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sched: move the __update_rq_clock() call to scheduler_tick()
[usb.git] / fs / affs / file.c
blobc314a35f09187bac060460a2fe948b4434f36c71
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 if (block > (sector_t)0x7fffffffUL)
329 BUG();
330
331 if (block >= AFFS_I(inode)->i_blkcnt) {
332 if (block > AFFS_I(inode)->i_blkcnt || !create)
333 goto err_big;
334 } else
335 create = 0;
336
337 //lock cache
338 affs_lock_ext(inode);
339
340 ext = (u32)block / AFFS_SB(sb)->s_hashsize;
341 block -= ext * AFFS_SB(sb)->s_hashsize;
342 ext_bh = affs_get_extblock(inode, ext);
343 if (IS_ERR(ext_bh))
344 goto err_ext;
345 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
346
347 if (create) {
348 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
349 if (!blocknr)
350 goto err_alloc;
351 set_buffer_new(bh_result);
352 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
353 AFFS_I(inode)->i_blkcnt++;
354
355 /* store new block */
356 if (bh_result->b_blocknr)
357 affs_warning(sb, "get_block", "block already set (%x)", bh_result->b_blocknr);
358 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
359 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
360 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
361 bh_result->b_blocknr = blocknr;
362
363 if (!block) {
364 /* insert first block into header block */
365 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
366 if (tmp)
367 affs_warning(sb, "get_block", "first block already set (%d)", tmp);
368 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
369 affs_adjust_checksum(ext_bh, blocknr - tmp);
370 }
371 }
372
373 affs_brelse(ext_bh);
374 //unlock cache
375 affs_unlock_ext(inode);
376 return 0;
377
378 err_big:
379 affs_error(inode->i_sb,"get_block","strange block request %d", block);
380 return -EIO;
381 err_ext:
382 // unlock cache
383 affs_unlock_ext(inode);
384 return PTR_ERR(ext_bh);
385 err_alloc:
386 brelse(ext_bh);
387 clear_buffer_mapped(bh_result);
388 bh_result->b_bdev = NULL;
389 // unlock cache
390 affs_unlock_ext(inode);
391 return -ENOSPC;
392 }
393
394 static int affs_writepage(struct page *page, struct writeback_control *wbc)
395 {
396 return block_write_full_page(page, affs_get_block, wbc);
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 static int affs_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
403 {
404 return cont_prepare_write(page, from, to, affs_get_block,
405 &AFFS_I(page->mapping->host)->mmu_private);
406 }
407 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
408 {
409 return generic_block_bmap(mapping,block,affs_get_block);
410 }
411 const struct address_space_operations affs_aops = {
412 .readpage = affs_readpage,
413 .writepage = affs_writepage,
414 .sync_page = block_sync_page,
415 .prepare_write = affs_prepare_write,
416 .commit_write = generic_commit_write,
417 .bmap = _affs_bmap
418 };
419
420 static inline struct buffer_head *
421 affs_bread_ino(struct inode *inode, int block, int create)
422 {
423 struct buffer_head *bh, tmp_bh;
424 int err;
425
426 tmp_bh.b_state = 0;
427 err = affs_get_block(inode, block, &tmp_bh, create);
428 if (!err) {
429 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
430 if (bh) {
431 bh->b_state |= tmp_bh.b_state;
432 return bh;
433 }
434 err = -EIO;
435 }
436 return ERR_PTR(err);
437 }
438
439 static inline struct buffer_head *
440 affs_getzeroblk_ino(struct inode *inode, int block)
441 {
442 struct buffer_head *bh, tmp_bh;
443 int err;
444
445 tmp_bh.b_state = 0;
446 err = affs_get_block(inode, block, &tmp_bh, 1);
447 if (!err) {
448 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
449 if (bh) {
450 bh->b_state |= tmp_bh.b_state;
451 return bh;
452 }
453 err = -EIO;
454 }
455 return ERR_PTR(err);
456 }
457
458 static inline struct buffer_head *
459 affs_getemptyblk_ino(struct inode *inode, int block)
460 {
461 struct buffer_head *bh, tmp_bh;
462 int err;
463
464 tmp_bh.b_state = 0;
465 err = affs_get_block(inode, block, &tmp_bh, 1);
466 if (!err) {
467 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
468 if (bh) {
469 bh->b_state |= tmp_bh.b_state;
470 return bh;
471 }
472 err = -EIO;
473 }
474 return ERR_PTR(err);
475 }
