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Merge remote-tracking branches 'asoc/topic/cx20442' and 'asoc/topic/davinci' into...
[linux-2.6-block.git] / fs / affs / file.c
CommitLineData
1da177e4
LT		 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
9abb4083 15#include <linux/aio.h>
1da177e4
LT		 16#include "affs.h"
17
1da177e4 18static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
1da177e4
LT		 19
20static int
21affs_file_open(struct inode *inode, struct file *filp)
22{
9606d9aa 23 pr_debug("open(%lu,%d)\n",
dca3c336
RZ		 24 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
25 atomic_inc(&AFFS_I(inode)->i_opencnt);
1da177e4
LT		 26 return 0;
27}
28
29static int
30affs_file_release(struct inode *inode, struct file *filp)
31{
9606d9aa 32 pr_debug("release(%lu, %d)\n",
dca3c336
RZ		 33 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
34
35 if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
36 mutex_lock(&inode->i_mutex);
37 if (inode->i_size != AFFS_I(inode)->mmu_private)
38 affs_truncate(inode);
1da177e4 39 affs_free_prealloc(inode);
dca3c336
RZ		 40 mutex_unlock(&inode->i_mutex);
41 }
1da177e4
LT		 42
43 return 0;
44}
45
46static int
47affs_grow_extcache(struct inode *inode, u32 lc_idx)
48{
49 struct super_block *sb = inode->i_sb;
50 struct buffer_head *bh;
51 u32 lc_max;
52 int i, j, key;
53
54 if (!AFFS_I(inode)->i_lc) {
55 char *ptr = (char *)get_zeroed_page(GFP_NOFS);
56 if (!ptr)
57 return -ENOMEM;
58 AFFS_I(inode)->i_lc = (u32 *)ptr;
59 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
60 }
61
62 lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
63
64 if (AFFS_I(inode)->i_extcnt > lc_max) {
65 u32 lc_shift, lc_mask, tmp, off;
66
67 /* need to recalculate linear cache, start from old size */
68 lc_shift = AFFS_I(inode)->i_lc_shift;
69 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
70 for (; tmp; tmp >>= 1)
71 lc_shift++;
72 lc_mask = (1 << lc_shift) - 1;
73
74 /* fix idx and old size to new shift */
75 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
76 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
77
78 /* first shrink old cache to make more space */
79 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
80 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
81 AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
82
83 AFFS_I(inode)->i_lc_shift = lc_shift;
84 AFFS_I(inode)->i_lc_mask = lc_mask;
85 }
86
87 /* fill cache to the needed index */
88 i = AFFS_I(inode)->i_lc_size;
89 AFFS_I(inode)->i_lc_size = lc_idx + 1;
90 for (; i <= lc_idx; i++) {
91 if (!i) {
92 AFFS_I(inode)->i_lc[0] = inode->i_ino;
93 continue;
94 }
95 key = AFFS_I(inode)->i_lc[i - 1];
96 j = AFFS_I(inode)->i_lc_mask + 1;
97 // unlock cache
98 for (; j > 0; j--) {
99 bh = affs_bread(sb, key);
100 if (!bh)
101 goto err;
102 key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
103 affs_brelse(bh);
104 }
105 // lock cache
106 AFFS_I(inode)->i_lc[i] = key;
107 }
108
109 return 0;
110
111err:
112 // lock cache
113 return -EIO;
114}
115
116static struct buffer_head *
117affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
118{
119 struct super_block *sb = inode->i_sb;
120 struct buffer_head *new_bh;
121 u32 blocknr, tmp;
122
123 blocknr = affs_alloc_block(inode, bh->b_blocknr);
124 if (!blocknr)
125 return ERR_PTR(-ENOSPC);
126
127 new_bh = affs_getzeroblk(sb, blocknr);
128 if (!new_bh) {
129 affs_free_block(sb, blocknr);
130 return ERR_PTR(-EIO);
131 }
132
133 AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
134 AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
135 AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
136 AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
