1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/affs/file.c
4 *
5 * (c) 1996 Hans-Joachim Widmaier - Rewritten
6 *
7 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
8 *
9 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
10 *
11 * (C) 1991 Linus Torvalds - minix filesystem
12 *
13 * affs regular file handling primitives
14 */
15
16 #include <linux/uio.h>
17 #include "affs.h"
18
19 static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
20
21 static int
affs_file_open(struct inode * inode,struct file * filp)22 affs_file_open(struct inode *inode, struct file *filp)
23 {
24 pr_debug("open(%lu,%d)\n",
25 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
26 atomic_inc(&AFFS_I(inode)->i_opencnt);
27 return 0;
28 }
29
30 static int
affs_file_release(struct inode * inode,struct file * filp)31 affs_file_release(struct inode *inode, struct file *filp)
32 {
33 pr_debug("release(%lu, %d)\n",
34 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
35
36 if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
37 inode_lock(inode);
38 if (inode->i_size != AFFS_I(inode)->mmu_private)
39 affs_truncate(inode);
40 affs_free_prealloc(inode);
41 inode_unlock(inode);
42 }
43
44 return 0;
45 }
46
47 static int
affs_grow_extcache(struct inode * inode,u32 lc_idx)48 affs_grow_extcache(struct inode *inode, u32 lc_idx)
49 {
50 struct super_block *sb = inode->i_sb;
51 struct buffer_head *bh;
52 u32 lc_max;
53 int i, j, key;
54
55 if (!AFFS_I(inode)->i_lc) {
56 char *ptr = (char *)get_zeroed_page(GFP_NOFS);
57 if (!ptr)
58 return -ENOMEM;
59 AFFS_I(inode)->i_lc = (u32 *)ptr;
60 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
61 }
62
63 lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
64
65 if (AFFS_I(inode)->i_extcnt > lc_max) {
66 u32 lc_shift, lc_mask, tmp, off;
67
68 /* need to recalculate linear cache, start from old size */
69 lc_shift = AFFS_I(inode)->i_lc_shift;
70 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
71 for (; tmp; tmp >>= 1)
72 lc_shift++;
73 lc_mask = (1 << lc_shift) - 1;
74
75 /* fix idx and old size to new shift */
76 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
77 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
78
79 /* first shrink old cache to make more space */
80 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
81 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
82 AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
83
84 AFFS_I(inode)->i_lc_shift = lc_shift;
85 AFFS_I(inode)->i_lc_mask = lc_mask;
86 }
87
88 /* fill cache to the needed index */
89 i = AFFS_I(inode)->i_lc_size;
90 AFFS_I(inode)->i_lc_size = lc_idx + 1;
91 for (; i <= lc_idx; i++) {
92 if (!i) {
93 AFFS_I(inode)->i_lc[0] = inode->i_ino;
94 continue;
95 }
96 key = AFFS_I(inode)->i_lc[i - 1];
97 j = AFFS_I(inode)->i_lc_mask + 1;
98 // unlock cache
99 for (; j > 0; j--) {
100 bh = affs_bread(sb, key);
101 if (!bh)
102 goto err;
103 key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
104 affs_brelse(bh);
105 }
106 // lock cache
107 AFFS_I(inode)->i_lc[i] = key;
108 }
109
110 return 0;
111
112 err:
113 // lock cache
114 return -EIO;
115 }
116
117 static struct buffer_head *
affs_alloc_extblock(struct inode * inode,struct buffer_head * bh,u32 ext)118 affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
119 {
120 struct super_block *sb = inode->i_sb;
121 struct buffer_head *new_bh;
122 u32 blocknr, tmp;
123
124 blocknr = affs_alloc_block(inode, bh->b_blocknr);
125 if (!blocknr)
126 return ERR_PTR(-ENOSPC);
127
128 new_bh = affs_getzeroblk(sb, blocknr);
129 if (!new_bh) {
130 affs_free_block(sb, blocknr);
131 return ERR_PTR(-EIO);
132 }
133
134 AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
135 AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
136 AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
