fs/affs/amigaffs.c - third_party/linux - Git at Google

 // 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=%lu, 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);
 	mark_buffer_dirty_inode(dir_bh, dir);
 	affs_brelse(dir_bh);

 	dir->i_mtime = dir->i_ctime = current_time(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=%lu, 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);
 			mark_buffer_dirty_inode(bh, dir);
 			AFFS_TAIL(sb, rem_bh)->parent = 0;
 			retval = 0;
 			break;
 		}
 		affs_brelse(bh);
 		bh = affs_bread(sb, hash_ino);
 		if (!bh)
 			return -EIO;
 		hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
 	}

 	affs_brelse(bh);

 	dir->i_mtime = dir->i_ctime = current_time(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);
 	hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {
 		if (entry_ino == (u32)(long)dentry->d_fsdata) {
 			dentry->d_fsdata = (void *)inode->i_ino;
 			break;
 		}
 	}
 	spin_unlock(&inode->i_lock);
 }


 /* Remove header from link chain */

 static int
 affs_remove_link(struct dentry *dentry)
 {
 	struct inode *dir, *inode = 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=%ld)\n", __func__, inode->i_ino);
 	retval = -EIO;
 	bh = affs_bread(sb, inode->i_ino);
 	if (!bh)
 		goto done;

 	link_ino = (u32)(long)dentry->d_fsdata;
 	if (inode->i_ino == link_ino) {
 		/* we can't remove the head of the link, as its blocknr is still used as ino,
 		 * so we remove the block of the first link instead.
 		 */
 		link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain);
 		link_bh = affs_bread(sb, link_ino);
 		if (!link_bh)
 			goto done;

 		dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));
 		if (IS_ERR(dir)) {
 			retval = PTR_ERR(dir);
 			goto done;
 		}

 		affs_lock_dir(dir);
 		/*
 		 * if there's a dentry for that block, make it
 		 * refer to inode itself.
 		 */
 		affs_fix_dcache(inode, link_ino);
 		retval = affs_remove_hash(dir, link_bh);
 		if (retval) {
 			affs_unlock_dir(dir);
 			goto done;
 		}
 		mark_buffer_dirty_inode(link_bh, inode);

 		memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32);
 		retval = affs_insert_hash(dir, bh);
 		if (retval) {
 			affs_unlock_dir(dir);
 			goto done;
 		}
 		mark_buffer_dirty_inode(bh, inode);

 		affs_unlock_dir(dir);
 		iput(dir);
 	} else {
 		link_bh = affs_bread(sb, link_ino);
 		if (!link_bh)
 			goto done;
 	}

 	while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) {
 		if (ino == link_ino) {
 			__be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain;
 			AFFS_TAIL(sb, bh)->link_chain = ino2;
 			affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino);
 			mark_buffer_dirty_inode(bh, inode);
 			retval = 0;
 			/* Fix the link count, if bh is a normal header block without links */
 			switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
 			case ST_LINKDIR:
 			case ST_LINKFILE:
 				break;
 			default:
 				if (!AFFS_TAIL(sb, bh)->link_chain)
 					set_nlink(inode, 1);
 			}
 			affs_free_block(sb, link_ino);
 			goto done;
 		}
 		affs_brelse(bh);
 		bh = affs_bread(sb, ino);
 		if (!bh)
 			goto done;
 	}
 	retval = -ENOENT;
 done:
 	affs_brelse(link_bh);
 	affs_brelse(bh);
 	return retval;
 }


 static int
 affs_empty_dir(struct inode *inode)
 {
 	struct super_block *sb = inode->i_sb;
 	struct buffer_head *bh;
 	int retval, size;

 	retval = -EIO;
 	bh = affs_bread(sb, inode->i_ino);
 	if (!bh)
 		goto done;

 	retval = -ENOTEMPTY;
 	for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--)
 		if (AFFS_HEAD(bh)->table[size])
 			goto not_empty;
 	retval = 0;
 not_empty:
 	affs_brelse(bh);
 done:
 	return retval;
 }


 /* Remove a filesystem object. If the object to be removed has
  * links to it, one of the links must be changed to inherit
  * the file or directory. As above, any inode will do.
  * The buffer will not be freed. If the header is a link, the
  * block will be marked as free.
  * This function returns a negative error number in case of
  * an error, else 0 if the inode is to be deleted or 1 if not.
  */

 int
 affs_remove_header(struct dentry *dentry)
 {
 	struct super_block *sb;
 	struct inode *inode, *dir;
 	struct buffer_head *bh = NULL;
 	int retval;

 	dir = d_inode(dentry->d_parent);
 	sb = dir->i_sb;

 	retval = -ENOENT;
 	inode = d_inode(dentry);
 	if (!inode)
 		goto done;

 	pr_debug("%s(key=%ld)\n", __func__, inode->i_ino);
 	retval = -EIO;
 	bh = affs_bread(sb, (u32)(long)dentry->d_fsdata);
 	if (!bh)
 		goto done;

 	affs_lock_link(inode);
 	affs_lock_dir(dir);
 	switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
 	case ST_USERDIR:
 		/* if we ever want to support links to dirs
 		 * i_hash_lock of the inode must only be
 		 * taken after some checks
 		 */
 		affs_lock_dir(inode);
 		retval = affs_empty_dir(inode);
 		affs_unlock_dir(inode);
 		if (retval)
 			goto done_unlock;
 		break;
 	default:
 		break;
 	}

 	retval = affs_remove_hash(dir, bh);
 	if (retval)
 		goto done_unlock;
 	mark_buffer_dirty_inode(bh, inode);

 	affs_unlock_dir(dir);

