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Char: rio, fix cirrus defines
[linux-2.6/mini2440.git] / fs / affs / file.c
blobe87ede608f77e303cfe55ffe0a51a242f51b1109
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 "affs.h"
16
17 #if PAGE_SIZE < 4096
18 #error PAGE_SIZE must be at least 4096
19 #endif
20
21 static int affs_grow_extcache(struct inode *inode, u32 lc_idx);
22 static struct buffer_head *affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext);
23 static inline struct buffer_head *affs_get_extblock(struct inode *inode, u32 ext);
24 static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
25 static int affs_file_open(struct inode *inode, struct file *filp);
26 static int affs_file_release(struct inode *inode, struct file *filp);
27
28 const struct file_operations affs_file_operations = {
29 .llseek = generic_file_llseek,
30 .read = do_sync_read,
31 .aio_read = generic_file_aio_read,
32 .write = do_sync_write,
33 .aio_write = generic_file_aio_write,
34 .mmap = generic_file_mmap,
35 .open = affs_file_open,
36 .release = affs_file_release,
37 .fsync = file_fsync,
38 .splice_read = generic_file_splice_read,
39 };
40
41 const struct inode_operations affs_file_inode_operations = {
42 .truncate = affs_truncate,
43 .setattr = affs_notify_change,
44 };
45
46 static int
47 affs_file_open(struct inode *inode, struct file *filp)
48 {
49 if (atomic_read(&filp->f_count) != 1)
50 return 0;
51 pr_debug("AFFS: open(%d)\n", AFFS_I(inode)->i_opencnt);
52 AFFS_I(inode)->i_opencnt++;
53 return 0;
54 }
55
56 static int
57 affs_file_release(struct inode *inode, struct file *filp)
58 {
59 if (atomic_read(&filp->f_count) != 0)
60 return 0;
61 pr_debug("AFFS: release(%d)\n", AFFS_I(inode)->i_opencnt);
62 AFFS_I(inode)->i_opencnt--;
63 if (!AFFS_I(inode)->i_opencnt)
64 affs_free_prealloc(inode);
65
66 return 0;
67 }
68
69 static int
70 affs_grow_extcache(struct inode *inode, u32 lc_idx)
71 {
72 struct super_block *sb = inode->i_sb;
73 struct buffer_head *bh;
74 u32 lc_max;
75 int i, j, key;
76
77 if (!AFFS_I(inode)->i_lc) {
78 char *ptr = (char *)get_zeroed_page(GFP_NOFS);
79 if (!ptr)
80 return -ENOMEM;
81 AFFS_I(inode)->i_lc = (u32 *)ptr;
82 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
83 }
84
85 lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
86
87 if (AFFS_I(inode)->i_extcnt > lc_max) {
88 u32 lc_shift, lc_mask, tmp, off;
89
90 /* need to recalculate linear cache, start from old size */
91 lc_shift = AFFS_I(inode)->i_lc_shift;
92 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
93 for (; tmp; tmp >>= 1)
94 lc_shift++;
95 lc_mask = (1 << lc_shift) - 1;
96
97 /* fix idx and old size to new shift */
98 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
99 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
100
101 /* first shrink old cache to make more space */
102 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
103 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
104 AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
105
106 AFFS_I(inode)->i_lc_shift = lc_shift;
107 AFFS_I(inode)->i_lc_mask = lc_mask;
108 }
109
110 /* fill cache to the needed index */
111 i = AFFS_I(inode)->i_lc_size;
112 AFFS_I(inode)->i_lc_size = lc_idx + 1;
113 for (; i <= lc_idx; i++) {
114 if (!i) {
115 AFFS_I(inode)->i_lc[0] = inode->i_ino;
116 continue;
117 }
118 key = AFFS_I(inode)->i_lc[i - 1];
119 j = AFFS_I(inode)->i_lc_mask + 1;
120 // unlock cache
121 for (; j > 0; j--) {
122 bh = affs_bread(sb, key);
123 if (!bh)
124 goto err;
125 key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
126 affs_brelse(bh);
127 }
128 // lock cache
129 AFFS_I(inode)->i_lc[i] = key;
130 }
131
132 return 0;
133
134 err:
135 // lock cache
136 return -EIO;
137 }
138
139 static struct buffer_head *
140 affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
141 {
142 struct super_block *sb = inode->i_sb;
143 struct buffer_head *new_bh;
144 u32 blocknr, tmp;
145
146 blocknr = affs_alloc_block(inode, bh->b_blocknr);
147 if (!blocknr)
148 return ERR_PTR(-ENOSPC);
