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Merge branch 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[deliverable/linux.git] / fs / affs / file.c
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
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
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 inode_lock(inode);
37 if (inode->i_size != AFFS_I(inode)->mmu_private)
38 affs_truncate(inode);
39 affs_free_prealloc(inode);
40 inode_unlock(inode);
41 }
42
43 return 0;
44 }
45
46 static int
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 *
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 *
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 *
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
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
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
376 static int affs_readpage(struct file *file, struct page *page)
377 {
378 return block_read_full_page(page, affs_get_block);
379 }
380
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
392 affs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
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 loff_t offset = iocb->ki_pos;
399 ssize_t ret;
400
401 if (iov_iter_rw(iter) == WRITE) {
402 loff_t size = offset + count;
403
404 if (AFFS_I(inode)->mmu_private < size)
405 return 0;
406 }
407
408 ret = blockdev_direct_IO(iocb, inode, iter, affs_get_block);
409 if (ret < 0 && iov_iter_rw(iter) == WRITE)
410 affs_write_failed(mapping, offset + count);
411 return ret;
412 }
413
414 static int affs_write_begin(struct file *file, struct address_space *mapping,
415 loff_t pos, unsigned len, unsigned flags,
416 struct page **pagep, void **fsdata)
417 {
418 int ret;
419
420 *pagep = NULL;
421 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
422 affs_get_block,
423 &AFFS_I(mapping->host)->mmu_private);
424 if (unlikely(ret))
425 affs_write_failed(mapping, pos + len);
426
427 return ret;
428 }
429
430 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
431 {
432 return generic_block_bmap(mapping,block,affs_get_block);
433 }
434
435 const struct address_space_operations affs_aops = {
436 .readpage = affs_readpage,
437 .writepage = affs_writepage,
438 .write_begin = affs_write_begin,
439 .write_end = generic_write_end,
440 .direct_IO = affs_direct_IO,
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(%lu, %ld, 0, %d)\n", __func__, inode->i_ino,
513 page->index, to);
514 BUG_ON(to > PAGE_SIZE);
515 bsize = AFFS_SB(sb)->s_data_blksize;
516 tmp = page->index << PAGE_SHIFT;
517 bidx = tmp / bsize;
518 boff = tmp % bsize;
519
520 while (pos < to) {
521 bh = affs_bread_ino(inode, bidx, 0);
522 if (IS_ERR(bh))
523 return PTR_ERR(bh);
524 tmp = min(bsize - boff, to - pos);
525 BUG_ON(pos + tmp > to || tmp > bsize);
526 data = kmap_atomic(page);
527 memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
528 kunmap_atomic(data);
529 affs_brelse(bh);
530 bidx++;
531 pos += tmp;
532 boff = 0;
533 }
534 flush_dcache_page(page);
535 return 0;
536 }
537
538 static int
539 affs_extent_file_ofs(struct inode *inode, u32 newsize)
540 {
541 struct super_block *sb = inode->i_sb;
542 struct buffer_head *bh, *prev_bh;
543 u32 bidx, boff;
544 u32 size, bsize;
545 u32 tmp;
546
547 pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize);
548 bsize = AFFS_SB(sb)->s_data_blksize;
549 bh = NULL;
550 size = AFFS_I(inode)->mmu_private;
551 bidx = size / bsize;
552 boff = size % bsize;
553 if (boff) {
554 bh = affs_bread_ino(inode, bidx, 0);
555 if (IS_ERR(bh))
556 return PTR_ERR(bh);
557 tmp = min(bsize - boff, newsize - size);
558 BUG_ON(boff + tmp > bsize || tmp > bsize);
