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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * Copyright (C) International Business Machines Corp., 2000-2004 | |
b40c2e66 | 4 | * Portions Copyright (C) Tino Reichardt, 2012 |
1da177e4 LT |
5 | */ |
6 | ||
7 | #include <linux/fs.h> | |
5a0e3ad6 | 8 | #include <linux/slab.h> |
1da177e4 LT |
9 | #include "jfs_incore.h" |
10 | #include "jfs_superblock.h" | |
11 | #include "jfs_dmap.h" | |
12 | #include "jfs_imap.h" | |
13 | #include "jfs_lock.h" | |
14 | #include "jfs_metapage.h" | |
15 | #include "jfs_debug.h" | |
b40c2e66 | 16 | #include "jfs_discard.h" |
1da177e4 | 17 | |
1da177e4 LT |
18 | /* |
19 | * SERIALIZATION of the Block Allocation Map. | |
20 | * | |
21 | * the working state of the block allocation map is accessed in | |
22 | * two directions: | |
63f83c9f | 23 | * |
1da177e4 LT |
24 | * 1) allocation and free requests that start at the dmap |
25 | * level and move up through the dmap control pages (i.e. | |
26 | * the vast majority of requests). | |
63f83c9f DK |
27 | * |
28 | * 2) allocation requests that start at dmap control page | |
1da177e4 | 29 | * level and work down towards the dmaps. |
1da177e4 | 30 | * |
63f83c9f DK |
31 | * the serialization scheme used here is as follows. |
32 | * | |
33 | * requests which start at the bottom are serialized against each | |
34 | * other through buffers and each requests holds onto its buffers | |
35 | * as it works it way up from a single dmap to the required level | |
1da177e4 LT |
36 | * of dmap control page. |
37 | * requests that start at the top are serialized against each other | |
38 | * and request that start from the bottom by the multiple read/single | |
39 | * write inode lock of the bmap inode. requests starting at the top | |
40 | * take this lock in write mode while request starting at the bottom | |
41 | * take the lock in read mode. a single top-down request may proceed | |
63f83c9f DK |
42 | * exclusively while multiple bottoms-up requests may proceed |
43 | * simultaneously (under the protection of busy buffers). | |
44 | * | |
1da177e4 LT |
45 | * in addition to information found in dmaps and dmap control pages, |
46 | * the working state of the block allocation map also includes read/ | |
47 | * write information maintained in the bmap descriptor (i.e. total | |
48 | * free block count, allocation group level free block counts). | |
49 | * a single exclusive lock (BMAP_LOCK) is used to guard this information | |
50 | * in the face of multiple-bottoms up requests. | |
51 | * (lock ordering: IREAD_LOCK, BMAP_LOCK); | |
63f83c9f | 52 | * |
1da177e4 LT |
53 | * accesses to the persistent state of the block allocation map (limited |
54 | * to the persistent bitmaps in dmaps) is guarded by (busy) buffers. | |
55 | */ | |
56 | ||
1de87444 IM |
57 | #define BMAP_LOCK_INIT(bmp) mutex_init(&bmp->db_bmaplock) |
58 | #define BMAP_LOCK(bmp) mutex_lock(&bmp->db_bmaplock) | |
59 | #define BMAP_UNLOCK(bmp) mutex_unlock(&bmp->db_bmaplock) | |
1da177e4 LT |
60 | |
61 | /* | |
62 | * forward references | |
63 | */ | |
64 | static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
65 | int nblocks); | |
66 | static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval); | |
b6a47fd8 | 67 | static int dbBackSplit(dmtree_t * tp, int leafno); |
56d12549 | 68 | static int dbJoin(dmtree_t * tp, int leafno, int newval); |
1da177e4 LT |
69 | static void dbAdjTree(dmtree_t * tp, int leafno, int newval); |
70 | static int dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, | |
71 | int level); | |
72 | static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results); | |
73 | static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
74 | int nblocks); | |
75 | static int dbAllocNear(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
76 | int nblocks, | |
77 | int l2nb, s64 * results); | |
78 | static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
79 | int nblocks); | |
80 | static int dbAllocDmapLev(struct bmap * bmp, struct dmap * dp, int nblocks, | |
81 | int l2nb, | |
82 | s64 * results); | |
83 | static int dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, | |
84 | s64 * results); | |
85 | static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, | |
86 | s64 * results); | |
87 | static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks); | |
88 | static int dbFindBits(u32 word, int l2nb); | |
89 | static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno); | |
90 | static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx); | |
56d12549 DK |
91 | static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
92 | int nblocks); | |
1da177e4 LT |
93 | static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, |
94 | int nblocks); | |
95 | static int dbMaxBud(u8 * cp); | |
1da177e4 LT |
96 | static int blkstol2(s64 nb); |
97 | ||
98 | static int cntlz(u32 value); | |
99 | static int cnttz(u32 word); | |
100 | ||
101 | static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
102 | int nblocks); | |
103 | static int dbInitDmap(struct dmap * dp, s64 blkno, int nblocks); | |
104 | static int dbInitDmapTree(struct dmap * dp); | |
105 | static int dbInitTree(struct dmaptree * dtp); | |
106 | static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i); | |
107 | static int dbGetL2AGSize(s64 nblocks); | |
108 | ||
109 | /* | |
110 | * buddy table | |
111 | * | |
63f83c9f | 112 | * table used for determining buddy sizes within characters of |
1da177e4 LT |
113 | * dmap bitmap words. the characters themselves serve as indexes |
114 | * into the table, with the table elements yielding the maximum | |
115 | * binary buddy of free bits within the character. | |
116 | */ | |
4d5dbd09 | 117 | static const s8 budtab[256] = { |
1da177e4 LT |
118 | 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
119 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
120 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
121 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
122 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
123 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
124 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
125 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
126 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
127 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
128 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
129 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
130 | 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
131 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
132 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, | |
133 | 2, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, -1 | |
134 | }; | |
135 | ||
1da177e4 | 136 | /* |
63f83c9f | 137 | * NAME: dbMount() |
1da177e4 LT |
138 | * |
139 | * FUNCTION: initializate the block allocation map. | |
140 | * | |
141 | * memory is allocated for the in-core bmap descriptor and | |
142 | * the in-core descriptor is initialized from disk. | |
143 | * | |
144 | * PARAMETERS: | |
f720e3ba | 145 | * ipbmap - pointer to in-core inode for the block map. |
1da177e4 LT |
146 | * |
147 | * RETURN VALUES: | |
f720e3ba DK |
148 | * 0 - success |
149 | * -ENOMEM - insufficient memory | |
150 | * -EIO - i/o error | |
2cc7cc01 | 151 | * -EINVAL - wrong bmap data |
1da177e4 LT |
152 | */ |
153 | int dbMount(struct inode *ipbmap) | |
154 | { | |
155 | struct bmap *bmp; | |
156 | struct dbmap_disk *dbmp_le; | |
157 | struct metapage *mp; | |
898f7066 | 158 | int i, err; |
1da177e4 LT |
159 | |
160 | /* | |
161 | * allocate/initialize the in-memory bmap descriptor | |
162 | */ | |
163 | /* allocate memory for the in-memory bmap descriptor */ | |
164 | bmp = kmalloc(sizeof(struct bmap), GFP_KERNEL); | |
165 | if (bmp == NULL) | |
166 | return -ENOMEM; | |
167 | ||
168 | /* read the on-disk bmap descriptor. */ | |
169 | mp = read_metapage(ipbmap, | |
170 | BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, | |
171 | PSIZE, 0); | |
172 | if (mp == NULL) { | |
898f7066 DM |
173 | err = -EIO; |
174 | goto err_kfree_bmp; | |
1da177e4 LT |
175 | } |
176 | ||
177 | /* copy the on-disk bmap descriptor to its in-memory version. */ | |
178 | dbmp_le = (struct dbmap_disk *) mp->data; | |
179 | bmp->db_mapsize = le64_to_cpu(dbmp_le->dn_mapsize); | |
180 | bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree); | |
11509910 | 181 | |
1da177e4 | 182 | bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage); |
11509910 SRP |
183 | if (bmp->db_l2nbperpage > L2PSIZE - L2MINBLOCKSIZE) { |
184 | err = -EINVAL; | |
185 | goto err_release_metapage; | |
186 | } | |
187 | ||
1da177e4 | 188 | bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag); |
2cc7cc01 | 189 | if (!bmp->db_numag) { |
898f7066 DM |
190 | err = -EINVAL; |
191 | goto err_release_metapage; | |
2cc7cc01 PS |
192 | } |
193 | ||
1da177e4 LT |
194 | bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel); |
195 | bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag); | |
196 | bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref); | |
197 | bmp->db_aglevel = le32_to_cpu(dbmp_le->dn_aglevel); | |
d7eecb48 | 198 | bmp->db_agheight = le32_to_cpu(dbmp_le->dn_agheight); |
1da177e4 LT |
199 | bmp->db_agwidth = le32_to_cpu(dbmp_le->dn_agwidth); |
200 | bmp->db_agstart = le32_to_cpu(dbmp_le->dn_agstart); | |
201 | bmp->db_agl2size = le32_to_cpu(dbmp_le->dn_agl2size); | |
fad376fc LSJ |
202 | if (bmp->db_agl2size > L2MAXL2SIZE - L2MAXAG || |
203 | bmp->db_agl2size < 0) { | |
898f7066 DM |
204 | err = -EINVAL; |
205 | goto err_release_metapage; | |
206 | } | |
207 | ||
25e70c61 HPW |
208 | if (((bmp->db_mapsize - 1) >> bmp->db_agl2size) > MAXAG) { |
209 | err = -EINVAL; | |
210 | goto err_release_metapage; | |
211 | } | |
212 | ||
1da177e4 LT |
213 | for (i = 0; i < MAXAG; i++) |
214 | bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]); | |
215 | bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize); | |
216 | bmp->db_maxfreebud = dbmp_le->dn_maxfreebud; | |
217 | ||
218 | /* release the buffer. */ | |
219 | release_metapage(mp); | |
220 | ||
221 | /* bind the bmap inode and the bmap descriptor to each other. */ | |
222 | bmp->db_ipbmap = ipbmap; | |
223 | JFS_SBI(ipbmap->i_sb)->bmap = bmp; | |
224 | ||
225 | memset(bmp->db_active, 0, sizeof(bmp->db_active)); | |
1da177e4 LT |
226 | |
227 | /* | |
228 | * allocate/initialize the bmap lock | |
229 | */ | |
230 | BMAP_LOCK_INIT(bmp); | |
231 | ||
232 | return (0); | |
898f7066 DM |
233 | |
234 | err_release_metapage: | |
235 | release_metapage(mp); | |
236 | err_kfree_bmp: | |
237 | kfree(bmp); | |
238 | return err; | |
1da177e4 LT |
239 | } |
240 | ||
241 | ||
242 | /* | |
63f83c9f | 243 | * NAME: dbUnmount() |
1da177e4 LT |
244 | * |
245 | * FUNCTION: terminate the block allocation map in preparation for | |
246 | * file system unmount. | |
247 | * | |
63f83c9f | 248 | * the in-core bmap descriptor is written to disk and |
1da177e4 LT |
249 | * the memory for this descriptor is freed. |
250 | * | |
251 | * PARAMETERS: | |
f720e3ba | 252 | * ipbmap - pointer to in-core inode for the block map. |
1da177e4 LT |
253 | * |
254 | * RETURN VALUES: | |
f720e3ba DK |
255 | * 0 - success |
256 | * -EIO - i/o error | |
1da177e4 LT |
257 | */ |
258 | int dbUnmount(struct inode *ipbmap, int mounterror) | |
259 | { | |
260 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
1da177e4 LT |
261 | |
262 | if (!(mounterror || isReadOnly(ipbmap))) | |
263 | dbSync(ipbmap); | |
264 | ||
265 | /* | |
266 | * Invalidate the page cache buffers | |
267 | */ | |
268 | truncate_inode_pages(ipbmap->i_mapping, 0); | |
269 | ||
1da177e4 LT |
270 | /* free the memory for the in-memory bmap. */ |
271 | kfree(bmp); | |
cade5397 | 272 | JFS_SBI(ipbmap->i_sb)->bmap = NULL; |
1da177e4 LT |
273 | |
274 | return (0); | |
275 | } | |
276 | ||
277 | /* | |
278 | * dbSync() | |
279 | */ | |
280 | int dbSync(struct inode *ipbmap) | |
281 | { | |
282 | struct dbmap_disk *dbmp_le; | |
283 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
284 | struct metapage *mp; | |
285 | int i; | |
286 | ||
287 | /* | |
288 | * write bmap global control page | |
289 | */ | |
290 | /* get the buffer for the on-disk bmap descriptor. */ | |
291 | mp = read_metapage(ipbmap, | |
292 | BMAPBLKNO << JFS_SBI(ipbmap->i_sb)->l2nbperpage, | |
293 | PSIZE, 0); | |
294 | if (mp == NULL) { | |
295 | jfs_err("dbSync: read_metapage failed!"); | |
296 | return -EIO; | |
297 | } | |
298 | /* copy the in-memory version of the bmap to the on-disk version */ | |
299 | dbmp_le = (struct dbmap_disk *) mp->data; | |
300 | dbmp_le->dn_mapsize = cpu_to_le64(bmp->db_mapsize); | |
301 | dbmp_le->dn_nfree = cpu_to_le64(bmp->db_nfree); | |
302 | dbmp_le->dn_l2nbperpage = cpu_to_le32(bmp->db_l2nbperpage); | |
303 | dbmp_le->dn_numag = cpu_to_le32(bmp->db_numag); | |
304 | dbmp_le->dn_maxlevel = cpu_to_le32(bmp->db_maxlevel); | |
305 | dbmp_le->dn_maxag = cpu_to_le32(bmp->db_maxag); | |
306 | dbmp_le->dn_agpref = cpu_to_le32(bmp->db_agpref); | |
307 | dbmp_le->dn_aglevel = cpu_to_le32(bmp->db_aglevel); | |
d7eecb48 | 308 | dbmp_le->dn_agheight = cpu_to_le32(bmp->db_agheight); |
1da177e4 LT |
309 | dbmp_le->dn_agwidth = cpu_to_le32(bmp->db_agwidth); |
310 | dbmp_le->dn_agstart = cpu_to_le32(bmp->db_agstart); | |
311 | dbmp_le->dn_agl2size = cpu_to_le32(bmp->db_agl2size); | |
312 | for (i = 0; i < MAXAG; i++) | |
313 | dbmp_le->dn_agfree[i] = cpu_to_le64(bmp->db_agfree[i]); | |
314 | dbmp_le->dn_agsize = cpu_to_le64(bmp->db_agsize); | |
315 | dbmp_le->dn_maxfreebud = bmp->db_maxfreebud; | |
316 | ||
317 | /* write the buffer */ | |
318 | write_metapage(mp); | |
319 | ||
320 | /* | |
321 | * write out dirty pages of bmap | |
322 | */ | |
28fd1298 | 323 | filemap_write_and_wait(ipbmap->i_mapping); |
1da177e4 | 324 | |
1da177e4 LT |
325 | diWriteSpecial(ipbmap, 0); |
326 | ||
327 | return (0); | |
328 | } | |
329 | ||
1da177e4 | 330 | /* |
63f83c9f | 331 | * NAME: dbFree() |
1da177e4 LT |
332 | * |
333 | * FUNCTION: free the specified block range from the working block | |
334 | * allocation map. | |
335 | * | |
336 | * the blocks will be free from the working map one dmap | |
337 | * at a time. | |
338 | * | |
339 | * PARAMETERS: | |
f720e3ba DK |
340 | * ip - pointer to in-core inode; |
341 | * blkno - starting block number to be freed. | |
342 | * nblocks - number of blocks to be freed. | |
1da177e4 LT |
343 | * |
344 | * RETURN VALUES: | |
f720e3ba DK |
345 | * 0 - success |
346 | * -EIO - i/o error | |
1da177e4 LT |
347 | */ |
348 | int dbFree(struct inode *ip, s64 blkno, s64 nblocks) | |
349 | { | |
350 | struct metapage *mp; | |
351 | struct dmap *dp; | |
352 | int nb, rc; | |
353 | s64 lblkno, rem; | |
354 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
355 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; | |
b40c2e66 | 356 | struct super_block *sb = ipbmap->i_sb; |
1da177e4 | 357 | |
82d5b9a7 | 358 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
359 | |
360 | /* block to be freed better be within the mapsize. */ | |
361 | if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) { | |
362 | IREAD_UNLOCK(ipbmap); | |
363 | printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", | |
364 | (unsigned long long) blkno, | |
365 | (unsigned long long) nblocks); | |
eb8630d7 | 366 | jfs_error(ip->i_sb, "block to be freed is outside the map\n"); |
1da177e4 LT |
367 | return -EIO; |
368 | } | |
369 | ||
b40c2e66 TR |
370 | /** |
371 | * TRIM the blocks, when mounted with discard option | |
372 | */ | |
373 | if (JFS_SBI(sb)->flag & JFS_DISCARD) | |
374 | if (JFS_SBI(sb)->minblks_trim <= nblocks) | |
375 | jfs_issue_discard(ipbmap, blkno, nblocks); | |
376 | ||
1da177e4 LT |
377 | /* |
378 | * free the blocks a dmap at a time. | |
379 | */ | |
380 | mp = NULL; | |
381 | for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { | |
382 | /* release previous dmap if any */ | |
383 | if (mp) { | |
384 | write_metapage(mp); | |
385 | } | |
386 | ||
387 | /* get the buffer for the current dmap. */ | |
388 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
389 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
390 | if (mp == NULL) { | |
391 | IREAD_UNLOCK(ipbmap); | |
392 | return -EIO; | |
393 | } | |
394 | dp = (struct dmap *) mp->data; | |
395 | ||
396 | /* determine the number of blocks to be freed from | |
397 | * this dmap. | |
398 | */ | |
399 | nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); | |
400 | ||
1da177e4 LT |
401 | /* free the blocks. */ |
402 | if ((rc = dbFreeDmap(bmp, dp, blkno, nb))) { | |
eb8630d7 | 403 | jfs_error(ip->i_sb, "error in block map\n"); |
1da177e4 LT |
404 | release_metapage(mp); |
405 | IREAD_UNLOCK(ipbmap); | |
406 | return (rc); | |
407 | } | |
1da177e4 LT |
408 | } |
409 | ||
410 | /* write the last buffer. */ | |
0d4837fd ZF |
411 | if (mp) |
412 | write_metapage(mp); | |
1da177e4 LT |
413 | |
414 | IREAD_UNLOCK(ipbmap); | |
415 | ||
416 | return (0); | |
417 | } | |
418 | ||
419 | ||
420 | /* | |
421 | * NAME: dbUpdatePMap() | |
422 | * | |
f720e3ba | 423 | * FUNCTION: update the allocation state (free or allocate) of the |
1da177e4 | 424 | * specified block range in the persistent block allocation map. |
63f83c9f | 425 | * |
1da177e4 LT |
426 | * the blocks will be updated in the persistent map one |
427 | * dmap at a time. | |
428 | * | |
429 | * PARAMETERS: | |
f720e3ba DK |
430 | * ipbmap - pointer to in-core inode for the block map. |
431 | * free - 'true' if block range is to be freed from the persistent | |
432 | * map; 'false' if it is to be allocated. | |
433 | * blkno - starting block number of the range. | |
434 | * nblocks - number of contiguous blocks in the range. | |
435 | * tblk - transaction block; | |
1da177e4 LT |
436 | * |
437 | * RETURN VALUES: | |
f720e3ba DK |
438 | * 0 - success |
439 | * -EIO - i/o error | |
1da177e4 LT |
440 | */ |
441 | int | |
442 | dbUpdatePMap(struct inode *ipbmap, | |
443 | int free, s64 blkno, s64 nblocks, struct tblock * tblk) | |
444 | { | |
445 | int nblks, dbitno, wbitno, rbits; | |
446 | int word, nbits, nwords; | |
447 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
448 | s64 lblkno, rem, lastlblkno; | |
449 | u32 mask; | |
450 | struct dmap *dp; | |
451 | struct metapage *mp; | |
452 | struct jfs_log *log; | |
453 | int lsn, difft, diffp; | |
7fab479b | 454 | unsigned long flags; |
1da177e4 LT |
455 | |
456 | /* the blocks better be within the mapsize. */ | |
457 | if (blkno + nblocks > bmp->db_mapsize) { | |
458 | printk(KERN_ERR "blkno = %Lx, nblocks = %Lx\n", | |
459 | (unsigned long long) blkno, | |
460 | (unsigned long long) nblocks); | |
eb8630d7 | 461 | jfs_error(ipbmap->i_sb, "blocks are outside the map\n"); |
1da177e4 LT |
462 | return -EIO; |
463 | } | |
464 | ||
465 | /* compute delta of transaction lsn from log syncpt */ | |
466 | lsn = tblk->lsn; | |
467 | log = (struct jfs_log *) JFS_SBI(tblk->sb)->log; | |
468 | logdiff(difft, lsn, log); | |
469 | ||
470 | /* | |
471 | * update the block state a dmap at a time. | |
472 | */ | |
473 | mp = NULL; | |
474 | lastlblkno = 0; | |
475 | for (rem = nblocks; rem > 0; rem -= nblks, blkno += nblks) { | |
