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1 | /* | |
2 | * Copyright (C) International Business Machines Corp., 2000-2004 | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See | |
12 | * the GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
17 | */ | |
18 | ||
19 | #include <linux/fs.h> | |
20 | #include <linux/quotaops.h> | |
21 | #include "jfs_incore.h" | |
22 | #include "jfs_inode.h" | |
23 | #include "jfs_superblock.h" | |
24 | #include "jfs_dmap.h" | |
25 | #include "jfs_extent.h" | |
26 | #include "jfs_debug.h" | |
27 | ||
28 | /* | |
29 | * forward references | |
30 | */ | |
31 | static int extBalloc(struct inode *, s64, s64 *, s64 *); | |
32 | #ifdef _NOTYET | |
33 | static int extBrealloc(struct inode *, s64, s64, s64 *, s64 *); | |
34 | #endif | |
35 | static s64 extRoundDown(s64 nb); | |
36 | ||
37 | #define DPD(a) (printk("(a): %d\n",(a))) | |
38 | #define DPC(a) (printk("(a): %c\n",(a))) | |
39 | #define DPL1(a) \ | |
40 | { \ | |
41 | if ((a) >> 32) \ | |
42 | printk("(a): %x%08x ",(a)); \ | |
43 | else \ | |
44 | printk("(a): %x ",(a) << 32); \ | |
45 | } | |
46 | #define DPL(a) \ | |
47 | { \ | |
48 | if ((a) >> 32) \ | |
49 | printk("(a): %x%08x\n",(a)); \ | |
50 | else \ | |
51 | printk("(a): %x\n",(a) << 32); \ | |
52 | } | |
53 | ||
54 | #define DPD1(a) (printk("(a): %d ",(a))) | |
55 | #define DPX(a) (printk("(a): %08x\n",(a))) | |
56 | #define DPX1(a) (printk("(a): %08x ",(a))) | |
57 | #define DPS(a) (printk("%s\n",(a))) | |
58 | #define DPE(a) (printk("\nENTERING: %s\n",(a))) | |
59 | #define DPE1(a) (printk("\nENTERING: %s",(a))) | |
60 | #define DPS1(a) (printk(" %s ",(a))) | |
61 | ||
62 | ||
63 | /* | |
64 | * NAME: extAlloc() | |
65 | * | |
66 | * FUNCTION: allocate an extent for a specified page range within a | |
67 | * file. | |
68 | * | |
69 | * PARAMETERS: | |
70 | * ip - the inode of the file. | |
71 | * xlen - requested extent length. | |
72 | * pno - the starting page number with the file. | |
73 | * xp - pointer to an xad. on entry, xad describes an | |
74 | * extent that is used as an allocation hint if the | |
75 | * xaddr of the xad is non-zero. on successful exit, | |
76 | * the xad describes the newly allocated extent. | |
77 | * abnr - bool indicating whether the newly allocated extent | |
78 | * should be marked as allocated but not recorded. | |
79 | * | |
80 | * RETURN VALUES: | |
81 | * 0 - success | |
82 | * -EIO - i/o error. | |
83 | * -ENOSPC - insufficient disk resources. | |
84 | */ | |
85 | int | |
86 | extAlloc(struct inode *ip, s64 xlen, s64 pno, xad_t * xp, bool abnr) | |
87 | { | |
88 | struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb); | |
89 | s64 nxlen, nxaddr, xoff, hint, xaddr = 0; | |
90 | int rc; | |
91 | int xflag; | |
92 | ||
93 | /* This blocks if we are low on resources */ | |
94 | txBeginAnon(ip->i_sb); | |
95 | ||
96 | /* Avoid race with jfs_commit_inode() */ | |
97 | mutex_lock(&JFS_IP(ip)->commit_mutex); | |
98 | ||
99 | /* validate extent length */ | |
100 | if (xlen > MAXXLEN) | |
101 | xlen = MAXXLEN; | |
102 | ||
103 | /* get the page's starting extent offset */ | |
104 | xoff = pno << sbi->l2nbperpage; | |
105 | ||
