extents_status.c 63 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * fs/ext4/extents_status.c
  4. *
  5. * Written by Yongqiang Yang <[email protected]>
  6. * Modified by
  7. * Allison Henderson <[email protected]>
  8. * Hugh Dickins <[email protected]>
  9. * Zheng Liu <[email protected]>
  10. *
  11. * Ext4 extents status tree core functions.
  12. */
  13. #include <linux/list_sort.h>
  14. #include <linux/proc_fs.h>
  15. #include <linux/seq_file.h>
  16. #include "ext4.h"
  17. #include <trace/events/ext4.h>
  18. /*
  19. * According to previous discussion in Ext4 Developer Workshop, we
  20. * will introduce a new structure called io tree to track all extent
  21. * status in order to solve some problems that we have met
  22. * (e.g. Reservation space warning), and provide extent-level locking.
  23. * Delay extent tree is the first step to achieve this goal. It is
  24. * original built by Yongqiang Yang. At that time it is called delay
  25. * extent tree, whose goal is only track delayed extents in memory to
  26. * simplify the implementation of fiemap and bigalloc, and introduce
  27. * lseek SEEK_DATA/SEEK_HOLE support. That is why it is still called
  28. * delay extent tree at the first commit. But for better understand
  29. * what it does, it has been rename to extent status tree.
  30. *
  31. * Step1:
  32. * Currently the first step has been done. All delayed extents are
  33. * tracked in the tree. It maintains the delayed extent when a delayed
  34. * allocation is issued, and the delayed extent is written out or
  35. * invalidated. Therefore the implementation of fiemap and bigalloc
  36. * are simplified, and SEEK_DATA/SEEK_HOLE are introduced.
  37. *
  38. * The following comment describes the implemenmtation of extent
  39. * status tree and future works.
  40. *
  41. * Step2:
  42. * In this step all extent status are tracked by extent status tree.
  43. * Thus, we can first try to lookup a block mapping in this tree before
  44. * finding it in extent tree. Hence, single extent cache can be removed
  45. * because extent status tree can do a better job. Extents in status
  46. * tree are loaded on-demand. Therefore, the extent status tree may not
  47. * contain all of the extents in a file. Meanwhile we define a shrinker
  48. * to reclaim memory from extent status tree because fragmented extent
  49. * tree will make status tree cost too much memory. written/unwritten/-
  50. * hole extents in the tree will be reclaimed by this shrinker when we
  51. * are under high memory pressure. Delayed extents will not be
  52. * reclimed because fiemap, bigalloc, and seek_data/hole need it.
  53. */
  54. /*
  55. * Extent status tree implementation for ext4.
  56. *
  57. *
  58. * ==========================================================================
  59. * Extent status tree tracks all extent status.
  60. *
  61. * 1. Why we need to implement extent status tree?
  62. *
  63. * Without extent status tree, ext4 identifies a delayed extent by looking
  64. * up page cache, this has several deficiencies - complicated, buggy,
  65. * and inefficient code.
  66. *
  67. * FIEMAP, SEEK_HOLE/DATA, bigalloc, and writeout all need to know if a
  68. * block or a range of blocks are belonged to a delayed extent.
  69. *
  70. * Let us have a look at how they do without extent status tree.
  71. * -- FIEMAP
  72. * FIEMAP looks up page cache to identify delayed allocations from holes.
  73. *
  74. * -- SEEK_HOLE/DATA
  75. * SEEK_HOLE/DATA has the same problem as FIEMAP.
  76. *
  77. * -- bigalloc
  78. * bigalloc looks up page cache to figure out if a block is
  79. * already under delayed allocation or not to determine whether
  80. * quota reserving is needed for the cluster.
  81. *
  82. * -- writeout
  83. * Writeout looks up whole page cache to see if a buffer is
  84. * mapped, If there are not very many delayed buffers, then it is
  85. * time consuming.
  86. *
  87. * With extent status tree implementation, FIEMAP, SEEK_HOLE/DATA,
  88. * bigalloc and writeout can figure out if a block or a range of
  89. * blocks is under delayed allocation(belonged to a delayed extent) or
  90. * not by searching the extent tree.
  91. *
  92. *
  93. * ==========================================================================
  94. * 2. Ext4 extent status tree impelmentation
  95. *
  96. * -- extent
  97. * A extent is a range of blocks which are contiguous logically and
  98. * physically. Unlike extent in extent tree, this extent in ext4 is
  99. * a in-memory struct, there is no corresponding on-disk data. There
  100. * is no limit on length of extent, so an extent can contain as many
  101. * blocks as they are contiguous logically and physically.
  102. *
  103. * -- extent status tree
  104. * Every inode has an extent status tree and all allocation blocks
  105. * are added to the tree with different status. The extent in the
  106. * tree are ordered by logical block no.
  107. *
  108. * -- operations on a extent status tree
  109. * There are three important operations on a delayed extent tree: find
  110. * next extent, adding a extent(a range of blocks) and removing a extent.
  111. *
  112. * -- race on a extent status tree
  113. * Extent status tree is protected by inode->i_es_lock.
  114. *
  115. * -- memory consumption
  116. * Fragmented extent tree will make extent status tree cost too much
  117. * memory. Hence, we will reclaim written/unwritten/hole extents from
  118. * the tree under a heavy memory pressure.
  119. *
  120. *
  121. * ==========================================================================
  122. * 3. Performance analysis
  123. *
  124. * -- overhead
  125. * 1. There is a cache extent for write access, so if writes are
  126. * not very random, adding space operaions are in O(1) time.
  127. *
  128. * -- gain
  129. * 2. Code is much simpler, more readable, more maintainable and
  130. * more efficient.
