~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/affs/file.c

Version: ~ [ linux-5.4-rc7 ] ~ [ linux-5.3.11 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.84 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.154 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.201 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.201 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.77 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 <linux/uio.h>
 16 #include "affs.h"
 17 
 18 static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
 19 
 20 static int
 21 affs_file_open(struct inode *inode, struct file *filp)
 22 {
 23         pr_debug("open(%lu,%d)\n",
 24                  inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
 25         atomic_inc(&AFFS_I(inode)->i_opencnt);
 26         return 0;
 27 }
 28 
 29 static int
 30 affs_file_release(struct inode *inode, struct file *filp)
 31 {
 32         pr_debug("release(%lu, %d)\n",
 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);
 39                 affs_free_prealloc(inode);
 40                 mutex_unlock(&inode->i_mutex);
 41         }
 42 
 43         return 0;
 44 }
 45 
 46 static int
 47 affs_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 
111 err:
112         // lock cache
113         return -EIO;
114 }
115 
116 static struct buffer_head *
117 affs_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 
154 static inline struct buffer_head *
155 affs_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)
160                 get_bh(bh);
161         else
162                 /* we have to do more (not inlined) */
163                 bh = affs_get_extblock_slow(inode, ext);
164 
165         return bh;
166 }
167 
168 static struct buffer_head *
169 affs_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;
183                 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
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 */
200                 BUG_ON(ext > AFFS_I(inode)->i_extcnt);
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 
213 again:
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];
253 find_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 
271 read_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 
279 store_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;
284         get_bh(bh);
285 
286         return bh;
287 
288 err_bread:
289         affs_brelse(bh);
290         return ERR_PTR(-EIO);
291 }
292 
293 static int
294 affs_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 
300         pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino,
301                  (unsigned long long)block);
302 
303         BUG_ON(block > (sector_t)0x7fffffffUL);
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)
331                         affs_warning(sb, "get_block",
332                                      "block already set (%llx)",
333                                      (unsigned long long)bh_result->b_blocknr);
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 
354 err_big:
355         affs_error(inode->i_sb, "get_block", "strange block request %llu",
356                    (unsigned long long)block);
357         return -EIO;
358 err_ext:
359         // unlock cache
360         affs_unlock_ext(inode);
361         return PTR_ERR(ext_bh);
362 err_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 
371 static int affs_writepage(struct page *page, struct writeback_control *wbc)
372 {
373         return block_write_full_page(page, affs_get_block, wbc);
374 }
375 
376 static int affs_readpage(struct file *file, struct page *page)
377 {
378         return block_read_full_page(page, affs_get_block);
379 }
380 
381 static 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) {
386                 truncate_pagecache(inode, inode->i_size);
387                 affs_truncate(inode);
388         }
389 }
390 
391 static ssize_t
392 affs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset)
393 {
394         struct file *file = iocb->ki_filp;
395         struct address_space *mapping = file->f_mapping;
396         struct inode *inode = mapping->host;
397         size_t count = iov_iter_count(iter);
398         ssize_t ret;
399 
400         if (iov_iter_rw(iter) == WRITE) {
401                 loff_t size = offset + count;
402 
403                 if (AFFS_I(inode)->mmu_private < size)
404                         return 0;
405         }
406 
407         ret = blockdev_direct_IO(iocb, inode, iter, offset, affs_get_block);
408         if (ret < 0 && iov_iter_rw(iter) == WRITE)
409                 affs_write_failed(mapping, offset + count);
410         return ret;
411 }
412 
413 static int affs_write_begin(struct file *file, struct address_space *mapping,
414                         loff_t pos, unsigned len, unsigned flags,
415                         struct page **pagep, void **fsdata)