476
477 static int
478 affs_do_readpage_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
479 {
480 struct inode *inode = page->mapping->host;
481 struct super_block *sb = inode->i_sb;
482 struct buffer_head *bh;
483 char *data;
484 u32 bidx, boff, bsize;
485 u32 tmp;
486
487 pr_debug("AFFS: read_page(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
488 if (from > to || to > PAGE_CACHE_SIZE)
489 BUG();
490 kmap(page);
491 data = page_address(page);
492 bsize = AFFS_SB(sb)->s_data_blksize;
493 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
494 bidx = tmp / bsize;
495 boff = tmp % bsize;
496
497 while (from < to) {
498 bh = affs_bread_ino(inode, bidx, 0);
499 if (IS_ERR(bh))
500 return PTR_ERR(bh);
501 tmp = min(bsize - boff, to - from);
502 if (from + tmp > to || tmp > bsize)
503 BUG();
504 memcpy(data + from, AFFS_DATA(bh) + boff, tmp);
505 affs_brelse(bh);
506 bidx++;
507 from += tmp;
508 boff = 0;
509 }
510 flush_dcache_page(page);
511 kunmap(page);
512 return 0;
513 }
514
515 static int
516 affs_extent_file_ofs(struct inode *inode, u32 newsize)
517 {
518 struct super_block *sb = inode->i_sb;
519 struct buffer_head *bh, *prev_bh;
520 u32 bidx, boff;
521 u32 size, bsize;
522 u32 tmp;
523
524 pr_debug("AFFS: extent_file(%u, %d)\n", (u32)inode->i_ino, newsize);
525 bsize = AFFS_SB(sb)->s_data_blksize;
526 bh = NULL;
527 size = AFFS_I(inode)->mmu_private;
528 bidx = size / bsize;
529 boff = size % bsize;
530 if (boff) {
531 bh = affs_bread_ino(inode, bidx, 0);
532 if (IS_ERR(bh))
533 return PTR_ERR(bh);
534 tmp = min(bsize - boff, newsize - size);
535 if (boff + tmp > bsize || tmp > bsize)
536 BUG();
537 memset(AFFS_DATA(bh) + boff, 0, tmp);
538 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(be32_to_cpu(AFFS_DATA_HEAD(bh)->size) + tmp);
539 affs_fix_checksum(sb, bh);
540 mark_buffer_dirty_inode(bh, inode);
541 size += tmp;
542 bidx++;
543 } else if (bidx) {
544 bh = affs_bread_ino(inode, bidx - 1, 0);
545 if (IS_ERR(bh))
546 return PTR_ERR(bh);
547 }
548
549 while (size < newsize) {
550 prev_bh = bh;
551 bh = affs_getzeroblk_ino(inode, bidx);
552 if (IS_ERR(bh))
553 goto out;
554 tmp = min(bsize, newsize - size);
555 if (tmp > bsize)
556 BUG();
557 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
558 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
559 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
560 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
561 affs_fix_checksum(sb, bh);
562 bh->b_state &= ~(1UL << BH_New);
563 mark_buffer_dirty_inode(bh, inode);
564 if (prev_bh) {
565 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
566 if (tmp)
567 affs_warning(sb, "extent_file_ofs", "next block already set for %d (%d)", bidx, tmp);
568 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
569 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
570 mark_buffer_dirty_inode(prev_bh, inode);
571 affs_brelse(prev_bh);
572 }
573 size += bsize;
574 bidx++;
575 }
576 affs_brelse(bh);
577 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
578 return 0;
579
580 out:
581 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
582 return PTR_ERR(bh);
583 }
584
585 static int
586 affs_readpage_ofs(struct file *file, struct page *page)
587 {
588 struct inode *inode = page->mapping->host;
589 u32 to;
590 int err;
591
592 pr_debug("AFFS: read_page(%u, %ld)\n", (u32)inode->i_ino, page->index);
593 to = PAGE_CACHE_SIZE;
594 if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
595 to = inode->i_size & ~PAGE_CACHE_MASK;
596 memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
597 }
598
599 err = affs_do_readpage_ofs(file, page, 0, to);
600 if (!err)
601 SetPageUptodate(page);
602 unlock_page(page);
603 return err;
604 }
605
606 static int affs_prepare_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
607 {
608 struct inode *inode = page->mapping->host;
609 u32 size, offset;
610 u32 tmp;
611 int err = 0;
612
613 pr_debug("AFFS: prepare_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
614 offset = page->index << PAGE_CACHE_SHIFT;
615 if (offset + from > AFFS_I(inode)->mmu_private) {
616 err = affs_extent_file_ofs(inode, offset + from);
617 if (err)
618 return err;
619 }
620 size = inode->i_size;
