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v5.9
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  linux/fs/adfs/inode.c
  4 *
  5 *  Copyright (C) 1997-1999 Russell King
  6 */
  7#include <linux/buffer_head.h>
 
  8#include <linux/writeback.h>
  9#include "adfs.h"
 10
 11/*
 12 * Lookup/Create a block at offset 'block' into 'inode'.  We currently do
 13 * not support creation of new blocks, so we return -EIO for this case.
 14 */
 15static int
 16adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh,
 17	       int create)
 18{
 19	if (!create) {
 20		if (block >= inode->i_blocks)
 21			goto abort_toobig;
 22
 23		block = __adfs_block_map(inode->i_sb, ADFS_I(inode)->indaddr,
 24					 block);
 25		if (block)
 26			map_bh(bh, inode->i_sb, block);
 27		return 0;
 28	}
 29	/* don't support allocation of blocks yet */
 30	return -EIO;
 31
 32abort_toobig:
 33	return 0;
 34}
 35
 36static int adfs_writepage(struct page *page, struct writeback_control *wbc)
 
 37{
 38	return block_write_full_page(page, adfs_get_block, wbc);
 39}
 40
 41static int adfs_readpage(struct file *file, struct page *page)
 42{
 43	return block_read_full_page(page, adfs_get_block);
 44}
 45
 46static void adfs_write_failed(struct address_space *mapping, loff_t to)
 47{
 48	struct inode *inode = mapping->host;
 49
 50	if (to > inode->i_size)
 51		truncate_pagecache(inode, inode->i_size);
 52}
 53
 54static int adfs_write_begin(struct file *file, struct address_space *mapping,
 55			loff_t pos, unsigned len, unsigned flags,
 56			struct page **pagep, void **fsdata)
 57{
 58	int ret;
 59
 60	*pagep = NULL;
 61	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 62				adfs_get_block,
 63				&ADFS_I(mapping->host)->mmu_private);
 64	if (unlikely(ret))
 65		adfs_write_failed(mapping, pos + len);
 66
 67	return ret;
 68}
 69
 70static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
 71{
 72	return generic_block_bmap(mapping, block, adfs_get_block);
 73}
 74
 75static const struct address_space_operations adfs_aops = {
 76	.readpage	= adfs_readpage,
 77	.writepage	= adfs_writepage,
 
 
 78	.write_begin	= adfs_write_begin,
 79	.write_end	= generic_write_end,
 80	.bmap		= _adfs_bmap
 
 81};
 82
 83/*
 84 * Convert ADFS attributes and filetype to Linux permission.
 85 */
 86static umode_t
 87adfs_atts2mode(struct super_block *sb, struct inode *inode)
 88{
 89	unsigned int attr = ADFS_I(inode)->attr;
 90	umode_t mode, rmask;
 91	struct adfs_sb_info *asb = ADFS_SB(sb);
 92
 93	if (attr & ADFS_NDA_DIRECTORY) {
 94		mode = S_IRUGO & asb->s_owner_mask;
 95		return S_IFDIR | S_IXUGO | mode;
 96	}
 97
 98	switch (adfs_filetype(ADFS_I(inode)->loadaddr)) {
 99	case 0xfc0:	/* LinkFS */
100		return S_IFLNK|S_IRWXUGO;
101
102	case 0xfe6:	/* UnixExec */
103		rmask = S_IRUGO | S_IXUGO;
104		break;
105
106	default:
107		rmask = S_IRUGO;
108	}
109
110	mode = S_IFREG;
111
112	if (attr & ADFS_NDA_OWNER_READ)
113		mode |= rmask & asb->s_owner_mask;
114
115	if (attr & ADFS_NDA_OWNER_WRITE)
116		mode |= S_IWUGO & asb->s_owner_mask;
117
118	if (attr & ADFS_NDA_PUBLIC_READ)
119		mode |= rmask & asb->s_other_mask;
120
121	if (attr & ADFS_NDA_PUBLIC_WRITE)
122		mode |= S_IWUGO & asb->s_other_mask;
123	return mode;
124}
125
126/*
127 * Convert Linux permission to ADFS attribute.  We try to do the reverse
128 * of atts2mode, but there is not a 1:1 translation.
