ia64/linux-2.6.18-xen.hg

view fs/affs/file.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
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 */
15 #include "affs.h"
17 #if PAGE_SIZE < 4096
18 #error PAGE_SIZE must be at least 4096
19 #endif
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);
28 const struct file_operations affs_file_operations = {
29 .llseek = generic_file_llseek,
30 .read = generic_file_read,
31 .write = generic_file_write,
32 .mmap = generic_file_mmap,
33 .open = affs_file_open,
34 .release = affs_file_release,
35 .fsync = file_fsync,
36 .sendfile = generic_file_sendfile,
37 };
39 struct inode_operations affs_file_inode_operations = {
40 .truncate = affs_truncate,
41 .setattr = affs_notify_change,
42 };
44 static int
45 affs_file_open(struct inode *inode, struct file *filp)
46 {
47 if (atomic_read(&filp->f_count) != 1)
48 return 0;
49 pr_debug("AFFS: open(%d)\n", AFFS_I(inode)->i_opencnt);
50 AFFS_I(inode)->i_opencnt++;
51 return 0;
52 }
54 static int
55 affs_file_release(struct inode *inode, struct file *filp)
56 {
57 if (atomic_read(&filp->f_count) != 0)
58 return 0;
59 pr_debug("AFFS: release(%d)\n", AFFS_I(inode)->i_opencnt);
60 AFFS_I(inode)->i_opencnt--;
61 if (!AFFS_I(inode)->i_opencnt)
62 affs_free_prealloc(inode);
64 return 0;
65 }
67 static int
68 affs_grow_extcache(struct inode *inode, u32 lc_idx)
69 {
70 struct super_block *sb = inode->i_sb;
71 struct buffer_head *bh;
72 u32 lc_max;
73 int i, j, key;
75 if (!AFFS_I(inode)->i_lc) {
76 char *ptr = (char *)get_zeroed_page(GFP_NOFS);
77 if (!ptr)
78 return -ENOMEM;
79 AFFS_I(inode)->i_lc = (u32 *)ptr;
80 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
81 }
83 lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
85 if (AFFS_I(inode)->i_extcnt > lc_max) {
86 u32 lc_shift, lc_mask, tmp, off;
88 /* need to recalculate linear cache, start from old size */
89 lc_shift = AFFS_I(inode)->i_lc_shift;
90 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
91 for (; tmp; tmp >>= 1)
92 lc_shift++;
93 lc_mask = (1 << lc_shift) - 1;
95 /* fix idx and old size to new shift */
96 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
97 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
99 /* first shrink old cache to make more space */
100 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
101 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
102 AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
104 AFFS_I(inode)->i_lc_shift = lc_shift;
105 AFFS_I(inode)->i_lc_mask = lc_mask;
106 }
108 /* fill cache to the needed index */
109 i = AFFS_I(inode)->i_lc_size;
110 AFFS_I(inode)->i_lc_size = lc_idx + 1;
111 for (; i <= lc_idx; i++) {
112 if (!i) {
113 AFFS_I(inode)->i_lc[0] = inode->i_ino;
114 continue;
115 }
116 key = AFFS_I(inode)->i_lc[i - 1];
117 j = AFFS_I(inode)->i_lc_mask + 1;
118 // unlock cache
119 for (; j > 0; j--) {
120 bh = affs_bread(sb, key);
121 if (!bh)
122 goto err;
123 key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
124 affs_brelse(bh);
125 }
126 // lock cache
127 AFFS_I(inode)->i_lc[i] = key;
128 }
130 return 0;
132 err:
133 // lock cache
134 return -EIO;
135 }
137 static struct buffer_head *
138 affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
139 {
140 struct super_block *sb = inode->i_sb;
141 struct buffer_head *new_bh;
142 u32 blocknr, tmp;
144 blocknr = affs_alloc_block(inode, bh->b_blocknr);
145 if (!blocknr)
146 return ERR_PTR(-ENOSPC);
148 new_bh = affs_getzeroblk(sb, blocknr);
149 if (!new_bh) {
150 affs_free_block(sb, blocknr);
151 return ERR_PTR(-EIO);
152 }
154 AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
155 AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
