blob: 370d7b6c5942ccedfa8dcd0c92c353badda41080 [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);
Joe Percheseb8630d2013-06-04 16:39:15 -0700349 jfs_error(ip->i_sb, "block to be freed is outside the map\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 return -EIO;
351 }
352
Tino Reichardtb40c2e62012-09-17 11:58:19 -0500353 /**
354 * TRIM the blocks, when mounted with discard option
355 */
356 if (JFS_SBI(sb)->flag & JFS_DISCARD)
357 if (JFS_SBI(sb)->minblks_trim <= nblocks)
358 jfs_issue_discard(ipbmap, blkno, nblocks);
359
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 /*
361 * free the blocks a dmap at a time.
362 */
363 mp = NULL;
364 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
365 /* release previous dmap if any */
366 if (mp) {
367 write_metapage(mp);
368 }
369
370 /* get the buffer for the current dmap. */
371 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
372 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
373 if (mp == NULL) {
374 IREAD_UNLOCK(ipbmap);
375 return -EIO;
376 }
377 dp = (struct dmap *) mp->data;
378
379 /* determine the number of blocks to be freed from
380 * this dmap.
381 */
382 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
383
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 /* free the blocks. */
385 if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) {
Joe Percheseb8630d2013-06-04 16:39:15 -0700386 jfs_error(ip->i_sb, "error in block map\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 release_metapage(mp);
388 IREAD_UNLOCK(ipbmap);
389 return (rc);
390 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 }
392
393 /* write the last buffer. */
394 write_metapage(mp);
395
396 IREAD_UNLOCK(ipbmap);
397
398 return (0);
399}
400
401
402/*
403 * NAME: dbUpdatePMap()
404 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500405 * FUNCTION: update the allocation state (free or allocate) of the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 * specified block range in the persistent block allocation map.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500407 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 * the blocks will be updated in the persistent map one
409 * dmap at a time.
410 *
411 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500412 * ipbmap - pointer to in-core inode for the block map.
413 * free - 'true' if block range is to be freed from the persistent
414 * map; 'false' if it is to be allocated.
415 * blkno - starting block number of the range.
416 * nblocks - number of contiguous blocks in the range.
417 * tblk - transaction block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 *
419 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500420 * 0 - success
421 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 */
423int
424dbUpdatePMap(struct inode *ipbmap,
425 int free, s64 blkno, s64 nblocks, struct tblock * tblk)
426{
427 int nblks, dbitno, wbitno, rbits;
428 int word, nbits, nwords;
429 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
430 s64 lblkno, rem, lastlblkno;
431 u32 mask;
432 struct dmap *dp;
433 struct metapage *mp;
434 struct jfs_log *log;
435 int lsn, difft, diffp;
Dave Kleikamp7fab4792005-05-02 12:25:02 -0600436 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437
438 /* the blocks better be within the mapsize. */
439 if (blkno + nblocks > bmp->db_mapsize) {
440 printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n",
441 (unsigned long long) blkno,
442 (unsigned long long) nblocks);
Joe Percheseb8630d2013-06-04 16:39:15 -0700443 jfs_error(ipbmap->i_sb, "blocks are outside the map\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 return -EIO;
445 }
446
447 /* compute delta of transaction lsn from log syncpt */
448 lsn = tblk->lsn;
449 log = (struct jfs_log *) JFS_SBI(tblk->sb)->log;
450 logdiff(difft, lsn, log);
451
452 /*
453 * update the block state a dmap at a time.
454 */
455 mp = NULL;
456 lastlblkno = 0;
457 for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) {
458 /* get the buffer for the current dmap. */
459 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
460 if (lblkno != lastlblkno) {
461 if (mp) {
462 write_metapage(mp);
463 }
464
465 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE,
466 0);
467 if (mp == NULL)
468 return -EIO;
Dave Kleikamp7fab4792005-05-02 12:25:02 -0600469 metapage_wait_for_io(mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 }
471 dp = (struct dmap *) mp->data;
472
473 /* determine the bit number and word within the dmap of
474 * the starting block. also determine how many blocks
475 * are to be updated within this dmap.
476 */
477 dbitno = blkno & (BPERDMAP - 1);
478 word = dbitno >> L2DBWORD;
479 nblks = min(rem, (s64)BPERDMAP - dbitno);
480
481 /* update the bits of the dmap words. the first and last
482 * words may only have a subset of their bits updated. if
483 * this is the case, we'll work against that word (i.e.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500484 * partial first and/or last) only in a single pass. a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 * single pass will also be used to update all words that
486 * are to have all their bits updated.
487 */
488 for (rbits = nblks; rbits > 0;
489 rbits -= nbits, dbitno += nbits) {
490 /* determine the bit number within the word and
491 * the number of bits within the word.
492 */
493 wbitno = dbitno & (DBWORD - 1);
494 nbits = min(rbits, DBWORD - wbitno);
495
496 /* check if only part of the word is to be updated. */
497 if (nbits < DBWORD) {
498 /* update (free or allocate) the bits
499 * in this word.
500 */
501 mask =
502 (ONES << (DBWORD - nbits) >> wbitno);
503 if (free)
504 dp->pmap[word] &=
505 cpu_to_le32(~mask);
506 else
507 dp->pmap[word] |=
508 cpu_to_le32(mask);
509
510 word += 1;
511 } else {
512 /* one or more words are to have all
513 * their bits updated. determine how
514 * many words and how many bits.
515 */
516 nwords = rbits >> L2DBWORD;
517 nbits = nwords << L2DBWORD;
518
519 /* update (free or allocate) the bits
520 * in these words.
521 */
522 if (free)
523 memset(&dp->pmap[word], 0,
524 nwords * 4);
525 else
526 memset(&dp->pmap[word], (int) ONES,
527 nwords * 4);
528
529 word += nwords;
530 }
531 }
532
533 /*
534 * update dmap lsn
535 */
536 if (lblkno == lastlblkno)
537 continue;
538
539 lastlblkno = lblkno;
540
Dave Kleikampbe0bf7d2006-03-08 10:59:15 -0600541 LOGSYNC_LOCK(log, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 if (mp->lsn != 0) {
543 /* inherit older/smaller lsn */
544 logdiff(diffp, mp->lsn, log);
545 if (difft < diffp) {
546 mp->lsn = lsn;
547
548 /* move bp after tblock in logsync list */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 list_move(&mp->synclist, &tblk->synclist);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 }
551
552 /* inherit younger/larger clsn */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 logdiff(difft, tblk->clsn, log);
554 logdiff(diffp, mp->clsn, log);
555 if (difft > diffp)
556 mp->clsn = tblk->clsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 } else {
558 mp->log = log;
559 mp->lsn = lsn;
560
561 /* insert bp after tblock in logsync list */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 log->count++;
563 list_add(&mp->synclist, &tblk->synclist);
564
565 mp->clsn = tblk->clsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 }
Dave Kleikampbe0bf7d2006-03-08 10:59:15 -0600567 LOGSYNC_UNLOCK(log, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 }
569
570 /* write the last buffer. */
571 if (mp) {
572 write_metapage(mp);
573 }
574
575 return (0);
576}
577
578
579/*
580 * NAME: dbNextAG()
581 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500582 * FUNCTION: find the preferred allocation group for new allocations.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 *
584 * Within the allocation groups, we maintain a preferred
585 * allocation group which consists of a group with at least
586 * average free space. It is the preferred group that we target
587 * new inode allocation towards. The tie-in between inode
588 * allocation and block allocation occurs as we allocate the
589 * first (data) block of an inode and specify the inode (block)
590 * as the allocation hint for this block.
591 *
592 * We try to avoid having more than one open file growing in
593 * an allocation group, as this will lead to fragmentation.
594 * This differs from the old OS/2 method of trying to keep
595 * empty ags around for large allocations.
596 *
597 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500598 * ipbmap - pointer to in-core inode for the block map.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 *
600 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500601 * the preferred allocation group number.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 */
603int dbNextAG(struct inode *ipbmap)
604{
605 s64 avgfree;
606 int agpref;
607 s64 hwm = 0;
608 int i;
609 int next_best = -1;
610 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
611
612 BMAP_LOCK(bmp);
613
614 /* determine the average number of free blocks within the ags. */
615 avgfree = (u32)bmp->db_nfree / bmp->db_numag;
616
617 /*
618 * if the current preferred ag does not have an active allocator
619 * and has at least average freespace, return it
620 */
621 agpref = bmp->db_agpref;
622 if ((atomic_read(&bmp->db_active[agpref]) == 0) &&
623 (bmp->db_agfree[agpref] >= avgfree))
624 goto unlock;
625
626 /* From the last preferred ag, find the next one with at least
627 * average free space.
628 */
629 for (i = 0 ; i < bmp->db_numag; i++, agpref++) {
630 if (agpref == bmp->db_numag)
631 agpref = 0;
632
633 if (atomic_read(&bmp->db_active[agpref]))
634 /* open file is currently growing in this ag */
635 continue;
636 if (bmp->db_agfree[agpref] >= avgfree) {
637 /* Return this one */
638 bmp->db_agpref = agpref;
639 goto unlock;
640 } else if (bmp->db_agfree[agpref] > hwm) {
641 /* Less than avg. freespace, but best so far */
642 hwm = bmp->db_agfree[agpref];
643 next_best = agpref;
644 }
645 }
646
647 /*
648 * If no inactive ag was found with average freespace, use the
649 * next best
650 */
651 if (next_best != -1)
652 bmp->db_agpref = next_best;
653 /* else leave db_agpref unchanged */
654unlock:
655 BMAP_UNLOCK(bmp);
656
657 /* return the preferred group.
658 */
659 return (bmp->db_agpref);
660}
661
662/*
663 * NAME: dbAlloc()
664 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500665 * FUNCTION: attempt to allocate a specified number of contiguous free
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 * blocks from the working allocation block map.
667 *
668 * the block allocation policy uses hints and a multi-step
669 * approach.
670 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500671 * for allocation requests smaller than the number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 * per dmap, we first try to allocate the new blocks
673 * immediately following the hint. if these blocks are not
674 * available, we try to allocate blocks near the hint. if
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500675 * no blocks near the hint are available, we next try to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 * allocate within the same dmap as contains the hint.
677 *
678 * if no blocks are available in the dmap or the allocation
679 * request is larger than the dmap size, we try to allocate
680 * within the same allocation group as contains the hint. if
681 * this does not succeed, we finally try to allocate anywhere
682 * within the aggregate.
683 *
684 * we also try to allocate anywhere within the aggregate for
685 * for allocation requests larger than the allocation group
686 * size or requests that specify no hint value.
687 *
688 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500689 * ip - pointer to in-core inode;
690 * hint - allocation hint.
691 * nblocks - number of contiguous blocks in the range.
692 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 * of the newly allocated contiguous range.
694 *
695 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500696 * 0 - success
697 * -ENOSPC - insufficient disk resources
698 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 */
700int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results)
701{
702 int rc, agno;
703 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
704 struct bmap *bmp;
705 struct metapage *mp;
706 s64 lblkno, blkno;
707 struct dmap *dp;
708 int l2nb;
709 s64 mapSize;
710 int writers;
711
712 /* assert that nblocks is valid */
713 assert(nblocks > 0);
714
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 /* get the log2 number of blocks to be allocated.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500716 * if the number of blocks is not a log2 multiple,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 * it will be rounded up to the next log2 multiple.
718 */
719 l2nb = BLKSTOL2(nblocks);
720
721 bmp = JFS_SBI(ip->i_sb)->bmap;
722
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 mapSize = bmp->db_mapsize;
724
725 /* the hint should be within the map */
726 if (hint >= mapSize) {
Joe Percheseb8630d2013-06-04 16:39:15 -0700727 jfs_error(ip->i_sb, "the hint is outside the map\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 return -EIO;
729 }
730
731 /* if the number of blocks to be allocated is greater than the
732 * allocation group size, try to allocate anywhere.
733 */
734 if (l2nb > bmp->db_agl2size) {
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600735 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
737 rc = dbAllocAny(bmp, nblocks, l2nb, results);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
739 goto write_unlock;
740 }
741
742 /*
743 * If no hint, let dbNextAG recommend an allocation group
744 */
745 if (hint == 0)
746 goto pref_ag;
747
748 /* we would like to allocate close to the hint. adjust the
749 * hint to the block following the hint since the allocators
750 * will start looking for free space starting at this point.
751 */
752 blkno = hint + 1;
753
754 if (blkno >= bmp->db_mapsize)
755 goto pref_ag;
756
757 agno = blkno >> bmp->db_agl2size;
758
759 /* check if blkno crosses over into a new allocation group.
760 * if so, check if we should allow allocations within this
761 * allocation group.
762 */
763 if ((blkno & (bmp->db_agsize - 1)) == 0)
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200764 /* check if the AG is currently being written to.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 * if so, call dbNextAG() to find a non-busy
766 * AG with sufficient free space.
767 */
768 if (atomic_read(&bmp->db_active[agno]))
769 goto pref_ag;
770
771 /* check if the allocation request size can be satisfied from a
772 * single dmap. if so, try to allocate from the dmap containing
773 * the hint using a tiered strategy.
774 */
775 if (nblocks <= BPERDMAP) {
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600776 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777
778 /* get the buffer for the dmap containing the hint.
779 */
780 rc = -EIO;
781 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
782 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
783 if (mp == NULL)
784 goto read_unlock;
785
786 dp = (struct dmap *) mp->data;
787
788 /* first, try to satisfy the allocation request with the
789 * blocks beginning at the hint.
790 */
791 if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks))
792 != -ENOSPC) {
793 if (rc == 0) {
794 *results = blkno;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 mark_metapage_dirty(mp);
796 }
797
798 release_metapage(mp);
799 goto read_unlock;
800 }
801
802 writers = atomic_read(&bmp->db_active[agno]);
803 if ((writers > 1) ||
804 ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) {
805 /*
806 * Someone else is writing in this allocation
807 * group. To avoid fragmenting, try another ag
808 */
809 release_metapage(mp);
810 IREAD_UNLOCK(ipbmap);
811 goto pref_ag;
812 }
813
814 /* next, try to satisfy the allocation request with blocks
815 * near the hint.
816 */
817 if ((rc =
818 dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results))
819 != -ENOSPC) {
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500820 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821 mark_metapage_dirty(mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822
823 release_metapage(mp);
824 goto read_unlock;
825 }
826
827 /* try to satisfy the allocation request with blocks within
828 * the same dmap as the hint.
829 */
830 if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results))
831 != -ENOSPC) {
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500832 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 mark_metapage_dirty(mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834
835 release_metapage(mp);
836 goto read_unlock;
837 }
838
839 release_metapage(mp);
840 IREAD_UNLOCK(ipbmap);
841 }
842
843 /* try to satisfy the allocation request with blocks within
844 * the same allocation group as the hint.
845 */
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600846 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500847 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 goto write_unlock;
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500849
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 IWRITE_UNLOCK(ipbmap);
851
852
853 pref_ag:
854 /*
855 * Let dbNextAG recommend a preferred allocation group
856 */
857 agno = dbNextAG(ipbmap);
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600858 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859
860 /* Try to allocate within this allocation group. if that fails, try to
861 * allocate anywhere in the map.