129 */
130static int adfs_mode2atts(struct super_block *sb, struct inode *inode,
131			  umode_t ia_mode)
132{
133	struct adfs_sb_info *asb = ADFS_SB(sb);
134	umode_t mode;
135	int attr;
136
137	/* FIXME: should we be able to alter a link? */
138	if (S_ISLNK(inode->i_mode))
139		return ADFS_I(inode)->attr;
140
141	/* Directories do not have read/write permissions on the media */
142	if (S_ISDIR(inode->i_mode))
143		return ADFS_NDA_DIRECTORY;
144
145	attr = 0;
146	mode = ia_mode & asb->s_owner_mask;
147	if (mode & S_IRUGO)
148		attr |= ADFS_NDA_OWNER_READ;
149	if (mode & S_IWUGO)
150		attr |= ADFS_NDA_OWNER_WRITE;
151
152	mode = ia_mode & asb->s_other_mask;
153	mode &= ~asb->s_owner_mask;
154	if (mode & S_IRUGO)
155		attr |= ADFS_NDA_PUBLIC_READ;
156	if (mode & S_IWUGO)
157		attr |= ADFS_NDA_PUBLIC_WRITE;
158
159	return attr;
160}
161
162static const s64 nsec_unix_epoch_diff_risc_os_epoch = 2208988800000000000LL;
163
164/*
165 * Convert an ADFS time to Unix time.  ADFS has a 40-bit centi-second time
166 * referenced to 1 Jan 1900 (til 2248) so we need to discard 2208988800 seconds
167 * of time to convert from RISC OS epoch to Unix epoch.
168 */
169static void
170adfs_adfs2unix_time(struct timespec64 *tv, struct inode *inode)
171{
172	unsigned int high, low;
173	/* 01 Jan 1970 00:00:00 (Unix epoch) as nanoseconds since
174	 * 01 Jan 1900 00:00:00 (RISC OS epoch)
175	 */
176	s64 nsec;
177
178	if (!adfs_inode_is_stamped(inode))
179		goto cur_time;
180
181	high = ADFS_I(inode)->loadaddr & 0xFF; /* top 8 bits of timestamp */
182	low  = ADFS_I(inode)->execaddr;    /* bottom 32 bits of timestamp */
183
184	/* convert 40-bit centi-seconds to 32-bit seconds
185	 * going via nanoseconds to retain precision
186	 */
187	nsec = (((s64) high << 32) | (s64) low) * 10000000; /* cs to ns */
188
189	/* Files dated pre  01 Jan 1970 00:00:00. */
190	if (nsec < nsec_unix_epoch_diff_risc_os_epoch)
191		goto too_early;
192
193	/* convert from RISC OS to Unix epoch */
194	nsec -= nsec_unix_epoch_diff_risc_os_epoch;
195
196	*tv = ns_to_timespec64(nsec);
197	return;
198
199 cur_time:
200	*tv = current_time(inode);
201	return;
202
203 too_early:
204	tv->tv_sec = tv->tv_nsec = 0;
205	return;
206}
207
208/* Convert an Unix time to ADFS time for an entry that is already stamped. */
209static void adfs_unix2adfs_time(struct inode *inode,
210				const struct timespec64 *ts)
211{
212	s64 cs, nsec = timespec64_to_ns(ts);
213
214	/* convert from Unix to RISC OS epoch */
215	nsec += nsec_unix_epoch_diff_risc_os_epoch;
216
217	/* convert from nanoseconds to centiseconds */
218	cs = div_s64(nsec, 10000000);
219
220	cs = clamp_t(s64, cs, 0, 0xffffffffff);
221
222	ADFS_I(inode)->loadaddr &= ~0xff;
223	ADFS_I(inode)->loadaddr |= (cs >> 32) & 0xff;
224	ADFS_I(inode)->execaddr = cs;
225}
226
227/*
228 * Fill in the inode information from the object information.
229 *
230 * Note that this is an inode-less filesystem, so we can't use the inode
231 * number to reference the metadata on the media.  Instead, we use the
232 * inode number to hold the object ID, which in turn will tell us where
233 * the data is held.  We also save the parent object ID, and with these
234 * two, we can locate the metadata.
235 *
236 * This does mean that we rely on an objects parent remaining the same at
237 * all times - we cannot cope with a cross-directory rename (yet).
238 */
239struct inode *
240adfs_iget(struct super_block *sb, struct object_info *obj)
241{
242	struct inode *inode;
 
243
244	inode = new_inode(sb);
245	if (!inode)
246		goto out;
247
248	inode->i_uid	 = ADFS_SB(sb)->s_uid;
249	inode->i_gid	 = ADFS_SB(sb)->s_gid;
250	inode->i_ino	 = obj->indaddr;
251	inode->i_size	 = obj->size;
252	set_nlink(inode, 2);
253	inode->i_blocks	 = (inode->i_size + sb->s_blocksize - 1) >>
254			    sb->s_blocksize_bits;
255
256	/*
257	 * we need to save the parent directory ID so that
258	 * write_inode can update the directory information
259	 * for this file.  This will need special handling
260	 * for cross-directory renames.