137 affs_fix_checksum(sb, new_bh);
138
139 mark_buffer_dirty_inode(new_bh, inode);
140
141 tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
142 if (tmp)
143 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
144 AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
145 affs_adjust_checksum(bh, blocknr - tmp);
146 mark_buffer_dirty_inode(bh, inode);
147
148 AFFS_I(inode)->i_extcnt++;
149 mark_inode_dirty(inode);
150
151 return new_bh;
152}
153
154static inline struct buffer_head *
155affs_get_extblock(struct inode *inode, u32 ext)
156{
157 /* inline the simplest case: same extended block as last time */
158 struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
159 if (ext == AFFS_I(inode)->i_ext_last)
dca3c336 160 get_bh(bh);
1da177e4
LT		 161 else
162 /* we have to do more (not inlined) */
163 bh = affs_get_extblock_slow(inode, ext);
164
165 return bh;
166}
167
168static struct buffer_head *
169affs_get_extblock_slow(struct inode *inode, u32 ext)
170{
171 struct super_block *sb = inode->i_sb;
172 struct buffer_head *bh;
173 u32 ext_key;
174 u32 lc_idx, lc_off, ac_idx;
175 u32 tmp, idx;
176
177 if (ext == AFFS_I(inode)->i_ext_last + 1) {
178 /* read the next extended block from the current one */
179 bh = AFFS_I(inode)->i_ext_bh;
180 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
181 if (ext < AFFS_I(inode)->i_extcnt)
182 goto read_ext;
afe305dc 183 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
1da177e4
LT		 184 bh = affs_alloc_extblock(inode, bh, ext);
185 if (IS_ERR(bh))
186 return bh;
187 goto store_ext;
188 }
189
190 if (ext == 0) {
191 /* we seek back to the file header block */
192 ext_key = inode->i_ino;
193 goto read_ext;
194 }
195
196 if (ext >= AFFS_I(inode)->i_extcnt) {
197 struct buffer_head *prev_bh;
198
199 /* allocate a new extended block */
afe305dc 200 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
1da177e4
LT		 201
202 /* get previous extended block */
203 prev_bh = affs_get_extblock(inode, ext - 1);
204 if (IS_ERR(prev_bh))
205 return prev_bh;
206 bh = affs_alloc_extblock(inode, prev_bh, ext);
207 affs_brelse(prev_bh);
208 if (IS_ERR(bh))
209 return bh;
210 goto store_ext;
211 }
212
213again:
214 /* check if there is an extended cache and whether it's large enough */
215 lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
216 lc_off = ext & AFFS_I(inode)->i_lc_mask;
217
218 if (lc_idx >= AFFS_I(inode)->i_lc_size) {
219 int err;
220
221 err = affs_grow_extcache(inode, lc_idx);
222 if (err)
223 return ERR_PTR(err);
224 goto again;
225 }
226
227 /* every n'th key we find in the linear cache */
228 if (!lc_off) {
229 ext_key = AFFS_I(inode)->i_lc[lc_idx];
230 goto read_ext;
231 }
232
233 /* maybe it's still in the associative cache */
234 ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
235 if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
236 ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
237 goto read_ext;
238 }
239
240 /* try to find one of the previous extended blocks */
241 tmp = ext;
242 idx = ac_idx;
243 while (--tmp, --lc_off > 0) {
244 idx = (idx - 1) & AFFS_AC_MASK;
245 if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
246 ext_key = AFFS_I(inode)->i_ac[idx].key;
247 goto find_ext;
248 }
249 }
250
251 /* fall back to the linear cache */
252 ext_key = AFFS_I(inode)->i_lc[lc_idx];
253find_ext:
254 /* read all extended blocks until we find the one we need */
255 //unlock cache
256 do {
257 bh = affs_bread(sb, ext_key);
258 if (!bh)
259 goto err_bread;
260 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
261 affs_brelse(bh);
262 tmp++;
263 } while (tmp < ext);
264 //lock cache
265
266 /* store it in the associative cache */
267 // recalculate ac_idx?