137 AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
138 affs_fix_checksum(sb, new_bh);
139
140 mark_buffer_dirty_inode(new_bh, inode);
141
142 tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
143 if (tmp)
144 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
145 AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
146 affs_adjust_checksum(bh, blocknr - tmp);
147 mark_buffer_dirty_inode(bh, inode);
148
149 AFFS_I(inode)->i_extcnt++;
150 mark_inode_dirty(inode);
151
152 return new_bh;
153 }
154
155 static inline struct buffer_head *
affs_get_extblock(struct inode * inode,u32 ext)156 affs_get_extblock(struct inode *inode, u32 ext)
157 {
158 /* inline the simplest case: same extended block as last time */
159 struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
160 if (ext == AFFS_I(inode)->i_ext_last)
161 get_bh(bh);
162 else
163 /* we have to do more (not inlined) */
164 bh = affs_get_extblock_slow(inode, ext);
165
166 return bh;
167 }
168
169 static struct buffer_head *
affs_get_extblock_slow(struct inode * inode,u32 ext)170 affs_get_extblock_slow(struct inode *inode, u32 ext)
171 {
172 struct super_block *sb = inode->i_sb;
173 struct buffer_head *bh;
174 u32 ext_key;
175 u32 lc_idx, lc_off, ac_idx;
176 u32 tmp, idx;
177
178 if (ext == AFFS_I(inode)->i_ext_last + 1) {
179 /* read the next extended block from the current one */
180 bh = AFFS_I(inode)->i_ext_bh;
181 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
182 if (ext < AFFS_I(inode)->i_extcnt)
183 goto read_ext;
184 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
185 bh = affs_alloc_extblock(inode, bh, ext);
186 if (IS_ERR(bh))
187 return bh;
188 goto store_ext;
189 }
190
191 if (ext == 0) {
192 /* we seek back to the file header block */
193 ext_key = inode->i_ino;
194 goto read_ext;
195 }
196
197 if (ext >= AFFS_I(inode)->i_extcnt) {
198 struct buffer_head *prev_bh;
199
200 /* allocate a new extended block */
201 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
202
203 /* get previous extended block */
204 prev_bh = affs_get_extblock(inode, ext - 1);
205 if (IS_ERR(prev_bh))
206 return prev_bh;
207 bh = affs_alloc_extblock(inode, prev_bh, ext);
208 affs_brelse(prev_bh);
209 if (IS_ERR(bh))
210 return bh;
211 goto store_ext;
212 }
213
214 again:
215 /* check if there is an extended cache and whether it's large enough */
216 lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
217 lc_off = ext & AFFS_I(inode)->i_lc_mask;
218
219 if (lc_idx >= AFFS_I(inode)->i_lc_size) {
220 int err;
221
222 err = affs_grow_extcache(inode, lc_idx);
223 if (err)
224 return ERR_PTR(err);
225 goto again;
226 }
227
228 /* every n'th key we find in the linear cache */
229 if (!lc_off) {
230 ext_key = AFFS_I(inode)->i_lc[lc_idx];
231 goto read_ext;
232 }
233
234 /* maybe it's still in the associative cache */
235 ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
236 if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
237 ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
238 goto read_ext;
239 }
240
241 /* try to find one of the previous extended blocks */
242 tmp = ext;
243 idx = ac_idx;
244 while (--tmp, --lc_off > 0) {
245 idx = (idx - 1) & AFFS_AC_MASK;
246 if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
247 ext_key = AFFS_I(inode)->i_ac[idx].key;
248 goto find_ext;
249 }
250 }
251
252 /* fall back to the linear cache */
253 ext_key = AFFS_I(inode)->i_lc[lc_idx];
254 find_ext:
255 /* read all extended blocks until we find the one we need */
256 //unlock cache
257 do {
258 bh = affs_bread(sb, ext_key);
259 if (!bh)
260 goto err_bread;
261 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
262 affs_brelse(bh);
263 tmp++;
264 } while (tmp < ext);
265 //lock cache
266
267 /* store it in the associative cache */
268 // recalculate ac_idx?
