Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/fs/adfs/inode.c | |
4 | * | |
5 | * Copyright (C) 1997-1999 Russell King | |
1da177e4 | 6 | */ |
1da177e4 | 7 | #include <linux/buffer_head.h> |
81d469d3 | 8 | #include <linux/mpage.h> |
a9185b41 | 9 | #include <linux/writeback.h> |
1da177e4 LT |
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 | */ | |
16 | static int | |
17 | adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh, | |
18 | int create) | |
19 | { | |
1da177e4 LT |
20 | if (!create) { |
21 | if (block >= inode->i_blocks) | |
22 | goto abort_toobig; | |
23 | ||
25e5d4df RK |
24 | block = __adfs_block_map(inode->i_sb, ADFS_I(inode)->indaddr, |
25 | block); | |
1da177e4 LT |
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 | ||
1da177e4 LT |
33 | abort_toobig: |
34 | return 0; | |
35 | } | |
36 | ||
81d469d3 MWO |
37 | static int adfs_writepages(struct address_space *mapping, |
38 | struct writeback_control *wbc) | |
1da177e4 | 39 | { |
81d469d3 | 40 | return mpage_writepages(mapping, wbc, adfs_get_block); |
1da177e4 LT |
41 | } |
42 | ||
2c69e205 | 43 | static int adfs_read_folio(struct file *file, struct folio *folio) |
1da177e4 | 44 | { |
2c69e205 | 45 | return block_read_full_folio(folio, adfs_get_block); |
1da177e4 LT |
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 | } |
55 | ||
b4585729 | 56 | static int adfs_write_begin(struct file *file, struct address_space *mapping, |
9d6b0cd7 | 57 | loff_t pos, unsigned len, |
b4585729 | 58 | struct page **pagep, void **fsdata) |
1da177e4 | 59 | { |
282dc178 CH |
60 | int ret; |
61 | ||
b4585729 | 62 | *pagep = NULL; |
be3bbbc5 | 63 | ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata, |
b4585729 NP |
64 | adfs_get_block, |
65 | &ADFS_I(mapping->host)->mmu_private); | |
62295183 MS |
66 | if (unlikely(ret)) |
67 | adfs_write_failed(mapping, pos + len); | |
282dc178 CH |
68 | |
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 = { |
e621900a | 78 | .dirty_folio = block_dirty_folio, |
7ba13abb | 79 | .invalidate_folio = block_invalidate_folio, |
2c69e205 | 80 | .read_folio = adfs_read_folio, |
81d469d3 | 81 | .writepages = adfs_writepages, |
b4585729 NP |
82 | .write_begin = adfs_write_begin, |
83 | .write_end = generic_write_end, | |
81d469d3 MWO |
84 | .migrate_folio = buffer_migrate_folio, |
85 | .bmap = _adfs_bmap, | |
1da177e4 LT |
86 | }; |
87 | ||
1da177e4 LT |
88 | /* |
89 | * Convert ADFS attributes and filetype to Linux permission. | |
90 | */ | |
91 | static umode_t | |
92 | adfs_atts2mode(struct super_block *sb, struct inode *inode) | |
93 | { | |
da23ef05 | 94 | unsigned int attr = ADFS_I(inode)->attr; |
1da177e4 LT |
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 | ||
b4ed8f75 | 103 | switch (adfs_filetype(ADFS_I(inode)->loadaddr)) { |
1da177e4 LT |
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 | */ | |
81916245 RK |
135 | static int adfs_mode2atts(struct super_block *sb, struct inode *inode, |
136 | umode_t ia_mode) | |
1da177e4 | 137 | { |
81916245 | 138 | struct adfs_sb_info *asb = ADFS_SB(sb); |
1da177e4 LT |
139 | umode_t mode; |
140 | int attr; | |
1da177e4 LT |
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 | ||
81916245 | 146 | /* Directories do not have read/write permissions on the media */ |
1da177e4 | 147 | if (S_ISDIR(inode->i_mode)) |
81916245 | 148 | return ADFS_NDA_DIRECTORY; |
1da177e4 | 149 | |
81916245 RK |
150 | attr = 0; |
151 | mode = ia_mode & asb->s_owner_mask; | |
1da177e4 LT |
152 | if (mode & S_IRUGO) |
153 | attr |= ADFS_NDA_OWNER_READ; | |
154 | if (mode & S_IWUGO) | |
155 | attr |= ADFS_NDA_OWNER_WRITE; | |
156 | ||
81916245 | 157 | mode = ia_mode & asb->s_other_mask; |
1da177e4 LT |
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 | ||
eeeb9dd9 RK |
167 | static const s64 nsec_unix_epoch_diff_risc_os_epoch = 2208988800000000000LL; |
168 | ||
1da177e4 LT |
169 | /* |
170 | * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time | |
7a9730af SS |
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. | |
1da177e4 LT |
173 | */ |
174 | static void | |
d9edcbc4 | 175 | adfs_adfs2unix_time(struct timespec64 *tv, struct inode *inode) |
1da177e4 LT |
176 | { |
177 | unsigned int high, low; | |
7a9730af SS |
178 | /* 01 Jan 1970 00:00:00 (Unix epoch) as nanoseconds since |
179 | * 01 Jan 1900 00:00:00 (RISC OS epoch) | |
180 | */ | |
7a9730af | 181 | s64 nsec; |
1da177e4 | 182 | |
b4ed8f75 | 183 | if (!adfs_inode_is_stamped(inode)) |
1da177e4 LT |
184 | goto cur_time; |
185 | ||
7a9730af SS |
186 | high = ADFS_I(inode)->loadaddr & 0xFF; /* top 8 bits of timestamp */ |