106 | /* check if an allocation hint was provided */ | |
107 | if ((hint = addressXAD(xp))) { | |
108 | /* get the size of the extent described by the hint */ | |
109 | nxlen = lengthXAD(xp); | |
110 | ||
111 | /* check if the hint is for the portion of the file | |
112 | * immediately previous to the current allocation | |
113 | * request and if hint extent has the same abnr | |
114 | * value as the current request. if so, we can | |
115 | * extend the hint extent to include the current | |
116 | * extent if we can allocate the blocks immediately | |
117 | * following the hint extent. | |
118 | */ | |
119 | if (offsetXAD(xp) + nxlen == xoff && | |
120 | abnr == ((xp->flag & XAD_NOTRECORDED) ? true : false)) | |
121 | xaddr = hint + nxlen; | |
122 | ||
123 | /* adjust the hint to the last block of the extent */ | |
124 | hint += (nxlen - 1); | |
125 | } | |
126 | ||
127 | /* allocate the disk blocks for the extent. initially, extBalloc() | |
128 | * will try to allocate disk blocks for the requested size (xlen). | |
129 | * if this fails (xlen contiguous free blocks not available), it'll | |
130 | * try to allocate a smaller number of blocks (producing a smaller | |
131 | * extent), with this smaller number of blocks consisting of the | |
132 | * requested number of blocks rounded down to the next smaller | |
133 | * power of 2 number (i.e. 16 -> 8). it'll continue to round down | |
134 | * and retry the allocation until the number of blocks to allocate | |
135 | * is smaller than the number of blocks per page. | |
136 | */ | |
137 | nxlen = xlen; | |
138 | if ((rc = extBalloc(ip, hint ? hint : INOHINT(ip), &nxlen, &nxaddr))) { | |
139 | mutex_unlock(&JFS_IP(ip)->commit_mutex); | |
140 | return (rc); | |
141 | } | |
142 | ||
143 | /* Allocate blocks to quota. */ | |
144 | rc = dquot_alloc_block(ip, nxlen); | |
145 | if (rc) { | |
146 | dbFree(ip, nxaddr, (s64) nxlen); | |
147 | mutex_unlock(&JFS_IP(ip)->commit_mutex); | |
148 | return rc; | |
149 | } | |
150 | ||
151 | /* determine the value of the extent flag */ | |
152 | xflag = abnr ? XAD_NOTRECORDED : 0; | |
153 | ||
154 | /* if we can extend the hint extent to cover the current request, | |
155 | * extend it. otherwise, insert a new extent to | |
156 | * cover the current request. | |
157 | */ | |
158 | if (xaddr && xaddr == nxaddr) | |
159 | rc = xtExtend(0, ip, xoff, (int) nxlen, 0); | |
160 | else | |
161 | rc = xtInsert(0, ip, xflag, xoff, (int) nxlen, &nxaddr, 0); | |
162 | ||
163 | /* if the extend or insert failed, | |
164 | * free the newly allocated blocks and return the error. | |
165 | */ | |
166 | if (rc) { | |
167 | dbFree(ip, nxaddr, nxlen); | |
168 | dquot_free_block(ip, nxlen); | |
169 | mutex_unlock(&JFS_IP(ip)->commit_mutex); | |
170 | return (rc); | |
171 | } | |
172 | ||
173 | /* set the results of the extent allocation */ | |
174 | XADaddress(xp, nxaddr); | |
175 | XADlength(xp, nxlen); | |
176 | XADoffset(xp, xoff); | |
177 | xp->flag = xflag; | |
178 | ||
179 | mark_inode_dirty(ip); | |
180 | ||
181 | mutex_unlock(&JFS_IP(ip)->commit_mutex); | |
182 | /* | |
183 | * COMMIT_SyncList flags an anonymous tlock on page that is on | |
184 | * sync list. | |
185 | * We need to commit the inode to get the page written disk. | |
