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> |
a9185b41 | 8 | #include <linux/writeback.h> |
1da177e4 LT |
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 | */ | |
15 | static int | |
16 | adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh, | |
17 | int create) | |
18 | { | |
1da177e4 LT |
19 | if (!create) { |
20 | if (block >= inode->i_blocks) | |
21 | goto abort_toobig; | |
22 | ||
25e5d4df RK |
23 | block = __adfs_block_map(inode->i_sb, ADFS_I(inode)->indaddr, |
24 | block); | |
1da177e4 LT |
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 | ||
1da177e4 LT |
32 | abort_toobig: |
33 | return 0; | |
34 | } | |
35 | ||
36 | static int adfs_writepage(struct page *page, struct writeback_control *wbc) | |
37 | { | |
38 | return block_write_full_page(page, adfs_get_block, wbc); | |
39 | } | |
40 | ||
41 | static int adfs_readpage(struct file *file, struct page *page) | |
42 | { | |
43 | return block_read_full_page(page, adfs_get_block); | |
44 | } | |
45 | ||
62295183 MS |
46 | static 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) | |
7caef267 | 51 | truncate_pagecache(inode, inode->i_size); |
62295183 MS |
52 | } |
53 | ||
b4585729 NP |
54 | static 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) | |
1da177e4 | 57 | { |
282dc178 CH |
58 | int ret; |
59 | ||
b4585729 | 60 | *pagep = NULL; |
282dc178 | 61 | ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, |
b4585729 NP |
62 | adfs_get_block, |
63 | &ADFS_I(mapping->host)->mmu_private); | |
62295183 MS |
64 | if (unlikely(ret)) |
65 | adfs_write_failed(mapping, pos + len); | |
282dc178 CH |
66 | |
67 | return ret; | |
1da177e4 LT |
68 | } |
69 | ||
70 | static sector_t _adfs_bmap(struct address_space *mapping, sector_t block) | |
71 | { | |
72 | return generic_block_bmap(mapping, block, adfs_get_block); | |
73 | } | |
74 | ||
f5e54d6e | 75 | static const struct address_space_operations adfs_aops = { |
0af57378 | 76 | .set_page_dirty = __set_page_dirty_buffers, |
1da177e4 LT |
77 | .readpage = adfs_readpage, |
78 | .writepage = adfs_writepage, | |
b4585729 NP |
79 | .write_begin = adfs_write_begin, |
80 | .write_end = generic_write_end, | |
1da177e4 LT |
81 | .bmap = _adfs_bmap |
82 | }; | |
83 | ||
1da177e4 LT |
84 | /* |
85 | * Convert ADFS attributes and filetype to Linux permission. | |
86 | */ | |
87 | static umode_t | |
88 | adfs_atts2mode(struct super_block *sb, struct inode *inode) | |
89 | { | |
da23ef05 | 90 | unsigned int attr = ADFS_I(inode)->attr; |
1da177e4 LT |
91 | umode_t mode, rmask; |
92 | struct adfs_sb_info *asb = ADFS_SB(sb); | |
93 | ||
94 | if (attr & ADFS_NDA_DIRECTORY) { | |
95 | mode = S_IRUGO & asb->s_owner_mask; | |
96 | return S_IFDIR | S_IXUGO | mode; | |
97 | } | |
98 | ||
b4ed8f75 | 99 | switch (adfs_filetype(ADFS_I(inode)->loadaddr)) { |
1da177e4 LT |
100 | case 0xfc0: /* LinkFS */ |
101 | return S_IFLNK|S_IRWXUGO; | |
102 | ||
103 | case 0xfe6: /* UnixExec */ | |
104 | rmask = S_IRUGO | S_IXUGO; | |
105 | break; | |
106 | ||
107 | default: | |
108 | rmask = S_IRUGO; | |
109 | } | |
110 | ||
111 | mode = S_IFREG; | |
112 | ||
113 | if (attr & ADFS_NDA_OWNER_READ) | |
114 | mode |= rmask & asb->s_owner_mask; | |
115 | ||
116 | if (attr & ADFS_NDA_OWNER_WRITE) | |
117 | mode |= S_IWUGO & asb->s_owner_mask; | |
118 | ||
119 | if (attr & ADFS_NDA_PUBLIC_READ) | |