 	if (inode->i_nlink > 1)
 		retval = affs_remove_link(dentry);
 	else
 		clear_nlink(inode);
 	affs_unlock_link(inode);
 	inode->i_ctime = current_time(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 + ((8 * 365 + 2) * 24 * 60 * 60);
 	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;
 }
	// 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=%lu, 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);
	mark_buffer_dirty_inode(dir_bh, dir);
	affs_brelse(dir_bh);

	dir->i_mtime = dir->i_ctime = current_time(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=%lu, 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);
	mark_buffer_dirty_inode(bh, dir);
	AFFS_TAIL(sb, rem_bh)->parent = 0;
	retval = 0;
	break;
	}
	affs_brelse(bh);
	bh = affs_bread(sb, hash_ino);
	if (!bh)
	return -EIO;
	hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
	}

	affs_brelse(bh);

	dir->i_mtime = dir->i_ctime = current_time(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);
	hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {
	if (entry_ino == (u32)(long)dentry->d_fsdata) {
	dentry->d_fsdata = (void *)inode->i_ino;
	break;
	}
	}
	spin_unlock(&inode->i_lock);
	}


	/* Remove header from link chain */

	static int
	affs_remove_link(struct dentry *dentry)
	{
	struct inode dir, inode = 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=%ld)\n", __func__, inode->i_ino);
	retval = -EIO;
	bh = affs_bread(sb, inode->i_ino);
	if (!bh)
	goto done;

	link_ino = (u32)(long)dentry->d_fsdata;
	if (inode->i_ino == link_ino) {
	/* we can't remove the head of the link, as its blocknr is still used as ino,
	* so we remove the block of the first link instead.
	*/
	link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain);
	link_bh = affs_bread(sb, link_ino);
	if (!link_bh)
	goto done;

	dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));
	if (IS_ERR(dir)) {
	retval = PTR_ERR(dir);
	goto done;
	}

	affs_lock_dir(dir);
	/*
	* if there's a dentry for that block, make it
	* refer to inode itself.
	*/
	affs_fix_dcache(inode, link_ino);
	retval = affs_remove_hash(dir, link_bh);
	if (retval) {
	affs_unlock_dir(dir);
	goto done;
	}
	mark_buffer_dirty_inode(link_bh, inode);

	memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32);
	retval = affs_insert_hash(dir, bh);
	if (retval) {
	affs_unlock_dir(dir);
	goto done;
	}
	mark_buffer_dirty_inode(bh, inode);

	affs_unlock_dir(dir);
	iput(dir);
	} else {
	link_bh = affs_bread(sb, link_ino);
	if (!link_bh)
	goto done;
	}

	while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) {
	if (ino == link_ino) {
	__be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain;
	AFFS_TAIL(sb, bh)->link_chain = ino2;
	affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino);
	mark_buffer_dirty_inode(bh, inode);
	retval = 0;
	/* Fix the link count, if bh is a normal header block without links */
	switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
	case ST_LINKDIR:
	case ST_LINKFILE:
	break;
	default:
	if (!AFFS_TAIL(sb, bh)->link_chain)
	set_nlink(inode, 1);
	}
	affs_free_block(sb, link_ino);
	goto done;
	}
	affs_brelse(bh);
	bh = affs_bread(sb, ino);
	if (!bh)
	goto done;
	}
	retval = -ENOENT;
	done:
	affs_brelse(link_bh);
	affs_brelse(bh);
	return retval;
	}


	static int
	affs_empty_dir(struct inode *inode)
	{
	struct super_block *sb = inode->i_sb;
	struct buffer_head *bh;
	int retval, size;

	retval = -EIO;
	bh = affs_bread(sb, inode->i_ino);
	if (!bh)
	goto done;

	retval = -ENOTEMPTY;
	for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--)
	if (AFFS_HEAD(bh)->table[size])
	goto not_empty;
	retval = 0;
	not_empty:
	affs_brelse(bh);
	done:
	return retval;
	}


	/* Remove a filesystem object. If the object to be removed has
	* links to it, one of the links must be changed to inherit
	* the file or directory. As above, any inode will do.
	* The buffer will not be freed. If the header is a link, the
	* block will be marked as free.
	* This function returns a negative error number in case of
	* an error, else 0 if the inode is to be deleted or 1 if not.
	*/

	int
	affs_remove_header(struct dentry *dentry)
	{
	struct super_block *sb;
	struct inode inode, dir;
	struct buffer_head *bh = NULL;
	int retval;

	dir = d_inode(dentry->d_parent);
	sb = dir->i_sb;

	retval = -ENOENT;
	inode = d_inode(dentry);
	if (!inode)
	goto done;

	pr_debug("%s(key=%ld)\n", __func__, inode->i_ino);
	retval = -EIO;
	bh = affs_bread(sb, (u32)(long)dentry->d_fsdata);
	if (!bh)
	goto done;

	affs_lock_link(inode);
	affs_lock_dir(dir);
	switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
	case ST_USERDIR:
	/* if we ever want to support links to dirs
	* i_hash_lock of the inode must only be
	* taken after some checks
	*/
	affs_lock_dir(inode);
	retval = affs_empty_dir(inode);
	affs_unlock_dir(inode);
	if (retval)
	goto done_unlock;
	break;
	default:
	break;
	}

	retval = affs_remove_hash(dir, bh);
	if (retval)
	goto done_unlock;
	mark_buffer_dirty_inode(bh, inode);

	affs_unlock_dir(dir);

	if (inode->i_nlink > 1)
	retval = affs_remove_link(dentry);
	else
	clear_nlink(inode);
	affs_unlock_link(inode);
	inode->i_ctime = current_time(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 + ((8 * 365 + 2) * 24 * 60 * 60);
	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;
	}