dquot: move dquot initialization responsibility into the filesystem
[linux-2.6.git] / fs / ufs / truncate.c
1 /*
2  *  linux/fs/ufs/truncate.c
3  *
4  * Copyright (C) 1998
5  * Daniel Pirkl <daniel.pirkl@email.cz>
6  * Charles University, Faculty of Mathematics and Physics
7  *
8  *  from
9  *
10  *  linux/fs/ext2/truncate.c
11  *
12  * Copyright (C) 1992, 1993, 1994, 1995
13  * Remy Card (card@masi.ibp.fr)
14  * Laboratoire MASI - Institut Blaise Pascal
15  * Universite Pierre et Marie Curie (Paris VI)
16  *
17  *  from
18  *
19  *  linux/fs/minix/truncate.c
20  *
21  *  Copyright (C) 1991, 1992  Linus Torvalds
22  *
23  *  Big-endian to little-endian byte-swapping/bitmaps by
24  *        David S. Miller (davem@caip.rutgers.edu), 1995
25  */
26
27 /*
28  * Real random numbers for secure rm added 94/02/18
29  * Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
30  */
31
32 /*
33  * Adoptation to use page cache and UFS2 write support by
34  * Evgeniy Dushistov <dushistov@mail.ru>, 2006-2007
35  */
36
37 #include <linux/errno.h>
38 #include <linux/fs.h>
39 #include <linux/fcntl.h>
40 #include <linux/time.h>
41 #include <linux/stat.h>
42 #include <linux/string.h>
43 #include <linux/smp_lock.h>
44 #include <linux/buffer_head.h>
45 #include <linux/blkdev.h>
46 #include <linux/sched.h>
47 #include <linux/quotaops.h>
48
49 #include "ufs_fs.h"
50 #include "ufs.h"
51 #include "swab.h"
52 #include "util.h"
53
54 /*
55  * Secure deletion currently doesn't work. It interacts very badly
56  * with buffers shared with memory mappings, and for that reason
57  * can't be done in the truncate() routines. It should instead be
58  * done separately in "release()" before calling the truncate routines
59  * that will release the actual file blocks.
60  *
61  *              Linus
62  */
63
64 #define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
65 #define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)
66
67
68 static int ufs_trunc_direct(struct inode *inode)
69 {
70         struct ufs_inode_info *ufsi = UFS_I(inode);
71         struct super_block * sb;
72         struct ufs_sb_private_info * uspi;
73         void *p;
74         u64 frag1, frag2, frag3, frag4, block1, block2;
75         unsigned frag_to_free, free_count;
76         unsigned i, tmp;
77         int retry;
78         
79         UFSD("ENTER: ino %lu\n", inode->i_ino);
80
81         sb = inode->i_sb;
82         uspi = UFS_SB(sb)->s_uspi;
83         
84         frag_to_free = 0;
85         free_count = 0;
86         retry = 0;
87         
88         frag1 = DIRECT_FRAGMENT;
89         frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
90         frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
91         frag3 = frag4 & ~uspi->s_fpbmask;
92         block1 = block2 = 0;
93         if (frag2 > frag3) {
94                 frag2 = frag4;
95                 frag3 = frag4 = 0;
96         } else if (frag2 < frag3) {
97                 block1 = ufs_fragstoblks (frag2);
98                 block2 = ufs_fragstoblks (frag3);
99         }
100
101         UFSD("ino %lu, frag1 %llu, frag2 %llu, block1 %llu, block2 %llu,"
102              " frag3 %llu, frag4 %llu\n", inode->i_ino,
103              (unsigned long long)frag1, (unsigned long long)frag2,
104              (unsigned long long)block1, (unsigned long long)block2,
105              (unsigned long long)frag3, (unsigned long long)frag4);
106
107         if (frag1 >= frag2)
108                 goto next1;             
109
110         /*
111          * Free first free fragments
112          */
113         p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag1));
114         tmp = ufs_data_ptr_to_cpu(sb, p);
115         if (!tmp )
116                 ufs_panic (sb, "ufs_trunc_direct", "internal error");
117         frag2 -= frag1;
118         frag1 = ufs_fragnum (frag1);
119
120         ufs_free_fragments(inode, tmp + frag1, frag2);
121         mark_inode_dirty(inode);
122         frag_to_free = tmp + frag1;
123
124 next1:
125         /*
126          * Free whole blocks
127          */
128         for (i = block1 ; i < block2; i++) {
129                 p = ufs_get_direct_data_ptr(uspi, ufsi, i);
130                 tmp = ufs_data_ptr_to_cpu(sb, p);
131                 if (!tmp)
132                         continue;
133                 ufs_data_ptr_clear(uspi, p);
134
135                 if (free_count == 0) {
136                         frag_to_free = tmp;
137                         free_count = uspi->s_fpb;
138                 } else if (free_count > 0 && frag_to_free == tmp - free_count)
139                         free_count += uspi->s_fpb;
140                 else {
141                         ufs_free_blocks (inode, frag_to_free, free_count);
142                         frag_to_free = tmp;
143                         free_count = uspi->s_fpb;
144                 }
145                 mark_inode_dirty(inode);