269 AFFS_I(inode)->i_ac[ac_idx].ext = ext;
270 AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
271
272 read_ext:
273 /* finally read the right extended block */
274 //unlock cache
275 bh = affs_bread(sb, ext_key);
276 if (!bh)
277 goto err_bread;
278 //lock cache
279
280 store_ext:
281 /* release old cached extended block and store the new one */
282 affs_brelse(AFFS_I(inode)->i_ext_bh);
283 AFFS_I(inode)->i_ext_last = ext;
284 AFFS_I(inode)->i_ext_bh = bh;
285 get_bh(bh);
286
287 return bh;
288
289 err_bread:
290 affs_brelse(bh);
291 return ERR_PTR(-EIO);
292 }
293
294 static int
affs_get_block(struct inode * inode,sector_t block,struct buffer_head * bh_result,int create)295 affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
296 {
297 struct super_block *sb = inode->i_sb;
298 struct buffer_head *ext_bh;
299 u32 ext;
300
301 pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino,
302 (unsigned long long)block);
303
304 BUG_ON(block > (sector_t)0x7fffffffUL);
305
306 if (block >= AFFS_I(inode)->i_blkcnt) {
307 if (block > AFFS_I(inode)->i_blkcnt || !create)
308 goto err_big;
309 } else
310 create = 0;
311
312 //lock cache
313 affs_lock_ext(inode);
314
315 ext = (u32)block / AFFS_SB(sb)->s_hashsize;
316 block -= ext * AFFS_SB(sb)->s_hashsize;
317 ext_bh = affs_get_extblock(inode, ext);
318 if (IS_ERR(ext_bh))
319 goto err_ext;
320 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
321
322 if (create) {
323 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
324 if (!blocknr)
325 goto err_alloc;
326 set_buffer_new(bh_result);
327 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
328 AFFS_I(inode)->i_blkcnt++;
329
330 /* store new block */
331 if (bh_result->b_blocknr)
332 affs_warning(sb, "get_block",
333 "block already set (%llx)",
334 (unsigned long long)bh_result->b_blocknr);
335 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
336 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
337 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
338 bh_result->b_blocknr = blocknr;
339
340 if (!block) {
341 /* insert first block into header block */
342 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
343 if (tmp)
344 affs_warning(sb, "get_block", "first block already set (%d)", tmp);
345 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
346 affs_adjust_checksum(ext_bh, blocknr - tmp);
347 }
348 }
349
350 affs_brelse(ext_bh);
351 //unlock cache
352 affs_unlock_ext(inode);
353 return 0;
354
355 err_big:
356 affs_error(inode->i_sb, "get_block", "strange block request %llu",
357 (unsigned long long)block);
358 return -EIO;
359 err_ext:
360 // unlock cache
361 affs_unlock_ext(inode);
362 return PTR_ERR(ext_bh);
363 err_alloc:
364 brelse(ext_bh);
365 clear_buffer_mapped(bh_result);
366 bh_result->b_bdev = NULL;
367 // unlock cache
368 affs_unlock_ext(inode);
369 return -ENOSPC;
370 }
371
affs_writepage(struct page * page,struct writeback_control * wbc)372 static int affs_writepage(struct page *page, struct writeback_control *wbc)
373 {
374 return block_write_full_page(page, affs_get_block, wbc);
375 }
376
affs_readpage(struct file * file,struct page * page)377 static int affs_readpage(struct file *file, struct page *page)
378 {
379 return block_read_full_page(page, affs_get_block);
380 }
381
affs_write_failed(struct address_space * mapping,loff_t to)382 static void affs_write_failed(struct address_space *mapping, loff_t to)
383 {
384 struct inode *inode = mapping->host;
385
386 if (to > inode->i_size) {
387 truncate_pagecache(inode, inode->i_size);
388 affs_truncate(inode);
389 }
390 }
391
392 static ssize_t
