sufile.c 19 KB

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  1. /*
  2. * sufile.c - NILFS segment usage file.
  3. *
  4. * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
  5. *
  6. * This program is free software; you can redistribute it and/or modify
  7. * it under the terms of the GNU General Public License as published by
  8. * the Free Software Foundation; either version 2 of the License, or
  9. * (at your option) any later version.
  10. *
  11. * This program is distributed in the hope that it will be useful,
  12. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14. * GNU General Public License for more details.
  15. *
  16. * You should have received a copy of the GNU General Public License
  17. * along with this program; if not, write to the Free Software
  18. * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19. *
  20. * Written by Koji Sato <koji@osrg.net>.
  21. * Rivised by Ryusuke Konishi <ryusuke@osrg.net>.
  22. */
  23. #include <linux/kernel.h>
  24. #include <linux/fs.h>
  25. #include <linux/string.h>
  26. #include <linux/buffer_head.h>
  27. #include <linux/errno.h>
  28. #include <linux/nilfs2_fs.h>
  29. #include "mdt.h"
  30. #include "sufile.h"
  31. struct nilfs_sufile_info {
  32. struct nilfs_mdt_info mi;
  33. unsigned long ncleansegs;
  34. };
  35. static inline struct nilfs_sufile_info *NILFS_SUI(struct inode *sufile)
  36. {
  37. return (struct nilfs_sufile_info *)NILFS_MDT(sufile);
  38. }
  39. static inline unsigned long
  40. nilfs_sufile_segment_usages_per_block(const struct inode *sufile)
  41. {
  42. return NILFS_MDT(sufile)->mi_entries_per_block;
  43. }
  44. static unsigned long
  45. nilfs_sufile_get_blkoff(const struct inode *sufile, __u64 segnum)
  46. {
  47. __u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
  48. do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
  49. return (unsigned long)t;
  50. }
  51. static unsigned long
  52. nilfs_sufile_get_offset(const struct inode *sufile, __u64 segnum)
  53. {
  54. __u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
  55. return do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
  56. }
  57. static unsigned long
  58. nilfs_sufile_segment_usages_in_block(const struct inode *sufile, __u64 curr,
  59. __u64 max)
  60. {
  61. return min_t(unsigned long,
  62. nilfs_sufile_segment_usages_per_block(sufile) -
  63. nilfs_sufile_get_offset(sufile, curr),
  64. max - curr + 1);
  65. }
  66. static struct nilfs_segment_usage *
  67. nilfs_sufile_block_get_segment_usage(const struct inode *sufile, __u64 segnum,
  68. struct buffer_head *bh, void *kaddr)
  69. {
  70. return kaddr + bh_offset(bh) +
  71. nilfs_sufile_get_offset(sufile, segnum) *
  72. NILFS_MDT(sufile)->mi_entry_size;
  73. }
  74. static inline int nilfs_sufile_get_header_block(struct inode *sufile,
  75. struct buffer_head **bhp)
  76. {
  77. return nilfs_mdt_get_block(sufile, 0, 0, NULL, bhp);
  78. }
  79. static inline int
  80. nilfs_sufile_get_segment_usage_block(struct inode *sufile, __u64 segnum,
  81. int create, struct buffer_head **bhp)
  82. {
  83. return nilfs_mdt_get_block(sufile,
  84. nilfs_sufile_get_blkoff(sufile, segnum),
  85. create, NULL, bhp);
  86. }
  87. static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
  88. u64 ncleanadd, u64 ndirtyadd)
  89. {
  90. struct nilfs_sufile_header *header;
  91. void *kaddr;
  92. kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
  93. header = kaddr + bh_offset(header_bh);
  94. le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
  95. le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
  96. kunmap_atomic(kaddr, KM_USER0);
  97. nilfs_mdt_mark_buffer_dirty(header_bh);
  98. }
  99. /**
  100. * nilfs_sufile_get_ncleansegs - return the number of clean segments
  101. * @sufile: inode of segment usage file
  102. */
  103. unsigned long nilfs_sufile_get_ncleansegs(struct inode *sufile)
  104. {
  105. return NILFS_SUI(sufile)->ncleansegs;
  106. }
  107. /**
  108. * nilfs_sufile_updatev - modify multiple segment usages at a time
  109. * @sufile: inode of segment usage file
  110. * @segnumv: array of segment numbers
  111. * @nsegs: size of @segnumv array
  112. * @create: creation flag
  113. * @ndone: place to store number of modified segments on @segnumv
  114. * @dofunc: primitive operation for the update
  115. *
  116. * Description: nilfs_sufile_updatev() repeatedly calls @dofunc
  117. * against the given array of segments. The @dofunc is called with
  118. * buffers of a header block and the sufile block in which the target
  119. * segment usage entry is contained. If @ndone is given, the number
  120. * of successfully modified segments from the head is stored in the
  121. * place @ndone points to.