261	 */
262	ADFS_I(inode)->parent_id = obj->parent_id;
263	ADFS_I(inode)->indaddr   = obj->indaddr;
264	ADFS_I(inode)->loadaddr  = obj->loadaddr;
265	ADFS_I(inode)->execaddr  = obj->execaddr;
266	ADFS_I(inode)->attr      = obj->attr;
267
268	inode->i_mode	 = adfs_atts2mode(sb, inode);
269	adfs_adfs2unix_time(&inode->i_mtime, inode);
270	inode->i_atime = inode->i_mtime;
271	inode->i_ctime = inode->i_mtime;
 
272
273	if (S_ISDIR(inode->i_mode)) {
274		inode->i_op	= &adfs_dir_inode_operations;
275		inode->i_fop	= &adfs_dir_operations;
276	} else if (S_ISREG(inode->i_mode)) {
277		inode->i_op	= &adfs_file_inode_operations;
278		inode->i_fop	= &adfs_file_operations;
279		inode->i_mapping->a_ops = &adfs_aops;
280		ADFS_I(inode)->mmu_private = inode->i_size;
281	}
282
283	inode_fake_hash(inode);
284
285out:
286	return inode;
287}
288
289/*
290 * Validate and convert a changed access mode/time to their ADFS equivalents.
291 * adfs_write_inode will actually write the information back to the directory
292 * later.
293 */
294int
295adfs_notify_change(struct dentry *dentry, struct iattr *attr)
 
296{
297	struct inode *inode = d_inode(dentry);
298	struct super_block *sb = inode->i_sb;
299	unsigned int ia_valid = attr->ia_valid;
300	int error;
301	
302	error = setattr_prepare(dentry, attr);
303
304	/*
305	 * we can't change the UID or GID of any file -
306	 * we have a global UID/GID in the superblock
307	 */
308	if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, ADFS_SB(sb)->s_uid)) ||
309	    (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, ADFS_SB(sb)->s_gid)))
310		error = -EPERM;
311
312	if (error)
313		goto out;
314
315	/* XXX: this is missing some actual on-disk truncation.. */
316	if (ia_valid & ATTR_SIZE)
317		truncate_setsize(inode, attr->ia_size);
318
319	if (ia_valid & ATTR_MTIME && adfs_inode_is_stamped(inode)) {
320		adfs_unix2adfs_time(inode, &attr->ia_mtime);
321		adfs_adfs2unix_time(&inode->i_mtime, inode);
 
322	}
323
324	/*
325	 * FIXME: should we make these == to i_mtime since we don't
326	 * have the ability to represent them in our filesystem?
327	 */
328	if (ia_valid & ATTR_ATIME)
329		inode->i_atime = attr->ia_atime;
330	if (ia_valid & ATTR_CTIME)
331		inode->i_ctime = attr->ia_ctime;
332	if (ia_valid & ATTR_MODE) {
333		ADFS_I(inode)->attr = adfs_mode2atts(sb, inode, attr->ia_mode);
334		inode->i_mode = adfs_atts2mode(sb, inode);
335	}
336
337	/*
338	 * FIXME: should we be marking this inode dirty even if
339	 * we don't have any metadata to write back?
340	 */
341	if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE))
342		mark_inode_dirty(inode);
343out:
344	return error;
345}
346
347/*
348 * write an existing inode back to the directory, and therefore the disk.
349 * The adfs-specific inode data has already been updated by
350 * adfs_notify_change()
351 */
352int adfs_write_inode(struct inode *inode, struct writeback_control *wbc)
353{
354	struct super_block *sb = inode->i_sb;
355	struct object_info obj;
356	int ret;
357
358	obj.indaddr	= ADFS_I(inode)->indaddr;
359	obj.name_len	= 0;
360	obj.parent_id	= ADFS_I(inode)->parent_id;
361	obj.loadaddr	= ADFS_I(inode)->loadaddr;
362	obj.execaddr	= ADFS_I(inode)->execaddr;
363	obj.attr	= ADFS_I(inode)->attr;
364	obj.size	= inode->i_size;
365
366	ret = adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL);
367	return ret;
368}
v6.9.4
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  linux/fs/adfs/inode.c
  4 *
  5 *  Copyright (C) 1997-1999 Russell King
  6 */
  7#include <linux/buffer_head.h>
  8#include <linux/mpage.h>
  9#include <linux/writeback.h>
 10#include "adfs.h"
 11
 12/*
 13 * Lookup/Create a block at offset 'block' into 'inode'.  We currently do
 14 * not support creation of new blocks, so we return -EIO for this case.
