blob: 9a55f53be5ff6a38678a8d52253b14c7e8004941 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C) International Business Machines Corp., 2000-2004
Tino Reichardtb40c2e62012-09-17 11:58:19 -05003 * Portions Copyright (C) Tino Reichardt, 2012
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
Dave Kleikamp63f83c92006-10-02 09:55:27 -05007 * the Free Software Foundation; either version 2 of the License, or
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * (at your option) any later version.
Dave Kleikamp63f83c92006-10-02 09:55:27 -05009 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
Dave Kleikamp63f83c92006-10-02 09:55:27 -050016 * along with this program; if not, write to the Free Software
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090021#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include "jfs_incore.h"
23#include "jfs_superblock.h"
24#include "jfs_dmap.h"
25#include "jfs_imap.h"
26#include "jfs_lock.h"
27#include "jfs_metapage.h"
28#include "jfs_debug.h"
Tino Reichardtb40c2e62012-09-17 11:58:19 -050029#include "jfs_discard.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
31/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 * SERIALIZATION of the Block Allocation Map.
33 *
34 * the working state of the block allocation map is accessed in
35 * two directions:
Dave Kleikamp63f83c92006-10-02 09:55:27 -050036 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 * 1) allocation and free requests that start at the dmap
38 * level and move up through the dmap control pages (i.e.
39 * the vast majority of requests).
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -050041 * 2) allocation requests that start at dmap control page
42 * level and work down towards the dmaps.
43 *
44 * the serialization scheme used here is as follows.
45 *
46 * requests which start at the bottom are serialized against each
47 * other through buffers and each requests holds onto its buffers
48 * as it works it way up from a single dmap to the required level
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 * of dmap control page.
50 * requests that start at the top are serialized against each other
51 * and request that start from the bottom by the multiple read/single
52 * write inode lock of the bmap inode. requests starting at the top
53 * take this lock in write mode while request starting at the bottom
54 * take the lock in read mode. a single top-down request may proceed
Dave Kleikamp63f83c92006-10-02 09:55:27 -050055 * exclusively while multiple bottoms-up requests may proceed
56 * simultaneously (under the protection of busy buffers).
57 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 * in addition to information found in dmaps and dmap control pages,
59 * the working state of the block allocation map also includes read/
60 * write information maintained in the bmap descriptor (i.e. total
61 * free block count, allocation group level free block counts).
62 * a single exclusive lock (BMAP_LOCK) is used to guard this information
63 * in the face of multiple-bottoms up requests.
64 * (lock ordering: IREAD_LOCK, BMAP_LOCK);
Dave Kleikamp63f83c92006-10-02 09:55:27 -050065 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 * accesses to the persistent state of the block allocation map (limited
67 * to the persistent bitmaps in dmaps) is guarded by (busy) buffers.
68 */
69
Ingo Molnar1de87442006-01-24 15:22:50 -060070#define BMAP_LOCK_INIT(bmp) mutex_init(&bmp->db_bmaplock)
71#define BMAP_LOCK(bmp) mutex_lock(&bmp->db_bmaplock)
72#define BMAP_UNLOCK(bmp) mutex_unlock(&bmp->db_bmaplock)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74/*
75 * forward references
76 */
77static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
78 int nblocks);
79static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval);
Dave Kleikampb6a47fd2005-10-11 09:06:59 -050080static int dbBackSplit(dmtree_t * tp, int leafno);
Dave Kleikamp56d12542005-07-15 09:43:36 -050081static int dbJoin(dmtree_t * tp, int leafno, int newval);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082static void dbAdjTree(dmtree_t * tp, int leafno, int newval);
83static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc,
84 int level);
85static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results);
86static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno,
87 int nblocks);
88static int dbAllocNear(struct bmap * bmp, struct dmap * dp, s64 blkno,
89 int nblocks,
90 int l2nb, s64 * results);
91static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
92 int nblocks);
93static int dbAllocDmapLev(struct bmap * bmp, struct dmap * dp, int nblocks,
94 int l2nb,
95 s64 * results);
96static int dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb,
97 s64 * results);
98static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno,
99 s64 * results);
100static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks);
101static int dbFindBits(u32 word, int l2nb);
102static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno);
103static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx);
Dave Kleikamp56d12542005-07-15 09:43:36 -0500104static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
105 int nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
107 int nblocks);
108static int dbMaxBud(u8 * cp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109static int blkstol2(s64 nb);
110
111static int cntlz(u32 value);
112static int cnttz(u32 word);
113
114static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno,
115 int nblocks);
116static int dbInitDmap(struct dmap * dp, s64 blkno, int nblocks);
117static int dbInitDmapTree(struct dmap * dp);
118static int dbInitTree(struct dmaptree * dtp);
119static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i);
120static int dbGetL2AGSize(s64 nblocks);
121
122/*
123 * buddy table
124 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500125 * table used for determining buddy sizes within characters of
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 * dmap bitmap words. the characters themselves serve as indexes
127 * into the table, with the table elements yielding the maximum
128 * binary buddy of free bits within the character.
129 */
Arjan van de Ven4d5dbd02005-11-29 08:28:58 -0600130static const s8 budtab[256] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
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, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
139 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0,
143 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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, 0,
146 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -1
147};
148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313/*
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500314 * NAME: dbFree()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 *
316 * FUNCTION: free the specified block range from the working block
317 * allocation map.
318 *
319 * the blocks will be free from the working map one dmap
320 * at a time.
321 *
322 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500323 * ip - pointer to in-core inode;
324 * blkno - starting block number to be freed.
325 * nblocks - number of blocks to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 *
327 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500328 * 0 - success
329 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 */
331int dbFree(struct inode *ip, s64 blkno, s64 nblocks)
332{
333 struct metapage *mp;
334 struct dmap *dp;
335 int nb, rc;
336 s64 lblkno, rem;
337 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
338 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
Tino Reichardtb40c2e62012-09-17 11:58:19 -0500339 struct super_block *sb = ipbmap->i_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
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
Tino Reichardtb40c2e62012-09-17 11:58:19 -0500354 /**
355 * TRIM the blocks, when mounted with discard option
356 */
357 if (JFS_SBI(sb)->flag & JFS_DISCARD)
358 if (JFS_SBI(sb)->minblks_trim <= nblocks)
359 jfs_issue_discard(ipbmap, blkno, nblocks);
360
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 /*
362 * free the blocks a dmap at a time.
363 */
364 mp = NULL;
365 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
366 /* release previous dmap if any */
367 if (mp) {
368 write_metapage(mp);
369 }
370
371 /* get the buffer for the current dmap. */
372 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
373 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
374 if (mp == NULL) {
375 IREAD_UNLOCK(ipbmap);
376 return -EIO;
377 }
378 dp = (struct dmap *) mp->data;
379
380 /* determine the number of blocks to be freed from
381 * this dmap.
382 */
383 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
384
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 /* free the blocks. */
386 if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) {
Dave Kleikamp56d12542005-07-15 09:43:36 -0500387 jfs_error(ip->i_sb, "dbFree: error in block map\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 release_metapage(mp);
389 IREAD_UNLOCK(ipbmap);
390 return (rc);
391 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 }
393
394 /* write the last buffer. */
395 write_metapage(mp);
396
397 IREAD_UNLOCK(ipbmap);
398
399 return (0);
400}
401
402
403/*
404 * NAME: dbUpdatePMap()
405 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500406 * FUNCTION: update the allocation state (free or allocate) of the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 * specified block range in the persistent block allocation map.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500408 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 * the blocks will be updated in the persistent map one
410 * dmap at a time.
411 *
412 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500413 * ipbmap - pointer to in-core inode for the block map.
414 * free - 'true' if block range is to be freed from the persistent
415 * map; 'false' if it is to be allocated.
416 * blkno - starting block number of the range.
417 * nblocks - number of contiguous blocks in the range.
418 * tblk - transaction block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 *
420 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500421 * 0 - success
422 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 */
424int
425dbUpdatePMap(struct inode *ipbmap,
426 int free, s64 blkno, s64 nblocks, struct tblock * tblk)
427{
428 int nblks, dbitno, wbitno, rbits;
429 int word, nbits, nwords;
430 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
431 s64 lblkno, rem, lastlblkno;
432 u32 mask;
433 struct dmap *dp;
434 struct metapage *mp;
435 struct jfs_log *log;
436 int lsn, difft, diffp;
Dave Kleikamp7fab4792005-05-02 12:25:02 -0600437 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
439 /* the blocks better be within the mapsize. */
440 if (blkno + nblocks > bmp->db_mapsize) {
441 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n",
442 (unsigned long long) blkno,
443 (unsigned long long) nblocks);
444 jfs_error(ipbmap->i_sb,
445 "dbUpdatePMap: blocks are outside the map");
446 return -EIO;
447 }
448
449 /* compute delta of transaction lsn from log syncpt */
450 lsn = tblk->lsn;
451 log = (struct jfs_log *) JFS_SBI(tblk->sb)->log;
452 logdiff(difft, lsn, log);
453
454 /*
455 * update the block state a dmap at a time.
456 */
457 mp = NULL;
458 lastlblkno = 0;
459 for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) {
460 /* get the buffer for the current dmap. */
461 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
462 if (lblkno != lastlblkno) {
463 if (mp) {
464 write_metapage(mp);
465 }
466
467 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE,
468 0);
469 if (mp == NULL)
470 return -EIO;
Dave Kleikamp7fab4792005-05-02 12:25:02 -0600471 metapage_wait_for_io(mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 }
473 dp = (struct dmap *) mp->data;
474
475 /* determine the bit number and word within the dmap of
476 * the starting block. also determine how many blocks
477 * are to be updated within this dmap.
478 */
479 dbitno = blkno & (BPERDMAP - 1);
480 word = dbitno >> L2DBWORD;
481 nblks = min(rem, (s64)BPERDMAP - dbitno);
482
483 /* update the bits of the dmap words. the first and last
484 * words may only have a subset of their bits updated. if
485 * this is the case, we'll work against that word (i.e.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500486 * partial first and/or last) only in a single pass. a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 * single pass will also be used to update all words that
488 * are to have all their bits updated.
489 */
490 for (rbits = nblks; rbits > 0;
491 rbits -= nbits, dbitno += nbits) {
492 /* determine the bit number within the word and
493 * the number of bits within the word.
494 */
495 wbitno = dbitno & (DBWORD - 1);
496 nbits = min(rbits, DBWORD - wbitno);
497
498 /* check if only part of the word is to be updated. */
499 if (nbits < DBWORD) {
500 /* update (free or allocate) the bits
501 * in this word.
502 */
503 mask =
504 (ONES << (DBWORD - nbits) >> wbitno);
505 if (free)
506 dp->pmap[word] &=
507 cpu_to_le32(~mask);
508 else
509 dp->pmap[word] |=
510 cpu_to_le32(mask);
511
512 word += 1;
513 } else {
514 /* one or more words are to have all
515 * their bits updated. determine how
516 * many words and how many bits.
517 */
518 nwords = rbits >> L2DBWORD;
519 nbits = nwords << L2DBWORD;
520
521 /* update (free or allocate) the bits
522 * in these words.
523 */
524 if (free)
525 memset(&dp->pmap[word], 0,
526 nwords * 4);
527 else
528 memset(&dp->pmap[word], (int) ONES,
529 nwords * 4);
530
531 word += nwords;
532 }
533 }
534
535 /*
536 * update dmap lsn
537 */
538 if (lblkno == lastlblkno)
539 continue;
540
541 lastlblkno = lblkno;
542
Dave Kleikampbe0bf7d2006-03-08 10:59:15 -0600543 LOGSYNC_LOCK(log, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 if (mp->lsn != 0) {
545 /* inherit older/smaller lsn */
546 logdiff(diffp, mp->lsn, log);
547 if (difft < diffp) {
548 mp->lsn = lsn;
549
550 /* move bp after tblock in logsync list */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 list_move(&mp->synclist, &tblk->synclist);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 }
553
554 /* inherit younger/larger clsn */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 logdiff(difft, tblk->clsn, log);
556 logdiff(diffp, mp->clsn, log);
557 if (difft > diffp)
558 mp->clsn = tblk->clsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 } else {
560 mp->log = log;
561 mp->lsn = lsn;
562
563 /* insert bp after tblock in logsync list */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 log->count++;
565 list_add(&mp->synclist, &tblk->synclist);
566
567 mp->clsn = tblk->clsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 }
Dave Kleikampbe0bf7d2006-03-08 10:59:15 -0600569 LOGSYNC_UNLOCK(log, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 }
571
572 /* write the last buffer. */
573 if (mp) {
574 write_metapage(mp);
575 }
576
577 return (0);
578}
579
580
581/*
582 * NAME: dbNextAG()
583 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500584 * FUNCTION: find the preferred allocation group for new allocations.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 *
586 * Within the allocation groups, we maintain a preferred
587 * allocation group which consists of a group with at least
588 * average free space. It is the preferred group that we target
589 * new inode allocation towards. The tie-in between inode
590 * allocation and block allocation occurs as we allocate the
591 * first (data) block of an inode and specify the inode (block)
592 * as the allocation hint for this block.
593 *
594 * We try to avoid having more than one open file growing in
595 * an allocation group, as this will lead to fragmentation.
596 * This differs from the old OS/2 method of trying to keep
597 * empty ags around for large allocations.
598 *
599 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500600 * ipbmap - pointer to in-core inode for the block map.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 *
602 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500603 * the preferred allocation group number.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 */
605int dbNextAG(struct inode *ipbmap)
606{
607 s64 avgfree;
608 int agpref;
609 s64 hwm = 0;
610 int i;
611 int next_best = -1;
612 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
613
614 BMAP_LOCK(bmp);
615
616 /* determine the average number of free blocks within the ags. */
617 avgfree = (u32)bmp->db_nfree / bmp->db_numag;
618
619 /*
620 * if the current preferred ag does not have an active allocator
621 * and has at least average freespace, return it
622 */
623 agpref = bmp->db_agpref;
624 if ((atomic_read(&bmp->db_active[agpref]) == 0) &&
625 (bmp->db_agfree[agpref] >= avgfree))
626 goto unlock;
627
628 /* From the last preferred ag, find the next one with at least
629 * average free space.
630 */
631 for (i = 0 ; i < bmp->db_numag; i++, agpref++) {
632 if (agpref == bmp->db_numag)
633 agpref = 0;
634
635 if (atomic_read(&bmp->db_active[agpref]))
636 /* open file is currently growing in this ag */
637 continue;
638 if (bmp->db_agfree[agpref] >= avgfree) {
639 /* Return this one */
640 bmp->db_agpref = agpref;
641 goto unlock;
642 } else if (bmp->db_agfree[agpref] > hwm) {
643 /* Less than avg. freespace, but best so far */
644 hwm = bmp->db_agfree[agpref];
645 next_best = agpref;
646 }
647 }
648
649 /*
650 * If no inactive ag was found with average freespace, use the
651 * next best
652 */
653 if (next_best != -1)
654 bmp->db_agpref = next_best;
655 /* else leave db_agpref unchanged */
656unlock:
657 BMAP_UNLOCK(bmp);
658
659 /* return the preferred group.
660 */
661 return (bmp->db_agpref);
662}
663
664/*
665 * NAME: dbAlloc()
666 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500667 * FUNCTION: attempt to allocate a specified number of contiguous free
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 * blocks from the working allocation block map.
669 *
670 * the block allocation policy uses hints and a multi-step
671 * approach.
672 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500673 * for allocation requests smaller than the number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 * per dmap, we first try to allocate the new blocks
675 * immediately following the hint. if these blocks are not
676 * available, we try to allocate blocks near the hint. if
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500677 * no blocks near the hint are available, we next try to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 * allocate within the same dmap as contains the hint.
679 *
680 * if no blocks are available in the dmap or the allocation
681 * request is larger than the dmap size, we try to allocate
682 * within the same allocation group as contains the hint. if
683 * this does not succeed, we finally try to allocate anywhere
684 * within the aggregate.
685 *
686 * we also try to allocate anywhere within the aggregate for
687 * for allocation requests larger than the allocation group
688 * size or requests that specify no hint value.
689 *
690 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500691 * ip - pointer to in-core inode;
692 * hint - allocation hint.
693 * nblocks - number of contiguous blocks in the range.