862 */
863 if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC)
864 rc = dbAllocAny(bmp, nblocks, l2nb, results);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865
866 write_unlock:
867 IWRITE_UNLOCK(ipbmap);
868
869 return (rc);
870
871 read_unlock:
872 IREAD_UNLOCK(ipbmap);
873
874 return (rc);
875}
876
877#ifdef _NOTYET
878/*
879 * NAME: dbAllocExact()
880 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500881 * FUNCTION: try to allocate the requested extent;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 *
883 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500884 * ip - pointer to in-core inode;
885 * blkno - extent address;
886 * nblocks - extent length;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 *
888 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500889 * 0 - success
890 * -ENOSPC - insufficient disk resources
891 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 */
893int dbAllocExact(struct inode *ip, s64 blkno, int nblocks)
894{
895 int rc;
896 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
897 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
898 struct dmap *dp;
899 s64 lblkno;
900 struct metapage *mp;
901
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -0600902 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
904 /*
905 * validate extent request:
906 *
907 * note: defragfs policy:
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500908 * max 64 blocks will be moved.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909 * allocation request size must be satisfied from a single dmap.
910 */
911 if (nblocks <= 0 || nblocks > BPERDMAP || blkno >= bmp->db_mapsize) {
912 IREAD_UNLOCK(ipbmap);
913 return -EINVAL;
914 }
915
916 if (nblocks > ((s64) 1 << bmp->db_maxfreebud)) {
917 /* the free space is no longer available */
918 IREAD_UNLOCK(ipbmap);
919 return -ENOSPC;
920 }
921
922 /* read in the dmap covering the extent */
923 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
924 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
925 if (mp == NULL) {
926 IREAD_UNLOCK(ipbmap);
927 return -EIO;
928 }
929 dp = (struct dmap *) mp->data;
930
931 /* try to allocate the requested extent */
932 rc = dbAllocNext(bmp, dp, blkno, nblocks);
933
934 IREAD_UNLOCK(ipbmap);
935
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500936 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 mark_metapage_dirty(mp);
Dave Kleikampb38a3ab2005-06-27 15:35:37 -0500938
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 release_metapage(mp);
940
941 return (rc);
942}
943#endif /* _NOTYET */
944
945/*
946 * NAME: dbReAlloc()
947 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500948 * FUNCTION: attempt to extend a current allocation by a specified
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 * number of blocks.
950 *
951 * this routine attempts to satisfy the allocation request
952 * by first trying to extend the existing allocation in
953 * place by allocating the additional blocks as the blocks
954 * immediately following the current allocation. if these
955 * blocks are not available, this routine will attempt to
956 * allocate a new set of contiguous blocks large enough
957 * to cover the existing allocation plus the additional
958 * number of blocks required.
959 *
960 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500961 * ip - pointer to in-core inode requiring allocation.
962 * blkno - starting block of the current allocation.
963 * nblocks - number of contiguous blocks within the current
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 * allocation.
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500965 * addnblocks - number of blocks to add to the allocation.
966 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 * of the existing allocation if the existing allocation
968 * was extended in place or to a newly allocated contiguous
969 * range if the existing allocation could not be extended
970 * in place.
971 *
972 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500973 * 0 - success
974 * -ENOSPC - insufficient disk resources
975 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 */
977int
978dbReAlloc(struct inode *ip,
979 s64 blkno, s64 nblocks, s64 addnblocks, s64 * results)
980{
981 int rc;
982
983 /* try to extend the allocation in place.
984 */
985 if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) {
986 *results = blkno;
987 return (0);
988 } else {
989 if (rc != -ENOSPC)
990 return (rc);
991 }
992
993 /* could not extend the allocation in place, so allocate a
994 * new set of blocks for the entire request (i.e. try to get
995 * a range of contiguous blocks large enough to cover the
996 * existing allocation plus the additional blocks.)
997 */
998 return (dbAlloc
999 (ip, blkno + nblocks - 1, addnblocks + nblocks, results));
1000}
1001
1002
1003/*
1004 * NAME: dbExtend()
1005 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001006 * FUNCTION: attempt to extend a current allocation by a specified
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007 * number of blocks.
1008 *
1009 * this routine attempts to satisfy the allocation request
1010 * by first trying to extend the existing allocation in
1011 * place by allocating the additional blocks as the blocks
1012 * immediately following the current allocation.
1013 *
1014 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001015 * ip - pointer to in-core inode requiring allocation.
1016 * blkno - starting block of the current allocation.
1017 * nblocks - number of contiguous blocks within the current
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 * allocation.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001019 * addnblocks - number of blocks to add to the allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 *
1021 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001022 * 0 - success
1023 * -ENOSPC - insufficient disk resources
1024 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025 */
1026static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks)
1027{
1028 struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
1029 s64 lblkno, lastblkno, extblkno;
1030 uint rel_block;
1031 struct metapage *mp;
1032 struct dmap *dp;
1033 int rc;
1034 struct inode *ipbmap = sbi->ipbmap;
1035 struct bmap *bmp;
1036
1037 /*
1038 * We don't want a non-aligned extent to cross a page boundary
1039 */
1040 if (((rel_block = blkno & (sbi->nbperpage - 1))) &&
1041 (rel_block + nblocks + addnblocks > sbi->nbperpage))
1042 return -ENOSPC;
1043
1044 /* get the last block of the current allocation */
1045 lastblkno = blkno + nblocks - 1;
1046
1047 /* determine the block number of the block following
1048 * the existing allocation.
1049 */
1050 extblkno = lastblkno + 1;
1051
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -06001052 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053
1054 /* better be within the file system */
1055 bmp = sbi->bmap;
1056 if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) {
1057 IREAD_UNLOCK(ipbmap);
Joe Percheseb8630d2013-06-04 16:39:15 -07001058 jfs_error(ip->i_sb, "the block is outside the filesystem\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 return -EIO;
1060 }
1061
1062 /* we'll attempt to extend the current allocation in place by
1063 * allocating the additional blocks as the blocks immediately
1064 * following the current allocation. we only try to extend the
1065 * current allocation in place if the number of additional blocks
1066 * can fit into a dmap, the last block of the current allocation
1067 * is not the last block of the file system, and the start of the
1068 * inplace extension is not on an allocation group boundary.
1069 */
1070 if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize ||
1071 (extblkno & (bmp->db_agsize - 1)) == 0) {
1072 IREAD_UNLOCK(ipbmap);
1073 return -ENOSPC;
1074 }
1075
1076 /* get the buffer for the dmap containing the first block
1077 * of the extension.
1078 */
1079 lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage);
1080 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
1081 if (mp == NULL) {
1082 IREAD_UNLOCK(ipbmap);
1083 return -EIO;
1084 }
1085
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086 dp = (struct dmap *) mp->data;
1087
1088 /* try to allocate the blocks immediately following the
1089 * current allocation.
1090 */
1091 rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks);
1092
1093 IREAD_UNLOCK(ipbmap);
1094
1095 /* were we successful ? */
Dave Kleikampb38a3ab2005-06-27 15:35:37 -05001096 if (rc == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097 write_metapage(mp);
Dave Kleikampb38a3ab2005-06-27 15:35:37 -05001098 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099 /* we were not successful */
1100 release_metapage(mp);
1101
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 return (rc);
1103}
1104
1105
1106/*
1107 * NAME: dbAllocNext()
1108 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001109 * FUNCTION: attempt to allocate the blocks of the specified block
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110 * range within a dmap.
1111 *
1112 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001113 * bmp - pointer to bmap descriptor
1114 * dp - pointer to dmap.
1115 * blkno - starting block number of the range.
1116 * nblocks - number of contiguous free blocks of the range.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 *
1118 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001119 * 0 - success
1120 * -ENOSPC - insufficient disk resources
1121 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 *
1123 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1124 */
1125static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno,
1126 int nblocks)
1127{
1128 int dbitno, word, rembits, nb, nwords, wbitno, nw;
1129 int l2size;
1130 s8 *leaf;
1131 u32 mask;
1132
1133 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
Joe Percheseb8630d2013-06-04 16:39:15 -07001134 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135 return -EIO;
1136 }
1137
1138 /* pick up a pointer to the leaves of the dmap tree.
1139 */
1140 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1141
1142 /* determine the bit number and word within the dmap of the
1143 * starting block.
1144 */
1145 dbitno = blkno & (BPERDMAP - 1);
1146 word = dbitno >> L2DBWORD;
1147
1148 /* check if the specified block range is contained within
1149 * this dmap.
1150 */
1151 if (dbitno + nblocks > BPERDMAP)
1152 return -ENOSPC;
1153
1154 /* check if the starting leaf indicates that anything
1155 * is free.
1156 */
1157 if (leaf[word] == NOFREE)
1158 return -ENOSPC;
1159
1160 /* check the dmaps words corresponding to block range to see
1161 * if the block range is free. not all bits of the first and
1162 * last words may be contained within the block range. if this
1163 * is the case, we'll work against those words (i.e. partial first
1164 * and/or last) on an individual basis (a single pass) and examine
1165 * the actual bits to determine if they are free. a single pass
1166 * will be used for all dmap words fully contained within the
1167 * specified range. within this pass, the leaves of the dmap
1168 * tree will be examined to determine if the blocks are free. a
1169 * single leaf may describe the free space of multiple dmap
1170 * words, so we may visit only a subset of the actual leaves
1171 * corresponding to the dmap words of the block range.
1172 */
1173 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
1174 /* determine the bit number within the word and
1175 * the number of bits within the word.
1176 */
1177 wbitno = dbitno & (DBWORD - 1);
1178 nb = min(rembits, DBWORD - wbitno);
1179
1180 /* check if only part of the word is to be examined.
1181 */
1182 if (nb < DBWORD) {
1183 /* check if the bits are free.
1184 */
1185 mask = (ONES << (DBWORD - nb) >> wbitno);
1186 if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask)
1187 return -ENOSPC;
1188
1189 word += 1;
1190 } else {
1191 /* one or more dmap words are fully contained
1192 * within the block range. determine how many
1193 * words and how many bits.
1194 */
1195 nwords = rembits >> L2DBWORD;
1196 nb = nwords << L2DBWORD;
1197
1198 /* now examine the appropriate leaves to determine
1199 * if the blocks are free.
1200 */
1201 while (nwords > 0) {
1202 /* does the leaf describe any free space ?
1203 */
1204 if (leaf[word] < BUDMIN)
1205 return -ENOSPC;
1206
1207 /* determine the l2 number of bits provided
1208 * by this leaf.
1209 */
1210 l2size =
1211 min((int)leaf[word], NLSTOL2BSZ(nwords));
1212
1213 /* determine how many words were handled.
1214 */
1215 nw = BUDSIZE(l2size, BUDMIN);
1216
1217 nwords -= nw;
1218 word += nw;
1219 }
1220 }
1221 }
1222
1223 /* allocate the blocks.
1224 */
1225 return (dbAllocDmap(bmp, dp, blkno, nblocks));
1226}
1227
1228
1229/*
1230 * NAME: dbAllocNear()
1231 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001232 * FUNCTION: attempt to allocate a number of contiguous free blocks near
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 * a specified block (hint) within a dmap.
1234 *
1235 * starting with the dmap leaf that covers the hint, we'll
1236 * check the next four contiguous leaves for sufficient free
1237 * space. if sufficient free space is found, we'll allocate
1238 * the desired free space.
1239 *
1240 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001241 * bmp - pointer to bmap descriptor
1242 * dp - pointer to dmap.
1243 * blkno - block number to allocate near.
1244 * nblocks - actual number of contiguous free blocks desired.
1245 * l2nb - log2 number of contiguous free blocks desired.
1246 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 * of the newly allocated range.
1248 *
1249 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001250 * 0 - success
1251 * -ENOSPC - insufficient disk resources
1252 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001253 *
1254 * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
1255 */
1256static int
1257dbAllocNear(struct bmap * bmp,
1258 struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results)
1259{
1260 int word, lword, rc;
1261 s8 *leaf;
1262
1263 if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) {
Joe Percheseb8630d2013-06-04 16:39:15 -07001264 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265 return -EIO;
1266 }
1267
1268 leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx);
1269
1270 /* determine the word within the dmap that holds the hint
1271 * (i.e. blkno). also, determine the last word in the dmap
1272 * that we'll include in our examination.
1273 */
1274 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
1275 lword = min(word + 4, LPERDMAP);
1276
1277 /* examine the leaves for sufficient free space.
1278 */
1279 for (; word < lword; word++) {
1280 /* does the leaf describe sufficient free space ?
1281 */
1282 if (leaf[word] < l2nb)
1283 continue;
1284
1285 /* determine the block number within the file system
1286 * of the first block described by this dmap word.
1287 */
1288 blkno = le64_to_cpu(dp->start) + (word << L2DBWORD);
1289
1290 /* if not all bits of the dmap word are free, get the
1291 * starting bit number within the dmap word of the required
1292 * string of free bits and adjust the block number with the
1293 * value.
1294 */
1295 if (leaf[word] < BUDMIN)
1296 blkno +=
1297 dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb);
1298
1299 /* allocate the blocks.
1300 */
1301 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
1302 *results = blkno;
1303
1304 return (rc);
1305 }
1306
1307 return -ENOSPC;
1308}
1309
1310
1311/*
1312 * NAME: dbAllocAG()
1313 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001314 * FUNCTION: attempt to allocate the specified number of contiguous
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 * free blocks within the specified allocation group.
1316 *
1317 * unless the allocation group size is equal to the number
1318 * of blocks per dmap, the dmap control pages will be used to
1319 * find the required free space, if available. we start the
1320 * search at the highest dmap control page level which
1321 * distinctly describes the allocation group's free space
1322 * (i.e. the highest level at which the allocation group's
1323 * free space is not mixed in with that of any other group).
1324 * in addition, we start the search within this level at a
1325 * height of the dmapctl dmtree at which the nodes distinctly
1326 * describe the allocation group's free space. at this height,
1327 * the allocation group's free space may be represented by 1
1328 * or two sub-trees, depending on the allocation group size.
1329 * we search the top nodes of these subtrees left to right for
1330 * sufficient free space. if sufficient free space is found,
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001331 * the subtree is searched to find the leftmost leaf that
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 * has free space. once we have made it to the leaf, we
1333 * move the search to the next lower level dmap control page
1334 * corresponding to this leaf. we continue down the dmap control
1335 * pages until we find the dmap that contains or starts the
1336 * sufficient free space and we allocate at this dmap.
1337 *
1338 * if the allocation group size is equal to the dmap size,
1339 * we'll start at the dmap corresponding to the allocation
1340 * group and attempt the allocation at this level.
1341 *
1342 * the dmap control page search is also not performed if the
1343 * allocation group is completely free and we go to the first
1344 * dmap of the allocation group to do the allocation. this is
1345 * done because the allocation group may be part (not the first
1346 * part) of a larger binary buddy system, causing the dmap
1347 * control pages to indicate no free space (NOFREE) within
1348 * the allocation group.
1349 *
1350 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001351 * bmp - pointer to bmap descriptor
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 * agno - allocation group number.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001353 * nblocks - actual number of contiguous free blocks desired.
1354 * l2nb - log2 number of contiguous free blocks desired.
1355 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001356 * of the newly allocated range.
1357 *
1358 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001359 * 0 - success
1360 * -ENOSPC - insufficient disk resources
1361 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 *
1363 * note: IWRITE_LOCK(ipmap) held on entry/exit;
1364 */
1365static int
1366dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results)
1367{
1368 struct metapage *mp;
1369 struct dmapctl *dcp;
1370 int rc, ti, i, k, m, n, agperlev;
1371 s64 blkno, lblkno;
1372 int budmin;
1373
1374 /* allocation request should not be for more than the
1375 * allocation group size.
1376 */
1377 if (l2nb > bmp->db_agl2size) {
1378 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07001379 "allocation request is larger than the allocation group size\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380 return -EIO;
1381 }
1382
1383 /* determine the starting block number of the allocation
1384 * group.
1385 */
1386 blkno = (s64) agno << bmp->db_agl2size;
1387
1388 /* check if the allocation group size is the minimum allocation
1389 * group size or if the allocation group is completely free. if
1390 * the allocation group size is the minimum size of BPERDMAP (i.e.