affs_direct_IO(struct kiocb * iocb,struct iov_iter * iter)393 affs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
394 {
395 struct file *file = iocb->ki_filp;
396 struct address_space *mapping = file->f_mapping;
397 struct inode *inode = mapping->host;
398 size_t count = iov_iter_count(iter);
399 loff_t offset = iocb->ki_pos;
400 ssize_t ret;
401
402 if (iov_iter_rw(iter) == WRITE) {
403 loff_t size = offset + count;
404
405 if (AFFS_I(inode)->mmu_private < size)
406 return 0;
407 }
408
409 ret = blockdev_direct_IO(iocb, inode, iter, affs_get_block);
410 if (ret < 0 && iov_iter_rw(iter) == WRITE)
411 affs_write_failed(mapping, offset + count);
412 return ret;
413 }
414
affs_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)415 static int affs_write_begin(struct file *file, struct address_space *mapping,
416 loff_t pos, unsigned len, unsigned flags,
417 struct page **pagep, void **fsdata)
418 {
419 int ret;
420
421 *pagep = NULL;
422 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
423 affs_get_block,
424 &AFFS_I(mapping->host)->mmu_private);
425 if (unlikely(ret))
426 affs_write_failed(mapping, pos + len);
427
428 return ret;
429 }
430
affs_write_end(struct file * file,struct address_space * mapping,loff_t pos,unsigned int len,unsigned int copied,struct page * page,void * fsdata)431 static int affs_write_end(struct file *file, struct address_space *mapping,
432 loff_t pos, unsigned int len, unsigned int copied,
433 struct page *page, void *fsdata)
434 {
435 struct inode *inode = mapping->host;
436 int ret;
437
438 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
439
440 /* Clear Archived bit on file writes, as AmigaOS would do */
441 if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
442 AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
443 mark_inode_dirty(inode);
444 }
445
446 return ret;
447 }
448
_affs_bmap(struct address_space * mapping,sector_t block)449 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
450 {
451 return generic_block_bmap(mapping,block,affs_get_block);
452 }
453
454 const struct address_space_operations affs_aops = {
455 .readpage = affs_readpage,
456 .writepage = affs_writepage,
457 .write_begin = affs_write_begin,
458 .write_end = affs_write_end,
459 .direct_IO = affs_direct_IO,
460 .bmap = _affs_bmap
461 };
462
463 static inline struct buffer_head *
affs_bread_ino(struct inode * inode,int block,int create)464 affs_bread_ino(struct inode *inode, int block, int create)
465 {
466 struct buffer_head *bh, tmp_bh;
467 int err;
468
469 tmp_bh.b_state = 0;
470 err = affs_get_block(inode, block, &tmp_bh, create);
471 if (!err) {
472 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
473 if (bh) {
474 bh->b_state |= tmp_bh.b_state;
475 return bh;
476 }
477 err = -EIO;
478 }
479 return ERR_PTR(err);
480 }
481
482 static inline struct buffer_head *
affs_getzeroblk_ino(struct inode * inode,int block)483 affs_getzeroblk_ino(struct inode *inode, int block)
484 {
485 struct buffer_head *bh, tmp_bh;
486 int err;
487
488 tmp_bh.b_state = 0;
489 err = affs_get_block(inode, block, &tmp_bh, 1);
490 if (!err) {
491 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
492 if (bh) {
493 bh->b_state |= tmp_bh.b_state;
494 return bh;
495 }
496 err = -EIO;
497 }
498 return ERR_PTR(err);
499 }
500
501 static inline struct buffer_head *
affs_getemptyblk_ino(struct inode * inode,int block)502 affs_getemptyblk_ino(struct inode *inode, int block)
503 {
504 struct buffer_head *bh, tmp_bh;
505 int err;
506
507 tmp_bh.b_state = 0;
508 err = affs_get_block(inode, block, &tmp_bh, 1);
509 if (!err) {
510 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
511 if (bh) {
