check ATTR_SIZE contraints in inode_change_ok
[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
48 #include "ufs_fs.h"
49 #include "ufs.h"
50 #include "swab.h"
51 #include "util.h"
52
53 /*
54  * Secure deletion currently doesn't work. It interacts very badly
55  * with buffers shared with memory mappings, and for that reason
56  * can't be done in the truncate() routines. It should instead be
57  * done separately in "release()" before calling the truncate routines
58  * that will release the actual file blocks.
59  *
60  *              Linus
61  */
62
63 #define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
64 #define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)
65
66
67 static int ufs_trunc_direct(struct inode *inode)
68 {
69         struct ufs_inode_info *ufsi = UFS_I(inode);
70         struct super_block * sb;
71         struct ufs_sb_private_info * uspi;
72         void *p;
73         u64 frag1, frag2, frag3, frag4, block1, block2;
74         unsigned frag_to_free, free_count;
75         unsigned i, tmp;
76         int retry;
77         
78         UFSD("ENTER: ino %lu\n", inode->i_ino);
79
80         sb = inode->i_sb;
81         uspi = UFS_SB(sb)->s_uspi;
82         
83         frag_to_free = 0;
84         free_count = 0;
85         retry = 0;
86         
87         frag1 = DIRECT_FRAGMENT;
88         frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
89         frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
90         frag3 = frag4 & ~uspi->s_fpbmask;
91         block1 = block2 = 0;
92         if (frag2 > frag3) {
93                 frag2 = frag4;
94                 frag3 = frag4 = 0;
95         } else if (frag2 < frag3) {
96                 block1 = ufs_fragstoblks (frag2);
97                 block2 = ufs_fragstoblks (frag3);
98         }
99
100         UFSD("ino %lu, frag1 %llu, frag2 %llu, block1 %llu, block2 %llu,"
101              " frag3 %llu, frag4 %llu\n", inode->i_ino,
102              (unsigned long long)frag1, (unsigned long long)frag2,
103              (unsigned long long)block1, (unsigned long long)block2,
104              (unsigned long long)frag3, (unsigned long long)frag4);
105
106         if (frag1 >= frag2)
107                 goto next1;             
108
109         /*
110          * Free first free fragments
111          */
112         p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag1));
113         tmp = ufs_data_ptr_to_cpu(sb, p);
114         if (!tmp )
115                 ufs_panic (sb, "ufs_trunc_direct", "internal error");
116         frag2 -= frag1;
117         frag1 = ufs_fragnum (frag1);
118
119         ufs_free_fragments(inode, tmp + frag1, frag2);
120         mark_inode_dirty(inode);
121         frag_to_free = tmp + frag1;
122
123 next1:
124         /*
125          * Free whole blocks
126          */
127         for (i = block1 ; i < block2; i++) {
128                 p = ufs_get_direct_data_ptr(uspi, ufsi, i);
129                 tmp = ufs_data_ptr_to_cpu(sb, p);
130                 if (!tmp)
131                         continue;
132                 ufs_data_ptr_clear(uspi, p);
133
134                 if (free_count == 0) {
135                         frag_to_free = tmp;
136                         free_count = uspi->s_fpb;
137                 } else if (free_count > 0 && frag_to_free == tmp - free_count)
138                         free_count += uspi->s_fpb;
139                 else {
140                         ufs_free_blocks (inode, frag_to_free, free_count);
141                         frag_to_free = tmp;
142                         free_count = uspi->s_fpb;
143                 }
144                 mark_inode_dirty(inode);
145         }
146         
147         if (free_count > 0)
148                 ufs_free_blocks (inode, frag_to_free, free_count);
149
150         if (frag3 >= frag4)
151                 goto next3;
152
153         /*
154          * Free last free fragments
155          */
156         p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag3));
157         tmp = ufs_data_ptr_to_cpu(sb, p);
158         if (!tmp )
159                 ufs_panic(sb, "ufs_truncate_direct", "internal error");
160         frag4 = ufs_fragnum (frag4);
161         ufs_data_ptr_clear(uspi, p);
162
163         ufs_free_fragments (inode, tmp, frag4);
164         mark_inode_dirty(inode);
165  next3:
166
167         UFSD("EXIT: ino %lu\n", inode->i_ino);
168         return retry;
169 }
170
171
