Commit | Line | Data |
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1da177e4 LT |
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 | #include <linux/errno.h> | |
33 | #include <linux/fs.h> | |
34 | #include <linux/ufs_fs.h> | |
35 | #include <linux/fcntl.h> | |
36 | #include <linux/time.h> | |
37 | #include <linux/stat.h> | |
38 | #include <linux/string.h> | |
39 | #include <linux/smp_lock.h> | |
40 | #include <linux/buffer_head.h> | |
41 | #include <linux/blkdev.h> | |
42 | #include <linux/sched.h> | |
43 | ||
44 | #include "swab.h" | |
45 | #include "util.h" | |
46 | ||
47 | #undef UFS_TRUNCATE_DEBUG | |
48 | ||
49 | #ifdef UFS_TRUNCATE_DEBUG | |
50 | #define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x; | |
51 | #else | |
52 | #define UFSD(x) | |
53 | #endif | |
54 | ||
55 | /* | |
56 | * Secure deletion currently doesn't work. It interacts very badly | |
57 | * with buffers shared with memory mappings, and for that reason | |
58 | * can't be done in the truncate() routines. It should instead be | |
59 | * done separately in "release()" before calling the truncate routines | |
60 | * that will release the actual file blocks. | |
61 | * | |
62 | * Linus | |
63 | */ | |
64 | ||
65 | #define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift) | |
66 | #define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift) | |
67 | ||
68 | #define DATA_BUFFER_USED(bh) \ | |
69 | (atomic_read(&bh->b_count)>1 || buffer_locked(bh)) | |
70 | ||
71 | static int ufs_trunc_direct (struct inode * inode) | |
72 | { | |
73 | struct ufs_inode_info *ufsi = UFS_I(inode); | |
74 | struct super_block * sb; | |
75 | struct ufs_sb_private_info * uspi; | |
76 | struct buffer_head * bh; | |
77 | __fs32 * p; | |
78 | unsigned frag1, frag2, frag3, frag4, block1, block2; | |
79 | unsigned frag_to_free, free_count; | |
80 | unsigned i, j, tmp; | |
81 | int retry; | |
82 | ||
83 | UFSD(("ENTER\n")) | |
84 | ||
85 | sb = inode->i_sb; | |
86 | uspi = UFS_SB(sb)->s_uspi; | |
87 | ||
88 | frag_to_free = 0; | |
89 | free_count = 0; | |
90 | retry = 0; | |
91 | ||
92 | frag1 = DIRECT_FRAGMENT; | |
93 | frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag); | |
94 | frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1); | |
95 | frag3 = frag4 & ~uspi->s_fpbmask; | |
96 | block1 = block2 = 0; | |
97 | if (frag2 > frag3) { | |
98 | frag2 = frag4; | |
99 | frag3 = frag4 = 0; | |
100 | } | |
101 | else if (frag2 < frag3) { | |
102 | block1 = ufs_fragstoblks (frag2); | |
103 | block2 = ufs_fragstoblks (frag3); | |
104 | } | |
105 | ||
106 | UFSD(("frag1 %u, frag2 %u, block1 %u, block2 %u, frag3 %u, frag4 %u\n", frag1, frag2, block1, block2, frag3, frag4)) | |
107 | ||
108 | if (frag1 >= frag2) | |
109 | goto next1; | |
110 | ||
111 | /* | |
112 | * Free first free fragments | |
113 | */ | |
114 | p = ufsi->i_u1.i_data + ufs_fragstoblks (frag1); | |
115 | tmp = fs32_to_cpu(sb, *p); | |
116 | if (!tmp ) | |
117 | ufs_panic (sb, "ufs_trunc_direct", "internal error"); | |
118 | frag1 = ufs_fragnum (frag1); | |
119 | frag2 = ufs_fragnum (frag2); | |
120 | for (j = frag1; j < frag2; j++) { | |
121 | bh = sb_find_get_block (sb, tmp + j); | |
122 | if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) { | |
123 | retry = 1; | |
124 | brelse (bh); | |
125 | goto next1; | |
126 | } | |
127 | bforget (bh); | |
128 | } | |
129 | inode->i_blocks -= (frag2-frag1) << uspi->s_nspfshift; | |
130 | mark_inode_dirty(inode); | |
131 | ufs_free_fragments (inode, tmp + frag1, frag2 - frag1); | |
132 | frag_to_free = tmp + frag1; | |
