Resguardo inicial

linux-7.2.3/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'.

linux-7.2.3/fs/affs/Kconfig

@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config AFFS_FS
+	tristate "Amiga FFS file system support"
+	depends on BLOCK
+	select BUFFER_HEAD
+	select LEGACY_DIRECT_IO
+	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.rst>
+	  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.

linux-7.2.3/fs/affs/Makefile

@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# 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

linux-7.2.3/fs/affs/affs.h

@@ -0,0 +1,324 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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 "amigaffs.h"
+#include <linux/mutex.h>
+#include <linux/workqueue.h>
+
+/* Ugly macros make the code more pretty. */
+
+#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)
+
+#define AFFSNAMEMAX 30U
+
+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 mutex i_link_lock;		/* Protects internal inode access. */
+	struct mutex i_ext_lock;		/* Protects internal inode access. */
+#define i_hash_lock i_ext_lock
+	struct mapping_metadata_bhs i_metadata_bhs;
+	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 container_of(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 */
+	struct rcu_head rcu;
+};
+
+#define AFFS_MOUNT_SF_INTL		0x0001 /* International filesystem. */
+#define AFFS_MOUNT_SF_BM_VALID		0x0002 /* Bitmap is valid. */
+#define AFFS_MOUNT_SF_IMMUTABLE		0x0004 /* Protection bits cannot be changed */
+#define AFFS_MOUNT_SF_QUIET		0x0008 /* chmod errors will be not reported */
+#define AFFS_MOUNT_SF_SETUID		0x0010 /* Ignore Amiga uid */
+#define AFFS_MOUNT_SF_SETGID		0x0020 /* Ignore Amiga gid */
+#define AFFS_MOUNT_SF_SETMODE		0x0040 /* Ignore Amiga protection bits */
+#define AFFS_MOUNT_SF_MUFS		0x0100 /* Use MUFS uid/gid mapping */
+#define AFFS_MOUNT_SF_OFS		0x0200 /* Old filesystem */
+#define AFFS_MOUNT_SF_PREFIX		0x0400 /* Buffer for prefix is allocated */
+#define AFFS_MOUNT_SF_VERBOSE		0x0800 /* Talk about fs when mounting */
+#define AFFS_MOUNT_SF_NO_TRUNCATE	0x1000 /* Don't truncate filenames */
+
+#define affs_clear_opt(o, opt)    (o &= ~AFFS_MOUNT_##opt)
+#define affs_set_opt(o, opt)      (o |= AFFS_MOUNT_##opt)
+#define affs_test_opt(o, opt)     ((o) & AFFS_MOUNT_##opt)
+
+/* 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	affs_secs_to_datestamp(time64_t secs, struct affs_date *ds);
+extern umode_t	affs_prot_to_mode(u32 prot);
+extern void	affs_mode_to_prot(struct inode *inode);
+__printf(3, 4)
+extern void	affs_error(struct super_block *sb, const char *function,
+			   const char *fmt, ...);
+__printf(3, 4)
+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);
+struct mapping_metadata_bhs *affs_get_metadata_bhs(struct inode *inode);
+
+/* 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 const struct export_operations affs_export_ops;
+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 mnt_idmap *idmap, struct inode *dir,
+			struct dentry *dentry, umode_t mode, bool);
+extern struct dentry *affs_mkdir(struct mnt_idmap *idmap, 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 mnt_idmap *idmap,
+			struct inode *dir, struct dentry *dentry,
+			const char *symname);
+extern int	affs_rename2(struct mnt_idmap *idmap,
+			struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry,
+			unsigned int flags);
+
+/* inode.c */
+
+extern struct inode		*affs_new_inode(struct inode *dir);
+extern int			 affs_setattr(struct mnt_idmap *idmap,
+					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 bool affs_validblock(struct super_block *sb, int block)
+{
+	return(block >= AFFS_SB(sb)->s_reserved &&
+	       block < AFFS_SB(sb)->s_partition_size);
+}
+
+static inline struct buffer_head *
+affs_bread(struct super_block *sb, int block)
+{
+	pr_debug("%s: %d\n", __func__, block);
+	if (affs_validblock(sb, block))
+		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 (affs_validblock(sb, block))
+		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 (affs_validblock(sb, block)) {
+		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 (affs_validblock(sb, block)) {
+		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)
+{
+	mutex_lock(&AFFS_I(inode)->i_link_lock);
+}
+static inline void
+affs_unlock_link(struct inode *inode)
+{
+	mutex_unlock(&AFFS_I(inode)->i_link_lock);
+}
+static inline void
+affs_lock_dir(struct inode *inode)
+{
+	mutex_lock_nested(&AFFS_I(inode)->i_hash_lock, SINGLE_DEPTH_NESTING);
+}
+static inline void
+affs_unlock_dir(struct inode *inode)
+{
+	mutex_unlock(&AFFS_I(inode)->i_hash_lock);
+}
+static inline void
+affs_lock_ext(struct inode *inode)
+{
+	mutex_lock(&AFFS_I(inode)->i_ext_lock);
+}
+static inline void
+affs_unlock_ext(struct inode *inode)
+{
+	mutex_unlock(&AFFS_I(inode)->i_ext_lock);
+}

