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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/slab.h> |
21 | #include "jfs_incore.h" |
22 | #include "jfs_superblock.h" |
23 | #include "jfs_dmap.h" |
24 | #include "jfs_imap.h" |
25 | #include "jfs_lock.h" |
26 | #include "jfs_metapage.h" |
27 | #include "jfs_debug.h" |
28 | |
29 | /* |
30 | * SERIALIZATION of the Block Allocation Map. |
31 | * |
32 | * the working state of the block allocation map is accessed in |
33 | * two directions: |
34 | * |
35 | * 1) allocation and free requests that start at the dmap |
36 | * level and move up through the dmap control pages (i.e. |
37 | * the vast majority of requests). |
38 | * |
39 | * 2) allocation requests that start at dmap control page |
40 | * level and work down towards the dmaps. |
41 | * |
42 | * the serialization scheme used here is as follows. |
43 | * |
44 | * requests which start at the bottom are serialized against each |
45 | * other through buffers and each requests holds onto its buffers |
46 | * as it works it way up from a single dmap to the required level |
47 | * of dmap control page. |
48 | * requests that start at the top are serialized against each other |
49 | * and request that start from the bottom by the multiple read/single |
50 | * write inode lock of the bmap inode. requests starting at the top |
51 | * take this lock in write mode while request starting at the bottom |
52 | * take the lock in read mode. a single top-down request may proceed |
53 | * exclusively while multiple bottoms-up requests may proceed |
54 | * simultaneously (under the protection of busy buffers). |
55 | * |
56 | * in addition to information found in dmaps and dmap control pages, |
57 | * the working state of the block allocation map also includes read/ |
58 | * write information maintained in the bmap descriptor (i.e. total |
59 | * free block count, allocation group level free block counts). |
60 | * a single exclusive lock (BMAP_LOCK) is used to guard this information |
61 | * in the face of multiple-bottoms up requests. |
62 | * (lock ordering: IREAD_LOCK, BMAP_LOCK); |
63 | * |
64 | * accesses to the persistent state of the block allocation map (limited |
65 | * to the persistent bitmaps in dmaps) is guarded by (busy) buffers. |
66 | */ |
67 | |
68 | #define BMAP_LOCK_INIT(bmp) mutex_init(&bmp->db_bmaplock) |
69 | #define BMAP_LOCK(bmp) mutex_lock(&bmp->db_bmaplock) |
70 | #define BMAP_UNLOCK(bmp) mutex_unlock(&bmp->db_bmaplock) |
71 | |
72 | /* |
73 | * forward references |
74 | */ |
75 | static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
76 | int nblocks); |
77 | static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval); |
78 | static int dbBackSplit(dmtree_t * tp, int leafno); |
79 | static int dbJoin(dmtree_t * tp, int leafno, int newval); |
80 | static void dbAdjTree(dmtree_t * tp, int leafno, int newval); |
81 | static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, |
82 | int level); |
83 | static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results); |
84 | static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, |
85 | int nblocks); |
86 | static int dbAllocNear(struct bmap * bmp, struct dmap * dp, s64 blkno, |
87 | int nblocks, |
88 | int l2nb, s64 * results); |
89 | static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
90 | int nblocks); |
91 | static int dbAllocDmapLev(struct bmap * bmp, struct dmap * dp, int nblocks, |
92 | int l2nb, |
93 | s64 * results); |
94 | static int dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, |
95 | s64 * results); |
96 | static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, |
97 | s64 * results); |
98 | static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks); |
99 | static int dbFindBits(u32 word, int l2nb); |
100 | static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno); |
101 | static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx); |
102 | static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
103 | int nblocks); |
104 | static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
105 | int nblocks); |
106 | static int dbMaxBud(u8 * cp); |
107 | s64 dbMapFileSizeToMapSize(struct inode *ipbmap); |
108 | static int blkstol2(s64 nb); |
109 | |
110 | static int cntlz(u32 value); |
111 | static int cnttz(u32 word); |
112 | |
113 | static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, |
114 | int nblocks); |
115 | static int dbInitDmap(struct dmap * dp, s64 blkno, int nblocks); |
116 | static int dbInitDmapTree(struct dmap * dp); |
117 | static int dbInitTree(struct dmaptree * dtp); |
118 | static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i); |
119 | static int dbGetL2AGSize(s64 nblocks); |
120 | |
121 | /* |
122 | * buddy table |
123 | * |
124 | * table used for determining buddy sizes within characters of |
125 | * dmap bitmap words. the characters themselves serve as indexes |
126 | * into the table, with the table elements yielding the maximum |
127 | * binary buddy of free bits within the character. |
128 | */ |
129 | static const s8 budtab[256] = { |
130 | 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
131 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
132 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
133 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
134 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
135 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
136 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
137 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
138 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
139 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
140 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
141 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
142 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
143 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
144 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, |
145 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -1 |
146 | }; |
147 | |
148 | |
149 | /* |
150 | * NAME: dbMount() |
151 | * |
152 | * FUNCTION: initializate the block allocation map. |
153 | * |
154 | * memory is allocated for the in-core bmap descriptor and |
155 | * the in-core descriptor is initialized from disk. |
156 | * |
157 | * PARAMETERS: |
158 | * ipbmap - pointer to in-core inode for the block map. |
159 | * |
160 | * RETURN VALUES: |
161 | * 0 - success |
162 | * -ENOMEM - insufficient memory |
163 | * -EIO - i/o error |
164 | */ |
165 | int dbMount(struct inode *ipbmap) |
166 | { |
167 | struct bmap *bmp; |
168 | struct dbmap_disk *dbmp_le; |
169 | struct metapage *mp; |
170 | int i; |
171 | |
172 | /* |
173 | * allocate/initialize the in-memory bmap descriptor |
174 | */ |
175 | /* allocate memory for the in-memory bmap descriptor */ |
176 | bmp = kmalloc(sizeof(struct bmap), GFP_KERNEL); |
177 | if (bmp == NULL) |
178 | return -ENOMEM; |
179 | |
180 | /* read the on-disk bmap descriptor. */ |
181 | mp = read_metapage(ipbmap, |
182 | BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, |
183 | PSIZE, 0); |
184 | if (mp == NULL) { |
185 | kfree(bmp); |
186 | return -EIO; |
187 | } |
188 | |
189 | /* copy the on-disk bmap descriptor to its in-memory version. */ |
190 | dbmp_le = (struct dbmap_disk *) mp->data; |
191 | bmp->db_mapsize = le64_to_cpu(dbmp_le->dn_mapsize); |
192 | bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree); |
193 | bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage); |
194 | bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag); |
195 | bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel); |
196 | bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag); |
197 | bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref); |
198 | bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel); |
199 | bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight); |
200 | bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth); |
201 | bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart); |
202 | bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size); |
203 | for (i = 0; i < MAXAG; i++) |
204 | bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]); |
205 | bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize); |
206 | bmp->db_maxfreebud = dbmp_le->dn_maxfreebud; |
207 | |
208 | /* release the buffer. */ |
209 | release_metapage(mp); |
210 | |
211 | /* bind the bmap inode and the bmap descriptor to each other. */ |
212 | bmp->db_ipbmap = ipbmap; |
213 | JFS_SBI(ipbmap->i_sb)->bmap = bmp; |
214 | |
215 | memset(bmp->db_active, 0, sizeof(bmp->db_active)); |
216 | |
217 | /* |
218 | * allocate/initialize the bmap lock |
219 | */ |
220 | BMAP_LOCK_INIT(bmp); |
221 | |
222 | return (0); |
223 | } |
224 | |
225 | |
226 | /* |
227 | * NAME: dbUnmount() |
228 | * |
229 | * FUNCTION: terminate the block allocation map in preparation for |
230 | * file system unmount. |
231 | * |
232 | * the in-core bmap descriptor is written to disk and |
233 | * the memory for this descriptor is freed. |
234 | * |
235 | * PARAMETERS: |
236 | * ipbmap - pointer to in-core inode for the block map. |
237 | * |
238 | * RETURN VALUES: |
239 | * 0 - success |
240 | * -EIO - i/o error |
241 | */ |
242 | int dbUnmount(struct inode *ipbmap, int mounterror) |
243 | { |
244 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; |
245 | |
246 | if (!(mounterror || isReadOnly(ipbmap))) |
247 | dbSync(ipbmap); |
248 | |
249 | /* |
250 | * Invalidate the page cache buffers |
251 | */ |
252 | truncate_inode_pages(ipbmap->i_mapping, 0); |
253 | |
254 | /* free the memory for the in-memory bmap. */ |
255 | kfree(bmp); |
256 | |
257 | return (0); |
258 | } |
259 | |
260 | /* |
261 | * dbSync() |
262 | */ |
263 | int dbSync(struct inode *ipbmap) |
264 | { |
265 | struct dbmap_disk *dbmp_le; |
266 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; |
267 | struct metapage *mp; |
268 | int i; |
269 | |
270 | /* |
271 | * write bmap global control page |
272 | */ |
273 | /* get the buffer for the on-disk bmap descriptor. */ |
274 | mp = read_metapage(ipbmap, |
275 | BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, |
276 | PSIZE, 0); |
277 | if (mp == NULL) { |
278 | jfs_err("dbSync: read_metapage failed!"); |
279 | return -EIO; |
280 | } |
281 | /* copy the in-memory version of the bmap to the on-disk version */ |
282 | dbmp_le = (struct dbmap_disk *) mp->data; |
283 | dbmp_le->dn_mapsize = cpu_to_le64(bmp->db_mapsize); |
284 | dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree); |
285 | dbmp_le->dn_l2nbperpage = cpu_to_le32(bmp->db_l2nbperpage); |
286 | dbmp_le->dn_numag = cpu_to_le32(bmp->db_numag); |
287 | dbmp_le->dn_maxlevel = cpu_to_le32(bmp->db_maxlevel); |
288 | dbmp_le->dn_maxag = cpu_to_le32(bmp->db_maxag); |
289 | dbmp_le->dn_agpref = cpu_to_le32(bmp->db_agpref); |
290 | dbmp_le->dn_aglevel = cpu_to_le32(bmp->db_aglevel); |
291 | dbmp_le->dn_agheight = cpu_to_le32(bmp->db_agheight); |
292 | dbmp_le->dn_agwidth = cpu_to_le32(bmp->db_agwidth); |
293 | dbmp_le->dn_agstart = cpu_to_le32(bmp->db_agstart); |
294 | dbmp_le->dn_agl2size = cpu_to_le32(bmp->db_agl2size); |
295 | for (i = 0; i < MAXAG; i++) |
296 | dbmp_le->dn_agfree[i] = cpu_to_le64(bmp->db_agfree[i]); |
297 | dbmp_le->dn_agsize = cpu_to_le64(bmp->db_agsize); |
298 | dbmp_le->dn_maxfreebud = bmp->db_maxfreebud; |
299 | |
300 | /* write the buffer */ |
301 | write_metapage(mp); |
302 | |
303 | /* |
304 | * write out dirty pages of bmap |
305 | */ |
306 | filemap_write_and_wait(ipbmap->i_mapping); |
307 | |
308 | diWriteSpecial(ipbmap, 0); |
309 | |
310 | return (0); |
311 | } |
312 | |
313 | |
314 | /* |
315 | * NAME: dbFree() |
316 | * |
317 | * FUNCTION: free the specified block range from the working block |
318 | * allocation map. |
319 | * |
320 | * the blocks will be free from the working map one dmap |
321 | * at a time. |
322 | * |
323 | * PARAMETERS: |
324 | * ip - pointer to in-core inode; |
325 | * blkno - starting block number to be freed. |
326 | * nblocks - number of blocks to be freed. |
327 | * |
328 | * RETURN VALUES: |
329 | * 0 - success |
330 | * -EIO - i/o error |
331 | */ |
332 | int dbFree(struct inode *ip, s64 blkno, s64 nblocks) |
333 | { |
334 | struct metapage *mp; |
335 | struct dmap *dp; |
336 | int nb, rc; |
337 | s64 lblkno, rem; |
338 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; |
339 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; |
340 | |
341 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
342 | |
343 | /* block to be freed better be within the mapsize. */ |
344 | if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) { |
345 | IREAD_UNLOCK(ipbmap); |
346 | printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", |
347 | (unsigned long long) blkno, |
348 | (unsigned long long) nblocks); |
349 | jfs_error(ip->i_sb, |
350 | "dbFree: block to be freed is outside the map"); |
351 | return -EIO; |
352 | } |
353 | |
354 | /* |
355 | * free the blocks a dmap at a time. |
356 | */ |
357 | mp = NULL; |
358 | for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { |
359 | /* release previous dmap if any */ |
360 | if (mp) { |
361 | write_metapage(mp); |
362 | } |
363 | |
364 | /* get the buffer for the current dmap. */ |
365 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
366 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); |
367 | if (mp == NULL) { |
368 | IREAD_UNLOCK(ipbmap); |
369 | return -EIO; |
370 | } |
371 | dp = (struct dmap *) mp->data; |
372 | |
373 | /* determine the number of blocks to be freed from |
374 | * this dmap. |
375 | */ |
376 | nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); |
377 | |
378 | /* free the blocks. */ |
379 | if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) { |
380 | jfs_error(ip->i_sb, "dbFree: error in block map\n"); |
381 | release_metapage(mp); |
382 | IREAD_UNLOCK(ipbmap); |
383 | return (rc); |
384 | } |
385 | } |
386 | |
387 | /* write the last buffer. */ |
388 | write_metapage(mp); |
389 | |
390 | IREAD_UNLOCK(ipbmap); |
391 | |
392 | return (0); |
393 | } |
394 | |
395 | |
396 | /* |
397 | * NAME: dbUpdatePMap() |
398 | * |
399 | * FUNCTION: update the allocation state (free or allocate) of the |
400 | * specified block range in the persistent block allocation map. |
401 | * |
402 | * the blocks will be updated in the persistent map one |
403 | * dmap at a time. |
404 | * |
405 | * PARAMETERS: |
406 | * ipbmap - pointer to in-core inode for the block map. |
407 | * free - 'true' if block range is to be freed from the persistent |
408 | * map; 'false' if it is to be allocated. |
409 | * blkno - starting block number of the range. |
410 | * nblocks - number of contiguous blocks in the range. |
411 | * tblk - transaction block; |
412 | * |
413 | * RETURN VALUES: |
414 | * 0 - success |
415 | * -EIO - i/o error |
416 | */ |
417 | int |
418 | dbUpdatePMap(struct inode *ipbmap, |
419 | int free, s64 blkno, s64 nblocks, struct tblock * tblk) |
420 | { |
421 | int nblks, dbitno, wbitno, rbits; |
422 | int word, nbits, nwords; |
423 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; |
424 | s64 lblkno, rem, lastlblkno; |
425 | u32 mask; |
426 | struct dmap *dp; |
427 | struct metapage *mp; |
428 | struct jfs_log *log; |
429 | int lsn, difft, diffp; |
430 | unsigned long flags; |
431 | |
432 | /* the blocks better be within the mapsize. */ |
433 | if (blkno + nblocks > bmp->db_mapsize) { |
434 | printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", |
435 | (unsigned long long) blkno, |
436 | (unsigned long long) nblocks); |
437 | jfs_error(ipbmap->i_sb, |
438 | "dbUpdatePMap: blocks are outside the map"); |
439 | return -EIO; |
440 | } |
441 | |
442 | /* compute delta of transaction lsn from log syncpt */ |
443 | lsn = tblk->lsn; |
444 | log = (struct jfs_log *) JFS_SBI(tblk->sb)->log; |
445 | logdiff(difft, lsn, log); |
446 | |
447 | /* |
448 | * update the block state a dmap at a time. |
449 | */ |
450 | mp = NULL; |
451 | lastlblkno = 0; |
452 | for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) { |
453 | /* get the buffer for the current dmap. */ |
454 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
455 | if (lblkno != lastlblkno) { |
456 | if (mp) { |
457 | write_metapage(mp); |
458 | } |
459 | |
460 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, |
461 | 0); |
462 | if (mp == NULL) |
463 | return -EIO; |
464 | metapage_wait_for_io(mp); |
465 | } |
466 | dp = (struct dmap *) mp->data; |
467 | |
468 | /* determine the bit number and word within the dmap of |
469 | * the starting block. also determine how many blocks |
470 | * are to be updated within this dmap. |
471 | */ |
472 | dbitno = blkno & (BPERDMAP - 1); |
473 | word = dbitno >> L2DBWORD; |
474 | nblks = min(rem, (s64)BPERDMAP - dbitno); |
475 | |
476 | /* update the bits of the dmap words. the first and last |
477 | * words may only have a subset of their bits updated. if |
478 | * this is the case, we'll work against that word (i.e. |
479 | * partial first and/or last) only in a single pass. a |
480 | * single pass will also be used to update all words that |
481 | * are to have all their bits updated. |
482 | */ |
483 | for (rbits = nblks; rbits > 0; |