186 | */ | |
187 | if (test_and_clear_cflag(COMMIT_Synclist,ip)) | |
188 | jfs_commit_inode(ip, 0); | |
189 | ||
190 | return (0); | |
191 | } | |
192 | ||
193 | ||
194 | #ifdef _NOTYET | |
195 | /* | |
196 | * NAME: extRealloc() | |
197 | * | |
198 | * FUNCTION: extend the allocation of a file extent containing a | |
199 | * partial back last page. | |
200 | * | |
201 | * PARAMETERS: | |
202 | * ip - the inode of the file. | |
203 | * cp - cbuf for the partial backed last page. | |
204 | * xlen - request size of the resulting extent. | |
205 | * xp - pointer to an xad. on successful exit, the xad | |
206 | * describes the newly allocated extent. | |
207 | * abnr - bool indicating whether the newly allocated extent | |
208 | * should be marked as allocated but not recorded. | |
209 | * | |
210 | * RETURN VALUES: | |
211 | * 0 - success | |
212 | * -EIO - i/o error. | |
213 | * -ENOSPC - insufficient disk resources. | |
214 | */ | |
215 | int extRealloc(struct inode *ip, s64 nxlen, xad_t * xp, bool abnr) | |
216 | { | |
217 | struct super_block *sb = ip->i_sb; | |
218 | s64 xaddr, xlen, nxaddr, delta, xoff; | |
219 | s64 ntail, nextend, ninsert; | |
220 | int rc, nbperpage = JFS_SBI(sb)->nbperpage; | |
221 | int xflag; | |
222 | ||
223 | /* This blocks if we are low on resources */ | |
224 | txBeginAnon(ip->i_sb); | |
225 | ||
226 | mutex_lock(&JFS_IP(ip)->commit_mutex); | |
227 | /* validate extent length */ | |
228 | if (nxlen > MAXXLEN) | |
229 | nxlen = MAXXLEN; | |
230 | ||
231 | /* get the extend (partial) page's disk block address and | |
232 | * number of blocks. | |
233 | */ | |
234 | xaddr = addressXAD(xp); | |
235 | xlen = lengthXAD(xp); | |
236 | xoff = offsetXAD(xp); | |
237 | ||
238 | /* if the extend page is abnr and if the request is for | |
239 | * the extent to be allocated and recorded, | |
240 | * make the page allocated and recorded. | |
241 | */ | |
242 | if ((xp->flag & XAD_NOTRECORDED) && !abnr) { | |
243 | xp->flag = 0; | |
244 | if ((rc = xtUpdate(0, ip, xp))) | |
245 | goto exit; | |
246 | } | |
247 | ||
248 | /* try to allocated the request number of blocks for the | |
249 | * extent. dbRealloc() first tries to satisfy the request | |
250 | * by extending the allocation in place. otherwise, it will | |
251 | * try to allocate a new set of blocks large enough for the | |
252 | * request. in satisfying a request, dbReAlloc() may allocate | |
253 | * less than what was request but will always allocate enough | |
254 | * space as to satisfy the extend page. | |
255 | */ | |
256 | if ((rc = extBrealloc(ip, xaddr, xlen, &nxlen, &nxaddr))) | |
257 | goto exit; | |
258 | ||
259 | /* Allocat blocks to quota. */ | |
260 | rc = dquot_alloc_block(ip, nxlen); | |
261 | if (rc) { | |
262 | dbFree(ip, nxaddr, (s64) nxlen); | |
263 | mutex_unlock(&JFS_IP(ip)->commit_mutex); | |
264 | return rc; | |
265 | } | |
266 | ||
267 | delta = nxlen - xlen; | |
268 | ||
269 | /* check if the extend page is not abnr but the request is abnr | |
270 | * and the allocated disk space is for more than one page. if this | |
271 | * is the case, there is a miss match of abnr between the extend page | |
