the_nilfs.c 20 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * the_nilfs.c - the_nilfs shared structure.
  4. *
  5. * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
  6. *
  7. * Written by Ryusuke Konishi.
  8. *
  9. */
  10. #include <linux/buffer_head.h>
  11. #include <linux/slab.h>
  12. #include <linux/blkdev.h>
  13. #include <linux/backing-dev.h>
  14. #include <linux/random.h>
  15. #include <linux/crc32.h>
  16. #include "nilfs.h"
  17. #include "segment.h"
  18. #include "alloc.h"
  19. #include "cpfile.h"
  20. #include "sufile.h"
  21. #include "dat.h"
  22. #include "segbuf.h"
  23. static int nilfs_valid_sb(struct nilfs_super_block *sbp);
  24. void nilfs_set_last_segment(struct the_nilfs *nilfs,
  25. sector_t start_blocknr, u64 seq, __u64 cno)
  26. {
  27. spin_lock(&nilfs->ns_last_segment_lock);
  28. nilfs->ns_last_pseg = start_blocknr;
  29. nilfs->ns_last_seq = seq;
  30. nilfs->ns_last_cno = cno;
  31. if (!nilfs_sb_dirty(nilfs)) {
  32. if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
  33. goto stay_cursor;
  34. set_nilfs_sb_dirty(nilfs);
  35. }
  36. nilfs->ns_prev_seq = nilfs->ns_last_seq;
  37. stay_cursor:
  38. spin_unlock(&nilfs->ns_last_segment_lock);
  39. }
  40. /**
  41. * alloc_nilfs - allocate a nilfs object
  42. * @sb: super block instance
  43. *
  44. * Return Value: On success, pointer to the_nilfs is returned.
  45. * On error, NULL is returned.
  46. */
  47. struct the_nilfs *alloc_nilfs(struct super_block *sb)
  48. {
  49. struct the_nilfs *nilfs;
  50. nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
  51. if (!nilfs)
  52. return NULL;
  53. nilfs->ns_sb = sb;
  54. nilfs->ns_bdev = sb->s_bdev;
  55. atomic_set(&nilfs->ns_ndirtyblks, 0);
  56. init_rwsem(&nilfs->ns_sem);
  57. mutex_init(&nilfs->ns_snapshot_mount_mutex);
  58. INIT_LIST_HEAD(&nilfs->ns_dirty_files);
  59. INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
  60. spin_lock_init(&nilfs->ns_inode_lock);
  61. spin_lock_init(&nilfs->ns_next_gen_lock);
  62. spin_lock_init(&nilfs->ns_last_segment_lock);
  63. nilfs->ns_cptree = RB_ROOT;
  64. spin_lock_init(&nilfs->ns_cptree_lock);
  65. init_rwsem(&nilfs->ns_segctor_sem);
  66. nilfs->ns_sb_update_freq = NILFS_SB_FREQ;
  67. return nilfs;
  68. }
  69. /**
  70. * destroy_nilfs - destroy nilfs object
  71. * @nilfs: nilfs object to be released
  72. */
  73. void destroy_nilfs(struct the_nilfs *nilfs)
  74. {
  75. might_sleep();
  76. if (nilfs_init(nilfs)) {
  77. nilfs_sysfs_delete_device_group(nilfs);
  78. brelse(nilfs->ns_sbh[0]);
  79. brelse(nilfs->ns_sbh[1]);
  80. }
  81. kfree(nilfs);
  82. }
  83. static int nilfs_load_super_root(struct the_nilfs *nilfs,
  84. struct super_block *sb, sector_t sr_block)
  85. {
  86. struct buffer_head *bh_sr;
  87. struct nilfs_super_root *raw_sr;
  88. struct nilfs_super_block **sbp = nilfs->ns_sbp;
  89. struct nilfs_inode *rawi;
  90. unsigned int dat_entry_size, segment_usage_size, checkpoint_size;
  91. unsigned int inode_size;
  92. int err;
  93. err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
  94. if (unlikely(err))
  95. return err;
  96. down_read(&nilfs->ns_sem);
  97. dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
  98. checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
  99. segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
  100. up_read(&nilfs->ns_sem);
  101. inode_size = nilfs->ns_inode_size;
  102. rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
  103. err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
  104. if (err)
  105. goto failed;
  106. rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