133 | ||
134 | next1: | |
135 | /* | |
136 | * Free whole blocks | |
137 | */ | |
138 | for (i = block1 ; i < block2; i++) { | |
139 | p = ufsi->i_u1.i_data + i; | |
140 | tmp = fs32_to_cpu(sb, *p); | |
141 | if (!tmp) | |
142 | continue; | |
143 | for (j = 0; j < uspi->s_fpb; j++) { | |
144 | bh = sb_find_get_block(sb, tmp + j); | |
145 | if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) { | |
146 | retry = 1; | |
147 | brelse (bh); | |
148 | goto next2; | |
149 | } | |
150 | bforget (bh); | |
151 | } | |
152 | *p = 0; | |
153 | inode->i_blocks -= uspi->s_nspb; | |
154 | mark_inode_dirty(inode); | |
155 | if (free_count == 0) { | |
156 | frag_to_free = tmp; | |
157 | free_count = uspi->s_fpb; | |
158 | } else if (free_count > 0 && frag_to_free == tmp - free_count) | |
159 | free_count += uspi->s_fpb; | |
160 | else { | |
161 | ufs_free_blocks (inode, frag_to_free, free_count); | |
162 | frag_to_free = tmp; | |
163 | free_count = uspi->s_fpb; | |
164 | } | |
165 | next2:; | |
166 | } | |
167 | ||
168 | if (free_count > 0) | |
169 | ufs_free_blocks (inode, frag_to_free, free_count); | |
170 | ||
171 | if (frag3 >= frag4) | |
172 | goto next3; | |
173 | ||
174 | /* | |
175 | * Free last free fragments | |
176 | */ | |
177 | p = ufsi->i_u1.i_data + ufs_fragstoblks (frag3); | |
178 | tmp = fs32_to_cpu(sb, *p); | |
179 | if (!tmp ) | |
180 | ufs_panic(sb, "ufs_truncate_direct", "internal error"); | |
181 | frag4 = ufs_fragnum (frag4); | |
182 | for (j = 0; j < frag4; j++) { | |
183 | bh = sb_find_get_block (sb, tmp + j); | |
184 | if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) { | |
185 | retry = 1; | |
186 | brelse (bh); | |
187 | goto next1; | |
188 | } | |
189 | bforget (bh); | |
190 | } | |
191 | *p = 0; | |
192 | inode->i_blocks -= frag4 << uspi->s_nspfshift; | |
193 | mark_inode_dirty(inode); | |
194 | ufs_free_fragments (inode, tmp, frag4); | |
195 | next3: | |
196 | ||
197 | UFSD(("EXIT\n")) | |
198 | return retry; | |
199 | } | |
200 | ||
201 | ||
202 | static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p) | |
203 | { | |
204 | struct super_block * sb; | |
205 | struct ufs_sb_private_info * uspi; | |
206 | struct ufs_buffer_head * ind_ubh; | |
207 | struct buffer_head * bh; | |
208 | __fs32 * ind; | |
209 | unsigned indirect_block, i, j, tmp; | |
210 | unsigned frag_to_free, free_count; | |
211 | int retry; | |
212 | ||
213 | UFSD(("ENTER\n")) | |
214 | ||
215 | sb = inode->i_sb; | |
216 | uspi = UFS_SB(sb)->s_uspi; | |
217 | ||
218 | frag_to_free = 0; | |
219 | free_count = 0; | |
220 | retry = 0; | |
221 | ||
222 | tmp = fs32_to_cpu(sb, *p); | |
223 | if (!tmp) | |
224 | return 0; | |
225 | ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize); | |
226 | if (tmp != fs32_to_cpu(sb, *p)) { | |
227 | ubh_brelse (ind_ubh); | |
228 | return 1; | |
229 | } | |
230 | if (!ind_ubh) { | |
231 | *p = 0; | |
232 | return 0; | |
233 | } | |
234 | ||
235 | indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0; | |
236 | for (i = indirect_block; i < uspi->s_apb; i++) { | |
237 | ind = ubh_get_addr32 (ind_ubh, i); | |
238 | tmp = fs32_to_cpu(sb, *ind); | |
239 | if (!tmp) | |
240 | continue; | |
241 | for (j = 0; j < uspi->s_fpb; j++) { | |
242 | bh = sb_find_get_block(sb, tmp + j); | |
243 | if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *ind)) { | |
244 | retry = 1; | |
245 | brelse (bh); | |
246 | goto next; | |
247 | } | |
248 | bforget (bh); | |
249 | } | |
250 | *ind = 0; | |
251 | ubh_mark_buffer_dirty(ind_ubh); | |
252 | if (free_count == 0) { | |
253 | frag_to_free = tmp; | |
