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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Dave Kleikamp63f83c92006-10-02 09:55:27 -05006 * the Free Software Foundation; either version 2 of the License, or
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * (at your option) any later version.
Dave Kleikamp63f83c92006-10-02 09:55:27 -05008 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * 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
Dave Kleikamp63f83c92006-10-02 09:55:27 -050015 * along with this program; if not, write to the Free Software
Linus Torvalds1da177e2005-04-16 15:20:36 -070016 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19#include <linux/fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090020#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include "jfs_incore.h"
22#include "jfs_superblock.h"
23#include "jfs_dmap.h"
24#include "jfs_imap.h"
25#include "jfs_lock.h"
26#include "jfs_metapage.h"
27#include "jfs_debug.h"
28
29/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 * SERIALIZATION of the Block Allocation Map.
31 *
32 * the working state of the block allocation map is accessed in
33 * two directions:
Dave Kleikamp63f83c92006-10-02 09:55:27 -050034 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 * 1) allocation and free requests that start at the dmap
36 * level and move up through the dmap control pages (i.e.
37 * the vast majority of requests).
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -050039 * 2) allocation requests that start at dmap control page
40 * level and work down towards the dmaps.
41 *
42 * the serialization scheme used here is as follows.
43 *
44 * requests which start at the bottom are serialized against each
45 * other through buffers and each requests holds onto its buffers
46 * as it works it way up from a single dmap to the required level
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 * of dmap control page.
48 * requests that start at the top are serialized against each other
49 * and request that start from the bottom by the multiple read/single
50 * write inode lock of the bmap inode. requests starting at the top
51 * take this lock in write mode while request starting at the bottom
52 * take the lock in read mode. a single top-down request may proceed
Dave Kleikamp63f83c92006-10-02 09:55:27 -050053 * exclusively while multiple bottoms-up requests may proceed
54 * simultaneously (under the protection of busy buffers).
55 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 * in addition to information found in dmaps and dmap control pages,
57 * the working state of the block allocation map also includes read/
58 * write information maintained in the bmap descriptor (i.e. total
59 * free block count, allocation group level free block counts).
60 * a single exclusive lock (BMAP_LOCK) is used to guard this information
61 * in the face of multiple-bottoms up requests.
62 * (lock ordering: IREAD_LOCK, BMAP_LOCK);
Dave Kleikamp63f83c92006-10-02 09:55:27 -050063 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 * accesses to the persistent state of the block allocation map (limited
65 * to the persistent bitmaps in dmaps) is guarded by (busy) buffers.
66 */
67
Ingo Molnar1de87442006-01-24 15:22:50 -060068#define BMAP_LOCK_INIT(bmp) mutex_init(&bmp->db_bmaplock)
69#define BMAP_LOCK(bmp) mutex_lock(&bmp->db_bmaplock)
70#define BMAP_UNLOCK(bmp) mutex_unlock(&bmp->db_bmaplock)
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
72/*
73 * forward references
74 */
75static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
76 int nblocks);
77static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval);
Dave Kleikampb6a47fd2005-10-11 09:06:59 -050078static int dbBackSplit(dmtree_t * tp, int leafno);
Dave Kleikamp56d12542005-07-15 09:43:36 -050079static int dbJoin(dmtree_t * tp, int leafno, int newval);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080static void dbAdjTree(dmtree_t * tp, int leafno, int newval);
81static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc,
82 int level);
83static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results);
84static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno,
85 int nblocks);
86static int dbAllocNear(struct bmap * bmp, struct dmap * dp, s64 blkno,
87 int nblocks,
88 int l2nb, s64 * results);
89static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
90 int nblocks);
91static int dbAllocDmapLev(struct bmap * bmp, struct dmap * dp, int nblocks,
92 int l2nb,
93 s64 * results);
94static int dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb,
95 s64 * results);
96static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno,
97 s64 * results);
98static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks);
99static int dbFindBits(u32 word, int l2nb);
100static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno);
101static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx);
Dave Kleikamp56d12542005-07-15 09:43:36 -0500102static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
103 int nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
105 int nblocks);
106static int dbMaxBud(u8 * cp);
107s64 dbMapFileSizeToMapSize(struct inode *ipbmap);
108static int blkstol2(s64 nb);
109
110static int cntlz(u32 value);
111static int cnttz(u32 word);
112
113static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno,
114 int nblocks);
115static int dbInitDmap(struct dmap * dp, s64 blkno, int nblocks);
116static int dbInitDmapTree(struct dmap * dp);
117static int dbInitTree(struct dmaptree * dtp);
118static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i);
119static int dbGetL2AGSize(s64 nblocks);
120
121/*
122 * buddy table
123 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500124 * table used for determining buddy sizes within characters of
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 * dmap bitmap words. the characters themselves serve as indexes
126 * into the table, with the table elements yielding the maximum
127 * binary buddy of free bits within the character.
128 */
Arjan van de Ven4d5dbd02005-11-29 08:28:58 -0600129static const s8 budtab[256] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
131 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
132 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
133 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
134 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
135 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
136 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
137 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
138 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
139 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
140 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
141 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
142 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
143 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
144 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
145 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -1
146};
147
148
149/*
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500150 * NAME: dbMount()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 *
152 * FUNCTION: initializate the block allocation map.
153 *
154 * memory is allocated for the in-core bmap descriptor and
155 * the in-core descriptor is initialized from disk.
156 *
157 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500158 * ipbmap - pointer to in-core inode for the block map.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 *
160 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500161 * 0 - success
162 * -ENOMEM - insufficient memory
163 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 */
165int dbMount(struct inode *ipbmap)
166{
167 struct bmap *bmp;
168 struct dbmap_disk *dbmp_le;
169 struct metapage *mp;
170 int i;
171
172 /*
173 * allocate/initialize the in-memory bmap descriptor
174 */
175 /* allocate memory for the in-memory bmap descriptor */
176 bmp = kmalloc(sizeof(struct bmap), GFP_KERNEL);
177 if (bmp == NULL)
178 return -ENOMEM;
179
180 /* read the on-disk bmap descriptor. */
181 mp = read_metapage(ipbmap,
182 BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
183 PSIZE, 0);
184 if (mp == NULL) {
185 kfree(bmp);
186 return -EIO;
187 }
188
189 /* copy the on-disk bmap descriptor to its in-memory version. */
190 dbmp_le = (struct dbmap_disk *) mp->data;
191 bmp->db_mapsize = le64_to_cpu(dbmp_le->dn_mapsize);
192 bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree);
193 bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
194 bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag);
195 bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel);
196 bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag);
197 bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref);
198 bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel);
Daniel Mackd7eecb42010-01-28 16:13:01 +0800199 bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth);
201 bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart);
202 bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size);
203 for (i = 0; i < MAXAG; i++)
204 bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]);
205 bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize);
206 bmp->db_maxfreebud = dbmp_le->dn_maxfreebud;
207
208 /* release the buffer. */
209 release_metapage(mp);
210
211 /* bind the bmap inode and the bmap descriptor to each other. */
212 bmp->db_ipbmap = ipbmap;
213 JFS_SBI(ipbmap->i_sb)->bmap = bmp;
214
215 memset(bmp->db_active, 0, sizeof(bmp->db_active));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
217 /*
218 * allocate/initialize the bmap lock
219 */
220 BMAP_LOCK_INIT(bmp);
221
222 return (0);
223}
224
225
226/*
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500227 * NAME: dbUnmount()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 *
229 * FUNCTION: terminate the block allocation map in preparation for
230 * file system unmount.
231 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500232 * the in-core bmap descriptor is written to disk and
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 * the memory for this descriptor is freed.
234 *
235 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500236 * ipbmap - pointer to in-core inode for the block map.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 *
238 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500239 * 0 - success
240 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 */
242int dbUnmount(struct inode *ipbmap, int mounterror)
243{
244 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
246 if (!(mounterror || isReadOnly(ipbmap)))
247 dbSync(ipbmap);
248
249 /*
250 * Invalidate the page cache buffers
251 */
252 truncate_inode_pages(ipbmap->i_mapping, 0);
253
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 /* free the memory for the in-memory bmap. */
255 kfree(bmp);
256
257 return (0);
258}
259
260/*
261 * dbSync()
262 */
263int dbSync(struct inode *ipbmap)
264{
265 struct dbmap_disk *dbmp_le;
266 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
267 struct metapage *mp;
268 int i;
269
270 /*
271 * write bmap global control page
272 */
273 /* get the buffer for the on-disk bmap descriptor. */
274 mp = read_metapage(ipbmap,
275 BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage,
276 PSIZE, 0);
277 if (mp == NULL) {
278 jfs_err("dbSync: read_metapage failed!");
279 return -EIO;
280 }
281 /* copy the in-memory version of the bmap to the on-disk version */
282 dbmp_le = (struct dbmap_disk *) mp->data;
283 dbmp_le->dn_mapsize = cpu_to_le64(bmp->db_mapsize);
284 dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree);
285 dbmp_le->dn_l2nbperpage = cpu_to_le32(bmp->db_l2nbperpage);
286 dbmp_le->dn_numag = cpu_to_le32(bmp->db_numag);
287 dbmp_le->dn_maxlevel = cpu_to_le32(bmp->db_maxlevel);
288 dbmp_le->dn_maxag = cpu_to_le32(bmp->db_maxag);
289 dbmp_le->dn_agpref = cpu_to_le32(bmp->db_agpref);
290 dbmp_le->dn_aglevel = cpu_to_le32(bmp->db_aglevel);
Daniel Mackd7eecb42010-01-28 16:13:01 +0800291 dbmp_le->dn_agheight = cpu_to_le32(bmp->db_agheight);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 dbmp_le->dn_agwidth = cpu_to_le32(bmp->db_agwidth);
293 dbmp_le->dn_agstart = cpu_to_le32(bmp->db_agstart);
294 dbmp_le->dn_agl2size = cpu_to_le32(bmp->db_agl2size);
295 for (i = 0; i < MAXAG; i++)
296 dbmp_le->dn_agfree[i] = cpu_to_le64(bmp->db_agfree[i]);
297 dbmp_le->dn_agsize = cpu_to_le64(bmp->db_agsize);
298 dbmp_le->dn_maxfreebud = bmp->db_maxfreebud;
299
300 /* write the buffer */
301 write_metapage(mp);
302
303 /*
304 * write out dirty pages of bmap
305 */
OGAWA Hirofumi28fd1292006-01-08 01:02:14 -0800306 filemap_write_and_wait(ipbmap->i_mapping);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 diWriteSpecial(ipbmap, 0);
309
310 return (0);
311}
312
313
314/*
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500315 * NAME: dbFree()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 *
317 * FUNCTION: free the specified block range from the working block
318 * allocation map.
319 *
320 * the blocks will be free from the working map one dmap
321 * at a time.
322 *
323 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500324 * ip - pointer to in-core inode;
325 * blkno - starting block number to be freed.
326 * nblocks - number of blocks to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 *
328 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500329 * 0 - success
330 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 */
332int dbFree(struct inode *ip, s64 blkno, s64 nblocks)
333{
334 struct metapage *mp;
335 struct dmap *dp;
336 int nb, rc;
337 s64 lblkno, rem;
338 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
339 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
340
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600341 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342
343 /* block to be freed better be within the mapsize. */
344 if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) {
345 IREAD_UNLOCK(ipbmap);
346 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n",
347 (unsigned long long) blkno,
348 (unsigned long long) nblocks);
349 jfs_error(ip->i_sb,
350 "dbFree: block to be freed is outside the map");
351 return -EIO;
352 }
353
354 /*
355 * free the blocks a dmap at a time.
356 */
357 mp = NULL;
358 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
359 /* release previous dmap if any */
360 if (mp) {
361 write_metapage(mp);
362 }
363
364 /* get the buffer for the current dmap. */
365 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
366 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
367 if (mp == NULL) {
368 IREAD_UNLOCK(ipbmap);
369 return -EIO;
370 }
371 dp = (struct dmap *) mp->data;
372
373 /* determine the number of blocks to be freed from
374 * this dmap.
375 */
376 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 /* free the blocks. */
379 if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) {
Dave Kleikamp56d12542005-07-15 09:43:36 -0500380 jfs_error(ip->i_sb, "dbFree: error in block map\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 release_metapage(mp);
382 IREAD_UNLOCK(ipbmap);
383 return (rc);
384 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 }
386
387 /* write the last buffer. */
388 write_metapage(mp);
389
390 IREAD_UNLOCK(ipbmap);
391
392 return (0);
393}
394
395
396/*
397 * NAME: dbUpdatePMap()
398 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500399 * FUNCTION: update the allocation state (free or allocate) of the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 * specified block range in the persistent block allocation map.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500401 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 * the blocks will be updated in the persistent map one
403 * dmap at a time.
404 *
405 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500406 * ipbmap - pointer to in-core inode for the block map.
407 * free - 'true' if block range is to be freed from the persistent
408 * map; 'false' if it is to be allocated.
409 * blkno - starting block number of the range.
410 * nblocks - number of contiguous blocks in the range.
411 * tblk - transaction block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 *
413 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500414 * 0 - success
415 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 */
417int
418dbUpdatePMap(struct inode *ipbmap,
419 int free, s64 blkno, s64 nblocks, struct tblock * tblk)
420{
421 int nblks, dbitno, wbitno, rbits;
422 int word, nbits, nwords;
423 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
424 s64 lblkno, rem, lastlblkno;
425 u32 mask;
426 struct dmap *dp;
427 struct metapage *mp;
428 struct jfs_log *log;
429 int lsn, difft, diffp;
Dave Kleikamp7fab4792005-05-02 12:25:02 -0600430 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
432 /* the blocks better be within the mapsize. */
433 if (blkno + nblocks > bmp->db_mapsize) {
434 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n",
435 (unsigned long long) blkno,
436 (unsigned long long) nblocks);
437 jfs_error(ipbmap->i_sb,
438 "dbUpdatePMap: blocks are outside the map");
439 return -EIO;
440 }
441
442 /* compute delta of transaction lsn from log syncpt */
443 lsn = tblk->lsn;
444 log = (struct jfs_log *) JFS_SBI(tblk->sb)->log;
445 logdiff(difft, lsn, log);
446
447 /*
448 * update the block state a dmap at a time.
449 */
450 mp = NULL;
451 lastlblkno = 0;
452 for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) {
453 /* get the buffer for the current dmap. */
454 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
455 if (lblkno != lastlblkno) {
456 if (mp) {
457 write_metapage(mp);
458 }
459
460 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE,
461 0);
462 if (mp == NULL)
463 return -EIO;
Dave Kleikamp7fab4792005-05-02 12:25:02 -0600464 metapage_wait_for_io(mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 }
466 dp = (struct dmap *) mp->data;
467
468 /* determine the bit number and word within the dmap of
469 * the starting block. also determine how many blocks
470 * are to be updated within this dmap.
471 */
472 dbitno = blkno & (BPERDMAP - 1);
473 word = dbitno >> L2DBWORD;
474 nblks = min(rem, (s64)BPERDMAP - dbitno);
475
476 /* update the bits of the dmap words. the first and last
477 * words may only have a subset of their bits updated. if
478 * this is the case, we'll work against that word (i.e.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500479 * partial first and/or last) only in a single pass. a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 * single pass will also be used to update all words that
481 * are to have all their bits updated.
482 */
483 for (rbits = nblks; rbits > 0;
484 rbits -= nbits, dbitno += nbits) {
485 /* determine the bit number within the word and
486 * the number of bits within the word.
487 */
488 wbitno = dbitno & (DBWORD - 1);
489 nbits = min(rbits, DBWORD - wbitno);
490
491 /* check if only part of the word is to be updated. */
492 if (nbits < DBWORD) {
493 /* update (free or allocate) the bits
494 * in this word.
495 */
496 mask =
497 (ONES << (DBWORD - nbits) >> wbitno);
498 if (free)
499 dp->pmap[word] &=
500 cpu_to_le32(~mask);
501 else
502 dp->pmap[word] |=
503 cpu_to_le32(mask);
504
505 word += 1;
506 } else {
507 /* one or more words are to have all
508 * their bits updated. determine how
509 * many words and how many bits.
510 */
511 nwords = rbits >> L2DBWORD;
512 nbits = nwords << L2DBWORD;
513
514 /* update (free or allocate) the bits
515 * in these words.