272 | * and the one or more pages following the extend page. as a result, | |
273 | * two extents will have to be manipulated. the first will be that | |
274 | * of the extent of the extend page and will be manipulated thru | |
275 | * an xtExtend() or an xtTailgate(), depending upon whether the | |
276 | * disk allocation occurred as an inplace extension. the second | |
277 | * extent will be manipulated (created) through an xtInsert() and | |
278 | * will be for the pages following the extend page. | |
279 | */ | |
280 | if (abnr && (!(xp->flag & XAD_NOTRECORDED)) && (nxlen > nbperpage)) { | |
281 | ntail = nbperpage; | |
282 | nextend = ntail - xlen; | |
283 | ninsert = nxlen - nbperpage; | |
284 | ||
285 | xflag = XAD_NOTRECORDED; | |
286 | } else { | |
287 | ntail = nxlen; | |
288 | nextend = delta; | |
289 | ninsert = 0; | |
290 | ||
291 | xflag = xp->flag; | |
292 | } | |
293 | ||
294 | /* if we were able to extend the disk allocation in place, | |
295 | * extend the extent. otherwise, move the extent to a | |
296 | * new disk location. | |
297 | */ | |
298 | if (xaddr == nxaddr) { | |
299 | /* extend the extent */ | |
300 | if ((rc = xtExtend(0, ip, xoff + xlen, (int) nextend, 0))) { | |
301 | dbFree(ip, xaddr + xlen, delta); | |
302 | dquot_free_block(ip, nxlen); | |
303 | goto exit; | |
304 | } | |
305 | } else { | |
306 | /* | |
307 | * move the extent to a new location: | |
308 | * | |
309 | * xtTailgate() accounts for relocated tail extent; | |
310 | */ | |
311 | if ((rc = xtTailgate(0, ip, xoff, (int) ntail, nxaddr, 0))) { | |
312 | dbFree(ip, nxaddr, nxlen); | |
313 | dquot_free_block(ip, nxlen); | |
314 | goto exit; | |
315 | } | |
316 | } | |
317 | ||
318 | ||
319 | /* check if we need to also insert a new extent */ | |
320 | if (ninsert) { | |
321 | /* perform the insert. if it fails, free the blocks | |
322 | * to be inserted and make it appear that we only did | |
323 | * the xtExtend() or xtTailgate() above. | |
324 | */ | |
325 | xaddr = nxaddr + ntail; | |
326 | if (xtInsert (0, ip, xflag, xoff + ntail, (int) ninsert, | |
327 | &xaddr, 0)) { | |
328 | dbFree(ip, xaddr, (s64) ninsert); | |
329 | delta = nextend; | |
330 | nxlen = ntail; | |
331 | xflag = 0; | |
332 | } | |
333 | } | |
334 | ||
335 | /* set the return results */ | |
336 | XADaddress(xp, nxaddr); | |
337 | XADlength(xp, nxlen); | |
338 | XADoffset(xp, xoff); | |
339 | xp->flag = xflag; | |
340 | ||
341 | mark_inode_dirty(ip); | |
342 | exit: | |
343 | mutex_unlock(&JFS_IP(ip)->commit_mutex); | |
344 | return (rc); | |
345 | } | |
346 | #endif /* _NOTYET */ | |
347 | ||
348 | ||
349 | /* | |
350 | * NAME: extHint() | |
351 | * | |
352 | * FUNCTION: produce an extent allocation hint for a file offset. | |
353 | * | |
354 | * PARAMETERS: | |
355 | * ip - the inode of the file. | |
356 | * offset - file offset for which the hint is needed. | |
357 | * xp - pointer to the xad that is to be filled in with | |
358 | * the hint. | |
359 | * | |
360 | * RETURN VALUES: | |
361 | * 0 - success | |
362 | * -EIO - i/o error. | |
363 | */ | |
364 | int extHint(struct inode *ip, s64 offset, xad_t * xp) | |
365 | { | |
366 | struct super_block *sb = ip->i_sb; | |
367 | int nbperpage = JFS_SBI(sb)->nbperpage; | |