  131. *
  132. *
  133. * ==========================================================================
  134. * 4. TODO list
  135. *
  136. * -- Refactor delayed space reservation
  137. *
  138. * -- Extent-level locking
  139. */
  140. static struct kmem_cache *ext4_es_cachep;
  141. static struct kmem_cache *ext4_pending_cachep;
  142. static int __es_insert_extent(struct inode *inode, struct extent_status *newes,
  143. struct extent_status *prealloc);
  144. static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
  145. ext4_lblk_t end, int *reserved,
  146. struct extent_status *prealloc);
  147. static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan);
  148. static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
  149. struct ext4_inode_info *locked_ei);
  150. static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
  151. ext4_lblk_t len,
  152. struct pending_reservation **prealloc);
  153. int __init ext4_init_es(void)
  154. {
  155. ext4_es_cachep = kmem_cache_create("ext4_extent_status",
  156. sizeof(struct extent_status),
  157. 0, (SLAB_RECLAIM_ACCOUNT), NULL);
  158. if (ext4_es_cachep == NULL)
  159. return -ENOMEM;
  160. return 0;
  161. }
  162. void ext4_exit_es(void)
  163. {
  164. kmem_cache_destroy(ext4_es_cachep);
  165. }
  166. void ext4_es_init_tree(struct ext4_es_tree *tree)
  167. {
  168. tree->root = RB_ROOT;
  169. tree->cache_es = NULL;
  170. }
  171. #ifdef ES_DEBUG__
  172. static void ext4_es_print_tree(struct inode *inode)
  173. {
  174. struct ext4_es_tree *tree;
  175. struct rb_node *node;
  176. printk(KERN_DEBUG "status extents for inode %lu:", inode->i_ino);
  177. tree = &EXT4_I(inode)->i_es_tree;
  178. node = rb_first(&tree->root);
  179. while (node) {
  180. struct extent_status *es;
  181. es = rb_entry(node, struct extent_status, rb_node);
  182. printk(KERN_DEBUG " [%u/%u) %llu %x",
  183. es->es_lblk, es->es_len,
  184. ext4_es_pblock(es), ext4_es_status(es));
  185. node = rb_next(node);
  186. }
  187. printk(KERN_DEBUG "\n");
  188. }
  189. #else
  190. #define ext4_es_print_tree(inode)
  191. #endif
  192. static inline ext4_lblk_t ext4_es_end(struct extent_status *es)
  193. {
  194. BUG_ON(es->es_lblk + es->es_len < es->es_lblk);
  195. return es->es_lblk + es->es_len - 1;
  196. }
  197. /*
  198. * search through the tree for an delayed extent with a given offset. If
  199. * it can't be found, try to find next extent.
  200. */
  201. static struct extent_status *__es_tree_search(struct rb_root *root,
  202. ext4_lblk_t lblk)
  203. {
  204. struct rb_node *node = root->rb_node;
  205. struct extent_status *es = NULL;
  206. while (node) {
  207. es = rb_entry(node, struct extent_status, rb_node);
  208. if (lblk < es->es_lblk)
  209. node = node->rb_left;
  210. else if (lblk > ext4_es_end(es))
  211. node = node->rb_right;
  212. else
  213. return es;
  214. }
  215. if (es && lblk < es->es_lblk)
  216. return es;
  217. if (es && lblk > ext4_es_end(es)) {
  218. node = rb_next(&es->rb_node);
  219. return node ? rb_entry(node, struct extent_status, rb_node) :
  220. NULL;
  221. }
  222. return NULL;
  223. }
  224. /*
  225. * ext4_es_find_extent_range - find extent with specified status within block
  226. * range or next extent following block range in
  227. * extents status tree
  228. *
  229. * @inode - file containing the range
  230. * @matching_fn - pointer to function that matches extents with desired status
  231. * @lblk - logical block defining start of range
  232. * @end - logical block defining end of range
  233. * @es - extent found, if any
  234. *
  235. * Find the first extent within the block range specified by @lblk and @end
  236. * in the extents status tree that satisfies @matching_fn. If a match
  237. * is found, it's returned in @es. If not, and a matching extent is found
  238. * beyond the block range, it's returned in @es. If no match is found, an
  239. * extent is returned in @es whose es_lblk, es_len, and es_pblk components
  240. * are 0.
  241. */
  242. static void __es_find_extent_range(struct inode *inode,
  243. int (*matching_fn)(struct extent_status *es),
  244. ext4_lblk_t lblk, ext4_lblk_t end,
  245. struct extent_status *es)
  246. {
  247. struct ext4_es_tree *tree = NULL;
  248. struct extent_status *es1 = NULL;
  249. struct rb_node *node;
  250. WARN_ON(es == NULL);
  251. WARN_ON(end < lblk);
  252. tree = &EXT4_I(inode)->i_es_tree;
  253. /* see if the extent has been cached */
  254. es->es_lblk = es->es_len = es->es_pblk = 0;
  255. es1 = READ_ONCE(tree->cache_es);
  256. if (es1 && in_range(lblk, es1->es_lblk, es1->es_len)) {
  257. es_debug("%u cached by [%u/%u) %llu %x\n",
  258. lblk, es1->es_lblk, es1->es_len,
  259. ext4_es_pblock(es1), ext4_es_status(es1));
  260. goto out;
  261. }
  262. es1 = __es_tree_search(&tree->root, lblk);
  263. out:
  264. if (es1 && !matching_fn(es1)) {
  265. while ((node = rb_next(&es1->rb_node)) != NULL) {
  266. es1 = rb_entry(node, struct extent_status, rb_node);
  267. if (es1->es_lblk > end) {
  268. es1 = NULL;
  269. break;
  270. }
  271. if (matching_fn(es1))
  272. break;
  273. }
  274. }
  275. if (es1 && matching_fn(es1)) {
  276. WRITE_ONCE(tree->cache_es, es1);
  277. es->es_lblk = es1->es_lblk;
  278. es->es_len = es1->es_len;
  279. es->es_pblk = es1->es_pblk;
  280. }
  281. }
  282. /*
  283. * Locking for __es_find_extent_range() for external use
  284. */
  285. void ext4_es_find_extent_range(struct inode *inode,
  286. int (*matching_fn)(struct extent_status *es),
  287. ext4_lblk_t lblk, ext4_lblk_t end,
  288. struct extent_status *es)
  289. {
  290. if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
  291. return;
  292. trace_ext4_es_find_extent_range_enter(inode, lblk);
  293. read_lock(&EXT4_I(inode)->i_es_lock);
  294. __es_find_extent_range(inode, matching_fn, lblk, end, es);
  295. read_unlock(&EXT4_I(inode)->i_es_lock);
  296. trace_ext4_es_find_extent_range_exit(inode, es);
  297. }
  298. /*
  299. * __es_scan_range - search block range for block with specified status
  300. * in extents status tree
  301. *
  302. * @inode - file containing the range
  303. * @matching_fn - pointer to function that matches extents with desired status
  304. * @lblk - logical block defining start of range
  305. * @end - logical block defining end of range
  306. *
  307. * Returns true if at least one block in the specified block range satisfies
  308. * the criterion specified by @matching_fn, and false if not. If at least
  309. * one extent has the specified status, then there is at least one block
  310. * in the cluster with that status. Should only be called by code that has
  311. * taken i_es_lock.