156 AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
157 AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
158 affs_fix_checksum(sb, new_bh);
160 mark_buffer_dirty_inode(new_bh, inode);
162 tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
163 if (tmp)
164 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
165 AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
166 affs_adjust_checksum(bh, blocknr - tmp);
167 mark_buffer_dirty_inode(bh, inode);
169 AFFS_I(inode)->i_extcnt++;
170 mark_inode_dirty(inode);
172 return new_bh;
173 }
175 static inline struct buffer_head *
176 affs_get_extblock(struct inode *inode, u32 ext)
177 {
178 /* inline the simplest case: same extended block as last time */
179 struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
180 if (ext == AFFS_I(inode)->i_ext_last)
181 atomic_inc(&bh->b_count);
182 else
183 /* we have to do more (not inlined) */
184 bh = affs_get_extblock_slow(inode, ext);
186 return bh;
187 }
189 static struct buffer_head *
190 affs_get_extblock_slow(struct inode *inode, u32 ext)
191 {
192 struct super_block *sb = inode->i_sb;
193 struct buffer_head *bh;
194 u32 ext_key;
195 u32 lc_idx, lc_off, ac_idx;
196 u32 tmp, idx;
198 if (ext == AFFS_I(inode)->i_ext_last + 1) {
199 /* read the next extended block from the current one */
200 bh = AFFS_I(inode)->i_ext_bh;
201 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
202 if (ext < AFFS_I(inode)->i_extcnt)
203 goto read_ext;
204 if (ext > AFFS_I(inode)->i_extcnt)
205 BUG();
206 bh = affs_alloc_extblock(inode, bh, ext);
207 if (IS_ERR(bh))
208 return bh;
209 goto store_ext;
210 }
212 if (ext == 0) {
213 /* we seek back to the file header block */
214 ext_key = inode->i_ino;
215 goto read_ext;
216 }
218 if (ext >= AFFS_I(inode)->i_extcnt) {
219 struct buffer_head *prev_bh;
221 /* allocate a new extended block */
222 if (ext > AFFS_I(inode)->i_extcnt)
223 BUG();
225 /* get previous extended block */
226 prev_bh = affs_get_extblock(inode, ext - 1);
227 if (IS_ERR(prev_bh))
228 return prev_bh;
229 bh = affs_alloc_extblock(inode, prev_bh, ext);
230 affs_brelse(prev_bh);
231 if (IS_ERR(bh))
232 return bh;
233 goto store_ext;
234 }
236 again:
237 /* check if there is an extended cache and whether it's large enough */
238 lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
239 lc_off = ext & AFFS_I(inode)->i_lc_mask;
241 if (lc_idx >= AFFS_I(inode)->i_lc_size) {
242 int err;
244 err = affs_grow_extcache(inode, lc_idx);
245 if (err)
246 return ERR_PTR(err);
247 goto again;
248 }
250 /* every n'th key we find in the linear cache */
251 if (!lc_off) {
252 ext_key = AFFS_I(inode)->i_lc[lc_idx];
253 goto read_ext;
254 }
256 /* maybe it's still in the associative cache */
257 ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
258 if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
259 ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
260 goto read_ext;
261 }
263 /* try to find one of the previous extended blocks */
264 tmp = ext;
265 idx = ac_idx;
266 while (--tmp, --lc_off > 0) {
267 idx = (idx - 1) & AFFS_AC_MASK;
268 if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
269 ext_key = AFFS_I(inode)->i_ac[idx].key;
270 goto find_ext;
271 }
272 }
274 /* fall back to the linear cache */
275 ext_key = AFFS_I(inode)->i_lc[lc_idx];
276 find_ext:
277 /* read all extended blocks until we find the one we need */
278 //unlock cache
279 do {
280 bh = affs_bread(sb, ext_key);
281 if (!bh)
282 goto err_bread;
283 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
284 affs_brelse(bh);
285 tmp++;
286 } while (tmp < ext);
287 //lock cache
289 /* store it in the associative cache */
290 // recalculate ac_idx?
