projects / linux-2.6-block.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[linux-2.6-block.git] / fs / affs / file.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
1da177e4
LT		 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
e2e40f2c 16#include <linux/uio.h>
1da177e4
LT		 17#include "affs.h"
18
1da177e4 19static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
1da177e4
LT		 20
21static int
22affs_file_open(struct inode *inode, struct file *filp)
23{
9606d9aa 24 pr_debug("open(%lu,%d)\n",
dca3c336
RZ		 25 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
26 atomic_inc(&AFFS_I(inode)->i_opencnt);
1da177e4
LT		 27 return 0;
28}
29
30static int
31affs_file_release(struct inode *inode, struct file *filp)
32{
9606d9aa 33 pr_debug("release(%lu, %d)\n",
dca3c336
RZ		 34 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
35
36 if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
5955102c 37 inode_lock(inode);
dca3c336
RZ		 38 if (inode->i_size != AFFS_I(inode)->mmu_private)
39 affs_truncate(inode);
1da177e4 40 affs_free_prealloc(inode);
5955102c 41 inode_unlock(inode);
dca3c336 42 }
1da177e4
LT		 43
44 return 0;
45}
46
47static int
48affs_grow_extcache(struct inode *inode, u32 lc_idx)
49{
50 struct super_block *sb = inode->i_sb;
51 struct buffer_head *bh;
52 u32 lc_max;
53 int i, j, key;
54
55 if (!AFFS_I(inode)->i_lc) {
56 char *ptr = (char *)get_zeroed_page(GFP_NOFS);
57 if (!ptr)
58 return -ENOMEM;
59 AFFS_I(inode)->i_lc = (u32 *)ptr;
60 AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
61 }
62
63 lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
64
65 if (AFFS_I(inode)->i_extcnt > lc_max) {
66 u32 lc_shift, lc_mask, tmp, off;
67
68 /* need to recalculate linear cache, start from old size */
69 lc_shift = AFFS_I(inode)->i_lc_shift;
70 tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
71 for (; tmp; tmp >>= 1)
72 lc_shift++;
73 lc_mask = (1 << lc_shift) - 1;
74
75 /* fix idx and old size to new shift */
76 lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
77 AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
78
79 /* first shrink old cache to make more space */
80 off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
81 for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
82 AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
83
84 AFFS_I(inode)->i_lc_shift = lc_shift;
85 AFFS_I(inode)->i_lc_mask = lc_mask;
86 }
87
88 /* fill cache to the needed index */
89 i = AFFS_I(inode)->i_lc_size;
90 AFFS_I(inode)->i_lc_size = lc_idx + 1;
91 for (; i <= lc_idx; i++) {
92 if (!i) {
93 AFFS_I(inode)->i_lc[0] = inode->i_ino;
94 continue;
95 }
96 key = AFFS_I(inode)->i_lc[i - 1];
97 j = AFFS_I(inode)->i_lc_mask + 1;
98 // unlock cache
99 for (; j > 0; j--) {
100 bh = affs_bread(sb, key);
101 if (!bh)
102 goto err;
103 key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
104 affs_brelse(bh);
105 }
106 // lock cache
107 AFFS_I(inode)->i_lc[i] = key;
108 }
109
110 return 0;
111
112err:
113 // lock cache
114 return -EIO;
115}
116
117static struct buffer_head *
118affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
119{
120 struct super_block *sb = inode->i_sb;
121 struct buffer_head *new_bh;
122 u32 blocknr, tmp;
123
124 blocknr = affs_alloc_block(inode, bh->b_blocknr);
125 if (!blocknr)
126 return ERR_PTR(-ENOSPC);
127
128 new_bh = affs_getzeroblk(sb, blocknr);
129 if (!new_bh) {
130 affs_free_block(sb, blocknr);
131 return ERR_PTR(-EIO);
132 }
133
134 AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
135 AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
136 AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
137 AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
138 affs_fix_checksum(sb, new_bh);
139
140 mark_buffer_dirty_inode(new_bh, inode);
141
142 tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
143 if (tmp)
144 affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
145 AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
146 affs_adjust_checksum(bh, blocknr - tmp);
147 mark_buffer_dirty_inode(bh, inode);
148
149 AFFS_I(inode)->i_extcnt++;
150 mark_inode_dirty(inode);
151
152 return new_bh;
153}
154
155static inline struct buffer_head *
156affs_get_extblock(struct inode *inode, u32 ext)
157{
158 /* inline the simplest case: same extended block as last time */