512 bh->b_state |= tmp_bh.b_state;
513 return bh;
514 }
515 err = -EIO;
516 }
517 return ERR_PTR(err);
518 }
519
520 static int
affs_do_readpage_ofs(struct page * page,unsigned to,int create)521 affs_do_readpage_ofs(struct page *page, unsigned to, int create)
522 {
523 struct inode *inode = page->mapping->host;
524 struct super_block *sb = inode->i_sb;
525 struct buffer_head *bh;
526 char *data;
527 unsigned pos = 0;
528 u32 bidx, boff, bsize;
529 u32 tmp;
530
531 pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino,
532 page->index, to);
533 BUG_ON(to > PAGE_SIZE);
534 bsize = AFFS_SB(sb)->s_data_blksize;
535 tmp = page->index << PAGE_SHIFT;
536 bidx = tmp / bsize;
537 boff = tmp % bsize;
538
539 while (pos < to) {
540 bh = affs_bread_ino(inode, bidx, create);
541 if (IS_ERR(bh))
542 return PTR_ERR(bh);
543 tmp = min(bsize - boff, to - pos);
544 BUG_ON(pos + tmp > to || tmp > bsize);
545 data = kmap_atomic(page);
546 memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
547 kunmap_atomic(data);
548 affs_brelse(bh);
549 bidx++;
550 pos += tmp;
551 boff = 0;
552 }
553 flush_dcache_page(page);
554 return 0;
555 }
556
557 static int
affs_extent_file_ofs(struct inode * inode,u32 newsize)558 affs_extent_file_ofs(struct inode *inode, u32 newsize)
559 {
560 struct super_block *sb = inode->i_sb;
561 struct buffer_head *bh, *prev_bh;
562 u32 bidx, boff;
563 u32 size, bsize;
564 u32 tmp;
565
566 pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize);
567 bsize = AFFS_SB(sb)->s_data_blksize;
568 bh = NULL;
569 size = AFFS_I(inode)->mmu_private;
570 bidx = size / bsize;
571 boff = size % bsize;
572 if (boff) {
573 bh = affs_bread_ino(inode, bidx, 0);
574 if (IS_ERR(bh))
575 return PTR_ERR(bh);
576 tmp = min(bsize - boff, newsize - size);
577 BUG_ON(boff + tmp > bsize || tmp > bsize);
578 memset(AFFS_DATA(bh) + boff, 0, tmp);
579 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
580 affs_fix_checksum(sb, bh);
581 mark_buffer_dirty_inode(bh, inode);
582 size += tmp;
583 bidx++;
584 } else if (bidx) {
585 bh = affs_bread_ino(inode, bidx - 1, 0);
586 if (IS_ERR(bh))
587 return PTR_ERR(bh);
588 }
589
590 while (size < newsize) {
591 prev_bh = bh;
592 bh = affs_getzeroblk_ino(inode, bidx);
593 if (IS_ERR(bh))
594 goto out;
595 tmp = min(bsize, newsize - size);
596 BUG_ON(tmp > bsize);
597 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
598 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
599 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
600 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
601 affs_fix_checksum(sb, bh);
602 bh->b_state &= ~(1UL << BH_New);
603 mark_buffer_dirty_inode(bh, inode);
604 if (prev_bh) {
605 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
606
607 if (tmp_next)
608 affs_warning(sb, "extent_file_ofs",
609 "next block already set for %d (%d)",
610 bidx, tmp_next);
611 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
612 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
613 mark_buffer_dirty_inode(prev_bh, inode);
614 affs_brelse(prev_bh);
615 }
616 size += bsize;
617 bidx++;
618 }
619 affs_brelse(bh);
620 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
621 return 0;
622
623 out:
624 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
625 return PTR_ERR(bh);
626 }
627
628 static int
affs_readpage_ofs(struct file * file,struct page * page)629 affs_readpage_ofs(struct file *file, struct page *page)
630 {
631 struct inode *inode = page->mapping->host;
632 u32 to;
633 int err;
634
635 pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index);
636 to = PAGE_SIZE;
637 if (((page->index + 1) << PAGE_SHIFT) > inode->i_size) {
