ia64/linux-2.6.18-xen.hg

view fs/ufs/truncate.c @ 524:7f8b544237bf

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Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
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 */
27 /*
28 * Real random numbers for secure rm added 94/02/18
29 * Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
30 */
32 /*
33 * Modified to avoid infinite loop on 2006 by
34 * Evgeniy Dushistov <dushistov@mail.ru>
35 */
37 #include <linux/errno.h>
38 #include <linux/fs.h>
39 #include <linux/ufs_fs.h>
40 #include <linux/fcntl.h>
41 #include <linux/time.h>
42 #include <linux/stat.h>
43 #include <linux/string.h>
44 #include <linux/smp_lock.h>
45 #include <linux/buffer_head.h>
46 #include <linux/blkdev.h>
47 #include <linux/sched.h>
49 #include "swab.h"
50 #include "util.h"
52 /*
53 * Secure deletion currently doesn't work. It interacts very badly
54 * with buffers shared with memory mappings, and for that reason
55 * can't be done in the truncate() routines. It should instead be
56 * done separately in "release()" before calling the truncate routines
57 * that will release the actual file blocks.
58 *
59 * Linus
60 */
62 #define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
63 #define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)
66 static int ufs_trunc_direct (struct inode * inode)
67 {
68 struct ufs_inode_info *ufsi = UFS_I(inode);
69 struct super_block * sb;
70 struct ufs_sb_private_info * uspi;
71 __fs32 * p;
72 unsigned frag1, frag2, frag3, frag4, block1, block2;
73 unsigned frag_to_free, free_count;
74 unsigned i, tmp;
75 int retry;
77 UFSD("ENTER\n");
79 sb = inode->i_sb;
80 uspi = UFS_SB(sb)->s_uspi;
82 frag_to_free = 0;
83 free_count = 0;
84 retry = 0;
86 frag1 = DIRECT_FRAGMENT;
87 frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
88 frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
89 frag3 = frag4 & ~uspi->s_fpbmask;
90 block1 = block2 = 0;
91 if (frag2 > frag3) {
92 frag2 = frag4;
93 frag3 = frag4 = 0;
94 }
95 else if (frag2 < frag3) {
96 block1 = ufs_fragstoblks (frag2);
97 block2 = ufs_fragstoblks (frag3);
98 }
100 UFSD("frag1 %u, frag2 %u, block1 %u, block2 %u, frag3 %u, frag4 %u\n", frag1, frag2, block1, block2, frag3, frag4);
102 if (frag1 >= frag2)
103 goto next1;
105 /*
106 * Free first free fragments
107 */
108 p = ufsi->i_u1.i_data + ufs_fragstoblks (frag1);
109 tmp = fs32_to_cpu(sb, *p);
110 if (!tmp )
111 ufs_panic (sb, "ufs_trunc_direct", "internal error");
112 frag1 = ufs_fragnum (frag1);
113 frag2 = ufs_fragnum (frag2);
115 ufs_free_fragments (inode, tmp + frag1, frag2 - frag1);
116 mark_inode_dirty(inode);
117 frag_to_free = tmp + frag1;
119 next1:
120 /*
121 * Free whole blocks
122 */
123 for (i = block1 ; i < block2; i++) {
124 p = ufsi->i_u1.i_data + i;
125 tmp = fs32_to_cpu(sb, *p);
126 if (!tmp)
127 continue;
129 *p = 0;
131 if (free_count == 0) {
132 frag_to_free = tmp;
133 free_count = uspi->s_fpb;
134 } else if (free_count > 0 && frag_to_free == tmp - free_count)
135 free_count += uspi->s_fpb;
136 else {
137 ufs_free_blocks (inode, frag_to_free, free_count);
138 frag_to_free = tmp;
139 free_count = uspi->s_fpb;
140 }
141 mark_inode_dirty(inode);
142 }
144 if (free_count > 0)
145 ufs_free_blocks (inode, frag_to_free, free_count);
147 if (frag3 >= frag4)
148 goto next3;
150 /*
151 * Free last free fragments
152 */
153 p = ufsi->i_u1.i_data + ufs_fragstoblks (frag3);
154 tmp = fs32_to_cpu(sb, *p);
155 if (!tmp )
156 ufs_panic(sb, "ufs_truncate_direct", "internal error");
157 frag4 = ufs_fragnum (frag4);
159 *p = 0;
161 ufs_free_fragments (inode, tmp, frag4);
162 mark_inode_dirty(inode);
163 next3:
165 UFSD("EXIT\n");
166 return retry;
167 }
170 static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p)
171 {
172 struct super_block * sb;
173 struct ufs_sb_private_info * uspi;
174 struct ufs_buffer_head * ind_ubh;
175 __fs32 * ind;
176 unsigned indirect_block, i, tmp;
177 unsigned frag_to_free, free_count;
178 int retry;
180 UFSD("ENTER\n");