268 AFFS_I(inode)->i_ac[ac_idx].ext = ext;
269 AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
270
271read_ext:
272 /* finally read the right extended block */
273 //unlock cache
274 bh = affs_bread(sb, ext_key);
275 if (!bh)
276 goto err_bread;
277 //lock cache
278
279store_ext:
280 /* release old cached extended block and store the new one */
281 affs_brelse(AFFS_I(inode)->i_ext_bh);
282 AFFS_I(inode)->i_ext_last = ext;
283 AFFS_I(inode)->i_ext_bh = bh;
dca3c336 284 get_bh(bh);
1da177e4
LT		 285
286 return bh;
287
288err_bread:
289 affs_brelse(bh);
290 return ERR_PTR(-EIO);
291}
292
293static int
294affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
295{
296 struct super_block *sb = inode->i_sb;
297 struct buffer_head *ext_bh;
298 u32 ext;
299
08fe100d
GU		 300 pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino,
301 (unsigned long long)block);
1da177e4 302
8d4b6900 303 BUG_ON(block > (sector_t)0x7fffffffUL);
1da177e4
LT		 304
305 if (block >= AFFS_I(inode)->i_blkcnt) {
306 if (block > AFFS_I(inode)->i_blkcnt || !create)
307 goto err_big;
308 } else
309 create = 0;
310
311 //lock cache
312 affs_lock_ext(inode);
313
314 ext = (u32)block / AFFS_SB(sb)->s_hashsize;
315 block -= ext * AFFS_SB(sb)->s_hashsize;
316 ext_bh = affs_get_extblock(inode, ext);
317 if (IS_ERR(ext_bh))
318 goto err_ext;
319 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
320
321 if (create) {
322 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
323 if (!blocknr)
324 goto err_alloc;
325 set_buffer_new(bh_result);
326 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
327 AFFS_I(inode)->i_blkcnt++;
328
329 /* store new block */
330 if (bh_result->b_blocknr)
08fe100d
GU		 331 affs_warning(sb, "get_block",
332 "block already set (%llx)",
333 (unsigned long long)bh_result->b_blocknr);
1da177e4
LT		 334 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
335 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
336 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
337 bh_result->b_blocknr = blocknr;
338
339 if (!block) {
340 /* insert first block into header block */
341 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
342 if (tmp)
343 affs_warning(sb, "get_block", "first block already set (%d)", tmp);
344 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
345 affs_adjust_checksum(ext_bh, blocknr - tmp);
346 }
347 }
348
349 affs_brelse(ext_bh);
350 //unlock cache
351 affs_unlock_ext(inode);
352 return 0;
353
354err_big:
08fe100d
GU		 355 affs_error(inode->i_sb, "get_block", "strange block request %llu",
356 (unsigned long long)block);
1da177e4
LT		 357 return -EIO;
358err_ext:
359 // unlock cache
360 affs_unlock_ext(inode);
361 return PTR_ERR(ext_bh);
362err_alloc:
363 brelse(ext_bh);
364 clear_buffer_mapped(bh_result);
365 bh_result->b_bdev = NULL;
366 // unlock cache
367 affs_unlock_ext(inode);
368 return -ENOSPC;
369}
370
371static int affs_writepage(struct page *page, struct writeback_control *wbc)
372{
373 return block_write_full_page(page, affs_get_block, wbc);
374}
f2b6a16e 375
1da177e4
LT		 376static int affs_readpage(struct file *file, struct page *page)
377{
378 return block_read_full_page(page, affs_get_block);
379}
f2b6a16e 380
1dc1834f
MS		 381static void affs_write_failed(struct address_space *mapping, loff_t to)
382{
383 struct inode *inode = mapping->host;
384
385 if (to > inode->i_size) {
7caef267 386 truncate_pagecache(inode, inode->i_size);
1dc1834f
MS		 387 affs_truncate(inode);
388 }
389}
390
9abb4083
FF		 391static ssize_t
392affs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
393 loff_t offset)
