%s(%u, %lu)\n",
+		 __func__, (u32)inode->i_ino, (unsigned long)block);
+
+	BUG_ON(block > (sector_t)0x7fffffffUL);
+
+	if (block >= AFFS_I(inode)->i_blkcnt) {
+		if (block > AFFS_I(inode)->i_blkcnt || !create)
+			goto err_big;
+	} else
+		create = 0;
+
+	//lock cache
+	affs_lock_ext(inode);
+
+	ext = (u32)block / AFFS_SB(sb)->s_hashsize;
+	block -= ext * AFFS_SB(sb)->s_hashsize;
+	ext_bh = affs_get_extblock(inode, ext);
+	if (IS_ERR(ext_bh))
+		goto err_ext;
+	map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
+
+	if (create) {
+		u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
+		if (!blocknr)
+			goto err_alloc;
+		set_buffer_new(bh_result);
+		AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
+		AFFS_I(inode)->i_blkcnt++;
+
+		/* store new block */
+		if (bh_result->b_blocknr)
+			affs_warning(sb, "get_block", "block already set (%x)", bh_result->b_blocknr);
+		AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
+		AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
+		affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
+		bh_result->b_blocknr = blocknr;
+
+		if (!block) {
+			/* insert first block into header block */
+			u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
+			if (tmp)
+				affs_warning(sb, "get_block", "first block already set (%d)", tmp);
+			AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
+			affs_adjust_checksum(ext_bh, blocknr - tmp);
+		}
+	}
+
+	affs_brelse(ext_bh);
+	//unlock cache
+	affs_unlock_ext(inode);
+	return 0;
+
+err_big:
+	affs_error(inode->i_sb,"get_block","strange block request %d", block);
+	return -EIO;
+err_ext:
+	// unlock cache
+	affs_unlock_ext(inode);
+	return PTR_ERR(ext_bh);
+err_alloc:
+	brelse(ext_bh);
+	clear_buffer_mapped(bh_result);
+	bh_result->b_bdev = NULL;
+	// unlock cache
+	affs_unlock_ext(inode);
+	return -ENOSPC;
+}
+
+static int affs_writepage(struct page *page, struct writeback_control *wbc)
+{
+	return block_write_full_page(page, affs_get_block, wbc);
+}
+
+static int affs_readpage(struct file *file, struct page *page)
+{
+	return block_read_full_page(page, affs_get_block);
+}
+
+static void affs_write_failed(struct address_space *mapping, loff_t to)
+{
+	struct inode *inode = mapping->host;
+
+	if (to > inode->i_size) {
+		truncate_pagecache(inode, inode->i_size);
+		affs_truncate(inode);
+	}
+}
+
+static int affs_write_begin(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned flags,
+			struct page **pagep, void **fsdata)
+{
+	int ret;
+
+	*pagep = NULL;
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+				affs_get_block,
+				&AFFS_I(mapping->host)->mmu_private);
+	if (unlikely(ret))
+		affs_write_failed(mapping, pos + len);
+
+	return ret;
+}
+
+static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping,block,affs_get_block);
+}
+
+const struct address_space_operations affs_aops = {
+	.readpage = affs_readpage,
+	.writepage = affs_writepage,
+	.write_begin = affs_write_begin,
+	.write_end = generic_write_end,
+	.bmap = _affs_bmap
+};
+
+static inline struct buffer_head *
+affs_bread_ino(struct inode *inode, int block, int create)
+{
+	struct buffer_head *bh, tmp_bh;
+	int err;
+
+	tmp_bh.b_state = 0;
+	err = affs_get_block(inode, block, &tmp_bh, create);
+	if (!err) {
+		bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
+		if (bh) {
+			bh->b_state |= tmp_bh.b_state;
+			return bh;
+		}
+		err = -EIO;
+	}
+	return ERR_PTR(err);
+}
+
+static inline struct buffer_head *
+affs_getzeroblk_ino(struct inode *inode, int block)
+{
+	struct buffer_head *bh, tmp_bh;
+	int err;
+
+	tmp_bh.b_state = 0;
+	err = affs_get_block(inode, block, &tmp_bh, 1);
+	if (!err) {
+		bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
+		if (bh) {
+			bh->b_state |= tmp_bh.b_state;
+			return bh;
+		}
+		err = -EIO;
+	}
+	return ERR_PTR(err);
+}
+
+static inline struct buffer_head *
+affs_getemptyblk_ino(struct inode *inode, int block)
+{
+	struct buffer_head *bh, tmp_bh;
+	int err;
+
+	tmp_bh.b_state = 0;
+	err = affs_get_block(inode, block, &tmp_bh, 1);
+	if (!err) {
+		bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
+		if (bh) {
+			bh->b_state |= tmp_bh.b_state;
+			return bh;
+		}
+		err = -EIO;
+	}
+	return ERR_PTR(err);
+}
+
+static int
+affs_do_readpage_ofs(struct page *page, unsigned to)
+{
+	struct inode *inode = page->mapping->host;
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *bh;
+	char *data;
+	unsigned pos = 0;
+	u32 bidx, boff, bsize;
+	u32 tmp;
+
+	pr_debug("%s(%u, %ld, 0, %d)\n", __func__, (u32)inode->i_ino,
+		 page->index, to);
+	BUG_ON(to > PAGE_CACHE_SIZE);
+	kmap(page);
+	data = page_address(page);
+	bsize = AFFS_SB(sb)->s_data_blksize;
+	tmp = page->index << PAGE_CACHE_SHIFT;
+	bidx = tmp / bsize;
+	boff = tmp % bsize;
+
+	while (pos < to) {
+		bh = affs_bread_ino(inode, bidx, 0);
+		if (IS_ERR(bh))
+			return PTR_ERR(bh);
+		tmp = min(bsize - boff, to - pos);
+		BUG_ON(pos + tmp > to || tmp > bsize);
+		memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
+		affs_brelse(bh);
+		bidx++;
+		pos += tmp;
+		boff = 0;
+	}
+	flush_dcache_page(page);
+	kunmap(page);
+	return 0;
+}
+
+static int
+affs_extent_file_ofs(struct inode *inode, u32 newsize)
+{
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *bh, *prev_bh;
+	u32 bidx, boff;
+	u32 size, bsize;
+	u32 tmp;
+
+	pr_debug("%s(%u, %d)\n", __func__, (u32)inode->i_ino, newsize);
+	bsize = AFFS_SB(sb)->s_data_blksize;
+	bh = NULL;
+	size = AFFS_I(inode)->mmu_private;
+	bidx = size / bsize;
+	boff = size % bsize;
+	if (boff) {
+		bh = affs_bread_ino(inode, bidx, 0);
+		if (IS_ERR(bh))
+			return PTR_ERR(bh);
+		tmp = min(bsize - boff, newsize - size);
+		BUG_ON(boff + tmp > bsize || tmp > bsize);
+		memset(AFFS_DATA(bh) + boff, 0, tmp);
+		be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
+		affs_fix_checksum(sb, bh);
+		mark_buffer_dirty_inode(bh, inode);
+		size += tmp;
+		bidx++;
+	} else if (bidx) {
+		bh = affs_bread_ino(inode, bidx - 1, 0);
+		if (IS_ERR(bh))
+			return PTR_ERR(bh);
+	}
+
+	while (size < newsize) {
+		prev_bh = bh;
+		bh = affs_getzeroblk_ino(inode, bidx);
+		if (IS_ERR(bh))
+			goto out;
+		tmp = min(bsize, newsize - size);
+		BUG_ON(tmp > bsize);
+		AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
+		AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
+		AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
+		AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
+		affs_fix_checksum(sb, bh);
+		bh->b_state &= ~(1UL << BH_New);
+		mark_buffer_dirty_inode(bh, inode);
+		if (prev_bh) {
+			u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
+
+			if (tmp_next)
+				affs_warning(sb, "extent_file_ofs",
+					     "next block already set for %d (%d)",
+					     bidx, tmp_next);
+			AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
+			affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
+			mark_buffer_dirty_inode(prev_bh, inode);
+			affs_brelse(prev_bh);
+		}
+		size += bsize;
+		bidx++;
+	}
+	affs_brelse(bh);
+	inode->i_size = AFFS_I(inode)->mmu_private = newsize;
+	return 0;
+
+out:
+	inode->i_size = AFFS_I(inode)->mmu_private = newsize;
+	return PTR_ERR(bh);
+}
+
+static int
+affs_readpage_ofs(struct file *file, struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	u32 to;
+	int err;
+
+	pr_debug("%s(%u, %ld)\n", __func__, (u32)inode->i_ino, page->index);
+	to = PAGE_CACHE_SIZE;
+	if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
+		to = inode->i_size & ~PAGE_CACHE_MASK;
+		memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
+	}
+
+	err = affs_do_readpage_ofs(page, to);
+	if (!err)
+		SetPageUptodate(page);
+	unlock_page(page);
+	return err;
+}
+
+static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned flags,
+				struct page **pagep, void **fsdata)
+{
+	struct inode *inode = mapping->host;
+	struct page *page;
+	pgoff_t index;
+	int err = 0;
+
+	pr_debug("%s(%u, %llu, %llu)\n", __func__, (u32)inode->i_ino,
+		 (unsigned long long)pos, (unsigned long long)pos + len);
+	if (pos > AFFS_I(inode)->mmu_private) {
+		/* XXX: this probably leaves a too-big i_size in case of
+		 * failure. Should really be updating i_size at write_end time
+		 */
+		err = affs_extent_file_ofs(inode, pos);
+		if (err)
+			return err;
+	}
+
+	index = pos >> PAGE_CACHE_SHIFT;
+	page = grab_cache_page_write_begin(mapping, index, flags);
+	if (!page)
+		return -ENOMEM;
+	*pagep = page;
+
+	if (PageUptodate(page))
+		return 0;
+
+	/* XXX: inefficient but safe in the face of short writes */
+	err = affs_do_readpage_ofs(page, PAGE_CACHE_SIZE);
+	if (err) {
+		unlock_page(page);
+		page_cache_release(page);
+	}
+	return err;
+}
+
+static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned copied,
+				struct page *page, void *fsdata)
+{
+	struct inode *inode = mapping->host;
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *bh, *prev_bh;
+	char *data;
+	u32 bidx, boff, bsize;
+	unsigned from, to;
+	u32 tmp;
+	int written;
+
+	from = pos & (PAGE_CACHE_SIZE - 1);
+	to = pos + len;
+	/*
+	 * XXX: not sure if this can handle short copies (len < copied), but
+	 * we don't have to, because the page should always be uptodate here,
+	 * due to write_begin.
