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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/affs/file.c
4 *
5 * (c) 1996 Hans-Joachim Widmaier - Rewritten
6 *
7 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
8 *
9 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
10 *
11 * (C) 1991 Linus Torvalds - minix filesystem
12 *
13 * affs regular file handling primitives
14 */
15
16#include <linux/uio.h>
17#include <linux/blkdev.h>
18#include <linux/mpage.h>
19#include "affs.h"
20
21static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
22
23static int
24affs_file_open(struct inode *inode, struct file *filp)
25{
26 pr_debug("open(%lu,%d)\n",
27 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
28 atomic_inc(&AFFS_I(inode)->i_opencnt);
29 return 0;
30}
31
32static int
33affs_file_release(struct inode *inode, struct file *filp)
34{
35 pr_debug("release(%lu, %d)\n",
36 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
37
38 if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
39 inode_lock(inode);
40 if (inode->i_size != AFFS_I(inode)->mmu_private)
41 affs_truncate(inode);
42 affs_free_prealloc(inode);
43 inode_unlock(inode);
44 }
45
46 return 0;
47}
48
49static int
50affs_grow_extcache(struct inode *inode, u32 lc_idx)
51{
52 struct super_block *sb = inode->i_sb;
53 struct buffer_head *bh;
54 u32 lc_max;
55 int i, j, key;
56
57 if (!AFFS_I(inode)->i_lc) {
58 char *ptr = (char *)get_zeroed_page(GFP_NOFS);
59 if (!ptr)
60 return -ENOMEM;
61 AFFS_I(inode)->i_lc = (u32 *)ptr;
62 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
63 }
64
65 lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
66
67 if (AFFS_I(inode)->i_extcnt > lc_max) {
68 u32 lc_shift, lc_mask, tmp, off;
69
70 /* need to recalculate linear cache, start from old size */
71 lc_shift = AFFS_I(inode)->i_lc_shift;
72 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
73 for (; tmp; tmp >>= 1)
74 lc_shift++;
75 lc_mask = (1 << lc_shift) - 1;
76
77 /* fix idx and old size to new shift */
78 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
79 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
80
81 /* first shrink old cache to make more space */
82 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
83 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
84 AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
85
86 AFFS_I(inode)->i_lc_shift = lc_shift;
87 AFFS_I(inode)->i_lc_mask = lc_mask;
88 }
89
90 /* fill cache to the needed index */
91 i = AFFS_I(inode)->i_lc_size;
92 AFFS_I(inode)->i_lc_size = lc_idx + 1;
93 for (; i <= lc_idx; i++) {
94 if (!i) {
95 AFFS_I(inode)->i_lc[0] = inode->i_ino;
96 continue;
97 }
98 key = AFFS_I(inode)->i_lc[i - 1];
99 j = AFFS_I(inode)->i_lc_mask + 1;
100 // unlock cache
101 for (; j > 0; j--) {
102 bh = affs_bread(sb, key);
103 if (!bh)
104 goto err;
105 key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
106 affs_brelse(bh);
107 }
108 // lock cache
109 AFFS_I(inode)->i_lc[i] = key;
110 }
111
112 return 0;
113
114err:
115 // lock cache
116 return -EIO;
117}
118
119static struct buffer_head *
120affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
121{
122 struct super_block *sb = inode->i_sb;
123 struct buffer_head *new_bh;
124 u32 blocknr, tmp;
125
126 blocknr = affs_alloc_block(inode, bh->b_blocknr);
127 if (!blocknr)
128 return ERR_PTR(-ENOSPC);
129
130 new_bh = affs_getzeroblk(sb, blocknr);
131 if (!new_bh) {
132 affs_free_block(sb, blocknr);
133 return ERR_PTR(-EIO);
134 }
135
136 AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
137 AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
138 AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