484 | rbits -= nbits, dbitno += nbits) { |
485 | /* determine the bit number within the word and |
486 | * the number of bits within the word. |
487 | */ |
488 | wbitno = dbitno & (DBWORD - 1); |
489 | nbits = min(rbits, DBWORD - wbitno); |
490 | |
491 | /* check if only part of the word is to be updated. */ |
492 | if (nbits < DBWORD) { |
493 | /* update (free or allocate) the bits |
494 | * in this word. |
495 | */ |
496 | mask = |
497 | (ONES << (DBWORD - nbits) >> wbitno); |
498 | if (free) |
499 | dp->pmap[word] &= |
500 | cpu_to_le32(~mask); |
501 | else |
502 | dp->pmap[word] |= |
503 | cpu_to_le32(mask); |
504 | |
505 | word += 1; |
506 | } else { |
507 | /* one or more words are to have all |
508 | * their bits updated. determine how |
509 | * many words and how many bits. |
510 | */ |
511 | nwords = rbits >> L2DBWORD; |
512 | nbits = nwords << L2DBWORD; |
513 | |
514 | /* update (free or allocate) the bits |
515 | * in these words. |
516 | */ |
517 | if (free) |
518 | memset(&dp->pmap[word], 0, |
519 | nwords * 4); |
520 | else |
521 | memset(&dp->pmap[word], (int) ONES, |
522 | nwords * 4); |
523 | |
524 | word += nwords; |
525 | } |
526 | } |
527 | |
528 | /* |
529 | * update dmap lsn |
530 | */ |
531 | if (lblkno == lastlblkno) |
532 | continue; |
533 | |
534 | lastlblkno = lblkno; |
535 | |
536 | LOGSYNC_LOCK(log, flags); |
537 | if (mp->lsn != 0) { |
538 | /* inherit older/smaller lsn */ |
539 | logdiff(diffp, mp->lsn, log); |
540 | if (difft < diffp) { |
541 | mp->lsn = lsn; |
542 | |
543 | /* move bp after tblock in logsync list */ |
544 | list_move(&mp->synclist, &tblk->synclist); |
545 | } |
546 | |
547 | /* inherit younger/larger clsn */ |
548 | logdiff(difft, tblk->clsn, log); |
549 | logdiff(diffp, mp->clsn, log); |
550 | if (difft > diffp) |
551 | mp->clsn = tblk->clsn; |
552 | } else { |
553 | mp->log = log; |
554 | mp->lsn = lsn; |
555 | |
556 | /* insert bp after tblock in logsync list */ |
557 | log->count++; |
558 | list_add(&mp->synclist, &tblk->synclist); |
559 | |
560 | mp->clsn = tblk->clsn; |
561 | } |
562 | LOGSYNC_UNLOCK(log, flags); |
563 | } |
564 | |
565 | /* write the last buffer. */ |
566 | if (mp) { |
567 | write_metapage(mp); |
568 | } |
569 | |
570 | return (0); |
571 | } |
572 | |
573 | |
574 | /* |
575 | * NAME: dbNextAG() |
576 | * |
577 | * FUNCTION: find the preferred allocation group for new allocations. |
578 | * |
579 | * Within the allocation groups, we maintain a preferred |
580 | * allocation group which consists of a group with at least |
581 | * average free space. It is the preferred group that we target |
582 | * new inode allocation towards. The tie-in between inode |
583 | * allocation and block allocation occurs as we allocate the |
584 | * first (data) block of an inode and specify the inode (block) |
585 | * as the allocation hint for this block. |
586 | * |
587 | * We try to avoid having more than one open file growing in |
588 | * an allocation group, as this will lead to fragmentation. |
589 | * This differs from the old OS/2 method of trying to keep |
590 | * empty ags around for large allocations. |
591 | * |
592 | * PARAMETERS: |
593 | * ipbmap - pointer to in-core inode for the block map. |
594 | * |
595 | * RETURN VALUES: |
596 | * the preferred allocation group number. |
597 | */ |
598 | int dbNextAG(struct inode *ipbmap) |
599 | { |
600 | s64 avgfree; |
601 | int agpref; |
602 | s64 hwm = 0; |
603 | int i; |
604 | int next_best = -1; |
605 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; |
606 | |
607 | BMAP_LOCK(bmp); |
608 | |
609 | /* determine the average number of free blocks within the ags. */ |
610 | avgfree = (u32)bmp->db_nfree / bmp->db_numag; |
611 | |
612 | /* |
613 | * if the current preferred ag does not have an active allocator |
614 | * and has at least average freespace, return it |
615 | */ |
616 | agpref = bmp->db_agpref; |
617 | if ((atomic_read(&bmp->db_active[agpref]) == 0) && |
618 | (bmp->db_agfree[agpref] >= avgfree)) |
619 | goto unlock; |
620 | |
621 | /* From the last preferred ag, find the next one with at least |
622 | * average free space. |
623 | */ |
624 | for (i = 0 ; i < bmp->db_numag; i++, agpref++) { |
625 | if (agpref == bmp->db_numag) |
626 | agpref = 0; |
627 | |
628 | if (atomic_read(&bmp->db_active[agpref])) |
629 | /* open file is currently growing in this ag */ |
630 | continue; |
631 | if (bmp->db_agfree[agpref] >= avgfree) { |
632 | /* Return this one */ |
633 | bmp->db_agpref = agpref; |
634 | goto unlock; |
635 | } else if (bmp->db_agfree[agpref] > hwm) { |
636 | /* Less than avg. freespace, but best so far */ |
637 | hwm = bmp->db_agfree[agpref]; |
638 | next_best = agpref; |
639 | } |
640 | } |
641 | |
642 | /* |
643 | * If no inactive ag was found with average freespace, use the |
644 | * next best |
645 | */ |
646 | if (next_best != -1) |
647 | bmp->db_agpref = next_best; |
648 | /* else leave db_agpref unchanged */ |
649 | unlock: |
650 | BMAP_UNLOCK(bmp); |
651 | |
652 | /* return the preferred group. |
653 | */ |
654 | return (bmp->db_agpref); |
655 | } |
656 | |
657 | /* |
658 | * NAME: dbAlloc() |
659 | * |
660 | * FUNCTION: attempt to allocate a specified number of contiguous free |
661 | * blocks from the working allocation block map. |
662 | * |
663 | * the block allocation policy uses hints and a multi-step |
664 | * approach. |
665 | * |
666 | * for allocation requests smaller than the number of blocks |
667 | * per dmap, we first try to allocate the new blocks |
668 | * immediately following the hint. if these blocks are not |
669 | * available, we try to allocate blocks near the hint. if |
670 | * no blocks near the hint are available, we next try to |
671 | * allocate within the same dmap as contains the hint. |
672 | * |
673 | * if no blocks are available in the dmap or the allocation |
674 | * request is larger than the dmap size, we try to allocate |
675 | * within the same allocation group as contains the hint. if |
676 | * this does not succeed, we finally try to allocate anywhere |
677 | * within the aggregate. |
678 | * |
679 | * we also try to allocate anywhere within the aggregate for |
680 | * for allocation requests larger than the allocation group |
681 | * size or requests that specify no hint value. |
682 | * |
683 | * PARAMETERS: |
684 | * ip - pointer to in-core inode; |
685 | * hint - allocation hint. |
686 | * nblocks - number of contiguous blocks in the range. |
687 | * results - on successful return, set to the starting block number |
688 | * of the newly allocated contiguous range. |
689 | * |
690 | * RETURN VALUES: |
691 | * 0 - success |
692 | * -ENOSPC - insufficient disk resources |
693 | * -EIO - i/o error |
694 | */ |
695 | int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results) |
696 | { |
697 | int rc, agno; |
698 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; |
699 | struct bmap *bmp; |
700 | struct metapage *mp; |
701 | s64 lblkno, blkno; |
702 | struct dmap *dp; |
703 | int l2nb; |
704 | s64 mapSize; |
705 | int writers; |
706 | |
707 | /* assert that nblocks is valid */ |
708 | assert(nblocks > 0); |
709 | |
710 | /* get the log2 number of blocks to be allocated. |
711 | * if the number of blocks is not a log2 multiple, |
712 | * it will be rounded up to the next log2 multiple. |
713 | */ |
714 | l2nb = BLKSTOL2(nblocks); |
715 | |
716 | bmp = JFS_SBI(ip->i_sb)->bmap; |
717 | |
718 | mapSize = bmp->db_mapsize; |
719 | |
720 | /* the hint should be within the map */ |
721 | if (hint >= mapSize) { |
722 | jfs_error(ip->i_sb, "dbAlloc: the hint is outside the map"); |
723 | return -EIO; |
724 | } |
725 | |
726 | /* if the number of blocks to be allocated is greater than the |
727 | * allocation group size, try to allocate anywhere. |
728 | */ |
729 | if (l2nb > bmp->db_agl2size) { |
730 | IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
731 | |
732 | rc = dbAllocAny(bmp, nblocks, l2nb, results); |
733 | |
734 | goto write_unlock; |
735 | } |
736 | |
737 | /* |
738 | * If no hint, let dbNextAG recommend an allocation group |
739 | */ |
740 | if (hint == 0) |
741 | goto pref_ag; |
742 | |
743 | /* we would like to allocate close to the hint. adjust the |
744 | * hint to the block following the hint since the allocators |
745 | * will start looking for free space starting at this point. |
746 | */ |
747 | blkno = hint + 1; |
748 | |
749 | if (blkno >= bmp->db_mapsize) |
750 | goto pref_ag; |
751 | |
752 | agno = blkno >> bmp->db_agl2size; |
753 | |
754 | /* check if blkno crosses over into a new allocation group. |
755 | * if so, check if we should allow allocations within this |
756 | * allocation group. |
757 | */ |
758 | if ((blkno & (bmp->db_agsize - 1)) == 0) |
759 | /* check if the AG is currently being written to. |
760 | * if so, call dbNextAG() to find a non-busy |
761 | * AG with sufficient free space. |
762 | */ |
763 | if (atomic_read(&bmp->db_active[agno])) |
764 | goto pref_ag; |
765 | |
766 | /* check if the allocation request size can be satisfied from a |
767 | * single dmap. if so, try to allocate from the dmap containing |
768 | * the hint using a tiered strategy. |
769 | */ |
770 | if (nblocks <= BPERDMAP) { |
771 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
772 | |
773 | /* get the buffer for the dmap containing the hint. |
774 | */ |
775 | rc = -EIO; |
776 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
777 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); |
778 | if (mp == NULL) |
779 | goto read_unlock; |
780 | |
781 | dp = (struct dmap *) mp->data; |
782 | |
783 | /* first, try to satisfy the allocation request with the |
784 | * blocks beginning at the hint. |
785 | */ |
786 | if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks)) |
787 | != -ENOSPC) { |
788 | if (rc == 0) { |
789 | *results = blkno; |
790 | mark_metapage_dirty(mp); |
791 | } |
792 | |
793 | release_metapage(mp); |
794 | goto read_unlock; |
795 | } |
796 | |
797 | writers = atomic_read(&bmp->db_active[agno]); |
798 | if ((writers > 1) || |
799 | ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) { |
800 | /* |
801 | * Someone else is writing in this allocation |
802 | * group. To avoid fragmenting, try another ag |
803 | */ |
804 | release_metapage(mp); |
805 | IREAD_UNLOCK(ipbmap); |
806 | goto pref_ag; |
807 | } |
808 | |
809 | /* next, try to satisfy the allocation request with blocks |
810 | * near the hint. |
811 | */ |
812 | if ((rc = |
813 | dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results)) |
814 | != -ENOSPC) { |
815 | if (rc == 0) |
816 | mark_metapage_dirty(mp); |
817 | |
818 | release_metapage(mp); |
819 | goto read_unlock; |
820 | } |
821 | |
822 | /* try to satisfy the allocation request with blocks within |
823 | * the same dmap as the hint. |
824 | */ |
825 | if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results)) |
826 | != -ENOSPC) { |
827 | if (rc == 0) |
828 | mark_metapage_dirty(mp); |
829 | |
830 | release_metapage(mp); |
831 | goto read_unlock; |
832 | } |
833 | |
834 | release_metapage(mp); |
835 | IREAD_UNLOCK(ipbmap); |
836 | } |
837 | |
838 | /* try to satisfy the allocation request with blocks within |
839 | * the same allocation group as the hint. |
840 | */ |
841 | IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
842 | if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC) |
843 | goto write_unlock; |
844 | |
845 | IWRITE_UNLOCK(ipbmap); |
846 | |
847 | |
848 | pref_ag: |
849 | /* |
850 | * Let dbNextAG recommend a preferred allocation group |
851 | */ |
852 | agno = dbNextAG(ipbmap); |
853 | IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
854 | |
855 | /* Try to allocate within this allocation group. if that fails, try to |
856 | * allocate anywhere in the map. |
857 | */ |
858 | if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC) |
859 | rc = dbAllocAny(bmp, nblocks, l2nb, results); |
860 | |
861 | write_unlock: |
862 | IWRITE_UNLOCK(ipbmap); |
863 | |
864 | return (rc); |
865 | |
866 | read_unlock: |
867 | IREAD_UNLOCK(ipbmap); |
868 | |
869 | return (rc); |
870 | } |
871 | |
872 | #ifdef _NOTYET |
873 | /* |
874 | * NAME: dbAllocExact() |
875 | * |
876 | * FUNCTION: try to allocate the requested extent; |
877 | * |
878 | * PARAMETERS: |
879 | * ip - pointer to in-core inode; |
880 | * blkno - extent address; |
881 | * nblocks - extent length; |
882 | * |
883 | * RETURN VALUES: |
884 | * 0 - success |
885 | * -ENOSPC - insufficient disk resources |
886 | * -EIO - i/o error |
887 | */ |
888 | int dbAllocExact(struct inode *ip, s64 blkno, int nblocks) |
889 | { |
890 | int rc; |
891 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; |
892 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; |
893 | struct dmap *dp; |
894 | s64 lblkno; |
895 | struct metapage *mp; |
896 | |
897 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
898 | |
899 | /* |
900 | * validate extent request: |
901 | * |
902 | * note: defragfs policy: |
903 | * max 64 blocks will be moved. |
904 | * allocation request size must be satisfied from a single dmap. |
905 | */ |
906 | if (nblocks <= 0 || nblocks > BPERDMAP || blkno >= bmp->db_mapsize) { |
907 | IREAD_UNLOCK(ipbmap); |
908 | return -EINVAL; |
909 | } |
910 | |
911 | if (nblocks > ((s64) 1 << bmp->db_maxfreebud)) { |
912 | /* the free space is no longer available */ |
913 | IREAD_UNLOCK(ipbmap); |
914 | return -ENOSPC; |
915 | } |
916 | |
917 | /* read in the dmap covering the extent */ |
918 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
919 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); |
920 | if (mp == NULL) { |
921 | IREAD_UNLOCK(ipbmap); |
922 | return -EIO; |
923 | } |
924 | dp = (struct dmap *) mp->data; |
925 | |
926 | /* try to allocate the requested extent */ |
927 | rc = dbAllocNext(bmp, dp, blkno, nblocks); |
928 | |
929 | IREAD_UNLOCK(ipbmap); |
930 | |
931 | if (rc == 0) |
932 | mark_metapage_dirty(mp); |
933 | |
934 | release_metapage(mp); |
935 | |
936 | return (rc); |
937 | } |
938 | #endif /* _NOTYET */ |
939 | |
940 | /* |
941 | * NAME: dbReAlloc() |
942 | * |
943 | * FUNCTION: attempt to extend a current allocation by a specified |
944 | * number of blocks. |
945 | * |
946 | * this routine attempts to satisfy the allocation request |
947 | * by first trying to extend the existing allocation in |
948 | * place by allocating the additional blocks as the blocks |
949 | * immediately following the current allocation. if these |
950 | * blocks are not available, this routine will attempt to |
951 | * allocate a new set of contiguous blocks large enough |
952 | * to cover the existing allocation plus the additional |
953 | * number of blocks required. |
954 | * |
955 | * PARAMETERS: |
956 | * ip - pointer to in-core inode requiring allocation. |
957 | * blkno - starting block of the current allocation. |
958 | * nblocks - number of contiguous blocks within the current |
959 | * allocation. |
960 | * addnblocks - number of blocks to add to the allocation. |
961 | * results - on successful return, set to the starting block number |
962 | * of the existing allocation if the existing allocation |
963 | * was extended in place or to a newly allocated contiguous |
964 | * range if the existing allocation could not be extended |
965 | * in place. |
966 | * |
967 | * RETURN VALUES: |
968 | * 0 - success |
969 | * -ENOSPC - insufficient disk resources |
970 | * -EIO - i/o error |
971 | */ |
972 | int |
973 | dbReAlloc(struct inode *ip, |
974 | s64 blkno, s64 nblocks, s64 addnblocks, s64 * results) |
975 | { |
976 | int rc; |
977 | |
978 | /* try to extend the allocation in place. |
979 | */ |
980 | if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) { |
981 | *results = blkno; |
982 | return (0); |
983 | } else { |
984 | if (rc != -ENOSPC) |
985 | return (rc); |
986 | } |
987 | |
988 | /* could not extend the allocation in place, so allocate a |
989 | * new set of blocks for the entire request (i.e. try to get |
990 | * a range of contiguous blocks large enough to cover the |
991 | * existing allocation plus the additional blocks.) |
992 | */ |
993 | return (dbAlloc |
994 | (ip, blkno + nblocks - 1, addnblocks + nblocks, results)); |
995 | } |
996 | |
997 | |
998 | /* |
999 | * NAME: dbExtend() |
1000 | * |
1001 | * FUNCTION: attempt to extend a current allocation by a specified |
1002 | * number of blocks. |
1003 | * |
1004 | * this routine attempts to satisfy the allocation request |
1005 | * by first trying to extend the existing allocation in |
1006 | * place by allocating the additional blocks as the blocks |
1007 | * immediately following the current allocation. |
1008 | * |
1009 | * PARAMETERS: |
1010 | * ip - pointer to in-core inode requiring allocation. |
1011 | * blkno - starting block of the current allocation. |
1012 | * nblocks - number of contiguous blocks within the current |
1013 | * allocation. |
1014 | * addnblocks - number of blocks to add to the allocation. |
1015 | * |
1016 | * RETURN VALUES: |
1017 | * 0 - success |
1018 | * -ENOSPC - insufficient disk resources |
1019 | * -EIO - i/o error |
1020 | */ |
1021 | static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks) |
1022 | { |
1023 | struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb); |
1024 | s64 lblkno, lastblkno, extblkno; |