  107. err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
  108. if (err)
  109. goto failed_dat;
  110. rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
  111. err = nilfs_sufile_read(sb, segment_usage_size, rawi,
  112. &nilfs->ns_sufile);
  113. if (err)
  114. goto failed_cpfile;
  115. raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
  116. nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
  117. failed:
  118. brelse(bh_sr);
  119. return err;
  120. failed_cpfile:
  121. iput(nilfs->ns_cpfile);
  122. failed_dat:
  123. iput(nilfs->ns_dat);
  124. goto failed;
  125. }
  126. static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
  127. {
  128. memset(ri, 0, sizeof(*ri));
  129. INIT_LIST_HEAD(&ri->ri_used_segments);
  130. }
  131. static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
  132. {
  133. nilfs_dispose_segment_list(&ri->ri_used_segments);
  134. }
  135. /**
  136. * nilfs_store_log_cursor - load log cursor from a super block
  137. * @nilfs: nilfs object
  138. * @sbp: buffer storing super block to be read
  139. *
  140. * nilfs_store_log_cursor() reads the last position of the log
  141. * containing a super root from a given super block, and initializes
  142. * relevant information on the nilfs object preparatory for log
  143. * scanning and recovery.
  144. */
  145. static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
  146. struct nilfs_super_block *sbp)
  147. {
  148. int ret = 0;
  149. nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
  150. nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
  151. nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
  152. nilfs->ns_prev_seq = nilfs->ns_last_seq;
  153. nilfs->ns_seg_seq = nilfs->ns_last_seq;
  154. nilfs->ns_segnum =
  155. nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
  156. nilfs->ns_cno = nilfs->ns_last_cno + 1;
  157. if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
  158. nilfs_err(nilfs->ns_sb,
  159. "pointed segment number is out of range: segnum=%llu, nsegments=%lu",
  160. (unsigned long long)nilfs->ns_segnum,
  161. nilfs->ns_nsegments);
  162. ret = -EINVAL;
  163. }
  164. return ret;
  165. }
  166. /**
  167. * load_nilfs - load and recover the nilfs
  168. * @nilfs: the_nilfs structure to be released
  169. * @sb: super block isntance used to recover past segment
  170. *
  171. * load_nilfs() searches and load the latest super root,
  172. * attaches the last segment, and does recovery if needed.
  173. * The caller must call this exclusively for simultaneous mounts.
  174. */
  175. int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
  176. {
  177. struct nilfs_recovery_info ri;
  178. unsigned int s_flags = sb->s_flags;
  179. int really_read_only = bdev_read_only(nilfs->ns_bdev);
  180. int valid_fs = nilfs_valid_fs(nilfs);
  181. int err;
  182. if (!valid_fs) {
  183. nilfs_warn(sb, "mounting unchecked fs");
  184. if (s_flags & SB_RDONLY) {
  185. nilfs_info(sb,
  186. "recovery required for readonly filesystem");
  187. nilfs_info(sb,
  188. "write access will be enabled during recovery");
  189. }
  190. }
  191. nilfs_init_recovery_info(&ri);
  192. err = nilfs_search_super_root(nilfs, &ri);
  193. if (unlikely(err)) {
  194. struct nilfs_super_block **sbp = nilfs->ns_sbp;
  195. int blocksize;
  196. if (err != -EINVAL)
  197. goto scan_error;
  198. if (!nilfs_valid_sb(sbp[1])) {
  199. nilfs_warn(sb,
  200. "unable to fall back to spare super block");
  201. goto scan_error;
  202. }
  203. nilfs_info(sb, "trying rollback from an earlier position");
  204. /*
  205. * restore super block with its spare and reconfigure
  206. * relevant states of the nilfs object.