394{
395 struct file *file = iocb->ki_filp;
396 struct address_space *mapping = file->f_mapping;
397 struct inode *inode = mapping->host;
398 size_t count = iov_iter_count(iter);
399 ssize_t ret;
400
92b20708
FF		 401 if (rw == WRITE) {
402 loff_t size = offset + count;
403
404 if (AFFS_I(inode)->mmu_private < size)
405 return 0;
406 }
407
9abb4083
FF		 408 ret = blockdev_direct_IO(rw, iocb, inode, iter, offset, affs_get_block);
409 if (ret < 0 && (rw & WRITE))
410 affs_write_failed(mapping, offset + count);
411 return ret;
412}
413
f2b6a16e
NP		 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)
1da177e4 417{
282dc178
CH		 418 int ret;
419
f2b6a16e 420 *pagep = NULL;
282dc178 421 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
f2b6a16e
NP		 422 affs_get_block,
423 &AFFS_I(mapping->host)->mmu_private);
1dc1834f
MS		 424 if (unlikely(ret))
425 affs_write_failed(mapping, pos + len);
282dc178
CH		 426
427 return ret;
1da177e4 428}
f2b6a16e 429
1da177e4
LT		 430static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
431{
432 return generic_block_bmap(mapping,block,affs_get_block);
433}
f2b6a16e 434
f5e54d6e 435const struct address_space_operations affs_aops = {
1da177e4
LT		 436 .readpage = affs_readpage,
437 .writepage = affs_writepage,
f2b6a16e
NP		 438 .write_begin = affs_write_begin,
439 .write_end = generic_write_end,
9abb4083 440 .direct_IO = affs_direct_IO,
1da177e4
LT		 441 .bmap = _affs_bmap
442};
443
444static inline struct buffer_head *
445affs_bread_ino(struct inode *inode, int block, int create)
446{
447 struct buffer_head *bh, tmp_bh;
448 int err;
449
450 tmp_bh.b_state = 0;
451 err = affs_get_block(inode, block, &tmp_bh, create);
452 if (!err) {
453 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
454 if (bh) {
455 bh->b_state |= tmp_bh.b_state;
456 return bh;
457 }
458 err = -EIO;
459 }
460 return ERR_PTR(err);
461}
462
463static inline struct buffer_head *
464affs_getzeroblk_ino(struct inode *inode, int block)
465{
466 struct buffer_head *bh, tmp_bh;
467 int err;
468
469 tmp_bh.b_state = 0;
470 err = affs_get_block(inode, block, &tmp_bh, 1);
471 if (!err) {
472 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
473 if (bh) {
474 bh->b_state |= tmp_bh.b_state;
475 return bh;
476 }
477 err = -EIO;
478 }
479 return ERR_PTR(err);
480}
481
482static inline struct buffer_head *
483affs_getemptyblk_ino(struct inode *inode, int block)
484{
485 struct buffer_head *bh, tmp_bh;
486 int err;
487
488 tmp_bh.b_state = 0;
489 err = affs_get_block(inode, block, &tmp_bh, 1);
490 if (!err) {
491 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
492 if (bh) {
493 bh->b_state |= tmp_bh.b_state;
494 return bh;
495 }
496 err = -EIO;
497 }
498 return ERR_PTR(err);
499}
500
1da177e4 501static int
0c89d670 502affs_do_readpage_ofs(struct page *page, unsigned to)
1da177e4
LT		 503{
504 struct inode *inode = page->mapping->host;
505 struct super_block *sb = inode->i_sb;
506 struct buffer_head *bh;
507 char *data;
0c89d670 508 unsigned pos = 0;
1da177e4
LT		 509 u32 bidx, boff, bsize;
510 u32 tmp;
511
08fe100d 512 pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino,
0c89d670
FF		 513 page->index, to);
514 BUG_ON(to > PAGE_CACHE_SIZE);
1da177e4
LT		 515 kmap(page);
516 data = page_address(page);
517 bsize = AFFS_SB(sb)->s_data_blksize;
0c89d670 518 tmp = page->index << PAGE_CACHE_SHIFT;
1da177e4
LT		 519 bidx = tmp / bsize;
520 boff = tmp % bsize;
521
0c89d670 522 while (pos < to) {
1da177e4
LT		 523 bh = affs_bread_ino(inode, bidx, 0);
524 if (IS_ERR(bh))
525 return PTR_ERR(bh);
0c89d670
FF		 526 tmp = min(bsize - boff, to - pos);