1391 * 1 dmap), there is no need to search the dmap control page (below)
1392 * that fully describes the allocation group since the allocation
1393 * group is already fully described by a dmap. in this case, we
1394 * just call dbAllocCtl() to search the dmap tree and allocate the
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001395 * required space if available.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001396 *
1397 * if the allocation group is completely free, dbAllocCtl() is
1398 * also called to allocate the required space. this is done for
1399 * two reasons. first, it makes no sense searching the dmap control
1400 * pages for free space when we know that free space exists. second,
1401 * the dmap control pages may indicate that the allocation group
1402 * has no free space if the allocation group is part (not the first
1403 * part) of a larger binary buddy system.
1404 */
1405 if (bmp->db_agsize == BPERDMAP
1406 || bmp->db_agfree[agno] == bmp->db_agsize) {
1407 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1408 if ((rc == -ENOSPC) &&
1409 (bmp->db_agfree[agno] == bmp->db_agsize)) {
1410 printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n",
1411 (unsigned long long) blkno,
1412 (unsigned long long) nblocks);
1413 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07001414 "dbAllocCtl failed in free AG\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001415 }
1416 return (rc);
1417 }
1418
1419 /* the buffer for the dmap control page that fully describes the
1420 * allocation group.
1421 */
1422 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel);
1423 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1424 if (mp == NULL)
1425 return -EIO;
1426 dcp = (struct dmapctl *) mp->data;
1427 budmin = dcp->budmin;
1428
1429 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
Joe Percheseb8630d2013-06-04 16:39:15 -07001430 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431 release_metapage(mp);
1432 return -EIO;
1433 }
1434
1435 /* search the subtree(s) of the dmap control page that describes
1436 * the allocation group, looking for sufficient free space. to begin,
1437 * determine how many allocation groups are represented in a dmap
1438 * control page at the control page level (i.e. L0, L1, L2) that
1439 * fully describes an allocation group. next, determine the starting
1440 * tree index of this allocation group within the control page.
1441 */
1442 agperlev =
Daniel Mackd7eecb42010-01-28 16:13:01 +08001443 (1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001444 ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1));
1445
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001446 /* dmap control page trees fan-out by 4 and a single allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447 * group may be described by 1 or 2 subtrees within the ag level
1448 * dmap control page, depending upon the ag size. examine the ag's
1449 * subtrees for sufficient free space, starting with the leftmost
1450 * subtree.
1451 */
1452 for (i = 0; i < bmp->db_agwidth; i++, ti++) {
1453 /* is there sufficient free space ?
1454 */
1455 if (l2nb > dcp->stree[ti])
1456 continue;
1457
1458 /* sufficient free space found in a subtree. now search down
1459 * the subtree to find the leftmost leaf that describes this
1460 * free space.
1461 */
Daniel Mackd7eecb42010-01-28 16:13:01 +08001462 for (k = bmp->db_agheight; k > 0; k--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463 for (n = 0, m = (ti << 2) + 1; n < 4; n++) {
1464 if (l2nb <= dcp->stree[m + n]) {
1465 ti = m + n;
1466 break;
1467 }
1468 }
1469 if (n == 4) {
1470 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07001471 "failed descending stree\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001472 release_metapage(mp);
1473 return -EIO;
1474 }
1475 }
1476
1477 /* determine the block number within the file system
1478 * that corresponds to this leaf.
1479 */
1480 if (bmp->db_aglevel == 2)
1481 blkno = 0;
1482 else if (bmp->db_aglevel == 1)
1483 blkno &= ~(MAXL1SIZE - 1);
1484 else /* bmp->db_aglevel == 0 */
1485 blkno &= ~(MAXL0SIZE - 1);
1486
1487 blkno +=
1488 ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin;
1489
1490 /* release the buffer in preparation for going down
1491 * the next level of dmap control pages.
1492 */
1493 release_metapage(mp);
1494
1495 /* check if we need to continue to search down the lower
1496 * level dmap control pages. we need to if the number of
1497 * blocks required is less than maximum number of blocks
1498 * described at the next lower level.
1499 */
1500 if (l2nb < budmin) {
1501
1502 /* search the lower level dmap control pages to get
Michael Opdenacker59c51592007-05-09 08:57:56 +02001503 * the starting block number of the dmap that
Linus Torvalds1da177e2005-04-16 15:20:36 -07001504 * contains or starts off the free space.
1505 */
1506 if ((rc =
1507 dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1,
1508 &blkno))) {
1509 if (rc == -ENOSPC) {
1510 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07001511 "control page inconsistent\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512 return -EIO;
1513 }
1514 return (rc);
1515 }
1516 }
1517
1518 /* allocate the blocks.
1519 */
1520 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1521 if (rc == -ENOSPC) {
1522 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07001523 "unable to allocate blocks\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001524 rc = -EIO;
1525 }
1526 return (rc);
1527 }
1528
1529 /* no space in the allocation group. release the buffer and
1530 * return -ENOSPC.
1531 */
1532 release_metapage(mp);
1533
1534 return -ENOSPC;
1535}
1536
1537
1538/*
1539 * NAME: dbAllocAny()
1540 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001541 * FUNCTION: attempt to allocate the specified number of contiguous
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542 * free blocks anywhere in the file system.
1543 *
1544 * dbAllocAny() attempts to find the sufficient free space by
1545 * searching down the dmap control pages, starting with the
1546 * highest level (i.e. L0, L1, L2) control page. if free space
1547 * large enough to satisfy the desired free space is found, the
1548 * desired free space is allocated.
1549 *
1550 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001551 * bmp - pointer to bmap descriptor
1552 * nblocks - actual number of contiguous free blocks desired.
1553 * l2nb - log2 number of contiguous free blocks desired.
1554 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001555 * of the newly allocated range.
1556 *
1557 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001558 * 0 - success
1559 * -ENOSPC - insufficient disk resources
1560 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001561 *
1562 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1563 */
1564static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results)
1565{
1566 int rc;
1567 s64 blkno = 0;
1568
1569 /* starting with the top level dmap control page, search
1570 * down the dmap control levels for sufficient free space.
1571 * if free space is found, dbFindCtl() returns the starting
1572 * block number of the dmap that contains or starts off the
1573 * range of free space.
1574 */
1575 if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno)))
1576 return (rc);
1577
1578 /* allocate the blocks.
1579 */
1580 rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
1581 if (rc == -ENOSPC) {
Joe Percheseb8630d2013-06-04 16:39:15 -07001582 jfs_error(bmp->db_ipbmap->i_sb, "unable to allocate blocks\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001583 return -EIO;
1584 }
1585 return (rc);
1586}
1587
1588
1589/*
Tino Reichardtb40c2e62012-09-17 11:58:19 -05001590 * NAME: dbDiscardAG()
1591 *
1592 * FUNCTION: attempt to discard (TRIM) all free blocks of specific AG
1593 *
1594 * algorithm:
1595 * 1) allocate blocks, as large as possible and save them
1596 * while holding IWRITE_LOCK on ipbmap
1597 * 2) trim all these saved block/length values
1598 * 3) mark the blocks free again
1599 *
1600 * benefit:
1601 * - we work only on one ag at some time, minimizing how long we
1602 * need to lock ipbmap
1603 * - reading / writing the fs is possible most time, even on
1604 * trimming
1605 *
1606 * downside:
1607 * - we write two times to the dmapctl and dmap pages
1608 * - but for me, this seems the best way, better ideas?
1609 * /TR 2012
1610 *
1611 * PARAMETERS:
1612 * ip - pointer to in-core inode
1613 * agno - ag to trim
1614 * minlen - minimum value of contiguous blocks
1615 *
1616 * RETURN VALUES:
1617 * s64 - actual number of blocks trimmed
1618 */
1619s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen)
1620{
1621 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
1622 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
1623 s64 nblocks, blkno;
1624 u64 trimmed = 0;
1625 int rc, l2nb;
1626 struct super_block *sb = ipbmap->i_sb;
1627
1628 struct range2trim {
1629 u64 blkno;
1630 u64 nblocks;
1631 } *totrim, *tt;
1632
1633 /* max blkno / nblocks pairs to trim */
1634 int count = 0, range_cnt;
Dave Kleikamp84f41412012-09-18 11:27:22 -05001635 u64 max_ranges;
Tino Reichardtb40c2e62012-09-17 11:58:19 -05001636
1637 /* prevent others from writing new stuff here, while trimming */
1638 IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
1639
1640 nblocks = bmp->db_agfree[agno];
Dave Kleikamp84f41412012-09-18 11:27:22 -05001641 max_ranges = nblocks;
1642 do_div(max_ranges, minlen);
1643 range_cnt = min_t(u64, max_ranges + 1, 32 * 1024);
Tino Reichardtb40c2e62012-09-17 11:58:19 -05001644 totrim = kmalloc(sizeof(struct range2trim) * range_cnt, GFP_NOFS);
1645 if (totrim == NULL) {
Joe Percheseb8630d2013-06-04 16:39:15 -07001646 jfs_error(bmp->db_ipbmap->i_sb, "no memory for trim array\n");
Tino Reichardtb40c2e62012-09-17 11:58:19 -05001647 IWRITE_UNLOCK(ipbmap);
1648 return 0;
1649 }
1650
1651 tt = totrim;
1652 while (nblocks >= minlen) {
1653 l2nb = BLKSTOL2(nblocks);
1654
1655 /* 0 = okay, -EIO = fatal, -ENOSPC -> try smaller block */
1656 rc = dbAllocAG(bmp, agno, nblocks, l2nb, &blkno);
1657 if (rc == 0) {
1658 tt->blkno = blkno;
1659 tt->nblocks = nblocks;
1660 tt++; count++;
1661
1662 /* the whole ag is free, trim now */
1663 if (bmp->db_agfree[agno] == 0)
1664 break;
1665
1666 /* give a hint for the next while */
1667 nblocks = bmp->db_agfree[agno];
1668 continue;
1669 } else if (rc == -ENOSPC) {
1670 /* search for next smaller log2 block */
1671 l2nb = BLKSTOL2(nblocks) - 1;
1672 nblocks = 1 << l2nb;
1673 } else {
1674 /* Trim any already allocated blocks */
Joe Percheseb8630d2013-06-04 16:39:15 -07001675 jfs_error(bmp->db_ipbmap->i_sb, "-EIO\n");
Tino Reichardtb40c2e62012-09-17 11:58:19 -05001676 break;
1677 }
1678
1679 /* check, if our trim array is full */
1680 if (unlikely(count >= range_cnt - 1))
1681 break;
1682 }
1683 IWRITE_UNLOCK(ipbmap);
1684
1685 tt->nblocks = 0; /* mark the current end */
1686 for (tt = totrim; tt->nblocks != 0; tt++) {
1687 /* when mounted with online discard, dbFree() will
1688 * call jfs_issue_discard() itself */
1689 if (!(JFS_SBI(sb)->flag & JFS_DISCARD))
1690 jfs_issue_discard(ip, tt->blkno, tt->nblocks);
1691 dbFree(ip, tt->blkno, tt->nblocks);
1692 trimmed += tt->nblocks;
1693 }
1694 kfree(totrim);
1695
1696 return trimmed;
1697}
1698
1699/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001700 * NAME: dbFindCtl()
1701 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001702 * FUNCTION: starting at a specified dmap control page level and block
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703 * number, search down the dmap control levels for a range of
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001704 * contiguous free blocks large enough to satisfy an allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001705 * request for the specified number of free blocks.
1706 *
1707 * if sufficient contiguous free blocks are found, this routine
1708 * returns the starting block number within a dmap page that
1709 * contains or starts a range of contiqious free blocks that
1710 * is sufficient in size.
1711 *
1712 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001713 * bmp - pointer to bmap descriptor
1714 * level - starting dmap control page level.
1715 * l2nb - log2 number of contiguous free blocks desired.
1716 * *blkno - on entry, starting block number for conducting the search.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001717 * on successful return, the first block within a dmap page
1718 * that contains or starts a range of contiguous free blocks.
1719 *
1720 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001721 * 0 - success
1722 * -ENOSPC - insufficient disk resources
1723 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001724 *
1725 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1726 */
1727static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno)
1728{
1729 int rc, leafidx, lev;
1730 s64 b, lblkno;
1731 struct dmapctl *dcp;
1732 int budmin;
1733 struct metapage *mp;
1734
1735 /* starting at the specified dmap control page level and block
1736 * number, search down the dmap control levels for the starting
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001737 * block number of a dmap page that contains or starts off
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738 * sufficient free blocks.
1739 */
1740 for (lev = level, b = *blkno; lev >= 0; lev--) {
1741 /* get the buffer of the dmap control page for the block
1742 * number and level (i.e. L0, L1, L2).
1743 */
1744 lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev);
1745 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1746 if (mp == NULL)
1747 return -EIO;
1748 dcp = (struct dmapctl *) mp->data;
1749 budmin = dcp->budmin;
1750
1751 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
1752 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07001753 "Corrupt dmapctl page\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001754 release_metapage(mp);
1755 return -EIO;
1756 }
1757
1758 /* search the tree within the dmap control page for
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001759 * sufficient free space. if sufficient free space is found,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001760 * dbFindLeaf() returns the index of the leaf at which
1761 * free space was found.
1762 */
1763 rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx);
1764
1765 /* release the buffer.
1766 */
1767 release_metapage(mp);
1768
1769 /* space found ?
1770 */
1771 if (rc) {
1772 if (lev != level) {
1773 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07001774 "dmap inconsistent\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001775 return -EIO;
1776 }
1777 return -ENOSPC;
1778 }
1779
1780 /* adjust the block number to reflect the location within
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001781 * the dmap control page (i.e. the leaf) at which free
Linus Torvalds1da177e2005-04-16 15:20:36 -07001782 * space was found.
1783 */
1784 b += (((s64) leafidx) << budmin);
1785
1786 /* we stop the search at this dmap control page level if
1787 * the number of blocks required is greater than or equal
1788 * to the maximum number of blocks described at the next
1789 * (lower) level.
1790 */
1791 if (l2nb >= budmin)
1792 break;
1793 }
1794
1795 *blkno = b;
1796 return (0);
1797}
1798
1799
1800/*
1801 * NAME: dbAllocCtl()
1802 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001803 * FUNCTION: attempt to allocate a specified number of contiguous
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001804 * blocks starting within a specific dmap.
1805 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001806 * this routine is called by higher level routines that search
1807 * the dmap control pages above the actual dmaps for contiguous
1808 * free space. the result of successful searches by these
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001809 * routines are the starting block numbers within dmaps, with
Linus Torvalds1da177e2005-04-16 15:20:36 -07001810 * the dmaps themselves containing the desired contiguous free
1811 * space or starting a contiguous free space of desired size
1812 * that is made up of the blocks of one or more dmaps. these
1813 * calls should not fail due to insufficent resources.
1814 *
1815 * this routine is called in some cases where it is not known
1816 * whether it will fail due to insufficient resources. more
1817 * specifically, this occurs when allocating from an allocation
1818 * group whose size is equal to the number of blocks per dmap.
1819 * in this case, the dmap control pages are not examined prior
1820 * to calling this routine (to save pathlength) and the call
1821 * might fail.
1822 *
1823 * for a request size that fits within a dmap, this routine relies
1824 * upon the dmap's dmtree to find the requested contiguous free
1825 * space. for request sizes that are larger than a dmap, the
1826 * requested free space will start at the first block of the
1827 * first dmap (i.e. blkno).
1828 *
1829 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001830 * bmp - pointer to bmap descriptor
1831 * nblocks - actual number of contiguous free blocks to allocate.
1832 * l2nb - log2 number of contiguous free blocks to allocate.