149
150 new_bh = affs_getzeroblk(sb, blocknr);
151 if (!new_bh) {
152 affs_free_block(sb, blocknr);
153 return ERR_PTR(-EIO);
154 }
155
156 AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
157 AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
158 AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
159 AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
160 affs_fix_checksum(sb, new_bh);
161
162 mark_buffer_dirty_inode(new_bh, inode);
163
164 tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
165 if (tmp)
166 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
167 AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
168 affs_adjust_checksum(bh, blocknr - tmp);
169 mark_buffer_dirty_inode(bh, inode);
170
171 AFFS_I(inode)->i_extcnt++;
172 mark_inode_dirty(inode);
173
174 return new_bh;
175 }
176
177 static inline struct buffer_head *
178 affs_get_extblock(struct inode *inode, u32 ext)
179 {
180 /* inline the simplest case: same extended block as last time */
181 struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
182 if (ext == AFFS_I(inode)->i_ext_last)
183 atomic_inc(&bh->b_count);
184 else
185 /* we have to do more (not inlined) */
186 bh = affs_get_extblock_slow(inode, ext);
187
188 return bh;
189 }
190
191 static struct buffer_head *
192 affs_get_extblock_slow(struct inode *inode, u32 ext)
193 {
194 struct super_block *sb = inode->i_sb;
195 struct buffer_head *bh;
196 u32 ext_key;
197 u32 lc_idx, lc_off, ac_idx;
198 u32 tmp, idx;
199
200 if (ext == AFFS_I(inode)->i_ext_last + 1) {
201 /* read the next extended block from the current one */
202 bh = AFFS_I(inode)->i_ext_bh;
203 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
204 if (ext < AFFS_I(inode)->i_extcnt)
205 goto read_ext;
206 if (ext > AFFS_I(inode)->i_extcnt)
207 BUG();
208 bh = affs_alloc_extblock(inode, bh, ext);
209 if (IS_ERR(bh))
210 return bh;
211 goto store_ext;
212 }
213
214 if (ext == 0) {
215 /* we seek back to the file header block */
216 ext_key = inode->i_ino;
217 goto read_ext;
218 }
219
220 if (ext >= AFFS_I(inode)->i_extcnt) {
221 struct buffer_head *prev_bh;
222
223 /* allocate a new extended block */
224 if (ext > AFFS_I(inode)->i_extcnt)
225 BUG();
226
227 /* get previous extended block */
228 prev_bh = affs_get_extblock(inode, ext - 1);
229 if (IS_ERR(prev_bh))
230 return prev_bh;
231 bh = affs_alloc_extblock(inode, prev_bh, ext);
232 affs_brelse(prev_bh);
233 if (IS_ERR(bh))
234 return bh;
235 goto store_ext;
236 }
237
238 again:
239 /* check if there is an extended cache and whether it's large enough */
240 lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
241 lc_off = ext & AFFS_I(inode)->i_lc_mask;
242
243 if (lc_idx >= AFFS_I(inode)->i_lc_size) {
244 int err;
245
246 err = affs_grow_extcache(inode, lc_idx);
247 if (err)
248 return ERR_PTR(err);
249 goto again;
250 }
251
252 /* every n'th key we find in the linear cache */
253 if (!lc_off) {
254 ext_key = AFFS_I(inode)->i_lc[lc_idx];
255 goto read_ext;
256 }
257
258 /* maybe it's still in the associative cache */
259 ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
260 if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
261 ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
262 goto read_ext;
263 }
264
265 /* try to find one of the previous extended blocks */
266 tmp = ext;
267 idx = ac_idx;
268 while (--tmp, --lc_off > 0) {
269 idx = (idx - 1) & AFFS_AC_MASK;
270 if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
271 ext_key = AFFS_I(inode)->i_ac[idx].key;
272 goto find_ext;
273 }
274 }
275
276 /* fall back to the linear cache */
277 ext_key = AFFS_I(inode)->i_lc[lc_idx];
278 find_ext:
279 /* read all extended blocks until we find the one we need */
280 //unlock cache
281 do {
282 bh = affs_bread(sb, ext_key);
283 if (!bh)
284 goto err_bread;
285 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
286 affs_brelse(bh);
287 tmp++;
288 } while (tmp < ext);
289 //lock cache
290
291 /* store it in the associative cache */
292 // recalculate ac_idx?