291 AFFS_I(inode)->i_ac[ac_idx].ext = ext;
292 AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
294 read_ext:
295 /* finally read the right extended block */
296 //unlock cache
297 bh = affs_bread(sb, ext_key);
298 if (!bh)
299 goto err_bread;
300 //lock cache
302 store_ext:
303 /* release old cached extended block and store the new one */
304 affs_brelse(AFFS_I(inode)->i_ext_bh);
305 AFFS_I(inode)->i_ext_last = ext;
306 AFFS_I(inode)->i_ext_bh = bh;
307 atomic_inc(&bh->b_count);
309 return bh;
311 err_bread:
312 affs_brelse(bh);
313 return ERR_PTR(-EIO);
314 }
316 static int
317 affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
318 {
319 struct super_block *sb = inode->i_sb;
320 struct buffer_head *ext_bh;
321 u32 ext;
323 pr_debug("AFFS: get_block(%u, %lu)\n", (u32)inode->i_ino, (unsigned long)block);
326 if (block > (sector_t)0x7fffffffUL)
327 BUG();
329 if (block >= AFFS_I(inode)->i_blkcnt) {
330 if (block > AFFS_I(inode)->i_blkcnt || !create)
331 goto err_big;
332 } else
333 create = 0;
335 //lock cache
336 affs_lock_ext(inode);
338 ext = (u32)block / AFFS_SB(sb)->s_hashsize;
339 block -= ext * AFFS_SB(sb)->s_hashsize;
340 ext_bh = affs_get_extblock(inode, ext);
341 if (IS_ERR(ext_bh))
342 goto err_ext;
343 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
345 if (create) {
346 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
347 if (!blocknr)
348 goto err_alloc;
349 set_buffer_new(bh_result);
350 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
351 AFFS_I(inode)->i_blkcnt++;
353 /* store new block */
354 if (bh_result->b_blocknr)
355 affs_warning(sb, "get_block", "block already set (%x)", bh_result->b_blocknr);
356 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
357 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
358 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
359 bh_result->b_blocknr = blocknr;
361 if (!block) {
362 /* insert first block into header block */
363 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
364 if (tmp)
365 affs_warning(sb, "get_block", "first block already set (%d)", tmp);
366 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
367 affs_adjust_checksum(ext_bh, blocknr - tmp);
368 }
369 }
371 affs_brelse(ext_bh);
372 //unlock cache
373 affs_unlock_ext(inode);
374 return 0;
376 err_big:
377 affs_error(inode->i_sb,"get_block","strange block request %d", block);
378 return -EIO;
379 err_ext:
380 // unlock cache
381 affs_unlock_ext(inode);
382 return PTR_ERR(ext_bh);
383 err_alloc:
384 brelse(ext_bh);
385 clear_buffer_mapped(bh_result);
386 bh_result->b_bdev = NULL;
387 // unlock cache
388 affs_unlock_ext(inode);
389 return -ENOSPC;
390 }
392 static int affs_writepage(struct page *page, struct writeback_control *wbc)
393 {
394 return block_write_full_page(page, affs_get_block, wbc);
395 }
396 static int affs_readpage(struct file *file, struct page *page)
397 {
398 return block_read_full_page(page, affs_get_block);
399 }
400 static int affs_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
401 {
402 return cont_prepare_write(page, from, to, affs_get_block,
403 &AFFS_I(page->mapping->host)->mmu_private);
404 }
405 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
406 {
407 return generic_block_bmap(mapping,block,affs_get_block);
408 }
409 const struct address_space_operations affs_aops = {
410 .readpage = affs_readpage,
411 .writepage = affs_writepage,
412 .sync_page = block_sync_page,
413 .prepare_write = affs_prepare_write,