527 BUG_ON(pos + tmp > to || tmp > bsize);
528 memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
1da177e4
LT		 529 affs_brelse(bh);
530 bidx++;
0c89d670 531 pos += tmp;
1da177e4
LT		 532 boff = 0;
533 }
534 flush_dcache_page(page);
535 kunmap(page);
536 return 0;
537}
538
539static int
540affs_extent_file_ofs(struct inode *inode, u32 newsize)
541{
542 struct super_block *sb = inode->i_sb;
543 struct buffer_head *bh, *prev_bh;
544 u32 bidx, boff;
545 u32 size, bsize;
546 u32 tmp;
547
08fe100d 548 pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize);
1da177e4
LT		 549 bsize = AFFS_SB(sb)->s_data_blksize;
550 bh = NULL;
551 size = AFFS_I(inode)->mmu_private;
552 bidx = size / bsize;
553 boff = size % bsize;
554 if (boff) {
555 bh = affs_bread_ino(inode, bidx, 0);
556 if (IS_ERR(bh))
557 return PTR_ERR(bh);
558 tmp = min(bsize - boff, newsize - size);
8d4b6900 559 BUG_ON(boff + tmp > bsize || tmp > bsize);
1da177e4 560 memset(AFFS_DATA(bh) + boff, 0, tmp);
6369a4ab 561 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
1da177e4
LT		 562 affs_fix_checksum(sb, bh);
563 mark_buffer_dirty_inode(bh, inode);
564 size += tmp;
565 bidx++;
566 } else if (bidx) {
567 bh = affs_bread_ino(inode, bidx - 1, 0);
568 if (IS_ERR(bh))
569 return PTR_ERR(bh);
570 }
571
572 while (size < newsize) {
573 prev_bh = bh;
574 bh = affs_getzeroblk_ino(inode, bidx);
575 if (IS_ERR(bh))
576 goto out;
577 tmp = min(bsize, newsize - size);
8d4b6900 578 BUG_ON(tmp > bsize);
1da177e4
LT		 579 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
580 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
581 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
582 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
583 affs_fix_checksum(sb, bh);
584 bh->b_state &= ~(1UL << BH_New);
585 mark_buffer_dirty_inode(bh, inode);
586 if (prev_bh) {
73516ace
FF		 587 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
588
589 if (tmp_next)
590 affs_warning(sb, "extent_file_ofs",
591 "next block already set for %d (%d)",
592 bidx, tmp_next);
1da177e4 593 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
73516ace 594 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
1da177e4
LT		 595 mark_buffer_dirty_inode(prev_bh, inode);
596 affs_brelse(prev_bh);
597 }
598 size += bsize;
599 bidx++;
600 }
601 affs_brelse(bh);
602 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
603 return 0;
604
605out:
606 inode->i_size = AFFS_I(inode)->mmu_private = newsize;
607 return PTR_ERR(bh);
608}
609
610static int
611affs_readpage_ofs(struct file *file, struct page *page)
612{
613 struct inode *inode = page->mapping->host;
614 u32 to;
615 int err;
616
08fe100d 617 pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index);
1da177e4
LT		 618 to = PAGE_CACHE_SIZE;
619 if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
620 to = inode->i_size & ~PAGE_CACHE_MASK;
621 memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
622 }
623
0c89d670 624 err = affs_do_readpage_ofs(page, to);
1da177e4
LT		 625 if (!err)
626 SetPageUptodate(page);
627 unlock_page(page);
628 return err;
629}
630
f2b6a16e
NP		 631static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
632 loff_t pos, unsigned len, unsigned flags,
633 struct page **pagep, void **fsdata)
1da177e4 634{
f2b6a16e
NP		 635 struct inode *inode = mapping->host;
636 struct page *page;
637 pgoff_t index;
1da177e4
LT		 638 int err = 0;
639
08fe100d
GU		 640 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
641 pos + len);
f2b6a16e
NP		 642 if (pos > AFFS_I(inode)->mmu_private) {