694 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 * of the newly allocated contiguous range.
696 *
697 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500698 * 0 - success
699 * -ENOSPC - insufficient disk resources
700 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 */
702int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results)
703{
704 int rc, agno;
705 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
706 struct bmap *bmp;
707 struct metapage *mp;
708 s64 lblkno, blkno;
709 struct dmap *dp;
710 int l2nb;
711 s64 mapSize;
712 int writers;
713
714 /* assert that nblocks is valid */
715 assert(nblocks > 0);
716
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 /* get the log2 number of blocks to be allocated.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500718 * if the number of blocks is not a log2 multiple,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 * it will be rounded up to the next log2 multiple.
720 */
721 l2nb = BLKSTOL2(nblocks);
722
723 bmp = JFS_SBI(ip->i_sb)->bmap;
724
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 mapSize = bmp->db_mapsize;
726
727 /* the hint should be within the map */
728 if (hint >= mapSize) {
729 jfs_error(ip->i_sb, "dbAlloc: the hint is outside the map");
730 return -EIO;
731 }
732
733 /* if the number of blocks to be allocated is greater than the
734 * allocation group size, try to allocate anywhere.
735 */
736 if (l2nb > bmp->db_agl2size) {
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600737 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
739 rc = dbAllocAny(bmp, nblocks, l2nb, results);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740
741 goto write_unlock;
742 }
743
744 /*
745 * If no hint, let dbNextAG recommend an allocation group
746 */
747 if (hint == 0)
748 goto pref_ag;
749
750 /* we would like to allocate close to the hint. adjust the
751 * hint to the block following the hint since the allocators
752 * will start looking for free space starting at this point.
753 */
754 blkno = hint + 1;
755
756 if (blkno >= bmp->db_mapsize)
757 goto pref_ag;
758
759 agno = blkno >> bmp->db_agl2size;
760
761 /* check if blkno crosses over into a new allocation group.
762 * if so, check if we should allow allocations within this
763 * allocation group.
764 */
765 if ((blkno & (bmp->db_agsize - 1)) == 0)
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200766 /* check if the AG is currently being written to.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 * if so, call dbNextAG() to find a non-busy
768 * AG with sufficient free space.
769 */
770 if (atomic_read(&bmp->db_active[agno]))
771 goto pref_ag;
772
773 /* check if the allocation request size can be satisfied from a
774 * single dmap. if so, try to allocate from the dmap containing
775 * the hint using a tiered strategy.
776 */
777 if (nblocks <= BPERDMAP) {
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600778 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779
780 /* get the buffer for the dmap containing the hint.
781 */
782 rc = -EIO;
783 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
784 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
785 if (mp == NULL)
786 goto read_unlock;
787
788 dp = (struct dmap *) mp->data;
789
790 /* first, try to satisfy the allocation request with the
791 * blocks beginning at the hint.
792 */
793 if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks))
794 != -ENOSPC) {
795 if (rc == 0) {
796 *results = blkno;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 mark_metapage_dirty(mp);
798 }
799
800 release_metapage(mp);
801 goto read_unlock;
802 }
803
804 writers = atomic_read(&bmp->db_active[agno]);
805 if ((writers > 1) ||
806 ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) {
807 /*
808 * Someone else is writing in this allocation
809 * group. To avoid fragmenting, try another ag
810 */
811 release_metapage(mp);
812 IREAD_UNLOCK(ipbmap);
813 goto pref_ag;
814 }
815
816 /* next, try to satisfy the allocation request with blocks
817 * near the hint.
818 */
819 if ((rc =
820 dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results))
821 != -ENOSPC) {
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500822 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 mark_metapage_dirty(mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824
825 release_metapage(mp);
826 goto read_unlock;
827 }
828
829 /* try to satisfy the allocation request with blocks within
830 * the same dmap as the hint.
831 */
832 if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results))
833 != -ENOSPC) {
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500834 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 mark_metapage_dirty(mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836
837 release_metapage(mp);
838 goto read_unlock;
839 }
840
841 release_metapage(mp);
842 IREAD_UNLOCK(ipbmap);
843 }
844
845 /* try to satisfy the allocation request with blocks within
846 * the same allocation group as the hint.
847 */
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600848 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500849 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 goto write_unlock;
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500851
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 IWRITE_UNLOCK(ipbmap);
853
854
855 pref_ag:
856 /*
857 * Let dbNextAG recommend a preferred allocation group
858 */
859 agno = dbNextAG(ipbmap);
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600860 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
862 /* Try to allocate within this allocation group. if that fails, try to
863 * allocate anywhere in the map.
864 */
865 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC)
866 rc = dbAllocAny(bmp, nblocks, l2nb, results);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867
868 write_unlock:
869 IWRITE_UNLOCK(ipbmap);
870
871 return (rc);
872
873 read_unlock:
874 IREAD_UNLOCK(ipbmap);
875
876 return (rc);
877}
878
879#ifdef _NOTYET
880/*
881 * NAME: dbAllocExact()
882 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500883 * FUNCTION: try to allocate the requested extent;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 *
885 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500886 * ip - pointer to in-core inode;
887 * blkno - extent address;
888 * nblocks - extent length;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 *
890 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500891 * 0 - success
892 * -ENOSPC - insufficient disk resources
893 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 */
895int dbAllocExact(struct inode *ip, s64 blkno, int nblocks)
896{
897 int rc;
898 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
899 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
900 struct dmap *dp;
901 s64 lblkno;
902 struct metapage *mp;
903
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600904 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905
906 /*
907 * validate extent request:
908 *
909 * note: defragfs policy:
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500910 * max 64 blocks will be moved.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 * allocation request size must be satisfied from a single dmap.
912 */
913 if (nblocks <= 0 || nblocks > BPERDMAP || blkno >= bmp->db_mapsize) {
914 IREAD_UNLOCK(ipbmap);
915 return -EINVAL;
916 }
917
918 if (nblocks > ((s64) 1 << bmp->db_maxfreebud)) {
919 /* the free space is no longer available */
920 IREAD_UNLOCK(ipbmap);
921 return -ENOSPC;
922 }
923
924 /* read in the dmap covering the extent */
925 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
926 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
927 if (mp == NULL) {
928 IREAD_UNLOCK(ipbmap);
929 return -EIO;
930 }
931 dp = (struct dmap *) mp->data;
932
933 /* try to allocate the requested extent */
934 rc = dbAllocNext(bmp, dp, blkno, nblocks);
935
936 IREAD_UNLOCK(ipbmap);
937
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500938 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 mark_metapage_dirty(mp);
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500940
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 release_metapage(mp);
942
943 return (rc);
944}
945#endif /* _NOTYET */
946
947/*
948 * NAME: dbReAlloc()
949 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500950 * FUNCTION: attempt to extend a current allocation by a specified
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951 * number of blocks.
952 *
953 * this routine attempts to satisfy the allocation request
954 * by first trying to extend the existing allocation in
955 * place by allocating the additional blocks as the blocks
956 * immediately following the current allocation. if these
957 * blocks are not available, this routine will attempt to
958 * allocate a new set of contiguous blocks large enough
959 * to cover the existing allocation plus the additional
960 * number of blocks required.
961 *
962 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500963 * ip - pointer to in-core inode requiring allocation.
964 * blkno - starting block of the current allocation.
965 * nblocks - number of contiguous blocks within the current
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 * allocation.
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500967 * addnblocks - number of blocks to add to the allocation.
968 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 * of the existing allocation if the existing allocation
970 * was extended in place or to a newly allocated contiguous
971 * range if the existing allocation could not be extended
972 * in place.
973 *
974 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500975 * 0 - success
976 * -ENOSPC - insufficient disk resources
977 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 */
979int
980dbReAlloc(struct inode *ip,
981 s64 blkno, s64 nblocks, s64 addnblocks, s64 * results)
982{
983 int rc;
984
985 /* try to extend the allocation in place.
986 */
987 if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) {
988 *results = blkno;
989 return (0);
990 } else {
991 if (rc != -ENOSPC)
992 return (rc);
993 }
994
995 /* could not extend the allocation in place, so allocate a
996 * new set of blocks for the entire request (i.e. try to get
997 * a range of contiguous blocks large enough to cover the
998 * existing allocation plus the additional blocks.)
999 */
1000 return (dbAlloc
1001 (ip, blkno + nblocks - 1, addnblocks + nblocks, results));
1002}
1003
1004
1005/*
1006 * NAME: dbExtend()
1007 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001008 * FUNCTION: attempt to extend a current allocation by a specified
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 * number of blocks.
1010 *
1011 * this routine attempts to satisfy the allocation request
1012 * by first trying to extend the existing allocation in
1013 * place by allocating the additional blocks as the blocks
1014 * immediately following the current allocation.
1015 *
1016 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001017 * ip - pointer to in-core inode requiring allocation.
1018 * blkno - starting block of the current allocation.
1019 * nblocks - number of contiguous blocks within the current
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 * allocation.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001021 * addnblocks - number of blocks to add to the allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022 *
1023 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001024 * 0 - success
1025 * -ENOSPC - insufficient disk resources
1026 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 */
1028static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks)
1029{
1030 struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
1031 s64 lblkno, lastblkno, extblkno;
1032 uint rel_block;
1033 struct metapage *mp;
1034 struct dmap *dp;
1035 int rc;
1036 struct inode *ipbmap = sbi->ipbmap;
1037 struct bmap *bmp;
1038
1039 /*
1040 * We don't want a non-aligned extent to cross a page boundary
1041 */
1042 if (((rel_block = blkno & (sbi->nbperpage - 1))) &&
1043 (rel_block + nblocks + addnblocks > sbi->nbperpage))
1044 return -ENOSPC;
1045
1046 /* get the last block of the current allocation */
1047 lastblkno = blkno + nblocks - 1;
1048
1049 /* determine the block number of the block following
1050 * the existing allocation.
1051 */
1052 extblkno = lastblkno + 1;
1053
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -06001054 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055
1056 /* better be within the file system */
1057 bmp = sbi->bmap;
1058 if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) {
1059 IREAD_UNLOCK(ipbmap);
1060 jfs_error(ip->i_sb,
1061 "dbExtend: the block is outside the filesystem");
1062 return -EIO;
1063 }
1064
1065 /* we'll attempt to extend the current allocation in place by
1066 * allocating the additional blocks as the blocks immediately
1067 * following the current allocation. we only try to extend the
1068 * current allocation in place if the number of additional blocks
1069 * can fit into a dmap, the last block of the current allocation
1070 * is not the last block of the file system, and the start of the
1071 * inplace extension is not on an allocation group boundary.
1072 */
1073 if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize ||
1074 (extblkno & (bmp->db_agsize - 1)) == 0) {
1075 IREAD_UNLOCK(ipbmap);
1076 return -ENOSPC;
1077 }
1078
1079 /* get the buffer for the dmap containing the first block
1080 * of the extension.
1081 */
1082 lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage);
1083 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
1084 if (mp == NULL) {
1085 IREAD_UNLOCK(ipbmap);
1086 return -EIO;
1087 }
1088
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089 dp = (struct dmap *) mp->data;
1090
1091 /* try to allocate the blocks immediately following the
1092 * current allocation.
1093 */
1094 rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks);
1095
1096 IREAD_UNLOCK(ipbmap);
1097
1098 /* were we successful ? */
Dave Kleikampb38a3ab2005-06-27 15:35:37 -05001099 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001100 write_metapage(mp);
Dave Kleikampb38a3ab2005-06-27 15:35:37 -05001101 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 /* we were not successful */
1103 release_metapage(mp);
1104
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105 return (rc);
1106}
1107
1108
1109/*
1110 * NAME: dbAllocNext()
1111 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001112 * FUNCTION: attempt to allocate the blocks of the specified block
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113 * range within a dmap.
1114 *
1115 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001116 * bmp - pointer to bmap descriptor
1117 * dp - pointer to dmap.
1118 * blkno - starting block number of the range.
1119 * nblocks - number of contiguous free blocks of the range.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120 *
1121 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001122 * 0 - success
1123 * -ENOSPC - insufficient disk resources
1124 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 *
1126 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1127 */
1128static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno,
1129 int nblocks)
1130{
1131 int dbitno, word, rembits, nb, nwords, wbitno, nw;
1132 int l2size;
1133 s8 *leaf;
1134 u32 mask;
1135
1136 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
1137 jfs_error(bmp->db_ipbmap->i_sb,
1138 "dbAllocNext: Corrupt dmap page");
1139 return -EIO;
1140 }
1141
1142 /* pick up a pointer to the leaves of the dmap tree.
1143 */
1144 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1145
1146 /* determine the bit number and word within the dmap of the
1147 * starting block.
1148 */
1149 dbitno = blkno & (BPERDMAP - 1);
1150 word = dbitno >> L2DBWORD;
1151
1152 /* check if the specified block range is contained within
1153 * this dmap.
1154 */
1155 if (dbitno + nblocks > BPERDMAP)
1156 return -ENOSPC;
1157
1158 /* check if the starting leaf indicates that anything
1159 * is free.
1160 */
1161 if (leaf[word] == NOFREE)
1162 return -ENOSPC;
1163
1164 /* check the dmaps words corresponding to block range to see
1165 * if the block range is free. not all bits of the first and
1166 * last words may be contained within the block range. if this
1167 * is the case, we'll work against those words (i.e. partial first
1168 * and/or last) on an individual basis (a single pass) and examine
1169 * the actual bits to determine if they are free. a single pass
1170 * will be used for all dmap words fully contained within the
1171 * specified range. within this pass, the leaves of the dmap
1172 * tree will be examined to determine if the blocks are free. a
1173 * single leaf may describe the free space of multiple dmap
1174 * words, so we may visit only a subset of the actual leaves
1175 * corresponding to the dmap words of the block range.
1176 */
1177 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
1178 /* determine the bit number within the word and
1179 * the number of bits within the word.
1180 */
1181 wbitno = dbitno & (DBWORD - 1);
1182 nb = min(rembits, DBWORD - wbitno);
1183
1184 /* check if only part of the word is to be examined.
1185 */
1186 if (nb < DBWORD) {
1187 /* check if the bits are free.
1188 */
1189 mask = (ONES << (DBWORD - nb) >> wbitno);
1190 if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask)
1191 return -ENOSPC;
1192
1193 word += 1;
1194 } else {
1195 /* one or more dmap words are fully contained
1196 * within the block range. determine how many
1197 * words and how many bits.
1198 */
1199 nwords = rembits >> L2DBWORD;
1200 nb = nwords << L2DBWORD;
1201
1202 /* now examine the appropriate leaves to determine
1203 * if the blocks are free.
1204 */
1205 while (nwords > 0) {
1206 /* does the leaf describe any free space ?
1207 */
1208 if (leaf[word] < BUDMIN)
1209 return -ENOSPC;
1210
1211 /* determine the l2 number of bits provided
1212 * by this leaf.
1213 */
1214 l2size =
1215 min((int)leaf[word], NLSTOL2BSZ(nwords));
1216
1217 /* determine how many words were handled.
1218 */
1219 nw = BUDSIZE(l2size, BUDMIN);
1220
1221 nwords -= nw;
1222 word += nw;
1223 }
1224 }
1225 }
1226
1227 /* allocate the blocks.
1228 */
1229 return (dbAllocDmap(bmp, dp, blkno, nblocks));
1230}
1231
1232
1233/*
1234 * NAME: dbAllocNear()
1235 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001236 * FUNCTION: attempt to allocate a number of contiguous free blocks near
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237 * a specified block (hint) within a dmap.
1238 *
1239 * starting with the dmap leaf that covers the hint, we'll
1240 * check the next four contiguous leaves for sufficient free
1241 * space. if sufficient free space is found, we'll allocate
1242 * the desired free space.
1243 *
1244 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001245 * bmp - pointer to bmap descriptor
1246 * dp - pointer to dmap.
1247 * blkno - block number to allocate near.
1248 * nblocks - actual number of contiguous free blocks desired.
1249 * l2nb - log2 number of contiguous free blocks desired.
1250 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 * of the newly allocated range.