172 static int ufs_trunc_indirect(struct inode *inode, u64 offset, void *p)
173 {
174         struct super_block * sb;
175         struct ufs_sb_private_info * uspi;
176         struct ufs_buffer_head * ind_ubh;
177         void *ind;
178         u64 tmp, indirect_block, i, frag_to_free;
179         unsigned free_count;
180         int retry;
181
182         UFSD("ENTER: ino %lu, offset %llu, p: %p\n",
183              inode->i_ino, (unsigned long long)offset, p);
184
185         BUG_ON(!p);
186                 
187         sb = inode->i_sb;
188         uspi = UFS_SB(sb)->s_uspi;
189
190         frag_to_free = 0;
191         free_count = 0;
192         retry = 0;
193         
194         tmp = ufs_data_ptr_to_cpu(sb, p);
195         if (!tmp)
196                 return 0;
197         ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
198         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
199                 ubh_brelse (ind_ubh);
200                 return 1;
201         }
202         if (!ind_ubh) {
203                 ufs_data_ptr_clear(uspi, p);
204                 return 0;
205         }
206
207         indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
208         for (i = indirect_block; i < uspi->s_apb; i++) {
209                 ind = ubh_get_data_ptr(uspi, ind_ubh, i);
210                 tmp = ufs_data_ptr_to_cpu(sb, ind);
211                 if (!tmp)
212                         continue;
213
214                 ufs_data_ptr_clear(uspi, ind);
215                 ubh_mark_buffer_dirty(ind_ubh);
216                 if (free_count == 0) {
217                         frag_to_free = tmp;
218                         free_count = uspi->s_fpb;
219                 } else if (free_count > 0 && frag_to_free == tmp - free_count)
220                         free_count += uspi->s_fpb;
221                 else {
222                         ufs_free_blocks (inode, frag_to_free, free_count);
223                         frag_to_free = tmp;
224                         free_count = uspi->s_fpb;
225                 }
226
227                 mark_inode_dirty(inode);
228         }
229
230         if (free_count > 0) {
231                 ufs_free_blocks (inode, frag_to_free, free_count);
232         }
233         for (i = 0; i < uspi->s_apb; i++)
234                 if (!ufs_is_data_ptr_zero(uspi,
235                                           ubh_get_data_ptr(uspi, ind_ubh, i)))
236                         break;
237         if (i >= uspi->s_apb) {
238                 tmp = ufs_data_ptr_to_cpu(sb, p);
239                 ufs_data_ptr_clear(uspi, p);
240
241                 ufs_free_blocks (inode, tmp, uspi->s_fpb);
242                 mark_inode_dirty(inode);
243                 ubh_bforget(ind_ubh);
244                 ind_ubh = NULL;
245         }
246         if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
247                 ubh_ll_rw_block(SWRITE, ind_ubh);
248                 ubh_wait_on_buffer (ind_ubh);
249         }
250         ubh_brelse (ind_ubh);
251         
252         UFSD("EXIT: ino %lu\n", inode->i_ino);
253         
254         return retry;
255 }
256
257 static int ufs_trunc_dindirect(struct inode *inode, u64 offset, void *p)
258 {
259         struct super_block * sb;
260         struct ufs_sb_private_info * uspi;
261         struct ufs_buffer_head *dind_bh;
262         u64 i, tmp, dindirect_block;
263         void *dind;
264         int retry = 0;
265         
266         UFSD("ENTER: ino %lu\n", inode->i_ino);
267         
268         sb = inode->i_sb;
269         uspi = UFS_SB(sb)->s_uspi;
270
271         dindirect_block = (DIRECT_BLOCK > offset) 
272                 ? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
273         retry = 0;
274         
275         tmp = ufs_data_ptr_to_cpu(sb, p);
276         if (!tmp)
277                 return 0;
278         dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
279         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
280                 ubh_brelse (dind_bh);
281                 return 1;
282         }
283         if (!dind_bh) {
284                 ufs_data_ptr_clear(uspi, p);
285                 return 0;
286         }
287
288         for (i = dindirect_block ; i < uspi->s_apb ; i++) {
289                 dind = ubh_get_data_ptr(uspi, dind_bh, i);
290                 tmp = ufs_data_ptr_to_cpu(sb, dind);
291                 if (!tmp)
292                         continue;
293                 retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