416 {
417         int ret;
418 
419         *pagep = NULL;
420         ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
421                                 affs_get_block,
422                                 &AFFS_I(mapping->host)->mmu_private);
423         if (unlikely(ret))
424                 affs_write_failed(mapping, pos + len);
425 
426         return ret;
427 }
428 
429 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
430 {
431         return generic_block_bmap(mapping,block,affs_get_block);
432 }
433 
434 const struct address_space_operations affs_aops = {
435         .readpage = affs_readpage,
436         .writepage = affs_writepage,
437         .write_begin = affs_write_begin,
438         .write_end = generic_write_end,
439         .direct_IO = affs_direct_IO,
440         .bmap = _affs_bmap
441 };
442 
443 static inline struct buffer_head *
444 affs_bread_ino(struct inode *inode, int block, int create)
445 {
446         struct buffer_head *bh, tmp_bh;
447         int err;
448 
449         tmp_bh.b_state = 0;
450         err = affs_get_block(inode, block, &tmp_bh, create);
451         if (!err) {
452                 bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
453                 if (bh) {
454                         bh->b_state |= tmp_bh.b_state;
455                         return bh;
456                 }
457                 err = -EIO;
458         }
459         return ERR_PTR(err);
460 }
461 
462 static inline struct buffer_head *
463 affs_getzeroblk_ino(struct inode *inode, int block)
464 {
465         struct buffer_head *bh, tmp_bh;
466         int err;
467 
468         tmp_bh.b_state = 0;
469         err = affs_get_block(inode, block, &tmp_bh, 1);
470         if (!err) {
471                 bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
472                 if (bh) {
473                         bh->b_state |= tmp_bh.b_state;
474                         return bh;
475                 }
476                 err = -EIO;
477         }
478         return ERR_PTR(err);
479 }
480 
481 static inline struct buffer_head *
482 affs_getemptyblk_ino(struct inode *inode, int block)
483 {
484         struct buffer_head *bh, tmp_bh;
485         int err;
486 
487         tmp_bh.b_state = 0;
488         err = affs_get_block(inode, block, &tmp_bh, 1);
489         if (!err) {
490                 bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
491                 if (bh) {
492                         bh->b_state |= tmp_bh.b_state;
493                         return bh;
494                 }
495                 err = -EIO;
496         }
497         return ERR_PTR(err);
498 }
499 
500 static int
501 affs_do_readpage_ofs(struct page *page, 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         unsigned pos = 0;
508         u32 bidx, boff, bsize;
509         u32 tmp;
510 
511         pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino,
512                  page->index, to);
513         BUG_ON(to > PAGE_CACHE_SIZE);
514         kmap(page);
515         data = page_address(page);
516         bsize = AFFS_SB(sb)->s_data_blksize;
517         tmp = page->index << PAGE_CACHE_SHIFT;
518         bidx = tmp / bsize;
519         boff = tmp % bsize;
520 
521         while (pos < to) {
522                 bh = affs_bread_ino(inode, bidx, 0);
523                 if (IS_ERR(bh))
524                         return PTR_ERR(bh);
525                 tmp = min(bsize - boff, to - pos);
526                 BUG_ON(pos + tmp > to || tmp > bsize);
527                 memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
528                 affs_brelse(bh);
529                 bidx++;
530                 pos += tmp;
531                 boff = 0;
532         }
533         flush_dcache_page(page);
534         kunmap(page);
535         return 0;
536 }
537 
538 static int
539 affs_extent_file_ofs(struct inode *inode, u32 newsize)
540 {
541         struct super_block *sb = inode->i_sb;
542         struct buffer_head *bh, *prev_bh;
543         u32 bidx, boff;
544         u32 size, bsize;
545         u32 tmp;
546 
547         pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize);
548         bsize = AFFS_SB(sb)->s_data_blksize;
549         bh = NULL;
550         size = AFFS_I(inode)->mmu_private;
551         bidx = size / bsize;
552         boff = size % bsize;
553         if (boff) {
554                 bh = affs_bread_ino(inode, bidx, 0);
555                 if (IS_ERR(bh))
556                         return PTR_ERR(bh);
557                 tmp = min(bsize - boff, newsize - size);
558                 BUG_ON(boff + tmp > bsize || tmp > bsize);
559                 memset(AFFS_DATA(bh) + boff, 0, tmp);
560                 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
561                 affs_fix_checksum(sb, bh);
562                 mark_buffer_dirty_inode(bh, inode);
563                 size += tmp;