 15 */
 16static int
 17adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh,
 18	       int create)
 19{
 20	if (!create) {
 21		if (block >= inode->i_blocks)
 22			goto abort_toobig;
 23
 24		block = __adfs_block_map(inode->i_sb, ADFS_I(inode)->indaddr,
 25					 block);
 26		if (block)
 27			map_bh(bh, inode->i_sb, block);
 28		return 0;
 29	}
 30	/* don't support allocation of blocks yet */
 31	return -EIO;
 32
 33abort_toobig:
 34	return 0;
 35}
 36
 37static int adfs_writepages(struct address_space *mapping,
 38		struct writeback_control *wbc)
 39{
 40	return mpage_writepages(mapping, wbc, adfs_get_block);
 41}
 42
 43static int adfs_read_folio(struct file *file, struct folio *folio)
 44{
 45	return block_read_full_folio(folio, adfs_get_block);
 46}
 47
 48static 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)
 53		truncate_pagecache(inode, inode->i_size);
 54}
 55
 56static int adfs_write_begin(struct file *file, struct address_space *mapping,
 57			loff_t pos, unsigned len,
 58			struct page **pagep, void **fsdata)
 59{
 60	int ret;
 61
 62	*pagep = NULL;
 63	ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata,
 64				adfs_get_block,
 65				&ADFS_I(mapping->host)->mmu_private);
 66	if (unlikely(ret))
 67		adfs_write_failed(mapping, pos + len);
 68
 69	return ret;
 70}
 71
 72static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
 73{
 74	return generic_block_bmap(mapping, block, adfs_get_block);
 75}
 76
 77static const struct address_space_operations adfs_aops = {
 78	.dirty_folio	= block_dirty_folio,
 79	.invalidate_folio = block_invalidate_folio,
 80	.read_folio	= adfs_read_folio,
 81	.writepages	= adfs_writepages,
 82	.write_begin	= adfs_write_begin,
 83	.write_end	= generic_write_end,
 84	.migrate_folio	= buffer_migrate_folio,
 85	.bmap		= _adfs_bmap,
 86};
 87
 88/*
 89 * Convert ADFS attributes and filetype to Linux permission.
 90 */
 91static umode_t
 92adfs_atts2mode(struct super_block *sb, struct inode *inode)
 93{
 94	unsigned int attr = ADFS_I(inode)->attr;
 95	umode_t mode, rmask;
 96	struct adfs_sb_info *asb = ADFS_SB(sb);
 97
 98	if (attr & ADFS_NDA_DIRECTORY) {
 99		mode = S_IRUGO & asb->s_owner_mask;
100		return S_IFDIR | S_IXUGO | mode;
101	}
102
103	switch (adfs_filetype(ADFS_I(inode)->loadaddr)) {
104	case 0xfc0:	/* LinkFS */
105		return S_IFLNK|S_IRWXUGO;
106
107	case 0xfe6:	/* UnixExec */
108		rmask = S_IRUGO | S_IXUGO;
109		break;
110
111	default:
112		rmask = S_IRUGO;
113	}
114
115	mode = S_IFREG;
116
117	if (attr & ADFS_NDA_OWNER_READ)
118		mode |= rmask & asb->s_owner_mask;
119
120	if (attr & ADFS_NDA_OWNER_WRITE)
121		mode |= S_IWUGO & asb->s_owner_mask;
122
123	if (attr & ADFS_NDA_PUBLIC_READ)
124		mode |= rmask & asb->s_other_mask;
125
126	if (attr & ADFS_NDA_PUBLIC_WRITE)
127		mode |= S_IWUGO & asb->s_other_mask;
128	return mode;
129}
130
131/*
132 * Convert Linux permission to ADFS attribute.  We try to do the reverse
133 * of atts2mode, but there is not a 1:1 translation.