  312. */
  313. static bool __es_scan_range(struct inode *inode,
  314. int (*matching_fn)(struct extent_status *es),
  315. ext4_lblk_t start, ext4_lblk_t end)
  316. {
  317. struct extent_status es;
  318. __es_find_extent_range(inode, matching_fn, start, end, &es);
  319. if (es.es_len == 0)
  320. return false; /* no matching extent in the tree */
  321. else if (es.es_lblk <= start &&
  322. start < es.es_lblk + es.es_len)
  323. return true;
  324. else if (start <= es.es_lblk && es.es_lblk <= end)
  325. return true;
  326. else
  327. return false;
  328. }
  329. /*
  330. * Locking for __es_scan_range() for external use
  331. */
  332. bool ext4_es_scan_range(struct inode *inode,
  333. int (*matching_fn)(struct extent_status *es),
  334. ext4_lblk_t lblk, ext4_lblk_t end)
  335. {
  336. bool ret;
  337. if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
  338. return false;
  339. read_lock(&EXT4_I(inode)->i_es_lock);
  340. ret = __es_scan_range(inode, matching_fn, lblk, end);
  341. read_unlock(&EXT4_I(inode)->i_es_lock);
  342. return ret;
  343. }
  344. /*
  345. * __es_scan_clu - search cluster for block with specified status in
  346. * extents status tree
  347. *
  348. * @inode - file containing the cluster
  349. * @matching_fn - pointer to function that matches extents with desired status
  350. * @lblk - logical block in cluster to be searched
  351. *
  352. * Returns true if at least one extent in the cluster containing @lblk
  353. * satisfies the criterion specified by @matching_fn, and false if not. If at
  354. * least one extent has the specified status, then there is at least one block
  355. * in the cluster with that status. Should only be called by code that has
  356. * taken i_es_lock.
  357. */
  358. static bool __es_scan_clu(struct inode *inode,
  359. int (*matching_fn)(struct extent_status *es),
  360. ext4_lblk_t lblk)
  361. {
  362. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  363. ext4_lblk_t lblk_start, lblk_end;
  364. lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
  365. lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
  366. return __es_scan_range(inode, matching_fn, lblk_start, lblk_end);
  367. }
  368. /*
  369. * Locking for __es_scan_clu() for external use
  370. */
  371. bool ext4_es_scan_clu(struct inode *inode,
  372. int (*matching_fn)(struct extent_status *es),
  373. ext4_lblk_t lblk)
  374. {
  375. bool ret;
  376. if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
  377. return false;
  378. read_lock(&EXT4_I(inode)->i_es_lock);
  379. ret = __es_scan_clu(inode, matching_fn, lblk);
  380. read_unlock(&EXT4_I(inode)->i_es_lock);
  381. return ret;
  382. }
  383. static void ext4_es_list_add(struct inode *inode)
  384. {
  385. struct ext4_inode_info *ei = EXT4_I(inode);
  386. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  387. if (!list_empty(&ei->i_es_list))
  388. return;
  389. spin_lock(&sbi->s_es_lock);
  390. if (list_empty(&ei->i_es_list)) {
  391. list_add_tail(&ei->i_es_list, &sbi->s_es_list);
  392. sbi->s_es_nr_inode++;
  393. }
  394. spin_unlock(&sbi->s_es_lock);
  395. }
  396. static void ext4_es_list_del(struct inode *inode)
  397. {
  398. struct ext4_inode_info *ei = EXT4_I(inode);
  399. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  400. spin_lock(&sbi->s_es_lock);
  401. if (!list_empty(&ei->i_es_list)) {
  402. list_del_init(&ei->i_es_list);
  403. sbi->s_es_nr_inode--;
  404. WARN_ON_ONCE(sbi->s_es_nr_inode < 0);
  405. }
  406. spin_unlock(&sbi->s_es_lock);
  407. }
  408. static inline struct pending_reservation *__alloc_pending(bool nofail)
  409. {
  410. if (!nofail)
  411. return kmem_cache_alloc(ext4_pending_cachep, GFP_ATOMIC);
  412. return kmem_cache_zalloc(ext4_pending_cachep, GFP_KERNEL | __GFP_NOFAIL);
  413. }
  414. static inline void __free_pending(struct pending_reservation *pr)
  415. {
  416. kmem_cache_free(ext4_pending_cachep, pr);
  417. }
  418. /*
  419. * Returns true if we cannot fail to allocate memory for this extent_status
  420. * entry and cannot reclaim it until its status changes.