564                 bidx++;
565         } else if (bidx) {
566                 bh = affs_bread_ino(inode, bidx - 1, 0);
567                 if (IS_ERR(bh))
568                         return PTR_ERR(bh);
569         }
570 
571         while (size < newsize) {
572                 prev_bh = bh;
573                 bh = affs_getzeroblk_ino(inode, bidx);
574                 if (IS_ERR(bh))
575                         goto out;
576                 tmp = min(bsize, newsize - size);
577                 BUG_ON(tmp > bsize);
578                 AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
579                 AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
580                 AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
581                 AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
582                 affs_fix_checksum(sb, bh);
583                 bh->b_state &= ~(1UL << BH_New);
584                 mark_buffer_dirty_inode(bh, inode);
585                 if (prev_bh) {
586                         u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
587 
588                         if (tmp_next)
589                                 affs_warning(sb, "extent_file_ofs",
590                                              "next block already set for %d (%d)",
591                                              bidx, tmp_next);
592                         AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
593                         affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
594                         mark_buffer_dirty_inode(prev_bh, inode);
595                         affs_brelse(prev_bh);
596                 }
597                 size += bsize;
598                 bidx++;
599         }
600         affs_brelse(bh);
601         inode->i_size = AFFS_I(inode)->mmu_private = newsize;
602         return 0;
603 
604 out:
605         inode->i_size = AFFS_I(inode)->mmu_private = newsize;
606         return PTR_ERR(bh);
607 }
608 
609 static int
610 affs_readpage_ofs(struct file *file, struct page *page)
611 {
612         struct inode *inode = page->mapping->host;
613         u32 to;
614         int err;
615 
616         pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index);
617         to = PAGE_CACHE_SIZE;
618         if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
619                 to = inode->i_size & ~PAGE_CACHE_MASK;
620                 memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
621         }
622 
623         err = affs_do_readpage_ofs(page, to);
624         if (!err)
625                 SetPageUptodate(page);
626         unlock_page(page);
627         return err;
628 }
629 
630 static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
631                                 loff_t pos, unsigned len, unsigned flags,
632                                 struct page **pagep, void **fsdata)
633 {
634         struct inode *inode = mapping->host;
635         struct page *page;
636         pgoff_t index;
637         int err = 0;
638 
639         pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
640                  pos + len);
641         if (pos > AFFS_I(inode)->mmu_private) {
642                 /* XXX: this probably leaves a too-big i_size in case of
643                  * failure. Should really be updating i_size at write_end time
644                  */
645                 err = affs_extent_file_ofs(inode, pos);
646                 if (err)
647                         return err;
648         }
649 
650         index = pos >> PAGE_CACHE_SHIFT;
651         page = grab_cache_page_write_begin(mapping, index, flags);
652         if (!page)
653                 return -ENOMEM;
654         *pagep = page;
655 
656         if (PageUptodate(page))
657                 return 0;
658 
659         /* XXX: inefficient but safe in the face of short writes */
660         err = affs_do_readpage_ofs(page, PAGE_CACHE_SIZE);
661         if (err) {
662                 unlock_page(page);
663                 page_cache_release(page);
664         }
665         return err;
666 }
667 
668 static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
669                                 loff_t pos, unsigned len, unsigned copied,
670                                 struct page *page, void *fsdata)
671 {
672         struct inode *inode = mapping->host;
673         struct super_block *sb = inode->i_sb;
674         struct buffer_head *bh, *prev_bh;
675         char *data;
676         u32 bidx, boff, bsize;
677         unsigned from, to;
678         u32 tmp;
679         int written;
680 
681         from = pos & (PAGE_CACHE_SIZE - 1);
682         to = pos + len;
683         /*
684          * XXX: not sure if this can handle short copies (len < copied), but
685          * we don't have to, because the page should always be uptodate here,
686          * due to write_begin.
