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