516 */
517 if (free)
518 memset(&dp->pmap[word], 0,
519 nwords * 4);
520 else
521 memset(&dp->pmap[word], (int) ONES,
522 nwords * 4);
523
524 word += nwords;
525 }
526 }
527
528 /*
529 * update dmap lsn
530 */
531 if (lblkno == lastlblkno)
532 continue;
533
534 lastlblkno = lblkno;
535
Dave Kleikampbe0bf7d2006-03-08 10:59:15 -0600536 LOGSYNC_LOCK(log, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 if (mp->lsn != 0) {
538 /* inherit older/smaller lsn */
539 logdiff(diffp, mp->lsn, log);
540 if (difft < diffp) {
541 mp->lsn = lsn;
542
543 /* move bp after tblock in logsync list */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 list_move(&mp->synclist, &tblk->synclist);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 }
546
547 /* inherit younger/larger clsn */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 logdiff(difft, tblk->clsn, log);
549 logdiff(diffp, mp->clsn, log);
550 if (difft > diffp)
551 mp->clsn = tblk->clsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 } else {
553 mp->log = log;
554 mp->lsn = lsn;
555
556 /* insert bp after tblock in logsync list */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 log->count++;
558 list_add(&mp->synclist, &tblk->synclist);
559
560 mp->clsn = tblk->clsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 }
Dave Kleikampbe0bf7d2006-03-08 10:59:15 -0600562 LOGSYNC_UNLOCK(log, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 }
564
565 /* write the last buffer. */
566 if (mp) {
567 write_metapage(mp);
568 }
569
570 return (0);
571}
572
573
574/*
575 * NAME: dbNextAG()
576 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500577 * FUNCTION: find the preferred allocation group for new allocations.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 *
579 * Within the allocation groups, we maintain a preferred
580 * allocation group which consists of a group with at least
581 * average free space. It is the preferred group that we target
582 * new inode allocation towards. The tie-in between inode
583 * allocation and block allocation occurs as we allocate the
584 * first (data) block of an inode and specify the inode (block)
585 * as the allocation hint for this block.
586 *
587 * We try to avoid having more than one open file growing in
588 * an allocation group, as this will lead to fragmentation.
589 * This differs from the old OS/2 method of trying to keep
590 * empty ags around for large allocations.
591 *
592 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500593 * ipbmap - pointer to in-core inode for the block map.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 *
595 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500596 * the preferred allocation group number.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 */
598int dbNextAG(struct inode *ipbmap)
599{
600 s64 avgfree;
601 int agpref;
602 s64 hwm = 0;
603 int i;
604 int next_best = -1;
605 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
606
607 BMAP_LOCK(bmp);
608
609 /* determine the average number of free blocks within the ags. */
610 avgfree = (u32)bmp->db_nfree / bmp->db_numag;
611
612 /*
613 * if the current preferred ag does not have an active allocator
614 * and has at least average freespace, return it
615 */
616 agpref = bmp->db_agpref;
617 if ((atomic_read(&bmp->db_active[agpref]) == 0) &&
618 (bmp->db_agfree[agpref] >= avgfree))
619 goto unlock;
620
621 /* From the last preferred ag, find the next one with at least
622 * average free space.
623 */
624 for (i = 0 ; i < bmp->db_numag; i++, agpref++) {
625 if (agpref == bmp->db_numag)
626 agpref = 0;
627
628 if (atomic_read(&bmp->db_active[agpref]))
629 /* open file is currently growing in this ag */
630 continue;
631 if (bmp->db_agfree[agpref] >= avgfree) {
632 /* Return this one */
633 bmp->db_agpref = agpref;
634 goto unlock;
635 } else if (bmp->db_agfree[agpref] > hwm) {
636 /* Less than avg. freespace, but best so far */
637 hwm = bmp->db_agfree[agpref];
638 next_best = agpref;
639 }
640 }
641
642 /*
643 * If no inactive ag was found with average freespace, use the
644 * next best
645 */
646 if (next_best != -1)
647 bmp->db_agpref = next_best;
648 /* else leave db_agpref unchanged */
649unlock:
650 BMAP_UNLOCK(bmp);
651
652 /* return the preferred group.
653 */
654 return (bmp->db_agpref);
655}
656
657/*
658 * NAME: dbAlloc()
659 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500660 * FUNCTION: attempt to allocate a specified number of contiguous free
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 * blocks from the working allocation block map.
662 *
663 * the block allocation policy uses hints and a multi-step
664 * approach.
665 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500666 * for allocation requests smaller than the number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 * per dmap, we first try to allocate the new blocks
668 * immediately following the hint. if these blocks are not
669 * available, we try to allocate blocks near the hint. if
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500670 * no blocks near the hint are available, we next try to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 * allocate within the same dmap as contains the hint.
672 *
673 * if no blocks are available in the dmap or the allocation
674 * request is larger than the dmap size, we try to allocate
675 * within the same allocation group as contains the hint. if
676 * this does not succeed, we finally try to allocate anywhere
677 * within the aggregate.
678 *
679 * we also try to allocate anywhere within the aggregate for
680 * for allocation requests larger than the allocation group
681 * size or requests that specify no hint value.
682 *
683 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500684 * ip - pointer to in-core inode;
685 * hint - allocation hint.
686 * nblocks - number of contiguous blocks in the range.
687 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 * of the newly allocated contiguous range.
689 *
690 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500691 * 0 - success
692 * -ENOSPC - insufficient disk resources
693 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 */
695int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results)
696{
697 int rc, agno;
698 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
699 struct bmap *bmp;
700 struct metapage *mp;
701 s64 lblkno, blkno;
702 struct dmap *dp;
703 int l2nb;
704 s64 mapSize;
705 int writers;
706
707 /* assert that nblocks is valid */
708 assert(nblocks > 0);
709
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 /* get the log2 number of blocks to be allocated.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500711 * if the number of blocks is not a log2 multiple,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 * it will be rounded up to the next log2 multiple.
713 */
714 l2nb = BLKSTOL2(nblocks);
715
716 bmp = JFS_SBI(ip->i_sb)->bmap;
717
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 mapSize = bmp->db_mapsize;
719
720 /* the hint should be within the map */
721 if (hint >= mapSize) {
722 jfs_error(ip->i_sb, "dbAlloc: the hint is outside the map");
723 return -EIO;
724 }
725
726 /* if the number of blocks to be allocated is greater than the
727 * allocation group size, try to allocate anywhere.
728 */
729 if (l2nb > bmp->db_agl2size) {
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600730 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731
732 rc = dbAllocAny(bmp, nblocks, l2nb, results);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733
734 goto write_unlock;
735 }
736
737 /*
738 * If no hint, let dbNextAG recommend an allocation group
739 */
740 if (hint == 0)
741 goto pref_ag;
742
743 /* we would like to allocate close to the hint. adjust the
744 * hint to the block following the hint since the allocators
745 * will start looking for free space starting at this point.
746 */
747 blkno = hint + 1;
748
749 if (blkno >= bmp->db_mapsize)
750 goto pref_ag;
751
752 agno = blkno >> bmp->db_agl2size;
753
754 /* check if blkno crosses over into a new allocation group.
755 * if so, check if we should allow allocations within this
756 * allocation group.
757 */
758 if ((blkno & (bmp->db_agsize - 1)) == 0)
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200759 /* check if the AG is currently being written to.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 * if so, call dbNextAG() to find a non-busy
761 * AG with sufficient free space.
762 */
763 if (atomic_read(&bmp->db_active[agno]))
764 goto pref_ag;
765
766 /* check if the allocation request size can be satisfied from a
767 * single dmap. if so, try to allocate from the dmap containing
768 * the hint using a tiered strategy.
769 */
770 if (nblocks <= BPERDMAP) {
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600771 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772
773 /* get the buffer for the dmap containing the hint.
774 */
775 rc = -EIO;
776 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
777 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
778 if (mp == NULL)
779 goto read_unlock;
780
781 dp = (struct dmap *) mp->data;
782
783 /* first, try to satisfy the allocation request with the
784 * blocks beginning at the hint.
785 */
786 if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks))
787 != -ENOSPC) {
788 if (rc == 0) {
789 *results = blkno;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 mark_metapage_dirty(mp);
791 }
792
793 release_metapage(mp);
794 goto read_unlock;
795 }
796
797 writers = atomic_read(&bmp->db_active[agno]);
798 if ((writers > 1) ||
799 ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) {
800 /*
801 * Someone else is writing in this allocation
802 * group. To avoid fragmenting, try another ag
803 */
804 release_metapage(mp);
805 IREAD_UNLOCK(ipbmap);
806 goto pref_ag;
807 }
808
809 /* next, try to satisfy the allocation request with blocks
810 * near the hint.
811 */
812 if ((rc =
813 dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results))
814 != -ENOSPC) {
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500815 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 mark_metapage_dirty(mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817
818 release_metapage(mp);
819 goto read_unlock;
820 }
821
822 /* try to satisfy the allocation request with blocks within
823 * the same dmap as the hint.
824 */
825 if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results))
826 != -ENOSPC) {
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500827 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 mark_metapage_dirty(mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829
830 release_metapage(mp);
831 goto read_unlock;
832 }
833
834 release_metapage(mp);
835 IREAD_UNLOCK(ipbmap);
836 }
837
838 /* try to satisfy the allocation request with blocks within
839 * the same allocation group as the hint.
840 */
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600841 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500842 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843 goto write_unlock;
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500844
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 IWRITE_UNLOCK(ipbmap);
846
847
848 pref_ag:
849 /*
850 * Let dbNextAG recommend a preferred allocation group
851 */
852 agno = dbNextAG(ipbmap);
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600853 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854
855 /* Try to allocate within this allocation group. if that fails, try to
856 * allocate anywhere in the map.
857 */
858 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC)
859 rc = dbAllocAny(bmp, nblocks, l2nb, results);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860
861 write_unlock:
862 IWRITE_UNLOCK(ipbmap);
863
864 return (rc);
865
866 read_unlock:
867 IREAD_UNLOCK(ipbmap);
868
869 return (rc);
870}
871
872#ifdef _NOTYET
873/*
874 * NAME: dbAllocExact()
875 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500876 * FUNCTION: try to allocate the requested extent;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877 *
878 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500879 * ip - pointer to in-core inode;
880 * blkno - extent address;
881 * nblocks - extent length;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 *
883 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500884 * 0 - success
885 * -ENOSPC - insufficient disk resources
886 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 */
888int dbAllocExact(struct inode *ip, s64 blkno, int nblocks)
889{
890 int rc;
891 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
892 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
893 struct dmap *dp;
894 s64 lblkno;
895 struct metapage *mp;
896
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600897 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898
899 /*
900 * validate extent request:
901 *
902 * note: defragfs policy:
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500903 * max 64 blocks will be moved.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 * allocation request size must be satisfied from a single dmap.
905 */
906 if (nblocks <= 0 || nblocks > BPERDMAP || blkno >= bmp->db_mapsize) {
907 IREAD_UNLOCK(ipbmap);
908 return -EINVAL;
909 }
910
911 if (nblocks > ((s64) 1 << bmp->db_maxfreebud)) {
912 /* the free space is no longer available */
913 IREAD_UNLOCK(ipbmap);
914 return -ENOSPC;
915 }
916
917 /* read in the dmap covering the extent */
918 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
919 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
920 if (mp == NULL) {
921 IREAD_UNLOCK(ipbmap);
922 return -EIO;
923 }
924 dp = (struct dmap *) mp->data;
925
926 /* try to allocate the requested extent */
927 rc = dbAllocNext(bmp, dp, blkno, nblocks);
928
929 IREAD_UNLOCK(ipbmap);
930
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500931 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 mark_metapage_dirty(mp);
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500933
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 release_metapage(mp);
935
936 return (rc);
937}
938#endif /* _NOTYET */
939
940/*
941 * NAME: dbReAlloc()
942 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500943 * FUNCTION: attempt to extend a current allocation by a specified
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 * number of blocks.
945 *
946 * this routine attempts to satisfy the allocation request
947 * by first trying to extend the existing allocation in
948 * place by allocating the additional blocks as the blocks
949 * immediately following the current allocation. if these
950 * blocks are not available, this routine will attempt to
951 * allocate a new set of contiguous blocks large enough
952 * to cover the existing allocation plus the additional
953 * number of blocks required.
954 *
955 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500956 * ip - pointer to in-core inode requiring allocation.
957 * blkno - starting block of the current allocation.
958 * nblocks - number of contiguous blocks within the current
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 * allocation.
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500960 * addnblocks - number of blocks to add to the allocation.
961 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 * of the existing allocation if the existing allocation
963 * was extended in place or to a newly allocated contiguous
964 * range if the existing allocation could not be extended
965 * in place.
966 *
967 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500968 * 0 - success
969 * -ENOSPC - insufficient disk resources
970 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971 */
972int
973dbReAlloc(struct inode *ip,
974 s64 blkno, s64 nblocks, s64 addnblocks, s64 * results)
975{
976 int rc;
977
978 /* try to extend the allocation in place.
979 */
980 if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) {
981 *results = blkno;
982 return (0);
983 } else {
984 if (rc != -ENOSPC)
985 return (rc);
986 }
987
988 /* could not extend the allocation in place, so allocate a
989 * new set of blocks for the entire request (i.e. try to get
990 * a range of contiguous blocks large enough to cover the
991 * existing allocation plus the additional blocks.)
992 */
993 return (dbAlloc
994 (ip, blkno + nblocks - 1, addnblocks + nblocks, results));
995}
996
997
998/*
999 * NAME: dbExtend()
1000 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001001 * FUNCTION: attempt to extend a current allocation by a specified
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 * number of blocks.
1003 *
1004 * this routine attempts to satisfy the allocation request
1005 * by first trying to extend the existing allocation in
1006 * place by allocating the additional blocks as the blocks
1007 * immediately following the current allocation.
1008 *
1009 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001010 * ip - pointer to in-core inode requiring allocation.
1011 * blkno - starting block of the current allocation.
1012 * nblocks - number of contiguous blocks within the current
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 * allocation.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001014 * addnblocks - number of blocks to add to the allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015 *
1016 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001017 * 0 - success
1018 * -ENOSPC - insufficient disk resources
1019 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 */
1021static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks)
1022{
1023 struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
1024 s64 lblkno, lastblkno, extblkno;
1025 uint rel_block;
1026 struct metapage *mp;
1027 struct dmap *dp;
1028 int rc;
1029 struct inode *ipbmap = sbi->ipbmap;
1030 struct bmap *bmp;
1031
1032 /*
1033 * We don't want a non-aligned extent to cross a page boundary
1034 */
1035 if (((rel_block = blkno & (sbi->nbperpage - 1))) &&
1036 (rel_block + nblocks + addnblocks > sbi->nbperpage))
1037 return -ENOSPC;
1038
1039 /* get the last block of the current allocation */
1040 lastblkno = blkno + nblocks - 1;
1041
1042 /* determine the block number of the block following
1043 * the existing allocation.
1044 */
1045 extblkno = lastblkno + 1;
1046
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -06001047 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048
1049 /* better be within the file system */
1050 bmp = sbi->bmap;
1051 if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) {
1052 IREAD_UNLOCK(ipbmap);
1053 jfs_error(ip->i_sb,
1054 "dbExtend: the block is outside the filesystem");
1055 return -EIO;
1056 }
1057
1058 /* we'll attempt to extend the current allocation in place by
1059 * allocating the additional blocks as the blocks immediately
1060 * following the current allocation. we only try to extend the
1061 * current allocation in place if the number of additional blocks
1062 * can fit into a dmap, the last block of the current allocation
1063 * is not the last block of the file system, and the start of the
1064 * inplace extension is not on an allocation group boundary.
1065 */
1066 if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize ||
1067 (extblkno & (bmp->db_agsize - 1)) == 0) {
1068 IREAD_UNLOCK(ipbmap);
1069 return -ENOSPC;
1070 }
1071
1072 /* get the buffer for the dmap containing the first block
1073 * of the extension.
1074 */
1075 lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage);
1076 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
1077 if (mp == NULL) {
1078 IREAD_UNLOCK(ipbmap);
1079 return -EIO;
1080 }
1081
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082 dp = (struct dmap *) mp->data;
1083
1084 /* try to allocate the blocks immediately following the
1085 * current allocation.