293 AFFS_I(inode)->i_ac[ac_idx].ext = ext;
294 AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
295
296 read_ext:
297 /* finally read the right extended block */
298 //unlock cache
299 bh = affs_bread(sb, ext_key);
300 if (!bh)
301 goto err_bread;
302 //lock cache
303
304 store_ext:
305 /* release old cached extended block and store the new one */
306 affs_brelse(AFFS_I(inode)->i_ext_bh);
307 AFFS_I(inode)->i_ext_last = ext;
308 AFFS_I(inode)->i_ext_bh = bh;
309 atomic_inc(&bh->b_count);
310
311 return bh;
312
313 err_bread:
314 affs_brelse(bh);
315 return ERR_PTR(-EIO);
316 }
317
318 static int
319 affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
320 {
321 struct super_block *sb = inode->i_sb;
322 struct buffer_head *ext_bh;
323 u32 ext;
324
325 pr_debug("AFFS: get_block(%u, %lu)\n", (u32)inode->i_ino, (unsigned long)block);
326
327
328 BUG_ON(block > (sector_t)0x7fffffffUL);
329
330 if (block >= AFFS_I(inode)->i_blkcnt) {
331 if (block > AFFS_I(inode)->i_blkcnt || !create)
332 goto err_big;
333 } else
334 create = 0;
335
336 //lock cache
337 affs_lock_ext(inode);
338
339 ext = (u32)block / AFFS_SB(sb)->s_hashsize;
340 block -= ext * AFFS_SB(sb)->s_hashsize;
341 ext_bh = affs_get_extblock(inode, ext);
342 if (IS_ERR(ext_bh))
343 goto err_ext;
344 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
345
346 if (create) {
347 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
348 if (!blocknr)
349 goto err_alloc;
350 set_buffer_new(bh_result);
351 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
352 AFFS_I(inode)->i_blkcnt++;
353
354 /* store new block */
355 if (bh_result->b_blocknr)
356 affs_warning(sb, "get_block", "block already set (%x)", bh_result->b_blocknr);
357 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
358 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
359 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
360 bh_result->b_blocknr = blocknr;
361
362 if (!block) {
363 /* insert first block into header block */
364 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
365 if (tmp)
366 affs_warning(sb, "get_block", "first block already set (%d)", tmp);
367 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
368 affs_adjust_checksum(ext_bh, blocknr - tmp);
369 }
370 }
371
372 affs_brelse(ext_bh);
373 //unlock cache
374 affs_unlock_ext(inode);
375 return 0;
376
377 err_big:
378 affs_error(inode->i_sb,"get_block","strange block request %d", block);
379 return -EIO;
380 err_ext:
381 // unlock cache
382 affs_unlock_ext(inode);
383 return PTR_ERR(ext_bh);
384 err_alloc:
385 brelse(ext_bh);
386 clear_buffer_mapped(bh_result);
387 bh_result->b_bdev = NULL;
388 // unlock cache
389 affs_unlock_ext(inode);
390 return -ENOSPC;
391 }
392
393 static int affs_writepage(struct page *page, struct writeback_control *wbc)
394 {
395 return block_write_full_page(page, affs_get_block, wbc);
396 }
397
398 static int affs_readpage(struct file *file, struct page *page)
399 {
400 return block_read_full_page(page, affs_get_block);
401 }
402
403 static int affs_write_begin(struct file *file, struct address_space *mapping,
404 loff_t pos, unsigned len, unsigned flags,
405 struct page **pagep, void **fsdata)
406 {
407 *pagep = NULL;
408 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
409 affs_get_block,
410 &AFFS_I(mapping->host)->mmu_private);
411 }
412
413 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
414 {
415 return generic_block_bmap(mapping,block,affs_get_block);
