Commit | Line | Data |
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1da177e4 LT |
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 | |
63f83c9f | 6 | * the Free Software Foundation; either version 2 of the License, or |
1da177e4 | 7 | * (at your option) any later version. |
63f83c9f | 8 | * |
1da177e4 LT |
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 | |
63f83c9f | 15 | * along with this program; if not, write to the Free Software |
1da177e4 LT |
16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
17 | */ | |
18 | ||
19 | #include <linux/fs.h> | |
20 | #include "jfs_incore.h" | |
21 | #include "jfs_superblock.h" | |
22 | #include "jfs_dmap.h" | |
23 | #include "jfs_imap.h" | |
24 | #include "jfs_lock.h" | |
25 | #include "jfs_metapage.h" | |
26 | #include "jfs_debug.h" | |
27 | ||
1da177e4 LT |
28 | /* |
29 | * SERIALIZATION of the Block Allocation Map. | |
30 | * | |
31 | * the working state of the block allocation map is accessed in | |
32 | * two directions: | |
63f83c9f | 33 | * |
1da177e4 LT |
34 | * 1) allocation and free requests that start at the dmap |
35 | * level and move up through the dmap control pages (i.e. | |
36 | * the vast majority of requests). | |
63f83c9f DK |
37 | * |
38 | * 2) allocation requests that start at dmap control page | |
1da177e4 | 39 | * level and work down towards the dmaps. |
1da177e4 | 40 | * |
63f83c9f DK |
41 | * the serialization scheme used here is as follows. |
42 | * | |
43 | * requests which start at the bottom are serialized against each | |
44 | * other through buffers and each requests holds onto its buffers | |
45 | * as it works it way up from a single dmap to the required level | |
1da177e4 LT |
46 | * of dmap control page. |
47 | * requests that start at the top are serialized against each other | |
48 | * and request that start from the bottom by the multiple read/single | |
49 | * write inode lock of the bmap inode. requests starting at the top | |
50 | * take this lock in write mode while request starting at the bottom | |
51 | * take the lock in read mode. a single top-down request may proceed | |
63f83c9f DK |
52 | * exclusively while multiple bottoms-up requests may proceed |
53 | * simultaneously (under the protection of busy buffers). | |
54 | * | |
1da177e4 LT |
55 | * in addition to information found in dmaps and dmap control pages, |
56 | * the working state of the block allocation map also includes read/ | |
57 | * write information maintained in the bmap descriptor (i.e. total | |
58 | * free block count, allocation group level free block counts). | |
59 | * a single exclusive lock (BMAP_LOCK) is used to guard this information | |
60 | * in the face of multiple-bottoms up requests. | |
61 | * (lock ordering: IREAD_LOCK, BMAP_LOCK); | |
63f83c9f | 62 | * |
1da177e4 LT |
63 | * accesses to the persistent state of the block allocation map (limited |
64 | * to the persistent bitmaps in dmaps) is guarded by (busy) buffers. | |
65 | */ | |
66 | ||
1de87444 IM |
67 | #define BMAP_LOCK_INIT(bmp) mutex_init(&bmp->db_bmaplock) |
68 | #define BMAP_LOCK(bmp) mutex_lock(&bmp->db_bmaplock) | |
69 | #define BMAP_UNLOCK(bmp) mutex_unlock(&bmp->db_bmaplock) | |
1da177e4 LT |
70 | |
71 | /* | |
72 | * forward references | |
73 | */ | |
74 | static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
75 | int nblocks); | |
76 | static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval); | |
b6a47fd8 | 77 | static int dbBackSplit(dmtree_t * tp, int leafno); |
56d12549 | 78 | static int dbJoin(dmtree_t * tp, int leafno, int newval); |
1da177e4 LT |
79 | static void dbAdjTree(dmtree_t * tp, int leafno, int newval); |
80 | static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, | |
81 | int level); | |
82 | static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results); | |
83 | static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
84 | int nblocks); | |
85 | static int dbAllocNear(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
86 | int nblocks, | |
87 | int l2nb, s64 * results); | |
88 | static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
89 | int nblocks); | |
90 | static int dbAllocDmapLev(struct bmap * bmp, struct dmap * dp, int nblocks, | |
91 | int l2nb, | |
92 | s64 * results); | |
93 | static int dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, | |
94 | s64 * results); | |
95 | static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, | |
96 | s64 * results); | |
97 | static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks); | |
98 | static int dbFindBits(u32 word, int l2nb); | |
99 | static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno); | |
100 | static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx); | |
56d12549 DK |
101 | static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
102 | int nblocks); | |
1da177e4 LT |
103 | static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
104 | int nblocks); | |
105 | static int dbMaxBud(u8 * cp); | |
106 | s64 dbMapFileSizeToMapSize(struct inode *ipbmap); | |
107 | static int blkstol2(s64 nb); | |
108 | ||
109 | static int cntlz(u32 value); | |
110 | static int cnttz(u32 word); | |
111 | ||
112 | static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
113 | int nblocks); | |
114 | static int dbInitDmap(struct dmap * dp, s64 blkno, int nblocks); | |
115 | static int dbInitDmapTree(struct dmap * dp); | |
116 | static int dbInitTree(struct dmaptree * dtp); | |
117 | static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i); | |
118 | static int dbGetL2AGSize(s64 nblocks); | |
119 | ||
120 | /* | |
121 | * buddy table | |
122 | * | |
63f83c9f | 123 | * table used for determining buddy sizes within characters of |
1da177e4 LT |
124 | * dmap bitmap words. the characters themselves serve as indexes |
125 | * into the table, with the table elements yielding the maximum | |
126 | * binary buddy of free bits within the character. | |
127 | */ | |
4d5dbd09 | 128 | static const s8 budtab[256] = { |
1da177e4 LT |
129 | 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
130 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
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, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
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, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
138 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
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, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
142 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
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, -1 | |
145 | }; | |
146 | ||
147 | ||
148 | /* | |
63f83c9f | 149 | * NAME: dbMount() |
1da177e4 LT |
150 | * |
151 | * FUNCTION: initializate the block allocation map. | |
152 | * | |
153 | * memory is allocated for the in-core bmap descriptor and | |
154 | * the in-core descriptor is initialized from disk. | |
155 | * | |
156 | * PARAMETERS: | |
f720e3ba | 157 | * ipbmap - pointer to in-core inode for the block map. |
1da177e4 LT |
158 | * |
159 | * RETURN VALUES: | |
f720e3ba DK |
160 | * 0 - success |
161 | * -ENOMEM - insufficient memory | |
162 | * -EIO - i/o error | |
1da177e4 LT |
163 | */ |
164 | int dbMount(struct inode *ipbmap) | |
165 | { | |
166 | struct bmap *bmp; | |
167 | struct dbmap_disk *dbmp_le; | |
168 | struct metapage *mp; | |
169 | int i; | |
170 | ||
171 | /* | |
172 | * allocate/initialize the in-memory bmap descriptor | |
173 | */ | |
174 | /* allocate memory for the in-memory bmap descriptor */ | |
175 | bmp = kmalloc(sizeof(struct bmap), GFP_KERNEL); | |
176 | if (bmp == NULL) | |
177 | return -ENOMEM; | |
178 | ||
179 | /* read the on-disk bmap descriptor. */ | |
180 | mp = read_metapage(ipbmap, | |
181 | BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, | |
182 | PSIZE, 0); | |
183 | if (mp == NULL) { | |
184 | kfree(bmp); | |
185 | return -EIO; | |
186 | } | |
187 | ||
188 | /* copy the on-disk bmap descriptor to its in-memory version. */ | |
189 | dbmp_le = (struct dbmap_disk *) mp->data; | |
190 | bmp->db_mapsize = le64_to_cpu(dbmp_le->dn_mapsize); | |
191 | bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree); | |
192 | bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage); | |
193 | bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag); | |
194 | bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel); | |
195 | bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag); | |
196 | bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref); | |
197 | bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel); | |
198 | bmp->db_agheigth = le32_to_cpu(dbmp_le->dn_agheigth); | |
199 | bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth); | |
200 | bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart); | |
201 | bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size); | |
202 | for (i = 0; i < MAXAG; i++) | |
203 | bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]); | |
204 | bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize); | |
205 | bmp->db_maxfreebud = dbmp_le->dn_maxfreebud; | |
206 | ||
207 | /* release the buffer. */ | |
208 | release_metapage(mp); | |
209 | ||
210 | /* bind the bmap inode and the bmap descriptor to each other. */ | |
211 | bmp->db_ipbmap = ipbmap; | |
212 | JFS_SBI(ipbmap->i_sb)->bmap = bmp; | |
213 | ||
214 | memset(bmp->db_active, 0, sizeof(bmp->db_active)); | |
1da177e4 LT |
215 | |
216 | /* | |
217 | * allocate/initialize the bmap lock | |
218 | */ | |
219 | BMAP_LOCK_INIT(bmp); | |
220 | ||
221 | return (0); | |
222 | } | |
223 | ||
224 | ||
225 | /* | |
63f83c9f | 226 | * NAME: dbUnmount() |
1da177e4 LT |
227 | * |
228 | * FUNCTION: terminate the block allocation map in preparation for | |
229 | * file system unmount. | |
230 | * | |
63f83c9f | 231 | * the in-core bmap descriptor is written to disk and |
1da177e4 LT |
232 | * the memory for this descriptor is freed. |
233 | * | |
234 | * PARAMETERS: | |
f720e3ba | 235 | * ipbmap - pointer to in-core inode for the block map. |
1da177e4 LT |
236 | * |
237 | * RETURN VALUES: | |
f720e3ba DK |
238 | * 0 - success |
239 | * -EIO - i/o error | |
1da177e4 LT |
240 | */ |
241 | int dbUnmount(struct inode *ipbmap, int mounterror) | |
242 | { | |
243 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
1da177e4 LT |
244 | |
245 | if (!(mounterror || isReadOnly(ipbmap))) | |
246 | dbSync(ipbmap); | |
247 | ||
248 | /* | |
249 | * Invalidate the page cache buffers | |
250 | */ | |
251 | truncate_inode_pages(ipbmap->i_mapping, 0); | |
252 | ||
1da177e4 LT |
253 | /* free the memory for the in-memory bmap. */ |
254 | kfree(bmp); | |
255 | ||
256 | return (0); | |
257 | } | |
258 | ||
259 | /* | |
260 | * dbSync() | |
261 | */ | |
262 | int dbSync(struct inode *ipbmap) | |
263 | { | |
264 | struct dbmap_disk *dbmp_le; | |
265 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
266 | struct metapage *mp; | |
267 | int i; | |
268 | ||
269 | /* | |
270 | * write bmap global control page | |
271 | */ | |
272 | /* get the buffer for the on-disk bmap descriptor. */ | |
273 | mp = read_metapage(ipbmap, | |
274 | BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, | |
275 | PSIZE, 0); | |
276 | if (mp == NULL) { | |
277 | jfs_err("dbSync: read_metapage failed!"); | |
278 | return -EIO; | |
279 | } | |
280 | /* copy the in-memory version of the bmap to the on-disk version */ | |
281 | dbmp_le = (struct dbmap_disk *) mp->data; | |
282 | dbmp_le->dn_mapsize = cpu_to_le64(bmp->db_mapsize); | |
283 | dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree); | |
284 | dbmp_le->dn_l2nbperpage = cpu_to_le32(bmp->db_l2nbperpage); | |
285 | dbmp_le->dn_numag = cpu_to_le32(bmp->db_numag); | |
286 | dbmp_le->dn_maxlevel = cpu_to_le32(bmp->db_maxlevel); | |
287 | dbmp_le->dn_maxag = cpu_to_le32(bmp->db_maxag); | |
288 | dbmp_le->dn_agpref = cpu_to_le32(bmp->db_agpref); | |
289 | dbmp_le->dn_aglevel = cpu_to_le32(bmp->db_aglevel); | |
290 | dbmp_le->dn_agheigth = cpu_to_le32(bmp->db_agheigth); | |
291 | dbmp_le->dn_agwidth = cpu_to_le32(bmp->db_agwidth); | |
292 | dbmp_le->dn_agstart = cpu_to_le32(bmp->db_agstart); | |
293 | dbmp_le->dn_agl2size = cpu_to_le32(bmp->db_agl2size); | |
294 | for (i = 0; i < MAXAG; i++) | |
295 | dbmp_le->dn_agfree[i] = cpu_to_le64(bmp->db_agfree[i]); | |
296 | dbmp_le->dn_agsize = cpu_to_le64(bmp->db_agsize); | |
297 | dbmp_le->dn_maxfreebud = bmp->db_maxfreebud; | |
298 | ||
299 | /* write the buffer */ | |
300 | write_metapage(mp); | |
301 | ||
302 | /* | |
303 | * write out dirty pages of bmap | |
304 | */ | |
28fd1298 | 305 | filemap_write_and_wait(ipbmap->i_mapping); |
1da177e4 | 306 | |
1da177e4 LT |
307 | diWriteSpecial(ipbmap, 0); |
308 | ||
309 | return (0); | |
310 | } | |
311 | ||
312 | ||
313 | /* | |
63f83c9f | 314 | * NAME: dbFree() |
1da177e4 LT |
315 | * |
316 | * FUNCTION: free the specified block range from the working block | |
317 | * allocation map. | |
318 | * | |
319 | * the blocks will be free from the working map one dmap | |
320 | * at a time. | |
321 | * | |
322 | * PARAMETERS: | |
f720e3ba DK |
323 | * ip - pointer to in-core inode; |
324 | * blkno - starting block number to be freed. | |
325 | * nblocks - number of blocks to be freed. | |
1da177e4 LT |
326 | * |
327 | * RETURN VALUES: | |
f720e3ba DK |
328 | * 0 - success |
329 | * -EIO - i/o error | |
1da177e4 LT |
330 | */ |
331 | int dbFree(struct inode *ip, s64 blkno, s64 nblocks) | |
332 | { | |
333 | struct metapage *mp; | |
334 | struct dmap *dp; | |
335 | int nb, rc; | |
336 | s64 lblkno, rem; | |
337 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
338 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; | |
339 | ||
82d5b9a7 | 340 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
341 | |
342 | /* block to be freed better be within the mapsize. */ | |
343 | if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) { | |
344 | IREAD_UNLOCK(ipbmap); | |
345 | printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", | |
346 | (unsigned long long) blkno, | |
347 | (unsigned long long) nblocks); | |
348 | jfs_error(ip->i_sb, | |
349 | "dbFree: block to be freed is outside the map"); | |
350 | return -EIO; | |
351 | } | |
352 | ||
353 | /* | |
354 | * free the blocks a dmap at a time. | |
355 | */ | |
356 | mp = NULL; | |
357 | for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { | |
358 | /* release previous dmap if any */ | |
359 | if (mp) { | |
360 | write_metapage(mp); | |
361 | } | |
362 | ||
363 | /* get the buffer for the current dmap. */ | |
364 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
365 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
366 | if (mp == NULL) { | |
367 | IREAD_UNLOCK(ipbmap); | |
368 | return -EIO; | |
369 | } | |
370 | dp = (struct dmap *) mp->data; | |
371 | ||
372 | /* determine the number of blocks to be freed from | |
373 | * this dmap. | |
374 | */ | |
375 | nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); | |
376 | ||
1da177e4 LT |
377 | /* free the blocks. */ |
378 | if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) { | |
56d12549 | 379 | jfs_error(ip->i_sb, "dbFree: error in block map\n"); |
1da177e4 LT |
380 | release_metapage(mp); |
381 | IREAD_UNLOCK(ipbmap); | |
382 | return (rc); | |
383 | } | |
1da177e4 LT |
384 | } |
385 | ||
386 | /* write the last buffer. */ | |
387 | write_metapage(mp); | |
388 | ||
389 | IREAD_UNLOCK(ipbmap); | |
390 | ||
391 | return (0); | |
392 | } | |
393 | ||
394 | ||
395 | /* | |
396 | * NAME: dbUpdatePMap() | |
397 | * | |
f720e3ba | 398 | * FUNCTION: update the allocation state (free or allocate) of the |
1da177e4 | 399 | * specified block range in the persistent block allocation map. |
63f83c9f | 400 | * |
1da177e4 LT |
401 | * the blocks will be updated in the persistent map one |
402 | * dmap at a time. | |
403 | * | |
404 | * PARAMETERS: | |
f720e3ba DK |
405 | * ipbmap - pointer to in-core inode for the block map. |
406 | * free - 'true' if block range is to be freed from the persistent | |
407 | * map; 'false' if it is to be allocated. | |
408 | * blkno - starting block number of the range. | |
409 | * nblocks - number of contiguous blocks in the range. | |
410 | * tblk - transaction block; | |
1da177e4 LT |
411 | * |
412 | * RETURN VALUES: | |
f720e3ba DK |
413 | * 0 - success |
414 | * -EIO - i/o error | |
1da177e4 LT |
415 | */ |
416 | int | |
417 | dbUpdatePMap(struct inode *ipbmap, | |
418 | int free, s64 blkno, s64 nblocks, struct tblock * tblk) | |
419 | { | |
420 | int nblks, dbitno, wbitno, rbits; | |
421 | int word, nbits, nwords; | |
422 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
423 | s64 lblkno, rem, lastlblkno; | |
424 | u32 mask; | |
425 | struct dmap *dp; | |
426 | struct metapage *mp; | |
427 | struct jfs_log *log; | |
428 | int lsn, difft, diffp; | |
7fab479b | 429 | unsigned long flags; |
1da177e4 LT |
430 | |
431 | /* the blocks better be within the mapsize. */ | |
432 | if (blkno + nblocks > bmp->db_mapsize) { | |
433 | printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", | |
434 | (unsigned long long) blkno, | |
435 | (unsigned long long) nblocks); | |
436 | jfs_error(ipbmap->i_sb, | |
437 | "dbUpdatePMap: blocks are outside the map"); | |
438 | return -EIO; | |
439 | } | |
440 | ||
441 | /* compute delta of transaction lsn from log syncpt */ | |
442 | lsn = tblk->lsn; | |
443 | log = (struct jfs_log *) JFS_SBI(tblk->sb)->log; | |
444 | logdiff(difft, lsn, log); | |
445 | ||
446 | /* | |
447 | * update the block state a dmap at a time. | |
448 | */ | |
449 | mp = NULL; | |
450 | lastlblkno = 0; | |
451 | for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) { | |
452 | /* get the buffer for the current dmap. */ | |
453 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
454 | if (lblkno != lastlblkno) { | |
455 | if (mp) { | |
456 | write_metapage(mp); | |
457 | } | |
458 | ||
459 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, | |
460 | 0); | |
461 | if (mp == NULL) | |
462 | return -EIO; | |
7fab479b | 463 | metapage_wait_for_io(mp); |
1da177e4 LT |
464 | } |
465 | dp = (struct dmap *) mp->data; | |
466 | ||
467 | /* determine the bit number and word within the dmap of | |
468 | * the starting block. also determine how many blocks | |
469 | * are to be updated within this dmap. | |
470 | */ | |
471 | dbitno = blkno & (BPERDMAP - 1); | |
472 | word = dbitno >> L2DBWORD; | |
473 | nblks = min(rem, (s64)BPERDMAP - dbitno); | |
474 | ||
475 | /* update the bits of the dmap words. the first and last | |
476 | * words may only have a subset of their bits updated. if | |
477 | * this is the case, we'll work against that word (i.e. | |
63f83c9f | 478 | * partial first and/or last) only in a single pass. a |
