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 | } |
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; |
61 | ||
b4585729 | 62 | *pagep = NULL; |
282dc178 | 63 | ret = cont_write_begin(file, mapping, pos, len, flags, 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 = { |
1da177e4 LT |
78 | .readpage = adfs_readpage, |
79 | .writepage = adfs_writepage, | |
b4585729 NP |
80 | .write_begin = adfs_write_begin, |
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 |
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 */ |
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 | |
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; |
194 | ||
7a9730af SS |
195 | /* convert from RISC OS to Unix epoch */ |
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: | |
95582b00 | 202 | *tv = timespec64_to_timespec(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 | { | |
95582b00 | 245 | struct timespec ts; |
1da177e4 LT |
246 | struct inode *inode; |
247 | ||
248 | inode = new_inode(sb); | |
249 | if (!inode) | |
250 | goto out; | |
251 | ||
252 | inode->i_uid = ADFS_SB(sb)->s_uid; | |
253 | inode->i_gid = ADFS_SB(sb)->s_gid; | |
254 | inode->i_ino = obj->file_id; | |
255 | inode->i_size = obj->size; | |
bfe86848 | 256 | set_nlink(inode, 2); |
1da177e4 LT |
257 | inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >> |
258 | sb->s_blocksize_bits; | |
259 | ||
260 | /* | |
261 | * we need to save the parent directory ID so that | |
262 | * write_inode can update the directory information | |
263 | * for this file. This will need special handling | |
264 | * for cross-directory renames. | |
265 | */ | |
266 | ADFS_I(inode)->parent_id = obj->parent_id; | |
267 | ADFS_I(inode)->loadaddr = obj->loadaddr; | |
268 | ADFS_I(inode)->execaddr = obj->execaddr; | |
269 | ADFS_I(inode)->attr = obj->attr; | |
da23ef05 SS |
270 | ADFS_I(inode)->filetype = obj->filetype; |
271 | ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000); | |
1da177e4 LT |
272 | |
273 | inode->i_mode = adfs_atts2mode(sb, inode); | |
95582b00 DD |
274 | ts = timespec64_to_timespec(inode->i_mtime); |
275 | adfs_adfs2unix_time(&ts, inode); | |
276 | inode->i_mtime = timespec_to_timespec64(ts); | |
1da177e4 LT |
277 | inode->i_atime = inode->i_mtime; |
278 | inode->i_ctime = inode->i_mtime; | |
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 | insert_inode_hash(inode); | |
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 | |
302 | adfs_notify_change(struct dentry *dentry, struct iattr *attr) | |
303 | { | |
2b0143b5 | 304 | struct inode *inode = d_inode(dentry); |
1da177e4 LT |
305 | struct super_block *sb = inode->i_sb; |
306 | unsigned int ia_valid = attr->ia_valid; | |
307 | int error; | |
308 | ||
31051c85 | 309 | error = setattr_prepare(dentry, attr); |
1da177e4 LT |
310 | |
311 | /* | |
312 | * we can't change the UID or GID of any file - | |
313 | * we have a global UID/GID in the superblock | |
314 | */ | |
c010d1ff EB |
315 | if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, ADFS_SB(sb)->s_uid)) || |
316 | (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, ADFS_SB(sb)->s_gid))) | |
1da177e4 LT |
317 | error = -EPERM; |
318 | ||
319 | if (error) | |
320 | goto out; | |
321 | ||
15c6fd97 | 322 | /* XXX: this is missing some actual on-disk truncation.. */ |
1da177e4 | 323 | if (ia_valid & ATTR_SIZE) |
2c27c65e | 324 | truncate_setsize(inode, attr->ia_size); |
1da177e4 LT |
325 | |
326 | if (ia_valid & ATTR_MTIME) { | |
327 | inode->i_mtime = attr->ia_mtime; | |
328 | adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec); | |
329 | } | |
330 | /* | |
331 | * FIXME: should we make these == to i_mtime since we don't | |
332 | * have the ability to represent them in our filesystem? | |
333 | */ | |
334 | if (ia_valid & ATTR_ATIME) | |
335 | inode->i_atime = attr->ia_atime; | |
336 | if (ia_valid & ATTR_CTIME) | |
337 | inode->i_ctime = attr->ia_ctime; | |
338 | if (ia_valid & ATTR_MODE) { | |
339 | ADFS_I(inode)->attr = adfs_mode2atts(sb, inode); | |
340 | inode->i_mode = adfs_atts2mode(sb, inode); | |
341 | } | |
342 | ||
343 | /* | |
344 | * FIXME: should we be marking this inode dirty even if | |
345 | * we don't have any metadata to write back? | |
346 | */ | |
347 | if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE)) | |
348 | mark_inode_dirty(inode); | |
349 | out: | |
1da177e4 LT |
350 | return error; |
351 | } | |
352 | ||
353 | /* | |
354 | * write an existing inode back to the directory, and therefore the disk. | |
355 | * The adfs-specific inode data has already been updated by | |
356 | * adfs_notify_change() | |
357 | */ | |
a9185b41 | 358 | int adfs_write_inode(struct inode *inode, struct writeback_control *wbc) |
1da177e4 LT |
359 | { |
360 | struct super_block *sb = inode->i_sb; | |
361 | struct object_info obj; | |
362 | int ret; | |
363 | ||
1da177e4 LT |
364 | obj.file_id = inode->i_ino; |
365 | obj.name_len = 0; | |
366 | obj.parent_id = ADFS_I(inode)->parent_id; | |
367 | obj.loadaddr = ADFS_I(inode)->loadaddr; | |
368 | obj.execaddr = ADFS_I(inode)->execaddr; | |
369 | obj.attr = ADFS_I(inode)->attr; | |
370 | obj.size = inode->i_size; | |
371 | ||
a9185b41 | 372 | ret = adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL); |
1da177e4 LT |
373 | return ret; |
374 | } |