643 /* XXX: this probably leaves a too-big i_size in case of
644 * failure. Should really be updating i_size at write_end time
645 */
646 err = affs_extent_file_ofs(inode, pos);
1da177e4
LT		 647 if (err)
648 return err;
649 }
f2b6a16e
NP		 650
651 index = pos >> PAGE_CACHE_SHIFT;
54566b2c 652 page = grab_cache_page_write_begin(mapping, index, flags);
f2b6a16e
NP		 653 if (!page)
654 return -ENOMEM;
655 *pagep = page;
1da177e4
LT		 656
657 if (PageUptodate(page))
658 return 0;
659
f2b6a16e 660 /* XXX: inefficient but safe in the face of short writes */
0c89d670 661 err = affs_do_readpage_ofs(page, PAGE_CACHE_SIZE);
f2b6a16e
NP		 662 if (err) {
663 unlock_page(page);
664 page_cache_release(page);
1da177e4
LT		 665 }
666 return err;
667}
668
f2b6a16e
NP		 669static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
670 loff_t pos, unsigned len, unsigned copied,
671 struct page *page, void *fsdata)
1da177e4 672{
f2b6a16e 673 struct inode *inode = mapping->host;
1da177e4
LT		 674 struct super_block *sb = inode->i_sb;
675 struct buffer_head *bh, *prev_bh;
676 char *data;
677 u32 bidx, boff, bsize;
f2b6a16e 678 unsigned from, to;
1da177e4
LT		 679 u32 tmp;
680 int written;
681
f2b6a16e
NP		 682 from = pos & (PAGE_CACHE_SIZE - 1);
683 to = pos + len;
684 /*
685 * XXX: not sure if this can handle short copies (len < copied), but
686 * we don't have to, because the page should always be uptodate here,
687 * due to write_begin.
688 */
689
08fe100d
GU		 690 pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
691 pos + len);
1da177e4
LT		 692 bsize = AFFS_SB(sb)->s_data_blksize;
693 data = page_address(page);
694
695 bh = NULL;
696 written = 0;
697 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
698 bidx = tmp / bsize;
699 boff = tmp % bsize;
700 if (boff) {
701 bh = affs_bread_ino(inode, bidx, 0);
3d5d472c
TK		 702 if (IS_ERR(bh)) {
703 written = PTR_ERR(bh);
704 goto err_first_bh;
705 }
1da177e4 706 tmp = min(bsize - boff, to - from);
8d4b6900 707 BUG_ON(boff + tmp > bsize || tmp > bsize);
1da177e4 708 memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
6369a4ab 709 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
1da177e4
LT		 710 affs_fix_checksum(sb, bh);
711 mark_buffer_dirty_inode(bh, inode);
712 written += tmp;
713 from += tmp;
714 bidx++;
715 } else if (bidx) {
716 bh = affs_bread_ino(inode, bidx - 1, 0);
3d5d472c
TK		 717 if (IS_ERR(bh)) {
718 written = PTR_ERR(bh);
719 goto err_first_bh;
720 }
1da177e4
LT		 721 }
722 while (from + bsize <= to) {
723 prev_bh = bh;
724 bh = affs_getemptyblk_ino(inode, bidx);
725 if (IS_ERR(bh))
3d5d472c 726 goto err_bh;
1da177e4
LT		 727 memcpy(AFFS_DATA(bh), data + from, bsize);
728 if (buffer_new(bh)) {
729 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
730 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
731 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
732 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
733 AFFS_DATA_HEAD(bh)->next = 0;
734 bh->b_state &= ~(1UL << BH_New);
735 if (prev_bh) {
73516ace
FF		 736 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
737
738 if (tmp_next)
739 affs_warning(sb, "commit_write_ofs",
740 "next block already set for %d (%d)",
741 bidx, tmp_next);
1da177e4 742 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
73516ace 743 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
1da177e4
LT		 744 mark_buffer_dirty_inode(prev_bh, inode);
745 }
746 }
747 affs_brelse(prev_bh);
748 affs_fix_checksum(sb, bh);
749 mark_buffer_dirty_inode(bh, inode);
750 written += bsize;
751 from += bsize;
752 bidx++;
753 }
754 if (from < to) {
755 prev_bh = bh;