1da177e4 LT |
479 | * single pass will also be used to update all words that |
480 | * are to have all their bits updated. | |
481 | */ | |
482 | for (rbits = nblks; rbits > 0; | |
483 | rbits -= nbits, dbitno += nbits) { | |
484 | /* determine the bit number within the word and | |
485 | * the number of bits within the word. | |
486 | */ | |
487 | wbitno = dbitno & (DBWORD - 1); | |
488 | nbits = min(rbits, DBWORD - wbitno); | |
489 | ||
490 | /* check if only part of the word is to be updated. */ | |
491 | if (nbits < DBWORD) { | |
492 | /* update (free or allocate) the bits | |
493 | * in this word. | |
494 | */ | |
495 | mask = | |
496 | (ONES << (DBWORD - nbits) >> wbitno); | |
497 | if (free) | |
498 | dp->pmap[word] &= | |
499 | cpu_to_le32(~mask); | |
500 | else | |
501 | dp->pmap[word] |= | |
502 | cpu_to_le32(mask); | |
503 | ||
504 | word += 1; | |
505 | } else { | |
506 | /* one or more words are to have all | |
507 | * their bits updated. determine how | |
508 | * many words and how many bits. | |
509 | */ | |
510 | nwords = rbits >> L2DBWORD; | |
511 | nbits = nwords << L2DBWORD; | |
512 | ||
513 | /* update (free or allocate) the bits | |
514 | * in these words. | |
515 | */ | |
516 | if (free) | |
517 | memset(&dp->pmap[word], 0, | |
518 | nwords * 4); | |
519 | else | |
520 | memset(&dp->pmap[word], (int) ONES, | |
521 | nwords * 4); | |
522 | ||
523 | word += nwords; | |
524 | } | |
525 | } | |
526 | ||
527 | /* | |
528 | * update dmap lsn | |
529 | */ | |
530 | if (lblkno == lastlblkno) | |
531 | continue; | |
532 | ||
533 | lastlblkno = lblkno; | |
534 | ||
be0bf7da | 535 | LOGSYNC_LOCK(log, flags); |
1da177e4 LT |
536 | if (mp->lsn != 0) { |
537 | /* inherit older/smaller lsn */ | |
538 | logdiff(diffp, mp->lsn, log); | |
539 | if (difft < diffp) { | |
540 | mp->lsn = lsn; | |
541 | ||
542 | /* move bp after tblock in logsync list */ | |
1da177e4 | 543 | list_move(&mp->synclist, &tblk->synclist); |
1da177e4 LT |
544 | } |
545 | ||
546 | /* inherit younger/larger clsn */ | |
1da177e4 LT |
547 | logdiff(difft, tblk->clsn, log); |
548 | logdiff(diffp, mp->clsn, log); | |
549 | if (difft > diffp) | |
550 | mp->clsn = tblk->clsn; | |
1da177e4 LT |
551 | } else { |
552 | mp->log = log; | |
553 | mp->lsn = lsn; | |
554 | ||
555 | /* insert bp after tblock in logsync list */ | |
1da177e4 LT |
556 | log->count++; |
557 | list_add(&mp->synclist, &tblk->synclist); | |
558 | ||
559 | mp->clsn = tblk->clsn; | |
1da177e4 | 560 | } |
be0bf7da | 561 | LOGSYNC_UNLOCK(log, flags); |
1da177e4 LT |
562 | } |
563 | ||
564 | /* write the last buffer. */ | |
565 | if (mp) { | |
566 | write_metapage(mp); | |
567 | } | |
568 | ||
569 | return (0); | |
570 | } | |
571 | ||
572 | ||
573 | /* | |
574 | * NAME: dbNextAG() | |
575 | * | |
f720e3ba | 576 | * FUNCTION: find the preferred allocation group for new allocations. |
1da177e4 LT |
577 | * |
578 | * Within the allocation groups, we maintain a preferred | |
579 | * allocation group which consists of a group with at least | |
580 | * average free space. It is the preferred group that we target | |
581 | * new inode allocation towards. The tie-in between inode | |
582 | * allocation and block allocation occurs as we allocate the | |
583 | * first (data) block of an inode and specify the inode (block) | |
584 | * as the allocation hint for this block. | |
585 | * | |
586 | * We try to avoid having more than one open file growing in | |
587 | * an allocation group, as this will lead to fragmentation. | |
588 | * This differs from the old OS/2 method of trying to keep | |
589 | * empty ags around for large allocations. | |
590 | * | |
591 | * PARAMETERS: | |
f720e3ba | 592 | * ipbmap - pointer to in-core inode for the block map. |
1da177e4 LT |
593 | * |
594 | * RETURN VALUES: | |
f720e3ba | 595 | * the preferred allocation group number. |
1da177e4 LT |
596 | */ |
597 | int dbNextAG(struct inode *ipbmap) | |
598 | { | |
599 | s64 avgfree; | |
600 | int agpref; | |
601 | s64 hwm = 0; | |
602 | int i; | |
603 | int next_best = -1; | |
604 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
605 | ||
606 | BMAP_LOCK(bmp); | |
607 | ||
608 | /* determine the average number of free blocks within the ags. */ | |
609 | avgfree = (u32)bmp->db_nfree / bmp->db_numag; | |
610 | ||
611 | /* | |
612 | * if the current preferred ag does not have an active allocator | |
613 | * and has at least average freespace, return it | |
614 | */ | |
615 | agpref = bmp->db_agpref; | |
616 | if ((atomic_read(&bmp->db_active[agpref]) == 0) && | |
617 | (bmp->db_agfree[agpref] >= avgfree)) | |
618 | goto unlock; | |
619 | ||
620 | /* From the last preferred ag, find the next one with at least | |
621 | * average free space. | |
622 | */ | |
623 | for (i = 0 ; i < bmp->db_numag; i++, agpref++) { | |
624 | if (agpref == bmp->db_numag) | |
625 | agpref = 0; | |
626 | ||
627 | if (atomic_read(&bmp->db_active[agpref])) | |
628 | /* open file is currently growing in this ag */ | |
629 | continue; | |
630 | if (bmp->db_agfree[agpref] >= avgfree) { | |
631 | /* Return this one */ | |
632 | bmp->db_agpref = agpref; | |
633 | goto unlock; | |
634 | } else if (bmp->db_agfree[agpref] > hwm) { | |
635 | /* Less than avg. freespace, but best so far */ | |
636 | hwm = bmp->db_agfree[agpref]; | |
637 | next_best = agpref; | |
638 | } | |
639 | } | |
640 | ||
641 | /* | |
642 | * If no inactive ag was found with average freespace, use the | |
643 | * next best | |
644 | */ | |
645 | if (next_best != -1) | |
646 | bmp->db_agpref = next_best; | |
647 | /* else leave db_agpref unchanged */ | |
648 | unlock: | |
649 | BMAP_UNLOCK(bmp); | |
650 | ||
651 | /* return the preferred group. | |
652 | */ | |
653 | return (bmp->db_agpref); | |
654 | } | |
655 | ||
656 | /* | |
657 | * NAME: dbAlloc() | |
658 | * | |
f720e3ba | 659 | * FUNCTION: attempt to allocate a specified number of contiguous free |
1da177e4 LT |
660 | * blocks from the working allocation block map. |
661 | * | |
662 | * the block allocation policy uses hints and a multi-step | |
663 | * approach. | |
664 | * | |
63f83c9f | 665 | * for allocation requests smaller than the number of blocks |
1da177e4 LT |
666 | * per dmap, we first try to allocate the new blocks |
667 | * immediately following the hint. if these blocks are not | |
668 | * available, we try to allocate blocks near the hint. if | |
63f83c9f | 669 | * no blocks near the hint are available, we next try to |
1da177e4 LT |
670 | * allocate within the same dmap as contains the hint. |
671 | * | |
672 | * if no blocks are available in the dmap or the allocation | |
673 | * request is larger than the dmap size, we try to allocate | |
674 | * within the same allocation group as contains the hint. if | |
675 | * this does not succeed, we finally try to allocate anywhere | |
676 | * within the aggregate. | |
677 | * | |
678 | * we also try to allocate anywhere within the aggregate for | |
679 | * for allocation requests larger than the allocation group | |
680 | * size or requests that specify no hint value. | |
681 | * | |
682 | * PARAMETERS: | |
f720e3ba DK |
683 | * ip - pointer to in-core inode; |
684 | * hint - allocation hint. | |
685 | * nblocks - number of contiguous blocks in the range. | |
686 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
687 | * of the newly allocated contiguous range. |
688 | * | |
689 | * RETURN VALUES: | |
f720e3ba DK |
690 | * 0 - success |
691 | * -ENOSPC - insufficient disk resources | |
692 | * -EIO - i/o error | |
1da177e4 LT |
693 | */ |
694 | int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results) | |
695 | { | |
696 | int rc, agno; | |
697 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
698 | struct bmap *bmp; | |
699 | struct metapage *mp; | |
700 | s64 lblkno, blkno; | |
701 | struct dmap *dp; | |
702 | int l2nb; | |
703 | s64 mapSize; | |
704 | int writers; | |
705 | ||
706 | /* assert that nblocks is valid */ | |
707 | assert(nblocks > 0); | |
708 | ||
1da177e4 | 709 | /* get the log2 number of blocks to be allocated. |
63f83c9f | 710 | * if the number of blocks is not a log2 multiple, |
1da177e4 LT |
711 | * it will be rounded up to the next log2 multiple. |
712 | */ | |
713 | l2nb = BLKSTOL2(nblocks); | |
714 | ||
715 | bmp = JFS_SBI(ip->i_sb)->bmap; | |
716 | ||
1da177e4 LT |
717 | mapSize = bmp->db_mapsize; |
718 | ||
719 | /* the hint should be within the map */ | |
720 | if (hint >= mapSize) { | |
721 | jfs_error(ip->i_sb, "dbAlloc: the hint is outside the map"); | |
722 | return -EIO; | |
723 | } | |
724 | ||
725 | /* if the number of blocks to be allocated is greater than the | |
726 | * allocation group size, try to allocate anywhere. | |
727 | */ | |
728 | if (l2nb > bmp->db_agl2size) { | |
82d5b9a7 | 729 | IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
730 | |
731 | rc = dbAllocAny(bmp, nblocks, l2nb, results); | |
1da177e4 LT |
732 | |
733 | goto write_unlock; | |
734 | } | |
735 | ||
736 | /* | |
737 | * If no hint, let dbNextAG recommend an allocation group | |
738 | */ | |
739 | if (hint == 0) | |
740 | goto pref_ag; | |
741 | ||
742 | /* we would like to allocate close to the hint. adjust the | |
743 | * hint to the block following the hint since the allocators | |
744 | * will start looking for free space starting at this point. | |
745 | */ | |
746 | blkno = hint + 1; | |
747 | ||
748 | if (blkno >= bmp->db_mapsize) | |
749 | goto pref_ag; | |
750 | ||
751 | agno = blkno >> bmp->db_agl2size; | |
752 | ||
753 | /* check if blkno crosses over into a new allocation group. | |
754 | * if so, check if we should allow allocations within this | |
755 | * allocation group. | |
756 | */ | |
757 | if ((blkno & (bmp->db_agsize - 1)) == 0) | |
758 | /* check if the AG is currenly being written to. | |
759 | * if so, call dbNextAG() to find a non-busy | |
760 | * AG with sufficient free space. | |
761 | */ | |
762 | if (atomic_read(&bmp->db_active[agno])) | |
763 | goto pref_ag; | |
764 | ||
765 | /* check if the allocation request size can be satisfied from a | |
766 | * single dmap. if so, try to allocate from the dmap containing | |
767 | * the hint using a tiered strategy. | |
768 | */ | |
769 | if (nblocks <= BPERDMAP) { | |
82d5b9a7 | 770 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
771 | |
772 | /* get the buffer for the dmap containing the hint. | |
773 | */ | |
774 | rc = -EIO; | |
775 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
776 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
777 | if (mp == NULL) | |
778 | goto read_unlock; | |
779 | ||
780 | dp = (struct dmap *) mp->data; | |
781 | ||
782 | /* first, try to satisfy the allocation request with the | |
783 | * blocks beginning at the hint. | |
784 | */ | |
785 | if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks)) | |
786 | != -ENOSPC) { | |
787 | if (rc == 0) { | |
788 | *results = blkno; | |
1da177e4 LT |
789 | mark_metapage_dirty(mp); |
790 | } | |
791 | ||
792 | release_metapage(mp); | |
793 | goto read_unlock; | |
794 | } | |
795 | ||
796 | writers = atomic_read(&bmp->db_active[agno]); | |
797 | if ((writers > 1) || | |
798 | ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) { | |
799 | /* | |
800 | * Someone else is writing in this allocation | |
801 | * group. To avoid fragmenting, try another ag | |
802 | */ | |
803 | release_metapage(mp); | |
804 | IREAD_UNLOCK(ipbmap); | |
805 | goto pref_ag; | |
806 | } | |
807 | ||
808 | /* next, try to satisfy the allocation request with blocks | |
809 | * near the hint. | |
810 | */ | |
811 | if ((rc = | |
812 | dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results)) | |
813 | != -ENOSPC) { | |
b38a3ab3 | 814 | if (rc == 0) |
1da177e4 | 815 | mark_metapage_dirty(mp); |
1da177e4 LT |
816 | |
817 | release_metapage(mp); | |
818 | goto read_unlock; | |
819 | } | |
820 | ||
821 | /* try to satisfy the allocation request with blocks within | |
822 | * the same dmap as the hint. | |
823 | */ | |
824 | if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results)) | |
825 | != -ENOSPC) { | |
b38a3ab3 | 826 | if (rc == 0) |
1da177e4 | 827 | mark_metapage_dirty(mp); |
1da177e4 LT |
828 | |
829 | release_metapage(mp); | |
830 | goto read_unlock; | |
831 | } | |
832 | ||
833 | release_metapage(mp); | |
834 | IREAD_UNLOCK(ipbmap); | |
835 | } | |
836 | ||
837 | /* try to satisfy the allocation request with blocks within | |
838 | * the same allocation group as the hint. | |
839 | */ | |
82d5b9a7 | 840 | IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
b38a3ab3 | 841 | if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC) |
1da177e4 | 842 | goto write_unlock; |
b38a3ab3 | 843 | |
1da177e4 LT |
844 | IWRITE_UNLOCK(ipbmap); |
845 | ||
846 | ||
847 | pref_ag: | |
848 | /* | |
849 | * Let dbNextAG recommend a preferred allocation group | |
850 | */ | |
851 | agno = dbNextAG(ipbmap); | |
82d5b9a7 | 852 | IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
853 | |
854 | /* Try to allocate within this allocation group. if that fails, try to | |
855 | * allocate anywhere in the map. | |
856 | */ | |
857 | if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC) | |
858 | rc = dbAllocAny(bmp, nblocks, l2nb, results); | |
1da177e4 LT |
859 | |
860 | write_unlock: | |
861 | IWRITE_UNLOCK(ipbmap); | |
862 | ||
863 | return (rc); | |
864 | ||
865 | read_unlock: | |
866 | IREAD_UNLOCK(ipbmap); | |
867 | ||
868 | return (rc); | |
869 | } | |
870 | ||
871 | #ifdef _NOTYET | |
872 | /* | |
873 | * NAME: dbAllocExact() | |
874 | * | |
f720e3ba | 875 | * FUNCTION: try to allocate the requested extent; |
1da177e4 LT |
876 | * |
877 | * PARAMETERS: | |
f720e3ba DK |
878 | * ip - pointer to in-core inode; |
879 | * blkno - extent address; | |
880 | * nblocks - extent length; | |
1da177e4 LT |
881 | * |
882 | * RETURN VALUES: | |
f720e3ba DK |
883 | * 0 - success |
884 | * -ENOSPC - insufficient disk resources | |
885 | * -EIO - i/o error | |
1da177e4 LT |
886 | */ |
887 | int dbAllocExact(struct inode *ip, s64 blkno, int nblocks) | |
888 | { | |
889 | int rc; | |
890 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
891 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; | |
892 | struct dmap *dp; | |
893 | s64 lblkno; | |
894 | struct metapage *mp; | |
895 | ||
82d5b9a7 | 896 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
897 | |
898 | /* | |
899 | * validate extent request: | |
900 | * | |
901 | * note: defragfs policy: | |
63f83c9f | 902 | * max 64 blocks will be moved. |
1da177e4 LT |
903 | * allocation request size must be satisfied from a single dmap. |
904 | */ | |
905 | if (nblocks <= 0 || nblocks > BPERDMAP || blkno >= bmp->db_mapsize) { | |
906 | IREAD_UNLOCK(ipbmap); | |
907 | return -EINVAL; | |
908 | } | |
909 | ||
910 | if (nblocks > ((s64) 1 << bmp->db_maxfreebud)) { | |
911 | /* the free space is no longer available */ | |
912 | IREAD_UNLOCK(ipbmap); | |
913 | return -ENOSPC; | |
914 | } | |
915 | ||
916 | /* read in the dmap covering the extent */ | |
917 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
918 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
919 | if (mp == NULL) { | |
920 | IREAD_UNLOCK(ipbmap); | |
921 | return -EIO; | |
922 | } | |
923 | dp = (struct dmap *) mp->data; | |
924 | ||
925 | /* try to allocate the requested extent */ | |
926 | rc = dbAllocNext(bmp, dp, blkno, nblocks); | |
927 | ||
928 | IREAD_UNLOCK(ipbmap); | |
929 | ||
b38a3ab3 | 930 | if (rc == 0) |
1da177e4 | 931 | mark_metapage_dirty(mp); |
b38a3ab3 | 932 | |
1da177e4 LT |
933 | release_metapage(mp); |
934 | ||
935 | return (rc); | |
936 | } | |
937 | #endif /* _NOTYET */ | |
938 | ||
939 | /* | |
940 | * NAME: dbReAlloc() | |
941 | * | |
f720e3ba | 942 | * FUNCTION: attempt to extend a current allocation by a specified |
1da177e4 LT |
943 | * number of blocks. |
944 | * | |
945 | * this routine attempts to satisfy the allocation request | |
946 | * by first trying to extend the existing allocation in | |
947 | * place by allocating the additional blocks as the blocks | |
948 | * immediately following the current allocation. if these | |
949 | * blocks are not available, this routine will attempt to | |
950 | * allocate a new set of contiguous blocks large enough | |
951 | * to cover the existing allocation plus the additional | |
952 | * number of blocks required. | |
953 | * | |
954 | * PARAMETERS: | |
f720e3ba DK |
955 | * ip - pointer to in-core inode requiring allocation. |
956 | * blkno - starting block of the current allocation. | |
957 | * nblocks - number of contiguous blocks within the current | |
1da177e4 | 958 | * allocation. |
f720e3ba DK |
959 | * addnblocks - number of blocks to add to the allocation. |
960 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
961 | * of the existing allocation if the existing allocation |
962 | * was extended in place or to a newly allocated contiguous | |
963 | * range if the existing allocation could not be extended | |
964 | * in place. | |
965 | * | |
966 | * RETURN VALUES: | |
f720e3ba DK |
967 | * 0 - success |
968 | * -ENOSPC - insufficient disk resources | |
969 | * -EIO - i/o error | |
1da177e4 LT |
970 | */ |
971 | int | |
972 | dbReAlloc(struct inode *ip, | |
973 | s64 blkno, s64 nblocks, s64 addnblocks, s64 * results) | |
974 | { | |
975 | int rc; | |
976 | ||
977 | /* try to extend the allocation in place. | |
978 | */ | |
979 | if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) { | |
980 | *results = blkno; | |
981 | return (0); | |
982 | } else { | |
983 | if (rc != -ENOSPC) | |
984 | return (rc); | |
985 | } | |
986 | ||
987 | /* could not extend the allocation in place, so allocate a | |
988 | * new set of blocks for the entire request (i.e. try to get | |
989 | * a range of contiguous blocks large enough to cover the | |
990 | * existing allocation plus the additional blocks.) | |
991 | */ | |
992 | return (dbAlloc | |
993 | (ip, blkno + nblocks - 1, addnblocks + nblocks, results)); | |
994 | } | |
995 | ||
996 | ||
997 | /* | |
998 | * NAME: dbExtend() | |
999 | * | |
f720e3ba | 1000 | * FUNCTION: attempt to extend a current allocation by a specified |
1da177e4 LT |
1001 | * number of blocks. |
1002 | * | |
1003 | * this routine attempts to satisfy the allocation request | |
1004 | * by first trying to extend the existing allocation in | |
1005 | * place by allocating the additional blocks as the blocks | |
1006 | * immediately following the current allocation. | |
1007 | * | |
1008 | * PARAMETERS: | |
f720e3ba DK |
1009 | * ip - pointer to in-core inode requiring allocation. |
1010 | * blkno - starting block of the current allocation. | |
1011 | * nblocks - number of contiguous blocks within the current | |
1da177e4 | 1012 | * allocation. |
f720e3ba | 1013 | * addnblocks - number of blocks to add to the allocation. |