+	 */
+
+	pr_debug("%s(%u, %llu, %llu)\n",
+		 __func__, (u32)inode->i_ino, (unsigned long long)pos,
+		(unsigned long long)pos + len);
+	bsize = AFFS_SB(sb)->s_data_blksize;
+	data = page_address(page);
+
+	bh = NULL;
+	written = 0;
+	tmp = (page->index << PAGE_CACHE_SHIFT) + from;
+	bidx = tmp / bsize;
+	boff = tmp % bsize;
+	if (boff) {
+		bh = affs_bread_ino(inode, bidx, 0);
+		if (IS_ERR(bh))
+			return PTR_ERR(bh);
+		tmp = min(bsize - boff, to - from);
+		BUG_ON(boff + tmp > bsize || tmp > bsize);
+		memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
+		be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
+		affs_fix_checksum(sb, bh);
+		mark_buffer_dirty_inode(bh, inode);
+		written += tmp;
+		from += tmp;
+		bidx++;
+	} else if (bidx) {
+		bh = affs_bread_ino(inode, bidx - 1, 0);
+		if (IS_ERR(bh))
+			return PTR_ERR(bh);
+	}
+	while (from + bsize <= to) {
+		prev_bh = bh;
+		bh = affs_getemptyblk_ino(inode, bidx);
+		if (IS_ERR(bh))
+			goto out;
+		memcpy(AFFS_DATA(bh), data + from, bsize);
+		if (buffer_new(bh)) {
+			AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
+			AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
+			AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
+			AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
+			AFFS_DATA_HEAD(bh)->next = 0;
+			bh->b_state &= ~(1UL << BH_New);
+			if (prev_bh) {
+				u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
+
+				if (tmp_next)
+					affs_warning(sb, "commit_write_ofs",
+						     "next block already set for %d (%d)",
+						     bidx, tmp_next);
+				AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
+				affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
+				mark_buffer_dirty_inode(prev_bh, inode);
+			}
+		}
+		affs_brelse(prev_bh);
+		affs_fix_checksum(sb, bh);
+		mark_buffer_dirty_inode(bh, inode);
+		written += bsize;
+		from += bsize;
+		bidx++;
+	}
+	if (from < to) {
+		prev_bh = bh;
+		bh = affs_bread_ino(inode, bidx, 1);
+		if (IS_ERR(bh))
+			goto out;
+		tmp = min(bsize, to - from);
+		BUG_ON(tmp > bsize);
+		memcpy(AFFS_DATA(bh), data + from, tmp);
+		if (buffer_new(bh)) {
+			AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
+			AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
+			AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
+			AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
+			AFFS_DATA_HEAD(bh)->next = 0;
+			bh->b_state &= ~(1UL << BH_New);
+			if (prev_bh) {
+				u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
+
+				if (tmp_next)
+					affs_warning(sb, "commit_write_ofs",
+						     "next block already set for %d (%d)",
+						     bidx, tmp_next);
+				AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
+				affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
+				mark_buffer_dirty_inode(prev_bh, inode);
+			}
+		} else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
+			AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
+		affs_brelse(prev_bh);
+		affs_fix_checksum(sb, bh);
+		mark_buffer_dirty_inode(bh, inode);
+		written += tmp;
+		from += tmp;
+		bidx++;
+	}
+	SetPageUptodate(page);
+
+done:
+	affs_brelse(bh);
+	tmp = (page->index << PAGE_CACHE_SHIFT) + from;
+	if (tmp > inode->i_size)
+		inode->i_size = AFFS_I(inode)->mmu_private = tmp;
+
+	unlock_page(page);
+	page_cache_release(page);
+
+	return written;
+
+out:
+	bh = prev_bh;
+	if (!written)
+		written = PTR_ERR(bh);
+	goto done;
+}
+
+const struct address_space_operations affs_aops_ofs = {
+	.readpage = affs_readpage_ofs,
+	//.writepage = affs_writepage_ofs,
+	.write_begin = affs_write_begin_ofs,
+	.write_end = affs_write_end_ofs
+};
+
+/* Free any preallocated blocks. */
+
+void
+affs_free_prealloc(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+
+	pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
+
+	while (AFFS_I(inode)->i_pa_cnt) {
+		AFFS_I(inode)->i_pa_cnt--;
+		affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
+	}
+}
+
+/* Truncate (or enlarge) a file to the requested size. */
+
+void
+affs_truncate(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	u32 ext, ext_key;
+	u32 last_blk, blkcnt, blk;
+	u32 size;
+	struct buffer_head *ext_bh;
+	int i;
+
+	pr_debug("truncate(inode=%d, oldsize=%u, newsize=%u)\n",
+		 (u32)inode->i_ino, (u32)AFFS_I(inode)->mmu_private, (u32)inode->i_size);
+
+	last_blk = 0;
+	ext = 0;
+	if (inode->i_size) {
+		last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
+		ext = last_blk / AFFS_SB(sb)->s_hashsize;
+	}
+
+	if (inode->i_size > AFFS_I(inode)->mmu_private) {
+		struct address_space *mapping = inode->i_mapping;
+		struct page *page;
+		void *fsdata;
+		loff_t isize = inode->i_size;
+		int res;
+
+		res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
+		if (!res)
+			res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
+		else
+			inode->i_size = AFFS_I(inode)->mmu_private;
+		mark_inode_dirty(inode);
+		return;
+	} else if (inode->i_size == AFFS_I(inode)->mmu_private)
+		return;
+
+	// lock cache
+	ext_bh = affs_get_extblock(inode, ext);
+	if (IS_ERR(ext_bh)) {
+		affs_warning(sb, "truncate", "unexpected read error for ext block %u (%d)",
+			     ext, PTR_ERR(ext_bh));
+		return;
+	}
+	if (AFFS_I(inode)->i_lc) {
+		/* clear linear cache */
+		i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
+		if (AFFS_I(inode)->i_lc_size > i) {
+			AFFS_I(inode)->i_lc_size = i;
+			for (; i < AFFS_LC_SIZE; i++)
+				AFFS_I(inode)->i_lc[i] = 0;
+		}
+		/* clear associative cache */
+		for (i = 0; i < AFFS_AC_SIZE; i++)
+			if (AFFS_I(inode)->i_ac[i].ext >= ext)
+				AFFS_I(inode)->i_ac[i].ext = 0;
+	}
