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hyperv: Add processing of MTU reduced by the host
[linux/fpc-iii.git] / fs / affs / file.c
blob1ed590aafecf744884c3e55af7cd9627d1c729f8
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 = new_sync_read,
31 .read_iter = generic_file_read_iter,
32 .write = new_sync_write,
33 .write_iter = generic_file_write_iter,
34 .mmap = generic_file_mmap,
35 .open = affs_file_open,
36 .release = affs_file_release,
37 .fsync = affs_file_fsync,
38 .splice_read = generic_file_splice_read,
39 };
40
41 const struct inode_operations affs_file_inode_operations = {
42 .setattr = affs_notify_change,
43 };
44
45 static int
46 affs_file_open(struct inode *inode, struct file *filp)
47 {
48 pr_debug("open(%lu,%d)\n",
49 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
50 atomic_inc(&AFFS_I(inode)->i_opencnt);
51 return 0;
52 }
53
54 static int
55 affs_file_release(struct inode *inode, struct file *filp)
56 {
57 pr_debug("release(%lu, %d)\n",
58 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
59
60 if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
61 mutex_lock(&inode->i_mutex);
62 if (inode->i_size != AFFS_I(inode)->mmu_private)
63 affs_truncate(inode);
64 affs_free_prealloc(inode);
65 mutex_unlock(&inode->i_mutex);
66 }
67
68 return 0;
69 }
70
71 static int
72 affs_grow_extcache(struct inode *inode, u32 lc_idx)
73 {
74 struct super_block *sb = inode->i_sb;
75 struct buffer_head *bh;
76 u32 lc_max;
77 int i, j, key;
78
79 if (!AFFS_I(inode)->i_lc) {
80 char *ptr = (char *)get_zeroed_page(GFP_NOFS);
81 if (!ptr)
82 return -ENOMEM;
83 AFFS_I(inode)->i_lc = (u32 *)ptr;
84 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
85 }
86
87 lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
88
89 if (AFFS_I(inode)->i_extcnt > lc_max) {
90 u32 lc_shift, lc_mask, tmp, off;
91
92 /* need to recalculate linear cache, start from old size */
93 lc_shift = AFFS_I(inode)->i_lc_shift;
94 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
95 for (; tmp; tmp >>= 1)
96 lc_shift++;
97 lc_mask = (1 << lc_shift) - 1;
98
99 /* fix idx and old size to new shift */
100 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
101 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
102
103 /* first shrink old cache to make more space */
104 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
105 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
106 AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
107
108 AFFS_I(inode)->i_lc_shift = lc_shift;
109 AFFS_I(inode)->i_lc_mask = lc_mask;
110 }
111
112 /* fill cache to the needed index */
113 i = AFFS_I(inode)->i_lc_size;
114 AFFS_I(inode)->i_lc_size = lc_idx + 1;
115 for (; i <= lc_idx; i++) {
116 if (!i) {
117 AFFS_I(inode)->i_lc[0] = inode->i_ino;
118 continue;
119 }
120 key = AFFS_I(inode)->i_lc[i - 1];
121 j = AFFS_I(inode)->i_lc_mask + 1;
122 // unlock cache
123 for (; j > 0; j--) {
124 bh = affs_bread(sb, key);
125 if (!bh)
126 goto err;
127 key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
128 affs_brelse(bh);
129 }
130 // lock cache
131 AFFS_I(inode)->i_lc[i] = key;
132 }
133
134 return 0;
135
136 err:
137 // lock cache
138 return -EIO;
139 }
140
141 static struct buffer_head *
142 affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
143 {
144 struct super_block *sb = inode->i_sb;
145 struct buffer_head *new_bh;
146 u32 blocknr, tmp;
147
148 blocknr = affs_alloc_block(inode, bh->b_blocknr);
149 if (!blocknr)
150 return ERR_PTR(-ENOSPC);
151
152 new_bh = affs_getzeroblk(sb, blocknr);
153 if (!new_bh) {
154 affs_free_block(sb, blocknr);
155 return ERR_PTR(-EIO);
156 }
157
158 AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
159 AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