159 struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
160 if (ext == AFFS_I(inode)->i_ext_last)
dca3c336 161 get_bh(bh);
1da177e4
LT		 162 else
163 /* we have to do more (not inlined) */
164 bh = affs_get_extblock_slow(inode, ext);
165
166 return bh;
167}
168
169static struct buffer_head *
170affs_get_extblock_slow(struct inode *inode, u32 ext)
171{
172 struct super_block *sb = inode->i_sb;
173 struct buffer_head *bh;
174 u32 ext_key;
175 u32 lc_idx, lc_off, ac_idx;
176 u32 tmp, idx;
177
178 if (ext == AFFS_I(inode)->i_ext_last + 1) {
179 /* read the next extended block from the current one */
180 bh = AFFS_I(inode)->i_ext_bh;
181 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
182 if (ext < AFFS_I(inode)->i_extcnt)
183 goto read_ext;
afe305dc 184 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
1da177e4
LT		 185 bh = affs_alloc_extblock(inode, bh, ext);
186 if (IS_ERR(bh))
187 return bh;
188 goto store_ext;
189 }
190
191 if (ext == 0) {
192 /* we seek back to the file header block */
193 ext_key = inode->i_ino;
194 goto read_ext;
195 }
196
197 if (ext >= AFFS_I(inode)->i_extcnt) {
198 struct buffer_head *prev_bh;
199
200 /* allocate a new extended block */
afe305dc 201 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
1da177e4
LT		 202
203 /* get previous extended block */
204 prev_bh = affs_get_extblock(inode, ext - 1);
205 if (IS_ERR(prev_bh))
206 return prev_bh;
207 bh = affs_alloc_extblock(inode, prev_bh, ext);
208 affs_brelse(prev_bh);
209 if (IS_ERR(bh))
210 return bh;
211 goto store_ext;
212 }
213
214again:
215 /* check if there is an extended cache and whether it's large enough */
216 lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
217 lc_off = ext & AFFS_I(inode)->i_lc_mask;
218
219 if (lc_idx >= AFFS_I(inode)->i_lc_size) {
220 int err;
221
222 err = affs_grow_extcache(inode, lc_idx);
223 if (err)
224 return ERR_PTR(err);
225 goto again;
226 }
227
228 /* every n'th key we find in the linear cache */
229 if (!lc_off) {
230 ext_key = AFFS_I(inode)->i_lc[lc_idx];
231 goto read_ext;
232 }
233
234 /* maybe it's still in the associative cache */
235 ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
236 if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
237 ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
238 goto read_ext;
239 }
240
241 /* try to find one of the previous extended blocks */
242 tmp = ext;
243 idx = ac_idx;
244 while (--tmp, --lc_off > 0) {
245 idx = (idx - 1) & AFFS_AC_MASK;
246 if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
247 ext_key = AFFS_I(inode)->i_ac[idx].key;
248 goto find_ext;
249 }
250 }
251
252 /* fall back to the linear cache */
253 ext_key = AFFS_I(inode)->i_lc[lc_idx];
254find_ext:
255 /* read all extended blocks until we find the one we need */
256 //unlock cache
257 do {
258 bh = affs_bread(sb, ext_key);
259 if (!bh)
260 goto err_bread;
261 ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
262 affs_brelse(bh);
263 tmp++;
264 } while (tmp < ext);
265 //lock cache
266
267 /* store it in the associative cache */
268 // recalculate ac_idx?
269 AFFS_I(inode)->i_ac[ac_idx].ext = ext;
270 AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
271
272read_ext:
273 /* finally read the right extended block */
274 //unlock cache
275 bh = affs_bread(sb, ext_key);
276 if (!bh)
277 goto err_bread;
278 //lock cache
279
280store_ext:
281 /* release old cached extended block and store the new one */
282 affs_brelse(AFFS_I(inode)->i_ext_bh);
283 AFFS_I(inode)->i_ext_last = ext;
284 AFFS_I(inode)->i_ext_bh = bh;
dca3c336 285 get_bh(bh);
1da177e4
LT		 286
287 return bh;
288
289err_bread:
290 affs_brelse(bh);
291 return ERR_PTR(-EIO);
292}
293
294static int
295affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
296{
297 struct super_block *sb = inode->i_sb;
298 struct buffer_head *ext_bh;
299 u32 ext;
300
08fe100d
GU		 301 pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino,
302 (unsigned long long)block);
1da177e4 303
8d4b6900 304 BUG_ON(block > (sector_t)0x7fffffffUL);
1da177e4
LT		 305
306 if (block >= AFFS_I(inode)->i_blkcnt) {
307 if (block > AFFS_I(inode)->i_blkcnt || !create)
308 goto err_big;
309 } else
310 create = 0;
311
312 //lock cache
313 affs_lock_ext(inode);
314
315 ext = (u32)block / AFFS_SB(sb)->s_hashsize;
316 block -= ext * AFFS_SB(sb)->s_hashsize;