476 | /* get the buffer for the current dmap. */ | |
477 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
478 | if (lblkno != lastlblkno) { | |
479 | if (mp) { | |
480 | write_metapage(mp); | |
481 | } | |
482 | ||
483 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, | |
484 | 0); | |
485 | if (mp == NULL) | |
486 | return -EIO; | |
7fab479b | 487 | metapage_wait_for_io(mp); |
1da177e4 LT |
488 | } |
489 | dp = (struct dmap *) mp->data; | |
490 | ||
491 | /* determine the bit number and word within the dmap of | |
492 | * the starting block. also determine how many blocks | |
493 | * are to be updated within this dmap. | |
494 | */ | |
495 | dbitno = blkno & (BPERDMAP - 1); | |
496 | word = dbitno >> L2DBWORD; | |
497 | nblks = min(rem, (s64)BPERDMAP - dbitno); | |
498 | ||
499 | /* update the bits of the dmap words. the first and last | |
500 | * words may only have a subset of their bits updated. if | |
501 | * this is the case, we'll work against that word (i.e. | |
63f83c9f | 502 | * partial first and/or last) only in a single pass. a |
1da177e4 LT |
503 | * single pass will also be used to update all words that |
504 | * are to have all their bits updated. | |
505 | */ | |
506 | for (rbits = nblks; rbits > 0; | |
507 | rbits -= nbits, dbitno += nbits) { | |
508 | /* determine the bit number within the word and | |
509 | * the number of bits within the word. | |
510 | */ | |
511 | wbitno = dbitno & (DBWORD - 1); | |
512 | nbits = min(rbits, DBWORD - wbitno); | |
513 | ||
514 | /* check if only part of the word is to be updated. */ | |
515 | if (nbits < DBWORD) { | |
516 | /* update (free or allocate) the bits | |
517 | * in this word. | |
518 | */ | |
519 | mask = | |
520 | (ONES << (DBWORD - nbits) >> wbitno); | |
521 | if (free) | |
522 | dp->pmap[word] &= | |
523 | cpu_to_le32(~mask); | |
524 | else | |
525 | dp->pmap[word] |= | |
526 | cpu_to_le32(mask); | |
527 | ||
528 | word += 1; | |
529 | } else { | |
530 | /* one or more words are to have all | |
531 | * their bits updated. determine how | |
532 | * many words and how many bits. | |
533 | */ | |
534 | nwords = rbits >> L2DBWORD; | |
535 | nbits = nwords << L2DBWORD; | |
536 | ||
537 | /* update (free or allocate) the bits | |
538 | * in these words. | |
539 | */ | |
540 | if (free) | |
541 | memset(&dp->pmap[word], 0, | |
542 | nwords * 4); | |
543 | else | |
544 | memset(&dp->pmap[word], (int) ONES, | |
545 | nwords * 4); | |
546 | ||
547 | word += nwords; | |
548 | } | |
549 | } | |
550 | ||
551 | /* | |
552 | * update dmap lsn | |
553 | */ | |
554 | if (lblkno == lastlblkno) | |
555 | continue; | |
556 | ||
557 | lastlblkno = lblkno; | |
558 | ||
be0bf7da | 559 | LOGSYNC_LOCK(log, flags); |
1da177e4 LT |
560 | if (mp->lsn != 0) { |
561 | /* inherit older/smaller lsn */ | |
562 | logdiff(diffp, mp->lsn, log); | |
563 | if (difft < diffp) { | |
564 | mp->lsn = lsn; | |
565 | ||
566 | /* move bp after tblock in logsync list */ | |
1da177e4 | 567 | list_move(&mp->synclist, &tblk->synclist); |
1da177e4 LT |
568 | } |
569 | ||
570 | /* inherit younger/larger clsn */ | |
1da177e4 LT |
571 | logdiff(difft, tblk->clsn, log); |
572 | logdiff(diffp, mp->clsn, log); | |
573 | if (difft > diffp) | |
574 | mp->clsn = tblk->clsn; | |
1da177e4 LT |
575 | } else { |
576 | mp->log = log; | |
577 | mp->lsn = lsn; | |
578 | ||
579 | /* insert bp after tblock in logsync list */ | |
1da177e4 LT |
580 | log->count++; |
581 | list_add(&mp->synclist, &tblk->synclist); | |
582 | ||
583 | mp->clsn = tblk->clsn; | |
1da177e4 | 584 | } |
be0bf7da | 585 | LOGSYNC_UNLOCK(log, flags); |
1da177e4 LT |
586 | } |
587 | ||
588 | /* write the last buffer. */ | |
589 | if (mp) { | |
590 | write_metapage(mp); | |
591 | } | |
592 | ||
593 | return (0); | |
594 | } | |
595 | ||
596 | ||
597 | /* | |
598 | * NAME: dbNextAG() | |
599 | * | |
f720e3ba | 600 | * FUNCTION: find the preferred allocation group for new allocations. |
1da177e4 LT |
601 | * |
602 | * Within the allocation groups, we maintain a preferred | |
603 | * allocation group which consists of a group with at least | |
604 | * average free space. It is the preferred group that we target | |
605 | * new inode allocation towards. The tie-in between inode | |
606 | * allocation and block allocation occurs as we allocate the | |
607 | * first (data) block of an inode and specify the inode (block) | |
608 | * as the allocation hint for this block. | |
609 | * | |
610 | * We try to avoid having more than one open file growing in | |
611 | * an allocation group, as this will lead to fragmentation. | |
612 | * This differs from the old OS/2 method of trying to keep | |
613 | * empty ags around for large allocations. | |
614 | * | |
615 | * PARAMETERS: | |
f720e3ba | 616 | * ipbmap - pointer to in-core inode for the block map. |
1da177e4 LT |
617 | * |
618 | * RETURN VALUES: | |
f720e3ba | 619 | * the preferred allocation group number. |
1da177e4 LT |
620 | */ |
621 | int dbNextAG(struct inode *ipbmap) | |
622 | { | |
623 | s64 avgfree; | |
624 | int agpref; | |
625 | s64 hwm = 0; | |
626 | int i; | |
627 | int next_best = -1; | |
628 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
629 | ||
630 | BMAP_LOCK(bmp); | |
631 | ||
632 | /* determine the average number of free blocks within the ags. */ | |
633 | avgfree = (u32)bmp->db_nfree / bmp->db_numag; | |
634 | ||
635 | /* | |
636 | * if the current preferred ag does not have an active allocator | |
637 | * and has at least average freespace, return it | |
638 | */ | |
639 | agpref = bmp->db_agpref; | |
640 | if ((atomic_read(&bmp->db_active[agpref]) == 0) && | |
641 | (bmp->db_agfree[agpref] >= avgfree)) | |
642 | goto unlock; | |
643 | ||
644 | /* From the last preferred ag, find the next one with at least | |
645 | * average free space. | |
646 | */ | |
647 | for (i = 0 ; i < bmp->db_numag; i++, agpref++) { | |
648 | if (agpref == bmp->db_numag) | |
649 | agpref = 0; | |
650 | ||
651 | if (atomic_read(&bmp->db_active[agpref])) | |
652 | /* open file is currently growing in this ag */ | |
653 | continue; | |
654 | if (bmp->db_agfree[agpref] >= avgfree) { | |
655 | /* Return this one */ | |
656 | bmp->db_agpref = agpref; | |
657 | goto unlock; | |
658 | } else if (bmp->db_agfree[agpref] > hwm) { | |
659 | /* Less than avg. freespace, but best so far */ | |
660 | hwm = bmp->db_agfree[agpref]; | |
661 | next_best = agpref; | |
662 | } | |
663 | } | |
664 | ||
665 | /* | |
666 | * If no inactive ag was found with average freespace, use the | |
667 | * next best | |
668 | */ | |
669 | if (next_best != -1) | |
670 | bmp->db_agpref = next_best; | |
671 | /* else leave db_agpref unchanged */ | |
672 | unlock: | |
673 | BMAP_UNLOCK(bmp); | |
674 | ||
675 | /* return the preferred group. | |
676 | */ | |
677 | return (bmp->db_agpref); | |
678 | } | |
679 | ||
680 | /* | |
681 | * NAME: dbAlloc() | |
682 | * | |
f720e3ba | 683 | * FUNCTION: attempt to allocate a specified number of contiguous free |
1da177e4 LT |
684 | * blocks from the working allocation block map. |
685 | * | |
686 | * the block allocation policy uses hints and a multi-step | |
687 | * approach. | |
688 | * | |
63f83c9f | 689 | * for allocation requests smaller than the number of blocks |
1da177e4 LT |
690 | * per dmap, we first try to allocate the new blocks |
691 | * immediately following the hint. if these blocks are not | |
692 | * available, we try to allocate blocks near the hint. if | |
63f83c9f | 693 | * no blocks near the hint are available, we next try to |
1da177e4 LT |
694 | * allocate within the same dmap as contains the hint. |
695 | * | |
696 | * if no blocks are available in the dmap or the allocation | |
697 | * request is larger than the dmap size, we try to allocate | |
698 | * within the same allocation group as contains the hint. if | |
699 | * this does not succeed, we finally try to allocate anywhere | |
700 | * within the aggregate. | |
701 | * | |
ed1c9a7a | 702 | * we also try to allocate anywhere within the aggregate |
1da177e4 LT |
703 | * for allocation requests larger than the allocation group |
704 | * size or requests that specify no hint value. | |
705 | * | |
706 | * PARAMETERS: | |
f720e3ba DK |
707 | * ip - pointer to in-core inode; |
708 | * hint - allocation hint. | |
709 | * nblocks - number of contiguous blocks in the range. | |
710 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
711 | * of the newly allocated contiguous range. |
712 | * | |
713 | * RETURN VALUES: | |
f720e3ba DK |
714 | * 0 - success |
715 | * -ENOSPC - insufficient disk resources | |
716 | * -EIO - i/o error | |
1da177e4 LT |
717 | */ |
718 | int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results) | |
719 | { | |
720 | int rc, agno; | |
721 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
722 | struct bmap *bmp; | |
723 | struct metapage *mp; | |
724 | s64 lblkno, blkno; | |
725 | struct dmap *dp; | |
726 | int l2nb; | |
727 | s64 mapSize; | |
728 | int writers; | |
729 | ||
730 | /* assert that nblocks is valid */ | |
731 | assert(nblocks > 0); | |
732 | ||
1da177e4 | 733 | /* get the log2 number of blocks to be allocated. |
63f83c9f | 734 | * if the number of blocks is not a log2 multiple, |
1da177e4 LT |
735 | * it will be rounded up to the next log2 multiple. |
736 | */ | |
737 | l2nb = BLKSTOL2(nblocks); | |
738 | ||
739 | bmp = JFS_SBI(ip->i_sb)->bmap; | |
740 | ||
1da177e4 LT |
741 | mapSize = bmp->db_mapsize; |
742 | ||
743 | /* the hint should be within the map */ | |
744 | if (hint >= mapSize) { | |
eb8630d7 | 745 | jfs_error(ip->i_sb, "the hint is outside the map\n"); |
1da177e4 LT |
746 | return -EIO; |
747 | } | |
748 | ||
749 | /* if the number of blocks to be allocated is greater than the | |
750 | * allocation group size, try to allocate anywhere. | |
751 | */ | |
752 | if (l2nb > bmp->db_agl2size) { | |
82d5b9a7 | 753 | IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
754 | |
755 | rc = dbAllocAny(bmp, nblocks, l2nb, results); | |
1da177e4 LT |
756 | |
757 | goto write_unlock; | |
758 | } | |
759 | ||
760 | /* | |
761 | * If no hint, let dbNextAG recommend an allocation group | |
762 | */ | |
763 | if (hint == 0) | |
764 | goto pref_ag; | |
765 | ||
766 | /* we would like to allocate close to the hint. adjust the | |
767 | * hint to the block following the hint since the allocators | |
768 | * will start looking for free space starting at this point. | |
769 | */ | |
770 | blkno = hint + 1; | |
771 | ||
772 | if (blkno >= bmp->db_mapsize) | |
773 | goto pref_ag; | |
774 | ||
775 | agno = blkno >> bmp->db_agl2size; | |
776 | ||
777 | /* check if blkno crosses over into a new allocation group. | |
778 | * if so, check if we should allow allocations within this | |
779 | * allocation group. | |
780 | */ | |
781 | if ((blkno & (bmp->db_agsize - 1)) == 0) | |
af901ca1 | 782 | /* check if the AG is currently being written to. |
1da177e4 LT |
783 | * if so, call dbNextAG() to find a non-busy |
784 | * AG with sufficient free space. | |
785 | */ | |
786 | if (atomic_read(&bmp->db_active[agno])) | |
787 | goto pref_ag; | |
788 | ||
789 | /* check if the allocation request size can be satisfied from a | |
790 | * single dmap. if so, try to allocate from the dmap containing | |
791 | * the hint using a tiered strategy. | |
792 | */ | |
793 | if (nblocks <= BPERDMAP) { | |
82d5b9a7 | 794 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
795 | |
796 | /* get the buffer for the dmap containing the hint. | |
797 | */ | |
798 | rc = -EIO; | |
799 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
800 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
801 | if (mp == NULL) | |
802 | goto read_unlock; | |
803 | ||
804 | dp = (struct dmap *) mp->data; | |
805 | ||
806 | /* first, try to satisfy the allocation request with the | |
807 | * blocks beginning at the hint. | |
808 | */ | |
809 | if ((rc = dbAllocNext(bmp, dp, blkno, (int) nblocks)) | |
810 | != -ENOSPC) { | |
811 | if (rc == 0) { | |
812 | *results = blkno; | |
1da177e4 LT |
813 | mark_metapage_dirty(mp); |
814 | } | |
815 | ||
816 | release_metapage(mp); | |
817 | goto read_unlock; | |
818 | } | |
819 | ||
820 | writers = atomic_read(&bmp->db_active[agno]); | |
821 | if ((writers > 1) || | |
822 | ((writers == 1) && (JFS_IP(ip)->active_ag != agno))) { | |
823 | /* | |
824 | * Someone else is writing in this allocation | |
825 | * group. To avoid fragmenting, try another ag | |
826 | */ | |
827 | release_metapage(mp); | |
828 | IREAD_UNLOCK(ipbmap); | |
829 | goto pref_ag; | |
830 | } | |
831 | ||
832 | /* next, try to satisfy the allocation request with blocks | |
833 | * near the hint. | |
834 | */ | |
835 | if ((rc = | |
836 | dbAllocNear(bmp, dp, blkno, (int) nblocks, l2nb, results)) | |
837 | != -ENOSPC) { | |
b38a3ab3 | 838 | if (rc == 0) |
1da177e4 | 839 | mark_metapage_dirty(mp); |
1da177e4 LT |
840 | |
841 | release_metapage(mp); | |
842 | goto read_unlock; | |
843 | } | |
844 | ||
845 | /* try to satisfy the allocation request with blocks within | |
846 | * the same dmap as the hint. | |
847 | */ | |
848 | if ((rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results)) | |
849 | != -ENOSPC) { | |
b38a3ab3 | 850 | if (rc == 0) |
1da177e4 | 851 | mark_metapage_dirty(mp); |
1da177e4 LT |
852 | |
853 | release_metapage(mp); | |
854 | goto read_unlock; | |
855 | } | |
856 | ||
857 | release_metapage(mp); | |
858 | IREAD_UNLOCK(ipbmap); | |
859 | } | |
860 | ||
861 | /* try to satisfy the allocation request with blocks within | |
862 | * the same allocation group as the hint. | |
863 | */ | |
82d5b9a7 | 864 | IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
b38a3ab3 | 865 | if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC) |
1da177e4 | 866 | goto write_unlock; |
b38a3ab3 | 867 | |
1da177e4 LT |
868 | IWRITE_UNLOCK(ipbmap); |
869 | ||
870 | ||
871 | pref_ag: | |
872 | /* | |
873 | * Let dbNextAG recommend a preferred allocation group | |
874 | */ | |
875 | agno = dbNextAG(ipbmap); | |
82d5b9a7 | 876 | IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
877 | |
878 | /* Try to allocate within this allocation group. if that fails, try to | |
879 | * allocate anywhere in the map. | |
880 | */ | |
881 | if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) == -ENOSPC) | |
882 | rc = dbAllocAny(bmp, nblocks, l2nb, results); | |
1da177e4 LT |
883 | |
884 | write_unlock: | |
885 | IWRITE_UNLOCK(ipbmap); | |
886 | ||
887 | return (rc); | |
888 | ||
889 | read_unlock: | |
890 | IREAD_UNLOCK(ipbmap); | |
891 | ||
892 | return (rc); | |
893 | } | |
894 | ||
1da177e4 LT |
895 | /* |
896 | * NAME: dbReAlloc() | |
897 | * | |
f720e3ba | 898 | * FUNCTION: attempt to extend a current allocation by a specified |
1da177e4 LT |
899 | * number of blocks. |
900 | * | |
901 | * this routine attempts to satisfy the allocation request | |
902 | * by first trying to extend the existing allocation in | |
903 | * place by allocating the additional blocks as the blocks | |
904 | * immediately following the current allocation. if these | |
905 | * blocks are not available, this routine will attempt to | |
906 | * allocate a new set of contiguous blocks large enough | |
907 | * to cover the existing allocation plus the additional | |
908 | * number of blocks required. | |
909 | * | |
910 | * PARAMETERS: | |
f720e3ba DK |
911 | * ip - pointer to in-core inode requiring allocation. |
912 | * blkno - starting block of the current allocation. | |
913 | * nblocks - number of contiguous blocks within the current | |
1da177e4 | 914 | * allocation. |
f720e3ba DK |
915 | * addnblocks - number of blocks to add to the allocation. |
916 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
917 | * of the existing allocation if the existing allocation |
918 | * was extended in place or to a newly allocated contiguous | |
919 | * range if the existing allocation could not be extended | |
920 | * in place. | |
921 | * | |
922 | * RETURN VALUES: | |
f720e3ba DK |
923 | * 0 - success |
924 | * -ENOSPC - insufficient disk resources | |
925 | * -EIO - i/o error | |
1da177e4 LT |
926 | */ |
927 | int | |
928 | dbReAlloc(struct inode *ip, | |
929 | s64 blkno, s64 nblocks, s64 addnblocks, s64 * results) | |
930 | { | |
931 | int rc; | |
932 | ||
933 | /* try to extend the allocation in place. | |
934 | */ | |
935 | if ((rc = dbExtend(ip, blkno, nblocks, addnblocks)) == 0) { | |
936 | *results = blkno; | |
937 | return (0); | |
938 | } else { | |
939 | if (rc != -ENOSPC) | |
940 | return (rc); | |
941 | } | |
942 | ||
943 | /* could not extend the allocation in place, so allocate a | |
944 | * new set of blocks for the entire request (i.e. try to get | |
945 | * a range of contiguous blocks large enough to cover the | |
946 | * existing allocation plus the additional blocks.) | |
947 | */ | |
948 | return (dbAlloc | |
949 | (ip, blkno + nblocks - 1, addnblocks + nblocks, results)); | |
950 | } | |
951 | ||
952 | ||
953 | /* | |
954 | * NAME: dbExtend() | |
955 | * | |
f720e3ba | 956 | * FUNCTION: attempt to extend a current allocation by a specified |
1da177e4 LT |
957 | * number of blocks. |
958 | * | |
959 | * this routine attempts to satisfy the allocation request | |
960 | * by first trying to extend the existing allocation in | |
961 | * place by allocating the additional blocks as the blocks | |
962 | * immediately following the current allocation. | |
963 | * | |
964 | * PARAMETERS: | |
f720e3ba DK |
965 | * ip - pointer to in-core inode requiring allocation. |
966 | * blkno - starting block of the current allocation. | |
967 | * nblocks - number of contiguous blocks within the current | |
1da177e4 | 968 | * allocation. |
f720e3ba | 969 | * addnblocks - number of blocks to add to the allocation. |
1da177e4 LT |
970 | * |
971 | * RETURN VALUES: | |
f720e3ba DK |
972 | * 0 - success |
973 | * -ENOSPC - insufficient disk resources | |
974 | * -EIO - i/o error | |
1da177e4 LT |
975 | */ |
976 | static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks) | |
977 | { | |
978 | struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb); | |
979 | s64 lblkno, lastblkno, extblkno; | |
980 | uint rel_block; | |
981 | struct metapage *mp; | |
982 | struct dmap *dp; | |
983 | int rc; | |
984 | struct inode *ipbmap = sbi->ipbmap; | |
985 | struct bmap *bmp; | |
986 | ||
987 | /* | |
988 | * We don't want a non-aligned extent to cross a page boundary | |
989 | */ | |
990 | if (((rel_block = blkno & (sbi->nbperpage - 1))) && | |
991 | (rel_block + nblocks + addnblocks > sbi->nbperpage)) | |
992 | return -ENOSPC; | |
993 | ||
994 | /* get the last block of the current allocation */ | |
995 | lastblkno = blkno + nblocks - 1; | |
996 | ||
997 | /* determine the block number of the block following | |
998 | * the existing allocation. | |
999 | */ | |
1000 | extblkno = lastblkno + 1; | |
1001 | ||
82d5b9a7 | 1002 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
1003 | |
1004 | /* better be within the file system */ | |
1005 | bmp = sbi->bmap; | |
1006 | if (lastblkno < 0 || lastblkno >= bmp->db_mapsize) { | |
1007 | IREAD_UNLOCK(ipbmap); | |
eb8630d7 | 1008 | jfs_error(ip->i_sb, "the block is outside the filesystem\n"); |
1da177e4 LT |
1009 | return -EIO; |
1010 | } | |
1011 | ||
1012 | /* we'll attempt to extend the current allocation in place by | |