134 */
135static int adfs_mode2atts(struct super_block *sb, struct inode *inode,
136			  umode_t ia_mode)
137{
138	struct adfs_sb_info *asb = ADFS_SB(sb);
139	umode_t mode;
140	int attr;
141
142	/* FIXME: should we be able to alter a link? */
143	if (S_ISLNK(inode->i_mode))
144		return ADFS_I(inode)->attr;
145
146	/* Directories do not have read/write permissions on the media */
147	if (S_ISDIR(inode->i_mode))
148		return ADFS_NDA_DIRECTORY;
149
150	attr = 0;
151	mode = ia_mode & asb->s_owner_mask;
152	if (mode & S_IRUGO)
153		attr |= ADFS_NDA_OWNER_READ;
154	if (mode & S_IWUGO)
155		attr |= ADFS_NDA_OWNER_WRITE;
156
157	mode = ia_mode & asb->s_other_mask;
158	mode &= ~asb->s_owner_mask;
159	if (mode & S_IRUGO)
160		attr |= ADFS_NDA_PUBLIC_READ;
161	if (mode & S_IWUGO)
162		attr |= ADFS_NDA_PUBLIC_WRITE;
163
164	return attr;
165}
166
167static const s64 nsec_unix_epoch_diff_risc_os_epoch = 2208988800000000000LL;
168
169/*
170 * Convert an ADFS time to Unix time.  ADFS has a 40-bit centi-second time
171 * referenced to 1 Jan 1900 (til 2248) so we need to discard 2208988800 seconds
172 * of time to convert from RISC OS epoch to Unix epoch.
173 */
174static void
175adfs_adfs2unix_time(struct timespec64 *tv, struct inode *inode)
176{
177	unsigned int high, low;
178	/* 01 Jan 1970 00:00:00 (Unix epoch) as nanoseconds since
179	 * 01 Jan 1900 00:00:00 (RISC OS epoch)
180	 */
181	s64 nsec;
182
183	if (!adfs_inode_is_stamped(inode))
184		goto cur_time;
185
186	high = ADFS_I(inode)->loadaddr & 0xFF; /* top 8 bits of timestamp */
187	low  = ADFS_I(inode)->execaddr;    /* bottom 32 bits of timestamp */
188
189	/* convert 40-bit centi-seconds to 32-bit seconds
190	 * going via nanoseconds to retain precision
191	 */
192	nsec = (((s64) high << 32) | (s64) low) * 10000000; /* cs to ns */
193
194	/* Files dated pre  01 Jan 1970 00:00:00. */
195	if (nsec < nsec_unix_epoch_diff_risc_os_epoch)
196		goto too_early;
197
198	/* convert from RISC OS to Unix epoch */
199	nsec -= nsec_unix_epoch_diff_risc_os_epoch;
200
201	*tv = ns_to_timespec64(nsec);
202	return;
203
204 cur_time:
205	*tv = current_time(inode);
206	return;
207
208 too_early:
209	tv->tv_sec = tv->tv_nsec = 0;
210	return;
211}
212
213/* Convert an Unix time to ADFS time for an entry that is already stamped. */
214static void adfs_unix2adfs_time(struct inode *inode,
215				const struct timespec64 *ts)
216{
217	s64 cs, nsec = timespec64_to_ns(ts);
218
219	/* convert from Unix to RISC OS epoch */
220	nsec += nsec_unix_epoch_diff_risc_os_epoch;
221
222	/* convert from nanoseconds to centiseconds */
223	cs = div_s64(nsec, 10000000);
224
225	cs = clamp_t(s64, cs, 0, 0xffffffffff);
226
227	ADFS_I(inode)->loadaddr &= ~0xff;
228	ADFS_I(inode)->loadaddr |= (cs >> 32) & 0xff;
229	ADFS_I(inode)->execaddr = cs;
230}
231
232/*
233 * Fill in the inode information from the object information.
234 *
235 * Note that this is an inode-less filesystem, so we can't use the inode
236 * number to reference the metadata on the media.  Instead, we use the
237 * inode number to hold the object ID, which in turn will tell us where
238 * the data is held.  We also save the parent object ID, and with these
239 * two, we can locate the metadata.
240 *
241 * This does mean that we rely on an objects parent remaining the same at
242 * all times - we cannot cope with a cross-directory rename (yet).
243 */
244struct inode *
245adfs_iget(struct super_block *sb, struct object_info *obj)
246{
247	struct inode *inode;
248	struct timespec64 ts;
249
250	inode = new_inode(sb);
251	if (!inode)
252		goto out;
253
254	inode->i_uid	 = ADFS_SB(sb)->s_uid;
255	inode->i_gid	 = ADFS_SB(sb)->s_gid;
256	inode->i_ino	 = obj->indaddr;
257	inode->i_size	 = obj->size;
258	set_nlink(inode, 2);
259	inode->i_blocks	 = (inode->i_size + sb->s_blocksize - 1) >>
260			    sb->s_blocksize_bits;
261
262	/*
263	 * we need to save the parent directory ID so that
264	 * write_inode can update the directory information
265	 * for this file.  This will need special handling
266	 * for cross-directory renames.