1086 */
1087 rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks);
1088
1089 IREAD_UNLOCK(ipbmap);
1090
1091 /* were we successful ? */
Dave Kleikampb38a3ab2005-06-27 15:35:37 -05001092 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 write_metapage(mp);
Dave Kleikampb38a3ab2005-06-27 15:35:37 -05001094 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 /* we were not successful */
1096 release_metapage(mp);
1097
1098
1099 return (rc);
1100}
1101
1102
1103/*
1104 * NAME: dbAllocNext()
1105 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001106 * FUNCTION: attempt to allocate the blocks of the specified block
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 * range within a dmap.
1108 *
1109 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001110 * bmp - pointer to bmap descriptor
1111 * dp - pointer to dmap.
1112 * blkno - starting block number of the range.
1113 * nblocks - number of contiguous free blocks of the range.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114 *
1115 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001116 * 0 - success
1117 * -ENOSPC - insufficient disk resources
1118 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119 *
1120 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1121 */
1122static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno,
1123 int nblocks)
1124{
1125 int dbitno, word, rembits, nb, nwords, wbitno, nw;
1126 int l2size;
1127 s8 *leaf;
1128 u32 mask;
1129
1130 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
1131 jfs_error(bmp->db_ipbmap->i_sb,
1132 "dbAllocNext: Corrupt dmap page");
1133 return -EIO;
1134 }
1135
1136 /* pick up a pointer to the leaves of the dmap tree.
1137 */
1138 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1139
1140 /* determine the bit number and word within the dmap of the
1141 * starting block.
1142 */
1143 dbitno = blkno & (BPERDMAP - 1);
1144 word = dbitno >> L2DBWORD;
1145
1146 /* check if the specified block range is contained within
1147 * this dmap.
1148 */
1149 if (dbitno + nblocks > BPERDMAP)
1150 return -ENOSPC;
1151
1152 /* check if the starting leaf indicates that anything
1153 * is free.
1154 */
1155 if (leaf[word] == NOFREE)
1156 return -ENOSPC;
1157
1158 /* check the dmaps words corresponding to block range to see
1159 * if the block range is free. not all bits of the first and
1160 * last words may be contained within the block range. if this
1161 * is the case, we'll work against those words (i.e. partial first
1162 * and/or last) on an individual basis (a single pass) and examine
1163 * the actual bits to determine if they are free. a single pass
1164 * will be used for all dmap words fully contained within the
1165 * specified range. within this pass, the leaves of the dmap
1166 * tree will be examined to determine if the blocks are free. a
1167 * single leaf may describe the free space of multiple dmap
1168 * words, so we may visit only a subset of the actual leaves
1169 * corresponding to the dmap words of the block range.
1170 */
1171 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
1172 /* determine the bit number within the word and
1173 * the number of bits within the word.
1174 */
1175 wbitno = dbitno & (DBWORD - 1);
1176 nb = min(rembits, DBWORD - wbitno);
1177
1178 /* check if only part of the word is to be examined.
1179 */
1180 if (nb < DBWORD) {
1181 /* check if the bits are free.
1182 */
1183 mask = (ONES << (DBWORD - nb) >> wbitno);
1184 if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask)
1185 return -ENOSPC;
1186
1187 word += 1;
1188 } else {
1189 /* one or more dmap words are fully contained
1190 * within the block range. determine how many
1191 * words and how many bits.
1192 */
1193 nwords = rembits >> L2DBWORD;
1194 nb = nwords << L2DBWORD;
1195
1196 /* now examine the appropriate leaves to determine
1197 * if the blocks are free.
1198 */
1199 while (nwords > 0) {
1200 /* does the leaf describe any free space ?
1201 */
1202 if (leaf[word] < BUDMIN)
1203 return -ENOSPC;
1204
1205 /* determine the l2 number of bits provided
1206 * by this leaf.
1207 */
1208 l2size =
1209 min((int)leaf[word], NLSTOL2BSZ(nwords));
1210
1211 /* determine how many words were handled.
1212 */
1213 nw = BUDSIZE(l2size, BUDMIN);
1214
1215 nwords -= nw;
1216 word += nw;
1217 }
1218 }
1219 }
1220
1221 /* allocate the blocks.
1222 */
1223 return (dbAllocDmap(bmp, dp, blkno, nblocks));
1224}
1225
1226
1227/*
1228 * NAME: dbAllocNear()
1229 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001230 * FUNCTION: attempt to allocate a number of contiguous free blocks near
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 * a specified block (hint) within a dmap.
1232 *
1233 * starting with the dmap leaf that covers the hint, we'll
1234 * check the next four contiguous leaves for sufficient free
1235 * space. if sufficient free space is found, we'll allocate
1236 * the desired free space.
1237 *
1238 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001239 * bmp - pointer to bmap descriptor
1240 * dp - pointer to dmap.
1241 * blkno - block number to allocate near.
1242 * nblocks - actual number of contiguous free blocks desired.
1243 * l2nb - log2 number of contiguous free blocks desired.
1244 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245 * of the newly allocated range.
1246 *
1247 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001248 * 0 - success
1249 * -ENOSPC - insufficient disk resources
1250 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 *
1252 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1253 */
1254static int
1255dbAllocNear(struct bmap * bmp,
1256 struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results)
1257{
1258 int word, lword, rc;
1259 s8 *leaf;
1260
1261 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
1262 jfs_error(bmp->db_ipbmap->i_sb,
1263 "dbAllocNear: Corrupt dmap page");
1264 return -EIO;
1265 }
1266
1267 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1268
1269 /* determine the word within the dmap that holds the hint
1270 * (i.e. blkno). also, determine the last word in the dmap
1271 * that we'll include in our examination.
1272 */
1273 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
1274 lword = min(word + 4, LPERDMAP);
1275
1276 /* examine the leaves for sufficient free space.
1277 */
1278 for (; word < lword; word++) {
1279 /* does the leaf describe sufficient free space ?
1280 */
1281 if (leaf[word] < l2nb)
1282 continue;
1283
1284 /* determine the block number within the file system
1285 * of the first block described by this dmap word.
1286 */
1287 blkno = le64_to_cpu(dp->start) + (word << L2DBWORD);
1288
1289 /* if not all bits of the dmap word are free, get the
1290 * starting bit number within the dmap word of the required
1291 * string of free bits and adjust the block number with the
1292 * value.
1293 */
1294 if (leaf[word] < BUDMIN)
1295 blkno +=
1296 dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb);
1297
1298 /* allocate the blocks.
1299 */
1300 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
1301 *results = blkno;
1302
1303 return (rc);
1304 }
1305
1306 return -ENOSPC;
1307}
1308
1309
1310/*
1311 * NAME: dbAllocAG()
1312 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001313 * FUNCTION: attempt to allocate the specified number of contiguous
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 * free blocks within the specified allocation group.
1315 *
1316 * unless the allocation group size is equal to the number
1317 * of blocks per dmap, the dmap control pages will be used to
1318 * find the required free space, if available. we start the
1319 * search at the highest dmap control page level which
1320 * distinctly describes the allocation group's free space
1321 * (i.e. the highest level at which the allocation group's
1322 * free space is not mixed in with that of any other group).
1323 * in addition, we start the search within this level at a
1324 * height of the dmapctl dmtree at which the nodes distinctly
1325 * describe the allocation group's free space. at this height,
1326 * the allocation group's free space may be represented by 1
1327 * or two sub-trees, depending on the allocation group size.
1328 * we search the top nodes of these subtrees left to right for
1329 * sufficient free space. if sufficient free space is found,
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001330 * the subtree is searched to find the leftmost leaf that
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 * has free space. once we have made it to the leaf, we
1332 * move the search to the next lower level dmap control page
1333 * corresponding to this leaf. we continue down the dmap control
1334 * pages until we find the dmap that contains or starts the
1335 * sufficient free space and we allocate at this dmap.
1336 *
1337 * if the allocation group size is equal to the dmap size,
1338 * we'll start at the dmap corresponding to the allocation
1339 * group and attempt the allocation at this level.
1340 *
1341 * the dmap control page search is also not performed if the
1342 * allocation group is completely free and we go to the first
1343 * dmap of the allocation group to do the allocation. this is
1344 * done because the allocation group may be part (not the first
1345 * part) of a larger binary buddy system, causing the dmap
1346 * control pages to indicate no free space (NOFREE) within
1347 * the allocation group.
1348 *
1349 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001350 * bmp - pointer to bmap descriptor
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351 * agno - allocation group number.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001352 * nblocks - actual number of contiguous free blocks desired.
1353 * l2nb - log2 number of contiguous free blocks desired.
1354 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355 * of the newly allocated range.
1356 *
1357 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001358 * 0 - success
1359 * -ENOSPC - insufficient disk resources
1360 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361 *
1362 * note: IWRITE_LOCK(ipmap) held on entry/exit;
1363 */
1364static int
1365dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results)
1366{
1367 struct metapage *mp;
1368 struct dmapctl *dcp;
1369 int rc, ti, i, k, m, n, agperlev;
1370 s64 blkno, lblkno;
1371 int budmin;
1372
1373 /* allocation request should not be for more than the
1374 * allocation group size.
1375 */
1376 if (l2nb > bmp->db_agl2size) {
1377 jfs_error(bmp->db_ipbmap->i_sb,
1378 "dbAllocAG: allocation request is larger than the "
1379 "allocation group size");
1380 return -EIO;
1381 }
1382
1383 /* determine the starting block number of the allocation
1384 * group.
1385 */
1386 blkno = (s64) agno << bmp->db_agl2size;
1387
1388 /* check if the allocation group size is the minimum allocation
1389 * group size or if the allocation group is completely free. if
1390 * the allocation group size is the minimum size of BPERDMAP (i.e.
1391 * 1 dmap), there is no need to search the dmap control page (below)
1392 * that fully describes the allocation group since the allocation
1393 * group is already fully described by a dmap. in this case, we
1394 * just call dbAllocCtl() to search the dmap tree and allocate the
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001395 * required space if available.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001396 *
1397 * if the allocation group is completely free, dbAllocCtl() is
1398 * also called to allocate the required space. this is done for
1399 * two reasons. first, it makes no sense searching the dmap control
1400 * pages for free space when we know that free space exists. second,
1401 * the dmap control pages may indicate that the allocation group
1402 * has no free space if the allocation group is part (not the first
1403 * part) of a larger binary buddy system.
1404 */
1405 if (bmp->db_agsize == BPERDMAP
1406 || bmp->db_agfree[agno] == bmp->db_agsize) {
1407 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1408 if ((rc == -ENOSPC) &&
1409 (bmp->db_agfree[agno] == bmp->db_agsize)) {
1410 printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n",
1411 (unsigned long long) blkno,
1412 (unsigned long long) nblocks);
1413 jfs_error(bmp->db_ipbmap->i_sb,
1414 "dbAllocAG: dbAllocCtl failed in free AG");
1415 }
1416 return (rc);
1417 }
1418
1419 /* the buffer for the dmap control page that fully describes the
1420 * allocation group.
1421 */
1422 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel);
1423 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1424 if (mp == NULL)
1425 return -EIO;
1426 dcp = (struct dmapctl *) mp->data;
1427 budmin = dcp->budmin;
1428
1429 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1430 jfs_error(bmp->db_ipbmap->i_sb,
1431 "dbAllocAG: Corrupt dmapctl page");
1432 release_metapage(mp);
1433 return -EIO;
1434 }
1435
1436 /* search the subtree(s) of the dmap control page that describes
1437 * the allocation group, looking for sufficient free space. to begin,
1438 * determine how many allocation groups are represented in a dmap
1439 * control page at the control page level (i.e. L0, L1, L2) that
1440 * fully describes an allocation group. next, determine the starting
1441 * tree index of this allocation group within the control page.
1442 */
1443 agperlev =
Daniel Mackd7eecb42010-01-28 16:13:01 +08001444 (1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001445 ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1));
1446
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001447 /* dmap control page trees fan-out by 4 and a single allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448 * group may be described by 1 or 2 subtrees within the ag level
1449 * dmap control page, depending upon the ag size. examine the ag's
1450 * subtrees for sufficient free space, starting with the leftmost
1451 * subtree.
1452 */
1453 for (i = 0; i < bmp->db_agwidth; i++, ti++) {
1454 /* is there sufficient free space ?
1455 */
1456 if (l2nb > dcp->stree[ti])
1457 continue;
1458
1459 /* sufficient free space found in a subtree. now search down
1460 * the subtree to find the leftmost leaf that describes this
1461 * free space.
1462 */
Daniel Mackd7eecb42010-01-28 16:13:01 +08001463 for (k = bmp->db_agheight; k > 0; k--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001464 for (n = 0, m = (ti << 2) + 1; n < 4; n++) {
1465 if (l2nb <= dcp->stree[m + n]) {
1466 ti = m + n;
1467 break;
1468 }
1469 }
1470 if (n == 4) {
1471 jfs_error(bmp->db_ipbmap->i_sb,
1472 "dbAllocAG: failed descending stree");
1473 release_metapage(mp);
1474 return -EIO;
1475 }
1476 }
1477
1478 /* determine the block number within the file system
1479 * that corresponds to this leaf.
1480 */
1481 if (bmp->db_aglevel == 2)
1482 blkno = 0;
1483 else if (bmp->db_aglevel == 1)
1484 blkno &= ~(MAXL1SIZE - 1);
1485 else /* bmp->db_aglevel == 0 */
1486 blkno &= ~(MAXL0SIZE - 1);
1487
1488 blkno +=
1489 ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin;
1490
1491 /* release the buffer in preparation for going down
1492 * the next level of dmap control pages.
1493 */
1494 release_metapage(mp);
1495
1496 /* check if we need to continue to search down the lower
1497 * level dmap control pages. we need to if the number of
1498 * blocks required is less than maximum number of blocks
1499 * described at the next lower level.
1500 */
1501 if (l2nb < budmin) {
1502
1503 /* search the lower level dmap control pages to get
Michael Opdenacker59c51592007-05-09 08:57:56 +02001504 * the starting block number of the dmap that
Linus Torvalds1da177e2005-04-16 15:20:36 -07001505 * contains or starts off the free space.
1506 */
1507 if ((rc =
1508 dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1,
1509 &blkno))) {
1510 if (rc == -ENOSPC) {
1511 jfs_error(bmp->db_ipbmap->i_sb,
1512 "dbAllocAG: control page "
1513 "inconsistent");
1514 return -EIO;
1515 }
1516 return (rc);
1517 }
1518 }
1519
1520 /* allocate the blocks.
1521 */
1522 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1523 if (rc == -ENOSPC) {
1524 jfs_error(bmp->db_ipbmap->i_sb,
1525 "dbAllocAG: unable to allocate blocks");
1526 rc = -EIO;
1527 }
1528 return (rc);
1529 }
1530
1531 /* no space in the allocation group. release the buffer and
1532 * return -ENOSPC.
1533 */
1534 release_metapage(mp);
1535
1536 return -ENOSPC;
1537}
1538
1539
1540/*
1541 * NAME: dbAllocAny()
1542 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001543 * FUNCTION: attempt to allocate the specified number of contiguous
Linus Torvalds1da177e2005-04-16 15:20:36 -07001544 * free blocks anywhere in the file system.
1545 *
1546 * dbAllocAny() attempts to find the sufficient free space by
1547 * searching down the dmap control pages, starting with the
1548 * highest level (i.e. L0, L1, L2) control page. if free space
1549 * large enough to satisfy the desired free space is found, the
1550 * desired free space is allocated.
1551 *
1552 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001553 * bmp - pointer to bmap descriptor
1554 * nblocks - actual number of contiguous free blocks desired.
1555 * l2nb - log2 number of contiguous free blocks desired.
1556 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001557 * of the newly allocated range.
1558 *
1559 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001560 * 0 - success
1561 * -ENOSPC - insufficient disk resources
1562 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001563 *
1564 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1565 */
1566static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results)
1567{
1568 int rc;
1569 s64 blkno = 0;
1570
1571 /* starting with the top level dmap control page, search
1572 * down the dmap control levels for sufficient free space.
1573 * if free space is found, dbFindCtl() returns the starting
1574 * block number of the dmap that contains or starts off the
1575 * range of free space.
1576 */
1577 if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno)))
1578 return (rc);
1579
1580 /* allocate the blocks.