416 }
417
418 const struct address_space_operations affs_aops = {
419 .readpage = affs_readpage,
420 .writepage = affs_writepage,
421 .sync_page = block_sync_page,
422 .write_begin = affs_write_begin,
423 .write_end = generic_write_end,
424 .bmap = _affs_bmap
425 };
426
427 static inline struct buffer_head *
428 affs_bread_ino(struct inode *inode, int block, int create)
429 {
430 struct buffer_head *bh, tmp_bh;
431 int err;
432
433 tmp_bh.b_state = 0;
434 err = affs_get_block(inode, block, &tmp_bh, create);
435 if (!err) {
436 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
437 if (bh) {
438 bh->b_state |= tmp_bh.b_state;
439 return bh;
440 }
441 err = -EIO;
442 }
443 return ERR_PTR(err);
444 }
445
446 static inline struct buffer_head *
447 affs_getzeroblk_ino(struct inode *inode, int block)
448 {
449 struct buffer_head *bh, tmp_bh;
450 int err;
451
452 tmp_bh.b_state = 0;
453 err = affs_get_block(inode, block, &tmp_bh, 1);
454 if (!err) {
455 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
456 if (bh) {
457 bh->b_state |= tmp_bh.b_state;
458 return bh;
459 }
460 err = -EIO;
461 }
462 return ERR_PTR(err);
463 }
464
465 static inline struct buffer_head *
466 affs_getemptyblk_ino(struct inode *inode, int block)
467 {
468 struct buffer_head *bh, tmp_bh;
469 int err;
470
471 tmp_bh.b_state = 0;
472 err = affs_get_block(inode, block, &tmp_bh, 1);
473 if (!err) {
474 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
475 if (bh) {
476 bh->b_state |= tmp_bh.b_state;
477 return bh;
478 }
479 err = -EIO;
480 }
481 return ERR_PTR(err);
482 }
483
484 static int
485 affs_do_readpage_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
486 {
487 struct inode *inode = page->mapping->host;
488 struct super_block *sb = inode->i_sb;
489 struct buffer_head *bh;
490 char *data;
491 u32 bidx, boff, bsize;
492 u32 tmp;
493
494 pr_debug("AFFS: read_page(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
495 BUG_ON(from > to || to > PAGE_CACHE_SIZE);
496 kmap(page);
497 data = page_address(page);
498 bsize = AFFS_SB(sb)->s_data_blksize;
499 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
500 bidx = tmp / bsize;
501 boff = tmp % bsize;
502
503 while (from < to) {
504 bh = affs_bread_ino(inode, bidx, 0);
505 if (IS_ERR(bh))
506 return PTR_ERR(bh);
507 tmp = min(bsize - boff, to - from);
508 BUG_ON(from + tmp > to || tmp > bsize);
509 memcpy(data + from, AFFS_DATA(bh) + boff, tmp);
510 affs_brelse(bh);
511 bidx++;
512 from += tmp;
513 boff = 0;
514 }
515 flush_dcache_page(page);
516 kunmap(page);
517 return 0;
518 }
519
520 static int
521 affs_extent_file_ofs(struct inode *inode, u32 newsize)
522 {
523 struct super_block *sb = inode->i_sb;
524 struct buffer_head *bh, *prev_bh;
525 u32 bidx, boff;
526 u32 size, bsize;
527 u32 tmp;
528
529 pr_debug("AFFS: extent_file(%u, %d)\n", (u32)inode->i_ino, newsize);
530 bsize = AFFS_SB(sb)->s_data_blksize;
531 bh = NULL;
532 size = AFFS_I(inode)->mmu_private;
533 bidx = size / bsize;
534 boff = size % bsize;
535 if (boff) {
536 bh = affs_bread_ino(inode, bidx, 0);
537 if (IS_ERR(bh))
538 return PTR_ERR(bh);
539 tmp = min(bsize - boff, newsize - size);
540 BUG_ON(boff + tmp > bsize || tmp > bsize);
541 memset(AFFS_DATA(bh) + boff, 0, tmp);
542 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(be32_to_cpu(AFFS_DATA_HEAD(bh)->size) + tmp);
543 affs_fix_checksum(sb, bh);
544 mark_buffer_dirty_inode(bh, inode);
545 size += tmp;
