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Merge branch 'drm-nouveau-fixes-3.9' of git://anongit.freedesktop.org/git/nouveau...
[linux-2.6/libata-dev.git] / fs / affs / file.c
blobaf3261b781021f0a51dda6b73b5fb5b3d051baa7
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 = 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("AFFS: 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("AFFS: 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("AFFS: get_block(%u, %lu)\n", (u32)inode->i_ino, (unsigned long)block);
328
329 BUG_ON(block > (sector_t)0x7fffffffUL);
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
399 static int affs_readpage(struct file *file, struct page *page)
400 {
401 return block_read_full_page(page, affs_get_block);
402 }
403
404 static void affs_write_failed(struct address_space *mapping, loff_t to)
405 {
406 struct inode *inode = mapping->host;
407
408 if (to > inode->i_size) {
409 truncate_pagecache(inode, to, inode->i_size);
410 affs_truncate(inode);
411 }
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 .bmap = _affs_bmap
441 };
442
443 static inline struct buffer_head *
444 affs_bread_ino(struct inode *inode, int block, int create)
445 {
446 struct buffer_head *bh, tmp_bh;
447 int err;
448
449 tmp_bh.b_state = 0;
450 err = affs_get_block(inode, block, &tmp_bh, create);
451 if (!err) {
452 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
453 if (bh) {
454 bh->b_state |= tmp_bh.b_state;
455 return bh;
456 }
457 err = -EIO;
458 }
459 return ERR_PTR(err);
460 }
461
462 static inline struct buffer_head *
463 affs_getzeroblk_ino(struct inode *inode, int block)
464 {
465 struct buffer_head *bh, tmp_bh;
466 int err;
467
468 tmp_bh.b_state = 0;
469 err = affs_get_block(inode, block, &tmp_bh, 1);
470 if (!err) {
471 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
472 if (bh) {
473 bh->b_state |= tmp_bh.b_state;
474 return bh;
475 }
476 err = -EIO;
477 }
478 return ERR_PTR(err);
479 }
480
481 static inline struct buffer_head *
482 affs_getemptyblk_ino(struct inode *inode, int block)
483 {
484 struct buffer_head *bh, tmp_bh;
485 int err;
486
487 tmp_bh.b_state = 0;
488 err = affs_get_block(inode, block, &tmp_bh, 1);
489 if (!err) {
490 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
491 if (bh) {
492 bh->b_state |= tmp_bh.b_state;
493 return bh;
494 }
495 err = -EIO;
496 }
497 return ERR_PTR(err);
498 }
499
500 static int
501 affs_do_readpage_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
502 {
503 struct inode *inode = page->mapping->host;
504 struct super_block *sb = inode->i_sb;
505 struct buffer_head *bh;
506 char *data;
507 u32 bidx, boff, bsize;
508 u32 tmp;
509
510 pr_debug("AFFS: read_page(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
511 BUG_ON(from > to || to > PAGE_CACHE_SIZE);
512 kmap(page);
513 data = page_address(page);
514 bsize = AFFS_SB(sb)->s_data_blksize;
515 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
516 bidx = tmp / bsize;
517 boff = tmp % bsize;
518
519 while (from < to) {
520 bh = affs_bread_ino(inode, bidx, 0);
521 if (IS_ERR(bh))
522 return PTR_ERR(bh);
523 tmp = min(bsize - boff, to - from);
524 BUG_ON(from + tmp > to || tmp > bsize);
525 memcpy(data + from, AFFS_DATA(bh) + boff, tmp);
526 affs_brelse(bh);
527 bidx++;
528 from += tmp;
529 boff = 0;
530 }
531 flush_dcache_page(page);
532 kunmap(page);
533 return 0;
534 }
535
536 static int
537 affs_extent_file_ofs(struct inode *inode, u32 newsize)
538 {
539 struct super_block *sb = inode->i_sb;
540 struct buffer_head *bh, *prev_bh;
541 u32 bidx, boff;
542 u32 size, bsize;
543 u32 tmp;
544
545 pr_debug("AFFS: extent_file(%u, %d)\n", (u32)inode->i_ino, newsize);
546 bsize = AFFS_SB(sb)->s_data_blksize;
547 bh = NULL;
548 size = AFFS_I(inode)->mmu_private;
549 bidx = size / bsize;
550 boff = size % bsize;
551 if (boff) {