1581 */
1582 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1583 if (rc == -ENOSPC) {
1584 jfs_error(bmp->db_ipbmap->i_sb,
1585 "dbAllocAny: unable to allocate blocks");
1586 return -EIO;
1587 }
1588 return (rc);
1589}
1590
1591
1592/*
1593 * NAME: dbFindCtl()
1594 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001595 * FUNCTION: starting at a specified dmap control page level and block
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596 * number, search down the dmap control levels for a range of
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001597 * contiguous free blocks large enough to satisfy an allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001598 * request for the specified number of free blocks.
1599 *
1600 * if sufficient contiguous free blocks are found, this routine
1601 * returns the starting block number within a dmap page that
1602 * contains or starts a range of contiqious free blocks that
1603 * is sufficient in size.
1604 *
1605 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001606 * bmp - pointer to bmap descriptor
1607 * level - starting dmap control page level.
1608 * l2nb - log2 number of contiguous free blocks desired.
1609 * *blkno - on entry, starting block number for conducting the search.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001610 * on successful return, the first block within a dmap page
1611 * that contains or starts a range of contiguous free blocks.
1612 *
1613 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001614 * 0 - success
1615 * -ENOSPC - insufficient disk resources
1616 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001617 *
1618 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1619 */
1620static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno)
1621{
1622 int rc, leafidx, lev;
1623 s64 b, lblkno;
1624 struct dmapctl *dcp;
1625 int budmin;
1626 struct metapage *mp;
1627
1628 /* starting at the specified dmap control page level and block
1629 * number, search down the dmap control levels for the starting
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001630 * block number of a dmap page that contains or starts off
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 * sufficient free blocks.
1632 */
1633 for (lev = level, b = *blkno; lev >= 0; lev--) {
1634 /* get the buffer of the dmap control page for the block
1635 * number and level (i.e. L0, L1, L2).
1636 */
1637 lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev);
1638 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1639 if (mp == NULL)
1640 return -EIO;
1641 dcp = (struct dmapctl *) mp->data;
1642 budmin = dcp->budmin;
1643
1644 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1645 jfs_error(bmp->db_ipbmap->i_sb,
1646 "dbFindCtl: Corrupt dmapctl page");
1647 release_metapage(mp);
1648 return -EIO;
1649 }
1650
1651 /* search the tree within the dmap control page for
1652 * sufficent free space. if sufficient free space is found,
1653 * dbFindLeaf() returns the index of the leaf at which
1654 * free space was found.
1655 */
1656 rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx);
1657
1658 /* release the buffer.
1659 */
1660 release_metapage(mp);
1661
1662 /* space found ?
1663 */
1664 if (rc) {
1665 if (lev != level) {
1666 jfs_error(bmp->db_ipbmap->i_sb,
1667 "dbFindCtl: dmap inconsistent");
1668 return -EIO;
1669 }
1670 return -ENOSPC;
1671 }
1672
1673 /* adjust the block number to reflect the location within
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001674 * the dmap control page (i.e. the leaf) at which free
Linus Torvalds1da177e2005-04-16 15:20:36 -07001675 * space was found.
1676 */
1677 b += (((s64) leafidx) << budmin);
1678
1679 /* we stop the search at this dmap control page level if
1680 * the number of blocks required is greater than or equal
1681 * to the maximum number of blocks described at the next
1682 * (lower) level.
1683 */
1684 if (l2nb >= budmin)
1685 break;
1686 }
1687
1688 *blkno = b;
1689 return (0);
1690}
1691
1692
1693/*
1694 * NAME: dbAllocCtl()
1695 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001696 * FUNCTION: attempt to allocate a specified number of contiguous
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001697 * blocks starting within a specific dmap.
1698 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699 * this routine is called by higher level routines that search
1700 * the dmap control pages above the actual dmaps for contiguous
1701 * free space. the result of successful searches by these
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001702 * routines are the starting block numbers within dmaps, with
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703 * the dmaps themselves containing the desired contiguous free
1704 * space or starting a contiguous free space of desired size
1705 * that is made up of the blocks of one or more dmaps. these
1706 * calls should not fail due to insufficent resources.
1707 *
1708 * this routine is called in some cases where it is not known
1709 * whether it will fail due to insufficient resources. more
1710 * specifically, this occurs when allocating from an allocation
1711 * group whose size is equal to the number of blocks per dmap.
1712 * in this case, the dmap control pages are not examined prior
1713 * to calling this routine (to save pathlength) and the call
1714 * might fail.
1715 *
1716 * for a request size that fits within a dmap, this routine relies
1717 * upon the dmap's dmtree to find the requested contiguous free
1718 * space. for request sizes that are larger than a dmap, the
1719 * requested free space will start at the first block of the
1720 * first dmap (i.e. blkno).
1721 *
1722 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001723 * bmp - pointer to bmap descriptor
1724 * nblocks - actual number of contiguous free blocks to allocate.
1725 * l2nb - log2 number of contiguous free blocks to allocate.
1726 * blkno - starting block number of the dmap to start the allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001727 * from.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001728 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729 * of the newly allocated range.
1730 *
1731 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001732 * 0 - success
1733 * -ENOSPC - insufficient disk resources
1734 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735 *
1736 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1737 */
1738static int
1739dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results)
1740{
1741 int rc, nb;
1742 s64 b, lblkno, n;
1743 struct metapage *mp;
1744 struct dmap *dp;
1745
1746 /* check if the allocation request is confined to a single dmap.
1747 */
1748 if (l2nb <= L2BPERDMAP) {
1749 /* get the buffer for the dmap.
1750 */
1751 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
1752 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1753 if (mp == NULL)
1754 return -EIO;
1755 dp = (struct dmap *) mp->data;
1756
1757 /* try to allocate the blocks.
1758 */
1759 rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results);
1760 if (rc == 0)
1761 mark_metapage_dirty(mp);
1762
1763 release_metapage(mp);
1764
1765 return (rc);
1766 }
1767
1768 /* allocation request involving multiple dmaps. it must start on
1769 * a dmap boundary.
1770 */
1771 assert((blkno & (BPERDMAP - 1)) == 0);
1772
1773 /* allocate the blocks dmap by dmap.
1774 */
1775 for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) {
1776 /* get the buffer for the dmap.
1777 */
1778 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1779 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1780 if (mp == NULL) {
1781 rc = -EIO;
1782 goto backout;
1783 }
1784 dp = (struct dmap *) mp->data;
1785
1786 /* the dmap better be all free.
1787 */
1788 if (dp->tree.stree[ROOT] != L2BPERDMAP) {
1789 release_metapage(mp);
1790 jfs_error(bmp->db_ipbmap->i_sb,
1791 "dbAllocCtl: the dmap is not all free");
1792 rc = -EIO;
1793 goto backout;
1794 }
1795
1796 /* determine how many blocks to allocate from this dmap.
1797 */
1798 nb = min(n, (s64)BPERDMAP);
1799
1800 /* allocate the blocks from the dmap.
1801 */
1802 if ((rc = dbAllocDmap(bmp, dp, b, nb))) {
1803 release_metapage(mp);
1804 goto backout;
1805 }
1806
1807 /* write the buffer.
1808 */
1809 write_metapage(mp);
1810 }
1811
1812 /* set the results (starting block number) and return.
1813 */
1814 *results = blkno;
1815 return (0);
1816
1817 /* something failed in handling an allocation request involving
1818 * multiple dmaps. we'll try to clean up by backing out any
1819 * allocation that has already happened for this request. if
1820 * we fail in backing out the allocation, we'll mark the file
1821 * system to indicate that blocks have been leaked.
1822 */
1823 backout:
1824
1825 /* try to backout the allocations dmap by dmap.
1826 */
1827 for (n = nblocks - n, b = blkno; n > 0;
1828 n -= BPERDMAP, b += BPERDMAP) {
1829 /* get the buffer for this dmap.
1830 */
1831 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1832 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1833 if (mp == NULL) {
1834 /* could not back out. mark the file system
1835 * to indicate that we have leaked blocks.
1836 */
1837 jfs_error(bmp->db_ipbmap->i_sb,
1838 "dbAllocCtl: I/O Error: Block Leakage.");
1839 continue;
1840 }
1841 dp = (struct dmap *) mp->data;
1842
1843 /* free the blocks is this dmap.
1844 */
1845 if (dbFreeDmap(bmp, dp, b, BPERDMAP)) {
1846 /* could not back out. mark the file system
1847 * to indicate that we have leaked blocks.
1848 */
1849 release_metapage(mp);
1850 jfs_error(bmp->db_ipbmap->i_sb,
1851 "dbAllocCtl: Block Leakage.");
1852 continue;
1853 }
1854
1855 /* write the buffer.
1856 */
1857 write_metapage(mp);
1858 }
1859
1860 return (rc);
1861}
1862
1863
1864/*
1865 * NAME: dbAllocDmapLev()
1866 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001867 * FUNCTION: attempt to allocate a specified number of contiguous blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07001868 * from a specified dmap.
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001869 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001870 * this routine checks if the contiguous blocks are available.
1871 * if so, nblocks of blocks are allocated; otherwise, ENOSPC is
1872 * returned.
1873 *
1874 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001875 * mp - pointer to bmap descriptor
1876 * dp - pointer to dmap to attempt to allocate blocks from.
1877 * l2nb - log2 number of contiguous block desired.
1878 * nblocks - actual number of contiguous block desired.
1879 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001880 * of the newly allocated range.
1881 *
1882 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001883 * 0 - success
1884 * -ENOSPC - insufficient disk resources
1885 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001886 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001887 * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or
Linus Torvalds1da177e2005-04-16 15:20:36 -07001888 * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit;
1889 */
1890static int
1891dbAllocDmapLev(struct bmap * bmp,
1892 struct dmap * dp, int nblocks, int l2nb, s64 * results)
1893{
1894 s64 blkno;
1895 int leafidx, rc;
1896
1897 /* can't be more than a dmaps worth of blocks */
1898 assert(l2nb <= L2BPERDMAP);
1899
1900 /* search the tree within the dmap page for sufficient
1901 * free space. if sufficient free space is found, dbFindLeaf()
1902 * returns the index of the leaf at which free space was found.
1903 */
1904 if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx))
1905 return -ENOSPC;
1906
1907 /* determine the block number within the file system corresponding
1908 * to the leaf at which free space was found.
1909 */
1910 blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD);
1911
1912 /* if not all bits of the dmap word are free, get the starting
1913 * bit number within the dmap word of the required string of free
1914 * bits and adjust the block number with this value.
1915 */
1916 if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN)
1917 blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb);
1918
1919 /* allocate the blocks */
1920 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
1921 *results = blkno;
1922
1923 return (rc);
1924}
1925
1926
1927/*
1928 * NAME: dbAllocDmap()
1929 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001930 * FUNCTION: adjust the disk allocation map to reflect the allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001931 * of a specified block range within a dmap.
1932 *
1933 * this routine allocates the specified blocks from the dmap
1934 * through a call to dbAllocBits(). if the allocation of the
1935 * block range causes the maximum string of free blocks within
1936 * the dmap to change (i.e. the value of the root of the dmap's
1937 * dmtree), this routine will cause this change to be reflected
1938 * up through the appropriate levels of the dmap control pages
1939 * by a call to dbAdjCtl() for the L0 dmap control page that
1940 * covers this dmap.
1941 *
1942 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001943 * bmp - pointer to bmap descriptor
1944 * dp - pointer to dmap to allocate the block range from.
1945 * blkno - starting block number of the block to be allocated.
1946 * nblocks - number of blocks to be allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001947 *
1948 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001949 * 0 - success
1950 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001951 *
1952 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
1953 */
1954static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
1955 int nblocks)
1956{
1957 s8 oldroot;
1958 int rc;
1959
1960 /* save the current value of the root (i.e. maximum free string)
1961 * of the dmap tree.
1962 */
1963 oldroot = dp->tree.stree[ROOT];
1964
1965 /* allocate the specified (blocks) bits */
1966 dbAllocBits(bmp, dp, blkno, nblocks);
1967
1968 /* if the root has not changed, done. */
1969 if (dp->tree.stree[ROOT] == oldroot)
1970 return (0);
1971
1972 /* root changed. bubble the change up to the dmap control pages.
1973 * if the adjustment of the upper level control pages fails,
1974 * backout the bit allocation (thus making everything consistent).
1975 */
1976 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0)))
1977 dbFreeBits(bmp, dp, blkno, nblocks);
1978
1979 return (rc);
1980}
1981
1982
1983/*
1984 * NAME: dbFreeDmap()
1985 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001986 * FUNCTION: adjust the disk allocation map to reflect the allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001987 * of a specified block range within a dmap.
1988 *
1989 * this routine frees the specified blocks from the dmap through
1990 * a call to dbFreeBits(). if the deallocation of the block range
1991 * causes the maximum string of free blocks within the dmap to
1992 * change (i.e. the value of the root of the dmap's dmtree), this
1993 * routine will cause this change to be reflected up through the
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001994 * appropriate levels of the dmap control pages by a call to
Linus Torvalds1da177e2005-04-16 15:20:36 -07001995 * dbAdjCtl() for the L0 dmap control page that covers this dmap.
1996 *
1997 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001998 * bmp - pointer to bmap descriptor
1999 * dp - pointer to dmap to free the block range from.
2000 * blkno - starting block number of the block to be freed.
2001 * nblocks - number of blocks to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002002 *
2003 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002004 * 0 - success
2005 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07002006 *
2007 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2008 */
2009static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2010 int nblocks)
2011{
2012 s8 oldroot;
Dave Kleikamp56d12542005-07-15 09:43:36 -05002013 int rc = 0, word;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002014
2015 /* save the current value of the root (i.e. maximum free string)
2016 * of the dmap tree.
2017 */
2018 oldroot = dp->tree.stree[ROOT];
2019
2020 /* free the specified (blocks) bits */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002021 rc = dbFreeBits(bmp, dp, blkno, nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002022
Dave Kleikamp56d12542005-07-15 09:43:36 -05002023 /* if error or the root has not changed, done. */
2024 if (rc || (dp->tree.stree[ROOT] == oldroot))
2025 return (rc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002026
2027 /* root changed. bubble the change up to the dmap control pages.
2028 * if the adjustment of the upper level control pages fails,
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002029 * backout the deallocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002030 */
2031 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) {
2032 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
2033
2034 /* as part of backing out the deallocation, we will have
2035 * to back split the dmap tree if the deallocation caused
2036 * the freed blocks to become part of a larger binary buddy
2037 * system.
2038 */
2039 if (dp->tree.stree[word] == NOFREE)
2040 dbBackSplit((dmtree_t *) & dp->tree, word);
2041
2042 dbAllocBits(bmp, dp, blkno, nblocks);
2043 }
2044
2045 return (rc);
2046}
2047
2048
2049/*
2050 * NAME: dbAllocBits()
2051 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002052 * FUNCTION: allocate a specified block range from a dmap.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002053 *
2054 * this routine updates the dmap to reflect the working
2055 * state allocation of the specified block range. it directly
2056 * updates the bits of the working map and causes the adjustment
2057 * of the binary buddy system described by the dmap's dmtree
2058 * leaves to reflect the bits allocated. it also causes the
2059 * dmap's dmtree, as a whole, to reflect the allocated range.
2060 *
2061 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002062 * bmp - pointer to bmap descriptor
2063 * dp - pointer to dmap to allocate bits from.
2064 * blkno - starting block number of the bits to be allocated.
2065 * nblocks - number of bits to be allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002066 *
2067 * RETURN VALUES: none
2068 *
2069 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2070 */
2071static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
2072 int nblocks)
2073{
2074 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2075 dmtree_t *tp = (dmtree_t *) & dp->tree;
2076 int size;
2077 s8 *leaf;
2078
2079 /* pick up a pointer to the leaves of the dmap tree */
2080 leaf = dp->tree.stree + LEAFIND;
2081
2082 /* determine the bit number and word within the dmap of the
2083 * starting block.