317 ext_bh = affs_get_extblock(inode, ext);
318 if (IS_ERR(ext_bh))
319 goto err_ext;
320 map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
321
322 if (create) {
323 u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
324 if (!blocknr)
325 goto err_alloc;
326 set_buffer_new(bh_result);
327 AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
328 AFFS_I(inode)->i_blkcnt++;
329
330 /* store new block */
331 if (bh_result->b_blocknr)
08fe100d
GU		 332 affs_warning(sb, "get_block",
333 "block already set (%llx)",
334 (unsigned long long)bh_result->b_blocknr);
1da177e4
LT		 335 AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
336 AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
337 affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
338 bh_result->b_blocknr = blocknr;
339
340 if (!block) {
341 /* insert first block into header block */
342 u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
343 if (tmp)
344 affs_warning(sb, "get_block", "first block already set (%d)", tmp);
345 AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
346 affs_adjust_checksum(ext_bh, blocknr - tmp);
347 }
348 }
349
350 affs_brelse(ext_bh);
351 //unlock cache
352 affs_unlock_ext(inode);
353 return 0;
354
355err_big:
08fe100d
GU		 356 affs_error(inode->i_sb, "get_block", "strange block request %llu",
357 (unsigned long long)block);
1da177e4
LT		 358 return -EIO;
359err_ext:
360 // unlock cache
361 affs_unlock_ext(inode);
362 return PTR_ERR(ext_bh);
363err_alloc:
364 brelse(ext_bh);
365 clear_buffer_mapped(bh_result);
366 bh_result->b_bdev = NULL;
367 // unlock cache
368 affs_unlock_ext(inode);
369 return -ENOSPC;
370}
371
372static int affs_writepage(struct page *page, struct writeback_control *wbc)
373{
374 return block_write_full_page(page, affs_get_block, wbc);
375}
f2b6a16e 376
1da177e4
LT		 377static int affs_readpage(struct file *file, struct page *page)
378{
379 return block_read_full_page(page, affs_get_block);
380}
f2b6a16e 381
1dc1834f
MS		 382static void affs_write_failed(struct address_space *mapping, loff_t to)
383{
384 struct inode *inode = mapping->host;
385
386 if (to > inode->i_size) {
7caef267 387 truncate_pagecache(inode, inode->i_size);
1dc1834f
MS		 388 affs_truncate(inode);
389 }
390}
391
9abb4083 392static ssize_t
c8b8e32d 393affs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
9abb4083
FF		 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);
c8b8e32d 399 loff_t offset = iocb->ki_pos;
9abb4083
FF		 400 ssize_t ret;
401
6f673763 402 if (iov_iter_rw(iter) == WRITE) {
92b20708
FF		 403 loff_t size = offset + count;
404
405 if (AFFS_I(inode)->mmu_private < size)
406 return 0;
407 }
408
c8b8e32d 409 ret = blockdev_direct_IO(iocb, inode, iter, affs_get_block);
6f673763 410 if (ret < 0 && iov_iter_rw(iter) == WRITE)
9abb4083
FF		 411 affs_write_failed(mapping, offset + count);
412 return ret;
413}
414
f2b6a16e
NP		 415static int affs_write_begin(struct file *file, struct address_space *mapping,
416 loff_t pos, unsigned len, unsigned flags,
417 struct page **pagep, void **fsdata)
1da177e4 418{
282dc178
CH		 419 int ret;
420
f2b6a16e 421 *pagep = NULL;
282dc178 422 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
f2b6a16e
NP		 423 affs_get_block,
424 &AFFS_I(mapping->host)->mmu_private);
1dc1834f
MS		 425 if (unlikely(ret))
426 affs_write_failed(mapping, pos + len);
282dc178
CH		 427
428 return ret;
1da177e4 429}
f2b6a16e 430
1da177e4
LT		 431static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
432{
433 return generic_block_bmap(mapping,block,affs_get_block);
434}
f2b6a16e 435
f5e54d6e 436const struct address_space_operations affs_aops = {
1da177e4
LT		 437 .readpage = affs_readpage,
438 .writepage = affs_writepage,
f2b6a16e
NP		 439 .write_begin = affs_write_begin,
440 .write_end = generic_write_end,
9abb4083 441 .direct_IO = affs_direct_IO,
1da177e4
LT		 442 .bmap = _affs_bmap
443};
444
445static inline struct buffer_head *
446affs_bread_ino(struct inode *inode, int block, int create)
447{
448 struct buffer_head *bh, tmp_bh;
449 int err;
450
451 tmp_bh.b_state = 0;
452 err = affs_get_block(inode, block, &tmp_bh, create);
453 if (!err) {
454 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
455 if (bh) {
456 bh->b_state |= tmp_bh.b_state;
457 return bh;
458 }
459 err = -EIO;
460 }