552 bh = affs_bread_ino(inode, bidx, 0);
553 if (IS_ERR(bh))
554 return PTR_ERR(bh);
555 tmp = min(bsize - boff, newsize - size);
556 BUG_ON(boff + tmp > bsize || tmp > bsize);
557 memset(AFFS_DATA(bh) + boff, 0, tmp);
558 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
559 affs_fix_checksum(sb, bh);
560 mark_buffer_dirty_inode(bh, inode);
561 size += tmp;
562 bidx++;
563 } else if (bidx) {
564 bh = affs_bread_ino(inode, bidx - 1, 0);
565 if (IS_ERR(bh))
566 return PTR_ERR(bh);
567 }
568
569 while (size < newsize) {
570 prev_bh = bh;
571 bh = affs_getzeroblk_ino(inode, bidx);
572 if (IS_ERR(bh))
573 goto out;
574 tmp = min(bsize, newsize - size);
575 BUG_ON(tmp > bsize);
576 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
577 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
578 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
579 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
580 affs_fix_checksum(sb, bh);
581 bh->b_state &= ~(1UL << BH_New);
582 mark_buffer_dirty_inode(bh, inode);
583 if (prev_bh) {
584 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
585 if (tmp)
586 affs_warning(sb, "extent_file_ofs", "next block already set for %d (%d)", bidx, tmp);
587 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
588 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
589 mark_buffer_dirty_inode(prev_bh, inode);
590 affs_brelse(prev_bh);
591 }
592 size += bsize;
593 bidx++;
594 }
595 affs_brelse(bh);
596 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
597 return 0;
598
599 out:
600 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
601 return PTR_ERR(bh);
602 }
603
604 static int
605 affs_readpage_ofs(struct file *file, struct page *page)
606 {
607 struct inode *inode = page->mapping->host;
608 u32 to;
609 int err;
610
611 pr_debug("AFFS: read_page(%u, %ld)\n", (u32)inode->i_ino, page->index);
612 to = PAGE_CACHE_SIZE;
613 if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
614 to = inode->i_size & ~PAGE_CACHE_MASK;
615 memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
616 }
617
618 err = affs_do_readpage_ofs(file, page, 0, to);
619 if (!err)
620 SetPageUptodate(page);
621 unlock_page(page);
622 return err;
623 }
624
625 static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
626 loff_t pos, unsigned len, unsigned flags,
627 struct page **pagep, void **fsdata)
628 {
629 struct inode *inode = mapping->host;
630 struct page *page;
631 pgoff_t index;
632 int err = 0;
633
634 pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len);
635 if (pos > AFFS_I(inode)->mmu_private) {
636 /* XXX: this probably leaves a too-big i_size in case of
637 * failure. Should really be updating i_size at write_end time
638 */
639 err = affs_extent_file_ofs(inode, pos);
640 if (err)
641 return err;
642 }
643
644 index = pos >> PAGE_CACHE_SHIFT;
645 page = grab_cache_page_write_begin(mapping, index, flags);
646 if (!page)
647 return -ENOMEM;
648 *pagep = page;
649
650 if (PageUptodate(page))
651 return 0;
652
653 /* XXX: inefficient but safe in the face of short writes */
654 err = affs_do_readpage_ofs(file, page, 0, PAGE_CACHE_SIZE);
655 if (err) {
656 unlock_page(page);
657 page_cache_release(page);
658 }
659 return err;
660 }
661
662 static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
663 loff_t pos, unsigned len, unsigned copied,
664 struct page *page, void *fsdata)
665 {
666 struct inode *inode = mapping->host;
667 struct super_block *sb = inode->i_sb;
668 struct buffer_head *bh, *prev_bh;
669 char *data;
670 u32 bidx, boff, bsize;
671 unsigned from, to;
672 u32 tmp;
673 int written;
674
675 from = pos & (PAGE_CACHE_SIZE - 1);
676 to = pos + len;
677 /*
678 * XXX: not sure if this can handle short copies (len < copied), but
679 * we don't have to, because the page should always be uptodate here,
680 * due to write_begin.