linux-7.2.3/fs/affs/amigaffs.c

@@ -0,0 +1,543 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  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 <linux/math64.h>
+#include <linux/iversion.h>
+#include "affs.h"
+
+/*
+ * 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=%llu, ino=%d)\n", __func__, 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);
+	mmb_mark_buffer_dirty(dir_bh, &AFFS_I(dir)->i_metadata_bhs);
+	affs_brelse(dir_bh);
+
+	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+	inode_inc_iversion(dir);
+	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=%llu, ino=%d, hashval=%d)\n", __func__, 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);
+			mmb_mark_buffer_dirty(bh, &AFFS_I(dir)->i_metadata_bhs);
+			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);
+
+	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+	inode_inc_iversion(dir);
+	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);
+	for_each_alias(dentry, inode) {
+		if (entry_ino == (u32)(long)dentry->d_fsdata) {
+			dentry->d_fsdata = (void *)(unsigned long)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 = d_inode(dentry);
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *bh, *link_bh = NULL;
+	u32 link_ino, ino;
+	int retval;
+
+	pr_debug("%s(key=%llu)\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;
+		}
+		mmb_mark_buffer_dirty(link_bh, &AFFS_I(inode)->i_metadata_bhs);
+
+		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;
+		}
+		mmb_mark_buffer_dirty(bh, &AFFS_I(inode)->i_metadata_bhs);
+
+		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);
+			mmb_mark_buffer_dirty(bh, &AFFS_I(inode)->i_metadata_bhs);
+			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 = d_inode(dentry->d_parent);
+	sb = dir->i_sb;
+
+	retval = -ENOENT;
+	inode = d_inode(dentry);
+	if (!inode)
+		goto done;
+
+	pr_debug("%s(key=%llu)\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;
+	mmb_mark_buffer_dirty(bh, &AFFS_I(inode)->i_metadata_bhs);
+
+	affs_unlock_dir(dir);
+
+	if (inode->i_nlink > 1)
+		retval = affs_remove_link(dentry);
+	else
+		clear_nlink(inode);
+	affs_unlock_link(inode);
+	inode_set_ctime_current(inode);
+	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
+affs_secs_to_datestamp(time64_t secs, struct affs_date *ds)
+{
+	u32	 days;
+	u32	 minute;
+	s32	 rem;
+
+	secs -= sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA;
+	if (secs < 0)
+		secs = 0;
+	days    = div_s64_rem(secs, 86400, &rem);
+	minute  = rem / 60;
+	rem    -= minute * 60;
+
+	ds->days = cpu_to_be32(days);
+	ds->mins = cpu_to_be32(minute);
+	ds->ticks = cpu_to_be32(rem * 50);
+}
+
+umode_t
+affs_prot_to_mode(u32 prot)
+{
+	umode_t mode = 0;
+
+	if (!(prot & FIBF_NOWRITE))
+		mode |= 0200;
+	if (!(prot & FIBF_NOREAD))
+		mode |= 0400;
+	if (!(prot & FIBF_NOEXECUTE))
+		mode |= 0100;
+	if (prot & FIBF_GRP_WRITE)
+		mode |= 0020;
+	if (prot & FIBF_GRP_READ)
+		mode |= 0040;
+	if (prot & FIBF_GRP_EXECUTE)
+		mode |= 0010;
+	if (prot & FIBF_OTR_WRITE)
+		mode |= 0002;
+	if (prot & FIBF_OTR_READ)
+		mode |= 0004;
+	if (prot & FIBF_OTR_EXECUTE)
+		mode |= 0001;
+
+	return mode;
+}
+
+void
+affs_mode_to_prot(struct inode *inode)
+{
+	u32 prot = AFFS_I(inode)->i_protect;
+	umode_t mode = inode->i_mode;
+
+	/*
+	 * First, clear all RWED bits for owner, group, other.
+	 * Then, recalculate them afresh.
+	 *
+	 * We'll always clear the delete-inhibit bit for the owner, as that is
+	 * the classic single-user mode AmigaOS protection bit and we need to
+	 * stay compatible with all scenarios.
+	 *
+	 * Since multi-user AmigaOS is an extension, we'll only set the
+	 * delete-allow bit if any of the other bits in the same user class
+	 * (group/other) are used.
+	 */
+	prot &= ~(FIBF_NOEXECUTE | FIBF_NOREAD
+		  | FIBF_NOWRITE | FIBF_NODELETE
+		  | FIBF_GRP_EXECUTE | FIBF_GRP_READ
+		  | FIBF_GRP_WRITE   | FIBF_GRP_DELETE
+		  | FIBF_OTR_EXECUTE | FIBF_OTR_READ
+		  | FIBF_OTR_WRITE   | FIBF_OTR_DELETE);
+
+	/* Classic single-user AmigaOS flags. These are inverted. */
+	if (!(mode & 0100))
+		prot |= FIBF_NOEXECUTE;
+	if (!(mode & 0400))
+		prot |= FIBF_NOREAD;
+	if (!(mode & 0200))
+		prot |= FIBF_NOWRITE;
+
+	/* Multi-user extended flags. Not inverted. */
+	if (mode & 0010)
+		prot |= FIBF_GRP_EXECUTE;
+	if (mode & 0040)
+		prot |= FIBF_GRP_READ;
+	if (mode & 0020)
+		prot |= FIBF_GRP_WRITE;
+	if (mode & 0070)
+		prot |= FIBF_GRP_DELETE;
+
+	if (mode & 0001)
+		prot |= FIBF_OTR_EXECUTE;
+	if (mode & 0004)
+		prot |= FIBF_OTR_READ;
+	if (mode & 0002)
+		prot |= FIBF_OTR_WRITE;
+	if (mode & 0007)
+		prot |= FIBF_OTR_DELETE;
+
+	AFFS_I(inode)->i_protect = prot;
+}
+
+void
+affs_error(struct super_block *sb, const char *function, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	pr_crit("error (device %s): %s(): %pV\n", sb->s_id, function, &vaf);
+	if (!sb_rdonly(sb))
+		pr_warn("Remounting filesystem read-only\n");
+	sb->s_flags |= SB_RDONLY;
+	va_end(args);
+}
+
+void
+affs_warning(struct super_block *sb, const char *function, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	pr_warn("(device %s): %s(): %pV\n", sb->s_id, function, &vaf);
+	va_end(args);
+}
+
+bool
+affs_nofilenametruncate(const struct dentry *dentry)
+{
+	return affs_test_opt(AFFS_SB(dentry->d_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 > AFFSNAMEMAX) {
+		if (notruncate)
+			return -ENAMETOOLONG;
+		len = AFFSNAMEMAX;
+	}
+	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)
+{
+	u32 len = min(dentry->d_name.len, AFFSNAMEMAX);
+
+	*bstr++ = len;
+	memcpy(bstr, dentry->d_name.name, len);
+	return len;
+}