2084 */
2085 dbitno = blkno & (BPERDMAP - 1);
2086 word = dbitno >> L2DBWORD;
2087
2088 /* block range better be within the dmap */
2089 assert(dbitno + nblocks <= BPERDMAP);
2090
2091 /* allocate the bits of the dmap's words corresponding to the block
2092 * range. not all bits of the first and last words may be contained
2093 * within the block range. if this is the case, we'll work against
2094 * those words (i.e. partial first and/or last) on an individual basis
2095 * (a single pass), allocating the bits of interest by hand and
2096 * updating the leaf corresponding to the dmap word. a single pass
2097 * will be used for all dmap words fully contained within the
2098 * specified range. within this pass, the bits of all fully contained
2099 * dmap words will be marked as free in a single shot and the leaves
2100 * will be updated. a single leaf may describe the free space of
2101 * multiple dmap words, so we may update only a subset of the actual
2102 * leaves corresponding to the dmap words of the block range.
2103 */
2104 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2105 /* determine the bit number within the word and
2106 * the number of bits within the word.
2107 */
2108 wbitno = dbitno & (DBWORD - 1);
2109 nb = min(rembits, DBWORD - wbitno);
2110
2111 /* check if only part of a word is to be allocated.
2112 */
2113 if (nb < DBWORD) {
2114 /* allocate (set to 1) the appropriate bits within
2115 * this dmap word.
2116 */
2117 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
2118 >> wbitno);
2119
2120 /* update the leaf for this dmap word. in addition
2121 * to setting the leaf value to the binary buddy max
2122 * of the updated dmap word, dbSplit() will split
2123 * the binary system of the leaves if need be.
2124 */
2125 dbSplit(tp, word, BUDMIN,
2126 dbMaxBud((u8 *) & dp->wmap[word]));
2127
2128 word += 1;
2129 } else {
2130 /* one or more dmap words are fully contained
2131 * within the block range. determine how many
2132 * words and allocate (set to 1) the bits of these
2133 * words.
2134 */
2135 nwords = rembits >> L2DBWORD;
2136 memset(&dp->wmap[word], (int) ONES, nwords * 4);
2137
2138 /* determine how many bits.
2139 */
2140 nb = nwords << L2DBWORD;
2141
2142 /* now update the appropriate leaves to reflect
2143 * the allocated words.
2144 */
2145 for (; nwords > 0; nwords -= nw) {
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002146 if (leaf[word] < BUDMIN) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002147 jfs_error(bmp->db_ipbmap->i_sb,
2148 "dbAllocBits: leaf page "
2149 "corrupt");
2150 break;
2151 }
2152
2153 /* determine what the leaf value should be
2154 * updated to as the minimum of the l2 number
2155 * of bits being allocated and the l2 number
2156 * of bits currently described by this leaf.
2157 */
2158 size = min((int)leaf[word], NLSTOL2BSZ(nwords));
2159
2160 /* update the leaf to reflect the allocation.
2161 * in addition to setting the leaf value to
2162 * NOFREE, dbSplit() will split the binary
2163 * system of the leaves to reflect the current
2164 * allocation (size).
2165 */
2166 dbSplit(tp, word, size, NOFREE);
2167
2168 /* get the number of dmap words handled */
2169 nw = BUDSIZE(size, BUDMIN);
2170 word += nw;
2171 }
2172 }
2173 }
2174
2175 /* update the free count for this dmap */
Marcin Slusarz89145622008-02-13 15:34:20 -06002176 le32_add_cpu(&dp->nfree, -nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002177
2178 BMAP_LOCK(bmp);
2179
2180 /* if this allocation group is completely free,
2181 * update the maximum allocation group number if this allocation
2182 * group is the new max.
2183 */
2184 agno = blkno >> bmp->db_agl2size;
2185 if (agno > bmp->db_maxag)
2186 bmp->db_maxag = agno;
2187
2188 /* update the free count for the allocation group and map */
2189 bmp->db_agfree[agno] -= nblocks;
2190 bmp->db_nfree -= nblocks;
2191
2192 BMAP_UNLOCK(bmp);
2193}
2194
2195
2196/*
2197 * NAME: dbFreeBits()
2198 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002199 * FUNCTION: free a specified block range from a dmap.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002200 *
2201 * this routine updates the dmap to reflect the working
2202 * state allocation of the specified block range. it directly
2203 * updates the bits of the working map and causes the adjustment
2204 * of the binary buddy system described by the dmap's dmtree
2205 * leaves to reflect the bits freed. it also causes the dmap's
2206 * dmtree, as a whole, to reflect the deallocated range.
2207 *
2208 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002209 * bmp - pointer to bmap descriptor
2210 * dp - pointer to dmap to free bits from.
2211 * blkno - starting block number of the bits to be freed.
2212 * nblocks - number of bits to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002213 *
Dave Kleikamp56d12542005-07-15 09:43:36 -05002214 * RETURN VALUES: 0 for success
Linus Torvalds1da177e2005-04-16 15:20:36 -07002215 *
2216 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2217 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002218static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002219 int nblocks)
2220{
2221 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2222 dmtree_t *tp = (dmtree_t *) & dp->tree;
Dave Kleikamp56d12542005-07-15 09:43:36 -05002223 int rc = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002224 int size;
2225
2226 /* determine the bit number and word within the dmap of the
2227 * starting block.
2228 */
2229 dbitno = blkno & (BPERDMAP - 1);
2230 word = dbitno >> L2DBWORD;
2231
2232 /* block range better be within the dmap.
2233 */
2234 assert(dbitno + nblocks <= BPERDMAP);
2235
2236 /* free the bits of the dmaps words corresponding to the block range.
2237 * not all bits of the first and last words may be contained within
2238 * the block range. if this is the case, we'll work against those
2239 * words (i.e. partial first and/or last) on an individual basis
2240 * (a single pass), freeing the bits of interest by hand and updating
2241 * the leaf corresponding to the dmap word. a single pass will be used
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002242 * for all dmap words fully contained within the specified range.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002243 * within this pass, the bits of all fully contained dmap words will
2244 * be marked as free in a single shot and the leaves will be updated. a
2245 * single leaf may describe the free space of multiple dmap words,
2246 * so we may update only a subset of the actual leaves corresponding
2247 * to the dmap words of the block range.
2248 *
2249 * dbJoin() is used to update leaf values and will join the binary
2250 * buddy system of the leaves if the new leaf values indicate this
2251 * should be done.
2252 */
2253 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2254 /* determine the bit number within the word and
2255 * the number of bits within the word.
2256 */
2257 wbitno = dbitno & (DBWORD - 1);
2258 nb = min(rembits, DBWORD - wbitno);
2259
2260 /* check if only part of a word is to be freed.
2261 */
2262 if (nb < DBWORD) {
2263 /* free (zero) the appropriate bits within this
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002264 * dmap word.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002265 */
2266 dp->wmap[word] &=
2267 cpu_to_le32(~(ONES << (DBWORD - nb)
2268 >> wbitno));
2269
2270 /* update the leaf for this dmap word.
2271 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002272 rc = dbJoin(tp, word,
2273 dbMaxBud((u8 *) & dp->wmap[word]));
2274 if (rc)
2275 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002276
2277 word += 1;
2278 } else {
2279 /* one or more dmap words are fully contained
2280 * within the block range. determine how many
2281 * words and free (zero) the bits of these words.
2282 */
2283 nwords = rembits >> L2DBWORD;
2284 memset(&dp->wmap[word], 0, nwords * 4);
2285
2286 /* determine how many bits.
2287 */
2288 nb = nwords << L2DBWORD;
2289
2290 /* now update the appropriate leaves to reflect
2291 * the freed words.
2292 */
2293 for (; nwords > 0; nwords -= nw) {
2294 /* determine what the leaf value should be
2295 * updated to as the minimum of the l2 number
2296 * of bits being freed and the l2 (max) number
2297 * of bits that can be described by this leaf.
2298 */
2299 size =
2300 min(LITOL2BSZ
2301 (word, L2LPERDMAP, BUDMIN),
2302 NLSTOL2BSZ(nwords));
2303
2304 /* update the leaf.
2305 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002306 rc = dbJoin(tp, word, size);
2307 if (rc)
2308 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002309
2310 /* get the number of dmap words handled.
2311 */
2312 nw = BUDSIZE(size, BUDMIN);
2313 word += nw;
2314 }
2315 }
2316 }
2317
2318 /* update the free count for this dmap.
2319 */
Marcin Slusarz89145622008-02-13 15:34:20 -06002320 le32_add_cpu(&dp->nfree, nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002321
2322 BMAP_LOCK(bmp);
2323
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002324 /* update the free count for the allocation group and
Linus Torvalds1da177e2005-04-16 15:20:36 -07002325 * map.
2326 */
2327 agno = blkno >> bmp->db_agl2size;
2328 bmp->db_nfree += nblocks;
2329 bmp->db_agfree[agno] += nblocks;
2330
2331 /* check if this allocation group is not completely free and
2332 * if it is currently the maximum (rightmost) allocation group.
2333 * if so, establish the new maximum allocation group number by
2334 * searching left for the first allocation group with allocation.
2335 */
2336 if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) ||
2337 (agno == bmp->db_numag - 1 &&
2338 bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) {
2339 while (bmp->db_maxag > 0) {
2340 bmp->db_maxag -= 1;
2341 if (bmp->db_agfree[bmp->db_maxag] !=
2342 bmp->db_agsize)
2343 break;
2344 }
2345
2346 /* re-establish the allocation group preference if the
2347 * current preference is right of the maximum allocation
2348 * group.
2349 */
2350 if (bmp->db_agpref > bmp->db_maxag)
2351 bmp->db_agpref = bmp->db_maxag;
2352 }
2353
2354 BMAP_UNLOCK(bmp);
Dave Kleikamp56d12542005-07-15 09:43:36 -05002355
2356 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002357}
2358
2359
2360/*
2361 * NAME: dbAdjCtl()
2362 *
2363 * FUNCTION: adjust a dmap control page at a specified level to reflect
2364 * the change in a lower level dmap or dmap control page's
2365 * maximum string of free blocks (i.e. a change in the root
2366 * of the lower level object's dmtree) due to the allocation
2367 * or deallocation of a range of blocks with a single dmap.
2368 *
2369 * on entry, this routine is provided with the new value of
2370 * the lower level dmap or dmap control page root and the
2371 * starting block number of the block range whose allocation
2372 * or deallocation resulted in the root change. this range
2373 * is respresented by a single leaf of the current dmapctl
2374 * and the leaf will be updated with this value, possibly
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002375 * causing a binary buddy system within the leaves to be
Linus Torvalds1da177e2005-04-16 15:20:36 -07002376 * split or joined. the update may also cause the dmapctl's
2377 * dmtree to be updated.
2378 *
2379 * if the adjustment of the dmap control page, itself, causes its
2380 * root to change, this change will be bubbled up to the next dmap
2381 * control level by a recursive call to this routine, specifying
2382 * the new root value and the next dmap control page level to
2383 * be adjusted.
2384 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002385 * bmp - pointer to bmap descriptor
2386 * blkno - the first block of a block range within a dmap. it is
Linus Torvalds1da177e2005-04-16 15:20:36 -07002387 * the allocation or deallocation of this block range that
2388 * requires the dmap control page to be adjusted.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002389 * newval - the new value of the lower level dmap or dmap control
Linus Torvalds1da177e2005-04-16 15:20:36 -07002390 * page root.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002391 * alloc - 'true' if adjustment is due to an allocation.
2392 * level - current level of dmap control page (i.e. L0, L1, L2) to
Linus Torvalds1da177e2005-04-16 15:20:36 -07002393 * be adjusted.
2394 *
2395 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002396 * 0 - success
2397 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07002398 *
2399 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2400 */
2401static int
2402dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
2403{
2404 struct metapage *mp;
2405 s8 oldroot;
2406 int oldval;
2407 s64 lblkno;
2408 struct dmapctl *dcp;
2409 int rc, leafno, ti;
2410
2411 /* get the buffer for the dmap control page for the specified
2412 * block number and control page level.
2413 */
2414 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level);
2415 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
2416 if (mp == NULL)
2417 return -EIO;
2418 dcp = (struct dmapctl *) mp->data;
2419
2420 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
2421 jfs_error(bmp->db_ipbmap->i_sb,
2422 "dbAdjCtl: Corrupt dmapctl page");
2423 release_metapage(mp);
2424 return -EIO;
2425 }
2426
2427 /* determine the leaf number corresponding to the block and
2428 * the index within the dmap control tree.
2429 */
2430 leafno = BLKTOCTLLEAF(blkno, dcp->budmin);
2431 ti = leafno + le32_to_cpu(dcp->leafidx);
2432
2433 /* save the current leaf value and the current root level (i.e.
2434 * maximum l2 free string described by this dmapctl).
2435 */
2436 oldval = dcp->stree[ti];
2437 oldroot = dcp->stree[ROOT];
2438
2439 /* check if this is a control page update for an allocation.
2440 * if so, update the leaf to reflect the new leaf value using
Thomas Weber88393162010-03-16 11:47:56 +01002441 * dbSplit(); otherwise (deallocation), use dbJoin() to update
Linus Torvalds1da177e2005-04-16 15:20:36 -07002442 * the leaf with the new value. in addition to updating the
2443 * leaf, dbSplit() will also split the binary buddy system of
2444 * the leaves, if required, and bubble new values within the
2445 * dmapctl tree, if required. similarly, dbJoin() will join
2446 * the binary buddy system of leaves and bubble new values up
2447 * the dmapctl tree as required by the new leaf value.
2448 */
2449 if (alloc) {
2450 /* check if we are in the middle of a binary buddy
2451 * system. this happens when we are performing the
2452 * first allocation out of an allocation group that
2453 * is part (not the first part) of a larger binary
2454 * buddy system. if we are in the middle, back split
2455 * the system prior to calling dbSplit() which assumes
2456 * that it is at the front of a binary buddy system.
2457 */
2458 if (oldval == NOFREE) {
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002459 rc = dbBackSplit((dmtree_t *) dcp, leafno);
2460 if (rc)
2461 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002462 oldval = dcp->stree[ti];
2463 }
2464 dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval);
2465 } else {
Dave Kleikamp56d12542005-07-15 09:43:36 -05002466 rc = dbJoin((dmtree_t *) dcp, leafno, newval);
2467 if (rc)
2468 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002469 }
2470
2471 /* check if the root of the current dmap control page changed due
2472 * to the update and if the current dmap control page is not at
2473 * the current top level (i.e. L0, L1, L2) of the map. if so (i.e.
2474 * root changed and this is not the top level), call this routine
2475 * again (recursion) for the next higher level of the mapping to
2476 * reflect the change in root for the current dmap control page.
2477 */
2478 if (dcp->stree[ROOT] != oldroot) {
2479 /* are we below the top level of the map. if so,
2480 * bubble the root up to the next higher level.
2481 */
2482 if (level < bmp->db_maxlevel) {
2483 /* bubble up the new root of this dmap control page to
2484 * the next level.
2485 */
2486 if ((rc =
2487 dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc,
2488 level + 1))) {
2489 /* something went wrong in bubbling up the new
2490 * root value, so backout the changes to the
2491 * current dmap control page.
2492 */
2493 if (alloc) {
2494 dbJoin((dmtree_t *) dcp, leafno,
2495 oldval);
2496 } else {
2497 /* the dbJoin() above might have
2498 * caused a larger binary buddy system
2499 * to form and we may now be in the
2500 * middle of it. if this is the case,
2501 * back split the buddies.
2502 */
2503 if (dcp->stree[ti] == NOFREE)
2504 dbBackSplit((dmtree_t *)
2505 dcp, leafno);
2506 dbSplit((dmtree_t *) dcp, leafno,
2507 dcp->budmin, oldval);
2508 }
2509
2510 /* release the buffer and return the error.
2511 */
2512 release_metapage(mp);
2513 return (rc);
2514 }
2515 } else {
2516 /* we're at the top level of the map. update
2517 * the bmap control page to reflect the size
2518 * of the maximum free buddy system.
2519 */
2520 assert(level == bmp->db_maxlevel);
2521 if (bmp->db_maxfreebud != oldroot) {
2522 jfs_error(bmp->db_ipbmap->i_sb,
2523 "dbAdjCtl: the maximum free buddy is "
2524 "not the old root");
2525 }
2526 bmp->db_maxfreebud = dcp->stree[ROOT];
2527 }
2528 }
2529
2530 /* write the buffer.
2531 */
2532 write_metapage(mp);
2533
2534 return (0);
2535}
2536
2537
2538/*
2539 * NAME: dbSplit()
2540 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002541 * FUNCTION: update the leaf of a dmtree with a new value, splitting
Linus Torvalds1da177e2005-04-16 15:20:36 -07002542 * the leaf from the binary buddy system of the dmtree's
2543 * leaves, as required.