  122. *
  123. * Return Value: On success, zero is returned. On error, one of the
  124. * following negative error codes is returned.
  125. *
  126. * %-EIO - I/O error.
  127. *
  128. * %-ENOMEM - Insufficient amount of memory available.
  129. *
  130. * %-ENOENT - Given segment usage is in hole block (may be returned if
  131. * @create is zero)
  132. *
  133. * %-EINVAL - Invalid segment usage number
  134. */
  135. int nilfs_sufile_updatev(struct inode *sufile, __u64 *segnumv, size_t nsegs,
  136. int create, size_t *ndone,
  137. void (*dofunc)(struct inode *, __u64,
  138. struct buffer_head *,
  139. struct buffer_head *))
  140. {
  141. struct buffer_head *header_bh, *bh;
  142. unsigned long blkoff, prev_blkoff;
  143. __u64 *seg;
  144. size_t nerr = 0, n = 0;
  145. int ret = 0;
  146. if (unlikely(nsegs == 0))
  147. goto out;
  148. down_write(&NILFS_MDT(sufile)->mi_sem);
  149. for (seg = segnumv; seg < segnumv + nsegs; seg++) {
  150. if (unlikely(*seg >= nilfs_sufile_get_nsegments(sufile))) {
  151. printk(KERN_WARNING
  152. "%s: invalid segment number: %llu\n", __func__,
  153. (unsigned long long)*seg);
  154. nerr++;
  155. }
  156. }
  157. if (nerr > 0) {
  158. ret = -EINVAL;
  159. goto out_sem;
  160. }
  161. ret = nilfs_sufile_get_header_block(sufile, &header_bh);
  162. if (ret < 0)
  163. goto out_sem;
  164. seg = segnumv;
  165. blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
  166. ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
  167. if (ret < 0)
  168. goto out_header;
  169. for (;;) {
  170. dofunc(sufile, *seg, header_bh, bh);
  171. if (++seg >= segnumv + nsegs)
  172. break;
  173. prev_blkoff = blkoff;
  174. blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
  175. if (blkoff == prev_blkoff)
  176. continue;
  177. /* get different block */
  178. brelse(bh);
  179. ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
  180. if (unlikely(ret < 0))
  181. goto out_header;
  182. }
  183. brelse(bh);
  184. out_header:
  185. n = seg - segnumv;
  186. brelse(header_bh);
  187. out_sem:
  188. up_write(&NILFS_MDT(sufile)->mi_sem);
  189. out:
  190. if (ndone)
  191. *ndone = n;
  192. return ret;
  193. }
  194. int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
  195. void (*dofunc)(struct inode *, __u64,
  196. struct buffer_head *,
  197. struct buffer_head *))
  198. {
  199. struct buffer_head *header_bh, *bh;
  200. int ret;
  201. if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
  202. printk(KERN_WARNING "%s: invalid segment number: %llu\n",
  203. __func__, (unsigned long long)segnum);
  204. return -EINVAL;
  205. }
  206. down_write(&NILFS_MDT(sufile)->mi_sem);
  207. ret = nilfs_sufile_get_header_block(sufile, &header_bh);
  208. if (ret < 0)
  209. goto out_sem;
  210. ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh);
  211. if (!ret) {
  212. dofunc(sufile, segnum, header_bh, bh);
  213. brelse(bh);
  214. }
  215. brelse(header_bh);
  216. out_sem:
  217. up_write(&NILFS_MDT(sufile)->mi_sem);
  218. return ret;
  219. }
  220. /**
  221. * nilfs_sufile_alloc - allocate a segment
  222. * @sufile: inode of segment usage file
  223. * @segnump: pointer to segment number
  224. *
  225. * Description: nilfs_sufile_alloc() allocates a clean segment.