756 bh = affs_bread_ino(inode, bidx, 1);
757 if (IS_ERR(bh))
3d5d472c 758 goto err_bh;
1da177e4 759 tmp = min(bsize, to - from);
8d4b6900 760 BUG_ON(tmp > bsize);
1da177e4
LT		 761 memcpy(AFFS_DATA(bh), data + from, tmp);
762 if (buffer_new(bh)) {
763 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
764 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
765 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
766 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
767 AFFS_DATA_HEAD(bh)->next = 0;
768 bh->b_state &= ~(1UL << BH_New);
769 if (prev_bh) {
73516ace
FF		 770 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
771
772 if (tmp_next)
773 affs_warning(sb, "commit_write_ofs",
774 "next block already set for %d (%d)",
775 bidx, tmp_next);
1da177e4 776 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
73516ace 777 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
1da177e4
LT		 778 mark_buffer_dirty_inode(prev_bh, inode);
779 }
780 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
781 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
782 affs_brelse(prev_bh);
783 affs_fix_checksum(sb, bh);
784 mark_buffer_dirty_inode(bh, inode);
785 written += tmp;
786 from += tmp;
787 bidx++;
788 }
789 SetPageUptodate(page);
790
791done:
792 affs_brelse(bh);
793 tmp = (page->index << PAGE_CACHE_SHIFT) + from;
794 if (tmp > inode->i_size)
795 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
796
3d5d472c 797err_first_bh:
f2b6a16e
NP		 798 unlock_page(page);
799 page_cache_release(page);
800
1da177e4
LT		 801 return written;
802
3d5d472c 803err_bh:
1da177e4
LT		 804 bh = prev_bh;
805 if (!written)
806 written = PTR_ERR(bh);
807 goto done;
808}
809
f5e54d6e 810const struct address_space_operations affs_aops_ofs = {
1da177e4
LT		 811 .readpage = affs_readpage_ofs,
812 //.writepage = affs_writepage_ofs,
f2b6a16e
NP		 813 .write_begin = affs_write_begin_ofs,
814 .write_end = affs_write_end_ofs
1da177e4
LT		 815};
816
817/* Free any preallocated blocks. */
818
819void
820affs_free_prealloc(struct inode *inode)
821{
822 struct super_block *sb = inode->i_sb;
823
9606d9aa 824 pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
1da177e4
LT		 825
826 while (AFFS_I(inode)->i_pa_cnt) {
827 AFFS_I(inode)->i_pa_cnt--;
828 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
829 }
830}
831
832/* Truncate (or enlarge) a file to the requested size. */
833
834void
835affs_truncate(struct inode *inode)
836{
837 struct super_block *sb = inode->i_sb;
838 u32 ext, ext_key;
839 u32 last_blk, blkcnt, blk;
840 u32 size;
841 struct buffer_head *ext_bh;
842 int i;
843
08fe100d
GU		 844 pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
845 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
1da177e4
LT		 846
847 last_blk = 0;
848 ext = 0;
849 if (inode->i_size) {
850 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
851 ext = last_blk / AFFS_SB(sb)->s_hashsize;
852 }
853
854 if (inode->i_size > AFFS_I(inode)->mmu_private) {
855 struct address_space *mapping = inode->i_mapping;
856 struct page *page;
f2b6a16e 857 void *fsdata;
73516ace 858 loff_t isize = inode->i_size;
1da177e4
LT		 859 int res;
860
73516ace 861 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
1da177e4 862 if (!res)
73516ace 863 res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
dca3c336
RZ		 864 else
865 inode->i_size = AFFS_I(inode)->mmu_private;
1da177e4
LT		 866 mark_inode_dirty(inode);
867 return;
868 } else if (inode->i_size == AFFS_I(inode)->mmu_private)
869 return;
870
871 // lock cache
872 ext_bh = affs_get_extblock(inode, ext);