546 bidx++;
547 } else if (bidx) {
548 bh = affs_bread_ino(inode, bidx - 1, 0);
549 if (IS_ERR(bh))
550 return PTR_ERR(bh);
551 }
552
553 while (size < newsize) {
554 prev_bh = bh;
555 bh = affs_getzeroblk_ino(inode, bidx);
556 if (IS_ERR(bh))
557 goto out;
558 tmp = min(bsize, newsize - size);
559 BUG_ON(tmp > bsize);
560 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
561 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
562 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
563 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
564 affs_fix_checksum(sb, bh);
565 bh->b_state &= ~(1UL << BH_New);
566 mark_buffer_dirty_inode(bh, inode);
567 if (prev_bh) {
568 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
569 if (tmp)
570 affs_warning(sb, "extent_file_ofs", "next block already set for %d (%d)", bidx, tmp);
571 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
572 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
573 mark_buffer_dirty_inode(prev_bh, inode);
574 affs_brelse(prev_bh);
575 }
576 size += bsize;
577 bidx++;
578 }
579 affs_brelse(bh);
580 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
581 return 0;
582
583 out:
584 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
585 return PTR_ERR(bh);
586 }
587
588 static int
589 affs_readpage_ofs(struct file *file, struct page *page)
590 {
591 struct inode *inode = page->mapping->host;
592 u32 to;
593 int err;
594
595 pr_debug("AFFS: read_page(%u, %ld)\n", (u32)inode->i_ino, page->index);
596 to = PAGE_CACHE_SIZE;
597 if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
598 to = inode->i_size & ~PAGE_CACHE_MASK;
599 memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
600 }
601
602 err = affs_do_readpage_ofs(file, page, 0, to);
603 if (!err)
604 SetPageUptodate(page);
605 unlock_page(page);
606 return err;
607 }
608
609 static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
610 loff_t pos, unsigned len, unsigned flags,
611 struct page **pagep, void **fsdata)
612 {
613 struct inode *inode = mapping->host;
614 struct page *page;
615 pgoff_t index;
616 int err = 0;
617
618 pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len);
619 if (pos > AFFS_I(inode)->mmu_private) {
620 /* XXX: this probably leaves a too-big i_size in case of
621 * failure. Should really be updating i_size at write_end time
622 */
623 err = affs_extent_file_ofs(inode, pos);
624 if (err)
625 return err;
626 }
627
628 index = pos >> PAGE_CACHE_SHIFT;
629 page = __grab_cache_page(mapping, index);
630 if (!page)
631 return -ENOMEM;
632 *pagep = page;
633
634 if (PageUptodate(page))
635 return 0;
636
637 /* XXX: inefficient but safe in the face of short writes */
638 err = affs_do_readpage_ofs(file, page, 0, PAGE_CACHE_SIZE);
639 if (err) {
640 unlock_page(page);
641 page_cache_release(page);
642 }
643 return err;
644 }
645
646 static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
647 loff_t pos, unsigned len, unsigned copied,
648 struct page *page, void *fsdata)
649 {
650 struct inode *inode = mapping->host;
651 struct super_block *sb = inode->i_sb;
652 struct buffer_head *bh, *prev_bh;
653 char *data;
654 u32 bidx, boff, bsize;
655 unsigned from, to;
656 u32 tmp;
657 int written;
658
659 from = pos & (PAGE_CACHE_SIZE - 1);
660 to = pos + len;
661 /*
662 * XXX: not sure if this can handle short copies (len < copied), but
663 * we don't have to, because the page should always be uptodate here,
664 * due to write_begin.