  421. */
  422. static inline bool ext4_es_must_keep(struct extent_status *es)
  423. {
  424. /* fiemap, bigalloc, and seek_data/hole need to use it. */
  425. if (ext4_es_is_delayed(es))
  426. return true;
  427. return false;
  428. }
  429. static inline struct extent_status *__es_alloc_extent(bool nofail)
  430. {
  431. if (!nofail)
  432. return kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC);
  433. return kmem_cache_zalloc(ext4_es_cachep, GFP_KERNEL | __GFP_NOFAIL);
  434. }
  435. static void ext4_es_init_extent(struct inode *inode, struct extent_status *es,
  436. ext4_lblk_t lblk, ext4_lblk_t len, ext4_fsblk_t pblk)
  437. {
  438. es->es_lblk = lblk;
  439. es->es_len = len;
  440. es->es_pblk = pblk;
  441. /* We never try to reclaim a must kept extent, so we don't count it. */
  442. if (!ext4_es_must_keep(es)) {
  443. if (!EXT4_I(inode)->i_es_shk_nr++)
  444. ext4_es_list_add(inode);
  445. percpu_counter_inc(&EXT4_SB(inode->i_sb)->
  446. s_es_stats.es_stats_shk_cnt);
  447. }
  448. EXT4_I(inode)->i_es_all_nr++;
  449. percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
  450. }
  451. static inline void __es_free_extent(struct extent_status *es)
  452. {
  453. kmem_cache_free(ext4_es_cachep, es);
  454. }
  455. static void ext4_es_free_extent(struct inode *inode, struct extent_status *es)
  456. {
  457. EXT4_I(inode)->i_es_all_nr--;
  458. percpu_counter_dec(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
  459. /* Decrease the shrink counter when we can reclaim the extent. */
  460. if (!ext4_es_must_keep(es)) {
  461. BUG_ON(EXT4_I(inode)->i_es_shk_nr == 0);
  462. if (!--EXT4_I(inode)->i_es_shk_nr)
  463. ext4_es_list_del(inode);
  464. percpu_counter_dec(&EXT4_SB(inode->i_sb)->
  465. s_es_stats.es_stats_shk_cnt);
  466. }
  467. __es_free_extent(es);
  468. }
  469. /*
  470. * Check whether or not two extents can be merged
  471. * Condition:
  472. * - logical block number is contiguous
  473. * - physical block number is contiguous
  474. * - status is equal
  475. */
  476. static int ext4_es_can_be_merged(struct extent_status *es1,
  477. struct extent_status *es2)
  478. {
  479. if (ext4_es_type(es1) != ext4_es_type(es2))
  480. return 0;
  481. if (((__u64) es1->es_len) + es2->es_len > EXT_MAX_BLOCKS) {
  482. pr_warn("ES assertion failed when merging extents. "
  483. "The sum of lengths of es1 (%d) and es2 (%d) "
  484. "is bigger than allowed file size (%d)\n",
  485. es1->es_len, es2->es_len, EXT_MAX_BLOCKS);
  486. WARN_ON(1);
  487. return 0;
  488. }
  489. if (((__u64) es1->es_lblk) + es1->es_len != es2->es_lblk)
  490. return 0;
  491. if ((ext4_es_is_written(es1) || ext4_es_is_unwritten(es1)) &&
  492. (ext4_es_pblock(es1) + es1->es_len == ext4_es_pblock(es2)))
  493. return 1;
  494. if (ext4_es_is_hole(es1))
  495. return 1;
  496. /* we need to check delayed extent is without unwritten status */
  497. if (ext4_es_is_delayed(es1) && !ext4_es_is_unwritten(es1))
  498. return 1;
  499. return 0;
  500. }
  501. static struct extent_status *
  502. ext4_es_try_to_merge_left(struct inode *inode, struct extent_status *es)
  503. {
  504. struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
  505. struct extent_status *es1;
  506. struct rb_node *node;
  507. node = rb_prev(&es->rb_node);
  508. if (!node)
  509. return es;
  510. es1 = rb_entry(node, struct extent_status, rb_node);
  511. if (ext4_es_can_be_merged(es1, es)) {
  512. es1->es_len += es->es_len;
  513. if (ext4_es_is_referenced(es))
  514. ext4_es_set_referenced(es1);
  515. rb_erase(&es->rb_node, &tree->root);
  516. ext4_es_free_extent(inode, es);
  517. es = es1;
  518. }
  519. return es;
  520. }
  521. static struct extent_status *
  522. ext4_es_try_to_merge_right(struct inode *inode, struct extent_status *es)
  523. {
  524. struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
  525. struct extent_status *es1;
  526. struct rb_node *node;
  527. node = rb_next(&es->rb_node);
  528. if (!node)
  529. return es;
  530. es1 = rb_entry(node, struct extent_status, rb_node);
  531. if (ext4_es_can_be_merged(es, es1)) {
  532. es->es_len += es1->es_len;
  533. if (ext4_es_is_referenced(es1))
  534. ext4_es_set_referenced(es);
  535. rb_erase(node, &tree->root);
  536. ext4_es_free_extent(inode, es1);
  537. }
  538. return es;
  539. }
  540. #ifdef ES_AGGRESSIVE_TEST
  541. #include "ext4_extents.h" /* Needed when ES_AGGRESSIVE_TEST is defined */
  542. static void ext4_es_insert_extent_ext_check(struct inode *inode,
  543. struct extent_status *es)
  544. {
  545. struct ext4_ext_path *path = NULL;
  546. struct ext4_extent *ex;
  547. ext4_lblk_t ee_block;
  548. ext4_fsblk_t ee_start;
  549. unsigned short ee_len;
  550. int depth, ee_status, es_status;
  551. path = ext4_find_extent(inode, es->es_lblk, NULL, EXT4_EX_NOCACHE);
  552. if (IS_ERR(path))
  553. return;
  554. depth = ext_depth(inode);
  555. ex = path[depth].p_ext;
  556. if (ex) {
  557. ee_block = le32_to_cpu(ex->ee_block);
  558. ee_start = ext4_ext_pblock(ex);
  559. ee_len = ext4_ext_get_actual_len(ex);
  560. ee_status = ext4_ext_is_unwritten(ex) ? 1 : 0;
  561. es_status = ext4_es_is_unwritten(es) ? 1 : 0;
  562. /*
  563. * Make sure ex and es are not overlap when we try to insert
  564. * a delayed/hole extent.
  565. */
  566. if (!ext4_es_is_written(es) && !ext4_es_is_unwritten(es)) {
  567. if (in_range(es->es_lblk, ee_block, ee_len)) {
  568. pr_warn("ES insert assertion failed for "
  569. "inode: %lu we can find an extent "
  570. "at block [%d/%d/%llu/%c], but we "
  571. "want to add a delayed/hole extent "
  572. "[%d/%d/%llu/%x]\n",
  573. inode->i_ino, ee_block, ee_len,
  574. ee_start, ee_status ? 'u' : 'w',
  575. es->es_lblk, es->es_len,
  576. ext4_es_pblock(es), ext4_es_status(es));
  577. }
  578. goto out;
  579. }
  580. /*
  581. * We don't check ee_block == es->es_lblk, etc. because es
  582. * might be a part of whole extent, vice versa.
  583. */
  584. if (es->es_lblk < ee_block ||
  585. ext4_es_pblock(es) != ee_start + es->es_lblk - ee_block) {
  586. pr_warn("ES insert assertion failed for inode: %lu "
  587. "ex_status [%d/%d/%llu/%c] != "
  588. "es_status [%d/%d/%llu/%c]\n", inode->i_ino,
  589. ee_block, ee_len, ee_start,
  590. ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
  591. ext4_es_pblock(es), es_status ? 'u' : 'w');
  592. goto out;
  593. }
  594. if (ee_status ^ es_status) {
  595. pr_warn("ES insert assertion failed for inode: %lu "
  596. "ex_status [%d/%d/%llu/%c] != "
  597. "es_status [%d/%d/%llu/%c]\n", inode->i_ino,
  598. ee_block, ee_len, ee_start,
  599. ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
  600. ext4_es_pblock(es), es_status ? 'u' : 'w');
  601. }
  602. } else {
  603. /*
  604. * We can't find an extent on disk. So we need to make sure
  605. * that we don't want to add an written/unwritten extent.