linux-7.2.3/fs/affs/amigaffs.h

@@ -0,0 +1,149 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef AMIGAFFS_H
+#define AMIGAFFS_H
+
+#include <linux/types.h>
+#include <asm/byteorder.h>
+
+#define FS_OFS		0x444F5300
+#define FS_FFS		0x444F5301
+#define FS_INTLOFS	0x444F5302
+#define FS_INTLFFS	0x444F5303
+#define FS_DCOFS	0x444F5304
+#define FS_DCFFS	0x444F5305
+#define MUFS_FS		0x6d754653   /* 'muFS' */
+#define MUFS_OFS	0x6d754600   /* 'muF\0' */
+#define MUFS_FFS	0x6d754601   /* 'muF\1' */
+#define MUFS_INTLOFS	0x6d754602   /* 'muF\2' */
+#define MUFS_INTLFFS	0x6d754603   /* 'muF\3' */
+#define MUFS_DCOFS	0x6d754604   /* 'muF\4' */
+#define MUFS_DCFFS	0x6d754605   /* 'muF\5' */
+
+#define T_SHORT		2
+#define T_LIST		16
+#define T_DATA		8
+
+#define ST_LINKFILE	-4
+#define ST_FILE		-3
+#define ST_ROOT		1
+#define ST_USERDIR	2
+#define ST_SOFTLINK	3
+#define ST_LINKDIR	4
+
+#define AFFS_ROOT_BMAPS		25
+
+/* Seconds since Amiga epoch of 1978/01/01 to UNIX */
+#define AFFS_EPOCH_DELTA ((8 * 365 + 2) * 86400LL)
+
+struct affs_date {
+	__be32 days;
+	__be32 mins;
+	__be32 ticks;
+};
+
+struct affs_short_date {
+	__be16 days;
+	__be16 mins;
+	__be16 ticks;
+};
+
+struct affs_root_head {
+	__be32 ptype;
+	/* The following fields are not used, but kept as documentation. */
+	__be32 spare1;
+	__be32 spare2;
+	__be32 hash_size;
+	__be32 spare3;
+	__be32 checksum;
+	__be32 hashtable[];
+};
+
+struct affs_root_tail {
+	__be32 bm_flag;
+	__be32 bm_blk[AFFS_ROOT_BMAPS];
+	__be32 bm_ext;
+	struct affs_date root_change;
+	u8 disk_name[32];
+	__be32 spare1;
+	__be32 spare2;
+	struct affs_date disk_change;
+	struct affs_date disk_create;
+	__be32 spare3;
+	__be32 spare4;
+	__be32 dcache;
+	__be32 stype;
+};
+
+struct affs_head {
+	__be32 ptype;
+	__be32 key;
+	__be32 block_count;
+	__be32 spare1;
+	__be32 first_data;
+	__be32 checksum;
+	__be32 table[];
+};
+
+struct affs_tail {
+	__be32 spare1;
+	__be16 uid;
+	__be16 gid;
+	__be32 protect;
+	__be32 size;
+	u8 comment[92];
+	struct affs_date change;
+	u8 name[32];
+	__be32 spare2;
+	__be32 original;
+	__be32 link_chain;
+	__be32 spare[5];
+	__be32 hash_chain;
+	__be32 parent;
+	__be32 extension;
+	__be32 stype;
+};
+
+struct slink_front
+{
+	__be32 ptype;
+	__be32 key;
+	__be32 spare1[3];
+	__be32 checksum;
+	u8 symname[];	/* depends on block size */
+};
+
+struct affs_data_head
+{
+	__be32 ptype;
+	__be32 key;
+	__be32 sequence;
+	__be32 size;
+	__be32 next;
+	__be32 checksum;
+	u8 data[];	/* depends on block size */
+};
+
+/* Permission bits */
+
+#define FIBF_OTR_READ		0x8000
+#define FIBF_OTR_WRITE		0x4000
+#define FIBF_OTR_EXECUTE	0x2000
+#define FIBF_OTR_DELETE		0x1000
+#define FIBF_GRP_READ		0x0800
+#define FIBF_GRP_WRITE		0x0400
+#define FIBF_GRP_EXECUTE	0x0200
+#define FIBF_GRP_DELETE		0x0100
+
+#define FIBF_HIDDEN		0x0080
+#define FIBF_SCRIPT		0x0040
+#define FIBF_PURE		0x0020		/* no use under linux */
+#define FIBF_ARCHIVED		0x0010		/* never set, always cleared on write */
+#define FIBF_NOREAD		0x0008		/* 0 means allowed */
+#define FIBF_NOWRITE		0x0004		/* 0 means allowed */
+#define FIBF_NOEXECUTE		0x0002		/* 0 means allowed, ignored under linux */
+#define FIBF_NODELETE		0x0001		/* 0 means allowed */
+
+#define FIBF_OWNER		0x000F		/* Bits pertaining to owner */
+#define FIBF_MASK		0xEE0E		/* Bits modified by Linux */
+
+#endif

linux-7.2.3/fs/affs/bitmap.c

@@ -0,0 +1,365 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  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_rdonly(sb))
+		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);
+}
+
+/*
+ * 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=%llu,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 & SB_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 |= SB_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 |= SB_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;
+}

linux-7.2.3/fs/affs/dir.c

@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  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 <linux/iversion.h>
+#include <linux/filelock.h>
+#include "affs.h"
+
+struct affs_dir_data {
+	unsigned long ino;
+	u64 cookie;
+};
+
+static int affs_readdir(struct file *, struct dir_context *);
+
+static loff_t affs_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct affs_dir_data *data = file->private_data;
+
+	return generic_llseek_cookie(file, offset, whence, &data->cookie);
+}
+
+static int affs_dir_open(struct inode *inode, struct file *file)
+{
+	struct affs_dir_data	*data;
+
+	data = kzalloc_obj(struct affs_dir_data);
+	if (!data)
+		return -ENOMEM;
+	file->private_data = data;
+	return 0;
+}
+
+static int affs_dir_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	return 0;
+}
+
+const struct file_operations affs_dir_operations = {
+	.open		= affs_dir_open,
+	.read		= generic_read_dir,
+	.llseek		= affs_dir_llseek,
+	.iterate_shared	= affs_readdir,
+	.fsync		= affs_file_fsync,
+	.release	= affs_dir_release,
+	.setlease	= generic_setlease,
+};
+
+/*
+ * 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_rename2,
+	.setattr	= affs_setattr,
+};
+
+static int
+affs_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct inode		*inode = file_inode(file);
+	struct affs_dir_data	*data = file->private_data;
+	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=%llu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos);
+
+	if (ctx->pos < 2) {
+		data->ino = 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 = data->ino;
+	if (ino && inode_eq_iversion(inode, data->cookie)) {
+		pr_debug("readdir() left off=%d\n", ino);
+		goto inside;
+	}
+	if (hash_pos >= AFFS_SB(sb)->s_hashsize)
+		goto done;
+
+	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)AFFSNAMEMAX);
+			name = AFFS_TAIL(sb, fh_bh)->name + 1;
+			pr_debug("readdir(): dir_emit(\"%.*s\", ino=%u), hash=%d, f_pos=%llx\n",
+				 namelen, name, ino, hash_pos, 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:
+	data->cookie = inode_query_iversion(inode);
+	data->ino = ino;
+	affs_brelse(fh_bh);
+
+out_brelse_dir:
+	affs_brelse(dir_bh);
+
+out_unlock_dir:
+	affs_unlock_dir(inode);
+	return error;
+}