665 */
666
667 pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len);
668 bsize = AFFS_SB(sb)->s_data_blksize;
669 data = page_address(page);
670
671 bh = NULL;
672 written = 0;
673 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
674 bidx = tmp / bsize;
675 boff = tmp % bsize;
676 if (boff) {
677 bh = affs_bread_ino(inode, bidx, 0);
678 if (IS_ERR(bh))
679 return PTR_ERR(bh);
680 tmp = min(bsize - boff, to - from);
681 BUG_ON(boff + tmp > bsize || tmp > bsize);
682 memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
683 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(be32_to_cpu(AFFS_DATA_HEAD(bh)->size) + tmp);
684 affs_fix_checksum(sb, bh);
685 mark_buffer_dirty_inode(bh, inode);
686 written += tmp;
687 from += tmp;
688 bidx++;
689 } else if (bidx) {
690 bh = affs_bread_ino(inode, bidx - 1, 0);
691 if (IS_ERR(bh))
692 return PTR_ERR(bh);
693 }
694 while (from + bsize <= to) {
695 prev_bh = bh;
696 bh = affs_getemptyblk_ino(inode, bidx);
697 if (IS_ERR(bh))
698 goto out;
699 memcpy(AFFS_DATA(bh), data + from, bsize);
700 if (buffer_new(bh)) {
701 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
702 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
703 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
704 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
705 AFFS_DATA_HEAD(bh)->next = 0;
706 bh->b_state &= ~(1UL << BH_New);
707 if (prev_bh) {
708 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
709 if (tmp)
710 affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
711 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
712 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
713 mark_buffer_dirty_inode(prev_bh, inode);
714 }
715 }
716 affs_brelse(prev_bh);
717 affs_fix_checksum(sb, bh);
718 mark_buffer_dirty_inode(bh, inode);
719 written += bsize;
720 from += bsize;
721 bidx++;
722 }
723 if (from < to) {
724 prev_bh = bh;
725 bh = affs_bread_ino(inode, bidx, 1);
726 if (IS_ERR(bh))
727 goto out;
728 tmp = min(bsize, to - from);
729 BUG_ON(tmp > bsize);
730 memcpy(AFFS_DATA(bh), data + from, tmp);
731 if (buffer_new(bh)) {
732 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
733 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
734 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
735 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
736 AFFS_DATA_HEAD(bh)->next = 0;
737 bh->b_state &= ~(1UL << BH_New);
738 if (prev_bh) {
739 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
740 if (tmp)
741 affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
742 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
743 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
744 mark_buffer_dirty_inode(prev_bh, inode);
745 }
746 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
747 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
748 affs_brelse(prev_bh);
749 affs_fix_checksum(sb, bh);
750 mark_buffer_dirty_inode(bh, inode);
751 written += tmp;
752 from += tmp;
753 bidx++;
754 }
755 SetPageUptodate(page);
756
757 done:
758 affs_brelse(bh);
759 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
760 if (tmp > inode->i_size)
761 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
762
763 unlock_page(page);
764 page_cache_release(page);
765
766 return written;
767
768 out:
769 bh = prev_bh;
770 if (!written)
771 written = PTR_ERR(bh);
772 goto done;
773 }
774
775 const struct address_space_operations affs_aops_ofs = {
776 .readpage = affs_readpage_ofs,
777 //.writepage = affs_writepage_ofs,
778 //.sync_page = affs_sync_page_ofs,
779 .write_begin = affs_write_begin_ofs,
780 .write_end = affs_write_end_ofs
781 };
782
783 /* Free any preallocated blocks. */
784
785 void
786 affs_free_prealloc(struct inode *inode)
787 {