414 .commit_write = generic_commit_write,
415 .bmap = _affs_bmap
416 };
418 static inline struct buffer_head *
419 affs_bread_ino(struct inode *inode, int block, int create)
420 {
421 struct buffer_head *bh, tmp_bh;
422 int err;
424 tmp_bh.b_state = 0;
425 err = affs_get_block(inode, block, &tmp_bh, create);
426 if (!err) {
427 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
428 if (bh) {
429 bh->b_state |= tmp_bh.b_state;
430 return bh;
431 }
432 err = -EIO;
433 }
434 return ERR_PTR(err);
435 }
437 static inline struct buffer_head *
438 affs_getzeroblk_ino(struct inode *inode, int block)
439 {
440 struct buffer_head *bh, tmp_bh;
441 int err;
443 tmp_bh.b_state = 0;
444 err = affs_get_block(inode, block, &tmp_bh, 1);
445 if (!err) {
446 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
447 if (bh) {
448 bh->b_state |= tmp_bh.b_state;
449 return bh;
450 }
451 err = -EIO;
452 }
453 return ERR_PTR(err);
454 }
456 static inline struct buffer_head *
457 affs_getemptyblk_ino(struct inode *inode, int block)
458 {
459 struct buffer_head *bh, tmp_bh;
460 int err;
462 tmp_bh.b_state = 0;
463 err = affs_get_block(inode, block, &tmp_bh, 1);
464 if (!err) {
465 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
466 if (bh) {
467 bh->b_state |= tmp_bh.b_state;
468 return bh;
469 }
470 err = -EIO;
471 }
472 return ERR_PTR(err);
473 }
475 static int
476 affs_do_readpage_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
477 {
478 struct inode *inode = page->mapping->host;
479 struct super_block *sb = inode->i_sb;
480 struct buffer_head *bh;
481 char *data;
482 u32 bidx, boff, bsize;
483 u32 tmp;
485 pr_debug("AFFS: read_page(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
486 if (from > to || to > PAGE_CACHE_SIZE)
487 BUG();
488 kmap(page);
489 data = page_address(page);
490 bsize = AFFS_SB(sb)->s_data_blksize;
491 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
492 bidx = tmp / bsize;
493 boff = tmp % bsize;
495 while (from < to) {
496 bh = affs_bread_ino(inode, bidx, 0);
497 if (IS_ERR(bh))
498 return PTR_ERR(bh);
499 tmp = min(bsize - boff, to - from);
500 if (from + tmp > to || tmp > bsize)
501 BUG();
502 memcpy(data + from, AFFS_DATA(bh) + boff, tmp);
503 affs_brelse(bh);
504 bidx++;
505 from += tmp;
506 boff = 0;
507 }
508 flush_dcache_page(page);
509 kunmap(page);
510 return 0;
511 }
513 static int
514 affs_extent_file_ofs(struct inode *inode, u32 newsize)
515 {
516 struct super_block *sb = inode->i_sb;
517 struct buffer_head *bh, *prev_bh;
518 u32 bidx, boff;
519 u32 size, bsize;
520 u32 tmp;
522 pr_debug("AFFS: extent_file(%u, %d)\n", (u32)inode->i_ino, newsize);
523 bsize = AFFS_SB(sb)->s_data_blksize;
524 bh = NULL;
525 size = AFFS_I(inode)->mmu_private;
526 bidx = size / bsize;
527 boff = size % bsize;
528 if (boff) {
529 bh = affs_bread_ino(inode, bidx, 0);
530 if (IS_ERR(bh))
531 return PTR_ERR(bh);
532 tmp = min(bsize - boff, newsize - size);
533 if (boff + tmp > bsize || tmp > bsize)
534 BUG();
535 memset(AFFS_DATA(bh) + boff, 0, tmp);
536 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(be32_to_cpu(AFFS_DATA_HEAD(bh)->size) + tmp);
537 affs_fix_checksum(sb, bh);
538 mark_buffer_dirty_inode(bh, inode);
539 size += tmp;
540 bidx++;
541 } else if (bidx) {
542 bh = affs_bread_ino(inode, bidx - 1, 0);
543 if (IS_ERR(bh))
544 return PTR_ERR(bh);
545 }
547 while (size < newsize) {
548 prev_bh = bh;
549 bh = affs_getzeroblk_ino(inode, bidx);
550 if (IS_ERR(bh))
551 goto out;