1da177e4 LT |
1014 | * |
1015 | * RETURN VALUES: | |
f720e3ba DK |
1016 | * 0 - success |
1017 | * -ENOSPC - insufficient disk resources | |
1018 | * -EIO - i/o error | |
1da177e4 LT |
1019 | */ |
1020 | static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks) | |
1021 | { | |
1022 | struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb); | |
1023 | s64 lblkno, lastblkno, extblkno; | |
1024 | uint rel_block; | |
1025 | struct metapage *mp; | |
1026 | struct dmap *dp; | |
1027 | int rc; | |
1028 | struct inode *ipbmap = sbi->ipbmap; | |
1029 | struct bmap *bmp; | |
1030 | ||
1031 | /* | |
1032 | * We don't want a non-aligned extent to cross a page boundary | |
1033 | */ | |
1034 | if (((rel_block = blkno & (sbi->nbperpage - 1))) && | |
1035 | (rel_block + nblocks + addnblocks > sbi->nbperpage)) | |
1036 | return -ENOSPC; | |
1037 | ||
1038 | /* get the last block of the current allocation */ | |
1039 | lastblkno = blkno + nblocks - 1; | |
1040 | ||
1041 | /* determine the block number of the block following | |
1042 | * the existing allocation. | |
1043 | */ | |
1044 | extblkno = lastblkno + 1; | |
1045 | ||
82d5b9a7 | 1046 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
1047 | |
1048 | /* better be within the file system */ | |
1049 | bmp = sbi->bmap; | |
1050 | if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) { | |
1051 | IREAD_UNLOCK(ipbmap); | |
1052 | jfs_error(ip->i_sb, | |
1053 | "dbExtend: the block is outside the filesystem"); | |
1054 | return -EIO; | |
1055 | } | |
1056 | ||
1057 | /* we'll attempt to extend the current allocation in place by | |
1058 | * allocating the additional blocks as the blocks immediately | |
1059 | * following the current allocation. we only try to extend the | |
1060 | * current allocation in place if the number of additional blocks | |
1061 | * can fit into a dmap, the last block of the current allocation | |
1062 | * is not the last block of the file system, and the start of the | |
1063 | * inplace extension is not on an allocation group boundary. | |
1064 | */ | |
1065 | if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize || | |
1066 | (extblkno & (bmp->db_agsize - 1)) == 0) { | |
1067 | IREAD_UNLOCK(ipbmap); | |
1068 | return -ENOSPC; | |
1069 | } | |
1070 | ||
1071 | /* get the buffer for the dmap containing the first block | |
1072 | * of the extension. | |
1073 | */ | |
1074 | lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage); | |
1075 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
1076 | if (mp == NULL) { | |
1077 | IREAD_UNLOCK(ipbmap); | |
1078 | return -EIO; | |
1079 | } | |
1080 | ||
1da177e4 LT |
1081 | dp = (struct dmap *) mp->data; |
1082 | ||
1083 | /* try to allocate the blocks immediately following the | |
1084 | * current allocation. | |
1085 | */ | |
1086 | rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks); | |
1087 | ||
1088 | IREAD_UNLOCK(ipbmap); | |
1089 | ||
1090 | /* were we successful ? */ | |
b38a3ab3 | 1091 | if (rc == 0) |
1da177e4 | 1092 | write_metapage(mp); |
b38a3ab3 | 1093 | else |
1da177e4 LT |
1094 | /* we were not successful */ |
1095 | release_metapage(mp); | |
1096 | ||
1097 | ||
1098 | return (rc); | |
1099 | } | |
1100 | ||
1101 | ||
1102 | /* | |
1103 | * NAME: dbAllocNext() | |
1104 | * | |
f720e3ba | 1105 | * FUNCTION: attempt to allocate the blocks of the specified block |
1da177e4 LT |
1106 | * range within a dmap. |
1107 | * | |
1108 | * PARAMETERS: | |
f720e3ba DK |
1109 | * bmp - pointer to bmap descriptor |
1110 | * dp - pointer to dmap. | |
1111 | * blkno - starting block number of the range. | |
1112 | * nblocks - number of contiguous free blocks of the range. | |
1da177e4 LT |
1113 | * |
1114 | * RETURN VALUES: | |
f720e3ba DK |
1115 | * 0 - success |
1116 | * -ENOSPC - insufficient disk resources | |
1117 | * -EIO - i/o error | |
1da177e4 LT |
1118 | * |
1119 | * serialization: IREAD_LOCK(ipbmap) held on entry/exit; | |
1120 | */ | |
1121 | static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
1122 | int nblocks) | |
1123 | { | |
1124 | int dbitno, word, rembits, nb, nwords, wbitno, nw; | |
1125 | int l2size; | |
1126 | s8 *leaf; | |
1127 | u32 mask; | |
1128 | ||
1129 | if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { | |
1130 | jfs_error(bmp->db_ipbmap->i_sb, | |
1131 | "dbAllocNext: Corrupt dmap page"); | |
1132 | return -EIO; | |
1133 | } | |
1134 | ||
1135 | /* pick up a pointer to the leaves of the dmap tree. | |
1136 | */ | |
1137 | leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); | |
1138 | ||
1139 | /* determine the bit number and word within the dmap of the | |
1140 | * starting block. | |
1141 | */ | |
1142 | dbitno = blkno & (BPERDMAP - 1); | |
1143 | word = dbitno >> L2DBWORD; | |
1144 | ||
1145 | /* check if the specified block range is contained within | |
1146 | * this dmap. | |
1147 | */ | |
1148 | if (dbitno + nblocks > BPERDMAP) | |
1149 | return -ENOSPC; | |
1150 | ||
1151 | /* check if the starting leaf indicates that anything | |
1152 | * is free. | |
1153 | */ | |
1154 | if (leaf[word] == NOFREE) | |
1155 | return -ENOSPC; | |
1156 | ||
1157 | /* check the dmaps words corresponding to block range to see | |
1158 | * if the block range is free. not all bits of the first and | |
1159 | * last words may be contained within the block range. if this | |
1160 | * is the case, we'll work against those words (i.e. partial first | |
1161 | * and/or last) on an individual basis (a single pass) and examine | |
1162 | * the actual bits to determine if they are free. a single pass | |
1163 | * will be used for all dmap words fully contained within the | |
1164 | * specified range. within this pass, the leaves of the dmap | |
1165 | * tree will be examined to determine if the blocks are free. a | |
1166 | * single leaf may describe the free space of multiple dmap | |
1167 | * words, so we may visit only a subset of the actual leaves | |
1168 | * corresponding to the dmap words of the block range. | |
1169 | */ | |
1170 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
1171 | /* determine the bit number within the word and | |
1172 | * the number of bits within the word. | |
1173 | */ | |
1174 | wbitno = dbitno & (DBWORD - 1); | |
1175 | nb = min(rembits, DBWORD - wbitno); | |
1176 | ||
1177 | /* check if only part of the word is to be examined. | |
1178 | */ | |
1179 | if (nb < DBWORD) { | |
1180 | /* check if the bits are free. | |
1181 | */ | |
1182 | mask = (ONES << (DBWORD - nb) >> wbitno); | |
1183 | if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask) | |
1184 | return -ENOSPC; | |
1185 | ||
1186 | word += 1; | |
1187 | } else { | |
1188 | /* one or more dmap words are fully contained | |
1189 | * within the block range. determine how many | |
1190 | * words and how many bits. | |
1191 | */ | |
1192 | nwords = rembits >> L2DBWORD; | |
1193 | nb = nwords << L2DBWORD; | |
1194 | ||
1195 | /* now examine the appropriate leaves to determine | |
1196 | * if the blocks are free. | |
1197 | */ | |
1198 | while (nwords > 0) { | |
1199 | /* does the leaf describe any free space ? | |
1200 | */ | |
1201 | if (leaf[word] < BUDMIN) | |
1202 | return -ENOSPC; | |
1203 | ||
1204 | /* determine the l2 number of bits provided | |
1205 | * by this leaf. | |
1206 | */ | |
1207 | l2size = | |
1208 | min((int)leaf[word], NLSTOL2BSZ(nwords)); | |
1209 | ||
1210 | /* determine how many words were handled. | |
1211 | */ | |
1212 | nw = BUDSIZE(l2size, BUDMIN); | |
1213 | ||
1214 | nwords -= nw; | |
1215 | word += nw; | |
1216 | } | |
1217 | } | |
1218 | } | |
1219 | ||
1220 | /* allocate the blocks. | |
1221 | */ | |
1222 | return (dbAllocDmap(bmp, dp, blkno, nblocks)); | |
1223 | } | |
1224 | ||
1225 | ||
1226 | /* | |
1227 | * NAME: dbAllocNear() | |
1228 | * | |
f720e3ba | 1229 | * FUNCTION: attempt to allocate a number of contiguous free blocks near |
1da177e4 LT |
1230 | * a specified block (hint) within a dmap. |
1231 | * | |
1232 | * starting with the dmap leaf that covers the hint, we'll | |
1233 | * check the next four contiguous leaves for sufficient free | |
1234 | * space. if sufficient free space is found, we'll allocate | |
1235 | * the desired free space. | |
1236 | * | |
1237 | * PARAMETERS: | |
f720e3ba DK |
1238 | * bmp - pointer to bmap descriptor |
1239 | * dp - pointer to dmap. | |
1240 | * blkno - block number to allocate near. | |
1241 | * nblocks - actual number of contiguous free blocks desired. | |
1242 | * l2nb - log2 number of contiguous free blocks desired. | |
1243 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
1244 | * of the newly allocated range. |
1245 | * | |
1246 | * RETURN VALUES: | |
f720e3ba DK |
1247 | * 0 - success |
1248 | * -ENOSPC - insufficient disk resources | |
1249 | * -EIO - i/o error | |
1da177e4 LT |
1250 | * |
1251 | * serialization: IREAD_LOCK(ipbmap) held on entry/exit; | |
1252 | */ | |
1253 | static int | |
1254 | dbAllocNear(struct bmap * bmp, | |
1255 | struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results) | |
1256 | { | |
1257 | int word, lword, rc; | |
1258 | s8 *leaf; | |
1259 | ||
1260 | if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { | |
1261 | jfs_error(bmp->db_ipbmap->i_sb, | |
1262 | "dbAllocNear: Corrupt dmap page"); | |
1263 | return -EIO; | |
1264 | } | |
1265 | ||
1266 | leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); | |
1267 | ||
1268 | /* determine the word within the dmap that holds the hint | |
1269 | * (i.e. blkno). also, determine the last word in the dmap | |
1270 | * that we'll include in our examination. | |
1271 | */ | |
1272 | word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; | |
1273 | lword = min(word + 4, LPERDMAP); | |
1274 | ||
1275 | /* examine the leaves for sufficient free space. | |
1276 | */ | |
1277 | for (; word < lword; word++) { | |
1278 | /* does the leaf describe sufficient free space ? | |
1279 | */ | |
1280 | if (leaf[word] < l2nb) | |
1281 | continue; | |
1282 | ||
1283 | /* determine the block number within the file system | |
1284 | * of the first block described by this dmap word. | |
1285 | */ | |
1286 | blkno = le64_to_cpu(dp->start) + (word << L2DBWORD); | |
1287 | ||
1288 | /* if not all bits of the dmap word are free, get the | |
1289 | * starting bit number within the dmap word of the required | |
1290 | * string of free bits and adjust the block number with the | |
1291 | * value. | |
1292 | */ | |
1293 | if (leaf[word] < BUDMIN) | |
1294 | blkno += | |
1295 | dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb); | |
1296 | ||
1297 | /* allocate the blocks. | |
1298 | */ | |
1299 | if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) | |
1300 | *results = blkno; | |
1301 | ||
1302 | return (rc); | |
1303 | } | |
1304 | ||
1305 | return -ENOSPC; | |
1306 | } | |
1307 | ||
1308 | ||
1309 | /* | |
1310 | * NAME: dbAllocAG() | |
1311 | * | |
f720e3ba | 1312 | * FUNCTION: attempt to allocate the specified number of contiguous |
1da177e4 LT |
1313 | * free blocks within the specified allocation group. |
1314 | * | |
1315 | * unless the allocation group size is equal to the number | |
1316 | * of blocks per dmap, the dmap control pages will be used to | |
1317 | * find the required free space, if available. we start the | |
1318 | * search at the highest dmap control page level which | |
1319 | * distinctly describes the allocation group's free space | |
1320 | * (i.e. the highest level at which the allocation group's | |
1321 | * free space is not mixed in with that of any other group). | |
1322 | * in addition, we start the search within this level at a | |
1323 | * height of the dmapctl dmtree at which the nodes distinctly | |
1324 | * describe the allocation group's free space. at this height, | |
1325 | * the allocation group's free space may be represented by 1 | |
1326 | * or two sub-trees, depending on the allocation group size. | |
1327 | * we search the top nodes of these subtrees left to right for | |
1328 | * sufficient free space. if sufficient free space is found, | |
63f83c9f | 1329 | * the subtree is searched to find the leftmost leaf that |
1da177e4 LT |
1330 | * has free space. once we have made it to the leaf, we |
1331 | * move the search to the next lower level dmap control page | |
1332 | * corresponding to this leaf. we continue down the dmap control | |
1333 | * pages until we find the dmap that contains or starts the | |
1334 | * sufficient free space and we allocate at this dmap. | |
1335 | * | |
1336 | * if the allocation group size is equal to the dmap size, | |
1337 | * we'll start at the dmap corresponding to the allocation | |
1338 | * group and attempt the allocation at this level. | |
1339 | * | |
1340 | * the dmap control page search is also not performed if the | |
1341 | * allocation group is completely free and we go to the first | |
1342 | * dmap of the allocation group to do the allocation. this is | |
1343 | * done because the allocation group may be part (not the first | |
1344 | * part) of a larger binary buddy system, causing the dmap | |
1345 | * control pages to indicate no free space (NOFREE) within | |
1346 | * the allocation group. | |
1347 | * | |
1348 | * PARAMETERS: | |
f720e3ba | 1349 | * bmp - pointer to bmap descriptor |
1da177e4 | 1350 | * agno - allocation group number. |
f720e3ba DK |
1351 | * nblocks - actual number of contiguous free blocks desired. |
1352 | * l2nb - log2 number of contiguous free blocks desired. | |
1353 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
1354 | * of the newly allocated range. |
1355 | * | |
1356 | * RETURN VALUES: | |
f720e3ba DK |
1357 | * 0 - success |
1358 | * -ENOSPC - insufficient disk resources | |
1359 | * -EIO - i/o error | |
1da177e4 LT |
1360 | * |
1361 | * note: IWRITE_LOCK(ipmap) held on entry/exit; | |
1362 | */ | |
1363 | static int | |
1364 | dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results) | |
1365 | { | |
1366 | struct metapage *mp; | |
1367 | struct dmapctl *dcp; | |
1368 | int rc, ti, i, k, m, n, agperlev; | |
1369 | s64 blkno, lblkno; | |
1370 | int budmin; | |
1371 | ||
1372 | /* allocation request should not be for more than the | |
1373 | * allocation group size. | |
1374 | */ | |
1375 | if (l2nb > bmp->db_agl2size) { | |
1376 | jfs_error(bmp->db_ipbmap->i_sb, | |
1377 | "dbAllocAG: allocation request is larger than the " | |
1378 | "allocation group size"); | |
1379 | return -EIO; | |
1380 | } | |
1381 | ||
1382 | /* determine the starting block number of the allocation | |
1383 | * group. | |
1384 | */ | |
1385 | blkno = (s64) agno << bmp->db_agl2size; | |
1386 | ||
1387 | /* check if the allocation group size is the minimum allocation | |
1388 | * group size or if the allocation group is completely free. if | |
1389 | * the allocation group size is the minimum size of BPERDMAP (i.e. | |
1390 | * 1 dmap), there is no need to search the dmap control page (below) | |
1391 | * that fully describes the allocation group since the allocation | |
1392 | * group is already fully described by a dmap. in this case, we | |
1393 | * just call dbAllocCtl() to search the dmap tree and allocate the | |
63f83c9f | 1394 | * required space if available. |
1da177e4 LT |
1395 | * |
1396 | * if the allocation group is completely free, dbAllocCtl() is | |
1397 | * also called to allocate the required space. this is done for | |
1398 | * two reasons. first, it makes no sense searching the dmap control | |
1399 | * pages for free space when we know that free space exists. second, | |
1400 | * the dmap control pages may indicate that the allocation group | |
1401 | * has no free space if the allocation group is part (not the first | |
1402 | * part) of a larger binary buddy system. | |
1403 | */ | |
1404 | if (bmp->db_agsize == BPERDMAP | |
1405 | || bmp->db_agfree[agno] == bmp->db_agsize) { | |
1406 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); | |
1407 | if ((rc == -ENOSPC) && | |
1408 | (bmp->db_agfree[agno] == bmp->db_agsize)) { | |
1409 | printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n", | |
1410 | (unsigned long long) blkno, | |
1411 | (unsigned long long) nblocks); | |
1412 | jfs_error(bmp->db_ipbmap->i_sb, | |
1413 | "dbAllocAG: dbAllocCtl failed in free AG"); | |
1414 | } | |
1415 | return (rc); | |
1416 | } | |
1417 | ||
1418 | /* the buffer for the dmap control page that fully describes the | |
1419 | * allocation group. | |
1420 | */ | |
1421 | lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel); | |
1422 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1423 | if (mp == NULL) | |
1424 | return -EIO; | |
1425 | dcp = (struct dmapctl *) mp->data; | |
1426 | budmin = dcp->budmin; | |
1427 | ||
1428 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { | |
1429 | jfs_error(bmp->db_ipbmap->i_sb, | |
1430 | "dbAllocAG: Corrupt dmapctl page"); | |
1431 | release_metapage(mp); | |
1432 | return -EIO; | |
1433 | } | |
1434 | ||
1435 | /* search the subtree(s) of the dmap control page that describes | |
1436 | * the allocation group, looking for sufficient free space. to begin, | |
1437 | * determine how many allocation groups are represented in a dmap | |
1438 | * control page at the control page level (i.e. L0, L1, L2) that | |
1439 | * fully describes an allocation group. next, determine the starting | |
1440 | * tree index of this allocation group within the control page. | |
1441 | */ | |
1442 | agperlev = | |
1443 | (1 << (L2LPERCTL - (bmp->db_agheigth << 1))) / bmp->db_agwidth; | |
1444 | ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1)); | |
1445 | ||
63f83c9f | 1446 | /* dmap control page trees fan-out by 4 and a single allocation |
1da177e4 LT |
1447 | * group may be described by 1 or 2 subtrees within the ag level |
1448 | * dmap control page, depending upon the ag size. examine the ag's | |
1449 | * subtrees for sufficient free space, starting with the leftmost | |
1450 | * subtree. | |
1451 | */ | |
1452 | for (i = 0; i < bmp->db_agwidth; i++, ti++) { | |
1453 | /* is there sufficient free space ? | |
1454 | */ | |
1455 | if (l2nb > dcp->stree[ti]) | |
1456 | continue; | |
1457 | ||
1458 | /* sufficient free space found in a subtree. now search down | |
1459 | * the subtree to find the leftmost leaf that describes this | |
1460 | * free space. | |
1461 | */ | |
1462 | for (k = bmp->db_agheigth; k > 0; k--) { | |
1463 | for (n = 0, m = (ti << 2) + 1; n < 4; n++) { | |
1464 | if (l2nb <= dcp->stree[m + n]) { | |
1465 | ti = m + n; | |
1466 | break; | |
1467 | } | |
1468 | } | |
1469 | if (n == 4) { | |
1470 | jfs_error(bmp->db_ipbmap->i_sb, | |
1471 | "dbAllocAG: failed descending stree"); | |
1472 | release_metapage(mp); | |
1473 | return -EIO; | |
1474 | } | |
1475 | } | |
1476 | ||