  226. *
  227. * Return Value: On success, 0 is returned and the segment number of the
  228. * allocated segment is stored in the place pointed by @segnump. On error, one
  229. * of the following negative error codes is returned.
  230. *
  231. * %-EIO - I/O error.
  232. *
  233. * %-ENOMEM - Insufficient amount of memory available.
  234. *
  235. * %-ENOSPC - No clean segment left.
  236. */
  237. int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
  238. {
  239. struct buffer_head *header_bh, *su_bh;
  240. struct nilfs_sufile_header *header;
  241. struct nilfs_segment_usage *su;
  242. size_t susz = NILFS_MDT(sufile)->mi_entry_size;
  243. __u64 segnum, maxsegnum, last_alloc;
  244. void *kaddr;
  245. unsigned long nsegments, ncleansegs, nsus;
  246. int ret, i, j;
  247. down_write(&NILFS_MDT(sufile)->mi_sem);
  248. ret = nilfs_sufile_get_header_block(sufile, &header_bh);
  249. if (ret < 0)
  250. goto out_sem;
  251. kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
  252. header = kaddr + bh_offset(header_bh);
  253. ncleansegs = le64_to_cpu(header->sh_ncleansegs);
  254. last_alloc = le64_to_cpu(header->sh_last_alloc);
  255. kunmap_atomic(kaddr, KM_USER0);
  256. nsegments = nilfs_sufile_get_nsegments(sufile);
  257. segnum = last_alloc + 1;
  258. maxsegnum = nsegments - 1;
  259. for (i = 0; i < nsegments; i += nsus) {
  260. if (segnum >= nsegments) {
  261. /* wrap around */
  262. segnum = 0;
  263. maxsegnum = last_alloc;
  264. }
  265. ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
  266. &su_bh);
  267. if (ret < 0)
  268. goto out_header;
  269. kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
  270. su = nilfs_sufile_block_get_segment_usage(
  271. sufile, segnum, su_bh, kaddr);
  272. nsus = nilfs_sufile_segment_usages_in_block(
  273. sufile, segnum, maxsegnum);
  274. for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
  275. if (!nilfs_segment_usage_clean(su))
  276. continue;
  277. /* found a clean segment */
  278. nilfs_segment_usage_set_dirty(su);
  279. kunmap_atomic(kaddr, KM_USER0);
  280. kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
  281. header = kaddr + bh_offset(header_bh);
  282. le64_add_cpu(&header->sh_ncleansegs, -1);
  283. le64_add_cpu(&header->sh_ndirtysegs, 1);
  284. header->sh_last_alloc = cpu_to_le64(segnum);
  285. kunmap_atomic(kaddr, KM_USER0);
  286. NILFS_SUI(sufile)->ncleansegs--;
  287. nilfs_mdt_mark_buffer_dirty(header_bh);
  288. nilfs_mdt_mark_buffer_dirty(su_bh);
  289. nilfs_mdt_mark_dirty(sufile);
  290. brelse(su_bh);
  291. *segnump = segnum;
  292. goto out_header;
  293. }
  294. kunmap_atomic(kaddr, KM_USER0);
  295. brelse(su_bh);
  296. }
  297. /* no segments left */
  298. ret = -ENOSPC;
  299. out_header:
  300. brelse(header_bh);
  301. out_sem:
  302. up_write(&NILFS_MDT(sufile)->mi_sem);
  303. return ret;
  304. }
  305. void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
  306. struct buffer_head *header_bh,
  307. struct buffer_head *su_bh)
  308. {
  309. struct nilfs_segment_usage *su;
  310. void *kaddr;
  311. kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
  312. su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
  313. if (unlikely(!nilfs_segment_usage_clean(su))) {