+	ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
+
+	blkcnt = AFFS_I(inode)->i_blkcnt;
+	i = 0;
+	blk = last_blk;
+	if (inode->i_size) {
+		i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
+		blk++;
+	} else
+		AFFS_HEAD(ext_bh)->first_data = 0;
+	AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
+	size = AFFS_SB(sb)->s_hashsize;
+	if (size > blkcnt - blk + i)
+		size = blkcnt - blk + i;
+	for (; i < size; i++, blk++) {
+		affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
+		AFFS_BLOCK(sb, ext_bh, i) = 0;
+	}
+	AFFS_TAIL(sb, ext_bh)->extension = 0;
+	affs_fix_checksum(sb, ext_bh);
+	mark_buffer_dirty_inode(ext_bh, inode);
+	affs_brelse(ext_bh);
+
+	if (inode->i_size) {
+		AFFS_I(inode)->i_blkcnt = last_blk + 1;
+		AFFS_I(inode)->i_extcnt = ext + 1;
+		if (AFFS_SB(sb)->s_flags & SF_OFS) {
+			struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
+			u32 tmp;
+			if (IS_ERR(bh)) {
+				affs_warning(sb, "truncate", "unexpected read error for last block %u (%d)",
+					     ext, PTR_ERR(bh));
+				return;
+			}
+			tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
+			AFFS_DATA_HEAD(bh)->next = 0;
+			affs_adjust_checksum(bh, -tmp);
+			affs_brelse(bh);
+		}
+	} else {
+		AFFS_I(inode)->i_blkcnt = 0;
+		AFFS_I(inode)->i_extcnt = 1;
+	}
+	AFFS_I(inode)->mmu_private = inode->i_size;
+	// unlock cache
+
+	while (ext_key) {
+		ext_bh = affs_bread(sb, ext_key);
+		size = AFFS_SB(sb)->s_hashsize;
+		if (size > blkcnt - blk)
+			size = blkcnt - blk;
+		for (i = 0; i < size; i++, blk++)
+			affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
+		affs_free_block(sb, ext_key);
+		ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
+		affs_brelse(ext_bh);
+	}
+	affs_free_prealloc(inode);
+}
+
+int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
+{
+	struct inode *inode = filp->f_mapping->host;
+	int ret, err;
+
+	err = filemap_write_and_wait_range(inode->i_mapping, start, end);
+	if (err)
+		return err;
+
+	mutex_lock(&inode->i_mutex);
+	ret = write_inode_now(inode, 0);
+	err = sync_blockdev(inode->i_sb->s_bdev);
+	if (!ret)
+		ret = err;
+	mutex_unlock(&inode->i_mutex);
+	return ret;
+}

fs/affs/inode.c

@@ -0,0 +1,415 @@
+/*
+ *  linux/fs/affs/inode.c
+ *
+ *  (c) 1996  Hans-Joachim Widmaier - Rewritten
+ *
+ *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
+ *
+ *  (C) 1992  Eric Youngdale Modified for ISO9660 filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ */
+#include <linux/sched.h>
+#include <linux/gfp.h>
+#include "affs.h"
+
+extern const struct inode_operations affs_symlink_inode_operations;
+
+struct inode *affs_iget(struct super_block *sb, unsigned long ino)
+{
+	struct affs_sb_info	*sbi = AFFS_SB(sb);
+	struct buffer_head	*bh;
+	struct affs_tail	*tail;
+	struct inode		*inode;
+	u32			 block;
+	u32			 size;
+	u32			 prot;
+	u16			 id;
+
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	if (!(inode->i_state & I_NEW))
+		return inode;
+
+	pr_debug("affs_iget(%lu)\n", inode->i_ino);
+
+	block = inode->i_ino;
+	bh = affs_bread(sb, block);
+	if (!bh) {
+		affs_warning(sb, "read_inode", "Cannot read block %d", block);
+		goto bad_inode;
+	}
+	if (affs_checksum_block(sb, bh) || be32_to_cpu(AFFS_HEAD(bh)->ptype) != T_SHORT) {
+		affs_warning(sb,"read_inode",
+			   "Checksum or type (ptype=%d) error on inode %d",
+			   AFFS_HEAD(bh)->ptype, block);
+		goto bad_inode;
+	}
+
+	tail = AFFS_TAIL(sb, bh);
+	prot = be32_to_cpu(tail->protect);
+
+	inode->i_size = 0;
+	set_nlink(inode, 1);
+	inode->i_mode = 0;
+	AFFS_I(inode)->i_extcnt = 1;
+	AFFS_I(inode)->i_ext_last = ~1;
+	AFFS_I(inode)->i_protect = prot;
+	atomic_set(&AFFS_I(inode)->i_opencnt, 0);
+	AFFS_I(inode)->i_blkcnt = 0;
+	AFFS_I(inode)->i_lc = NULL;
+	AFFS_I(inode)->i_lc_size = 0;
+	AFFS_I(inode)->i_lc_shift = 0;
+	AFFS_I(inode)->i_lc_mask = 0;
+	AFFS_I(inode)->i_ac = NULL;
+	AFFS_I(inode)->i_ext_bh = NULL;
+	AFFS_I(inode)->mmu_private = 0;
+	AFFS_I(inode)->i_lastalloc = 0;
+	AFFS_I(inode)->i_pa_cnt = 0;
+
+	if (sbi->s_flags & SF_SETMODE)
+		inode->i_mode = sbi->s_mode;
+	else
+		inode->i_mode = prot_to_mode(prot);
+
+	id = be16_to_cpu(tail->uid);
+	if (id == 0 || sbi->s_flags & SF_SETUID)
+		inode->i_uid = sbi->s_uid;
+	else if (id == 0xFFFF && sbi->s_flags & SF_MUFS)
+		i_uid_write(inode, 0);
+	else
+		i_uid_write(inode, id);
+
+	id = be16_to_cpu(tail->gid);
+	if (id == 0 || sbi->s_flags & SF_SETGID)
+		inode->i_gid = sbi->s_gid;
+	else if (id == 0xFFFF && sbi->s_flags & SF_MUFS)
+		i_gid_write(inode, 0);
+	else
+		i_gid_write(inode, id);
+
+	switch (be32_to_cpu(tail->stype)) {
+	case ST_ROOT:
+		inode->i_uid = sbi->s_uid;
+		inode->i_gid = sbi->s_gid;
+		/* fall through */
+	case ST_USERDIR:
+		if (be32_to_cpu(tail->stype) == ST_USERDIR ||
+		    sbi->s_flags & SF_SETMODE) {
+			if (inode->i_mode & S_IRUSR)
+				inode->i_mode |= S_IXUSR;
+			if (inode->i_mode & S_IRGRP)
+				inode->i_mode |= S_IXGRP;
+			if (inode->i_mode & S_IROTH)
+				inode->i_mode |= S_IXOTH;
+			inode->i_mode |= S_IFDIR;
+		} else
+			inode->i_mode = S_IRUGO | S_IXUGO | S_IWUSR | S_IFDIR;
+		/* Maybe it should be controlled by mount parameter? */
+		//inode->i_mode |= S_ISVTX;
+		inode->i_op = &affs_dir_inode_operations;
+		inode->i_fop = &affs_dir_operations;
+		break;
+	case ST_LINKDIR:
+#if 0
+		affs_warning(sb, "read_inode", "inode is LINKDIR");
+		goto bad_inode;
+#else
+		inode->i_mode |= S_IFDIR;
+		/* ... and leave ->i_op and ->i_fop pointing to empty */
+		break;
+#endif
+	case ST_LINKFILE:
+		affs_warning(sb, "read_inode", "inode is LINKFILE");
+		goto bad_inode;
+	case ST_FILE:
+		size = be32_to_cpu(tail->size);