  606. */
  607. if (!ext4_es_is_delayed(es) && !ext4_es_is_hole(es)) {
  608. pr_warn("ES insert assertion failed for inode: %lu "
  609. "can't find an extent at block %d but we want "
  610. "to add a written/unwritten extent "
  611. "[%d/%d/%llu/%x]\n", inode->i_ino,
  612. es->es_lblk, es->es_lblk, es->es_len,
  613. ext4_es_pblock(es), ext4_es_status(es));
  614. }
  615. }
  616. out:
  617. ext4_free_ext_path(path);
  618. }
  619. static void ext4_es_insert_extent_ind_check(struct inode *inode,
  620. struct extent_status *es)
  621. {
  622. struct ext4_map_blocks map;
  623. int retval;
  624. /*
  625. * Here we call ext4_ind_map_blocks to lookup a block mapping because
  626. * 'Indirect' structure is defined in indirect.c. So we couldn't
  627. * access direct/indirect tree from outside. It is too dirty to define
  628. * this function in indirect.c file.
  629. */
  630. map.m_lblk = es->es_lblk;
  631. map.m_len = es->es_len;
  632. retval = ext4_ind_map_blocks(NULL, inode, &map, 0);
  633. if (retval > 0) {
  634. if (ext4_es_is_delayed(es) || ext4_es_is_hole(es)) {
  635. /*
  636. * We want to add a delayed/hole extent but this
  637. * block has been allocated.
  638. */
  639. pr_warn("ES insert assertion failed for inode: %lu "
  640. "We can find blocks but we want to add a "
  641. "delayed/hole extent [%d/%d/%llu/%x]\n",
  642. inode->i_ino, es->es_lblk, es->es_len,
  643. ext4_es_pblock(es), ext4_es_status(es));
  644. return;
  645. } else if (ext4_es_is_written(es)) {
  646. if (retval != es->es_len) {
  647. pr_warn("ES insert assertion failed for "
  648. "inode: %lu retval %d != es_len %d\n",
  649. inode->i_ino, retval, es->es_len);
  650. return;
  651. }
  652. if (map.m_pblk != ext4_es_pblock(es)) {
  653. pr_warn("ES insert assertion failed for "
  654. "inode: %lu m_pblk %llu != "
  655. "es_pblk %llu\n",
  656. inode->i_ino, map.m_pblk,
  657. ext4_es_pblock(es));
  658. return;
  659. }
  660. } else {
  661. /*
  662. * We don't need to check unwritten extent because
  663. * indirect-based file doesn't have it.
  664. */
  665. BUG();
  666. }
  667. } else if (retval == 0) {
  668. if (ext4_es_is_written(es)) {
  669. pr_warn("ES insert assertion failed for inode: %lu "
  670. "We can't find the block but we want to add "
  671. "a written extent [%d/%d/%llu/%x]\n",
  672. inode->i_ino, es->es_lblk, es->es_len,
  673. ext4_es_pblock(es), ext4_es_status(es));
  674. return;
  675. }
  676. }
  677. }
  678. static inline void ext4_es_insert_extent_check(struct inode *inode,
  679. struct extent_status *es)
  680. {
  681. /*
  682. * We don't need to worry about the race condition because
  683. * caller takes i_data_sem locking.
  684. */
  685. BUG_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
  686. if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
  687. ext4_es_insert_extent_ext_check(inode, es);
  688. else
  689. ext4_es_insert_extent_ind_check(inode, es);
  690. }
  691. #else
  692. static inline void ext4_es_insert_extent_check(struct inode *inode,
  693. struct extent_status *es)
  694. {
  695. }
  696. #endif
  697. static int __es_insert_extent(struct inode *inode, struct extent_status *newes,
  698. struct extent_status *prealloc)
  699. {
  700. struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
  701. struct rb_node **p = &tree->root.rb_node;
  702. struct rb_node *parent = NULL;
  703. struct extent_status *es;
  704. while (*p) {
  705. parent = *p;
  706. es = rb_entry(parent, struct extent_status, rb_node);
  707. if (newes->es_lblk < es->es_lblk) {
  708. if (ext4_es_can_be_merged(newes, es)) {
  709. /*
  710. * Here we can modify es_lblk directly
  711. * because it isn't overlapped.
  712. */
  713. es->es_lblk = newes->es_lblk;
  714. es->es_len += newes->es_len;
  715. if (ext4_es_is_written(es) ||
  716. ext4_es_is_unwritten(es))
  717. ext4_es_store_pblock(es,
  718. newes->es_pblk);
  719. es = ext4_es_try_to_merge_left(inode, es);
  720. goto out;
  721. }
  722. p = &(*p)->rb_left;
  723. } else if (newes->es_lblk > ext4_es_end(es)) {
  724. if (ext4_es_can_be_merged(es, newes)) {
  725. es->es_len += newes->es_len;
  726. es = ext4_es_try_to_merge_right(inode, es);
  727. goto out;
  728. }
  729. p = &(*p)->rb_right;
  730. } else {
  731. BUG();
  732. return -EINVAL;
  733. }
  734. }
  735. if (prealloc)
  736. es = prealloc;
  737. else
  738. es = __es_alloc_extent(false);
  739. if (!es)
  740. return -ENOMEM;
  741. ext4_es_init_extent(inode, es, newes->es_lblk, newes->es_len,
  742. newes->es_pblk);
  743. rb_link_node(&es->rb_node, parent, p);
  744. rb_insert_color(&es->rb_node, &tree->root);
  745. out:
  746. tree->cache_es = es;
  747. return 0;
  748. }
  749. /*
  750. * ext4_es_insert_extent() adds information to an inode's extent
  751. * status tree.
  752. *
  753. * Return 0 on success, error code on failure.