1252 *
1253 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001254 * 0 - success
1255 * -ENOSPC - insufficient disk resources
1256 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257 *
1258 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1259 */
1260static int
1261dbAllocNear(struct bmap * bmp,
1262 struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results)
1263{
1264 int word, lword, rc;
1265 s8 *leaf;
1266
1267 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
1268 jfs_error(bmp->db_ipbmap->i_sb,
1269 "dbAllocNear: Corrupt dmap page");
1270 return -EIO;
1271 }
1272
1273 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1274
1275 /* determine the word within the dmap that holds the hint
1276 * (i.e. blkno). also, determine the last word in the dmap
1277 * that we'll include in our examination.
1278 */
1279 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
1280 lword = min(word + 4, LPERDMAP);
1281
1282 /* examine the leaves for sufficient free space.
1283 */
1284 for (; word < lword; word++) {
1285 /* does the leaf describe sufficient free space ?
1286 */
1287 if (leaf[word] < l2nb)
1288 continue;
1289
1290 /* determine the block number within the file system
1291 * of the first block described by this dmap word.
1292 */
1293 blkno = le64_to_cpu(dp->start) + (word << L2DBWORD);
1294
1295 /* if not all bits of the dmap word are free, get the
1296 * starting bit number within the dmap word of the required
1297 * string of free bits and adjust the block number with the
1298 * value.
1299 */
1300 if (leaf[word] < BUDMIN)
1301 blkno +=
1302 dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb);
1303
1304 /* allocate the blocks.
1305 */
1306 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
1307 *results = blkno;
1308
1309 return (rc);
1310 }
1311
1312 return -ENOSPC;
1313}
1314
1315
1316/*
1317 * NAME: dbAllocAG()
1318 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001319 * FUNCTION: attempt to allocate the specified number of contiguous
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 * free blocks within the specified allocation group.
1321 *
1322 * unless the allocation group size is equal to the number
1323 * of blocks per dmap, the dmap control pages will be used to
1324 * find the required free space, if available. we start the
1325 * search at the highest dmap control page level which
1326 * distinctly describes the allocation group's free space
1327 * (i.e. the highest level at which the allocation group's
1328 * free space is not mixed in with that of any other group).
1329 * in addition, we start the search within this level at a
1330 * height of the dmapctl dmtree at which the nodes distinctly
1331 * describe the allocation group's free space. at this height,
1332 * the allocation group's free space may be represented by 1
1333 * or two sub-trees, depending on the allocation group size.
1334 * we search the top nodes of these subtrees left to right for
1335 * sufficient free space. if sufficient free space is found,
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001336 * the subtree is searched to find the leftmost leaf that
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 * has free space. once we have made it to the leaf, we
1338 * move the search to the next lower level dmap control page
1339 * corresponding to this leaf. we continue down the dmap control
1340 * pages until we find the dmap that contains or starts the
1341 * sufficient free space and we allocate at this dmap.
1342 *
1343 * if the allocation group size is equal to the dmap size,
1344 * we'll start at the dmap corresponding to the allocation
1345 * group and attempt the allocation at this level.
1346 *
1347 * the dmap control page search is also not performed if the
1348 * allocation group is completely free and we go to the first
1349 * dmap of the allocation group to do the allocation. this is
1350 * done because the allocation group may be part (not the first
1351 * part) of a larger binary buddy system, causing the dmap
1352 * control pages to indicate no free space (NOFREE) within
1353 * the allocation group.
1354 *
1355 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001356 * bmp - pointer to bmap descriptor
Linus Torvalds1da177e2005-04-16 15:20:36 -07001357 * agno - allocation group number.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001358 * nblocks - actual number of contiguous free blocks desired.
1359 * l2nb - log2 number of contiguous free blocks desired.
1360 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361 * of the newly allocated range.
1362 *
1363 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001364 * 0 - success
1365 * -ENOSPC - insufficient disk resources
1366 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367 *
1368 * note: IWRITE_LOCK(ipmap) held on entry/exit;
1369 */
1370static int
1371dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results)
1372{
1373 struct metapage *mp;
1374 struct dmapctl *dcp;
1375 int rc, ti, i, k, m, n, agperlev;
1376 s64 blkno, lblkno;
1377 int budmin;
1378
1379 /* allocation request should not be for more than the
1380 * allocation group size.
1381 */
1382 if (l2nb > bmp->db_agl2size) {
1383 jfs_error(bmp->db_ipbmap->i_sb,
1384 "dbAllocAG: allocation request is larger than the "
1385 "allocation group size");
1386 return -EIO;
1387 }
1388
1389 /* determine the starting block number of the allocation
1390 * group.
1391 */
1392 blkno = (s64) agno << bmp->db_agl2size;
1393
1394 /* check if the allocation group size is the minimum allocation
1395 * group size or if the allocation group is completely free. if
1396 * the allocation group size is the minimum size of BPERDMAP (i.e.
1397 * 1 dmap), there is no need to search the dmap control page (below)
1398 * that fully describes the allocation group since the allocation
1399 * group is already fully described by a dmap. in this case, we
1400 * just call dbAllocCtl() to search the dmap tree and allocate the
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001401 * required space if available.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 *
1403 * if the allocation group is completely free, dbAllocCtl() is
1404 * also called to allocate the required space. this is done for
1405 * two reasons. first, it makes no sense searching the dmap control
1406 * pages for free space when we know that free space exists. second,
1407 * the dmap control pages may indicate that the allocation group
1408 * has no free space if the allocation group is part (not the first
1409 * part) of a larger binary buddy system.
1410 */
1411 if (bmp->db_agsize == BPERDMAP
1412 || bmp->db_agfree[agno] == bmp->db_agsize) {
1413 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1414 if ((rc == -ENOSPC) &&
1415 (bmp->db_agfree[agno] == bmp->db_agsize)) {
1416 printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n",
1417 (unsigned long long) blkno,
1418 (unsigned long long) nblocks);
1419 jfs_error(bmp->db_ipbmap->i_sb,
1420 "dbAllocAG: dbAllocCtl failed in free AG");
1421 }
1422 return (rc);
1423 }
1424
1425 /* the buffer for the dmap control page that fully describes the
1426 * allocation group.
1427 */
1428 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel);
1429 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1430 if (mp == NULL)
1431 return -EIO;
1432 dcp = (struct dmapctl *) mp->data;
1433 budmin = dcp->budmin;
1434
1435 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1436 jfs_error(bmp->db_ipbmap->i_sb,
1437 "dbAllocAG: Corrupt dmapctl page");
1438 release_metapage(mp);
1439 return -EIO;
1440 }
1441
1442 /* search the subtree(s) of the dmap control page that describes
1443 * the allocation group, looking for sufficient free space. to begin,
1444 * determine how many allocation groups are represented in a dmap
1445 * control page at the control page level (i.e. L0, L1, L2) that
1446 * fully describes an allocation group. next, determine the starting
1447 * tree index of this allocation group within the control page.
1448 */
1449 agperlev =
Daniel Mackd7eecb42010-01-28 16:13:01 +08001450 (1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451 ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1));
1452
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001453 /* dmap control page trees fan-out by 4 and a single allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454 * group may be described by 1 or 2 subtrees within the ag level
1455 * dmap control page, depending upon the ag size. examine the ag's
1456 * subtrees for sufficient free space, starting with the leftmost
1457 * subtree.
1458 */
1459 for (i = 0; i < bmp->db_agwidth; i++, ti++) {
1460 /* is there sufficient free space ?
1461 */
1462 if (l2nb > dcp->stree[ti])
1463 continue;
1464
1465 /* sufficient free space found in a subtree. now search down
1466 * the subtree to find the leftmost leaf that describes this
1467 * free space.
1468 */
Daniel Mackd7eecb42010-01-28 16:13:01 +08001469 for (k = bmp->db_agheight; k > 0; k--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001470 for (n = 0, m = (ti << 2) + 1; n < 4; n++) {
1471 if (l2nb <= dcp->stree[m + n]) {
1472 ti = m + n;
1473 break;
1474 }
1475 }
1476 if (n == 4) {
1477 jfs_error(bmp->db_ipbmap->i_sb,
1478 "dbAllocAG: failed descending stree");
1479 release_metapage(mp);
1480 return -EIO;
1481 }
1482 }
1483
1484 /* determine the block number within the file system
1485 * that corresponds to this leaf.
1486 */
1487 if (bmp->db_aglevel == 2)
1488 blkno = 0;
1489 else if (bmp->db_aglevel == 1)
1490 blkno &= ~(MAXL1SIZE - 1);
1491 else /* bmp->db_aglevel == 0 */
1492 blkno &= ~(MAXL0SIZE - 1);
1493
1494 blkno +=
1495 ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin;
1496
1497 /* release the buffer in preparation for going down
1498 * the next level of dmap control pages.
1499 */
1500 release_metapage(mp);
1501
1502 /* check if we need to continue to search down the lower
1503 * level dmap control pages. we need to if the number of
1504 * blocks required is less than maximum number of blocks
1505 * described at the next lower level.
1506 */
1507 if (l2nb < budmin) {
1508
1509 /* search the lower level dmap control pages to get
Michael Opdenacker59c51592007-05-09 08:57:56 +02001510 * the starting block number of the dmap that
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 * contains or starts off the free space.
1512 */
1513 if ((rc =
1514 dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1,
1515 &blkno))) {
1516 if (rc == -ENOSPC) {
1517 jfs_error(bmp->db_ipbmap->i_sb,
1518 "dbAllocAG: control page "
1519 "inconsistent");
1520 return -EIO;
1521 }
1522 return (rc);
1523 }
1524 }
1525
1526 /* allocate the blocks.
1527 */
1528 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1529 if (rc == -ENOSPC) {
1530 jfs_error(bmp->db_ipbmap->i_sb,
1531 "dbAllocAG: unable to allocate blocks");
1532 rc = -EIO;
1533 }
1534 return (rc);
1535 }
1536
1537 /* no space in the allocation group. release the buffer and
1538 * return -ENOSPC.
1539 */
1540 release_metapage(mp);
1541
1542 return -ENOSPC;
1543}
1544
1545
1546/*
1547 * NAME: dbAllocAny()
1548 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001549 * FUNCTION: attempt to allocate the specified number of contiguous
Linus Torvalds1da177e2005-04-16 15:20:36 -07001550 * free blocks anywhere in the file system.
1551 *
1552 * dbAllocAny() attempts to find the sufficient free space by
1553 * searching down the dmap control pages, starting with the
1554 * highest level (i.e. L0, L1, L2) control page. if free space
1555 * large enough to satisfy the desired free space is found, the
1556 * desired free space is allocated.
1557 *
1558 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001559 * bmp - pointer to bmap descriptor
1560 * nblocks - actual number of contiguous free blocks desired.
1561 * l2nb - log2 number of contiguous free blocks desired.
1562 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001563 * of the newly allocated range.
1564 *
1565 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001566 * 0 - success
1567 * -ENOSPC - insufficient disk resources
1568 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569 *
1570 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1571 */
1572static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results)
1573{
1574 int rc;
1575 s64 blkno = 0;
1576
1577 /* starting with the top level dmap control page, search
1578 * down the dmap control levels for sufficient free space.
1579 * if free space is found, dbFindCtl() returns the starting
1580 * block number of the dmap that contains or starts off the
1581 * range of free space.
1582 */
1583 if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno)))
1584 return (rc);
1585
1586 /* allocate the blocks.
1587 */
1588 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1589 if (rc == -ENOSPC) {
1590 jfs_error(bmp->db_ipbmap->i_sb,
1591 "dbAllocAny: unable to allocate blocks");
1592 return -EIO;
1593 }
1594 return (rc);
1595}
1596
1597
1598/*
Tino Reichardtb40c2e62012-09-17 11:58:19 -05001599 * NAME: dbDiscardAG()
1600 *
1601 * FUNCTION: attempt to discard (TRIM) all free blocks of specific AG
1602 *
1603 * algorithm:
1604 * 1) allocate blocks, as large as possible and save them
1605 * while holding IWRITE_LOCK on ipbmap
1606 * 2) trim all these saved block/length values
1607 * 3) mark the blocks free again
1608 *
1609 * benefit:
1610 * - we work only on one ag at some time, minimizing how long we
1611 * need to lock ipbmap
1612 * - reading / writing the fs is possible most time, even on
1613 * trimming
1614 *
1615 * downside:
1616 * - we write two times to the dmapctl and dmap pages
1617 * - but for me, this seems the best way, better ideas?
1618 * /TR 2012
1619 *
1620 * PARAMETERS:
1621 * ip - pointer to in-core inode
1622 * agno - ag to trim
1623 * minlen - minimum value of contiguous blocks
1624 *
1625 * RETURN VALUES:
1626 * s64 - actual number of blocks trimmed
1627 */
1628s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen)
1629{
1630 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
1631 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
1632 s64 nblocks, blkno;
1633 u64 trimmed = 0;
1634 int rc, l2nb;
1635 struct super_block *sb = ipbmap->i_sb;
1636
1637 struct range2trim {
1638 u64 blkno;
1639 u64 nblocks;
1640 } *totrim, *tt;
1641
1642 /* max blkno / nblocks pairs to trim */
1643 int count = 0, range_cnt;
Dave Kleikamp84f41412012-09-18 11:27:22 -05001644 u64 max_ranges;
Tino Reichardtb40c2e62012-09-17 11:58:19 -05001645
1646 /* prevent others from writing new stuff here, while trimming */
1647 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
1648
1649 nblocks = bmp->db_agfree[agno];
Dave Kleikamp84f41412012-09-18 11:27:22 -05001650 max_ranges = nblocks;
1651 do_div(max_ranges, minlen);
1652 range_cnt = min_t(u64, max_ranges + 1, 32 * 1024);
Tino Reichardtb40c2e62012-09-17 11:58:19 -05001653 totrim = kmalloc(sizeof(struct range2trim) * range_cnt, GFP_NOFS);
1654 if (totrim == NULL) {
1655 jfs_error(bmp->db_ipbmap->i_sb,
1656 "dbDiscardAG: no memory for trim array");
1657 IWRITE_UNLOCK(ipbmap);
1658 return 0;
1659 }
1660
1661 tt = totrim;
1662 while (nblocks >= minlen) {
1663 l2nb = BLKSTOL2(nblocks);
1664
1665 /* 0 = okay, -EIO = fatal, -ENOSPC -> try smaller block */
1666 rc = dbAllocAG(bmp, agno, nblocks, l2nb, &blkno);
1667 if (rc == 0) {
1668 tt->blkno = blkno;
1669 tt->nblocks = nblocks;
1670 tt++; count++;
1671
1672 /* the whole ag is free, trim now */
1673 if (bmp->db_agfree[agno] == 0)
1674 break;
1675
1676 /* give a hint for the next while */
1677 nblocks = bmp->db_agfree[agno];
1678 continue;
1679 } else if (rc == -ENOSPC) {
1680 /* search for next smaller log2 block */
1681 l2nb = BLKSTOL2(nblocks) - 1;
1682 nblocks = 1 << l2nb;
1683 } else {
1684 /* Trim any already allocated blocks */
1685 jfs_error(bmp->db_ipbmap->i_sb,
1686 "dbDiscardAG: -EIO");
1687 break;
1688 }
1689
1690 /* check, if our trim array is full */
1691 if (unlikely(count >= range_cnt - 1))
1692 break;
1693 }
1694 IWRITE_UNLOCK(ipbmap);
1695
1696 tt->nblocks = 0; /* mark the current end */
1697 for (tt = totrim; tt->nblocks != 0; tt++) {
1698 /* when mounted with online discard, dbFree() will
1699 * call jfs_issue_discard() itself */
1700 if (!(JFS_SBI(sb)->flag & JFS_DISCARD))
1701 jfs_issue_discard(ip, tt->blkno, tt->nblocks);
1702 dbFree(ip, tt->blkno, tt->nblocks);
1703 trimmed += tt->nblocks;
1704 }
1705 kfree(totrim);
1706
1707 return trimmed;
1708}
1709
1710/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711 * NAME: dbFindCtl()
1712 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001713 * FUNCTION: starting at a specified dmap control page level and block
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 * number, search down the dmap control levels for a range of
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001715 * contiguous free blocks large enough to satisfy an allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001716 * request for the specified number of free blocks.
1717 *
1718 * if sufficient contiguous free blocks are found, this routine
1719 * returns the starting block number within a dmap page that
1720 * contains or starts a range of contiqious free blocks that
1721 * is sufficient in size.