160 AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
161 AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
162 affs_fix_checksum(sb, new_bh);
163
164 mark_buffer_dirty_inode(new_bh, inode);
165
166 tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
167 if (tmp)
168 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
169 AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
170 affs_adjust_checksum(bh, blocknr - tmp);
171 mark_buffer_dirty_inode(bh, inode);
172
173 AFFS_I(inode)->i_extcnt++;
174 mark_inode_dirty(inode);
175
176 return new_bh;
177 }
178
179 static inline struct buffer_head *
180 affs_get_extblock(struct inode *inode, u32 ext)
181 {
182 /* inline the simplest case: same extended block as last time */
183 struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
184 if (ext == AFFS_I(inode)->i_ext_last)
185 get_bh(bh);
186 else
187 /* we have to do more (not inlined) */
188 bh = affs_get_extblock_slow(inode, ext);
189
190 return bh;
191 }
192
193 static struct buffer_head *
194 affs_get_extblock_slow(struct inode *inode, u32 ext)
195 {
196 struct super_block *sb = inode->i_sb;
197 struct buffer_head *bh;
198 u32 ext_key;
199 u32 lc_idx, lc_off, ac_idx;
200 u32 tmp, idx;
201
202 if (ext == AFFS_I(inode)->i_ext_last + 1) {
203 /* read the next extended block from the current one */
204 bh = AFFS_I(inode)->i_ext_bh;
205 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
206 if (ext < AFFS_I(inode)->i_extcnt)
207 goto read_ext;
208 if (ext > AFFS_I(inode)->i_extcnt)
209 BUG();
210 bh = affs_alloc_extblock(inode, bh, ext);
211 if (IS_ERR(bh))
212 return bh;
213 goto store_ext;
214 }
215
216 if (ext == 0) {
217 /* we seek back to the file header block */
218 ext_key = inode->i_ino;
219 goto read_ext;
220 }
221
222 if (ext >= AFFS_I(inode)->i_extcnt) {
223 struct buffer_head *prev_bh;
224
225 /* allocate a new extended block */
226 if (ext > AFFS_I(inode)->i_extcnt)
227 BUG();
228
229 /* get previous extended block */
230 prev_bh = affs_get_extblock(inode, ext - 1);
231 if (IS_ERR(prev_bh))
232 return prev_bh;
233 bh = affs_alloc_extblock(inode, prev_bh, ext);
234 affs_brelse(prev_bh);
235 if (IS_ERR(bh))
236 return bh;
237 goto store_ext;
238 }
239
240 again:
241 /* check if there is an extended cache and whether it's large enough */
242 lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
243 lc_off = ext & AFFS_I(inode)->i_lc_mask;
244
245 if (lc_idx >= AFFS_I(inode)->i_lc_size) {
246 int err;
247
248 err = affs_grow_extcache(inode, lc_idx);
249 if (err)
250 return ERR_PTR(err);
251 goto again;
252 }
253
254 /* every n'th key we find in the linear cache */
255 if (!lc_off) {
256 ext_key = AFFS_I(inode)->i_lc[lc_idx];
257 goto read_ext;
258 }
259
260 /* maybe it's still in the associative cache */
261 ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
262 if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
263 ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
264 goto read_ext;
265 }
266
267 /* try to find one of the previous extended blocks */
268 tmp = ext;
269 idx = ac_idx;
270 while (--tmp, --lc_off > 0) {
271 idx = (idx - 1) & AFFS_AC_MASK;
272 if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
273 ext_key = AFFS_I(inode)->i_ac[idx].key;
274 goto find_ext;
275 }
276 }
277
278 /* fall back to the linear cache */
279 ext_key = AFFS_I(inode)->i_lc[lc_idx];
280 find_ext:
281 /* read all extended blocks until we find the one we need */
282 //unlock cache
283 do {
284 bh = affs_bread(sb, ext_key);
285 if (!bh)
286 goto err_bread;
287 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
288 affs_brelse(bh);
289 tmp++;
290 } while (tmp < ext);
291 //lock cache
292
293 /* store it in the associative cache */
294 // recalculate ac_idx?