1013 | * allocating the additional blocks as the blocks immediately | |
1014 | * following the current allocation. we only try to extend the | |
1015 | * current allocation in place if the number of additional blocks | |
1016 | * can fit into a dmap, the last block of the current allocation | |
1017 | * is not the last block of the file system, and the start of the | |
1018 | * inplace extension is not on an allocation group boundary. | |
1019 | */ | |
1020 | if (addnblocks > BPERDMAP || extblkno >= bmp->db_mapsize || | |
1021 | (extblkno & (bmp->db_agsize - 1)) == 0) { | |
1022 | IREAD_UNLOCK(ipbmap); | |
1023 | return -ENOSPC; | |
1024 | } | |
1025 | ||
1026 | /* get the buffer for the dmap containing the first block | |
1027 | * of the extension. | |
1028 | */ | |
1029 | lblkno = BLKTODMAP(extblkno, bmp->db_l2nbperpage); | |
1030 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
1031 | if (mp == NULL) { | |
1032 | IREAD_UNLOCK(ipbmap); | |
1033 | return -EIO; | |
1034 | } | |
1035 | ||
1da177e4 LT |
1036 | dp = (struct dmap *) mp->data; |
1037 | ||
1038 | /* try to allocate the blocks immediately following the | |
1039 | * current allocation. | |
1040 | */ | |
1041 | rc = dbAllocNext(bmp, dp, extblkno, (int) addnblocks); | |
1042 | ||
1043 | IREAD_UNLOCK(ipbmap); | |
1044 | ||
1045 | /* were we successful ? */ | |
b38a3ab3 | 1046 | if (rc == 0) |
1da177e4 | 1047 | write_metapage(mp); |
b38a3ab3 | 1048 | else |
1da177e4 LT |
1049 | /* we were not successful */ |
1050 | release_metapage(mp); | |
1051 | ||
1da177e4 LT |
1052 | return (rc); |
1053 | } | |
1054 | ||
1055 | ||
1056 | /* | |
1057 | * NAME: dbAllocNext() | |
1058 | * | |
f720e3ba | 1059 | * FUNCTION: attempt to allocate the blocks of the specified block |
1da177e4 LT |
1060 | * range within a dmap. |
1061 | * | |
1062 | * PARAMETERS: | |
f720e3ba DK |
1063 | * bmp - pointer to bmap descriptor |
1064 | * dp - pointer to dmap. | |
1065 | * blkno - starting block number of the range. | |
1066 | * nblocks - number of contiguous free blocks of the range. | |
1da177e4 LT |
1067 | * |
1068 | * RETURN VALUES: | |
f720e3ba DK |
1069 | * 0 - success |
1070 | * -ENOSPC - insufficient disk resources | |
1071 | * -EIO - i/o error | |
1da177e4 LT |
1072 | * |
1073 | * serialization: IREAD_LOCK(ipbmap) held on entry/exit; | |
1074 | */ | |
1075 | static int dbAllocNext(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
1076 | int nblocks) | |
1077 | { | |
1078 | int dbitno, word, rembits, nb, nwords, wbitno, nw; | |
1079 | int l2size; | |
1080 | s8 *leaf; | |
1081 | u32 mask; | |
1082 | ||
1083 | if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { | |
eb8630d7 | 1084 | jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n"); |
1da177e4 LT |
1085 | return -EIO; |
1086 | } | |
1087 | ||
1088 | /* pick up a pointer to the leaves of the dmap tree. | |
1089 | */ | |
1090 | leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); | |
1091 | ||
1092 | /* determine the bit number and word within the dmap of the | |
1093 | * starting block. | |
1094 | */ | |
1095 | dbitno = blkno & (BPERDMAP - 1); | |
1096 | word = dbitno >> L2DBWORD; | |
1097 | ||
1098 | /* check if the specified block range is contained within | |
1099 | * this dmap. | |
1100 | */ | |
1101 | if (dbitno + nblocks > BPERDMAP) | |
1102 | return -ENOSPC; | |
1103 | ||
1104 | /* check if the starting leaf indicates that anything | |
1105 | * is free. | |
1106 | */ | |
1107 | if (leaf[word] == NOFREE) | |
1108 | return -ENOSPC; | |
1109 | ||
1110 | /* check the dmaps words corresponding to block range to see | |
1111 | * if the block range is free. not all bits of the first and | |
1112 | * last words may be contained within the block range. if this | |
1113 | * is the case, we'll work against those words (i.e. partial first | |
1114 | * and/or last) on an individual basis (a single pass) and examine | |
1115 | * the actual bits to determine if they are free. a single pass | |
1116 | * will be used for all dmap words fully contained within the | |
1117 | * specified range. within this pass, the leaves of the dmap | |
1118 | * tree will be examined to determine if the blocks are free. a | |
1119 | * single leaf may describe the free space of multiple dmap | |
1120 | * words, so we may visit only a subset of the actual leaves | |
1121 | * corresponding to the dmap words of the block range. | |
1122 | */ | |
1123 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
1124 | /* determine the bit number within the word and | |
1125 | * the number of bits within the word. | |
1126 | */ | |
1127 | wbitno = dbitno & (DBWORD - 1); | |
1128 | nb = min(rembits, DBWORD - wbitno); | |
1129 | ||
1130 | /* check if only part of the word is to be examined. | |
1131 | */ | |
1132 | if (nb < DBWORD) { | |
1133 | /* check if the bits are free. | |
1134 | */ | |
1135 | mask = (ONES << (DBWORD - nb) >> wbitno); | |
1136 | if ((mask & ~le32_to_cpu(dp->wmap[word])) != mask) | |
1137 | return -ENOSPC; | |
1138 | ||
1139 | word += 1; | |
1140 | } else { | |
1141 | /* one or more dmap words are fully contained | |
1142 | * within the block range. determine how many | |
1143 | * words and how many bits. | |
1144 | */ | |
1145 | nwords = rembits >> L2DBWORD; | |
1146 | nb = nwords << L2DBWORD; | |
1147 | ||
1148 | /* now examine the appropriate leaves to determine | |
1149 | * if the blocks are free. | |
1150 | */ | |
1151 | while (nwords > 0) { | |
1152 | /* does the leaf describe any free space ? | |
1153 | */ | |
1154 | if (leaf[word] < BUDMIN) | |
1155 | return -ENOSPC; | |
1156 | ||
1157 | /* determine the l2 number of bits provided | |
1158 | * by this leaf. | |
1159 | */ | |
1160 | l2size = | |
4f65b6db | 1161 | min_t(int, leaf[word], NLSTOL2BSZ(nwords)); |
1da177e4 LT |
1162 | |
1163 | /* determine how many words were handled. | |
1164 | */ | |
1165 | nw = BUDSIZE(l2size, BUDMIN); | |
1166 | ||
1167 | nwords -= nw; | |
1168 | word += nw; | |
1169 | } | |
1170 | } | |
1171 | } | |
1172 | ||
1173 | /* allocate the blocks. | |
1174 | */ | |
1175 | return (dbAllocDmap(bmp, dp, blkno, nblocks)); | |
1176 | } | |
1177 | ||
1178 | ||
1179 | /* | |
1180 | * NAME: dbAllocNear() | |
1181 | * | |
f720e3ba | 1182 | * FUNCTION: attempt to allocate a number of contiguous free blocks near |
1da177e4 LT |
1183 | * a specified block (hint) within a dmap. |
1184 | * | |
1185 | * starting with the dmap leaf that covers the hint, we'll | |
1186 | * check the next four contiguous leaves for sufficient free | |
1187 | * space. if sufficient free space is found, we'll allocate | |
1188 | * the desired free space. | |
1189 | * | |
1190 | * PARAMETERS: | |
f720e3ba DK |
1191 | * bmp - pointer to bmap descriptor |
1192 | * dp - pointer to dmap. | |
1193 | * blkno - block number to allocate near. | |
1194 | * nblocks - actual number of contiguous free blocks desired. | |
1195 | * l2nb - log2 number of contiguous free blocks desired. | |
1196 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
1197 | * of the newly allocated range. |
1198 | * | |
1199 | * RETURN VALUES: | |
f720e3ba DK |
1200 | * 0 - success |
1201 | * -ENOSPC - insufficient disk resources | |
1202 | * -EIO - i/o error | |
1da177e4 LT |
1203 | * |
1204 | * serialization: IREAD_LOCK(ipbmap) held on entry/exit; | |
1205 | */ | |
1206 | static int | |
1207 | dbAllocNear(struct bmap * bmp, | |
1208 | struct dmap * dp, s64 blkno, int nblocks, int l2nb, s64 * results) | |
1209 | { | |
1210 | int word, lword, rc; | |
1211 | s8 *leaf; | |
1212 | ||
1213 | if (dp->tree.leafidx != cpu_to_le32(LEAFIND)) { | |
eb8630d7 | 1214 | jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmap page\n"); |
1da177e4 LT |
1215 | return -EIO; |
1216 | } | |
1217 | ||
1218 | leaf = dp->tree.stree + le32_to_cpu(dp->tree.leafidx); | |
1219 | ||
1220 | /* determine the word within the dmap that holds the hint | |
1221 | * (i.e. blkno). also, determine the last word in the dmap | |
1222 | * that we'll include in our examination. | |
1223 | */ | |
1224 | word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; | |
1225 | lword = min(word + 4, LPERDMAP); | |
1226 | ||
1227 | /* examine the leaves for sufficient free space. | |
1228 | */ | |
1229 | for (; word < lword; word++) { | |
1230 | /* does the leaf describe sufficient free space ? | |
1231 | */ | |
1232 | if (leaf[word] < l2nb) | |
1233 | continue; | |
1234 | ||
1235 | /* determine the block number within the file system | |
1236 | * of the first block described by this dmap word. | |
1237 | */ | |
1238 | blkno = le64_to_cpu(dp->start) + (word << L2DBWORD); | |
1239 | ||
1240 | /* if not all bits of the dmap word are free, get the | |
1241 | * starting bit number within the dmap word of the required | |
1242 | * string of free bits and adjust the block number with the | |
1243 | * value. | |
1244 | */ | |
1245 | if (leaf[word] < BUDMIN) | |
1246 | blkno += | |
1247 | dbFindBits(le32_to_cpu(dp->wmap[word]), l2nb); | |
1248 | ||
1249 | /* allocate the blocks. | |
1250 | */ | |
1251 | if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) | |
1252 | *results = blkno; | |
1253 | ||
1254 | return (rc); | |
1255 | } | |
1256 | ||
1257 | return -ENOSPC; | |
1258 | } | |
1259 | ||
1260 | ||
1261 | /* | |
1262 | * NAME: dbAllocAG() | |
1263 | * | |
f720e3ba | 1264 | * FUNCTION: attempt to allocate the specified number of contiguous |
1da177e4 LT |
1265 | * free blocks within the specified allocation group. |
1266 | * | |
1267 | * unless the allocation group size is equal to the number | |
1268 | * of blocks per dmap, the dmap control pages will be used to | |
1269 | * find the required free space, if available. we start the | |
1270 | * search at the highest dmap control page level which | |
1271 | * distinctly describes the allocation group's free space | |
1272 | * (i.e. the highest level at which the allocation group's | |
1273 | * free space is not mixed in with that of any other group). | |
1274 | * in addition, we start the search within this level at a | |
1275 | * height of the dmapctl dmtree at which the nodes distinctly | |
1276 | * describe the allocation group's free space. at this height, | |
1277 | * the allocation group's free space may be represented by 1 | |
1278 | * or two sub-trees, depending on the allocation group size. | |
1279 | * we search the top nodes of these subtrees left to right for | |
1280 | * sufficient free space. if sufficient free space is found, | |
63f83c9f | 1281 | * the subtree is searched to find the leftmost leaf that |
1da177e4 LT |
1282 | * has free space. once we have made it to the leaf, we |
1283 | * move the search to the next lower level dmap control page | |
1284 | * corresponding to this leaf. we continue down the dmap control | |
1285 | * pages until we find the dmap that contains or starts the | |
1286 | * sufficient free space and we allocate at this dmap. | |
1287 | * | |
1288 | * if the allocation group size is equal to the dmap size, | |
1289 | * we'll start at the dmap corresponding to the allocation | |
1290 | * group and attempt the allocation at this level. | |
1291 | * | |
1292 | * the dmap control page search is also not performed if the | |
1293 | * allocation group is completely free and we go to the first | |
1294 | * dmap of the allocation group to do the allocation. this is | |
1295 | * done because the allocation group may be part (not the first | |
1296 | * part) of a larger binary buddy system, causing the dmap | |
1297 | * control pages to indicate no free space (NOFREE) within | |
1298 | * the allocation group. | |
1299 | * | |
1300 | * PARAMETERS: | |
f720e3ba | 1301 | * bmp - pointer to bmap descriptor |
1da177e4 | 1302 | * agno - allocation group number. |
f720e3ba DK |
1303 | * nblocks - actual number of contiguous free blocks desired. |
1304 | * l2nb - log2 number of contiguous free blocks desired. | |
1305 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
1306 | * of the newly allocated range. |
1307 | * | |
1308 | * RETURN VALUES: | |
f720e3ba DK |
1309 | * 0 - success |
1310 | * -ENOSPC - insufficient disk resources | |
1311 | * -EIO - i/o error | |
1da177e4 LT |
1312 | * |
1313 | * note: IWRITE_LOCK(ipmap) held on entry/exit; | |
1314 | */ | |
1315 | static int | |
1316 | dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results) | |
1317 | { | |
1318 | struct metapage *mp; | |
1319 | struct dmapctl *dcp; | |
1320 | int rc, ti, i, k, m, n, agperlev; | |
1321 | s64 blkno, lblkno; | |
1322 | int budmin; | |
1323 | ||
1324 | /* allocation request should not be for more than the | |
1325 | * allocation group size. | |
1326 | */ | |
1327 | if (l2nb > bmp->db_agl2size) { | |
1328 | jfs_error(bmp->db_ipbmap->i_sb, | |
eb8630d7 | 1329 | "allocation request is larger than the allocation group size\n"); |
1da177e4 LT |
1330 | return -EIO; |
1331 | } | |
1332 | ||
1333 | /* determine the starting block number of the allocation | |
1334 | * group. | |
1335 | */ | |
1336 | blkno = (s64) agno << bmp->db_agl2size; | |
1337 | ||
1338 | /* check if the allocation group size is the minimum allocation | |
1339 | * group size or if the allocation group is completely free. if | |
1340 | * the allocation group size is the minimum size of BPERDMAP (i.e. | |
1341 | * 1 dmap), there is no need to search the dmap control page (below) | |
1342 | * that fully describes the allocation group since the allocation | |
1343 | * group is already fully described by a dmap. in this case, we | |
1344 | * just call dbAllocCtl() to search the dmap tree and allocate the | |
63f83c9f | 1345 | * required space if available. |
1da177e4 LT |
1346 | * |
1347 | * if the allocation group is completely free, dbAllocCtl() is | |
1348 | * also called to allocate the required space. this is done for | |
1349 | * two reasons. first, it makes no sense searching the dmap control | |
1350 | * pages for free space when we know that free space exists. second, | |
1351 | * the dmap control pages may indicate that the allocation group | |
1352 | * has no free space if the allocation group is part (not the first | |
1353 | * part) of a larger binary buddy system. | |
1354 | */ | |
1355 | if (bmp->db_agsize == BPERDMAP | |
1356 | || bmp->db_agfree[agno] == bmp->db_agsize) { | |
1357 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); | |
1358 | if ((rc == -ENOSPC) && | |
1359 | (bmp->db_agfree[agno] == bmp->db_agsize)) { | |
1360 | printk(KERN_ERR "blkno = %Lx, blocks = %Lx\n", | |
1361 | (unsigned long long) blkno, | |
1362 | (unsigned long long) nblocks); | |
1363 | jfs_error(bmp->db_ipbmap->i_sb, | |
eb8630d7 | 1364 | "dbAllocCtl failed in free AG\n"); |
1da177e4 LT |
1365 | } |
1366 | return (rc); | |
1367 | } | |
1368 | ||
1369 | /* the buffer for the dmap control page that fully describes the | |
1370 | * allocation group. | |
1371 | */ | |
1372 | lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, bmp->db_aglevel); | |
1373 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1374 | if (mp == NULL) | |
1375 | return -EIO; | |
1376 | dcp = (struct dmapctl *) mp->data; | |
1377 | budmin = dcp->budmin; | |
1378 | ||
1379 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { | |
eb8630d7 | 1380 | jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n"); |
1da177e4 LT |
1381 | release_metapage(mp); |
1382 | return -EIO; | |
1383 | } | |
1384 | ||
1385 | /* search the subtree(s) of the dmap control page that describes | |
1386 | * the allocation group, looking for sufficient free space. to begin, | |
1387 | * determine how many allocation groups are represented in a dmap | |
1388 | * control page at the control page level (i.e. L0, L1, L2) that | |
1389 | * fully describes an allocation group. next, determine the starting | |
1390 | * tree index of this allocation group within the control page. | |
1391 | */ | |
1392 | agperlev = | |
d7eecb48 | 1393 | (1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth; |
1da177e4 LT |
1394 | ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1)); |
1395 | ||
63f83c9f | 1396 | /* dmap control page trees fan-out by 4 and a single allocation |
1da177e4 LT |
1397 | * group may be described by 1 or 2 subtrees within the ag level |
1398 | * dmap control page, depending upon the ag size. examine the ag's | |
1399 | * subtrees for sufficient free space, starting with the leftmost | |
1400 | * subtree. | |
1401 | */ | |
1402 | for (i = 0; i < bmp->db_agwidth; i++, ti++) { | |
1403 | /* is there sufficient free space ? | |
1404 | */ | |
1405 | if (l2nb > dcp->stree[ti]) | |
1406 | continue; | |
1407 | ||
1408 | /* sufficient free space found in a subtree. now search down | |
1409 | * the subtree to find the leftmost leaf that describes this | |
1410 | * free space. | |
1411 | */ | |
d7eecb48 | 1412 | for (k = bmp->db_agheight; k > 0; k--) { |
1da177e4 LT |
1413 | for (n = 0, m = (ti << 2) + 1; n < 4; n++) { |
1414 | if (l2nb <= dcp->stree[m + n]) { | |
1415 | ti = m + n; | |
1416 | break; | |
1417 | } | |
1418 | } | |
1419 | if (n == 4) { | |
1420 | jfs_error(bmp->db_ipbmap->i_sb, | |
eb8630d7 | 1421 | "failed descending stree\n"); |
1da177e4 LT |
1422 | release_metapage(mp); |
1423 | return -EIO; | |
1424 | } | |
1425 | } | |
1426 | ||
1427 | /* determine the block number within the file system | |
1428 | * that corresponds to this leaf. | |
1429 | */ | |
1430 | if (bmp->db_aglevel == 2) | |
1431 | blkno = 0; | |
1432 | else if (bmp->db_aglevel == 1) | |
1433 | blkno &= ~(MAXL1SIZE - 1); | |
1434 | else /* bmp->db_aglevel == 0 */ | |
1435 | blkno &= ~(MAXL0SIZE - 1); | |
1436 | ||
1437 | blkno += | |
1438 | ((s64) (ti - le32_to_cpu(dcp->leafidx))) << budmin; | |
1439 | ||
1440 | /* release the buffer in preparation for going down | |
1441 | * the next level of dmap control pages. | |
1442 | */ | |
1443 | release_metapage(mp); | |
1444 | ||
1445 | /* check if we need to continue to search down the lower | |
1446 | * level dmap control pages. we need to if the number of | |
1447 | * blocks required is less than maximum number of blocks | |
1448 | * described at the next lower level. | |
1449 | */ | |
1450 | if (l2nb < budmin) { | |
1451 | ||
1452 | /* search the lower level dmap control pages to get | |
59c51591 | 1453 | * the starting block number of the dmap that |
1da177e4 LT |
1454 | * contains or starts off the free space. |
1455 | */ | |
1456 | if ((rc = | |
1457 | dbFindCtl(bmp, l2nb, bmp->db_aglevel - 1, | |
1458 | &blkno))) { | |
1459 | if (rc == -ENOSPC) { | |
1460 | jfs_error(bmp->db_ipbmap->i_sb, | |
eb8630d7 | 1461 | "control page inconsistent\n"); |
1da177e4 LT |
1462 | return -EIO; |
1463 | } | |
1464 | return (rc); | |
1465 | } | |
1466 | } | |
1467 | ||
1468 | /* allocate the blocks. | |
1469 | */ | |
1470 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); | |
1471 | if (rc == -ENOSPC) { | |
1472 | jfs_error(bmp->db_ipbmap->i_sb, | |
eb8630d7 | 1473 | "unable to allocate blocks\n"); |
1da177e4 LT |
1474 | rc = -EIO; |
1475 | } | |
1476 | return (rc); | |
1477 | } | |
1478 | ||
1479 | /* no space in the allocation group. release the buffer and | |
1480 | * return -ENOSPC. | |
1481 | */ | |
1482 | release_metapage(mp); | |
1483 | ||
1484 | return -ENOSPC; | |
1485 | } | |
1486 | ||
1487 | ||
1488 | /* | |
