[mirror_ubuntu-artful-kernel.git] / fs / adfs / inode.c

/*
 *  linux/fs/adfs/inode.c
 *
 *  Copyright (C) 1997-1999 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include "adfs.h"

/*
 * Lookup/Create a block at offset 'block' into 'inode'.  We currently do
 * not support creation of new blocks, so we return -EIO for this case.
 */
static int
adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh,
	       int create)
{
	if (!create) {
		if (block >= inode->i_blocks)
			goto abort_toobig;

		block = __adfs_block_map(inode->i_sb, inode->i_ino, block);
		if (block)
			map_bh(bh, inode->i_sb, block);
		return 0;
	}
	/* don't support allocation of blocks yet */
	return -EIO;

abort_toobig:
	return 0;
}

static int adfs_writepage(struct page *page, struct writeback_control *wbc)
{
	return block_write_full_page(page, adfs_get_block, wbc);
}

static int adfs_readpage(struct file *file, struct page *page)
{
	return block_read_full_page(page, adfs_get_block);
}

static void adfs_write_failed(struct address_space *mapping, loff_t to)
{
	struct inode *inode = mapping->host;

	if (to > inode->i_size)
		truncate_pagecache(inode, inode->i_size);
}

static int adfs_write_begin(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
{
	int ret;

	*pagep = NULL;
	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
				adfs_get_block,
				&ADFS_I(mapping->host)->mmu_private);
	if (unlikely(ret))
		adfs_write_failed(mapping, pos + len);

	return ret;
}

static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
{
	return generic_block_bmap(mapping, block, adfs_get_block);
}

static const struct address_space_operations adfs_aops = {
	.readpage	= adfs_readpage,
	.writepage	= adfs_writepage,
	.write_begin	= adfs_write_begin,
	.write_end	= generic_write_end,
	.bmap		= _adfs_bmap
};

/*
 * Convert ADFS attributes and filetype to Linux permission.
 */
static umode_t
adfs_atts2mode(struct super_block *sb, struct inode *inode)
{
	unsigned int attr = ADFS_I(inode)->attr;
	umode_t mode, rmask;
	struct adfs_sb_info *asb = ADFS_SB(sb);

	if (attr & ADFS_NDA_DIRECTORY) {
		mode = S_IRUGO & asb->s_owner_mask;
		return S_IFDIR | S_IXUGO | mode;
	}

	switch (ADFS_I(inode)->filetype) {
	case 0xfc0:	/* LinkFS */
		return S_IFLNK|S_IRWXUGO;

	case 0xfe6:	/* UnixExec */
		rmask = S_IRUGO | S_IXUGO;
		break;

	default:
		rmask = S_IRUGO;
	}

	mode = S_IFREG;

	if (attr & ADFS_NDA_OWNER_READ)
		mode |= rmask & asb->s_owner_mask;

	if (attr & ADFS_NDA_OWNER_WRITE)
		mode |= S_IWUGO & asb->s_owner_mask;

	if (attr & ADFS_NDA_PUBLIC_READ)
		mode |= rmask & asb->s_other_mask;

	if (attr & ADFS_NDA_PUBLIC_WRITE)
		mode |= S_IWUGO & asb->s_other_mask;
	return mode;
}

/*
 * Convert Linux permission to ADFS attribute.  We try to do the reverse
 * of atts2mode, but there is not a 1:1 translation.
 */
static int
adfs_mode2atts(struct super_block *sb, struct inode *inode)
{
	umode_t mode;
	int attr;
	struct adfs_sb_info *asb = ADFS_SB(sb);

	/* FIXME: should we be able to alter a link? */
	if (S_ISLNK(inode->i_mode))
		return ADFS_I(inode)->attr;

	if (S_ISDIR(inode->i_mode))
		attr = ADFS_NDA_DIRECTORY;
	else
		attr = 0;

	mode = inode->i_mode & asb->s_owner_mask;
	if (mode & S_IRUGO)
		attr |= ADFS_NDA_OWNER_READ;
	if (mode & S_IWUGO)
		attr |= ADFS_NDA_OWNER_WRITE;

	mode = inode->i_mode & asb->s_other_mask;
	mode &= ~asb->s_owner_mask;
	if (mode & S_IRUGO)
		attr |= ADFS_NDA_PUBLIC_READ;
	if (mode & S_IWUGO)
		attr |= ADFS_NDA_PUBLIC_WRITE;