  207. */
  208. memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
  209. nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
  210. nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
  211. /* verify consistency between two super blocks */
  212. blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
  213. if (blocksize != nilfs->ns_blocksize) {
  214. nilfs_warn(sb,
  215. "blocksize differs between two super blocks (%d != %d)",
  216. blocksize, nilfs->ns_blocksize);
  217. goto scan_error;
  218. }
  219. err = nilfs_store_log_cursor(nilfs, sbp[0]);
  220. if (err)
  221. goto scan_error;
  222. /* drop clean flag to allow roll-forward and recovery */
  223. nilfs->ns_mount_state &= ~NILFS_VALID_FS;
  224. valid_fs = 0;
  225. err = nilfs_search_super_root(nilfs, &ri);
  226. if (err)
  227. goto scan_error;
  228. }
  229. err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
  230. if (unlikely(err)) {
  231. nilfs_err(sb, "error %d while loading super root", err);
  232. goto failed;
  233. }
  234. if (valid_fs)
  235. goto skip_recovery;
  236. if (s_flags & SB_RDONLY) {
  237. __u64 features;
  238. if (nilfs_test_opt(nilfs, NORECOVERY)) {
  239. nilfs_info(sb,
  240. "norecovery option specified, skipping roll-forward recovery");
  241. goto skip_recovery;
  242. }
  243. features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
  244. ~NILFS_FEATURE_COMPAT_RO_SUPP;
  245. if (features) {
  246. nilfs_err(sb,
  247. "couldn't proceed with recovery because of unsupported optional features (%llx)",
  248. (unsigned long long)features);
  249. err = -EROFS;
  250. goto failed_unload;
  251. }
  252. if (really_read_only) {
  253. nilfs_err(sb,
  254. "write access unavailable, cannot proceed");
  255. err = -EROFS;
  256. goto failed_unload;
  257. }
  258. sb->s_flags &= ~SB_RDONLY;
  259. } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
  260. nilfs_err(sb,
  261. "recovery cancelled because norecovery option was specified for a read/write mount");
  262. err = -EINVAL;
  263. goto failed_unload;
  264. }
  265. err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
  266. if (err)
  267. goto failed_unload;
  268. down_write(&nilfs->ns_sem);
  269. nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
  270. err = nilfs_cleanup_super(sb);
  271. up_write(&nilfs->ns_sem);
  272. if (err) {
  273. nilfs_err(sb,
  274. "error %d updating super block. recovery unfinished.",
  275. err);
  276. goto failed_unload;
  277. }
  278. nilfs_info(sb, "recovery complete");
  279. skip_recovery:
  280. nilfs_clear_recovery_info(&ri);
  281. sb->s_flags = s_flags;
  282. return 0;
  283. scan_error:
  284. nilfs_err(sb, "error %d while searching super root", err);
  285. goto failed;
  286. failed_unload:
  287. iput(nilfs->ns_cpfile);
  288. iput(nilfs->ns_sufile);
  289. iput(nilfs->ns_dat);
  290. failed:
  291. nilfs_clear_recovery_info(&ri);
  292. sb->s_flags = s_flags;
  293. return err;
  294. }
  295. static unsigned long long nilfs_max_size(unsigned int blkbits)
  296. {
  297. unsigned int max_bits;
  298. unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
  299. max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
  300. if (max_bits < 64)
  301. res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
  302. return res;
  303. }
  304. /**
  305. * nilfs_nrsvsegs - calculate the number of reserved segments
  306. * @nilfs: nilfs object
  307. * @nsegs: total number of segments
  308. */
  309. unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
  310. {
  311. return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
  312. DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
  313. 100));
  314. }
  315. void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
  316. {
  317. nilfs->ns_nsegments = nsegs;
  318. nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
  319. }
  320. static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
  321. struct nilfs_super_block *sbp)
  322. {
  323. if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
  324. nilfs_err(nilfs->ns_sb,
  325. "unsupported revision (superblock rev.=%d.%d, current rev.=%d.%d). Please check the version of mkfs.nilfs(2).",
  326. le32_to_cpu(sbp->s_rev_level),
  327. le16_to_cpu(sbp->s_minor_rev_level),
  328. NILFS_CURRENT_REV, NILFS_MINOR_REV);