1489 | * NAME: dbAllocAny() | |
1490 | * | |
f720e3ba | 1491 | * FUNCTION: attempt to allocate the specified number of contiguous |
1da177e4 LT |
1492 | * free blocks anywhere in the file system. |
1493 | * | |
1494 | * dbAllocAny() attempts to find the sufficient free space by | |
1495 | * searching down the dmap control pages, starting with the | |
1496 | * highest level (i.e. L0, L1, L2) control page. if free space | |
1497 | * large enough to satisfy the desired free space is found, the | |
1498 | * desired free space is allocated. | |
1499 | * | |
1500 | * PARAMETERS: | |
f720e3ba DK |
1501 | * bmp - pointer to bmap descriptor |
1502 | * nblocks - actual number of contiguous free blocks desired. | |
1503 | * l2nb - log2 number of contiguous free blocks desired. | |
1504 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
1505 | * of the newly allocated range. |
1506 | * | |
1507 | * RETURN VALUES: | |
f720e3ba DK |
1508 | * 0 - success |
1509 | * -ENOSPC - insufficient disk resources | |
1510 | * -EIO - i/o error | |
1da177e4 LT |
1511 | * |
1512 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; | |
1513 | */ | |
1514 | static int dbAllocAny(struct bmap * bmp, s64 nblocks, int l2nb, s64 * results) | |
1515 | { | |
1516 | int rc; | |
1517 | s64 blkno = 0; | |
1518 | ||
1519 | /* starting with the top level dmap control page, search | |
1520 | * down the dmap control levels for sufficient free space. | |
1521 | * if free space is found, dbFindCtl() returns the starting | |
1522 | * block number of the dmap that contains or starts off the | |
1523 | * range of free space. | |
1524 | */ | |
1525 | if ((rc = dbFindCtl(bmp, l2nb, bmp->db_maxlevel, &blkno))) | |
1526 | return (rc); | |
1527 | ||
1528 | /* allocate the blocks. | |
1529 | */ | |
1530 | rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results); | |
1531 | if (rc == -ENOSPC) { | |
eb8630d7 | 1532 | jfs_error(bmp->db_ipbmap->i_sb, "unable to allocate blocks\n"); |
1da177e4 LT |
1533 | return -EIO; |
1534 | } | |
1535 | return (rc); | |
1536 | } | |
1537 | ||
1538 | ||
b40c2e66 TR |
1539 | /* |
1540 | * NAME: dbDiscardAG() | |
1541 | * | |
1542 | * FUNCTION: attempt to discard (TRIM) all free blocks of specific AG | |
1543 | * | |
1544 | * algorithm: | |
1545 | * 1) allocate blocks, as large as possible and save them | |
1546 | * while holding IWRITE_LOCK on ipbmap | |
1547 | * 2) trim all these saved block/length values | |
1548 | * 3) mark the blocks free again | |
1549 | * | |
1550 | * benefit: | |
1551 | * - we work only on one ag at some time, minimizing how long we | |
1552 | * need to lock ipbmap | |
1553 | * - reading / writing the fs is possible most time, even on | |
1554 | * trimming | |
1555 | * | |
1556 | * downside: | |
1557 | * - we write two times to the dmapctl and dmap pages | |
1558 | * - but for me, this seems the best way, better ideas? | |
1559 | * /TR 2012 | |
1560 | * | |
1561 | * PARAMETERS: | |
1562 | * ip - pointer to in-core inode | |
1563 | * agno - ag to trim | |
1564 | * minlen - minimum value of contiguous blocks | |
1565 | * | |
1566 | * RETURN VALUES: | |
1567 | * s64 - actual number of blocks trimmed | |
1568 | */ | |
1569 | s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen) | |
1570 | { | |
1571 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
1572 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; | |
1573 | s64 nblocks, blkno; | |
1574 | u64 trimmed = 0; | |
1575 | int rc, l2nb; | |
1576 | struct super_block *sb = ipbmap->i_sb; | |
1577 | ||
1578 | struct range2trim { | |
1579 | u64 blkno; | |
1580 | u64 nblocks; | |
1581 | } *totrim, *tt; | |
1582 | ||
1583 | /* max blkno / nblocks pairs to trim */ | |
1584 | int count = 0, range_cnt; | |
84f4141e | 1585 | u64 max_ranges; |
b40c2e66 TR |
1586 | |
1587 | /* prevent others from writing new stuff here, while trimming */ | |
1588 | IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP); | |
1589 | ||
1590 | nblocks = bmp->db_agfree[agno]; | |
84f4141e DK |
1591 | max_ranges = nblocks; |
1592 | do_div(max_ranges, minlen); | |
1593 | range_cnt = min_t(u64, max_ranges + 1, 32 * 1024); | |
6da2ec56 | 1594 | totrim = kmalloc_array(range_cnt, sizeof(struct range2trim), GFP_NOFS); |
b40c2e66 | 1595 | if (totrim == NULL) { |
eb8630d7 | 1596 | jfs_error(bmp->db_ipbmap->i_sb, "no memory for trim array\n"); |
b40c2e66 TR |
1597 | IWRITE_UNLOCK(ipbmap); |
1598 | return 0; | |
1599 | } | |
1600 | ||
1601 | tt = totrim; | |
1602 | while (nblocks >= minlen) { | |
1603 | l2nb = BLKSTOL2(nblocks); | |
1604 | ||
1605 | /* 0 = okay, -EIO = fatal, -ENOSPC -> try smaller block */ | |
1606 | rc = dbAllocAG(bmp, agno, nblocks, l2nb, &blkno); | |
1607 | if (rc == 0) { | |
1608 | tt->blkno = blkno; | |
1609 | tt->nblocks = nblocks; | |
1610 | tt++; count++; | |
1611 | ||
1612 | /* the whole ag is free, trim now */ | |
1613 | if (bmp->db_agfree[agno] == 0) | |
1614 | break; | |
1615 | ||
1616 | /* give a hint for the next while */ | |
1617 | nblocks = bmp->db_agfree[agno]; | |
1618 | continue; | |
1619 | } else if (rc == -ENOSPC) { | |
1620 | /* search for next smaller log2 block */ | |
1621 | l2nb = BLKSTOL2(nblocks) - 1; | |
4208c398 | 1622 | nblocks = 1LL << l2nb; |
b40c2e66 TR |
1623 | } else { |
1624 | /* Trim any already allocated blocks */ | |
eb8630d7 | 1625 | jfs_error(bmp->db_ipbmap->i_sb, "-EIO\n"); |
b40c2e66 TR |
1626 | break; |
1627 | } | |
1628 | ||
1629 | /* check, if our trim array is full */ | |
1630 | if (unlikely(count >= range_cnt - 1)) | |
1631 | break; | |
1632 | } | |
1633 | IWRITE_UNLOCK(ipbmap); | |
1634 | ||
1635 | tt->nblocks = 0; /* mark the current end */ | |
1636 | for (tt = totrim; tt->nblocks != 0; tt++) { | |
1637 | /* when mounted with online discard, dbFree() will | |
1638 | * call jfs_issue_discard() itself */ | |
1639 | if (!(JFS_SBI(sb)->flag & JFS_DISCARD)) | |
1640 | jfs_issue_discard(ip, tt->blkno, tt->nblocks); | |
1641 | dbFree(ip, tt->blkno, tt->nblocks); | |
1642 | trimmed += tt->nblocks; | |
1643 | } | |
1644 | kfree(totrim); | |
1645 | ||
1646 | return trimmed; | |
1647 | } | |
1648 | ||
1da177e4 LT |
1649 | /* |
1650 | * NAME: dbFindCtl() | |
1651 | * | |
f720e3ba | 1652 | * FUNCTION: starting at a specified dmap control page level and block |
1da177e4 | 1653 | * number, search down the dmap control levels for a range of |
f720e3ba | 1654 | * contiguous free blocks large enough to satisfy an allocation |
1da177e4 LT |
1655 | * request for the specified number of free blocks. |
1656 | * | |
1657 | * if sufficient contiguous free blocks are found, this routine | |
1658 | * returns the starting block number within a dmap page that | |
1659 | * contains or starts a range of contiqious free blocks that | |
1660 | * is sufficient in size. | |
1661 | * | |
1662 | * PARAMETERS: | |
f720e3ba DK |
1663 | * bmp - pointer to bmap descriptor |
1664 | * level - starting dmap control page level. | |
1665 | * l2nb - log2 number of contiguous free blocks desired. | |
1666 | * *blkno - on entry, starting block number for conducting the search. | |
1da177e4 LT |
1667 | * on successful return, the first block within a dmap page |
1668 | * that contains or starts a range of contiguous free blocks. | |
1669 | * | |
1670 | * RETURN VALUES: | |
f720e3ba DK |
1671 | * 0 - success |
1672 | * -ENOSPC - insufficient disk resources | |
1673 | * -EIO - i/o error | |
1da177e4 LT |
1674 | * |
1675 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; | |
1676 | */ | |
1677 | static int dbFindCtl(struct bmap * bmp, int l2nb, int level, s64 * blkno) | |
1678 | { | |
1679 | int rc, leafidx, lev; | |
1680 | s64 b, lblkno; | |
1681 | struct dmapctl *dcp; | |
1682 | int budmin; | |
1683 | struct metapage *mp; | |
1684 | ||
1685 | /* starting at the specified dmap control page level and block | |
1686 | * number, search down the dmap control levels for the starting | |
63f83c9f | 1687 | * block number of a dmap page that contains or starts off |
1da177e4 LT |
1688 | * sufficient free blocks. |
1689 | */ | |
1690 | for (lev = level, b = *blkno; lev >= 0; lev--) { | |
1691 | /* get the buffer of the dmap control page for the block | |
1692 | * number and level (i.e. L0, L1, L2). | |
1693 | */ | |
1694 | lblkno = BLKTOCTL(b, bmp->db_l2nbperpage, lev); | |
1695 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1696 | if (mp == NULL) | |
1697 | return -EIO; | |
1698 | dcp = (struct dmapctl *) mp->data; | |
1699 | budmin = dcp->budmin; | |
1700 | ||
1701 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { | |
1702 | jfs_error(bmp->db_ipbmap->i_sb, | |
eb8630d7 | 1703 | "Corrupt dmapctl page\n"); |
1da177e4 LT |
1704 | release_metapage(mp); |
1705 | return -EIO; | |
1706 | } | |
1707 | ||
1708 | /* search the tree within the dmap control page for | |
25985edc | 1709 | * sufficient free space. if sufficient free space is found, |
1da177e4 LT |
1710 | * dbFindLeaf() returns the index of the leaf at which |
1711 | * free space was found. | |
1712 | */ | |
1713 | rc = dbFindLeaf((dmtree_t *) dcp, l2nb, &leafidx); | |
1714 | ||
1715 | /* release the buffer. | |
1716 | */ | |
1717 | release_metapage(mp); | |
1718 | ||
1719 | /* space found ? | |
1720 | */ | |
1721 | if (rc) { | |
1722 | if (lev != level) { | |
1723 | jfs_error(bmp->db_ipbmap->i_sb, | |
eb8630d7 | 1724 | "dmap inconsistent\n"); |
1da177e4 LT |
1725 | return -EIO; |
1726 | } | |
1727 | return -ENOSPC; | |
1728 | } | |
1729 | ||
1730 | /* adjust the block number to reflect the location within | |
63f83c9f | 1731 | * the dmap control page (i.e. the leaf) at which free |
1da177e4 LT |
1732 | * space was found. |
1733 | */ | |
1734 | b += (((s64) leafidx) << budmin); | |
1735 | ||
1736 | /* we stop the search at this dmap control page level if | |
1737 | * the number of blocks required is greater than or equal | |
1738 | * to the maximum number of blocks described at the next | |
1739 | * (lower) level. | |
1740 | */ | |
1741 | if (l2nb >= budmin) | |
1742 | break; | |
1743 | } | |
1744 | ||
1745 | *blkno = b; | |
1746 | return (0); | |
1747 | } | |
1748 | ||
1749 | ||
1750 | /* | |
1751 | * NAME: dbAllocCtl() | |
1752 | * | |
f720e3ba | 1753 | * FUNCTION: attempt to allocate a specified number of contiguous |
63f83c9f DK |
1754 | * blocks starting within a specific dmap. |
1755 | * | |
1da177e4 LT |
1756 | * this routine is called by higher level routines that search |
1757 | * the dmap control pages above the actual dmaps for contiguous | |
1758 | * free space. the result of successful searches by these | |
63f83c9f | 1759 | * routines are the starting block numbers within dmaps, with |
1da177e4 LT |
1760 | * the dmaps themselves containing the desired contiguous free |
1761 | * space or starting a contiguous free space of desired size | |
1762 | * that is made up of the blocks of one or more dmaps. these | |
1763 | * calls should not fail due to insufficent resources. | |
1764 | * | |
1765 | * this routine is called in some cases where it is not known | |
1766 | * whether it will fail due to insufficient resources. more | |
1767 | * specifically, this occurs when allocating from an allocation | |
1768 | * group whose size is equal to the number of blocks per dmap. | |
1769 | * in this case, the dmap control pages are not examined prior | |
1770 | * to calling this routine (to save pathlength) and the call | |
1771 | * might fail. | |
1772 | * | |
1773 | * for a request size that fits within a dmap, this routine relies | |
1774 | * upon the dmap's dmtree to find the requested contiguous free | |
1775 | * space. for request sizes that are larger than a dmap, the | |
1776 | * requested free space will start at the first block of the | |
1777 | * first dmap (i.e. blkno). | |
1778 | * | |
1779 | * PARAMETERS: | |
f720e3ba DK |
1780 | * bmp - pointer to bmap descriptor |
1781 | * nblocks - actual number of contiguous free blocks to allocate. | |
1782 | * l2nb - log2 number of contiguous free blocks to allocate. | |
1783 | * blkno - starting block number of the dmap to start the allocation | |
1da177e4 | 1784 | * from. |
f720e3ba | 1785 | * results - on successful return, set to the starting block number |
1da177e4 LT |
1786 | * of the newly allocated range. |
1787 | * | |
1788 | * RETURN VALUES: | |
f720e3ba DK |
1789 | * 0 - success |
1790 | * -ENOSPC - insufficient disk resources | |
1791 | * -EIO - i/o error | |
1da177e4 LT |
1792 | * |
1793 | * serialization: IWRITE_LOCK(ipbmap) held on entry/exit; | |
1794 | */ | |
1795 | static int | |
1796 | dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno, s64 * results) | |
1797 | { | |
1798 | int rc, nb; | |
1799 | s64 b, lblkno, n; | |
1800 | struct metapage *mp; | |
1801 | struct dmap *dp; | |
1802 | ||
1803 | /* check if the allocation request is confined to a single dmap. | |
1804 | */ | |
1805 | if (l2nb <= L2BPERDMAP) { | |
1806 | /* get the buffer for the dmap. | |
1807 | */ | |
1808 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
1809 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1810 | if (mp == NULL) | |
1811 | return -EIO; | |
1812 | dp = (struct dmap *) mp->data; | |
1813 | ||
1814 | /* try to allocate the blocks. | |
1815 | */ | |
1816 | rc = dbAllocDmapLev(bmp, dp, (int) nblocks, l2nb, results); | |
1817 | if (rc == 0) | |
1818 | mark_metapage_dirty(mp); | |
1819 | ||
1820 | release_metapage(mp); | |
1821 | ||
1822 | return (rc); | |
1823 | } | |
1824 | ||
1825 | /* allocation request involving multiple dmaps. it must start on | |
1826 | * a dmap boundary. | |
1827 | */ | |
1828 | assert((blkno & (BPERDMAP - 1)) == 0); | |
1829 | ||
1830 | /* allocate the blocks dmap by dmap. | |
1831 | */ | |
1832 | for (n = nblocks, b = blkno; n > 0; n -= nb, b += nb) { | |
1833 | /* get the buffer for the dmap. | |
1834 | */ | |
1835 | lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); | |
1836 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1837 | if (mp == NULL) { | |
1838 | rc = -EIO; | |
1839 | goto backout; | |
1840 | } | |
1841 | dp = (struct dmap *) mp->data; | |
1842 | ||
1843 | /* the dmap better be all free. | |
1844 | */ | |
1845 | if (dp->tree.stree[ROOT] != L2BPERDMAP) { | |
1846 | release_metapage(mp); | |
1847 | jfs_error(bmp->db_ipbmap->i_sb, | |
eb8630d7 | 1848 | "the dmap is not all free\n"); |
1da177e4 LT |
1849 | rc = -EIO; |
1850 | goto backout; | |
1851 | } | |
1852 | ||
1853 | /* determine how many blocks to allocate from this dmap. | |
1854 | */ | |
4f65b6db | 1855 | nb = min_t(s64, n, BPERDMAP); |
1da177e4 LT |
1856 | |
1857 | /* allocate the blocks from the dmap. | |
1858 | */ | |
1859 | if ((rc = dbAllocDmap(bmp, dp, b, nb))) { | |
1860 | release_metapage(mp); | |
1861 | goto backout; | |
1862 | } | |
1863 | ||
1864 | /* write the buffer. | |
1865 | */ | |
1866 | write_metapage(mp); | |
1867 | } | |
1868 | ||
1869 | /* set the results (starting block number) and return. | |
1870 | */ | |
1871 | *results = blkno; | |
1872 | return (0); | |
1873 | ||
1874 | /* something failed in handling an allocation request involving | |
1875 | * multiple dmaps. we'll try to clean up by backing out any | |
1876 | * allocation that has already happened for this request. if | |
1877 | * we fail in backing out the allocation, we'll mark the file | |
1878 | * system to indicate that blocks have been leaked. | |
1879 | */ | |
1880 | backout: | |
1881 | ||
1882 | /* try to backout the allocations dmap by dmap. | |
1883 | */ | |
1884 | for (n = nblocks - n, b = blkno; n > 0; | |
1885 | n -= BPERDMAP, b += BPERDMAP) { | |
1886 | /* get the buffer for this dmap. | |
1887 | */ | |
1888 | lblkno = BLKTODMAP(b, bmp->db_l2nbperpage); | |
1889 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
1890 | if (mp == NULL) { | |
1891 | /* could not back out. mark the file system | |
1892 | * to indicate that we have leaked blocks. | |
1893 | */ | |
1894 | jfs_error(bmp->db_ipbmap->i_sb, | |
eb8630d7 | 1895 | "I/O Error: Block Leakage\n"); |
1da177e4 LT |
1896 | continue; |
1897 | } | |
1898 | dp = (struct dmap *) mp->data; | |
1899 | ||
1900 | /* free the blocks is this dmap. | |
1901 | */ | |
1902 | if (dbFreeDmap(bmp, dp, b, BPERDMAP)) { | |
1903 | /* could not back out. mark the file system | |
1904 | * to indicate that we have leaked blocks. | |
1905 | */ | |
1906 | release_metapage(mp); | |
eb8630d7 | 1907 | jfs_error(bmp->db_ipbmap->i_sb, "Block Leakage\n"); |
1da177e4 LT |
1908 | continue; |
1909 | } | |
1910 | ||
1911 | /* write the buffer. | |
1912 | */ | |
1913 | write_metapage(mp); | |
1914 | } | |
1915 | ||
1916 | return (rc); | |
1917 | } | |
1918 | ||
1919 | ||
1920 | /* | |
1921 | * NAME: dbAllocDmapLev() | |
1922 | * | |
f720e3ba | 1923 | * FUNCTION: attempt to allocate a specified number of contiguous blocks |
1da177e4 | 1924 | * from a specified dmap. |
63f83c9f | 1925 | * |
1da177e4 LT |
1926 | * this routine checks if the contiguous blocks are available. |
1927 | * if so, nblocks of blocks are allocated; otherwise, ENOSPC is | |
1928 | * returned. | |
1929 | * | |
1930 | * PARAMETERS: | |
f720e3ba DK |
1931 | * mp - pointer to bmap descriptor |
1932 | * dp - pointer to dmap to attempt to allocate blocks from. | |
1933 | * l2nb - log2 number of contiguous block desired. | |
1934 | * nblocks - actual number of contiguous block desired. | |
1935 | * results - on successful return, set to the starting block number | |
1da177e4 LT |
1936 | * of the newly allocated range. |
1937 | * | |
1938 | * RETURN VALUES: | |
f720e3ba DK |
1939 | * 0 - success |
1940 | * -ENOSPC - insufficient disk resources | |
1941 | * -EIO - i/o error | |
1da177e4 | 1942 | * |
63f83c9f | 1943 | * serialization: IREAD_LOCK(ipbmap), e.g., from dbAlloc(), or |
1da177e4 LT |
1944 | * IWRITE_LOCK(ipbmap), e.g., dbAllocCtl(), held on entry/exit; |
1945 | */ | |
1946 | static int | |
1947 | dbAllocDmapLev(struct bmap * bmp, | |
1948 | struct dmap * dp, int nblocks, int l2nb, s64 * results) | |
1949 | { | |
1950 | s64 blkno; | |
1951 | int leafidx, rc; | |
1952 | ||
1953 | /* can't be more than a dmaps worth of blocks */ | |
1954 | assert(l2nb <= L2BPERDMAP); | |
1955 | ||
1956 | /* search the tree within the dmap page for sufficient | |
1957 | * free space. if sufficient free space is found, dbFindLeaf() | |
1958 | * returns the index of the leaf at which free space was found. | |
1959 | */ | |
1960 | if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx)) | |
1961 | return -ENOSPC; | |
1962 | ||
4e302336 Y |
1963 | if (leafidx < 0) |
1964 | return -EIO; | |
1965 | ||
1da177e4 LT |
1966 | /* determine the block number within the file system corresponding |
1967 | * to the leaf at which free space was found. | |
1968 | */ | |
1969 | blkno = le64_to_cpu(dp->start) + (leafidx << L2DBWORD); | |
1970 | ||
1971 | /* if not all bits of the dmap word are free, get the starting | |
1972 | * bit number within the dmap word of the required string of free | |
1973 | * bits and adjust the block number with this value. | |
1974 | */ | |
1975 | if (dp->tree.stree[leafidx + LEAFIND] < BUDMIN) | |
1976 | blkno += dbFindBits(le32_to_cpu(dp->wmap[leafidx]), l2nb); | |
1977 | ||
1978 | /* allocate the blocks */ | |
1979 | if ((rc = dbAllocDmap(bmp, dp, blkno, nblocks)) == 0) | |
1980 | *results = blkno; | |
1981 | ||
1982 | return (rc); | |