	return attr;
}

/*
 * Convert an ADFS time to Unix time.  ADFS has a 40-bit centi-second time
 * referenced to 1 Jan 1900 (til 2248) so we need to discard 2208988800 seconds
 * of time to convert from RISC OS epoch to Unix epoch.
 */
static void
adfs_adfs2unix_time(struct timespec *tv, struct inode *inode)
{
	unsigned int high, low;
	/* 01 Jan 1970 00:00:00 (Unix epoch) as nanoseconds since
	 * 01 Jan 1900 00:00:00 (RISC OS epoch)
	 */
	static const s64 nsec_unix_epoch_diff_risc_os_epoch =
							2208988800000000000LL;
	s64 nsec;

	if (ADFS_I(inode)->stamped == 0)
		goto cur_time;

	high = ADFS_I(inode)->loadaddr & 0xFF; /* top 8 bits of timestamp */
	low  = ADFS_I(inode)->execaddr;    /* bottom 32 bits of timestamp */

	/* convert 40-bit centi-seconds to 32-bit seconds
	 * going via nanoseconds to retain precision
	 */
	nsec = (((s64) high << 32) | (s64) low) * 10000000; /* cs to ns */

	/* Files dated pre  01 Jan 1970 00:00:00. */
	if (nsec < nsec_unix_epoch_diff_risc_os_epoch)
		goto too_early;

	/* convert from RISC OS to Unix epoch */
	nsec -= nsec_unix_epoch_diff_risc_os_epoch;

	*tv = ns_to_timespec(nsec);
	return;

 cur_time:
	*tv = current_time(inode);
	return;

 too_early:
	tv->tv_sec = tv->tv_nsec = 0;
	return;
}

/*
 * Convert an Unix time to ADFS time.  We only do this if the entry has a
 * time/date stamp already.
 */
static void
adfs_unix2adfs_time(struct inode *inode, unsigned int secs)
{
	unsigned int high, low;

	if (ADFS_I(inode)->stamped) {
		/* convert 32-bit seconds to 40-bit centi-seconds */
		low  = (secs & 255) * 100;
		high = (secs / 256) * 100 + (low >> 8) + 0x336e996a;

		ADFS_I(inode)->loadaddr = (high >> 24) |
				(ADFS_I(inode)->loadaddr & ~0xff);
		ADFS_I(inode)->execaddr = (low & 255) | (high << 8);
	}
}

/*
 * Fill in the inode information from the object information.
 *
 * Note that this is an inode-less filesystem, so we can't use the inode
 * number to reference the metadata on the media.  Instead, we use the
 * inode number to hold the object ID, which in turn will tell us where
 * the data is held.  We also save the parent object ID, and with these
 * two, we can locate the metadata.
 *
 * This does mean that we rely on an objects parent remaining the same at
 * all times - we cannot cope with a cross-directory rename (yet).
 */
struct inode *
adfs_iget(struct super_block *sb, struct object_info *obj)
{
	struct inode *inode;

	inode = new_inode(sb);
	if (!inode)
		goto out;

	inode->i_uid	 = ADFS_SB(sb)->s_uid;
	inode->i_gid	 = ADFS_SB(sb)->s_gid;
	inode->i_ino	 = obj->file_id;
	inode->i_size	 = obj->size;
	set_nlink(inode, 2);
	inode->i_blocks	 = (inode->i_size + sb->s_blocksize - 1) >>
			    sb->s_blocksize_bits;

	/*
	 * we need to save the parent directory ID so that
	 * write_inode can update the directory information
	 * for this file.  This will need special handling
	 * for cross-directory renames.
	 */
	ADFS_I(inode)->parent_id = obj->parent_id;
	ADFS_I(inode)->loadaddr  = obj->loadaddr;
	ADFS_I(inode)->execaddr  = obj->execaddr;
	ADFS_I(inode)->attr      = obj->attr;
	ADFS_I(inode)->filetype  = obj->filetype;
	ADFS_I(inode)->stamped   = ((obj->loadaddr & 0xfff00000) == 0xfff00000);

	inode->i_mode	 = adfs_atts2mode(sb, inode);
	adfs_adfs2unix_time(&inode->i_mtime, inode);
	inode->i_atime = inode->i_mtime;
	inode->i_ctime = inode->i_mtime;