120 | mode |= rmask & asb->s_other_mask; | |
121 | ||
122 | if (attr & ADFS_NDA_PUBLIC_WRITE) | |
123 | mode |= S_IWUGO & asb->s_other_mask; | |
124 | return mode; | |
125 | } | |
126 | ||
127 | /* | |
128 | * Convert Linux permission to ADFS attribute. We try to do the reverse | |
129 | * of atts2mode, but there is not a 1:1 translation. | |
130 | */ | |
81916245 RK |
131 | static int adfs_mode2atts(struct super_block *sb, struct inode *inode, |
132 | umode_t ia_mode) | |
1da177e4 | 133 | { |
81916245 | 134 | struct adfs_sb_info *asb = ADFS_SB(sb); |
1da177e4 LT |
135 | umode_t mode; |
136 | int attr; | |
1da177e4 LT |
137 | |
138 | /* FIXME: should we be able to alter a link? */ | |
139 | if (S_ISLNK(inode->i_mode)) | |
140 | return ADFS_I(inode)->attr; | |
141 | ||
81916245 | 142 | /* Directories do not have read/write permissions on the media */ |
1da177e4 | 143 | if (S_ISDIR(inode->i_mode)) |
81916245 | 144 | return ADFS_NDA_DIRECTORY; |
1da177e4 | 145 | |
81916245 RK |
146 | attr = 0; |
147 | mode = ia_mode & asb->s_owner_mask; | |
1da177e4 LT |
148 | if (mode & S_IRUGO) |
149 | attr |= ADFS_NDA_OWNER_READ; | |
150 | if (mode & S_IWUGO) | |
151 | attr |= ADFS_NDA_OWNER_WRITE; | |
152 | ||
81916245 | 153 | mode = ia_mode & asb->s_other_mask; |
1da177e4 LT |
154 | mode &= ~asb->s_owner_mask; |
155 | if (mode & S_IRUGO) | |
156 | attr |= ADFS_NDA_PUBLIC_READ; | |
157 | if (mode & S_IWUGO) | |
158 | attr |= ADFS_NDA_PUBLIC_WRITE; | |
159 | ||
160 | return attr; | |
161 | } | |
162 | ||
eeeb9dd9 RK |
163 | static const s64 nsec_unix_epoch_diff_risc_os_epoch = 2208988800000000000LL; |
164 | ||
1da177e4 LT |
165 | /* |
166 | * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time | |
7a9730af SS |
167 | * referenced to 1 Jan 1900 (til 2248) so we need to discard 2208988800 seconds |
168 | * of time to convert from RISC OS epoch to Unix epoch. | |
1da177e4 LT |
169 | */ |
170 | static void | |
d9edcbc4 | 171 | adfs_adfs2unix_time(struct timespec64 *tv, struct inode *inode) |
1da177e4 LT |
172 | { |
173 | unsigned int high, low; | |
7a9730af SS |
174 | /* 01 Jan 1970 00:00:00 (Unix epoch) as nanoseconds since |
175 | * 01 Jan 1900 00:00:00 (RISC OS epoch) | |
176 | */ | |
7a9730af | 177 | s64 nsec; |
1da177e4 | 178 | |
b4ed8f75 | 179 | if (!adfs_inode_is_stamped(inode)) |
1da177e4 LT |
180 | goto cur_time; |
181 | ||
7a9730af SS |
182 | high = ADFS_I(inode)->loadaddr & 0xFF; /* top 8 bits of timestamp */ |
183 | low = ADFS_I(inode)->execaddr; /* bottom 32 bits of timestamp */ | |
1da177e4 | 184 | |
7a9730af SS |
185 | /* convert 40-bit centi-seconds to 32-bit seconds |
186 | * going via nanoseconds to retain precision | |
187 | */ | |
188 | nsec = (((s64) high << 32) | (s64) low) * 10000000; /* cs to ns */ | |
1da177e4 LT |
189 | |
190 | /* Files dated pre 01 Jan 1970 00:00:00. */ | |
7a9730af | 191 | if (nsec < nsec_unix_epoch_diff_risc_os_epoch) |
1da177e4 LT |
192 | goto too_early; |
193 | ||
7a9730af SS |
194 | /* convert from RISC OS to Unix epoch */ |
195 | nsec -= nsec_unix_epoch_diff_risc_os_epoch; | |
1da177e4 | 196 | |
d9edcbc4 | 197 | *tv = ns_to_timespec64(nsec); |
1da177e4 LT |
198 | return; |
199 | ||
200 | cur_time: | |
d9edcbc4 | 201 | *tv = current_time(inode); |
1da177e4 LT |
202 | return; |
203 | ||
204 | too_early: | |