1983 | } | |
1984 | ||
1985 | ||
1986 | /* | |
1987 | * NAME: dbAllocDmap() | |
1988 | * | |
f720e3ba | 1989 | * FUNCTION: adjust the disk allocation map to reflect the allocation |
1da177e4 LT |
1990 | * of a specified block range within a dmap. |
1991 | * | |
1992 | * this routine allocates the specified blocks from the dmap | |
1993 | * through a call to dbAllocBits(). if the allocation of the | |
1994 | * block range causes the maximum string of free blocks within | |
1995 | * the dmap to change (i.e. the value of the root of the dmap's | |
1996 | * dmtree), this routine will cause this change to be reflected | |
1997 | * up through the appropriate levels of the dmap control pages | |
1998 | * by a call to dbAdjCtl() for the L0 dmap control page that | |
1999 | * covers this dmap. | |
2000 | * | |
2001 | * PARAMETERS: | |
f720e3ba DK |
2002 | * bmp - pointer to bmap descriptor |
2003 | * dp - pointer to dmap to allocate the block range from. | |
2004 | * blkno - starting block number of the block to be allocated. | |
2005 | * nblocks - number of blocks to be allocated. | |
1da177e4 LT |
2006 | * |
2007 | * RETURN VALUES: | |
f720e3ba DK |
2008 | * 0 - success |
2009 | * -EIO - i/o error | |
1da177e4 LT |
2010 | * |
2011 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2012 | */ | |
2013 | static int dbAllocDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
2014 | int nblocks) | |
2015 | { | |
2016 | s8 oldroot; | |
2017 | int rc; | |
2018 | ||
2019 | /* save the current value of the root (i.e. maximum free string) | |
2020 | * of the dmap tree. | |
2021 | */ | |
2022 | oldroot = dp->tree.stree[ROOT]; | |
2023 | ||
2024 | /* allocate the specified (blocks) bits */ | |
2025 | dbAllocBits(bmp, dp, blkno, nblocks); | |
2026 | ||
2027 | /* if the root has not changed, done. */ | |
2028 | if (dp->tree.stree[ROOT] == oldroot) | |
2029 | return (0); | |
2030 | ||
2031 | /* root changed. bubble the change up to the dmap control pages. | |
2032 | * if the adjustment of the upper level control pages fails, | |
2033 | * backout the bit allocation (thus making everything consistent). | |
2034 | */ | |
2035 | if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 1, 0))) | |
2036 | dbFreeBits(bmp, dp, blkno, nblocks); | |
2037 | ||
2038 | return (rc); | |
2039 | } | |
2040 | ||
2041 | ||
2042 | /* | |
2043 | * NAME: dbFreeDmap() | |
2044 | * | |
f720e3ba | 2045 | * FUNCTION: adjust the disk allocation map to reflect the allocation |
1da177e4 LT |
2046 | * of a specified block range within a dmap. |
2047 | * | |
2048 | * this routine frees the specified blocks from the dmap through | |
2049 | * a call to dbFreeBits(). if the deallocation of the block range | |
2050 | * causes the maximum string of free blocks within the dmap to | |
2051 | * change (i.e. the value of the root of the dmap's dmtree), this | |
2052 | * routine will cause this change to be reflected up through the | |
f720e3ba | 2053 | * appropriate levels of the dmap control pages by a call to |
1da177e4 LT |
2054 | * dbAdjCtl() for the L0 dmap control page that covers this dmap. |
2055 | * | |
2056 | * PARAMETERS: | |
f720e3ba DK |
2057 | * bmp - pointer to bmap descriptor |
2058 | * dp - pointer to dmap to free the block range from. | |
2059 | * blkno - starting block number of the block to be freed. | |
2060 | * nblocks - number of blocks to be freed. | |
1da177e4 LT |
2061 | * |
2062 | * RETURN VALUES: | |
f720e3ba DK |
2063 | * 0 - success |
2064 | * -EIO - i/o error | |
1da177e4 LT |
2065 | * |
2066 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2067 | */ | |
2068 | static int dbFreeDmap(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
2069 | int nblocks) | |
2070 | { | |
2071 | s8 oldroot; | |
56d12549 | 2072 | int rc = 0, word; |
1da177e4 LT |
2073 | |
2074 | /* save the current value of the root (i.e. maximum free string) | |
2075 | * of the dmap tree. | |
2076 | */ | |
2077 | oldroot = dp->tree.stree[ROOT]; | |
2078 | ||
2079 | /* free the specified (blocks) bits */ | |
56d12549 | 2080 | rc = dbFreeBits(bmp, dp, blkno, nblocks); |
1da177e4 | 2081 | |
56d12549 DK |
2082 | /* if error or the root has not changed, done. */ |
2083 | if (rc || (dp->tree.stree[ROOT] == oldroot)) | |
2084 | return (rc); | |
1da177e4 LT |
2085 | |
2086 | /* root changed. bubble the change up to the dmap control pages. | |
2087 | * if the adjustment of the upper level control pages fails, | |
63f83c9f | 2088 | * backout the deallocation. |
1da177e4 LT |
2089 | */ |
2090 | if ((rc = dbAdjCtl(bmp, blkno, dp->tree.stree[ROOT], 0, 0))) { | |
2091 | word = (blkno & (BPERDMAP - 1)) >> L2DBWORD; | |
2092 | ||
2093 | /* as part of backing out the deallocation, we will have | |
2094 | * to back split the dmap tree if the deallocation caused | |
2095 | * the freed blocks to become part of a larger binary buddy | |
2096 | * system. | |
2097 | */ | |
2098 | if (dp->tree.stree[word] == NOFREE) | |
2099 | dbBackSplit((dmtree_t *) & dp->tree, word); | |
2100 | ||
2101 | dbAllocBits(bmp, dp, blkno, nblocks); | |
2102 | } | |
2103 | ||
2104 | return (rc); | |
2105 | } | |
2106 | ||
2107 | ||
2108 | /* | |
2109 | * NAME: dbAllocBits() | |
2110 | * | |
f720e3ba | 2111 | * FUNCTION: allocate a specified block range from a dmap. |
1da177e4 LT |
2112 | * |
2113 | * this routine updates the dmap to reflect the working | |
2114 | * state allocation of the specified block range. it directly | |
2115 | * updates the bits of the working map and causes the adjustment | |
2116 | * of the binary buddy system described by the dmap's dmtree | |
2117 | * leaves to reflect the bits allocated. it also causes the | |
2118 | * dmap's dmtree, as a whole, to reflect the allocated range. | |
2119 | * | |
2120 | * PARAMETERS: | |
f720e3ba DK |
2121 | * bmp - pointer to bmap descriptor |
2122 | * dp - pointer to dmap to allocate bits from. | |
2123 | * blkno - starting block number of the bits to be allocated. | |
2124 | * nblocks - number of bits to be allocated. | |
1da177e4 LT |
2125 | * |
2126 | * RETURN VALUES: none | |
2127 | * | |
2128 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2129 | */ | |
2130 | static void dbAllocBits(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
2131 | int nblocks) | |
2132 | { | |
2133 | int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; | |
2134 | dmtree_t *tp = (dmtree_t *) & dp->tree; | |
2135 | int size; | |
2136 | s8 *leaf; | |
2137 | ||
2138 | /* pick up a pointer to the leaves of the dmap tree */ | |
2139 | leaf = dp->tree.stree + LEAFIND; | |
2140 | ||
2141 | /* determine the bit number and word within the dmap of the | |
2142 | * starting block. | |
2143 | */ | |
2144 | dbitno = blkno & (BPERDMAP - 1); | |
2145 | word = dbitno >> L2DBWORD; | |
2146 | ||
2147 | /* block range better be within the dmap */ | |
2148 | assert(dbitno + nblocks <= BPERDMAP); | |
2149 | ||
2150 | /* allocate the bits of the dmap's words corresponding to the block | |
2151 | * range. not all bits of the first and last words may be contained | |
2152 | * within the block range. if this is the case, we'll work against | |
2153 | * those words (i.e. partial first and/or last) on an individual basis | |
2154 | * (a single pass), allocating the bits of interest by hand and | |
2155 | * updating the leaf corresponding to the dmap word. a single pass | |
2156 | * will be used for all dmap words fully contained within the | |
2157 | * specified range. within this pass, the bits of all fully contained | |
2158 | * dmap words will be marked as free in a single shot and the leaves | |
2159 | * will be updated. a single leaf may describe the free space of | |
2160 | * multiple dmap words, so we may update only a subset of the actual | |
2161 | * leaves corresponding to the dmap words of the block range. | |
2162 | */ | |
2163 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
2164 | /* determine the bit number within the word and | |
2165 | * the number of bits within the word. | |
2166 | */ | |
2167 | wbitno = dbitno & (DBWORD - 1); | |
2168 | nb = min(rembits, DBWORD - wbitno); | |
2169 | ||
2170 | /* check if only part of a word is to be allocated. | |
2171 | */ | |
2172 | if (nb < DBWORD) { | |
2173 | /* allocate (set to 1) the appropriate bits within | |
2174 | * this dmap word. | |
2175 | */ | |
2176 | dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) | |
2177 | >> wbitno); | |
2178 | ||
2179 | /* update the leaf for this dmap word. in addition | |
2180 | * to setting the leaf value to the binary buddy max | |
2181 | * of the updated dmap word, dbSplit() will split | |
2182 | * the binary system of the leaves if need be. | |
2183 | */ | |
2184 | dbSplit(tp, word, BUDMIN, | |
2185 | dbMaxBud((u8 *) & dp->wmap[word])); | |
2186 | ||
2187 | word += 1; | |
2188 | } else { | |
2189 | /* one or more dmap words are fully contained | |
2190 | * within the block range. determine how many | |
2191 | * words and allocate (set to 1) the bits of these | |
2192 | * words. | |
2193 | */ | |
2194 | nwords = rembits >> L2DBWORD; | |
2195 | memset(&dp->wmap[word], (int) ONES, nwords * 4); | |
2196 | ||
2197 | /* determine how many bits. | |
2198 | */ | |
2199 | nb = nwords << L2DBWORD; | |
2200 | ||
2201 | /* now update the appropriate leaves to reflect | |
2202 | * the allocated words. | |
2203 | */ | |
2204 | for (; nwords > 0; nwords -= nw) { | |
f720e3ba | 2205 | if (leaf[word] < BUDMIN) { |
1da177e4 | 2206 | jfs_error(bmp->db_ipbmap->i_sb, |
eb8630d7 | 2207 | "leaf page corrupt\n"); |
1da177e4 LT |
2208 | break; |
2209 | } | |
2210 | ||
2211 | /* determine what the leaf value should be | |
2212 | * updated to as the minimum of the l2 number | |
2213 | * of bits being allocated and the l2 number | |
2214 | * of bits currently described by this leaf. | |
2215 | */ | |
4f65b6db FF |
2216 | size = min_t(int, leaf[word], |
2217 | NLSTOL2BSZ(nwords)); | |
1da177e4 LT |
2218 | |
2219 | /* update the leaf to reflect the allocation. | |
2220 | * in addition to setting the leaf value to | |
2221 | * NOFREE, dbSplit() will split the binary | |
2222 | * system of the leaves to reflect the current | |
2223 | * allocation (size). | |
2224 | */ | |
2225 | dbSplit(tp, word, size, NOFREE); | |
2226 | ||
2227 | /* get the number of dmap words handled */ | |
2228 | nw = BUDSIZE(size, BUDMIN); | |
2229 | word += nw; | |
2230 | } | |
2231 | } | |
2232 | } | |
2233 | ||
2234 | /* update the free count for this dmap */ | |
89145622 | 2235 | le32_add_cpu(&dp->nfree, -nblocks); |
1da177e4 LT |
2236 | |
2237 | BMAP_LOCK(bmp); | |
2238 | ||
2239 | /* if this allocation group is completely free, | |
2240 | * update the maximum allocation group number if this allocation | |
2241 | * group is the new max. | |
2242 | */ | |
2243 | agno = blkno >> bmp->db_agl2size; | |
2244 | if (agno > bmp->db_maxag) | |
2245 | bmp->db_maxag = agno; | |
2246 | ||
2247 | /* update the free count for the allocation group and map */ | |
2248 | bmp->db_agfree[agno] -= nblocks; | |
2249 | bmp->db_nfree -= nblocks; | |
2250 | ||
2251 | BMAP_UNLOCK(bmp); | |
2252 | } | |
2253 | ||
2254 | ||
2255 | /* | |
2256 | * NAME: dbFreeBits() | |
2257 | * | |
f720e3ba | 2258 | * FUNCTION: free a specified block range from a dmap. |
1da177e4 LT |
2259 | * |
2260 | * this routine updates the dmap to reflect the working | |
2261 | * state allocation of the specified block range. it directly | |
2262 | * updates the bits of the working map and causes the adjustment | |
2263 | * of the binary buddy system described by the dmap's dmtree | |
2264 | * leaves to reflect the bits freed. it also causes the dmap's | |
2265 | * dmtree, as a whole, to reflect the deallocated range. | |
2266 | * | |
2267 | * PARAMETERS: | |
f720e3ba DK |
2268 | * bmp - pointer to bmap descriptor |
2269 | * dp - pointer to dmap to free bits from. | |
2270 | * blkno - starting block number of the bits to be freed. | |
2271 | * nblocks - number of bits to be freed. | |
1da177e4 | 2272 | * |
56d12549 | 2273 | * RETURN VALUES: 0 for success |
1da177e4 LT |
2274 | * |
2275 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2276 | */ | |
56d12549 | 2277 | static int dbFreeBits(struct bmap * bmp, struct dmap * dp, s64 blkno, |
1da177e4 LT |
2278 | int nblocks) |
2279 | { | |
2280 | int dbitno, word, rembits, nb, nwords, wbitno, nw, agno; | |
2281 | dmtree_t *tp = (dmtree_t *) & dp->tree; | |
56d12549 | 2282 | int rc = 0; |
1da177e4 LT |
2283 | int size; |
2284 | ||
2285 | /* determine the bit number and word within the dmap of the | |
2286 | * starting block. | |
2287 | */ | |
2288 | dbitno = blkno & (BPERDMAP - 1); | |
2289 | word = dbitno >> L2DBWORD; | |
2290 | ||
2291 | /* block range better be within the dmap. | |
2292 | */ | |
2293 | assert(dbitno + nblocks <= BPERDMAP); | |
2294 | ||
2295 | /* free the bits of the dmaps words corresponding to the block range. | |
2296 | * not all bits of the first and last words may be contained within | |
2297 | * the block range. if this is the case, we'll work against those | |
2298 | * words (i.e. partial first and/or last) on an individual basis | |
2299 | * (a single pass), freeing the bits of interest by hand and updating | |
2300 | * the leaf corresponding to the dmap word. a single pass will be used | |
63f83c9f | 2301 | * for all dmap words fully contained within the specified range. |
1da177e4 LT |
2302 | * within this pass, the bits of all fully contained dmap words will |
2303 | * be marked as free in a single shot and the leaves will be updated. a | |
2304 | * single leaf may describe the free space of multiple dmap words, | |
2305 | * so we may update only a subset of the actual leaves corresponding | |
2306 | * to the dmap words of the block range. | |
2307 | * | |
2308 | * dbJoin() is used to update leaf values and will join the binary | |
2309 | * buddy system of the leaves if the new leaf values indicate this | |
2310 | * should be done. | |
2311 | */ | |
2312 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
2313 | /* determine the bit number within the word and | |
2314 | * the number of bits within the word. | |
2315 | */ | |
2316 | wbitno = dbitno & (DBWORD - 1); | |
2317 | nb = min(rembits, DBWORD - wbitno); | |
2318 | ||
2319 | /* check if only part of a word is to be freed. | |
2320 | */ | |
2321 | if (nb < DBWORD) { | |
2322 | /* free (zero) the appropriate bits within this | |
63f83c9f | 2323 | * dmap word. |
1da177e4 LT |
2324 | */ |
2325 | dp->wmap[word] &= | |
2326 | cpu_to_le32(~(ONES << (DBWORD - nb) | |
2327 | >> wbitno)); | |
2328 | ||
2329 | /* update the leaf for this dmap word. | |
2330 | */ | |
56d12549 DK |
2331 | rc = dbJoin(tp, word, |
2332 | dbMaxBud((u8 *) & dp->wmap[word])); | |
2333 | if (rc) | |
2334 | return rc; | |
1da177e4 LT |
2335 | |
2336 | word += 1; | |
2337 | } else { | |
2338 | /* one or more dmap words are fully contained | |
2339 | * within the block range. determine how many | |
2340 | * words and free (zero) the bits of these words. | |
2341 | */ | |
2342 | nwords = rembits >> L2DBWORD; | |
2343 | memset(&dp->wmap[word], 0, nwords * 4); | |
2344 | ||
2345 | /* determine how many bits. | |
2346 | */ | |
2347 | nb = nwords << L2DBWORD; | |
2348 | ||
2349 | /* now update the appropriate leaves to reflect | |
2350 | * the freed words. | |
2351 | */ | |
2352 | for (; nwords > 0; nwords -= nw) { | |
2353 | /* determine what the leaf value should be | |
2354 | * updated to as the minimum of the l2 number | |
2355 | * of bits being freed and the l2 (max) number | |
2356 | * of bits that can be described by this leaf. | |
2357 | */ | |
2358 | size = | |
2359 | min(LITOL2BSZ | |
2360 | (word, L2LPERDMAP, BUDMIN), | |
2361 | NLSTOL2BSZ(nwords)); | |
2362 | ||
2363 | /* update the leaf. | |
2364 | */ | |
56d12549 DK |
2365 | rc = dbJoin(tp, word, size); |
2366 | if (rc) | |
2367 | return rc; | |
1da177e4 LT |
2368 | |
2369 | /* get the number of dmap words handled. | |
2370 | */ | |
2371 | nw = BUDSIZE(size, BUDMIN); | |
2372 | word += nw; | |
2373 | } | |
2374 | } | |
2375 | } | |
2376 | ||
2377 | /* update the free count for this dmap. | |
2378 | */ | |
89145622 | 2379 | le32_add_cpu(&dp->nfree, nblocks); |
1da177e4 LT |
2380 | |
2381 | BMAP_LOCK(bmp); | |
2382 | ||
63f83c9f | 2383 | /* update the free count for the allocation group and |
1da177e4 LT |
2384 | * map. |
2385 | */ | |
2386 | agno = blkno >> bmp->db_agl2size; | |
2387 | bmp->db_nfree += nblocks; | |
2388 | bmp->db_agfree[agno] += nblocks; | |
2389 | ||
2390 | /* check if this allocation group is not completely free and | |
2391 | * if it is currently the maximum (rightmost) allocation group. | |
2392 | * if so, establish the new maximum allocation group number by | |
2393 | * searching left for the first allocation group with allocation. | |
2394 | */ | |
2395 | if ((bmp->db_agfree[agno] == bmp->db_agsize && agno == bmp->db_maxag) || | |
2396 | (agno == bmp->db_numag - 1 && | |
2397 | bmp->db_agfree[agno] == (bmp-> db_mapsize & (BPERDMAP - 1)))) { | |
2398 | while (bmp->db_maxag > 0) { | |
2399 | bmp->db_maxag -= 1; | |
2400 | if (bmp->db_agfree[bmp->db_maxag] != | |
2401 | bmp->db_agsize) | |
2402 | break; | |
2403 | } | |
2404 | ||
2405 | /* re-establish the allocation group preference if the | |
2406 | * current preference is right of the maximum allocation | |
2407 | * group. | |
2408 | */ | |
2409 | if (bmp->db_agpref > bmp->db_maxag) | |
2410 | bmp->db_agpref = bmp->db_maxag; | |
2411 | } | |
2412 | ||
2413 | BMAP_UNLOCK(bmp); | |
56d12549 DK |
2414 | |
2415 | return 0; | |
1da177e4 LT |
2416 | } |
2417 | ||
2418 | ||
2419 | /* | |
2420 | * NAME: dbAdjCtl() | |
2421 | * | |
2422 | * FUNCTION: adjust a dmap control page at a specified level to reflect | |
2423 | * the change in a lower level dmap or dmap control page's | |
2424 | * maximum string of free blocks (i.e. a change in the root | |
2425 | * of the lower level object's dmtree) due to the allocation | |
2426 | * or deallocation of a range of blocks with a single dmap. | |
2427 | * | |
2428 | * on entry, this routine is provided with the new value of | |
2429 | * the lower level dmap or dmap control page root and the | |
2430 | * starting block number of the block range whose allocation | |
2431 | * or deallocation resulted in the root change. this range | |
2432 | * is respresented by a single leaf of the current dmapctl | |
2433 | * and the leaf will be updated with this value, possibly | |
63f83c9f | 2434 | * causing a binary buddy system within the leaves to be |
1da177e4 LT |
2435 | * split or joined. the update may also cause the dmapctl's |
2436 | * dmtree to be updated. | |
2437 | * | |
2438 | * if the adjustment of the dmap control page, itself, causes its | |
2439 | * root to change, this change will be bubbled up to the next dmap | |
2440 | * control level by a recursive call to this routine, specifying | |
2441 | * the new root value and the next dmap control page level to | |
2442 | * be adjusted. | |
2443 | * PARAMETERS: | |
f720e3ba DK |
2444 | * bmp - pointer to bmap descriptor |
2445 | * blkno - the first block of a block range within a dmap. it is | |
1da177e4 LT |
2446 | * the allocation or deallocation of this block range that |
2447 | * requires the dmap control page to be adjusted. | |