638 to = inode->i_size & ~PAGE_MASK;
639 memset(page_address(page) + to, 0, PAGE_SIZE - to);
640 }
641
642 err = affs_do_readpage_ofs(page, to, 0);
643 if (!err)
644 SetPageUptodate(page);
645 unlock_page(page);
646 return err;
647 }
648
affs_write_begin_ofs(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)649 static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
650 loff_t pos, unsigned len, unsigned flags,
651 struct page **pagep, void **fsdata)
652 {
653 struct inode *inode = mapping->host;
654 struct page *page;
655 pgoff_t index;
656 int err = 0;
657
658 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
659 pos + len);
660 if (pos > AFFS_I(inode)->mmu_private) {
661 /* XXX: this probably leaves a too-big i_size in case of
662 * failure. Should really be updating i_size at write_end time
663 */
664 err = affs_extent_file_ofs(inode, pos);
665 if (err)
666 return err;
667 }
668
669 index = pos >> PAGE_SHIFT;
670 page = grab_cache_page_write_begin(mapping, index, flags);
671 if (!page)
672 return -ENOMEM;
673 *pagep = page;
674
675 if (PageUptodate(page))
676 return 0;
677
678 /* XXX: inefficient but safe in the face of short writes */
679 err = affs_do_readpage_ofs(page, PAGE_SIZE, 1);
680 if (err) {
681 unlock_page(page);
682 put_page(page);
683 }
684 return err;
685 }
686
affs_write_end_ofs(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,struct page * page,void * fsdata)687 static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
688 loff_t pos, unsigned len, unsigned copied,
689 struct page *page, void *fsdata)
690 {
691 struct inode *inode = mapping->host;
692 struct super_block *sb = inode->i_sb;
693 struct buffer_head *bh, *prev_bh;
694 char *data;
695 u32 bidx, boff, bsize;
696 unsigned from, to;
697 u32 tmp;
698 int written;
699
700 from = pos & (PAGE_SIZE - 1);
701 to = from + len;
702 /*
703 * XXX: not sure if this can handle short copies (len < copied), but
704 * we don't have to, because the page should always be uptodate here,
705 * due to write_begin.
706 */
707
708 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
709 pos + len);
710 bsize = AFFS_SB(sb)->s_data_blksize;
711 data = page_address(page);
712
713 bh = NULL;
714 written = 0;
715 tmp = (page->index << PAGE_SHIFT) + from;
716 bidx = tmp / bsize;
717 boff = tmp % bsize;
718 if (boff) {
719 bh = affs_bread_ino(inode, bidx, 0);
720 if (IS_ERR(bh)) {
721 written = PTR_ERR(bh);
722 goto err_first_bh;
723 }
724 tmp = min(bsize - boff, to - from);
725 BUG_ON(boff + tmp > bsize || tmp > bsize);
726 memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
727 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
728 affs_fix_checksum(sb, bh);
729 mark_buffer_dirty_inode(bh, inode);
730 written += tmp;
731 from += tmp;
732 bidx++;
733 } else if (bidx) {
734 bh = affs_bread_ino(inode, bidx - 1, 0);
735 if (IS_ERR(bh)) {
736 written = PTR_ERR(bh);
737 goto err_first_bh;
738 }
739 }
740 while (from + bsize <= to) {
741 prev_bh = bh;
742 bh = affs_getemptyblk_ino(inode, bidx);
743 if (IS_ERR(bh))
744 goto err_bh;
745 memcpy(AFFS_DATA(bh), data + from, bsize);
746 if (buffer_new(bh)) {
747 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
748 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
749 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
750 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
751 AFFS_DATA_HEAD(bh)->next = 0;
752 bh->b_state &= ~(1UL << BH_New);
753 if (prev_bh) {
754 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
755
756 if (tmp_next)
757 affs_warning(sb, "commit_write_ofs",
758 "next block already set for %d (%d)",
759 bidx, tmp_next);