267	 */
268	ADFS_I(inode)->parent_id = obj->parent_id;
269	ADFS_I(inode)->indaddr   = obj->indaddr;
270	ADFS_I(inode)->loadaddr  = obj->loadaddr;
271	ADFS_I(inode)->execaddr  = obj->execaddr;
272	ADFS_I(inode)->attr      = obj->attr;
273
274	inode->i_mode	 = adfs_atts2mode(sb, inode);
275	adfs_adfs2unix_time(&ts, inode);
276	inode_set_atime_to_ts(inode, ts);
277	inode_set_mtime_to_ts(inode, ts);
278	inode_set_ctime_to_ts(inode, ts);
279
280	if (S_ISDIR(inode->i_mode)) {
281		inode->i_op	= &adfs_dir_inode_operations;
282		inode->i_fop	= &adfs_dir_operations;
283	} else if (S_ISREG(inode->i_mode)) {
284		inode->i_op	= &adfs_file_inode_operations;
285		inode->i_fop	= &adfs_file_operations;
286		inode->i_mapping->a_ops = &adfs_aops;
287		ADFS_I(inode)->mmu_private = inode->i_size;
288	}
289
290	inode_fake_hash(inode);
291
292out:
293	return inode;
294}
295
296/*
297 * Validate and convert a changed access mode/time to their ADFS equivalents.
298 * adfs_write_inode will actually write the information back to the directory
299 * later.
300 */
301int
302adfs_notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
303		   struct iattr *attr)
304{
305	struct inode *inode = d_inode(dentry);
306	struct super_block *sb = inode->i_sb;
307	unsigned int ia_valid = attr->ia_valid;
308	int error;
309	
310	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
311
312	/*
313	 * we can't change the UID or GID of any file -
314	 * we have a global UID/GID in the superblock
315	 */
316	if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, ADFS_SB(sb)->s_uid)) ||
317	    (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, ADFS_SB(sb)->s_gid)))
318		error = -EPERM;
319
320	if (error)
321		goto out;
322
323	/* XXX: this is missing some actual on-disk truncation.. */
324	if (ia_valid & ATTR_SIZE)
325		truncate_setsize(inode, attr->ia_size);
326
327	if (ia_valid & ATTR_MTIME && adfs_inode_is_stamped(inode)) {
328		adfs_unix2adfs_time(inode, &attr->ia_mtime);
329		adfs_adfs2unix_time(&attr->ia_mtime, inode);
330		inode_set_mtime_to_ts(inode, attr->ia_mtime);
331	}
332
333	/*
334	 * FIXME: should we make these == to i_mtime since we don't
335	 * have the ability to represent them in our filesystem?
336	 */
337	if (ia_valid & ATTR_ATIME)
338		inode_set_atime_to_ts(inode, attr->ia_atime);
339	if (ia_valid & ATTR_CTIME)
340		inode_set_ctime_to_ts(inode, attr->ia_ctime);
341	if (ia_valid & ATTR_MODE) {
342		ADFS_I(inode)->attr = adfs_mode2atts(sb, inode, attr->ia_mode);
343		inode->i_mode = adfs_atts2mode(sb, inode);
344	}
345
346	/*
347	 * FIXME: should we be marking this inode dirty even if
348	 * we don't have any metadata to write back?
349	 */
350	if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE))
351		mark_inode_dirty(inode);
352out:
353	return error;
354}
355
356/*
357 * write an existing inode back to the directory, and therefore the disk.
358 * The adfs-specific inode data has already been updated by
359 * adfs_notify_change()
360 */
361int adfs_write_inode(struct inode *inode, struct writeback_control *wbc)
362{
363	struct super_block *sb = inode->i_sb;
364	struct object_info obj;
 
365
366	obj.indaddr	= ADFS_I(inode)->indaddr;
367	obj.name_len	= 0;
368	obj.parent_id	= ADFS_I(inode)->parent_id;
369	obj.loadaddr	= ADFS_I(inode)->loadaddr;
370	obj.execaddr	= ADFS_I(inode)->execaddr;
371	obj.attr	= ADFS_I(inode)->attr;
372	obj.size	= inode->i_size;
373
374	return adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL);
 
375}