1477 | /* determine the block number within the file system | |
1478 | * that corresponds to this leaf. | |
1479 | */ | |
1480 | if (bmp->db_aglevel == 2) | |
1481 | blkno = 0; | |
1482 | else if (bmp->db_aglevel == 1) | |
1483 | blkno &= ~(MAXL1SIZE - 1); | |
1484 | else /* bmp->db_aglevel == 0 */ | |
1485 | blkno &= ~(MAXL0SIZE - 1); | |
1486 | ||
1487 | blkno += | |
1488 | ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin; | |
1489 | ||
1490 | /* release the buffer in preparation for going down | |
1491 | * the next level of dmap control pages. | |
1492 | */ | |
1493 | release_metapage(mp); | |
1494 | ||
1495 | /* check if we need to continue to search down the lower | |
1496 | * level dmap control pages. we need to if the number of | |
1497 | * blocks required is less than maximum number of blocks | |
1498 | * described at the next lower level. | |
1499 | */ | |
1500 | if (l2nb < budmin) { | |
1501 | ||
1502 | /* search the lower level dmap control pages to get | |
59c51591 | 1503 | * the starting block number of the dmap that |
1da177e4 LT |
1504 | * contains or starts off the free space. |
1505 | */ | |
1506 | if ((rc = | |
1507 | dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1, | |
1508 | &blkno))) { | |
1509 | if (rc == -ENOSPC) { | |
1510 | jfs_error(bmp->db_ipbmap->i_sb, | |
1511 | "dbAllocAG: control page " | |
1512 | "inconsistent"); | |
1513 | return -EIO; | |
1514 | } | |
1515 | return (rc); | |
1516 | } | |
1517 | } | |
1518 | ||
1519 | /* allocate the blocks. | |
1520 | */ | |
1521 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); | |
1522 | if (rc == -ENOSPC) { | |
1523 | jfs_error(bmp->db_ipbmap->i_sb, | |
1524 | "dbAllocAG: unable to allocate blocks"); | |
1525 | rc = -EIO; | |
1526 | } | |
1527 | return (rc); | |
1528 | } | |
1529 | ||
1530 | /* no space in the allocation group. release the buffer and | |
1531 | * return -ENOSPC. | |
1532 | */ | |
1533 | release_metapage(mp); | |
1534 | ||
1535 | return -ENOSPC; | |
1536 | } | |
1537 | ||
1538 | ||
1539 | /* | |
1540 | * NAME: dbAllocAny() | |
1541 | * | |
f720e3ba | 1542 | * FUNCTION: attempt to allocate the specified number of contiguous |
1da177e4 LT |
1543 | * free blocks anywhere in the file system. |
1544 | * | |
1545 | * dbAllocAny() attempts to find the sufficient free space by | |
1546 | * searching down the dmap control pages, starting with the | |
1547 | * highest level (i.e. L0, L1, L2) control page. if free space | |
1548 | * large enough to satisfy the desired free space is found, the | |
1549 | * desired free space is allocated. | |
1550 | * | |
1551 | * PARAMETERS: | |
f720e3ba DK |
1552 | * bmp - pointer to bmap descriptor |
1553 | * nblocks - actual number of contiguous free blocks desired. | |
1554 | * l2nb - log2 number of contiguous free blocks desired. | |
1555 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
1556 | * of the newly allocated range. |
1557 | * | |
1558 | * RETURN VALUES: | |
f720e3ba DK |
1559 | * 0 - success |
1560 | * -ENOSPC - insufficient disk resources | |
1561 | * -EIO - i/o error | |
1da177e4 LT |
1562 | * |
1563 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; | |
1564 | */ | |
1565 | static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results) | |
1566 | { | |
1567 | int rc; | |
1568 | s64 blkno = 0; | |
1569 | ||
1570 | /* starting with the top level dmap control page, search | |
1571 | * down the dmap control levels for sufficient free space. | |
1572 | * if free space is found, dbFindCtl() returns the starting | |
1573 | * block number of the dmap that contains or starts off the | |
1574 | * range of free space. | |
1575 | */ | |
1576 | if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno))) | |
1577 | return (rc); | |
1578 | ||
1579 | /* allocate the blocks. | |
1580 | */ | |
1581 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); | |
1582 | if (rc == -ENOSPC) { | |
1583 | jfs_error(bmp->db_ipbmap->i_sb, | |
1584 | "dbAllocAny: unable to allocate blocks"); | |
1585 | return -EIO; | |
1586 | } | |
1587 | return (rc); | |
1588 | } | |
1589 | ||
1590 | ||
1591 | /* | |
1592 | * NAME: dbFindCtl() | |
1593 | * | |
f720e3ba | 1594 | * FUNCTION: starting at a specified dmap control page level and block |
1da177e4 | 1595 | * number, search down the dmap control levels for a range of |
f720e3ba | 1596 | * contiguous free blocks large enough to satisfy an allocation |
1da177e4 LT |
1597 | * request for the specified number of free blocks. |
1598 | * | |
1599 | * if sufficient contiguous free blocks are found, this routine | |
1600 | * returns the starting block number within a dmap page that | |
1601 | * contains or starts a range of contiqious free blocks that | |
1602 | * is sufficient in size. | |
1603 | * | |
1604 | * PARAMETERS: | |
f720e3ba DK |
1605 | * bmp - pointer to bmap descriptor |
1606 | * level - starting dmap control page level. | |
1607 | * l2nb - log2 number of contiguous free blocks desired. | |
1608 | * *blkno - on entry, starting block number for conducting the search. | |
1da177e4 LT |
1609 | * on successful return, the first block within a dmap page |
1610 | * that contains or starts a range of contiguous free blocks. | |
1611 | * | |
1612 | * RETURN VALUES: | |
f720e3ba DK |
1613 | * 0 - success |
1614 | * -ENOSPC - insufficient disk resources | |
1615 | * -EIO - i/o error | |
1da177e4 LT |
1616 | * |
1617 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; | |
1618 | */ | |
1619 | static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno) | |
1620 | { | |
1621 | int rc, leafidx, lev; | |
1622 | s64 b, lblkno; | |
1623 | struct dmapctl *dcp; | |
1624 | int budmin; | |
1625 | struct metapage *mp; | |
1626 | ||
1627 | /* starting at the specified dmap control page level and block | |
1628 | * number, search down the dmap control levels for the starting | |
63f83c9f | 1629 | * block number of a dmap page that contains or starts off |
1da177e4 LT |
1630 | * sufficient free blocks. |
1631 | */ | |
1632 | for (lev = level, b = *blkno; lev >= 0; lev--) { | |
1633 | /* get the buffer of the dmap control page for the block | |
1634 | * number and level (i.e. L0, L1, L2). | |
1635 | */ | |
1636 | lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev); | |
1637 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1638 | if (mp == NULL) | |
1639 | return -EIO; | |
1640 | dcp = (struct dmapctl *) mp->data; | |
1641 | budmin = dcp->budmin; | |
1642 | ||
1643 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { | |
1644 | jfs_error(bmp->db_ipbmap->i_sb, | |
1645 | "dbFindCtl: Corrupt dmapctl page"); | |
1646 | release_metapage(mp); | |
1647 | return -EIO; | |
1648 | } | |
1649 | ||
1650 | /* search the tree within the dmap control page for | |
1651 | * sufficent free space. if sufficient free space is found, | |
1652 | * dbFindLeaf() returns the index of the leaf at which | |
1653 | * free space was found. | |
1654 | */ | |
1655 | rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx); | |
1656 | ||
1657 | /* release the buffer. | |
1658 | */ | |
1659 | release_metapage(mp); | |
1660 | ||
1661 | /* space found ? | |
1662 | */ | |
1663 | if (rc) { | |
1664 | if (lev != level) { | |
1665 | jfs_error(bmp->db_ipbmap->i_sb, | |
1666 | "dbFindCtl: dmap inconsistent"); | |
1667 | return -EIO; | |
1668 | } | |
1669 | return -ENOSPC; | |
1670 | } | |
1671 | ||
1672 | /* adjust the block number to reflect the location within | |
63f83c9f | 1673 | * the dmap control page (i.e. the leaf) at which free |
1da177e4 LT |
1674 | * space was found. |
1675 | */ | |
1676 | b += (((s64) leafidx) << budmin); | |
1677 | ||
1678 | /* we stop the search at this dmap control page level if | |
1679 | * the number of blocks required is greater than or equal | |
1680 | * to the maximum number of blocks described at the next | |
1681 | * (lower) level. | |
1682 | */ | |
1683 | if (l2nb >= budmin) | |
1684 | break; | |
1685 | } | |
1686 | ||
1687 | *blkno = b; | |
1688 | return (0); | |
1689 | } | |
1690 | ||
1691 | ||
1692 | /* | |
1693 | * NAME: dbAllocCtl() | |
1694 | * | |
f720e3ba | 1695 | * FUNCTION: attempt to allocate a specified number of contiguous |
63f83c9f DK |
1696 | * blocks starting within a specific dmap. |
1697 | * | |
1da177e4 LT |
1698 | * this routine is called by higher level routines that search |
1699 | * the dmap control pages above the actual dmaps for contiguous | |
1700 | * free space. the result of successful searches by these | |
63f83c9f | 1701 | * routines are the starting block numbers within dmaps, with |
1da177e4 LT |
1702 | * the dmaps themselves containing the desired contiguous free |
1703 | * space or starting a contiguous free space of desired size | |
1704 | * that is made up of the blocks of one or more dmaps. these | |
1705 | * calls should not fail due to insufficent resources. | |
1706 | * | |
1707 | * this routine is called in some cases where it is not known | |
1708 | * whether it will fail due to insufficient resources. more | |
1709 | * specifically, this occurs when allocating from an allocation | |
1710 | * group whose size is equal to the number of blocks per dmap. | |
1711 | * in this case, the dmap control pages are not examined prior | |
1712 | * to calling this routine (to save pathlength) and the call | |
1713 | * might fail. | |
1714 | * | |
1715 | * for a request size that fits within a dmap, this routine relies | |
1716 | * upon the dmap's dmtree to find the requested contiguous free | |
1717 | * space. for request sizes that are larger than a dmap, the | |
1718 | * requested free space will start at the first block of the | |
1719 | * first dmap (i.e. blkno). | |
1720 | * | |
1721 | * PARAMETERS: | |
f720e3ba DK |
1722 | * bmp - pointer to bmap descriptor |
1723 | * nblocks - actual number of contiguous free blocks to allocate. | |
1724 | * l2nb - log2 number of contiguous free blocks to allocate. | |
1725 | * blkno - starting block number of the dmap to start the allocation | |
1da177e4 | 1726 | * from. |
f720e3ba | 1727 | * results - on successful return, set to the starting block number |
1da177e4 LT |
1728 | * of the newly allocated range. |
1729 | * | |
1730 | * RETURN VALUES: | |
f720e3ba DK |
1731 | * 0 - success |
1732 | * -ENOSPC - insufficient disk resources | |
1733 | * -EIO - i/o error | |
1da177e4 LT |
1734 | * |
1735 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; | |
1736 | */ | |
1737 | static int | |
1738 | dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results) | |
1739 | { | |
1740 | int rc, nb; | |
1741 | s64 b, lblkno, n; | |
1742 | struct metapage *mp; | |
1743 | struct dmap *dp; | |
1744 | ||
1745 | /* check if the allocation request is confined to a single dmap. | |
1746 | */ | |
1747 | if (l2nb <= L2BPERDMAP) { | |
1748 | /* get the buffer for the dmap. | |
1749 | */ | |
1750 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
1751 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1752 | if (mp == NULL) | |
1753 | return -EIO; | |
1754 | dp = (struct dmap *) mp->data; | |
1755 | ||
1756 | /* try to allocate the blocks. | |
1757 | */ | |
1758 | rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results); | |
1759 | if (rc == 0) | |
1760 | mark_metapage_dirty(mp); | |
1761 | ||
1762 | release_metapage(mp); | |
1763 | ||
1764 | return (rc); | |
1765 | } | |
1766 | ||
1767 | /* allocation request involving multiple dmaps. it must start on | |
1768 | * a dmap boundary. | |
1769 | */ | |
1770 | assert((blkno & (BPERDMAP - 1)) == 0); | |
1771 | ||
1772 | /* allocate the blocks dmap by dmap. | |
1773 | */ | |
1774 | for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) { | |
1775 | /* get the buffer for the dmap. | |
1776 | */ | |
1777 | lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); | |
1778 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1779 | if (mp == NULL) { | |
1780 | rc = -EIO; | |
1781 | goto backout; | |
1782 | } | |
1783 | dp = (struct dmap *) mp->data; | |
1784 | ||
1785 | /* the dmap better be all free. | |
1786 | */ | |
1787 | if (dp->tree.stree[ROOT] != L2BPERDMAP) { | |
1788 | release_metapage(mp); | |
1789 | jfs_error(bmp->db_ipbmap->i_sb, | |
1790 | "dbAllocCtl: the dmap is not all free"); | |
1791 | rc = -EIO; | |
1792 | goto backout; | |
1793 | } | |
1794 | ||
1795 | /* determine how many blocks to allocate from this dmap. | |
1796 | */ | |
1797 | nb = min(n, (s64)BPERDMAP); | |
1798 | ||
1799 | /* allocate the blocks from the dmap. | |
1800 | */ | |
1801 | if ((rc = dbAllocDmap(bmp, dp, b, nb))) { | |
1802 | release_metapage(mp); | |
1803 | goto backout; | |
1804 | } | |
1805 | ||
1806 | /* write the buffer. | |
1807 | */ | |
1808 | write_metapage(mp); | |
1809 | } | |
1810 | ||
1811 | /* set the results (starting block number) and return. | |
1812 | */ | |
1813 | *results = blkno; | |
1814 | return (0); | |
1815 | ||
1816 | /* something failed in handling an allocation request involving | |
1817 | * multiple dmaps. we'll try to clean up by backing out any | |
1818 | * allocation that has already happened for this request. if | |
1819 | * we fail in backing out the allocation, we'll mark the file | |
1820 | * system to indicate that blocks have been leaked. | |
1821 | */ | |
1822 | backout: | |
1823 | ||
1824 | /* try to backout the allocations dmap by dmap. | |
1825 | */ | |
1826 | for (n = nblocks - n, b = blkno; n > 0; | |
1827 | n -= BPERDMAP, b += BPERDMAP) { | |
1828 | /* get the buffer for this dmap. | |
1829 | */ | |
1830 | lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); | |
1831 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1832 | if (mp == NULL) { | |
1833 | /* could not back out. mark the file system | |
1834 | * to indicate that we have leaked blocks. | |
1835 | */ | |
1836 | jfs_error(bmp->db_ipbmap->i_sb, | |
1837 | "dbAllocCtl: I/O Error: Block Leakage."); | |
1838 | continue; | |
1839 | } | |
1840 | dp = (struct dmap *) mp->data; | |
1841 | ||
1842 | /* free the blocks is this dmap. | |
1843 | */ | |
1844 | if (dbFreeDmap(bmp, dp, b, BPERDMAP)) { | |
1845 | /* could not back out. mark the file system | |
1846 | * to indicate that we have leaked blocks. | |
1847 | */ | |
1848 | release_metapage(mp); | |
1849 | jfs_error(bmp->db_ipbmap->i_sb, | |
1850 | "dbAllocCtl: Block Leakage."); | |
1851 | continue; | |
1852 | } | |
1853 | ||
1854 | /* write the buffer. | |
1855 | */ | |
1856 | write_metapage(mp); | |
1857 | } | |
1858 | ||
1859 | return (rc); | |
1860 | } | |
1861 | ||
1862 | ||
1863 | /* | |
1864 | * NAME: dbAllocDmapLev() | |
1865 | * | |
f720e3ba | 1866 | * FUNCTION: attempt to allocate a specified number of contiguous blocks |
1da177e4 | 1867 | * from a specified dmap. |
63f83c9f | 1868 | * |
1da177e4 LT |
1869 | * this routine checks if the contiguous blocks are available. |
1870 | * if so, nblocks of blocks are allocated; otherwise, ENOSPC is | |
1871 | * returned. | |
1872 | * | |
1873 | * PARAMETERS: | |
f720e3ba DK |
1874 | * mp - pointer to bmap descriptor |
1875 | * dp - pointer to dmap to attempt to allocate blocks from. | |
1876 | * l2nb - log2 number of contiguous block desired. | |
1877 | * nblocks - actual number of contiguous block desired. | |
1878 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
1879 | * of the newly allocated range. |
1880 | * | |
1881 | * RETURN VALUES: | |
f720e3ba DK |
1882 | * 0 - success |
1883 | * -ENOSPC - insufficient disk resources | |
1884 | * -EIO - i/o error | |
1da177e4 | 1885 | * |
63f83c9f | 1886 | * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or |
1da177e4 LT |
1887 | * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit; |
1888 | */ | |
1889 | static int | |
1890 | dbAllocDmapLev(struct bmap * bmp, | |
1891 | struct dmap * dp, int nblocks, int l2nb, s64 * results) | |
1892 | { | |
1893 | s64 blkno; | |
1894 | int leafidx, rc; | |
1895 | ||
1896 | /* can't be more than a dmaps worth of blocks */ | |
1897 | assert(l2nb <= L2BPERDMAP); | |
1898 | ||
1899 | /* search the tree within the dmap page for sufficient | |
1900 | * free space. if sufficient free space is found, dbFindLeaf() | |
1901 | * returns the index of the leaf at which free space was found. | |
1902 | */ | |
1903 | if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx)) | |
1904 | return -ENOSPC; | |
1905 | ||
1906 | /* determine the block number within the file system corresponding | |
1907 | * to the leaf at which free space was found. | |
1908 | */ | |
1909 | blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD); | |
1910 | ||
1911 | /* if not all bits of the dmap word are free, get the starting | |
1912 | * bit number within the dmap word of the required string of free | |
1913 | * bits and adjust the block number with this value. | |
1914 | */ | |
1915 | if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN) | |
1916 | blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb); | |
1917 | ||
1918 | /* allocate the blocks */ | |
1919 | if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) | |
1920 | *results = blkno; | |
1921 | ||
1922 | return (rc); | |
1923 | } | |
1924 | ||
1925 | ||
1926 | /* | |
1927 | * NAME: dbAllocDmap() | |
1928 | * | |
f720e3ba | 1929 | * FUNCTION: adjust the disk allocation map to reflect the allocation |
1da177e4 LT |
1930 | * of a specified block range within a dmap. |
1931 | * | |
1932 | * this routine allocates the specified blocks from the dmap | |
1933 | * through a call to dbAllocBits(). if the allocation of the | |
1934 | * block range causes the maximum string of free blocks within | |
1935 | * the dmap to change (i.e. the value of the root of the dmap's | |
1936 | * dmtree), this routine will cause this change to be reflected | |
1937 | * up through the appropriate levels of the dmap control pages | |
1938 | * by a call to dbAdjCtl() for the L0 dmap control page that | |
1939 | * covers this dmap. | |
1940 | * | |
1941 | * PARAMETERS: | |
f720e3ba DK |
1942 | * bmp - pointer to bmap descriptor |
1943 | * dp - pointer to dmap to allocate the block range from. | |
1944 | * blkno - starting block number of the block to be allocated. | |
1945 | * nblocks - number of blocks to be allocated. | |
1da177e4 LT |
1946 | * |
1947 | * RETURN VALUES: | |
f720e3ba DK |
1948 | * 0 - success |
1949 | * -EIO - i/o error | |
1da177e4 LT |
1950 | * |
1951 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
1952 | */ | |
1953 | static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
1954 | int nblocks) | |
1955 | { | |
1956 | s8 oldroot; | |
1957 | int rc; | |
1958 | ||
1959 | /* save the current value of the root (i.e. maximum free string) | |
1960 | * of the dmap tree. | |
1961 | */ | |
1962 | oldroot = dp->tree.stree[ROOT]; | |
1963 | ||
1964 | /* allocate the specified (blocks) bits */ | |
1965 | dbAllocBits(bmp, dp, blkno, nblocks); | |