552 tmp = min(bsize, newsize - size);
553 if (tmp > bsize)
554 BUG();
555 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
556 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
557 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
558 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
559 affs_fix_checksum(sb, bh);
560 bh->b_state &= ~(1UL << BH_New);
561 mark_buffer_dirty_inode(bh, inode);
562 if (prev_bh) {
563 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
564 if (tmp)
565 affs_warning(sb, "extent_file_ofs", "next block already set for %d (%d)", bidx, tmp);
566 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
567 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
568 mark_buffer_dirty_inode(prev_bh, inode);
569 affs_brelse(prev_bh);
570 }
571 size += bsize;
572 bidx++;
573 }
574 affs_brelse(bh);
575 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
576 return 0;
578 out:
579 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
580 return PTR_ERR(bh);
581 }
583 static int
584 affs_readpage_ofs(struct file *file, struct page *page)
585 {
586 struct inode *inode = page->mapping->host;
587 u32 to;
588 int err;
590 pr_debug("AFFS: read_page(%u, %ld)\n", (u32)inode->i_ino, page->index);
591 to = PAGE_CACHE_SIZE;
592 if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
593 to = inode->i_size & ~PAGE_CACHE_MASK;
594 memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
595 }
597 err = affs_do_readpage_ofs(file, page, 0, to);
598 if (!err)
599 SetPageUptodate(page);
600 unlock_page(page);
601 return err;
602 }
604 static int affs_prepare_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
605 {
606 struct inode *inode = page->mapping->host;
607 u32 size, offset;
608 u32 tmp;
609 int err = 0;
611 pr_debug("AFFS: prepare_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
612 offset = page->index << PAGE_CACHE_SHIFT;
613 if (offset + from > AFFS_I(inode)->mmu_private) {
614 err = affs_extent_file_ofs(inode, offset + from);
615 if (err)
616 return err;
617 }
618 size = inode->i_size;
620 if (PageUptodate(page))
621 return 0;
623 if (from) {
624 err = affs_do_readpage_ofs(file, page, 0, from);
625 if (err)
626 return err;
627 }
628 if (to < PAGE_CACHE_SIZE) {
629 char *kaddr = kmap_atomic(page, KM_USER0);
631 memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
632 flush_dcache_page(page);
633 kunmap_atomic(kaddr, KM_USER0);
634 if (size > offset + to) {
635 if (size < offset + PAGE_CACHE_SIZE)
636 tmp = size & ~PAGE_CACHE_MASK;
637 else
638 tmp = PAGE_CACHE_SIZE;
639 err = affs_do_readpage_ofs(file, page, to, tmp);
640 }
641 }
642 return err;
643 }
645 static int affs_commit_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
646 {
647 struct inode *inode = page->mapping->host;
648 struct super_block *sb = inode->i_sb;
649 struct buffer_head *bh, *prev_bh;
650 char *data;
651 u32 bidx, boff, bsize;
652 u32 tmp;
653 int written;
655 pr_debug("AFFS: commit_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
656 bsize = AFFS_SB(sb)->s_data_blksize;
657 data = page_address(page);
659 bh = NULL;
660 written = 0;
661 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
662 bidx = tmp / bsize;
663 boff = tmp % bsize;
664 if (boff) {
665 bh = affs_bread_ino(inode, bidx, 0);
666 if (IS_ERR(bh))
667 return PTR_ERR(bh);
668 tmp = min(bsize - boff, to - from);
669 if (boff + tmp > bsize || tmp > bsize)
670 BUG();
671 memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