559 memset(AFFS_DATA(bh) + boff, 0, tmp);
560 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
561 affs_fix_checksum(sb, bh);
562 mark_buffer_dirty_inode(bh, inode);
563 size += tmp;
564 bidx++;
565 } else if (bidx) {
566 bh = affs_bread_ino(inode, bidx - 1, 0);
567 if (IS_ERR(bh))
568 return PTR_ERR(bh);
569 }
570
571 while (size < newsize) {
572 prev_bh = bh;
573 bh = affs_getzeroblk_ino(inode, bidx);
574 if (IS_ERR(bh))
575 goto out;
576 tmp = min(bsize, newsize - size);
577 BUG_ON(tmp > bsize);
578 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
579 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
580 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
581 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
582 affs_fix_checksum(sb, bh);
583 bh->b_state &= ~(1UL << BH_New);
584 mark_buffer_dirty_inode(bh, inode);
585 if (prev_bh) {
586 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
587
588 if (tmp_next)
589 affs_warning(sb, "extent_file_ofs",
590 "next block already set for %d (%d)",
591 bidx, tmp_next);
592 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
593 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
594 mark_buffer_dirty_inode(prev_bh, inode);
595 affs_brelse(prev_bh);
596 }
597 size += bsize;
598 bidx++;
599 }
600 affs_brelse(bh);
601 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
602 return 0;
603
604 out:
605 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
606 return PTR_ERR(bh);
607 }
608
609 static int
610 affs_readpage_ofs(struct file *file, struct page *page)
611 {
612 struct inode *inode = page->mapping->host;
613 u32 to;
614 int err;
615
616 pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index);
617 to = PAGE_SIZE;
618 if (((page->index + 1) << PAGE_SHIFT) > inode->i_size) {
619 to = inode->i_size & ~PAGE_MASK;
620 memset(page_address(page) + to, 0, PAGE_SIZE - to);
621 }
622
623 err = affs_do_readpage_ofs(page, to);
624 if (!err)
625 SetPageUptodate(page);
626 unlock_page(page);
627 return err;
628 }
629
630 static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
631 loff_t pos, unsigned len, unsigned flags,
632 struct page **pagep, void **fsdata)
633 {
634 struct inode *inode = mapping->host;
635 struct page *page;
636 pgoff_t index;
637 int err = 0;
638
639 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
640 pos + len);
641 if (pos > AFFS_I(inode)->mmu_private) {
642 /* XXX: this probably leaves a too-big i_size in case of
643 * failure. Should really be updating i_size at write_end time
644 */
645 err = affs_extent_file_ofs(inode, pos);
646 if (err)
647 return err;
648 }
649
650 index = pos >> PAGE_SHIFT;
651 page = grab_cache_page_write_begin(mapping, index, flags);
652 if (!page)
653 return -ENOMEM;
654 *pagep = page;
655
656 if (PageUptodate(page))
657 return 0;
658
659 /* XXX: inefficient but safe in the face of short writes */
660 err = affs_do_readpage_ofs(page, PAGE_SIZE);
661 if (err) {
662 unlock_page(page);
663 put_page(page);
664 }
665 return err;
666 }
667
668 static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
669 loff_t pos, unsigned len, unsigned copied,
670 struct page *page, void *fsdata)
671 {
672 struct inode *inode = mapping->host;
673 struct super_block *sb = inode->i_sb;
674 struct buffer_head *bh, *prev_bh;
675 char *data;
676 u32 bidx, boff, bsize;
677 unsigned from, to;
678 u32 tmp;
679 int written;
680
681 from = pos & (PAGE_SIZE - 1);
682 to = pos + len;
683 /*
684 * XXX: not sure if this can handle short copies (len < copied), but
685 * we don't have to, because the page should always be uptodate here,
686 * due to write_begin.