681 */
682
683 pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len);
684 bsize = AFFS_SB(sb)->s_data_blksize;
685 data = page_address(page);
686
687 bh = NULL;
688 written = 0;
689 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
690 bidx = tmp / bsize;
691 boff = tmp % bsize;
692 if (boff) {
693 bh = affs_bread_ino(inode, bidx, 0);
694 if (IS_ERR(bh))
695 return PTR_ERR(bh);
696 tmp = min(bsize - boff, to - from);
697 BUG_ON(boff + tmp > bsize || tmp > bsize);
698 memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
699 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
700 affs_fix_checksum(sb, bh);
701 mark_buffer_dirty_inode(bh, inode);
702 written += tmp;
703 from += tmp;
704 bidx++;
705 } else if (bidx) {
706 bh = affs_bread_ino(inode, bidx - 1, 0);
707 if (IS_ERR(bh))
708 return PTR_ERR(bh);
709 }
710 while (from + bsize <= to) {
711 prev_bh = bh;
712 bh = affs_getemptyblk_ino(inode, bidx);
713 if (IS_ERR(bh))
714 goto out;
715 memcpy(AFFS_DATA(bh), data + from, bsize);
716 if (buffer_new(bh)) {
717 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
718 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
719 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
720 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
721 AFFS_DATA_HEAD(bh)->next = 0;
722 bh->b_state &= ~(1UL << BH_New);
723 if (prev_bh) {
724 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
725 if (tmp)
726 affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
727 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
728 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
729 mark_buffer_dirty_inode(prev_bh, inode);
730 }
731 }
732 affs_brelse(prev_bh);
733 affs_fix_checksum(sb, bh);
734 mark_buffer_dirty_inode(bh, inode);
735 written += bsize;
736 from += bsize;
737 bidx++;
738 }
739 if (from < to) {
740 prev_bh = bh;
741 bh = affs_bread_ino(inode, bidx, 1);
742 if (IS_ERR(bh))
743 goto out;
744 tmp = min(bsize, to - from);
745 BUG_ON(tmp > bsize);
746 memcpy(AFFS_DATA(bh), data + from, tmp);
747 if (buffer_new(bh)) {
748 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
749 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
750 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
751 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
752 AFFS_DATA_HEAD(bh)->next = 0;
753 bh->b_state &= ~(1UL << BH_New);
754 if (prev_bh) {
755 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
756 if (tmp)
757 affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
758 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
759 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
760 mark_buffer_dirty_inode(prev_bh, inode);
761 }
762 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
763 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
764 affs_brelse(prev_bh);
765 affs_fix_checksum(sb, bh);
766 mark_buffer_dirty_inode(bh, inode);
767 written += tmp;
768 from += tmp;
769 bidx++;
770 }
771 SetPageUptodate(page);
772
773 done:
774 affs_brelse(bh);
775 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
776 if (tmp > inode->i_size)
777 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
778
779 unlock_page(page);
780 page_cache_release(page);
781
782 return written;
783
784 out:
785 bh = prev_bh;
786 if (!written)
787 written = PTR_ERR(bh);
788 goto done;
789 }
790
791 const struct address_space_operations affs_aops_ofs = {
792 .readpage = affs_readpage_ofs,
793 //.writepage = affs_writepage_ofs,
794 .write_begin = affs_write_begin_ofs,
795 .write_end = affs_write_end_ofs
796 };
797
798 /* Free any preallocated blocks. */
799
800 void
801 affs_free_prealloc(struct inode *inode)
802 {
803 struct super_block *sb = inode->i_sb;
804
805 pr_debug("AFFS: free_prealloc(ino=%lu)\n", inode->i_ino);
806
807 while (AFFS_I(inode)->i_pa_cnt) {
808 AFFS_I(inode)->i_pa_cnt--;
809 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
810 }
811 }
812
813 /* Truncate (or enlarge) a file to the requested size. */