+		inode->i_mode |= S_IFREG;
+		AFFS_I(inode)->mmu_private = inode->i_size = size;
+		if (inode->i_size) {
+			AFFS_I(inode)->i_blkcnt = (size - 1) /
+					       sbi->s_data_blksize + 1;
+			AFFS_I(inode)->i_extcnt = (AFFS_I(inode)->i_blkcnt - 1) /
+					       sbi->s_hashsize + 1;
+		}
+		if (tail->link_chain)
+			set_nlink(inode, 2);
+		inode->i_mapping->a_ops = (sbi->s_flags & SF_OFS) ? &affs_aops_ofs : &affs_aops;
+		inode->i_op = &affs_file_inode_operations;
+		inode->i_fop = &affs_file_operations;
+		break;
+	case ST_SOFTLINK:
+		inode->i_mode |= S_IFLNK;
+		inode->i_op = &affs_symlink_inode_operations;
+		inode->i_data.a_ops = &affs_symlink_aops;
+		break;
+	}
+
+	inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec
+		       = (be32_to_cpu(tail->change.days) * (24 * 60 * 60) +
+		         be32_to_cpu(tail->change.mins) * 60 +
+			 be32_to_cpu(tail->change.ticks) / 50 +
+			 ((8 * 365 + 2) * 24 * 60 * 60)) +
+			 sys_tz.tz_minuteswest * 60;
+	inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_atime.tv_nsec = 0;
+	affs_brelse(bh);
+	unlock_new_inode(inode);
+	return inode;
+
+bad_inode:
+	affs_brelse(bh);
+	iget_failed(inode);
+	return ERR_PTR(-EIO);
+}
+
+int
+affs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	struct super_block	*sb = inode->i_sb;
+	struct buffer_head	*bh;
+	struct affs_tail	*tail;
+	uid_t			 uid;
+	gid_t			 gid;
+
+	pr_debug("write_inode(%lu)\n", inode->i_ino);
+
+	if (!inode->i_nlink)
+		// possibly free block
+		return 0;
+	bh = affs_bread(sb, inode->i_ino);
+	if (!bh) {
+		affs_error(sb,"write_inode","Cannot read block %lu",inode->i_ino);
+		return -EIO;
+	}
+	tail = AFFS_TAIL(sb, bh);
+	if (tail->stype == cpu_to_be32(ST_ROOT)) {
+		secs_to_datestamp(inode->i_mtime.tv_sec,&AFFS_ROOT_TAIL(sb, bh)->root_change);
+	} else {
+		tail->protect = cpu_to_be32(AFFS_I(inode)->i_protect);
+		tail->size = cpu_to_be32(inode->i_size);
+		secs_to_datestamp(inode->i_mtime.tv_sec,&tail->change);
+		if (!(inode->i_ino == AFFS_SB(sb)->s_root_block)) {
+			uid = i_uid_read(inode);
+			gid = i_gid_read(inode);
+			if (AFFS_SB(sb)->s_flags & SF_MUFS) {
+				if (uid == 0 || uid == 0xFFFF)
+					uid = uid ^ ~0;
+				if (gid == 0 || gid == 0xFFFF)
+					gid = gid ^ ~0;
+			}
+			if (!(AFFS_SB(sb)->s_flags & SF_SETUID))
+				tail->uid = cpu_to_be16(uid);
+			if (!(AFFS_SB(sb)->s_flags & SF_SETGID))
+				tail->gid = cpu_to_be16(gid);
+		}
+	}
+	affs_fix_checksum(sb, bh);
+	mark_buffer_dirty_inode(bh, inode);
+	affs_brelse(bh);
+	affs_free_prealloc(inode);
+	return 0;
+}
+
+int
+affs_notify_change(struct dentry *dentry, struct iattr *attr)
+{
+	struct inode *inode = dentry->d_inode;
+	int error;
+
+	pr_debug("notify_change(%lu,0x%x)\n", inode->i_ino, attr->ia_valid);
+
+	error = inode_change_ok(inode,attr);
+	if (error)
+		goto out;
+
+	if (((attr->ia_valid & ATTR_UID) && (AFFS_SB(inode->i_sb)->s_flags & SF_SETUID)) ||
+	    ((attr->ia_valid & ATTR_GID) && (AFFS_SB(inode->i_sb)->s_flags & SF_SETGID)) ||
+	    ((attr->ia_valid & ATTR_MODE) &&
+	     (AFFS_SB(inode->i_sb)->s_flags & (SF_SETMODE | SF_IMMUTABLE)))) {
+		if (!(AFFS_SB(inode->i_sb)->s_flags & SF_QUIET))
+			error = -EPERM;
+		goto out;
+	}
+
+	if ((attr->ia_valid & ATTR_SIZE) &&
+	    attr->ia_size != i_size_read(inode)) {
+		error = inode_newsize_ok(inode, attr->ia_size);
+		if (error)
+			return error;
+
+		truncate_setsize(inode, attr->ia_size);
+		affs_truncate(inode);
+	}
+
+	setattr_copy(inode, attr);
+	mark_inode_dirty(inode);
+
+	if (attr->ia_valid & ATTR_MODE)
+		mode_to_prot(inode);
+out:
+	return error;
+}
+
+void
+affs_evict_inode(struct inode *inode)
+{
+	unsigned long cache_page;
+	pr_debug("evict_inode(ino=%lu, nlink=%u)\n",
+		 inode->i_ino, inode->i_nlink);
+	truncate_inode_pages_final(&inode->i_data);
+
+	if (!inode->i_nlink) {
+		inode->i_size = 0;
+		affs_truncate(inode);
+	}
+
+	invalidate_inode_buffers(inode);
+	clear_inode(inode);
+	affs_free_prealloc(inode);
+	cache_page = (unsigned long)AFFS_I(inode)->i_lc;
+	if (cache_page) {
+		pr_debug("freeing ext cache\n");
+		AFFS_I(inode)->i_lc = NULL;
+		AFFS_I(inode)->i_ac = NULL;
+		free_page(cache_page);
+	}
+	affs_brelse(AFFS_I(inode)->i_ext_bh);
+	AFFS_I(inode)->i_ext_last = ~1;
+	AFFS_I(inode)->i_ext_bh = NULL;
+
+	if (!inode->i_nlink)
+		affs_free_block(inode->i_sb, inode->i_ino);
+}
+
+struct inode *
+affs_new_inode(struct inode *dir)
+{
+	struct super_block	*sb = dir->i_sb;
+	struct inode		*inode;
+	u32			 block;
+	struct buffer_head	*bh;
+
+	if (!(inode = new_inode(sb)))
+		goto err_inode;
+
+	if (!(block = affs_alloc_block(dir, dir->i_ino)))
+		goto err_block;
+
+	bh = affs_getzeroblk(sb, block);
+	if (!bh)
+		goto err_bh;
+	mark_buffer_dirty_inode(bh, inode);
+	affs_brelse(bh);
+
+	inode->i_uid     = current_fsuid();
+	inode->i_gid     = current_fsgid();
+	inode->i_ino     = block;
+	set_nlink(inode, 1);
+	inode->i_mtime   = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
+	atomic_set(&AFFS_I(inode)->i_opencnt, 0);
+	AFFS_I(inode)->i_blkcnt = 0;
+	AFFS_I(inode)->i_lc = NULL;
+	AFFS_I(inode)->i_lc_size = 0;
+	AFFS_I(inode)->i_lc_shift = 0;
+	AFFS_I(inode)->i_lc_mask = 0;
+	AFFS_I(inode)->i_ac = NULL;
+	AFFS_I(inode)->i_ext_bh = NULL;
+	AFFS_I(inode)->mmu_private = 0;
+	AFFS_I(inode)->i_protect = 0;
+	AFFS_I(inode)->i_lastalloc = 0;
+	AFFS_I(inode)->i_pa_cnt = 0;
+	AFFS_I(inode)->i_extcnt = 1;
+	AFFS_I(inode)->i_ext_last = ~1;
+
+	insert_inode_hash(inode);
+
+	return inode;
+
+err_bh:
+	affs_free_block(sb, block);
+err_block:
+	iput(inode);
+err_inode:
+	return NULL;
+}
+
+/*
+ * Add an entry to a directory. Create the header block
+ * and insert it into the hash table.