139 AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
140 affs_fix_checksum(sb, new_bh);
141
142 mark_buffer_dirty_inode(new_bh, inode);
143
144 tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
145 if (tmp)
146 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
147 AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
148 affs_adjust_checksum(bh, blocknr - tmp);
149 mark_buffer_dirty_inode(bh, inode);
150
151 AFFS_I(inode)->i_extcnt++;
152 mark_inode_dirty(inode);
153
154 return new_bh;
155}
156
157static inline struct buffer_head *
158affs_get_extblock(struct inode *inode, u32 ext)
159{
160 /* inline the simplest case: same extended block as last time */
161 struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
162 if (ext == AFFS_I(inode)->i_ext_last)
163 get_bh(bh);
164 else
165 /* we have to do more (not inlined) */
166 bh = affs_get_extblock_slow(inode, ext);
167
168 return bh;
169}
170
171static struct buffer_head *
172affs_get_extblock_slow(struct inode *inode, u32 ext)
173{
174 struct super_block *sb = inode->i_sb;
175 struct buffer_head *bh;
176 u32 ext_key;
177 u32 lc_idx, lc_off, ac_idx;
178 u32 tmp, idx;
179
180 if (ext == AFFS_I(inode)->i_ext_last + 1) {
181 /* read the next extended block from the current one */
182 bh = AFFS_I(inode)->i_ext_bh;
183 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
184 if (ext < AFFS_I(inode)->i_extcnt)
185 goto read_ext;
186 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
187 bh = affs_alloc_extblock(inode, bh, ext);
188 if (IS_ERR(bh))
189 return bh;
190 goto store_ext;
191 }
192
193 if (ext == 0) {
194 /* we seek back to the file header block */
195 ext_key = inode->i_ino;
196 goto read_ext;
197 }
198
199 if (ext >= AFFS_I(inode)->i_extcnt) {
200 struct buffer_head *prev_bh;
201
202 /* allocate a new extended block */
203 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
204
205 /* get previous extended block */
206 prev_bh = affs_get_extblock(inode, ext - 1);
207 if (IS_ERR(prev_bh))
208 return prev_bh;
209 bh = affs_alloc_extblock(inode, prev_bh, ext);
210 affs_brelse(prev_bh);
211 if (IS_ERR(bh))
212 return bh;
213 goto store_ext;
214 }
215
216again:
217 /* check if there is an extended cache and whether it's large enough */
218 lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
219 lc_off = ext & AFFS_I(inode)->i_lc_mask;
220
221 if (lc_idx >= AFFS_I(inode)->i_lc_size) {
222 int err;
223
224 err = affs_grow_extcache(inode, lc_idx);
225 if (err)
226 return ERR_PTR(err);
227 goto again;
228 }
229
230 /* every n'th key we find in the linear cache */
231 if (!lc_off) {
232 ext_key = AFFS_I(inode)->i_lc[lc_idx];
233 goto read_ext;
234 }
235
236 /* maybe it's still in the associative cache */
237 ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
238 if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
239 ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
240 goto read_ext;
241 }
242
243 /* try to find one of the previous extended blocks */
244 tmp = ext;
245 idx = ac_idx;
246 while (--tmp, --lc_off > 0) {
247 idx = (idx - 1) & AFFS_AC_MASK;
248 if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
249 ext_key = AFFS_I(inode)->i_ac[idx].key;
250 goto find_ext;
251 }
252 }
253
254 /* fall back to the linear cache */
255 ext_key = AFFS_I(inode)->i_lc[lc_idx];
256find_ext:
257 /* read all extended blocks until we find the one we need */
258 //unlock cache
259 do {
260 bh = affs_bread(sb, ext_key);
261 if (!bh)
262 goto err_bread;
263 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
264 affs_brelse(bh);
265 tmp++;
266 } while (tmp < ext);
267 //lock cache
268
269 /* store it in the associative cache */
270 // recalculate ac_idx?