1833 * blkno - starting block number of the dmap to start the allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07001834 * from.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001835 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001836 * of the newly allocated range.
1837 *
1838 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001839 * 0 - success
1840 * -ENOSPC - insufficient disk resources
1841 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001842 *
1843 * serialization: IWRITE_LOCK(ipbmap) held on entry/exit;
1844 */
1845static int
1846dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results)
1847{
1848 int rc, nb;
1849 s64 b, lblkno, n;
1850 struct metapage *mp;
1851 struct dmap *dp;
1852
1853 /* check if the allocation request is confined to a single dmap.
1854 */
1855 if (l2nb <= L2BPERDMAP) {
1856 /* get the buffer for the dmap.
1857 */
1858 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
1859 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1860 if (mp == NULL)
1861 return -EIO;
1862 dp = (struct dmap *) mp->data;
1863
1864 /* try to allocate the blocks.
1865 */
1866 rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results);
1867 if (rc == 0)
1868 mark_metapage_dirty(mp);
1869
1870 release_metapage(mp);
1871
1872 return (rc);
1873 }
1874
1875 /* allocation request involving multiple dmaps. it must start on
1876 * a dmap boundary.
1877 */
1878 assert((blkno & (BPERDMAP - 1)) == 0);
1879
1880 /* allocate the blocks dmap by dmap.
1881 */
1882 for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) {
1883 /* get the buffer for the dmap.
1884 */
1885 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1886 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1887 if (mp == NULL) {
1888 rc = -EIO;
1889 goto backout;
1890 }
1891 dp = (struct dmap *) mp->data;
1892
1893 /* the dmap better be all free.
1894 */
1895 if (dp->tree.stree[ROOT] != L2BPERDMAP) {
1896 release_metapage(mp);
1897 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07001898 "the dmap is not all free\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001899 rc = -EIO;
1900 goto backout;
1901 }
1902
1903 /* determine how many blocks to allocate from this dmap.
1904 */
1905 nb = min(n, (s64)BPERDMAP);
1906
1907 /* allocate the blocks from the dmap.
1908 */
1909 if ((rc = dbAllocDmap(bmp, dp, b, nb))) {
1910 release_metapage(mp);
1911 goto backout;
1912 }
1913
1914 /* write the buffer.
1915 */
1916 write_metapage(mp);
1917 }
1918
1919 /* set the results (starting block number) and return.
1920 */
1921 *results = blkno;
1922 return (0);
1923
1924 /* something failed in handling an allocation request involving
1925 * multiple dmaps. we'll try to clean up by backing out any
1926 * allocation that has already happened for this request. if
1927 * we fail in backing out the allocation, we'll mark the file
1928 * system to indicate that blocks have been leaked.
1929 */
1930 backout:
1931
1932 /* try to backout the allocations dmap by dmap.
1933 */
1934 for (n = nblocks - n, b = blkno; n > 0;
1935 n -= BPERDMAP, b += BPERDMAP) {
1936 /* get the buffer for this dmap.
1937 */
1938 lblkno = BLKTODMAP(b, bmp->db_l2nbperpage);
1939 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
1940 if (mp == NULL) {
1941 /* could not back out. mark the file system
1942 * to indicate that we have leaked blocks.
1943 */
1944 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07001945 "I/O Error: Block Leakage\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001946 continue;
1947 }
1948 dp = (struct dmap *) mp->data;
1949
1950 /* free the blocks is this dmap.
1951 */
1952 if (dbFreeDmap(bmp, dp, b, BPERDMAP)) {
1953 /* could not back out. mark the file system
1954 * to indicate that we have leaked blocks.
1955 */
1956 release_metapage(mp);
Joe Percheseb8630d2013-06-04 16:39:15 -07001957 jfs_error(bmp->db_ipbmap->i_sb, "Block Leakage\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001958 continue;
1959 }
1960
1961 /* write the buffer.
1962 */
1963 write_metapage(mp);
1964 }
1965
1966 return (rc);
1967}
1968
1969
1970/*
1971 * NAME: dbAllocDmapLev()
1972 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001973 * FUNCTION: attempt to allocate a specified number of contiguous blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07001974 * from a specified dmap.
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001975 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976 * this routine checks if the contiguous blocks are available.
1977 * if so, nblocks of blocks are allocated; otherwise, ENOSPC is
1978 * returned.
1979 *
1980 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001981 * mp - pointer to bmap descriptor
1982 * dp - pointer to dmap to attempt to allocate blocks from.
1983 * l2nb - log2 number of contiguous block desired.
1984 * nblocks - actual number of contiguous block desired.
1985 * results - on successful return, set to the starting block number
Linus Torvalds1da177e2005-04-16 15:20:36 -07001986 * of the newly allocated range.
1987 *
1988 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05001989 * 0 - success
1990 * -ENOSPC - insufficient disk resources
1991 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05001993 * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or
Linus Torvalds1da177e2005-04-16 15:20:36 -07001994 * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit;
1995 */
1996static int
1997dbAllocDmapLev(struct bmap * bmp,
1998 struct dmap * dp, int nblocks, int l2nb, s64 * results)
1999{
2000 s64 blkno;
2001 int leafidx, rc;
2002
2003 /* can't be more than a dmaps worth of blocks */
2004 assert(l2nb <= L2BPERDMAP);
2005
2006 /* search the tree within the dmap page for sufficient
2007 * free space. if sufficient free space is found, dbFindLeaf()
2008 * returns the index of the leaf at which free space was found.
2009 */
2010 if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx))
2011 return -ENOSPC;
2012
2013 /* determine the block number within the file system corresponding
2014 * to the leaf at which free space was found.
2015 */
2016 blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD);
2017
2018 /* if not all bits of the dmap word are free, get the starting
2019 * bit number within the dmap word of the required string of free
2020 * bits and adjust the block number with this value.
2021 */
2022 if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN)
2023 blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb);
2024
2025 /* allocate the blocks */
2026 if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0)
2027 *results = blkno;
2028
2029 return (rc);
2030}
2031
2032
2033/*
2034 * NAME: dbAllocDmap()
2035 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002036 * FUNCTION: adjust the disk allocation map to reflect the allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002037 * of a specified block range within a dmap.
2038 *
2039 * this routine allocates the specified blocks from the dmap
2040 * through a call to dbAllocBits(). if the allocation of the
2041 * block range causes the maximum string of free blocks within
2042 * the dmap to change (i.e. the value of the root of the dmap's
2043 * dmtree), this routine will cause this change to be reflected
2044 * up through the appropriate levels of the dmap control pages
2045 * by a call to dbAdjCtl() for the L0 dmap control page that
2046 * covers this dmap.
2047 *
2048 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002049 * bmp - pointer to bmap descriptor
2050 * dp - pointer to dmap to allocate the block range from.
2051 * blkno - starting block number of the block to be allocated.
2052 * nblocks - number of blocks to be allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002053 *
2054 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002055 * 0 - success
2056 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07002057 *
2058 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2059 */
2060static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2061 int nblocks)
2062{
2063 s8 oldroot;
2064 int rc;
2065
2066 /* save the current value of the root (i.e. maximum free string)
2067 * of the dmap tree.
2068 */
2069 oldroot = dp->tree.stree[ROOT];
2070
2071 /* allocate the specified (blocks) bits */
2072 dbAllocBits(bmp, dp, blkno, nblocks);
2073
2074 /* if the root has not changed, done. */
2075 if (dp->tree.stree[ROOT] == oldroot)
2076 return (0);
2077
2078 /* root changed. bubble the change up to the dmap control pages.
2079 * if the adjustment of the upper level control pages fails,
2080 * backout the bit allocation (thus making everything consistent).
2081 */
2082 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0)))
2083 dbFreeBits(bmp, dp, blkno, nblocks);
2084
2085 return (rc);
2086}
2087
2088
2089/*
2090 * NAME: dbFreeDmap()
2091 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002092 * FUNCTION: adjust the disk allocation map to reflect the allocation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002093 * of a specified block range within a dmap.
2094 *
2095 * this routine frees the specified blocks from the dmap through
2096 * a call to dbFreeBits(). if the deallocation of the block range
2097 * causes the maximum string of free blocks within the dmap to
2098 * change (i.e. the value of the root of the dmap's dmtree), this
2099 * routine will cause this change to be reflected up through the
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002100 * appropriate levels of the dmap control pages by a call to
Linus Torvalds1da177e2005-04-16 15:20:36 -07002101 * dbAdjCtl() for the L0 dmap control page that covers this dmap.
2102 *
2103 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002104 * bmp - pointer to bmap descriptor
2105 * dp - pointer to dmap to free the block range from.
2106 * blkno - starting block number of the block to be freed.
2107 * nblocks - number of blocks to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002108 *
2109 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002110 * 0 - success
2111 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07002112 *
2113 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2114 */
2115static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno,
2116 int nblocks)
2117{
2118 s8 oldroot;
Dave Kleikamp56d12542005-07-15 09:43:36 -05002119 int rc = 0, word;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002120
2121 /* save the current value of the root (i.e. maximum free string)
2122 * of the dmap tree.
2123 */
2124 oldroot = dp->tree.stree[ROOT];
2125
2126 /* free the specified (blocks) bits */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002127 rc = dbFreeBits(bmp, dp, blkno, nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002128
Dave Kleikamp56d12542005-07-15 09:43:36 -05002129 /* if error or the root has not changed, done. */
2130 if (rc || (dp->tree.stree[ROOT] == oldroot))
2131 return (rc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002132
2133 /* root changed. bubble the change up to the dmap control pages.
2134 * if the adjustment of the upper level control pages fails,
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002135 * backout the deallocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002136 */
2137 if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) {
2138 word = (blkno & (BPERDMAP - 1)) >> L2DBWORD;
2139
2140 /* as part of backing out the deallocation, we will have
2141 * to back split the dmap tree if the deallocation caused
2142 * the freed blocks to become part of a larger binary buddy
2143 * system.
2144 */
2145 if (dp->tree.stree[word] == NOFREE)
2146 dbBackSplit((dmtree_t *) & dp->tree, word);
2147
2148 dbAllocBits(bmp, dp, blkno, nblocks);
2149 }
2150
2151 return (rc);
2152}
2153
2154
2155/*
2156 * NAME: dbAllocBits()
2157 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002158 * FUNCTION: allocate a specified block range from a dmap.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002159 *
2160 * this routine updates the dmap to reflect the working
2161 * state allocation of the specified block range. it directly
2162 * updates the bits of the working map and causes the adjustment
2163 * of the binary buddy system described by the dmap's dmtree
2164 * leaves to reflect the bits allocated. it also causes the
2165 * dmap's dmtree, as a whole, to reflect the allocated range.
2166 *
2167 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002168 * bmp - pointer to bmap descriptor
2169 * dp - pointer to dmap to allocate bits from.
2170 * blkno - starting block number of the bits to be allocated.
2171 * nblocks - number of bits to be allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002172 *
2173 * RETURN VALUES: none
2174 *
2175 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2176 */
2177static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
2178 int nblocks)
2179{
2180 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2181 dmtree_t *tp = (dmtree_t *) & dp->tree;
2182 int size;
2183 s8 *leaf;
2184
2185 /* pick up a pointer to the leaves of the dmap tree */
2186 leaf = dp->tree.stree + LEAFIND;
2187
2188 /* determine the bit number and word within the dmap of the
2189 * starting block.
2190 */
2191 dbitno = blkno & (BPERDMAP - 1);
2192 word = dbitno >> L2DBWORD;
2193
2194 /* block range better be within the dmap */
2195 assert(dbitno + nblocks <= BPERDMAP);
2196
2197 /* allocate the bits of the dmap's words corresponding to the block
2198 * range. not all bits of the first and last words may be contained
2199 * within the block range. if this is the case, we'll work against
2200 * those words (i.e. partial first and/or last) on an individual basis
2201 * (a single pass), allocating the bits of interest by hand and
2202 * updating the leaf corresponding to the dmap word. a single pass
2203 * will be used for all dmap words fully contained within the
2204 * specified range. within this pass, the bits of all fully contained
2205 * dmap words will be marked as free in a single shot and the leaves
2206 * will be updated. a single leaf may describe the free space of
2207 * multiple dmap words, so we may update only a subset of the actual
2208 * leaves corresponding to the dmap words of the block range.
2209 */
2210 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2211 /* determine the bit number within the word and
2212 * the number of bits within the word.
2213 */
2214 wbitno = dbitno & (DBWORD - 1);
2215 nb = min(rembits, DBWORD - wbitno);
2216
2217 /* check if only part of a word is to be allocated.
2218 */
2219 if (nb < DBWORD) {
2220 /* allocate (set to 1) the appropriate bits within
2221 * this dmap word.
2222 */
2223 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
2224 >> wbitno);
2225
2226 /* update the leaf for this dmap word. in addition
2227 * to setting the leaf value to the binary buddy max
2228 * of the updated dmap word, dbSplit() will split
2229 * the binary system of the leaves if need be.
2230 */
2231 dbSplit(tp, word, BUDMIN,
2232 dbMaxBud((u8 *) & dp->wmap[word]));
2233
2234 word += 1;
2235 } else {
2236 /* one or more dmap words are fully contained
2237 * within the block range. determine how many
2238 * words and allocate (set to 1) the bits of these
2239 * words.
2240 */
2241 nwords = rembits >> L2DBWORD;
2242 memset(&dp->wmap[word], (int) ONES, nwords * 4);
2243
2244 /* determine how many bits.
2245 */
2246 nb = nwords << L2DBWORD;
2247
2248 /* now update the appropriate leaves to reflect
2249 * the allocated words.
2250 */
2251 for (; nwords > 0; nwords -= nw) {
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002252 if (leaf[word] < BUDMIN) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002253 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07002254 "leaf page corrupt\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002255 break;
2256 }
2257
2258 /* determine what the leaf value should be
2259 * updated to as the minimum of the l2 number
2260 * of bits being allocated and the l2 number
2261 * of bits currently described by this leaf.
2262 */
2263 size = min((int)leaf[word], NLSTOL2BSZ(nwords));
2264
2265 /* update the leaf to reflect the allocation.
2266 * in addition to setting the leaf value to
2267 * NOFREE, dbSplit() will split the binary
2268 * system of the leaves to reflect the current
2269 * allocation (size).
2270 */
2271 dbSplit(tp, word, size, NOFREE);
2272
2273 /* get the number of dmap words handled */
2274 nw = BUDSIZE(size, BUDMIN);
2275 word += nw;
2276 }
2277 }
2278 }
2279
2280 /* update the free count for this dmap */
Marcin Slusarz89145622008-02-13 15:34:20 -06002281 le32_add_cpu(&dp->nfree, -nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002282
2283 BMAP_LOCK(bmp);
2284
2285 /* if this allocation group is completely free,
2286 * update the maximum allocation group number if this allocation
2287 * group is the new max.
2288 */
2289 agno = blkno >> bmp->db_agl2size;
2290 if (agno > bmp->db_maxag)
2291 bmp->db_maxag = agno;
2292
2293 /* update the free count for the allocation group and map */
2294 bmp->db_agfree[agno] -= nblocks;
2295 bmp->db_nfree -= nblocks;
2296
2297 BMAP_UNLOCK(bmp);
2298}
2299
2300
2301/*
2302 * NAME: dbFreeBits()
2303 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002304 * FUNCTION: free a specified block range from a dmap.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002305 *
2306 * this routine updates the dmap to reflect the working
2307 * state allocation of the specified block range. it directly
2308 * updates the bits of the working map and causes the adjustment
2309 * of the binary buddy system described by the dmap's dmtree
2310 * leaves to reflect the bits freed. it also causes the dmap's
2311 * dmtree, as a whole, to reflect the deallocated range.