1722 *
1723 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001724 * bmp - pointer to bmap descriptor
1725 * level - starting dmap control page level.
1726 * l2nb - log2 number of contiguous free blocks desired.
1727 * *blkno - on entry, starting block number for conducting the search.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001728 * on successful return, the first block within a dmap page
1729 * that contains or starts a range of contiguous free blocks.
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 dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno)
1739{
1740 int rc, leafidx, lev;
1741 s64 b, lblkno;
1742 struct dmapctl *dcp;
1743 int budmin;
1744 struct metapage *mp;
1745
1746 /* starting at the specified dmap control page level and block
1747 * number, search down the dmap control levels for the starting
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001748 * block number of a dmap page that contains or starts off
Linus Torvalds1da177e2005-04-16 15:20:36 -07001749 * sufficient free blocks.
1750 */
1751 for (lev = level, b = *blkno; lev >= 0; lev--) {
1752 /* get the buffer of the dmap control page for the block
1753 * number and level (i.e. L0, L1, L2).
1754 */
1755 lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev);
1756 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1757 if (mp == NULL)
1758 return -EIO;
1759 dcp = (struct dmapctl *) mp->data;
1760 budmin = dcp->budmin;
1761
1762 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1763 jfs_error(bmp->db_ipbmap->i_sb,
1764 "dbFindCtl: Corrupt dmapctl page");
1765 release_metapage(mp);
1766 return -EIO;
1767 }
1768
1769 /* search the tree within the dmap control page for
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001770 * sufficient free space. if sufficient free space is found,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001771 * dbFindLeaf() returns the index of the leaf at which
1772 * free space was found.
1773 */
1774 rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx);
1775
1776 /* release the buffer.
1777 */
1778 release_metapage(mp);
1779
1780 /* space found ?
1781 */
1782 if (rc) {
1783 if (lev != level) {
1784 jfs_error(bmp->db_ipbmap->i_sb,
1785 "dbFindCtl: dmap inconsistent");
1786 return -EIO;
1787 }
1788 return -ENOSPC;
1789 }
1790
1791 /* adjust the block number to reflect the location within
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001792 * the dmap control page (i.e. the leaf) at which free
Linus Torvalds1da177e2005-04-16 15:20:36 -07001793 * space was found.
1794 */
1795 b += (((s64) leafidx) << budmin);
1796
1797 /* we stop the search at this dmap control page level if
1798 * the number of blocks required is greater than or equal
1799 * to the maximum number of blocks described at the next
1800 * (lower) level.
1801 */
1802 if (l2nb >= budmin)
1803 break;
1804 }
1805
1806 *blkno = b;
1807 return (0);
1808}
1809
1810
1811/*
1812 * NAME: dbAllocCtl()
1813 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001814 * FUNCTION: attempt to allocate a specified number of contiguous
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001815 * blocks starting within a specific dmap.
1816 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001817 * this routine is called by higher level routines that search
1818 * the dmap control pages above the actual dmaps for contiguous
1819 * free space. the result of successful searches by these
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001820 * routines are the starting block numbers within dmaps, with
Linus Torvalds1da177e2005-04-16 15:20:36 -07001821 * the dmaps themselves containing the desired contiguous free
1822 * space or starting a contiguous free space of desired size
1823 * that is made up of the blocks of one or more dmaps. these
1824 * calls should not fail due to insufficent resources.
1825 *
1826 * this routine is called in some cases where it is not known
1827 * whether it will fail due to insufficient resources. more
1828 * specifically, this occurs when allocating from an allocation
1829 * group whose size is equal to the number of blocks per dmap.
1830 * in this case, the dmap control pages are not examined prior
1831 * to calling this routine (to save pathlength) and the call
1832 * might fail.
1833 *
1834 * for a request size that fits within a dmap, this routine relies
1835 * upon the dmap's dmtree to find the requested contiguous free
1836 * space. for request sizes that are larger than a dmap, the
1837 * requested free space will start at the first block of the
1838 * first dmap (i.e. blkno).
1839 *
1840 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001841 * bmp - pointer to bmap descriptor
1842 * nblocks - actual number of contiguous free blocks to allocate.
1843 * l2nb - log2 number of contiguous free blocks to allocate.
1844 * blkno - starting block number of the dmap to start the allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001845 * from.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001846 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001847 * of the newly allocated range.
1848 *
1849 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001850 * 0 - success
1851 * -ENOSPC - insufficient disk resources
1852 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001853 *
1854 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1855 */
1856static int
1857dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results)
1858{
1859 int rc, nb;
1860 s64 b, lblkno, n;
1861 struct metapage *mp;
1862 struct dmap *dp;
1863
1864 /* check if the allocation request is confined to a single dmap.
1865 */
1866 if (l2nb <= L2BPERDMAP) {
1867 /* get the buffer for the dmap.
1868 */
1869 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
1870 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1871 if (mp == NULL)
1872 return -EIO;
1873 dp = (struct dmap *) mp->data;
1874
1875 /* try to allocate the blocks.
1876 */
1877 rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results);
1878 if (rc == 0)
1879 mark_metapage_dirty(mp);
1880
1881 release_metapage(mp);
1882
1883 return (rc);
1884 }
1885
1886 /* allocation request involving multiple dmaps. it must start on
1887 * a dmap boundary.
1888 */
1889 assert((blkno & (BPERDMAP - 1)) == 0);
1890
1891 /* allocate the blocks dmap by dmap.
1892 */
1893 for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) {
1894 /* get the buffer for the dmap.
1895 */
1896 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1897 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1898 if (mp == NULL) {
1899 rc = -EIO;
1900 goto backout;
1901 }
1902 dp = (struct dmap *) mp->data;
1903
1904 /* the dmap better be all free.
1905 */
1906 if (dp->tree.stree[ROOT] != L2BPERDMAP) {
1907 release_metapage(mp);
1908 jfs_error(bmp->db_ipbmap->i_sb,
1909 "dbAllocCtl: the dmap is not all free");
1910 rc = -EIO;
1911 goto backout;
1912 }
1913
1914 /* determine how many blocks to allocate from this dmap.
1915 */
1916 nb = min(n, (s64)BPERDMAP);
1917
1918 /* allocate the blocks from the dmap.
1919 */
1920 if ((rc = dbAllocDmap(bmp, dp, b, nb))) {
1921 release_metapage(mp);
1922 goto backout;
1923 }
1924
1925 /* write the buffer.
1926 */
1927 write_metapage(mp);
1928 }
1929
1930 /* set the results (starting block number) and return.
1931 */
1932 *results = blkno;
1933 return (0);
1934
1935 /* something failed in handling an allocation request involving
1936 * multiple dmaps. we'll try to clean up by backing out any
1937 * allocation that has already happened for this request. if
1938 * we fail in backing out the allocation, we'll mark the file
1939 * system to indicate that blocks have been leaked.
1940 */
1941 backout:
1942
1943 /* try to backout the allocations dmap by dmap.
1944 */
1945 for (n = nblocks - n, b = blkno; n > 0;
1946 n -= BPERDMAP, b += BPERDMAP) {
1947 /* get the buffer for this dmap.
1948 */
1949 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1950 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1951 if (mp == NULL) {
1952 /* could not back out. mark the file system
1953 * to indicate that we have leaked blocks.
1954 */
1955 jfs_error(bmp->db_ipbmap->i_sb,
1956 "dbAllocCtl: I/O Error: Block Leakage.");
1957 continue;
1958 }
1959 dp = (struct dmap *) mp->data;
1960
1961 /* free the blocks is this dmap.
1962 */
1963 if (dbFreeDmap(bmp, dp, b, BPERDMAP)) {
1964 /* could not back out. mark the file system
1965 * to indicate that we have leaked blocks.
1966 */
1967 release_metapage(mp);
1968 jfs_error(bmp->db_ipbmap->i_sb,
1969 "dbAllocCtl: Block Leakage.");
1970 continue;
1971 }
1972
1973 /* write the buffer.
1974 */
1975 write_metapage(mp);
1976 }
1977
1978 return (rc);
1979}
1980
1981
1982/*
1983 * NAME: dbAllocDmapLev()
1984 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001985 * FUNCTION: attempt to allocate a specified number of contiguous blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07001986 * from a specified dmap.
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001987 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001988 * this routine checks if the contiguous blocks are available.
1989 * if so, nblocks of blocks are allocated; otherwise, ENOSPC is
1990 * returned.
1991 *
1992 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001993 * mp - pointer to bmap descriptor
1994 * dp - pointer to dmap to attempt to allocate blocks from.
1995 * l2nb - log2 number of contiguous block desired.
1996 * nblocks - actual number of contiguous block desired.
1997 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001998 * of the newly allocated range.
1999 *
2000 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002001 * 0 - success
2002 * -ENOSPC - insufficient disk resources
2003 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07002004 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002005 * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or
Linus Torvalds1da177e2005-04-16 15:20:36 -07002006 * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit;
2007 */
2008static int
2009dbAllocDmapLev(struct bmap * bmp,
2010 struct dmap * dp, int nblocks, int l2nb, s64 * results)
2011{
2012 s64 blkno;
2013 int leafidx, rc;
2014
2015 /* can't be more than a dmaps worth of blocks */
2016 assert(l2nb <= L2BPERDMAP);
2017
2018 /* search the tree within the dmap page for sufficient
2019 * free space. if sufficient free space is found, dbFindLeaf()
2020 * returns the index of the leaf at which free space was found.
2021 */
2022 if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx))
2023 return -ENOSPC;
2024
2025 /* determine the block number within the file system corresponding
2026 * to the leaf at which free space was found.
2027 */
2028 blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD);
2029
2030 /* if not all bits of the dmap word are free, get the starting
2031 * bit number within the dmap word of the required string of free
2032 * bits and adjust the block number with this value.
2033 */
2034 if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN)
2035 blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb);
2036
2037 /* allocate the blocks */
2038 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
2039 *results = blkno;
2040
2041 return (rc);
2042}
2043
2044
2045/*
2046 * NAME: dbAllocDmap()
2047 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002048 * FUNCTION: adjust the disk allocation map to reflect the allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002049 * of a specified block range within a dmap.
2050 *
2051 * this routine allocates the specified blocks from the dmap
2052 * through a call to dbAllocBits(). if the allocation of the
2053 * block range causes the maximum string of free blocks within
2054 * the dmap to change (i.e. the value of the root of the dmap's
2055 * dmtree), this routine will cause this change to be reflected
2056 * up through the appropriate levels of the dmap control pages
2057 * by a call to dbAdjCtl() for the L0 dmap control page that
2058 * covers this dmap.
2059 *
2060 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002061 * bmp - pointer to bmap descriptor
2062 * dp - pointer to dmap to allocate the block range from.
2063 * blkno - starting block number of the block to be allocated.
2064 * nblocks - number of blocks to be allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002065 *
2066 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002067 * 0 - success
2068 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07002069 *
2070 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2071 */
2072static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2073 int nblocks)
2074{
2075 s8 oldroot;
2076 int rc;
2077
2078 /* save the current value of the root (i.e. maximum free string)
2079 * of the dmap tree.
2080 */
2081 oldroot = dp->tree.stree[ROOT];
2082
2083 /* allocate the specified (blocks) bits */
2084 dbAllocBits(bmp, dp, blkno, nblocks);
2085
2086 /* if the root has not changed, done. */
2087 if (dp->tree.stree[ROOT] == oldroot)
2088 return (0);
2089
2090 /* root changed. bubble the change up to the dmap control pages.
2091 * if the adjustment of the upper level control pages fails,
2092 * backout the bit allocation (thus making everything consistent).
2093 */
2094 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0)))
2095 dbFreeBits(bmp, dp, blkno, nblocks);
2096
2097 return (rc);
2098}
2099
2100
2101/*
2102 * NAME: dbFreeDmap()
2103 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002104 * FUNCTION: adjust the disk allocation map to reflect the allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002105 * of a specified block range within a dmap.
2106 *
2107 * this routine frees the specified blocks from the dmap through
2108 * a call to dbFreeBits(). if the deallocation of the block range
2109 * causes the maximum string of free blocks within the dmap to
2110 * change (i.e. the value of the root of the dmap's dmtree), this
2111 * routine will cause this change to be reflected up through the
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002112 * appropriate levels of the dmap control pages by a call to
Linus Torvalds1da177e2005-04-16 15:20:36 -07002113 * dbAdjCtl() for the L0 dmap control page that covers this dmap.
2114 *
2115 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002116 * bmp - pointer to bmap descriptor
2117 * dp - pointer to dmap to free the block range from.
2118 * blkno - starting block number of the block to be freed.
2119 * nblocks - number of blocks to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002120 *
2121 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002122 * 0 - success
2123 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07002124 *
2125 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2126 */
2127static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2128 int nblocks)
2129{
2130 s8 oldroot;
Dave Kleikamp56d12542005-07-15 09:43:36 -05002131 int rc = 0, word;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002132
2133 /* save the current value of the root (i.e. maximum free string)
2134 * of the dmap tree.
2135 */
2136 oldroot = dp->tree.stree[ROOT];
2137
2138 /* free the specified (blocks) bits */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002139 rc = dbFreeBits(bmp, dp, blkno, nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002140
Dave Kleikamp56d12542005-07-15 09:43:36 -05002141 /* if error or the root has not changed, done. */
2142 if (rc || (dp->tree.stree[ROOT] == oldroot))
2143 return (rc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002144
2145 /* root changed. bubble the change up to the dmap control pages.
2146 * if the adjustment of the upper level control pages fails,
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002147 * backout the deallocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002148 */
2149 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) {
2150 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
2151
2152 /* as part of backing out the deallocation, we will have
2153 * to back split the dmap tree if the deallocation caused
2154 * the freed blocks to become part of a larger binary buddy
2155 * system.
2156 */
2157 if (dp->tree.stree[word] == NOFREE)
2158 dbBackSplit((dmtree_t *) & dp->tree, word);
2159
2160 dbAllocBits(bmp, dp, blkno, nblocks);
2161 }
2162
2163 return (rc);
2164}
2165
2166
2167/*
2168 * NAME: dbAllocBits()
2169 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002170 * FUNCTION: allocate a specified block range from a dmap.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002171 *
2172 * this routine updates the dmap to reflect the working
2173 * state allocation of the specified block range. it directly
2174 * updates the bits of the working map and causes the adjustment
2175 * of the binary buddy system described by the dmap's dmtree
2176 * leaves to reflect the bits allocated. it also causes the
2177 * dmap's dmtree, as a whole, to reflect the allocated range.
2178 *
2179 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002180 * bmp - pointer to bmap descriptor
2181 * dp - pointer to dmap to allocate bits from.
2182 * blkno - starting block number of the bits to be allocated.
2183 * nblocks - number of bits to be allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002184 *
2185 * RETURN VALUES: none
2186 *
2187 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2188 */
2189static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
2190 int nblocks)
2191{
2192 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2193 dmtree_t *tp = (dmtree_t *) & dp->tree;
2194 int size;
2195 s8 *leaf;
2196
2197 /* pick up a pointer to the leaves of the dmap tree */
2198 leaf = dp->tree.stree + LEAFIND;
2199
2200 /* determine the bit number and word within the dmap of the
2201 * starting block.
2202 */
2203 dbitno = blkno & (BPERDMAP - 1);
2204 word = dbitno >> L2DBWORD;
2205
2206 /* block range better be within the dmap */
2207 assert(dbitno + nblocks <= BPERDMAP);
2208
2209 /* allocate the bits of the dmap's words corresponding to the block
2210 * range. not all bits of the first and last words may be contained
2211 * within the block range. if this is the case, we'll work against
2212 * those words (i.e. partial first and/or last) on an individual basis
2213 * (a single pass), allocating the bits of interest by hand and
2214 * updating the leaf corresponding to the dmap word. a single pass
2215 * will be used for all dmap words fully contained within the
2216 * specified range. within this pass, the bits of all fully contained
2217 * dmap words will be marked as free in a single shot and the leaves
2218 * will be updated. a single leaf may describe the free space of
2219 * multiple dmap words, so we may update only a subset of the actual
2220 * leaves corresponding to the dmap words of the block range.
2221 */
2222 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2223 /* determine the bit number within the word and
2224 * the number of bits within the word.