2544 *
2545 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002546 * tp - pointer to the tree containing the leaf.
2547 * leafno - the number of the leaf to be updated.
2548 * splitsz - the size the binary buddy system starting at the leaf
Linus Torvalds1da177e2005-04-16 15:20:36 -07002549 * must be split to, specified as the log2 number of blocks.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002550 * newval - the new value for the leaf.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002551 *
2552 * RETURN VALUES: none
2553 *
2554 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2555 */
2556static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval)
2557{
2558 int budsz;
2559 int cursz;
2560 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2561
2562 /* check if the leaf needs to be split.
2563 */
2564 if (leaf[leafno] > tp->dmt_budmin) {
2565 /* the split occurs by cutting the buddy system in half
2566 * at the specified leaf until we reach the specified
2567 * size. pick up the starting split size (current size
2568 * - 1 in l2) and the corresponding buddy size.
2569 */
2570 cursz = leaf[leafno] - 1;
2571 budsz = BUDSIZE(cursz, tp->dmt_budmin);
2572
2573 /* split until we reach the specified size.
2574 */
2575 while (cursz >= splitsz) {
2576 /* update the buddy's leaf with its new value.
2577 */
2578 dbAdjTree(tp, leafno ^ budsz, cursz);
2579
2580 /* on to the next size and buddy.
2581 */
2582 cursz -= 1;
2583 budsz >>= 1;
2584 }
2585 }
2586
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002587 /* adjust the dmap tree to reflect the specified leaf's new
Linus Torvalds1da177e2005-04-16 15:20:36 -07002588 * value.
2589 */
2590 dbAdjTree(tp, leafno, newval);
2591}
2592
2593
2594/*
2595 * NAME: dbBackSplit()
2596 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002597 * FUNCTION: back split the binary buddy system of dmtree leaves
Linus Torvalds1da177e2005-04-16 15:20:36 -07002598 * that hold a specified leaf until the specified leaf
2599 * starts its own binary buddy system.
2600 *
2601 * the allocators typically perform allocations at the start
2602 * of binary buddy systems and dbSplit() is used to accomplish
2603 * any required splits. in some cases, however, allocation
2604 * may occur in the middle of a binary system and requires a
2605 * back split, with the split proceeding out from the middle of
2606 * the system (less efficient) rather than the start of the
2607 * system (more efficient). the cases in which a back split
2608 * is required are rare and are limited to the first allocation
2609 * within an allocation group which is a part (not first part)
2610 * of a larger binary buddy system and a few exception cases
2611 * in which a previous join operation must be backed out.
2612 *
2613 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002614 * tp - pointer to the tree containing the leaf.
2615 * leafno - the number of the leaf to be updated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002616 *
2617 * RETURN VALUES: none
2618 *
2619 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2620 */
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002621static int dbBackSplit(dmtree_t * tp, int leafno)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002622{
2623 int budsz, bud, w, bsz, size;
2624 int cursz;
2625 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2626
2627 /* leaf should be part (not first part) of a binary
2628 * buddy system.
2629 */
2630 assert(leaf[leafno] == NOFREE);
2631
2632 /* the back split is accomplished by iteratively finding the leaf
2633 * that starts the buddy system that contains the specified leaf and
2634 * splitting that system in two. this iteration continues until
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002635 * the specified leaf becomes the start of a buddy system.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002636 *
2637 * determine maximum possible l2 size for the specified leaf.
2638 */
2639 size =
2640 LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs),
2641 tp->dmt_budmin);
2642
2643 /* determine the number of leaves covered by this size. this
2644 * is the buddy size that we will start with as we search for
2645 * the buddy system that contains the specified leaf.
2646 */
2647 budsz = BUDSIZE(size, tp->dmt_budmin);
2648
2649 /* back split.
2650 */
2651 while (leaf[leafno] == NOFREE) {
2652 /* find the leftmost buddy leaf.
2653 */
2654 for (w = leafno, bsz = budsz;; bsz <<= 1,
2655 w = (w < bud) ? w : bud) {
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002656 if (bsz >= le32_to_cpu(tp->dmt_nleafs)) {
2657 jfs_err("JFS: block map error in dbBackSplit");
2658 return -EIO;
2659 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002660
2661 /* determine the buddy.
2662 */
2663 bud = w ^ bsz;
2664
2665 /* check if this buddy is the start of the system.
2666 */
2667 if (leaf[bud] != NOFREE) {
2668 /* split the leaf at the start of the
2669 * system in two.
2670 */
2671 cursz = leaf[bud] - 1;
2672 dbSplit(tp, bud, cursz, cursz);
2673 break;
2674 }
2675 }
2676 }
2677
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002678 if (leaf[leafno] != size) {
2679 jfs_err("JFS: wrong leaf value in dbBackSplit");
2680 return -EIO;
2681 }
2682 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002683}
2684
2685
2686/*
2687 * NAME: dbJoin()
2688 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002689 * FUNCTION: update the leaf of a dmtree with a new value, joining
Linus Torvalds1da177e2005-04-16 15:20:36 -07002690 * the leaf with other leaves of the dmtree into a multi-leaf
2691 * binary buddy system, as required.
2692 *
2693 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002694 * tp - pointer to the tree containing the leaf.
2695 * leafno - the number of the leaf to be updated.
2696 * newval - the new value for the leaf.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002697 *
2698 * RETURN VALUES: none
2699 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002700static int dbJoin(dmtree_t * tp, int leafno, int newval)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002701{
2702 int budsz, buddy;
2703 s8 *leaf;
2704
2705 /* can the new leaf value require a join with other leaves ?
2706 */
2707 if (newval >= tp->dmt_budmin) {
2708 /* pickup a pointer to the leaves of the tree.
2709 */
2710 leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2711
2712 /* try to join the specified leaf into a large binary
2713 * buddy system. the join proceeds by attempting to join
2714 * the specified leafno with its buddy (leaf) at new value.
2715 * if the join occurs, we attempt to join the left leaf
2716 * of the joined buddies with its buddy at new value + 1.
2717 * we continue to join until we find a buddy that cannot be
2718 * joined (does not have a value equal to the size of the
2719 * last join) or until all leaves have been joined into a
2720 * single system.
2721 *
2722 * get the buddy size (number of words covered) of
2723 * the new value.
2724 */
2725 budsz = BUDSIZE(newval, tp->dmt_budmin);
2726
2727 /* try to join.
2728 */
2729 while (budsz < le32_to_cpu(tp->dmt_nleafs)) {
2730 /* get the buddy leaf.
2731 */
2732 buddy = leafno ^ budsz;
2733
2734 /* if the leaf's new value is greater than its
2735 * buddy's value, we join no more.
2736 */
2737 if (newval > leaf[buddy])
2738 break;
2739
Dave Kleikamp56d12542005-07-15 09:43:36 -05002740 /* It shouldn't be less */
2741 if (newval < leaf[buddy])
2742 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002743
2744 /* check which (leafno or buddy) is the left buddy.
2745 * the left buddy gets to claim the blocks resulting
2746 * from the join while the right gets to claim none.
2747 * the left buddy is also eligable to participate in
2748 * a join at the next higher level while the right
2749 * is not.
2750 *
2751 */
2752 if (leafno < buddy) {
2753 /* leafno is the left buddy.
2754 */
2755 dbAdjTree(tp, buddy, NOFREE);
2756 } else {
2757 /* buddy is the left buddy and becomes
2758 * leafno.
2759 */
2760 dbAdjTree(tp, leafno, NOFREE);
2761 leafno = buddy;
2762 }
2763
2764 /* on to try the next join.
2765 */
2766 newval += 1;
2767 budsz <<= 1;
2768 }
2769 }
2770
2771 /* update the leaf value.
2772 */
2773 dbAdjTree(tp, leafno, newval);
Dave Kleikamp56d12542005-07-15 09:43:36 -05002774
2775 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002776}
2777
2778
2779/*
2780 * NAME: dbAdjTree()
2781 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002782 * FUNCTION: update a leaf of a dmtree with a new value, adjusting
Linus Torvalds1da177e2005-04-16 15:20:36 -07002783 * the dmtree, as required, to reflect the new leaf value.
2784 * the combination of any buddies must already be done before
2785 * this is called.
2786 *
2787 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002788 * tp - pointer to the tree to be adjusted.
2789 * leafno - the number of the leaf to be updated.
2790 * newval - the new value for the leaf.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002791 *
2792 * RETURN VALUES: none
2793 */
2794static void dbAdjTree(dmtree_t * tp, int leafno, int newval)
2795{
2796 int lp, pp, k;
2797 int max;
2798
2799 /* pick up the index of the leaf for this leafno.
2800 */
2801 lp = leafno + le32_to_cpu(tp->dmt_leafidx);
2802
2803 /* is the current value the same as the old value ? if so,
2804 * there is nothing to do.
2805 */
2806 if (tp->dmt_stree[lp] == newval)
2807 return;
2808
2809 /* set the new value.
2810 */
2811 tp->dmt_stree[lp] = newval;
2812
2813 /* bubble the new value up the tree as required.
2814 */
2815 for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) {
2816 /* get the index of the first leaf of the 4 leaf
2817 * group containing the specified leaf (leafno).
2818 */
2819 lp = ((lp - 1) & ~0x03) + 1;
2820
2821 /* get the index of the parent of this 4 leaf group.
2822 */
2823 pp = (lp - 1) >> 2;
2824
2825 /* determine the maximum of the 4 leaves.
2826 */
2827 max = TREEMAX(&tp->dmt_stree[lp]);
2828
2829 /* if the maximum of the 4 is the same as the
2830 * parent's value, we're done.
2831 */
2832 if (tp->dmt_stree[pp] == max)
2833 break;
2834
2835 /* parent gets new value.
2836 */
2837 tp->dmt_stree[pp] = max;
2838
2839 /* parent becomes leaf for next go-round.
2840 */
2841 lp = pp;
2842 }
2843}
2844
2845
2846/*
2847 * NAME: dbFindLeaf()
2848 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002849 * FUNCTION: search a dmtree_t for sufficient free blocks, returning
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002850 * the index of a leaf describing the free blocks if
Linus Torvalds1da177e2005-04-16 15:20:36 -07002851 * sufficient free blocks are found.
2852 *
2853 * the search starts at the top of the dmtree_t tree and
2854 * proceeds down the tree to the leftmost leaf with sufficient
2855 * free space.
2856 *
2857 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002858 * tp - pointer to the tree to be searched.
2859 * l2nb - log2 number of free blocks to search for.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002860 * leafidx - return pointer to be set to the index of the leaf
2861 * describing at least l2nb free blocks if sufficient
2862 * free blocks are found.
2863 *
2864 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002865 * 0 - success
2866 * -ENOSPC - insufficient free blocks.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002867 */
2868static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx)
2869{
2870 int ti, n = 0, k, x = 0;
2871
2872 /* first check the root of the tree to see if there is
2873 * sufficient free space.
2874 */
2875 if (l2nb > tp->dmt_stree[ROOT])
2876 return -ENOSPC;
2877
2878 /* sufficient free space available. now search down the tree
2879 * starting at the next level for the leftmost leaf that
2880 * describes sufficient free space.
2881 */
2882 for (k = le32_to_cpu(tp->dmt_height), ti = 1;
2883 k > 0; k--, ti = ((ti + n) << 2) + 1) {
2884 /* search the four nodes at this level, starting from
2885 * the left.
2886 */
2887 for (x = ti, n = 0; n < 4; n++) {
2888 /* sufficient free space found. move to the next
2889 * level (or quit if this is the last level).
2890 */
2891 if (l2nb <= tp->dmt_stree[x + n])
2892 break;
2893 }
2894
2895 /* better have found something since the higher
2896 * levels of the tree said it was here.
2897 */
2898 assert(n < 4);
2899 }
2900
2901 /* set the return to the leftmost leaf describing sufficient
2902 * free space.
2903 */
2904 *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx);
2905
2906 return (0);
2907}
2908
2909
2910/*
2911 * NAME: dbFindBits()
2912 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002913 * FUNCTION: find a specified number of binary buddy free bits within a
Linus Torvalds1da177e2005-04-16 15:20:36 -07002914 * dmap bitmap word value.
2915 *
2916 * this routine searches the bitmap value for (1 << l2nb) free
2917 * bits at (1 << l2nb) alignments within the value.
2918 *
2919 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002920 * word - dmap bitmap word value.
2921 * l2nb - number of free bits specified as a log2 number.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002922 *
2923 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002924 * starting bit number of free bits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002925 */
2926static int dbFindBits(u32 word, int l2nb)
2927{
2928 int bitno, nb;
2929 u32 mask;
2930
2931 /* get the number of bits.
2932 */
2933 nb = 1 << l2nb;
2934 assert(nb <= DBWORD);
2935
2936 /* complement the word so we can use a mask (i.e. 0s represent
2937 * free bits) and compute the mask.
2938 */
2939 word = ~word;
2940 mask = ONES << (DBWORD - nb);
2941
2942 /* scan the word for nb free bits at nb alignments.
2943 */
2944 for (bitno = 0; mask != 0; bitno += nb, mask >>= nb) {
2945 if ((mask & word) == mask)
2946 break;
2947 }
2948
2949 ASSERT(bitno < 32);
2950
2951 /* return the bit number.
2952 */
2953 return (bitno);
2954}
2955
2956
2957/*
2958 * NAME: dbMaxBud(u8 *cp)
2959 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002960 * FUNCTION: determine the largest binary buddy string of free
Linus Torvalds1da177e2005-04-16 15:20:36 -07002961 * bits within 32-bits of the map.
2962 *
2963 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002964 * cp - pointer to the 32-bit value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002965 *
2966 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002967 * largest binary buddy of free bits within a dmap word.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002968 */
2969static int dbMaxBud(u8 * cp)
2970{
2971 signed char tmp1, tmp2;
2972
2973 /* check if the wmap word is all free. if so, the
2974 * free buddy size is BUDMIN.
2975 */
2976 if (*((uint *) cp) == 0)
2977 return (BUDMIN);
2978
2979 /* check if the wmap word is half free. if so, the
2980 * free buddy size is BUDMIN-1.
2981 */
2982 if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0)
2983 return (BUDMIN - 1);
2984
2985 /* not all free or half free. determine the free buddy
2986 * size thru table lookup using quarters of the wmap word.
2987 */
2988 tmp1 = max(budtab[cp[2]], budtab[cp[3]]);
2989 tmp2 = max(budtab[cp[0]], budtab[cp[1]]);
2990 return (max(tmp1, tmp2));
2991}
2992
2993
2994/*
2995 * NAME: cnttz(uint word)
2996 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002997 * FUNCTION: determine the number of trailing zeros within a 32-bit
Linus Torvalds1da177e2005-04-16 15:20:36 -07002998 * value.
2999 *
3000 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003001 * value - 32-bit value to be examined.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003002 *
3003 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003004 * count of trailing zeros
Linus Torvalds1da177e2005-04-16 15:20:36 -07003005 */
3006static int cnttz(u32 word)
3007{
3008 int n;
3009
3010 for (n = 0; n < 32; n++, word >>= 1) {
3011 if (word & 0x01)
3012 break;
3013 }
3014
3015 return (n);
3016}
3017
3018
3019/*
3020 * NAME: cntlz(u32 value)
3021 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003022 * FUNCTION: determine the number of leading zeros within a 32-bit
Linus Torvalds1da177e2005-04-16 15:20:36 -07003023 * value.
3024 *
3025 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003026 * value - 32-bit value to be examined.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003027 *
3028 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003029 * count of leading zeros
Linus Torvalds1da177e2005-04-16 15:20:36 -07003030 */
3031static int cntlz(u32 value)
3032{
3033 int n;
3034
3035 for (n = 0; n < 32; n++, value <<= 1) {
3036 if (value & HIGHORDER)
3037 break;
3038 }
3039 return (n);
3040}
3041
3042
3043/*
3044 * NAME: blkstol2(s64 nb)
3045 *
3046 * FUNCTION: convert a block count to its log2 value. if the block
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003047 * count is not a l2 multiple, it is rounded up to the next
Linus Torvalds1da177e2005-04-16 15:20:36 -07003048 * larger l2 multiple.