f720e3ba | 2448 | * newval - the new value of the lower level dmap or dmap control |
1da177e4 | 2449 | * page root. |
f720e3ba DK |
2450 | * alloc - 'true' if adjustment is due to an allocation. |
2451 | * level - current level of dmap control page (i.e. L0, L1, L2) to | |
1da177e4 LT |
2452 | * be adjusted. |
2453 | * | |
2454 | * RETURN VALUES: | |
f720e3ba DK |
2455 | * 0 - success |
2456 | * -EIO - i/o error | |
1da177e4 LT |
2457 | * |
2458 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2459 | */ | |
2460 | static int | |
2461 | dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level) | |
2462 | { | |
2463 | struct metapage *mp; | |
2464 | s8 oldroot; | |
2465 | int oldval; | |
2466 | s64 lblkno; | |
2467 | struct dmapctl *dcp; | |
2468 | int rc, leafno, ti; | |
2469 | ||
2470 | /* get the buffer for the dmap control page for the specified | |
2471 | * block number and control page level. | |
2472 | */ | |
2473 | lblkno = BLKTOCTL(blkno, bmp->db_l2nbperpage, level); | |
2474 | mp = read_metapage(bmp->db_ipbmap, lblkno, PSIZE, 0); | |
2475 | if (mp == NULL) | |
2476 | return -EIO; | |
2477 | dcp = (struct dmapctl *) mp->data; | |
2478 | ||
2479 | if (dcp->leafidx != cpu_to_le32(CTLLEAFIND)) { | |
eb8630d7 | 2480 | jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n"); |
1da177e4 LT |
2481 | release_metapage(mp); |
2482 | return -EIO; | |
2483 | } | |
2484 | ||
2485 | /* determine the leaf number corresponding to the block and | |
2486 | * the index within the dmap control tree. | |
2487 | */ | |
2488 | leafno = BLKTOCTLLEAF(blkno, dcp->budmin); | |
2489 | ti = leafno + le32_to_cpu(dcp->leafidx); | |
2490 | ||
2491 | /* save the current leaf value and the current root level (i.e. | |
2492 | * maximum l2 free string described by this dmapctl). | |
2493 | */ | |
2494 | oldval = dcp->stree[ti]; | |
2495 | oldroot = dcp->stree[ROOT]; | |
2496 | ||
2497 | /* check if this is a control page update for an allocation. | |
2498 | * if so, update the leaf to reflect the new leaf value using | |
88393161 | 2499 | * dbSplit(); otherwise (deallocation), use dbJoin() to update |
1da177e4 LT |
2500 | * the leaf with the new value. in addition to updating the |
2501 | * leaf, dbSplit() will also split the binary buddy system of | |
2502 | * the leaves, if required, and bubble new values within the | |
2503 | * dmapctl tree, if required. similarly, dbJoin() will join | |
2504 | * the binary buddy system of leaves and bubble new values up | |
2505 | * the dmapctl tree as required by the new leaf value. | |
2506 | */ | |
2507 | if (alloc) { | |
2508 | /* check if we are in the middle of a binary buddy | |
2509 | * system. this happens when we are performing the | |
2510 | * first allocation out of an allocation group that | |
2511 | * is part (not the first part) of a larger binary | |
2512 | * buddy system. if we are in the middle, back split | |
2513 | * the system prior to calling dbSplit() which assumes | |
2514 | * that it is at the front of a binary buddy system. | |
2515 | */ | |
2516 | if (oldval == NOFREE) { | |
b6a47fd8 | 2517 | rc = dbBackSplit((dmtree_t *) dcp, leafno); |
751341b4 DL |
2518 | if (rc) { |
2519 | release_metapage(mp); | |
b6a47fd8 | 2520 | return rc; |
751341b4 | 2521 | } |
1da177e4 LT |
2522 | oldval = dcp->stree[ti]; |
2523 | } | |
2524 | dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval); | |
2525 | } else { | |
56d12549 | 2526 | rc = dbJoin((dmtree_t *) dcp, leafno, newval); |
751341b4 DL |
2527 | if (rc) { |
2528 | release_metapage(mp); | |
56d12549 | 2529 | return rc; |
751341b4 | 2530 | } |
1da177e4 LT |
2531 | } |
2532 | ||
2533 | /* check if the root of the current dmap control page changed due | |
2534 | * to the update and if the current dmap control page is not at | |
2535 | * the current top level (i.e. L0, L1, L2) of the map. if so (i.e. | |
2536 | * root changed and this is not the top level), call this routine | |
2537 | * again (recursion) for the next higher level of the mapping to | |
2538 | * reflect the change in root for the current dmap control page. | |
2539 | */ | |
2540 | if (dcp->stree[ROOT] != oldroot) { | |
2541 | /* are we below the top level of the map. if so, | |
2542 | * bubble the root up to the next higher level. | |
2543 | */ | |
2544 | if (level < bmp->db_maxlevel) { | |
2545 | /* bubble up the new root of this dmap control page to | |
2546 | * the next level. | |
2547 | */ | |
2548 | if ((rc = | |
2549 | dbAdjCtl(bmp, blkno, dcp->stree[ROOT], alloc, | |
2550 | level + 1))) { | |
2551 | /* something went wrong in bubbling up the new | |
2552 | * root value, so backout the changes to the | |
2553 | * current dmap control page. | |
2554 | */ | |
2555 | if (alloc) { | |
2556 | dbJoin((dmtree_t *) dcp, leafno, | |
2557 | oldval); | |
2558 | } else { | |
2559 | /* the dbJoin() above might have | |
2560 | * caused a larger binary buddy system | |
2561 | * to form and we may now be in the | |
2562 | * middle of it. if this is the case, | |
2563 | * back split the buddies. | |
2564 | */ | |
2565 | if (dcp->stree[ti] == NOFREE) | |
2566 | dbBackSplit((dmtree_t *) | |
2567 | dcp, leafno); | |
2568 | dbSplit((dmtree_t *) dcp, leafno, | |
2569 | dcp->budmin, oldval); | |
2570 | } | |
2571 | ||
2572 | /* release the buffer and return the error. | |
2573 | */ | |
2574 | release_metapage(mp); | |
2575 | return (rc); | |
2576 | } | |
2577 | } else { | |
2578 | /* we're at the top level of the map. update | |
2579 | * the bmap control page to reflect the size | |
2580 | * of the maximum free buddy system. | |
2581 | */ | |
2582 | assert(level == bmp->db_maxlevel); | |
2583 | if (bmp->db_maxfreebud != oldroot) { | |
2584 | jfs_error(bmp->db_ipbmap->i_sb, | |
eb8630d7 | 2585 | "the maximum free buddy is not the old root\n"); |
1da177e4 LT |
2586 | } |
2587 | bmp->db_maxfreebud = dcp->stree[ROOT]; | |
2588 | } | |
2589 | } | |
2590 | ||
2591 | /* write the buffer. | |
2592 | */ | |
2593 | write_metapage(mp); | |
2594 | ||
2595 | return (0); | |
2596 | } | |
2597 | ||
2598 | ||
2599 | /* | |
2600 | * NAME: dbSplit() | |
2601 | * | |
f720e3ba | 2602 | * FUNCTION: update the leaf of a dmtree with a new value, splitting |
1da177e4 LT |
2603 | * the leaf from the binary buddy system of the dmtree's |
2604 | * leaves, as required. | |
2605 | * | |
2606 | * PARAMETERS: | |
f720e3ba DK |
2607 | * tp - pointer to the tree containing the leaf. |
2608 | * leafno - the number of the leaf to be updated. | |
2609 | * splitsz - the size the binary buddy system starting at the leaf | |
1da177e4 | 2610 | * must be split to, specified as the log2 number of blocks. |
f720e3ba | 2611 | * newval - the new value for the leaf. |
1da177e4 LT |
2612 | * |
2613 | * RETURN VALUES: none | |
2614 | * | |
2615 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2616 | */ | |
2617 | static void dbSplit(dmtree_t * tp, int leafno, int splitsz, int newval) | |
2618 | { | |
2619 | int budsz; | |
2620 | int cursz; | |
2621 | s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); | |
2622 | ||
2623 | /* check if the leaf needs to be split. | |
2624 | */ | |
2625 | if (leaf[leafno] > tp->dmt_budmin) { | |
2626 | /* the split occurs by cutting the buddy system in half | |
2627 | * at the specified leaf until we reach the specified | |
2628 | * size. pick up the starting split size (current size | |
2629 | * - 1 in l2) and the corresponding buddy size. | |
2630 | */ | |
2631 | cursz = leaf[leafno] - 1; | |
2632 | budsz = BUDSIZE(cursz, tp->dmt_budmin); | |
2633 | ||
2634 | /* split until we reach the specified size. | |
2635 | */ | |
2636 | while (cursz >= splitsz) { | |
2637 | /* update the buddy's leaf with its new value. | |
2638 | */ | |
2639 | dbAdjTree(tp, leafno ^ budsz, cursz); | |
2640 | ||
2641 | /* on to the next size and buddy. | |
2642 | */ | |
2643 | cursz -= 1; | |
2644 | budsz >>= 1; | |
2645 | } | |
2646 | } | |
2647 | ||
63f83c9f | 2648 | /* adjust the dmap tree to reflect the specified leaf's new |
1da177e4 LT |
2649 | * value. |
2650 | */ | |
2651 | dbAdjTree(tp, leafno, newval); | |
2652 | } | |
2653 | ||
2654 | ||
2655 | /* | |
2656 | * NAME: dbBackSplit() | |
2657 | * | |
f720e3ba | 2658 | * FUNCTION: back split the binary buddy system of dmtree leaves |
1da177e4 LT |
2659 | * that hold a specified leaf until the specified leaf |
2660 | * starts its own binary buddy system. | |
2661 | * | |
2662 | * the allocators typically perform allocations at the start | |
2663 | * of binary buddy systems and dbSplit() is used to accomplish | |
2664 | * any required splits. in some cases, however, allocation | |
2665 | * may occur in the middle of a binary system and requires a | |
2666 | * back split, with the split proceeding out from the middle of | |
2667 | * the system (less efficient) rather than the start of the | |
2668 | * system (more efficient). the cases in which a back split | |
2669 | * is required are rare and are limited to the first allocation | |
2670 | * within an allocation group which is a part (not first part) | |
2671 | * of a larger binary buddy system and a few exception cases | |
2672 | * in which a previous join operation must be backed out. | |
2673 | * | |
2674 | * PARAMETERS: | |
f720e3ba DK |
2675 | * tp - pointer to the tree containing the leaf. |
2676 | * leafno - the number of the leaf to be updated. | |
1da177e4 LT |
2677 | * |
2678 | * RETURN VALUES: none | |
2679 | * | |
2680 | * serialization: IREAD_LOCK(ipbmap) or IWRITE_LOCK(ipbmap) held on entry/exit; | |
2681 | */ | |
b6a47fd8 | 2682 | static int dbBackSplit(dmtree_t * tp, int leafno) |
1da177e4 LT |
2683 | { |
2684 | int budsz, bud, w, bsz, size; | |
2685 | int cursz; | |
2686 | s8 *leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); | |
2687 | ||
2688 | /* leaf should be part (not first part) of a binary | |
2689 | * buddy system. | |
2690 | */ | |
2691 | assert(leaf[leafno] == NOFREE); | |
2692 | ||
2693 | /* the back split is accomplished by iteratively finding the leaf | |
2694 | * that starts the buddy system that contains the specified leaf and | |
2695 | * splitting that system in two. this iteration continues until | |
63f83c9f | 2696 | * the specified leaf becomes the start of a buddy system. |
1da177e4 LT |
2697 | * |
2698 | * determine maximum possible l2 size for the specified leaf. | |
2699 | */ | |
2700 | size = | |
2701 | LITOL2BSZ(leafno, le32_to_cpu(tp->dmt_l2nleafs), | |
2702 | tp->dmt_budmin); | |
2703 | ||
2704 | /* determine the number of leaves covered by this size. this | |
2705 | * is the buddy size that we will start with as we search for | |
2706 | * the buddy system that contains the specified leaf. | |
2707 | */ | |
2708 | budsz = BUDSIZE(size, tp->dmt_budmin); | |
2709 | ||
2710 | /* back split. | |
2711 | */ | |
2712 | while (leaf[leafno] == NOFREE) { | |
2713 | /* find the leftmost buddy leaf. | |
2714 | */ | |
2715 | for (w = leafno, bsz = budsz;; bsz <<= 1, | |
2716 | w = (w < bud) ? w : bud) { | |
b6a47fd8 DK |
2717 | if (bsz >= le32_to_cpu(tp->dmt_nleafs)) { |
2718 | jfs_err("JFS: block map error in dbBackSplit"); | |
2719 | return -EIO; | |
2720 | } | |
1da177e4 LT |
2721 | |
2722 | /* determine the buddy. | |
2723 | */ | |
2724 | bud = w ^ bsz; | |
2725 | ||
2726 | /* check if this buddy is the start of the system. | |
2727 | */ | |
2728 | if (leaf[bud] != NOFREE) { | |
2729 | /* split the leaf at the start of the | |
2730 | * system in two. | |
2731 | */ | |
2732 | cursz = leaf[bud] - 1; | |
2733 | dbSplit(tp, bud, cursz, cursz); | |
2734 | break; | |
2735 | } | |
2736 | } | |
2737 | } | |
2738 | ||
b6a47fd8 DK |
2739 | if (leaf[leafno] != size) { |
2740 | jfs_err("JFS: wrong leaf value in dbBackSplit"); | |
2741 | return -EIO; | |
2742 | } | |
2743 | return 0; | |
1da177e4 LT |
2744 | } |
2745 | ||
2746 | ||
2747 | /* | |
2748 | * NAME: dbJoin() | |
2749 | * | |
f720e3ba | 2750 | * FUNCTION: update the leaf of a dmtree with a new value, joining |
1da177e4 LT |
2751 | * the leaf with other leaves of the dmtree into a multi-leaf |
2752 | * binary buddy system, as required. | |
2753 | * | |
2754 | * PARAMETERS: | |
f720e3ba DK |
2755 | * tp - pointer to the tree containing the leaf. |
2756 | * leafno - the number of the leaf to be updated. | |
2757 | * newval - the new value for the leaf. | |
1da177e4 LT |
2758 | * |
2759 | * RETURN VALUES: none | |
2760 | */ | |
56d12549 | 2761 | static int dbJoin(dmtree_t * tp, int leafno, int newval) |
1da177e4 LT |
2762 | { |
2763 | int budsz, buddy; | |
2764 | s8 *leaf; | |
2765 | ||
2766 | /* can the new leaf value require a join with other leaves ? | |
2767 | */ | |
2768 | if (newval >= tp->dmt_budmin) { | |
2769 | /* pickup a pointer to the leaves of the tree. | |
2770 | */ | |
2771 | leaf = tp->dmt_stree + le32_to_cpu(tp->dmt_leafidx); | |
2772 | ||
2773 | /* try to join the specified leaf into a large binary | |
2774 | * buddy system. the join proceeds by attempting to join | |
2775 | * the specified leafno with its buddy (leaf) at new value. | |
2776 | * if the join occurs, we attempt to join the left leaf | |
2777 | * of the joined buddies with its buddy at new value + 1. | |
2778 | * we continue to join until we find a buddy that cannot be | |
2779 | * joined (does not have a value equal to the size of the | |
2780 | * last join) or until all leaves have been joined into a | |
2781 | * single system. | |
2782 | * | |
2783 | * get the buddy size (number of words covered) of | |
2784 | * the new value. | |
2785 | */ | |
2786 | budsz = BUDSIZE(newval, tp->dmt_budmin); | |
2787 | ||
2788 | /* try to join. | |
2789 | */ | |
2790 | while (budsz < le32_to_cpu(tp->dmt_nleafs)) { | |
2791 | /* get the buddy leaf. | |
2792 | */ | |
2793 | buddy = leafno ^ budsz; | |
2794 | ||
2795 | /* if the leaf's new value is greater than its | |
2796 | * buddy's value, we join no more. | |
2797 | */ | |
2798 | if (newval > leaf[buddy]) | |
2799 | break; | |
2800 | ||
56d12549 DK |
2801 | /* It shouldn't be less */ |
2802 | if (newval < leaf[buddy]) | |
2803 | return -EIO; | |
1da177e4 LT |
2804 | |
2805 | /* check which (leafno or buddy) is the left buddy. | |
2806 | * the left buddy gets to claim the blocks resulting | |
2807 | * from the join while the right gets to claim none. | |
25985edc | 2808 | * the left buddy is also eligible to participate in |
1da177e4 LT |
2809 | * a join at the next higher level while the right |
2810 | * is not. | |
2811 | * | |
2812 | */ | |
2813 | if (leafno < buddy) { | |
2814 | /* leafno is the left buddy. | |
2815 | */ | |
2816 | dbAdjTree(tp, buddy, NOFREE); | |
2817 | } else { | |
2818 | /* buddy is the left buddy and becomes | |
2819 | * leafno. | |
2820 | */ | |
2821 | dbAdjTree(tp, leafno, NOFREE); | |
2822 | leafno = buddy; | |
2823 | } | |
2824 | ||
2825 | /* on to try the next join. | |
2826 | */ | |
2827 | newval += 1; | |
2828 | budsz <<= 1; | |
2829 | } | |
2830 | } | |
2831 | ||
2832 | /* update the leaf value. | |
2833 | */ | |
2834 | dbAdjTree(tp, leafno, newval); | |
56d12549 DK |
2835 | |
2836 | return 0; | |
1da177e4 LT |
2837 | } |
2838 | ||
2839 | ||
2840 | /* | |
2841 | * NAME: dbAdjTree() | |
2842 | * | |
f720e3ba | 2843 | * FUNCTION: update a leaf of a dmtree with a new value, adjusting |
1da177e4 LT |
2844 | * the dmtree, as required, to reflect the new leaf value. |
2845 | * the combination of any buddies must already be done before | |
2846 | * this is called. | |
2847 | * | |
2848 | * PARAMETERS: | |
f720e3ba DK |
2849 | * tp - pointer to the tree to be adjusted. |
2850 | * leafno - the number of the leaf to be updated. | |
2851 | * newval - the new value for the leaf. | |
1da177e4 LT |
2852 | * |
2853 | * RETURN VALUES: none | |
2854 | */ | |
2855 | static void dbAdjTree(dmtree_t * tp, int leafno, int newval) | |
2856 | { | |
2857 | int lp, pp, k; | |
2858 | int max; | |
2859 | ||
2860 | /* pick up the index of the leaf for this leafno. | |
2861 | */ | |
2862 | lp = leafno + le32_to_cpu(tp->dmt_leafidx); | |
2863 | ||
2864 | /* is the current value the same as the old value ? if so, | |
2865 | * there is nothing to do. | |
2866 | */ | |
2867 | if (tp->dmt_stree[lp] == newval) | |
2868 | return; | |
2869 | ||
2870 | /* set the new value. | |
2871 | */ | |
2872 | tp->dmt_stree[lp] = newval; | |
2873 | ||
2874 | /* bubble the new value up the tree as required. | |
2875 | */ | |
2876 | for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) { | |
2877 | /* get the index of the first leaf of the 4 leaf | |
2878 | * group containing the specified leaf (leafno). | |
2879 | */ | |
2880 | lp = ((lp - 1) & ~0x03) + 1; | |
2881 | ||
2882 | /* get the index of the parent of this 4 leaf group. | |
2883 | */ | |
2884 | pp = (lp - 1) >> 2; | |
2885 | ||
2886 | /* determine the maximum of the 4 leaves. | |
2887 | */ | |
2888 | max = TREEMAX(&tp->dmt_stree[lp]); | |
2889 | ||
2890 | /* if the maximum of the 4 is the same as the | |
2891 | * parent's value, we're done. | |
2892 | */ | |
2893 | if (tp->dmt_stree[pp] == max) | |
2894 | break; | |
2895 | ||
2896 | /* parent gets new value. | |
2897 | */ | |
2898 | tp->dmt_stree[pp] = max; | |
2899 | ||
2900 | /* parent becomes leaf for next go-round. | |
2901 | */ | |
2902 | lp = pp; | |
2903 | } | |
2904 | } | |
2905 | ||
2906 | ||
2907 | /* | |
2908 | * NAME: dbFindLeaf() | |
2909 | * | |
f720e3ba | 2910 | * FUNCTION: search a dmtree_t for sufficient free blocks, returning |
63f83c9f | 2911 | * the index of a leaf describing the free blocks if |
1da177e4 LT |
2912 | * sufficient free blocks are found. |
2913 | * | |
2914 | * the search starts at the top of the dmtree_t tree and | |
2915 | * proceeds down the tree to the leftmost leaf with sufficient | |
2916 | * free space. | |
2917 | * | |
2918 | * PARAMETERS: | |
f720e3ba DK |
2919 | * tp - pointer to the tree to be searched. |
2920 | * l2nb - log2 number of free blocks to search for. | |
1da177e4 LT |
2921 | * leafidx - return pointer to be set to the index of the leaf |
2922 | * describing at least l2nb free blocks if sufficient | |
2923 | * free blocks are found. | |
2924 | * | |
2925 | * RETURN VALUES: | |
f720e3ba DK |
2926 | * 0 - success |
2927 | * -ENOSPC - insufficient free blocks. | |
1da177e4 LT |
2928 | */ |
2929 | static int dbFindLeaf(dmtree_t * tp, int l2nb, int *leafidx) | |
2930 | { | |
2931 | int ti, n = 0, k, x = 0; | |
2932 | ||
2933 | /* first check the root of the tree to see if there is | |
2934 | * sufficient free space. | |
2935 | */ | |
2936 | if (l2nb > tp->dmt_stree[ROOT]) | |
2937 | return -ENOSPC; | |
2938 | ||
2939 | /* sufficient free space available. now search down the tree | |
2940 | * starting at the next level for the leftmost leaf that | |
2941 | * describes sufficient free space. | |
2942 | */ | |
2943 | for (k = le32_to_cpu(tp->dmt_height), ti = 1; | |
2944 | k > 0; k--, ti = ((ti + n) << 2) + 1) { | |
2945 | /* search the four nodes at this level, starting from | |
2946 | * the left. | |
2947 | */ | |
2948 | for (x = ti, n = 0; n < 4; n++) { | |
2949 | /* sufficient free space found. move to the next | |
2950 | * level (or quit if this is the last level). | |
2951 | */ | |
2952 | if (l2nb <= tp->dmt_stree[x + n]) | |
2953 | break; | |
2954 | } | |
2955 | ||
2956 | /* better have found something since the higher | |