1025 | uint rel_block; |
1026 | struct metapage *mp; |
1027 | struct dmap *dp; |
1028 | int rc; |
1029 | struct inode *ipbmap = sbi->ipbmap; |
1030 | struct bmap *bmp; |
1031 | |
1032 | /* |
1033 | * We don't want a non-aligned extent to cross a page boundary |
1034 | */ |
1035 | if (((rel_block = blkno & (sbi->nbperpage - 1))) && |
1036 | (rel_block + nblocks + addnblocks > sbi->nbperpage)) |
1037 | return -ENOSPC; |
1038 | |
1039 | /* get the last block of the current allocation */ |
1040 | lastblkno = blkno + nblocks - 1; |
1041 | |
1042 | /* determine the block number of the block following |
1043 | * the existing allocation. |
1044 | */ |
1045 | extblkno = lastblkno + 1; |
1046 | |
1047 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
1048 | |
1049 | /* better be within the file system */ |
1050 | bmp = sbi->bmap; |
1051 | if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) { |
1052 | IREAD_UNLOCK(ipbmap); |
1053 | jfs_error(ip->i_sb, |
1054 | "dbExtend: the block is outside the filesystem"); |
1055 | return -EIO; |
1056 | } |
1057 | |
1058 | /* we'll attempt to extend the current allocation in place by |
1059 | * allocating the additional blocks as the blocks immediately |
1060 | * following the current allocation. we only try to extend the |
1061 | * current allocation in place if the number of additional blocks |
1062 | * can fit into a dmap, the last block of the current allocation |
1063 | * is not the last block of the file system, and the start of the |
1064 | * inplace extension is not on an allocation group boundary. |
1065 | */ |
1066 | if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize || |
1067 | (extblkno & (bmp->db_agsize - 1)) == 0) { |
1068 | IREAD_UNLOCK(ipbmap); |
1069 | return -ENOSPC; |
1070 | } |
1071 | |
1072 | /* get the buffer for the dmap containing the first block |
1073 | * of the extension. |
1074 | */ |
1075 | lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage); |
1076 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); |
1077 | if (mp == NULL) { |
1078 | IREAD_UNLOCK(ipbmap); |
1079 | return -EIO; |
1080 | } |
1081 | |
1082 | dp = (struct dmap *) mp->data; |
1083 | |
1084 | /* try to allocate the blocks immediately following the |
1085 | * current allocation. |
1086 | */ |
1087 | rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks); |
1088 | |
1089 | IREAD_UNLOCK(ipbmap); |
1090 | |
1091 | /* were we successful ? */ |
1092 | if (rc == 0) |
1093 | write_metapage(mp); |
1094 | else |
1095 | /* we were not successful */ |
1096 | release_metapage(mp); |
1097 | |
1098 | |
1099 | return (rc); |
1100 | } |
1101 | |
1102 | |
1103 | /* |
1104 | * NAME: dbAllocNext() |
1105 | * |
1106 | * FUNCTION: attempt to allocate the blocks of the specified block |
1107 | * range within a dmap. |
1108 | * |
1109 | * PARAMETERS: |
1110 | * bmp - pointer to bmap descriptor |
1111 | * dp - pointer to dmap. |
1112 | * blkno - starting block number of the range. |
1113 | * nblocks - number of contiguous free blocks of the range. |
1114 | * |
1115 | * RETURN VALUES: |
1116 | * 0 - success |
1117 | * -ENOSPC - insufficient disk resources |
1118 | * -EIO - i/o error |
1119 | * |
1120 | * serialization: IREAD_LOCK(ipbmap) held on entry/exit; |
1121 | */ |
1122 | static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, |
1123 | int nblocks) |
1124 | { |
1125 | int dbitno, word, rembits, nb, nwords, wbitno, nw; |
1126 | int l2size; |
1127 | s8 *leaf; |
1128 | u32 mask; |
1129 | |
1130 | if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { |
1131 | jfs_error(bmp->db_ipbmap->i_sb, |
1132 | "dbAllocNext: Corrupt dmap page"); |
1133 | return -EIO; |
1134 | } |
1135 | |
1136 | /* pick up a pointer to the leaves of the dmap tree. |
1137 | */ |
1138 | leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); |
1139 | |
1140 | /* determine the bit number and word within the dmap of the |
1141 | * starting block. |
1142 | */ |
1143 | dbitno = blkno & (BPERDMAP - 1); |
1144 | word = dbitno >> L2DBWORD; |
1145 | |
1146 | /* check if the specified block range is contained within |
1147 | * this dmap. |
1148 | */ |
1149 | if (dbitno + nblocks > BPERDMAP) |
1150 | return -ENOSPC; |
1151 | |
1152 | /* check if the starting leaf indicates that anything |
1153 | * is free. |
1154 | */ |
1155 | if (leaf[word] == NOFREE) |
1156 | return -ENOSPC; |
1157 | |
1158 | /* check the dmaps words corresponding to block range to see |
1159 | * if the block range is free. not all bits of the first and |
1160 | * last words may be contained within the block range. if this |
1161 | * is the case, we'll work against those words (i.e. partial first |
1162 | * and/or last) on an individual basis (a single pass) and examine |
1163 | * the actual bits to determine if they are free. a single pass |
1164 | * will be used for all dmap words fully contained within the |
1165 | * specified range. within this pass, the leaves of the dmap |
1166 | * tree will be examined to determine if the blocks are free. a |
1167 | * single leaf may describe the free space of multiple dmap |
1168 | * words, so we may visit only a subset of the actual leaves |
1169 | * corresponding to the dmap words of the block range. |
1170 | */ |
1171 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { |
1172 | /* determine the bit number within the word and |
1173 | * the number of bits within the word. |
1174 | */ |
1175 | wbitno = dbitno & (DBWORD - 1); |
1176 | nb = min(rembits, DBWORD - wbitno); |
1177 | |
1178 | /* check if only part of the word is to be examined. |
1179 | */ |
1180 | if (nb < DBWORD) { |
1181 | /* check if the bits are free. |
1182 | */ |
1183 | mask = (ONES << (DBWORD - nb) >> wbitno); |
1184 | if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask) |
1185 | return -ENOSPC; |
1186 | |
1187 | word += 1; |
1188 | } else { |
1189 | /* one or more dmap words are fully contained |
1190 | * within the block range. determine how many |
1191 | * words and how many bits. |
1192 | */ |
1193 | nwords = rembits >> L2DBWORD; |
1194 | nb = nwords << L2DBWORD; |
1195 | |
1196 | /* now examine the appropriate leaves to determine |
1197 | * if the blocks are free. |
1198 | */ |
1199 | while (nwords > 0) { |
1200 | /* does the leaf describe any free space ? |
1201 | */ |
1202 | if (leaf[word] < BUDMIN) |
1203 | return -ENOSPC; |
1204 | |
1205 | /* determine the l2 number of bits provided |
1206 | * by this leaf. |
1207 | */ |
1208 | l2size = |
1209 | min((int)leaf[word], NLSTOL2BSZ(nwords)); |
1210 | |
1211 | /* determine how many words were handled. |
1212 | */ |
1213 | nw = BUDSIZE(l2size, BUDMIN); |
1214 | |
1215 | nwords -= nw; |
1216 | word += nw; |
1217 | } |
1218 | } |
1219 | } |
1220 | |
1221 | /* allocate the blocks. |
1222 | */ |
1223 | return (dbAllocDmap(bmp, dp, blkno, nblocks)); |
1224 | } |
1225 | |
1226 | |
1227 | /* |
1228 | * NAME: dbAllocNear() |
1229 | * |
1230 | * FUNCTION: attempt to allocate a number of contiguous free blocks near |
1231 | * a specified block (hint) within a dmap. |
1232 | * |
1233 | * starting with the dmap leaf that covers the hint, we'll |
1234 | * check the next four contiguous leaves for sufficient free |
1235 | * space. if sufficient free space is found, we'll allocate |
1236 | * the desired free space. |
1237 | * |
1238 | * PARAMETERS: |
1239 | * bmp - pointer to bmap descriptor |
1240 | * dp - pointer to dmap. |
1241 | * blkno - block number to allocate near. |
1242 | * nblocks - actual number of contiguous free blocks desired. |
1243 | * l2nb - log2 number of contiguous free blocks desired. |
1244 | * results - on successful return, set to the starting block number |
1245 | * of the newly allocated range. |
1246 | * |
1247 | * RETURN VALUES: |
1248 | * 0 - success |
1249 | * -ENOSPC - insufficient disk resources |
1250 | * -EIO - i/o error |
1251 | * |
1252 | * serialization: IREAD_LOCK(ipbmap) held on entry/exit; |
1253 | */ |
1254 | static int |
1255 | dbAllocNear(struct bmap * bmp, |
1256 | struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results) |
1257 | { |
1258 | int word, lword, rc; |
1259 | s8 *leaf; |
1260 | |
1261 | if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { |
1262 | jfs_error(bmp->db_ipbmap->i_sb, |
1263 | "dbAllocNear: Corrupt dmap page"); |
1264 | return -EIO; |
1265 | } |
1266 | |
1267 | leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); |
1268 | |
1269 | /* determine the word within the dmap that holds the hint |
1270 | * (i.e. blkno). also, determine the last word in the dmap |
1271 | * that we'll include in our examination. |
1272 | */ |
1273 | word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; |
1274 | lword = min(word + 4, LPERDMAP); |
1275 | |
1276 | /* examine the leaves for sufficient free space. |
1277 | */ |
1278 | for (; word < lword; word++) { |
1279 | /* does the leaf describe sufficient free space ? |
1280 | */ |
1281 | if (leaf[word] < l2nb) |
1282 | continue; |
1283 | |
1284 | /* determine the block number within the file system |
1285 | * of the first block described by this dmap word. |
1286 | */ |
1287 | blkno = le64_to_cpu(dp->start) + (word << L2DBWORD); |
1288 | |
1289 | /* if not all bits of the dmap word are free, get the |
1290 | * starting bit number within the dmap word of the required |
1291 | * string of free bits and adjust the block number with the |
1292 | * value. |
1293 | */ |
1294 | if (leaf[word] < BUDMIN) |
1295 | blkno += |
1296 | dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb); |
1297 | |
1298 | /* allocate the blocks. |
1299 | */ |
1300 | if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) |
1301 | *results = blkno; |
1302 | |
1303 | return (rc); |
1304 | } |
1305 | |
1306 | return -ENOSPC; |
1307 | } |
1308 | |
1309 | |
1310 | /* |
1311 | * NAME: dbAllocAG() |
1312 | * |
1313 | * FUNCTION: attempt to allocate the specified number of contiguous |
1314 | * free blocks within the specified allocation group. |
1315 | * |
1316 | * unless the allocation group size is equal to the number |
1317 | * of blocks per dmap, the dmap control pages will be used to |
1318 | * find the required free space, if available. we start the |
1319 | * search at the highest dmap control page level which |
1320 | * distinctly describes the allocation group's free space |
1321 | * (i.e. the highest level at which the allocation group's |
1322 | * free space is not mixed in with that of any other group). |
1323 | * in addition, we start the search within this level at a |
1324 | * height of the dmapctl dmtree at which the nodes distinctly |
1325 | * describe the allocation group's free space. at this height, |
1326 | * the allocation group's free space may be represented by 1 |
1327 | * or two sub-trees, depending on the allocation group size. |
1328 | * we search the top nodes of these subtrees left to right for |
1329 | * sufficient free space. if sufficient free space is found, |
1330 | * the subtree is searched to find the leftmost leaf that |
1331 | * has free space. once we have made it to the leaf, we |
1332 | * move the search to the next lower level dmap control page |
1333 | * corresponding to this leaf. we continue down the dmap control |
1334 | * pages until we find the dmap that contains or starts the |
1335 | * sufficient free space and we allocate at this dmap. |
1336 | * |
1337 | * if the allocation group size is equal to the dmap size, |
1338 | * we'll start at the dmap corresponding to the allocation |
1339 | * group and attempt the allocation at this level. |
1340 | * |
1341 | * the dmap control page search is also not performed if the |
1342 | * allocation group is completely free and we go to the first |
1343 | * dmap of the allocation group to do the allocation. this is |
1344 | * done because the allocation group may be part (not the first |
1345 | * part) of a larger binary buddy system, causing the dmap |
1346 | * control pages to indicate no free space (NOFREE) within |
1347 | * the allocation group. |
1348 | * |
1349 | * PARAMETERS: |
1350 | * bmp - pointer to bmap descriptor |
1351 | * agno - allocation group number. |
1352 | * nblocks - actual number of contiguous free blocks desired. |
1353 | * l2nb - log2 number of contiguous free blocks desired. |
1354 | * results - on successful return, set to the starting block number |
1355 | * of the newly allocated range. |
1356 | * |
1357 | * RETURN VALUES: |
1358 | * 0 - success |
1359 | * -ENOSPC - insufficient disk resources |
1360 | * -EIO - i/o error |
1361 | * |
1362 | * note: IWRITE_LOCK(ipmap) held on entry/exit; |
1363 | */ |
1364 | static int |
1365 | dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results) |
1366 | { |
1367 | struct metapage *mp; |
1368 | struct dmapctl *dcp; |
1369 | int rc, ti, i, k, m, n, agperlev; |
1370 | s64 blkno, lblkno; |
1371 | int budmin; |
1372 | |
1373 | /* allocation request should not be for more than the |
1374 | * allocation group size. |
1375 | */ |
1376 | if (l2nb > bmp->db_agl2size) { |
1377 | jfs_error(bmp->db_ipbmap->i_sb, |
1378 | "dbAllocAG: allocation request is larger than the " |
1379 | "allocation group size"); |
1380 | return -EIO; |
1381 | } |
1382 | |
1383 | /* determine the starting block number of the allocation |
1384 | * group. |
1385 | */ |
1386 | blkno = (s64) agno << bmp->db_agl2size; |
1387 | |
1388 | /* check if the allocation group size is the minimum allocation |
1389 | * group size or if the allocation group is completely free. if |
1390 | * the allocation group size is the minimum size of BPERDMAP (i.e. |
1391 | * 1 dmap), there is no need to search the dmap control page (below) |
1392 | * that fully describes the allocation group since the allocation |
1393 | * group is already fully described by a dmap. in this case, we |
1394 | * just call dbAllocCtl() to search the dmap tree and allocate the |
1395 | * required space if available. |
1396 | * |
1397 | * if the allocation group is completely free, dbAllocCtl() is |
1398 | * also called to allocate the required space. this is done for |
1399 | * two reasons. first, it makes no sense searching the dmap control |
1400 | * pages for free space when we know that free space exists. second, |
1401 | * the dmap control pages may indicate that the allocation group |
1402 | * has no free space if the allocation group is part (not the first |
1403 | * part) of a larger binary buddy system. |
1404 | */ |
1405 | if (bmp->db_agsize == BPERDMAP |
1406 | || bmp->db_agfree[agno] == bmp->db_agsize) { |
1407 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); |
1408 | if ((rc == -ENOSPC) && |
1409 | (bmp->db_agfree[agno] == bmp->db_agsize)) { |
1410 | printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n", |
1411 | (unsigned long long) blkno, |
1412 | (unsigned long long) nblocks); |
1413 | jfs_error(bmp->db_ipbmap->i_sb, |
1414 | "dbAllocAG: dbAllocCtl failed in free AG"); |
1415 | } |
1416 | return (rc); |
1417 | } |
1418 | |
1419 | /* the buffer for the dmap control page that fully describes the |
1420 | * allocation group. |
1421 | */ |
1422 | lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel); |
1423 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
1424 | if (mp == NULL) |
1425 | return -EIO; |
1426 | dcp = (struct dmapctl *) mp->data; |
1427 | budmin = dcp->budmin; |
1428 | |
1429 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { |
1430 | jfs_error(bmp->db_ipbmap->i_sb, |
1431 | "dbAllocAG: Corrupt dmapctl page"); |
1432 | release_metapage(mp); |
1433 | return -EIO; |
1434 | } |
1435 | |
1436 | /* search the subtree(s) of the dmap control page that describes |
1437 | * the allocation group, looking for sufficient free space. to begin, |
1438 | * determine how many allocation groups are represented in a dmap |
1439 | * control page at the control page level (i.e. L0, L1, L2) that |
1440 | * fully describes an allocation group. next, determine the starting |
1441 | * tree index of this allocation group within the control page. |
1442 | */ |
1443 | agperlev = |
1444 | (1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth; |
1445 | ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1)); |
1446 | |
1447 | /* dmap control page trees fan-out by 4 and a single allocation |
1448 | * group may be described by 1 or 2 subtrees within the ag level |
1449 | * dmap control page, depending upon the ag size. examine the ag's |
1450 | * subtrees for sufficient free space, starting with the leftmost |
1451 | * subtree. |
1452 | */ |
1453 | for (i = 0; i < bmp->db_agwidth; i++, ti++) { |
1454 | /* is there sufficient free space ? |
1455 | */ |
1456 | if (l2nb > dcp->stree[ti]) |
1457 | continue; |
1458 | |
1459 | /* sufficient free space found in a subtree. now search down |
1460 | * the subtree to find the leftmost leaf that describes this |
1461 | * free space. |
1462 | */ |
1463 | for (k = bmp->db_agheight; k > 0; k--) { |
1464 | for (n = 0, m = (ti << 2) + 1; n < 4; n++) { |
1465 | if (l2nb <= dcp->stree[m + n]) { |
1466 | ti = m + n; |
1467 | break; |
1468 | } |
1469 | } |
1470 | if (n == 4) { |
1471 | jfs_error(bmp->db_ipbmap->i_sb, |
1472 | "dbAllocAG: failed descending stree"); |
1473 | release_metapage(mp); |
1474 | return -EIO; |
1475 | } |
1476 | } |
1477 | |
1478 | /* determine the block number within the file system |