687          */
688 
689         pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
690                  pos + len);
691         bsize = AFFS_SB(sb)->s_data_blksize;
692         data = page_address(page);
693 
694         bh = NULL;
695         written = 0;
696         tmp = (page->index << PAGE_CACHE_SHIFT) + from;
697         bidx = tmp / bsize;
698         boff = tmp % bsize;
699         if (boff) {
700                 bh = affs_bread_ino(inode, bidx, 0);
701                 if (IS_ERR(bh)) {
702                         written = PTR_ERR(bh);
703                         goto err_first_bh;
704                 }
705                 tmp = min(bsize - boff, to - from);
706                 BUG_ON(boff + tmp > bsize || tmp > bsize);
707                 memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
708                 be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
709                 affs_fix_checksum(sb, bh);
710                 mark_buffer_dirty_inode(bh, inode);
711                 written += tmp;
712                 from += tmp;
713                 bidx++;
714         } else if (bidx) {
715                 bh = affs_bread_ino(inode, bidx - 1, 0);
716                 if (IS_ERR(bh)) {
717                         written = PTR_ERR(bh);
718                         goto err_first_bh;
719                 }
720         }
721         while (from + bsize <= to) {
722                 prev_bh = bh;
723                 bh = affs_getemptyblk_ino(inode, bidx);
724                 if (IS_ERR(bh))
725                         goto err_bh;
726                 memcpy(AFFS_DATA(bh), data + from, bsize);
727                 if (buffer_new(bh)) {
728                         AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
729                         AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
730                         AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
731                         AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
732                         AFFS_DATA_HEAD(bh)->next = 0;
733                         bh->b_state &= ~(1UL << BH_New);
734                         if (prev_bh) {
735                                 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
736 
737                                 if (tmp_next)
738                                         affs_warning(sb, "commit_write_ofs",
739                                                      "next block already set for %d (%d)",
740                                                      bidx, tmp_next);
741                                 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
742                                 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
743                                 mark_buffer_dirty_inode(prev_bh, inode);
744                         }
745                 }
746                 affs_brelse(prev_bh);
747                 affs_fix_checksum(sb, bh);
748                 mark_buffer_dirty_inode(bh, inode);
749                 written += bsize;
750                 from += bsize;
751                 bidx++;
752         }
753         if (from < to) {
754                 prev_bh = bh;
755                 bh = affs_bread_ino(inode, bidx, 1);
756                 if (IS_ERR(bh))
757                         goto err_bh;
758                 tmp = min(bsize, to - from);
759                 BUG_ON(tmp > bsize);
760                 memcpy(AFFS_DATA(bh), data + from, tmp);
761                 if (buffer_new(bh)) {
762                         AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
763                         AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
764                         AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
765                         AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
766                         AFFS_DATA_HEAD(bh)->next = 0;
767                         bh->b_state &= ~(1UL << BH_New);
768                         if (prev_bh) {
769                                 u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
770 
771                                 if (tmp_next)
772                                         affs_warning(sb, "commit_write_ofs",
773                                                      "next block already set for %d (%d)",
774                                                      bidx, tmp_next);
775                                 AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
776                                 affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
777                                 mark_buffer_dirty_inode(prev_bh, inode);
778                         }
779                 } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
780                         AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
781                 affs_brelse(prev_bh);
782                 affs_fix_checksum(sb, bh);
783                 mark_buffer_dirty_inode(bh, inode);
784                 written += tmp;
785                 from += tmp;
786                 bidx++;
787         }
788         SetPageUptodate(page);
789 
790 done:
791         affs_brelse(bh);
792         tmp = (page->index << PAGE_CACHE_SHIFT) + from;
793         if (tmp > inode->i_size)
794                 inode->i_size = AFFS_I(inode)->mmu_private = tmp;
795 
796 err_first_bh:
797         unlock_page(page);
798         page_cache_release(page);
799 
800         return written;
801 
802 err_bh:
803         bh = prev_bh;
804         if (!written)
805                 written = PTR_ERR(bh);
806         goto done;
807 }
808 
809 const struct address_space_operations affs_aops_ofs = {
810         .readpage = affs_readpage_ofs,
811         //.writepage = affs_writepage_ofs,
812         .write_begin = affs_write_begin_ofs,
813         .write_end = affs_write_end_ofs
814 };
815 
816 /* Free any preallocated blocks. */
817 
818 void
819 affs_free_prealloc(struct inode *inode)
820 {
821         struct super_block *sb = inode->i_sb;
822 
823         pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
824 
825         while (AFFS_I(inode)->i_pa_cnt) {
826                 AFFS_I(inode)->i_pa_cnt--;
827                 affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
828         }
829 }
830 
831 /* Truncate (or enlarge) a file to the requested size. */