271 AFFS_I(inode)->i_ac[ac_idx].ext = ext;
272 AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
273
274read_ext:
275 /* finally read the right extended block */
276 //unlock cache
277 bh = affs_bread(sb, ext_key);
278 if (!bh)
279 goto err_bread;
280 //lock cache
281
282store_ext:
283 /* release old cached extended block and store the new one */
284 affs_brelse(AFFS_I(inode)->i_ext_bh);
285 AFFS_I(inode)->i_ext_last = ext;
286 AFFS_I(inode)->i_ext_bh = bh;
287 get_bh(bh);
288
289 return bh;
290
291err_bread:
292 affs_brelse(bh);
293 return ERR_PTR(-EIO);
294}
295
296static int
297affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
298{
299 struct super_block *sb = inode->i_sb;
300 struct buffer_head *ext_bh;
301 u32 ext;
302
303 pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino,
304 (unsigned long long)block);
305
306 BUG_ON(block > (sector_t)0x7fffffffUL);
307
308 if (block >= AFFS_I(inode)->i_blkcnt) {
309 if (block > AFFS_I(inode)->i_blkcnt || !create)
310 goto err_big;
311 } else
312 create = 0;
313
314 //lock cache
315 affs_lock_ext(inode);
316
317 ext = (u32)block / AFFS_SB(sb)->s_hashsize;
318 block -= ext * AFFS_SB(sb)->s_hashsize;
319 ext_bh = affs_get_extblock(inode, ext);
320 if (IS_ERR(ext_bh))
321 goto err_ext;
322 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
323
324 if (create) {
325 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
326 if (!blocknr)
327 goto err_alloc;
328 set_buffer_new(bh_result);
329 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
330 AFFS_I(inode)->i_blkcnt++;
331
332 /* store new block */
333 if (bh_result->b_blocknr)
334 affs_warning(sb, "get_block",
335 "block already set (%llx)",
336 (unsigned long long)bh_result->b_blocknr);
337 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
338 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
339 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
340 bh_result->b_blocknr = blocknr;
341
342 if (!block) {
343 /* insert first block into header block */
344 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
345 if (tmp)
346 affs_warning(sb, "get_block", "first block already set (%d)", tmp);
347 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
348 affs_adjust_checksum(ext_bh, blocknr - tmp);
349 }
350 }
351
352 affs_brelse(ext_bh);
353 //unlock cache
354 affs_unlock_ext(inode);
355 return 0;
356
357err_big:
358 affs_error(inode->i_sb, "get_block", "strange block request %llu",
359 (unsigned long long)block);
360 return -EIO;
361err_ext:
362 // unlock cache
363 affs_unlock_ext(inode);
364 return PTR_ERR(ext_bh);
365err_alloc:
366 brelse(ext_bh);
367 clear_buffer_mapped(bh_result);
368 bh_result->b_bdev = NULL;
369 // unlock cache
370 affs_unlock_ext(inode);
371 return -ENOSPC;
372}
373
374static int affs_writepages(struct address_space *mapping,
375 struct writeback_control *wbc)
376{
377 return mpage_writepages(mapping, wbc, affs_get_block);
378}
379
380static int affs_read_folio(struct file *file, struct folio *folio)
381{
382 return block_read_full_folio(folio, affs_get_block);
383}
384
385static void affs_write_failed(struct address_space *mapping, loff_t to)
386{
387 struct inode *inode = mapping->host;
388
389 if (to > inode->i_size) {
390 truncate_pagecache(inode, inode->i_size);
391 affs_truncate(inode);
392 }
393}
394
395static ssize_t
396affs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
397{
398 struct file *file = iocb->ki_filp;
399 struct address_space *mapping = file->f_mapping;
400 struct inode *inode = mapping->host;
401 size_t count = iov_iter_count(iter);
402 loff_t offset = iocb->ki_pos;
403 ssize_t ret;
404
405 if (iov_iter_rw(iter) == WRITE) {
406 loff_t size = offset + count;
407
408 if (AFFS_I(inode)->mmu_private < size)
409 return 0;
410 }
411
412 ret = blockdev_direct_IO(iocb, inode, iter, affs_get_block);
413 if (ret < 0 && iov_iter_rw(iter) == WRITE)
414 affs_write_failed(mapping, offset + count);
415 return ret;
416}
417