1479 | * that corresponds to this leaf. |
1480 | */ |
1481 | if (bmp->db_aglevel == 2) |
1482 | blkno = 0; |
1483 | else if (bmp->db_aglevel == 1) |
1484 | blkno &= ~(MAXL1SIZE - 1); |
1485 | else /* bmp->db_aglevel == 0 */ |
1486 | blkno &= ~(MAXL0SIZE - 1); |
1487 | |
1488 | blkno += |
1489 | ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin; |
1490 | |
1491 | /* release the buffer in preparation for going down |
1492 | * the next level of dmap control pages. |
1493 | */ |
1494 | release_metapage(mp); |
1495 | |
1496 | /* check if we need to continue to search down the lower |
1497 | * level dmap control pages. we need to if the number of |
1498 | * blocks required is less than maximum number of blocks |
1499 | * described at the next lower level. |
1500 | */ |
1501 | if (l2nb < budmin) { |
1502 | |
1503 | /* search the lower level dmap control pages to get |
1504 | * the starting block number of the dmap that |
1505 | * contains or starts off the free space. |
1506 | */ |
1507 | if ((rc = |
1508 | dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1, |
1509 | &blkno))) { |
1510 | if (rc == -ENOSPC) { |
1511 | jfs_error(bmp->db_ipbmap->i_sb, |
1512 | "dbAllocAG: control page " |
1513 | "inconsistent"); |
1514 | return -EIO; |
1515 | } |
1516 | return (rc); |
1517 | } |
1518 | } |
1519 | |
1520 | /* allocate the blocks. |
1521 | */ |
1522 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); |
1523 | if (rc == -ENOSPC) { |
1524 | jfs_error(bmp->db_ipbmap->i_sb, |
1525 | "dbAllocAG: unable to allocate blocks"); |
1526 | rc = -EIO; |
1527 | } |
1528 | return (rc); |
1529 | } |
1530 | |
1531 | /* no space in the allocation group. release the buffer and |
1532 | * return -ENOSPC. |
1533 | */ |
1534 | release_metapage(mp); |
1535 | |
1536 | return -ENOSPC; |
1537 | } |
1538 | |
1539 | |
1540 | /* |
1541 | * NAME: dbAllocAny() |
1542 | * |
1543 | * FUNCTION: attempt to allocate the specified number of contiguous |
1544 | * free blocks anywhere in the file system. |
1545 | * |
1546 | * dbAllocAny() attempts to find the sufficient free space by |
1547 | * searching down the dmap control pages, starting with the |
1548 | * highest level (i.e. L0, L1, L2) control page. if free space |
1549 | * large enough to satisfy the desired free space is found, the |
1550 | * desired free space is allocated. |
1551 | * |
1552 | * PARAMETERS: |
1553 | * bmp - pointer to bmap descriptor |
1554 | * nblocks - actual number of contiguous free blocks desired. |
1555 | * l2nb - log2 number of contiguous free blocks desired. |
1556 | * results - on successful return, set to the starting block number |
1557 | * of the newly allocated range. |
1558 | * |
1559 | * RETURN VALUES: |
1560 | * 0 - success |
1561 | * -ENOSPC - insufficient disk resources |
1562 | * -EIO - i/o error |
1563 | * |
1564 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; |
1565 | */ |
1566 | static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results) |
1567 | { |
1568 | int rc; |
1569 | s64 blkno = 0; |
1570 | |
1571 | /* starting with the top level dmap control page, search |
1572 | * down the dmap control levels for sufficient free space. |
1573 | * if free space is found, dbFindCtl() returns the starting |
1574 | * block number of the dmap that contains or starts off the |
1575 | * range of free space. |
1576 | */ |
1577 | if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno))) |
1578 | return (rc); |
1579 | |
1580 | /* allocate the blocks. |
1581 | */ |
1582 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); |
1583 | if (rc == -ENOSPC) { |
1584 | jfs_error(bmp->db_ipbmap->i_sb, |
1585 | "dbAllocAny: unable to allocate blocks"); |
1586 | return -EIO; |
1587 | } |
1588 | return (rc); |
1589 | } |
1590 | |
1591 | |
1592 | /* |
1593 | * NAME: dbFindCtl() |
1594 | * |
1595 | * FUNCTION: starting at a specified dmap control page level and block |
1596 | * number, search down the dmap control levels for a range of |
1597 | * contiguous free blocks large enough to satisfy an allocation |
1598 | * request for the specified number of free blocks. |
1599 | * |
1600 | * if sufficient contiguous free blocks are found, this routine |
1601 | * returns the starting block number within a dmap page that |
1602 | * contains or starts a range of contiqious free blocks that |
1603 | * is sufficient in size. |
1604 | * |
1605 | * PARAMETERS: |
1606 | * bmp - pointer to bmap descriptor |
1607 | * level - starting dmap control page level. |
1608 | * l2nb - log2 number of contiguous free blocks desired. |
1609 | * *blkno - on entry, starting block number for conducting the search. |
1610 | * on successful return, the first block within a dmap page |
1611 | * that contains or starts a range of contiguous free blocks. |
1612 | * |
1613 | * RETURN VALUES: |
1614 | * 0 - success |
1615 | * -ENOSPC - insufficient disk resources |
1616 | * -EIO - i/o error |
1617 | * |
1618 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; |
1619 | */ |
1620 | static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno) |
1621 | { |
1622 | int rc, leafidx, lev; |
1623 | s64 b, lblkno; |
1624 | struct dmapctl *dcp; |
1625 | int budmin; |
1626 | struct metapage *mp; |
1627 | |
1628 | /* starting at the specified dmap control page level and block |
1629 | * number, search down the dmap control levels for the starting |
1630 | * block number of a dmap page that contains or starts off |
1631 | * sufficient free blocks. |
1632 | */ |
1633 | for (lev = level, b = *blkno; lev >= 0; lev--) { |
1634 | /* get the buffer of the dmap control page for the block |
1635 | * number and level (i.e. L0, L1, L2). |
1636 | */ |
1637 | lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev); |
1638 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
1639 | if (mp == NULL) |
1640 | return -EIO; |
1641 | dcp = (struct dmapctl *) mp->data; |
1642 | budmin = dcp->budmin; |
1643 | |
1644 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { |
1645 | jfs_error(bmp->db_ipbmap->i_sb, |
1646 | "dbFindCtl: Corrupt dmapctl page"); |
1647 | release_metapage(mp); |
1648 | return -EIO; |
1649 | } |
1650 | |
1651 | /* search the tree within the dmap control page for |
1652 | * sufficient free space. if sufficient free space is found, |
1653 | * dbFindLeaf() returns the index of the leaf at which |
1654 | * free space was found. |
1655 | */ |
1656 | rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx); |
1657 | |
1658 | /* release the buffer. |
1659 | */ |
1660 | release_metapage(mp); |
1661 | |
1662 | /* space found ? |
1663 | */ |
1664 | if (rc) { |
1665 | if (lev != level) { |
1666 | jfs_error(bmp->db_ipbmap->i_sb, |
1667 | "dbFindCtl: dmap inconsistent"); |
1668 | return -EIO; |
1669 | } |
1670 | return -ENOSPC; |
1671 | } |
1672 | |
1673 | /* adjust the block number to reflect the location within |
1674 | * the dmap control page (i.e. the leaf) at which free |
1675 | * space was found. |
1676 | */ |
1677 | b += (((s64) leafidx) << budmin); |
1678 | |
1679 | /* we stop the search at this dmap control page level if |
1680 | * the number of blocks required is greater than or equal |
1681 | * to the maximum number of blocks described at the next |
1682 | * (lower) level. |
1683 | */ |
1684 | if (l2nb >= budmin) |
1685 | break; |
1686 | } |
1687 | |
1688 | *blkno = b; |
1689 | return (0); |
1690 | } |
1691 | |
1692 | |
1693 | /* |
1694 | * NAME: dbAllocCtl() |
1695 | * |
1696 | * FUNCTION: attempt to allocate a specified number of contiguous |
1697 | * blocks starting within a specific dmap. |
1698 | * |
1699 | * this routine is called by higher level routines that search |
1700 | * the dmap control pages above the actual dmaps for contiguous |
1701 | * free space. the result of successful searches by these |
1702 | * routines are the starting block numbers within dmaps, with |
1703 | * the dmaps themselves containing the desired contiguous free |
1704 | * space or starting a contiguous free space of desired size |
1705 | * that is made up of the blocks of one or more dmaps. these |
1706 | * calls should not fail due to insufficent resources. |
1707 | * |
1708 | * this routine is called in some cases where it is not known |
1709 | * whether it will fail due to insufficient resources. more |
1710 | * specifically, this occurs when allocating from an allocation |
1711 | * group whose size is equal to the number of blocks per dmap. |
1712 | * in this case, the dmap control pages are not examined prior |
1713 | * to calling this routine (to save pathlength) and the call |
1714 | * might fail. |
1715 | * |
1716 | * for a request size that fits within a dmap, this routine relies |
1717 | * upon the dmap's dmtree to find the requested contiguous free |
1718 | * space. for request sizes that are larger than a dmap, the |
1719 | * requested free space will start at the first block of the |
1720 | * first dmap (i.e. blkno). |
1721 | * |
1722 | * PARAMETERS: |
1723 | * bmp - pointer to bmap descriptor |
1724 | * nblocks - actual number of contiguous free blocks to allocate. |
1725 | * l2nb - log2 number of contiguous free blocks to allocate. |
1726 | * blkno - starting block number of the dmap to start the allocation |
1727 | * from. |
1728 | * results - on successful return, set to the starting block number |
1729 | * of the newly allocated range. |
1730 | * |
1731 | * RETURN VALUES: |
1732 | * 0 - success |
1733 | * -ENOSPC - insufficient disk resources |
1734 | * -EIO - i/o error |
1735 | * |
1736 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; |
1737 | */ |
1738 | static int |
1739 | dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results) |
1740 | { |
1741 | int rc, nb; |
1742 | s64 b, lblkno, n; |
1743 | struct metapage *mp; |
1744 | struct dmap *dp; |
1745 | |
1746 | /* check if the allocation request is confined to a single dmap. |
1747 | */ |
1748 | if (l2nb <= L2BPERDMAP) { |
1749 | /* get the buffer for the dmap. |
1750 | */ |
1751 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
1752 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
1753 | if (mp == NULL) |
1754 | return -EIO; |
1755 | dp = (struct dmap *) mp->data; |
1756 | |
1757 | /* try to allocate the blocks. |
1758 | */ |
1759 | rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results); |
1760 | if (rc == 0) |
1761 | mark_metapage_dirty(mp); |
1762 | |
1763 | release_metapage(mp); |
1764 | |
1765 | return (rc); |
1766 | } |
1767 | |
1768 | /* allocation request involving multiple dmaps. it must start on |
1769 | * a dmap boundary. |
1770 | */ |
1771 | assert((blkno & (BPERDMAP - 1)) == 0); |
1772 | |
1773 | /* allocate the blocks dmap by dmap. |
1774 | */ |
1775 | for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) { |
1776 | /* get the buffer for the dmap. |
1777 | */ |
1778 | lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); |
1779 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
1780 | if (mp == NULL) { |
1781 | rc = -EIO; |
1782 | goto backout; |
1783 | } |
1784 | dp = (struct dmap *) mp->data; |
1785 | |
1786 | /* the dmap better be all free. |
1787 | */ |
1788 | if (dp->tree.stree[ROOT] != L2BPERDMAP) { |
1789 | release_metapage(mp); |
1790 | jfs_error(bmp->db_ipbmap->i_sb, |
1791 | "dbAllocCtl: the dmap is not all free"); |
1792 | rc = -EIO; |
1793 | goto backout; |
1794 | } |
1795 | |
1796 | /* determine how many blocks to allocate from this dmap. |
1797 | */ |
1798 | nb = min(n, (s64)BPERDMAP); |
1799 | |
1800 | /* allocate the blocks from the dmap. |
1801 | */ |
1802 | if ((rc = dbAllocDmap(bmp, dp, b, nb))) { |
1803 | release_metapage(mp); |
1804 | goto backout; |
1805 | } |
1806 | |
1807 | /* write the buffer. |
1808 | */ |
1809 | write_metapage(mp); |
1810 | } |
1811 | |
1812 | /* set the results (starting block number) and return. |
1813 | */ |
1814 | *results = blkno; |
1815 | return (0); |
1816 | |
1817 | /* something failed in handling an allocation request involving |
1818 | * multiple dmaps. we'll try to clean up by backing out any |
1819 | * allocation that has already happened for this request. if |
1820 | * we fail in backing out the allocation, we'll mark the file |
1821 | * system to indicate that blocks have been leaked. |
1822 | */ |
1823 | backout: |
1824 | |
1825 | /* try to backout the allocations dmap by dmap. |
1826 | */ |
1827 | for (n = nblocks - n, b = blkno; n > 0; |
1828 | n -= BPERDMAP, b += BPERDMAP) { |
1829 | /* get the buffer for this dmap. |
1830 | */ |
1831 | lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); |
1832 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
1833 | if (mp == NULL) { |
1834 | /* could not back out. mark the file system |
1835 | * to indicate that we have leaked blocks. |
1836 | */ |
1837 | jfs_error(bmp->db_ipbmap->i_sb, |
1838 | "dbAllocCtl: I/O Error: Block Leakage."); |
1839 | continue; |
1840 | } |
1841 | dp = (struct dmap *) mp->data; |
1842 | |
1843 | /* free the blocks is this dmap. |
1844 | */ |
1845 | if (dbFreeDmap(bmp, dp, b, BPERDMAP)) { |
1846 | /* could not back out. mark the file system |
1847 | * to indicate that we have leaked blocks. |
1848 | */ |
1849 | release_metapage(mp); |
1850 | jfs_error(bmp->db_ipbmap->i_sb, |
1851 | "dbAllocCtl: Block Leakage."); |
1852 | continue; |
1853 | } |
1854 | |
1855 | /* write the buffer. |
1856 | */ |
1857 | write_metapage(mp); |
1858 | } |
1859 | |
1860 | return (rc); |
1861 | } |
1862 | |
1863 | |
1864 | /* |
1865 | * NAME: dbAllocDmapLev() |
1866 | * |
1867 | * FUNCTION: attempt to allocate a specified number of contiguous blocks |
1868 | * from a specified dmap. |
1869 | * |
1870 | * this routine checks if the contiguous blocks are available. |
1871 | * if so, nblocks of blocks are allocated; otherwise, ENOSPC is |
1872 | * returned. |
1873 | * |
1874 | * PARAMETERS: |
1875 | * mp - pointer to bmap descriptor |
1876 | * dp - pointer to dmap to attempt to allocate blocks from. |
1877 | * l2nb - log2 number of contiguous block desired. |
1878 | * nblocks - actual number of contiguous block desired. |
1879 | * results - on successful return, set to the starting block number |
1880 | * of the newly allocated range. |
1881 | * |
1882 | * RETURN VALUES: |
1883 | * 0 - success |
1884 | * -ENOSPC - insufficient disk resources |
1885 | * -EIO - i/o error |
1886 | * |
1887 | * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or |
1888 | * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit; |
1889 | */ |
1890 | static int |
1891 | dbAllocDmapLev(struct bmap * bmp, |
1892 | struct dmap * dp, int nblocks, int l2nb, s64 * results) |
1893 | { |
1894 | s64 blkno; |
1895 | int leafidx, rc; |
1896 | |
1897 | /* can't be more than a dmaps worth of blocks */ |
1898 | assert(l2nb <= L2BPERDMAP); |
1899 | |
1900 | /* search the tree within the dmap page for sufficient |
1901 | * free space. if sufficient free space is found, dbFindLeaf() |
1902 | * returns the index of the leaf at which free space was found. |
1903 | */ |
1904 | if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx)) |
1905 | return -ENOSPC; |
1906 | |
1907 | /* determine the block number within the file system corresponding |
1908 | * to the leaf at which free space was found. |
1909 | */ |
1910 | blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD); |
1911 | |
1912 | /* if not all bits of the dmap word are free, get the starting |
1913 | * bit number within the dmap word of the required string of free |
1914 | * bits and adjust the block number with this value. |
1915 | */ |
1916 | if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN) |
1917 | blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb); |
1918 | |
1919 | /* allocate the blocks */ |
1920 | if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) |
1921 | *results = blkno; |
1922 | |
1923 | return (rc); |
1924 | } |
1925 | |
1926 | |
1927 | /* |
1928 | * NAME: dbAllocDmap() |
1929 | * |
1930 | * FUNCTION: adjust the disk allocation map to reflect the allocation |
1931 | * of a specified block range within a dmap. |
1932 | * |
1933 | * this routine allocates the specified blocks from the dmap |
1934 | * through a call to dbAllocBits(). if the allocation of the |
1935 | * block range causes the maximum string of free blocks within |
1936 | * the dmap to change (i.e. the value of the root of the dmap's |
1937 | * dmtree), this routine will cause this change to be reflected |
1938 | * up through the appropriate levels of the dmap control pages |
1939 | * by a call to dbAdjCtl() for the L0 dmap control page that |
1940 | * covers this dmap. |
1941 | * |
1942 | * PARAMETERS: |
1943 | * bmp - pointer to bmap descriptor |
1944 | * dp - pointer to dmap to allocate the block range from. |
1945 | * blkno - starting block number of the block to be allocated. |
1946 | * nblocks - number of blocks to be allocated. |
1947 | * |
1948 | * RETURN VALUES: |
1949 | * 0 - success |
1950 | * -EIO - i/o error |
1951 | * |
1952 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
1953 | */ |
1954 | static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
1955 | int nblocks) |
1956 | { |
1957 | s8 oldroot; |
1958 | int rc; |
1959 | |
1960 | /* save the current value of the root (i.e. maximum free string) |
1961 | * of the dmap tree. |
1962 | */ |
1963 | oldroot = dp->tree.stree[ROOT]; |