  329. return -EINVAL;
  330. }
  331. nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
  332. if (nilfs->ns_sbsize > BLOCK_SIZE)
  333. return -EINVAL;
  334. nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
  335. if (nilfs->ns_inode_size > nilfs->ns_blocksize) {
  336. nilfs_err(nilfs->ns_sb, "too large inode size: %d bytes",
  337. nilfs->ns_inode_size);
  338. return -EINVAL;
  339. } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) {
  340. nilfs_err(nilfs->ns_sb, "too small inode size: %d bytes",
  341. nilfs->ns_inode_size);
  342. return -EINVAL;
  343. }
  344. nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
  345. nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
  346. if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
  347. nilfs_err(nilfs->ns_sb, "too short segment: %lu blocks",
  348. nilfs->ns_blocks_per_segment);
  349. return -EINVAL;
  350. }
  351. nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
  352. nilfs->ns_r_segments_percentage =
  353. le32_to_cpu(sbp->s_r_segments_percentage);
  354. if (nilfs->ns_r_segments_percentage < 1 ||
  355. nilfs->ns_r_segments_percentage > 99) {
  356. nilfs_err(nilfs->ns_sb,
  357. "invalid reserved segments percentage: %lu",
  358. nilfs->ns_r_segments_percentage);
  359. return -EINVAL;
  360. }
  361. nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
  362. nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
  363. return 0;
  364. }
  365. static int nilfs_valid_sb(struct nilfs_super_block *sbp)
  366. {
  367. static unsigned char sum[4];
  368. const int sumoff = offsetof(struct nilfs_super_block, s_sum);
  369. size_t bytes;
  370. u32 crc;
  371. if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
  372. return 0;
  373. bytes = le16_to_cpu(sbp->s_bytes);
  374. if (bytes < sumoff + 4 || bytes > BLOCK_SIZE)
  375. return 0;
  376. crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
  377. sumoff);
  378. crc = crc32_le(crc, sum, 4);
  379. crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
  380. bytes - sumoff - 4);
  381. return crc == le32_to_cpu(sbp->s_sum);
  382. }
  383. static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
  384. {
  385. return offset < ((le64_to_cpu(sbp->s_nsegments) *
  386. le32_to_cpu(sbp->s_blocks_per_segment)) <<
  387. (le32_to_cpu(sbp->s_log_block_size) + 10));
  388. }
  389. static void nilfs_release_super_block(struct the_nilfs *nilfs)
  390. {
  391. int i;
  392. for (i = 0; i < 2; i++) {
  393. if (nilfs->ns_sbp[i]) {
  394. brelse(nilfs->ns_sbh[i]);
  395. nilfs->ns_sbh[i] = NULL;
  396. nilfs->ns_sbp[i] = NULL;
  397. }
  398. }
  399. }
  400. void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
  401. {
  402. brelse(nilfs->ns_sbh[0]);
  403. nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
  404. nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
  405. nilfs->ns_sbh[1] = NULL;
  406. nilfs->ns_sbp[1] = NULL;
  407. }
  408. void nilfs_swap_super_block(struct the_nilfs *nilfs)
  409. {
  410. struct buffer_head *tsbh = nilfs->ns_sbh[0];
  411. struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
  412. nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
  413. nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
  414. nilfs->ns_sbh[1] = tsbh;
  415. nilfs->ns_sbp[1] = tsbp;
  416. }
  417. static int nilfs_load_super_block(struct the_nilfs *nilfs,
  418. struct super_block *sb, int blocksize,
  419. struct nilfs_super_block **sbpp)
  420. {
  421. struct nilfs_super_block **sbp = nilfs->ns_sbp;
  422. struct buffer_head **sbh = nilfs->ns_sbh;
  423. u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
  424. int valid[2], swp = 0;
  425. sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
  426. &sbh[0]);
  427. sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
  428. if (!sbp[0]) {
  429. if (!sbp[1]) {
  430. nilfs_err(sb, "unable to read superblock");
  431. return -EIO;
  432. }
  433. nilfs_warn(sb,
  434. "unable to read primary superblock (blocksize = %d)",
  435. blocksize);
  436. } else if (!sbp[1]) {
  437. nilfs_warn(sb,
  438. "unable to read secondary superblock (blocksize = %d)",
  439. blocksize);
  440. }
  441. /*
  442. * Compare two super blocks and set 1 in swp if the secondary
  443. * super block is valid and newer. Otherwise, set 0 in swp.