1966 | ||
1967 | /* if the root has not changed, done. */ | |
1968 | if (dp->tree.stree[ROOT] == oldroot) | |
1969 | return (0); | |
1970 | ||
1971 | /* root changed. bubble the change up to the dmap control pages. | |
1972 | * if the adjustment of the upper level control pages fails, | |
1973 | * backout the bit allocation (thus making everything consistent). | |
1974 | */ | |
1975 | if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0))) | |
1976 | dbFreeBits(bmp, dp, blkno, nblocks); | |
1977 | ||
1978 | return (rc); | |
1979 | } | |
1980 | ||
1981 | ||
1982 | /* | |
1983 | * NAME: dbFreeDmap() | |
1984 | * | |
f720e3ba | 1985 | * FUNCTION: adjust the disk allocation map to reflect the allocation |
1da177e4 LT |
1986 | * of a specified block range within a dmap. |
1987 | * | |
1988 | * this routine frees the specified blocks from the dmap through | |
1989 | * a call to dbFreeBits(). if the deallocation of the block range | |
1990 | * causes the maximum string of free blocks within the dmap to | |
1991 | * change (i.e. the value of the root of the dmap's dmtree), this | |
1992 | * routine will cause this change to be reflected up through the | |
f720e3ba | 1993 | * appropriate levels of the dmap control pages by a call to |
1da177e4 LT |
1994 | * dbAdjCtl() for the L0 dmap control page that covers this dmap. |
1995 | * | |
1996 | * PARAMETERS: | |
f720e3ba DK |
1997 | * bmp - pointer to bmap descriptor |
1998 | * dp - pointer to dmap to free the block range from. | |
1999 | * blkno - starting block number of the block to be freed. | |
2000 | * nblocks - number of blocks to be freed. | |
1da177e4 LT |
2001 | * |
2002 | * RETURN VALUES: | |
f720e3ba DK |
2003 | * 0 - success |
2004 | * -EIO - i/o error | |
1da177e4 LT |
2005 | * |
2006 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2007 | */ | |
2008 | static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
2009 | int nblocks) | |
2010 | { | |
2011 | s8 oldroot; | |
56d12549 | 2012 | int rc = 0, word; |
1da177e4 LT |
2013 | |
2014 | /* save the current value of the root (i.e. maximum free string) | |
2015 | * of the dmap tree. | |
2016 | */ | |
2017 | oldroot = dp->tree.stree[ROOT]; | |
2018 | ||
2019 | /* free the specified (blocks) bits */ | |
56d12549 | 2020 | rc = dbFreeBits(bmp, dp, blkno, nblocks); |
1da177e4 | 2021 | |
56d12549 DK |
2022 | /* if error or the root has not changed, done. */ |
2023 | if (rc || (dp->tree.stree[ROOT] == oldroot)) | |
2024 | return (rc); | |
1da177e4 LT |
2025 | |
2026 | /* root changed. bubble the change up to the dmap control pages. | |
2027 | * if the adjustment of the upper level control pages fails, | |
63f83c9f | 2028 | * backout the deallocation. |
1da177e4 LT |
2029 | */ |
2030 | if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) { | |
2031 | word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; | |
2032 | ||
2033 | /* as part of backing out the deallocation, we will have | |
2034 | * to back split the dmap tree if the deallocation caused | |
2035 | * the freed blocks to become part of a larger binary buddy | |
2036 | * system. | |
2037 | */ | |
2038 | if (dp->tree.stree[word] == NOFREE) | |
2039 | dbBackSplit((dmtree_t *) & dp->tree, word); | |
2040 | ||
2041 | dbAllocBits(bmp, dp, blkno, nblocks); | |
2042 | } | |
2043 | ||
2044 | return (rc); | |
2045 | } | |
2046 | ||
2047 | ||
2048 | /* | |
2049 | * NAME: dbAllocBits() | |
2050 | * | |
f720e3ba | 2051 | * FUNCTION: allocate a specified block range from a dmap. |
1da177e4 LT |
2052 | * |
2053 | * this routine updates the dmap to reflect the working | |
2054 | * state allocation of the specified block range. it directly | |
2055 | * updates the bits of the working map and causes the adjustment | |
2056 | * of the binary buddy system described by the dmap's dmtree | |
2057 | * leaves to reflect the bits allocated. it also causes the | |
2058 | * dmap's dmtree, as a whole, to reflect the allocated range. | |
2059 | * | |
2060 | * PARAMETERS: | |
f720e3ba DK |
2061 | * bmp - pointer to bmap descriptor |
2062 | * dp - pointer to dmap to allocate bits from. | |
2063 | * blkno - starting block number of the bits to be allocated. | |
2064 | * nblocks - number of bits to be allocated. | |
1da177e4 LT |
2065 | * |
2066 | * RETURN VALUES: none | |
2067 | * | |
2068 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2069 | */ | |
2070 | static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
2071 | int nblocks) | |
2072 | { | |
2073 | int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; | |
2074 | dmtree_t *tp = (dmtree_t *) & dp->tree; | |
2075 | int size; | |
2076 | s8 *leaf; | |
2077 | ||
2078 | /* pick up a pointer to the leaves of the dmap tree */ | |
2079 | leaf = dp->tree.stree + LEAFIND; | |
2080 | ||
2081 | /* determine the bit number and word within the dmap of the | |
2082 | * starting block. | |
2083 | */ | |
2084 | dbitno = blkno & (BPERDMAP - 1); | |
2085 | word = dbitno >> L2DBWORD; | |
2086 | ||
2087 | /* block range better be within the dmap */ | |
2088 | assert(dbitno + nblocks <= BPERDMAP); | |
2089 | ||
2090 | /* allocate the bits of the dmap's words corresponding to the block | |
2091 | * range. not all bits of the first and last words may be contained | |
2092 | * within the block range. if this is the case, we'll work against | |
2093 | * those words (i.e. partial first and/or last) on an individual basis | |
2094 | * (a single pass), allocating the bits of interest by hand and | |
2095 | * updating the leaf corresponding to the dmap word. a single pass | |
2096 | * will be used for all dmap words fully contained within the | |
2097 | * specified range. within this pass, the bits of all fully contained | |
2098 | * dmap words will be marked as free in a single shot and the leaves | |
2099 | * will be updated. a single leaf may describe the free space of | |
2100 | * multiple dmap words, so we may update only a subset of the actual | |
2101 | * leaves corresponding to the dmap words of the block range. | |
2102 | */ | |
2103 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
2104 | /* determine the bit number within the word and | |
2105 | * the number of bits within the word. | |
2106 | */ | |
2107 | wbitno = dbitno & (DBWORD - 1); | |
2108 | nb = min(rembits, DBWORD - wbitno); | |
2109 | ||
2110 | /* check if only part of a word is to be allocated. | |
2111 | */ | |
2112 | if (nb < DBWORD) { | |
2113 | /* allocate (set to 1) the appropriate bits within | |
2114 | * this dmap word. | |
2115 | */ | |
2116 | dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) | |
2117 | >> wbitno); | |
2118 | ||
2119 | /* update the leaf for this dmap word. in addition | |
2120 | * to setting the leaf value to the binary buddy max | |
2121 | * of the updated dmap word, dbSplit() will split | |
2122 | * the binary system of the leaves if need be. | |
2123 | */ | |
2124 | dbSplit(tp, word, BUDMIN, | |
2125 | dbMaxBud((u8 *) & dp->wmap[word])); | |
2126 | ||
2127 | word += 1; | |
2128 | } else { | |
2129 | /* one or more dmap words are fully contained | |
2130 | * within the block range. determine how many | |
2131 | * words and allocate (set to 1) the bits of these | |
2132 | * words. | |
2133 | */ | |
2134 | nwords = rembits >> L2DBWORD; | |
2135 | memset(&dp->wmap[word], (int) ONES, nwords * 4); | |
2136 | ||
2137 | /* determine how many bits. | |
2138 | */ | |
2139 | nb = nwords << L2DBWORD; | |
2140 | ||
2141 | /* now update the appropriate leaves to reflect | |
2142 | * the allocated words. | |
2143 | */ | |
2144 | for (; nwords > 0; nwords -= nw) { | |
f720e3ba | 2145 | if (leaf[word] < BUDMIN) { |
1da177e4 LT |
2146 | jfs_error(bmp->db_ipbmap->i_sb, |
2147 | "dbAllocBits: leaf page " | |
2148 | "corrupt"); | |
2149 | break; | |
2150 | } | |
2151 | ||
2152 | /* determine what the leaf value should be | |
2153 | * updated to as the minimum of the l2 number | |
2154 | * of bits being allocated and the l2 number | |
2155 | * of bits currently described by this leaf. | |
2156 | */ | |
2157 | size = min((int)leaf[word], NLSTOL2BSZ(nwords)); | |
2158 | ||
2159 | /* update the leaf to reflect the allocation. | |
2160 | * in addition to setting the leaf value to | |
2161 | * NOFREE, dbSplit() will split the binary | |
2162 | * system of the leaves to reflect the current | |
2163 | * allocation (size). | |
2164 | */ | |
2165 | dbSplit(tp, word, size, NOFREE); | |
2166 | ||
2167 | /* get the number of dmap words handled */ | |
2168 | nw = BUDSIZE(size, BUDMIN); | |
2169 | word += nw; | |
2170 | } | |
2171 | } | |
2172 | } | |
2173 | ||
2174 | /* update the free count for this dmap */ | |
89145622 | 2175 | le32_add_cpu(&dp->nfree, -nblocks); |
1da177e4 LT |
2176 | |
2177 | BMAP_LOCK(bmp); | |
2178 | ||
2179 | /* if this allocation group is completely free, | |
2180 | * update the maximum allocation group number if this allocation | |
2181 | * group is the new max. | |
2182 | */ | |
2183 | agno = blkno >> bmp->db_agl2size; | |
2184 | if (agno > bmp->db_maxag) | |
2185 | bmp->db_maxag = agno; | |
2186 | ||
2187 | /* update the free count for the allocation group and map */ | |
2188 | bmp->db_agfree[agno] -= nblocks; | |
2189 | bmp->db_nfree -= nblocks; | |
2190 | ||
2191 | BMAP_UNLOCK(bmp); | |
2192 | } | |
2193 | ||
2194 | ||
2195 | /* | |
2196 | * NAME: dbFreeBits() | |
2197 | * | |
f720e3ba | 2198 | * FUNCTION: free a specified block range from a dmap. |
1da177e4 LT |
2199 | * |
2200 | * this routine updates the dmap to reflect the working | |
2201 | * state allocation of the specified block range. it directly | |
2202 | * updates the bits of the working map and causes the adjustment | |
2203 | * of the binary buddy system described by the dmap's dmtree | |
2204 | * leaves to reflect the bits freed. it also causes the dmap's | |
2205 | * dmtree, as a whole, to reflect the deallocated range. | |
2206 | * | |
2207 | * PARAMETERS: | |
f720e3ba DK |
2208 | * bmp - pointer to bmap descriptor |
2209 | * dp - pointer to dmap to free bits from. | |
2210 | * blkno - starting block number of the bits to be freed. | |
2211 | * nblocks - number of bits to be freed. | |
1da177e4 | 2212 | * |
56d12549 | 2213 | * RETURN VALUES: 0 for success |
1da177e4 LT |
2214 | * |
2215 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2216 | */ | |
56d12549 | 2217 | static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
1da177e4 LT |
2218 | int nblocks) |
2219 | { | |
2220 | int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; | |
2221 | dmtree_t *tp = (dmtree_t *) & dp->tree; | |
56d12549 | 2222 | int rc = 0; |
1da177e4 LT |
2223 | int size; |
2224 | ||
2225 | /* determine the bit number and word within the dmap of the | |
2226 | * starting block. | |
2227 | */ | |
2228 | dbitno = blkno & (BPERDMAP - 1); | |
2229 | word = dbitno >> L2DBWORD; | |
2230 | ||
2231 | /* block range better be within the dmap. | |
2232 | */ | |
2233 | assert(dbitno + nblocks <= BPERDMAP); | |
2234 | ||
2235 | /* free the bits of the dmaps words corresponding to the block range. | |
2236 | * not all bits of the first and last words may be contained within | |
2237 | * the block range. if this is the case, we'll work against those | |
2238 | * words (i.e. partial first and/or last) on an individual basis | |
2239 | * (a single pass), freeing the bits of interest by hand and updating | |
2240 | * the leaf corresponding to the dmap word. a single pass will be used | |
63f83c9f | 2241 | * for all dmap words fully contained within the specified range. |
1da177e4 LT |
2242 | * within this pass, the bits of all fully contained dmap words will |
2243 | * be marked as free in a single shot and the leaves will be updated. a | |
2244 | * single leaf may describe the free space of multiple dmap words, | |
2245 | * so we may update only a subset of the actual leaves corresponding | |
2246 | * to the dmap words of the block range. | |
2247 | * | |
2248 | * dbJoin() is used to update leaf values and will join the binary | |
2249 | * buddy system of the leaves if the new leaf values indicate this | |
2250 | * should be done. | |
2251 | */ | |
2252 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
2253 | /* determine the bit number within the word and | |
2254 | * the number of bits within the word. | |
2255 | */ | |
2256 | wbitno = dbitno & (DBWORD - 1); | |
2257 | nb = min(rembits, DBWORD - wbitno); | |
2258 | ||
2259 | /* check if only part of a word is to be freed. | |
2260 | */ | |
2261 | if (nb < DBWORD) { | |
2262 | /* free (zero) the appropriate bits within this | |
63f83c9f | 2263 | * dmap word. |
1da177e4 LT |
2264 | */ |
2265 | dp->wmap[word] &= | |
2266 | cpu_to_le32(~(ONES << (DBWORD - nb) | |
2267 | >> wbitno)); | |
2268 | ||
2269 | /* update the leaf for this dmap word. | |
2270 | */ | |
56d12549 DK |
2271 | rc = dbJoin(tp, word, |
2272 | dbMaxBud((u8 *) & dp->wmap[word])); | |
2273 | if (rc) | |
2274 | return rc; | |
1da177e4 LT |
2275 | |
2276 | word += 1; | |
2277 | } else { | |
2278 | /* one or more dmap words are fully contained | |
2279 | * within the block range. determine how many | |
2280 | * words and free (zero) the bits of these words. | |
2281 | */ | |
2282 | nwords = rembits >> L2DBWORD; | |
2283 | memset(&dp->wmap[word], 0, nwords * 4); | |
2284 | ||
2285 | /* determine how many bits. | |
2286 | */ | |
2287 | nb = nwords << L2DBWORD; | |
2288 | ||
2289 | /* now update the appropriate leaves to reflect | |
2290 | * the freed words. | |
2291 | */ | |
2292 | for (; nwords > 0; nwords -= nw) { | |
2293 | /* determine what the leaf value should be | |
2294 | * updated to as the minimum of the l2 number | |
2295 | * of bits being freed and the l2 (max) number | |
2296 | * of bits that can be described by this leaf. | |
2297 | */ | |
2298 | size = | |
2299 | min(LITOL2BSZ | |
2300 | (word, L2LPERDMAP, BUDMIN), | |
2301 | NLSTOL2BSZ(nwords)); | |
2302 | ||
2303 | /* update the leaf. | |
2304 | */ | |
56d12549 DK |
2305 | rc = dbJoin(tp, word, size); |
2306 | if (rc) | |
2307 | return rc; | |
1da177e4 LT |
2308 | |
2309 | /* get the number of dmap words handled. | |
2310 | */ | |
2311 | nw = BUDSIZE(size, BUDMIN); | |
2312 | word += nw; | |
2313 | } | |
2314 | } | |
2315 | } | |
2316 | ||
2317 | /* update the free count for this dmap. | |
2318 | */ | |
89145622 | 2319 | le32_add_cpu(&dp->nfree, nblocks); |
1da177e4 LT |
2320 | |
2321 | BMAP_LOCK(bmp); | |
2322 | ||
63f83c9f | 2323 | /* update the free count for the allocation group and |
1da177e4 LT |
2324 | * map. |
2325 | */ | |
2326 | agno = blkno >> bmp->db_agl2size; | |
2327 | bmp->db_nfree += nblocks; | |
2328 | bmp->db_agfree[agno] += nblocks; | |
2329 | ||
2330 | /* check if this allocation group is not completely free and | |
2331 | * if it is currently the maximum (rightmost) allocation group. | |
2332 | * if so, establish the new maximum allocation group number by | |
2333 | * searching left for the first allocation group with allocation. | |
2334 | */ | |
2335 | if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) || | |
2336 | (agno == bmp->db_numag - 1 && | |
2337 | bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) { | |
2338 | while (bmp->db_maxag > 0) { | |
2339 | bmp->db_maxag -= 1; | |
2340 | if (bmp->db_agfree[bmp->db_maxag] != | |
2341 | bmp->db_agsize) | |
2342 | break; | |
2343 | } | |
2344 | ||
2345 | /* re-establish the allocation group preference if the | |
2346 | * current preference is right of the maximum allocation | |
2347 | * group. | |
2348 | */ | |
2349 | if (bmp->db_agpref > bmp->db_maxag) | |
2350 | bmp->db_agpref = bmp->db_maxag; | |
2351 | } | |
2352 | ||
2353 | BMAP_UNLOCK(bmp); | |
56d12549 DK |
2354 | |
2355 | return 0; | |
1da177e4 LT |
2356 | } |
2357 | ||
2358 | ||
2359 | /* | |
2360 | * NAME: dbAdjCtl() | |
2361 | * | |
2362 | * FUNCTION: adjust a dmap control page at a specified level to reflect | |
2363 | * the change in a lower level dmap or dmap control page's | |
2364 | * maximum string of free blocks (i.e. a change in the root | |
2365 | * of the lower level object's dmtree) due to the allocation | |
2366 | * or deallocation of a range of blocks with a single dmap. | |
2367 | * | |
2368 | * on entry, this routine is provided with the new value of | |
2369 | * the lower level dmap or dmap control page root and the | |
2370 | * starting block number of the block range whose allocation | |
2371 | * or deallocation resulted in the root change. this range | |
2372 | * is respresented by a single leaf of the current dmapctl | |
2373 | * and the leaf will be updated with this value, possibly | |
63f83c9f | 2374 | * causing a binary buddy system within the leaves to be |
1da177e4 LT |
2375 | * split or joined. the update may also cause the dmapctl's |
2376 | * dmtree to be updated. | |
2377 | * | |
2378 | * if the adjustment of the dmap control page, itself, causes its | |
2379 | * root to change, this change will be bubbled up to the next dmap | |
2380 | * control level by a recursive call to this routine, specifying | |
2381 | * the new root value and the next dmap control page level to | |
2382 | * be adjusted. | |
2383 | * PARAMETERS: | |
f720e3ba DK |
2384 | * bmp - pointer to bmap descriptor |
2385 | * blkno - the first block of a block range within a dmap. it is | |
1da177e4 LT |
2386 | * the allocation or deallocation of this block range that |
2387 | * requires the dmap control page to be adjusted. | |
f720e3ba | 2388 | * newval - the new value of the lower level dmap or dmap control |
1da177e4 | 2389 | * page root. |
f720e3ba DK |
2390 | * alloc - 'true' if adjustment is due to an allocation. |
2391 | * level - current level of dmap control page (i.e. L0, L1, L2) to | |
1da177e4 LT |
2392 | * be adjusted. |
2393 | * | |
2394 | * RETURN VALUES: | |
f720e3ba DK |
2395 | * 0 - success |
2396 | * -EIO - i/o error | |
1da177e4 LT |
2397 | * |
2398 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2399 | */ | |
2400 | static int | |
2401 | dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level) | |
2402 | { | |
2403 | struct metapage *mp; | |
2404 | s8 oldroot; | |
2405 | int oldval; | |
2406 | s64 lblkno; | |
2407 | struct dmapctl *dcp; | |
2408 | int rc, leafno, ti; | |
2409 | ||
2410 | /* get the buffer for the dmap control page for the specified | |
2411 | * block number and control page level. | |
2412 | */ | |
2413 | lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level); | |
2414 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
2415 | if (mp == NULL) | |
2416 | return -EIO; | |
2417 | dcp = (struct dmapctl *) mp->data; | |
2418 | ||
2419 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { | |
2420 | jfs_error(bmp->db_ipbmap->i_sb, | |
2421 | "dbAdjCtl: Corrupt dmapctl page"); | |
2422 | release_metapage(mp); | |
2423 | return -EIO; | |