418static int affs_write_begin(struct file *file, struct address_space *mapping,
419 loff_t pos, unsigned len,
420 struct folio **foliop, void **fsdata)
421{
422 int ret;
423
424 ret = cont_write_begin(file, mapping, pos, len, foliop, fsdata,
425 affs_get_block,
426 &AFFS_I(mapping->host)->mmu_private);
427 if (unlikely(ret))
428 affs_write_failed(mapping, pos + len);
429
430 return ret;
431}
432
433static int affs_write_end(struct file *file, struct address_space *mapping,
434 loff_t pos, unsigned int len, unsigned int copied,
435 struct folio *folio, void *fsdata)
436{
437 struct inode *inode = mapping->host;
438 int ret;
439
440 ret = generic_write_end(file, mapping, pos, len, copied, folio, fsdata);
441
442 /* Clear Archived bit on file writes, as AmigaOS would do */
443 if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
444 AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
445 mark_inode_dirty(inode);
446 }
447
448 return ret;
449}
450
451static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
452{
453 return generic_block_bmap(mapping,block,affs_get_block);
454}
455
456const struct address_space_operations affs_aops = {
457 .dirty_folio = block_dirty_folio,
458 .invalidate_folio = block_invalidate_folio,
459 .read_folio = affs_read_folio,
460 .writepages = affs_writepages,
461 .write_begin = affs_write_begin,
462 .write_end = affs_write_end,
463 .direct_IO = affs_direct_IO,
464 .migrate_folio = buffer_migrate_folio,
465 .bmap = _affs_bmap
466};
467
468static inline struct buffer_head *
469affs_bread_ino(struct inode *inode, int block, int create)
470{
471 struct buffer_head *bh, tmp_bh;
472 int err;
473
474 tmp_bh.b_state = 0;
475 err = affs_get_block(inode, block, &tmp_bh, create);
476 if (!err) {
477 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
478 if (bh) {
479 bh->b_state |= tmp_bh.b_state;
480 return bh;
481 }
482 err = -EIO;
483 }
484 return ERR_PTR(err);
485}
486
487static inline struct buffer_head *
488affs_getzeroblk_ino(struct inode *inode, int block)
489{
490 struct buffer_head *bh, tmp_bh;
491 int err;
492
493 tmp_bh.b_state = 0;
494 err = affs_get_block(inode, block, &tmp_bh, 1);
495 if (!err) {
496 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
497 if (bh) {
498 bh->b_state |= tmp_bh.b_state;
499 return bh;
500 }
501 err = -EIO;
502 }
503 return ERR_PTR(err);
504}
505
506static inline struct buffer_head *
507affs_getemptyblk_ino(struct inode *inode, int block)
508{
509 struct buffer_head *bh, tmp_bh;
510 int err;
511
512 tmp_bh.b_state = 0;
513 err = affs_get_block(inode, block, &tmp_bh, 1);
514 if (!err) {
515 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
516 if (bh) {
517 bh->b_state |= tmp_bh.b_state;
518 return bh;
519 }
520 err = -EIO;
521 }
522 return ERR_PTR(err);
523}
524
525static int affs_do_read_folio_ofs(struct folio *folio, size_t to, int create)
526{
527 struct inode *inode = folio->mapping->host;
528 struct super_block *sb = inode->i_sb;
529 struct buffer_head *bh;
530 size_t pos = 0;
531 size_t bidx, boff, bsize;
532 u32 tmp;
533
534 pr_debug("%s(%lu, %ld, 0, %zu)\n", __func__, inode->i_ino,
535 folio->index, to);
536 BUG_ON(to > folio_size(folio));
537 bsize = AFFS_SB(sb)->s_data_blksize;
538 tmp = folio_pos(folio);
539 bidx = tmp / bsize;
540 boff = tmp % bsize;
541
542 while (pos < to) {
543 bh = affs_bread_ino(inode, bidx, create);
544 if (IS_ERR(bh))
545 return PTR_ERR(bh);
546 tmp = min(bsize - boff, to - pos);
547 BUG_ON(pos + tmp > to || tmp > bsize);
548 memcpy_to_folio(folio, pos, AFFS_DATA(bh) + boff, tmp);
549 affs_brelse(bh);
550 bidx++;
551 pos += tmp;
552 boff = 0;
553 }
554 return 0;
555}
556
557static int
558affs_extent_file_ofs(struct inode *inode, u32 newsize)
559{
560 struct super_block *sb = inode->i_sb;
561 struct buffer_head *bh, *prev_bh;
562 u32 bidx, boff;
563 u32 size, bsize;
564 u32 tmp;
565
566 pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize);
567 bsize = AFFS_SB(sb)->s_data_blksize;
568 bh = NULL;