linux-7.2.3/fs/affs/inode.c

@@ -0,0 +1,420 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  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/cred.h>
+#include <linux/gfp.h>
+#include "affs.h"
+
+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_state_read_once(inode) & I_NEW))
+		return inode;
+
+	pr_debug("affs_iget(%llu)\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 (affs_test_opt(sbi->s_flags, SF_SETMODE))
+		inode->i_mode = sbi->s_mode;
+	else
+		inode->i_mode = affs_prot_to_mode(prot);
+
+	id = be16_to_cpu(tail->uid);
+	if (id == 0 || affs_test_opt(sbi->s_flags, SF_SETUID))
+		inode->i_uid = sbi->s_uid;
+	else if (id == 0xFFFF && affs_test_opt(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 || affs_test_opt(sbi->s_flags, SF_SETGID))
+		inode->i_gid = sbi->s_gid;
+	else if (id == 0xFFFF && affs_test_opt(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;
+		fallthrough;
+	case ST_USERDIR:
+		if (be32_to_cpu(tail->stype) == ST_USERDIR ||
+		    affs_test_opt(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 = affs_test_opt(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_size = strlen((char *)AFFS_HEAD(bh)->table);
+		inode->i_mode |= S_IFLNK;
+		inode_nohighmem(inode);
+		inode->i_op = &affs_symlink_inode_operations;
+		inode->i_data.a_ops = &affs_symlink_aops;
+		break;
+	}
+
+	inode_set_mtime(inode,
+			inode_set_atime(inode, inode_set_ctime(inode, (be32_to_cpu(tail->change.days) * 86400LL + be32_to_cpu(tail->change.mins) * 60 + be32_to_cpu(tail->change.ticks) / 50 + AFFS_EPOCH_DELTA) + sys_tz.tz_minuteswest * 60, 0).tv_sec, 0).tv_sec,
+			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(%llu)\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 %llu", inode->i_ino);
+		return -EIO;
+	}
+	tail = AFFS_TAIL(sb, bh);
+	if (tail->stype == cpu_to_be32(ST_ROOT)) {
+		affs_secs_to_datestamp(inode_get_mtime_sec(inode),
+				       &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);
+		affs_secs_to_datestamp(inode_get_mtime_sec(inode),
+				       &tail->change);
+		if (!(inode->i_ino == AFFS_SB(sb)->s_root_block)) {
+			uid = i_uid_read(inode);
+			gid = i_gid_read(inode);
+			if (affs_test_opt(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_test_opt(AFFS_SB(sb)->s_flags, SF_SETUID))
+				tail->uid = cpu_to_be16(uid);
+			if (!affs_test_opt(AFFS_SB(sb)->s_flags, SF_SETGID))
+				tail->gid = cpu_to_be16(gid);
+		}
+	}
+	affs_fix_checksum(sb, bh);
+	mmb_mark_buffer_dirty(bh, &AFFS_I(inode)->i_metadata_bhs);
+	affs_brelse(bh);
+	affs_free_prealloc(inode);
+	return 0;
+}
+
+int
+affs_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *attr)
+{
+	struct inode *inode = d_inode(dentry);
+	int error;
+
+	pr_debug("setattr(%llu,0x%x)\n", inode->i_ino, attr->ia_valid);
+
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
+	if (error)
+		goto out;
+
+	if (((attr->ia_valid & ATTR_UID) &&
+	      affs_test_opt(AFFS_SB(inode->i_sb)->s_flags, SF_SETUID)) ||
+	    ((attr->ia_valid & ATTR_GID) &&
+	      affs_test_opt(AFFS_SB(inode->i_sb)->s_flags, SF_SETGID)) ||
+	    ((attr->ia_valid & ATTR_MODE) &&
+	     (AFFS_SB(inode->i_sb)->s_flags &
+	      (AFFS_MOUNT_SF_SETMODE | AFFS_MOUNT_SF_IMMUTABLE)))) {
+		if (!affs_test_opt(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(&nop_mnt_idmap, inode, attr);
+	mark_inode_dirty(inode);
+
+	if (attr->ia_valid & ATTR_MODE)
+		affs_mode_to_prot(inode);
+out:
+	return error;
+}
+
+void
+affs_evict_inode(struct inode *inode)
+{
+	unsigned long cache_page;
+	pr_debug("evict_inode(ino=%llu, 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);
+	} else {
+		mmb_sync(&AFFS_I(inode)->i_metadata_bhs);
+	}
+
+	mmb_invalidate(&AFFS_I(inode)->i_metadata_bhs);
+	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;
+	mmb_mark_buffer_dirty(bh, &AFFS_I(inode)->i_metadata_bhs);
+	affs_brelse(bh);
+
+	inode->i_uid     = current_fsuid();
+	inode->i_gid     = current_fsgid();
+	inode->i_ino     = block;
+	set_nlink(inode, 1);
+	simple_inode_init_ts(inode);
+	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;
+	u32 block = 0;
+	int retval;
+
+	pr_debug("%s(dir=%llu, inode=%llu, \"%pd\", type=%d)\n", __func__,
+		 dir->i_ino, inode->i_ino, dentry, 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));
+		mmb_mark_buffer_dirty(inode_bh, &AFFS_I(inode)->i_metadata_bhs);
+		set_nlink(inode, 2);
+		ihold(inode);
+	}
+	affs_fix_checksum(sb, bh);
+	mmb_mark_buffer_dirty(bh, &AFFS_I(inode)->i_metadata_bhs);
+	dentry->d_fsdata = (void *)(long)bh->b_blocknr;
+
+	affs_lock_dir(dir);
+	retval = affs_insert_hash(dir, bh);
+	mmb_mark_buffer_dirty(bh, &AFFS_I(inode)->i_metadata_bhs);
+	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;
+}