788 struct super_block *sb = inode->i_sb;
789
790 pr_debug("AFFS: free_prealloc(ino=%lu)\n", inode->i_ino);
791
792 while (AFFS_I(inode)->i_pa_cnt) {
793 AFFS_I(inode)->i_pa_cnt--;
794 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
795 }
796 }
797
798 /* Truncate (or enlarge) a file to the requested size. */
799
800 void
801 affs_truncate(struct inode *inode)
802 {
803 struct super_block *sb = inode->i_sb;
804 u32 ext, ext_key;
805 u32 last_blk, blkcnt, blk;
806 u32 size;
807 struct buffer_head *ext_bh;
808 int i;
809
810 pr_debug("AFFS: truncate(inode=%d, oldsize=%u, newsize=%u)\n",
811 (u32)inode->i_ino, (u32)AFFS_I(inode)->mmu_private, (u32)inode->i_size);
812
813 last_blk = 0;
814 ext = 0;
815 if (inode->i_size) {
816 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
817 ext = last_blk / AFFS_SB(sb)->s_hashsize;
818 }
819
820 if (inode->i_size > AFFS_I(inode)->mmu_private) {
821 struct address_space *mapping = inode->i_mapping;
822 struct page *page;
823 void *fsdata;
824 u32 size = inode->i_size;
825 int res;
826
827 res = mapping->a_ops->write_begin(NULL, mapping, size, 0, 0, &page, &fsdata);
828 if (!res)
829 res = mapping->a_ops->write_end(NULL, mapping, size, 0, 0, page, fsdata);
830 mark_inode_dirty(inode);
831 return;
832 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
833 return;
834
835 // lock cache
836 ext_bh = affs_get_extblock(inode, ext);
837 if (IS_ERR(ext_bh)) {
838 affs_warning(sb, "truncate", "unexpected read error for ext block %u (%d)",
839 ext, PTR_ERR(ext_bh));
840 return;
841 }
842 if (AFFS_I(inode)->i_lc) {
843 /* clear linear cache */
844 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
845 if (AFFS_I(inode)->i_lc_size > i) {
846 AFFS_I(inode)->i_lc_size = i;
847 for (; i < AFFS_LC_SIZE; i++)
848 AFFS_I(inode)->i_lc[i] = 0;
849 }
850 /* clear associative cache */
851 for (i = 0; i < AFFS_AC_SIZE; i++)
852 if (AFFS_I(inode)->i_ac[i].ext >= ext)
853 AFFS_I(inode)->i_ac[i].ext = 0;
854 }
855 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
856
857 blkcnt = AFFS_I(inode)->i_blkcnt;
858 i = 0;
859 blk = last_blk;
860 if (inode->i_size) {
861 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
862 blk++;
863 } else
864 AFFS_HEAD(ext_bh)->first_data = 0;
865 size = AFFS_SB(sb)->s_hashsize;
866 if (size > blkcnt - blk + i)
867 size = blkcnt - blk + i;
868 for (; i < size; i++, blk++) {
869 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
870 AFFS_BLOCK(sb, ext_bh, i) = 0;
871 }
872 AFFS_TAIL(sb, ext_bh)->extension = 0;
873 affs_fix_checksum(sb, ext_bh);
874 mark_buffer_dirty_inode(ext_bh, inode);
875 affs_brelse(ext_bh);
876
877 if (inode->i_size) {
878 AFFS_I(inode)->i_blkcnt = last_blk + 1;
879 AFFS_I(inode)->i_extcnt = ext + 1;
880 if (AFFS_SB(sb)->s_flags & SF_OFS) {
881 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
882 u32 tmp;
883 if (IS_ERR(ext_bh)) {
884 affs_warning(sb, "truncate", "unexpected read error for last block %u (%d)",
885 ext, PTR_ERR(ext_bh));
886 return;
887 }
888 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
889 AFFS_DATA_HEAD(bh)->next = 0;
890 affs_adjust_checksum(bh, -tmp);
891 affs_brelse(bh);
892 }
893 } else {
894 AFFS_I(inode)->i_blkcnt = 0;
895 AFFS_I(inode)->i_extcnt = 1;
896 }
897 AFFS_I(inode)->mmu_private = inode->i_size;
898 // unlock cache
899
900 while (ext_key) {
901 ext_bh = affs_bread(sb, ext_key);
902 size = AFFS_SB(sb)->s_hashsize;
903 if (size > blkcnt - blk)
904 size = blkcnt - blk;
905 for (i = 0; i < size; i++, blk++)
906 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
907 affs_free_block(sb, ext_key);
908 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
909 affs_brelse(ext_bh);
910 }
911 affs_free_prealloc(inode);
912 }
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