672 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(be32_to_cpu(AFFS_DATA_HEAD(bh)->size) + tmp);
673 affs_fix_checksum(sb, bh);
674 mark_buffer_dirty_inode(bh, inode);
675 written += tmp;
676 from += tmp;
677 bidx++;
678 } else if (bidx) {
679 bh = affs_bread_ino(inode, bidx - 1, 0);
680 if (IS_ERR(bh))
681 return PTR_ERR(bh);
682 }
683 while (from + bsize <= to) {
684 prev_bh = bh;
685 bh = affs_getemptyblk_ino(inode, bidx);
686 if (IS_ERR(bh))
687 goto out;
688 memcpy(AFFS_DATA(bh), data + from, bsize);
689 if (buffer_new(bh)) {
690 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
691 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
692 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
693 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
694 AFFS_DATA_HEAD(bh)->next = 0;
695 bh->b_state &= ~(1UL << BH_New);
696 if (prev_bh) {
697 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
698 if (tmp)
699 affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
700 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
701 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
702 mark_buffer_dirty_inode(prev_bh, inode);
703 }
704 }
705 affs_brelse(prev_bh);
706 affs_fix_checksum(sb, bh);
707 mark_buffer_dirty_inode(bh, inode);
708 written += bsize;
709 from += bsize;
710 bidx++;
711 }
712 if (from < to) {
713 prev_bh = bh;
714 bh = affs_bread_ino(inode, bidx, 1);
715 if (IS_ERR(bh))
716 goto out;
717 tmp = min(bsize, to - from);
718 if (tmp > bsize)
719 BUG();
720 memcpy(AFFS_DATA(bh), data + from, tmp);
721 if (buffer_new(bh)) {
722 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
723 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
724 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
725 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
726 AFFS_DATA_HEAD(bh)->next = 0;
727 bh->b_state &= ~(1UL << BH_New);
728 if (prev_bh) {
729 u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
730 if (tmp)
731 affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
732 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
733 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
734 mark_buffer_dirty_inode(prev_bh, inode);
735 }
736 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
737 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
738 affs_brelse(prev_bh);
739 affs_fix_checksum(sb, bh);
740 mark_buffer_dirty_inode(bh, inode);
741 written += tmp;
742 from += tmp;
743 bidx++;
744 }
745 SetPageUptodate(page);
747 done:
748 affs_brelse(bh);
749 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
750 if (tmp > inode->i_size)
751 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
753 return written;
755 out:
756 bh = prev_bh;
757 if (!written)
758 written = PTR_ERR(bh);
759 goto done;
760 }
762 const struct address_space_operations affs_aops_ofs = {
763 .readpage = affs_readpage_ofs,
764 //.writepage = affs_writepage_ofs,
765 //.sync_page = affs_sync_page_ofs,
766 .prepare_write = affs_prepare_write_ofs,
767 .commit_write = affs_commit_write_ofs
768 };
770 /* Free any preallocated blocks. */
772 void
773 affs_free_prealloc(struct inode *inode)
774 {
775 struct super_block *sb = inode->i_sb;
777 pr_debug("AFFS: free_prealloc(ino=%lu)\n", inode->i_ino);
779 while (AFFS_I(inode)->i_pa_cnt) {
780 AFFS_I(inode)->i_pa_cnt--;
781 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
782 }
783 }
785 /* Truncate (or enlarge) a file to the requested size. */
787 void
788 affs_truncate(struct inode *inode)