1964 | |
1965 | /* allocate the specified (blocks) bits */ |
1966 | dbAllocBits(bmp, dp, blkno, nblocks); |
1967 | |
1968 | /* if the root has not changed, done. */ |
1969 | if (dp->tree.stree[ROOT] == oldroot) |
1970 | return (0); |
1971 | |
1972 | /* root changed. bubble the change up to the dmap control pages. |
1973 | * if the adjustment of the upper level control pages fails, |
1974 | * backout the bit allocation (thus making everything consistent). |
1975 | */ |
1976 | if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0))) |
1977 | dbFreeBits(bmp, dp, blkno, nblocks); |
1978 | |
1979 | return (rc); |
1980 | } |
1981 | |
1982 | |
1983 | /* |
1984 | * NAME: dbFreeDmap() |
1985 | * |
1986 | * FUNCTION: adjust the disk allocation map to reflect the allocation |
1987 | * of a specified block range within a dmap. |
1988 | * |
1989 | * this routine frees the specified blocks from the dmap through |
1990 | * a call to dbFreeBits(). if the deallocation of the block range |
1991 | * causes the maximum string of free blocks within the dmap to |
1992 | * change (i.e. the value of the root of the dmap's dmtree), this |
1993 | * routine will cause this change to be reflected up through the |
1994 | * appropriate levels of the dmap control pages by a call to |
1995 | * dbAdjCtl() for the L0 dmap control page that covers this dmap. |
1996 | * |
1997 | * PARAMETERS: |
1998 | * bmp - pointer to bmap descriptor |
1999 | * dp - pointer to dmap to free the block range from. |
2000 | * blkno - starting block number of the block to be freed. |
2001 | * nblocks - number of blocks to be freed. |
2002 | * |
2003 | * RETURN VALUES: |
2004 | * 0 - success |
2005 | * -EIO - i/o error |
2006 | * |
2007 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
2008 | */ |
2009 | static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
2010 | int nblocks) |
2011 | { |
2012 | s8 oldroot; |
2013 | int rc = 0, word; |
2014 | |
2015 | /* save the current value of the root (i.e. maximum free string) |
2016 | * of the dmap tree. |
2017 | */ |
2018 | oldroot = dp->tree.stree[ROOT]; |
2019 | |
2020 | /* free the specified (blocks) bits */ |
2021 | rc = dbFreeBits(bmp, dp, blkno, nblocks); |
2022 | |
2023 | /* if error or the root has not changed, done. */ |
2024 | if (rc || (dp->tree.stree[ROOT] == oldroot)) |
2025 | return (rc); |
2026 | |
2027 | /* root changed. bubble the change up to the dmap control pages. |
2028 | * if the adjustment of the upper level control pages fails, |
2029 | * backout the deallocation. |
2030 | */ |
2031 | if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) { |
2032 | word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; |
2033 | |
2034 | /* as part of backing out the deallocation, we will have |
2035 | * to back split the dmap tree if the deallocation caused |
2036 | * the freed blocks to become part of a larger binary buddy |
2037 | * system. |
2038 | */ |
2039 | if (dp->tree.stree[word] == NOFREE) |
2040 | dbBackSplit((dmtree_t *) & dp->tree, word); |
2041 | |
2042 | dbAllocBits(bmp, dp, blkno, nblocks); |
2043 | } |
2044 | |
2045 | return (rc); |
2046 | } |
2047 | |
2048 | |
2049 | /* |
2050 | * NAME: dbAllocBits() |
2051 | * |
2052 | * FUNCTION: allocate a specified block range from a dmap. |
2053 | * |
2054 | * this routine updates the dmap to reflect the working |
2055 | * state allocation of the specified block range. it directly |
2056 | * updates the bits of the working map and causes the adjustment |
2057 | * of the binary buddy system described by the dmap's dmtree |
2058 | * leaves to reflect the bits allocated. it also causes the |
2059 | * dmap's dmtree, as a whole, to reflect the allocated range. |
2060 | * |
2061 | * PARAMETERS: |
2062 | * bmp - pointer to bmap descriptor |
2063 | * dp - pointer to dmap to allocate bits from. |
2064 | * blkno - starting block number of the bits to be allocated. |
2065 | * nblocks - number of bits to be allocated. |
2066 | * |
2067 | * RETURN VALUES: none |
2068 | * |
2069 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
2070 | */ |
2071 | static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
2072 | int nblocks) |
2073 | { |
2074 | int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; |
2075 | dmtree_t *tp = (dmtree_t *) & dp->tree; |
2076 | int size; |
2077 | s8 *leaf; |
2078 | |
2079 | /* pick up a pointer to the leaves of the dmap tree */ |
2080 | leaf = dp->tree.stree + LEAFIND; |
2081 | |
2082 | /* determine the bit number and word within the dmap of the |
2083 | * starting block. |
2084 | */ |
2085 | dbitno = blkno & (BPERDMAP - 1); |
2086 | word = dbitno >> L2DBWORD; |
2087 | |
2088 | /* block range better be within the dmap */ |
2089 | assert(dbitno + nblocks <= BPERDMAP); |
2090 | |
2091 | /* allocate the bits of the dmap's words corresponding to the block |
2092 | * range. not all bits of the first and last words may be contained |
2093 | * within the block range. if this is the case, we'll work against |
2094 | * those words (i.e. partial first and/or last) on an individual basis |
2095 | * (a single pass), allocating the bits of interest by hand and |
2096 | * updating the leaf corresponding to the dmap word. a single pass |
2097 | * will be used for all dmap words fully contained within the |
2098 | * specified range. within this pass, the bits of all fully contained |
2099 | * dmap words will be marked as free in a single shot and the leaves |
2100 | * will be updated. a single leaf may describe the free space of |
2101 | * multiple dmap words, so we may update only a subset of the actual |
2102 | * leaves corresponding to the dmap words of the block range. |
2103 | */ |
2104 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { |
2105 | /* determine the bit number within the word and |
2106 | * the number of bits within the word. |
2107 | */ |
2108 | wbitno = dbitno & (DBWORD - 1); |
2109 | nb = min(rembits, DBWORD - wbitno); |
2110 | |
2111 | /* check if only part of a word is to be allocated. |
2112 | */ |
2113 | if (nb < DBWORD) { |
2114 | /* allocate (set to 1) the appropriate bits within |
2115 | * this dmap word. |
2116 | */ |
2117 | dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) |
2118 | >> wbitno); |
2119 | |
2120 | /* update the leaf for this dmap word. in addition |
2121 | * to setting the leaf value to the binary buddy max |
2122 | * of the updated dmap word, dbSplit() will split |
2123 | * the binary system of the leaves if need be. |
2124 | */ |
2125 | dbSplit(tp, word, BUDMIN, |
2126 | dbMaxBud((u8 *) & dp->wmap[word])); |
2127 | |
2128 | word += 1; |
2129 | } else { |
2130 | /* one or more dmap words are fully contained |
2131 | * within the block range. determine how many |
2132 | * words and allocate (set to 1) the bits of these |
2133 | * words. |
2134 | */ |
2135 | nwords = rembits >> L2DBWORD; |
2136 | memset(&dp->wmap[word], (int) ONES, nwords * 4); |
2137 | |
2138 | /* determine how many bits. |
2139 | */ |
2140 | nb = nwords << L2DBWORD; |
2141 | |
2142 | /* now update the appropriate leaves to reflect |
2143 | * the allocated words. |
2144 | */ |
2145 | for (; nwords > 0; nwords -= nw) { |
2146 | if (leaf[word] < BUDMIN) { |
2147 | jfs_error(bmp->db_ipbmap->i_sb, |
2148 | "dbAllocBits: leaf page " |
2149 | "corrupt"); |
2150 | break; |
2151 | } |
2152 | |
2153 | /* determine what the leaf value should be |
2154 | * updated to as the minimum of the l2 number |
2155 | * of bits being allocated and the l2 number |
2156 | * of bits currently described by this leaf. |
2157 | */ |
2158 | size = min((int)leaf[word], NLSTOL2BSZ(nwords)); |
2159 | |
2160 | /* update the leaf to reflect the allocation. |
2161 | * in addition to setting the leaf value to |
2162 | * NOFREE, dbSplit() will split the binary |
2163 | * system of the leaves to reflect the current |
2164 | * allocation (size). |
2165 | */ |
2166 | dbSplit(tp, word, size, NOFREE); |
2167 | |
2168 | /* get the number of dmap words handled */ |
2169 | nw = BUDSIZE(size, BUDMIN); |
2170 | word += nw; |
2171 | } |
2172 | } |
2173 | } |
2174 | |
2175 | /* update the free count for this dmap */ |
2176 | le32_add_cpu(&dp->nfree, -nblocks); |
2177 | |
2178 | BMAP_LOCK(bmp); |
2179 | |
2180 | /* if this allocation group is completely free, |
2181 | * update the maximum allocation group number if this allocation |
2182 | * group is the new max. |
2183 | */ |
2184 | agno = blkno >> bmp->db_agl2size; |
2185 | if (agno > bmp->db_maxag) |
2186 | bmp->db_maxag = agno; |
2187 | |
2188 | /* update the free count for the allocation group and map */ |
2189 | bmp->db_agfree[agno] -= nblocks; |
2190 | bmp->db_nfree -= nblocks; |
2191 | |
2192 | BMAP_UNLOCK(bmp); |
2193 | } |
2194 | |
2195 | |
2196 | /* |
2197 | * NAME: dbFreeBits() |
2198 | * |
2199 | * FUNCTION: free a specified block range from a dmap. |
2200 | * |
2201 | * this routine updates the dmap to reflect the working |
2202 | * state allocation of the specified block range. it directly |
2203 | * updates the bits of the working map and causes the adjustment |
2204 | * of the binary buddy system described by the dmap's dmtree |
2205 | * leaves to reflect the bits freed. it also causes the dmap's |
2206 | * dmtree, as a whole, to reflect the deallocated range. |
2207 | * |
2208 | * PARAMETERS: |
2209 | * bmp - pointer to bmap descriptor |
2210 | * dp - pointer to dmap to free bits from. |
2211 | * blkno - starting block number of the bits to be freed. |
2212 | * nblocks - number of bits to be freed. |
2213 | * |
2214 | * RETURN VALUES: 0 for success |
2215 | * |
2216 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
2217 | */ |
2218 | static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
2219 | int nblocks) |
2220 | { |
2221 | int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; |
2222 | dmtree_t *tp = (dmtree_t *) & dp->tree; |
2223 | int rc = 0; |
2224 | int size; |
2225 | |
2226 | /* determine the bit number and word within the dmap of the |
2227 | * starting block. |
2228 | */ |
2229 | dbitno = blkno & (BPERDMAP - 1); |
2230 | word = dbitno >> L2DBWORD; |
2231 | |
2232 | /* block range better be within the dmap. |
2233 | */ |
2234 | assert(dbitno + nblocks <= BPERDMAP); |
2235 | |
2236 | /* free the bits of the dmaps words corresponding to the block range. |
2237 | * not all bits of the first and last words may be contained within |
2238 | * the block range. if this is the case, we'll work against those |
2239 | * words (i.e. partial first and/or last) on an individual basis |
2240 | * (a single pass), freeing the bits of interest by hand and updating |
2241 | * the leaf corresponding to the dmap word. a single pass will be used |
2242 | * for all dmap words fully contained within the specified range. |
2243 | * within this pass, the bits of all fully contained dmap words will |
2244 | * be marked as free in a single shot and the leaves will be updated. a |
2245 | * single leaf may describe the free space of multiple dmap words, |
2246 | * so we may update only a subset of the actual leaves corresponding |
2247 | * to the dmap words of the block range. |
2248 | * |
2249 | * dbJoin() is used to update leaf values and will join the binary |
2250 | * buddy system of the leaves if the new leaf values indicate this |
2251 | * should be done. |
2252 | */ |
2253 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { |
2254 | /* determine the bit number within the word and |
2255 | * the number of bits within the word. |
2256 | */ |
2257 | wbitno = dbitno & (DBWORD - 1); |
2258 | nb = min(rembits, DBWORD - wbitno); |
2259 | |
2260 | /* check if only part of a word is to be freed. |
2261 | */ |
2262 | if (nb < DBWORD) { |
2263 | /* free (zero) the appropriate bits within this |
2264 | * dmap word. |
2265 | */ |
2266 | dp->wmap[word] &= |
2267 | cpu_to_le32(~(ONES << (DBWORD - nb) |
2268 | >> wbitno)); |
2269 | |
2270 | /* update the leaf for this dmap word. |
2271 | */ |
2272 | rc = dbJoin(tp, word, |
2273 | dbMaxBud((u8 *) & dp->wmap[word])); |
2274 | if (rc) |
2275 | return rc; |
2276 | |
2277 | word += 1; |
2278 | } else { |
2279 | /* one or more dmap words are fully contained |
2280 | * within the block range. determine how many |
2281 | * words and free (zero) the bits of these words. |
2282 | */ |
2283 | nwords = rembits >> L2DBWORD; |
2284 | memset(&dp->wmap[word], 0, nwords * 4); |
2285 | |
2286 | /* determine how many bits. |
2287 | */ |
2288 | nb = nwords << L2DBWORD; |
2289 | |
2290 | /* now update the appropriate leaves to reflect |
2291 | * the freed words. |
2292 | */ |
2293 | for (; nwords > 0; nwords -= nw) { |
2294 | /* determine what the leaf value should be |
2295 | * updated to as the minimum of the l2 number |
2296 | * of bits being freed and the l2 (max) number |
2297 | * of bits that can be described by this leaf. |
2298 | */ |
2299 | size = |
2300 | min(LITOL2BSZ |
2301 | (word, L2LPERDMAP, BUDMIN), |
2302 | NLSTOL2BSZ(nwords)); |
2303 | |
2304 | /* update the leaf. |
2305 | */ |
2306 | rc = dbJoin(tp, word, size); |
2307 | if (rc) |
2308 | return rc; |
2309 | |
2310 | /* get the number of dmap words handled. |
2311 | */ |
2312 | nw = BUDSIZE(size, BUDMIN); |
2313 | word += nw; |
2314 | } |
2315 | } |
2316 | } |
2317 | |
2318 | /* update the free count for this dmap. |
2319 | */ |
2320 | le32_add_cpu(&dp->nfree, nblocks); |
2321 | |
2322 | BMAP_LOCK(bmp); |
2323 | |
2324 | /* update the free count for the allocation group and |
2325 | * map. |
2326 | */ |
2327 | agno = blkno >> bmp->db_agl2size; |
2328 | bmp->db_nfree += nblocks; |
2329 | bmp->db_agfree[agno] += nblocks; |
2330 | |
2331 | /* check if this allocation group is not completely free and |
2332 | * if it is currently the maximum (rightmost) allocation group. |
2333 | * if so, establish the new maximum allocation group number by |
2334 | * searching left for the first allocation group with allocation. |
2335 | */ |
2336 | if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) || |
2337 | (agno == bmp->db_numag - 1 && |
2338 | bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) { |
2339 | while (bmp->db_maxag > 0) { |
2340 | bmp->db_maxag -= 1; |
2341 | if (bmp->db_agfree[bmp->db_maxag] != |
2342 | bmp->db_agsize) |
2343 | break; |
2344 | } |
2345 | |
2346 | /* re-establish the allocation group preference if the |
2347 | * current preference is right of the maximum allocation |
2348 | * group. |
2349 | */ |
2350 | if (bmp->db_agpref > bmp->db_maxag) |
2351 | bmp->db_agpref = bmp->db_maxag; |
2352 | } |
2353 | |
2354 | BMAP_UNLOCK(bmp); |
2355 | |
2356 | return 0; |
2357 | } |
2358 | |
2359 | |
2360 | /* |
2361 | * NAME: dbAdjCtl() |
2362 | * |
2363 | * FUNCTION: adjust a dmap control page at a specified level to reflect |
2364 | * the change in a lower level dmap or dmap control page's |
2365 | * maximum string of free blocks (i.e. a change in the root |
2366 | * of the lower level object's dmtree) due to the allocation |
2367 | * or deallocation of a range of blocks with a single dmap. |
2368 | * |
2369 | * on entry, this routine is provided with the new value of |
2370 | * the lower level dmap or dmap control page root and the |
2371 | * starting block number of the block range whose allocation |
2372 | * or deallocation resulted in the root change. this range |
2373 | * is respresented by a single leaf of the current dmapctl |
2374 | * and the leaf will be updated with this value, possibly |
2375 | * causing a binary buddy system within the leaves to be |
2376 | * split or joined. the update may also cause the dmapctl's |
2377 | * dmtree to be updated. |
2378 | * |
2379 | * if the adjustment of the dmap control page, itself, causes its |
2380 | * root to change, this change will be bubbled up to the next dmap |
2381 | * control level by a recursive call to this routine, specifying |
2382 | * the new root value and the next dmap control page level to |
2383 | * be adjusted. |
2384 | * PARAMETERS: |
2385 | * bmp - pointer to bmap descriptor |
2386 | * blkno - the first block of a block range within a dmap. it is |
2387 | * the allocation or deallocation of this block range that |
2388 | * requires the dmap control page to be adjusted. |
2389 | * newval - the new value of the lower level dmap or dmap control |
2390 | * page root. |
2391 | * alloc - 'true' if adjustment is due to an allocation. |
2392 | * level - current level of dmap control page (i.e. L0, L1, L2) to |
2393 | * be adjusted. |
2394 | * |
2395 | * RETURN VALUES: |
2396 | * 0 - success |
2397 | * -EIO - i/o error |
2398 | * |
2399 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
2400 | */ |
2401 | static int |
2402 | dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level) |
2403 | { |
2404 | struct metapage *mp; |
2405 | s8 oldroot; |
2406 | int oldval; |
2407 | s64 lblkno; |
2408 | struct dmapctl *dcp; |
2409 | int rc, leafno, ti; |
2410 | |
2411 | /* get the buffer for the dmap control page for the specified |
2412 | * block number and control page level. |
2413 | */ |
2414 | lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level); |
2415 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); |
2416 | if (mp == NULL) |
2417 | return -EIO; |
2418 | dcp = (struct dmapctl *) mp->data; |
2419 | |
2420 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { |
2421 | jfs_error(bmp->db_ipbmap->i_sb, |
2422 | "dbAdjCtl: Corrupt dmapctl page"); |
2423 | release_metapage(mp); |
2424 | return -EIO; |
2425 | } |
2426 | |
2427 | /* determine the leaf number corresponding to the block and |
2428 | * the index within the dmap control tree. |
2429 | */ |
2430 | leafno = BLKTOCTLLEAF(blkno, dcp->budmin); |
2431 | ti = leafno + le32_to_cpu(dcp->leafidx); |
2432 | |
2433 | /* save the current leaf value and the current root level (i.e. |
2434 | * maximum l2 free string described by this dmapctl). |
2435 | */ |
2436 | oldval = dcp->stree[ti]; |
2437 | oldroot = dcp->stree[ROOT]; |
2438 | |
2439 | /* check if this is a control page update for an allocation. |
2440 | * if so, update the leaf to reflect the new leaf value using |
2441 | * dbSplit(); otherwise (deallocation), use dbJoin() to update |
2442 | * the leaf with the new value. in addition to updating the |
2443 | * leaf, dbSplit() will also split the binary buddy system of |
2444 | * the leaves, if required, and bubble new values within the |
2445 | * dmapctl tree, if required. similarly, dbJoin() will join |
2446 | * the binary buddy system of leaves and bubble new values up |
2447 | * the dmapctl tree as required by the new leaf value. |
2448 | */ |
2449 | if (alloc) { |
2450 | /* check if we are in the middle of a binary buddy |
2451 | * system. this happens when we are performing the |
2452 | * first allocation out of an allocation group that |
2453 | * is part (not the first part) of a larger binary |
2454 | * buddy system. if we are in the middle, back split |
2455 | * the system prior to calling dbSplit() which assumes |
2456 | * that it is at the front of a binary buddy system. |
2457 | */ |
2458 | if (oldval == NOFREE) { |
2459 | rc = dbBackSplit((dmtree_t *) dcp, leafno); |
2460 | if (rc) |
2461 | return rc; |
2462 | oldval = dcp->stree[ti]; |
2463 | } |
2464 | dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval); |
2465 | } else { |
2466 | rc = dbJoin((dmtree_t *) dcp, leafno, newval); |
2467 | if (rc) |
2468 | return rc; |
2469 | } |
2470 | |
2471 | /* check if the root of the current dmap control page changed due |
2472 | * to the update and if the current dmap control page is not at |
2473 | * the current top level (i.e. L0, L1, L2) of the map. if so (i.e. |
2474 | * root changed and this is not the top level), call this routine |
2475 | * again (recursion) for the next higher level of the mapping to |
2476 | * reflect the change in root for the current dmap control page. |
2477 | */ |
2478 | if (dcp->stree[ROOT] != oldroot) { |
2479 | /* are we below the top level of the map. if so, |
2480 | * bubble the root up to the next higher level. |
2481 | */ |
2482 | if (level < bmp->db_maxlevel) { |
2483 | /* bubble up the new root of this dmap control page to |
2484 | * the next level. |
2485 | */ |
2486 | if ((rc = |
2487 | dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc, |
2488 | level + 1))) { |
2489 | /* something went wrong in bubbling up the new |
2490 | * root value, so backout the changes to the |
2491 | * current dmap control page. |
2492 | */ |
2493 | if (alloc) { |
2494 | dbJoin((dmtree_t *) dcp, leafno, |
2495 | oldval); |
2496 | } else { |
2497 | /* the dbJoin() above might have |
2498 | * caused a larger binary buddy system |
2499 | * to form and we may now be in the |
2500 | * middle of it. if this is the case, |
2501 | * back split the buddies. |
2502 | */ |
2503 | if (dcp->stree[ti] == NOFREE) |
2504 | dbBackSplit((dmtree_t *) |
2505 | dcp, leafno); |
2506 | dbSplit((dmtree_t *) dcp, leafno, |
2507 | dcp->budmin, oldval); |
2508 | } |
2509 | |
2510 | /* release the buffer and return the error. |
2511 | */ |
2512 | release_metapage(mp); |
2513 | return (rc); |
2514 | } |
2515 | } else { |
2516 | /* we're at the top level of the map. update |
2517 | * the bmap control page to reflect the size |
2518 | * of the maximum free buddy system. |
2519 | */ |
2520 | assert(level == bmp->db_maxlevel); |
2521 | if (bmp->db_maxfreebud != oldroot) { |
2522 | jfs_error(bmp->db_ipbmap->i_sb, |
2523 | "dbAdjCtl: the maximum free buddy is " |
2524 | "not the old root"); |
2525 | } |
2526 | bmp->db_maxfreebud = dcp->stree[ROOT]; |
2527 | } |
2528 | } |
2529 | |
2530 | /* write the buffer. |
2531 | */ |
2532 | write_metapage(mp); |
2533 | |
2534 | return (0); |
2535 | } |
2536 | |
2537 | |
2538 | /* |
2539 | * NAME: dbSplit() |
2540 | * |
2541 | * FUNCTION: update the leaf of a dmtree with a new value, splitting |
2542 | * the leaf from the binary buddy system of the dmtree's |
2543 | * leaves, as required. |
2544 | * |
2545 | * PARAMETERS: |
2546 | * tp - pointer to the tree containing the leaf. |
2547 | * leafno - the number of the leaf to be updated. |
2548 | * splitsz - the size the binary buddy system starting at the leaf |
2549 | * must be split to, specified as the log2 number of blocks. |
2550 | * newval - the new value for the leaf. |
2551 | * |
2552 | * RETURN VALUES: none |
2553 | * |
2554 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
2555 | */ |
2556 | static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval) |
2557 | { |
2558 | int budsz; |
2559 | int cursz; |
2560 | s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); |
2561 | |
2562 | /* check if the leaf needs to be split. |
2563 | */ |
2564 | if (leaf[leafno] > tp->dmt_budmin) { |
2565 | /* the split occurs by cutting the buddy system in half |
2566 | * at the specified leaf until we reach the specified |
2567 | * size. pick up the starting split size (current size |
2568 | * - 1 in l2) and the corresponding buddy size. |
2569 | */ |
2570 | cursz = leaf[leafno] - 1; |
2571 | budsz = BUDSIZE(cursz, tp->dmt_budmin); |
2572 | |
2573 | /* split until we reach the specified size. |
2574 | */ |
2575 | while (cursz >= splitsz) { |
2576 | /* update the buddy's leaf with its new value. |
2577 | */ |
2578 | dbAdjTree(tp, leafno ^ budsz, cursz); |
2579 | |
2580 | /* on to the next size and buddy. |
2581 | */ |
2582 | cursz -= 1; |
2583 | budsz >>= 1; |
2584 | } |
2585 | } |
2586 | |
2587 | /* adjust the dmap tree to reflect the specified leaf's new |
2588 | * value. |
2589 | */ |
2590 | dbAdjTree(tp, leafno, newval); |
2591 | } |
2592 | |
2593 | |
2594 | /* |
2595 | * NAME: dbBackSplit() |
2596 | * |
2597 | * FUNCTION: back split the binary buddy system of dmtree leaves |
2598 | * that hold a specified leaf until the specified leaf |
2599 | * starts its own binary buddy system. |
2600 | * |
2601 | * the allocators typically perform allocations at the start |
2602 | * of binary buddy systems and dbSplit() is used to accomplish |
2603 | * any required splits. in some cases, however, allocation |
2604 | * may occur in the middle of a binary system and requires a |
2605 | * back split, with the split proceeding out from the middle of |
2606 | * the system (less efficient) rather than the start of the |
2607 | * system (more efficient). the cases in which a back split |
2608 | * is required are rare and are limited to the first allocation |
2609 | * within an allocation group which is a part (not first part) |
2610 | * of a larger binary buddy system and a few exception cases |
2611 | * in which a previous join operation must be backed out. |
2612 | * |
2613 | * PARAMETERS: |
2614 | * tp - pointer to the tree containing the leaf. |
2615 | * leafno - the number of the leaf to be updated. |
2616 | * |
2617 | * RETURN VALUES: none |
2618 | * |
2619 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; |
2620 | */ |
2621 | static int dbBackSplit(dmtree_t * tp, int leafno) |
2622 | { |
2623 | int budsz, bud, w, bsz, size; |
2624 | int cursz; |
2625 | s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); |
2626 | |
2627 | /* leaf should be part (not first part) of a binary |
2628 | * buddy system. |
2629 | */ |
2630 | assert(leaf[leafno] == NOFREE); |
2631 | |
2632 | /* the back split is accomplished by iteratively finding the leaf |
2633 | * that starts the buddy system that contains the specified leaf and |
2634 | * splitting that system in two. this iteration continues until |
2635 | * the specified leaf becomes the start of a buddy system. |
2636 | * |
2637 | * determine maximum possible l2 size for the specified leaf. |
2638 | */ |
2639 | size = |
2640 | LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs), |
2641 | tp->dmt_budmin); |
2642 | |
2643 | /* determine the number of leaves covered by this size. this |
2644 | * is the buddy size that we will start with as we search for |
2645 | * the buddy system that contains the specified leaf. |
2646 | */ |
2647 | budsz = BUDSIZE(size, tp->dmt_budmin); |
2648 | |
2649 | /* back split. |
2650 | */ |
2651 | while (leaf[leafno] == NOFREE) { |
2652 | /* find the leftmost buddy leaf. |
2653 | */ |
2654 | for (w = leafno, bsz = budsz;; bsz <<= 1, |
2655 | w = (w < bud) ? w : bud) { |
2656 | if (bsz >= le32_to_cpu(tp->dmt_nleafs)) { |
2657 | jfs_err("JFS: block map error in dbBackSplit"); |
2658 | return -EIO; |
2659 | } |
2660 | |
2661 | /* determine the buddy. |
2662 | */ |
2663 | bud = w ^ bsz; |
2664 | |
2665 | /* check if this buddy is the start of the system. |
2666 | */ |
2667 | if (leaf[bud] != NOFREE) { |
2668 | /* split the leaf at the start of the |
2669 | * system in two. |
2670 | */ |
2671 | cursz = leaf[bud] - 1; |
2672 | dbSplit(tp, bud, cursz, cursz); |
2673 | break; |
2674 | } |
2675 | } |
2676 | } |
2677 | |
2678 | if (leaf[leafno] != size) { |
2679 | jfs_err("JFS: wrong leaf value in dbBackSplit"); |
2680 | return -EIO; |
2681 | } |
2682 | return 0; |
2683 | } |
2684 | |
2685 | |
2686 | /* |
2687 | * NAME: dbJoin() |
2688 | * |
2689 | * FUNCTION: update the leaf of a dmtree with a new value, joining |
2690 | * the leaf with other leaves of the dmtree into a multi-leaf |
2691 | * binary buddy system, as required. |
2692 | * |
2693 | * PARAMETERS: |
2694 | * tp - pointer to the tree containing the leaf. |
2695 | * leafno - the number of the leaf to be updated. |
2696 | * newval - the new value for the leaf. |
2697 | * |
2698 | * RETURN VALUES: none |
2699 | */ |
2700 | static int dbJoin(dmtree_t * tp, int leafno, int newval) |
2701 | { |
2702 | int budsz, buddy; |
2703 | s8 *leaf; |
2704 | |
2705 | /* can the new leaf value require a join with other leaves ? |
2706 | */ |
2707 | if (newval >= tp->dmt_budmin) { |
2708 | /* pickup a pointer to the leaves of the tree. |
2709 | */ |
2710 | leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); |
2711 | |
2712 | /* try to join the specified leaf into a large binary |
2713 | * buddy system. the join proceeds by attempting to join |
2714 | * the specified leafno with its buddy (leaf) at new value. |
2715 | * if the join occurs, we attempt to join the left leaf |
2716 | * of the joined buddies with its buddy at new value + 1. |
2717 | * we continue to join until we find a buddy that cannot be |
2718 | * joined (does not have a value equal to the size of the |
2719 | * last join) or until all leaves have been joined into a |
2720 | * single system. |
2721 | * |
2722 | * get the buddy size (number of words covered) of |
2723 | * the new value. |
2724 | */ |
2725 | budsz = BUDSIZE(newval, tp->dmt_budmin); |
2726 | |
2727 | /* try to join. |
2728 | */ |
2729 | while (budsz < le32_to_cpu(tp->dmt_nleafs)) { |
2730 | /* get the buddy leaf. |
2731 | */ |
2732 | buddy = leafno ^ budsz; |
2733 | |
2734 | /* if the leaf's new value is greater than its |
2735 | * buddy's value, we join no more. |
2736 | */ |
2737 | if (newval > leaf[buddy]) |
2738 | break; |
2739 | |
2740 | /* It shouldn't be less */ |
2741 | if (newval < leaf[buddy]) |
2742 | return -EIO; |
2743 | |
2744 | /* check which (leafno or buddy) is the left buddy. |
2745 | * the left buddy gets to claim the blocks resulting |
2746 | * from the join while the right gets to claim none. |
2747 | * the left buddy is also eligible to participate in |
2748 | * a join at the next higher level while the right |
2749 | * is not. |
2750 | * |
2751 | */ |
2752 | if (leafno < buddy) { |
2753 | /* leafno is the left buddy. |
2754 | */ |
2755 | dbAdjTree(tp, buddy, NOFREE); |
2756 | } else { |
2757 | /* buddy is the left buddy and becomes |
2758 | * leafno. |
2759 | */ |
2760 | dbAdjTree(tp, leafno, NOFREE); |
2761 | leafno = buddy; |
2762 | } |
2763 | |
2764 | /* on to try the next join. |
2765 | */ |
2766 | newval += 1; |
2767 | budsz <<= 1; |
2768 | } |
2769 | } |
2770 | |
2771 | /* update the leaf value. |
2772 | */ |
2773 | dbAdjTree(tp, leafno, newval); |
2774 | |
2775 | return 0; |
2776 | } |
2777 | |
2778 | |
2779 | /* |
2780 | * NAME: dbAdjTree() |
2781 | * |
2782 | * FUNCTION: update a leaf of a dmtree with a new value, adjusting |
2783 | * the dmtree, as required, to reflect the new leaf value. |
2784 | * the combination of any buddies must already be done before |
2785 | * this is called. |
2786 | * |
2787 | * PARAMETERS: |
2788 | * tp - pointer to the tree to be adjusted. |
2789 | * leafno - the number of the leaf to be updated. |
2790 | * newval - the new value for the leaf. |
2791 | * |
2792 | * RETURN VALUES: none |
2793 | */ |
2794 | static void dbAdjTree(dmtree_t * tp, int leafno, int newval) |
2795 | { |
2796 | int lp, pp, k; |
2797 | int max; |
2798 | |
2799 | /* pick up the index of the leaf for this leafno. |
2800 | */ |
2801 | lp = leafno + le32_to_cpu(tp->dmt_leafidx); |
2802 | |
2803 | /* is the current value the same as the old value ? if so, |
2804 | * there is nothing to do. |
2805 | */ |
2806 | if (tp->dmt_stree[lp] == newval) |
2807 | return; |
2808 | |
2809 | /* set the new value. |
2810 | */ |
2811 | tp->dmt_stree[lp] = newval; |
2812 | |
2813 | /* bubble the new value up the tree as required. |
2814 | */ |
2815 | for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) { |
2816 | /* get the index of the first leaf of the 4 leaf |
2817 | * group containing the specified leaf (leafno). |
2818 | */ |
2819 | lp = ((lp - 1) & ~0x03) + 1; |
2820 | |
2821 | /* get the index of the parent of this 4 leaf group. |
2822 | */ |
2823 | pp = (lp - 1) >> 2; |
2824 | |
2825 | /* determine the maximum of the 4 leaves. |
2826 | */ |
2827 | max = TREEMAX(&tp->dmt_stree[lp]); |
2828 | |
2829 | /* if the maximum of the 4 is the same as the |
2830 | * parent's value, we're done. |
2831 | */ |
2832 | if (tp->dmt_stree[pp] == max) |
2833 | break; |
2834 | |
2835 | /* parent gets new value. |
2836 | */ |
2837 | tp->dmt_stree[pp] = max; |
2838 | |
2839 | /* parent becomes leaf for next go-round. |
2840 | */ |
2841 | lp = pp; |
2842 | } |
2843 | } |
2844 | |
2845 | |
2846 | /* |
2847 | * NAME: dbFindLeaf() |
2848 | * |
2849 | * FUNCTION: search a dmtree_t for sufficient free blocks, returning |
2850 | * the index of a leaf describing the free blocks if |
2851 | * sufficient free blocks are found. |
2852 | * |
2853 | * the search starts at the top of the dmtree_t tree and |
2854 | * proceeds down the tree to the leftmost leaf with sufficient |
2855 | * free space. |
2856 | * |
2857 | * PARAMETERS: |
2858 | * tp - pointer to the tree to be searched. |
2859 | * l2nb - log2 number of free blocks to search for. |
2860 | * leafidx - return pointer to be set to the index of the leaf |
2861 | * describing at least l2nb free blocks if sufficient |
2862 | * free blocks are found. |
2863 | * |
2864 | * RETURN VALUES: |
2865 | * 0 - success |
2866 | * -ENOSPC - insufficient free blocks. |
2867 | */ |
2868 | static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx) |
2869 | { |
2870 | int ti, n = 0, k, x = 0; |
2871 | |
2872 | /* first check the root of the tree to see if there is |
2873 | * sufficient free space. |
2874 | */ |
2875 | if (l2nb > tp->dmt_stree[ROOT]) |
2876 | return -ENOSPC; |
2877 | |
2878 | /* sufficient free space available. now search down the tree |
2879 | * starting at the next level for the leftmost leaf that |
2880 | * describes sufficient free space. |
2881 | */ |
2882 | for (k = le32_to_cpu(tp->dmt_height), ti = 1; |
2883 | k > 0; k--, ti = ((ti + n) << 2) + 1) { |
2884 | /* search the four nodes at this level, starting from |
2885 | * the left. |
2886 | */ |
2887 | for (x = ti, n = 0; n < 4; n++) { |
2888 | /* sufficient free space found. move to the next |
2889 | * level (or quit if this is the last level). |
2890 | */ |
2891 | if (l2nb <= tp->dmt_stree[x + n]) |
2892 | break; |
2893 | } |
2894 | |
2895 | /* better have found something since the higher |
2896 | * levels of the tree said it was here. |
2897 | */ |
2898 | assert(n < 4); |
2899 | } |
2900 | |
2901 | /* set the return to the leftmost leaf describing sufficient |
2902 | * free space. |
2903 | */ |
2904 | *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx); |
2905 | |
2906 | return (0); |
2907 | } |
2908 | |
2909 | |
2910 | /* |
2911 | * NAME: dbFindBits() |
2912 | * |
2913 | * FUNCTION: find a specified number of binary buddy free bits within a |
2914 | * dmap bitmap word value. |
2915 | * |
2916 | * this routine searches the bitmap value for (1 << l2nb) free |
2917 | * bits at (1 << l2nb) alignments within the value. |
2918 | * |
2919 | * PARAMETERS: |
2920 | * word - dmap bitmap word value. |
2921 | * l2nb - number of free bits specified as a log2 number. |
2922 | * |
2923 | * RETURN VALUES: |
2924 | * starting bit number of free bits. |