2424 | } | |
2425 | ||
2426 | /* determine the leaf number corresponding to the block and | |
2427 | * the index within the dmap control tree. | |
2428 | */ | |
2429 | leafno = BLKTOCTLLEAF(blkno, dcp->budmin); | |
2430 | ti = leafno + le32_to_cpu(dcp->leafidx); | |
2431 | ||
2432 | /* save the current leaf value and the current root level (i.e. | |
2433 | * maximum l2 free string described by this dmapctl). | |
2434 | */ | |
2435 | oldval = dcp->stree[ti]; | |
2436 | oldroot = dcp->stree[ROOT]; | |
2437 | ||
2438 | /* check if this is a control page update for an allocation. | |
2439 | * if so, update the leaf to reflect the new leaf value using | |
2440 | * dbSplit(); otherwise (deallocation), use dbJoin() to udpate | |
2441 | * the leaf with the new value. in addition to updating the | |
2442 | * leaf, dbSplit() will also split the binary buddy system of | |
2443 | * the leaves, if required, and bubble new values within the | |
2444 | * dmapctl tree, if required. similarly, dbJoin() will join | |
2445 | * the binary buddy system of leaves and bubble new values up | |
2446 | * the dmapctl tree as required by the new leaf value. | |
2447 | */ | |
2448 | if (alloc) { | |
2449 | /* check if we are in the middle of a binary buddy | |
2450 | * system. this happens when we are performing the | |
2451 | * first allocation out of an allocation group that | |
2452 | * is part (not the first part) of a larger binary | |
2453 | * buddy system. if we are in the middle, back split | |
2454 | * the system prior to calling dbSplit() which assumes | |
2455 | * that it is at the front of a binary buddy system. | |
2456 | */ | |
2457 | if (oldval == NOFREE) { | |
b6a47fd8 DK |
2458 | rc = dbBackSplit((dmtree_t *) dcp, leafno); |
2459 | if (rc) | |
2460 | return rc; | |
1da177e4 LT |
2461 | oldval = dcp->stree[ti]; |
2462 | } | |
2463 | dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval); | |
2464 | } else { | |
56d12549 DK |
2465 | rc = dbJoin((dmtree_t *) dcp, leafno, newval); |
2466 | if (rc) | |
2467 | return rc; | |
1da177e4 LT |
2468 | } |
2469 | ||
2470 | /* check if the root of the current dmap control page changed due | |
2471 | * to the update and if the current dmap control page is not at | |
2472 | * the current top level (i.e. L0, L1, L2) of the map. if so (i.e. | |
2473 | * root changed and this is not the top level), call this routine | |
2474 | * again (recursion) for the next higher level of the mapping to | |
2475 | * reflect the change in root for the current dmap control page. | |
2476 | */ | |
2477 | if (dcp->stree[ROOT] != oldroot) { | |
2478 | /* are we below the top level of the map. if so, | |
2479 | * bubble the root up to the next higher level. | |
2480 | */ | |
2481 | if (level < bmp->db_maxlevel) { | |
2482 | /* bubble up the new root of this dmap control page to | |
2483 | * the next level. | |
2484 | */ | |
2485 | if ((rc = | |
2486 | dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc, | |
2487 | level + 1))) { | |
2488 | /* something went wrong in bubbling up the new | |
2489 | * root value, so backout the changes to the | |
2490 | * current dmap control page. | |
2491 | */ | |
2492 | if (alloc) { | |
2493 | dbJoin((dmtree_t *) dcp, leafno, | |
2494 | oldval); | |
2495 | } else { | |
2496 | /* the dbJoin() above might have | |
2497 | * caused a larger binary buddy system | |
2498 | * to form and we may now be in the | |
2499 | * middle of it. if this is the case, | |
2500 | * back split the buddies. | |
2501 | */ | |
2502 | if (dcp->stree[ti] == NOFREE) | |
2503 | dbBackSplit((dmtree_t *) | |
2504 | dcp, leafno); | |
2505 | dbSplit((dmtree_t *) dcp, leafno, | |
2506 | dcp->budmin, oldval); | |
2507 | } | |
2508 | ||
2509 | /* release the buffer and return the error. | |
2510 | */ | |
2511 | release_metapage(mp); | |
2512 | return (rc); | |
2513 | } | |
2514 | } else { | |
2515 | /* we're at the top level of the map. update | |
2516 | * the bmap control page to reflect the size | |
2517 | * of the maximum free buddy system. | |
2518 | */ | |
2519 | assert(level == bmp->db_maxlevel); | |
2520 | if (bmp->db_maxfreebud != oldroot) { | |
2521 | jfs_error(bmp->db_ipbmap->i_sb, | |
2522 | "dbAdjCtl: the maximum free buddy is " | |
2523 | "not the old root"); | |
2524 | } | |
2525 | bmp->db_maxfreebud = dcp->stree[ROOT]; | |
2526 | } | |
2527 | } | |
2528 | ||
2529 | /* write the buffer. | |
2530 | */ | |
2531 | write_metapage(mp); | |
2532 | ||
2533 | return (0); | |
2534 | } | |
2535 | ||
2536 | ||
2537 | /* | |
2538 | * NAME: dbSplit() | |
2539 | * | |
f720e3ba | 2540 | * FUNCTION: update the leaf of a dmtree with a new value, splitting |
1da177e4 LT |
2541 | * the leaf from the binary buddy system of the dmtree's |
2542 | * leaves, as required. | |
2543 | * | |
2544 | * PARAMETERS: | |
f720e3ba DK |
2545 | * tp - pointer to the tree containing the leaf. |
2546 | * leafno - the number of the leaf to be updated. | |
2547 | * splitsz - the size the binary buddy system starting at the leaf | |
1da177e4 | 2548 | * must be split to, specified as the log2 number of blocks. |
f720e3ba | 2549 | * newval - the new value for the leaf. |
1da177e4 LT |
2550 | * |
2551 | * RETURN VALUES: none | |
2552 | * | |
2553 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2554 | */ | |
2555 | static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval) | |
2556 | { | |
2557 | int budsz; | |
2558 | int cursz; | |
2559 | s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); | |
2560 | ||
2561 | /* check if the leaf needs to be split. | |
2562 | */ | |
2563 | if (leaf[leafno] > tp->dmt_budmin) { | |
2564 | /* the split occurs by cutting the buddy system in half | |
2565 | * at the specified leaf until we reach the specified | |
2566 | * size. pick up the starting split size (current size | |
2567 | * - 1 in l2) and the corresponding buddy size. | |
2568 | */ | |
2569 | cursz = leaf[leafno] - 1; | |
2570 | budsz = BUDSIZE(cursz, tp->dmt_budmin); | |
2571 | ||
2572 | /* split until we reach the specified size. | |
2573 | */ | |
2574 | while (cursz >= splitsz) { | |
2575 | /* update the buddy's leaf with its new value. | |
2576 | */ | |
2577 | dbAdjTree(tp, leafno ^ budsz, cursz); | |
2578 | ||
2579 | /* on to the next size and buddy. | |
2580 | */ | |
2581 | cursz -= 1; | |
2582 | budsz >>= 1; | |
2583 | } | |
2584 | } | |
2585 | ||
63f83c9f | 2586 | /* adjust the dmap tree to reflect the specified leaf's new |
1da177e4 LT |
2587 | * value. |
2588 | */ | |
2589 | dbAdjTree(tp, leafno, newval); | |
2590 | } | |
2591 | ||
2592 | ||
2593 | /* | |
2594 | * NAME: dbBackSplit() | |
2595 | * | |
f720e3ba | 2596 | * FUNCTION: back split the binary buddy system of dmtree leaves |
1da177e4 LT |
2597 | * that hold a specified leaf until the specified leaf |
2598 | * starts its own binary buddy system. | |
2599 | * | |
2600 | * the allocators typically perform allocations at the start | |
2601 | * of binary buddy systems and dbSplit() is used to accomplish | |
2602 | * any required splits. in some cases, however, allocation | |
2603 | * may occur in the middle of a binary system and requires a | |
2604 | * back split, with the split proceeding out from the middle of | |
2605 | * the system (less efficient) rather than the start of the | |
2606 | * system (more efficient). the cases in which a back split | |
2607 | * is required are rare and are limited to the first allocation | |
2608 | * within an allocation group which is a part (not first part) | |
2609 | * of a larger binary buddy system and a few exception cases | |
2610 | * in which a previous join operation must be backed out. | |
2611 | * | |
2612 | * PARAMETERS: | |
f720e3ba DK |
2613 | * tp - pointer to the tree containing the leaf. |
2614 | * leafno - the number of the leaf to be updated. | |
1da177e4 LT |
2615 | * |
2616 | * RETURN VALUES: none | |
2617 | * | |
2618 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2619 | */ | |
b6a47fd8 | 2620 | static int dbBackSplit(dmtree_t * tp, int leafno) |
1da177e4 LT |
2621 | { |
2622 | int budsz, bud, w, bsz, size; | |
2623 | int cursz; | |
2624 | s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); | |
2625 | ||
2626 | /* leaf should be part (not first part) of a binary | |
2627 | * buddy system. | |
2628 | */ | |
2629 | assert(leaf[leafno] == NOFREE); | |
2630 | ||
2631 | /* the back split is accomplished by iteratively finding the leaf | |
2632 | * that starts the buddy system that contains the specified leaf and | |
2633 | * splitting that system in two. this iteration continues until | |
63f83c9f | 2634 | * the specified leaf becomes the start of a buddy system. |
1da177e4 LT |
2635 | * |
2636 | * determine maximum possible l2 size for the specified leaf. | |
2637 | */ | |
2638 | size = | |
2639 | LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs), | |
2640 | tp->dmt_budmin); | |
2641 | ||
2642 | /* determine the number of leaves covered by this size. this | |
2643 | * is the buddy size that we will start with as we search for | |
2644 | * the buddy system that contains the specified leaf. | |
2645 | */ | |
2646 | budsz = BUDSIZE(size, tp->dmt_budmin); | |
2647 | ||
2648 | /* back split. | |
2649 | */ | |
2650 | while (leaf[leafno] == NOFREE) { | |
2651 | /* find the leftmost buddy leaf. | |
2652 | */ | |
2653 | for (w = leafno, bsz = budsz;; bsz <<= 1, | |
2654 | w = (w < bud) ? w : bud) { | |
b6a47fd8 DK |
2655 | if (bsz >= le32_to_cpu(tp->dmt_nleafs)) { |
2656 | jfs_err("JFS: block map error in dbBackSplit"); | |
2657 | return -EIO; | |
2658 | } | |
1da177e4 LT |
2659 | |
2660 | /* determine the buddy. | |
2661 | */ | |
2662 | bud = w ^ bsz; | |
2663 | ||
2664 | /* check if this buddy is the start of the system. | |
2665 | */ | |
2666 | if (leaf[bud] != NOFREE) { | |
2667 | /* split the leaf at the start of the | |
2668 | * system in two. | |
2669 | */ | |
2670 | cursz = leaf[bud] - 1; | |
2671 | dbSplit(tp, bud, cursz, cursz); | |
2672 | break; | |
2673 | } | |
2674 | } | |
2675 | } | |
2676 | ||
b6a47fd8 DK |
2677 | if (leaf[leafno] != size) { |
2678 | jfs_err("JFS: wrong leaf value in dbBackSplit"); | |
2679 | return -EIO; | |
2680 | } | |
2681 | return 0; | |
1da177e4 LT |
2682 | } |
2683 | ||
2684 | ||
2685 | /* | |
2686 | * NAME: dbJoin() | |
2687 | * | |
f720e3ba | 2688 | * FUNCTION: update the leaf of a dmtree with a new value, joining |
1da177e4 LT |
2689 | * the leaf with other leaves of the dmtree into a multi-leaf |
2690 | * binary buddy system, as required. | |
2691 | * | |
2692 | * PARAMETERS: | |
f720e3ba DK |
2693 | * tp - pointer to the tree containing the leaf. |
2694 | * leafno - the number of the leaf to be updated. | |
2695 | * newval - the new value for the leaf. | |
1da177e4 LT |
2696 | * |
2697 | * RETURN VALUES: none | |
2698 | */ | |
56d12549 | 2699 | static int dbJoin(dmtree_t * tp, int leafno, int newval) |
1da177e4 LT |
2700 | { |
2701 | int budsz, buddy; | |
2702 | s8 *leaf; | |
2703 | ||
2704 | /* can the new leaf value require a join with other leaves ? | |
2705 | */ | |
2706 | if (newval >= tp->dmt_budmin) { | |
2707 | /* pickup a pointer to the leaves of the tree. | |
2708 | */ | |
2709 | leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); | |
2710 | ||
2711 | /* try to join the specified leaf into a large binary | |
2712 | * buddy system. the join proceeds by attempting to join | |
2713 | * the specified leafno with its buddy (leaf) at new value. | |
2714 | * if the join occurs, we attempt to join the left leaf | |
2715 | * of the joined buddies with its buddy at new value + 1. | |
2716 | * we continue to join until we find a buddy that cannot be | |
2717 | * joined (does not have a value equal to the size of the | |
2718 | * last join) or until all leaves have been joined into a | |
2719 | * single system. | |
2720 | * | |
2721 | * get the buddy size (number of words covered) of | |
2722 | * the new value. | |
2723 | */ | |
2724 | budsz = BUDSIZE(newval, tp->dmt_budmin); | |
2725 | ||
2726 | /* try to join. | |
2727 | */ | |
2728 | while (budsz < le32_to_cpu(tp->dmt_nleafs)) { | |
2729 | /* get the buddy leaf. | |
2730 | */ | |
2731 | buddy = leafno ^ budsz; | |
2732 | ||
2733 | /* if the leaf's new value is greater than its | |
2734 | * buddy's value, we join no more. | |
2735 | */ | |
2736 | if (newval > leaf[buddy]) | |
2737 | break; | |
2738 | ||
56d12549 DK |
2739 | /* It shouldn't be less */ |
2740 | if (newval < leaf[buddy]) | |
2741 | return -EIO; | |
1da177e4 LT |
2742 | |
2743 | /* check which (leafno or buddy) is the left buddy. | |
2744 | * the left buddy gets to claim the blocks resulting | |
2745 | * from the join while the right gets to claim none. | |
2746 | * the left buddy is also eligable to participate in | |
2747 | * a join at the next higher level while the right | |
2748 | * is not. | |
2749 | * | |
2750 | */ | |
2751 | if (leafno < buddy) { | |
2752 | /* leafno is the left buddy. | |
2753 | */ | |
2754 | dbAdjTree(tp, buddy, NOFREE); | |
2755 | } else { | |
2756 | /* buddy is the left buddy and becomes | |
2757 | * leafno. | |
2758 | */ | |
2759 | dbAdjTree(tp, leafno, NOFREE); | |
2760 | leafno = buddy; | |
2761 | } | |
2762 | ||
2763 | /* on to try the next join. | |
2764 | */ | |
2765 | newval += 1; | |
2766 | budsz <<= 1; | |
2767 | } | |
2768 | } | |
2769 | ||
2770 | /* update the leaf value. | |
2771 | */ | |
2772 | dbAdjTree(tp, leafno, newval); | |
56d12549 DK |
2773 | |
2774 | return 0; | |
1da177e4 LT |
2775 | } |
2776 | ||
2777 | ||
2778 | /* | |
2779 | * NAME: dbAdjTree() | |
2780 | * | |
f720e3ba | 2781 | * FUNCTION: update a leaf of a dmtree with a new value, adjusting |
1da177e4 LT |
2782 | * the dmtree, as required, to reflect the new leaf value. |
2783 | * the combination of any buddies must already be done before | |
2784 | * this is called. | |
2785 | * | |
2786 | * PARAMETERS: | |
f720e3ba DK |
2787 | * tp - pointer to the tree to be adjusted. |
2788 | * leafno - the number of the leaf to be updated. | |
2789 | * newval - the new value for the leaf. | |
1da177e4 LT |
2790 | * |
2791 | * RETURN VALUES: none | |
2792 | */ | |
2793 | static void dbAdjTree(dmtree_t * tp, int leafno, int newval) | |
2794 | { | |
2795 | int lp, pp, k; | |
2796 | int max; | |
2797 | ||
2798 | /* pick up the index of the leaf for this leafno. | |
2799 | */ | |
2800 | lp = leafno + le32_to_cpu(tp->dmt_leafidx); | |
2801 | ||
2802 | /* is the current value the same as the old value ? if so, | |
2803 | * there is nothing to do. | |
2804 | */ | |
2805 | if (tp->dmt_stree[lp] == newval) | |
2806 | return; | |
2807 | ||
2808 | /* set the new value. | |
2809 | */ | |
2810 | tp->dmt_stree[lp] = newval; | |
2811 | ||
2812 | /* bubble the new value up the tree as required. | |
2813 | */ | |
2814 | for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) { | |
2815 | /* get the index of the first leaf of the 4 leaf | |
2816 | * group containing the specified leaf (leafno). | |
2817 | */ | |
2818 | lp = ((lp - 1) & ~0x03) + 1; | |
2819 | ||
2820 | /* get the index of the parent of this 4 leaf group. | |
2821 | */ | |
2822 | pp = (lp - 1) >> 2; | |
2823 | ||
2824 | /* determine the maximum of the 4 leaves. | |
2825 | */ | |
2826 | max = TREEMAX(&tp->dmt_stree[lp]); | |
2827 | ||
2828 | /* if the maximum of the 4 is the same as the | |
2829 | * parent's value, we're done. | |
2830 | */ | |
2831 | if (tp->dmt_stree[pp] == max) | |
2832 | break; | |
2833 | ||
2834 | /* parent gets new value. | |
2835 | */ | |
2836 | tp->dmt_stree[pp] = max; | |
2837 | ||
2838 | /* parent becomes leaf for next go-round. | |
2839 | */ | |
2840 | lp = pp; | |
2841 | } | |
2842 | } | |
2843 | ||
2844 | ||
2845 | /* | |
2846 | * NAME: dbFindLeaf() | |
2847 | * | |
f720e3ba | 2848 | * FUNCTION: search a dmtree_t for sufficient free blocks, returning |
63f83c9f | 2849 | * the index of a leaf describing the free blocks if |
1da177e4 LT |
2850 | * sufficient free blocks are found. |
2851 | * | |
2852 | * the search starts at the top of the dmtree_t tree and | |
2853 | * proceeds down the tree to the leftmost leaf with sufficient | |
2854 | * free space. | |
2855 | * | |
2856 | * PARAMETERS: | |
f720e3ba DK |
2857 | * tp - pointer to the tree to be searched. |
2858 | * l2nb - log2 number of free blocks to search for. | |
1da177e4 LT |
2859 | * leafidx - return pointer to be set to the index of the leaf |
2860 | * describing at least l2nb free blocks if sufficient | |
2861 | * free blocks are found. | |
2862 | * | |
2863 | * RETURN VALUES: | |
f720e3ba DK |
2864 | * 0 - success |
2865 | * -ENOSPC - insufficient free blocks. | |
1da177e4 LT |
2866 | */ |
2867 | static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx) | |
2868 | { | |
2869 | int ti, n = 0, k, x = 0; | |
2870 | ||
2871 | /* first check the root of the tree to see if there is | |
2872 | * sufficient free space. | |
2873 | */ | |
2874 | if (l2nb > tp->dmt_stree[ROOT]) | |
2875 | return -ENOSPC; | |
2876 | ||
2877 | /* sufficient free space available. now search down the tree | |
2878 | * starting at the next level for the leftmost leaf that | |
2879 | * describes sufficient free space. | |
2880 | */ | |
2881 | for (k = le32_to_cpu(tp->dmt_height), ti = 1; | |
2882 | k > 0; k--, ti = ((ti + n) << 2) + 1) { | |
2883 | /* search the four nodes at this level, starting from | |
2884 | * the left. | |
2885 | */ | |
2886 | for (x = ti, n = 0; n < 4; n++) { | |
2887 | /* sufficient free space found. move to the next | |
2888 | * level (or quit if this is the last level). | |
2889 | */ | |
2890 | if (l2nb <= tp->dmt_stree[x + n]) | |
2891 | break; | |
2892 | } | |
2893 | ||
2894 | /* better have found something since the higher | |
2895 | * levels of the tree said it was here. | |
2896 | */ | |
2897 | assert(n < 4); | |
2898 | } | |
2899 | ||
2900 | /* set the return to the leftmost leaf describing sufficient | |
2901 | * free space. | |
2902 | */ | |
2903 | *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx); | |
2904 | ||
2905 | return (0); | |
2906 | } | |
2907 | ||
2908 | ||
2909 | /* | |
2910 | * NAME: dbFindBits() | |
2911 | * | |
f720e3ba | 2912 | * FUNCTION: find a specified number of binary buddy free bits within a |
1da177e4 LT |
2913 | * dmap bitmap word value. |
2914 | * | |
2915 | * this routine searches the bitmap value for (1 << l2nb) free | |
2916 | * bits at (1 << l2nb) alignments within the value. | |
2917 | * | |
2918 | * PARAMETERS: | |
f720e3ba DK |
2919 | * word - dmap bitmap word value. |
2920 | * l2nb - number of free bits specified as a log2 number. | |
1da177e4 LT |
2921 | * |
2922 | * RETURN VALUES: | |
f720e3ba | 2923 | * starting bit number of free bits. |
1da177e4 LT |
2924 | */ |
2925 | static int dbFindBits(u32 word, int l2nb) | |
2926 | { | |
2927 | int bitno, nb; | |