146         }
147         
148         if (free_count > 0)
149                 ufs_free_blocks (inode, frag_to_free, free_count);
150
151         if (frag3 >= frag4)
152                 goto next3;
153
154         /*
155          * Free last free fragments
156          */
157         p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag3));
158         tmp = ufs_data_ptr_to_cpu(sb, p);
159         if (!tmp )
160                 ufs_panic(sb, "ufs_truncate_direct", "internal error");
161         frag4 = ufs_fragnum (frag4);
162         ufs_data_ptr_clear(uspi, p);
163
164         ufs_free_fragments (inode, tmp, frag4);
165         mark_inode_dirty(inode);
166  next3:
167
168         UFSD("EXIT: ino %lu\n", inode->i_ino);
169         return retry;
170 }
171
172
173 static int ufs_trunc_indirect(struct inode *inode, u64 offset, void *p)
174 {
175         struct super_block * sb;
176         struct ufs_sb_private_info * uspi;
177         struct ufs_buffer_head * ind_ubh;
178         void *ind;
179         u64 tmp, indirect_block, i, frag_to_free;
180         unsigned free_count;
181         int retry;
182
183         UFSD("ENTER: ino %lu, offset %llu, p: %p\n",
184              inode->i_ino, (unsigned long long)offset, p);
185
186         BUG_ON(!p);
187                 
188         sb = inode->i_sb;
189         uspi = UFS_SB(sb)->s_uspi;
190
191         frag_to_free = 0;
192         free_count = 0;
193         retry = 0;
194         
195         tmp = ufs_data_ptr_to_cpu(sb, p);
196         if (!tmp)
197                 return 0;
198         ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
199         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
200                 ubh_brelse (ind_ubh);
201                 return 1;
202         }
203         if (!ind_ubh) {
204                 ufs_data_ptr_clear(uspi, p);
205                 return 0;
206         }
207
208         indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
209         for (i = indirect_block; i < uspi->s_apb; i++) {
210                 ind = ubh_get_data_ptr(uspi, ind_ubh, i);
211                 tmp = ufs_data_ptr_to_cpu(sb, ind);
212                 if (!tmp)
213                         continue;
214
215                 ufs_data_ptr_clear(uspi, ind);
216                 ubh_mark_buffer_dirty(ind_ubh);
217                 if (free_count == 0) {
218                         frag_to_free = tmp;
219                         free_count = uspi->s_fpb;
220                 } else if (free_count > 0 && frag_to_free == tmp - free_count)
221                         free_count += uspi->s_fpb;
222                 else {
223                         ufs_free_blocks (inode, frag_to_free, free_count);
224                         frag_to_free = tmp;
225                         free_count = uspi->s_fpb;
226                 }
227
228                 mark_inode_dirty(inode);
229         }
230
231         if (free_count > 0) {
232                 ufs_free_blocks (inode, frag_to_free, free_count);
233         }
234         for (i = 0; i < uspi->s_apb; i++)
235                 if (!ufs_is_data_ptr_zero(uspi,
236                                           ubh_get_data_ptr(uspi, ind_ubh, i)))
237                         break;
238         if (i >= uspi->s_apb) {
239                 tmp = ufs_data_ptr_to_cpu(sb, p);
240                 ufs_data_ptr_clear(uspi, p);
241
242                 ufs_free_blocks (inode, tmp, uspi->s_fpb);
243                 mark_inode_dirty(inode);
244                 ubh_bforget(ind_ubh);
245                 ind_ubh = NULL;
246         }
247         if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
248                 ubh_ll_rw_block(SWRITE, ind_ubh);
249                 ubh_wait_on_buffer (ind_ubh);
250         }
251         ubh_brelse (ind_ubh);
252         
253         UFSD("EXIT: ino %lu\n", inode->i_ino);
254         
255         return retry;
256 }
257
258 static int ufs_trunc_dindirect(struct inode *inode, u64 offset, void *p)
259 {
260         struct super_block * sb;
261         struct ufs_sb_private_info * uspi;
262         struct ufs_buffer_head *dind_bh;
263         u64 i, tmp, dindirect_block;
264         void *dind;
265         int retry = 0;
266         
267         UFSD("ENTER: ino %lu\n", inode->i_ino);
268         
269         sb = inode->i_sb;
270         uspi = UFS_SB(sb)->s_uspi;
271
272         dindirect_block = (DIRECT_BLOCK > offset) 
273                 ? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
274         retry = 0;
275         
276         tmp = ufs_data_ptr_to_cpu(sb, p);
277         if (!tmp)
278                 return 0;
279         dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
280         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
281                 ubh_brelse (dind_bh);
282                 return 1;
283         }
284         if (!dind_bh) {
285                 ufs_data_ptr_clear(uspi, p);