368 | s64 prev; | |
369 | int rc = 0; | |
370 | s64 xaddr; | |
371 | int xlen; | |
372 | int xflag; | |
373 | ||
374 | /* init the hint as "no hint provided" */ | |
375 | XADaddress(xp, 0); | |
376 | ||
377 | /* determine the starting extent offset of the page previous | |
378 | * to the page containing the offset. | |
379 | */ | |
380 | prev = ((offset & ~POFFSET) >> JFS_SBI(sb)->l2bsize) - nbperpage; | |
381 | ||
382 | /* if the offset is in the first page of the file, no hint provided. | |
383 | */ | |
384 | if (prev < 0) | |
385 | goto out; | |
386 | ||
387 | rc = xtLookup(ip, prev, nbperpage, &xflag, &xaddr, &xlen, 0); | |
388 | ||
389 | if ((rc == 0) && xlen) { | |
390 | if (xlen != nbperpage) { | |
391 | jfs_error(ip->i_sb, "corrupt xtree\n"); | |
392 | rc = -EIO; | |
393 | } | |
394 | XADaddress(xp, xaddr); | |
395 | XADlength(xp, xlen); | |
396 | XADoffset(xp, prev); | |
397 | /* | |
398 | * only preserve the abnr flag within the xad flags | |
399 | * of the returned hint. | |
400 | */ | |
401 | xp->flag = xflag & XAD_NOTRECORDED; | |
402 | } else | |
403 | rc = 0; | |
404 | ||
405 | out: | |
406 | return (rc); | |
407 | } | |
408 | ||
409 | ||
410 | /* | |
411 | * NAME: extRecord() | |
412 | * | |
413 | * FUNCTION: change a page with a file from not recorded to recorded. | |
414 | * | |
415 | * PARAMETERS: | |
416 | * ip - inode of the file. | |
417 | * cp - cbuf of the file page. | |
418 | * | |
419 | * RETURN VALUES: | |
420 | * 0 - success | |
421 | * -EIO - i/o error. | |
422 | * -ENOSPC - insufficient disk resources. | |
423 | */ | |
424 | int extRecord(struct inode *ip, xad_t * xp) | |
425 | { | |
426 | int rc; | |
427 | ||
428 | txBeginAnon(ip->i_sb); | |
429 | ||
430 | mutex_lock(&JFS_IP(ip)->commit_mutex); | |
431 | ||
432 | /* update the extent */ | |
433 | rc = xtUpdate(0, ip, xp); | |
434 | ||
435 | mutex_unlock(&JFS_IP(ip)->commit_mutex); | |
436 | return rc; | |
437 | } | |
438 | ||
439 | ||
440 | #ifdef _NOTYET | |
441 | /* | |
442 | * NAME: extFill() | |
443 | * | |
444 | * FUNCTION: allocate disk space for a file page that represents | |
445 | * a file hole. | |
446 | * | |
447 | * PARAMETERS: | |
448 | * ip - the inode of the file. | |
449 | * cp - cbuf of the file page represent the hole. | |
450 | * | |
451 | * RETURN VALUES: | |
452 | * 0 - success | |
453 | * -EIO - i/o error. | |
454 | * -ENOSPC - insufficient disk resources. | |
455 | */ | |
456 | int extFill(struct inode *ip, xad_t * xp) | |
457 | { | |
458 | int rc, nbperpage = JFS_SBI(ip->i_sb)->nbperpage; | |
459 | s64 blkno = offsetXAD(xp) >> ip->i_blkbits; | |
460 | ||
461 | // assert(ISSPARSE(ip)); | |
462 | ||
463 | /* initialize the extent allocation hint */ | |
464 | XADaddress(xp, 0); | |
465 | ||
466 | /* allocate an extent to fill the hole */ | |
467 | if ((rc = extAlloc(ip, nbperpage, blkno, xp, false))) | |
468 | return (rc); | |
469 | ||
470 | assert(lengthPXD(xp) == nbperpage); | |
471 | ||
472 | return (0); | |
473 | } | |
474 | #endif /* _NOTYET */ | |
475 | ||
476 | ||
477 | /* | |
478 | * NAME: extBalloc() | |
479 | * | |
480 | * FUNCTION: allocate disk blocks to form an extent. | |
481 | * | |