3049 *
3050 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003051 * nb - number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003052 *
3053 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003054 * log2 number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003055 */
Dave Kleikamp6cb12692005-09-15 23:25:41 -05003056static int blkstol2(s64 nb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003057{
3058 int l2nb;
3059 s64 mask; /* meant to be signed */
3060
3061 mask = (s64) 1 << (64 - 1);
3062
3063 /* count the leading bits.
3064 */
3065 for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) {
3066 /* leading bit found.
3067 */
3068 if (nb & mask) {
3069 /* determine the l2 value.
3070 */
3071 l2nb = (64 - 1) - l2nb;
3072
3073 /* check if we need to round up.
3074 */
3075 if (~mask & nb)
3076 l2nb++;
3077
3078 return (l2nb);
3079 }
3080 }
3081 assert(0);
3082 return 0; /* fix compiler warning */
3083}
3084
3085
3086/*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003087 * NAME: dbAllocBottomUp()
Linus Torvalds1da177e2005-04-16 15:20:36 -07003088 *
3089 * FUNCTION: alloc the specified block range from the working block
3090 * allocation map.
3091 *
3092 * the blocks will be alloc from the working map one dmap
3093 * at a time.
3094 *
3095 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003096 * ip - pointer to in-core inode;
3097 * blkno - starting block number to be freed.
3098 * nblocks - number of blocks to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003099 *
3100 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003101 * 0 - success
3102 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07003103 */
3104int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks)
3105{
3106 struct metapage *mp;
3107 struct dmap *dp;
3108 int nb, rc;
3109 s64 lblkno, rem;
3110 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
3111 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
3112
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -06003113 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003114
3115 /* block to be allocated better be within the mapsize. */
3116 ASSERT(nblocks <= bmp->db_mapsize - blkno);
3117
3118 /*
3119 * allocate the blocks a dmap at a time.
3120 */
3121 mp = NULL;
3122 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
3123 /* release previous dmap if any */
3124 if (mp) {
3125 write_metapage(mp);
3126 }
3127
3128 /* get the buffer for the current dmap. */
3129 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
3130 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
3131 if (mp == NULL) {
3132 IREAD_UNLOCK(ipbmap);
3133 return -EIO;
3134 }
3135 dp = (struct dmap *) mp->data;
3136
3137 /* determine the number of blocks to be allocated from
3138 * this dmap.
3139 */
3140 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
3141
Linus Torvalds1da177e2005-04-16 15:20:36 -07003142 /* allocate the blocks. */
3143 if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) {
3144 release_metapage(mp);
3145 IREAD_UNLOCK(ipbmap);
3146 return (rc);
3147 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003148 }
3149
3150 /* write the last buffer. */
3151 write_metapage(mp);
3152
3153 IREAD_UNLOCK(ipbmap);
3154
3155 return (0);
3156}
3157
3158
3159static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno,
3160 int nblocks)
3161{
3162 int rc;
3163 int dbitno, word, rembits, nb, nwords, wbitno, agno;
3164 s8 oldroot, *leaf;
3165 struct dmaptree *tp = (struct dmaptree *) & dp->tree;
3166
3167 /* save the current value of the root (i.e. maximum free string)
3168 * of the dmap tree.
3169 */
3170 oldroot = tp->stree[ROOT];
3171
3172 /* pick up a pointer to the leaves of the dmap tree */
3173 leaf = tp->stree + LEAFIND;
3174
3175 /* determine the bit number and word within the dmap of the
3176 * starting block.
3177 */
3178 dbitno = blkno & (BPERDMAP - 1);
3179 word = dbitno >> L2DBWORD;
3180
3181 /* block range better be within the dmap */
3182 assert(dbitno + nblocks <= BPERDMAP);
3183
3184 /* allocate the bits of the dmap's words corresponding to the block
3185 * range. not all bits of the first and last words may be contained
3186 * within the block range. if this is the case, we'll work against
3187 * those words (i.e. partial first and/or last) on an individual basis
3188 * (a single pass), allocating the bits of interest by hand and
3189 * updating the leaf corresponding to the dmap word. a single pass
3190 * will be used for all dmap words fully contained within the
3191 * specified range. within this pass, the bits of all fully contained
3192 * dmap words will be marked as free in a single shot and the leaves
3193 * will be updated. a single leaf may describe the free space of
3194 * multiple dmap words, so we may update only a subset of the actual
3195 * leaves corresponding to the dmap words of the block range.
3196 */
3197 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
3198 /* determine the bit number within the word and
3199 * the number of bits within the word.
3200 */
3201 wbitno = dbitno & (DBWORD - 1);
3202 nb = min(rembits, DBWORD - wbitno);
3203
3204 /* check if only part of a word is to be allocated.
3205 */
3206 if (nb < DBWORD) {
3207 /* allocate (set to 1) the appropriate bits within
3208 * this dmap word.
3209 */
3210 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
3211 >> wbitno);
3212
3213 word++;
3214 } else {
3215 /* one or more dmap words are fully contained
3216 * within the block range. determine how many
3217 * words and allocate (set to 1) the bits of these
3218 * words.
3219 */
3220 nwords = rembits >> L2DBWORD;
3221 memset(&dp->wmap[word], (int) ONES, nwords * 4);
3222
3223 /* determine how many bits */
3224 nb = nwords << L2DBWORD;
3225 word += nwords;
3226 }
3227 }
3228
3229 /* update the free count for this dmap */
Marcin Slusarz89145622008-02-13 15:34:20 -06003230 le32_add_cpu(&dp->nfree, -nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003231
3232 /* reconstruct summary tree */
3233 dbInitDmapTree(dp);
3234
3235 BMAP_LOCK(bmp);
3236
3237 /* if this allocation group is completely free,
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003238 * update the highest active allocation group number
Linus Torvalds1da177e2005-04-16 15:20:36 -07003239 * if this allocation group is the new max.
3240 */
3241 agno = blkno >> bmp->db_agl2size;
3242 if (agno > bmp->db_maxag)
3243 bmp->db_maxag = agno;
3244
3245 /* update the free count for the allocation group and map */
3246 bmp->db_agfree[agno] -= nblocks;
3247 bmp->db_nfree -= nblocks;
3248
3249 BMAP_UNLOCK(bmp);
3250
3251 /* if the root has not changed, done. */
3252 if (tp->stree[ROOT] == oldroot)
3253 return (0);
3254
3255 /* root changed. bubble the change up to the dmap control pages.
3256 * if the adjustment of the upper level control pages fails,
3257 * backout the bit allocation (thus making everything consistent).
3258 */
3259 if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0)))
3260 dbFreeBits(bmp, dp, blkno, nblocks);
3261
3262 return (rc);
3263}
3264
3265
3266/*
3267 * NAME: dbExtendFS()
3268 *
3269 * FUNCTION: extend bmap from blkno for nblocks;
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003270 * dbExtendFS() updates bmap ready for dbAllocBottomUp();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003271 *
3272 * L2
3273 * |
3274 * L1---------------------------------L1
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003275 * | |
3276 * L0---------L0---------L0 L0---------L0---------L0
3277 * | | | | | |
3278 * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003279 * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm
3280 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003281 * <---old---><----------------------------extend----------------------->
Linus Torvalds1da177e2005-04-16 15:20:36 -07003282 */
3283int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks)
3284{
3285 struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb);
3286 int nbperpage = sbi->nbperpage;
Richard Knutsson4d817152006-09-30 23:27:14 -07003287 int i, i0 = true, j, j0 = true, k, n;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003288 s64 newsize;
3289 s64 p;
3290 struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL;
3291 struct dmapctl *l2dcp, *l1dcp, *l0dcp;
3292 struct dmap *dp;
3293 s8 *l0leaf, *l1leaf, *l2leaf;
3294 struct bmap *bmp = sbi->bmap;
3295 int agno, l2agsize, oldl2agsize;
3296 s64 ag_rem;
3297
3298 newsize = blkno + nblocks;
3299
3300 jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld",
3301 (long long) blkno, (long long) nblocks, (long long) newsize);
3302
3303 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003304 * initialize bmap control page.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003305 *
3306 * all the data in bmap control page should exclude
3307 * the mkfs hidden dmap page.
3308 */
3309
3310 /* update mapsize */
3311 bmp->db_mapsize = newsize;
3312 bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize);
3313
3314 /* compute new AG size */
3315 l2agsize = dbGetL2AGSize(newsize);
3316 oldl2agsize = bmp->db_agl2size;
3317
3318 bmp->db_agl2size = l2agsize;
3319 bmp->db_agsize = 1 << l2agsize;
3320
3321 /* compute new number of AG */
3322 agno = bmp->db_numag;
3323 bmp->db_numag = newsize >> l2agsize;
3324 bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0;
3325
3326 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003327 * reconfigure db_agfree[]
Linus Torvalds1da177e2005-04-16 15:20:36 -07003328 * from old AG configuration to new AG configuration;
3329 *
3330 * coalesce contiguous k (newAGSize/oldAGSize) AGs;
3331 * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn;
3332 * note: new AG size = old AG size * (2**x).
3333 */
3334 if (l2agsize == oldl2agsize)
3335 goto extend;
3336 k = 1 << (l2agsize - oldl2agsize);
3337 ag_rem = bmp->db_agfree[0]; /* save agfree[0] */
3338 for (i = 0, n = 0; i < agno; n++) {
3339 bmp->db_agfree[n] = 0; /* init collection point */
3340
André Goddard Rosaaf901ca2009-11-14 13:09:05 -02003341 /* coalesce contiguous k AGs; */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003342 for (j = 0; j < k && i < agno; j++, i++) {
3343 /* merge AGi to AGn */
3344 bmp->db_agfree[n] += bmp->db_agfree[i];
3345 }
3346 }
3347 bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */
3348
3349 for (; n < MAXAG; n++)
3350 bmp->db_agfree[n] = 0;
3351
3352 /*
3353 * update highest active ag number
3354 */
3355
3356 bmp->db_maxag = bmp->db_maxag / k;
3357
3358 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003359 * extend bmap
Linus Torvalds1da177e2005-04-16 15:20:36 -07003360 *
3361 * update bit maps and corresponding level control pages;
3362 * global control page db_nfree, db_agfree[agno], db_maxfreebud;
3363 */
3364 extend:
3365 /* get L2 page */
3366 p = BMAPBLKNO + nbperpage; /* L2 page */
3367 l2mp = read_metapage(ipbmap, p, PSIZE, 0);
3368 if (!l2mp) {
3369 jfs_error(ipbmap->i_sb, "dbExtendFS: L2 page could not be read");
3370 return -EIO;
3371 }
3372 l2dcp = (struct dmapctl *) l2mp->data;
3373
3374 /* compute start L1 */
3375 k = blkno >> L2MAXL1SIZE;
3376 l2leaf = l2dcp->stree + CTLLEAFIND + k;
3377 p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */
3378
3379 /*
3380 * extend each L1 in L2
3381 */
3382 for (; k < LPERCTL; k++, p += nbperpage) {
3383 /* get L1 page */
3384 if (j0) {
3385 /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */
3386 l1mp = read_metapage(ipbmap, p, PSIZE, 0);
3387 if (l1mp == NULL)
3388 goto errout;
3389 l1dcp = (struct dmapctl *) l1mp->data;
3390
3391 /* compute start L0 */
3392 j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE;
3393 l1leaf = l1dcp->stree + CTLLEAFIND + j;
3394 p = BLKTOL0(blkno, sbi->l2nbperpage);
Richard Knutsson4d817152006-09-30 23:27:14 -07003395 j0 = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003396 } else {
3397 /* assign/init L1 page */
3398 l1mp = get_metapage(ipbmap, p, PSIZE, 0);
3399 if (l1mp == NULL)
3400 goto errout;
3401
3402 l1dcp = (struct dmapctl *) l1mp->data;
3403
3404 /* compute start L0 */
3405 j = 0;
3406 l1leaf = l1dcp->stree + CTLLEAFIND;
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003407 p += nbperpage; /* 1st L0 of L1.k */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003408 }
3409
3410 /*
3411 * extend each L0 in L1
3412 */
3413 for (; j < LPERCTL; j++) {
3414 /* get L0 page */
3415 if (i0) {
3416 /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */
3417
3418 l0mp = read_metapage(ipbmap, p, PSIZE, 0);
3419 if (l0mp == NULL)
3420 goto errout;
3421 l0dcp = (struct dmapctl *) l0mp->data;
3422
3423 /* compute start dmap */
3424 i = (blkno & (MAXL0SIZE - 1)) >>
3425 L2BPERDMAP;
3426 l0leaf = l0dcp->stree + CTLLEAFIND + i;
3427 p = BLKTODMAP(blkno,
3428 sbi->l2nbperpage);
Richard Knutsson4d817152006-09-30 23:27:14 -07003429 i0 = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003430 } else {
3431 /* assign/init L0 page */
3432 l0mp = get_metapage(ipbmap, p, PSIZE, 0);
3433 if (l0mp == NULL)
3434 goto errout;
3435
3436 l0dcp = (struct dmapctl *) l0mp->data;
3437
3438 /* compute start dmap */
3439 i = 0;
3440 l0leaf = l0dcp->stree + CTLLEAFIND;
3441 p += nbperpage; /* 1st dmap of L0.j */
3442 }
3443
3444 /*
3445 * extend each dmap in L0
3446 */
3447 for (; i < LPERCTL; i++) {
3448 /*
3449 * reconstruct the dmap page, and
3450 * initialize corresponding parent L0 leaf
3451 */
3452 if ((n = blkno & (BPERDMAP - 1))) {
3453 /* read in dmap page: */
3454 mp = read_metapage(ipbmap, p,
3455 PSIZE, 0);
3456 if (mp == NULL)
3457 goto errout;
3458 n = min(nblocks, (s64)BPERDMAP - n);
3459 } else {
3460 /* assign/init dmap page */
3461 mp = read_metapage(ipbmap, p,
3462 PSIZE, 0);
3463 if (mp == NULL)
3464 goto errout;
3465
3466 n = min(nblocks, (s64)BPERDMAP);
3467 }
3468
3469 dp = (struct dmap *) mp->data;
3470 *l0leaf = dbInitDmap(dp, blkno, n);
3471
3472 bmp->db_nfree += n;
3473 agno = le64_to_cpu(dp->start) >> l2agsize;
3474 bmp->db_agfree[agno] += n;
3475
3476 write_metapage(mp);
3477
3478 l0leaf++;
3479 p += nbperpage;
3480
3481 blkno += n;
3482 nblocks -= n;
3483 if (nblocks == 0)
3484 break;
3485 } /* for each dmap in a L0 */
3486
3487 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003488 * build current L0 page from its leaves, and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003489 * initialize corresponding parent L1 leaf
3490 */
3491 *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i);
3492 write_metapage(l0mp);
3493 l0mp = NULL;
3494
3495 if (nblocks)
3496 l1leaf++; /* continue for next L0 */
3497 else {
3498 /* more than 1 L0 ? */
3499 if (j > 0)
3500 break; /* build L1 page */
3501 else {
3502 /* summarize in global bmap page */
3503 bmp->db_maxfreebud = *l1leaf;
3504 release_metapage(l1mp);
3505 release_metapage(l2mp);
3506 goto finalize;
3507 }
3508 }
3509 } /* for each L0 in a L1 */
3510
3511 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003512 * build current L1 page from its leaves, and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003513 * initialize corresponding parent L2 leaf
3514 */
3515 *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j);
3516 write_metapage(l1mp);
3517 l1mp = NULL;
3518
3519 if (nblocks)
3520 l2leaf++; /* continue for next L1 */
3521 else {
3522 /* more than 1 L1 ? */
3523 if (k > 0)
3524 break; /* build L2 page */
3525 else {
3526 /* summarize in global bmap page */
3527 bmp->db_maxfreebud = *l2leaf;
3528 release_metapage(l2mp);
3529 goto finalize;
3530 }
3531 }
3532 } /* for each L1 in a L2 */
3533
3534 jfs_error(ipbmap->i_sb,
3535 "dbExtendFS: function has not returned as expected");
3536errout:
3537 if (l0mp)
3538 release_metapage(l0mp);
3539 if (l1mp)
3540 release_metapage(l1mp);
3541 release_metapage(l2mp);
3542 return -EIO;
3543
3544 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003545 * finalize bmap control page
Linus Torvalds1da177e2005-04-16 15:20:36 -07003546 */
3547finalize:
3548
3549 return 0;
3550}
3551
3552
3553/*
3554 * dbFinalizeBmap()
3555 */
3556void dbFinalizeBmap(struct inode *ipbmap)
3557{
3558 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
3559 int actags, inactags, l2nl;
3560 s64 ag_rem, actfree, inactfree, avgfree;
3561 int i, n;
3562
3563 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003564 * finalize bmap control page
Linus Torvalds1da177e2005-04-16 15:20:36 -07003565 */
3566//finalize:
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003567 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003568 * compute db_agpref: preferred ag to allocate from
3569 * (the leftmost ag with average free space in it);
3570 */
3571//agpref:
3572 /* get the number of active ags and inacitve ags */
3573 actags = bmp->db_maxag + 1;
3574 inactags = bmp->db_numag - actags;
3575 ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */
3576
3577 /* determine how many blocks are in the inactive allocation
3578 * groups. in doing this, we must account for the fact that
3579 * the rightmost group might be a partial group (i.e. file
3580 * system size is not a multiple of the group size).