  314. printk(KERN_WARNING "%s: segment %llu must be clean\n",
  315. __func__, (unsigned long long)segnum);
  316. kunmap_atomic(kaddr, KM_USER0);
  317. return;
  318. }
  319. nilfs_segment_usage_set_dirty(su);
  320. kunmap_atomic(kaddr, KM_USER0);
  321. nilfs_sufile_mod_counter(header_bh, -1, 1);
  322. NILFS_SUI(sufile)->ncleansegs--;
  323. nilfs_mdt_mark_buffer_dirty(su_bh);
  324. nilfs_mdt_mark_dirty(sufile);
  325. }
  326. void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
  327. struct buffer_head *header_bh,
  328. struct buffer_head *su_bh)
  329. {
  330. struct nilfs_segment_usage *su;
  331. void *kaddr;
  332. int clean, dirty;
  333. kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
  334. su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
  335. if (su->su_flags == cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY) &&
  336. su->su_nblocks == cpu_to_le32(0)) {
  337. kunmap_atomic(kaddr, KM_USER0);
  338. return;
  339. }
  340. clean = nilfs_segment_usage_clean(su);
  341. dirty = nilfs_segment_usage_dirty(su);
  342. /* make the segment garbage */
  343. su->su_lastmod = cpu_to_le64(0);
  344. su->su_nblocks = cpu_to_le32(0);
  345. su->su_flags = cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY);
  346. kunmap_atomic(kaddr, KM_USER0);
  347. nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
  348. NILFS_SUI(sufile)->ncleansegs -= clean;
  349. nilfs_mdt_mark_buffer_dirty(su_bh);
  350. nilfs_mdt_mark_dirty(sufile);
  351. }
  352. void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
  353. struct buffer_head *header_bh,
  354. struct buffer_head *su_bh)
  355. {
  356. struct nilfs_segment_usage *su;
  357. void *kaddr;
  358. int sudirty;
  359. kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
  360. su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
  361. if (nilfs_segment_usage_clean(su)) {
  362. printk(KERN_WARNING "%s: segment %llu is already clean\n",
  363. __func__, (unsigned long long)segnum);
  364. kunmap_atomic(kaddr, KM_USER0);
  365. return;
  366. }
  367. WARN_ON(nilfs_segment_usage_error(su));
  368. WARN_ON(!nilfs_segment_usage_dirty(su));
  369. sudirty = nilfs_segment_usage_dirty(su);
  370. nilfs_segment_usage_set_clean(su);
  371. kunmap_atomic(kaddr, KM_USER0);
  372. nilfs_mdt_mark_buffer_dirty(su_bh);
  373. nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
  374. NILFS_SUI(sufile)->ncleansegs++;
  375. nilfs_mdt_mark_dirty(sufile);
  376. }
  377. /**
  378. * nilfs_sufile_get_segment_usage - get a segment usage
  379. * @sufile: inode of segment usage file
  380. * @segnum: segment number
  381. * @sup: pointer to segment usage
  382. * @bhp: pointer to buffer head
  383. *
  384. * Description: nilfs_sufile_get_segment_usage() acquires the segment usage
  385. * specified by @segnum.
  386. *
  387. * Return Value: On success, 0 is returned, and the segment usage and the
  388. * buffer head of the buffer on which the segment usage is located are stored
  389. * in the place pointed by @sup and @bhp, respectively. On error, one of the
  390. * following negative error codes is returned.
  391. *
  392. * %-EIO - I/O error.
  393. *
  394. * %-ENOMEM - Insufficient amount of memory available.
  395. *
  396. * %-EINVAL - Invalid segment usage number.