2225 */
2226 wbitno = dbitno & (DBWORD - 1);
2227 nb = min(rembits, DBWORD - wbitno);
2228
2229 /* check if only part of a word is to be allocated.
2230 */
2231 if (nb < DBWORD) {
2232 /* allocate (set to 1) the appropriate bits within
2233 * this dmap word.
2234 */
2235 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
2236 >> wbitno);
2237
2238 /* update the leaf for this dmap word. in addition
2239 * to setting the leaf value to the binary buddy max
2240 * of the updated dmap word, dbSplit() will split
2241 * the binary system of the leaves if need be.
2242 */
2243 dbSplit(tp, word, BUDMIN,
2244 dbMaxBud((u8 *) & dp->wmap[word]));
2245
2246 word += 1;
2247 } else {
2248 /* one or more dmap words are fully contained
2249 * within the block range. determine how many
2250 * words and allocate (set to 1) the bits of these
2251 * words.
2252 */
2253 nwords = rembits >> L2DBWORD;
2254 memset(&dp->wmap[word], (int) ONES, nwords * 4);
2255
2256 /* determine how many bits.
2257 */
2258 nb = nwords << L2DBWORD;
2259
2260 /* now update the appropriate leaves to reflect
2261 * the allocated words.
2262 */
2263 for (; nwords > 0; nwords -= nw) {
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002264 if (leaf[word] < BUDMIN) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002265 jfs_error(bmp->db_ipbmap->i_sb,
2266 "dbAllocBits: leaf page "
2267 "corrupt");
2268 break;
2269 }
2270
2271 /* determine what the leaf value should be
2272 * updated to as the minimum of the l2 number
2273 * of bits being allocated and the l2 number
2274 * of bits currently described by this leaf.
2275 */
2276 size = min((int)leaf[word], NLSTOL2BSZ(nwords));
2277
2278 /* update the leaf to reflect the allocation.
2279 * in addition to setting the leaf value to
2280 * NOFREE, dbSplit() will split the binary
2281 * system of the leaves to reflect the current
2282 * allocation (size).
2283 */
2284 dbSplit(tp, word, size, NOFREE);
2285
2286 /* get the number of dmap words handled */
2287 nw = BUDSIZE(size, BUDMIN);
2288 word += nw;
2289 }
2290 }
2291 }
2292
2293 /* update the free count for this dmap */
Marcin Slusarz89145622008-02-13 15:34:20 -06002294 le32_add_cpu(&dp->nfree, -nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002295
2296 BMAP_LOCK(bmp);
2297
2298 /* if this allocation group is completely free,
2299 * update the maximum allocation group number if this allocation
2300 * group is the new max.
2301 */
2302 agno = blkno >> bmp->db_agl2size;
2303 if (agno > bmp->db_maxag)
2304 bmp->db_maxag = agno;
2305
2306 /* update the free count for the allocation group and map */
2307 bmp->db_agfree[agno] -= nblocks;
2308 bmp->db_nfree -= nblocks;
2309
2310 BMAP_UNLOCK(bmp);
2311}
2312
2313
2314/*
2315 * NAME: dbFreeBits()
2316 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002317 * FUNCTION: free a specified block range from a dmap.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002318 *
2319 * this routine updates the dmap to reflect the working
2320 * state allocation of the specified block range. it directly
2321 * updates the bits of the working map and causes the adjustment
2322 * of the binary buddy system described by the dmap's dmtree
2323 * leaves to reflect the bits freed. it also causes the dmap's
2324 * dmtree, as a whole, to reflect the deallocated range.
2325 *
2326 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002327 * bmp - pointer to bmap descriptor
2328 * dp - pointer to dmap to free bits from.
2329 * blkno - starting block number of the bits to be freed.
2330 * nblocks - number of bits to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002331 *
Dave Kleikamp56d12542005-07-15 09:43:36 -05002332 * RETURN VALUES: 0 for success
Linus Torvalds1da177e2005-04-16 15:20:36 -07002333 *
2334 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2335 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002336static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002337 int nblocks)
2338{
2339 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2340 dmtree_t *tp = (dmtree_t *) & dp->tree;
Dave Kleikamp56d12542005-07-15 09:43:36 -05002341 int rc = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002342 int size;
2343
2344 /* determine the bit number and word within the dmap of the
2345 * starting block.
2346 */
2347 dbitno = blkno & (BPERDMAP - 1);
2348 word = dbitno >> L2DBWORD;
2349
2350 /* block range better be within the dmap.
2351 */
2352 assert(dbitno + nblocks <= BPERDMAP);
2353
2354 /* free the bits of the dmaps words corresponding to the block range.
2355 * not all bits of the first and last words may be contained within
2356 * the block range. if this is the case, we'll work against those
2357 * words (i.e. partial first and/or last) on an individual basis
2358 * (a single pass), freeing the bits of interest by hand and updating
2359 * the leaf corresponding to the dmap word. a single pass will be used
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002360 * for all dmap words fully contained within the specified range.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002361 * within this pass, the bits of all fully contained dmap words will
2362 * be marked as free in a single shot and the leaves will be updated. a
2363 * single leaf may describe the free space of multiple dmap words,
2364 * so we may update only a subset of the actual leaves corresponding
2365 * to the dmap words of the block range.
2366 *
2367 * dbJoin() is used to update leaf values and will join the binary
2368 * buddy system of the leaves if the new leaf values indicate this
2369 * should be done.
2370 */
2371 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2372 /* determine the bit number within the word and
2373 * the number of bits within the word.
2374 */
2375 wbitno = dbitno & (DBWORD - 1);
2376 nb = min(rembits, DBWORD - wbitno);
2377
2378 /* check if only part of a word is to be freed.
2379 */
2380 if (nb < DBWORD) {
2381 /* free (zero) the appropriate bits within this
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002382 * dmap word.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002383 */
2384 dp->wmap[word] &=
2385 cpu_to_le32(~(ONES << (DBWORD - nb)
2386 >> wbitno));
2387
2388 /* update the leaf for this dmap word.
2389 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002390 rc = dbJoin(tp, word,
2391 dbMaxBud((u8 *) & dp->wmap[word]));
2392 if (rc)
2393 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002394
2395 word += 1;
2396 } else {
2397 /* one or more dmap words are fully contained
2398 * within the block range. determine how many
2399 * words and free (zero) the bits of these words.
2400 */
2401 nwords = rembits >> L2DBWORD;
2402 memset(&dp->wmap[word], 0, nwords * 4);
2403
2404 /* determine how many bits.
2405 */
2406 nb = nwords << L2DBWORD;
2407
2408 /* now update the appropriate leaves to reflect
2409 * the freed words.
2410 */
2411 for (; nwords > 0; nwords -= nw) {
2412 /* determine what the leaf value should be
2413 * updated to as the minimum of the l2 number
2414 * of bits being freed and the l2 (max) number
2415 * of bits that can be described by this leaf.
2416 */
2417 size =
2418 min(LITOL2BSZ
2419 (word, L2LPERDMAP, BUDMIN),
2420 NLSTOL2BSZ(nwords));
2421
2422 /* update the leaf.
2423 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002424 rc = dbJoin(tp, word, size);
2425 if (rc)
2426 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002427
2428 /* get the number of dmap words handled.
2429 */
2430 nw = BUDSIZE(size, BUDMIN);
2431 word += nw;
2432 }
2433 }
2434 }
2435
2436 /* update the free count for this dmap.
2437 */
Marcin Slusarz89145622008-02-13 15:34:20 -06002438 le32_add_cpu(&dp->nfree, nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002439
2440 BMAP_LOCK(bmp);
2441
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002442 /* update the free count for the allocation group and
Linus Torvalds1da177e2005-04-16 15:20:36 -07002443 * map.
2444 */
2445 agno = blkno >> bmp->db_agl2size;
2446 bmp->db_nfree += nblocks;
2447 bmp->db_agfree[agno] += nblocks;
2448
2449 /* check if this allocation group is not completely free and
2450 * if it is currently the maximum (rightmost) allocation group.
2451 * if so, establish the new maximum allocation group number by
2452 * searching left for the first allocation group with allocation.
2453 */
2454 if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) ||
2455 (agno == bmp->db_numag - 1 &&
2456 bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) {
2457 while (bmp->db_maxag > 0) {
2458 bmp->db_maxag -= 1;
2459 if (bmp->db_agfree[bmp->db_maxag] !=
2460 bmp->db_agsize)
2461 break;
2462 }
2463
2464 /* re-establish the allocation group preference if the
2465 * current preference is right of the maximum allocation
2466 * group.
2467 */
2468 if (bmp->db_agpref > bmp->db_maxag)
2469 bmp->db_agpref = bmp->db_maxag;
2470 }
2471
2472 BMAP_UNLOCK(bmp);
Dave Kleikamp56d12542005-07-15 09:43:36 -05002473
2474 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002475}
2476
2477
2478/*
2479 * NAME: dbAdjCtl()
2480 *
2481 * FUNCTION: adjust a dmap control page at a specified level to reflect
2482 * the change in a lower level dmap or dmap control page's
2483 * maximum string of free blocks (i.e. a change in the root
2484 * of the lower level object's dmtree) due to the allocation
2485 * or deallocation of a range of blocks with a single dmap.
2486 *
2487 * on entry, this routine is provided with the new value of
2488 * the lower level dmap or dmap control page root and the
2489 * starting block number of the block range whose allocation
2490 * or deallocation resulted in the root change. this range
2491 * is respresented by a single leaf of the current dmapctl
2492 * and the leaf will be updated with this value, possibly
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002493 * causing a binary buddy system within the leaves to be
Linus Torvalds1da177e2005-04-16 15:20:36 -07002494 * split or joined. the update may also cause the dmapctl's
2495 * dmtree to be updated.
2496 *
2497 * if the adjustment of the dmap control page, itself, causes its
2498 * root to change, this change will be bubbled up to the next dmap
2499 * control level by a recursive call to this routine, specifying
2500 * the new root value and the next dmap control page level to
2501 * be adjusted.
2502 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002503 * bmp - pointer to bmap descriptor
2504 * blkno - the first block of a block range within a dmap. it is
Linus Torvalds1da177e2005-04-16 15:20:36 -07002505 * the allocation or deallocation of this block range that
2506 * requires the dmap control page to be adjusted.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002507 * newval - the new value of the lower level dmap or dmap control
Linus Torvalds1da177e2005-04-16 15:20:36 -07002508 * page root.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002509 * alloc - 'true' if adjustment is due to an allocation.
2510 * level - current level of dmap control page (i.e. L0, L1, L2) to
Linus Torvalds1da177e2005-04-16 15:20:36 -07002511 * be adjusted.
2512 *
2513 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002514 * 0 - success
2515 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07002516 *
2517 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2518 */
2519static int
2520dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
2521{
2522 struct metapage *mp;
2523 s8 oldroot;
2524 int oldval;
2525 s64 lblkno;
2526 struct dmapctl *dcp;
2527 int rc, leafno, ti;
2528
2529 /* get the buffer for the dmap control page for the specified
2530 * block number and control page level.
2531 */
2532 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level);
2533 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
2534 if (mp == NULL)
2535 return -EIO;
2536 dcp = (struct dmapctl *) mp->data;
2537
2538 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
2539 jfs_error(bmp->db_ipbmap->i_sb,
2540 "dbAdjCtl: Corrupt dmapctl page");
2541 release_metapage(mp);
2542 return -EIO;
2543 }
2544
2545 /* determine the leaf number corresponding to the block and
2546 * the index within the dmap control tree.
2547 */
2548 leafno = BLKTOCTLLEAF(blkno, dcp->budmin);
2549 ti = leafno + le32_to_cpu(dcp->leafidx);
2550
2551 /* save the current leaf value and the current root level (i.e.
2552 * maximum l2 free string described by this dmapctl).
2553 */
2554 oldval = dcp->stree[ti];
2555 oldroot = dcp->stree[ROOT];
2556
2557 /* check if this is a control page update for an allocation.
2558 * if so, update the leaf to reflect the new leaf value using
Thomas Weber88393162010-03-16 11:47:56 +01002559 * dbSplit(); otherwise (deallocation), use dbJoin() to update
Linus Torvalds1da177e2005-04-16 15:20:36 -07002560 * the leaf with the new value. in addition to updating the
2561 * leaf, dbSplit() will also split the binary buddy system of
2562 * the leaves, if required, and bubble new values within the
2563 * dmapctl tree, if required. similarly, dbJoin() will join
2564 * the binary buddy system of leaves and bubble new values up
2565 * the dmapctl tree as required by the new leaf value.
2566 */
2567 if (alloc) {
2568 /* check if we are in the middle of a binary buddy
2569 * system. this happens when we are performing the
2570 * first allocation out of an allocation group that
2571 * is part (not the first part) of a larger binary
2572 * buddy system. if we are in the middle, back split
2573 * the system prior to calling dbSplit() which assumes
2574 * that it is at the front of a binary buddy system.
2575 */
2576 if (oldval == NOFREE) {
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002577 rc = dbBackSplit((dmtree_t *) dcp, leafno);
2578 if (rc)
2579 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002580 oldval = dcp->stree[ti];
2581 }
2582 dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval);
2583 } else {
Dave Kleikamp56d12542005-07-15 09:43:36 -05002584 rc = dbJoin((dmtree_t *) dcp, leafno, newval);
2585 if (rc)
2586 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002587 }
2588
2589 /* check if the root of the current dmap control page changed due
2590 * to the update and if the current dmap control page is not at
2591 * the current top level (i.e. L0, L1, L2) of the map. if so (i.e.
2592 * root changed and this is not the top level), call this routine
2593 * again (recursion) for the next higher level of the mapping to
2594 * reflect the change in root for the current dmap control page.
2595 */
2596 if (dcp->stree[ROOT] != oldroot) {
2597 /* are we below the top level of the map. if so,
2598 * bubble the root up to the next higher level.
2599 */
2600 if (level < bmp->db_maxlevel) {
2601 /* bubble up the new root of this dmap control page to
2602 * the next level.
2603 */
2604 if ((rc =
2605 dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc,
2606 level + 1))) {
2607 /* something went wrong in bubbling up the new
2608 * root value, so backout the changes to the
2609 * current dmap control page.
2610 */
2611 if (alloc) {
2612 dbJoin((dmtree_t *) dcp, leafno,
2613 oldval);
2614 } else {
2615 /* the dbJoin() above might have
2616 * caused a larger binary buddy system
2617 * to form and we may now be in the
2618 * middle of it. if this is the case,
2619 * back split the buddies.
2620 */
2621 if (dcp->stree[ti] == NOFREE)
2622 dbBackSplit((dmtree_t *)
2623 dcp, leafno);
2624 dbSplit((dmtree_t *) dcp, leafno,
2625 dcp->budmin, oldval);
2626 }
2627
2628 /* release the buffer and return the error.
2629 */
2630 release_metapage(mp);
2631 return (rc);
2632 }
2633 } else {
2634 /* we're at the top level of the map. update
2635 * the bmap control page to reflect the size
2636 * of the maximum free buddy system.
2637 */
2638 assert(level == bmp->db_maxlevel);
2639 if (bmp->db_maxfreebud != oldroot) {
2640 jfs_error(bmp->db_ipbmap->i_sb,
2641 "dbAdjCtl: the maximum free buddy is "
2642 "not the old root");
2643 }
2644 bmp->db_maxfreebud = dcp->stree[ROOT];
2645 }
2646 }
2647
2648 /* write the buffer.
2649 */
2650 write_metapage(mp);
2651
2652 return (0);
2653}
2654
2655
2656/*
2657 * NAME: dbSplit()
2658 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002659 * FUNCTION: update the leaf of a dmtree with a new value, splitting
Linus Torvalds1da177e2005-04-16 15:20:36 -07002660 * the leaf from the binary buddy system of the dmtree's
2661 * leaves, as required.
2662 *
2663 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002664 * tp - pointer to the tree containing the leaf.
2665 * leafno - the number of the leaf to be updated.
2666 * splitsz - the size the binary buddy system starting at the leaf
Linus Torvalds1da177e2005-04-16 15:20:36 -07002667 * must be split to, specified as the log2 number of blocks.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002668 * newval - the new value for the leaf.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002669 *
2670 * RETURN VALUES: none
2671 *
2672 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2673 */
2674static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval)
2675{
2676 int budsz;
2677 int cursz;
2678 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2679
2680 /* check if the leaf needs to be split.