760 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
761 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
762 mark_buffer_dirty_inode(prev_bh, inode);
763 }
764 }
765 affs_brelse(prev_bh);
766 affs_fix_checksum(sb, bh);
767 mark_buffer_dirty_inode(bh, inode);
768 written += bsize;
769 from += bsize;
770 bidx++;
771 }
772 if (from < to) {
773 prev_bh = bh;
774 bh = affs_bread_ino(inode, bidx, 1);
775 if (IS_ERR(bh))
776 goto err_bh;
777 tmp = min(bsize, to - from);
778 BUG_ON(tmp > bsize);
779 memcpy(AFFS_DATA(bh), data + from, tmp);
780 if (buffer_new(bh)) {
781 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
782 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
783 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
784 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
785 AFFS_DATA_HEAD(bh)->next = 0;
786 bh->b_state &= ~(1UL << BH_New);
787 if (prev_bh) {
788 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
789
790 if (tmp_next)
791 affs_warning(sb, "commit_write_ofs",
792 "next block already set for %d (%d)",
793 bidx, tmp_next);
794 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
795 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
796 mark_buffer_dirty_inode(prev_bh, inode);
797 }
798 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
799 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
800 affs_brelse(prev_bh);
801 affs_fix_checksum(sb, bh);
802 mark_buffer_dirty_inode(bh, inode);
803 written += tmp;
804 from += tmp;
805 bidx++;
806 }
807 SetPageUptodate(page);
808
809 done:
810 affs_brelse(bh);
811 tmp = (page->index << PAGE_SHIFT) + from;
812 if (tmp > inode->i_size)
813 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
814
815 /* Clear Archived bit on file writes, as AmigaOS would do */
816 if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
817 AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
818 mark_inode_dirty(inode);
819 }
820
821 err_first_bh:
822 unlock_page(page);
823 put_page(page);
824
825 return written;
826
827 err_bh:
828 bh = prev_bh;
829 if (!written)
830 written = PTR_ERR(bh);
831 goto done;
832 }
833
834 const struct address_space_operations affs_aops_ofs = {
835 .readpage = affs_readpage_ofs,
836 //.writepage = affs_writepage_ofs,
837 .write_begin = affs_write_begin_ofs,
838 .write_end = affs_write_end_ofs
839 };
840
841 /* Free any preallocated blocks. */
842
843 void
affs_free_prealloc(struct inode * inode)844 affs_free_prealloc(struct inode *inode)
845 {
846 struct super_block *sb = inode->i_sb;
847
848 pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
849
850 while (AFFS_I(inode)->i_pa_cnt) {
851 AFFS_I(inode)->i_pa_cnt--;
852 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
853 }
854 }
855
856 /* Truncate (or enlarge) a file to the requested size. */
857
858 void
affs_truncate(struct inode * inode)859 affs_truncate(struct inode *inode)
860 {
861 struct super_block *sb = inode->i_sb;
862 u32 ext, ext_key;
863 u32 last_blk, blkcnt, blk;
864 u32 size;
865 struct buffer_head *ext_bh;
866 int i;
867
868 pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
869 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
870
871 last_blk = 0;
872 ext = 0;
873 if (inode->i_size) {
874 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
875 ext = last_blk / AFFS_SB(sb)->s_hashsize;
876 }
877
878 if (inode->i_size > AFFS_I(inode)->mmu_private) {
879 struct address_space *mapping = inode->i_mapping;
880 struct page *page;
881 void *fsdata = NULL;
882 loff_t isize = inode->i_size;
883 int res;
884
885 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
886 if (!res)