295 AFFS_I(inode)->i_ac[ac_idx].ext = ext;
296 AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
297
298 read_ext:
299 /* finally read the right extended block */
300 //unlock cache
301 bh = affs_bread(sb, ext_key);
302 if (!bh)
303 goto err_bread;
304 //lock cache
305
306 store_ext:
307 /* release old cached extended block and store the new one */
308 affs_brelse(AFFS_I(inode)->i_ext_bh);
309 AFFS_I(inode)->i_ext_last = ext;
310 AFFS_I(inode)->i_ext_bh = bh;
311 get_bh(bh);
312
313 return bh;
314
315 err_bread:
316 affs_brelse(bh);
317 return ERR_PTR(-EIO);
318 }
319
320 static int
321 affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
322 {
323 struct super_block *sb = inode->i_sb;
324 struct buffer_head *ext_bh;
325 u32 ext;
326
327 pr_debug("%s(%u, %lu)\n",
328 __func__, (u32)inode->i_ino, (unsigned long)block);
329
330 BUG_ON(block > (sector_t)0x7fffffffUL);
331
332 if (block >= AFFS_I(inode)->i_blkcnt) {
333 if (block > AFFS_I(inode)->i_blkcnt || !create)
334 goto err_big;
335 } else
336 create = 0;
337
338 //lock cache
339 affs_lock_ext(inode);
340
341 ext = (u32)block / AFFS_SB(sb)->s_hashsize;
342 block -= ext * AFFS_SB(sb)->s_hashsize;
343 ext_bh = affs_get_extblock(inode, ext);
344 if (IS_ERR(ext_bh))
345 goto err_ext;
346 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
347
348 if (create) {
349 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
350 if (!blocknr)
351 goto err_alloc;
352 set_buffer_new(bh_result);
353 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
354 AFFS_I(inode)->i_blkcnt++;
355
356 /* store new block */
357 if (bh_result->b_blocknr)
358 affs_warning(sb, "get_block", "block already set (%x)", bh_result->b_blocknr);
359 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
360 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
361 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
362 bh_result->b_blocknr = blocknr;
363
364 if (!block) {
365 /* insert first block into header block */
366 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
367 if (tmp)
368 affs_warning(sb, "get_block", "first block already set (%d)", tmp);
369 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
370 affs_adjust_checksum(ext_bh, blocknr - tmp);
371 }
372 }
373
374 affs_brelse(ext_bh);
375 //unlock cache
376 affs_unlock_ext(inode);
377 return 0;
378
379 err_big:
380 affs_error(inode->i_sb,"get_block","strange block request %d", block);
381 return -EIO;
382 err_ext:
383 // unlock cache
384 affs_unlock_ext(inode);
385 return PTR_ERR(ext_bh);
386 err_alloc:
387 brelse(ext_bh);
388 clear_buffer_mapped(bh_result);
389 bh_result->b_bdev = NULL;
390 // unlock cache
391 affs_unlock_ext(inode);
392 return -ENOSPC;
393 }
394
395 static int affs_writepage(struct page *page, struct writeback_control *wbc)
396 {
397 return block_write_full_page(page, affs_get_block, wbc);
398 }
399
400 static int affs_readpage(struct file *file, struct page *page)
401 {
402 return block_read_full_page(page, affs_get_block);
403 }
404
405 static void affs_write_failed(struct address_space *mapping, loff_t to)
406 {
407 struct inode *inode = mapping->host;
408
409 if (to > inode->i_size) {
410 truncate_pagecache(inode, inode->i_size);
411 affs_truncate(inode);
412 }
413 }
414