294                 ubh_mark_buffer_dirty(dind_bh);
295         }
296
297         for (i = 0; i < uspi->s_apb; i++)
298                 if (!ufs_is_data_ptr_zero(uspi,
299                                           ubh_get_data_ptr(uspi, dind_bh, i)))
300                         break;
301         if (i >= uspi->s_apb) {
302                 tmp = ufs_data_ptr_to_cpu(sb, p);
303                 ufs_data_ptr_clear(uspi, p);
304
305                 ufs_free_blocks(inode, tmp, uspi->s_fpb);
306                 mark_inode_dirty(inode);
307                 ubh_bforget(dind_bh);
308                 dind_bh = NULL;
309         }
310         if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
311                 ubh_ll_rw_block(SWRITE, dind_bh);
312                 ubh_wait_on_buffer (dind_bh);
313         }
314         ubh_brelse (dind_bh);
315         
316         UFSD("EXIT: ino %lu\n", inode->i_ino);
317         
318         return retry;
319 }
320
321 static int ufs_trunc_tindirect(struct inode *inode)
322 {
323         struct super_block *sb = inode->i_sb;
324         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
325         struct ufs_inode_info *ufsi = UFS_I(inode);
326         struct ufs_buffer_head * tind_bh;
327         u64 tindirect_block, tmp, i;
328         void *tind, *p;
329         int retry;
330         
331         UFSD("ENTER: ino %lu\n", inode->i_ino);
332
333         retry = 0;
334         
335         tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
336                 ? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
337
338         p = ufs_get_direct_data_ptr(uspi, ufsi, UFS_TIND_BLOCK);
339         if (!(tmp = ufs_data_ptr_to_cpu(sb, p)))
340                 return 0;
341         tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
342         if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
343                 ubh_brelse (tind_bh);
344                 return 1;
345         }
346         if (!tind_bh) {
347                 ufs_data_ptr_clear(uspi, p);
348                 return 0;
349         }
350
351         for (i = tindirect_block ; i < uspi->s_apb ; i++) {
352                 tind = ubh_get_data_ptr(uspi, tind_bh, i);
353                 retry |= ufs_trunc_dindirect(inode, UFS_NDADDR + 
354                         uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
355                 ubh_mark_buffer_dirty(tind_bh);
356         }
357         for (i = 0; i < uspi->s_apb; i++)
358                 if (!ufs_is_data_ptr_zero(uspi,
359                                           ubh_get_data_ptr(uspi, tind_bh, i)))
360                         break;
361         if (i >= uspi->s_apb) {
362                 tmp = ufs_data_ptr_to_cpu(sb, p);
363                 ufs_data_ptr_clear(uspi, p);
364
365                 ufs_free_blocks(inode, tmp, uspi->s_fpb);
366                 mark_inode_dirty(inode);
367                 ubh_bforget(tind_bh);
368                 tind_bh = NULL;
369         }
370         if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
371                 ubh_ll_rw_block(SWRITE, tind_bh);
372                 ubh_wait_on_buffer (tind_bh);
373         }
374         ubh_brelse (tind_bh);
375         
376         UFSD("EXIT: ino %lu\n", inode->i_ino);
377         return retry;
378 }
379
380 static int ufs_alloc_lastblock(struct inode *inode)
381 {
382         int err = 0;
383         struct super_block *sb = inode->i_sb;
384         struct address_space *mapping = inode->i_mapping;
385         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
386         unsigned i, end;
387         sector_t lastfrag;
388         struct page *lastpage;
389         struct buffer_head *bh;
390         u64 phys64;
391
392         lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
393
394         if (!lastfrag)
395                 goto out;
396
397         lastfrag--;
398
399         lastpage = ufs_get_locked_page(mapping, lastfrag >>
400                                        (PAGE_CACHE_SHIFT - inode->i_blkbits));
401        if (IS_ERR(lastpage)) {
402                err = -EIO;
403                goto out;
404        }
405
406        end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
407        bh = page_buffers(lastpage);
408        for (i = 0; i < end; ++i)
409                bh = bh->b_this_page;
410
411
412        err = ufs_getfrag_block(inode, lastfrag, bh, 1);
413
414        if (unlikely(err))