  754. */
  755. int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
  756. ext4_lblk_t len, ext4_fsblk_t pblk,
  757. unsigned int status)
  758. {
  759. struct extent_status newes;
  760. ext4_lblk_t end = lblk + len - 1;
  761. int err1 = 0, err2 = 0, err3 = 0;
  762. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  763. struct extent_status *es1 = NULL;
  764. struct extent_status *es2 = NULL;
  765. struct pending_reservation *pr = NULL;
  766. bool revise_pending = false;
  767. if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
  768. return 0;
  769. es_debug("add [%u/%u) %llu %x to extent status tree of inode %lu\n",
  770. lblk, len, pblk, status, inode->i_ino);
  771. if (!len)
  772. return 0;
  773. BUG_ON(end < lblk);
  774. if ((status & EXTENT_STATUS_DELAYED) &&
  775. (status & EXTENT_STATUS_WRITTEN)) {
  776. ext4_warning(inode->i_sb, "Inserting extent [%u/%u] as "
  777. " delayed and written which can potentially "
  778. " cause data loss.", lblk, len);
  779. WARN_ON(1);
  780. }
  781. newes.es_lblk = lblk;
  782. newes.es_len = len;
  783. ext4_es_store_pblock_status(&newes, pblk, status);
  784. trace_ext4_es_insert_extent(inode, &newes);
  785. ext4_es_insert_extent_check(inode, &newes);
  786. revise_pending = sbi->s_cluster_ratio > 1 &&
  787. test_opt(inode->i_sb, DELALLOC) &&
  788. (status & (EXTENT_STATUS_WRITTEN |
  789. EXTENT_STATUS_UNWRITTEN));
  790. retry:
  791. if (err1 && !es1)
  792. es1 = __es_alloc_extent(true);
  793. if ((err1 || err2) && !es2)
  794. es2 = __es_alloc_extent(true);
  795. if ((err1 || err2 || err3) && revise_pending && !pr)
  796. pr = __alloc_pending(true);
  797. write_lock(&EXT4_I(inode)->i_es_lock);
  798. err1 = __es_remove_extent(inode, lblk, end, NULL, es1);
  799. if (err1 != 0)
  800. goto error;
  801. /* Free preallocated extent if it didn't get used. */
  802. if (es1) {
  803. if (!es1->es_len)
  804. __es_free_extent(es1);
  805. es1 = NULL;
  806. }
  807. err2 = __es_insert_extent(inode, &newes, es2);
  808. if (err2 == -ENOMEM && !ext4_es_must_keep(&newes))
  809. err2 = 0;
  810. if (err2 != 0)
  811. goto error;
  812. /* Free preallocated extent if it didn't get used. */
  813. if (es2) {
  814. if (!es2->es_len)
  815. __es_free_extent(es2);
  816. es2 = NULL;
  817. }
  818. if (revise_pending) {
  819. err3 = __revise_pending(inode, lblk, len, &pr);
  820. if (err3 != 0)
  821. goto error;
  822. if (pr) {
  823. __free_pending(pr);
  824. pr = NULL;
  825. }
  826. }
  827. error:
  828. write_unlock(&EXT4_I(inode)->i_es_lock);
  829. if (err1 || err2 || err3)
  830. goto retry;
  831. ext4_es_print_tree(inode);
  832. return 0;
  833. }
  834. /*
  835. * ext4_es_cache_extent() inserts information into the extent status
  836. * tree if and only if there isn't information about the range in
  837. * question already.
  838. */
  839. void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
  840. ext4_lblk_t len, ext4_fsblk_t pblk,
  841. unsigned int status)
  842. {
  843. struct extent_status *es;
  844. struct extent_status newes;
  845. ext4_lblk_t end = lblk + len - 1;
  846. if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
  847. return;
  848. newes.es_lblk = lblk;
  849. newes.es_len = len;
  850. ext4_es_store_pblock_status(&newes, pblk, status);
  851. trace_ext4_es_cache_extent(inode, &newes);
  852. if (!len)
  853. return;
  854. BUG_ON(end < lblk);
  855. write_lock(&EXT4_I(inode)->i_es_lock);
  856. es = __es_tree_search(&EXT4_I(inode)->i_es_tree.root, lblk);
  857. if (!es || es->es_lblk > end)
  858. __es_insert_extent(inode, &newes, NULL);
  859. write_unlock(&EXT4_I(inode)->i_es_lock);
  860. }
  861. /*
  862. * ext4_es_lookup_extent() looks up an extent in extent status tree.
  863. *
  864. * ext4_es_lookup_extent is called by ext4_map_blocks/ext4_da_map_blocks.
  865. *
  866. * Return: 1 on found, 0 on not
  867. */
  868. int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
  869. ext4_lblk_t *next_lblk,
  870. struct extent_status *es)
  871. {
  872. struct ext4_es_tree *tree;
  873. struct ext4_es_stats *stats;
  874. struct extent_status *es1 = NULL;
  875. struct rb_node *node;
  876. int found = 0;
  877. if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
  878. return 0;
  879. trace_ext4_es_lookup_extent_enter(inode, lblk);
  880. es_debug("lookup extent in block %u\n", lblk);
  881. tree = &EXT4_I(inode)->i_es_tree;
  882. read_lock(&EXT4_I(inode)->i_es_lock);
  883. /* find extent in cache firstly */
  884. es->es_lblk = es->es_len = es->es_pblk = 0;
  885. es1 = READ_ONCE(tree->cache_es);
  886. if (es1 && in_range(lblk, es1->es_lblk, es1->es_len)) {
  887. es_debug("%u cached by [%u/%u)\n",
  888. lblk, es1->es_lblk, es1->es_len);
  889. found = 1;
  890. goto out;
  891. }
  892. node = tree->root.rb_node;
  893. while (node) {
  894. es1 = rb_entry(node, struct extent_status, rb_node);
  895. if (lblk < es1->es_lblk)
  896. node = node->rb_left;
  897. else if (lblk > ext4_es_end(es1))
  898. node = node->rb_right;
  899. else {
  900. found = 1;
  901. break;
  902. }
  903. }
  904. out:
  905. stats = &EXT4_SB(inode->i_sb)->s_es_stats;
  906. if (found) {
  907. BUG_ON(!es1);