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
431 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
432 {
433 return generic_block_bmap(mapping,block,affs_get_block);
434 }
435
436 const struct address_space_operations affs_aops = {
437 .readpage = affs_readpage,
438 .writepage = affs_writepage,
439 .write_begin = affs_write_begin,
440 .write_end = generic_write_end,
441 .bmap = _affs_bmap
442 };
443
444 static inline struct buffer_head *
445 affs_bread_ino(struct inode *inode, int block, int create)
446 {
447 struct buffer_head *bh, tmp_bh;
448 int err;
449
450 tmp_bh.b_state = 0;
451 err = affs_get_block(inode, block, &tmp_bh, create);
452 if (!err) {
453 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
454 if (bh) {
455 bh->b_state |= tmp_bh.b_state;
456 return bh;
457 }
458 err = -EIO;
459 }
460 return ERR_PTR(err);
461 }
462
463 static inline struct buffer_head *
464 affs_getzeroblk_ino(struct inode *inode, int block)
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, 1);
471 if (!err) {
472 bh = affs_getzeroblk(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 *
483 affs_getemptyblk_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_getemptyblk(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 int
502 affs_do_readpage_ofs(struct page *page, unsigned to)
503 {
504 struct inode *inode = page->mapping->host;
505 struct super_block *sb = inode->i_sb;
506 struct buffer_head *bh;
507 char *data;
508 unsigned pos = 0;
509 u32 bidx, boff, bsize;
510 u32 tmp;
511
512 pr_debug("%s(%u, %ld, 0, %d)\n", __func__, (u32)inode->i_ino,
513 page->index, to);
514 BUG_ON(to > PAGE_CACHE_SIZE);
515 kmap(page);
516 data = page_address(page);
517 bsize = AFFS_SB(sb)->s_data_blksize;
518 tmp = page->index << PAGE_CACHE_SHIFT;
519 bidx = tmp / bsize;
520 boff = tmp % bsize;
521
522 while (pos < to) {
523 bh = affs_bread_ino(inode, bidx, 0);
524 if (IS_ERR(bh))
525 return PTR_ERR(bh);
526 tmp = min(bsize - boff, to - pos);
527 BUG_ON(pos + tmp > to || tmp > bsize);
528 memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
529 affs_brelse(bh);
530 bidx++;
531 pos += tmp;
532 boff = 0;
533 }
534 flush_dcache_page(page);
535 kunmap(page);
536 return 0;
537 }
538
539 static int
540 affs_extent_file_ofs(struct inode *inode, u32 newsize)
541 {
542 struct super_block *sb = inode->i_sb;
543 struct buffer_head *bh, *prev_bh;
544 u32 bidx, boff;
545 u32 size, bsize;
546 u32 tmp;
547
548 pr_debug("%s(%u, %d)\n", __func__, (u32)inode->i_ino, newsize);
549 bsize = AFFS_SB(sb)->s_data_blksize;
550 bh = NULL;
551 size = AFFS_I(inode)->mmu_private;
552 bidx = size / bsize;
553 boff = size % bsize;
554 if (boff) {
555 bh = affs_bread_ino(inode, bidx, 0);
556 if (IS_ERR(bh))
557 return PTR_ERR(bh);
558 tmp = min(bsize - boff, newsize - size);
559 BUG_ON(boff + tmp > bsize || tmp > bsize);
560 memset(AFFS_DATA(bh) + boff, 0, tmp);
561 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
562 affs_fix_checksum(sb, bh);
563 mark_buffer_dirty_inode(bh, inode);
564 size += tmp;
565 bidx++;
566 } else if (bidx) {
567 bh = affs_bread_ino(inode, bidx - 1, 0);
568 if (IS_ERR(bh))
569 return PTR_ERR(bh);
570 }
571
572 while (size < newsize) {
573 prev_bh = bh;
574 bh = affs_getzeroblk_ino(inode, bidx);
575 if (IS_ERR(bh))
576 goto out;