2312 *
2313 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002314 * bmp - pointer to bmap descriptor
2315 * dp - pointer to dmap to free bits from.
2316 * blkno - starting block number of the bits to be freed.
2317 * nblocks - number of bits to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002318 *
Dave Kleikamp56d12542005-07-15 09:43:36 -05002319 * RETURN VALUES: 0 for success
Linus Torvalds1da177e2005-04-16 15:20:36 -07002320 *
2321 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2322 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002323static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002324 int nblocks)
2325{
2326 int dbitno, word, rembits, nb, nwords, wbitno, nw, agno;
2327 dmtree_t *tp = (dmtree_t *) & dp->tree;
Dave Kleikamp56d12542005-07-15 09:43:36 -05002328 int rc = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002329 int size;
2330
2331 /* determine the bit number and word within the dmap of the
2332 * starting block.
2333 */
2334 dbitno = blkno & (BPERDMAP - 1);
2335 word = dbitno >> L2DBWORD;
2336
2337 /* block range better be within the dmap.
2338 */
2339 assert(dbitno + nblocks <= BPERDMAP);
2340
2341 /* free the bits of the dmaps words corresponding to the block range.
2342 * not all bits of the first and last words may be contained within
2343 * the block range. if this is the case, we'll work against those
2344 * words (i.e. partial first and/or last) on an individual basis
2345 * (a single pass), freeing the bits of interest by hand and updating
2346 * the leaf corresponding to the dmap word. a single pass will be used
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002347 * for all dmap words fully contained within the specified range.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002348 * within this pass, the bits of all fully contained dmap words will
2349 * be marked as free in a single shot and the leaves will be updated. a
2350 * single leaf may describe the free space of multiple dmap words,
2351 * so we may update only a subset of the actual leaves corresponding
2352 * to the dmap words of the block range.
2353 *
2354 * dbJoin() is used to update leaf values and will join the binary
2355 * buddy system of the leaves if the new leaf values indicate this
2356 * should be done.
2357 */
2358 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
2359 /* determine the bit number within the word and
2360 * the number of bits within the word.
2361 */
2362 wbitno = dbitno & (DBWORD - 1);
2363 nb = min(rembits, DBWORD - wbitno);
2364
2365 /* check if only part of a word is to be freed.
2366 */
2367 if (nb < DBWORD) {
2368 /* free (zero) the appropriate bits within this
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002369 * dmap word.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002370 */
2371 dp->wmap[word] &=
2372 cpu_to_le32(~(ONES << (DBWORD - nb)
2373 >> wbitno));
2374
2375 /* update the leaf for this dmap word.
2376 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002377 rc = dbJoin(tp, word,
2378 dbMaxBud((u8 *) & dp->wmap[word]));
2379 if (rc)
2380 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002381
2382 word += 1;
2383 } else {
2384 /* one or more dmap words are fully contained
2385 * within the block range. determine how many
2386 * words and free (zero) the bits of these words.
2387 */
2388 nwords = rembits >> L2DBWORD;
2389 memset(&dp->wmap[word], 0, nwords * 4);
2390
2391 /* determine how many bits.
2392 */
2393 nb = nwords << L2DBWORD;
2394
2395 /* now update the appropriate leaves to reflect
2396 * the freed words.
2397 */
2398 for (; nwords > 0; nwords -= nw) {
2399 /* determine what the leaf value should be
2400 * updated to as the minimum of the l2 number
2401 * of bits being freed and the l2 (max) number
2402 * of bits that can be described by this leaf.
2403 */
2404 size =
2405 min(LITOL2BSZ
2406 (word, L2LPERDMAP, BUDMIN),
2407 NLSTOL2BSZ(nwords));
2408
2409 /* update the leaf.
2410 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002411 rc = dbJoin(tp, word, size);
2412 if (rc)
2413 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002414
2415 /* get the number of dmap words handled.
2416 */
2417 nw = BUDSIZE(size, BUDMIN);
2418 word += nw;
2419 }
2420 }
2421 }
2422
2423 /* update the free count for this dmap.
2424 */
Marcin Slusarz89145622008-02-13 15:34:20 -06002425 le32_add_cpu(&dp->nfree, nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002426
2427 BMAP_LOCK(bmp);
2428
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002429 /* update the free count for the allocation group and
Linus Torvalds1da177e2005-04-16 15:20:36 -07002430 * map.
2431 */
2432 agno = blkno >> bmp->db_agl2size;
2433 bmp->db_nfree += nblocks;
2434 bmp->db_agfree[agno] += nblocks;
2435
2436 /* check if this allocation group is not completely free and
2437 * if it is currently the maximum (rightmost) allocation group.
2438 * if so, establish the new maximum allocation group number by
2439 * searching left for the first allocation group with allocation.
2440 */
2441 if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) ||
2442 (agno == bmp->db_numag - 1 &&
2443 bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) {
2444 while (bmp->db_maxag > 0) {
2445 bmp->db_maxag -= 1;
2446 if (bmp->db_agfree[bmp->db_maxag] !=
2447 bmp->db_agsize)
2448 break;
2449 }
2450
2451 /* re-establish the allocation group preference if the
2452 * current preference is right of the maximum allocation
2453 * group.
2454 */
2455 if (bmp->db_agpref > bmp->db_maxag)
2456 bmp->db_agpref = bmp->db_maxag;
2457 }
2458
2459 BMAP_UNLOCK(bmp);
Dave Kleikamp56d12542005-07-15 09:43:36 -05002460
2461 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002462}
2463
2464
2465/*
2466 * NAME: dbAdjCtl()
2467 *
2468 * FUNCTION: adjust a dmap control page at a specified level to reflect
2469 * the change in a lower level dmap or dmap control page's
2470 * maximum string of free blocks (i.e. a change in the root
2471 * of the lower level object's dmtree) due to the allocation
2472 * or deallocation of a range of blocks with a single dmap.
2473 *
2474 * on entry, this routine is provided with the new value of
2475 * the lower level dmap or dmap control page root and the
2476 * starting block number of the block range whose allocation
2477 * or deallocation resulted in the root change. this range
2478 * is respresented by a single leaf of the current dmapctl
2479 * and the leaf will be updated with this value, possibly
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002480 * causing a binary buddy system within the leaves to be
Linus Torvalds1da177e2005-04-16 15:20:36 -07002481 * split or joined. the update may also cause the dmapctl's
2482 * dmtree to be updated.
2483 *
2484 * if the adjustment of the dmap control page, itself, causes its
2485 * root to change, this change will be bubbled up to the next dmap
2486 * control level by a recursive call to this routine, specifying
2487 * the new root value and the next dmap control page level to
2488 * be adjusted.
2489 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002490 * bmp - pointer to bmap descriptor
2491 * blkno - the first block of a block range within a dmap. it is
Linus Torvalds1da177e2005-04-16 15:20:36 -07002492 * the allocation or deallocation of this block range that
2493 * requires the dmap control page to be adjusted.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002494 * newval - the new value of the lower level dmap or dmap control
Linus Torvalds1da177e2005-04-16 15:20:36 -07002495 * page root.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002496 * alloc - 'true' if adjustment is due to an allocation.
2497 * level - current level of dmap control page (i.e. L0, L1, L2) to
Linus Torvalds1da177e2005-04-16 15:20:36 -07002498 * be adjusted.
2499 *
2500 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002501 * 0 - success
2502 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07002503 *
2504 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2505 */
2506static int
2507dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
2508{
2509 struct metapage *mp;
2510 s8 oldroot;
2511 int oldval;
2512 s64 lblkno;
2513 struct dmapctl *dcp;
2514 int rc, leafno, ti;
2515
2516 /* get the buffer for the dmap control page for the specified
2517 * block number and control page level.
2518 */
2519 lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level);
2520 mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0);
2521 if (mp == NULL)
2522 return -EIO;
2523 dcp = (struct dmapctl *) mp->data;
2524
2525 if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) {
Joe Percheseb8630d2013-06-04 16:39:15 -07002526 jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002527 release_metapage(mp);
2528 return -EIO;
2529 }
2530
2531 /* determine the leaf number corresponding to the block and
2532 * the index within the dmap control tree.
2533 */
2534 leafno = BLKTOCTLLEAF(blkno, dcp->budmin);
2535 ti = leafno + le32_to_cpu(dcp->leafidx);
2536
2537 /* save the current leaf value and the current root level (i.e.
2538 * maximum l2 free string described by this dmapctl).
2539 */
2540 oldval = dcp->stree[ti];
2541 oldroot = dcp->stree[ROOT];
2542
2543 /* check if this is a control page update for an allocation.
2544 * if so, update the leaf to reflect the new leaf value using
Thomas Weber88393162010-03-16 11:47:56 +01002545 * dbSplit(); otherwise (deallocation), use dbJoin() to update
Linus Torvalds1da177e2005-04-16 15:20:36 -07002546 * the leaf with the new value. in addition to updating the
2547 * leaf, dbSplit() will also split the binary buddy system of
2548 * the leaves, if required, and bubble new values within the
2549 * dmapctl tree, if required. similarly, dbJoin() will join
2550 * the binary buddy system of leaves and bubble new values up
2551 * the dmapctl tree as required by the new leaf value.
2552 */
2553 if (alloc) {
2554 /* check if we are in the middle of a binary buddy
2555 * system. this happens when we are performing the
2556 * first allocation out of an allocation group that
2557 * is part (not the first part) of a larger binary
2558 * buddy system. if we are in the middle, back split
2559 * the system prior to calling dbSplit() which assumes
2560 * that it is at the front of a binary buddy system.
2561 */
2562 if (oldval == NOFREE) {
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002563 rc = dbBackSplit((dmtree_t *) dcp, leafno);
2564 if (rc)
2565 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002566 oldval = dcp->stree[ti];
2567 }
2568 dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval);
2569 } else {
Dave Kleikamp56d12542005-07-15 09:43:36 -05002570 rc = dbJoin((dmtree_t *) dcp, leafno, newval);
2571 if (rc)
2572 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002573 }
2574
2575 /* check if the root of the current dmap control page changed due
2576 * to the update and if the current dmap control page is not at
2577 * the current top level (i.e. L0, L1, L2) of the map. if so (i.e.
2578 * root changed and this is not the top level), call this routine
2579 * again (recursion) for the next higher level of the mapping to
2580 * reflect the change in root for the current dmap control page.
2581 */
2582 if (dcp->stree[ROOT] != oldroot) {
2583 /* are we below the top level of the map. if so,
2584 * bubble the root up to the next higher level.
2585 */
2586 if (level < bmp->db_maxlevel) {
2587 /* bubble up the new root of this dmap control page to
2588 * the next level.
2589 */
2590 if ((rc =
2591 dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc,
2592 level + 1))) {
2593 /* something went wrong in bubbling up the new
2594 * root value, so backout the changes to the
2595 * current dmap control page.
2596 */
2597 if (alloc) {
2598 dbJoin((dmtree_t *) dcp, leafno,
2599 oldval);
2600 } else {
2601 /* the dbJoin() above might have
2602 * caused a larger binary buddy system
2603 * to form and we may now be in the
2604 * middle of it. if this is the case,
2605 * back split the buddies.
2606 */
2607 if (dcp->stree[ti] == NOFREE)
2608 dbBackSplit((dmtree_t *)
2609 dcp, leafno);
2610 dbSplit((dmtree_t *) dcp, leafno,
2611 dcp->budmin, oldval);
2612 }
2613
2614 /* release the buffer and return the error.
2615 */
2616 release_metapage(mp);
2617 return (rc);
2618 }
2619 } else {
2620 /* we're at the top level of the map. update
2621 * the bmap control page to reflect the size
2622 * of the maximum free buddy system.
2623 */
2624 assert(level == bmp->db_maxlevel);
2625 if (bmp->db_maxfreebud != oldroot) {
2626 jfs_error(bmp->db_ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07002627 "the maximum free buddy is not the old root\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002628 }
2629 bmp->db_maxfreebud = dcp->stree[ROOT];
2630 }
2631 }
2632
2633 /* write the buffer.
2634 */
2635 write_metapage(mp);
2636
2637 return (0);
2638}
2639
2640
2641/*
2642 * NAME: dbSplit()
2643 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002644 * FUNCTION: update the leaf of a dmtree with a new value, splitting
Linus Torvalds1da177e2005-04-16 15:20:36 -07002645 * the leaf from the binary buddy system of the dmtree's
2646 * leaves, as required.
2647 *
2648 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002649 * tp - pointer to the tree containing the leaf.
2650 * leafno - the number of the leaf to be updated.
2651 * splitsz - the size the binary buddy system starting at the leaf
Linus Torvalds1da177e2005-04-16 15:20:36 -07002652 * must be split to, specified as the log2 number of blocks.
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002653 * newval - the new value for the leaf.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002654 *
2655 * RETURN VALUES: none
2656 *
2657 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2658 */
2659static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval)
2660{
2661 int budsz;
2662 int cursz;
2663 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2664
2665 /* check if the leaf needs to be split.
2666 */
2667 if (leaf[leafno] > tp->dmt_budmin) {
2668 /* the split occurs by cutting the buddy system in half
2669 * at the specified leaf until we reach the specified
2670 * size. pick up the starting split size (current size
2671 * - 1 in l2) and the corresponding buddy size.
2672 */
2673 cursz = leaf[leafno] - 1;
2674 budsz = BUDSIZE(cursz, tp->dmt_budmin);
2675
2676 /* split until we reach the specified size.
2677 */
2678 while (cursz >= splitsz) {
2679 /* update the buddy's leaf with its new value.
2680 */
2681 dbAdjTree(tp, leafno ^ budsz, cursz);
2682
2683 /* on to the next size and buddy.
2684 */
2685 cursz -= 1;
2686 budsz >>= 1;
2687 }
2688 }
2689
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002690 /* adjust the dmap tree to reflect the specified leaf's new
Linus Torvalds1da177e2005-04-16 15:20:36 -07002691 * value.
2692 */
2693 dbAdjTree(tp, leafno, newval);
2694}
2695
2696
2697/*
2698 * NAME: dbBackSplit()
2699 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002700 * FUNCTION: back split the binary buddy system of dmtree leaves
Linus Torvalds1da177e2005-04-16 15:20:36 -07002701 * that hold a specified leaf until the specified leaf
2702 * starts its own binary buddy system.
2703 *
2704 * the allocators typically perform allocations at the start
2705 * of binary buddy systems and dbSplit() is used to accomplish
2706 * any required splits. in some cases, however, allocation
2707 * may occur in the middle of a binary system and requires a
2708 * back split, with the split proceeding out from the middle of
2709 * the system (less efficient) rather than the start of the
2710 * system (more efficient). the cases in which a back split
2711 * is required are rare and are limited to the first allocation
2712 * within an allocation group which is a part (not first part)
2713 * of a larger binary buddy system and a few exception cases
2714 * in which a previous join operation must be backed out.
2715 *
2716 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002717 * tp - pointer to the tree containing the leaf.
2718 * leafno - the number of the leaf to be updated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002719 *
2720 * RETURN VALUES: none
2721 *
2722 * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit;
2723 */
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002724static int dbBackSplit(dmtree_t * tp, int leafno)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002725{
2726 int budsz, bud, w, bsz, size;
2727 int cursz;
2728 s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2729
2730 /* leaf should be part (not first part) of a binary
2731 * buddy system.
2732 */
2733 assert(leaf[leafno] == NOFREE);
2734
2735 /* the back split is accomplished by iteratively finding the leaf
2736 * that starts the buddy system that contains the specified leaf and
2737 * splitting that system in two. this iteration continues until
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002738 * the specified leaf becomes the start of a buddy system.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002739 *
2740 * determine maximum possible l2 size for the specified leaf.