linux-7.2.3/fs/affs/namei.c

@@ -0,0 +1,583 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  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"
+#include <linux/exportfs.h>
+
+typedef int (*toupper_t)(int);
+
+/* 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_test_opt(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(const struct dentry *dentry, struct qstr *qstr, toupper_t fn, bool notruncate)
+{
+	const u8 *name = qstr->name;
+	unsigned long hash;
+	int retval;
+	u32 len;
+
+	retval = affs_check_name(qstr->name, qstr->len, notruncate);
+	if (retval)
+		return retval;
+
+	hash = init_name_hash(dentry);
+	len = min(qstr->len, AFFSNAMEMAX);
+	for (; len > 0; name++, len--)
+		hash = partial_name_hash(fn(*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(dentry, qstr, affs_toupper,
+				  affs_nofilenametruncate(dentry));
+
+}
+
+static int
+affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
+{
+	return __affs_hash_dentry(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 fn,
+		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 >= AFFSNAMEMAX) {
+		if (name->len < AFFSNAMEMAX)
+			return 1;
+		len = AFFSNAMEMAX;
+	} else if (len != name->len)
+		return 1;
+
+	for (; len > 0; len--)
+		if (fn(*aname++) != fn(*bname++))
+			return 1;
+
+	return 0;
+}
+
+static int
+affs_compare_dentry(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(dentry));
+}
+
+static int
+affs_intl_compare_dentry(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(dentry));
+
+}
+
+/*
+ * 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 fn)
+{
+	const u8 *name = dentry->d_name.name;
+	int len = dentry->d_name.len;
+
+	if (len >= AFFSNAMEMAX) {
+		if (*name2 < AFFSNAMEMAX)
+			return 0;
+		len = AFFSNAMEMAX;
+	} else if (len != *name2)
+		return 0;
+
+	for (name2++; len > 0; len--)
+		if (fn(*name++) != fn(*name2++))
+			return 0;
+	return 1;
+}
+
+int
+affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
+{
+	toupper_t fn = affs_get_toupper(sb);
+	u32 hash;
+
+	hash = len = min(len, AFFSNAMEMAX);
+	for (; len > 0; len--)
+		hash = (hash * 13 + fn(*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 fn = affs_get_toupper(sb);
+	u32 key;
+
+	pr_debug("%s(\"%pd\")\n", __func__, dentry);
+
+	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, fn))
+			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;
+	struct dentry *res;
+
+	pr_debug("%s(\"%pd\")\n", __func__, dentry);
+
+	affs_lock_dir(dir);
+	bh = affs_find_entry(dir, dentry);
+	if (IS_ERR(bh)) {
+		affs_unlock_dir(dir);
+		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);
+	}
+	res = d_splice_alias(inode, dentry);
+	if (!IS_ERR_OR_NULL(res))
+		res->d_fsdata = dentry->d_fsdata;
+	affs_unlock_dir(dir);
+	return res;
+}
+
+int
+affs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	pr_debug("%s(dir=%llu, %llu \"%pd\")\n", __func__, dir->i_ino,
+		 d_inode(dentry)->i_ino, dentry);
+
+	return affs_remove_header(dentry);
+}
+
+int
+affs_create(struct mnt_idmap *idmap, 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(%llu,\"%pd\",0%ho)\n",
+		 __func__, dir->i_ino, dentry, mode);
+
+	inode = affs_new_inode(dir);
+	if (!inode)
+		return -ENOSPC;
+
+	inode->i_mode = mode;
+	affs_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_test_opt(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;
+}
+
+struct dentry *
+affs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+	   struct dentry *dentry, umode_t mode)
+{
+	struct inode		*inode;
+	int			 error;
+
+	pr_debug("%s(%llu,\"%pd\",0%ho)\n",
+		 __func__, dir->i_ino, dentry, mode);
+
+	inode = affs_new_inode(dir);
+	if (!inode)
+		return ERR_PTR(-ENOSPC);
+
+	inode->i_mode = S_IFDIR | mode;
+	affs_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 ERR_PTR(error);
+	}
+	return NULL;
+}
+
+int
+affs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	pr_debug("%s(dir=%llu, %llu \"%pd\")\n", __func__, dir->i_ino,
+		 d_inode(dentry)->i_ino, dentry);
+
+	return affs_remove_header(dentry);
+}
+
+int
+affs_symlink(struct mnt_idmap *idmap, 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(%llu,\"%pd\" -> \"%s\")\n",
+		 __func__, dir->i_ino, dentry, 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_nohighmem(inode);