569 size = AFFS_I(inode)->mmu_private;
570 bidx = size / bsize;
571 boff = size % bsize;
572 if (boff) {
573 bh = affs_bread_ino(inode, bidx, 0);
574 if (IS_ERR(bh))
575 return PTR_ERR(bh);
576 tmp = min(bsize - boff, newsize - size);
577 BUG_ON(boff + tmp > bsize || tmp > bsize);
578 memset(AFFS_DATA(bh) + boff, 0, tmp);
579 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
580 affs_fix_checksum(sb, bh);
581 mark_buffer_dirty_inode(bh, inode);
582 size += tmp;
583 bidx++;
584 } else if (bidx) {
585 bh = affs_bread_ino(inode, bidx - 1, 0);
586 if (IS_ERR(bh))
587 return PTR_ERR(bh);
588 }
589
590 while (size < newsize) {
591 prev_bh = bh;
592 bh = affs_getzeroblk_ino(inode, bidx);
593 if (IS_ERR(bh))
594 goto out;
595 tmp = min(bsize, newsize - size);
596 BUG_ON(tmp > bsize);
597 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
598 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
599 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
600 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
601 affs_fix_checksum(sb, bh);
602 bh->b_state &= ~(1UL << BH_New);
603 mark_buffer_dirty_inode(bh, inode);
604 if (prev_bh) {
605 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
606
607 if (tmp_next)
608 affs_warning(sb, "extent_file_ofs",
609 "next block already set for %d (%d)",
610 bidx, tmp_next);
611 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
612 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
613 mark_buffer_dirty_inode(prev_bh, inode);
614 affs_brelse(prev_bh);
615 }
616 size += bsize;
617 bidx++;
618 }
619 affs_brelse(bh);
620 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
621 return 0;
622
623out:
624 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
625 return PTR_ERR(bh);
626}
627
628static int affs_read_folio_ofs(struct file *file, struct folio *folio)
629{
630 struct inode *inode = folio->mapping->host;
631 size_t to;
632 int err;
633
634 pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, folio->index);
635 to = folio_size(folio);
636 if (folio_pos(folio) + to > inode->i_size) {
637 to = inode->i_size - folio_pos(folio);
638 folio_zero_segment(folio, to, folio_size(folio));
639 }
640
641 err = affs_do_read_folio_ofs(folio, to, 0);
642 if (!err)
643 folio_mark_uptodate(folio);
644 folio_unlock(folio);
645 return err;
646}
647
648static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
649 loff_t pos, unsigned len,
650 struct folio **foliop, void **fsdata)
651{
652 struct inode *inode = mapping->host;
653 struct folio *folio;
654 pgoff_t index;
655 int err = 0;
656
657 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
658 pos + len);
659 if (pos > AFFS_I(inode)->mmu_private) {
660 /* XXX: this probably leaves a too-big i_size in case of
661 * failure. Should really be updating i_size at write_end time
662 */
663 err = affs_extent_file_ofs(inode, pos);
664 if (err)
665 return err;
666 }
667
668 index = pos >> PAGE_SHIFT;
669 folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
670 mapping_gfp_mask(mapping));
671 if (IS_ERR(folio))
672 return PTR_ERR(folio);
673 *foliop = folio;
674
675 if (folio_test_uptodate(folio))
676 return 0;
677
678 /* XXX: inefficient but safe in the face of short writes */
679 err = affs_do_read_folio_ofs(folio, folio_size(folio), 1);
680 if (err) {
681 folio_unlock(folio);
682 folio_put(folio);
683 }
684 return err;
685}
686
687static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
688 loff_t pos, unsigned len, unsigned copied,
689 struct folio *folio, void *fsdata)
690{
691 struct inode *inode = mapping->host;
692 struct super_block *sb = inode->i_sb;
693 struct buffer_head *bh, *prev_bh;
694 char *data;
695 u32 bidx, boff, bsize;
696 unsigned from, to;
697 u32 tmp;
698 int written;
699
700 from = pos & (PAGE_SIZE - 1);
701 to = from + len;
702 /*
703 * XXX: not sure if this can handle short copies (len < copied), but
704 * we don't have to, because the folio should always be uptodate here,
705 * due to write_begin.