  908. es->es_lblk = es1->es_lblk;
  909. es->es_len = es1->es_len;
  910. es->es_pblk = es1->es_pblk;
  911. if (!ext4_es_is_referenced(es1))
  912. ext4_es_set_referenced(es1);
  913. percpu_counter_inc(&stats->es_stats_cache_hits);
  914. if (next_lblk) {
  915. node = rb_next(&es1->rb_node);
  916. if (node) {
  917. es1 = rb_entry(node, struct extent_status,
  918. rb_node);
  919. *next_lblk = es1->es_lblk;
  920. } else
  921. *next_lblk = 0;
  922. }
  923. } else {
  924. percpu_counter_inc(&stats->es_stats_cache_misses);
  925. }
  926. read_unlock(&EXT4_I(inode)->i_es_lock);
  927. trace_ext4_es_lookup_extent_exit(inode, es, found);
  928. return found;
  929. }
  930. struct rsvd_count {
  931. int ndelonly;
  932. bool first_do_lblk_found;
  933. ext4_lblk_t first_do_lblk;
  934. ext4_lblk_t last_do_lblk;
  935. struct extent_status *left_es;
  936. bool partial;
  937. ext4_lblk_t lclu;
  938. };
  939. /*
  940. * init_rsvd - initialize reserved count data before removing block range
  941. * in file from extent status tree
  942. *
  943. * @inode - file containing range
  944. * @lblk - first block in range
  945. * @es - pointer to first extent in range
  946. * @rc - pointer to reserved count data
  947. *
  948. * Assumes es is not NULL
  949. */
  950. static void init_rsvd(struct inode *inode, ext4_lblk_t lblk,
  951. struct extent_status *es, struct rsvd_count *rc)
  952. {
  953. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  954. struct rb_node *node;
  955. rc->ndelonly = 0;
  956. /*
  957. * for bigalloc, note the first delonly block in the range has not
  958. * been found, record the extent containing the block to the left of
  959. * the region to be removed, if any, and note that there's no partial
  960. * cluster to track
  961. */
  962. if (sbi->s_cluster_ratio > 1) {
  963. rc->first_do_lblk_found = false;
  964. if (lblk > es->es_lblk) {
  965. rc->left_es = es;
  966. } else {
  967. node = rb_prev(&es->rb_node);
  968. rc->left_es = node ? rb_entry(node,
  969. struct extent_status,
  970. rb_node) : NULL;
  971. }
  972. rc->partial = false;
  973. }
  974. }
  975. /*
  976. * count_rsvd - count the clusters containing delayed and not unwritten
  977. * (delonly) blocks in a range within an extent and add to
  978. * the running tally in rsvd_count
  979. *
  980. * @inode - file containing extent
  981. * @lblk - first block in range
  982. * @len - length of range in blocks
  983. * @es - pointer to extent containing clusters to be counted
  984. * @rc - pointer to reserved count data
  985. *
  986. * Tracks partial clusters found at the beginning and end of extents so
  987. * they aren't overcounted when they span adjacent extents
  988. */
  989. static void count_rsvd(struct inode *inode, ext4_lblk_t lblk, long len,
  990. struct extent_status *es, struct rsvd_count *rc)
  991. {
  992. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  993. ext4_lblk_t i, end, nclu;
  994. if (!ext4_es_is_delonly(es))
  995. return;
  996. WARN_ON(len <= 0);
  997. if (sbi->s_cluster_ratio == 1) {
  998. rc->ndelonly += (int) len;
  999. return;
  1000. }
  1001. /* bigalloc */
  1002. i = (lblk < es->es_lblk) ? es->es_lblk : lblk;
  1003. end = lblk + (ext4_lblk_t) len - 1;
  1004. end = (end > ext4_es_end(es)) ? ext4_es_end(es) : end;
  1005. /* record the first block of the first delonly extent seen */
  1006. if (!rc->first_do_lblk_found) {
  1007. rc->first_do_lblk = i;
  1008. rc->first_do_lblk_found = true;
  1009. }
  1010. /* update the last lblk in the region seen so far */
  1011. rc->last_do_lblk = end;
  1012. /*
  1013. * if we're tracking a partial cluster and the current extent
  1014. * doesn't start with it, count it and stop tracking
  1015. */
  1016. if (rc->partial && (rc->lclu != EXT4_B2C(sbi, i))) {
  1017. rc->ndelonly++;
  1018. rc->partial = false;
  1019. }
  1020. /*
  1021. * if the first cluster doesn't start on a cluster boundary but
  1022. * ends on one, count it
  1023. */
  1024. if (EXT4_LBLK_COFF(sbi, i) != 0) {
  1025. if (end >= EXT4_LBLK_CFILL(sbi, i)) {
  1026. rc->ndelonly++;
  1027. rc->partial = false;
  1028. i = EXT4_LBLK_CFILL(sbi, i) + 1;
  1029. }
  1030. }
  1031. /*
  1032. * if the current cluster starts on a cluster boundary, count the
  1033. * number of whole delonly clusters in the extent
  1034. */
  1035. if ((i + sbi->s_cluster_ratio - 1) <= end) {
  1036. nclu = (end - i + 1) >> sbi->s_cluster_bits;
  1037. rc->ndelonly += nclu;
  1038. i += nclu << sbi->s_cluster_bits;
  1039. }
  1040. /*
  1041. * start tracking a partial cluster if there's a partial at the end
  1042. * of the current extent and we're not already tracking one
  1043. */
  1044. if (!rc->partial && i <= end) {
  1045. rc->partial = true;
  1046. rc->lclu = EXT4_B2C(sbi, i);
  1047. }
  1048. }
  1049. /*
  1050. * __pr_tree_search - search for a pending cluster reservation
  1051. *
  1052. * @root - root of pending reservation tree
  1053. * @lclu - logical cluster to search for
  1054. *
  1055. * Returns the pending reservation for the cluster identified by @lclu
  1056. * if found. If not, returns a reservation for the next cluster if any,
  1057. * and if not, returns NULL.