	if (S_ISDIR(inode->i_mode)) {
		inode->i_op	= &adfs_dir_inode_operations;
		inode->i_fop	= &adfs_dir_operations;
	} else if (S_ISREG(inode->i_mode)) {
		inode->i_op	= &adfs_file_inode_operations;
		inode->i_fop	= &adfs_file_operations;
		inode->i_mapping->a_ops = &adfs_aops;
		ADFS_I(inode)->mmu_private = inode->i_size;
	}

	insert_inode_hash(inode);

out:
	return inode;
}

/*
 * Validate and convert a changed access mode/time to their ADFS equivalents.
 * adfs_write_inode will actually write the information back to the directory
 * later.
 */
int
adfs_notify_change(struct dentry *dentry, struct iattr *attr)
{
	struct inode *inode = d_inode(dentry);
	struct super_block *sb = inode->i_sb;
	unsigned int ia_valid = attr->ia_valid;
	int error;
	
	error = setattr_prepare(dentry, attr);

	/*
	 * we can't change the UID or GID of any file -
	 * we have a global UID/GID in the superblock
	 */
	if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, ADFS_SB(sb)->s_uid)) ||
	    (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, ADFS_SB(sb)->s_gid)))
		error = -EPERM;

	if (error)
		goto out;

	/* XXX: this is missing some actual on-disk truncation.. */
	if (ia_valid & ATTR_SIZE)
		truncate_setsize(inode, attr->ia_size);

	if (ia_valid & ATTR_MTIME) {
		inode->i_mtime = attr->ia_mtime;
		adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec);
	}
	/*
	 * FIXME: should we make these == to i_mtime since we don't
	 * have the ability to represent them in our filesystem?
	 */
	if (ia_valid & ATTR_ATIME)
		inode->i_atime = attr->ia_atime;
	if (ia_valid & ATTR_CTIME)
		inode->i_ctime = attr->ia_ctime;
	if (ia_valid & ATTR_MODE) {
		ADFS_I(inode)->attr = adfs_mode2atts(sb, inode);
		inode->i_mode = adfs_atts2mode(sb, inode);
	}

	/*
	 * FIXME: should we be marking this inode dirty even if
	 * we don't have any metadata to write back?
	 */
	if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE))
		mark_inode_dirty(inode);
out:
	return error;
}

/*
 * write an existing inode back to the directory, and therefore the disk.
 * The adfs-specific inode data has already been updated by
 * adfs_notify_change()
 */
int adfs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
	struct super_block *sb = inode->i_sb;
	struct object_info obj;
	int ret;

	obj.file_id	= inode->i_ino;
	obj.name_len	= 0;
	obj.parent_id	= ADFS_I(inode)->parent_id;
	obj.loadaddr	= ADFS_I(inode)->loadaddr;
	obj.execaddr	= ADFS_I(inode)->execaddr;
	obj.attr	= ADFS_I(inode)->attr;
	obj.size	= inode->i_size;