577 tmp = min(bsize, newsize - size);
578 BUG_ON(tmp > bsize);
579 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
580 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
581 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
582 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
583 affs_fix_checksum(sb, bh);
584 bh->b_state &= ~(1UL << BH_New);
585 mark_buffer_dirty_inode(bh, inode);
586 if (prev_bh) {
587 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
588
589 if (tmp_next)
590 affs_warning(sb, "extent_file_ofs",
591 "next block already set for %d (%d)",
592 bidx, tmp_next);
593 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
594 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
595 mark_buffer_dirty_inode(prev_bh, inode);
596 affs_brelse(prev_bh);
597 }
598 size += bsize;
599 bidx++;
600 }
601 affs_brelse(bh);
602 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
603 return 0;
604
605 out:
606 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
607 return PTR_ERR(bh);
608 }
609
610 static int
611 affs_readpage_ofs(struct file *file, struct page *page)
612 {
613 struct inode *inode = page->mapping->host;
614 u32 to;
615 int err;
616
617 pr_debug("%s(%u, %ld)\n", __func__, (u32)inode->i_ino, page->index);
618 to = PAGE_CACHE_SIZE;
619 if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
620 to = inode->i_size & ~PAGE_CACHE_MASK;
621 memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
622 }
623
624 err = affs_do_readpage_ofs(page, to);
625 if (!err)
626 SetPageUptodate(page);
627 unlock_page(page);
628 return err;
629 }
630
631 static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
632 loff_t pos, unsigned len, unsigned flags,
633 struct page **pagep, void **fsdata)
634 {
635 struct inode *inode = mapping->host;
636 struct page *page;
637 pgoff_t index;
638 int err = 0;
639
640 pr_debug("%s(%u, %llu, %llu)\n", __func__, (u32)inode->i_ino,
641 (unsigned long long)pos, (unsigned long long)pos + len);
642 if (pos > AFFS_I(inode)->mmu_private) {
643 /* XXX: this probably leaves a too-big i_size in case of
644 * failure. Should really be updating i_size at write_end time
645 */
646 err = affs_extent_file_ofs(inode, pos);
647 if (err)
648 return err;
649 }
650
651 index = pos >> PAGE_CACHE_SHIFT;
652 page = grab_cache_page_write_begin(mapping, index, flags);
653 if (!page)
654 return -ENOMEM;
655 *pagep = page;
656
657 if (PageUptodate(page))
658 return 0;
659
660 /* XXX: inefficient but safe in the face of short writes */
661 err = affs_do_readpage_ofs(page, PAGE_CACHE_SIZE);
662 if (err) {
663 unlock_page(page);
664 page_cache_release(page);
665 }
666 return err;
667 }
668
669 static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
670 loff_t pos, unsigned len, unsigned copied,
671 struct page *page, void *fsdata)
672 {
673 struct inode *inode = mapping->host;
674 struct super_block *sb = inode->i_sb;
675 struct buffer_head *bh, *prev_bh;
676 char *data;
677 u32 bidx, boff, bsize;
678 unsigned from, to;
679 u32 tmp;
680 int written;
681
682 from = pos & (PAGE_CACHE_SIZE - 1);
683 to = pos + len;
684 /*
685 * XXX: not sure if this can handle short copies (len < copied), but
686 * we don't have to, because the page should always be uptodate here,
687 * due to write_begin.