  397. */
  398. int nilfs_sufile_get_segment_usage(struct inode *sufile, __u64 segnum,
  399. struct nilfs_segment_usage **sup,
  400. struct buffer_head **bhp)
  401. {
  402. struct buffer_head *bh;
  403. struct nilfs_segment_usage *su;
  404. void *kaddr;
  405. int ret;
  406. /* segnum is 0 origin */
  407. if (segnum >= nilfs_sufile_get_nsegments(sufile))
  408. return -EINVAL;
  409. down_write(&NILFS_MDT(sufile)->mi_sem);
  410. ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1, &bh);
  411. if (ret < 0)
  412. goto out_sem;
  413. kaddr = kmap(bh->b_page);
  414. su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
  415. if (nilfs_segment_usage_error(su)) {
  416. kunmap(bh->b_page);
  417. brelse(bh);
  418. ret = -EINVAL;
  419. goto out_sem;
  420. }
  421. if (sup != NULL)
  422. *sup = su;
  423. *bhp = bh;
  424. out_sem:
  425. up_write(&NILFS_MDT(sufile)->mi_sem);
  426. return ret;
  427. }
  428. /**
  429. * nilfs_sufile_put_segment_usage - put a segment usage
  430. * @sufile: inode of segment usage file
  431. * @segnum: segment number
  432. * @bh: buffer head
  433. *
  434. * Description: nilfs_sufile_put_segment_usage() releases the segment usage
  435. * specified by @segnum. @bh must be the buffer head which have been returned
  436. * by a previous call to nilfs_sufile_get_segment_usage() with @segnum.
  437. */
  438. void nilfs_sufile_put_segment_usage(struct inode *sufile, __u64 segnum,
  439. struct buffer_head *bh)
  440. {
  441. kunmap(bh->b_page);
  442. brelse(bh);
  443. }
  444. /**
  445. * nilfs_sufile_get_stat - get segment usage statistics
  446. * @sufile: inode of segment usage file
  447. * @stat: pointer to a structure of segment usage statistics
  448. *
  449. * Description: nilfs_sufile_get_stat() returns information about segment
  450. * usage.
  451. *
  452. * Return Value: On success, 0 is returned, and segment usage information is
  453. * stored in the place pointed by @stat. On error, one of the following
  454. * negative error codes is returned.
  455. *
  456. * %-EIO - I/O error.
  457. *
  458. * %-ENOMEM - Insufficient amount of memory available.
  459. */
  460. int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
  461. {
  462. struct buffer_head *header_bh;
  463. struct nilfs_sufile_header *header;
  464. struct the_nilfs *nilfs = NILFS_MDT(sufile)->mi_nilfs;
  465. void *kaddr;
  466. int ret;
  467. down_read(&NILFS_MDT(sufile)->mi_sem);
  468. ret = nilfs_sufile_get_header_block(sufile, &header_bh);
  469. if (ret < 0)
  470. goto out_sem;
  471. kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
  472. header = kaddr + bh_offset(header_bh);
  473. sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
  474. sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
  475. sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
  476. sustat->ss_ctime = nilfs->ns_ctime;
  477. sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
  478. spin_lock(&nilfs->ns_last_segment_lock);
  479. sustat->ss_prot_seq = nilfs->ns_prot_seq;
  480. spin_unlock(&nilfs->ns_last_segment_lock);
  481. kunmap_atomic(kaddr, KM_USER0);
  482. brelse(header_bh);
  483. out_sem:
  484. up_read(&NILFS_MDT(sufile)->mi_sem);
  485. return ret;
  486. }
  487. void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
  488. struct buffer_head *header_bh,
  489. struct buffer_head *su_bh)
  490. {
  491. struct nilfs_segment_usage *su;
  492. void *kaddr;
  493. int suclean;
  494. kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
  495. su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
  496. if (nilfs_segment_usage_error(su)) {
  497. kunmap_atomic(kaddr, KM_USER0);
  498. return;
  499. }
  500. suclean = nilfs_segment_usage_clean(su);
  501. nilfs_segment_usage_set_error(su);
  502. kunmap_atomic(kaddr, KM_USER0);
  503. if (suclean) {
  504. nilfs_sufile_mod_counter(header_bh, -1, 0);
  505. NILFS_SUI(sufile)->ncleansegs--;
  506. }
  507. nilfs_mdt_mark_buffer_dirty(su_bh);
  508. nilfs_mdt_mark_dirty(sufile);
  509. }
  510. /**
  511. * nilfs_sufile_get_suinfo -
  512. * @sufile: inode of segment usage file
  513. * @segnum: segment number to start looking
  514. * @buf: array of suinfo
  515. * @sisz: byte size of suinfo
  516. * @nsi: size of suinfo array
  517. *
  518. * Description:
  519. *
  520. * Return Value: On success, 0 is returned and .... On error, one of the
  521. * following negative error codes is returned.