205 | tv->tv_sec = tv->tv_nsec = 0; | |
206 | return; | |
1da177e4 LT |
207 | } |
208 | ||
eeeb9dd9 RK |
209 | /* Convert an Unix time to ADFS time for an entry that is already stamped. */ |
210 | static void adfs_unix2adfs_time(struct inode *inode, | |
211 | const struct timespec64 *ts) | |
1da177e4 | 212 | { |
eeeb9dd9 | 213 | s64 cs, nsec = timespec64_to_ns(ts); |
1da177e4 | 214 | |
eeeb9dd9 RK |
215 | /* convert from Unix to RISC OS epoch */ |
216 | nsec += nsec_unix_epoch_diff_risc_os_epoch; | |
1da177e4 | 217 | |
eeeb9dd9 RK |
218 | /* convert from nanoseconds to centiseconds */ |
219 | cs = div_s64(nsec, 10000000); | |
220 | ||
221 | cs = clamp_t(s64, cs, 0, 0xffffffffff); | |
222 | ||
223 | ADFS_I(inode)->loadaddr &= ~0xff; | |
224 | ADFS_I(inode)->loadaddr |= (cs >> 32) & 0xff; | |
225 | ADFS_I(inode)->execaddr = cs; | |
1da177e4 LT |
226 | } |
227 | ||
228 | /* | |
229 | * Fill in the inode information from the object information. | |
230 | * | |
231 | * Note that this is an inode-less filesystem, so we can't use the inode | |
232 | * number to reference the metadata on the media. Instead, we use the | |
233 | * inode number to hold the object ID, which in turn will tell us where | |
234 | * the data is held. We also save the parent object ID, and with these | |
235 | * two, we can locate the metadata. | |
236 | * | |
237 | * This does mean that we rely on an objects parent remaining the same at | |
238 | * all times - we cannot cope with a cross-directory rename (yet). | |
239 | */ | |
240 | struct inode * | |
241 | adfs_iget(struct super_block *sb, struct object_info *obj) | |
242 | { | |
243 | struct inode *inode; | |
244 | ||
245 | inode = new_inode(sb); | |
246 | if (!inode) | |
247 | goto out; | |
248 | ||
249 | inode->i_uid = ADFS_SB(sb)->s_uid; | |
250 | inode->i_gid = ADFS_SB(sb)->s_gid; | |
5ed70bb4 | 251 | inode->i_ino = obj->indaddr; |
1da177e4 | 252 | inode->i_size = obj->size; |
bfe86848 | 253 | set_nlink(inode, 2); |
1da177e4 LT |
254 | inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >> |
255 | sb->s_blocksize_bits; | |
256 | ||
257 | /* | |
258 | * we need to save the parent directory ID so that | |
259 | * write_inode can update the directory information | |
260 | * for this file. This will need special handling | |
261 | * for cross-directory renames. | |
262 | */ | |
263 | ADFS_I(inode)->parent_id = obj->parent_id; | |
25e5d4df | 264 | ADFS_I(inode)->indaddr = obj->indaddr; |
1da177e4 LT |
265 | ADFS_I(inode)->loadaddr = obj->loadaddr; |
266 | ADFS_I(inode)->execaddr = obj->execaddr; | |
267 | ADFS_I(inode)->attr = obj->attr; | |
1da177e4 LT |
268 | |
269 | inode->i_mode = adfs_atts2mode(sb, inode); | |
d9edcbc4 | 270 | adfs_adfs2unix_time(&inode->i_mtime, inode); |
1da177e4 LT |
271 | inode->i_atime = inode->i_mtime; |
272 | inode->i_ctime = inode->i_mtime; | |
273 | ||
274 | if (S_ISDIR(inode->i_mode)) { | |
275 | inode->i_op = &adfs_dir_inode_operations; | |
276 | inode->i_fop = &adfs_dir_operations; | |
277 | } else if (S_ISREG(inode->i_mode)) { | |
278 | inode->i_op = &adfs_file_inode_operations; | |
279 | inode->i_fop = &adfs_file_operations; | |
280 | inode->i_mapping->a_ops = &adfs_aops; | |
281 | ADFS_I(inode)->mmu_private = inode->i_size; | |
282 | } | |
283 | ||
d8e78da8 | 284 | inode_fake_hash(inode); |
1da177e4 LT |
285 | |