+ */
+
+int
+affs_add_entry(struct inode *dir, struct inode *inode, struct dentry *dentry, s32 type)
+{
+	struct super_block *sb = dir->i_sb;
+	struct buffer_head *inode_bh = NULL;
+	struct buffer_head *bh = NULL;
+	u32 block = 0;
+	int retval;
+
+	pr_debug("%s(dir=%u, inode=%u, \"%*s\", type=%d)\n",
+		 __func__, (u32)dir->i_ino,
+	         (u32)inode->i_ino, (int)dentry->d_name.len, dentry->d_name.name, type);
+
+	retval = -EIO;
+	bh = affs_bread(sb, inode->i_ino);
+	if (!bh)
+		goto done;
+
+	affs_lock_link(inode);
+	switch (type) {
+	case ST_LINKFILE:
+	case ST_LINKDIR:
+		retval = -ENOSPC;
+		block = affs_alloc_block(dir, dir->i_ino);
+		if (!block)
+			goto err;
+		retval = -EIO;
+		inode_bh = bh;
+		bh = affs_getzeroblk(sb, block);
+		if (!bh)
+			goto err;
+		break;
+	default:
+		break;
+	}
+
+	AFFS_HEAD(bh)->ptype = cpu_to_be32(T_SHORT);
+	AFFS_HEAD(bh)->key = cpu_to_be32(bh->b_blocknr);
+	affs_copy_name(AFFS_TAIL(sb, bh)->name, dentry);
+	AFFS_TAIL(sb, bh)->stype = cpu_to_be32(type);
+	AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);
+
+	if (inode_bh) {
+		__be32 chain;
+	       	chain = AFFS_TAIL(sb, inode_bh)->link_chain;
+		AFFS_TAIL(sb, bh)->original = cpu_to_be32(inode->i_ino);
+		AFFS_TAIL(sb, bh)->link_chain = chain;
+		AFFS_TAIL(sb, inode_bh)->link_chain = cpu_to_be32(block);
+		affs_adjust_checksum(inode_bh, block - be32_to_cpu(chain));
+		mark_buffer_dirty_inode(inode_bh, inode);
+		set_nlink(inode, 2);
+		ihold(inode);
+	}
+	affs_fix_checksum(sb, bh);
+	mark_buffer_dirty_inode(bh, inode);
+	dentry->d_fsdata = (void *)(long)bh->b_blocknr;
+
+	affs_lock_dir(dir);
+	retval = affs_insert_hash(dir, bh);
+	mark_buffer_dirty_inode(bh, inode);
+	affs_unlock_dir(dir);
+	affs_unlock_link(inode);
+
+	d_instantiate(dentry, inode);
+done:
+	affs_brelse(inode_bh);
+	affs_brelse(bh);
+	return retval;
+err:
+	if (block)
+		affs_free_block(sb, block);
+	affs_unlock_link(inode);
+	goto done;
+}

fs/affs/namei.c

@@ -0,0 +1,469 @@
+/*
+ *  linux/fs/affs/namei.c
+ *
+ *  (c) 1996  Hans-Joachim Widmaier - Rewritten
+ *
+ *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ */
+
+#include "affs.h"
+
+typedef int (*toupper_t)(int);
+
+static int	 affs_toupper(int ch);
+static int	 affs_hash_dentry(const struct dentry *, struct qstr *);
+static int       affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name);
+static int	 affs_intl_toupper(int ch);
+static int	 affs_intl_hash_dentry(const struct dentry *, struct qstr *);
+static int       affs_intl_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name);
+
+const struct dentry_operations affs_dentry_operations = {
+	.d_hash		= affs_hash_dentry,
+	.d_compare	= affs_compare_dentry,
+};
+
+const struct dentry_operations affs_intl_dentry_operations = {
+	.d_hash		= affs_intl_hash_dentry,
+	.d_compare	= affs_intl_compare_dentry,
+};
+
+
+/* Simple toupper() for DOS\1 */
+
+static int
+affs_toupper(int ch)
+{
+	return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
+}
+
+/* International toupper() for DOS\3 ("international") */
+
+static int
+affs_intl_toupper(int ch)
+{
+	return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0
+		&& ch <= 0xFE && ch != 0xF7) ?
+		ch - ('a' - 'A') : ch;
+}
+
+static inline toupper_t
+affs_get_toupper(struct super_block *sb)
+{
+	return AFFS_SB(sb)->s_flags & SF_INTL ? affs_intl_toupper : affs_toupper;
+}
+
+/*
+ * Note: the dentry argument is the parent dentry.
+ */
+static inline int
+__affs_hash_dentry(struct qstr *qstr, toupper_t toupper, bool notruncate)
+{
+	const u8 *name = qstr->name;
+	unsigned long hash;
+	int i;
+
+	i = affs_check_name(qstr->name, qstr->len, notruncate);
+	if (i)
+		return i;
+
+	hash = init_name_hash();
+	i = min(qstr->len, 30u);
+	for (; i > 0; name++, i--)
+		hash = partial_name_hash(toupper(*name), hash);
+	qstr->hash = end_name_hash(hash);
+
+	return 0;
+}
+
+static int
+affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
+{
+	return __affs_hash_dentry(qstr, affs_toupper,
+				  affs_nofilenametruncate(dentry));
+
+}
+
+static int
+affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
+{
+	return __affs_hash_dentry(qstr, affs_intl_toupper,
+				  affs_nofilenametruncate(dentry));
+
+}
+
+static inline int __affs_compare_dentry(unsigned int len,
+		const char *str, const struct qstr *name, toupper_t toupper,
+		bool notruncate)
+{
+	const u8 *aname = str;
+	const u8 *bname = name->name;
+
+	/*
+	 * 'str' is the name of an already existing dentry, so the name
+	 * must be valid. 'name' must be validated first.
+	 */
+
+	if (affs_check_name(name->name, name->len, notruncate))
+		return 1;
+
+	/*
+	 * If the names are longer than the allowed 30 chars,
+	 * the excess is ignored, so their length may differ.
+	 */
+	if (len >= 30) {
+		if (name->len < 30)
+			return 1;
+		len = 30;
+	} else if (len != name->len)
+		return 1;
+
+	for (; len > 0; len--)
+		if (toupper(*aname++) != toupper(*bname++))
+			return 1;
+
+	return 0;
+}
+
+static int
+affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name)
+{
+
+	return __affs_compare_dentry(len, str, name, affs_toupper,
+				     affs_nofilenametruncate(parent));
+}
+
+static int
+affs_intl_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name)
+{
+	return __affs_compare_dentry(len, str, name, affs_intl_toupper,
+				     affs_nofilenametruncate(parent));
+
+}
+
+/*
+ * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
+ */
+
+static inline int
+affs_match(struct dentry *dentry, const u8 *name2, toupper_t toupper)
+{
+	const u8 *name = dentry->d_name.name;
+	int len = dentry->d_name.len;
+
+	if (len >= 30) {
+		if (*name2 < 30)
+			return 0;
+		len = 30;
+	} else if (len != *name2)
+		return 0;
+
+	for (name2++; len > 0; len--)
+		if (toupper(*name++) != toupper(*name2++))
+			return 0;
+	return 1;
+}
+
+int
+affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
+{
+	toupper_t toupper = affs_get_toupper(sb);
+	int hash;
+
+	hash = len = min(len, 30u);
+	for (; len > 0; len--)
+		hash = (hash * 13 + toupper(*name++)) & 0x7ff;
+
+	return hash % AFFS_SB(sb)->s_hashsize;
+}
+
+static struct buffer_head *
+affs_find_entry(struct inode *dir, struct dentry *dentry)
+{
+	struct super_block *sb = dir->i_sb;
+	struct buffer_head *bh;
+	toupper_t toupper = affs_get_toupper(sb);
+	u32 key;
+
+	pr_debug("%s(\"%.*s\")\n",
+		 __func__, (int)dentry->d_name.len, dentry->d_name.name);
+
+	bh = affs_bread(sb, dir->i_ino);
+	if (!bh)
+		return ERR_PTR(-EIO);
+
+	key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);
+
+	for (;;) {
+		affs_brelse(bh);
+		if (key == 0)
+			return NULL;
+		bh = affs_bread(sb, key);
+		if (!bh)
+			return ERR_PTR(-EIO);
+		if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, toupper))
+			return bh;
+		key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
+	}
+}
+
+struct dentry *
+affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+	struct super_block *sb = dir->i_sb;
+	struct buffer_head *bh;
+	struct inode *inode = NULL;
+
+	pr_debug("%s(\"%.*s\")\n",
+		 __func__, (int)dentry->d_name.len, dentry->d_name.name);
+
+	affs_lock_dir(dir);
+	bh = affs_find_entry(dir, dentry);
+	affs_unlock_dir(dir);
+	if (IS_ERR(bh))
+		return ERR_CAST(bh);
+	if (bh) {
+		u32 ino = bh->b_blocknr;
+
+		/* store the real header ino in d_fsdata for faster lookups */
+		dentry->d_fsdata = (void *)(long)ino;
+		switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
+		//link to dirs disabled
+		//case ST_LINKDIR:
+		case ST_LINKFILE:
+			ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
+		}
+		affs_brelse(bh);
+		inode = affs_iget(sb, ino);
+		if (IS_ERR(inode))
+			return ERR_CAST(inode);
+	}
+	d_add(dentry, inode);
+	return NULL;
+}
+
+int
+affs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	pr_debug("%s(dir=%d, %lu \"%.*s\")\n",