182 sb = inode->i_sb;
183 uspi = UFS_SB(sb)->s_uspi;
185 frag_to_free = 0;
186 free_count = 0;
187 retry = 0;
189 tmp = fs32_to_cpu(sb, *p);
190 if (!tmp)
191 return 0;
192 ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
193 if (tmp != fs32_to_cpu(sb, *p)) {
194 ubh_brelse (ind_ubh);
195 return 1;
196 }
197 if (!ind_ubh) {
198 *p = 0;
199 return 0;
200 }
202 indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
203 for (i = indirect_block; i < uspi->s_apb; i++) {
204 ind = ubh_get_addr32 (ind_ubh, i);
205 tmp = fs32_to_cpu(sb, *ind);
206 if (!tmp)
207 continue;
209 *ind = 0;
210 ubh_mark_buffer_dirty(ind_ubh);
211 if (free_count == 0) {
212 frag_to_free = tmp;
213 free_count = uspi->s_fpb;
214 } else if (free_count > 0 && frag_to_free == tmp - free_count)
215 free_count += uspi->s_fpb;
216 else {
217 ufs_free_blocks (inode, frag_to_free, free_count);
218 frag_to_free = tmp;
219 free_count = uspi->s_fpb;
220 }
222 mark_inode_dirty(inode);
223 }
225 if (free_count > 0) {
226 ufs_free_blocks (inode, frag_to_free, free_count);
227 }
228 for (i = 0; i < uspi->s_apb; i++)
229 if (*ubh_get_addr32(ind_ubh,i))
230 break;
231 if (i >= uspi->s_apb) {
232 tmp = fs32_to_cpu(sb, *p);
233 *p = 0;
235 ufs_free_blocks (inode, tmp, uspi->s_fpb);
236 mark_inode_dirty(inode);
237 ubh_bforget(ind_ubh);
238 ind_ubh = NULL;
239 }
240 if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
241 ubh_ll_rw_block(SWRITE, ind_ubh);
242 ubh_wait_on_buffer (ind_ubh);
243 }
244 ubh_brelse (ind_ubh);
246 UFSD("EXIT\n");
248 return retry;
249 }
251 static int ufs_trunc_dindirect (struct inode *inode, unsigned offset, __fs32 *p)
252 {
253 struct super_block * sb;
254 struct ufs_sb_private_info * uspi;
255 struct ufs_buffer_head * dind_bh;
256 unsigned i, tmp, dindirect_block;
257 __fs32 * dind;
258 int retry = 0;
260 UFSD("ENTER\n");
262 sb = inode->i_sb;
263 uspi = UFS_SB(sb)->s_uspi;
265 dindirect_block = (DIRECT_BLOCK > offset)
266 ? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
267 retry = 0;
269 tmp = fs32_to_cpu(sb, *p);
270 if (!tmp)
271 return 0;
272 dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
273 if (tmp != fs32_to_cpu(sb, *p)) {
274 ubh_brelse (dind_bh);
275 return 1;
276 }
277 if (!dind_bh) {
278 *p = 0;
279 return 0;
280 }
282 for (i = dindirect_block ; i < uspi->s_apb ; i++) {
283 dind = ubh_get_addr32 (dind_bh, i);
284 tmp = fs32_to_cpu(sb, *dind);
285 if (!tmp)
286 continue;
287 retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
288 ubh_mark_buffer_dirty(dind_bh);
289 }
291 for (i = 0; i < uspi->s_apb; i++)
292 if (*ubh_get_addr32 (dind_bh, i))
293 break;
294 if (i >= uspi->s_apb) {
295 tmp = fs32_to_cpu(sb, *p);
296 *p = 0;
298 ufs_free_blocks(inode, tmp, uspi->s_fpb);
299 mark_inode_dirty(inode);
300 ubh_bforget(dind_bh);
301 dind_bh = NULL;
302 }
303 if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
304 ubh_ll_rw_block(SWRITE, dind_bh);
305 ubh_wait_on_buffer (dind_bh);
306 }
307 ubh_brelse (dind_bh);
309 UFSD("EXIT\n");
311 return retry;
312 }
314 static int ufs_trunc_tindirect (struct inode * inode)
315 {
316 struct ufs_inode_info *ufsi = UFS_I(inode);
317 struct super_block * sb;
318 struct ufs_sb_private_info * uspi;
319 struct ufs_buffer_head * tind_bh;
320 unsigned tindirect_block, tmp, i;
321 __fs32 * tind, * p;
322 int retry;
324 UFSD("ENTER\n");
326 sb = inode->i_sb;
327 uspi = UFS_SB(sb)->s_uspi;
328 retry = 0;
330 tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
331 ? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
332 p = ufsi->i_u1.i_data + UFS_TIND_BLOCK;
333 if (!(tmp = fs32_to_cpu(sb, *p)))
334 return 0;
335 tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
336 if (tmp != fs32_to_cpu(sb, *p)) {
337 ubh_brelse (tind_bh);
338 return 1;
339 }
340 if (!tind_bh) {
341 *p = 0;
342 return 0;
343 }
345 for (i = tindirect_block ; i < uspi->s_apb ; i++) {
346 tind = ubh_get_addr32 (tind_bh, i);
347 retry |= ufs_trunc_dindirect(inode, UFS_NDADDR +
348 uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