706 */
707
708 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
709 pos + len);
710 bsize = AFFS_SB(sb)->s_data_blksize;
711 data = folio_address(folio);
712
713 bh = NULL;
714 written = 0;
715 tmp = (folio->index << PAGE_SHIFT) + from;
716 bidx = tmp / bsize;
717 boff = tmp % bsize;
718 if (boff) {
719 bh = affs_bread_ino(inode, bidx, 0);
720 if (IS_ERR(bh)) {
721 written = PTR_ERR(bh);
722 goto err_first_bh;
723 }
724 tmp = min(bsize - boff, to - from);
725 BUG_ON(boff + tmp > bsize || tmp > bsize);
726 memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
727 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
728 affs_fix_checksum(sb, bh);
729 mark_buffer_dirty_inode(bh, inode);
730 written += tmp;
731 from += tmp;
732 bidx++;
733 } else if (bidx) {
734 bh = affs_bread_ino(inode, bidx - 1, 0);
735 if (IS_ERR(bh)) {
736 written = PTR_ERR(bh);
737 goto err_first_bh;
738 }
739 }
740 while (from + bsize <= to) {
741 prev_bh = bh;
742 bh = affs_getemptyblk_ino(inode, bidx);
743 if (IS_ERR(bh))
744 goto err_bh;
745 memcpy(AFFS_DATA(bh), data + from, bsize);
746 if (buffer_new(bh)) {
747 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
748 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
749 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
750 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
751 AFFS_DATA_HEAD(bh)->next = 0;
752 bh->b_state &= ~(1UL << BH_New);
753 if (prev_bh) {
754 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
755
756 if (tmp_next)
757 affs_warning(sb, "commit_write_ofs",
758 "next block already set for %d (%d)",
759 bidx, tmp_next);
760 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
761 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
762 mark_buffer_dirty_inode(prev_bh, inode);
763 }
764 }
765 affs_brelse(prev_bh);
766 affs_fix_checksum(sb, bh);
767 mark_buffer_dirty_inode(bh, inode);
768 written += bsize;
769 from += bsize;
770 bidx++;
771 }
772 if (from < to) {
773 prev_bh = bh;
774 bh = affs_bread_ino(inode, bidx, 1);
775 if (IS_ERR(bh))
776 goto err_bh;
777 tmp = min(bsize, to - from);
778 BUG_ON(tmp > bsize);
779 memcpy(AFFS_DATA(bh), data + from, tmp);
780 if (buffer_new(bh)) {
781 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
782 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
783 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
784 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
785 AFFS_DATA_HEAD(bh)->next = 0;
786 bh->b_state &= ~(1UL << BH_New);
787 if (prev_bh) {
788 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
789
790 if (tmp_next)
791 affs_warning(sb, "commit_write_ofs",
792 "next block already set for %d (%d)",
793 bidx, tmp_next);
794 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
795 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
796 mark_buffer_dirty_inode(prev_bh, inode);
797 }
798 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
799 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
800 affs_brelse(prev_bh);
801 affs_fix_checksum(sb, bh);
802 mark_buffer_dirty_inode(bh, inode);
803 written += tmp;
804 from += tmp;
805 bidx++;
806 }
807 folio_mark_uptodate(folio);
808
809done:
810 affs_brelse(bh);
811 tmp = (folio->index << PAGE_SHIFT) + from;
812 if (tmp > inode->i_size)
813 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
814
815 /* Clear Archived bit on file writes, as AmigaOS would do */
816 if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
817 AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
818 mark_inode_dirty(inode);
819 }
820
821err_first_bh:
822 folio_unlock(folio);
823 folio_put(folio);
824
825 return written;
826
827err_bh:
828 bh = prev_bh;
829 if (!written)
830 written = PTR_ERR(bh);
831 goto done;
832}
833
834const struct address_space_operations affs_aops_ofs = {
835 .dirty_folio = block_dirty_folio,
836 .invalidate_folio = block_invalidate_folio,
837 .read_folio = affs_read_folio_ofs,
838 //.writepages = affs_writepages_ofs,
839 .write_begin = affs_write_begin_ofs,
840 .write_end = affs_write_end_ofs,
841 .migrate_folio = filemap_migrate_folio,
842};
843
844/* Free any preallocated blocks. */
845
846void
847affs_free_prealloc(struct inode *inode)
848{
849 struct super_block *sb = inode->i_sb;