+	inode->i_data.a_ops = &affs_symlink_aops;
+	inode->i_mode = S_IFLNK | 0777;
+	affs_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;
+	inode->i_size = i + 1;
+	mmb_mark_buffer_dirty(bh, &AFFS_I(inode)->i_metadata_bhs);
+	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 = d_inode(old_dentry);
+
+	pr_debug("%s(%llu, %llu, \"%pd\")\n", __func__, inode->i_ino, dir->i_ino,
+		 dentry);
+
+	return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
+}
+
+static 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;
+
+	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 (d_really_is_positive(new_dentry)) {
+		retval = affs_remove_header(new_dentry);
+		if (retval)
+			return retval;
+	}
+
+	bh = affs_bread(sb, d_inode(old_dentry)->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:
+	mmb_mark_buffer_dirty(bh,
+			&AFFS_I(retval ? old_dir : new_dir)->i_metadata_bhs);
+	affs_brelse(bh);
+	return retval;
+}
+
+static int
+affs_xrename(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_old = NULL;
+	struct buffer_head *bh_new = NULL;
+	int retval;
+
+	bh_old = affs_bread(sb, d_inode(old_dentry)->i_ino);
+	if (!bh_old)
+		return -EIO;
+
+	bh_new = affs_bread(sb, d_inode(new_dentry)->i_ino);
+	if (!bh_new) {
+		affs_brelse(bh_old);
+		return -EIO;
+	}
+
+	/* Remove old header from its parent directory. */
+	affs_lock_dir(old_dir);
+	retval = affs_remove_hash(old_dir, bh_old);
+	affs_unlock_dir(old_dir);
+	if (retval)
+		goto done;
+
+	/* Remove new header from its parent directory. */
+	affs_lock_dir(new_dir);
+	retval = affs_remove_hash(new_dir, bh_new);
+	affs_unlock_dir(new_dir);
+	if (retval)
+		goto done;
+
+	/* Insert old into the new directory with the new name. */
+	affs_copy_name(AFFS_TAIL(sb, bh_old)->name, new_dentry);
+	affs_fix_checksum(sb, bh_old);
+	affs_lock_dir(new_dir);
+	retval = affs_insert_hash(new_dir, bh_old);
+	affs_unlock_dir(new_dir);
+
+	/* Insert new into the old directory with the old name. */
+	affs_copy_name(AFFS_TAIL(sb, bh_new)->name, old_dentry);
+	affs_fix_checksum(sb, bh_new);
+	affs_lock_dir(old_dir);
+	retval = affs_insert_hash(old_dir, bh_new);
+	affs_unlock_dir(old_dir);
+done:
+	mmb_mark_buffer_dirty(bh_old, &AFFS_I(new_dir)->i_metadata_bhs);
+	mmb_mark_buffer_dirty(bh_new, &AFFS_I(old_dir)->i_metadata_bhs);
+	affs_brelse(bh_old);
+	affs_brelse(bh_new);
+	return retval;
+}
+
+int affs_rename2(struct mnt_idmap *idmap, struct inode *old_dir,
+		 struct dentry *old_dentry, struct inode *new_dir,
+		 struct dentry *new_dentry, unsigned int flags)
+{
+
+	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+		return -EINVAL;
+
+	pr_debug("%s(old=%llu,\"%pd\" to new=%llu,\"%pd\")\n", __func__,
+		 old_dir->i_ino, old_dentry, new_dir->i_ino, new_dentry);
+
+	if (flags & RENAME_EXCHANGE)
+		return affs_xrename(old_dir, old_dentry, new_dir, new_dentry);
+
+	return affs_rename(old_dir, old_dentry, new_dir, new_dentry);
+}
+
+static struct dentry *affs_get_parent(struct dentry *child)
+{
+	struct inode *parent;
+	struct buffer_head *bh;
+
+	bh = affs_bread(child->d_sb, d_inode(child)->i_ino);
+	if (!bh)
+		return ERR_PTR(-EIO);
+
+	parent = affs_iget(child->d_sb,
+			   be32_to_cpu(AFFS_TAIL(child->d_sb, bh)->parent));
+	brelse(bh);
+	return d_obtain_alias(parent);
+}
+
+static struct inode *affs_nfs_get_inode(struct super_block *sb, u64 ino,
+					u32 generation)
+{
+	struct inode *inode;
+
+	if (!affs_validblock(sb, ino))
+		return ERR_PTR(-ESTALE);
+
+	inode = affs_iget(sb, ino);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+
+	return inode;
+}
+
+static struct dentry *affs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+					int fh_len, int fh_type)
+{
+	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+				    affs_nfs_get_inode);
+}
+
+static struct dentry *affs_fh_to_parent(struct super_block *sb, struct fid *fid,
+					int fh_len, int fh_type)
+{
+	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+				    affs_nfs_get_inode);
+}
+
+const struct export_operations affs_export_ops = {
+	.encode_fh = generic_encode_ino32_fh,
+	.fh_to_dentry = affs_fh_to_dentry,
+	.fh_to_parent = affs_fh_to_parent,
+	.get_parent = affs_get_parent,
+};
+
+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,
+};