688 */
689
690 pr_debug("%s(%u, %llu, %llu)\n",
691 __func__, (u32)inode->i_ino, (unsigned long long)pos,
692 (unsigned long long)pos + len);
693 bsize = AFFS_SB(sb)->s_data_blksize;
694 data = page_address(page);
695
696 bh = NULL;
697 written = 0;
698 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
699 bidx = tmp / bsize;
700 boff = tmp % bsize;
701 if (boff) {
702 bh = affs_bread_ino(inode, bidx, 0);
703 if (IS_ERR(bh))
704 return PTR_ERR(bh);
705 tmp = min(bsize - boff, to - from);
706 BUG_ON(boff + tmp > bsize || tmp > bsize);
707 memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
708 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
709 affs_fix_checksum(sb, bh);
710 mark_buffer_dirty_inode(bh, inode);
711 written += tmp;
712 from += tmp;
713 bidx++;
714 } else if (bidx) {
715 bh = affs_bread_ino(inode, bidx - 1, 0);
716 if (IS_ERR(bh))
717 return PTR_ERR(bh);
718 }
719 while (from + bsize <= to) {
720 prev_bh = bh;
721 bh = affs_getemptyblk_ino(inode, bidx);
722 if (IS_ERR(bh))
723 goto out;
724 memcpy(AFFS_DATA(bh), data + from, bsize);
725 if (buffer_new(bh)) {
726 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
727 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
728 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
729 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
730 AFFS_DATA_HEAD(bh)->next = 0;
731 bh->b_state &= ~(1UL << BH_New);
732 if (prev_bh) {
733 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
734
735 if (tmp_next)
736 affs_warning(sb, "commit_write_ofs",
737 "next block already set for %d (%d)",
738 bidx, tmp_next);
739 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
740 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
741 mark_buffer_dirty_inode(prev_bh, inode);
742 }
743 }
744 affs_brelse(prev_bh);
745 affs_fix_checksum(sb, bh);
746 mark_buffer_dirty_inode(bh, inode);
747 written += bsize;
748 from += bsize;
749 bidx++;
750 }
751 if (from < to) {
752 prev_bh = bh;
753 bh = affs_bread_ino(inode, bidx, 1);
754 if (IS_ERR(bh))
755 goto out;
756 tmp = min(bsize, to - from);
757 BUG_ON(tmp > bsize);
758 memcpy(AFFS_DATA(bh), data + from, tmp);
759 if (buffer_new(bh)) {
760 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
761 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
762 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
763 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
764 AFFS_DATA_HEAD(bh)->next = 0;
765 bh->b_state &= ~(1UL << BH_New);
766 if (prev_bh) {
767 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
768
769 if (tmp_next)
770 affs_warning(sb, "commit_write_ofs",
771 "next block already set for %d (%d)",
772 bidx, tmp_next);
773 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
774 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
775 mark_buffer_dirty_inode(prev_bh, inode);
776 }
777 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
778 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
779 affs_brelse(prev_bh);
780 affs_fix_checksum(sb, bh);
781 mark_buffer_dirty_inode(bh, inode);
782 written += tmp;
783 from += tmp;
784 bidx++;
785 }
786 SetPageUptodate(page);
787
788 done:
789 affs_brelse(bh);
790 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
791 if (tmp > inode->i_size)
792 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
793
794 unlock_page(page);
795 page_cache_release(page);
796
797 return written;
798
799 out:
800 bh = prev_bh;
801 if (!written)
802 written = PTR_ERR(bh);
803 goto done;
804 }
805
806 const struct address_space_operations affs_aops_ofs = {
807 .readpage = affs_readpage_ofs,
808 //.writepage = affs_writepage_ofs,
809 .write_begin = affs_write_begin_ofs,
810 .write_end = affs_write_end_ofs
811 };
812
813 /* Free any preallocated blocks. */
814
815 void
816 affs_free_prealloc(struct inode *inode)
817 {
818 struct super_block *sb = inode->i_sb;
819
820 pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
821
822 while (AFFS_I(inode)->i_pa_cnt) {
823 AFFS_I(inode)->i_pa_cnt--;
824 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