2957 | * levels of the tree said it was here. | |
2958 | */ | |
2959 | assert(n < 4); | |
2960 | } | |
2961 | ||
2962 | /* set the return to the leftmost leaf describing sufficient | |
2963 | * free space. | |
2964 | */ | |
2965 | *leafidx = x + n - le32_to_cpu(tp->dmt_leafidx); | |
2966 | ||
2967 | return (0); | |
2968 | } | |
2969 | ||
2970 | ||
2971 | /* | |
2972 | * NAME: dbFindBits() | |
2973 | * | |
f720e3ba | 2974 | * FUNCTION: find a specified number of binary buddy free bits within a |
1da177e4 LT |
2975 | * dmap bitmap word value. |
2976 | * | |
2977 | * this routine searches the bitmap value for (1 << l2nb) free | |
2978 | * bits at (1 << l2nb) alignments within the value. | |
2979 | * | |
2980 | * PARAMETERS: | |
f720e3ba DK |
2981 | * word - dmap bitmap word value. |
2982 | * l2nb - number of free bits specified as a log2 number. | |
1da177e4 LT |
2983 | * |
2984 | * RETURN VALUES: | |
f720e3ba | 2985 | * starting bit number of free bits. |
1da177e4 LT |
2986 | */ |
2987 | static int dbFindBits(u32 word, int l2nb) | |
2988 | { | |
2989 | int bitno, nb; | |
2990 | u32 mask; | |
2991 | ||
2992 | /* get the number of bits. | |
2993 | */ | |
2994 | nb = 1 << l2nb; | |
2995 | assert(nb <= DBWORD); | |
2996 | ||
2997 | /* complement the word so we can use a mask (i.e. 0s represent | |
2998 | * free bits) and compute the mask. | |
2999 | */ | |
3000 | word = ~word; | |
3001 | mask = ONES << (DBWORD - nb); | |
3002 | ||
3003 | /* scan the word for nb free bits at nb alignments. | |
3004 | */ | |
3005 | for (bitno = 0; mask != 0; bitno += nb, mask >>= nb) { | |
3006 | if ((mask & word) == mask) | |
3007 | break; | |
3008 | } | |
3009 | ||
3010 | ASSERT(bitno < 32); | |
3011 | ||
3012 | /* return the bit number. | |
3013 | */ | |
3014 | return (bitno); | |
3015 | } | |
3016 | ||
3017 | ||
3018 | /* | |
3019 | * NAME: dbMaxBud(u8 *cp) | |
3020 | * | |
f720e3ba | 3021 | * FUNCTION: determine the largest binary buddy string of free |
1da177e4 LT |
3022 | * bits within 32-bits of the map. |
3023 | * | |
3024 | * PARAMETERS: | |
f720e3ba | 3025 | * cp - pointer to the 32-bit value. |
1da177e4 LT |
3026 | * |
3027 | * RETURN VALUES: | |
f720e3ba | 3028 | * largest binary buddy of free bits within a dmap word. |
1da177e4 LT |
3029 | */ |
3030 | static int dbMaxBud(u8 * cp) | |
3031 | { | |
3032 | signed char tmp1, tmp2; | |
3033 | ||
3034 | /* check if the wmap word is all free. if so, the | |
3035 | * free buddy size is BUDMIN. | |
3036 | */ | |
3037 | if (*((uint *) cp) == 0) | |
3038 | return (BUDMIN); | |
3039 | ||
3040 | /* check if the wmap word is half free. if so, the | |
3041 | * free buddy size is BUDMIN-1. | |
3042 | */ | |
3043 | if (*((u16 *) cp) == 0 || *((u16 *) cp + 1) == 0) | |
3044 | return (BUDMIN - 1); | |
3045 | ||
3046 | /* not all free or half free. determine the free buddy | |
3047 | * size thru table lookup using quarters of the wmap word. | |
3048 | */ | |
3049 | tmp1 = max(budtab[cp[2]], budtab[cp[3]]); | |
3050 | tmp2 = max(budtab[cp[0]], budtab[cp[1]]); | |
3051 | return (max(tmp1, tmp2)); | |
3052 | } | |
3053 | ||
3054 | ||
3055 | /* | |
3056 | * NAME: cnttz(uint word) | |
3057 | * | |
f720e3ba | 3058 | * FUNCTION: determine the number of trailing zeros within a 32-bit |
1da177e4 LT |
3059 | * value. |
3060 | * | |
3061 | * PARAMETERS: | |
f720e3ba | 3062 | * value - 32-bit value to be examined. |
1da177e4 LT |
3063 | * |
3064 | * RETURN VALUES: | |
f720e3ba | 3065 | * count of trailing zeros |
1da177e4 LT |
3066 | */ |
3067 | static int cnttz(u32 word) | |
3068 | { | |
3069 | int n; | |
3070 | ||
3071 | for (n = 0; n < 32; n++, word >>= 1) { | |
3072 | if (word & 0x01) | |
3073 | break; | |
3074 | } | |
3075 | ||
3076 | return (n); | |
3077 | } | |
3078 | ||
3079 | ||
3080 | /* | |
3081 | * NAME: cntlz(u32 value) | |
3082 | * | |
f720e3ba | 3083 | * FUNCTION: determine the number of leading zeros within a 32-bit |
1da177e4 LT |
3084 | * value. |
3085 | * | |
3086 | * PARAMETERS: | |
f720e3ba | 3087 | * value - 32-bit value to be examined. |
1da177e4 LT |
3088 | * |
3089 | * RETURN VALUES: | |
f720e3ba | 3090 | * count of leading zeros |
1da177e4 LT |
3091 | */ |
3092 | static int cntlz(u32 value) | |
3093 | { | |
3094 | int n; | |
3095 | ||
3096 | for (n = 0; n < 32; n++, value <<= 1) { | |
3097 | if (value & HIGHORDER) | |
3098 | break; | |
3099 | } | |
3100 | return (n); | |
3101 | } | |
3102 | ||
3103 | ||
3104 | /* | |
3105 | * NAME: blkstol2(s64 nb) | |
3106 | * | |
3107 | * FUNCTION: convert a block count to its log2 value. if the block | |
f720e3ba | 3108 | * count is not a l2 multiple, it is rounded up to the next |
1da177e4 LT |
3109 | * larger l2 multiple. |
3110 | * | |
3111 | * PARAMETERS: | |
f720e3ba | 3112 | * nb - number of blocks |
1da177e4 LT |
3113 | * |
3114 | * RETURN VALUES: | |
f720e3ba | 3115 | * log2 number of blocks |
1da177e4 | 3116 | */ |
6cb1269b | 3117 | static int blkstol2(s64 nb) |
1da177e4 LT |
3118 | { |
3119 | int l2nb; | |
3120 | s64 mask; /* meant to be signed */ | |
3121 | ||
3122 | mask = (s64) 1 << (64 - 1); | |
3123 | ||
3124 | /* count the leading bits. | |
3125 | */ | |
3126 | for (l2nb = 0; l2nb < 64; l2nb++, mask >>= 1) { | |
3127 | /* leading bit found. | |
3128 | */ | |
3129 | if (nb & mask) { | |
3130 | /* determine the l2 value. | |
3131 | */ | |
3132 | l2nb = (64 - 1) - l2nb; | |
3133 | ||
3134 | /* check if we need to round up. | |
3135 | */ | |
3136 | if (~mask & nb) | |
3137 | l2nb++; | |
3138 | ||
3139 | return (l2nb); | |
3140 | } | |
3141 | } | |
3142 | assert(0); | |
3143 | return 0; /* fix compiler warning */ | |
3144 | } | |
3145 | ||
3146 | ||
3147 | /* | |
63f83c9f | 3148 | * NAME: dbAllocBottomUp() |
1da177e4 LT |
3149 | * |
3150 | * FUNCTION: alloc the specified block range from the working block | |
3151 | * allocation map. | |
3152 | * | |
3153 | * the blocks will be alloc from the working map one dmap | |
3154 | * at a time. | |
3155 | * | |
3156 | * PARAMETERS: | |
f720e3ba DK |
3157 | * ip - pointer to in-core inode; |
3158 | * blkno - starting block number to be freed. | |
3159 | * nblocks - number of blocks to be freed. | |
1da177e4 LT |
3160 | * |
3161 | * RETURN VALUES: | |
f720e3ba DK |
3162 | * 0 - success |
3163 | * -EIO - i/o error | |
1da177e4 LT |
3164 | */ |
3165 | int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks) | |
3166 | { | |
3167 | struct metapage *mp; | |
3168 | struct dmap *dp; | |
3169 | int nb, rc; | |
3170 | s64 lblkno, rem; | |
3171 | struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap; | |
3172 | struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap; | |
3173 | ||
82d5b9a7 | 3174 | IREAD_LOCK(ipbmap, RDWRLOCK_DMAP); |
1da177e4 LT |
3175 | |
3176 | /* block to be allocated better be within the mapsize. */ | |
3177 | ASSERT(nblocks <= bmp->db_mapsize - blkno); | |
3178 | ||
3179 | /* | |
3180 | * allocate the blocks a dmap at a time. | |
3181 | */ | |
3182 | mp = NULL; | |
3183 | for (rem = nblocks; rem > 0; rem -= nb, blkno += nb) { | |
3184 | /* release previous dmap if any */ | |
3185 | if (mp) { | |
3186 | write_metapage(mp); | |
3187 | } | |
3188 | ||
3189 | /* get the buffer for the current dmap. */ | |
3190 | lblkno = BLKTODMAP(blkno, bmp->db_l2nbperpage); | |
3191 | mp = read_metapage(ipbmap, lblkno, PSIZE, 0); | |
3192 | if (mp == NULL) { | |
3193 | IREAD_UNLOCK(ipbmap); | |
3194 | return -EIO; | |
3195 | } | |
3196 | dp = (struct dmap *) mp->data; | |
3197 | ||
3198 | /* determine the number of blocks to be allocated from | |
3199 | * this dmap. | |
3200 | */ | |
3201 | nb = min(rem, BPERDMAP - (blkno & (BPERDMAP - 1))); | |
3202 | ||
1da177e4 LT |
3203 | /* allocate the blocks. */ |
3204 | if ((rc = dbAllocDmapBU(bmp, dp, blkno, nb))) { | |
3205 | release_metapage(mp); | |
3206 | IREAD_UNLOCK(ipbmap); | |
3207 | return (rc); | |
3208 | } | |
1da177e4 LT |
3209 | } |
3210 | ||
3211 | /* write the last buffer. */ | |
3212 | write_metapage(mp); | |
3213 | ||
3214 | IREAD_UNLOCK(ipbmap); | |
3215 | ||
3216 | return (0); | |
3217 | } | |
3218 | ||
3219 | ||
3220 | static int dbAllocDmapBU(struct bmap * bmp, struct dmap * dp, s64 blkno, | |
3221 | int nblocks) | |
3222 | { | |
3223 | int rc; | |
3224 | int dbitno, word, rembits, nb, nwords, wbitno, agno; | |
3c2c2262 | 3225 | s8 oldroot; |
1da177e4 LT |
3226 | struct dmaptree *tp = (struct dmaptree *) & dp->tree; |
3227 | ||
3228 | /* save the current value of the root (i.e. maximum free string) | |
3229 | * of the dmap tree. | |
3230 | */ | |
3231 | oldroot = tp->stree[ROOT]; | |
3232 | ||
1da177e4 LT |
3233 | /* determine the bit number and word within the dmap of the |
3234 | * starting block. | |
3235 | */ | |
3236 | dbitno = blkno & (BPERDMAP - 1); | |
3237 | word = dbitno >> L2DBWORD; | |
3238 | ||
3239 | /* block range better be within the dmap */ | |
3240 | assert(dbitno + nblocks <= BPERDMAP); | |
3241 | ||
3242 | /* allocate the bits of the dmap's words corresponding to the block | |
3243 | * range. not all bits of the first and last words may be contained | |
3244 | * within the block range. if this is the case, we'll work against | |
3245 | * those words (i.e. partial first and/or last) on an individual basis | |
3246 | * (a single pass), allocating the bits of interest by hand and | |
3247 | * updating the leaf corresponding to the dmap word. a single pass | |
3248 | * will be used for all dmap words fully contained within the | |
3249 | * specified range. within this pass, the bits of all fully contained | |
3250 | * dmap words will be marked as free in a single shot and the leaves | |
3251 | * will be updated. a single leaf may describe the free space of | |
3252 | * multiple dmap words, so we may update only a subset of the actual | |
3253 | * leaves corresponding to the dmap words of the block range. | |
3254 | */ | |
3255 | for (rembits = nblocks; rembits > 0; rembits -= nb, dbitno += nb) { | |
3256 | /* determine the bit number within the word and | |
3257 | * the number of bits within the word. | |
3258 | */ | |
3259 | wbitno = dbitno & (DBWORD - 1); | |
3260 | nb = min(rembits, DBWORD - wbitno); | |
3261 | ||
3262 | /* check if only part of a word is to be allocated. | |
3263 | */ | |
3264 | if (nb < DBWORD) { | |
3265 | /* allocate (set to 1) the appropriate bits within | |
3266 | * this dmap word. | |
3267 | */ | |
3268 | dp->wmap[word] |= cpu_to_le32(ONES << (DBWORD - nb) | |
3269 | >> wbitno); | |
3270 | ||
3271 | word++; | |
3272 | } else { | |
3273 | /* one or more dmap words are fully contained | |
3274 | * within the block range. determine how many | |
3275 | * words and allocate (set to 1) the bits of these | |
3276 | * words. | |
3277 | */ | |
3278 | nwords = rembits >> L2DBWORD; | |
3279 | memset(&dp->wmap[word], (int) ONES, nwords * 4); | |
3280 | ||
3281 | /* determine how many bits */ | |
3282 | nb = nwords << L2DBWORD; | |
3283 | word += nwords; | |
3284 | } | |
3285 | } | |
3286 | ||
3287 | /* update the free count for this dmap */ | |
89145622 | 3288 | le32_add_cpu(&dp->nfree, -nblocks); |
1da177e4 LT |
3289 | |
3290 | /* reconstruct summary tree */ | |
3291 | dbInitDmapTree(dp); | |
3292 | ||
3293 | BMAP_LOCK(bmp); | |
3294 | ||
3295 | /* if this allocation group is completely free, | |
63f83c9f | 3296 | * update the highest active allocation group number |
1da177e4 LT |
3297 | * if this allocation group is the new max. |
3298 | */ | |
3299 | agno = blkno >> bmp->db_agl2size; | |
3300 | if (agno > bmp->db_maxag) | |
3301 | bmp->db_maxag = agno; | |
3302 | ||
3303 | /* update the free count for the allocation group and map */ | |
3304 | bmp->db_agfree[agno] -= nblocks; | |
3305 | bmp->db_nfree -= nblocks; | |
3306 | ||
3307 | BMAP_UNLOCK(bmp); | |
3308 | ||
3309 | /* if the root has not changed, done. */ | |
3310 | if (tp->stree[ROOT] == oldroot) | |
3311 | return (0); | |
3312 | ||
3313 | /* root changed. bubble the change up to the dmap control pages. | |
3314 | * if the adjustment of the upper level control pages fails, | |
3315 | * backout the bit allocation (thus making everything consistent). | |
3316 | */ | |
3317 | if ((rc = dbAdjCtl(bmp, blkno, tp->stree[ROOT], 1, 0))) | |
3318 | dbFreeBits(bmp, dp, blkno, nblocks); | |
3319 | ||
3320 | return (rc); | |
3321 | } | |
3322 | ||
3323 | ||
3324 | /* | |
3325 | * NAME: dbExtendFS() | |
3326 | * | |
3327 | * FUNCTION: extend bmap from blkno for nblocks; | |
63f83c9f | 3328 | * dbExtendFS() updates bmap ready for dbAllocBottomUp(); |
1da177e4 LT |
3329 | * |
3330 | * L2 | |
3331 | * | | |
3332 | * L1---------------------------------L1 | |
f720e3ba DK |
3333 | * | | |
3334 | * L0---------L0---------L0 L0---------L0---------L0 | |
3335 | * | | | | | | | |
3336 | * d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,...,dn d0,.,dm; | |
1da177e4 LT |
3337 | * L2L1L0d0,...,dnL0d0,...,dnL0d0,...,dnL1L0d0,...,dnL0d0,...,dnL0d0,..dm |
3338 | * | |
63f83c9f | 3339 | * <---old---><----------------------------extend-----------------------> |
1da177e4 LT |
3340 | */ |
3341 | int dbExtendFS(struct inode *ipbmap, s64 blkno, s64 nblocks) | |
3342 | { | |
3343 | struct jfs_sb_info *sbi = JFS_SBI(ipbmap->i_sb); | |
3344 | int nbperpage = sbi->nbperpage; | |
4d81715f | 3345 | int i, i0 = true, j, j0 = true, k, n; |
1da177e4 LT |
3346 | s64 newsize; |
3347 | s64 p; | |
3348 | struct metapage *mp, *l2mp, *l1mp = NULL, *l0mp = NULL; | |
3349 | struct dmapctl *l2dcp, *l1dcp, *l0dcp; | |
3350 | struct dmap *dp; | |
3351 | s8 *l0leaf, *l1leaf, *l2leaf; | |
3352 | struct bmap *bmp = sbi->bmap; | |
3353 | int agno, l2agsize, oldl2agsize; | |
3354 | s64 ag_rem; | |
3355 | ||
3356 | newsize = blkno + nblocks; | |
3357 | ||
3358 | jfs_info("dbExtendFS: blkno:%Ld nblocks:%Ld newsize:%Ld", | |
3359 | (long long) blkno, (long long) nblocks, (long long) newsize); | |
3360 | ||
3361 | /* | |
f720e3ba | 3362 | * initialize bmap control page. |
1da177e4 LT |
3363 | * |
3364 | * all the data in bmap control page should exclude | |
3365 | * the mkfs hidden dmap page. | |
3366 | */ | |
3367 | ||
3368 | /* update mapsize */ | |
3369 | bmp->db_mapsize = newsize; | |
3370 | bmp->db_maxlevel = BMAPSZTOLEV(bmp->db_mapsize); | |
3371 | ||
3372 | /* compute new AG size */ | |
3373 | l2agsize = dbGetL2AGSize(newsize); | |
3374 | oldl2agsize = bmp->db_agl2size; | |
3375 | ||
3376 | bmp->db_agl2size = l2agsize; | |
3377 | bmp->db_agsize = 1 << l2agsize; | |
3378 | ||
3379 | /* compute new number of AG */ | |
3380 | agno = bmp->db_numag; | |
3381 | bmp->db_numag = newsize >> l2agsize; | |
3382 | bmp->db_numag += ((u32) newsize % (u32) bmp->db_agsize) ? 1 : 0; | |
3383 | ||
3384 | /* | |
f720e3ba | 3385 | * reconfigure db_agfree[] |
1da177e4 LT |
3386 | * from old AG configuration to new AG configuration; |
3387 | * | |
3388 | * coalesce contiguous k (newAGSize/oldAGSize) AGs; | |
3389 | * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn; | |
3390 | * note: new AG size = old AG size * (2**x). | |
3391 | */ | |
3392 | if (l2agsize == oldl2agsize) | |
3393 | goto extend; | |
3394 | k = 1 << (l2agsize - oldl2agsize); | |
3395 | ag_rem = bmp->db_agfree[0]; /* save agfree[0] */ | |
3396 | for (i = 0, n = 0; i < agno; n++) { | |
3397 | bmp->db_agfree[n] = 0; /* init collection point */ | |
3398 | ||
af901ca1 | 3399 | /* coalesce contiguous k AGs; */ |
1da177e4 LT |
3400 | for (j = 0; j < k && i < agno; j++, i++) { |
3401 | /* merge AGi to AGn */ | |
3402 | bmp->db_agfree[n] += bmp->db_agfree[i]; | |
3403 | } | |
3404 | } | |
3405 | bmp->db_agfree[0] += ag_rem; /* restore agfree[0] */ | |
3406 | ||
3407 | for (; n < MAXAG; n++) | |
3408 | bmp->db_agfree[n] = 0; | |
3409 | ||
3410 | /* | |
3411 | * update highest active ag number | |
3412 | */ | |
3413 | ||
3414 | bmp->db_maxag = bmp->db_maxag / k; | |
3415 | ||
3416 | /* | |
f720e3ba | 3417 | * extend bmap |
1da177e4 LT |
3418 | * |
3419 | * update bit maps and corresponding level control pages; | |
3420 | * global control page db_nfree, db_agfree[agno], db_maxfreebud; | |
3421 | */ | |
3422 | extend: | |
3423 | /* get L2 page */ | |
3424 | p = BMAPBLKNO + nbperpage; /* L2 page */ | |
3425 | l2mp = read_metapage(ipbmap, p, PSIZE, 0); | |
3426 | if (!l2mp) { | |
eb8630d7 | 3427 | jfs_error(ipbmap->i_sb, "L2 page could not be read\n"); |
1da177e4 LT |
3428 | return -EIO; |
3429 | } | |
3430 | l2dcp = (struct dmapctl *) l2mp->data; | |
3431 | ||
3432 | /* compute start L1 */ | |
3433 | k = blkno >> L2MAXL1SIZE; | |
3434 | l2leaf = l2dcp->stree + CTLLEAFIND + k; | |
3435 | p = BLKTOL1(blkno, sbi->l2nbperpage); /* L1 page */ | |
3436 | ||
3437 | /* | |
3438 | * extend each L1 in L2 | |
3439 | */ | |
3440 | for (; k < LPERCTL; k++, p += nbperpage) { | |
3441 | /* get L1 page */ | |
3442 | if (j0) { | |
3443 | /* read in L1 page: (blkno & (MAXL1SIZE - 1)) */ | |
3444 | l1mp = read_metapage(ipbmap, p, PSIZE, 0); | |
3445 | if (l1mp == NULL) | |
3446 | goto errout; | |
3447 | l1dcp = (struct dmapctl *) l1mp->data; | |
3448 | ||
3449 | /* compute start L0 */ | |
3450 | j = (blkno & (MAXL1SIZE - 1)) >> L2MAXL0SIZE; | |
3451 | l1leaf = l1dcp->stree + CTLLEAFIND + j; | |
3452 | p = BLKTOL0(blkno, sbi->l2nbperpage); | |
4d81715f | 3453 | j0 = false; |
1da177e4 LT |
3454 | } else { |
3455 | /* assign/init L1 page */ | |
3456 | l1mp = get_metapage(ipbmap, p, PSIZE, 0); | |
3457 | if (l1mp == NULL) | |
3458 | goto errout; | |
3459 | ||
3460 | l1dcp = (struct dmapctl *) l1mp->data; | |
3461 | ||
3462 | /* compute start L0 */ | |
3463 | j = 0; | |
3464 | l1leaf = l1dcp->stree + CTLLEAFIND; | |
f720e3ba | 3465 | p += nbperpage; /* 1st L0 of L1.k */ |
1da177e4 LT |
3466 | } |
3467 | ||
3468 | /* | |
3469 | * extend each L0 in L1 | |
3470 | */ | |
3471 | for (; j < LPERCTL; j++) { | |
3472 | /* get L0 page */ | |
3473 | if (i0) { | |
3474 | /* read in L0 page: (blkno & (MAXL0SIZE - 1)) */ | |
3475 | ||
3476 | l0mp = read_metapage(ipbmap, p, PSIZE, 0); | |
3477 | if (l0mp == NULL) | |
3478 | goto errout; | |
3479 | l0dcp = (struct dmapctl *) l0mp->data; | |
3480 | ||
3481 | /* compute start dmap */ | |
3482 | i = (blkno & (MAXL0SIZE - 1)) >> | |
3483 | L2BPERDMAP; | |
3484 | l0leaf = l0dcp->stree + CTLLEAFIND + i; | |
3485 | p = BLKTODMAP(blkno, | |
3486 | sbi->l2nbperpage); | |
4d81715f | 3487 | i0 = false; |
1da177e4 LT |
3488 | } else { |
3489 | /* assign/init L0 page */ | |
3490 | l0mp = get_metapage(ipbmap, p, PSIZE, 0); | |
3491 | if (l0mp == NULL) | |
3492 | goto errout; | |
3493 | ||
3494 | l0dcp = (struct dmapctl *) l0mp->data; | |
3495 | ||
3496 | /* compute start dmap */ | |
3497 | i = 0; | |
3498 | l0leaf = l0dcp->stree + CTLLEAFIND; | |
3499 | p += nbperpage; /* 1st dmap of L0.j */ | |
3500 | } | |
3501 | ||
3502 | /* | |
3503 | * extend each dmap in L0 | |
3504 | */ | |
3505 | for (; i < LPERCTL; i++) { | |
3506 | /* | |
3507 | * reconstruct the dmap page, and | |
3508 | * initialize corresponding parent L0 leaf | |
3509 | */ | |
3510 | if ((n = blkno & (BPERDMAP - 1))) { | |
3511 | /* read in dmap page: */ | |
3512 | mp = read_metapage(ipbmap, p, | |
3513 | PSIZE, 0); | |
3514 | if (mp == NULL) | |
3515 | goto errout; | |
3516 | n = min(nblocks, (s64)BPERDMAP - n); | |
3517 | } else { | |
3518 | /* assign/init dmap page */ | |
3519 | mp = read_metapage(ipbmap, p, | |
3520 | PSIZE, 0); | |
3521 | if (mp == NULL) | |
3522 | goto errout; | |
3523 | ||
4f65b6db | 3524 | n = min_t(s64, nblocks, BPERDMAP); |
1da177e4 LT |
3525 | } |
3526 | ||
3527 | dp = (struct dmap *) mp->data; | |
3528 | *l0leaf = dbInitDmap(dp, blkno, n); | |
3529 | ||
3530 | bmp->db_nfree += n; | |
3531 | agno = le64_to_cpu(dp->start) >> l2agsize; | |
3532 | bmp->db_agfree[agno] += n; | |
3533 | ||
3534 | write_metapage(mp); | |
3535 | ||
3536 | l0leaf++; | |
3537 | p += nbperpage; | |
3538 | ||
3539 | blkno += n; | |
3540 | nblocks -= n; | |
3541 | if (nblocks == 0) | |
3542 | break; | |
3543 | } /* for each dmap in a L0 */ | |
3544 | ||
3545 | /* | |
63f83c9f | 3546 | * build current L0 page from its leaves, and |
1da177e4 LT |
3547 | * initialize corresponding parent L1 leaf |
3548 | */ | |
3549 | *l1leaf = dbInitDmapCtl(l0dcp, 0, ++i); | |
3550 | write_metapage(l0mp); | |
3551 | l0mp = NULL; | |
3552 | ||
3553 | if (nblocks) | |
3554 | l1leaf++; /* continue for next L0 */ | |
3555 | else { | |
3556 | /* more than 1 L0 ? */ | |
3557 | if (j > 0) | |
3558 | break; /* build L1 page */ | |
3559 | else { | |
3560 | /* summarize in global bmap page */ | |
3561 | bmp->db_maxfreebud = *l1leaf; | |
3562 | release_metapage(l1mp); | |
3563 | release_metapage(l2mp); | |
3564 | goto finalize; | |
3565 | } | |
3566 | } | |
3567 | } /* for each L0 in a L1 */ | |
3568 | ||
3569 | /* | |
63f83c9f | 3570 | * build current L1 page from its leaves, and |
1da177e4 LT |
3571 | * initialize corresponding parent L2 leaf |
3572 | */ | |
3573 | *l2leaf = dbInitDmapCtl(l1dcp, 1, ++j); | |
3574 | write_metapage(l1mp); | |
3575 | l1mp = NULL; | |
3576 | ||
3577 | if (nblocks) | |
3578 | l2leaf++; /* continue for next L1 */ | |
3579 | else { | |
3580 | /* more than 1 L1 ? */ | |
3581 | if (k > 0) | |
3582 | break; /* build L2 page */ | |
3583 | else { | |
3584 | /* summarize in global bmap page */ | |
3585 | bmp->db_maxfreebud = *l2leaf; | |
3586 | release_metapage(l2mp); | |
3587 | goto finalize; | |
3588 | } | |
3589 | } | |
3590 | } /* for each L1 in a L2 */ | |
3591 | ||
eb8630d7 | 3592 | jfs_error(ipbmap->i_sb, "function has not returned as expected\n"); |
1da177e4 LT |
3593 | errout: |
3594 | if (l0mp) | |
3595 | release_metapage(l0mp); | |
3596 | if (l1mp) | |
3597 | release_metapage(l1mp); | |
3598 | release_metapage(l2mp); | |
3599 | return -EIO; | |
3600 | ||
3601 | /* | |
f720e3ba | 3602 | * finalize bmap control page |
1da177e4 LT |
3603 | */ |
3604 | finalize: | |
3605 | ||
3606 | return 0; | |
3607 | } | |
3608 | ||
3609 | ||
3610 | /* | |
3611 | * dbFinalizeBmap() | |
3612 | */ | |
3613 | void dbFinalizeBmap(struct inode *ipbmap) | |
3614 | { | |
3615 | struct bmap *bmp = JFS_SBI(ipbmap->i_sb)->bmap; | |
3616 | int actags, inactags, l2nl; | |
3617 | s64 ag_rem, actfree, inactfree, avgfree; | |
3618 | int i, n; | |
3619 | ||
3620 | /* | |
f720e3ba | 3621 | * finalize bmap control page |
1da177e4 LT |
3622 | */ |
3623 | //finalize: | |
63f83c9f | 3624 | /* |
1da177e4 LT |
3625 | * compute db_agpref: preferred ag to allocate from |
3626 | * (the leftmost ag with average free space in it); | |
3627 | */ | |
3628 | //agpref: | |
577ebd19 | 3629 | /* get the number of active ags and inactive ags */ |
1da177e4 LT |
3630 | actags = bmp->db_maxag + 1; |
3631 | inactags = bmp->db_numag - actags; | |
3632 | ag_rem = bmp->db_mapsize & (bmp->db_agsize - 1); /* ??? */ | |
3633 | ||
3634 | /* determine how many blocks are in the inactive allocation | |
3635 | * groups. in doing this, we must account for the fact that | |
3636 | * the rightmost group might be a partial group (i.e. file | |
3637 | * system size is not a multiple of the group size). | |
3638 | */ | |
3639 | inactfree = (inactags && ag_rem) ? | |
3640 | ((inactags - 1) << bmp->db_agl2size) + ag_rem | |
3641 | : inactags << bmp->db_agl2size; | |
3642 | ||
3643 | /* determine how many free blocks are in the active | |
3644 | * allocation groups plus the average number of free blocks | |
3645 | * within the active ags. | |
3646 | */ | |
3647 | actfree = bmp->db_nfree - inactfree; | |
3648 | avgfree = (u32) actfree / (u32) actags; | |
3649 | ||
3650 | /* if the preferred allocation group has not average free space. | |
3651 | * re-establish the preferred group as the leftmost | |
3652 | * group with average free space. | |
3653 | */ | |
3654 | if (bmp->db_agfree[bmp->db_agpref] < avgfree) { | |
3655 | for (bmp->db_agpref = 0; bmp->db_agpref < actags; | |
3656 | bmp->db_agpref++) { | |
3657 | if (bmp->db_agfree[bmp->db_agpref] >= avgfree) | |
3658 | break; | |
3659 | } | |
3660 | if (bmp->db_agpref >= bmp->db_numag) { | |
3661 | jfs_error(ipbmap->i_sb, | |
eb8630d7 | 3662 | "cannot find ag with average freespace\n"); |
1da177e4 LT |
3663 | } |
3664 | } | |
3665 | ||
3666 | /* | |
d7eecb48 | 3667 | * compute db_aglevel, db_agheight, db_width, db_agstart: |
63f83c9f DK |
3668 | * an ag is covered in aglevel dmapctl summary tree, |
3669 | * at agheight level height (from leaf) with agwidth number of nodes | |
3670 | * each, which starts at agstart index node of the smmary tree node | |
1da177e4 LT |
3671 | * array; |
3672 | */ | |
3673 | bmp->db_aglevel = BMAPSZTOLEV(bmp->db_agsize); | |
3674 | l2nl = | |
3675 | bmp->db_agl2size - (L2BPERDMAP + bmp->db_aglevel * L2LPERCTL); | |
d7eecb48 DM |
3676 | bmp->db_agheight = l2nl >> 1; |
3677 | bmp->db_agwidth = 1 << (l2nl - (bmp->db_agheight << 1)); | |
3678 | for (i = 5 - bmp->db_agheight, bmp->db_agstart = 0, n = 1; i > 0; | |
1da177e4 LT |
3679 | i--) { |
3680 | bmp->db_agstart += n; | |
3681 | n <<= 2; | |
3682 | } | |
3683 | ||
3684 | } | |
3685 | ||
3686 | ||
3687 | /* | |
3688 | * NAME: dbInitDmap()/ujfs_idmap_page() | |
63f83c9f | 3689 | * |
1da177e4 LT |
3690 | * FUNCTION: initialize working/persistent bitmap of the dmap page |
3691 | * for the specified number of blocks: | |
63f83c9f | 3692 | * |
1da177e4 | 3693 | * at entry, the bitmaps had been initialized as free (ZEROS); |
63f83c9f DK |
3694 | * The number of blocks will only account for the actually |
3695 | * existing blocks. Blocks which don't actually exist in | |
1da177e4 LT |
3696 | * the aggregate will be marked as allocated (ONES); |
3697 | * | |
3698 | * PARAMETERS: | |
3699 | * dp - pointer to page of map | |
3700 | * nblocks - number of blocks this page | |
3701 | * | |
3702 | * RETURNS: NONE | |
3703 | */ | |
3704 | static int dbInitDmap(struct dmap * dp, s64 Blkno, int nblocks) | |
3705 | { | |
3706 | int blkno, w, b, r, nw, nb, i; | |
3707 | ||
3708 | /* starting block number within the dmap */ | |
3709 | blkno = Blkno & (BPERDMAP - 1); | |
3710 | ||
3711 | if (blkno == 0) { | |
3712 | dp->nblocks = dp->nfree = cpu_to_le32(nblocks); | |
3713 | dp->start = cpu_to_le64(Blkno); | |
3714 | ||
3715 | if (nblocks == BPERDMAP) { | |
3716 | memset(&dp->wmap[0], 0, LPERDMAP * 4); | |
3717 | memset(&dp->pmap[0], 0, LPERDMAP * 4); | |
3718 | goto initTree; | |
3719 | } | |
3720 | } else { | |
89145622 MS |
3721 | le32_add_cpu(&dp->nblocks, nblocks); |
3722 | le32_add_cpu(&dp->nfree, nblocks); | |
1da177e4 LT |
3723 | } |
3724 | ||
3725 | /* word number containing start block number */ | |
3726 | w = blkno >> L2DBWORD; | |
3727 | ||
3728 | /* | |
3729 | * free the bits corresponding to the block range (ZEROS): | |
63f83c9f | 3730 | * note: not all bits of the first and last words may be contained |
1da177e4 LT |
3731 | * within the block range. |
3732 | */ | |
3733 | for (r = nblocks; r > 0; r -= nb, blkno += nb) { | |
3734 | /* number of bits preceding range to be freed in the word */ | |
3735 | b = blkno & (DBWORD - 1); | |
3736 | /* number of bits to free in the word */ | |
3737 | nb = min(r, DBWORD - b); | |
3738 | ||
3739 | /* is partial word to be freed ? */ | |
3740 | if (nb < DBWORD) { | |
3741 | /* free (set to 0) from the bitmap word */ | |
3742 | dp->wmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) | |
3743 | >> b)); | |
3744 | dp->pmap[w] &= cpu_to_le32(~(ONES << (DBWORD - nb) | |
3745 | >> b)); | |
3746 | ||
3747 | /* skip the word freed */ | |
3748 | w++; | |
3749 | } else { | |
3750 | /* free (set to 0) contiguous bitmap words */ | |
3751 | nw = r >> L2DBWORD; | |
3752 | memset(&dp->wmap[w], 0, nw * 4); | |
3753 | memset(&dp->pmap[w], 0, nw * 4); | |
3754 | ||
3755 | /* skip the words freed */ | |
3756 | nb = nw << L2DBWORD; | |
3757 | w += nw; | |
3758 | } | |
3759 | } | |
3760 | ||
3761 | /* | |
63f83c9f | 3762 | * mark bits following the range to be freed (non-existing |
1da177e4 LT |
3763 | * blocks) as allocated (ONES) |
3764 | */ | |
3765 | ||
3766 | if (blkno == BPERDMAP) | |
3767 | goto initTree; | |
3768 | ||
3769 | /* the first word beyond the end of existing blocks */ | |
3770 | w = blkno >> L2DBWORD; | |
3771 | ||
3772 | /* does nblocks fall on a 32-bit boundary ? */ | |
3773 | b = blkno & (DBWORD - 1); | |
3774 | if (b) { | |
3775 | /* mark a partial word allocated */ | |
3776 | dp->wmap[w] = dp->pmap[w] = cpu_to_le32(ONES >> b); | |
3777 | w++; | |
3778 | } | |
3779 | ||
3780 | /* set the rest of the words in the page to allocated (ONES) */ | |
3781 | for (i = w; i < LPERDMAP; i++) | |
3782 | dp->pmap[i] = dp->wmap[i] = cpu_to_le32(ONES); | |
3783 | ||
3784 | /* | |
3785 | * init tree | |
3786 | */ | |
3787 | initTree: | |
3788 | return (dbInitDmapTree(dp)); | |
3789 | } | |
3790 | ||
3791 | ||
3792 | /* | |
3793 | * NAME: dbInitDmapTree()/ujfs_complete_dmap() | |
63f83c9f | 3794 | * |
1da177e4 LT |
3795 | * FUNCTION: initialize summary tree of the specified dmap: |
3796 | * | |
3797 | * at entry, bitmap of the dmap has been initialized; | |
63f83c9f | 3798 | * |
1da177e4 LT |
3799 | * PARAMETERS: |
3800 | * dp - dmap to complete | |
3801 | * blkno - starting block number for this dmap | |
3802 | * treemax - will be filled in with max free for this dmap | |
3803 | * | |
3804 | * RETURNS: max free string at the root of the tree | |
3805 | */ | |
3806 | static int dbInitDmapTree(struct dmap * dp) | |
3807 | { | |
3808 | struct dmaptree *tp; | |
3809 | s8 *cp; | |
3810 | int i; | |
3811 | ||
3812 | /* init fixed info of tree */ | |
3813 | tp = &dp->tree; | |
3814 | tp->nleafs = cpu_to_le32(LPERDMAP); | |
3815 | tp->l2nleafs = cpu_to_le32(L2LPERDMAP); | |
3816 | tp->leafidx = cpu_to_le32(LEAFIND); | |
3817 | tp->height = cpu_to_le32(4); | |
3818 | tp->budmin = BUDMIN; | |
3819 | ||
3820 | /* init each leaf from corresponding wmap word: | |
3821 | * note: leaf is set to NOFREE(-1) if all blocks of corresponding | |
63f83c9f | 3822 | * bitmap word are allocated. |
1da177e4 LT |
3823 | */ |
3824 | cp = tp->stree + le32_to_cpu(tp->leafidx); | |
3825 | for (i = 0; i < LPERDMAP; i++) | |
3826 | *cp++ = dbMaxBud((u8 *) & dp->wmap[i]); | |
3827 | ||
3828 | /* build the dmap's binary buddy summary tree */ | |
3829 | return (dbInitTree(tp)); | |
3830 | } | |
3831 | ||
3832 | ||
3833 | /* | |
3834 | * NAME: dbInitTree()/ujfs_adjtree() | |
63f83c9f | 3835 | * |
1da177e4 LT |
3836 | * FUNCTION: initialize binary buddy summary tree of a dmap or dmapctl. |
3837 | * | |
63f83c9f | 3838 | * at entry, the leaves of the tree has been initialized |
1da177e4 LT |
3839 | * from corresponding bitmap word or root of summary tree |
3840 | * of the child control page; | |
3841 | * configure binary buddy system at the leaf level, then | |
3842 | * bubble up the values of the leaf nodes up the tree. | |
3843 | * | |
3844 | * PARAMETERS: | |
3845 | * cp - Pointer to the root of the tree | |
3846 | * l2leaves- Number of leaf nodes as a power of 2 | |
3847 | * l2min - Number of blocks that can be covered by a leaf | |
3848 | * as a power of 2 | |
3849 | * | |
3850 | * RETURNS: max free string at the root of the tree | |
3851 | */ | |
3852 | static int dbInitTree(struct dmaptree * dtp) | |
3853 | { | |
3854 | int l2max, l2free, bsize, nextb, i; | |
3855 | int child, parent, nparent; | |
3856 | s8 *tp, *cp, *cp1; | |
3857 | ||
3858 | tp = dtp->stree; | |
3859 | ||
3860 | /* Determine the maximum free string possible for the leaves */ | |
3861 | l2max = le32_to_cpu(dtp->l2nleafs) + dtp->budmin; | |
3862 | ||
3863 | /* | |
f3fb4624 | 3864 | * configure the leaf level into binary buddy system |
1da177e4 | 3865 | * |
63f83c9f DK |
3866 | * Try to combine buddies starting with a buddy size of 1 |
3867 | * (i.e. two leaves). At a buddy size of 1 two buddy leaves | |
3868 | * can be combined if both buddies have a maximum free of l2min; | |
3869 | * the combination will result in the left-most buddy leaf having | |
3870 | * a maximum free of l2min+1. | |
3871 | * After processing all buddies for a given size, process buddies | |
3872 | * at the next higher buddy size (i.e. current size * 2) and | |
3873 | * the next maximum free (current free + 1). | |
3874 | * This continues until the maximum possible buddy combination | |
1da177e4 LT |
3875 | * yields maximum free. |
3876 | */ | |
3877 | for (l2free = dtp->budmin, bsize = 1; l2free < l2max; | |
3878 | l2free++, bsize = nextb) { | |
3879 | /* get next buddy size == current buddy pair size */ | |
3880 | nextb = bsize << 1; | |
3881 | ||
3882 | /* scan each adjacent buddy pair at current buddy size */ | |
3883 | for (i = 0, cp = tp + le32_to_cpu(dtp->leafidx); | |
3884 | i < le32_to_cpu(dtp->nleafs); | |
3885 | i += nextb, cp += nextb) { | |
3886 | /* coalesce if both adjacent buddies are max free */ | |
3887 | if (*cp == l2free && *(cp + bsize) == l2free) { | |
3888 | *cp = l2free + 1; /* left take right */ | |
3889 | *(cp + bsize) = -1; /* right give left */ | |
3890 | } | |
3891 | } | |
3892 | } | |
3893 | ||
3894 | /* | |
3895 | * bubble summary information of leaves up the tree. | |
3896 | * | |
3897 | * Starting at the leaf node level, the four nodes described by | |
63f83c9f DK |
3898 | * the higher level parent node are compared for a maximum free and |
3899 | * this maximum becomes the value of the parent node. | |
3900 | * when all lower level nodes are processed in this fashion then | |
3901 | * move up to the next level (parent becomes a lower level node) and | |
1da177e4 LT |
3902 | * continue the process for that level. |
3903 | */ | |
3904 | for (child = le32_to_cpu(dtp->leafidx), | |
3905 | nparent = le32_to_cpu(dtp->nleafs) >> 2; | |
3906 | nparent > 0; nparent >>= 2, child = parent) { | |
3907 | /* get index of 1st node of parent level */ | |
3908 | parent = (child - 1) >> 2; | |
3909 | ||
63f83c9f | 3910 | /* set the value of the parent node as the maximum |
1da177e4 LT |
3911 | * of the four nodes of the current level. |
3912 | */ | |
3913 | for (i = 0, cp = tp + child, cp1 = tp + parent; | |
3914 | i < nparent; i++, cp += 4, cp1++) | |
3915 | *cp1 = TREEMAX(cp); | |
3916 | } | |
3917 | ||
3918 | return (*tp); | |
3919 | } | |
3920 | ||
3921 | ||
3922 | /* | |
3923 | * dbInitDmapCtl() | |
3924 | * | |
3925 | * function: initialize dmapctl page | |
3926 | */ | |
3927 | static int dbInitDmapCtl(struct dmapctl * dcp, int level, int i) | |
3928 | { /* start leaf index not covered by range */ | |
3929 | s8 *cp; | |
3930 | ||
3931 | dcp->nleafs = cpu_to_le32(LPERCTL); | |
3932 | dcp->l2nleafs = cpu_to_le32(L2LPERCTL); | |
3933 | dcp->leafidx = cpu_to_le32(CTLLEAFIND); | |
3934 | dcp->height = cpu_to_le32(5); | |
3935 | dcp->budmin = L2BPERDMAP + L2LPERCTL * level; | |
3936 | ||
3937 | /* | |
63f83c9f DK |
3938 | * initialize the leaves of current level that were not covered |
3939 | * by the specified input block range (i.e. the leaves have no | |
1da177e4 LT |
3940 | * low level dmapctl or dmap). |
3941 | */ | |
3942 | cp = &dcp->stree[CTLLEAFIND + i]; | |
3943 | for (; i < LPERCTL; i++) | |
3944 | *cp++ = NOFREE; | |
3945 | ||
3946 | /* build the dmap's binary buddy summary tree */ | |
3947 | return (dbInitTree((struct dmaptree *) dcp)); | |
3948 | } | |
3949 | ||
3950 | ||
3951 | /* | |
3952 | * NAME: dbGetL2AGSize()/ujfs_getagl2size() | |
63f83c9f | 3953 | * |
1da177e4 | 3954 | * FUNCTION: Determine log2(allocation group size) from aggregate size |
63f83c9f | 3955 | * |
1da177e4 LT |
3956 | * PARAMETERS: |
3957 | * nblocks - Number of blocks in aggregate | |
3958 | * | |
3959 | * RETURNS: log2(allocation group size) in aggregate blocks | |
3960 | */ | |
3961 | static int dbGetL2AGSize(s64 nblocks) | |
3962 | { | |
3963 | s64 sz; | |
3964 | s64 m; | |
3965 | int l2sz; | |
3966 | ||
3967 | if (nblocks < BPERDMAP * MAXAG) | |
3968 | return (L2BPERDMAP); | |
3969 | ||
3970 | /* round up aggregate size to power of 2 */ | |
3971 | m = ((u64) 1 << (64 - 1)); | |
3972 | for (l2sz = 64; l2sz >= 0; l2sz--, m >>= 1) { | |
3973 | if (m & nblocks) | |
3974 | break; | |
3975 | } | |
3976 | ||
3977 | sz = (s64) 1 << l2sz; | |
3978 | if (sz < nblocks) | |
3979 | l2sz += 1; | |
3980 | ||
3981 | /* agsize = roundupSize/max_number_of_ag */ | |
3982 | return (l2sz - L2MAXAG); | |
3983 | } | |
3984 | ||
3985 | ||
3986 | /* | |
3987 | * NAME: dbMapFileSizeToMapSize() | |
63f83c9f DK |
3988 | * |
3989 | * FUNCTION: compute number of blocks the block allocation map file | |
1da177e4 LT |
3990 | * can cover from the map file size; |
3991 | * | |
3992 | * RETURNS: Number of blocks which can be covered by this block map file; | |
3993 | */ | |
3994 | ||
3995 | /* | |
3996 | * maximum number of map pages at each level including control pages | |
3997 | */ | |
3998 | #define MAXL0PAGES (1 + LPERCTL) | |
3999 | #define MAXL1PAGES (1 + LPERCTL * MAXL0PAGES) | |
1da177e4 LT |
4000 | |
4001 | /* | |
4002 | * convert number of map pages to the zero origin top dmapctl level | |
4003 | */ | |
4004 | #define BMAPPGTOLEV(npages) \ | |
f720e3ba DK |
4005 | (((npages) <= 3 + MAXL0PAGES) ? 0 : \ |
4006 | ((npages) <= 2 + MAXL1PAGES) ? 1 : 2) | |
1da177e4 LT |
4007 | |
4008 | s64 dbMapFileSizeToMapSize(struct inode * ipbmap) | |
4009 | { | |
4010 | struct super_block *sb = ipbmap->i_sb; | |
4011 | s64 nblocks; | |
4012 | s64 npages, ndmaps; | |
4013 | int level, i; | |
4014 | int complete, factor; | |
4015 | ||
4016 | nblocks = ipbmap->i_size >> JFS_SBI(sb)->l2bsize; | |
4017 | npages = nblocks >> JFS_SBI(sb)->l2nbperpage; | |
4018 | level = BMAPPGTOLEV(npages); | |
4019 | ||
63f83c9f | 4020 | /* At each level, accumulate the number of dmap pages covered by |
1da177e4 LT |
4021 | * the number of full child levels below it; |
4022 | * repeat for the last incomplete child level. | |
4023 | */ | |
4024 | ndmaps = 0; | |
4025 | npages--; /* skip the first global control page */ | |
4026 | /* skip higher level control pages above top level covered by map */ | |
4027 | npages -= (2 - level); | |
4028 | npages--; /* skip top level's control page */ | |
4029 | for (i = level; i >= 0; i--) { | |
4030 | factor = | |
4031 | (i == 2) ? MAXL1PAGES : ((i == 1) ? MAXL0PAGES : 1); | |
4032 | complete = (u32) npages / factor; | |
f720e3ba DK |
4033 | ndmaps += complete * ((i == 2) ? LPERCTL * LPERCTL : |
4034 | ((i == 1) ? LPERCTL : 1)); | |
1da177e4 LT |
4035 | |
4036 | /* pages in last/incomplete child */ | |
4037 | npages = (u32) npages % factor; | |
4038 | /* skip incomplete child's level control page */ | |
4039 | npages--; | |
4040 | } | |
4041 | ||
63f83c9f | 4042 | /* convert the number of dmaps into the number of blocks |
1da177e4 LT |
4043 | * which can be covered by the dmaps; |
4044 | */ | |
4045 | nblocks = ndmaps << L2BPERDMAP; | |
4046 | ||
4047 | return (nblocks); | |
4048 | } |