482 | * initially, we will try to allocate disk blocks for the | |
483 | * requested size (nblocks). if this fails (nblocks | |
484 | * contiguous free blocks not available), we'll try to allocate | |
485 | * a smaller number of blocks (producing a smaller extent), with | |
486 | * this smaller number of blocks consisting of the requested | |
487 | * number of blocks rounded down to the next smaller power of 2 | |
488 | * number (i.e. 16 -> 8). we'll continue to round down and | |
489 | * retry the allocation until the number of blocks to allocate | |
490 | * is smaller than the number of blocks per page. | |
491 | * | |
492 | * PARAMETERS: | |
493 | * ip - the inode of the file. | |
494 | * hint - disk block number to be used as an allocation hint. | |
495 | * *nblocks - pointer to an s64 value. on entry, this value specifies | |
496 | * the desired number of block to be allocated. on successful | |
497 | * exit, this value is set to the number of blocks actually | |
498 | * allocated. | |
499 | * blkno - pointer to a block address that is filled in on successful | |
500 | * return with the starting block number of the newly | |
501 | * allocated block range. | |
502 | * | |
503 | * RETURN VALUES: | |
504 | * 0 - success | |
505 | * -EIO - i/o error. | |
506 | * -ENOSPC - insufficient disk resources. | |
507 | */ | |
508 | static int | |
509 | extBalloc(struct inode *ip, s64 hint, s64 * nblocks, s64 * blkno) | |
510 | { | |
511 | struct jfs_inode_info *ji = JFS_IP(ip); | |
512 | struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb); | |
513 | s64 nb, nblks, daddr, max; | |
514 | int rc, nbperpage = sbi->nbperpage; | |
515 | struct bmap *bmp = sbi->bmap; | |
516 | int ag; | |
517 | ||
518 | /* get the number of blocks to initially attempt to allocate. | |
519 | * we'll first try the number of blocks requested unless this | |
520 | * number is greater than the maximum number of contiguous free | |
521 | * blocks in the map. in that case, we'll start off with the | |
522 | * maximum free. | |
523 | */ | |
524 | max = (s64) 1 << bmp->db_maxfreebud; | |
525 | if (*nblocks >= max && *nblocks > nbperpage) | |
526 | nb = nblks = (max > nbperpage) ? max : nbperpage; | |
527 | else | |
528 | nb = nblks = *nblocks; | |
529 | ||
530 | /* try to allocate blocks */ | |
531 | while ((rc = dbAlloc(ip, hint, nb, &daddr)) != 0) { | |
532 | /* if something other than an out of space error, | |
533 | * stop and return this error. | |
534 | */ | |
535 | if (rc != -ENOSPC) | |
536 | return (rc); | |
537 | ||
538 | /* decrease the allocation request size */ | |
539 | nb = min(nblks, extRoundDown(nb)); | |
540 | ||
541 | /* give up if we cannot cover a page */ | |
542 | if (nb < nbperpage) | |
543 | return (rc); | |
544 | } | |
545 | ||
546 | *nblocks = nb; | |
547 | *blkno = daddr; | |
548 | ||
549 | if (S_ISREG(ip->i_mode) && (ji->fileset == FILESYSTEM_I)) { | |
550 | ag = BLKTOAG(daddr, sbi); | |
551 | spin_lock_irq(&ji->ag_lock); | |
552 | if (ji->active_ag == -1) { | |
553 | atomic_inc(&bmp->db_active[ag]); | |
554 | ji->active_ag = ag; | |
555 | } else if (ji->active_ag != ag) { | |
556 | atomic_dec(&bmp->db_active[ji->active_ag]); | |
557 | atomic_inc(&bmp->db_active[ag]); | |