873 if (IS_ERR(ext_bh)) {
1ee54b09
FF		 874 affs_warning(sb, "truncate",
875 "unexpected read error for ext block %u (%ld)",
08fe100d 876 ext, PTR_ERR(ext_bh));
1da177e4
LT		 877 return;
878 }
879 if (AFFS_I(inode)->i_lc) {
880 /* clear linear cache */
881 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
882 if (AFFS_I(inode)->i_lc_size > i) {
883 AFFS_I(inode)->i_lc_size = i;
884 for (; i < AFFS_LC_SIZE; i++)
885 AFFS_I(inode)->i_lc[i] = 0;
886 }
887 /* clear associative cache */
888 for (i = 0; i < AFFS_AC_SIZE; i++)
889 if (AFFS_I(inode)->i_ac[i].ext >= ext)
890 AFFS_I(inode)->i_ac[i].ext = 0;
891 }
892 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
893
894 blkcnt = AFFS_I(inode)->i_blkcnt;
895 i = 0;
896 blk = last_blk;
897 if (inode->i_size) {
898 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
899 blk++;
900 } else
901 AFFS_HEAD(ext_bh)->first_data = 0;
dca3c336 902 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
1da177e4
LT		 903 size = AFFS_SB(sb)->s_hashsize;
904 if (size > blkcnt - blk + i)
905 size = blkcnt - blk + i;
906 for (; i < size; i++, blk++) {
907 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
908 AFFS_BLOCK(sb, ext_bh, i) = 0;
909 }
910 AFFS_TAIL(sb, ext_bh)->extension = 0;
911 affs_fix_checksum(sb, ext_bh);
912 mark_buffer_dirty_inode(ext_bh, inode);
913 affs_brelse(ext_bh);
914
915 if (inode->i_size) {
916 AFFS_I(inode)->i_blkcnt = last_blk + 1;
917 AFFS_I(inode)->i_extcnt = ext + 1;
918 if (AFFS_SB(sb)->s_flags & SF_OFS) {
919 struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
920 u32 tmp;
0e45b67d 921 if (IS_ERR(bh)) {
1ee54b09
FF		 922 affs_warning(sb, "truncate",
923 "unexpected read error for last block %u (%ld)",
08fe100d 924 ext, PTR_ERR(bh));
1da177e4
LT		 925 return;
926 }
927 tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
928 AFFS_DATA_HEAD(bh)->next = 0;
929 affs_adjust_checksum(bh, -tmp);
930 affs_brelse(bh);
931 }
932 } else {
933 AFFS_I(inode)->i_blkcnt = 0;
934 AFFS_I(inode)->i_extcnt = 1;
935 }
936 AFFS_I(inode)->mmu_private = inode->i_size;
937 // unlock cache
938
939 while (ext_key) {
940 ext_bh = affs_bread(sb, ext_key);
941 size = AFFS_SB(sb)->s_hashsize;
942 if (size > blkcnt - blk)
943 size = blkcnt - blk;
944 for (i = 0; i < size; i++, blk++)
945 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
946 affs_free_block(sb, ext_key);
947 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
948 affs_brelse(ext_bh);
949 }
950 affs_free_prealloc(inode);
951}
c4758795 952
02c24a82 953int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
c4758795 954{
7ea80859 955 struct inode *inode = filp->f_mapping->host;
c4758795
AV		 956 int ret, err;
957
02c24a82
JB		 958 err = filemap_write_and_wait_range(inode->i_mapping, start, end);
959 if (err)
960 return err;
961
962 mutex_lock(&inode->i_mutex);
c4758795
AV		 963 ret = write_inode_now(inode, 0);
964 err = sync_blockdev(inode->i_sb->s_bdev);
965 if (!ret)
966 ret = err;
02c24a82 967 mutex_unlock(&inode->i_mutex);
c4758795
AV		 968 return ret;
969}
7633978b
FF		 970const struct file_operations affs_file_operations = {
971 .llseek = generic_file_llseek,
972 .read = new_sync_read,
973 .read_iter = generic_file_read_iter,
974 .write = new_sync_write,
975 .write_iter = generic_file_write_iter,
976 .mmap = generic_file_mmap,
977 .open = affs_file_open,
978 .release = affs_file_release,
979 .fsync = affs_file_fsync,
980 .splice_read = generic_file_splice_read,
981};
982
983const struct inode_operations affs_file_inode_operations = {
984 .setattr = affs_notify_change,
985};
Linux 6.x block layer and io_uring tree(s)