2681 */
2682 if (leaf[leafno] > tp->dmt_budmin) {
2683 /* the split occurs by cutting the buddy system in half
2684 * at the specified leaf until we reach the specified
2685 * size. pick up the starting split size (current size
2686 * - 1 in l2) and the corresponding buddy size.
2687 */
2688 cursz = leaf[leafno] - 1;
2689 budsz = BUDSIZE(cursz, tp->dmt_budmin);
2690
2691 /* split until we reach the specified size.
2692 */
2693 while (cursz >= splitsz) {
2694 /* update the buddy's leaf with its new value.
2695 */
2696 dbAdjTree(tp, leafno ^ budsz, cursz);
2697
2698 /* on to the next size and buddy.
2699 */
2700 cursz -= 1;
2701 budsz >>= 1;
2702 }
2703 }
2704
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002705 /* adjust the dmap tree to reflect the specified leaf's new
Linus Torvalds1da177e2005-04-16 15:20:36 -07002706 * value.
2707 */
2708 dbAdjTree(tp, leafno, newval);
2709}
2710
2711
2712/*
2713 * NAME: dbBackSplit()
2714 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002715 * FUNCTION: back split the binary buddy system of dmtree leaves
Linus Torvalds1da177e2005-04-16 15:20:36 -07002716 * that hold a specified leaf until the specified leaf
2717 * starts its own binary buddy system.
2718 *
2719 * the allocators typically perform allocations at the start
2720 * of binary buddy systems and dbSplit() is used to accomplish
2721 * any required splits. in some cases, however, allocation
2722 * may occur in the middle of a binary system and requires a
2723 * back split, with the split proceeding out from the middle of
2724 * the system (less efficient) rather than the start of the
2725 * system (more efficient). the cases in which a back split
2726 * is required are rare and are limited to the first allocation
2727 * within an allocation group which is a part (not first part)
2728 * of a larger binary buddy system and a few exception cases
2729 * in which a previous join operation must be backed out.
2730 *
2731 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002732 * tp - pointer to the tree containing the leaf.
2733 * leafno - the number of the leaf to be updated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002734 *
2735 * RETURN VALUES: none
2736 *
2737 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2738 */
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002739static int dbBackSplit(dmtree_t * tp, int leafno)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002740{
2741 int budsz, bud, w, bsz, size;
2742 int cursz;
2743 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2744
2745 /* leaf should be part (not first part) of a binary
2746 * buddy system.
2747 */
2748 assert(leaf[leafno] == NOFREE);
2749
2750 /* the back split is accomplished by iteratively finding the leaf
2751 * that starts the buddy system that contains the specified leaf and
2752 * splitting that system in two. this iteration continues until
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002753 * the specified leaf becomes the start of a buddy system.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002754 *
2755 * determine maximum possible l2 size for the specified leaf.
2756 */
2757 size =
2758 LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs),
2759 tp->dmt_budmin);
2760
2761 /* determine the number of leaves covered by this size. this
2762 * is the buddy size that we will start with as we search for
2763 * the buddy system that contains the specified leaf.
2764 */
2765 budsz = BUDSIZE(size, tp->dmt_budmin);
2766
2767 /* back split.
2768 */
2769 while (leaf[leafno] == NOFREE) {
2770 /* find the leftmost buddy leaf.
2771 */
2772 for (w = leafno, bsz = budsz;; bsz <<= 1,
2773 w = (w < bud) ? w : bud) {
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002774 if (bsz >= le32_to_cpu(tp->dmt_nleafs)) {
2775 jfs_err("JFS: block map error in dbBackSplit");
2776 return -EIO;
2777 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002778
2779 /* determine the buddy.
2780 */
2781 bud = w ^ bsz;
2782
2783 /* check if this buddy is the start of the system.
2784 */
2785 if (leaf[bud] != NOFREE) {
2786 /* split the leaf at the start of the
2787 * system in two.
2788 */
2789 cursz = leaf[bud] - 1;
2790 dbSplit(tp, bud, cursz, cursz);
2791 break;
2792 }
2793 }
2794 }
2795
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002796 if (leaf[leafno] != size) {
2797 jfs_err("JFS: wrong leaf value in dbBackSplit");
2798 return -EIO;
2799 }
2800 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002801}
2802
2803
2804/*
2805 * NAME: dbJoin()
2806 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002807 * FUNCTION: update the leaf of a dmtree with a new value, joining
Linus Torvalds1da177e2005-04-16 15:20:36 -07002808 * the leaf with other leaves of the dmtree into a multi-leaf
2809 * binary buddy system, as required.
2810 *
2811 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002812 * tp - pointer to the tree containing the leaf.
2813 * leafno - the number of the leaf to be updated.
2814 * newval - the new value for the leaf.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002815 *
2816 * RETURN VALUES: none
2817 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002818static int dbJoin(dmtree_t * tp, int leafno, int newval)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002819{
2820 int budsz, buddy;
2821 s8 *leaf;
2822
2823 /* can the new leaf value require a join with other leaves ?
2824 */
2825 if (newval >= tp->dmt_budmin) {
2826 /* pickup a pointer to the leaves of the tree.
2827 */
2828 leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2829
2830 /* try to join the specified leaf into a large binary
2831 * buddy system. the join proceeds by attempting to join
2832 * the specified leafno with its buddy (leaf) at new value.
2833 * if the join occurs, we attempt to join the left leaf
2834 * of the joined buddies with its buddy at new value + 1.
2835 * we continue to join until we find a buddy that cannot be
2836 * joined (does not have a value equal to the size of the
2837 * last join) or until all leaves have been joined into a
2838 * single system.
2839 *
2840 * get the buddy size (number of words covered) of
2841 * the new value.
2842 */
2843 budsz = BUDSIZE(newval, tp->dmt_budmin);
2844
2845 /* try to join.
2846 */
2847 while (budsz < le32_to_cpu(tp->dmt_nleafs)) {
2848 /* get the buddy leaf.
2849 */
2850 buddy = leafno ^ budsz;
2851
2852 /* if the leaf's new value is greater than its
2853 * buddy's value, we join no more.
2854 */
2855 if (newval > leaf[buddy])
2856 break;
2857
Dave Kleikamp56d12542005-07-15 09:43:36 -05002858 /* It shouldn't be less */
2859 if (newval < leaf[buddy])
2860 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002861
2862 /* check which (leafno or buddy) is the left buddy.
2863 * the left buddy gets to claim the blocks resulting
2864 * from the join while the right gets to claim none.
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002865 * the left buddy is also eligible to participate in
Linus Torvalds1da177e2005-04-16 15:20:36 -07002866 * a join at the next higher level while the right
2867 * is not.
2868 *
2869 */
2870 if (leafno < buddy) {
2871 /* leafno is the left buddy.
2872 */
2873 dbAdjTree(tp, buddy, NOFREE);
2874 } else {
2875 /* buddy is the left buddy and becomes
2876 * leafno.
2877 */
2878 dbAdjTree(tp, leafno, NOFREE);
2879 leafno = buddy;
2880 }
2881
2882 /* on to try the next join.
2883 */
2884 newval += 1;
2885 budsz <<= 1;
2886 }
2887 }
2888
2889 /* update the leaf value.
2890 */
2891 dbAdjTree(tp, leafno, newval);
Dave Kleikamp56d12542005-07-15 09:43:36 -05002892
2893 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002894}
2895
2896
2897/*
2898 * NAME: dbAdjTree()
2899 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002900 * FUNCTION: update a leaf of a dmtree with a new value, adjusting
Linus Torvalds1da177e2005-04-16 15:20:36 -07002901 * the dmtree, as required, to reflect the new leaf value.
2902 * the combination of any buddies must already be done before
2903 * this is called.
2904 *
2905 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002906 * tp - pointer to the tree to be adjusted.
2907 * leafno - the number of the leaf to be updated.
2908 * newval - the new value for the leaf.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002909 *
2910 * RETURN VALUES: none
2911 */
2912static void dbAdjTree(dmtree_t * tp, int leafno, int newval)
2913{
2914 int lp, pp, k;
2915 int max;
2916
2917 /* pick up the index of the leaf for this leafno.
2918 */
2919 lp = leafno + le32_to_cpu(tp->dmt_leafidx);
2920
2921 /* is the current value the same as the old value ? if so,
2922 * there is nothing to do.
2923 */
2924 if (tp->dmt_stree[lp] == newval)
2925 return;
2926
2927 /* set the new value.
2928 */
2929 tp->dmt_stree[lp] = newval;
2930
2931 /* bubble the new value up the tree as required.
2932 */
2933 for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) {
2934 /* get the index of the first leaf of the 4 leaf
2935 * group containing the specified leaf (leafno).
2936 */
2937 lp = ((lp - 1) & ~0x03) + 1;
2938
2939 /* get the index of the parent of this 4 leaf group.
2940 */
2941 pp = (lp - 1) >> 2;
2942
2943 /* determine the maximum of the 4 leaves.
2944 */
2945 max = TREEMAX(&tp->dmt_stree[lp]);
2946
2947 /* if the maximum of the 4 is the same as the
2948 * parent's value, we're done.
2949 */
2950 if (tp->dmt_stree[pp] == max)
2951 break;
2952
2953 /* parent gets new value.
2954 */
2955 tp->dmt_stree[pp] = max;
2956
2957 /* parent becomes leaf for next go-round.
2958 */
2959 lp = pp;
2960 }
2961}
2962
2963
2964/*
2965 * NAME: dbFindLeaf()
2966 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002967 * FUNCTION: search a dmtree_t for sufficient free blocks, returning
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002968 * the index of a leaf describing the free blocks if
Linus Torvalds1da177e2005-04-16 15:20:36 -07002969 * sufficient free blocks are found.
2970 *
2971 * the search starts at the top of the dmtree_t tree and
2972 * proceeds down the tree to the leftmost leaf with sufficient
2973 * free space.
2974 *
2975 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002976 * tp - pointer to the tree to be searched.
2977 * l2nb - log2 number of free blocks to search for.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002978 * leafidx - return pointer to be set to the index of the leaf
2979 * describing at least l2nb free blocks if sufficient
2980 * free blocks are found.
2981 *
2982 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002983 * 0 - success
2984 * -ENOSPC - insufficient free blocks.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002985 */
2986static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx)
2987{
2988 int ti, n = 0, k, x = 0;
2989
2990 /* first check the root of the tree to see if there is
2991 * sufficient free space.
2992 */
2993 if (l2nb > tp->dmt_stree[ROOT])
2994 return -ENOSPC;
2995
2996 /* sufficient free space available. now search down the tree
2997 * starting at the next level for the leftmost leaf that
2998 * describes sufficient free space.
2999 */
3000 for (k = le32_to_cpu(tp->dmt_height), ti = 1;
3001 k > 0; k--, ti = ((ti + n) << 2) + 1) {
3002 /* search the four nodes at this level, starting from
3003 * the left.
3004 */
3005 for (x = ti, n = 0; n < 4; n++) {
3006 /* sufficient free space found. move to the next
3007 * level (or quit if this is the last level).
3008 */
3009 if (l2nb <= tp->dmt_stree[x + n])
3010 break;
3011 }
3012
3013 /* better have found something since the higher
3014 * levels of the tree said it was here.
3015 */
3016 assert(n < 4);
3017 }
3018
3019 /* set the return to the leftmost leaf describing sufficient
3020 * free space.
3021 */
3022 *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx);
3023
3024 return (0);
3025}
3026
3027
3028/*
3029 * NAME: dbFindBits()
3030 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003031 * FUNCTION: find a specified number of binary buddy free bits within a
Linus Torvalds1da177e2005-04-16 15:20:36 -07003032 * dmap bitmap word value.
3033 *
3034 * this routine searches the bitmap value for (1 << l2nb) free
3035 * bits at (1 << l2nb) alignments within the value.
3036 *
3037 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003038 * word - dmap bitmap word value.
3039 * l2nb - number of free bits specified as a log2 number.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003040 *
3041 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003042 * starting bit number of free bits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003043 */
3044static int dbFindBits(u32 word, int l2nb)
3045{
3046 int bitno, nb;
3047 u32 mask;
3048
3049 /* get the number of bits.
3050 */
3051 nb = 1 << l2nb;
3052 assert(nb <= DBWORD);
3053
3054 /* complement the word so we can use a mask (i.e. 0s represent
3055 * free bits) and compute the mask.
3056 */
3057 word = ~word;
3058 mask = ONES << (DBWORD - nb);
3059
3060 /* scan the word for nb free bits at nb alignments.
3061 */
3062 for (bitno = 0; mask != 0; bitno += nb, mask >>= nb) {
3063 if ((mask & word) == mask)
3064 break;
3065 }
3066
3067 ASSERT(bitno < 32);
3068
3069 /* return the bit number.
3070 */
3071 return (bitno);
3072}
3073
3074
3075/*
3076 * NAME: dbMaxBud(u8 *cp)
3077 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003078 * FUNCTION: determine the largest binary buddy string of free
Linus Torvalds1da177e2005-04-16 15:20:36 -07003079 * bits within 32-bits of the map.
3080 *
3081 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003082 * cp - pointer to the 32-bit value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003083 *
3084 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003085 * largest binary buddy of free bits within a dmap word.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003086 */
3087static int dbMaxBud(u8 * cp)
3088{
3089 signed char tmp1, tmp2;
3090
3091 /* check if the wmap word is all free. if so, the
3092 * free buddy size is BUDMIN.
3093 */
3094 if (*((uint *) cp) == 0)
3095 return (BUDMIN);
3096
3097 /* check if the wmap word is half free. if so, the
3098 * free buddy size is BUDMIN-1.
3099 */
3100 if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0)
3101 return (BUDMIN - 1);
3102
3103 /* not all free or half free. determine the free buddy
3104 * size thru table lookup using quarters of the wmap word.
3105 */
3106 tmp1 = max(budtab[cp[2]], budtab[cp[3]]);
3107 tmp2 = max(budtab[cp[0]], budtab[cp[1]]);
3108 return (max(tmp1, tmp2));
3109}
3110
3111
3112/*
3113 * NAME: cnttz(uint word)
3114 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003115 * FUNCTION: determine the number of trailing zeros within a 32-bit
Linus Torvalds1da177e2005-04-16 15:20:36 -07003116 * value.
3117 *
3118 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003119 * value - 32-bit value to be examined.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003120 *
3121 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003122 * count of trailing zeros
Linus Torvalds1da177e2005-04-16 15:20:36 -07003123 */
3124static int cnttz(u32 word)
3125{
3126 int n;
3127
3128 for (n = 0; n < 32; n++, word >>= 1) {
3129 if (word & 0x01)
3130 break;
3131 }
3132
3133 return (n);
3134}
3135
3136
3137/*
3138 * NAME: cntlz(u32 value)
3139 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003140 * FUNCTION: determine the number of leading zeros within a 32-bit
Linus Torvalds1da177e2005-04-16 15:20:36 -07003141 * value.
3142 *
3143 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003144 * value - 32-bit value to be examined.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003145 *
3146 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003147 * count of leading zeros
Linus Torvalds1da177e2005-04-16 15:20:36 -07003148 */
3149static int cntlz(u32 value)
3150{
3151 int n;
3152
3153 for (n = 0; n < 32; n++, value <<= 1) {
3154 if (value & HIGHORDER)
3155 break;
3156 }
3157 return (n);
3158}
3159
3160
3161/*
3162 * NAME: blkstol2(s64 nb)
3163 *
3164 * FUNCTION: convert a block count to its log2 value. if the block
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003165 * count is not a l2 multiple, it is rounded up to the next
Linus Torvalds1da177e2005-04-16 15:20:36 -07003166 * larger l2 multiple.
3167 *
3168 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003169 * nb - number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003170 *
3171 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003172 * log2 number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003173 */
Dave Kleikamp6cb12692005-09-15 23:25:41 -05003174static int blkstol2(s64 nb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003175{
3176 int l2nb;
3177 s64 mask; /* meant to be signed */
3178
3179 mask = (s64) 1 << (64 - 1);
3180
3181 /* count the leading bits.
3182 */
3183 for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) {
3184 /* leading bit found.
3185 */
3186 if (nb & mask) {
3187 /* determine the l2 value.