286                 return 0;
287         }
288
289         for (i = dindirect_block ; i < uspi->s_apb ; i++) {
290                 dind = ubh_get_data_ptr(uspi, dind_bh, i);
291                 tmp = ufs_data_ptr_to_cpu(sb, dind);
292                 if (!tmp)
293                         continue;
294                 retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
295                 ubh_mark_buffer_dirty(dind_bh);
296         }
297
298         for (i = 0; i < uspi->s_apb; i++)
299                 if (!ufs_is_data_ptr_zero(uspi,
300                                           ubh_get_data_ptr(uspi, dind_bh, i)))
301                         break;
302         if (i >= uspi->s_apb) {
303                 tmp = ufs_data_ptr_to_cpu(sb, p);
304                 ufs_data_ptr_clear(uspi, p);
305
306                 ufs_free_blocks(inode, tmp, uspi->s_fpb);
307                 mark_inode_dirty(inode);
308                 ubh_bforget(dind_bh);
309                 dind_bh = NULL;
310         }
311         if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
312                 ubh_ll_rw_block(SWRITE, dind_bh);
313                 ubh_wait_on_buffer (dind_bh);
314         }
315         ubh_brelse (dind_bh);
316         
317         UFSD("EXIT: ino %lu\n", inode->i_ino);
318         
319         return retry;
320 }
321
322 static int ufs_trunc_tindirect(struct inode *inode)
323 {
324         struct super_block *sb = inode->i_sb;
325         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
326         struct ufs_inode_info *ufsi = UFS_I(inode);
327         struct ufs_buffer_head * tind_bh;
328         u64 tindirect_block, tmp, i;
329         void *tind, *p;
330         int retry;
331         
332         UFSD("ENTER: ino %lu\n", inode->i_ino);
333
334         retry = 0;
335         
336         tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
337                 ? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
338
339         p = ufs_get_direct_data_ptr(uspi, ufsi, UFS_TIND_BLOCK);
340         if (!(tmp = ufs_data_ptr_to_cpu(sb, p)))
341                 return 0;
342         tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
343         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
344                 ubh_brelse (tind_bh);
345                 return 1;
346         }
347         if (!tind_bh) {
348                 ufs_data_ptr_clear(uspi, p);
349                 return 0;
350         }
351
352         for (i = tindirect_block ; i < uspi->s_apb ; i++) {
353                 tind = ubh_get_data_ptr(uspi, tind_bh, i);
354                 retry |= ufs_trunc_dindirect(inode, UFS_NDADDR + 
355                         uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
356                 ubh_mark_buffer_dirty(tind_bh);
357         }
358         for (i = 0; i < uspi->s_apb; i++)
359                 if (!ufs_is_data_ptr_zero(uspi,
360                                           ubh_get_data_ptr(uspi, tind_bh, i)))
361                         break;
362         if (i >= uspi->s_apb) {
363                 tmp = ufs_data_ptr_to_cpu(sb, p);
364                 ufs_data_ptr_clear(uspi, p);
365
366                 ufs_free_blocks(inode, tmp, uspi->s_fpb);
367                 mark_inode_dirty(inode);
368                 ubh_bforget(tind_bh);
369                 tind_bh = NULL;
370         }
371         if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
372                 ubh_ll_rw_block(SWRITE, tind_bh);
373                 ubh_wait_on_buffer (tind_bh);
374         }
375         ubh_brelse (tind_bh);
376         
377         UFSD("EXIT: ino %lu\n", inode->i_ino);
378         return retry;
379 }
380
381 static int ufs_alloc_lastblock(struct inode *inode)
382 {
383         int err = 0;
384         struct super_block *sb = inode->i_sb;
385         struct address_space *mapping = inode->i_mapping;
386         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
387         unsigned i, end;
388         sector_t lastfrag;
389         struct page *lastpage;
390         struct buffer_head *bh;
391         u64 phys64;
392
393         lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
394
395         if (!lastfrag)
396                 goto out;
397
398         lastfrag--;
399
400         lastpage = ufs_get_locked_page(mapping, lastfrag >>
401                                        (PAGE_CACHE_SHIFT - inode->i_blkbits));
402        if (IS_ERR(lastpage)) {
403                err = -EIO;
404                goto out;
405        }
406
407        end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
408        bh = page_buffers(lastpage);
409        for (i = 0; i < end; ++i)
410                bh = bh->b_this_page;
411
412
413        err = ufs_getfrag_block(inode, lastfrag, bh, 1);
414
415        if (unlikely(err))
416                goto out_unlock;
417
418        if (buffer_new(bh)) {