2741 */
2742 size =
2743 LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs),
2744 tp->dmt_budmin);
2745
2746 /* determine the number of leaves covered by this size. this
2747 * is the buddy size that we will start with as we search for
2748 * the buddy system that contains the specified leaf.
2749 */
2750 budsz = BUDSIZE(size, tp->dmt_budmin);
2751
2752 /* back split.
2753 */
2754 while (leaf[leafno] == NOFREE) {
2755 /* find the leftmost buddy leaf.
2756 */
2757 for (w = leafno, bsz = budsz;; bsz <<= 1,
2758 w = (w < bud) ? w : bud) {
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002759 if (bsz >= le32_to_cpu(tp->dmt_nleafs)) {
2760 jfs_err("JFS: block map error in dbBackSplit");
2761 return -EIO;
2762 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002763
2764 /* determine the buddy.
2765 */
2766 bud = w ^ bsz;
2767
2768 /* check if this buddy is the start of the system.
2769 */
2770 if (leaf[bud] != NOFREE) {
2771 /* split the leaf at the start of the
2772 * system in two.
2773 */
2774 cursz = leaf[bud] - 1;
2775 dbSplit(tp, bud, cursz, cursz);
2776 break;
2777 }
2778 }
2779 }
2780
Dave Kleikampb6a47fd2005-10-11 09:06:59 -05002781 if (leaf[leafno] != size) {
2782 jfs_err("JFS: wrong leaf value in dbBackSplit");
2783 return -EIO;
2784 }
2785 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002786}
2787
2788
2789/*
2790 * NAME: dbJoin()
2791 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002792 * FUNCTION: update the leaf of a dmtree with a new value, joining
Linus Torvalds1da177e2005-04-16 15:20:36 -07002793 * the leaf with other leaves of the dmtree into a multi-leaf
2794 * binary buddy system, as required.
2795 *
2796 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002797 * tp - pointer to the tree containing the leaf.
2798 * leafno - the number of the leaf to be updated.
2799 * newval - the new value for the leaf.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002800 *
2801 * RETURN VALUES: none
2802 */
Dave Kleikamp56d12542005-07-15 09:43:36 -05002803static int dbJoin(dmtree_t * tp, int leafno, int newval)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002804{
2805 int budsz, buddy;
2806 s8 *leaf;
2807
2808 /* can the new leaf value require a join with other leaves ?
2809 */
2810 if (newval >= tp->dmt_budmin) {
2811 /* pickup a pointer to the leaves of the tree.
2812 */
2813 leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx);
2814
2815 /* try to join the specified leaf into a large binary
2816 * buddy system. the join proceeds by attempting to join
2817 * the specified leafno with its buddy (leaf) at new value.
2818 * if the join occurs, we attempt to join the left leaf
2819 * of the joined buddies with its buddy at new value + 1.
2820 * we continue to join until we find a buddy that cannot be
2821 * joined (does not have a value equal to the size of the
2822 * last join) or until all leaves have been joined into a
2823 * single system.
2824 *
2825 * get the buddy size (number of words covered) of
2826 * the new value.
2827 */
2828 budsz = BUDSIZE(newval, tp->dmt_budmin);
2829
2830 /* try to join.
2831 */
2832 while (budsz < le32_to_cpu(tp->dmt_nleafs)) {
2833 /* get the buddy leaf.
2834 */
2835 buddy = leafno ^ budsz;
2836
2837 /* if the leaf's new value is greater than its
2838 * buddy's value, we join no more.
2839 */
2840 if (newval > leaf[buddy])
2841 break;
2842
Dave Kleikamp56d12542005-07-15 09:43:36 -05002843 /* It shouldn't be less */
2844 if (newval < leaf[buddy])
2845 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002846
2847 /* check which (leafno or buddy) is the left buddy.
2848 * the left buddy gets to claim the blocks resulting
2849 * from the join while the right gets to claim none.
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002850 * the left buddy is also eligible to participate in
Linus Torvalds1da177e2005-04-16 15:20:36 -07002851 * a join at the next higher level while the right
2852 * is not.
2853 *
2854 */
2855 if (leafno < buddy) {
2856 /* leafno is the left buddy.
2857 */
2858 dbAdjTree(tp, buddy, NOFREE);
2859 } else {
2860 /* buddy is the left buddy and becomes
2861 * leafno.
2862 */
2863 dbAdjTree(tp, leafno, NOFREE);
2864 leafno = buddy;
2865 }
2866
2867 /* on to try the next join.
2868 */
2869 newval += 1;
2870 budsz <<= 1;
2871 }
2872 }
2873
2874 /* update the leaf value.
2875 */
2876 dbAdjTree(tp, leafno, newval);
Dave Kleikamp56d12542005-07-15 09:43:36 -05002877
2878 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002879}
2880
2881
2882/*
2883 * NAME: dbAdjTree()
2884 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002885 * FUNCTION: update a leaf of a dmtree with a new value, adjusting
Linus Torvalds1da177e2005-04-16 15:20:36 -07002886 * the dmtree, as required, to reflect the new leaf value.
2887 * the combination of any buddies must already be done before
2888 * this is called.
2889 *
2890 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002891 * tp - pointer to the tree to be adjusted.
2892 * leafno - the number of the leaf to be updated.
2893 * newval - the new value for the leaf.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002894 *
2895 * RETURN VALUES: none
2896 */
2897static void dbAdjTree(dmtree_t * tp, int leafno, int newval)
2898{
2899 int lp, pp, k;
2900 int max;
2901
2902 /* pick up the index of the leaf for this leafno.
2903 */
2904 lp = leafno + le32_to_cpu(tp->dmt_leafidx);
2905
2906 /* is the current value the same as the old value ? if so,
2907 * there is nothing to do.
2908 */
2909 if (tp->dmt_stree[lp] == newval)
2910 return;
2911
2912 /* set the new value.
2913 */
2914 tp->dmt_stree[lp] = newval;
2915
2916 /* bubble the new value up the tree as required.
2917 */
2918 for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) {
2919 /* get the index of the first leaf of the 4 leaf
2920 * group containing the specified leaf (leafno).
2921 */
2922 lp = ((lp - 1) & ~0x03) + 1;
2923
2924 /* get the index of the parent of this 4 leaf group.
2925 */
2926 pp = (lp - 1) >> 2;
2927
2928 /* determine the maximum of the 4 leaves.
2929 */
2930 max = TREEMAX(&tp->dmt_stree[lp]);
2931
2932 /* if the maximum of the 4 is the same as the
2933 * parent's value, we're done.
2934 */
2935 if (tp->dmt_stree[pp] == max)
2936 break;
2937
2938 /* parent gets new value.
2939 */
2940 tp->dmt_stree[pp] = max;
2941
2942 /* parent becomes leaf for next go-round.
2943 */
2944 lp = pp;
2945 }
2946}
2947
2948
2949/*
2950 * NAME: dbFindLeaf()
2951 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002952 * FUNCTION: search a dmtree_t for sufficient free blocks, returning
Dave Kleikamp63f83c92006-10-02 09:55:27 -05002953 * the index of a leaf describing the free blocks if
Linus Torvalds1da177e2005-04-16 15:20:36 -07002954 * sufficient free blocks are found.
2955 *
2956 * the search starts at the top of the dmtree_t tree and
2957 * proceeds down the tree to the leftmost leaf with sufficient
2958 * free space.
2959 *
2960 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002961 * tp - pointer to the tree to be searched.
2962 * l2nb - log2 number of free blocks to search for.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002963 * leafidx - return pointer to be set to the index of the leaf
2964 * describing at least l2nb free blocks if sufficient
2965 * free blocks are found.
2966 *
2967 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05002968 * 0 - success
2969 * -ENOSPC - insufficient free blocks.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002970 */
2971static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx)
2972{
2973 int ti, n = 0, k, x = 0;
2974
2975 /* first check the root of the tree to see if there is
2976 * sufficient free space.
2977 */
2978 if (l2nb > tp->dmt_stree[ROOT])
2979 return -ENOSPC;
2980
2981 /* sufficient free space available. now search down the tree
2982 * starting at the next level for the leftmost leaf that
2983 * describes sufficient free space.
2984 */
2985 for (k = le32_to_cpu(tp->dmt_height), ti = 1;
2986 k > 0; k--, ti = ((ti + n) << 2) + 1) {
2987 /* search the four nodes at this level, starting from
2988 * the left.
2989 */
2990 for (x = ti, n = 0; n < 4; n++) {
2991 /* sufficient free space found. move to the next
2992 * level (or quit if this is the last level).
2993 */
2994 if (l2nb <= tp->dmt_stree[x + n])
2995 break;
2996 }
2997
2998 /* better have found something since the higher
2999 * levels of the tree said it was here.
3000 */
3001 assert(n < 4);
3002 }
3003
3004 /* set the return to the leftmost leaf describing sufficient
3005 * free space.
3006 */
3007 *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx);
3008
3009 return (0);
3010}
3011
3012
3013/*
3014 * NAME: dbFindBits()
3015 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003016 * FUNCTION: find a specified number of binary buddy free bits within a
Linus Torvalds1da177e2005-04-16 15:20:36 -07003017 * dmap bitmap word value.
3018 *
3019 * this routine searches the bitmap value for (1 << l2nb) free
3020 * bits at (1 << l2nb) alignments within the value.
3021 *
3022 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003023 * word - dmap bitmap word value.
3024 * l2nb - number of free bits specified as a log2 number.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003025 *
3026 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003027 * starting bit number of free bits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003028 */
3029static int dbFindBits(u32 word, int l2nb)
3030{
3031 int bitno, nb;
3032 u32 mask;
3033
3034 /* get the number of bits.
3035 */
3036 nb = 1 << l2nb;
3037 assert(nb <= DBWORD);
3038
3039 /* complement the word so we can use a mask (i.e. 0s represent
3040 * free bits) and compute the mask.
3041 */
3042 word = ~word;
3043 mask = ONES << (DBWORD - nb);
3044
3045 /* scan the word for nb free bits at nb alignments.
3046 */
3047 for (bitno = 0; mask != 0; bitno += nb, mask >>= nb) {
3048 if ((mask & word) == mask)
3049 break;
3050 }
3051
3052 ASSERT(bitno < 32);
3053
3054 /* return the bit number.
3055 */
3056 return (bitno);
3057}
3058
3059
3060/*
3061 * NAME: dbMaxBud(u8 *cp)
3062 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003063 * FUNCTION: determine the largest binary buddy string of free
Linus Torvalds1da177e2005-04-16 15:20:36 -07003064 * bits within 32-bits of the map.
3065 *
3066 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003067 * cp - pointer to the 32-bit value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003068 *
3069 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003070 * largest binary buddy of free bits within a dmap word.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003071 */
3072static int dbMaxBud(u8 * cp)
3073{
3074 signed char tmp1, tmp2;
3075
3076 /* check if the wmap word is all free. if so, the
3077 * free buddy size is BUDMIN.
3078 */
3079 if (*((uint *) cp) == 0)
3080 return (BUDMIN);
3081
3082 /* check if the wmap word is half free. if so, the
3083 * free buddy size is BUDMIN-1.
3084 */
3085 if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0)
3086 return (BUDMIN - 1);
3087
3088 /* not all free or half free. determine the free buddy
3089 * size thru table lookup using quarters of the wmap word.
3090 */
3091 tmp1 = max(budtab[cp[2]], budtab[cp[3]]);
3092 tmp2 = max(budtab[cp[0]], budtab[cp[1]]);
3093 return (max(tmp1, tmp2));
3094}
3095
3096
3097/*
3098 * NAME: cnttz(uint word)
3099 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003100 * FUNCTION: determine the number of trailing zeros within a 32-bit
Linus Torvalds1da177e2005-04-16 15:20:36 -07003101 * value.
3102 *
3103 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003104 * value - 32-bit value to be examined.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003105 *
3106 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003107 * count of trailing zeros
Linus Torvalds1da177e2005-04-16 15:20:36 -07003108 */
3109static int cnttz(u32 word)
3110{
3111 int n;
3112
3113 for (n = 0; n < 32; n++, word >>= 1) {
3114 if (word & 0x01)
3115 break;
3116 }
3117
3118 return (n);
3119}
3120
3121
3122/*
3123 * NAME: cntlz(u32 value)
3124 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003125 * FUNCTION: determine the number of leading zeros within a 32-bit
Linus Torvalds1da177e2005-04-16 15:20:36 -07003126 * value.
3127 *
3128 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003129 * value - 32-bit value to be examined.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003130 *
3131 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003132 * count of leading zeros
Linus Torvalds1da177e2005-04-16 15:20:36 -07003133 */
3134static int cntlz(u32 value)
3135{
3136 int n;
3137
3138 for (n = 0; n < 32; n++, value <<= 1) {
3139 if (value & HIGHORDER)
3140 break;
3141 }
3142 return (n);
3143}
3144
3145
3146/*
3147 * NAME: blkstol2(s64 nb)
3148 *
3149 * FUNCTION: convert a block count to its log2 value. if the block
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003150 * count is not a l2 multiple, it is rounded up to the next
Linus Torvalds1da177e2005-04-16 15:20:36 -07003151 * larger l2 multiple.
3152 *
3153 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003154 * nb - number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003155 *
3156 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003157 * log2 number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003158 */
Dave Kleikamp6cb12692005-09-15 23:25:41 -05003159static int blkstol2(s64 nb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003160{
3161 int l2nb;
3162 s64 mask; /* meant to be signed */
3163
3164 mask = (s64) 1 << (64 - 1);
3165
3166 /* count the leading bits.
3167 */
3168 for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) {
3169 /* leading bit found.
3170 */
3171 if (nb & mask) {
3172 /* determine the l2 value.
3173 */
3174 l2nb = (64 - 1) - l2nb;
3175
3176 /* check if we need to round up.
3177 */
3178 if (~mask & nb)
3179 l2nb++;
3180
3181 return (l2nb);
3182 }
3183 }
3184 assert(0);
3185 return 0; /* fix compiler warning */
3186}
3187
3188
3189/*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003190 * NAME: dbAllocBottomUp()
Linus Torvalds1da177e2005-04-16 15:20:36 -07003191 *
3192 * FUNCTION: alloc the specified block range from the working block
3193 * allocation map.
3194 *
3195 * the blocks will be alloc from the working map one dmap
3196 * at a time.
3197 *
3198 * PARAMETERS:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003199 * ip - pointer to in-core inode;
3200 * blkno - starting block number to be freed.
3201 * nblocks - number of blocks to be freed.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003202 *
3203 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003204 * 0 - success
3205 * -EIO - i/o error
Linus Torvalds1da177e2005-04-16 15:20:36 -07003206 */
3207int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks)
3208{
3209 struct metapage *mp;
3210 struct dmap *dp;
3211 int nb, rc;
3212 s64 lblkno, rem;
3213 struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
3214 struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
3215
Dave Kleikamp82d5b9a2007-01-09 14:14:48 -06003216 IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003217
3218 /* block to be allocated better be within the mapsize. */
3219 ASSERT(nblocks <= bmp->db_mapsize - blkno);
3220
3221 /*
3222 * allocate the blocks a dmap at a time.
3223 */
3224 mp = NULL;
3225 for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) {
3226 /* release previous dmap if any */
3227 if (mp) {
3228 write_metapage(mp);
3229 }
3230
3231 /* get the buffer for the current dmap. */
3232 lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage);
3233 mp = read_metapage(ipbmap, lblkno, PSIZE, 0);
3234 if (mp == NULL) {
3235 IREAD_UNLOCK(ipbmap);
3236 return -EIO;
3237 }
3238 dp = (struct dmap *) mp->data;
3239
3240 /* determine the number of blocks to be allocated from
3241 * this dmap.