  444. */
  445. valid[0] = nilfs_valid_sb(sbp[0]);
  446. valid[1] = nilfs_valid_sb(sbp[1]);
  447. swp = valid[1] && (!valid[0] ||
  448. le64_to_cpu(sbp[1]->s_last_cno) >
  449. le64_to_cpu(sbp[0]->s_last_cno));
  450. if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
  451. brelse(sbh[1]);
  452. sbh[1] = NULL;
  453. sbp[1] = NULL;
  454. valid[1] = 0;
  455. swp = 0;
  456. }
  457. if (!valid[swp]) {
  458. nilfs_release_super_block(nilfs);
  459. nilfs_err(sb, "couldn't find nilfs on the device");
  460. return -EINVAL;
  461. }
  462. if (!valid[!swp])
  463. nilfs_warn(sb,
  464. "broken superblock, retrying with spare superblock (blocksize = %d)",
  465. blocksize);
  466. if (swp)
  467. nilfs_swap_super_block(nilfs);
  468. nilfs->ns_sbwcount = 0;
  469. nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
  470. nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
  471. *sbpp = sbp[0];
  472. return 0;
  473. }
  474. /**
  475. * init_nilfs - initialize a NILFS instance.
  476. * @nilfs: the_nilfs structure
  477. * @sb: super block
  478. * @data: mount options
  479. *
  480. * init_nilfs() performs common initialization per block device (e.g.
  481. * reading the super block, getting disk layout information, initializing
  482. * shared fields in the_nilfs).
  483. *
  484. * Return Value: On success, 0 is returned. On error, a negative error
  485. * code is returned.
  486. */
  487. int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
  488. {
  489. struct nilfs_super_block *sbp;
  490. int blocksize;
  491. int err;
  492. down_write(&nilfs->ns_sem);
  493. blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
  494. if (!blocksize) {
  495. nilfs_err(sb, "unable to set blocksize");
  496. err = -EINVAL;
  497. goto out;
  498. }
  499. err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
  500. if (err)
  501. goto out;
  502. err = nilfs_store_magic_and_option(sb, sbp, data);
  503. if (err)
  504. goto failed_sbh;
  505. err = nilfs_check_feature_compatibility(sb, sbp);
  506. if (err)
  507. goto failed_sbh;
  508. blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
  509. if (blocksize < NILFS_MIN_BLOCK_SIZE ||
  510. blocksize > NILFS_MAX_BLOCK_SIZE) {
  511. nilfs_err(sb,
  512. "couldn't mount because of unsupported filesystem blocksize %d",
  513. blocksize);
  514. err = -EINVAL;
  515. goto failed_sbh;
  516. }
  517. if (sb->s_blocksize != blocksize) {
  518. int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
  519. if (blocksize < hw_blocksize) {
  520. nilfs_err(sb,
  521. "blocksize %d too small for device (sector-size = %d)",
  522. blocksize, hw_blocksize);
  523. err = -EINVAL;
  524. goto failed_sbh;
  525. }
  526. nilfs_release_super_block(nilfs);
  527. sb_set_blocksize(sb, blocksize);
  528. err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
  529. if (err)
  530. goto out;
  531. /*
  532. * Not to failed_sbh; sbh is released automatically
  533. * when reloading fails.