3188 */
3189 l2nb = (64 - 1) - l2nb;
3190
3191 /* check if we need to round up.
3192 */
3193 if (~mask & nb)
3194 l2nb++;
3195
3196 return (l2nb);
3197 }
3198 }
3199 assert(0);
3200 return 0; /* fix compiler warning */
3201}
3202
3203
3204/*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003205 * NAME: dbAllocBottomUp()
Linus Torvalds1da177e2005-04-16 15:20:36 -07003206 *
3207 * FUNCTION: alloc the specified block range from the working block
3208 * allocation map.
3209 *
3210 * the blocks will be alloc from the working map one dmap
3211 * at a time.
3212 *
3213 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003214 * ip - pointer to in-core inode;
3215 * blkno - starting block number to be freed.
3216 * nblocks - number of blocks to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003217 *
3218 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003219 * 0 - success
3220 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07003221 */
3222int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks)
3223{
3224 struct metapage *mp;
3225 struct dmap *dp;
3226 int nb, rc;
3227 s64 lblkno, rem;
3228 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
3229 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
3230
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -06003231 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003232
3233 /* block to be allocated better be within the mapsize. */
3234 ASSERT(nblocks <= bmp->db_mapsize - blkno);
3235
3236 /*
3237 * allocate the blocks a dmap at a time.
3238 */
3239 mp = NULL;
3240 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
3241 /* release previous dmap if any */
3242 if (mp) {
3243 write_metapage(mp);
3244 }
3245
3246 /* get the buffer for the current dmap. */
3247 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
3248 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
3249 if (mp == NULL) {
3250 IREAD_UNLOCK(ipbmap);
3251 return -EIO;
3252 }
3253 dp = (struct dmap *) mp->data;
3254
3255 /* determine the number of blocks to be allocated from
3256 * this dmap.
3257 */
3258 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
3259
Linus Torvalds1da177e2005-04-16 15:20:36 -07003260 /* allocate the blocks. */
3261 if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) {
3262 release_metapage(mp);
3263 IREAD_UNLOCK(ipbmap);
3264 return (rc);
3265 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003266 }
3267
3268 /* write the last buffer. */
3269 write_metapage(mp);
3270
3271 IREAD_UNLOCK(ipbmap);
3272
3273 return (0);
3274}
3275
3276
3277static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno,
3278 int nblocks)
3279{
3280 int rc;
3281 int dbitno, word, rembits, nb, nwords, wbitno, agno;
Dave Kleikamp3c2c2262011-06-20 13:00:27 -05003282 s8 oldroot;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003283 struct dmaptree *tp = (struct dmaptree *) & dp->tree;
3284
3285 /* save the current value of the root (i.e. maximum free string)
3286 * of the dmap tree.
3287 */
3288 oldroot = tp->stree[ROOT];
3289
Linus Torvalds1da177e2005-04-16 15:20:36 -07003290 /* determine the bit number and word within the dmap of the
3291 * starting block.
3292 */
3293 dbitno = blkno & (BPERDMAP - 1);
3294 word = dbitno >> L2DBWORD;
3295
3296 /* block range better be within the dmap */
3297 assert(dbitno + nblocks <= BPERDMAP);
3298
3299 /* allocate the bits of the dmap's words corresponding to the block
3300 * range. not all bits of the first and last words may be contained
3301 * within the block range. if this is the case, we'll work against
3302 * those words (i.e. partial first and/or last) on an individual basis
3303 * (a single pass), allocating the bits of interest by hand and
3304 * updating the leaf corresponding to the dmap word. a single pass
3305 * will be used for all dmap words fully contained within the
3306 * specified range. within this pass, the bits of all fully contained
3307 * dmap words will be marked as free in a single shot and the leaves
3308 * will be updated. a single leaf may describe the free space of
3309 * multiple dmap words, so we may update only a subset of the actual
3310 * leaves corresponding to the dmap words of the block range.
3311 */
3312 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
3313 /* determine the bit number within the word and
3314 * the number of bits within the word.
3315 */
3316 wbitno = dbitno & (DBWORD - 1);
3317 nb = min(rembits, DBWORD - wbitno);
3318
3319 /* check if only part of a word is to be allocated.
3320 */
3321 if (nb < DBWORD) {
3322 /* allocate (set to 1) the appropriate bits within
3323 * this dmap word.
3324 */
3325 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
3326 >> wbitno);
3327
3328 word++;
3329 } else {
3330 /* one or more dmap words are fully contained
3331 * within the block range. determine how many
3332 * words and allocate (set to 1) the bits of these
3333 * words.
3334 */
3335 nwords = rembits >> L2DBWORD;
3336 memset(&dp->wmap[word], (int) ONES, nwords * 4);
3337
3338 /* determine how many bits */
3339 nb = nwords << L2DBWORD;
3340 word += nwords;
3341 }
3342 }
3343
3344 /* update the free count for this dmap */
Marcin Slusarz89145622008-02-13 15:34:20 -06003345 le32_add_cpu(&dp->nfree, -nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003346
3347 /* reconstruct summary tree */
3348 dbInitDmapTree(dp);
3349
3350 BMAP_LOCK(bmp);
3351
3352 /* if this allocation group is completely free,
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003353 * update the highest active allocation group number
Linus Torvalds1da177e2005-04-16 15:20:36 -07003354 * if this allocation group is the new max.
3355 */
3356 agno = blkno >> bmp->db_agl2size;
3357 if (agno > bmp->db_maxag)
3358 bmp->db_maxag = agno;
3359
3360 /* update the free count for the allocation group and map */
3361 bmp->db_agfree[agno] -= nblocks;
3362 bmp->db_nfree -= nblocks;
3363
3364 BMAP_UNLOCK(bmp);
3365
3366 /* if the root has not changed, done. */
3367 if (tp->stree[ROOT] == oldroot)
3368 return (0);
3369
3370 /* root changed. bubble the change up to the dmap control pages.
3371 * if the adjustment of the upper level control pages fails,
3372 * backout the bit allocation (thus making everything consistent).
3373 */
3374 if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0)))
3375 dbFreeBits(bmp, dp, blkno, nblocks);
3376
3377 return (rc);
3378}
3379
3380
3381/*
3382 * NAME: dbExtendFS()
3383 *
3384 * FUNCTION: extend bmap from blkno for nblocks;
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003385 * dbExtendFS() updates bmap ready for dbAllocBottomUp();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003386 *
3387 * L2
3388 * |
3389 * L1---------------------------------L1
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003390 * | |
3391 * L0---------L0---------L0 L0---------L0---------L0
3392 * | | | | | |
3393 * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003394 * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm
3395 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003396 * <---old---><----------------------------extend----------------------->
Linus Torvalds1da177e2005-04-16 15:20:36 -07003397 */
3398int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks)
3399{
3400 struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb);
3401 int nbperpage = sbi->nbperpage;
Richard Knutsson4d817152006-09-30 23:27:14 -07003402 int i, i0 = true, j, j0 = true, k, n;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003403 s64 newsize;
3404 s64 p;
3405 struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL;
3406 struct dmapctl *l2dcp, *l1dcp, *l0dcp;
3407 struct dmap *dp;
3408 s8 *l0leaf, *l1leaf, *l2leaf;
3409 struct bmap *bmp = sbi->bmap;
3410 int agno, l2agsize, oldl2agsize;
3411 s64 ag_rem;
3412
3413 newsize = blkno + nblocks;
3414
3415 jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld",
3416 (long long) blkno, (long long) nblocks, (long long) newsize);
3417
3418 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003419 * initialize bmap control page.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003420 *
3421 * all the data in bmap control page should exclude
3422 * the mkfs hidden dmap page.
3423 */
3424
3425 /* update mapsize */
3426 bmp->db_mapsize = newsize;
3427 bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize);
3428
3429 /* compute new AG size */
3430 l2agsize = dbGetL2AGSize(newsize);
3431 oldl2agsize = bmp->db_agl2size;
3432
3433 bmp->db_agl2size = l2agsize;
3434 bmp->db_agsize = 1 << l2agsize;
3435
3436 /* compute new number of AG */
3437 agno = bmp->db_numag;
3438 bmp->db_numag = newsize >> l2agsize;
3439 bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0;
3440
3441 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003442 * reconfigure db_agfree[]
Linus Torvalds1da177e2005-04-16 15:20:36 -07003443 * from old AG configuration to new AG configuration;
3444 *
3445 * coalesce contiguous k (newAGSize/oldAGSize) AGs;
3446 * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn;
3447 * note: new AG size = old AG size * (2**x).
3448 */
3449 if (l2agsize == oldl2agsize)
3450 goto extend;
3451 k = 1 << (l2agsize - oldl2agsize);
3452 ag_rem = bmp->db_agfree[0]; /* save agfree[0] */
3453 for (i = 0, n = 0; i < agno; n++) {
3454 bmp->db_agfree[n] = 0; /* init collection point */
3455
André Goddard Rosaaf901ca2009-11-14 13:09:05 -02003456 /* coalesce contiguous k AGs; */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003457 for (j = 0; j < k && i < agno; j++, i++) {
3458 /* merge AGi to AGn */
3459 bmp->db_agfree[n] += bmp->db_agfree[i];
3460 }
3461 }
3462 bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */
3463
3464 for (; n < MAXAG; n++)
3465 bmp->db_agfree[n] = 0;
3466
3467 /*
3468 * update highest active ag number
3469 */
3470
3471 bmp->db_maxag = bmp->db_maxag / k;
3472
3473 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003474 * extend bmap
Linus Torvalds1da177e2005-04-16 15:20:36 -07003475 *
3476 * update bit maps and corresponding level control pages;
3477 * global control page db_nfree, db_agfree[agno], db_maxfreebud;
3478 */
3479 extend:
3480 /* get L2 page */
3481 p = BMAPBLKNO + nbperpage; /* L2 page */
3482 l2mp = read_metapage(ipbmap, p, PSIZE, 0);
3483 if (!l2mp) {
3484 jfs_error(ipbmap->i_sb, "dbExtendFS: L2 page could not be read");
3485 return -EIO;
3486 }
3487 l2dcp = (struct dmapctl *) l2mp->data;
3488
3489 /* compute start L1 */
3490 k = blkno >> L2MAXL1SIZE;
3491 l2leaf = l2dcp->stree + CTLLEAFIND + k;
3492 p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */
3493
3494 /*
3495 * extend each L1 in L2
3496 */
3497 for (; k < LPERCTL; k++, p += nbperpage) {
3498 /* get L1 page */
3499 if (j0) {
3500 /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */
3501 l1mp = read_metapage(ipbmap, p, PSIZE, 0);
3502 if (l1mp == NULL)
3503 goto errout;
3504 l1dcp = (struct dmapctl *) l1mp->data;
3505
3506 /* compute start L0 */
3507 j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE;
3508 l1leaf = l1dcp->stree + CTLLEAFIND + j;
3509 p = BLKTOL0(blkno, sbi->l2nbperpage);
Richard Knutsson4d817152006-09-30 23:27:14 -07003510 j0 = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003511 } else {
3512 /* assign/init L1 page */
3513 l1mp = get_metapage(ipbmap, p, PSIZE, 0);
3514 if (l1mp == NULL)
3515 goto errout;
3516
3517 l1dcp = (struct dmapctl *) l1mp->data;
3518
3519 /* compute start L0 */
3520 j = 0;
3521 l1leaf = l1dcp->stree + CTLLEAFIND;
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003522 p += nbperpage; /* 1st L0 of L1.k */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003523 }
3524
3525 /*
3526 * extend each L0 in L1
3527 */
3528 for (; j < LPERCTL; j++) {
3529 /* get L0 page */
3530 if (i0) {
3531 /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */
3532
3533 l0mp = read_metapage(ipbmap, p, PSIZE, 0);
3534 if (l0mp == NULL)
3535 goto errout;
3536 l0dcp = (struct dmapctl *) l0mp->data;
3537
3538 /* compute start dmap */
3539 i = (blkno & (MAXL0SIZE - 1)) >>
3540 L2BPERDMAP;
3541 l0leaf = l0dcp->stree + CTLLEAFIND + i;
3542 p = BLKTODMAP(blkno,
3543 sbi->l2nbperpage);
Richard Knutsson4d817152006-09-30 23:27:14 -07003544 i0 = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003545 } else {
3546 /* assign/init L0 page */
3547 l0mp = get_metapage(ipbmap, p, PSIZE, 0);
3548 if (l0mp == NULL)
3549 goto errout;
3550
3551 l0dcp = (struct dmapctl *) l0mp->data;
3552
3553 /* compute start dmap */
3554 i = 0;
3555 l0leaf = l0dcp->stree + CTLLEAFIND;
3556 p += nbperpage; /* 1st dmap of L0.j */
3557 }
3558
3559 /*
3560 * extend each dmap in L0
3561 */
3562 for (; i < LPERCTL; i++) {
3563 /*
3564 * reconstruct the dmap page, and
3565 * initialize corresponding parent L0 leaf
3566 */
3567 if ((n = blkno & (BPERDMAP - 1))) {
3568 /* read in dmap page: */
3569 mp = read_metapage(ipbmap, p,
3570 PSIZE, 0);
3571 if (mp == NULL)
3572 goto errout;
3573 n = min(nblocks, (s64)BPERDMAP - n);
3574 } else {
3575 /* assign/init dmap page */
3576 mp = read_metapage(ipbmap, p,
3577 PSIZE, 0);
3578 if (mp == NULL)
3579 goto errout;
3580
3581 n = min(nblocks, (s64)BPERDMAP);
3582 }
3583
3584 dp = (struct dmap *) mp->data;
3585 *l0leaf = dbInitDmap(dp, blkno, n);
3586
3587 bmp->db_nfree += n;
3588 agno = le64_to_cpu(dp->start) >> l2agsize;
3589 bmp->db_agfree[agno] += n;
3590
3591 write_metapage(mp);
3592
3593 l0leaf++;
3594 p += nbperpage;
3595
3596 blkno += n;
3597 nblocks -= n;
3598 if (nblocks == 0)
3599 break;
3600 } /* for each dmap in a L0 */
3601
3602 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003603 * build current L0 page from its leaves, and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003604 * initialize corresponding parent L1 leaf
3605 */
3606 *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i);
3607 write_metapage(l0mp);
3608 l0mp = NULL;
3609
3610 if (nblocks)
3611 l1leaf++; /* continue for next L0 */
3612 else {
3613 /* more than 1 L0 ? */
3614 if (j > 0)
3615 break; /* build L1 page */
3616 else {
3617 /* summarize in global bmap page */
3618 bmp->db_maxfreebud = *l1leaf;
3619 release_metapage(l1mp);
3620 release_metapage(l2mp);
3621 goto finalize;
3622 }
3623 }
3624 } /* for each L0 in a L1 */
3625
3626 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003627 * build current L1 page from its leaves, and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003628 * initialize corresponding parent L2 leaf
3629 */
3630 *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j);
3631 write_metapage(l1mp);
3632 l1mp = NULL;
3633
3634 if (nblocks)
3635 l2leaf++; /* continue for next L1 */
3636 else {
3637 /* more than 1 L1 ? */
3638 if (k > 0)
3639 break; /* build L2 page */
3640 else {
3641 /* summarize in global bmap page */
3642 bmp->db_maxfreebud = *l2leaf;
3643 release_metapage(l2mp);
3644 goto finalize;
3645 }
3646 }
3647 } /* for each L1 in a L2 */
3648
3649 jfs_error(ipbmap->i_sb,
3650 "dbExtendFS: function has not returned as expected");
3651errout:
3652 if (l0mp)
3653 release_metapage(l0mp);
3654 if (l1mp)
3655 release_metapage(l1mp);
3656 release_metapage(l2mp);
3657 return -EIO;
3658
3659 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003660 * finalize bmap control page
Linus Torvalds1da177e2005-04-16 15:20:36 -07003661 */
3662finalize:
3663
3664 return 0;
3665}
3666
3667
3668/*
3669 * dbFinalizeBmap()
3670 */
3671void dbFinalizeBmap(struct inode *ipbmap)
3672{
3673 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
3674 int actags, inactags, l2nl;
3675 s64 ag_rem, actfree, inactfree, avgfree;
3676 int i, n;
3677
3678 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003679 * finalize bmap control page
Linus Torvalds1da177e2005-04-16 15:20:36 -07003680 */
3681//finalize:
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003682 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003683 * compute db_agpref: preferred ag to allocate from
3684 * (the leftmost ag with average free space in it);
3685 */
3686//agpref:
3687 /* get the number of active ags and inacitve ags */
3688 actags = bmp->db_maxag + 1;
3689 inactags = bmp->db_numag - actags;
3690 ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */
3691
3692 /* determine how many blocks are in the inactive allocation
3693 * groups. in doing this, we must account for the fact that
3694 * the rightmost group might be a partial group (i.e. file
3695 * system size is not a multiple of the group size).