2928 | u32 mask; | |
2929 | ||
2930 | /* get the number of bits. | |
2931 | */ | |
2932 | nb = 1 << l2nb; | |
2933 | assert(nb <= DBWORD); | |
2934 | ||
2935 | /* complement the word so we can use a mask (i.e. 0s represent | |
2936 | * free bits) and compute the mask. | |
2937 | */ | |
2938 | word = ~word; | |
2939 | mask = ONES << (DBWORD - nb); | |
2940 | ||
2941 | /* scan the word for nb free bits at nb alignments. | |
2942 | */ | |
2943 | for (bitno = 0; mask != 0; bitno += nb, mask >>= nb) { | |
2944 | if ((mask & word) == mask) | |
2945 | break; | |
2946 | } | |
2947 | ||
2948 | ASSERT(bitno < 32); | |
2949 | ||
2950 | /* return the bit number. | |
2951 | */ | |
2952 | return (bitno); | |
2953 | } | |
2954 | ||
2955 | ||
2956 | /* | |
2957 | * NAME: dbMaxBud(u8 *cp) | |
2958 | * | |
f720e3ba | 2959 | * FUNCTION: determine the largest binary buddy string of free |
1da177e4 LT |
2960 | * bits within 32-bits of the map. |
2961 | * | |
2962 | * PARAMETERS: | |
f720e3ba | 2963 | * cp - pointer to the 32-bit value. |
1da177e4 LT |
2964 | * |
2965 | * RETURN VALUES: | |
f720e3ba | 2966 | * largest binary buddy of free bits within a dmap word. |
1da177e4 LT |
2967 | */ |
2968 | static int dbMaxBud(u8 * cp) | |
2969 | { | |
2970 | signed char tmp1, tmp2; | |
2971 | ||
2972 | /* check if the wmap word is all free. if so, the | |
2973 | * free buddy size is BUDMIN. | |
2974 | */ | |
2975 | if (*((uint *) cp) == 0) | |
2976 | return (BUDMIN); | |
2977 | ||
2978 | /* check if the wmap word is half free. if so, the | |
2979 | * free buddy size is BUDMIN-1. | |
2980 | */ | |
2981 | if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0) | |
2982 | return (BUDMIN - 1); | |
2983 | ||
2984 | /* not all free or half free. determine the free buddy | |
2985 | * size thru table lookup using quarters of the wmap word. | |
2986 | */ | |
2987 | tmp1 = max(budtab[cp[2]], budtab[cp[3]]); | |
2988 | tmp2 = max(budtab[cp[0]], budtab[cp[1]]); | |
2989 | return (max(tmp1, tmp2)); | |
2990 | } | |
2991 | ||
2992 | ||
2993 | /* | |
2994 | * NAME: cnttz(uint word) | |
2995 | * | |
f720e3ba | 2996 | * FUNCTION: determine the number of trailing zeros within a 32-bit |
1da177e4 LT |
2997 | * value. |
2998 | * | |
2999 | * PARAMETERS: | |
f720e3ba | 3000 | * value - 32-bit value to be examined. |
1da177e4 LT |
3001 | * |
3002 | * RETURN VALUES: | |
f720e3ba | 3003 | * count of trailing zeros |
1da177e4 LT |
3004 | */ |
3005 | static int cnttz(u32 word) | |
3006 | { | |
3007 | int n; | |
3008 | ||
3009 | for (n = 0; n < 32; n++, word >>= 1) { | |
3010 | if (word & 0x01) | |
3011 | break; | |
3012 | } | |
3013 | ||
3014 | return (n); | |
3015 | } | |
3016 | ||
3017 | ||
3018 | /* | |
3019 | * NAME: cntlz(u32 value) | |
3020 | * | |
f720e3ba | 3021 | * FUNCTION: determine the number of leading zeros within a 32-bit |
1da177e4 LT |
3022 | * value. |
3023 | * | |
3024 | * PARAMETERS: | |
f720e3ba | 3025 | * value - 32-bit value to be examined. |
1da177e4 LT |
3026 | * |
3027 | * RETURN VALUES: | |
f720e3ba | 3028 | * count of leading zeros |
1da177e4 LT |
3029 | */ |
3030 | static int cntlz(u32 value) | |
3031 | { | |
3032 | int n; | |
3033 | ||
3034 | for (n = 0; n < 32; n++, value <<= 1) { | |
3035 | if (value & HIGHORDER) | |
3036 | break; | |
3037 | } | |
3038 | return (n); | |
3039 | } | |
3040 | ||
3041 | ||
3042 | /* | |
3043 | * NAME: blkstol2(s64 nb) | |
3044 | * | |
3045 | * FUNCTION: convert a block count to its log2 value. if the block | |
f720e3ba | 3046 | * count is not a l2 multiple, it is rounded up to the next |
1da177e4 LT |
3047 | * larger l2 multiple. |
3048 | * | |
3049 | * PARAMETERS: | |
f720e3ba | 3050 | * nb - number of blocks |
1da177e4 LT |
3051 | * |
3052 | * RETURN VALUES: | |
f720e3ba | 3053 | * log2 number of blocks |
1da177e4 | 3054 | */ |
6cb1269b | 3055 | static int blkstol2(s64 nb) |
1da177e4 LT |
3056 | { |
3057 | int l2nb; | |
3058 | s64 mask; /* meant to be signed */ | |
3059 | ||
3060 | mask = (s64) 1 << (64 - 1); | |
3061 | ||
3062 | /* count the leading bits. | |
3063 | */ | |
3064 | for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) { | |
3065 | /* leading bit found. | |
3066 | */ | |
3067 | if (nb & mask) { | |
3068 | /* determine the l2 value. | |
3069 | */ | |
3070 | l2nb = (64 - 1) - l2nb; | |
3071 | ||
3072 | /* check if we need to round up. | |
3073 | */ | |
3074 | if (~mask & nb) | |
3075 | l2nb++; | |
3076 | ||
3077 | return (l2nb); | |
3078 | } | |
3079 | } | |
3080 | assert(0); | |
3081 | return 0; /* fix compiler warning */ | |
3082 | } | |
3083 | ||
3084 | ||
3085 | /* | |
63f83c9f | 3086 | * NAME: dbAllocBottomUp() |
1da177e4 LT |
3087 | * |
3088 | * FUNCTION: alloc the specified block range from the working block | |
3089 | * allocation map. | |
3090 | * | |
3091 | * the blocks will be alloc from the working map one dmap | |
3092 | * at a time. | |
3093 | * | |
3094 | * PARAMETERS: | |
f720e3ba DK |
3095 | * ip - pointer to in-core inode; |
3096 | * blkno - starting block number to be freed. | |
3097 | * nblocks - number of blocks to be freed. | |
1da177e4 LT |
3098 | * |
3099 | * RETURN VALUES: | |
f720e3ba DK |
3100 | * 0 - success |
3101 | * -EIO - i/o error | |
1da177e4 LT |
3102 | */ |
3103 | int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks) | |
3104 | { | |
3105 | struct metapage *mp; | |
3106 | struct dmap *dp; | |
3107 | int nb, rc; | |
3108 | s64 lblkno, rem; | |
3109 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
3110 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; | |
3111 | ||
82d5b9a7 | 3112 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
3113 | |
3114 | /* block to be allocated better be within the mapsize. */ | |
3115 | ASSERT(nblocks <= bmp->db_mapsize - blkno); | |
3116 | ||
3117 | /* | |
3118 | * allocate the blocks a dmap at a time. | |
3119 | */ | |
3120 | mp = NULL; | |
3121 | for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { | |
3122 | /* release previous dmap if any */ | |
3123 | if (mp) { | |
3124 | write_metapage(mp); | |
3125 | } | |
3126 | ||
3127 | /* get the buffer for the current dmap. */ | |
3128 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
3129 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
3130 | if (mp == NULL) { | |
3131 | IREAD_UNLOCK(ipbmap); | |
3132 | return -EIO; | |
3133 | } | |
3134 | dp = (struct dmap *) mp->data; | |
3135 | ||
3136 | /* determine the number of blocks to be allocated from | |
3137 | * this dmap. | |
3138 | */ | |
3139 | nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); | |
3140 | ||
1da177e4 LT |
3141 | /* allocate the blocks. */ |
3142 | if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) { | |
3143 | release_metapage(mp); | |
3144 | IREAD_UNLOCK(ipbmap); | |
3145 | return (rc); | |
3146 | } | |
1da177e4 LT |
3147 | } |
3148 | ||
3149 | /* write the last buffer. */ | |
3150 | write_metapage(mp); | |
3151 | ||
3152 | IREAD_UNLOCK(ipbmap); | |
3153 | ||
3154 | return (0); | |
3155 | } | |
3156 | ||
3157 | ||
3158 | static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
3159 | int nblocks) | |
3160 | { | |
3161 | int rc; | |
3162 | int dbitno, word, rembits, nb, nwords, wbitno, agno; | |
3163 | s8 oldroot, *leaf; | |
3164 | struct dmaptree *tp = (struct dmaptree *) & dp->tree; | |
3165 | ||
3166 | /* save the current value of the root (i.e. maximum free string) | |
3167 | * of the dmap tree. | |
3168 | */ | |
3169 | oldroot = tp->stree[ROOT]; | |
3170 | ||
3171 | /* pick up a pointer to the leaves of the dmap tree */ | |
3172 | leaf = tp->stree + LEAFIND; | |
3173 | ||
3174 | /* determine the bit number and word within the dmap of the | |
3175 | * starting block. | |
3176 | */ | |
3177 | dbitno = blkno & (BPERDMAP - 1); | |
3178 | word = dbitno >> L2DBWORD; | |
3179 | ||
3180 | /* block range better be within the dmap */ | |
3181 | assert(dbitno + nblocks <= BPERDMAP); | |
3182 | ||
3183 | /* allocate the bits of the dmap's words corresponding to the block | |
3184 | * range. not all bits of the first and last words may be contained | |
3185 | * within the block range. if this is the case, we'll work against | |
3186 | * those words (i.e. partial first and/or last) on an individual basis | |
3187 | * (a single pass), allocating the bits of interest by hand and | |
3188 | * updating the leaf corresponding to the dmap word. a single pass | |
3189 | * will be used for all dmap words fully contained within the | |
3190 | * specified range. within this pass, the bits of all fully contained | |
3191 | * dmap words will be marked as free in a single shot and the leaves | |
3192 | * will be updated. a single leaf may describe the free space of | |
3193 | * multiple dmap words, so we may update only a subset of the actual | |
3194 | * leaves corresponding to the dmap words of the block range. | |
3195 | */ | |
3196 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
3197 | /* determine the bit number within the word and | |
3198 | * the number of bits within the word. | |
3199 | */ | |
3200 | wbitno = dbitno & (DBWORD - 1); | |
3201 | nb = min(rembits, DBWORD - wbitno); | |
3202 | ||
3203 | /* check if only part of a word is to be allocated. | |
3204 | */ | |
3205 | if (nb < DBWORD) { | |
3206 | /* allocate (set to 1) the appropriate bits within | |
3207 | * this dmap word. | |
3208 | */ | |
3209 | dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) | |
3210 | >> wbitno); | |
3211 | ||
3212 | word++; | |
3213 | } else { | |
3214 | /* one or more dmap words are fully contained | |
3215 | * within the block range. determine how many | |
3216 | * words and allocate (set to 1) the bits of these | |
3217 | * words. | |
3218 | */ | |
3219 | nwords = rembits >> L2DBWORD; | |
3220 | memset(&dp->wmap[word], (int) ONES, nwords * 4); | |
3221 | ||
3222 | /* determine how many bits */ | |
3223 | nb = nwords << L2DBWORD; | |
3224 | word += nwords; | |
3225 | } | |
3226 | } | |
3227 | ||
3228 | /* update the free count for this dmap */ | |
89145622 | 3229 | le32_add_cpu(&dp->nfree, -nblocks); |
1da177e4 LT |
3230 | |
3231 | /* reconstruct summary tree */ | |
3232 | dbInitDmapTree(dp); | |
3233 | ||
3234 | BMAP_LOCK(bmp); | |
3235 | ||
3236 | /* if this allocation group is completely free, | |
63f83c9f | 3237 | * update the highest active allocation group number |
1da177e4 LT |
3238 | * if this allocation group is the new max. |
3239 | */ | |
3240 | agno = blkno >> bmp->db_agl2size; | |
3241 | if (agno > bmp->db_maxag) | |
3242 | bmp->db_maxag = agno; | |
3243 | ||
3244 | /* update the free count for the allocation group and map */ | |
3245 | bmp->db_agfree[agno] -= nblocks; | |
3246 | bmp->db_nfree -= nblocks; | |
3247 | ||
3248 | BMAP_UNLOCK(bmp); | |
3249 | ||
3250 | /* if the root has not changed, done. */ | |
3251 | if (tp->stree[ROOT] == oldroot) | |
3252 | return (0); | |
3253 | ||
3254 | /* root changed. bubble the change up to the dmap control pages. | |
3255 | * if the adjustment of the upper level control pages fails, | |
3256 | * backout the bit allocation (thus making everything consistent). | |
3257 | */ | |
3258 | if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0))) | |
3259 | dbFreeBits(bmp, dp, blkno, nblocks); | |
3260 | ||
3261 | return (rc); | |
3262 | } | |
3263 | ||
3264 | ||
3265 | /* | |
3266 | * NAME: dbExtendFS() | |
3267 | * | |
3268 | * FUNCTION: extend bmap from blkno for nblocks; | |
63f83c9f | 3269 | * dbExtendFS() updates bmap ready for dbAllocBottomUp(); |
1da177e4 LT |
3270 | * |
3271 | * L2 | |
3272 | * | | |
3273 | * L1---------------------------------L1 | |
f720e3ba DK |
3274 | * | | |
3275 | * L0---------L0---------L0 L0---------L0---------L0 | |
3276 | * | | | | | | | |
3277 | * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm; | |
1da177e4 LT |
3278 | * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm |
3279 | * | |
63f83c9f | 3280 | * <---old---><----------------------------extend-----------------------> |
1da177e4 LT |
3281 | */ |
3282 | int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks) | |
3283 | { | |
3284 | struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb); | |
3285 | int nbperpage = sbi->nbperpage; | |
4d81715f | 3286 | int i, i0 = true, j, j0 = true, k, n; |
1da177e4 LT |
3287 | s64 newsize; |
3288 | s64 p; | |
3289 | struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL; | |
3290 | struct dmapctl *l2dcp, *l1dcp, *l0dcp; | |
3291 | struct dmap *dp; | |
3292 | s8 *l0leaf, *l1leaf, *l2leaf; | |
3293 | struct bmap *bmp = sbi->bmap; | |
3294 | int agno, l2agsize, oldl2agsize; | |
3295 | s64 ag_rem; | |
3296 | ||
3297 | newsize = blkno + nblocks; | |
3298 | ||
3299 | jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld", | |
3300 | (long long) blkno, (long long) nblocks, (long long) newsize); | |
3301 | ||
3302 | /* | |
f720e3ba | 3303 | * initialize bmap control page. |
1da177e4 LT |
3304 | * |
3305 | * all the data in bmap control page should exclude | |
3306 | * the mkfs hidden dmap page. | |
3307 | */ | |
3308 | ||
3309 | /* update mapsize */ | |
3310 | bmp->db_mapsize = newsize; | |
3311 | bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize); | |
3312 | ||
3313 | /* compute new AG size */ | |
3314 | l2agsize = dbGetL2AGSize(newsize); | |
3315 | oldl2agsize = bmp->db_agl2size; | |
3316 | ||
3317 | bmp->db_agl2size = l2agsize; | |
3318 | bmp->db_agsize = 1 << l2agsize; | |
3319 | ||
3320 | /* compute new number of AG */ | |
3321 | agno = bmp->db_numag; | |
3322 | bmp->db_numag = newsize >> l2agsize; | |
3323 | bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0; | |
3324 | ||
3325 | /* | |
f720e3ba | 3326 | * reconfigure db_agfree[] |
1da177e4 LT |
3327 | * from old AG configuration to new AG configuration; |
3328 | * | |
3329 | * coalesce contiguous k (newAGSize/oldAGSize) AGs; | |
3330 | * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn; | |
3331 | * note: new AG size = old AG size * (2**x). | |
3332 | */ | |
3333 | if (l2agsize == oldl2agsize) | |
3334 | goto extend; | |
3335 | k = 1 << (l2agsize - oldl2agsize); | |
3336 | ag_rem = bmp->db_agfree[0]; /* save agfree[0] */ | |
3337 | for (i = 0, n = 0; i < agno; n++) { | |
3338 | bmp->db_agfree[n] = 0; /* init collection point */ | |
3339 | ||
3340 | /* coalesce cotiguous k AGs; */ | |
3341 | for (j = 0; j < k && i < agno; j++, i++) { | |
3342 | /* merge AGi to AGn */ | |
3343 | bmp->db_agfree[n] += bmp->db_agfree[i]; | |
3344 | } | |
3345 | } | |
3346 | bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */ | |
3347 | ||
3348 | for (; n < MAXAG; n++) | |
3349 | bmp->db_agfree[n] = 0; | |
3350 | ||
3351 | /* | |
3352 | * update highest active ag number | |
3353 | */ | |
3354 | ||
3355 | bmp->db_maxag = bmp->db_maxag / k; | |
3356 | ||
3357 | /* | |
f720e3ba | 3358 | * extend bmap |
1da177e4 LT |
3359 | * |
3360 | * update bit maps and corresponding level control pages; | |
3361 | * global control page db_nfree, db_agfree[agno], db_maxfreebud; | |
3362 | */ | |
3363 | extend: | |
3364 | /* get L2 page */ | |
3365 | p = BMAPBLKNO + nbperpage; /* L2 page */ | |
3366 | l2mp = read_metapage(ipbmap, p, PSIZE, 0); | |
3367 | if (!l2mp) { | |
3368 | jfs_error(ipbmap->i_sb, "dbExtendFS: L2 page could not be read"); | |
3369 | return -EIO; | |
3370 | } | |
3371 | l2dcp = (struct dmapctl *) l2mp->data; | |
3372 | ||
3373 | /* compute start L1 */ | |
3374 | k = blkno >> L2MAXL1SIZE; | |
3375 | l2leaf = l2dcp->stree + CTLLEAFIND + k; | |
3376 | p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */ | |
3377 | ||
3378 | /* | |
3379 | * extend each L1 in L2 | |
3380 | */ | |
3381 | for (; k < LPERCTL; k++, p += nbperpage) { | |
3382 | /* get L1 page */ | |
3383 | if (j0) { | |
3384 | /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */ | |
3385 | l1mp = read_metapage(ipbmap, p, PSIZE, 0); | |
3386 | if (l1mp == NULL) | |
3387 | goto errout; | |
3388 | l1dcp = (struct dmapctl *) l1mp->data; | |
3389 | ||
3390 | /* compute start L0 */ | |
3391 | j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE; | |
3392 | l1leaf = l1dcp->stree + CTLLEAFIND + j; | |
3393 | p = BLKTOL0(blkno, sbi->l2nbperpage); | |
4d81715f | 3394 | j0 = false; |
1da177e4 LT |
3395 | } else { |
3396 | /* assign/init L1 page */ | |
3397 | l1mp = get_metapage(ipbmap, p, PSIZE, 0); | |
3398 | if (l1mp == NULL) | |
3399 | goto errout; | |
3400 | ||
3401 | l1dcp = (struct dmapctl *) l1mp->data; | |
3402 | ||
3403 | /* compute start L0 */ | |
3404 | j = 0; | |
3405 | l1leaf = l1dcp->stree + CTLLEAFIND; | |
f720e3ba | 3406 | p += nbperpage; /* 1st L0 of L1.k */ |
1da177e4 LT |
3407 | } |
3408 | ||
3409 | /* | |
3410 | * extend each L0 in L1 | |
3411 | */ | |
3412 | for (; j < LPERCTL; j++) { | |
3413 | /* get L0 page */ | |
3414 | if (i0) { | |
3415 | /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */ | |
3416 | ||
3417 | l0mp = read_metapage(ipbmap, p, PSIZE, 0); | |
3418 | if (l0mp == NULL) | |
3419 | goto errout; | |
3420 | l0dcp = (struct dmapctl *) l0mp->data; | |
3421 | ||
3422 | /* compute start dmap */ | |
3423 | i = (blkno & (MAXL0SIZE - 1)) >> | |
3424 | L2BPERDMAP; | |
3425 | l0leaf = l0dcp->stree + CTLLEAFIND + i; | |
3426 | p = BLKTODMAP(blkno, | |
3427 | sbi->l2nbperpage); | |
4d81715f | 3428 | i0 = false; |
1da177e4 LT |
3429 | } else { |
3430 | /* assign/init L0 page */ | |
3431 | l0mp = get_metapage(ipbmap, p, PSIZE, 0); | |
3432 | if (l0mp == NULL) | |
3433 | goto errout; | |
3434 | ||
3435 | l0dcp = (struct dmapctl *) l0mp->data; | |
3436 | ||
3437 | /* compute start dmap */ | |
3438 | i = 0; | |
3439 | l0leaf = l0dcp->stree + CTLLEAFIND; | |
3440 | p += nbperpage; /* 1st dmap of L0.j */ | |
3441 | } | |
3442 | ||
3443 | /* | |
3444 | * extend each dmap in L0 | |
3445 | */ | |
3446 | for (; i < LPERCTL; i++) { | |
3447 | /* | |
3448 | * reconstruct the dmap page, and | |
3449 | * initialize corresponding parent L0 leaf | |
3450 | */ | |
3451 | if ((n = blkno & (BPERDMAP - 1))) { | |
3452 | /* read in dmap page: */ | |
3453 | mp = read_metapage(ipbmap, p, | |
3454 | PSIZE, 0); | |
3455 | if (mp == NULL) | |
3456 | goto errout; | |
3457 | n = min(nblocks, (s64)BPERDMAP - n); | |
3458 | } else { | |
3459 | /* assign/init dmap page */ | |
3460 | mp = read_metapage(ipbmap, p, | |
3461 | PSIZE, 0); | |
3462 | if (mp == NULL) | |
3463 | goto errout; | |
3464 | ||
3465 | n = min(nblocks, (s64)BPERDMAP); | |
3466 | } | |
3467 | ||
3468 | dp = (struct dmap *) mp->data; | |
3469 | *l0leaf = dbInitDmap(dp, blkno, n); | |
3470 | ||
3471 | bmp->db_nfree += n; | |
3472 | agno = le64_to_cpu(dp->start) >> l2agsize; | |
3473 | bmp->db_agfree[agno] += n; | |
3474 | ||
3475 | write_metapage(mp); | |
3476 | ||
3477 | l0leaf++; | |
3478 | p += nbperpage; | |
3479 | ||
3480 | blkno += n; | |
3481 | nblocks -= n; | |
3482 | if (nblocks == 0) | |
3483 | break; | |