linux-7.2.3/fs/affs/super.c

@@ -0,0 +1,685 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  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/fs_parser.h>
+#include <linux/fs_context.h>
+#include <linux/magic.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/slab.h>
+#include <linux/writeback.h>
+#include <linux/blkdev.h>
+#include <linux/seq_file.h>
+#include <linux/iversion.h>
+#include "affs.h"
+
+static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
+static int affs_show_options(struct seq_file *m, struct dentry *root);
+
+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);
+	affs_secs_to_datestamp(ktime_get_real_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_rdonly(sb))
+	       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 = alloc_inode_sb(sb, affs_inode_cachep, GFP_KERNEL);
+	if (!i)
+		return NULL;
+
+	inode_set_iversion(&i->vfs_inode, 1);
+	i->i_lc = NULL;
+	i->i_ext_bh = NULL;
+	i->i_pa_cnt = 0;
+	mmb_init(&i->i_metadata_bhs, &i->vfs_inode.i_data);
+
+	return &i->vfs_inode;
+}
+
+static void affs_free_inode(struct inode *inode)
+{
+	kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
+}
+
+static void init_once(void *foo)
+{
+	struct affs_inode_info *ei = (struct affs_inode_info *) foo;
+
+	mutex_init(&ei->i_link_lock);
+	mutex_init(&ei->i_ext_lock);
+	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_ACCOUNT),
+					     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,
+	.free_inode	= affs_free_inode,
+	.write_inode	= affs_write_inode,
+	.evict_inode	= affs_evict_inode,
+	.put_super	= affs_put_super,
+	.sync_fs	= affs_sync_fs,
+	.statfs		= affs_statfs,
+	.show_options	= affs_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,
+};
+
+struct affs_context {
+	kuid_t		uid;		/* uid to override */
+	kgid_t		gid;		/* gid to override */
+	unsigned int	mode;		/* mode to override */
+	unsigned int	reserved;	/* Number of reserved blocks */
+	int		root_block;	/* FFS root block number */
+	int		blocksize;	/* Initial device blksize */
+	char		*prefix;	/* Prefix for volumes and assigns */
+	char		volume[32];	/* Vol. prefix for absolute symlinks */
+	unsigned long	mount_flags;	/* Options */
+};
+
+static const struct fs_parameter_spec affs_param_spec[] = {
+	fsparam_u32	("bs",		Opt_bs),
+	fsparam_u32oct	("mode",	Opt_mode),
+	fsparam_flag	("mufs",	Opt_mufs),
+	fsparam_flag	("nofilenametruncate",	Opt_notruncate),
+	fsparam_string	("prefix",	Opt_prefix),
+	fsparam_flag	("protect",	Opt_protect),
+	fsparam_u32	("reserved",	Opt_reserved),
+	fsparam_u32	("root",	Opt_root),
+	fsparam_gid	("setgid",	Opt_setgid),
+	fsparam_uid	("setuid",	Opt_setuid),
+	fsparam_flag	("verbose",	Opt_verbose),
+	fsparam_string	("volume",	Opt_volume),
+	fsparam_flag	("grpquota",	Opt_ignore),
+	fsparam_flag	("noquota",	Opt_ignore),
+	fsparam_flag	("quota",	Opt_ignore),
+	fsparam_flag	("usrquota",	Opt_ignore),
+	{},
+};
+
+static int affs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct affs_context *ctx = fc->fs_private;
+	struct fs_parse_result result;
+	int n;
+	int opt;
+
+	opt = fs_parse(fc, affs_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_bs:
+		n = result.uint_32;
+		if (n != 512 && n != 1024 && n != 2048
+		    && n != 4096) {
+			pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
+			return -EINVAL;
+		}
+		ctx->blocksize = n;
+		break;
+	case Opt_mode:
+		ctx->mode = result.uint_32 & 0777;
+		affs_set_opt(ctx->mount_flags, SF_SETMODE);
+		break;
+	case Opt_mufs:
+		affs_set_opt(ctx->mount_flags, SF_MUFS);
+		break;
+	case Opt_notruncate:
+		affs_set_opt(ctx->mount_flags, SF_NO_TRUNCATE);
+		break;
+	case Opt_prefix:
+		kfree(ctx->prefix);
+		ctx->prefix = param->string;
+		param->string = NULL;
+		affs_set_opt(ctx->mount_flags, SF_PREFIX);
+		break;
+	case Opt_protect:
+		affs_set_opt(ctx->mount_flags, SF_IMMUTABLE);
+		break;
+	case Opt_reserved:
+		ctx->reserved = result.uint_32;
+		break;
+	case Opt_root:
+		ctx->root_block = result.uint_32;
+		break;
+	case Opt_setgid:
+		ctx->gid = result.gid;
+		affs_set_opt(ctx->mount_flags, SF_SETGID);
+		break;
+	case Opt_setuid:
+		ctx->uid = result.uid;
+		affs_set_opt(ctx->mount_flags, SF_SETUID);
+		break;
+	case Opt_verbose:
+		affs_set_opt(ctx->mount_flags, SF_VERBOSE);
+		break;
+	case Opt_volume:
+		strscpy(ctx->volume, param->string, 32);
+		break;
+	case Opt_ignore:
+		/* Silently ignore the quota options */
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int affs_show_options(struct seq_file *m, struct dentry *root)
+{
+	struct super_block *sb = root->d_sb;
+	struct affs_sb_info *sbi = AFFS_SB(sb);
+
+	if (sb->s_blocksize)
+		seq_printf(m, ",bs=%lu", sb->s_blocksize);
+	if (affs_test_opt(sbi->s_flags, SF_SETMODE))
+		seq_printf(m, ",mode=%o", sbi->s_mode);
+	if (affs_test_opt(sbi->s_flags, SF_MUFS))
+		seq_puts(m, ",mufs");
+	if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE))
+		seq_puts(m, ",nofilenametruncate");
+	if (affs_test_opt(sbi->s_flags, SF_PREFIX))
+		seq_printf(m, ",prefix=%s", sbi->s_prefix);
+	if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE))
+		seq_puts(m, ",protect");
+	if (sbi->s_reserved != 2)
+		seq_printf(m, ",reserved=%u", sbi->s_reserved);
+	if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2)
+		seq_printf(m, ",root=%u", sbi->s_root_block);
+	if (affs_test_opt(sbi->s_flags, SF_SETGID))
+		seq_printf(m, ",setgid=%u",
+			   from_kgid_munged(&init_user_ns, sbi->s_gid));
+	if (affs_test_opt(sbi->s_flags, SF_SETUID))
+		seq_printf(m, ",setuid=%u",
+			   from_kuid_munged(&init_user_ns, sbi->s_uid));
+	if (affs_test_opt(sbi->s_flags, SF_VERBOSE))
+		seq_puts(m, ",verbose");
+	if (sbi->s_volume[0])
+		seq_printf(m, ",volume=%s", sbi->s_volume);
+	return 0;
+}
+
+/* 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, struct fs_context *fc)
+{
+	struct affs_sb_info	*sbi;
+	struct affs_context	*ctx = fc->fs_private;
+	struct buffer_head	*root_bh = NULL;
+	struct buffer_head	*boot_bh;
+	struct inode		*root_inode = NULL;
+	int			 silent = fc->sb_flags & SB_SILENT;
+	int			 size, blocksize;
+	u32			 chksum;
+	int			 num_bm;
+	int			 i, j;
+	int			 tmp_flags;	/* fix remount prototype... */
+	u8			 sig[4];
+	int			 ret;
+
+	sb->s_magic             = AFFS_SUPER_MAGIC;
+	sb->s_op                = &affs_sops;
+	sb->s_flags |= SB_NODIRATIME;
+
+	sb->s_time_gran = NSEC_PER_SEC;
+	sb->s_time_min = sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA;