2925 | */ |
2926 | static int dbFindBits(u32 word, int l2nb) |
2927 | { |
2928 | int bitno, nb; |
2929 | u32 mask; |
2930 | |
2931 | /* get the number of bits. |
2932 | */ |
2933 | nb = 1 << l2nb; |
2934 | assert(nb <= DBWORD); |
2935 | |
2936 | /* complement the word so we can use a mask (i.e. 0s represent |
2937 | * free bits) and compute the mask. |
2938 | */ |
2939 | word = ~word; |
2940 | mask = ONES << (DBWORD - nb); |
2941 | |
2942 | /* scan the word for nb free bits at nb alignments. |
2943 | */ |
2944 | for (bitno = 0; mask != 0; bitno += nb, mask >>= nb) { |
2945 | if ((mask & word) == mask) |
2946 | break; |
2947 | } |
2948 | |
2949 | ASSERT(bitno < 32); |
2950 | |
2951 | /* return the bit number. |
2952 | */ |
2953 | return (bitno); |
2954 | } |
2955 | |
2956 | |
2957 | /* |
2958 | * NAME: dbMaxBud(u8 *cp) |
2959 | * |
2960 | * FUNCTION: determine the largest binary buddy string of free |
2961 | * bits within 32-bits of the map. |
2962 | * |
2963 | * PARAMETERS: |
2964 | * cp - pointer to the 32-bit value. |
2965 | * |
2966 | * RETURN VALUES: |
2967 | * largest binary buddy of free bits within a dmap word. |
2968 | */ |
2969 | static int dbMaxBud(u8 * cp) |
2970 | { |
2971 | signed char tmp1, tmp2; |
2972 | |
2973 | /* check if the wmap word is all free. if so, the |
2974 | * free buddy size is BUDMIN. |
2975 | */ |
2976 | if (*((uint *) cp) == 0) |
2977 | return (BUDMIN); |
2978 | |
2979 | /* check if the wmap word is half free. if so, the |
2980 | * free buddy size is BUDMIN-1. |
2981 | */ |
2982 | if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0) |
2983 | return (BUDMIN - 1); |
2984 | |
2985 | /* not all free or half free. determine the free buddy |
2986 | * size thru table lookup using quarters of the wmap word. |
2987 | */ |
2988 | tmp1 = max(budtab[cp[2]], budtab[cp[3]]); |
2989 | tmp2 = max(budtab[cp[0]], budtab[cp[1]]); |
2990 | return (max(tmp1, tmp2)); |
2991 | } |
2992 | |
2993 | |
2994 | /* |
2995 | * NAME: cnttz(uint word) |
2996 | * |
2997 | * FUNCTION: determine the number of trailing zeros within a 32-bit |
2998 | * value. |
2999 | * |
3000 | * PARAMETERS: |
3001 | * value - 32-bit value to be examined. |
3002 | * |
3003 | * RETURN VALUES: |
3004 | * count of trailing zeros |
3005 | */ |
3006 | static int cnttz(u32 word) |
3007 | { |
3008 | int n; |
3009 | |
3010 | for (n = 0; n < 32; n++, word >>= 1) { |
3011 | if (word & 0x01) |
3012 | break; |
3013 | } |
3014 | |
3015 | return (n); |
3016 | } |
3017 | |
3018 | |
3019 | /* |
3020 | * NAME: cntlz(u32 value) |
3021 | * |
3022 | * FUNCTION: determine the number of leading zeros within a 32-bit |
3023 | * value. |
3024 | * |
3025 | * PARAMETERS: |
3026 | * value - 32-bit value to be examined. |
3027 | * |
3028 | * RETURN VALUES: |
3029 | * count of leading zeros |
3030 | */ |
3031 | static int cntlz(u32 value) |
3032 | { |
3033 | int n; |
3034 | |
3035 | for (n = 0; n < 32; n++, value <<= 1) { |
3036 | if (value & HIGHORDER) |
3037 | break; |
3038 | } |
3039 | return (n); |
3040 | } |
3041 | |
3042 | |
3043 | /* |
3044 | * NAME: blkstol2(s64 nb) |
3045 | * |
3046 | * FUNCTION: convert a block count to its log2 value. if the block |
3047 | * count is not a l2 multiple, it is rounded up to the next |
3048 | * larger l2 multiple. |
3049 | * |
3050 | * PARAMETERS: |
3051 | * nb - number of blocks |
3052 | * |
3053 | * RETURN VALUES: |
3054 | * log2 number of blocks |
3055 | */ |
3056 | static int blkstol2(s64 nb) |
3057 | { |
3058 | int l2nb; |
3059 | s64 mask; /* meant to be signed */ |
3060 | |
3061 | mask = (s64) 1 << (64 - 1); |
3062 | |
3063 | /* count the leading bits. |
3064 | */ |
3065 | for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) { |
3066 | /* leading bit found. |
3067 | */ |
3068 | if (nb & mask) { |
3069 | /* determine the l2 value. |
3070 | */ |
3071 | l2nb = (64 - 1) - l2nb; |
3072 | |
3073 | /* check if we need to round up. |
3074 | */ |
3075 | if (~mask & nb) |
3076 | l2nb++; |
3077 | |
3078 | return (l2nb); |
3079 | } |
3080 | } |
3081 | assert(0); |
3082 | return 0; /* fix compiler warning */ |
3083 | } |
3084 | |
3085 | |
3086 | /* |
3087 | * NAME: dbAllocBottomUp() |
3088 | * |
3089 | * FUNCTION: alloc the specified block range from the working block |
3090 | * allocation map. |
3091 | * |
3092 | * the blocks will be alloc from the working map one dmap |
3093 | * at a time. |
3094 | * |
3095 | * PARAMETERS: |
3096 | * ip - pointer to in-core inode; |
3097 | * blkno - starting block number to be freed. |
3098 | * nblocks - number of blocks to be freed. |
3099 | * |
3100 | * RETURN VALUES: |
3101 | * 0 - success |
3102 | * -EIO - i/o error |
3103 | */ |
3104 | int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks) |
3105 | { |
3106 | struct metapage *mp; |
3107 | struct dmap *dp; |
3108 | int nb, rc; |
3109 | s64 lblkno, rem; |
3110 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; |
3111 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; |
3112 | |
3113 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
3114 | |
3115 | /* block to be allocated better be within the mapsize. */ |
3116 | ASSERT(nblocks <= bmp->db_mapsize - blkno); |
3117 | |
3118 | /* |
3119 | * allocate the blocks a dmap at a time. |
3120 | */ |
3121 | mp = NULL; |
3122 | for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { |
3123 | /* release previous dmap if any */ |
3124 | if (mp) { |
3125 | write_metapage(mp); |
3126 | } |
3127 | |
3128 | /* get the buffer for the current dmap. */ |
3129 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); |
3130 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); |
3131 | if (mp == NULL) { |
3132 | IREAD_UNLOCK(ipbmap); |
3133 | return -EIO; |
3134 | } |
3135 | dp = (struct dmap *) mp->data; |
3136 | |
3137 | /* determine the number of blocks to be allocated from |
3138 | * this dmap. |
3139 | */ |
3140 | nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); |
3141 | |
3142 | /* allocate the blocks. */ |
3143 | if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) { |
3144 | release_metapage(mp); |
3145 | IREAD_UNLOCK(ipbmap); |
3146 | return (rc); |
3147 | } |
3148 | } |
3149 | |
3150 | /* write the last buffer. */ |
3151 | write_metapage(mp); |
3152 | |
3153 | IREAD_UNLOCK(ipbmap); |
3154 | |
3155 | return (0); |
3156 | } |
3157 | |
3158 | |
3159 | static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, |
3160 | int nblocks) |
3161 | { |
3162 | int rc; |
3163 | int dbitno, word, rembits, nb, nwords, wbitno, agno; |
3164 | s8 oldroot, *leaf; |
3165 | struct dmaptree *tp = (struct dmaptree *) & dp->tree; |
3166 | |
3167 | /* save the current value of the root (i.e. maximum free string) |
3168 | * of the dmap tree. |
3169 | */ |
3170 | oldroot = tp->stree[ROOT]; |
3171 | |
3172 | /* pick up a pointer to the leaves of the dmap tree */ |
3173 | leaf = tp->stree + LEAFIND; |
3174 | |
3175 | /* determine the bit number and word within the dmap of the |
3176 | * starting block. |
3177 | */ |
3178 | dbitno = blkno & (BPERDMAP - 1); |
3179 | word = dbitno >> L2DBWORD; |
3180 | |
3181 | /* block range better be within the dmap */ |
3182 | assert(dbitno + nblocks <= BPERDMAP); |
3183 | |
3184 | /* allocate the bits of the dmap's words corresponding to the block |
3185 | * range. not all bits of the first and last words may be contained |
3186 | * within the block range. if this is the case, we'll work against |
3187 | * those words (i.e. partial first and/or last) on an individual basis |
3188 | * (a single pass), allocating the bits of interest by hand and |
3189 | * updating the leaf corresponding to the dmap word. a single pass |
3190 | * will be used for all dmap words fully contained within the |
3191 | * specified range. within this pass, the bits of all fully contained |
3192 | * dmap words will be marked as free in a single shot and the leaves |
3193 | * will be updated. a single leaf may describe the free space of |
3194 | * multiple dmap words, so we may update only a subset of the actual |
3195 | * leaves corresponding to the dmap words of the block range. |
3196 | */ |
3197 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { |
3198 | /* determine the bit number within the word and |
3199 | * the number of bits within the word. |
3200 | */ |
3201 | wbitno = dbitno & (DBWORD - 1); |
3202 | nb = min(rembits, DBWORD - wbitno); |
3203 | |
3204 | /* check if only part of a word is to be allocated. |
3205 | */ |
3206 | if (nb < DBWORD) { |
3207 | /* allocate (set to 1) the appropriate bits within |
3208 | * this dmap word. |
3209 | */ |
3210 | dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) |
3211 | >> wbitno); |
3212 | |
3213 | word++; |
3214 | } else { |
3215 | /* one or more dmap words are fully contained |
3216 | * within the block range. determine how many |
3217 | * words and allocate (set to 1) the bits of these |
3218 | * words. |
3219 | */ |
3220 | nwords = rembits >> L2DBWORD; |
3221 | memset(&dp->wmap[word], (int) ONES, nwords * 4); |
3222 | |
3223 | /* determine how many bits */ |
3224 | nb = nwords << L2DBWORD; |
3225 | word += nwords; |
3226 | } |
3227 | } |
3228 | |
3229 | /* update the free count for this dmap */ |
3230 | le32_add_cpu(&dp->nfree, -nblocks); |
3231 | |
3232 | /* reconstruct summary tree */ |
3233 | dbInitDmapTree(dp); |
3234 | |
3235 | BMAP_LOCK(bmp); |
3236 | |
3237 | /* if this allocation group is completely free, |
3238 | * update the highest active allocation group number |
3239 | * if this allocation group is the new max. |
3240 | */ |
3241 | agno = blkno >> bmp->db_agl2size; |
3242 | if (agno > bmp->db_maxag) |
3243 | bmp->db_maxag = agno; |
3244 | |
3245 | /* update the free count for the allocation group and map */ |
3246 | bmp->db_agfree[agno] -= nblocks; |
3247 | bmp->db_nfree -= nblocks; |
3248 | |
3249 | BMAP_UNLOCK(bmp); |
3250 | |
3251 | /* if the root has not changed, done. */ |
3252 | if (tp->stree[ROOT] == oldroot) |
3253 | return (0); |
3254 | |
3255 | /* root changed. bubble the change up to the dmap control pages. |
3256 | * if the adjustment of the upper level control pages fails, |
3257 | * backout the bit allocation (thus making everything consistent). |
3258 | */ |
3259 | if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0))) |
3260 | dbFreeBits(bmp, dp, blkno, nblocks); |
3261 | |
3262 | return (rc); |
3263 | } |
3264 | |
3265 | |
3266 | /* |
3267 | * NAME: dbExtendFS() |
3268 | * |
3269 | * FUNCTION: extend bmap from blkno for nblocks; |
3270 | * dbExtendFS() updates bmap ready for dbAllocBottomUp(); |
3271 | * |
3272 | * L2 |
3273 | * | |
3274 | * L1---------------------------------L1 |
3275 | * | | |
3276 | * L0---------L0---------L0 L0---------L0---------L0 |
3277 | * | | | | | | |
3278 | * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm; |
3279 | * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm |
3280 | * |
3281 | * <---old---><----------------------------extend-----------------------> |
3282 | */ |
3283 | int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks) |
3284 | { |
3285 | struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb); |
3286 | int nbperpage = sbi->nbperpage; |
3287 | int i, i0 = true, j, j0 = true, k, n; |
3288 | s64 newsize; |
3289 | s64 p; |
3290 | struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL; |
3291 | struct dmapctl *l2dcp, *l1dcp, *l0dcp; |
3292 | struct dmap *dp; |
3293 | s8 *l0leaf, *l1leaf, *l2leaf; |
3294 | struct bmap *bmp = sbi->bmap; |
3295 | int agno, l2agsize, oldl2agsize; |
3296 | s64 ag_rem; |
3297 | |
3298 | newsize = blkno + nblocks; |
3299 | |
3300 | jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld", |
3301 | (long long) blkno, (long long) nblocks, (long long) newsize); |
3302 | |
3303 | /* |
3304 | * initialize bmap control page. |
3305 | * |
3306 | * all the data in bmap control page should exclude |
3307 | * the mkfs hidden dmap page. |
3308 | */ |
3309 | |
3310 | /* update mapsize */ |
3311 | bmp->db_mapsize = newsize; |
3312 | bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize); |
3313 | |
3314 | /* compute new AG size */ |
3315 | l2agsize = dbGetL2AGSize(newsize); |
3316 | oldl2agsize = bmp->db_agl2size; |
3317 | |
3318 | bmp->db_agl2size = l2agsize; |
3319 | bmp->db_agsize = 1 << l2agsize; |
3320 | |
3321 | /* compute new number of AG */ |
3322 | agno = bmp->db_numag; |
3323 | bmp->db_numag = newsize >> l2agsize; |
3324 | bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0; |
3325 | |
3326 | /* |
3327 | * reconfigure db_agfree[] |
3328 | * from old AG configuration to new AG configuration; |
3329 | * |
3330 | * coalesce contiguous k (newAGSize/oldAGSize) AGs; |
3331 | * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn; |
3332 | * note: new AG size = old AG size * (2**x). |
3333 | */ |
3334 | if (l2agsize == oldl2agsize) |
3335 | goto extend; |
3336 | k = 1 << (l2agsize - oldl2agsize); |
3337 | ag_rem = bmp->db_agfree[0]; /* save agfree[0] */ |
3338 | for (i = 0, n = 0; i < agno; n++) { |
3339 | bmp->db_agfree[n] = 0; /* init collection point */ |
3340 | |
3341 | /* coalesce contiguous k AGs; */ |
3342 | for (j = 0; j < k && i < agno; j++, i++) { |
3343 | /* merge AGi to AGn */ |
3344 | bmp->db_agfree[n] += bmp->db_agfree[i]; |
3345 | } |
3346 | } |
3347 | bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */ |
3348 | |
3349 | for (; n < MAXAG; n++) |
3350 | bmp->db_agfree[n] = 0; |
3351 | |
3352 | /* |
3353 | * update highest active ag number |
3354 | */ |
3355 | |
3356 | bmp->db_maxag = bmp->db_maxag / k; |
3357 | |
3358 | /* |
3359 | * extend bmap |
3360 | * |
3361 | * update bit maps and corresponding level control pages; |
3362 | * global control page db_nfree, db_agfree[agno], db_maxfreebud; |
3363 | */ |
3364 | extend: |
3365 | /* get L2 page */ |
3366 | p = BMAPBLKNO + nbperpage; /* L2 page */ |
3367 | l2mp = read_metapage(ipbmap, p, PSIZE, 0); |
3368 | if (!l2mp) { |
3369 | jfs_error(ipbmap->i_sb, "dbExtendFS: L2 page could not be read"); |
3370 | return -EIO; |
3371 | } |
3372 | l2dcp = (struct dmapctl *) l2mp->data; |
3373 | |
3374 | /* compute start L1 */ |
3375 | k = blkno >> L2MAXL1SIZE; |
3376 | l2leaf = l2dcp->stree + CTLLEAFIND + k; |
3377 | p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */ |
3378 | |
3379 | /* |
3380 | * extend each L1 in L2 |
3381 | */ |
3382 | for (; k < LPERCTL; k++, p += nbperpage) { |
3383 | /* get L1 page */ |
3384 | if (j0) { |
3385 | /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */ |
3386 | l1mp = read_metapage(ipbmap, p, PSIZE, 0); |
3387 | if (l1mp == NULL) |
3388 | goto errout; |
3389 | l1dcp = (struct dmapctl *) l1mp->data; |
3390 | |
3391 | /* compute start L0 */ |
3392 | j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE; |
3393 | l1leaf = l1dcp->stree + CTLLEAFIND + j; |
3394 | p = BLKTOL0(blkno, sbi->l2nbperpage); |
3395 | j0 = false; |
3396 | } else { |
3397 | /* assign/init L1 page */ |
3398 | l1mp = get_metapage(ipbmap, p, PSIZE, 0); |
3399 | if (l1mp == NULL) |
3400 | goto errout; |
3401 | |
3402 | l1dcp = (struct dmapctl *) l1mp->data; |
3403 | |
3404 | /* compute start L0 */ |
3405 | j = 0; |
3406 | l1leaf = l1dcp->stree + CTLLEAFIND; |
3407 | p += nbperpage; /* 1st L0 of L1.k */ |
3408 | } |
3409 | |
3410 | /* |
3411 | * extend each L0 in L1 |
3412 | */ |
3413 | for (; j < LPERCTL; j++) { |
3414 | /* get L0 page */ |
3415 | if (i0) { |
3416 | /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */ |
3417 | |
3418 | l0mp = read_metapage(ipbmap, p, PSIZE, 0); |
3419 | if (l0mp == NULL) |
3420 | goto errout; |
3421 | l0dcp = (struct dmapctl *) l0mp->data; |
3422 | |
3423 | /* compute start dmap */ |
3424 | i = (blkno & (MAXL0SIZE - 1)) >> |
3425 | L2BPERDMAP; |
3426 | l0leaf = l0dcp->stree + CTLLEAFIND + i; |
3427 | p = BLKTODMAP(blkno, |
3428 | sbi->l2nbperpage); |
3429 | i0 = false; |
3430 | } else { |
3431 | /* assign/init L0 page */ |
3432 | l0mp = get_metapage(ipbmap, p, PSIZE, 0); |
3433 | if (l0mp == NULL) |
3434 | goto errout; |
3435 | |
3436 | l0dcp = (struct dmapctl *) l0mp->data; |
3437 | |
3438 | /* compute start dmap */ |
3439 | i = 0; |
3440 | l0leaf = l0dcp->stree + CTLLEAFIND; |
3441 | p += nbperpage; /* 1st dmap of L0.j */ |
3442 | } |
3443 | |
3444 | /* |
3445 | * extend each dmap in L0 |
3446 | */ |
3447 | for (; i < LPERCTL; i++) { |
3448 | /* |
3449 | * reconstruct the dmap page, and |
3450 | * initialize corresponding parent L0 leaf |
3451 | */ |
3452 | if ((n = blkno & (BPERDMAP - 1))) { |
3453 | /* read in dmap page: */ |
3454 | mp = read_metapage(ipbmap, p, |
3455 | PSIZE, 0); |
3456 | if (mp == NULL) |
3457 | goto errout; |
3458 | n = min(nblocks, (s64)BPERDMAP - n); |
3459 | } else { |
3460 | /* assign/init dmap page */ |
3461 | mp = read_metapage(ipbmap, p, |
3462 | PSIZE, 0); |
3463 | if (mp == NULL) |
3464 | goto errout; |
3465 | |
3466 | n = min(nblocks, (s64)BPERDMAP); |
3467 | } |
3468 | |
3469 | dp = (struct dmap *) mp->data; |
3470 | *l0leaf = dbInitDmap(dp, blkno, n); |
3471 | |
3472 | bmp->db_nfree += n; |
3473 | agno = le64_to_cpu(dp->start) >> l2agsize; |
3474 | bmp->db_agfree[agno] += n; |
3475 | |
3476 | write_metapage(mp); |
3477 | |
3478 | l0leaf++; |
3479 | p += nbperpage; |
3480 | |
3481 | blkno += n; |
3482 | nblocks -= n; |
3483 | if (nblocks == 0) |
3484 | break; |
