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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 
ufs_trunc_direct(struct inode * inode)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 
ufs_trunc_indirect(struct inode * inode,u64 offset,void * p)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 
ufs_trunc_dindirect(struct inode * inode,u64 offset,void * p)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 
ufs_trunc_tindirect(struct inode * inode)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 
ufs_alloc_lastblock(struct inode * inode)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 
ufs_truncate(struct inode * inode,loff_t old_i_size)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 
504 /*
505  * We don't define our `inode->i_op->truncate', and call it here,
506  * because of:
507  * - there is no way to know old size
508  * - there is no way inform user about error, if it happens in `truncate'
509  */
ufs_setattr(struct dentry * dentry,struct iattr * attr)510 static int ufs_setattr(struct dentry *dentry, struct iattr *attr)
511 {
512 	struct inode *inode = dentry->d_inode;
513 	unsigned int ia_valid = attr->ia_valid;
514 	int error;
515 
516 	error = inode_change_ok(inode, attr);
517 	if (error)
518 		return error;
519 
520 	if (ia_valid & ATTR_SIZE &&
521 	    attr->ia_size != i_size_read(inode)) {
522 		loff_t old_i_size = inode->i_size;
523 		error = vmtruncate(inode, attr->ia_size);
524 		if (error)
525 			return error;
526 		error = ufs_truncate(inode, old_i_size);
527 		if (error)
528 			return error;
529 	}
530 	return inode_setattr(inode, attr);
531 }
532 
533 const struct inode_operations ufs_file_inode_operations = {
534 	.setattr = ufs_setattr,
535 };
536