349 ubh_mark_buffer_dirty(tind_bh);
350 }
351 for (i = 0; i < uspi->s_apb; i++)
352 if (*ubh_get_addr32 (tind_bh, i))
353 break;
354 if (i >= uspi->s_apb) {
355 tmp = fs32_to_cpu(sb, *p);
356 *p = 0;
358 ufs_free_blocks(inode, tmp, uspi->s_fpb);
359 mark_inode_dirty(inode);
360 ubh_bforget(tind_bh);
361 tind_bh = NULL;
362 }
363 if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
364 ubh_ll_rw_block(SWRITE, tind_bh);
365 ubh_wait_on_buffer (tind_bh);
366 }
367 ubh_brelse (tind_bh);
369 UFSD("EXIT\n");
370 return retry;
371 }
373 static int ufs_alloc_lastblock(struct inode *inode)
374 {
375 int err = 0;
376 struct address_space *mapping = inode->i_mapping;
377 struct ufs_sb_private_info *uspi = UFS_SB(inode->i_sb)->s_uspi;
378 unsigned lastfrag, i, end;
379 struct page *lastpage;
380 struct buffer_head *bh;
382 lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
384 if (!lastfrag)
385 goto out;
387 lastfrag--;
389 lastpage = ufs_get_locked_page(mapping, lastfrag >>
390 (PAGE_CACHE_SHIFT - inode->i_blkbits));
391 if (IS_ERR(lastpage)) {
392 err = -EIO;
393 goto out;
394 }
396 end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
397 bh = page_buffers(lastpage);
398 for (i = 0; i < end; ++i)
399 bh = bh->b_this_page;
402 err = ufs_getfrag_block(inode, lastfrag, bh, 1);
404 if (unlikely(err))
405 goto out_unlock;
407 if (buffer_new(bh)) {
408 clear_buffer_new(bh);
409 unmap_underlying_metadata(bh->b_bdev,
410 bh->b_blocknr);
411 /*
412 * we do not zeroize fragment, because of
413 * if it maped to hole, it already contains zeroes
414 */
415 set_buffer_uptodate(bh);
416 mark_buffer_dirty(bh);
417 set_page_dirty(lastpage);
418 }
420 out_unlock:
421 ufs_put_locked_page(lastpage);
422 out:
423 return err;
424 }
426 int ufs_truncate(struct inode *inode, loff_t old_i_size)
427 {
428 struct ufs_inode_info *ufsi = UFS_I(inode);
429 struct super_block *sb = inode->i_sb;
430 struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
431 int retry, err = 0;
433 UFSD("ENTER\n");
435 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
436 S_ISLNK(inode->i_mode)))
437 return -EINVAL;
438 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
439 return -EPERM;
441 err = ufs_alloc_lastblock(inode);
443 if (err) {
444 i_size_write(inode, old_i_size);
445 goto out;
446 }
448 block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
450 lock_kernel();
451 while (1) {
452 retry = ufs_trunc_direct(inode);
453 retry |= ufs_trunc_indirect (inode, UFS_IND_BLOCK,
454 (__fs32 *) &ufsi->i_u1.i_data[UFS_IND_BLOCK]);
455 retry |= ufs_trunc_dindirect (inode, UFS_IND_BLOCK + uspi->s_apb,
456 (__fs32 *) &ufsi->i_u1.i_data[UFS_DIND_BLOCK]);
457 retry |= ufs_trunc_tindirect (inode);
458 if (!retry)
459 break;
460 if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
461 ufs_sync_inode (inode);
462 blk_run_address_space(inode->i_mapping);
463 yield();
464 }
466 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
467 ufsi->i_lastfrag = DIRECT_FRAGMENT;
468 unlock_kernel();
469 mark_inode_dirty(inode);
470 out:
471 UFSD("EXIT: err %d\n", err);
472 return err;
473 }
476 /*
477 * We don't define our `inode->i_op->truncate', and call it here,
478 * because of:
479 * - there is no way to know old size
480 * - there is no way inform user about error, if it happens in `truncate'
481 */
482 static int ufs_setattr(struct dentry *dentry, struct iattr *attr)
483 {
484 struct inode *inode = dentry->d_inode;
485 unsigned int ia_valid = attr->ia_valid;
486 int error;
488 error = inode_change_ok(inode, attr);
489 if (error)
490 return error;
492 if (ia_valid & ATTR_SIZE &&
493 attr->ia_size != i_size_read(inode)) {
494 loff_t old_i_size = inode->i_size;
495 error = vmtruncate(inode, attr->ia_size);
496 if (error)
497 return error;
498 error = ufs_truncate(inode, old_i_size);
499 if (error)
500 return error;
501 }
502 return inode_setattr(inode, attr);
503 }
505 struct inode_operations ufs_file_inode_operations = {
506 .setattr = ufs_setattr,
507 };