3484 | } /* for each dmap in a L0 */ | |
3485 | ||
3486 | /* | |
63f83c9f | 3487 | * build current L0 page from its leaves, and |
1da177e4 LT |
3488 | * initialize corresponding parent L1 leaf |
3489 | */ | |
3490 | *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i); | |
3491 | write_metapage(l0mp); | |
3492 | l0mp = NULL; | |
3493 | ||
3494 | if (nblocks) | |
3495 | l1leaf++; /* continue for next L0 */ | |
3496 | else { | |
3497 | /* more than 1 L0 ? */ | |
3498 | if (j > 0) | |
3499 | break; /* build L1 page */ | |
3500 | else { | |
3501 | /* summarize in global bmap page */ | |
3502 | bmp->db_maxfreebud = *l1leaf; | |
3503 | release_metapage(l1mp); | |
3504 | release_metapage(l2mp); | |
3505 | goto finalize; | |
3506 | } | |
3507 | } | |
3508 | } /* for each L0 in a L1 */ | |
3509 | ||
3510 | /* | |
63f83c9f | 3511 | * build current L1 page from its leaves, and |
1da177e4 LT |
3512 | * initialize corresponding parent L2 leaf |
3513 | */ | |
3514 | *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j); | |
3515 | write_metapage(l1mp); | |
3516 | l1mp = NULL; | |
3517 | ||
3518 | if (nblocks) | |
3519 | l2leaf++; /* continue for next L1 */ | |
3520 | else { | |
3521 | /* more than 1 L1 ? */ | |
3522 | if (k > 0) | |
3523 | break; /* build L2 page */ | |
3524 | else { | |
3525 | /* summarize in global bmap page */ | |
3526 | bmp->db_maxfreebud = *l2leaf; | |
3527 | release_metapage(l2mp); | |
3528 | goto finalize; | |
3529 | } | |
3530 | } | |
3531 | } /* for each L1 in a L2 */ | |
3532 | ||
3533 | jfs_error(ipbmap->i_sb, | |
3534 | "dbExtendFS: function has not returned as expected"); | |
3535 | errout: | |
3536 | if (l0mp) | |
3537 | release_metapage(l0mp); | |
3538 | if (l1mp) | |
3539 | release_metapage(l1mp); | |
3540 | release_metapage(l2mp); | |
3541 | return -EIO; | |
3542 | ||
3543 | /* | |
f720e3ba | 3544 | * finalize bmap control page |
1da177e4 LT |
3545 | */ |
3546 | finalize: | |
3547 | ||
3548 | return 0; | |
3549 | } | |
3550 | ||
3551 | ||
3552 | /* | |
3553 | * dbFinalizeBmap() | |
3554 | */ | |
3555 | void dbFinalizeBmap(struct inode *ipbmap) | |
3556 | { | |
3557 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
3558 | int actags, inactags, l2nl; | |
3559 | s64 ag_rem, actfree, inactfree, avgfree; | |
3560 | int i, n; | |
3561 | ||
3562 | /* | |
f720e3ba | 3563 | * finalize bmap control page |
1da177e4 LT |
3564 | */ |
3565 | //finalize: | |
63f83c9f | 3566 | /* |
1da177e4 LT |
3567 | * compute db_agpref: preferred ag to allocate from |
3568 | * (the leftmost ag with average free space in it); | |
3569 | */ | |
3570 | //agpref: | |
3571 | /* get the number of active ags and inacitve ags */ | |
3572 | actags = bmp->db_maxag + 1; | |
3573 | inactags = bmp->db_numag - actags; | |
3574 | ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */ | |
3575 | ||
3576 | /* determine how many blocks are in the inactive allocation | |
3577 | * groups. in doing this, we must account for the fact that | |
3578 | * the rightmost group might be a partial group (i.e. file | |
3579 | * system size is not a multiple of the group size). | |
3580 | */ | |
3581 | inactfree = (inactags && ag_rem) ? | |
3582 | ((inactags - 1) << bmp->db_agl2size) + ag_rem | |
3583 | : inactags << bmp->db_agl2size; | |
3584 | ||
3585 | /* determine how many free blocks are in the active | |
3586 | * allocation groups plus the average number of free blocks | |
3587 | * within the active ags. | |
3588 | */ | |
3589 | actfree = bmp->db_nfree - inactfree; | |
3590 | avgfree = (u32) actfree / (u32) actags; | |
3591 | ||
3592 | /* if the preferred allocation group has not average free space. | |
3593 | * re-establish the preferred group as the leftmost | |
3594 | * group with average free space. | |
3595 | */ | |
3596 | if (bmp->db_agfree[bmp->db_agpref] < avgfree) { | |
3597 | for (bmp->db_agpref = 0; bmp->db_agpref < actags; | |
3598 | bmp->db_agpref++) { | |
3599 | if (bmp->db_agfree[bmp->db_agpref] >= avgfree) | |
3600 | break; | |
3601 | } | |
3602 | if (bmp->db_agpref >= bmp->db_numag) { | |
3603 | jfs_error(ipbmap->i_sb, | |
3604 | "cannot find ag with average freespace"); | |
3605 | } | |
3606 | } | |
3607 | ||
3608 | /* | |
3609 | * compute db_aglevel, db_agheigth, db_width, db_agstart: | |
63f83c9f DK |
3610 | * an ag is covered in aglevel dmapctl summary tree, |
3611 | * at agheight level height (from leaf) with agwidth number of nodes | |
3612 | * each, which starts at agstart index node of the smmary tree node | |
1da177e4 LT |
3613 | * array; |
3614 | */ | |
3615 | bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize); | |
3616 | l2nl = | |
3617 | bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL); | |
3618 | bmp->db_agheigth = l2nl >> 1; | |
3619 | bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheigth << 1)); | |
3620 | for (i = 5 - bmp->db_agheigth, bmp->db_agstart = 0, n = 1; i > 0; | |
3621 | i--) { | |
3622 | bmp->db_agstart += n; | |
3623 | n <<= 2; | |
3624 | } | |
3625 | ||
3626 | } | |
3627 | ||
3628 | ||
3629 | /* | |
3630 | * NAME: dbInitDmap()/ujfs_idmap_page() | |
63f83c9f | 3631 | * |
1da177e4 LT |
3632 | * FUNCTION: initialize working/persistent bitmap of the dmap page |
3633 | * for the specified number of blocks: | |
63f83c9f | 3634 | * |
1da177e4 | 3635 | * at entry, the bitmaps had been initialized as free (ZEROS); |
63f83c9f DK |
3636 | * The number of blocks will only account for the actually |
3637 | * existing blocks. Blocks which don't actually exist in | |
1da177e4 LT |
3638 | * the aggregate will be marked as allocated (ONES); |
3639 | * | |
3640 | * PARAMETERS: | |
3641 | * dp - pointer to page of map | |
3642 | * nblocks - number of blocks this page | |
3643 | * | |
3644 | * RETURNS: NONE | |
3645 | */ | |
3646 | static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks) | |
3647 | { | |
3648 | int blkno, w, b, r, nw, nb, i; | |
3649 | ||
3650 | /* starting block number within the dmap */ | |
3651 | blkno = Blkno & (BPERDMAP - 1); | |
3652 | ||
3653 | if (blkno == 0) { | |
3654 | dp->nblocks = dp->nfree = cpu_to_le32(nblocks); | |
3655 | dp->start = cpu_to_le64(Blkno); | |
3656 | ||
3657 | if (nblocks == BPERDMAP) { | |
3658 | memset(&dp->wmap[0], 0, LPERDMAP * 4); | |
3659 | memset(&dp->pmap[0], 0, LPERDMAP * 4); | |
3660 | goto initTree; | |
3661 | } | |
3662 | } else { | |
89145622 MS |
3663 | le32_add_cpu(&dp->nblocks, nblocks); |
3664 | le32_add_cpu(&dp->nfree, nblocks); | |
1da177e4 LT |
3665 | } |
3666 | ||
3667 | /* word number containing start block number */ | |
3668 | w = blkno >> L2DBWORD; | |
3669 | ||
3670 | /* | |
3671 | * free the bits corresponding to the block range (ZEROS): | |
63f83c9f | 3672 | * note: not all bits of the first and last words may be contained |
1da177e4 LT |
3673 | * within the block range. |
3674 | */ | |
3675 | for (r = nblocks; r > 0; r -= nb, blkno += nb) { | |
3676 | /* number of bits preceding range to be freed in the word */ | |
3677 | b = blkno & (DBWORD - 1); | |
3678 | /* number of bits to free in the word */ | |
3679 | nb = min(r, DBWORD - b); | |
3680 | ||
3681 | /* is partial word to be freed ? */ | |
3682 | if (nb < DBWORD) { | |
3683 | /* free (set to 0) from the bitmap word */ | |
3684 | dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) | |
3685 | >> b)); | |
3686 | dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) | |
3687 | >> b)); | |
3688 | ||
3689 | /* skip the word freed */ | |
3690 | w++; | |
3691 | } else { | |
3692 | /* free (set to 0) contiguous bitmap words */ | |
3693 | nw = r >> L2DBWORD; | |
3694 | memset(&dp->wmap[w], 0, nw * 4); | |
3695 | memset(&dp->pmap[w], 0, nw * 4); | |
3696 | ||
3697 | /* skip the words freed */ | |
3698 | nb = nw << L2DBWORD; | |
3699 | w += nw; | |
3700 | } | |
3701 | } | |
3702 | ||
3703 | /* | |
63f83c9f | 3704 | * mark bits following the range to be freed (non-existing |
1da177e4 LT |
3705 | * blocks) as allocated (ONES) |
3706 | */ | |
3707 | ||
3708 | if (blkno == BPERDMAP) | |
3709 | goto initTree; | |
3710 | ||
3711 | /* the first word beyond the end of existing blocks */ | |
3712 | w = blkno >> L2DBWORD; | |
3713 | ||
3714 | /* does nblocks fall on a 32-bit boundary ? */ | |
3715 | b = blkno & (DBWORD - 1); | |
3716 | if (b) { | |
3717 | /* mark a partial word allocated */ | |
3718 | dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b); | |
3719 | w++; | |
3720 | } | |
3721 | ||
3722 | /* set the rest of the words in the page to allocated (ONES) */ | |
3723 | for (i = w; i < LPERDMAP; i++) | |
3724 | dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES); | |
3725 | ||
3726 | /* | |
3727 | * init tree | |
3728 | */ | |
3729 | initTree: | |
3730 | return (dbInitDmapTree(dp)); | |
3731 | } | |
3732 | ||
3733 | ||
3734 | /* | |
3735 | * NAME: dbInitDmapTree()/ujfs_complete_dmap() | |
63f83c9f | 3736 | * |
1da177e4 LT |
3737 | * FUNCTION: initialize summary tree of the specified dmap: |
3738 | * | |
3739 | * at entry, bitmap of the dmap has been initialized; | |
63f83c9f | 3740 | * |
1da177e4 LT |
3741 | * PARAMETERS: |
3742 | * dp - dmap to complete | |
3743 | * blkno - starting block number for this dmap | |
3744 | * treemax - will be filled in with max free for this dmap | |
3745 | * | |
3746 | * RETURNS: max free string at the root of the tree | |
3747 | */ | |
3748 | static int dbInitDmapTree(struct dmap * dp) | |
3749 | { | |
3750 | struct dmaptree *tp; | |
3751 | s8 *cp; | |
3752 | int i; | |
3753 | ||
3754 | /* init fixed info of tree */ | |
3755 | tp = &dp->tree; | |
3756 | tp->nleafs = cpu_to_le32(LPERDMAP); | |
3757 | tp->l2nleafs = cpu_to_le32(L2LPERDMAP); | |
3758 | tp->leafidx = cpu_to_le32(LEAFIND); | |
3759 | tp->height = cpu_to_le32(4); | |
3760 | tp->budmin = BUDMIN; | |
3761 | ||
3762 | /* init each leaf from corresponding wmap word: | |
3763 | * note: leaf is set to NOFREE(-1) if all blocks of corresponding | |
63f83c9f | 3764 | * bitmap word are allocated. |
1da177e4 LT |
3765 | */ |
3766 | cp = tp->stree + le32_to_cpu(tp->leafidx); | |
3767 | for (i = 0; i < LPERDMAP; i++) | |
3768 | *cp++ = dbMaxBud((u8 *) & dp->wmap[i]); | |
3769 | ||
3770 | /* build the dmap's binary buddy summary tree */ | |
3771 | return (dbInitTree(tp)); | |
3772 | } | |
3773 | ||
3774 | ||
3775 | /* | |
3776 | * NAME: dbInitTree()/ujfs_adjtree() | |
63f83c9f | 3777 | * |
1da177e4 LT |
3778 | * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl. |
3779 | * | |
63f83c9f | 3780 | * at entry, the leaves of the tree has been initialized |
1da177e4 LT |
3781 | * from corresponding bitmap word or root of summary tree |
3782 | * of the child control page; | |
3783 | * configure binary buddy system at the leaf level, then | |
3784 | * bubble up the values of the leaf nodes up the tree. | |
3785 | * | |
3786 | * PARAMETERS: | |
3787 | * cp - Pointer to the root of the tree | |
3788 | * l2leaves- Number of leaf nodes as a power of 2 | |
3789 | * l2min - Number of blocks that can be covered by a leaf | |
3790 | * as a power of 2 | |
3791 | * | |
3792 | * RETURNS: max free string at the root of the tree | |
3793 | */ | |
3794 | static int dbInitTree(struct dmaptree * dtp) | |
3795 | { | |
3796 | int l2max, l2free, bsize, nextb, i; | |
3797 | int child, parent, nparent; | |
3798 | s8 *tp, *cp, *cp1; | |
3799 | ||
3800 | tp = dtp->stree; | |
3801 | ||
3802 | /* Determine the maximum free string possible for the leaves */ | |
3803 | l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin; | |
3804 | ||
3805 | /* | |
3806 | * configure the leaf levevl into binary buddy system | |
3807 | * | |
63f83c9f DK |
3808 | * Try to combine buddies starting with a buddy size of 1 |
3809 | * (i.e. two leaves). At a buddy size of 1 two buddy leaves | |
3810 | * can be combined if both buddies have a maximum free of l2min; | |
3811 | * the combination will result in the left-most buddy leaf having | |
3812 | * a maximum free of l2min+1. | |
3813 | * After processing all buddies for a given size, process buddies | |
3814 | * at the next higher buddy size (i.e. current size * 2) and | |
3815 | * the next maximum free (current free + 1). | |
3816 | * This continues until the maximum possible buddy combination | |
1da177e4 LT |
3817 | * yields maximum free. |
3818 | */ | |
3819 | for (l2free = dtp->budmin, bsize = 1; l2free < l2max; | |
3820 | l2free++, bsize = nextb) { | |
3821 | /* get next buddy size == current buddy pair size */ | |
3822 | nextb = bsize << 1; | |
3823 | ||
3824 | /* scan each adjacent buddy pair at current buddy size */ | |
3825 | for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx); | |
3826 | i < le32_to_cpu(dtp->nleafs); | |
3827 | i += nextb, cp += nextb) { | |
3828 | /* coalesce if both adjacent buddies are max free */ | |
3829 | if (*cp == l2free && *(cp + bsize) == l2free) { | |
3830 | *cp = l2free + 1; /* left take right */ | |
3831 | *(cp + bsize) = -1; /* right give left */ | |
3832 | } | |
3833 | } | |
3834 | } | |
3835 | ||
3836 | /* | |
3837 | * bubble summary information of leaves up the tree. | |
3838 | * | |
3839 | * Starting at the leaf node level, the four nodes described by | |
63f83c9f DK |
3840 | * the higher level parent node are compared for a maximum free and |
3841 | * this maximum becomes the value of the parent node. | |
3842 | * when all lower level nodes are processed in this fashion then | |
3843 | * move up to the next level (parent becomes a lower level node) and | |
1da177e4 LT |
3844 | * continue the process for that level. |
3845 | */ | |
3846 | for (child = le32_to_cpu(dtp->leafidx), | |
3847 | nparent = le32_to_cpu(dtp->nleafs) >> 2; | |
3848 | nparent > 0; nparent >>= 2, child = parent) { | |
3849 | /* get index of 1st node of parent level */ | |
3850 | parent = (child - 1) >> 2; | |
3851 | ||
63f83c9f | 3852 | /* set the value of the parent node as the maximum |
1da177e4 LT |
3853 | * of the four nodes of the current level. |
3854 | */ | |
3855 | for (i = 0, cp = tp + child, cp1 = tp + parent; | |
3856 | i < nparent; i++, cp += 4, cp1++) | |
3857 | *cp1 = TREEMAX(cp); | |
3858 | } | |
3859 | ||
3860 | return (*tp); | |
3861 | } | |
3862 | ||
3863 | ||
3864 | /* | |
3865 | * dbInitDmapCtl() | |
3866 | * | |
3867 | * function: initialize dmapctl page | |
3868 | */ | |
3869 | static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i) | |
3870 | { /* start leaf index not covered by range */ | |
3871 | s8 *cp; | |
3872 | ||
3873 | dcp->nleafs = cpu_to_le32(LPERCTL); | |
3874 | dcp->l2nleafs = cpu_to_le32(L2LPERCTL); | |
3875 | dcp->leafidx = cpu_to_le32(CTLLEAFIND); | |
3876 | dcp->height = cpu_to_le32(5); | |
3877 | dcp->budmin = L2BPERDMAP + L2LPERCTL * level; | |
3878 | ||
3879 | /* | |
63f83c9f DK |
3880 | * initialize the leaves of current level that were not covered |
3881 | * by the specified input block range (i.e. the leaves have no | |
1da177e4 LT |
3882 | * low level dmapctl or dmap). |
3883 | */ | |
3884 | cp = &dcp->stree[CTLLEAFIND + i]; | |
3885 | for (; i < LPERCTL; i++) | |
3886 | *cp++ = NOFREE; | |
3887 | ||
3888 | /* build the dmap's binary buddy summary tree */ | |
3889 | return (dbInitTree((struct dmaptree *) dcp)); | |
3890 | } | |
3891 | ||
3892 | ||
3893 | /* | |
3894 | * NAME: dbGetL2AGSize()/ujfs_getagl2size() | |
63f83c9f | 3895 | * |
1da177e4 | 3896 | * FUNCTION: Determine log2(allocation group size) from aggregate size |
63f83c9f | 3897 | * |
1da177e4 LT |
3898 | * PARAMETERS: |
3899 | * nblocks - Number of blocks in aggregate | |
3900 | * | |
3901 | * RETURNS: log2(allocation group size) in aggregate blocks | |
3902 | */ | |
3903 | static int dbGetL2AGSize(s64 nblocks) | |
3904 | { | |
3905 | s64 sz; | |
3906 | s64 m; | |
3907 | int l2sz; | |
3908 | ||
3909 | if (nblocks < BPERDMAP * MAXAG) | |
3910 | return (L2BPERDMAP); | |
3911 | ||
3912 | /* round up aggregate size to power of 2 */ | |
3913 | m = ((u64) 1 << (64 - 1)); | |
3914 | for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) { | |
3915 | if (m & nblocks) | |
3916 | break; | |
3917 | } | |
3918 | ||
3919 | sz = (s64) 1 << l2sz; | |
3920 | if (sz < nblocks) | |
3921 | l2sz += 1; | |
3922 | ||
3923 | /* agsize = roundupSize/max_number_of_ag */ | |
3924 | return (l2sz - L2MAXAG); | |
3925 | } | |
3926 | ||
3927 | ||
3928 | /* | |
3929 | * NAME: dbMapFileSizeToMapSize() | |
63f83c9f DK |
3930 | * |
3931 | * FUNCTION: compute number of blocks the block allocation map file | |
1da177e4 LT |
3932 | * can cover from the map file size; |
3933 | * | |
3934 | * RETURNS: Number of blocks which can be covered by this block map file; | |
3935 | */ | |
3936 | ||
3937 | /* | |
3938 | * maximum number of map pages at each level including control pages | |
3939 | */ | |
3940 | #define MAXL0PAGES (1 + LPERCTL) | |
3941 | #define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES) | |
3942 | #define MAXL2PAGES (1 + LPERCTL * MAXL1PAGES) | |
3943 | ||
3944 | /* | |
3945 | * convert number of map pages to the zero origin top dmapctl level | |
3946 | */ | |
3947 | #define BMAPPGTOLEV(npages) \ | |
f720e3ba DK |
3948 | (((npages) <= 3 + MAXL0PAGES) ? 0 : \ |
3949 | ((npages) <= 2 + MAXL1PAGES) ? 1 : 2) | |
1da177e4 LT |
3950 | |
3951 | s64 dbMapFileSizeToMapSize(struct inode * ipbmap) | |
3952 | { | |
3953 | struct super_block *sb = ipbmap->i_sb; | |
3954 | s64 nblocks; | |
3955 | s64 npages, ndmaps; | |
3956 | int level, i; | |
3957 | int complete, factor; | |
3958 | ||
3959 | nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize; | |
3960 | npages = nblocks >> JFS_SBI(sb)->l2nbperpage; | |
3961 | level = BMAPPGTOLEV(npages); | |
3962 | ||
63f83c9f | 3963 | /* At each level, accumulate the number of dmap pages covered by |
1da177e4 LT |
3964 | * the number of full child levels below it; |
3965 | * repeat for the last incomplete child level. | |
3966 | */ | |
3967 | ndmaps = 0; | |
3968 | npages--; /* skip the first global control page */ | |
3969 | /* skip higher level control pages above top level covered by map */ | |
3970 | npages -= (2 - level); | |
3971 | npages--; /* skip top level's control page */ | |
3972 | for (i = level; i >= 0; i--) { | |
3973 | factor = | |
3974 | (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1); | |
3975 | complete = (u32) npages / factor; | |
f720e3ba DK |
3976 | ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL : |
3977 | ((i == 1) ? LPERCTL : 1)); | |
1da177e4 LT |
3978 | |
3979 | /* pages in last/incomplete child */ | |
3980 | npages = (u32) npages % factor; | |
3981 | /* skip incomplete child's level control page */ | |
3982 | npages--; | |
3983 | } | |
3984 | ||
63f83c9f | 3985 | /* convert the number of dmaps into the number of blocks |
1da177e4 LT |
3986 | * which can be covered by the dmaps; |
3987 | */ | |
3988 | nblocks = ndmaps << L2BPERDMAP; | |
3989 | ||
3990 | return (nblocks); | |
3991 | } |