850
851 pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
852
853 while (AFFS_I(inode)->i_pa_cnt) {
854 AFFS_I(inode)->i_pa_cnt--;
855 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
856 }
857}
858
859/* Truncate (or enlarge) a file to the requested size. */
860
861void
862affs_truncate(struct inode *inode)
863{
864 struct super_block *sb = inode->i_sb;
865 u32 ext, ext_key;
866 u32 last_blk, blkcnt, blk;
867 u32 size;
868 struct buffer_head *ext_bh;
869 int i;
870
871 pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
872 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
873
874 last_blk = 0;
875 ext = 0;
876 if (inode->i_size) {
877 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
878 ext = last_blk / AFFS_SB(sb)->s_hashsize;
879 }
880
881 if (inode->i_size > AFFS_I(inode)->mmu_private) {
882 struct address_space *mapping = inode->i_mapping;
883 struct folio *folio;
884 void *fsdata = NULL;
885 loff_t isize = inode->i_size;
886 int res;
887
888 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, &folio, &fsdata);
889 if (!res)
890 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, folio, fsdata);
891 else
892 inode->i_size = AFFS_I(inode)->mmu_private;
893 mark_inode_dirty(inode);
894 return;
895 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
896 return;
897
898 // lock cache
899 ext_bh = affs_get_extblock(inode, ext);
900 if (IS_ERR(ext_bh)) {
901 affs_warning(sb, "truncate",
902 "unexpected read error for ext block %u (%ld)",
903 ext, PTR_ERR(ext_bh));
904 return;
905 }
906 if (AFFS_I(inode)->i_lc) {
907 /* clear linear cache */
908 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
909 if (AFFS_I(inode)->i_lc_size > i) {
910 AFFS_I(inode)->i_lc_size = i;
911 for (; i < AFFS_LC_SIZE; i++)
912 AFFS_I(inode)->i_lc[i] = 0;
913 }
914 /* clear associative cache */
915 for (i = 0; i < AFFS_AC_SIZE; i++)
916 if (AFFS_I(inode)->i_ac[i].ext >= ext)
917 AFFS_I(inode)->i_ac[i].ext = 0;
918 }
919 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
920
921 blkcnt = AFFS_I(inode)->i_blkcnt;
922 i = 0;
923 blk = last_blk;
924 if (inode->i_size) {
925 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
926 blk++;
927 } else
928 AFFS_HEAD(ext_bh)->first_data = 0;
929 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
930 size = AFFS_SB(sb)->s_hashsize;
931 if (size > blkcnt - blk + i)
932 size = blkcnt - blk + i;
933 for (; i < size; i++, blk++) {
934 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
935 AFFS_BLOCK(sb, ext_bh, i) = 0;
936 }
937 AFFS_TAIL(sb, ext_bh)->extension = 0;
938 affs_fix_checksum(sb, ext_bh);
939 mark_buffer_dirty_inode(ext_bh, inode);
940 affs_brelse(ext_bh);
941
942 if (inode->i_size) {
943 AFFS_I(inode)->i_blkcnt = last_blk + 1;
944 AFFS_I(inode)->i_extcnt = ext + 1;
945 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) {
946 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
947 u32 tmp;
948 if (IS_ERR(bh)) {
949 affs_warning(sb, "truncate",
950 "unexpected read error for last block %u (%ld)",
951 ext, PTR_ERR(bh));
952 return;
953 }
954 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
955 AFFS_DATA_HEAD(bh)->next = 0;
956 affs_adjust_checksum(bh, -tmp);
957 affs_brelse(bh);
958 }
959 } else {
960 AFFS_I(inode)->i_blkcnt = 0;
961 AFFS_I(inode)->i_extcnt = 1;
962 }
963 AFFS_I(inode)->mmu_private = inode->i_size;
964 // unlock cache
965
966 while (ext_key) {
967 ext_bh = affs_bread(sb, ext_key);
968 size = AFFS_SB(sb)->s_hashsize;
969 if (size > blkcnt - blk)
970 size = blkcnt - blk;
971 for (i = 0; i < size; i++, blk++)
972 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
973 affs_free_block(sb, ext_key);
974 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
975 affs_brelse(ext_bh);
976 }
977 affs_free_prealloc(inode);
978}
979
980int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
981{
982 struct inode *inode = filp->f_mapping->host;
983 int ret, err;
984
985 err = file_write_and_wait_range(filp, start, end);
986 if (err)
987 return err;
988
989 inode_lock(inode);
990 ret = write_inode_now(inode, 0);
991 err = sync_blockdev(inode->i_sb->s_bdev);
992 if (!ret)
993 ret = err;
994 inode_unlock(inode);
995 return ret;
996}
997const struct file_operations affs_file_operations = {