3485 | } /* for each dmap in a L0 */ |
3486 | |
3487 | /* |
3488 | * build current L0 page from its leaves, and |
3489 | * initialize corresponding parent L1 leaf |
3490 | */ |
3491 | *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i); |
3492 | write_metapage(l0mp); |
3493 | l0mp = NULL; |
3494 | |
3495 | if (nblocks) |
3496 | l1leaf++; /* continue for next L0 */ |
3497 | else { |
3498 | /* more than 1 L0 ? */ |
3499 | if (j > 0) |
3500 | break; /* build L1 page */ |
3501 | else { |
3502 | /* summarize in global bmap page */ |
3503 | bmp->db_maxfreebud = *l1leaf; |
3504 | release_metapage(l1mp); |
3505 | release_metapage(l2mp); |
3506 | goto finalize; |
3507 | } |
3508 | } |
3509 | } /* for each L0 in a L1 */ |
3510 | |
3511 | /* |
3512 | * build current L1 page from its leaves, and |
3513 | * initialize corresponding parent L2 leaf |
3514 | */ |
3515 | *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j); |
3516 | write_metapage(l1mp); |
3517 | l1mp = NULL; |
3518 | |
3519 | if (nblocks) |
3520 | l2leaf++; /* continue for next L1 */ |
3521 | else { |
3522 | /* more than 1 L1 ? */ |
3523 | if (k > 0) |
3524 | break; /* build L2 page */ |
3525 | else { |
3526 | /* summarize in global bmap page */ |
3527 | bmp->db_maxfreebud = *l2leaf; |
3528 | release_metapage(l2mp); |
3529 | goto finalize; |
3530 | } |
3531 | } |
3532 | } /* for each L1 in a L2 */ |
3533 | |
3534 | jfs_error(ipbmap->i_sb, |
3535 | "dbExtendFS: function has not returned as expected"); |
3536 | errout: |
3537 | if (l0mp) |
3538 | release_metapage(l0mp); |
3539 | if (l1mp) |
3540 | release_metapage(l1mp); |
3541 | release_metapage(l2mp); |
3542 | return -EIO; |
3543 | |
3544 | /* |
3545 | * finalize bmap control page |
3546 | */ |
3547 | finalize: |
3548 | |
3549 | return 0; |
3550 | } |
3551 | |
3552 | |
3553 | /* |
3554 | * dbFinalizeBmap() |
3555 | */ |
3556 | void dbFinalizeBmap(struct inode *ipbmap) |
3557 | { |
3558 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; |
3559 | int actags, inactags, l2nl; |
3560 | s64 ag_rem, actfree, inactfree, avgfree; |
3561 | int i, n; |
3562 | |
3563 | /* |
3564 | * finalize bmap control page |
3565 | */ |
3566 | //finalize: |
3567 | /* |
3568 | * compute db_agpref: preferred ag to allocate from |
3569 | * (the leftmost ag with average free space in it); |
3570 | */ |
3571 | //agpref: |
3572 | /* get the number of active ags and inacitve ags */ |
3573 | actags = bmp->db_maxag + 1; |
3574 | inactags = bmp->db_numag - actags; |
3575 | ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */ |
3576 | |
3577 | /* determine how many blocks are in the inactive allocation |
3578 | * groups. in doing this, we must account for the fact that |
3579 | * the rightmost group might be a partial group (i.e. file |
3580 | * system size is not a multiple of the group size). |
3581 | */ |
3582 | inactfree = (inactags && ag_rem) ? |
3583 | ((inactags - 1) << bmp->db_agl2size) + ag_rem |
3584 | : inactags << bmp->db_agl2size; |
3585 | |
3586 | /* determine how many free blocks are in the active |
3587 | * allocation groups plus the average number of free blocks |
3588 | * within the active ags. |
3589 | */ |
3590 | actfree = bmp->db_nfree - inactfree; |
3591 | avgfree = (u32) actfree / (u32) actags; |
3592 | |
3593 | /* if the preferred allocation group has not average free space. |
3594 | * re-establish the preferred group as the leftmost |
3595 | * group with average free space. |
3596 | */ |
3597 | if (bmp->db_agfree[bmp->db_agpref] < avgfree) { |
3598 | for (bmp->db_agpref = 0; bmp->db_agpref < actags; |
3599 | bmp->db_agpref++) { |
3600 | if (bmp->db_agfree[bmp->db_agpref] >= avgfree) |
3601 | break; |
3602 | } |
3603 | if (bmp->db_agpref >= bmp->db_numag) { |
3604 | jfs_error(ipbmap->i_sb, |
3605 | "cannot find ag with average freespace"); |
3606 | } |
3607 | } |
3608 | |
3609 | /* |
3610 | * compute db_aglevel, db_agheight, db_width, db_agstart: |
3611 | * an ag is covered in aglevel dmapctl summary tree, |
3612 | * at agheight level height (from leaf) with agwidth number of nodes |
3613 | * each, which starts at agstart index node of the smmary tree node |
3614 | * array; |
3615 | */ |
3616 | bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize); |
3617 | l2nl = |
3618 | bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL); |
3619 | bmp->db_agheight = l2nl >> 1; |
3620 | bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheight << 1)); |
3621 | for (i = 5 - bmp->db_agheight, bmp->db_agstart = 0, n = 1; i > 0; |
3622 | i--) { |
3623 | bmp->db_agstart += n; |
3624 | n <<= 2; |
3625 | } |
3626 | |
3627 | } |
3628 | |
3629 | |
3630 | /* |
3631 | * NAME: dbInitDmap()/ujfs_idmap_page() |
3632 | * |
3633 | * FUNCTION: initialize working/persistent bitmap of the dmap page |
3634 | * for the specified number of blocks: |
3635 | * |
3636 | * at entry, the bitmaps had been initialized as free (ZEROS); |
3637 | * The number of blocks will only account for the actually |
3638 | * existing blocks. Blocks which don't actually exist in |
3639 | * the aggregate will be marked as allocated (ONES); |
3640 | * |
3641 | * PARAMETERS: |
3642 | * dp - pointer to page of map |
3643 | * nblocks - number of blocks this page |
3644 | * |
3645 | * RETURNS: NONE |
3646 | */ |
3647 | static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks) |
3648 | { |
3649 | int blkno, w, b, r, nw, nb, i; |
3650 | |
3651 | /* starting block number within the dmap */ |
3652 | blkno = Blkno & (BPERDMAP - 1); |
3653 | |
3654 | if (blkno == 0) { |
3655 | dp->nblocks = dp->nfree = cpu_to_le32(nblocks); |
3656 | dp->start = cpu_to_le64(Blkno); |
3657 | |
3658 | if (nblocks == BPERDMAP) { |
3659 | memset(&dp->wmap[0], 0, LPERDMAP * 4); |
3660 | memset(&dp->pmap[0], 0, LPERDMAP * 4); |
3661 | goto initTree; |
3662 | } |
3663 | } else { |
3664 | le32_add_cpu(&dp->nblocks, nblocks); |
3665 | le32_add_cpu(&dp->nfree, nblocks); |
3666 | } |
3667 | |
3668 | /* word number containing start block number */ |
3669 | w = blkno >> L2DBWORD; |
3670 | |
3671 | /* |
3672 | * free the bits corresponding to the block range (ZEROS): |
3673 | * note: not all bits of the first and last words may be contained |
3674 | * within the block range. |
3675 | */ |
3676 | for (r = nblocks; r > 0; r -= nb, blkno += nb) { |
3677 | /* number of bits preceding range to be freed in the word */ |
3678 | b = blkno & (DBWORD - 1); |
3679 | /* number of bits to free in the word */ |
3680 | nb = min(r, DBWORD - b); |
3681 | |
3682 | /* is partial word to be freed ? */ |
3683 | if (nb < DBWORD) { |
3684 | /* free (set to 0) from the bitmap word */ |
3685 | dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) |
3686 | >> b)); |
3687 | dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) |
3688 | >> b)); |
3689 | |
3690 | /* skip the word freed */ |
3691 | w++; |
3692 | } else { |
3693 | /* free (set to 0) contiguous bitmap words */ |
3694 | nw = r >> L2DBWORD; |
3695 | memset(&dp->wmap[w], 0, nw * 4); |
3696 | memset(&dp->pmap[w], 0, nw * 4); |
3697 | |
3698 | /* skip the words freed */ |
3699 | nb = nw << L2DBWORD; |
3700 | w += nw; |
3701 | } |
3702 | } |
3703 | |
3704 | /* |
3705 | * mark bits following the range to be freed (non-existing |
3706 | * blocks) as allocated (ONES) |
3707 | */ |
3708 | |
3709 | if (blkno == BPERDMAP) |
3710 | goto initTree; |
3711 | |
3712 | /* the first word beyond the end of existing blocks */ |
3713 | w = blkno >> L2DBWORD; |
3714 | |
3715 | /* does nblocks fall on a 32-bit boundary ? */ |
3716 | b = blkno & (DBWORD - 1); |
3717 | if (b) { |
3718 | /* mark a partial word allocated */ |
3719 | dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b); |
3720 | w++; |
3721 | } |
3722 | |
3723 | /* set the rest of the words in the page to allocated (ONES) */ |
3724 | for (i = w; i < LPERDMAP; i++) |
3725 | dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES); |
3726 | |
3727 | /* |
3728 | * init tree |
3729 | */ |
3730 | initTree: |
3731 | return (dbInitDmapTree(dp)); |
3732 | } |
3733 | |
3734 | |
3735 | /* |
3736 | * NAME: dbInitDmapTree()/ujfs_complete_dmap() |
3737 | * |
3738 | * FUNCTION: initialize summary tree of the specified dmap: |
3739 | * |
3740 | * at entry, bitmap of the dmap has been initialized; |
3741 | * |
3742 | * PARAMETERS: |
3743 | * dp - dmap to complete |
3744 | * blkno - starting block number for this dmap |
3745 | * treemax - will be filled in with max free for this dmap |
3746 | * |
3747 | * RETURNS: max free string at the root of the tree |
3748 | */ |
3749 | static int dbInitDmapTree(struct dmap * dp) |
3750 | { |
3751 | struct dmaptree *tp; |
3752 | s8 *cp; |
3753 | int i; |
3754 | |
3755 | /* init fixed info of tree */ |
3756 | tp = &dp->tree; |
3757 | tp->nleafs = cpu_to_le32(LPERDMAP); |
3758 | tp->l2nleafs = cpu_to_le32(L2LPERDMAP); |
3759 | tp->leafidx = cpu_to_le32(LEAFIND); |
3760 | tp->height = cpu_to_le32(4); |
3761 | tp->budmin = BUDMIN; |
3762 | |
3763 | /* init each leaf from corresponding wmap word: |
3764 | * note: leaf is set to NOFREE(-1) if all blocks of corresponding |
3765 | * bitmap word are allocated. |
3766 | */ |
3767 | cp = tp->stree + le32_to_cpu(tp->leafidx); |
3768 | for (i = 0; i < LPERDMAP; i++) |
3769 | *cp++ = dbMaxBud((u8 *) & dp->wmap[i]); |
3770 | |
3771 | /* build the dmap's binary buddy summary tree */ |
3772 | return (dbInitTree(tp)); |
3773 | } |
3774 | |
3775 | |
3776 | /* |
3777 | * NAME: dbInitTree()/ujfs_adjtree() |
3778 | * |
3779 | * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl. |
3780 | * |
3781 | * at entry, the leaves of the tree has been initialized |
3782 | * from corresponding bitmap word or root of summary tree |
3783 | * of the child control page; |
3784 | * configure binary buddy system at the leaf level, then |
3785 | * bubble up the values of the leaf nodes up the tree. |
3786 | * |
3787 | * PARAMETERS: |
3788 | * cp - Pointer to the root of the tree |
3789 | * l2leaves- Number of leaf nodes as a power of 2 |
3790 | * l2min - Number of blocks that can be covered by a leaf |
3791 | * as a power of 2 |
3792 | * |
3793 | * RETURNS: max free string at the root of the tree |
3794 | */ |
3795 | static int dbInitTree(struct dmaptree * dtp) |
3796 | { |
3797 | int l2max, l2free, bsize, nextb, i; |
3798 | int child, parent, nparent; |
3799 | s8 *tp, *cp, *cp1; |
3800 | |
3801 | tp = dtp->stree; |
3802 | |
3803 | /* Determine the maximum free string possible for the leaves */ |
3804 | l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin; |
3805 | |
3806 | /* |
3807 | * configure the leaf levevl into binary buddy system |
3808 | * |
3809 | * Try to combine buddies starting with a buddy size of 1 |
3810 | * (i.e. two leaves). At a buddy size of 1 two buddy leaves |
3811 | * can be combined if both buddies have a maximum free of l2min; |
3812 | * the combination will result in the left-most buddy leaf having |
3813 | * a maximum free of l2min+1. |
3814 | * After processing all buddies for a given size, process buddies |
3815 | * at the next higher buddy size (i.e. current size * 2) and |
3816 | * the next maximum free (current free + 1). |
3817 | * This continues until the maximum possible buddy combination |
3818 | * yields maximum free. |
3819 | */ |
3820 | for (l2free = dtp->budmin, bsize = 1; l2free < l2max; |
3821 | l2free++, bsize = nextb) { |
3822 | /* get next buddy size == current buddy pair size */ |
3823 | nextb = bsize << 1; |
3824 | |
3825 | /* scan each adjacent buddy pair at current buddy size */ |
3826 | for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx); |
3827 | i < le32_to_cpu(dtp->nleafs); |
3828 | i += nextb, cp += nextb) { |
3829 | /* coalesce if both adjacent buddies are max free */ |
3830 | if (*cp == l2free && *(cp + bsize) == l2free) { |
3831 | *cp = l2free + 1; /* left take right */ |
3832 | *(cp + bsize) = -1; /* right give left */ |
3833 | } |
3834 | } |
3835 | } |
3836 | |
3837 | /* |
3838 | * bubble summary information of leaves up the tree. |
3839 | * |
3840 | * Starting at the leaf node level, the four nodes described by |
3841 | * the higher level parent node are compared for a maximum free and |
3842 | * this maximum becomes the value of the parent node. |
3843 | * when all lower level nodes are processed in this fashion then |
3844 | * move up to the next level (parent becomes a lower level node) and |
3845 | * continue the process for that level. |
3846 | */ |
3847 | for (child = le32_to_cpu(dtp->leafidx), |
3848 | nparent = le32_to_cpu(dtp->nleafs) >> 2; |
3849 | nparent > 0; nparent >>= 2, child = parent) { |
3850 | /* get index of 1st node of parent level */ |
3851 | parent = (child - 1) >> 2; |
3852 | |
3853 | /* set the value of the parent node as the maximum |
3854 | * of the four nodes of the current level. |
3855 | */ |
3856 | for (i = 0, cp = tp + child, cp1 = tp + parent; |
3857 | i < nparent; i++, cp += 4, cp1++) |
3858 | *cp1 = TREEMAX(cp); |
3859 | } |
3860 | |
3861 | return (*tp); |
3862 | } |
3863 | |
3864 | |
3865 | /* |
3866 | * dbInitDmapCtl() |
3867 | * |
3868 | * function: initialize dmapctl page |
3869 | */ |
3870 | static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i) |
3871 | { /* start leaf index not covered by range */ |
3872 | s8 *cp; |
3873 | |
3874 | dcp->nleafs = cpu_to_le32(LPERCTL); |
3875 | dcp->l2nleafs = cpu_to_le32(L2LPERCTL); |
3876 | dcp->leafidx = cpu_to_le32(CTLLEAFIND); |
3877 | dcp->height = cpu_to_le32(5); |
3878 | dcp->budmin = L2BPERDMAP + L2LPERCTL * level; |
3879 | |
3880 | /* |
3881 | * initialize the leaves of current level that were not covered |
3882 | * by the specified input block range (i.e. the leaves have no |
3883 | * low level dmapctl or dmap). |
3884 | */ |
3885 | cp = &dcp->stree[CTLLEAFIND + i]; |
3886 | for (; i < LPERCTL; i++) |
3887 | *cp++ = NOFREE; |
3888 | |
3889 | /* build the dmap's binary buddy summary tree */ |
3890 | return (dbInitTree((struct dmaptree *) dcp)); |
3891 | } |
3892 | |
3893 | |
3894 | /* |
3895 | * NAME: dbGetL2AGSize()/ujfs_getagl2size() |
3896 | * |
3897 | * FUNCTION: Determine log2(allocation group size) from aggregate size |
3898 | * |
3899 | * PARAMETERS: |
3900 | * nblocks - Number of blocks in aggregate |
3901 | * |
3902 | * RETURNS: log2(allocation group size) in aggregate blocks |
3903 | */ |
3904 | static int dbGetL2AGSize(s64 nblocks) |
3905 | { |
3906 | s64 sz; |
3907 | s64 m; |
3908 | int l2sz; |
3909 | |
3910 | if (nblocks < BPERDMAP * MAXAG) |
3911 | return (L2BPERDMAP); |
3912 | |
3913 | /* round up aggregate size to power of 2 */ |
3914 | m = ((u64) 1 << (64 - 1)); |
3915 | for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) { |
3916 | if (m & nblocks) |
3917 | break; |
3918 | } |
3919 | |
3920 | sz = (s64) 1 << l2sz; |
3921 | if (sz < nblocks) |
3922 | l2sz += 1; |
3923 | |
3924 | /* agsize = roundupSize/max_number_of_ag */ |
3925 | return (l2sz - L2MAXAG); |
3926 | } |
3927 | |
3928 | |
3929 | /* |
3930 | * NAME: dbMapFileSizeToMapSize() |
3931 | * |
3932 | * FUNCTION: compute number of blocks the block allocation map file |
3933 | * can cover from the map file size; |
3934 | * |
3935 | * RETURNS: Number of blocks which can be covered by this block map file; |
3936 | */ |
3937 | |
3938 | /* |
3939 | * maximum number of map pages at each level including control pages |
3940 | */ |
3941 | #define MAXL0PAGES (1 + LPERCTL) |
3942 | #define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES) |
3943 | #define MAXL2PAGES (1 + LPERCTL * MAXL1PAGES) |
3944 | |
3945 | /* |
3946 | * convert number of map pages to the zero origin top dmapctl level |
3947 | */ |
3948 | #define BMAPPGTOLEV(npages) \ |
3949 | (((npages) <= 3 + MAXL0PAGES) ? 0 : \ |
3950 | ((npages) <= 2 + MAXL1PAGES) ? 1 : 2) |
3951 | |
3952 | s64 dbMapFileSizeToMapSize(struct inode * ipbmap) |
3953 | { |
3954 | struct super_block *sb = ipbmap->i_sb; |
3955 | s64 nblocks; |
3956 | s64 npages, ndmaps; |
3957 | int level, i; |
3958 | int complete, factor; |
3959 | |
3960 | nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize; |
3961 | npages = nblocks >> JFS_SBI(sb)->l2nbperpage; |
3962 | level = BMAPPGTOLEV(npages); |
3963 | |
3964 | /* At each level, accumulate the number of dmap pages covered by |
3965 | * the number of full child levels below it; |
3966 | * repeat for the last incomplete child level. |
3967 | */ |
3968 | ndmaps = 0; |
3969 | npages--; /* skip the first global control page */ |
3970 | /* skip higher level control pages above top level covered by map */ |
3971 | npages -= (2 - level); |
3972 | npages--; /* skip top level's control page */ |
3973 | for (i = level; i >= 0; i--) { |
3974 | factor = |
3975 | (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1); |
3976 | complete = (u32) npages / factor; |
3977 | ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL : |
3978 | ((i == 1) ? LPERCTL : 1)); |
3979 | |
3980 | /* pages in last/incomplete child */ |
3981 | npages = (u32) npages % factor; |
3982 | /* skip incomplete child's level control page */ |
3983 | npages--; |
3984 | } |
3985 | |
3986 | /* convert the number of dmaps into the number of blocks |
3987 | * which can be covered by the dmaps; |
3988 | */ |
3989 | nblocks = ndmaps << L2BPERDMAP; |
3990 | |
3991 | return (nblocks); |
3992 | } |
3993 |
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