+		 __func__, (u32)dir->i_ino, dentry->d_inode->i_ino,
+		(int)dentry->d_name.len, dentry->d_name.name);
+
+	return affs_remove_header(dentry);
+}
+
+int
+affs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode	*inode;
+	int		 error;
+
+	pr_debug("%s(%lu,\"%.*s\",0%ho)\n",
+		 __func__, dir->i_ino, (int)dentry->d_name.len,
+		 dentry->d_name.name,mode);
+
+	inode = affs_new_inode(dir);
+	if (!inode)
+		return -ENOSPC;
+
+	inode->i_mode = mode;
+	mode_to_prot(inode);
+	mark_inode_dirty(inode);
+
+	inode->i_op = &affs_file_inode_operations;
+	inode->i_fop = &affs_file_operations;
+	inode->i_mapping->a_ops = (AFFS_SB(sb)->s_flags & SF_OFS) ? &affs_aops_ofs : &affs_aops;
+	error = affs_add_entry(dir, inode, dentry, ST_FILE);
+	if (error) {
+		clear_nlink(inode);
+		iput(inode);
+		return error;
+	}
+	return 0;
+}
+
+int
+affs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	struct inode		*inode;
+	int			 error;
+
+	pr_debug("%s(%lu,\"%.*s\",0%ho)\n",
+		 __func__, dir->i_ino, (int)dentry->d_name.len,
+		 dentry->d_name.name, mode);
+
+	inode = affs_new_inode(dir);
+	if (!inode)
+		return -ENOSPC;
+
+	inode->i_mode = S_IFDIR | mode;
+	mode_to_prot(inode);
+
+	inode->i_op = &affs_dir_inode_operations;
+	inode->i_fop = &affs_dir_operations;
+
+	error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
+	if (error) {
+		clear_nlink(inode);
+		mark_inode_dirty(inode);
+		iput(inode);
+		return error;
+	}
+	return 0;
+}
+
+int
+affs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	pr_debug("%s(dir=%u, %lu \"%.*s\")\n",
+		__func__, (u32)dir->i_ino, dentry->d_inode->i_ino,
+		 (int)dentry->d_name.len, dentry->d_name.name);
+
+	return affs_remove_header(dentry);
+}
+
+int
+affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+	struct super_block	*sb = dir->i_sb;
+	struct buffer_head	*bh;
+	struct inode		*inode;
+	char			*p;
+	int			 i, maxlen, error;
+	char			 c, lc;
+
+	pr_debug("%s(%lu,\"%.*s\" -> \"%s\")\n",
+		 __func__, dir->i_ino, (int)dentry->d_name.len,
+		 dentry->d_name.name, symname);
+
+	maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1;
+	inode  = affs_new_inode(dir);
+	if (!inode)
+		return -ENOSPC;
+
+	inode->i_op = &affs_symlink_inode_operations;
+	inode->i_data.a_ops = &affs_symlink_aops;
+	inode->i_mode = S_IFLNK | 0777;
+	mode_to_prot(inode);
+
+	error = -EIO;
+	bh = affs_bread(sb, inode->i_ino);
+	if (!bh)
+		goto err;
+	i  = 0;
+	p  = (char *)AFFS_HEAD(bh)->table;
+	lc = '/';
+	if (*symname == '/') {
+		struct affs_sb_info *sbi = AFFS_SB(sb);
+		while (*symname == '/')
+			symname++;
+		spin_lock(&sbi->symlink_lock);
+		while (sbi->s_volume[i])	/* Cannot overflow */
+			*p++ = sbi->s_volume[i++];
+		spin_unlock(&sbi->symlink_lock);
+	}
+	while (i < maxlen && (c = *symname++)) {
+		if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
+			*p++ = '/';
+			i++;
+			symname += 2;
+			lc = '/';
+		} else if (c == '.' && lc == '/' && *symname == '/') {
+			symname++;
+			lc = '/';
+		} else {
+			*p++ = c;
+			lc   = c;
+			i++;
+		}
+		if (lc == '/')
+			while (*symname == '/')
+				symname++;
+	}
+	*p = 0;
+	mark_buffer_dirty_inode(bh, inode);
+	affs_brelse(bh);
+	mark_inode_dirty(inode);
+
+	error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
+	if (error)
+		goto err;
+
+	return 0;
+
+err:
+	clear_nlink(inode);
+	mark_inode_dirty(inode);
+	iput(inode);
+	return error;
+}
+
+int
+affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = old_dentry->d_inode;
+
+	pr_debug("%s(%u, %u, \"%.*s\")\n",
+		 __func__, (u32)inode->i_ino, (u32)dir->i_ino,
+		 (int)dentry->d_name.len,dentry->d_name.name);
+
+	return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
+}
+
+int
+affs_rename(struct inode *old_dir, struct dentry *old_dentry,
+	    struct inode *new_dir, struct dentry *new_dentry)
+{
+	struct super_block *sb = old_dir->i_sb;
+	struct buffer_head *bh = NULL;
+	int retval;
+
+	pr_debug("%s(old=%u,\"%*s\" to new=%u,\"%*s\")\n",
+		 __func__, (u32)old_dir->i_ino, (int)old_dentry->d_name.len,
+		 old_dentry->d_name.name, (u32)new_dir->i_ino,
+		(int)new_dentry->d_name.len, new_dentry->d_name.name);
+
+	retval = affs_check_name(new_dentry->d_name.name,
+				 new_dentry->d_name.len,
+				 affs_nofilenametruncate(old_dentry));
+
+	if (retval)
+		return retval;
+
+	/* Unlink destination if it already exists */
+	if (new_dentry->d_inode) {
+		retval = affs_remove_header(new_dentry);
+		if (retval)
+			return retval;
+	}
+
+	bh = affs_bread(sb, old_dentry->d_inode->i_ino);
+	if (!bh)
+		return -EIO;
+
+	/* Remove header from its parent directory. */
+	affs_lock_dir(old_dir);
+	retval = affs_remove_hash(old_dir, bh);
+	affs_unlock_dir(old_dir);
+	if (retval)
+		goto done;
+
+	/* And insert it into the new directory with the new name. */
+	affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
+	affs_fix_checksum(sb, bh);
+	affs_lock_dir(new_dir);
+	retval = affs_insert_hash(new_dir, bh);
+	affs_unlock_dir(new_dir);
+	/* TODO: move it back to old_dir, if error? */
+
+done:
+	mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
+	affs_brelse(bh);
+	return retval;
+}

fs/affs/super.c

@@ -0,0 +1,643 @@
+/*
+ *  linux/fs/affs/inode.c
+ *
+ *  (c) 1996  Hans-Joachim Widmaier - Rewritten
+ *
+ *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
+ *
+ *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/statfs.h>
+#include <linux/parser.h>
+#include <linux/magic.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/writeback.h>
+#include "affs.h"
+
+static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
+static int affs_remount (struct super_block *sb, int *flags, char *data);
+
+static void
+affs_commit_super(struct super_block *sb, int wait)
+{
+	struct affs_sb_info *sbi = AFFS_SB(sb);
+	struct buffer_head *bh = sbi->s_root_bh;
+	struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
+
+	lock_buffer(bh);
+	secs_to_datestamp(get_seconds(), &tail->disk_change);
+	affs_fix_checksum(sb, bh);
+	unlock_buffer(bh);
+
+	mark_buffer_dirty(bh);
+	if (wait)
+		sync_dirty_buffer(bh);
+}
+
+static void
+affs_put_super(struct super_block *sb)
+{
+	struct affs_sb_info *sbi = AFFS_SB(sb);
+	pr_debug("%s()\n", __func__);
+
+	cancel_delayed_work_sync(&sbi->sb_work);
+}
+
+static int
+affs_sync_fs(struct super_block *sb, int wait)
+{
+	affs_commit_super(sb, wait);
+	return 0;
+}
+
+static void flush_superblock(struct work_struct *work)
+{
+	struct affs_sb_info *sbi;
+	struct super_block *sb;
+
+	sbi = container_of(work, struct affs_sb_info, sb_work.work);
+	sb = sbi->sb;
+
+	spin_lock(&sbi->work_lock);
+	sbi->work_queued = 0;
+	spin_unlock(&sbi->work_lock);
+
+	affs_commit_super(sb, 1);
+}
+
+void affs_mark_sb_dirty(struct super_block *sb)
+{
+	struct affs_sb_info *sbi = AFFS_SB(sb);
+	unsigned long delay;
+
+	if (sb->s_flags & MS_RDONLY)
+	       return;
+
+	spin_lock(&sbi->work_lock);
+	if (!sbi->work_queued) {
+	       delay = msecs_to_jiffies(dirty_writeback_interval * 10);
+	       queue_delayed_work(system_long_wq, &sbi->sb_work, delay);
+	       sbi->work_queued = 1;
+	}
+	spin_unlock(&sbi->work_lock);
+}
+
+static struct kmem_cache * affs_inode_cachep;
+
+static struct inode *affs_alloc_inode(struct super_block *sb)
+{
+	struct affs_inode_info *i;
+
+	i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
+	if (!i)
+		return NULL;
+
+	i->vfs_inode.i_version = 1;
+	i->i_lc = NULL;
+	i->i_ext_bh = NULL;
+	i->i_pa_cnt = 0;
+
+	return &i->vfs_inode;
+}
+
+static void affs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
+}
+
+static void affs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, affs_i_callback);
+}
+
+static void init_once(void *foo)
+{
+	struct affs_inode_info *ei = (struct affs_inode_info *) foo;
+
+	sema_init(&ei->i_link_lock, 1);
+	sema_init(&ei->i_ext_lock, 1);