  534. */
  535. }
  536. nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
  537. nilfs->ns_blocksize = blocksize;
  538. get_random_bytes(&nilfs->ns_next_generation,
  539. sizeof(nilfs->ns_next_generation));
  540. err = nilfs_store_disk_layout(nilfs, sbp);
  541. if (err)
  542. goto failed_sbh;
  543. sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
  544. nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
  545. err = nilfs_store_log_cursor(nilfs, sbp);
  546. if (err)
  547. goto failed_sbh;
  548. err = nilfs_sysfs_create_device_group(sb);
  549. if (err)
  550. goto failed_sbh;
  551. set_nilfs_init(nilfs);
  552. err = 0;
  553. out:
  554. up_write(&nilfs->ns_sem);
  555. return err;
  556. failed_sbh:
  557. nilfs_release_super_block(nilfs);
  558. goto out;
  559. }
  560. int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
  561. size_t nsegs)
  562. {
  563. sector_t seg_start, seg_end;
  564. sector_t start = 0, nblocks = 0;
  565. unsigned int sects_per_block;
  566. __u64 *sn;
  567. int ret = 0;
  568. sects_per_block = (1 << nilfs->ns_blocksize_bits) /
  569. bdev_logical_block_size(nilfs->ns_bdev);
  570. for (sn = segnump; sn < segnump + nsegs; sn++) {
  571. nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
  572. if (!nblocks) {
  573. start = seg_start;
  574. nblocks = seg_end - seg_start + 1;
  575. } else if (start + nblocks == seg_start) {
  576. nblocks += seg_end - seg_start + 1;
  577. } else {
  578. ret = blkdev_issue_discard(nilfs->ns_bdev,
  579. start * sects_per_block,
  580. nblocks * sects_per_block,
  581. GFP_NOFS, 0);
  582. if (ret < 0)
  583. return ret;
  584. nblocks = 0;
  585. }
  586. }
  587. if (nblocks)
  588. ret = blkdev_issue_discard(nilfs->ns_bdev,
  589. start * sects_per_block,
  590. nblocks * sects_per_block,
  591. GFP_NOFS, 0);
  592. return ret;
  593. }
  594. int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
  595. {
  596. unsigned long ncleansegs;
  597. down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  598. ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
  599. up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  600. *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
  601. return 0;
  602. }
  603. int nilfs_near_disk_full(struct the_nilfs *nilfs)
  604. {
  605. unsigned long ncleansegs, nincsegs;
  606. ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
  607. nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
  608. nilfs->ns_blocks_per_segment + 1;
  609. return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
  610. }
  611. struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
  612. {
  613. struct rb_node *n;
  614. struct nilfs_root *root;
  615. spin_lock(&nilfs->ns_cptree_lock);
  616. n = nilfs->ns_cptree.rb_node;
  617. while (n) {
  618. root = rb_entry(n, struct nilfs_root, rb_node);
  619. if (cno < root->cno) {
  620. n = n->rb_left;
  621. } else if (cno > root->cno) {
  622. n = n->rb_right;
  623. } else {
  624. refcount_inc(&root->count);
  625. spin_unlock(&nilfs->ns_cptree_lock);
  626. return root;
  627. }
  628. }
  629. spin_unlock(&nilfs->ns_cptree_lock);
  630. return NULL;
  631. }
  632. struct nilfs_root *
  633. nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
  634. {
  635. struct rb_node **p, *parent;
  636. struct nilfs_root *root, *new;
  637. int err;
  638. root = nilfs_lookup_root(nilfs, cno);
  639. if (root)
  640. return root;
  641. new = kzalloc(sizeof(*root), GFP_KERNEL);
  642. if (!new)
  643. return NULL;
  644. spin_lock(&nilfs->ns_cptree_lock);
  645. p = &nilfs->ns_cptree.rb_node;
  646. parent = NULL;
  647. while (*p) {
  648. parent = *p;
  649. root = rb_entry(parent, struct nilfs_root, rb_node);
  650. if (cno < root->cno) {
  651. p = &(*p)->rb_left;
  652. } else if (cno > root->cno) {
  653. p = &(*p)->rb_right;
  654. } else {
  655. refcount_inc(&root->count);
  656. spin_unlock(&nilfs->ns_cptree_lock);
  657. kfree(new);
  658. return root;
  659. }
  660. }
  661. new->cno = cno;
  662. new->ifile = NULL;
  663. new->nilfs = nilfs;
  664. refcount_set(&new->count, 1);
  665. atomic64_set(&new->inodes_count, 0);
  666. atomic64_set(&new->blocks_count, 0);
  667. rb_link_node(&new->rb_node, parent, p);
  668. rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
  669. spin_unlock(&nilfs->ns_cptree_lock);
  670. err = nilfs_sysfs_create_snapshot_group(new);
  671. if (err) {
  672. kfree(new);
  673. new = NULL;
  674. }
  675. return new;
  676. }
  677. void nilfs_put_root(struct nilfs_root *root)
  678. {
  679. struct the_nilfs *nilfs = root->nilfs;
  680. if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) {
  681. rb_erase(&root->rb_node, &nilfs->ns_cptree);
  682. spin_unlock(&nilfs->ns_cptree_lock);
  683. nilfs_sysfs_delete_snapshot_group(root);
  684. iput(root->ifile);
  685. kfree(root);
  686. }
  687. }