461 return ERR_PTR(err);
462}
463
464static inline struct buffer_head *
465affs_getzeroblk_ino(struct inode *inode, int block)
466{
467 struct buffer_head *bh, tmp_bh;
468 int err;
469
470 tmp_bh.b_state = 0;
471 err = affs_get_block(inode, block, &tmp_bh, 1);
472 if (!err) {
473 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
474 if (bh) {
475 bh->b_state |= tmp_bh.b_state;
476 return bh;
477 }
478 err = -EIO;
479 }
480 return ERR_PTR(err);
481}
482
483static inline struct buffer_head *
484affs_getemptyblk_ino(struct inode *inode, int block)
485{
486 struct buffer_head *bh, tmp_bh;
487 int err;
488
489 tmp_bh.b_state = 0;
490 err = affs_get_block(inode, block, &tmp_bh, 1);
491 if (!err) {
492 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
493 if (bh) {
494 bh->b_state |= tmp_bh.b_state;
495 return bh;
496 }
497 err = -EIO;
498 }
499 return ERR_PTR(err);
500}
501
1da177e4 502static int
077e073e 503affs_do_readpage_ofs(struct page *page, unsigned to, int create)
1da177e4
LT		 504{
505 struct inode *inode = page->mapping->host;
506 struct super_block *sb = inode->i_sb;
507 struct buffer_head *bh;
508 char *data;
0c89d670 509 unsigned pos = 0;
1da177e4
LT		 510 u32 bidx, boff, bsize;
511 u32 tmp;
512
08fe100d 513 pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino,
0c89d670 514 page->index, to);
09cbfeaf 515 BUG_ON(to > PAGE_SIZE);
1da177e4 516 bsize = AFFS_SB(sb)->s_data_blksize;
09cbfeaf 517 tmp = page->index << PAGE_SHIFT;
1da177e4
LT		 518 bidx = tmp / bsize;
519 boff = tmp % bsize;
520
0c89d670 521 while (pos < to) {
077e073e 522 bh = affs_bread_ino(inode, bidx, create);
1da177e4
LT		 523 if (IS_ERR(bh))
524 return PTR_ERR(bh);
0c89d670
FF		 525 tmp = min(bsize - boff, to - pos);
526 BUG_ON(pos + tmp > to || tmp > bsize);
0bacbe52 527 data = kmap_atomic(page);
0c89d670 528 memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
0bacbe52 529 kunmap_atomic(data);
1da177e4
LT		 530 affs_brelse(bh);
531 bidx++;
0c89d670 532 pos += tmp;
1da177e4
LT		 533 boff = 0;
534 }
535 flush_dcache_page(page);
1da177e4
LT		 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);
09cbfeaf
KS		 618 to = PAGE_SIZE;
619 if (((page->index + 1) << PAGE_SHIFT) > inode->i_size) {
620 to = inode->i_size & ~PAGE_MASK;
621 memset(page_address(page) + to, 0, PAGE_SIZE - to);
1da177e4
LT		 622 }
623
077e073e 624 err = affs_do_readpage_ofs(page, to, 0);
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 650
09cbfeaf 651 index = pos >> PAGE_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 */
077e073e 661 err = affs_do_readpage_ofs(page, PAGE_SIZE, 1);
f2b6a16e
NP		 662 if (err) {
663 unlock_page(page);
09cbfeaf 664 put_page(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
09cbfeaf 682 from = pos & (PAGE_SIZE - 1);
a80f2d22 683 to = from + len;
f2b6a16e
NP		 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;
09cbfeaf 697 tmp = (page->index << PAGE_SHIFT) + from;
1da177e4
LT		 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);
09cbfeaf 793 tmp = (page->index << PAGE_SHIFT) + from;
1da177e4
LT		 794 if (tmp > inode->i_size)
795 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
796
3d5d472c 797err_first_bh:
f2b6a16e 798 unlock_page(page);
09cbfeaf 799 put_page(page);
f2b6a16e 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;
79bda4d5 918 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) {
1da177e4
LT		 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
3b49c9a1 958 err = file_write_and_wait_range(filp, start, end);
02c24a82
JB		 959 if (err)
960 return err;
961
5955102c 962 inode_lock(inode);
c4758795
AV		 963 ret = write_inode_now(inode, 0);
964 err = sync_blockdev(inode->i_sb->s_bdev);
965 if (!ret)
966 ret = err;
5955102c 967 inode_unlock(inode);
c4758795
AV		 968 return ret;
969}
7633978b
FF		 970const struct file_operations affs_file_operations = {
971 .llseek = generic_file_llseek,
7633978b 972 .read_iter = generic_file_read_iter,
7633978b
FF		 973 .write_iter = generic_file_write_iter,
974 .mmap = generic_file_mmap,
975 .open = affs_file_open,
976 .release = affs_file_release,
977 .fsync = affs_file_fsync,
978 .splice_read = generic_file_splice_read,
979};
980
981const struct inode_operations affs_file_inode_operations = {
982 .setattr = affs_notify_change,
983};
Linux 6.x block layer and io_uring tree(s)