687 */
688
689 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
690 pos + len);
691 bsize = AFFS_SB(sb)->s_data_blksize;
692 data = page_address(page);
693
694 bh = NULL;
695 written = 0;
696 tmp = (page->index << PAGE_SHIFT) + from;
697 bidx = tmp / bsize;
698 boff = tmp % bsize;
699 if (boff) {
700 bh = affs_bread_ino(inode, bidx, 0);
701 if (IS_ERR(bh)) {
702 written = PTR_ERR(bh);
703 goto err_first_bh;
704 }
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 written = PTR_ERR(bh);
718 goto err_first_bh;
719 }
720 }
721 while (from + bsize <= to) {
722 prev_bh = bh;
723 bh = affs_getemptyblk_ino(inode, bidx);
724 if (IS_ERR(bh))
725 goto err_bh;
726 memcpy(AFFS_DATA(bh), data + from, bsize);
727 if (buffer_new(bh)) {
728 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
729 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
730 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
731 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
732 AFFS_DATA_HEAD(bh)->next = 0;
733 bh->b_state &= ~(1UL << BH_New);
734 if (prev_bh) {
735 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
736
737 if (tmp_next)
738 affs_warning(sb, "commit_write_ofs",
739 "next block already set for %d (%d)",
740 bidx, tmp_next);
741 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
742 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
743 mark_buffer_dirty_inode(prev_bh, inode);
744 }
745 }
746 affs_brelse(prev_bh);
747 affs_fix_checksum(sb, bh);
748 mark_buffer_dirty_inode(bh, inode);
749 written += bsize;
750 from += bsize;
751 bidx++;
752 }
753 if (from < to) {
754 prev_bh = bh;
755 bh = affs_bread_ino(inode, bidx, 1);
756 if (IS_ERR(bh))
757 goto err_bh;
758 tmp = min(bsize, to - from);
759 BUG_ON(tmp > bsize);
760 memcpy(AFFS_DATA(bh), data + from, tmp);
761 if (buffer_new(bh)) {
762 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
763 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
764 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
765 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
766 AFFS_DATA_HEAD(bh)->next = 0;
767 bh->b_state &= ~(1UL << BH_New);
768 if (prev_bh) {
769 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
770
771 if (tmp_next)
772 affs_warning(sb, "commit_write_ofs",
773 "next block already set for %d (%d)",
774 bidx, tmp_next);
775 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
776 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
777 mark_buffer_dirty_inode(prev_bh, inode);
778 }
779 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
780 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
781 affs_brelse(prev_bh);
782 affs_fix_checksum(sb, bh);
783 mark_buffer_dirty_inode(bh, inode);
784 written += tmp;
785 from += tmp;
786 bidx++;
787 }
788 SetPageUptodate(page);
789
790 done:
791 affs_brelse(bh);
792 tmp = (page->index << PAGE_SHIFT) + from;
793 if (tmp > inode->i_size)
794 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
795
796 err_first_bh:
797 unlock_page(page);
798 put_page(page);
799
800 return written;
801
802 err_bh:
803 bh = prev_bh;
804 if (!written)
805 written = PTR_ERR(bh);
806 goto done;
807 }
808
809 const struct address_space_operations affs_aops_ofs = {
810 .readpage = affs_readpage_ofs,
811 //.writepage = affs_writepage_ofs,
812 .write_begin = affs_write_begin_ofs,
813 .write_end = affs_write_end_ofs
814 };
815
816 /* Free any preallocated blocks. */
817
818 void
819 affs_free_prealloc(struct inode *inode)
820 {
821 struct super_block *sb = inode->i_sb;
822
823 pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
824
825 while (AFFS_I(inode)->i_pa_cnt) {
826 AFFS_I(inode)->i_pa_cnt--;
827 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
828 }
829 }
830
831 /* Truncate (or enlarge) a file to the requested size. */
832
833 void
834 affs_truncate(struct inode *inode)
835 {
836 struct super_block *sb = inode->i_sb;
837 u32 ext, ext_key;
838 u32 last_blk, blkcnt, blk;
839 u32 size;
840 struct buffer_head *ext_bh;
841 int i;
842
843 pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
844 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