254 | free_count = uspi->s_fpb; | |
255 | } else if (free_count > 0 && frag_to_free == tmp - free_count) | |
256 | free_count += uspi->s_fpb; | |
257 | else { | |
258 | ufs_free_blocks (inode, frag_to_free, free_count); | |
259 | frag_to_free = tmp; | |
260 | free_count = uspi->s_fpb; | |
261 | } | |
262 | inode->i_blocks -= uspi->s_nspb; | |
263 | mark_inode_dirty(inode); | |
264 | next:; | |
265 | } | |
266 | ||
267 | if (free_count > 0) { | |
268 | ufs_free_blocks (inode, frag_to_free, free_count); | |
269 | } | |
270 | for (i = 0; i < uspi->s_apb; i++) | |
271 | if (*ubh_get_addr32(ind_ubh,i)) | |
272 | break; | |
273 | if (i >= uspi->s_apb) { | |
274 | if (ubh_max_bcount(ind_ubh) != 1) { | |
275 | retry = 1; | |
276 | } | |
277 | else { | |
278 | tmp = fs32_to_cpu(sb, *p); | |
279 | *p = 0; | |
280 | inode->i_blocks -= uspi->s_nspb; | |
281 | mark_inode_dirty(inode); | |
282 | ufs_free_blocks (inode, tmp, uspi->s_fpb); | |
283 | ubh_bforget(ind_ubh); | |
284 | ind_ubh = NULL; | |
285 | } | |
286 | } | |
287 | if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) { | |
096125f3 | 288 | ubh_ll_rw_block (SWRITE, 1, &ind_ubh); |
1da177e4 LT |
289 | ubh_wait_on_buffer (ind_ubh); |
290 | } | |
291 | ubh_brelse (ind_ubh); | |
292 | ||
293 | UFSD(("EXIT\n")) | |
294 | ||
295 | return retry; | |
296 | } | |
297 | ||
298 | static int ufs_trunc_dindirect (struct inode *inode, unsigned offset, __fs32 *p) | |
299 | { | |
300 | struct super_block * sb; | |
301 | struct ufs_sb_private_info * uspi; | |
302 | struct ufs_buffer_head * dind_bh; | |
303 | unsigned i, tmp, dindirect_block; | |
304 | __fs32 * dind; | |
305 | int retry = 0; | |
306 | ||
307 | UFSD(("ENTER\n")) | |
308 | ||
309 | sb = inode->i_sb; | |
310 | uspi = UFS_SB(sb)->s_uspi; | |
311 | ||
312 | dindirect_block = (DIRECT_BLOCK > offset) | |
313 | ? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0; | |
314 | retry = 0; | |
315 | ||
316 | tmp = fs32_to_cpu(sb, *p); | |
317 | if (!tmp) | |
318 | return 0; | |
319 | dind_bh = ubh_bread(sb, tmp, uspi->s_bsize); | |
320 | if (tmp != fs32_to_cpu(sb, *p)) { | |
321 | ubh_brelse (dind_bh); | |
322 | return 1; | |
323 | } | |
324 | if (!dind_bh) { | |
325 | *p = 0; | |
326 | return 0; | |
327 | } | |
328 | ||
329 | for (i = dindirect_block ; i < uspi->s_apb ; i++) { | |
330 | dind = ubh_get_addr32 (dind_bh, i); | |
331 | tmp = fs32_to_cpu(sb, *dind); | |
332 | if (!tmp) | |
333 | continue; | |
334 | retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind); | |
335 | ubh_mark_buffer_dirty(dind_bh); | |
336 | } | |
337 | ||
338 | for (i = 0; i < uspi->s_apb; i++) | |
339 | if (*ubh_get_addr32 (dind_bh, i)) | |
340 | break; | |
341 | if (i >= uspi->s_apb) { | |
342 | if (ubh_max_bcount(dind_bh) != 1) | |
343 | retry = 1; | |
344 | else { | |
345 | tmp = fs32_to_cpu(sb, *p); | |
346 | *p = 0; | |
347 | inode->i_blocks -= uspi->s_nspb; | |
348 | mark_inode_dirty(inode); | |
349 | ufs_free_blocks (inode, tmp, uspi->s_fpb); | |
350 | ubh_bforget(dind_bh); | |
351 | dind_bh = NULL; | |
352 | } | |
353 | } | |
354 | if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) { | |
096125f3 | 355 | ubh_ll_rw_block (SWRITE, 1, &dind_bh); |
1da177e4 LT |
356 | ubh_wait_on_buffer (dind_bh); |
357 | } | |
358 | ubh_brelse (dind_bh); | |
359 | ||
360 | UFSD(("EXIT\n")) | |
361 | ||
362 | return retry; | |
363 | } | |
364 | ||
365 | static int ufs_trunc_tindirect (struct inode * inode) | |
366 | { | |
367 | struct ufs_inode_info *ufsi = UFS_I(inode); | |
368 | struct super_block * sb; | |
369 | struct ufs_sb_private_info * uspi; | |