3696 */
3697 inactfree = (inactags && ag_rem) ?
3698 ((inactags - 1) << bmp->db_agl2size) + ag_rem
3699 : inactags << bmp->db_agl2size;
3700
3701 /* determine how many free blocks are in the active
3702 * allocation groups plus the average number of free blocks
3703 * within the active ags.
3704 */
3705 actfree = bmp->db_nfree - inactfree;
3706 avgfree = (u32) actfree / (u32) actags;
3707
3708 /* if the preferred allocation group has not average free space.
3709 * re-establish the preferred group as the leftmost
3710 * group with average free space.
3711 */
3712 if (bmp->db_agfree[bmp->db_agpref] < avgfree) {
3713 for (bmp->db_agpref = 0; bmp->db_agpref < actags;
3714 bmp->db_agpref++) {
3715 if (bmp->db_agfree[bmp->db_agpref] >= avgfree)
3716 break;
3717 }
3718 if (bmp->db_agpref >= bmp->db_numag) {
3719 jfs_error(ipbmap->i_sb,
3720 "cannot find ag with average freespace");
3721 }
3722 }
3723
3724 /*
Daniel Mackd7eecb42010-01-28 16:13:01 +08003725 * compute db_aglevel, db_agheight, db_width, db_agstart:
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003726 * an ag is covered in aglevel dmapctl summary tree,
3727 * at agheight level height (from leaf) with agwidth number of nodes
3728 * each, which starts at agstart index node of the smmary tree node
Linus Torvalds1da177e2005-04-16 15:20:36 -07003729 * array;
3730 */
3731 bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize);
3732 l2nl =
3733 bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL);
Daniel Mackd7eecb42010-01-28 16:13:01 +08003734 bmp->db_agheight = l2nl >> 1;
3735 bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheight << 1));
3736 for (i = 5 - bmp->db_agheight, bmp->db_agstart = 0, n = 1; i > 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003737 i--) {
3738 bmp->db_agstart += n;
3739 n <<= 2;
3740 }
3741
3742}
3743
3744
3745/*
3746 * NAME: dbInitDmap()/ujfs_idmap_page()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003747 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003748 * FUNCTION: initialize working/persistent bitmap of the dmap page
3749 * for the specified number of blocks:
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003750 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003751 * at entry, the bitmaps had been initialized as free (ZEROS);
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003752 * The number of blocks will only account for the actually
3753 * existing blocks. Blocks which don't actually exist in
Linus Torvalds1da177e2005-04-16 15:20:36 -07003754 * the aggregate will be marked as allocated (ONES);
3755 *
3756 * PARAMETERS:
3757 * dp - pointer to page of map
3758 * nblocks - number of blocks this page
3759 *
3760 * RETURNS: NONE
3761 */
3762static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks)
3763{
3764 int blkno, w, b, r, nw, nb, i;
3765
3766 /* starting block number within the dmap */
3767 blkno = Blkno & (BPERDMAP - 1);
3768
3769 if (blkno == 0) {
3770 dp->nblocks = dp->nfree = cpu_to_le32(nblocks);
3771 dp->start = cpu_to_le64(Blkno);
3772
3773 if (nblocks == BPERDMAP) {
3774 memset(&dp->wmap[0], 0, LPERDMAP * 4);
3775 memset(&dp->pmap[0], 0, LPERDMAP * 4);
3776 goto initTree;
3777 }
3778 } else {
Marcin Slusarz89145622008-02-13 15:34:20 -06003779 le32_add_cpu(&dp->nblocks, nblocks);
3780 le32_add_cpu(&dp->nfree, nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003781 }
3782
3783 /* word number containing start block number */
3784 w = blkno >> L2DBWORD;
3785
3786 /*
3787 * free the bits corresponding to the block range (ZEROS):
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003788 * note: not all bits of the first and last words may be contained
Linus Torvalds1da177e2005-04-16 15:20:36 -07003789 * within the block range.
3790 */
3791 for (r = nblocks; r > 0; r -= nb, blkno += nb) {
3792 /* number of bits preceding range to be freed in the word */
3793 b = blkno & (DBWORD - 1);
3794 /* number of bits to free in the word */
3795 nb = min(r, DBWORD - b);
3796
3797 /* is partial word to be freed ? */
3798 if (nb < DBWORD) {
3799 /* free (set to 0) from the bitmap word */
3800 dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3801 >> b));
3802 dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3803 >> b));
3804
3805 /* skip the word freed */
3806 w++;
3807 } else {
3808 /* free (set to 0) contiguous bitmap words */
3809 nw = r >> L2DBWORD;
3810 memset(&dp->wmap[w], 0, nw * 4);
3811 memset(&dp->pmap[w], 0, nw * 4);
3812
3813 /* skip the words freed */
3814 nb = nw << L2DBWORD;
3815 w += nw;
3816 }
3817 }
3818
3819 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003820 * mark bits following the range to be freed (non-existing
Linus Torvalds1da177e2005-04-16 15:20:36 -07003821 * blocks) as allocated (ONES)
3822 */
3823
3824 if (blkno == BPERDMAP)
3825 goto initTree;
3826
3827 /* the first word beyond the end of existing blocks */
3828 w = blkno >> L2DBWORD;
3829
3830 /* does nblocks fall on a 32-bit boundary ? */
3831 b = blkno & (DBWORD - 1);
3832 if (b) {
3833 /* mark a partial word allocated */
3834 dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b);
3835 w++;
3836 }
3837
3838 /* set the rest of the words in the page to allocated (ONES) */
3839 for (i = w; i < LPERDMAP; i++)
3840 dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES);
3841
3842 /*
3843 * init tree
3844 */
3845 initTree:
3846 return (dbInitDmapTree(dp));
3847}
3848
3849
3850/*
3851 * NAME: dbInitDmapTree()/ujfs_complete_dmap()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003852 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003853 * FUNCTION: initialize summary tree of the specified dmap:
3854 *
3855 * at entry, bitmap of the dmap has been initialized;
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003856 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003857 * PARAMETERS:
3858 * dp - dmap to complete
3859 * blkno - starting block number for this dmap
3860 * treemax - will be filled in with max free for this dmap
3861 *
3862 * RETURNS: max free string at the root of the tree
3863 */
3864static int dbInitDmapTree(struct dmap * dp)
3865{
3866 struct dmaptree *tp;
3867 s8 *cp;
3868 int i;
3869
3870 /* init fixed info of tree */
3871 tp = &dp->tree;
3872 tp->nleafs = cpu_to_le32(LPERDMAP);
3873 tp->l2nleafs = cpu_to_le32(L2LPERDMAP);
3874 tp->leafidx = cpu_to_le32(LEAFIND);
3875 tp->height = cpu_to_le32(4);
3876 tp->budmin = BUDMIN;
3877
3878 /* init each leaf from corresponding wmap word:
3879 * note: leaf is set to NOFREE(-1) if all blocks of corresponding
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003880 * bitmap word are allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003881 */
3882 cp = tp->stree + le32_to_cpu(tp->leafidx);
3883 for (i = 0; i < LPERDMAP; i++)
3884 *cp++ = dbMaxBud((u8 *) & dp->wmap[i]);
3885
3886 /* build the dmap's binary buddy summary tree */
3887 return (dbInitTree(tp));
3888}
3889
3890
3891/*
3892 * NAME: dbInitTree()/ujfs_adjtree()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003893 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003894 * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl.
3895 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003896 * at entry, the leaves of the tree has been initialized
Linus Torvalds1da177e2005-04-16 15:20:36 -07003897 * from corresponding bitmap word or root of summary tree
3898 * of the child control page;
3899 * configure binary buddy system at the leaf level, then
3900 * bubble up the values of the leaf nodes up the tree.
3901 *
3902 * PARAMETERS:
3903 * cp - Pointer to the root of the tree
3904 * l2leaves- Number of leaf nodes as a power of 2
3905 * l2min - Number of blocks that can be covered by a leaf
3906 * as a power of 2
3907 *
3908 * RETURNS: max free string at the root of the tree
3909 */
3910static int dbInitTree(struct dmaptree * dtp)
3911{
3912 int l2max, l2free, bsize, nextb, i;
3913 int child, parent, nparent;
3914 s8 *tp, *cp, *cp1;
3915
3916 tp = dtp->stree;
3917
3918 /* Determine the maximum free string possible for the leaves */
3919 l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin;
3920
3921 /*
3922 * configure the leaf levevl into binary buddy system
3923 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003924 * Try to combine buddies starting with a buddy size of 1
3925 * (i.e. two leaves). At a buddy size of 1 two buddy leaves
3926 * can be combined if both buddies have a maximum free of l2min;
3927 * the combination will result in the left-most buddy leaf having
3928 * a maximum free of l2min+1.
3929 * After processing all buddies for a given size, process buddies
3930 * at the next higher buddy size (i.e. current size * 2) and
3931 * the next maximum free (current free + 1).
3932 * This continues until the maximum possible buddy combination
Linus Torvalds1da177e2005-04-16 15:20:36 -07003933 * yields maximum free.
3934 */
3935 for (l2free = dtp->budmin, bsize = 1; l2free < l2max;
3936 l2free++, bsize = nextb) {
3937 /* get next buddy size == current buddy pair size */
3938 nextb = bsize << 1;
3939
3940 /* scan each adjacent buddy pair at current buddy size */
3941 for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx);
3942 i < le32_to_cpu(dtp->nleafs);
3943 i += nextb, cp += nextb) {
3944 /* coalesce if both adjacent buddies are max free */
3945 if (*cp == l2free && *(cp + bsize) == l2free) {
3946 *cp = l2free + 1; /* left take right */
3947 *(cp + bsize) = -1; /* right give left */
3948 }
3949 }
3950 }
3951
3952 /*
3953 * bubble summary information of leaves up the tree.
3954 *
3955 * Starting at the leaf node level, the four nodes described by
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003956 * the higher level parent node are compared for a maximum free and
3957 * this maximum becomes the value of the parent node.
3958 * when all lower level nodes are processed in this fashion then
3959 * move up to the next level (parent becomes a lower level node) and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003960 * continue the process for that level.
3961 */
3962 for (child = le32_to_cpu(dtp->leafidx),
3963 nparent = le32_to_cpu(dtp->nleafs) >> 2;
3964 nparent > 0; nparent >>= 2, child = parent) {
3965 /* get index of 1st node of parent level */
3966 parent = (child - 1) >> 2;
3967
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003968 /* set the value of the parent node as the maximum
Linus Torvalds1da177e2005-04-16 15:20:36 -07003969 * of the four nodes of the current level.
3970 */
3971 for (i = 0, cp = tp + child, cp1 = tp + parent;
3972 i < nparent; i++, cp += 4, cp1++)
3973 *cp1 = TREEMAX(cp);
3974 }
3975
3976 return (*tp);
3977}
3978
3979
3980/*
3981 * dbInitDmapCtl()
3982 *
3983 * function: initialize dmapctl page
3984 */
3985static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i)
3986{ /* start leaf index not covered by range */
3987 s8 *cp;
3988
3989 dcp->nleafs = cpu_to_le32(LPERCTL);
3990 dcp->l2nleafs = cpu_to_le32(L2LPERCTL);
3991 dcp->leafidx = cpu_to_le32(CTLLEAFIND);
3992 dcp->height = cpu_to_le32(5);
3993 dcp->budmin = L2BPERDMAP + L2LPERCTL * level;
3994
3995 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003996 * initialize the leaves of current level that were not covered
3997 * by the specified input block range (i.e. the leaves have no
Linus Torvalds1da177e2005-04-16 15:20:36 -07003998 * low level dmapctl or dmap).
3999 */
4000 cp = &dcp->stree[CTLLEAFIND + i];
4001 for (; i < LPERCTL; i++)
4002 *cp++ = NOFREE;
4003
4004 /* build the dmap's binary buddy summary tree */
4005 return (dbInitTree((struct dmaptree *) dcp));
4006}
4007
4008
4009/*
4010 * NAME: dbGetL2AGSize()/ujfs_getagl2size()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05004011 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07004012 * FUNCTION: Determine log2(allocation group size) from aggregate size
Dave Kleikamp63f83c92006-10-02 09:55:27 -05004013 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07004014 * PARAMETERS:
4015 * nblocks - Number of blocks in aggregate
4016 *
4017 * RETURNS: log2(allocation group size) in aggregate blocks
4018 */
4019static int dbGetL2AGSize(s64 nblocks)
4020{
4021 s64 sz;
4022 s64 m;
4023 int l2sz;
4024
4025 if (nblocks < BPERDMAP * MAXAG)
4026 return (L2BPERDMAP);
4027
4028 /* round up aggregate size to power of 2 */
4029 m = ((u64) 1 << (64 - 1));
4030 for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) {
4031 if (m & nblocks)
4032 break;
4033 }
4034
4035 sz = (s64) 1 << l2sz;
4036 if (sz < nblocks)
4037 l2sz += 1;
4038
4039 /* agsize = roundupSize/max_number_of_ag */
4040 return (l2sz - L2MAXAG);
4041}
4042
4043
4044/*
4045 * NAME: dbMapFileSizeToMapSize()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05004046 *
4047 * FUNCTION: compute number of blocks the block allocation map file
Linus Torvalds1da177e2005-04-16 15:20:36 -07004048 * can cover from the map file size;
4049 *
4050 * RETURNS: Number of blocks which can be covered by this block map file;
4051 */
4052
4053/*
4054 * maximum number of map pages at each level including control pages
4055 */
4056#define MAXL0PAGES (1 + LPERCTL)
4057#define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES)
4058#define MAXL2PAGES (1 + LPERCTL * MAXL1PAGES)
4059
4060/*
4061 * convert number of map pages to the zero origin top dmapctl level
4062 */
4063#define BMAPPGTOLEV(npages) \
Dave Kleikampf720e3b2007-06-06 15:28:35 -05004064 (((npages) <= 3 + MAXL0PAGES) ? 0 : \
4065 ((npages) <= 2 + MAXL1PAGES) ? 1 : 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004066
4067s64 dbMapFileSizeToMapSize(struct inode * ipbmap)
4068{
4069 struct super_block *sb = ipbmap->i_sb;
4070 s64 nblocks;
4071 s64 npages, ndmaps;
4072 int level, i;
4073 int complete, factor;
4074
4075 nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize;
4076 npages = nblocks >> JFS_SBI(sb)->l2nbperpage;
4077 level = BMAPPGTOLEV(npages);
4078
Dave Kleikamp63f83c92006-10-02 09:55:27 -05004079 /* At each level, accumulate the number of dmap pages covered by
Linus Torvalds1da177e2005-04-16 15:20:36 -07004080 * the number of full child levels below it;
4081 * repeat for the last incomplete child level.
4082 */
4083 ndmaps = 0;
4084 npages--; /* skip the first global control page */
4085 /* skip higher level control pages above top level covered by map */
4086 npages -= (2 - level);
4087 npages--; /* skip top level's control page */
4088 for (i = level; i >= 0; i--) {
4089 factor =
4090 (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1);
4091 complete = (u32) npages / factor;
Dave Kleikampf720e3b2007-06-06 15:28:35 -05004092 ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL :
4093 ((i == 1) ? LPERCTL : 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004094
4095 /* pages in last/incomplete child */
4096 npages = (u32) npages % factor;
4097 /* skip incomplete child's level control page */
4098 npages--;
4099 }
4100
Dave Kleikamp63f83c92006-10-02 09:55:27 -05004101 /* convert the number of dmaps into the number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07004102 * which can be covered by the dmaps;
4103 */
4104 nblocks = ndmaps << L2BPERDMAP;
4105
4106 return (nblocks);
4107}