V4L/DVB (9657): em28xx: add a functio to write on a single register
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ufs / truncate.c
blob41dd431ce228e409d9efdbbf63865feea608625c
1 /*
2 * linux/fs/ufs/truncate.c
4 * Copyright (C) 1998
5 * Daniel Pirkl <daniel.pirkl@email.cz>
6 * Charles University, Faculty of Mathematics and Physics
8 * from
10 * linux/fs/ext2/truncate.c
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)
17 * from
19 * linux/fs/minix/truncate.c
21 * Copyright (C) 1991, 1992 Linus Torvalds
23 * Big-endian to little-endian byte-swapping/bitmaps by
24 * David S. Miller (davem@caip.rutgers.edu), 1995
28 * Real random numbers for secure rm added 94/02/18
29 * Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
33 * Adoptation to use page cache and UFS2 write support by
34 * Evgeniy Dushistov <dushistov@mail.ru>, 2006-2007
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>
48 #include "ufs_fs.h"
49 #include "ufs.h"
50 #include "swab.h"
51 #include "util.h"
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.
60 * Linus
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)
67 static int ufs_trunc_direct(struct inode *inode)
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;
78 UFSD("ENTER: ino %lu\n", inode->i_ino);
80 sb = inode->i_sb;
81 uspi = UFS_SB(sb)->s_uspi;
83 frag_to_free = 0;
84 free_count = 0;
85 retry = 0;
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);
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);
106 if (frag1 >= frag2)
107 goto next1;
110 * Free first free fragments
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);
119 ufs_free_fragments(inode, tmp + frag1, frag2);
120 mark_inode_dirty(inode);
121 frag_to_free = tmp + frag1;
123 next1:
125 * Free whole blocks
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);
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;
144 mark_inode_dirty(inode);
147 if (free_count > 0)
148 ufs_free_blocks (inode, frag_to_free, free_count);
150 if (frag3 >= frag4)
151 goto next3;
154 * Free last free fragments
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);
163 ufs_free_fragments (inode, tmp, frag4);
164 mark_inode_dirty(inode);
165 next3:
167 UFSD("EXIT: ino %lu\n", inode->i_ino);
168 return retry;
172 static int ufs_trunc_indirect(struct inode *inode, u64 offset, void *p)
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;
182 UFSD("ENTER: ino %lu, offset %llu, p: %p\n",
183 inode->i_ino, (unsigned long long)offset, p);
185 BUG_ON(!p);
187 sb = inode->i_sb;
188 uspi = UFS_SB(sb)->s_uspi;
190 frag_to_free = 0;
191 free_count = 0;
192 retry = 0;
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;
202 if (!ind_ubh) {
203 ufs_data_ptr_clear(uspi, p);
204 return 0;
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;
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;
227 mark_inode_dirty(inode);
230 if (free_count > 0) {
231 ufs_free_blocks (inode, frag_to_free, free_count);
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);
241 ufs_free_blocks (inode, tmp, uspi->s_fpb);
242 mark_inode_dirty(inode);
243 ubh_bforget(ind_ubh);
244 ind_ubh = NULL;
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);
250 ubh_brelse (ind_ubh);
252 UFSD("EXIT: ino %lu\n", inode->i_ino);
254 return retry;
257 static int ufs_trunc_dindirect(struct inode *inode, u64 offset, void *p)
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;
266 UFSD("ENTER: ino %lu\n", inode->i_ino);
268 sb = inode->i_sb;
269 uspi = UFS_SB(sb)->s_uspi;
271 dindirect_block = (DIRECT_BLOCK > offset)
272 ? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
273 retry = 0;
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;
283 if (!dind_bh) {
284 ufs_data_ptr_clear(uspi, p);
285 return 0;
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);
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);
305 ufs_free_blocks(inode, tmp, uspi->s_fpb);
306 mark_inode_dirty(inode);
307 ubh_bforget(dind_bh);
308 dind_bh = NULL;
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);
314 ubh_brelse (dind_bh);
316 UFSD("EXIT: ino %lu\n", inode->i_ino);
318 return retry;
321 static int ufs_trunc_tindirect(struct inode *inode)
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;
331 UFSD("ENTER: ino %lu\n", inode->i_ino);
333 retry = 0;
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;
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;
346 if (!tind_bh) {
347 ufs_data_ptr_clear(uspi, p);
348 return 0;
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);
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);
365 ufs_free_blocks(inode, tmp, uspi->s_fpb);
366 mark_inode_dirty(inode);
367 ubh_bforget(tind_bh);
368 tind_bh = NULL;
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);
374 ubh_brelse (tind_bh);
376 UFSD("EXIT: ino %lu\n", inode->i_ino);
377 return retry;
380 static int ufs_alloc_lastblock(struct inode *inode)
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;
392 lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
394 if (!lastfrag)
395 goto out;
397 lastfrag--;
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;
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;
412 err = ufs_getfrag_block(inode, lastfrag, bh, 1);
414 if (unlikely(err))
415 goto out_unlock;
417 if (buffer_new(bh)) {
418 clear_buffer_new(bh);
419 unmap_underlying_metadata(bh->b_bdev,
420 bh->b_blocknr);
422 * we do not zeroize fragment, because of
423 * if it maped to hole, it already contains zeroes
425 set_buffer_uptodate(bh);
426 mark_buffer_dirty(bh);
427 set_page_dirty(lastpage);
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);
444 out_unlock:
445 ufs_put_locked_page(lastpage);
446 out:
447 return err;
450 int ufs_truncate(struct inode *inode, loff_t old_i_size)
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;
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);
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;
467 err = ufs_alloc_lastblock(inode);
469 if (err) {
470 i_size_write(inode, old_i_size);
471 goto out;
474 block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
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();
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;
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'
510 static int ufs_setattr(struct dentry *dentry, struct iattr *attr)
512 struct inode *inode = dentry->d_inode;
513 unsigned int ia_valid = attr->ia_valid;
514 int error;
516 error = inode_change_ok(inode, attr);
517 if (error)
518 return error;
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;
530 return inode_setattr(inode, attr);
533 const struct inode_operations ufs_file_inode_operations = {
534 .setattr = ufs_setattr,