187 | low = ADFS_I(inode)->execaddr; /* bottom 32 bits of timestamp */ | |
1da177e4 | 188 | |
7a9730af SS |
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 */ | |
1da177e4 LT |
193 | |
194 | /* Files dated pre 01 Jan 1970 00:00:00. */ | |
7a9730af | 195 | if (nsec < nsec_unix_epoch_diff_risc_os_epoch) |
1da177e4 LT |
196 | goto too_early; |
197 | ||
7a9730af SS |
198 | /* convert from RISC OS to Unix epoch */ |
199 | nsec -= nsec_unix_epoch_diff_risc_os_epoch; | |
1da177e4 | 200 | |
d9edcbc4 | 201 | *tv = ns_to_timespec64(nsec); |
1da177e4 LT |
202 | return; |
203 | ||
204 | cur_time: | |
d9edcbc4 | 205 | *tv = current_time(inode); |
1da177e4 LT |
206 | return; |
207 | ||
208 | too_early: | |
209 | tv->tv_sec = tv->tv_nsec = 0; | |
210 | return; | |
1da177e4 LT |
211 | } |
212 | ||
eeeb9dd9 RK |
213 | /* Convert an Unix time to ADFS time for an entry that is already stamped. */ |
214 | static void adfs_unix2adfs_time(struct inode *inode, | |
215 | const struct timespec64 *ts) | |
1da177e4 | 216 | { |
eeeb9dd9 | 217 | s64 cs, nsec = timespec64_to_ns(ts); |
1da177e4 | 218 | |
eeeb9dd9 RK |
219 | /* convert from Unix to RISC OS epoch */ |
220 | nsec += nsec_unix_epoch_diff_risc_os_epoch; | |
1da177e4 | 221 | |
eeeb9dd9 RK |
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; | |
1da177e4 LT |
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 | */ | |
244 | struct inode * | |
245 | adfs_iget(struct super_block *sb, struct object_info *obj) | |
246 | { | |
247 | struct inode *inode; | |
ca9649e9 | 248 | struct timespec64 ts; |
1da177e4 LT |
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; | |
5ed70bb4 | 256 | inode->i_ino = obj->indaddr; |
1da177e4 | 257 | inode->i_size = obj->size; |
bfe86848 | 258 | set_nlink(inode, 2); |
1da177e4 LT |
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; | |
25e5d4df | 269 | ADFS_I(inode)->indaddr = obj->indaddr; |
1da177e4 LT |
270 | ADFS_I(inode)->loadaddr = obj->loadaddr; |
271 | ADFS_I(inode)->execaddr = obj->execaddr; | |
272 | ADFS_I(inode)->attr = obj->attr; | |
1da177e4 LT |
273 | |
274 | inode->i_mode = adfs_atts2mode(sb, inode); | |
ca9649e9 JL |
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); | |
1da177e4 LT |
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 | ||
d8e78da8 | 290 | inode_fake_hash(inode); |
1da177e4 LT |
291 | |
292 | out: | |
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 | */ | |
301 | int | |
c1632a0f | 302 | adfs_notify_change(struct mnt_idmap *idmap, struct dentry *dentry, |
549c7297 | 303 | struct iattr *attr) |
1da177e4 | 304 | { |
2b0143b5 | 305 | struct inode *inode = d_inode(dentry); |
1da177e4 LT |
306 | struct super_block *sb = inode->i_sb; |
307 | unsigned int ia_valid = attr->ia_valid; | |
308 | int error; | |
309 | ||
c1632a0f | 310 | error = setattr_prepare(&nop_mnt_idmap, dentry, attr); |
1da177e4 LT |
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 | */ | |
c010d1ff EB |
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))) | |
1da177e4 LT |
318 | error = -EPERM; |
319 | ||
320 | if (error) | |
321 | goto out; | |
322 | ||
15c6fd97 | 323 | /* XXX: this is missing some actual on-disk truncation.. */ |
1da177e4 | 324 | if (ia_valid & ATTR_SIZE) |
2c27c65e | 325 | truncate_setsize(inode, attr->ia_size); |
1da177e4 | 326 | |
eeeb9dd9 RK |
327 | if (ia_valid & ATTR_MTIME && adfs_inode_is_stamped(inode)) { |
328 | adfs_unix2adfs_time(inode, &attr->ia_mtime); | |
ca9649e9 JL |
329 | adfs_adfs2unix_time(&attr->ia_mtime, inode); |
330 | inode_set_mtime_to_ts(inode, attr->ia_mtime); | |
1da177e4 | 331 | } |
eeeb9dd9 | 332 | |
1da177e4 LT |
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) | |
ca9649e9 | 338 | inode_set_atime_to_ts(inode, attr->ia_atime); |
1da177e4 | 339 | if (ia_valid & ATTR_CTIME) |
96894147 | 340 | inode_set_ctime_to_ts(inode, attr->ia_ctime); |
1da177e4 | 341 | if (ia_valid & ATTR_MODE) { |
81916245 | 342 | ADFS_I(inode)->attr = adfs_mode2atts(sb, inode, attr->ia_mode); |
1da177e4 LT |
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); | |
352 | out: | |
1da177e4 LT |
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 | */ | |
a9185b41 | 361 | int adfs_write_inode(struct inode *inode, struct writeback_control *wbc) |
1da177e4 LT |
362 | { |
363 | struct super_block *sb = inode->i_sb; | |
364 | struct object_info obj; | |
1da177e4 | 365 | |
25e5d4df | 366 | obj.indaddr = ADFS_I(inode)->indaddr; |
1da177e4 LT |
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 | ||
25d2e886 | 374 | return adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL); |
1da177e4 | 375 | } |