998 .llseek = generic_file_llseek,
999 .read_iter = generic_file_read_iter,
1000 .write_iter = generic_file_write_iter,
1001 .mmap = generic_file_mmap,
1002 .open = affs_file_open,
1003 .release = affs_file_release,
1004 .fsync = affs_file_fsync,
1005 .splice_read = filemap_splice_read,
1006};
1007
1008const struct inode_operations affs_file_inode_operations = {
1009 .setattr = affs_notify_change,
1010};
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
21static int affs_grow_extcache(struct inode *inode, u32 lc_idx);
22static struct buffer_head *affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext);
23static inline struct buffer_head *affs_get_extblock(struct inode *inode, u32 ext);
24static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
25static int affs_file_open(struct inode *inode, struct file *filp);
26static int affs_file_release(struct inode *inode, struct file *filp);
27
28const 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
41const struct inode_operations affs_file_inode_operations = {
42 .setattr = affs_notify_change,
43};
44
45static int
46affs_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
54static int
55affs_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
71static int
72affs_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
136err:
137 // lock cache
138 return -EIO;
139}
140
141static struct buffer_head *
142affs_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
179static inline struct buffer_head *
180affs_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
193static struct buffer_head *
194affs_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
240again:
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];
280find_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
298read_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
306store_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
315err_bread:
316 affs_brelse(bh);
317 return ERR_PTR(-EIO);
318}
319
320static int
321affs_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
378err_big:
379 affs_error(inode->i_sb,"get_block","strange block request %d", block);
380 return -EIO;
381err_ext:
382 // unlock cache
383 affs_unlock_ext(inode);
384 return PTR_ERR(ext_bh);
385err_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
394static int affs_writepage(struct page *page, struct writeback_control *wbc)
395{
396 return block_write_full_page(page, affs_get_block, wbc);
397}
398
399static int affs_readpage(struct file *file, struct page *page)
400{
401 return block_read_full_page(page, affs_get_block);
402}
403
404static 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, inode->i_size);
410 affs_truncate(inode);
411 }
412}
413
414static 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
430static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
431{
432 return generic_block_bmap(mapping,block,affs_get_block);
433}
434
435const 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
443static inline struct buffer_head *
444affs_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
462static inline struct buffer_head *
463affs_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
481static inline struct buffer_head *
482affs_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
500static int
501affs_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
536static int
537affs_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
599out:
600 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
601 return PTR_ERR(bh);
602}
603
604static int
605affs_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
625static 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
662static 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
773done:
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
784out:
785 bh = prev_bh;
786 if (!written)
787 written = PTR_ERR(bh);
788 goto done;
789}
790
791const 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
800void
801affs_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
815void
816affs_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 loff_t 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
932int 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}