3581 */
3582 inactfree = (inactags && ag_rem) ?
3583 ((inactags - 1) << bmp->db_agl2size) + ag_rem
3584 : inactags << bmp->db_agl2size;
3585
3586 /* determine how many free blocks are in the active
3587 * allocation groups plus the average number of free blocks
3588 * within the active ags.
3589 */
3590 actfree = bmp->db_nfree - inactfree;
3591 avgfree = (u32) actfree / (u32) actags;
3592
3593 /* if the preferred allocation group has not average free space.
3594 * re-establish the preferred group as the leftmost
3595 * group with average free space.
3596 */
3597 if (bmp->db_agfree[bmp->db_agpref] < avgfree) {
3598 for (bmp->db_agpref = 0; bmp->db_agpref < actags;
3599 bmp->db_agpref++) {
3600 if (bmp->db_agfree[bmp->db_agpref] >= avgfree)
3601 break;
3602 }
3603 if (bmp->db_agpref >= bmp->db_numag) {
3604 jfs_error(ipbmap->i_sb,
3605 "cannot find ag with average freespace");
3606 }
3607 }
3608
3609 /*
Daniel Mackd7eecb42010-01-28 16:13:01 +08003610 * compute db_aglevel, db_agheight, db_width, db_agstart:
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003611 * an ag is covered in aglevel dmapctl summary tree,
3612 * at agheight level height (from leaf) with agwidth number of nodes
3613 * each, which starts at agstart index node of the smmary tree node
Linus Torvalds1da177e2005-04-16 15:20:36 -07003614 * array;
3615 */
3616 bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize);
3617 l2nl =
3618 bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL);
Daniel Mackd7eecb42010-01-28 16:13:01 +08003619 bmp->db_agheight = l2nl >> 1;
3620 bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheight << 1));
3621 for (i = 5 - bmp->db_agheight, bmp->db_agstart = 0, n = 1; i > 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003622 i--) {
3623 bmp->db_agstart += n;
3624 n <<= 2;
3625 }
3626
3627}
3628
3629
3630/*
3631 * NAME: dbInitDmap()/ujfs_idmap_page()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003632 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003633 * FUNCTION: initialize working/persistent bitmap of the dmap page
3634 * for the specified number of blocks:
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003635 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003636 * at entry, the bitmaps had been initialized as free (ZEROS);
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003637 * The number of blocks will only account for the actually
3638 * existing blocks. Blocks which don't actually exist in
Linus Torvalds1da177e2005-04-16 15:20:36 -07003639 * the aggregate will be marked as allocated (ONES);
3640 *
3641 * PARAMETERS:
3642 * dp - pointer to page of map
3643 * nblocks - number of blocks this page
3644 *
3645 * RETURNS: NONE
3646 */
3647static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks)
3648{
3649 int blkno, w, b, r, nw, nb, i;
3650
3651 /* starting block number within the dmap */
3652 blkno = Blkno & (BPERDMAP - 1);
3653
3654 if (blkno == 0) {
3655 dp->nblocks = dp->nfree = cpu_to_le32(nblocks);
3656 dp->start = cpu_to_le64(Blkno);
3657
3658 if (nblocks == BPERDMAP) {
3659 memset(&dp->wmap[0], 0, LPERDMAP * 4);
3660 memset(&dp->pmap[0], 0, LPERDMAP * 4);
3661 goto initTree;
3662 }
3663 } else {
Marcin Slusarz89145622008-02-13 15:34:20 -06003664 le32_add_cpu(&dp->nblocks, nblocks);
3665 le32_add_cpu(&dp->nfree, nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003666 }
3667
3668 /* word number containing start block number */
3669 w = blkno >> L2DBWORD;
3670
3671 /*
3672 * free the bits corresponding to the block range (ZEROS):
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003673 * note: not all bits of the first and last words may be contained
Linus Torvalds1da177e2005-04-16 15:20:36 -07003674 * within the block range.
3675 */
3676 for (r = nblocks; r > 0; r -= nb, blkno += nb) {
3677 /* number of bits preceding range to be freed in the word */
3678 b = blkno & (DBWORD - 1);
3679 /* number of bits to free in the word */
3680 nb = min(r, DBWORD - b);
3681
3682 /* is partial word to be freed ? */
3683 if (nb < DBWORD) {
3684 /* free (set to 0) from the bitmap word */
3685 dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3686 >> b));
3687 dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3688 >> b));
3689
3690 /* skip the word freed */
3691 w++;
3692 } else {
3693 /* free (set to 0) contiguous bitmap words */
3694 nw = r >> L2DBWORD;
3695 memset(&dp->wmap[w], 0, nw * 4);
3696 memset(&dp->pmap[w], 0, nw * 4);
3697
3698 /* skip the words freed */
3699 nb = nw << L2DBWORD;
3700 w += nw;
3701 }
3702 }
3703
3704 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003705 * mark bits following the range to be freed (non-existing
Linus Torvalds1da177e2005-04-16 15:20:36 -07003706 * blocks) as allocated (ONES)
3707 */
3708
3709 if (blkno == BPERDMAP)
3710 goto initTree;
3711
3712 /* the first word beyond the end of existing blocks */
3713 w = blkno >> L2DBWORD;
3714
3715 /* does nblocks fall on a 32-bit boundary ? */
3716 b = blkno & (DBWORD - 1);
3717 if (b) {
3718 /* mark a partial word allocated */
3719 dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b);
3720 w++;
3721 }
3722
3723 /* set the rest of the words in the page to allocated (ONES) */
3724 for (i = w; i < LPERDMAP; i++)
3725 dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES);
3726
3727 /*
3728 * init tree
3729 */
3730 initTree:
3731 return (dbInitDmapTree(dp));
3732}
3733
3734
3735/*
3736 * NAME: dbInitDmapTree()/ujfs_complete_dmap()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003737 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003738 * FUNCTION: initialize summary tree of the specified dmap:
3739 *
3740 * at entry, bitmap of the dmap has been initialized;
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003741 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003742 * PARAMETERS:
3743 * dp - dmap to complete
3744 * blkno - starting block number for this dmap
3745 * treemax - will be filled in with max free for this dmap
3746 *
3747 * RETURNS: max free string at the root of the tree
3748 */
3749static int dbInitDmapTree(struct dmap * dp)
3750{
3751 struct dmaptree *tp;
3752 s8 *cp;
3753 int i;
3754
3755 /* init fixed info of tree */
3756 tp = &dp->tree;
3757 tp->nleafs = cpu_to_le32(LPERDMAP);
3758 tp->l2nleafs = cpu_to_le32(L2LPERDMAP);
3759 tp->leafidx = cpu_to_le32(LEAFIND);
3760 tp->height = cpu_to_le32(4);
3761 tp->budmin = BUDMIN;
3762
3763 /* init each leaf from corresponding wmap word:
3764 * note: leaf is set to NOFREE(-1) if all blocks of corresponding
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003765 * bitmap word are allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003766 */
3767 cp = tp->stree + le32_to_cpu(tp->leafidx);
3768 for (i = 0; i < LPERDMAP; i++)
3769 *cp++ = dbMaxBud((u8 *) & dp->wmap[i]);
3770
3771 /* build the dmap's binary buddy summary tree */
3772 return (dbInitTree(tp));
3773}
3774
3775
3776/*
3777 * NAME: dbInitTree()/ujfs_adjtree()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003778 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003779 * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl.
3780 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003781 * at entry, the leaves of the tree has been initialized
Linus Torvalds1da177e2005-04-16 15:20:36 -07003782 * from corresponding bitmap word or root of summary tree
3783 * of the child control page;
3784 * configure binary buddy system at the leaf level, then
3785 * bubble up the values of the leaf nodes up the tree.
3786 *
3787 * PARAMETERS:
3788 * cp - Pointer to the root of the tree
3789 * l2leaves- Number of leaf nodes as a power of 2
3790 * l2min - Number of blocks that can be covered by a leaf
3791 * as a power of 2
3792 *
3793 * RETURNS: max free string at the root of the tree
3794 */
3795static int dbInitTree(struct dmaptree * dtp)
3796{
3797 int l2max, l2free, bsize, nextb, i;
3798 int child, parent, nparent;
3799 s8 *tp, *cp, *cp1;
3800
3801 tp = dtp->stree;
3802
3803 /* Determine the maximum free string possible for the leaves */
3804 l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin;
3805
3806 /*
3807 * configure the leaf levevl into binary buddy system
3808 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003809 * Try to combine buddies starting with a buddy size of 1
3810 * (i.e. two leaves). At a buddy size of 1 two buddy leaves
3811 * can be combined if both buddies have a maximum free of l2min;
3812 * the combination will result in the left-most buddy leaf having
3813 * a maximum free of l2min+1.
3814 * After processing all buddies for a given size, process buddies
3815 * at the next higher buddy size (i.e. current size * 2) and
3816 * the next maximum free (current free + 1).
3817 * This continues until the maximum possible buddy combination
Linus Torvalds1da177e2005-04-16 15:20:36 -07003818 * yields maximum free.
3819 */
3820 for (l2free = dtp->budmin, bsize = 1; l2free < l2max;
3821 l2free++, bsize = nextb) {
3822 /* get next buddy size == current buddy pair size */
3823 nextb = bsize << 1;
3824
3825 /* scan each adjacent buddy pair at current buddy size */
3826 for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx);
3827 i < le32_to_cpu(dtp->nleafs);
3828 i += nextb, cp += nextb) {
3829 /* coalesce if both adjacent buddies are max free */
3830 if (*cp == l2free && *(cp + bsize) == l2free) {
3831 *cp = l2free + 1; /* left take right */
3832 *(cp + bsize) = -1; /* right give left */
3833 }
3834 }
3835 }
3836
3837 /*
3838 * bubble summary information of leaves up the tree.
3839 *
3840 * Starting at the leaf node level, the four nodes described by
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003841 * the higher level parent node are compared for a maximum free and
3842 * this maximum becomes the value of the parent node.
3843 * when all lower level nodes are processed in this fashion then
3844 * move up to the next level (parent becomes a lower level node) and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003845 * continue the process for that level.
3846 */
3847 for (child = le32_to_cpu(dtp->leafidx),
3848 nparent = le32_to_cpu(dtp->nleafs) >> 2;
3849 nparent > 0; nparent >>= 2, child = parent) {
3850 /* get index of 1st node of parent level */
3851 parent = (child - 1) >> 2;
3852
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003853 /* set the value of the parent node as the maximum
Linus Torvalds1da177e2005-04-16 15:20:36 -07003854 * of the four nodes of the current level.
3855 */
3856 for (i = 0, cp = tp + child, cp1 = tp + parent;
3857 i < nparent; i++, cp += 4, cp1++)
3858 *cp1 = TREEMAX(cp);
3859 }
3860
3861 return (*tp);
3862}
3863
3864
3865/*
3866 * dbInitDmapCtl()
3867 *
3868 * function: initialize dmapctl page
3869 */
3870static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i)
3871{ /* start leaf index not covered by range */
3872 s8 *cp;
3873
3874 dcp->nleafs = cpu_to_le32(LPERCTL);
3875 dcp->l2nleafs = cpu_to_le32(L2LPERCTL);
3876 dcp->leafidx = cpu_to_le32(CTLLEAFIND);
3877 dcp->height = cpu_to_le32(5);
3878 dcp->budmin = L2BPERDMAP + L2LPERCTL * level;
3879
3880 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003881 * initialize the leaves of current level that were not covered
3882 * by the specified input block range (i.e. the leaves have no
Linus Torvalds1da177e2005-04-16 15:20:36 -07003883 * low level dmapctl or dmap).
3884 */
3885 cp = &dcp->stree[CTLLEAFIND + i];
3886 for (; i < LPERCTL; i++)
3887 *cp++ = NOFREE;
3888
3889 /* build the dmap's binary buddy summary tree */
3890 return (dbInitTree((struct dmaptree *) dcp));
3891}
3892
3893
3894/*
3895 * NAME: dbGetL2AGSize()/ujfs_getagl2size()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003896 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003897 * FUNCTION: Determine log2(allocation group size) from aggregate size
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003898 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003899 * PARAMETERS:
3900 * nblocks - Number of blocks in aggregate
3901 *
3902 * RETURNS: log2(allocation group size) in aggregate blocks
3903 */
3904static int dbGetL2AGSize(s64 nblocks)
3905{
3906 s64 sz;
3907 s64 m;
3908 int l2sz;
3909
3910 if (nblocks < BPERDMAP * MAXAG)
3911 return (L2BPERDMAP);
3912
3913 /* round up aggregate size to power of 2 */
3914 m = ((u64) 1 << (64 - 1));
3915 for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) {
3916 if (m & nblocks)
3917 break;
3918 }
3919
3920 sz = (s64) 1 << l2sz;
3921 if (sz < nblocks)
3922 l2sz += 1;
3923
3924 /* agsize = roundupSize/max_number_of_ag */
3925 return (l2sz - L2MAXAG);
3926}
3927
3928
3929/*
3930 * NAME: dbMapFileSizeToMapSize()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003931 *
3932 * FUNCTION: compute number of blocks the block allocation map file
Linus Torvalds1da177e2005-04-16 15:20:36 -07003933 * can cover from the map file size;
3934 *
3935 * RETURNS: Number of blocks which can be covered by this block map file;
3936 */
3937
3938/*
3939 * maximum number of map pages at each level including control pages
3940 */
3941#define MAXL0PAGES (1 + LPERCTL)
3942#define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES)
3943#define MAXL2PAGES (1 + LPERCTL * MAXL1PAGES)
3944
3945/*
3946 * convert number of map pages to the zero origin top dmapctl level
3947 */
3948#define BMAPPGTOLEV(npages) \
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003949 (((npages) <= 3 + MAXL0PAGES) ? 0 : \
3950 ((npages) <= 2 + MAXL1PAGES) ? 1 : 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003951
3952s64 dbMapFileSizeToMapSize(struct inode * ipbmap)
3953{
3954 struct super_block *sb = ipbmap->i_sb;
3955 s64 nblocks;
3956 s64 npages, ndmaps;
3957 int level, i;
3958 int complete, factor;
3959
3960 nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize;
3961 npages = nblocks >> JFS_SBI(sb)->l2nbperpage;
3962 level = BMAPPGTOLEV(npages);
3963
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003964 /* At each level, accumulate the number of dmap pages covered by
Linus Torvalds1da177e2005-04-16 15:20:36 -07003965 * the number of full child levels below it;
3966 * repeat for the last incomplete child level.
3967 */
3968 ndmaps = 0;
3969 npages--; /* skip the first global control page */
3970 /* skip higher level control pages above top level covered by map */
3971 npages -= (2 - level);
3972 npages--; /* skip top level's control page */
3973 for (i = level; i >= 0; i--) {
3974 factor =
3975 (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1);
3976 complete = (u32) npages / factor;
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003977 ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL :
3978 ((i == 1) ? LPERCTL : 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003979
3980 /* pages in last/incomplete child */
3981 npages = (u32) npages % factor;
3982 /* skip incomplete child's level control page */
3983 npages--;
3984 }
3985
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003986 /* convert the number of dmaps into the number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003987 * which can be covered by the dmaps;
3988 */
3989 nblocks = ndmaps << L2BPERDMAP;
3990
3991 return (nblocks);
3992}