621
622 if (PageUptodate(page))
623 return 0;
624
625 if (from) {
626 err = affs_do_readpage_ofs(file, page, 0, from);
627 if (err)
628 return err;
629 }
630 if (to < PAGE_CACHE_SIZE) {
631 zero_user_page(page, to, PAGE_CACHE_SIZE - to, KM_USER0);
632 if (size > offset + to) {
633 if (size < offset + PAGE_CACHE_SIZE)
634 tmp = size & ~PAGE_CACHE_MASK;
635 else
636 tmp = PAGE_CACHE_SIZE;
637 err = affs_do_readpage_ofs(file, page, to, tmp);
638 }
639 }
640 return err;
641 }
642
643 static int affs_commit_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
644 {
645 struct inode *inode = page->mapping->host;
646 struct super_block *sb = inode->i_sb;
647 struct buffer_head *bh, *prev_bh;
648 char *data;
649 u32 bidx, boff, bsize;
650 u32 tmp;
651 int written;
652
653 pr_debug("AFFS: commit_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
654 bsize = AFFS_SB(sb)->s_data_blksize;
655 data = page_address(page);
656
657 bh = NULL;
658 written = 0;
659 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
660 bidx = tmp / bsize;
661 boff = tmp % bsize;
662 if (boff) {
663 bh = affs_bread_ino(inode, bidx, 0);
664 if (IS_ERR(bh))
665 return PTR_ERR(bh);
666 tmp = min(bsize - boff, to - from);
667 if (boff + tmp > bsize || tmp > bsize)
668 BUG();
669 memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
670 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(be32_to_cpu(AFFS_DATA_HEAD(bh)->size) + tmp);
671 affs_fix_checksum(sb, bh);
672 mark_buffer_dirty_inode(bh, inode);
673 written += tmp;
674 from += tmp;
675 bidx++;
676 } else if (bidx) {
677 bh = affs_bread_ino(inode, bidx - 1, 0);
678 if (IS_ERR(bh))
679 return PTR_ERR(bh);
680 }
681 while (from + bsize <= to) {
682 prev_bh = bh;
683 bh = affs_getemptyblk_ino(inode, bidx);
684 if (IS_ERR(bh))
685 goto out;
686 memcpy(AFFS_DATA(bh), data + from, bsize);
687 if (buffer_new(bh)) {
688 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
689 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
690 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
691 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
692 AFFS_DATA_HEAD(bh)->next = 0;
693 bh->b_state &= ~(1UL << BH_New);
694 if (prev_bh) {
695 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
696 if (tmp)
697 affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
698 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
699 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
700 mark_buffer_dirty_inode(prev_bh, inode);
701 }
702 }
703 affs_brelse(prev_bh);
704 affs_fix_checksum(sb, bh);
705 mark_buffer_dirty_inode(bh, inode);
706 written += bsize;
707 from += bsize;
708 bidx++;
709 }
710 if (from < to) {
711 prev_bh = bh;
712 bh = affs_bread_ino(inode, bidx, 1);
713 if (IS_ERR(bh))
714 goto out;
715 tmp = min(bsize, to - from);
716 if (tmp > bsize)
717 BUG();
718 memcpy(AFFS_DATA(bh), data + from, tmp);
719 if (buffer_new(bh)) {
720 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
721 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
722 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
723 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
724 AFFS_DATA_HEAD(bh)->next = 0;
725 bh->b_state &= ~(1UL << BH_New);
726 if (prev_bh) {
727 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
728 if (tmp)
729 affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
730 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
731 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
732 mark_buffer_dirty_inode(prev_bh, inode);
733 }
734 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
735 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
736 affs_brelse(prev_bh);
737 affs_fix_checksum(sb, bh);
738 mark_buffer_dirty_inode(bh, inode);
739 written += tmp;
740 from += tmp;
741 bidx++;
742 }
743 SetPageUptodate(page);
744
745 done:
746 affs_brelse(bh);
747 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
748 if (tmp > inode->i_size)
749 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
750
751 return written;
752
753 out:
754 bh = prev_bh;
755 if (!written)
756 written = PTR_ERR(bh);
757 goto done;
758 }
759
760 const struct address_space_operations affs_aops_ofs = {
761 .readpage = affs_readpage_ofs,