370 | struct ufs_buffer_head * tind_bh; | |
371 | unsigned tindirect_block, tmp, i; | |
372 | __fs32 * tind, * p; | |
373 | int retry; | |
374 | ||
375 | UFSD(("ENTER\n")) | |
376 | ||
377 | sb = inode->i_sb; | |
378 | uspi = UFS_SB(sb)->s_uspi; | |
379 | retry = 0; | |
380 | ||
381 | tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb)) | |
382 | ? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0; | |
383 | p = ufsi->i_u1.i_data + UFS_TIND_BLOCK; | |
384 | if (!(tmp = fs32_to_cpu(sb, *p))) | |
385 | return 0; | |
386 | tind_bh = ubh_bread (sb, tmp, uspi->s_bsize); | |
387 | if (tmp != fs32_to_cpu(sb, *p)) { | |
388 | ubh_brelse (tind_bh); | |
389 | return 1; | |
390 | } | |
391 | if (!tind_bh) { | |
392 | *p = 0; | |
393 | return 0; | |
394 | } | |
395 | ||
396 | for (i = tindirect_block ; i < uspi->s_apb ; i++) { | |
397 | tind = ubh_get_addr32 (tind_bh, i); | |
398 | retry |= ufs_trunc_dindirect(inode, UFS_NDADDR + | |
399 | uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind); | |
400 | ubh_mark_buffer_dirty(tind_bh); | |
401 | } | |
402 | for (i = 0; i < uspi->s_apb; i++) | |
403 | if (*ubh_get_addr32 (tind_bh, i)) | |
404 | break; | |
405 | if (i >= uspi->s_apb) { | |
406 | if (ubh_max_bcount(tind_bh) != 1) | |
407 | retry = 1; | |
408 | else { | |
409 | tmp = fs32_to_cpu(sb, *p); | |
410 | *p = 0; | |
411 | inode->i_blocks -= uspi->s_nspb; | |
412 | mark_inode_dirty(inode); | |
413 | ufs_free_blocks (inode, tmp, uspi->s_fpb); | |
414 | ubh_bforget(tind_bh); | |
415 | tind_bh = NULL; | |
416 | } | |
417 | } | |
418 | if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) { | |
096125f3 | 419 | ubh_ll_rw_block (SWRITE, 1, &tind_bh); |
1da177e4 LT |
420 | ubh_wait_on_buffer (tind_bh); |
421 | } | |
422 | ubh_brelse (tind_bh); | |
423 | ||
424 | UFSD(("EXIT\n")) | |
425 | return retry; | |
426 | } | |
427 | ||
428 | void ufs_truncate (struct inode * inode) | |
429 | { | |
430 | struct ufs_inode_info *ufsi = UFS_I(inode); | |
431 | struct super_block * sb; | |
432 | struct ufs_sb_private_info * uspi; | |
433 | struct buffer_head * bh; | |
434 | unsigned offset; | |
435 | int err, retry; | |
436 | ||
437 | UFSD(("ENTER\n")) | |
438 | sb = inode->i_sb; | |
439 | uspi = UFS_SB(sb)->s_uspi; | |
440 | ||
441 | if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) | |
442 | return; | |
443 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | |
444 | return; | |
445 | lock_kernel(); | |
446 | while (1) { | |
447 | retry = ufs_trunc_direct(inode); | |
448 | retry |= ufs_trunc_indirect (inode, UFS_IND_BLOCK, | |
449 | (__fs32 *) &ufsi->i_u1.i_data[UFS_IND_BLOCK]); | |
450 | retry |= ufs_trunc_dindirect (inode, UFS_IND_BLOCK + uspi->s_apb, | |
451 | (__fs32 *) &ufsi->i_u1.i_data[UFS_DIND_BLOCK]); | |
452 | retry |= ufs_trunc_tindirect (inode); | |
453 | if (!retry) | |
454 | break; | |
455 | if (IS_SYNC(inode) && (inode->i_state & I_DIRTY)) | |
456 | ufs_sync_inode (inode); | |
457 | blk_run_address_space(inode->i_mapping); | |
458 | yield(); | |
459 | } | |
460 | offset = inode->i_size & uspi->s_fshift; | |
461 | if (offset) { | |
462 | bh = ufs_bread (inode, inode->i_size >> uspi->s_fshift, 0, &err); | |
463 | if (bh) { | |
464 | memset (bh->b_data + offset, 0, uspi->s_fsize - offset); | |
465 | mark_buffer_dirty (bh); | |
466 | brelse (bh); | |
467 | } | |
468 | } | |
469 | inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; | |
470 | ufsi->i_lastfrag = DIRECT_FRAGMENT; | |
471 | unlock_kernel(); | |
472 | mark_inode_dirty(inode); | |
473 | UFSD(("EXIT\n")) | |
474 | } |