558 | ji->active_ag = ag; | |
559 | } | |
560 | spin_unlock_irq(&ji->ag_lock); | |
561 | } | |
562 | ||
563 | return (0); | |
564 | } | |
565 | ||
566 | ||
567 | #ifdef _NOTYET | |
568 | /* | |
569 | * NAME: extBrealloc() | |
570 | * | |
571 | * FUNCTION: attempt to extend an extent's allocation. | |
572 | * | |
573 | * Initially, we will try to extend the extent's allocation | |
574 | * in place. If this fails, we'll try to move the extent | |
575 | * to a new set of blocks. If moving the extent, we initially | |
576 | * will try to allocate disk blocks for the requested size | |
577 | * (newnblks). if this fails (new contiguous free blocks not | |
578 | * available), we'll try to allocate a smaller number of | |
579 | * blocks (producing a smaller extent), with this smaller | |
580 | * number of blocks consisting of the requested number of | |
581 | * blocks rounded down to the next smaller power of 2 | |
582 | * number (i.e. 16 -> 8). We'll continue to round down and | |
583 | * retry the allocation until the number of blocks to allocate | |
584 | * is smaller than the number of blocks per page. | |
585 | * | |
586 | * PARAMETERS: | |
587 | * ip - the inode of the file. | |
588 | * blkno - starting block number of the extents current allocation. | |
589 | * nblks - number of blocks within the extents current allocation. | |
590 | * newnblks - pointer to a s64 value. on entry, this value is the | |
591 | * the new desired extent size (number of blocks). on | |
592 | * successful exit, this value is set to the extent's actual | |
593 | * new size (new number of blocks). | |
594 | * newblkno - the starting block number of the extents new allocation. | |
595 | * | |
596 | * RETURN VALUES: | |
597 | * 0 - success | |
598 | * -EIO - i/o error. | |
599 | * -ENOSPC - insufficient disk resources. | |
600 | */ | |
601 | static int | |
602 | extBrealloc(struct inode *ip, | |
603 | s64 blkno, s64 nblks, s64 * newnblks, s64 * newblkno) | |
604 | { | |
605 | int rc; | |
606 | ||
607 | /* try to extend in place */ | |
608 | if ((rc = dbExtend(ip, blkno, nblks, *newnblks - nblks)) == 0) { | |
609 | *newblkno = blkno; | |
610 | return (0); | |
611 | } else { | |
612 | if (rc != -ENOSPC) | |
613 | return (rc); | |
614 | } | |
615 | ||
616 | /* in place extension not possible. | |
617 | * try to move the extent to a new set of blocks. | |
618 | */ | |
619 | return (extBalloc(ip, blkno, newnblks, newblkno)); | |
620 | } | |
621 | #endif /* _NOTYET */ | |
622 | ||
623 | ||
624 | /* | |
625 | * NAME: extRoundDown() | |
626 | * | |
627 | * FUNCTION: round down a specified number of blocks to the next | |
628 | * smallest power of 2 number. | |
629 | * | |
630 | * PARAMETERS: | |
631 | * nb - the inode of the file. | |
632 | * | |
633 | * RETURN VALUES: | |
634 | * next smallest power of 2 number. | |
635 | */ | |
636 | static s64 extRoundDown(s64 nb) | |
637 | { | |
638 | int i; | |
639 | u64 m, k; | |
640 | ||
641 | for (i = 0, m = (u64) 1 << 63; i < 64; i++, m >>= 1) { | |
642 | if (m & nb) | |
643 | break; | |
644 | } | |
645 | ||
646 | i = 63 - i; | |
647 | k = (u64) 1 << i; | |
648 | k = ((k - 1) & nb) ? k : k >> 1; | |
649 | ||
650 | return (k); | |
651 | } |