825 }
826 }
827
828 /* Truncate (or enlarge) a file to the requested size. */
829
830 void
831 affs_truncate(struct inode *inode)
832 {
833 struct super_block *sb = inode->i_sb;
834 u32 ext, ext_key;
835 u32 last_blk, blkcnt, blk;
836 u32 size;
837 struct buffer_head *ext_bh;
838 int i;
839
840 pr_debug("truncate(inode=%d, oldsize=%u, newsize=%u)\n",
841 (u32)inode->i_ino, (u32)AFFS_I(inode)->mmu_private, (u32)inode->i_size);
842
843 last_blk = 0;
844 ext = 0;
845 if (inode->i_size) {
846 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
847 ext = last_blk / AFFS_SB(sb)->s_hashsize;
848 }
849
850 if (inode->i_size > AFFS_I(inode)->mmu_private) {
851 struct address_space *mapping = inode->i_mapping;
852 struct page *page;
853 void *fsdata;
854 loff_t isize = inode->i_size;
855 int res;
856
857 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
858 if (!res)
859 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
860 else
861 inode->i_size = AFFS_I(inode)->mmu_private;
862 mark_inode_dirty(inode);
863 return;
864 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
865 return;
866
867 // lock cache
868 ext_bh = affs_get_extblock(inode, ext);
869 if (IS_ERR(ext_bh)) {
870 affs_warning(sb, "truncate", "unexpected read error for ext block %u (%d)",
871 ext, PTR_ERR(ext_bh));
872 return;
873 }
874 if (AFFS_I(inode)->i_lc) {
875 /* clear linear cache */
876 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
877 if (AFFS_I(inode)->i_lc_size > i) {
878 AFFS_I(inode)->i_lc_size = i;
879 for (; i < AFFS_LC_SIZE; i++)
880 AFFS_I(inode)->i_lc[i] = 0;
881 }
882 /* clear associative cache */
883 for (i = 0; i < AFFS_AC_SIZE; i++)
884 if (AFFS_I(inode)->i_ac[i].ext >= ext)
885 AFFS_I(inode)->i_ac[i].ext = 0;
886 }
887 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
888
889 blkcnt = AFFS_I(inode)->i_blkcnt;
890 i = 0;
891 blk = last_blk;
892 if (inode->i_size) {
893 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
894 blk++;
895 } else
896 AFFS_HEAD(ext_bh)->first_data = 0;
897 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
898 size = AFFS_SB(sb)->s_hashsize;
899 if (size > blkcnt - blk + i)
900 size = blkcnt - blk + i;
901 for (; i < size; i++, blk++) {
902 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
903 AFFS_BLOCK(sb, ext_bh, i) = 0;
904 }
905 AFFS_TAIL(sb, ext_bh)->extension = 0;
906 affs_fix_checksum(sb, ext_bh);
907 mark_buffer_dirty_inode(ext_bh, inode);
908 affs_brelse(ext_bh);
909
910 if (inode->i_size) {
911 AFFS_I(inode)->i_blkcnt = last_blk + 1;
912 AFFS_I(inode)->i_extcnt = ext + 1;
913 if (AFFS_SB(sb)->s_flags & SF_OFS) {
914 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
915 u32 tmp;
916 if (IS_ERR(bh)) {
917 affs_warning(sb, "truncate", "unexpected read error for last block %u (%d)",
918 ext, PTR_ERR(bh));
919 return;
920 }
921 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
922 AFFS_DATA_HEAD(bh)->next = 0;
923 affs_adjust_checksum(bh, -tmp);
924 affs_brelse(bh);
925 }
926 } else {
927 AFFS_I(inode)->i_blkcnt = 0;
928 AFFS_I(inode)->i_extcnt = 1;
929 }
930 AFFS_I(inode)->mmu_private = inode->i_size;
931 // unlock cache
932
933 while (ext_key) {
934 ext_bh = affs_bread(sb, ext_key);
935 size = AFFS_SB(sb)->s_hashsize;
936 if (size > blkcnt - blk)
937 size = blkcnt - blk;
938 for (i = 0; i < size; i++, blk++)
939 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
940 affs_free_block(sb, ext_key);
941 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
942 affs_brelse(ext_bh);
943 }
944 affs_free_prealloc(inode);
945 }
946
947 int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
948 {
949 struct inode *inode = filp->f_mapping->host;
950 int ret, err;
951
952 err = filemap_write_and_wait_range(inode->i_mapping, start, end);
953 if (err)
954 return err;
955
956 mutex_lock(&inode->i_mutex);
957 ret = write_inode_now(inode, 0);
958 err = sync_blockdev(inode->i_sb->s_bdev);
959 if (!ret)
960 ret = err;
961 mutex_unlock(&inode->i_mutex);
962 return ret;
963 }
Linux with added FPC-III support