+	inode_init_once(&ei->vfs_inode);
+}
+
+static int __init init_inodecache(void)
+{
+	affs_inode_cachep = kmem_cache_create("affs_inode_cache",
+					     sizeof(struct affs_inode_info),
+					     0, (SLAB_RECLAIM_ACCOUNT|
+						SLAB_MEM_SPREAD),
+					     init_once);
+	if (affs_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(affs_inode_cachep);
+}
+
+static const struct super_operations affs_sops = {
+	.alloc_inode	= affs_alloc_inode,
+	.destroy_inode	= affs_destroy_inode,
+	.write_inode	= affs_write_inode,
+	.evict_inode	= affs_evict_inode,
+	.put_super	= affs_put_super,
+	.sync_fs	= affs_sync_fs,
+	.statfs		= affs_statfs,
+	.remount_fs	= affs_remount,
+	.show_options	= generic_show_options,
+};
+
+enum {
+	Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
+	Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
+	Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
+};
+
+static const match_table_t tokens = {
+	{Opt_bs, "bs=%u"},
+	{Opt_mode, "mode=%o"},
+	{Opt_mufs, "mufs"},
+	{Opt_notruncate, "nofilenametruncate"},
+	{Opt_prefix, "prefix=%s"},
+	{Opt_protect, "protect"},
+	{Opt_reserved, "reserved=%u"},
+	{Opt_root, "root=%u"},
+	{Opt_setgid, "setgid=%u"},
+	{Opt_setuid, "setuid=%u"},
+	{Opt_verbose, "verbose"},
+	{Opt_volume, "volume=%s"},
+	{Opt_ignore, "grpquota"},
+	{Opt_ignore, "noquota"},
+	{Opt_ignore, "quota"},
+	{Opt_ignore, "usrquota"},
+	{Opt_err, NULL},
+};
+
+static int
+parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root,
+		int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
+{
+	char *p;
+	substring_t args[MAX_OPT_ARGS];
+
+	/* Fill in defaults */
+
+	*uid        = current_uid();
+	*gid        = current_gid();
+	*reserved   = 2;
+	*root       = -1;
+	*blocksize  = -1;
+	volume[0]   = ':';
+	volume[1]   = 0;
+	*mount_opts = 0;
+	if (!options)
+		return 1;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token, n, option;
+		if (!*p)
+			continue;
+
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case Opt_bs:
+			if (match_int(&args[0], &n))
+				return 0;
+			if (n != 512 && n != 1024 && n != 2048
+			    && n != 4096) {
+				pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
+				return 0;
+			}
+			*blocksize = n;
+			break;
+		case Opt_mode:
+			if (match_octal(&args[0], &option))
+				return 0;
+			*mode = option & 0777;
+			*mount_opts |= SF_SETMODE;
+			break;
+		case Opt_mufs:
+			*mount_opts |= SF_MUFS;
+			break;
+		case Opt_notruncate:
+			*mount_opts |= SF_NO_TRUNCATE;
+			break;
+		case Opt_prefix:
+			*prefix = match_strdup(&args[0]);
+			if (!*prefix)
+				return 0;
+			*mount_opts |= SF_PREFIX;
+			break;
+		case Opt_protect:
+			*mount_opts |= SF_IMMUTABLE;
+			break;
+		case Opt_reserved:
+			if (match_int(&args[0], reserved))
+				return 0;
+			break;
+		case Opt_root:
+			if (match_int(&args[0], root))
+				return 0;
+			break;
+		case Opt_setgid:
+			if (match_int(&args[0], &option))
+				return 0;
+			*gid = make_kgid(current_user_ns(), option);
+			if (!gid_valid(*gid))
+				return 0;
+			*mount_opts |= SF_SETGID;
+			break;
+		case Opt_setuid:
+			if (match_int(&args[0], &option))
+				return 0;
+			*uid = make_kuid(current_user_ns(), option);
+			if (!uid_valid(*uid))
+				return 0;
+			*mount_opts |= SF_SETUID;
+			break;
+		case Opt_verbose:
+			*mount_opts |= SF_VERBOSE;
+			break;
+		case Opt_volume: {
+			char *vol = match_strdup(&args[0]);
+			if (!vol)
+				return 0;
+			strlcpy(volume, vol, 32);
+			kfree(vol);
+			break;
+		}
+		case Opt_ignore:
+		 	/* Silently ignore the quota options */
+			break;
+		default:
+			pr_warn("Unrecognized mount option \"%s\" or missing value\n",
+				p);
+			return 0;
+		}
+	}
+	return 1;
+}
+
+/* This function definitely needs to be split up. Some fine day I'll
+ * hopefully have the guts to do so. Until then: sorry for the mess.
+ */
+
+static int affs_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct affs_sb_info	*sbi;
+	struct buffer_head	*root_bh = NULL;
+	struct buffer_head	*boot_bh;
+	struct inode		*root_inode = NULL;
+	s32			 root_block;
+	int			 size, blocksize;
+	u32			 chksum;
+	int			 num_bm;
+	int			 i, j;
+	kuid_t			 uid;
+	kgid_t			 gid;
+	int			 reserved;
+	unsigned long		 mount_flags;
+	int			 tmp_flags;	/* fix remount prototype... */
+	u8			 sig[4];
+	int			 ret;
+
+	save_mount_options(sb, data);
+
+	pr_debug("read_super(%s)\n", data ? (const char *)data : "no options");
+
+	sb->s_magic             = AFFS_SUPER_MAGIC;
+	sb->s_op                = &affs_sops;
+	sb->s_flags |= MS_NODIRATIME;
+
+	sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+
+	sb->s_fs_info = sbi;
+	sbi->sb = sb;
+	mutex_init(&sbi->s_bmlock);
+	spin_lock_init(&sbi->symlink_lock);
+	spin_lock_init(&sbi->work_lock);
+	INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
+
+	if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
+				&blocksize,&sbi->s_prefix,
+				sbi->s_volume, &mount_flags)) {
+		pr_err("Error parsing options\n");
+		return -EINVAL;
+	}
+	/* N.B. after this point s_prefix must be released */
+
+	sbi->s_flags   = mount_flags;
+	sbi->s_mode    = i;
+	sbi->s_uid     = uid;
+	sbi->s_gid     = gid;
+	sbi->s_reserved= reserved;
+
+	/* Get the size of the device in 512-byte blocks.
+	 * If we later see that the partition uses bigger
+	 * blocks, we will have to change it.
+	 */
+
+	size = sb->s_bdev->bd_inode->i_size >> 9;
+	pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
+
+	affs_set_blocksize(sb, PAGE_SIZE);
+	/* Try to find root block. Its location depends on the block size. */
+
+	i = 512;
+	j = 4096;
+	if (blocksize > 0) {
+		i = j = blocksize;
+		size = size / (blocksize / 512);
+	}
+	for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
+		sbi->s_root_block = root_block;
+		if (root_block < 0)
+			sbi->s_root_block = (reserved + size - 1) / 2;
+		pr_debug("setting blocksize to %d\n", blocksize);
+		affs_set_blocksize(sb, blocksize);
+		sbi->s_partition_size = size;
+
+		/* The root block location that was calculated above is not
+		 * correct if the partition size is an odd number of 512-
+		 * byte blocks, which will be rounded down to a number of
+		 * 1024-byte blocks, and if there were an even number of
+		 * reserved blocks. Ideally, all partition checkers should
+		 * report the real number of blocks of the real blocksize,
+		 * but since this just cannot be done, we have to try to
+		 * find the root block anyways. In the above case, it is one
+		 * block behind the calculated one. So we check this one, too.
+		 */
+		for (num_bm = 0; num_bm < 2; num_bm++) {
+			pr_debug("Dev %s, trying root=%u, bs=%d, "
+				"size=%d, reserved=%d\n",
+				sb->s_id,
+				sbi->s_root_block + num_bm,
+				blocksize, size, reserved);
+			root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
+			if (!root_bh)
+				continue;
+			if (!affs_checksum_block(sb, root_bh) &&
+			    be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
+			    be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
+				sbi->s_hashsize    = blocksize / 4 - 56;
+				sbi->s_root_block += num_bm;
+				goto got_root;
+			}
+			affs_brelse(root_bh);
+			root_bh = NULL;
+		}
+	}
+	if (!silent)
+		pr_err("No valid root block on device %s\n", sb->s_id);
+	return -EINVAL;
+
+	/* N.B. after this point bh must be released */
+got_root:
+	/* Keep super block in cache */
+	sbi->s_root_bh = root_bh;
+	root_block = sbi->s_root_block;
+
+	/* Find out which kind of FS we have */
+	boot_bh = sb_bread(sb, 0);
+	if (!boot_bh) {
+		pr_err("Cannot read boot block\n");
+		return -EINVAL;
+	}
+	memcpy(sig, boot_bh->b_data, 4);
+	brelse(boot_bh);
+	chksum = be32_to_cpu(*(__be32 *)sig);
+
+	/* Dircache filesystems are compatible with non-dircache ones
+	 * when reading. As long as they aren't supported, writing is
+	 * not recommended.