814
815 void
816 affs_truncate(struct inode *inode)
817 {
818 struct super_block *sb = inode->i_sb;
819 u32 ext, ext_key;
820 u32 last_blk, blkcnt, blk;
821 u32 size;
822 struct buffer_head *ext_bh;
823 int i;
824
825 pr_debug("AFFS: truncate(inode=%d, oldsize=%u, newsize=%u)\n",
826 (u32)inode->i_ino, (u32)AFFS_I(inode)->mmu_private, (u32)inode->i_size);
827
828 last_blk = 0;
829 ext = 0;
830 if (inode->i_size) {
831 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
832 ext = last_blk / AFFS_SB(sb)->s_hashsize;
833 }
834
835 if (inode->i_size > AFFS_I(inode)->mmu_private) {
836 struct address_space *mapping = inode->i_mapping;
837 struct page *page;
838 void *fsdata;
839 u32 size = inode->i_size;
840 int res;
841
842 res = mapping->a_ops->write_begin(NULL, mapping, size, 0, 0, &page, &fsdata);
843 if (!res)
844 res = mapping->a_ops->write_end(NULL, mapping, size, 0, 0, page, fsdata);
845 else
846 inode->i_size = AFFS_I(inode)->mmu_private;
847 mark_inode_dirty(inode);
848 return;
849 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
850 return;
851
852 // lock cache
853 ext_bh = affs_get_extblock(inode, ext);
854 if (IS_ERR(ext_bh)) {
855 affs_warning(sb, "truncate", "unexpected read error for ext block %u (%d)",
856 ext, PTR_ERR(ext_bh));
857 return;
858 }
859 if (AFFS_I(inode)->i_lc) {
860 /* clear linear cache */
861 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
862 if (AFFS_I(inode)->i_lc_size > i) {
863 AFFS_I(inode)->i_lc_size = i;
864 for (; i < AFFS_LC_SIZE; i++)
865 AFFS_I(inode)->i_lc[i] = 0;
866 }
867 /* clear associative cache */
868 for (i = 0; i < AFFS_AC_SIZE; i++)
869 if (AFFS_I(inode)->i_ac[i].ext >= ext)
870 AFFS_I(inode)->i_ac[i].ext = 0;
871 }
872 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
873
874 blkcnt = AFFS_I(inode)->i_blkcnt;
875 i = 0;
876 blk = last_blk;
877 if (inode->i_size) {
878 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
879 blk++;
880 } else
881 AFFS_HEAD(ext_bh)->first_data = 0;
882 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
883 size = AFFS_SB(sb)->s_hashsize;
884 if (size > blkcnt - blk + i)
885 size = blkcnt - blk + i;
886 for (; i < size; i++, blk++) {
887 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
888 AFFS_BLOCK(sb, ext_bh, i) = 0;
889 }
890 AFFS_TAIL(sb, ext_bh)->extension = 0;
891 affs_fix_checksum(sb, ext_bh);
892 mark_buffer_dirty_inode(ext_bh, inode);
893 affs_brelse(ext_bh);
894
895 if (inode->i_size) {
896 AFFS_I(inode)->i_blkcnt = last_blk + 1;
897 AFFS_I(inode)->i_extcnt = ext + 1;
898 if (AFFS_SB(sb)->s_flags & SF_OFS) {
899 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
900 u32 tmp;
901 if (IS_ERR(bh)) {
902 affs_warning(sb, "truncate", "unexpected read error for last block %u (%d)",
903 ext, PTR_ERR(bh));
904 return;
905 }
906 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
907 AFFS_DATA_HEAD(bh)->next = 0;
908 affs_adjust_checksum(bh, -tmp);
909 affs_brelse(bh);
910 }
911 } else {
912 AFFS_I(inode)->i_blkcnt = 0;
913 AFFS_I(inode)->i_extcnt = 1;
914 }
915 AFFS_I(inode)->mmu_private = inode->i_size;
916 // unlock cache
917
918 while (ext_key) {
919 ext_bh = affs_bread(sb, ext_key);
920 size = AFFS_SB(sb)->s_hashsize;
921 if (size > blkcnt - blk)
922 size = blkcnt - blk;
923 for (i = 0; i < size; i++, blk++)
924 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
925 affs_free_block(sb, ext_key);
926 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
927 affs_brelse(ext_bh);
928 }
929 affs_free_prealloc(inode);
930 }
931
932 int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
933 {
934 struct inode *inode = filp->f_mapping->host;
935 int ret, err;
936
937 err = filemap_write_and_wait_range(inode->i_mapping, start, end);
938 if (err)
939 return err;
940
941 mutex_lock(&inode->i_mutex);
942 ret = write_inode_now(inode, 0);
943 err = sync_blockdev(inode->i_sb->s_bdev);
944 if (!ret)
945 ret = err;
946 mutex_unlock(&inode->i_mutex);
947 return ret;
948 }
Linux 2.6 libata-dev (mirror)