887 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
888 else
889 inode->i_size = AFFS_I(inode)->mmu_private;
890 mark_inode_dirty(inode);
891 return;
892 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
893 return;
894
895 // lock cache
896 ext_bh = affs_get_extblock(inode, ext);
897 if (IS_ERR(ext_bh)) {
898 affs_warning(sb, "truncate",
899 "unexpected read error for ext block %u (%ld)",
900 ext, PTR_ERR(ext_bh));
901 return;
902 }
903 if (AFFS_I(inode)->i_lc) {
904 /* clear linear cache */
905 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
906 if (AFFS_I(inode)->i_lc_size > i) {
907 AFFS_I(inode)->i_lc_size = i;
908 for (; i < AFFS_LC_SIZE; i++)
909 AFFS_I(inode)->i_lc[i] = 0;
910 }
911 /* clear associative cache */
912 for (i = 0; i < AFFS_AC_SIZE; i++)
913 if (AFFS_I(inode)->i_ac[i].ext >= ext)
914 AFFS_I(inode)->i_ac[i].ext = 0;
915 }
916 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
917
918 blkcnt = AFFS_I(inode)->i_blkcnt;
919 i = 0;
920 blk = last_blk;
921 if (inode->i_size) {
922 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
923 blk++;
924 } else
925 AFFS_HEAD(ext_bh)->first_data = 0;
926 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
927 size = AFFS_SB(sb)->s_hashsize;
928 if (size > blkcnt - blk + i)
929 size = blkcnt - blk + i;
930 for (; i < size; i++, blk++) {
931 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
932 AFFS_BLOCK(sb, ext_bh, i) = 0;
933 }
934 AFFS_TAIL(sb, ext_bh)->extension = 0;
935 affs_fix_checksum(sb, ext_bh);
936 mark_buffer_dirty_inode(ext_bh, inode);
937 affs_brelse(ext_bh);
938
939 if (inode->i_size) {
940 AFFS_I(inode)->i_blkcnt = last_blk + 1;
941 AFFS_I(inode)->i_extcnt = ext + 1;
942 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) {
943 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
944 u32 tmp;
945 if (IS_ERR(bh)) {
946 affs_warning(sb, "truncate",
947 "unexpected read error for last block %u (%ld)",
948 ext, PTR_ERR(bh));
949 return;
950 }
951 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
952 AFFS_DATA_HEAD(bh)->next = 0;
953 affs_adjust_checksum(bh, -tmp);
954 affs_brelse(bh);
955 }
956 } else {
957 AFFS_I(inode)->i_blkcnt = 0;
958 AFFS_I(inode)->i_extcnt = 1;
959 }
960 AFFS_I(inode)->mmu_private = inode->i_size;
961 // unlock cache
962
963 while (ext_key) {
964 ext_bh = affs_bread(sb, ext_key);
965 size = AFFS_SB(sb)->s_hashsize;
966 if (size > blkcnt - blk)
967 size = blkcnt - blk;
968 for (i = 0; i < size; i++, blk++)
969 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
970 affs_free_block(sb, ext_key);
971 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
972 affs_brelse(ext_bh);
973 }
974 affs_free_prealloc(inode);
975 }
976
affs_file_fsync(struct file * filp,loff_t start,loff_t end,int datasync)977 int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
978 {
979 struct inode *inode = filp->f_mapping->host;
980 int ret, err;
981
982 err = file_write_and_wait_range(filp, start, end);
983 if (err)
984 return err;
985
986 inode_lock(inode);
987 ret = write_inode_now(inode, 0);
988 err = sync_blockdev(inode->i_sb->s_bdev);
989 if (!ret)
990 ret = err;
991 inode_unlock(inode);
992 return ret;
993 }
994 const struct file_operations affs_file_operations = {
995 .llseek = generic_file_llseek,
996 .read_iter = generic_file_read_iter,
997 .write_iter = generic_file_write_iter,
998 .mmap = generic_file_mmap,
999 .open = affs_file_open,
1000 .release = affs_file_release,
1001 .fsync = affs_file_fsync,
1002 .splice_read = generic_file_splice_read,
1003 };
1004
1005 const struct inode_operations affs_file_inode_operations = {
1006 .setattr = affs_notify_change,
1007 };
1008