832 
833 void
834 affs_truncate(struct inode *inode)
835 {
836         struct super_block *sb = inode->i_sb;
837         u32 ext, ext_key;
838         u32 last_blk, blkcnt, blk;
839         u32 size;
840         struct buffer_head *ext_bh;
841         int i;
842 
843         pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
844                  inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
845 
846         last_blk = 0;
847         ext = 0;
848         if (inode->i_size) {
849                 last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
850                 ext = last_blk / AFFS_SB(sb)->s_hashsize;
851         }
852 
853         if (inode->i_size > AFFS_I(inode)->mmu_private) {
854                 struct address_space *mapping = inode->i_mapping;
855                 struct page *page;
856                 void *fsdata;
857                 loff_t isize = inode->i_size;
858                 int res;
859 
860                 res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
861                 if (!res)
862                         res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
863                 else
864                         inode->i_size = AFFS_I(inode)->mmu_private;
865                 mark_inode_dirty(inode);
866                 return;
867         } else if (inode->i_size == AFFS_I(inode)->mmu_private)
868                 return;
869 
870         // lock cache
871         ext_bh = affs_get_extblock(inode, ext);
872         if (IS_ERR(ext_bh)) {
873                 affs_warning(sb, "truncate",
874                              "unexpected read error for ext block %u (%ld)",
875                              ext, PTR_ERR(ext_bh));
876                 return;
877         }
878         if (AFFS_I(inode)->i_lc) {
879                 /* clear linear cache */
880                 i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
881                 if (AFFS_I(inode)->i_lc_size > i) {
882                         AFFS_I(inode)->i_lc_size = i;
883                         for (; i < AFFS_LC_SIZE; i++)
884                                 AFFS_I(inode)->i_lc[i] = 0;
885                 }
886                 /* clear associative cache */
887                 for (i = 0; i < AFFS_AC_SIZE; i++)
888                         if (AFFS_I(inode)->i_ac[i].ext >= ext)
889                                 AFFS_I(inode)->i_ac[i].ext = 0;
890         }
891         ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
892 
893         blkcnt = AFFS_I(inode)->i_blkcnt;
894         i = 0;
895         blk = last_blk;
896         if (inode->i_size) {
897                 i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
898                 blk++;
899         } else
900                 AFFS_HEAD(ext_bh)->first_data = 0;
901         AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
902         size = AFFS_SB(sb)->s_hashsize;
903         if (size > blkcnt - blk + i)
904                 size = blkcnt - blk + i;
905         for (; i < size; i++, blk++) {
906                 affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
907                 AFFS_BLOCK(sb, ext_bh, i) = 0;
908         }
909         AFFS_TAIL(sb, ext_bh)->extension = 0;
910         affs_fix_checksum(sb, ext_bh);
911         mark_buffer_dirty_inode(ext_bh, inode);
912         affs_brelse(ext_bh);
913 
914         if (inode->i_size) {
915                 AFFS_I(inode)->i_blkcnt = last_blk + 1;
916                 AFFS_I(inode)->i_extcnt = ext + 1;
917                 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) {
918                         struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
919                         u32 tmp;
920                         if (IS_ERR(bh)) {
921                                 affs_warning(sb, "truncate",
922                                              "unexpected read error for last block %u (%ld)",
923                                              ext, PTR_ERR(bh));
924                                 return;
925                         }
926                         tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
927                         AFFS_DATA_HEAD(bh)->next = 0;
928                         affs_adjust_checksum(bh, -tmp);
929                         affs_brelse(bh);
930                 }
931         } else {
932                 AFFS_I(inode)->i_blkcnt = 0;
933                 AFFS_I(inode)->i_extcnt = 1;
934         }
935         AFFS_I(inode)->mmu_private = inode->i_size;
936         // unlock cache
937 
938         while (ext_key) {
939                 ext_bh = affs_bread(sb, ext_key);
940                 size = AFFS_SB(sb)->s_hashsize;
941                 if (size > blkcnt - blk)
942                         size = blkcnt - blk;
943                 for (i = 0; i < size; i++, blk++)
944                         affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
945                 affs_free_block(sb, ext_key);
946                 ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
947                 affs_brelse(ext_bh);
948         }
949         affs_free_prealloc(inode);
950 }
951 
952 int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
953 {
954         struct inode *inode = filp->f_mapping->host;
955         int ret, err;
956 
957         err = filemap_write_and_wait_range(inode->i_mapping, start, end);
958         if (err)
959                 return err;
960 
961         mutex_lock(&inode->i_mutex);
962         ret = write_inode_now(inode, 0);
963         err = sync_blockdev(inode->i_sb->s_bdev);
964         if (!ret)
965                 ret = err;
966         mutex_unlock(&inode->i_mutex);
967         return ret;
968 }
969 const struct file_operations affs_file_operations = {
970         .llseek         = generic_file_llseek,
971         .read_iter      = generic_file_read_iter,
972         .write_iter     = generic_file_write_iter,
973         .mmap           = generic_file_mmap,
974         .open           = affs_file_open,
975         .release        = affs_file_release,
976         .fsync          = affs_file_fsync,
977         .splice_read    = generic_file_splice_read,
978 };
979 
980 const struct inode_operations affs_file_inode_operations = {
981         .setattr        = affs_notify_change,
982 };
983 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp