blob: e5fe8506ed16a5305f9c69db5dfbf111ecd085ba [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C) International Business Machines Corp., 2000-2004
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
Dave Kleikamp63f83c92006-10-02 09:55:27 -05006 * the Free Software Foundation; either version 2 of the License, or
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * (at your option) any later version.
Dave Kleikamp63f83c92006-10-02 09:55:27 -05008 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
Dave Kleikamp63f83c92006-10-02 09:55:27 -050015 * along with this program; if not, write to the Free Software
Linus Torvalds1da177e2005-04-16 15:20:36 -070016 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19#include <linux/fs.h>
20#include <linux/quotaops.h>
21#include "jfs_incore.h"
Dave Kleikamp1868f4a2005-05-04 15:29:35 -050022#include "jfs_inode.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include "jfs_superblock.h"
24#include "jfs_dmap.h"
25#include "jfs_extent.h"
26#include "jfs_debug.h"
27
28/*
29 * forward references
30 */
31static int extBalloc(struct inode *, s64, s64 *, s64 *);
32#ifdef _NOTYET
33static int extBrealloc(struct inode *, s64, s64, s64 *, s64 *);
34#endif
35static s64 extRoundDown(s64 nb);
36
Dave Kleikampf720e3b2007-06-06 15:28:35 -050037#define DPD(a) (printk("(a): %d\n",(a)))
38#define DPC(a) (printk("(a): %c\n",(a)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#define DPL1(a) \
40{ \
41 if ((a) >> 32) \
42 printk("(a): %x%08x ",(a)); \
43 else \
44 printk("(a): %x ",(a) << 32); \
45}
46#define DPL(a) \
47{ \
48 if ((a) >> 32) \
49 printk("(a): %x%08x\n",(a)); \
50 else \
51 printk("(a): %x\n",(a) << 32); \
52}
53
Dave Kleikampf720e3b2007-06-06 15:28:35 -050054#define DPD1(a) (printk("(a): %d ",(a)))
55#define DPX(a) (printk("(a): %08x\n",(a)))
56#define DPX1(a) (printk("(a): %08x ",(a)))
57#define DPS(a) (printk("%s\n",(a)))
58#define DPE(a) (printk("\nENTERING: %s\n",(a)))
59#define DPE1(a) (printk("\nENTERING: %s",(a)))
60#define DPS1(a) (printk(" %s ",(a)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
62
63/*
64 * NAME: extAlloc()
65 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -050066 * FUNCTION: allocate an extent for a specified page range within a
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 * file.
68 *
69 * PARAMETERS:
70 * ip - the inode of the file.
71 * xlen - requested extent length.
72 * pno - the starting page number with the file.
73 * xp - pointer to an xad. on entry, xad describes an
74 * extent that is used as an allocation hint if the
75 * xaddr of the xad is non-zero. on successful exit,
76 * the xad describes the newly allocated extent.
Richard Knutsson4d817152006-09-30 23:27:14 -070077 * abnr - bool indicating whether the newly allocated extent
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 * should be marked as allocated but not recorded.
79 *
80 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -050081 * 0 - success
82 * -EIO - i/o error.
83 * -ENOSPC - insufficient disk resources.
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 */
85int
Richard Knutsson4d817152006-09-30 23:27:14 -070086extAlloc(struct inode *ip, s64 xlen, s64 pno, xad_t * xp, bool abnr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087{
88 struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
89 s64 nxlen, nxaddr, xoff, hint, xaddr = 0;
90 int rc;
91 int xflag;
92
93 /* This blocks if we are low on resources */
94 txBeginAnon(ip->i_sb);
95
96 /* Avoid race with jfs_commit_inode() */
Ingo Molnar1de87442006-01-24 15:22:50 -060097 mutex_lock(&JFS_IP(ip)->commit_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99 /* validate extent length */
100 if (xlen > MAXXLEN)
101 xlen = MAXXLEN;
102
103 /* get the page's starting extent offset */
104 xoff = pno << sbi->l2nbperpage;
105
106 /* check if an allocation hint was provided */
107 if ((hint = addressXAD(xp))) {
108 /* get the size of the extent described by the hint */
109 nxlen = lengthXAD(xp);
110
111 /* check if the hint is for the portion of the file
112 * immediately previous to the current allocation
113 * request and if hint extent has the same abnr
114 * value as the current request. if so, we can
115 * extend the hint extent to include the current
116 * extent if we can allocate the blocks immediately
117 * following the hint extent.
118 */
119 if (offsetXAD(xp) + nxlen == xoff &&
Richard Knutsson4d817152006-09-30 23:27:14 -0700120 abnr == ((xp->flag & XAD_NOTRECORDED) ? true : false))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 xaddr = hint + nxlen;
122
123 /* adjust the hint to the last block of the extent */
124 hint += (nxlen - 1);
125 }
126
127 /* allocate the disk blocks for the extent. initially, extBalloc()
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500128 * will try to allocate disk blocks for the requested size (xlen).
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300129 * if this fails (xlen contiguous free blocks not available), it'll
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 * try to allocate a smaller number of blocks (producing a smaller
131 * extent), with this smaller number of blocks consisting of the
132 * requested number of blocks rounded down to the next smaller
133 * power of 2 number (i.e. 16 -> 8). it'll continue to round down
134 * and retry the allocation until the number of blocks to allocate
135 * is smaller than the number of blocks per page.
136 */
137 nxlen = xlen;
138 if ((rc = extBalloc(ip, hint ? hint : INOHINT(ip), &nxlen, &nxaddr))) {
Ingo Molnar1de87442006-01-24 15:22:50 -0600139 mutex_unlock(&JFS_IP(ip)->commit_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 return (rc);
141 }
142
143 /* Allocate blocks to quota. */
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500144 rc = dquot_alloc_block(ip, nxlen);
145 if (rc) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 dbFree(ip, nxaddr, (s64) nxlen);
Ingo Molnar1de87442006-01-24 15:22:50 -0600147 mutex_unlock(&JFS_IP(ip)->commit_mutex);
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500148 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 }
150
151 /* determine the value of the extent flag */
Richard Knutsson4d817152006-09-30 23:27:14 -0700152 xflag = abnr ? XAD_NOTRECORDED : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500154 /* if we can extend the hint extent to cover the current request,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 * extend it. otherwise, insert a new extent to
156 * cover the current request.
157 */
158 if (xaddr && xaddr == nxaddr)
159 rc = xtExtend(0, ip, xoff, (int) nxlen, 0);
160 else
161 rc = xtInsert(0, ip, xflag, xoff, (int) nxlen, &nxaddr, 0);
162
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500163 /* if the extend or insert failed,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 * free the newly allocated blocks and return the error.
165 */
166 if (rc) {
167 dbFree(ip, nxaddr, nxlen);
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500168 dquot_free_block(ip, nxlen);
Ingo Molnar1de87442006-01-24 15:22:50 -0600169 mutex_unlock(&JFS_IP(ip)->commit_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 return (rc);
171 }
172
173 /* set the results of the extent allocation */
174 XADaddress(xp, nxaddr);
175 XADlength(xp, nxlen);
176 XADoffset(xp, xoff);
177 xp->flag = xflag;
178
179 mark_inode_dirty(ip);
180
Ingo Molnar1de87442006-01-24 15:22:50 -0600181 mutex_unlock(&JFS_IP(ip)->commit_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 /*
183 * COMMIT_SyncList flags an anonymous tlock on page that is on
184 * sync list.
185 * We need to commit the inode to get the page written disk.
186 */
187 if (test_and_clear_cflag(COMMIT_Synclist,ip))
188 jfs_commit_inode(ip, 0);
189
190 return (0);
191}
192
193
194#ifdef _NOTYET
195/*
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500196 * NAME: extRealloc()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500198 * FUNCTION: extend the allocation of a file extent containing a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 * partial back last page.
200 *
201 * PARAMETERS:
202 * ip - the inode of the file.
203 * cp - cbuf for the partial backed last page.
204 * xlen - request size of the resulting extent.
205 * xp - pointer to an xad. on successful exit, the xad
206 * describes the newly allocated extent.
Richard Knutsson4d817152006-09-30 23:27:14 -0700207 * abnr - bool indicating whether the newly allocated extent
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 * should be marked as allocated but not recorded.
209 *
210 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500211 * 0 - success
212 * -EIO - i/o error.
213 * -ENOSPC - insufficient disk resources.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 */
Richard Knutsson4d817152006-09-30 23:27:14 -0700215int extRealloc(struct inode *ip, s64 nxlen, xad_t * xp, bool abnr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216{
217 struct super_block *sb = ip->i_sb;
218 s64 xaddr, xlen, nxaddr, delta, xoff;
219 s64 ntail, nextend, ninsert;
220 int rc, nbperpage = JFS_SBI(sb)->nbperpage;
221 int xflag;
222
223 /* This blocks if we are low on resources */
224 txBeginAnon(ip->i_sb);
225
Ingo Molnar1de87442006-01-24 15:22:50 -0600226 mutex_lock(&JFS_IP(ip)->commit_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 /* validate extent length */
228 if (nxlen > MAXXLEN)
229 nxlen = MAXXLEN;
230
231 /* get the extend (partial) page's disk block address and
232 * number of blocks.
233 */
234 xaddr = addressXAD(xp);
235 xlen = lengthXAD(xp);
236 xoff = offsetXAD(xp);
237
238 /* if the extend page is abnr and if the request is for
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500239 * the extent to be allocated and recorded,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 * make the page allocated and recorded.
241 */
242 if ((xp->flag & XAD_NOTRECORDED) && !abnr) {
243 xp->flag = 0;
244 if ((rc = xtUpdate(0, ip, xp)))
245 goto exit;
246 }
247
248 /* try to allocated the request number of blocks for the
249 * extent. dbRealloc() first tries to satisfy the request
250 * by extending the allocation in place. otherwise, it will
251 * try to allocate a new set of blocks large enough for the
252 * request. in satisfying a request, dbReAlloc() may allocate
253 * less than what was request but will always allocate enough
254 * space as to satisfy the extend page.
255 */
256 if ((rc = extBrealloc(ip, xaddr, xlen, &nxlen, &nxaddr)))
257 goto exit;
258
259 /* Allocat blocks to quota. */
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500260 rc = dquot_alloc_block(ip, nxlen);
261 if (rc) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 dbFree(ip, nxaddr, (s64) nxlen);
Ingo Molnar1de87442006-01-24 15:22:50 -0600263 mutex_unlock(&JFS_IP(ip)->commit_mutex);
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500264 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 }
266
267 delta = nxlen - xlen;
268
269 /* check if the extend page is not abnr but the request is abnr
270 * and the allocated disk space is for more than one page. if this
271 * is the case, there is a miss match of abnr between the extend page
272 * and the one or more pages following the extend page. as a result,
273 * two extents will have to be manipulated. the first will be that
274 * of the extent of the extend page and will be manipulated thru
275 * an xtExtend() or an xtTailgate(), depending upon whether the
276 * disk allocation occurred as an inplace extension. the second
277 * extent will be manipulated (created) through an xtInsert() and
278 * will be for the pages following the extend page.
279 */
280 if (abnr && (!(xp->flag & XAD_NOTRECORDED)) && (nxlen > nbperpage)) {
281 ntail = nbperpage;
282 nextend = ntail - xlen;
283 ninsert = nxlen - nbperpage;
284
285 xflag = XAD_NOTRECORDED;
286 } else {
287 ntail = nxlen;
288 nextend = delta;
289 ninsert = 0;
290
291 xflag = xp->flag;
292 }
293
294 /* if we were able to extend the disk allocation in place,
295 * extend the extent. otherwise, move the extent to a
296 * new disk location.
297 */
298 if (xaddr == nxaddr) {
299 /* extend the extent */
300 if ((rc = xtExtend(0, ip, xoff + xlen, (int) nextend, 0))) {
301 dbFree(ip, xaddr + xlen, delta);
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500302 dquot_free_block(ip, nxlen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 goto exit;
304 }
305 } else {
306 /*
307 * move the extent to a new location:
308 *
309 * xtTailgate() accounts for relocated tail extent;
310 */
311 if ((rc = xtTailgate(0, ip, xoff, (int) ntail, nxaddr, 0))) {
312 dbFree(ip, nxaddr, nxlen);
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500313 dquot_free_block(ip, nxlen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 goto exit;
315 }
316 }
317
318
319 /* check if we need to also insert a new extent */
320 if (ninsert) {
321 /* perform the insert. if it fails, free the blocks
322 * to be inserted and make it appear that we only did
323 * the xtExtend() or xtTailgate() above.
324 */
325 xaddr = nxaddr + ntail;
326 if (xtInsert (0, ip, xflag, xoff + ntail, (int) ninsert,
327 &xaddr, 0)) {
328 dbFree(ip, xaddr, (s64) ninsert);
329 delta = nextend;
330 nxlen = ntail;
331 xflag = 0;
332 }
333 }
334
335 /* set the return results */
336 XADaddress(xp, nxaddr);
337 XADlength(xp, nxlen);
338 XADoffset(xp, xoff);
339 xp->flag = xflag;
340
341 mark_inode_dirty(ip);
342exit:
Ingo Molnar1de87442006-01-24 15:22:50 -0600343 mutex_unlock(&JFS_IP(ip)->commit_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 return (rc);
345}
346#endif /* _NOTYET */
347
348
349/*
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500350 * NAME: extHint()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500352 * FUNCTION: produce an extent allocation hint for a file offset.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 *
354 * PARAMETERS:
355 * ip - the inode of the file.
356 * offset - file offset for which the hint is needed.
357 * xp - pointer to the xad that is to be filled in with
358 * the hint.
359 *
360 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500361 * 0 - success
362 * -EIO - i/o error.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 */
364int extHint(struct inode *ip, s64 offset, xad_t * xp)
365{
366 struct super_block *sb = ip->i_sb;
Dave Kleikampfec18782009-01-09 15:42:04 -0600367 int nbperpage = JFS_SBI(sb)->nbperpage;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 s64 prev;
Dave Kleikampfec18782009-01-09 15:42:04 -0600369 int rc = 0;
370 s64 xaddr;
371 int xlen;
372 int xflag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373
374 /* init the hint as "no hint provided" */
375 XADaddress(xp, 0);
376
377 /* determine the starting extent offset of the page previous
378 * to the page containing the offset.
379 */
380 prev = ((offset & ~POFFSET) >> JFS_SBI(sb)->l2bsize) - nbperpage;
381
Dave Kleikampfec18782009-01-09 15:42:04 -0600382 /* if the offset is in the first page of the file, no hint provided.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 */
384 if (prev < 0)
Dave Kleikampfec18782009-01-09 15:42:04 -0600385 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
Dave Kleikampfec18782009-01-09 15:42:04 -0600387 rc = xtLookup(ip, prev, nbperpage, &xflag, &xaddr, &xlen, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388
Dave Kleikampfec18782009-01-09 15:42:04 -0600389 if ((rc == 0) && xlen) {
390 if (xlen != nbperpage) {
391 jfs_error(ip->i_sb, "extHint: corrupt xtree");
392 rc = -EIO;
393 }
394 XADaddress(xp, xaddr);
395 XADlength(xp, xlen);
Dave Kleikampf7c52fd2009-06-16 13:43:22 -0500396 XADoffset(xp, prev);
Dave Kleikampfec18782009-01-09 15:42:04 -0600397 /*
398 * only preserve the abnr flag within the xad flags
399 * of the returned hint.
400 */
401 xp->flag = xflag & XAD_NOTRECORDED;
402 } else
403 rc = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404
Dave Kleikampfec18782009-01-09 15:42:04 -0600405out:
406 return (rc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407}
408
409
410/*
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500411 * NAME: extRecord()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500413 * FUNCTION: change a page with a file from not recorded to recorded.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 *
415 * PARAMETERS:
416 * ip - inode of the file.
417 * cp - cbuf of the file page.
418 *
419 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500420 * 0 - success
421 * -EIO - i/o error.
422 * -ENOSPC - insufficient disk resources.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 */
424int extRecord(struct inode *ip, xad_t * xp)
425{
426 int rc;
427
428 txBeginAnon(ip->i_sb);
429
Ingo Molnar1de87442006-01-24 15:22:50 -0600430 mutex_lock(&JFS_IP(ip)->commit_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
432 /* update the extent */
433 rc = xtUpdate(0, ip, xp);
434
Ingo Molnar1de87442006-01-24 15:22:50 -0600435 mutex_unlock(&JFS_IP(ip)->commit_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 return rc;
437}
438
439
440#ifdef _NOTYET
441/*
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500442 * NAME: extFill()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500444 * FUNCTION: allocate disk space for a file page that represents
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 * a file hole.
446 *
447 * PARAMETERS:
448 * ip - the inode of the file.
449 * cp - cbuf of the file page represent the hole.
450 *
451 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500452 * 0 - success
453 * -EIO - i/o error.
454 * -ENOSPC - insufficient disk resources.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 */
456int extFill(struct inode *ip, xad_t * xp)
457{
458 int rc, nbperpage = JFS_SBI(ip->i_sb)->nbperpage;
Theodore Ts'oba52de12006-09-27 01:50:49 -0700459 s64 blkno = offsetXAD(xp) >> ip->i_blkbits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500461// assert(ISSPARSE(ip));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462
463 /* initialize the extent allocation hint */
464 XADaddress(xp, 0);
465
466 /* allocate an extent to fill the hole */
Richard Knutsson4d817152006-09-30 23:27:14 -0700467 if ((rc = extAlloc(ip, nbperpage, blkno, xp, false)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 return (rc);
469
470 assert(lengthPXD(xp) == nbperpage);
471
472 return (0);
473}
474#endif /* _NOTYET */
475
476
477/*
478 * NAME: extBalloc()
479 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500480 * FUNCTION: allocate disk blocks to form an extent.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 *
482 * initially, we will try to allocate disk blocks for the
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500483 * requested size (nblocks). if this fails (nblocks
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300484 * contiguous free blocks not available), we'll try to allocate
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 * a smaller number of blocks (producing a smaller extent), with
486 * this smaller number of blocks consisting of the requested
487 * number of blocks rounded down to the next smaller power of 2
488 * number (i.e. 16 -> 8). we'll continue to round down and
489 * retry the allocation until the number of blocks to allocate
490 * is smaller than the number of blocks per page.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500491 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 * PARAMETERS:
493 * ip - the inode of the file.
494 * hint - disk block number to be used as an allocation hint.
495 * *nblocks - pointer to an s64 value. on entry, this value specifies
496 * the desired number of block to be allocated. on successful
497 * exit, this value is set to the number of blocks actually
498 * allocated.
499 * blkno - pointer to a block address that is filled in on successful
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500500 * return with the starting block number of the newly
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 * allocated block range.
502 *
503 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500504 * 0 - success
505 * -EIO - i/o error.
506 * -ENOSPC - insufficient disk resources.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 */
508static int
509extBalloc(struct inode *ip, s64 hint, s64 * nblocks, s64 * blkno)
510{
511 struct jfs_inode_info *ji = JFS_IP(ip);
512 struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
513 s64 nb, nblks, daddr, max;
514 int rc, nbperpage = sbi->nbperpage;
515 struct bmap *bmp = sbi->bmap;
516 int ag;
517
518 /* get the number of blocks to initially attempt to allocate.
519 * we'll first try the number of blocks requested unless this
Andreas Mohrd6e05ed2006-06-26 18:35:02 +0200520 * number is greater than the maximum number of contiguous free
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500521 * blocks in the map. in that case, we'll start off with the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 * maximum free.
523 */
524 max = (s64) 1 << bmp->db_maxfreebud;
525 if (*nblocks >= max && *nblocks > nbperpage)
526 nb = nblks = (max > nbperpage) ? max : nbperpage;
527 else
528 nb = nblks = *nblocks;
529
530 /* try to allocate blocks */
531 while ((rc = dbAlloc(ip, hint, nb, &daddr)) != 0) {
532 /* if something other than an out of space error,
533 * stop and return this error.
534 */
535 if (rc != -ENOSPC)
536 return (rc);
537
538 /* decrease the allocation request size */
539 nb = min(nblks, extRoundDown(nb));
540
541 /* give up if we cannot cover a page */
542 if (nb < nbperpage)
543 return (rc);
544 }
545
546 *nblocks = nb;
547 *blkno = daddr;
548
549 if (S_ISREG(ip->i_mode) && (ji->fileset == FILESYSTEM_I)) {
550 ag = BLKTOAG(daddr, sbi);
551 spin_lock_irq(&ji->ag_lock);
552 if (ji->active_ag == -1) {
553 atomic_inc(&bmp->db_active[ag]);
554 ji->active_ag = ag;
555 } else if (ji->active_ag != ag) {
556 atomic_dec(&bmp->db_active[ji->active_ag]);
557 atomic_inc(&bmp->db_active[ag]);
558 ji->active_ag = ag;
559 }
560 spin_unlock_irq(&ji->ag_lock);
561 }
562
563 return (0);
564}
565
566
567#ifdef _NOTYET
568/*
569 * NAME: extBrealloc()
570 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500571 * FUNCTION: attempt to extend an extent's allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 *
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500573 * Initially, we will try to extend the extent's allocation
574 * in place. If this fails, we'll try to move the extent
575 * to a new set of blocks. If moving the extent, we initially
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 * will try to allocate disk blocks for the requested size
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500577 * (newnblks). if this fails (new contiguous free blocks not
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300578 * available), we'll try to allocate a smaller number of
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 * blocks (producing a smaller extent), with this smaller
580 * number of blocks consisting of the requested number of
581 * blocks rounded down to the next smaller power of 2
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500582 * number (i.e. 16 -> 8). We'll continue to round down and
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 * retry the allocation until the number of blocks to allocate
584 * is smaller than the number of blocks per page.
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500585 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 * PARAMETERS:
587 * ip - the inode of the file.
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500588 * blkno - starting block number of the extents current allocation.
589 * nblks - number of blocks within the extents current allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 * newnblks - pointer to a s64 value. on entry, this value is the
591 * the new desired extent size (number of blocks). on
592 * successful exit, this value is set to the extent's actual
593 * new size (new number of blocks).
594 * newblkno - the starting block number of the extents new allocation.
595 *
596 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500597 * 0 - success
598 * -EIO - i/o error.
599 * -ENOSPC - insufficient disk resources.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 */
601static int
602extBrealloc(struct inode *ip,
603 s64 blkno, s64 nblks, s64 * newnblks, s64 * newblkno)
604{
605 int rc;
606
607 /* try to extend in place */
608 if ((rc = dbExtend(ip, blkno, nblks, *newnblks - nblks)) == 0) {
609 *newblkno = blkno;
610 return (0);
611 } else {
612 if (rc != -ENOSPC)
613 return (rc);
614 }
615
Dave Kleikamp63f83c92006-10-02 09:55:27 -0500616 /* in place extension not possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 * try to move the extent to a new set of blocks.
618 */
619 return (extBalloc(ip, blkno, newnblks, newblkno));
620}
621#endif /* _NOTYET */
622
623
624/*
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500625 * NAME: extRoundDown()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 *
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500627 * FUNCTION: round down a specified number of blocks to the next
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 * smallest power of 2 number.
629 *
630 * PARAMETERS:
631 * nb - the inode of the file.
632 *
633 * RETURN VALUES:
Dave Kleikampf720e3b2007-06-06 15:28:35 -0500634 * next smallest power of 2 number.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 */
636static s64 extRoundDown(s64 nb)
637{
638 int i;
639 u64 m, k;
640
641 for (i = 0, m = (u64) 1 << 63; i < 64; i++, m >>= 1) {
642 if (m & nb)
643 break;
644 }
645
646 i = 63 - i;
647 k = (u64) 1 << i;
648 k = ((k - 1) & nb) ? k : k >> 1;
649
650 return (k);
651}