	ret = adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL);
	return ret;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/adfs/inode.c
	3	*
	4	* Copyright (C) 1997-1999 Russell King
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
1da177e4	10	#include <linux/buffer_head.h>
a9185b41	11	#include <linux/writeback.h>
1da177e4 LT	12	#include "adfs.h"
	13
	14	/*
	15	* Lookup/Create a block at offset 'block' into 'inode'. We currently do
	16	* not support creation of new blocks, so we return -EIO for this case.
	17	*/
	18	static int
	19	adfs_get_block(struct inode inode, sector_t block, struct buffer_head bh,
	20	int create)
	21	{
1da177e4 LT	22	if (!create) {
	23	if (block >= inode->i_blocks)
	24	goto abort_toobig;
	25
	26	block = __adfs_block_map(inode->i_sb, inode->i_ino, block);
	27	if (block)
	28	map_bh(bh, inode->i_sb, block);
	29	return 0;
	30	}
	31	/* don't support allocation of blocks yet */
	32	return -EIO;
	33
1da177e4 LT	34	abort_toobig:
	35	return 0;
	36	}
	37
	38	static int adfs_writepage(struct page page, struct writeback_control wbc)
	39	{
	40	return block_write_full_page(page, adfs_get_block, wbc);
	41	}
	42
	43	static int adfs_readpage(struct file file, struct page page)
	44	{
	45	return block_read_full_page(page, adfs_get_block);
	46	}
	47
62295183 MS	48	static void adfs_write_failed(struct address_space *mapping, loff_t to)
	49	{
	50	struct inode *inode = mapping->host;
	51
	52	if (to > inode->i_size)
7caef267	53	truncate_pagecache(inode, inode->i_size);
62295183 MS	54	}
62295183 MS	55
b4585729 NP	56	static int adfs_write_begin(struct file file, struct address_space mapping,
	57	loff_t pos, unsigned len, unsigned flags,
	58	struct page pagep, void fsdata)
1da177e4	59	{
282dc178 CH	60	int ret;
282dc178 CH	61
b4585729	62	*pagep = NULL;
282dc178	63	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
b4585729 NP	64	adfs_get_block,
b4585729 NP	65	&ADFS_I(mapping->host)->mmu_private);
62295183 MS	66	if (unlikely(ret))
62295183 MS	67	adfs_write_failed(mapping, pos + len);
282dc178 CH	68
282dc178 CH	69	return ret;
1da177e4 LT	70	}
	71
	72	static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
	73	{
	74	return generic_block_bmap(mapping, block, adfs_get_block);
	75	}
	76
f5e54d6e	77	static const struct address_space_operations adfs_aops = {
1da177e4 LT	78	.readpage = adfs_readpage,
1da177e4 LT	79	.writepage = adfs_writepage,
b4585729 NP	80	.write_begin = adfs_write_begin,
b4585729 NP	81	.write_end = generic_write_end,
1da177e4 LT	82	.bmap = _adfs_bmap
	83	};
	84
1da177e4 LT	85	/*
	86	* Convert ADFS attributes and filetype to Linux permission.
	87	*/
	88	static umode_t
	89	adfs_atts2mode(struct super_block sb, struct inode inode)
	90	{
da23ef05	91	unsigned int attr = ADFS_I(inode)->attr;
1da177e4 LT	92	umode_t mode, rmask;
	93	struct adfs_sb_info *asb = ADFS_SB(sb);
	94
	95	if (attr & ADFS_NDA_DIRECTORY) {
	96	mode = S_IRUGO & asb->s_owner_mask;
	97	return S_IFDIR \| S_IXUGO \| mode;
	98	}
	99
da23ef05	100	switch (ADFS_I(inode)->filetype) {
1da177e4 LT	101	case 0xfc0: /* LinkFS */
	102	return S_IFLNK\|S_IRWXUGO;
	103
	104	case 0xfe6: /* UnixExec */
	105	rmask = S_IRUGO \| S_IXUGO;
	106	break;
	107
	108	default:
	109	rmask = S_IRUGO;
	110	}
	111
	112	mode = S_IFREG;
	113
	114	if (attr & ADFS_NDA_OWNER_READ)
	115	mode \|= rmask & asb->s_owner_mask;
	116
	117	if (attr & ADFS_NDA_OWNER_WRITE)
	118	mode \|= S_IWUGO & asb->s_owner_mask;
	119
	120	if (attr & ADFS_NDA_PUBLIC_READ)
	121	mode \|= rmask & asb->s_other_mask;
	122
	123	if (attr & ADFS_NDA_PUBLIC_WRITE)
	124	mode \|= S_IWUGO & asb->s_other_mask;
	125	return mode;
	126	}
	127
	128	/*
	129	* Convert Linux permission to ADFS attribute. We try to do the reverse
	130	* of atts2mode, but there is not a 1:1 translation.
	131	*/
	132	static int
	133	adfs_mode2atts(struct super_block sb, struct inode inode)
	134	{
	135	umode_t mode;
	136	int attr;