+	sb->s_time_max = 86400LL * U32_MAX + 86400 + sb->s_time_min;
+
+	sbi = kzalloc_obj(struct affs_sb_info);
+	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);
+
+	sbi->s_flags	= ctx->mount_flags;
+	sbi->s_mode	= ctx->mode;
+	sbi->s_uid	= ctx->uid;
+	sbi->s_gid	= ctx->gid;
+	sbi->s_reserved	= ctx->reserved;
+	sbi->s_prefix	= ctx->prefix;
+	ctx->prefix	= NULL;
+	memcpy(sbi->s_volume, ctx->volume, 32);
+
+	/* N.B. after this point s_prefix must be released */
+
+	/* 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 = bdev_nr_sectors(sb->s_bdev);
+	pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
+
+	if (!sb_set_blocksize(sb, PAGE_SIZE))
+		return -EINVAL;
+	/* Try to find root block. Its location depends on the block size. */
+
+	i = bdev_logical_block_size(sb->s_bdev);
+	j = PAGE_SIZE;
+	blocksize = ctx->blocksize;
+	if (blocksize > 0) {
+		i = j = blocksize;
+		size = size / (blocksize / 512);
+	}
+
+	for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
+		sbi->s_root_block = ctx->root_block;
+		if (ctx->root_block < 0)
+			sbi->s_root_block = (ctx->reserved + size - 1) / 2;
+		pr_debug("setting blocksize to %d\n", blocksize);
+		if (!sb_set_blocksize(sb, blocksize))
+			return -EINVAL;
+		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,
+				ctx->blocksize, size, ctx->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;
+	ctx->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_rdonly(sb)) {
+		pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
+		sb->s_flags |= SB_RDONLY;
+	}
+	switch (chksum) {
+	case MUFS_FS:
+	case MUFS_INTLFFS:
+	case MUFS_DCFFS:
+		affs_set_opt(sbi->s_flags, SF_MUFS);
+		fallthrough;
+	case FS_INTLFFS:
+	case FS_DCFFS:
+		affs_set_opt(sbi->s_flags, SF_INTL);
+		break;
+	case MUFS_FFS:
+		affs_set_opt(sbi->s_flags, SF_MUFS);
+		break;
+	case FS_FFS:
+		break;
+	case MUFS_OFS:
+		affs_set_opt(sbi->s_flags, SF_MUFS);
+		fallthrough;
+	case FS_OFS:
+		affs_set_opt(sbi->s_flags, SF_OFS);
+		sb->s_flags |= SB_NOEXEC;
+		break;
+	case MUFS_DCOFS:
+	case MUFS_INTLOFS:
+		affs_set_opt(sbi->s_flags, SF_MUFS);
+		fallthrough;
+	case FS_DCOFS:
+	case FS_INTLOFS:
+		affs_set_opt(sbi->s_flags, SF_INTL);
+		affs_set_opt(sbi->s_flags, SF_OFS);
+		sb->s_flags |= SB_NOEXEC;
+		break;
+	default:
+		pr_err("Unknown filesystem on device %s: %08X\n",
+		       sb->s_id, chksum);
+		return -EINVAL;
+	}
+
+	if (affs_test_opt(ctx->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 |= SB_NODEV | SB_NOSUID;
+
+	sbi->s_data_blksize = sb->s_blocksize;
+	if (affs_test_opt(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, ctx->root_block);
+	if (IS_ERR(root_inode))
+		return PTR_ERR(root_inode);
+
+	if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL))
+		set_default_d_op(sb, &affs_intl_dentry_operations);
+	else
+		set_default_d_op(sb, &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;
+	}
+
+	sb->s_export_op = &affs_export_ops;
+	pr_debug("s_flags=%lX\n", sb->s_flags);
+	return 0;
+}
+
+static int affs_reconfigure(struct fs_context *fc)
+{
+	struct super_block	*sb = fc->root->d_sb;
+	struct affs_context	*ctx = fc->fs_private;
+	struct affs_sb_info	*sbi = AFFS_SB(sb);
+	int			 res = 0;
+
+	sync_filesystem(sb);
+	fc->sb_flags |= SB_NODIRATIME;
+
+	flush_delayed_work(&sbi->sb_work);
+
+	/*
+	 * NB: Historically, only mount_flags, mode, uid, gic, prefix,
+	 * and volume are accepted during remount.
+	 */
+	sbi->s_flags = ctx->mount_flags;
+	sbi->s_mode  = ctx->mode;
+	sbi->s_uid   = ctx->uid;
+	sbi->s_gid   = ctx->gid;
+	/* protect against readers */
+	spin_lock(&sbi->symlink_lock);
+	if (ctx->prefix) {
+		kfree(sbi->s_prefix);
+		sbi->s_prefix = ctx->prefix;
+		ctx->prefix = NULL;
+	}
+	memcpy(sbi->s_volume, ctx->volume, 32);
+	spin_unlock(&sbi->symlink_lock);
+
+	if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
+		return 0;
+
+	if (fc->sb_flags & SB_RDONLY)
+		affs_free_bitmap(sb);
+	else
+		res = affs_init_bitmap(sb, &fc->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    = u64_to_fsid(id);
+	buf->f_namelen = AFFSNAMEMAX;
+	return 0;
+}
+
+static int affs_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, 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);
+		mutex_destroy(&sbi->s_bmlock);
+		kfree_rcu(sbi, rcu);
+	}
+}
+
+static void affs_free_fc(struct fs_context *fc)
+{
+	struct affs_context *ctx = fc->fs_private;
+
+	kfree(ctx->prefix);
+	kfree(ctx);
+}
+
+static const struct fs_context_operations affs_context_ops = {
+	.parse_param	= affs_parse_param,
+	.get_tree	= affs_get_tree,
+	.reconfigure	= affs_reconfigure,
+	.free		= affs_free_fc,
+};
+
+static int affs_init_fs_context(struct fs_context *fc)
+{
+	struct affs_context *ctx;
+
+	ctx = kzalloc_obj(struct affs_context);
+	if (!ctx)
+		return -ENOMEM;
+
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
+		struct super_block *sb = fc->root->d_sb;
+		struct affs_sb_info *sbi = AFFS_SB(sb);
+
+		/*
+		 * NB: historically, no options other than volume were
+		 * preserved across a remount unless they were explicitly
+		 * passed in.
+		 */
+		memcpy(ctx->volume, sbi->s_volume, 32);
+	} else {
+		ctx->uid	= current_uid();
+		ctx->gid	= current_gid();
+		ctx->reserved	= 2;
+		ctx->root_block	= -1;
+		ctx->blocksize	= -1;
+		ctx->volume[0]	= ':';
+	}
+
+	fc->ops = &affs_context_ops;
+	fc->fs_private = ctx;
+
+	return 0;
+}
+
+static struct file_system_type affs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "affs",
+	.kill_sb	= affs_kill_sb,
+	.fs_flags	= FS_REQUIRES_DEV,
+	.init_fs_context = affs_init_fs_context,
+	.parameters	= affs_param_spec,
+};
+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)

linux-7.2.3/fs/affs/symlink.c

@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  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_read_folio(struct file *file, struct folio *folio)
+{
+	struct buffer_head *bh;
+	struct inode *inode = folio->mapping->host;
+	char *link = folio_address(folio);
+	struct slink_front *lf;
+	int			 i, j;
+	char			 c;
+	char			 lc;
+
+	pr_debug("get_link(ino=%llu)\n", inode->i_ino);
+
+	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);
+	folio_mark_uptodate(folio);
+	folio_unlock(folio);
+	return 0;
+fail:
+	folio_unlock(folio);
+	return -EIO;
+}
+
+const struct address_space_operations affs_symlink_aops = {
+	.read_folio	= affs_symlink_read_folio,
+};
+
+const struct inode_operations affs_symlink_inode_operations = {
+	.get_link	= page_get_link,
+	.setattr	= affs_setattr,
+};