  522. *
  523. * %-EIO - I/O error.
  524. *
  525. * %-ENOMEM - Insufficient amount of memory available.
  526. */
  527. ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf,
  528. unsigned sisz, size_t nsi)
  529. {
  530. struct buffer_head *su_bh;
  531. struct nilfs_segment_usage *su;
  532. struct nilfs_suinfo *si = buf;
  533. size_t susz = NILFS_MDT(sufile)->mi_entry_size;
  534. struct the_nilfs *nilfs = NILFS_MDT(sufile)->mi_nilfs;
  535. void *kaddr;
  536. unsigned long nsegs, segusages_per_block;
  537. ssize_t n;
  538. int ret, i, j;
  539. down_read(&NILFS_MDT(sufile)->mi_sem);
  540. segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
  541. nsegs = min_t(unsigned long,
  542. nilfs_sufile_get_nsegments(sufile) - segnum,
  543. nsi);
  544. for (i = 0; i < nsegs; i += n, segnum += n) {
  545. n = min_t(unsigned long,
  546. segusages_per_block -
  547. nilfs_sufile_get_offset(sufile, segnum),
  548. nsegs - i);
  549. ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
  550. &su_bh);
  551. if (ret < 0) {
  552. if (ret != -ENOENT)
  553. goto out;
  554. /* hole */
  555. memset(si, 0, sisz * n);
  556. si = (void *)si + sisz * n;
  557. continue;
  558. }
  559. kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
  560. su = nilfs_sufile_block_get_segment_usage(
  561. sufile, segnum, su_bh, kaddr);
  562. for (j = 0; j < n;
  563. j++, su = (void *)su + susz, si = (void *)si + sisz) {
  564. si->sui_lastmod = le64_to_cpu(su->su_lastmod);
  565. si->sui_nblocks = le32_to_cpu(su->su_nblocks);
  566. si->sui_flags = le32_to_cpu(su->su_flags) &
  567. ~(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
  568. if (nilfs_segment_is_active(nilfs, segnum + j))
  569. si->sui_flags |=
  570. (1UL << NILFS_SEGMENT_USAGE_ACTIVE);
  571. }
  572. kunmap_atomic(kaddr, KM_USER0);
  573. brelse(su_bh);
  574. }
  575. ret = nsegs;
  576. out:
  577. up_read(&NILFS_MDT(sufile)->mi_sem);
  578. return ret;
  579. }
  580. /**
  581. * nilfs_sufile_read - read sufile inode
  582. * @sufile: sufile inode
  583. * @raw_inode: on-disk sufile inode
  584. */
  585. int nilfs_sufile_read(struct inode *sufile, struct nilfs_inode *raw_inode)
  586. {
  587. struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
  588. struct buffer_head *header_bh;
  589. struct nilfs_sufile_header *header;
  590. void *kaddr;
  591. int ret;
  592. ret = nilfs_read_inode_common(sufile, raw_inode);
  593. if (ret < 0)
  594. return ret;
  595. ret = nilfs_sufile_get_header_block(sufile, &header_bh);
  596. if (!ret) {
  597. kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
  598. header = kaddr + bh_offset(header_bh);
  599. sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
  600. kunmap_atomic(kaddr, KM_USER0);
  601. brelse(header_bh);
  602. }
  603. return ret;
  604. }
  605. /**
  606. * nilfs_sufile_new - create sufile
  607. * @nilfs: nilfs object
  608. * @susize: size of a segment usage entry
  609. */
  610. struct inode *nilfs_sufile_new(struct the_nilfs *nilfs, size_t susize)
  611. {
  612. struct inode *sufile;
  613. sufile = nilfs_mdt_new(nilfs, NULL, NILFS_SUFILE_INO,
  614. sizeof(struct nilfs_sufile_info));
  615. if (sufile)
  616. nilfs_mdt_set_entry_size(sufile, susize,
  617. sizeof(struct nilfs_sufile_header));
  618. return sufile;
  619. }