	137	struct adfs_sb_info *asb = ADFS_SB(sb);
	138
	139	/* FIXME: should we be able to alter a link? */
	140	if (S_ISLNK(inode->i_mode))
	141	return ADFS_I(inode)->attr;
	142
	143	if (S_ISDIR(inode->i_mode))
	144	attr = ADFS_NDA_DIRECTORY;
	145	else
	146	attr = 0;
	147
	148	mode = inode->i_mode & asb->s_owner_mask;
	149	if (mode & S_IRUGO)
	150	attr \|= ADFS_NDA_OWNER_READ;
	151	if (mode & S_IWUGO)
	152	attr \|= ADFS_NDA_OWNER_WRITE;
	153
	154	mode = inode->i_mode & asb->s_other_mask;
	155	mode &= ~asb->s_owner_mask;
	156	if (mode & S_IRUGO)
	157	attr \|= ADFS_NDA_PUBLIC_READ;
	158	if (mode & S_IWUGO)
	159	attr \|= ADFS_NDA_PUBLIC_WRITE;
	160
	161	return attr;
	162	}
	163
	164	/*
165	* Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time
7a9730af SS	166	* referenced to 1 Jan 1900 (til 2248) so we need to discard 2208988800 seconds
7a9730af SS	167	* of time to convert from RISC OS epoch to Unix epoch.
1da177e4 LT	168	*/
	169	static void
	170	adfs_adfs2unix_time(struct timespec tv, struct inode inode)
	171	{
	172	unsigned int high, low;
7a9730af SS	173	/* 01 Jan 1970 00:00:00 (Unix epoch) as nanoseconds since
	174	* 01 Jan 1900 00:00:00 (RISC OS epoch)
	175	*/
	176	static const s64 nsec_unix_epoch_diff_risc_os_epoch =
	177	2208988800000000000LL;
	178	s64 nsec;
1da177e4 LT	179
	180	if (ADFS_I(inode)->stamped == 0)
	181	goto cur_time;
	182
7a9730af SS	183	high = ADFS_I(inode)->loadaddr & 0xFF; /* top 8 bits of timestamp */
7a9730af SS	184	low = ADFS_I(inode)->execaddr; /* bottom 32 bits of timestamp */
1da177e4	185
7a9730af SS	186	/* convert 40-bit centi-seconds to 32-bit seconds
	187	* going via nanoseconds to retain precision
	188	*/
	189	nsec = (((s64) high << 32) \| (s64) low) * 10000000; /* cs to ns */
1da177e4 LT	190
1da177e4 LT	191	/* Files dated pre 01 Jan 1970 00:00:00. */
7a9730af	192	if (nsec < nsec_unix_epoch_diff_risc_os_epoch)
1da177e4 LT	193	goto too_early;
1da177e4 LT	194
7a9730af SS	195	/* convert from RISC OS to Unix epoch */
7a9730af SS	196	nsec -= nsec_unix_epoch_diff_risc_os_epoch;
1da177e4	197
7a9730af	198	*tv = ns_to_timespec(nsec);
1da177e4 LT	199	return;
	200
	201	cur_time:
078cd827	202	*tv = current_time(inode);
1da177e4 LT	203	return;
	204
	205	too_early:
	206	tv->tv_sec = tv->tv_nsec = 0;
	207	return;
1da177e4 LT	208	}
	209
	210	/*
	211	* Convert an Unix time to ADFS time. We only do this if the entry has a
	212	* time/date stamp already.
	213	*/
	214	static void
	215	adfs_unix2adfs_time(struct inode *inode, unsigned int secs)
	216	{
	217	unsigned int high, low;
	218
	219	if (ADFS_I(inode)->stamped) {
	220	/* convert 32-bit seconds to 40-bit centi-seconds */
	221	low = (secs & 255) * 100;
	222	high = (secs / 256) * 100 + (low >> 8) + 0x336e996a;
	223
	224	ADFS_I(inode)->loadaddr = (high >> 24) \|
	225	(ADFS_I(inode)->loadaddr & ~0xff);
	226	ADFS_I(inode)->execaddr = (low & 255) \| (high << 8);
	227	}
	228	}
	229
	230	/*
	231	* Fill in the inode information from the object information.
	232	*
	233	* Note that this is an inode-less filesystem, so we can't use the inode
	234	* number to reference the metadata on the media. Instead, we use the
	235	* inode number to hold the object ID, which in turn will tell us where
	236	* the data is held. We also save the parent object ID, and with these
	237	* two, we can locate the metadata.
	238	*
	239	* This does mean that we rely on an objects parent remaining the same at
	240	* all times - we cannot cope with a cross-directory rename (yet).
	241	*/
	242	struct inode *
	243	adfs_iget(struct super_block sb, struct object_info obj)
	244	{
	245	struct inode *inode;
	246
	247	inode = new_inode(sb);
	248	if (!inode)
	249	goto out;
	250
	251	inode->i_uid = ADFS_SB(sb)->s_uid;
	252	inode->i_gid = ADFS_SB(sb)->s_gid;
	253	inode->i_ino = obj->file_id;
	254	inode->i_size = obj->size;
bfe86848	255	set_nlink(inode, 2);
1da177e4 LT	256	inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >>