789 {
790 struct super_block *sb = inode->i_sb;
791 u32 ext, ext_key;
792 u32 last_blk, blkcnt, blk;
793 u32 size;
794 struct buffer_head *ext_bh;
795 int i;
797 pr_debug("AFFS: truncate(inode=%d, oldsize=%u, newsize=%u)\n",
798 (u32)inode->i_ino, (u32)AFFS_I(inode)->mmu_private, (u32)inode->i_size);
800 last_blk = 0;
801 ext = 0;
802 if (inode->i_size) {
803 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
804 ext = last_blk / AFFS_SB(sb)->s_hashsize;
805 }
807 if (inode->i_size > AFFS_I(inode)->mmu_private) {
808 struct address_space *mapping = inode->i_mapping;
809 struct page *page;
810 u32 size = inode->i_size - 1;
811 int res;
813 page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT);
814 if (!page)
815 return;
816 size = (size & (PAGE_CACHE_SIZE - 1)) + 1;
817 res = mapping->a_ops->prepare_write(NULL, page, size, size);
818 if (!res)
819 res = mapping->a_ops->commit_write(NULL, page, size, size);
820 unlock_page(page);
821 page_cache_release(page);
822 mark_inode_dirty(inode);
823 return;
824 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
825 return;
827 // lock cache
828 ext_bh = affs_get_extblock(inode, ext);
829 if (IS_ERR(ext_bh)) {
830 affs_warning(sb, "truncate", "unexpected read error for ext block %u (%d)",
831 ext, PTR_ERR(ext_bh));
832 return;
833 }
834 if (AFFS_I(inode)->i_lc) {
835 /* clear linear cache */
836 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
837 if (AFFS_I(inode)->i_lc_size > i) {
838 AFFS_I(inode)->i_lc_size = i;
839 for (; i < AFFS_LC_SIZE; i++)
840 AFFS_I(inode)->i_lc[i] = 0;
841 }
842 /* clear associative cache */
843 for (i = 0; i < AFFS_AC_SIZE; i++)
844 if (AFFS_I(inode)->i_ac[i].ext >= ext)
845 AFFS_I(inode)->i_ac[i].ext = 0;
846 }
847 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
849 blkcnt = AFFS_I(inode)->i_blkcnt;
850 i = 0;
851 blk = last_blk;
852 if (inode->i_size) {
853 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
854 blk++;
855 } else
856 AFFS_HEAD(ext_bh)->first_data = 0;
857 size = AFFS_SB(sb)->s_hashsize;
858 if (size > blkcnt - blk + i)
859 size = blkcnt - blk + i;
860 for (; i < size; i++, blk++) {
861 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
862 AFFS_BLOCK(sb, ext_bh, i) = 0;
863 }
864 AFFS_TAIL(sb, ext_bh)->extension = 0;
865 affs_fix_checksum(sb, ext_bh);
866 mark_buffer_dirty_inode(ext_bh, inode);
867 affs_brelse(ext_bh);
869 if (inode->i_size) {
870 AFFS_I(inode)->i_blkcnt = last_blk + 1;
871 AFFS_I(inode)->i_extcnt = ext + 1;
872 if (AFFS_SB(sb)->s_flags & SF_OFS) {
873 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
874 u32 tmp;
875 if (IS_ERR(ext_bh)) {
876 affs_warning(sb, "truncate", "unexpected read error for last block %u (%d)",
877 ext, PTR_ERR(ext_bh));
878 return;
879 }
880 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
881 AFFS_DATA_HEAD(bh)->next = 0;
882 affs_adjust_checksum(bh, -tmp);
883 affs_brelse(bh);
884 }
885 } else {
886 AFFS_I(inode)->i_blkcnt = 0;
887 AFFS_I(inode)->i_extcnt = 1;
888 }
889 AFFS_I(inode)->mmu_private = inode->i_size;
890 // unlock cache
892 while (ext_key) {
893 ext_bh = affs_bread(sb, ext_key);
894 size = AFFS_SB(sb)->s_hashsize;
895 if (size > blkcnt - blk)
896 size = blkcnt - blk;
897 for (i = 0; i < size; i++, blk++)
898 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
899 affs_free_block(sb, ext_key);
900 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
901 affs_brelse(ext_bh);
902 }
903 affs_free_prealloc(inode);
904 }