286 | out: | |
287 | return inode; | |
288 | } | |
289 | ||
290 | /* | |
291 | * Validate and convert a changed access mode/time to their ADFS equivalents. | |
292 | * adfs_write_inode will actually write the information back to the directory | |
293 | * later. | |
294 | */ | |
295 | int | |
549c7297 CB |
296 | adfs_notify_change(struct user_namespace *mnt_userns, struct dentry *dentry, |
297 | struct iattr *attr) | |
1da177e4 | 298 | { |
2b0143b5 | 299 | struct inode *inode = d_inode(dentry); |
1da177e4 LT |
300 | struct super_block *sb = inode->i_sb; |
301 | unsigned int ia_valid = attr->ia_valid; | |
302 | int error; | |
303 | ||
2f221d6f | 304 | error = setattr_prepare(&init_user_ns, dentry, attr); |
1da177e4 LT |
305 | |
306 | /* | |
307 | * we can't change the UID or GID of any file - | |
308 | * we have a global UID/GID in the superblock | |
309 | */ | |
c010d1ff EB |
310 | if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, ADFS_SB(sb)->s_uid)) || |
311 | (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, ADFS_SB(sb)->s_gid))) | |
1da177e4 LT |
312 | error = -EPERM; |
313 | ||
314 | if (error) | |
315 | goto out; | |
316 | ||
15c6fd97 | 317 | /* XXX: this is missing some actual on-disk truncation.. */ |
1da177e4 | 318 | if (ia_valid & ATTR_SIZE) |
2c27c65e | 319 | truncate_setsize(inode, attr->ia_size); |
1da177e4 | 320 | |
eeeb9dd9 RK |
321 | if (ia_valid & ATTR_MTIME && adfs_inode_is_stamped(inode)) { |
322 | adfs_unix2adfs_time(inode, &attr->ia_mtime); | |
323 | adfs_adfs2unix_time(&inode->i_mtime, inode); | |
1da177e4 | 324 | } |
eeeb9dd9 | 325 | |
1da177e4 LT |
326 | /* |
327 | * FIXME: should we make these == to i_mtime since we don't | |
328 | * have the ability to represent them in our filesystem? | |
329 | */ | |
330 | if (ia_valid & ATTR_ATIME) | |
331 | inode->i_atime = attr->ia_atime; | |
332 | if (ia_valid & ATTR_CTIME) | |
333 | inode->i_ctime = attr->ia_ctime; | |
334 | if (ia_valid & ATTR_MODE) { | |
81916245 | 335 | ADFS_I(inode)->attr = adfs_mode2atts(sb, inode, attr->ia_mode); |
1da177e4 LT |
336 | inode->i_mode = adfs_atts2mode(sb, inode); |
337 | } | |
338 | ||
339 | /* | |
340 | * FIXME: should we be marking this inode dirty even if | |
341 | * we don't have any metadata to write back? | |
342 | */ | |
343 | if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE)) | |
344 | mark_inode_dirty(inode); | |
345 | out: | |
1da177e4 LT |
346 | return error; |
347 | } | |
348 | ||
349 | /* | |
350 | * write an existing inode back to the directory, and therefore the disk. | |
351 | * The adfs-specific inode data has already been updated by | |
352 | * adfs_notify_change() | |
353 | */ | |
a9185b41 | 354 | int adfs_write_inode(struct inode *inode, struct writeback_control *wbc) |
1da177e4 LT |
355 | { |
356 | struct super_block *sb = inode->i_sb; | |
357 | struct object_info obj; | |
1da177e4 | 358 | |
25e5d4df | 359 | obj.indaddr = ADFS_I(inode)->indaddr; |
1da177e4 LT |
360 | obj.name_len = 0; |
361 | obj.parent_id = ADFS_I(inode)->parent_id; | |
362 | obj.loadaddr = ADFS_I(inode)->loadaddr; | |
363 | obj.execaddr = ADFS_I(inode)->execaddr; | |
364 | obj.attr = ADFS_I(inode)->attr; | |
365 | obj.size = inode->i_size; | |
366 | ||
25d2e886 | 367 | return adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL); |
1da177e4 | 368 | } |