+	 */
+	if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
+	     || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
+		pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
+		sb->s_flags |= MS_RDONLY;
+	}
+	switch (chksum) {
+		case MUFS_FS:
+		case MUFS_INTLFFS:
+		case MUFS_DCFFS:
+			sbi->s_flags |= SF_MUFS;
+			/* fall thru */
+		case FS_INTLFFS:
+		case FS_DCFFS:
+			sbi->s_flags |= SF_INTL;
+			break;
+		case MUFS_FFS:
+			sbi->s_flags |= SF_MUFS;
+			break;
+		case FS_FFS:
+			break;
+		case MUFS_OFS:
+			sbi->s_flags |= SF_MUFS;
+			/* fall thru */
+		case FS_OFS:
+			sbi->s_flags |= SF_OFS;
+			sb->s_flags |= MS_NOEXEC;
+			break;
+		case MUFS_DCOFS:
+		case MUFS_INTLOFS:
+			sbi->s_flags |= SF_MUFS;
+		case FS_DCOFS:
+		case FS_INTLOFS:
+			sbi->s_flags |= SF_INTL | SF_OFS;
+			sb->s_flags |= MS_NOEXEC;
+			break;
+		default:
+			pr_err("Unknown filesystem on device %s: %08X\n",
+			       sb->s_id, chksum);
+			return -EINVAL;
+	}
+
+	if (mount_flags & SF_VERBOSE) {
+		u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
+		pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
+			len > 31 ? 31 : len,
+			AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
+			sig, sig[3] + '0', blocksize);
+	}
+
+	sb->s_flags |= MS_NODEV | MS_NOSUID;
+
+	sbi->s_data_blksize = sb->s_blocksize;
+	if (sbi->s_flags & SF_OFS)
+		sbi->s_data_blksize -= 24;
+
+	tmp_flags = sb->s_flags;
+	ret = affs_init_bitmap(sb, &tmp_flags);
+	if (ret)
+		return ret;
+	sb->s_flags = tmp_flags;
+
+	/* set up enough so that it can read an inode */
+
+	root_inode = affs_iget(sb, root_block);
+	if (IS_ERR(root_inode))
+		return PTR_ERR(root_inode);
+
+	if (AFFS_SB(sb)->s_flags & SF_INTL)
+		sb->s_d_op = &affs_intl_dentry_operations;
+	else
+		sb->s_d_op = &affs_dentry_operations;
+
+	sb->s_root = d_make_root(root_inode);
+	if (!sb->s_root) {
+		pr_err("AFFS: Get root inode failed\n");
+		return -ENOMEM;
+	}
+
+	pr_debug("s_flags=%lX\n", sb->s_flags);
+	return 0;
+}
+
+static int
+affs_remount(struct super_block *sb, int *flags, char *data)
+{
+	struct affs_sb_info	*sbi = AFFS_SB(sb);
+	int			 blocksize;
+	kuid_t			 uid;
+	kgid_t			 gid;
+	int			 mode;
+	int			 reserved;
+	int			 root_block;
+	unsigned long		 mount_flags;
+	int			 res = 0;
+	char			*new_opts = kstrdup(data, GFP_KERNEL);
+	char			 volume[32];
+	char			*prefix = NULL;
+
+	pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data);
+
+	sync_filesystem(sb);
+	*flags |= MS_NODIRATIME;
+
+	memcpy(volume, sbi->s_volume, 32);
+	if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
+			   &blocksize, &prefix, volume,
+			   &mount_flags)) {
+		kfree(prefix);
+		kfree(new_opts);
+		return -EINVAL;
+	}
+
+	flush_delayed_work(&sbi->sb_work);
+	replace_mount_options(sb, new_opts);
+
+	sbi->s_flags = mount_flags;
+	sbi->s_mode  = mode;
+	sbi->s_uid   = uid;
+	sbi->s_gid   = gid;
+	/* protect against readers */
+	spin_lock(&sbi->symlink_lock);
+	if (prefix) {
+		kfree(sbi->s_prefix);
+		sbi->s_prefix = prefix;
+	}
+	memcpy(sbi->s_volume, volume, 32);
+	spin_unlock(&sbi->symlink_lock);
+
+	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
+		return 0;
+
+	if (*flags & MS_RDONLY)
+		affs_free_bitmap(sb);
+	else
+		res = affs_init_bitmap(sb, flags);
+
+	return res;
+}
+
+static int
+affs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	int		 free;
+	u64		 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+	pr_debug("%s() partsize=%d, reserved=%d\n",
+		 __func__, AFFS_SB(sb)->s_partition_size,
+		 AFFS_SB(sb)->s_reserved);
+
+	free          = affs_count_free_blocks(sb);
+	buf->f_type    = AFFS_SUPER_MAGIC;
+	buf->f_bsize   = sb->s_blocksize;
+	buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
+	buf->f_bfree   = free;
+	buf->f_bavail  = free;
+	buf->f_fsid.val[0] = (u32)id;
+	buf->f_fsid.val[1] = (u32)(id >> 32);
+	buf->f_namelen = 30;
+	return 0;
+}
+
+static struct dentry *affs_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
+}
+
+static void affs_kill_sb(struct super_block *sb)
+{
+	struct affs_sb_info *sbi = AFFS_SB(sb);
+	kill_block_super(sb);
+	if (sbi) {
+		affs_free_bitmap(sb);
+		affs_brelse(sbi->s_root_bh);
+		kfree(sbi->s_prefix);
+		kfree(sbi);
+	}
+}
+
+static struct file_system_type affs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "affs",
+	.mount		= affs_mount,
+	.kill_sb	= affs_kill_sb,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("affs");
+
+static int __init init_affs_fs(void)
+{
+	int err = init_inodecache();
+	if (err)
+		goto out1;
+	err = register_filesystem(&affs_fs_type);
+	if (err)
+		goto out;
+	return 0;
+out:
+	destroy_inodecache();
+out1:
+	return err;
+}
+
+static void __exit exit_affs_fs(void)
+{
+	unregister_filesystem(&affs_fs_type);
+	destroy_inodecache();
+}
+
+MODULE_DESCRIPTION("Amiga filesystem support for Linux");
+MODULE_LICENSE("GPL");
+
+module_init(init_affs_fs)
+module_exit(exit_affs_fs)

fs/affs/symlink.c

@@ -0,0 +1,81 @@
+/*
+ *  linux/fs/affs/symlink.c
+ *
+ *  1995  Hans-Joachim Widmaier - Modified for affs.
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  affs symlink handling code
+ */
+
+#include "affs.h"
+
+static int affs_symlink_readpage(struct file *file, struct page *page)
+{
+	struct buffer_head *bh;
+	struct inode *inode = page->mapping->host;
+	char *link = kmap(page);
+	struct slink_front *lf;
+	int err;
+	int			 i, j;
+	char			 c;
+	char			 lc;
+
+	pr_debug("follow_link(ino=%lu)\n", inode->i_ino);
+
+	err = -EIO;
+	bh = affs_bread(inode->i_sb, inode->i_ino);
+	if (!bh)
+		goto fail;
+	i  = 0;
+	j  = 0;
+	lf = (struct slink_front *)bh->b_data;
+	lc = 0;
+
+	if (strchr(lf->symname,':')) {	/* Handle assign or volume name */
+		struct affs_sb_info *sbi = AFFS_SB(inode->i_sb);
+		char *pf;
+		spin_lock(&sbi->symlink_lock);
+		pf = sbi->s_prefix ? sbi->s_prefix : "/";
+		while (i < 1023 && (c = pf[i]))
+			link[i++] = c;
+		spin_unlock(&sbi->symlink_lock);
+		while (i < 1023 && lf->symname[j] != ':')
+			link[i++] = lf->symname[j++];
+		if (i < 1023)
+			link[i++] = '/';
+		j++;
+		lc = '/';
+	}
+	while (i < 1023 && (c = lf->symname[j])) {
+		if (c == '/' && lc == '/' && i < 1020) {	/* parent dir */
+			link[i++] = '.';
+			link[i++] = '.';
+		}
+		link[i++] = c;
+		lc = c;
+		j++;
+	}
+	link[i] = '\0';
+	affs_brelse(bh);
+	SetPageUptodate(page);
+	kunmap(page);
+	unlock_page(page);
+	return 0;
+fail:
+	SetPageError(page);
+	kunmap(page);
+	unlock_page(page);
+	return err;
+}
+
+const struct address_space_operations affs_symlink_aops = {
+	.readpage	= affs_symlink_readpage,
+};
+
+const struct inode_operations affs_symlink_inode_operations = {
+	.readlink	= generic_readlink,
+	.follow_link	= page_follow_link_light,
+	.put_link	= page_put_link,
+	.setattr	= affs_notify_change,
+};