419                clear_buffer_new(bh);
420                unmap_underlying_metadata(bh->b_bdev,
421                                          bh->b_blocknr);
422                /*
423                 * we do not zeroize fragment, because of
424                 * if it maped to hole, it already contains zeroes
425                 */
426                set_buffer_uptodate(bh);
427                mark_buffer_dirty(bh);
428                set_page_dirty(lastpage);
429        }
430
431        if (lastfrag >= UFS_IND_FRAGMENT) {
432                end = uspi->s_fpb - ufs_fragnum(lastfrag) - 1;
433                phys64 = bh->b_blocknr + 1;
434                for (i = 0; i < end; ++i) {
435                        bh = sb_getblk(sb, i + phys64);
436                        lock_buffer(bh);
437                        memset(bh->b_data, 0, sb->s_blocksize);
438                        set_buffer_uptodate(bh);
439                        mark_buffer_dirty(bh);
440                        unlock_buffer(bh);
441                        sync_dirty_buffer(bh);
442                        brelse(bh);
443                }
444        }
445 out_unlock:
446        ufs_put_locked_page(lastpage);
447 out:
448        return err;
449 }
450
451 int ufs_truncate(struct inode *inode, loff_t old_i_size)
452 {
453         struct ufs_inode_info *ufsi = UFS_I(inode);
454         struct super_block *sb = inode->i_sb;
455         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
456         int retry, err = 0;
457         
458         UFSD("ENTER: ino %lu, i_size: %llu, old_i_size: %llu\n",
459              inode->i_ino, (unsigned long long)i_size_read(inode),
460              (unsigned long long)old_i_size);
461
462         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
463               S_ISLNK(inode->i_mode)))
464                 return -EINVAL;
465         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
466                 return -EPERM;
467
468         err = ufs_alloc_lastblock(inode);
469
470         if (err) {
471                 i_size_write(inode, old_i_size);
472                 goto out;
473         }
474
475         block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
476
477         lock_kernel();
478         while (1) {
479                 retry = ufs_trunc_direct(inode);
480                 retry |= ufs_trunc_indirect(inode, UFS_IND_BLOCK,
481                                             ufs_get_direct_data_ptr(uspi, ufsi,
482                                                                     UFS_IND_BLOCK));
483                 retry |= ufs_trunc_dindirect(inode, UFS_IND_BLOCK + uspi->s_apb,
484                                              ufs_get_direct_data_ptr(uspi, ufsi,
485                                                                      UFS_DIND_BLOCK));
486                 retry |= ufs_trunc_tindirect (inode);
487                 if (!retry)
488                         break;
489                 if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
490                         ufs_sync_inode (inode);
491                 blk_run_address_space(inode->i_mapping);
492                 yield();
493         }
494
495         inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
496         ufsi->i_lastfrag = DIRECT_FRAGMENT;
497         unlock_kernel();
498         mark_inode_dirty(inode);
499 out:
500         UFSD("EXIT: err %d\n", err);
501         return err;
502 }
503
504
505 /*
506  * We don't define our `inode->i_op->truncate', and call it here,
507  * because of:
508  * - there is no way to know old size
509  * - there is no way inform user about error, if it happens in `truncate'
510  */
511 static int ufs_setattr(struct dentry *dentry, struct iattr *attr)
512 {
513         struct inode *inode = dentry->d_inode;
514         unsigned int ia_valid = attr->ia_valid;
515         int error;
516
517         error = inode_change_ok(inode, attr);
518         if (error)
519                 return error;
520
521         if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
522             (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
523                 error = dquot_transfer(inode, attr);
524                 if (error)
525                         return error;
526         }
527         if (ia_valid & ATTR_SIZE &&
528             attr->ia_size != i_size_read(inode)) {
529                 loff_t old_i_size = inode->i_size;
530
531                 vfs_dq_init(inode);
532
533                 error = vmtruncate(inode, attr->ia_size);
534                 if (error)
535                         return error;
536                 error = ufs_truncate(inode, old_i_size);
537                 if (error)
538                         return error;
539         }
540         return inode_setattr(inode, attr);
541 }
542
543 const struct inode_operations ufs_file_inode_operations = {
544         .setattr = ufs_setattr,
545 };