762 //.writepage = affs_writepage_ofs,
763 //.sync_page = affs_sync_page_ofs,
764 .prepare_write = affs_prepare_write_ofs,
765 .commit_write = affs_commit_write_ofs
766 };
767
768 /* Free any preallocated blocks. */
769
770 void
771 affs_free_prealloc(struct inode *inode)
772 {
773 struct super_block *sb = inode->i_sb;
774
775 pr_debug("AFFS: free_prealloc(ino=%lu)\n", inode->i_ino);
776
777 while (AFFS_I(inode)->i_pa_cnt) {
778 AFFS_I(inode)->i_pa_cnt--;
779 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
780 }
781 }
782
783 /* Truncate (or enlarge) a file to the requested size. */
784
785 void
786 affs_truncate(struct inode *inode)
787 {
788 struct super_block *sb = inode->i_sb;
789 u32 ext, ext_key;
790 u32 last_blk, blkcnt, blk;
791 u32 size;
792 struct buffer_head *ext_bh;
793 int i;
794
795 pr_debug("AFFS: truncate(inode=%d, oldsize=%u, newsize=%u)\n",
796 (u32)inode->i_ino, (u32)AFFS_I(inode)->mmu_private, (u32)inode->i_size);
797
798 last_blk = 0;
799 ext = 0;
800 if (inode->i_size) {
801 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
802 ext = last_blk / AFFS_SB(sb)->s_hashsize;
803 }
804
805 if (inode->i_size > AFFS_I(inode)->mmu_private) {
806 struct address_space *mapping = inode->i_mapping;
807 struct page *page;
808 u32 size = inode->i_size - 1;
809 int res;
810
811 page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT);
812 if (!page)
813 return;
814 size = (size & (PAGE_CACHE_SIZE - 1)) + 1;
815 res = mapping->a_ops->prepare_write(NULL, page, size, size);
816 if (!res)
817 res = mapping->a_ops->commit_write(NULL, page, size, size);
818 unlock_page(page);
819 page_cache_release(page);
820 mark_inode_dirty(inode);
821 return;
822 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
823 return;
824
825 // lock cache
826 ext_bh = affs_get_extblock(inode, ext);
827 if (IS_ERR(ext_bh)) {
828 affs_warning(sb, "truncate", "unexpected read error for ext block %u (%d)",
829 ext, PTR_ERR(ext_bh));
830 return;
831 }
832 if (AFFS_I(inode)->i_lc) {
833 /* clear linear cache */
834 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
835 if (AFFS_I(inode)->i_lc_size > i) {
836 AFFS_I(inode)->i_lc_size = i;
837 for (; i < AFFS_LC_SIZE; i++)
838 AFFS_I(inode)->i_lc[i] = 0;
839 }
840 /* clear associative cache */
841 for (i = 0; i < AFFS_AC_SIZE; i++)
842 if (AFFS_I(inode)->i_ac[i].ext >= ext)
843 AFFS_I(inode)->i_ac[i].ext = 0;
844 }
845 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
846
847 blkcnt = AFFS_I(inode)->i_blkcnt;
848 i = 0;
849 blk = last_blk;
850 if (inode->i_size) {
851 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
852 blk++;
853 } else
854 AFFS_HEAD(ext_bh)->first_data = 0;
855 size = AFFS_SB(sb)->s_hashsize;
856 if (size > blkcnt - blk + i)
857 size = blkcnt - blk + i;
858 for (; i < size; i++, blk++) {
859 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
860 AFFS_BLOCK(sb, ext_bh, i) = 0;
861 }
862 AFFS_TAIL(sb, ext_bh)->extension = 0;
863 affs_fix_checksum(sb, ext_bh);
864 mark_buffer_dirty_inode(ext_bh, inode);
865 affs_brelse(ext_bh);
866
867 if (inode->i_size) {
868 AFFS_I(inode)->i_blkcnt = last_blk + 1;
869 AFFS_I(inode)->i_extcnt = ext + 1;
870 if (AFFS_SB(sb)->s_flags & SF_OFS) {
871 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
872 u32 tmp;
873 if (IS_ERR(ext_bh)) {
874 affs_warning(sb, "truncate", "unexpected read error for last block %u (%d)",
875 ext, PTR_ERR(ext_bh));
876 return;
877 }
878 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
879 AFFS_DATA_HEAD(bh)->next = 0;
880 affs_adjust_checksum(bh, -tmp);
881 affs_brelse(bh);
882 }
883 } else {
884 AFFS_I(inode)->i_blkcnt = 0;
885 AFFS_I(inode)->i_extcnt = 1;
886 }
887 AFFS_I(inode)->mmu_private = inode->i_size;
888 // unlock cache
889
890 while (ext_key) {
891 ext_bh = affs_bread(sb, ext_key);
892 size = AFFS_SB(sb)->s_hashsize;
893 if (size > blkcnt - blk)
894 size = blkcnt - blk;
895 for (i = 0; i < size; i++, blk++)
896 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
897 affs_free_block(sb, ext_key);
898 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
899 affs_brelse(ext_bh);
900 }
901 affs_free_prealloc(inode);
902 }
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