	257	sb->s_blocksize_bits;
	258
	259	/*
	260	* we need to save the parent directory ID so that
	261	* write_inode can update the directory information
	262	* for this file. This will need special handling
	263	* for cross-directory renames.
	264	*/
	265	ADFS_I(inode)->parent_id = obj->parent_id;
	266	ADFS_I(inode)->loadaddr = obj->loadaddr;
	267	ADFS_I(inode)->execaddr = obj->execaddr;
	268	ADFS_I(inode)->attr = obj->attr;
da23ef05 SS	269	ADFS_I(inode)->filetype = obj->filetype;
da23ef05 SS	270	ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000);
1da177e4 LT	271
	272	inode->i_mode = adfs_atts2mode(sb, inode);
	273	adfs_adfs2unix_time(&inode->i_mtime, inode);
	274	inode->i_atime = inode->i_mtime;
	275	inode->i_ctime = inode->i_mtime;
	276
	277	if (S_ISDIR(inode->i_mode)) {
	278	inode->i_op = &adfs_dir_inode_operations;
	279	inode->i_fop = &adfs_dir_operations;
	280	} else if (S_ISREG(inode->i_mode)) {
	281	inode->i_op = &adfs_file_inode_operations;
	282	inode->i_fop = &adfs_file_operations;
	283	inode->i_mapping->a_ops = &adfs_aops;
	284	ADFS_I(inode)->mmu_private = inode->i_size;
	285	}
	286
	287	insert_inode_hash(inode);
	288
	289	out:
	290	return inode;
	291	}
	292
	293	/*
	294	* Validate and convert a changed access mode/time to their ADFS equivalents.
	295	* adfs_write_inode will actually write the information back to the directory
	296	* later.
	297	*/
	298	int
	299	adfs_notify_change(struct dentry dentry, struct iattr attr)
	300	{
2b0143b5	301	struct inode *inode = d_inode(dentry);
1da177e4 LT	302	struct super_block *sb = inode->i_sb;
	303	unsigned int ia_valid = attr->ia_valid;
	304	int error;
	305
31051c85	306	error = setattr_prepare(dentry, attr);
1da177e4 LT	307
	308	/*
	309	* we can't change the UID or GID of any file -
	310	* we have a global UID/GID in the superblock
	311	*/
c010d1ff EB	312	if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, ADFS_SB(sb)->s_uid)) \|\|
c010d1ff EB	313	(ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, ADFS_SB(sb)->s_gid)))
1da177e4 LT	314	error = -EPERM;
	315
	316	if (error)
	317	goto out;
	318
15c6fd97	319	/* XXX: this is missing some actual on-disk truncation.. */
1da177e4	320	if (ia_valid & ATTR_SIZE)
2c27c65e	321	truncate_setsize(inode, attr->ia_size);
1da177e4 LT	322
	323	if (ia_valid & ATTR_MTIME) {
	324	inode->i_mtime = attr->ia_mtime;
	325	adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec);
	326	}
	327	/*
	328	* FIXME: should we make these == to i_mtime since we don't
	329	* have the ability to represent them in our filesystem?
	330	*/
	331	if (ia_valid & ATTR_ATIME)
	332	inode->i_atime = attr->ia_atime;
	333	if (ia_valid & ATTR_CTIME)
	334	inode->i_ctime = attr->ia_ctime;
	335	if (ia_valid & ATTR_MODE) {
	336	ADFS_I(inode)->attr = adfs_mode2atts(sb, inode);
	337	inode->i_mode = adfs_atts2mode(sb, inode);
	338	}
	339
	340	/*
	341	* FIXME: should we be marking this inode dirty even if
	342	* we don't have any metadata to write back?
	343	*/
	344	if (ia_valid & (ATTR_SIZE \| ATTR_MTIME \| ATTR_MODE))
	345	mark_inode_dirty(inode);
	346	out:
1da177e4 LT	347	return error;
	348	}
	349
	350	/*
	351	* write an existing inode back to the directory, and therefore the disk.
	352	* The adfs-specific inode data has already been updated by
	353	* adfs_notify_change()
	354	*/
a9185b41	355	int adfs_write_inode(struct inode inode, struct writeback_control wbc)
1da177e4 LT	356	{
	357	struct super_block *sb = inode->i_sb;
	358	struct object_info obj;
	359	int ret;
	360
1da177e4 LT	361	obj.file_id = inode->i_ino;
	362	obj.name_len = 0;
	363	obj.parent_id = ADFS_I(inode)->parent_id;
	364	obj.loadaddr = ADFS_I(inode)->loadaddr;
	365	obj.execaddr = ADFS_I(inode)->execaddr;
	366	obj.attr = ADFS_I(inode)->attr;
	367	obj.size = inode->i_size;
	368
a9185b41	369	ret = adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL);
1da177e4 LT	370	return ret;
1da177e4 LT	371	}