415                goto out_unlock;
416
417        if (buffer_new(bh)) {
418                clear_buffer_new(bh);
419                unmap_underlying_metadata(bh->b_bdev,
420                                          bh->b_blocknr);
421                /*
422                 * we do not zeroize fragment, because of
423                 * if it maped to hole, it already contains zeroes
424                 */
425                set_buffer_uptodate(bh);
426                mark_buffer_dirty(bh);
427                set_page_dirty(lastpage);
428        }
429
430        if (lastfrag >= UFS_IND_FRAGMENT) {
431                end = uspi->s_fpb - ufs_fragnum(lastfrag) - 1;
432                phys64 = bh->b_blocknr + 1;
433                for (i = 0; i < end; ++i) {
434                        bh = sb_getblk(sb, i + phys64);
435                        lock_buffer(bh);
436                        memset(bh->b_data, 0, sb->s_blocksize);
437                        set_buffer_uptodate(bh);
438                        mark_buffer_dirty(bh);
439                        unlock_buffer(bh);
440                        sync_dirty_buffer(bh);
441                        brelse(bh);
442                }
443        }
444 out_unlock:
445        ufs_put_locked_page(lastpage);
446 out:
447        return err;
448 }
449
450 int ufs_truncate(struct inode *inode, loff_t old_i_size)
451 {
452         struct ufs_inode_info *ufsi = UFS_I(inode);
453         struct super_block *sb = inode->i_sb;
454         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
455         int retry, err = 0;
456         
457         UFSD("ENTER: ino %lu, i_size: %llu, old_i_size: %llu\n",
458              inode->i_ino, (unsigned long long)i_size_read(inode),
459              (unsigned long long)old_i_size);
460
461         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
462               S_ISLNK(inode->i_mode)))
463                 return -EINVAL;
464         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
465                 return -EPERM;
466
467         err = ufs_alloc_lastblock(inode);
468
469         if (err) {
470                 i_size_write(inode, old_i_size);
471                 goto out;
472         }
473
474         block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
475
476         lock_kernel();
477         while (1) {
478                 retry = ufs_trunc_direct(inode);
479                 retry |= ufs_trunc_indirect(inode, UFS_IND_BLOCK,
480                                             ufs_get_direct_data_ptr(uspi, ufsi,
481                                                                     UFS_IND_BLOCK));
482                 retry |= ufs_trunc_dindirect(inode, UFS_IND_BLOCK + uspi->s_apb,
483                                              ufs_get_direct_data_ptr(uspi, ufsi,
484                                                                      UFS_DIND_BLOCK));
485                 retry |= ufs_trunc_tindirect (inode);
486                 if (!retry)
487                         break;
488                 if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
489                         ufs_sync_inode (inode);
490                 blk_run_address_space(inode->i_mapping);
491                 yield();
492         }
493
494         inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
495         ufsi->i_lastfrag = DIRECT_FRAGMENT;
496         unlock_kernel();
497         mark_inode_dirty(inode);
498 out:
499         UFSD("EXIT: err %d\n", err);
500         return err;
501 }
502
503 int ufs_setattr(struct dentry *dentry, struct iattr *attr)
504 {
505         struct inode *inode = dentry->d_inode;
506         unsigned int ia_valid = attr->ia_valid;
507         int error;
508
509         error = inode_change_ok(inode, attr);
510         if (error)
511                 return error;
512
513         if (ia_valid & ATTR_SIZE && attr->ia_size != inode->i_size) {
514                 loff_t old_i_size = inode->i_size;
515
516                 /* XXX(truncate): truncate_setsize should be called last */
517                 truncate_setsize(inode, attr->ia_size);
518
519                 error = ufs_truncate(inode, old_i_size);
520                 if (error)
521                         return error;
522         }
523
524         setattr_copy(inode, attr);
525         mark_inode_dirty(inode);
526         return 0;
527 }
528
529 const struct inode_operations ufs_file_inode_operations = {
530         .setattr = ufs_setattr,
531 };