3242 */
3243 nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1)));
3244
Linus Torvalds1da177e2005-04-16 15:20:36 -07003245 /* allocate the blocks. */
3246 if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) {
3247 release_metapage(mp);
3248 IREAD_UNLOCK(ipbmap);
3249 return (rc);
3250 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003251 }
3252
3253 /* write the last buffer. */
3254 write_metapage(mp);
3255
3256 IREAD_UNLOCK(ipbmap);
3257
3258 return (0);
3259}
3260
3261
3262static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno,
3263 int nblocks)
3264{
3265 int rc;
3266 int dbitno, word, rembits, nb, nwords, wbitno, agno;
Dave Kleikamp3c2c2262011-06-20 13:00:27 -05003267 s8 oldroot;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003268 struct dmaptree *tp = (struct dmaptree *) & dp->tree;
3269
3270 /* save the current value of the root (i.e. maximum free string)
3271 * of the dmap tree.
3272 */
3273 oldroot = tp->stree[ROOT];
3274
Linus Torvalds1da177e2005-04-16 15:20:36 -07003275 /* determine the bit number and word within the dmap of the
3276 * starting block.
3277 */
3278 dbitno = blkno & (BPERDMAP - 1);
3279 word = dbitno >> L2DBWORD;
3280
3281 /* block range better be within the dmap */
3282 assert(dbitno + nblocks <= BPERDMAP);
3283
3284 /* allocate the bits of the dmap's words corresponding to the block
3285 * range. not all bits of the first and last words may be contained
3286 * within the block range. if this is the case, we'll work against
3287 * those words (i.e. partial first and/or last) on an individual basis
3288 * (a single pass), allocating the bits of interest by hand and
3289 * updating the leaf corresponding to the dmap word. a single pass
3290 * will be used for all dmap words fully contained within the
3291 * specified range. within this pass, the bits of all fully contained
3292 * dmap words will be marked as free in a single shot and the leaves
3293 * will be updated. a single leaf may describe the free space of
3294 * multiple dmap words, so we may update only a subset of the actual
3295 * leaves corresponding to the dmap words of the block range.
3296 */
3297 for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) {
3298 /* determine the bit number within the word and
3299 * the number of bits within the word.
3300 */
3301 wbitno = dbitno & (DBWORD - 1);
3302 nb = min(rembits, DBWORD - wbitno);
3303
3304 /* check if only part of a word is to be allocated.
3305 */
3306 if (nb < DBWORD) {
3307 /* allocate (set to 1) the appropriate bits within
3308 * this dmap word.
3309 */
3310 dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb)
3311 >> wbitno);
3312
3313 word++;
3314 } else {
3315 /* one or more dmap words are fully contained
3316 * within the block range. determine how many
3317 * words and allocate (set to 1) the bits of these
3318 * words.
3319 */
3320 nwords = rembits >> L2DBWORD;
3321 memset(&dp->wmap[word], (int) ONES, nwords * 4);
3322
3323 /* determine how many bits */
3324 nb = nwords << L2DBWORD;
3325 word += nwords;
3326 }
3327 }
3328
3329 /* update the free count for this dmap */
Marcin Slusarz89145622008-02-13 15:34:20 -06003330 le32_add_cpu(&dp->nfree, -nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003331
3332 /* reconstruct summary tree */
3333 dbInitDmapTree(dp);
3334
3335 BMAP_LOCK(bmp);
3336
3337 /* if this allocation group is completely free,
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003338 * update the highest active allocation group number
Linus Torvalds1da177e2005-04-16 15:20:36 -07003339 * if this allocation group is the new max.
3340 */
3341 agno = blkno >> bmp->db_agl2size;
3342 if (agno > bmp->db_maxag)
3343 bmp->db_maxag = agno;
3344
3345 /* update the free count for the allocation group and map */
3346 bmp->db_agfree[agno] -= nblocks;
3347 bmp->db_nfree -= nblocks;
3348
3349 BMAP_UNLOCK(bmp);
3350
3351 /* if the root has not changed, done. */
3352 if (tp->stree[ROOT] == oldroot)
3353 return (0);
3354
3355 /* root changed. bubble the change up to the dmap control pages.
3356 * if the adjustment of the upper level control pages fails,
3357 * backout the bit allocation (thus making everything consistent).
3358 */
3359 if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0)))
3360 dbFreeBits(bmp, dp, blkno, nblocks);
3361
3362 return (rc);
3363}
3364
3365
3366/*
3367 * NAME: dbExtendFS()
3368 *
3369 * FUNCTION: extend bmap from blkno for nblocks;
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003370 * dbExtendFS() updates bmap ready for dbAllocBottomUp();
Linus Torvalds1da177e2005-04-16 15:20:36 -07003371 *
3372 * L2
3373 * |
3374 * L1---------------------------------L1
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003375 * | |
3376 * L0---------L0---------L0 L0---------L0---------L0
3377 * | | | | | |
3378 * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003379 * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm
3380 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003381 * <---old---><----------------------------extend----------------------->
Linus Torvalds1da177e2005-04-16 15:20:36 -07003382 */
3383int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks)
3384{
3385 struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb);
3386 int nbperpage = sbi->nbperpage;
Richard Knutsson4d817152006-09-30 23:27:14 -07003387 int i, i0 = true, j, j0 = true, k, n;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003388 s64 newsize;
3389 s64 p;
3390 struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL;
3391 struct dmapctl *l2dcp, *l1dcp, *l0dcp;
3392 struct dmap *dp;
3393 s8 *l0leaf, *l1leaf, *l2leaf;
3394 struct bmap *bmp = sbi->bmap;
3395 int agno, l2agsize, oldl2agsize;
3396 s64 ag_rem;
3397
3398 newsize = blkno + nblocks;
3399
3400 jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld",
3401 (long long) blkno, (long long) nblocks, (long long) newsize);
3402
3403 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003404 * initialize bmap control page.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003405 *
3406 * all the data in bmap control page should exclude
3407 * the mkfs hidden dmap page.
3408 */
3409
3410 /* update mapsize */
3411 bmp->db_mapsize = newsize;
3412 bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize);
3413
3414 /* compute new AG size */
3415 l2agsize = dbGetL2AGSize(newsize);
3416 oldl2agsize = bmp->db_agl2size;
3417
3418 bmp->db_agl2size = l2agsize;
3419 bmp->db_agsize = 1 << l2agsize;
3420
3421 /* compute new number of AG */
3422 agno = bmp->db_numag;
3423 bmp->db_numag = newsize >> l2agsize;
3424 bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0;
3425
3426 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003427 * reconfigure db_agfree[]
Linus Torvalds1da177e2005-04-16 15:20:36 -07003428 * from old AG configuration to new AG configuration;
3429 *
3430 * coalesce contiguous k (newAGSize/oldAGSize) AGs;
3431 * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn;
3432 * note: new AG size = old AG size * (2**x).
3433 */
3434 if (l2agsize == oldl2agsize)
3435 goto extend;
3436 k = 1 << (l2agsize - oldl2agsize);
3437 ag_rem = bmp->db_agfree[0]; /* save agfree[0] */
3438 for (i = 0, n = 0; i < agno; n++) {
3439 bmp->db_agfree[n] = 0; /* init collection point */
3440
André Goddard Rosaaf901ca2009-11-14 13:09:05 -02003441 /* coalesce contiguous k AGs; */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003442 for (j = 0; j < k && i < agno; j++, i++) {
3443 /* merge AGi to AGn */
3444 bmp->db_agfree[n] += bmp->db_agfree[i];
3445 }
3446 }
3447 bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */
3448
3449 for (; n < MAXAG; n++)
3450 bmp->db_agfree[n] = 0;
3451
3452 /*
3453 * update highest active ag number
3454 */
3455
3456 bmp->db_maxag = bmp->db_maxag / k;
3457
3458 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003459 * extend bmap
Linus Torvalds1da177e2005-04-16 15:20:36 -07003460 *
3461 * update bit maps and corresponding level control pages;
3462 * global control page db_nfree, db_agfree[agno], db_maxfreebud;
3463 */
3464 extend:
3465 /* get L2 page */
3466 p = BMAPBLKNO + nbperpage; /* L2 page */
3467 l2mp = read_metapage(ipbmap, p, PSIZE, 0);
3468 if (!l2mp) {
Joe Percheseb8630d2013-06-04 16:39:15 -07003469 jfs_error(ipbmap->i_sb, "L2 page could not be read\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003470 return -EIO;
3471 }
3472 l2dcp = (struct dmapctl *) l2mp->data;
3473
3474 /* compute start L1 */
3475 k = blkno >> L2MAXL1SIZE;
3476 l2leaf = l2dcp->stree + CTLLEAFIND + k;
3477 p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */
3478
3479 /*
3480 * extend each L1 in L2
3481 */
3482 for (; k < LPERCTL; k++, p += nbperpage) {
3483 /* get L1 page */
3484 if (j0) {
3485 /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */
3486 l1mp = read_metapage(ipbmap, p, PSIZE, 0);
3487 if (l1mp == NULL)
3488 goto errout;
3489 l1dcp = (struct dmapctl *) l1mp->data;
3490
3491 /* compute start L0 */
3492 j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE;
3493 l1leaf = l1dcp->stree + CTLLEAFIND + j;
3494 p = BLKTOL0(blkno, sbi->l2nbperpage);
Richard Knutsson4d817152006-09-30 23:27:14 -07003495 j0 = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003496 } else {
3497 /* assign/init L1 page */
3498 l1mp = get_metapage(ipbmap, p, PSIZE, 0);
3499 if (l1mp == NULL)
3500 goto errout;
3501
3502 l1dcp = (struct dmapctl *) l1mp->data;
3503
3504 /* compute start L0 */
3505 j = 0;
3506 l1leaf = l1dcp->stree + CTLLEAFIND;
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003507 p += nbperpage; /* 1st L0 of L1.k */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003508 }
3509
3510 /*
3511 * extend each L0 in L1
3512 */
3513 for (; j < LPERCTL; j++) {
3514 /* get L0 page */
3515 if (i0) {
3516 /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */
3517
3518 l0mp = read_metapage(ipbmap, p, PSIZE, 0);
3519 if (l0mp == NULL)
3520 goto errout;
3521 l0dcp = (struct dmapctl *) l0mp->data;
3522
3523 /* compute start dmap */
3524 i = (blkno & (MAXL0SIZE - 1)) >>
3525 L2BPERDMAP;
3526 l0leaf = l0dcp->stree + CTLLEAFIND + i;
3527 p = BLKTODMAP(blkno,
3528 sbi->l2nbperpage);
Richard Knutsson4d817152006-09-30 23:27:14 -07003529 i0 = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003530 } else {
3531 /* assign/init L0 page */
3532 l0mp = get_metapage(ipbmap, p, PSIZE, 0);
3533 if (l0mp == NULL)
3534 goto errout;
3535
3536 l0dcp = (struct dmapctl *) l0mp->data;
3537
3538 /* compute start dmap */
3539 i = 0;
3540 l0leaf = l0dcp->stree + CTLLEAFIND;
3541 p += nbperpage; /* 1st dmap of L0.j */
3542 }
3543
3544 /*
3545 * extend each dmap in L0
3546 */
3547 for (; i < LPERCTL; i++) {
3548 /*
3549 * reconstruct the dmap page, and
3550 * initialize corresponding parent L0 leaf
3551 */
3552 if ((n = blkno & (BPERDMAP - 1))) {
3553 /* read in dmap page: */
3554 mp = read_metapage(ipbmap, p,
3555 PSIZE, 0);
3556 if (mp == NULL)
3557 goto errout;
3558 n = min(nblocks, (s64)BPERDMAP - n);
3559 } else {
3560 /* assign/init dmap page */
3561 mp = read_metapage(ipbmap, p,
3562 PSIZE, 0);
3563 if (mp == NULL)
3564 goto errout;
3565
3566 n = min(nblocks, (s64)BPERDMAP);
3567 }
3568
3569 dp = (struct dmap *) mp->data;
3570 *l0leaf = dbInitDmap(dp, blkno, n);
3571
3572 bmp->db_nfree += n;
3573 agno = le64_to_cpu(dp->start) >> l2agsize;
3574 bmp->db_agfree[agno] += n;
3575
3576 write_metapage(mp);
3577
3578 l0leaf++;
3579 p += nbperpage;
3580
3581 blkno += n;
3582 nblocks -= n;
3583 if (nblocks == 0)
3584 break;
3585 } /* for each dmap in a L0 */
3586
3587 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003588 * build current L0 page from its leaves, and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003589 * initialize corresponding parent L1 leaf
3590 */
3591 *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i);
3592 write_metapage(l0mp);
3593 l0mp = NULL;
3594
3595 if (nblocks)
3596 l1leaf++; /* continue for next L0 */
3597 else {
3598 /* more than 1 L0 ? */
3599 if (j > 0)
3600 break; /* build L1 page */
3601 else {
3602 /* summarize in global bmap page */
3603 bmp->db_maxfreebud = *l1leaf;
3604 release_metapage(l1mp);
3605 release_metapage(l2mp);
3606 goto finalize;
3607 }
3608 }
3609 } /* for each L0 in a L1 */
3610
3611 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003612 * build current L1 page from its leaves, and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003613 * initialize corresponding parent L2 leaf
3614 */
3615 *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j);
3616 write_metapage(l1mp);
3617 l1mp = NULL;
3618
3619 if (nblocks)
3620 l2leaf++; /* continue for next L1 */
3621 else {
3622 /* more than 1 L1 ? */
3623 if (k > 0)
3624 break; /* build L2 page */
3625 else {
3626 /* summarize in global bmap page */
3627 bmp->db_maxfreebud = *l2leaf;
3628 release_metapage(l2mp);
3629 goto finalize;
3630 }
3631 }
3632 } /* for each L1 in a L2 */
3633
Joe Percheseb8630d2013-06-04 16:39:15 -07003634 jfs_error(ipbmap->i_sb, "function has not returned as expected\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003635errout:
3636 if (l0mp)
3637 release_metapage(l0mp);
3638 if (l1mp)
3639 release_metapage(l1mp);
3640 release_metapage(l2mp);
3641 return -EIO;
3642
3643 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003644 * finalize bmap control page
Linus Torvalds1da177e2005-04-16 15:20:36 -07003645 */
3646finalize:
3647
3648 return 0;
3649}
3650
3651
3652/*
3653 * dbFinalizeBmap()
3654 */
3655void dbFinalizeBmap(struct inode *ipbmap)
3656{
3657 struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap;
3658 int actags, inactags, l2nl;
3659 s64 ag_rem, actfree, inactfree, avgfree;
3660 int i, n;
3661
3662 /*
Dave Kleikampf720e3b2007-06-06 15:28:35 -05003663 * finalize bmap control page
Linus Torvalds1da177e2005-04-16 15:20:36 -07003664 */
3665//finalize:
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003666 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003667 * compute db_agpref: preferred ag to allocate from
3668 * (the leftmost ag with average free space in it);
3669 */
3670//agpref:
3671 /* get the number of active ags and inacitve ags */
3672 actags = bmp->db_maxag + 1;
3673 inactags = bmp->db_numag - actags;
3674 ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */
3675
3676 /* determine how many blocks are in the inactive allocation
3677 * groups. in doing this, we must account for the fact that
3678 * the rightmost group might be a partial group (i.e. file
3679 * system size is not a multiple of the group size).
3680 */
3681 inactfree = (inactags && ag_rem) ?