845
846 last_blk = 0;
847 ext = 0;
848 if (inode->i_size) {
849 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
850 ext = last_blk / AFFS_SB(sb)->s_hashsize;
851 }
852
853 if (inode->i_size > AFFS_I(inode)->mmu_private) {
854 struct address_space *mapping = inode->i_mapping;
855 struct page *page;
856 void *fsdata;
857 loff_t isize = inode->i_size;
858 int res;
859
860 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
861 if (!res)
862 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
863 else
864 inode->i_size = AFFS_I(inode)->mmu_private;
865 mark_inode_dirty(inode);
866 return;
867 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
868 return;
869
870 // lock cache
871 ext_bh = affs_get_extblock(inode, ext);
872 if (IS_ERR(ext_bh)) {
873 affs_warning(sb, "truncate",
874 "unexpected read error for ext block %u (%ld)",
875 ext, PTR_ERR(ext_bh));
876 return;
877 }
878 if (AFFS_I(inode)->i_lc) {
879 /* clear linear cache */
880 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
881 if (AFFS_I(inode)->i_lc_size > i) {
882 AFFS_I(inode)->i_lc_size = i;
883 for (; i < AFFS_LC_SIZE; i++)
884 AFFS_I(inode)->i_lc[i] = 0;
885 }
886 /* clear associative cache */
887 for (i = 0; i < AFFS_AC_SIZE; i++)
888 if (AFFS_I(inode)->i_ac[i].ext >= ext)
889 AFFS_I(inode)->i_ac[i].ext = 0;
890 }
891 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
892
893 blkcnt = AFFS_I(inode)->i_blkcnt;
894 i = 0;
895 blk = last_blk;
896 if (inode->i_size) {
897 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
898 blk++;
899 } else
900 AFFS_HEAD(ext_bh)->first_data = 0;
901 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
902 size = AFFS_SB(sb)->s_hashsize;
903 if (size > blkcnt - blk + i)
904 size = blkcnt - blk + i;
905 for (; i < size; i++, blk++) {
906 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
907 AFFS_BLOCK(sb, ext_bh, i) = 0;
908 }
909 AFFS_TAIL(sb, ext_bh)->extension = 0;
910 affs_fix_checksum(sb, ext_bh);
911 mark_buffer_dirty_inode(ext_bh, inode);
912 affs_brelse(ext_bh);
913
914 if (inode->i_size) {
915 AFFS_I(inode)->i_blkcnt = last_blk + 1;
916 AFFS_I(inode)->i_extcnt = ext + 1;
917 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) {
918 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
919 u32 tmp;
920 if (IS_ERR(bh)) {
921 affs_warning(sb, "truncate",
922 "unexpected read error for last block %u (%ld)",
923 ext, PTR_ERR(bh));
924 return;
925 }
926 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
927 AFFS_DATA_HEAD(bh)->next = 0;
928 affs_adjust_checksum(bh, -tmp);
929 affs_brelse(bh);
930 }
931 } else {
932 AFFS_I(inode)->i_blkcnt = 0;
933 AFFS_I(inode)->i_extcnt = 1;
934 }
935 AFFS_I(inode)->mmu_private = inode->i_size;
936 // unlock cache
937
938 while (ext_key) {
939 ext_bh = affs_bread(sb, ext_key);
940 size = AFFS_SB(sb)->s_hashsize;
941 if (size > blkcnt - blk)
942 size = blkcnt - blk;
943 for (i = 0; i < size; i++, blk++)
944 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
945 affs_free_block(sb, ext_key);
946 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
947 affs_brelse(ext_bh);
948 }
949 affs_free_prealloc(inode);
950 }
951
952 int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
953 {
954 struct inode *inode = filp->f_mapping->host;
955 int ret, err;
956
957 err = filemap_write_and_wait_range(inode->i_mapping, start, end);
958 if (err)
959 return err;
960
961 inode_lock(inode);
962 ret = write_inode_now(inode, 0);
963 err = sync_blockdev(inode->i_sb->s_bdev);
964 if (!ret)
965 ret = err;
966 inode_unlock(inode);
967 return ret;
968 }
969 const struct file_operations affs_file_operations = {
970 .llseek = generic_file_llseek,
971 .read_iter = generic_file_read_iter,
972 .write_iter = generic_file_write_iter,
973 .mmap = generic_file_mmap,
974 .open = affs_file_open,
975 .release = affs_file_release,
976 .fsync = affs_file_fsync,
977 .splice_read = generic_file_splice_read,
978 };
979
980 const struct inode_operations affs_file_inode_operations = {
981 .setattr = affs_notify_change,
982 };
Linux kernel - Deliverables
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