3682 ((inactags - 1) << bmp->db_agl2size) + ag_rem
3683 : inactags << bmp->db_agl2size;
3684
3685 /* determine how many free blocks are in the active
3686 * allocation groups plus the average number of free blocks
3687 * within the active ags.
3688 */
3689 actfree = bmp->db_nfree - inactfree;
3690 avgfree = (u32) actfree / (u32) actags;
3691
3692 /* if the preferred allocation group has not average free space.
3693 * re-establish the preferred group as the leftmost
3694 * group with average free space.
3695 */
3696 if (bmp->db_agfree[bmp->db_agpref] < avgfree) {
3697 for (bmp->db_agpref = 0; bmp->db_agpref < actags;
3698 bmp->db_agpref++) {
3699 if (bmp->db_agfree[bmp->db_agpref] >= avgfree)
3700 break;
3701 }
3702 if (bmp->db_agpref >= bmp->db_numag) {
3703 jfs_error(ipbmap->i_sb,
Joe Percheseb8630d2013-06-04 16:39:15 -07003704 "cannot find ag with average freespace\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003705 }
3706 }
3707
3708 /*
Daniel Mackd7eecb42010-01-28 16:13:01 +08003709 * compute db_aglevel, db_agheight, db_width, db_agstart:
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003710 * an ag is covered in aglevel dmapctl summary tree,
3711 * at agheight level height (from leaf) with agwidth number of nodes
3712 * each, which starts at agstart index node of the smmary tree node
Linus Torvalds1da177e2005-04-16 15:20:36 -07003713 * array;
3714 */
3715 bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize);
3716 l2nl =
3717 bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL);
Daniel Mackd7eecb42010-01-28 16:13:01 +08003718 bmp->db_agheight = l2nl >> 1;
3719 bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheight << 1));
3720 for (i = 5 - bmp->db_agheight, bmp->db_agstart = 0, n = 1; i > 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003721 i--) {
3722 bmp->db_agstart += n;
3723 n <<= 2;
3724 }
3725
3726}
3727
3728
3729/*
3730 * NAME: dbInitDmap()/ujfs_idmap_page()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003731 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003732 * FUNCTION: initialize working/persistent bitmap of the dmap page
3733 * for the specified number of blocks:
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003734 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003735 * at entry, the bitmaps had been initialized as free (ZEROS);
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003736 * The number of blocks will only account for the actually
3737 * existing blocks. Blocks which don't actually exist in
Linus Torvalds1da177e2005-04-16 15:20:36 -07003738 * the aggregate will be marked as allocated (ONES);
3739 *
3740 * PARAMETERS:
3741 * dp - pointer to page of map
3742 * nblocks - number of blocks this page
3743 *
3744 * RETURNS: NONE
3745 */
3746static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks)
3747{
3748 int blkno, w, b, r, nw, nb, i;
3749
3750 /* starting block number within the dmap */
3751 blkno = Blkno & (BPERDMAP - 1);
3752
3753 if (blkno == 0) {
3754 dp->nblocks = dp->nfree = cpu_to_le32(nblocks);
3755 dp->start = cpu_to_le64(Blkno);
3756
3757 if (nblocks == BPERDMAP) {
3758 memset(&dp->wmap[0], 0, LPERDMAP * 4);
3759 memset(&dp->pmap[0], 0, LPERDMAP * 4);
3760 goto initTree;
3761 }
3762 } else {
Marcin Slusarz89145622008-02-13 15:34:20 -06003763 le32_add_cpu(&dp->nblocks, nblocks);
3764 le32_add_cpu(&dp->nfree, nblocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003765 }
3766
3767 /* word number containing start block number */
3768 w = blkno >> L2DBWORD;
3769
3770 /*
3771 * free the bits corresponding to the block range (ZEROS):
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003772 * note: not all bits of the first and last words may be contained
Linus Torvalds1da177e2005-04-16 15:20:36 -07003773 * within the block range.
3774 */
3775 for (r = nblocks; r > 0; r -= nb, blkno += nb) {
3776 /* number of bits preceding range to be freed in the word */
3777 b = blkno & (DBWORD - 1);
3778 /* number of bits to free in the word */
3779 nb = min(r, DBWORD - b);
3780
3781 /* is partial word to be freed ? */
3782 if (nb < DBWORD) {
3783 /* free (set to 0) from the bitmap word */
3784 dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3785 >> b));
3786 dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb)
3787 >> b));
3788
3789 /* skip the word freed */
3790 w++;
3791 } else {
3792 /* free (set to 0) contiguous bitmap words */
3793 nw = r >> L2DBWORD;
3794 memset(&dp->wmap[w], 0, nw * 4);
3795 memset(&dp->pmap[w], 0, nw * 4);
3796
3797 /* skip the words freed */
3798 nb = nw << L2DBWORD;
3799 w += nw;
3800 }
3801 }
3802
3803 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003804 * mark bits following the range to be freed (non-existing
Linus Torvalds1da177e2005-04-16 15:20:36 -07003805 * blocks) as allocated (ONES)
3806 */
3807
3808 if (blkno == BPERDMAP)
3809 goto initTree;
3810
3811 /* the first word beyond the end of existing blocks */
3812 w = blkno >> L2DBWORD;
3813
3814 /* does nblocks fall on a 32-bit boundary ? */
3815 b = blkno & (DBWORD - 1);
3816 if (b) {
3817 /* mark a partial word allocated */
3818 dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b);
3819 w++;
3820 }
3821
3822 /* set the rest of the words in the page to allocated (ONES) */
3823 for (i = w; i < LPERDMAP; i++)
3824 dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES);
3825
3826 /*
3827 * init tree
3828 */
3829 initTree:
3830 return (dbInitDmapTree(dp));
3831}
3832
3833
3834/*
3835 * NAME: dbInitDmapTree()/ujfs_complete_dmap()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003836 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003837 * FUNCTION: initialize summary tree of the specified dmap:
3838 *
3839 * at entry, bitmap of the dmap has been initialized;
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003840 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003841 * PARAMETERS:
3842 * dp - dmap to complete
3843 * blkno - starting block number for this dmap
3844 * treemax - will be filled in with max free for this dmap
3845 *
3846 * RETURNS: max free string at the root of the tree
3847 */
3848static int dbInitDmapTree(struct dmap * dp)
3849{
3850 struct dmaptree *tp;
3851 s8 *cp;
3852 int i;
3853
3854 /* init fixed info of tree */
3855 tp = &dp->tree;
3856 tp->nleafs = cpu_to_le32(LPERDMAP);
3857 tp->l2nleafs = cpu_to_le32(L2LPERDMAP);
3858 tp->leafidx = cpu_to_le32(LEAFIND);
3859 tp->height = cpu_to_le32(4);
3860 tp->budmin = BUDMIN;
3861
3862 /* init each leaf from corresponding wmap word:
3863 * note: leaf is set to NOFREE(-1) if all blocks of corresponding
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003864 * bitmap word are allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003865 */
3866 cp = tp->stree + le32_to_cpu(tp->leafidx);
3867 for (i = 0; i < LPERDMAP; i++)
3868 *cp++ = dbMaxBud((u8 *) & dp->wmap[i]);
3869
3870 /* build the dmap's binary buddy summary tree */
3871 return (dbInitTree(tp));
3872}
3873
3874
3875/*
3876 * NAME: dbInitTree()/ujfs_adjtree()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003877 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003878 * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl.
3879 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003880 * at entry, the leaves of the tree has been initialized
Linus Torvalds1da177e2005-04-16 15:20:36 -07003881 * from corresponding bitmap word or root of summary tree
3882 * of the child control page;
3883 * configure binary buddy system at the leaf level, then
3884 * bubble up the values of the leaf nodes up the tree.
3885 *
3886 * PARAMETERS:
3887 * cp - Pointer to the root of the tree
3888 * l2leaves- Number of leaf nodes as a power of 2
3889 * l2min - Number of blocks that can be covered by a leaf
3890 * as a power of 2
3891 *
3892 * RETURNS: max free string at the root of the tree
3893 */
3894static int dbInitTree(struct dmaptree * dtp)
3895{
3896 int l2max, l2free, bsize, nextb, i;
3897 int child, parent, nparent;
3898 s8 *tp, *cp, *cp1;
3899
3900 tp = dtp->stree;
3901
3902 /* Determine the maximum free string possible for the leaves */
3903 l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin;
3904
3905 /*
3906 * configure the leaf levevl into binary buddy system
3907 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003908 * Try to combine buddies starting with a buddy size of 1
3909 * (i.e. two leaves). At a buddy size of 1 two buddy leaves
3910 * can be combined if both buddies have a maximum free of l2min;
3911 * the combination will result in the left-most buddy leaf having
3912 * a maximum free of l2min+1.
3913 * After processing all buddies for a given size, process buddies
3914 * at the next higher buddy size (i.e. current size * 2) and
3915 * the next maximum free (current free + 1).
3916 * This continues until the maximum possible buddy combination
Linus Torvalds1da177e2005-04-16 15:20:36 -07003917 * yields maximum free.
3918 */
3919 for (l2free = dtp->budmin, bsize = 1; l2free < l2max;
3920 l2free++, bsize = nextb) {
3921 /* get next buddy size == current buddy pair size */
3922 nextb = bsize << 1;
3923
3924 /* scan each adjacent buddy pair at current buddy size */
3925 for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx);
3926 i < le32_to_cpu(dtp->nleafs);
3927 i += nextb, cp += nextb) {
3928 /* coalesce if both adjacent buddies are max free */
3929 if (*cp == l2free && *(cp + bsize) == l2free) {
3930 *cp = l2free + 1; /* left take right */
3931 *(cp + bsize) = -1; /* right give left */
3932 }
3933 }
3934 }
3935
3936 /*
3937 * bubble summary information of leaves up the tree.
3938 *
3939 * Starting at the leaf node level, the four nodes described by
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003940 * the higher level parent node are compared for a maximum free and
3941 * this maximum becomes the value of the parent node.
3942 * when all lower level nodes are processed in this fashion then
3943 * move up to the next level (parent becomes a lower level node) and
Linus Torvalds1da177e2005-04-16 15:20:36 -07003944 * continue the process for that level.
3945 */
3946 for (child = le32_to_cpu(dtp->leafidx),
3947 nparent = le32_to_cpu(dtp->nleafs) >> 2;
3948 nparent > 0; nparent >>= 2, child = parent) {
3949 /* get index of 1st node of parent level */
3950 parent = (child - 1) >> 2;
3951
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003952 /* set the value of the parent node as the maximum
Linus Torvalds1da177e2005-04-16 15:20:36 -07003953 * of the four nodes of the current level.
3954 */
3955 for (i = 0, cp = tp + child, cp1 = tp + parent;
3956 i < nparent; i++, cp += 4, cp1++)
3957 *cp1 = TREEMAX(cp);
3958 }
3959
3960 return (*tp);
3961}
3962
3963
3964/*
3965 * dbInitDmapCtl()
3966 *
3967 * function: initialize dmapctl page
3968 */
3969static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i)
3970{ /* start leaf index not covered by range */
3971 s8 *cp;
3972
3973 dcp->nleafs = cpu_to_le32(LPERCTL);
3974 dcp->l2nleafs = cpu_to_le32(L2LPERCTL);
3975 dcp->leafidx = cpu_to_le32(CTLLEAFIND);
3976 dcp->height = cpu_to_le32(5);
3977 dcp->budmin = L2BPERDMAP + L2LPERCTL * level;
3978
3979 /*
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003980 * initialize the leaves of current level that were not covered
3981 * by the specified input block range (i.e. the leaves have no
Linus Torvalds1da177e2005-04-16 15:20:36 -07003982 * low level dmapctl or dmap).
3983 */
3984 cp = &dcp->stree[CTLLEAFIND + i];
3985 for (; i < LPERCTL; i++)
3986 *cp++ = NOFREE;
3987
3988 /* build the dmap's binary buddy summary tree */
3989 return (dbInitTree((struct dmaptree *) dcp));
3990}
3991
3992
3993/*
3994 * NAME: dbGetL2AGSize()/ujfs_getagl2size()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003995 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003996 * FUNCTION: Determine log2(allocation group size) from aggregate size
Dave Kleikamp63f83c92006-10-02 09:55:27 -05003997 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003998 * PARAMETERS:
3999 * nblocks - Number of blocks in aggregate
4000 *
4001 * RETURNS: log2(allocation group size) in aggregate blocks
4002 */
4003static int dbGetL2AGSize(s64 nblocks)
4004{
4005 s64 sz;
4006 s64 m;
4007 int l2sz;
4008
4009 if (nblocks < BPERDMAP * MAXAG)
4010 return (L2BPERDMAP);
4011
4012 /* round up aggregate size to power of 2 */
4013 m = ((u64) 1 << (64 - 1));
4014 for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) {
4015 if (m & nblocks)
4016 break;
4017 }
4018
4019 sz = (s64) 1 << l2sz;
4020 if (sz < nblocks)
4021 l2sz += 1;
4022
4023 /* agsize = roundupSize/max_number_of_ag */
4024 return (l2sz - L2MAXAG);
4025}
4026
4027
4028/*
4029 * NAME: dbMapFileSizeToMapSize()
Dave Kleikamp63f83c92006-10-02 09:55:27 -05004030 *
4031 * FUNCTION: compute number of blocks the block allocation map file
Linus Torvalds1da177e2005-04-16 15:20:36 -07004032 * can cover from the map file size;
4033 *
4034 * RETURNS: Number of blocks which can be covered by this block map file;
4035 */
4036
4037/*
4038 * maximum number of map pages at each level including control pages
4039 */
4040#define MAXL0PAGES (1 + LPERCTL)
4041#define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES)
4042#define MAXL2PAGES (1 + LPERCTL * MAXL1PAGES)
4043
4044/*
4045 * convert number of map pages to the zero origin top dmapctl level
4046 */
4047#define BMAPPGTOLEV(npages) \
Dave Kleikampf720e3b2007-06-06 15:28:35 -05004048 (((npages) <= 3 + MAXL0PAGES) ? 0 : \
4049 ((npages) <= 2 + MAXL1PAGES) ? 1 : 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004050
4051s64 dbMapFileSizeToMapSize(struct inode * ipbmap)
4052{
4053 struct super_block *sb = ipbmap->i_sb;
4054 s64 nblocks;
4055 s64 npages, ndmaps;
4056 int level, i;
4057 int complete, factor;
4058
4059 nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize;
4060 npages = nblocks >> JFS_SBI(sb)->l2nbperpage;
4061 level = BMAPPGTOLEV(npages);
4062
Dave Kleikamp63f83c92006-10-02 09:55:27 -05004063 /* At each level, accumulate the number of dmap pages covered by
Linus Torvalds1da177e2005-04-16 15:20:36 -07004064 * the number of full child levels below it;
4065 * repeat for the last incomplete child level.
4066 */
4067 ndmaps = 0;
4068 npages--; /* skip the first global control page */
4069 /* skip higher level control pages above top level covered by map */
4070 npages -= (2 - level);
4071 npages--; /* skip top level's control page */
4072 for (i = level; i >= 0; i--) {
4073 factor =
4074 (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1);
4075 complete = (u32) npages / factor;
Dave Kleikampf720e3b2007-06-06 15:28:35 -05004076 ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL :
4077 ((i == 1) ? LPERCTL : 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004078
4079 /* pages in last/incomplete child */
4080 npages = (u32) npages % factor;
4081 /* skip incomplete child's level control page */
4082 npages--;
4083 }
4084
Dave Kleikamp63f83c92006-10-02 09:55:27 -05004085 /* convert the number of dmaps into the number of blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07004086 * which can be covered by the dmaps;
4087 */
4088 nblocks = ndmaps << L2BPERDMAP;
4089
4090 return (nblocks);
4091}