  1058. */
  1059. static struct pending_reservation *__pr_tree_search(struct rb_root *root,
  1060. ext4_lblk_t lclu)
  1061. {
  1062. struct rb_node *node = root->rb_node;
  1063. struct pending_reservation *pr = NULL;
  1064. while (node) {
  1065. pr = rb_entry(node, struct pending_reservation, rb_node);
  1066. if (lclu < pr->lclu)
  1067. node = node->rb_left;
  1068. else if (lclu > pr->lclu)
  1069. node = node->rb_right;
  1070. else
  1071. return pr;
  1072. }
  1073. if (pr && lclu < pr->lclu)
  1074. return pr;
  1075. if (pr && lclu > pr->lclu) {
  1076. node = rb_next(&pr->rb_node);
  1077. return node ? rb_entry(node, struct pending_reservation,
  1078. rb_node) : NULL;
  1079. }
  1080. return NULL;
  1081. }
  1082. /*
  1083. * get_rsvd - calculates and returns the number of cluster reservations to be
  1084. * released when removing a block range from the extent status tree
  1085. * and releases any pending reservations within the range
  1086. *
  1087. * @inode - file containing block range
  1088. * @end - last block in range
  1089. * @right_es - pointer to extent containing next block beyond end or NULL
  1090. * @rc - pointer to reserved count data
  1091. *
  1092. * The number of reservations to be released is equal to the number of
  1093. * clusters containing delayed and not unwritten (delonly) blocks within
  1094. * the range, minus the number of clusters still containing delonly blocks
  1095. * at the ends of the range, and minus the number of pending reservations
  1096. * within the range.
  1097. */
  1098. static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
  1099. struct extent_status *right_es,
  1100. struct rsvd_count *rc)
  1101. {
  1102. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  1103. struct pending_reservation *pr;
  1104. struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
  1105. struct rb_node *node;
  1106. ext4_lblk_t first_lclu, last_lclu;
  1107. bool left_delonly, right_delonly, count_pending;
  1108. struct extent_status *es;
  1109. if (sbi->s_cluster_ratio > 1) {
  1110. /* count any remaining partial cluster */
  1111. if (rc->partial)
  1112. rc->ndelonly++;
  1113. if (rc->ndelonly == 0)
  1114. return 0;
  1115. first_lclu = EXT4_B2C(sbi, rc->first_do_lblk);
  1116. last_lclu = EXT4_B2C(sbi, rc->last_do_lblk);
  1117. /*
  1118. * decrease the delonly count by the number of clusters at the
  1119. * ends of the range that still contain delonly blocks -
  1120. * these clusters still need to be reserved
  1121. */
  1122. left_delonly = right_delonly = false;
  1123. es = rc->left_es;
  1124. while (es && ext4_es_end(es) >=
  1125. EXT4_LBLK_CMASK(sbi, rc->first_do_lblk)) {
  1126. if (ext4_es_is_delonly(es)) {
  1127. rc->ndelonly--;
  1128. left_delonly = true;
  1129. break;
  1130. }
  1131. node = rb_prev(&es->rb_node);
  1132. if (!node)
  1133. break;
  1134. es = rb_entry(node, struct extent_status, rb_node);
  1135. }
  1136. if (right_es && (!left_delonly || first_lclu != last_lclu)) {
  1137. if (end < ext4_es_end(right_es)) {
  1138. es = right_es;
  1139. } else {
  1140. node = rb_next(&right_es->rb_node);
  1141. es = node ? rb_entry(node, struct extent_status,
  1142. rb_node) : NULL;
  1143. }
  1144. while (es && es->es_lblk <=
  1145. EXT4_LBLK_CFILL(sbi, rc->last_do_lblk)) {
  1146. if (ext4_es_is_delonly(es)) {
  1147. rc->ndelonly--;
  1148. right_delonly = true;
  1149. break;
  1150. }
  1151. node = rb_next(&es->rb_node);
  1152. if (!node)
  1153. break;
  1154. es = rb_entry(node, struct extent_status,
  1155. rb_node);
  1156. }
  1157. }
  1158. /*
  1159. * Determine the block range that should be searched for
  1160. * pending reservations, if any. Clusters on the ends of the
  1161. * original removed range containing delonly blocks are
  1162. * excluded. They've already been accounted for and it's not
  1163. * possible to determine if an associated pending reservation
  1164. * should be released with the information available in the
  1165. * extents status tree.
  1166. */
  1167. if (first_lclu == last_lclu) {
  1168. if (left_delonly | right_delonly)
  1169. count_pending = false;
  1170. else
  1171. count_pending = true;
  1172. } else {
  1173. if (left_delonly)
  1174. first_lclu++;
  1175. if (right_delonly)
  1176. last_lclu--;
  1177. if (first_lclu <= last_lclu)
  1178. count_pending = true;
  1179. else
  1180. count_pending = false;
  1181. }
  1182. /*
  1183. * a pending reservation found between first_lclu and last_lclu
  1184. * represents an allocated cluster that contained at least one
  1185. * delonly block, so the delonly total must be reduced by one
  1186. * for each pending reservation found and released
  1187. */
  1188. if (count_pending) {
  1189. pr = __pr_tree_search(&tree->root, first_lclu);
  1190. while (pr && pr->lclu <= last_lclu) {
  1191. rc->ndelonly--;
  1192. node = rb_next(&pr->rb_node);
  1193. rb_erase(&pr->rb_node, &tree->root);
  1194. __free_pending(pr);
  1195. if (!node)
  1196. break;
  1197. pr = rb_entry(node, struct pending_reservation,
  1198. rb_node);
  1199. }
  1200. }
  1201. }
  1202. return rc->ndelonly;
  1203. }
  1204. /*
  1205. * __es_remove_extent - removes block range from extent status tree
  1206. *
  1207. * @inode - file containing range
  1208. * @lblk - first block in range
  1209. * @end - last block in range
  1210. * @reserved - number of cluster reservations released
  1211. * @prealloc - pre-allocated es to avoid memory allocation failures
  1212. *
  1213. * If @reserved is not NULL and delayed allocation is enabled, counts
  1214. * block/cluster reservations freed by removing range and if bigalloc
  1215. * enabled cancels pending reservations as needed. Returns 0 on success,
  1216. * error code on failure.
  1217. */
  1218. static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
  1219. ext4_lblk_t end, int *reserved,
  1220. struct extent_status *prealloc)
  1221. {
  1222. struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
  1223. struct rb_node *node;
  1224. struct extent_status *es;
  1225. struct extent_status orig_es;
  1226. ext4_lblk_t len1, len2;
  1227. ext4_fsblk_t block;
  1228. int err = 0;
  1229. bool count_reserved = true;
  1230. struct rsvd_count rc;
  1231. if (reserved == NULL || !test_opt(inode->i_sb, DELALLOC))
  1232. count_reserved = false;
  1233. es = __es_tree_search(&tree->root, lblk);
  1234. if (!es)
  1235. goto out;
  1236. if (es->es_lblk > end)
  1237. goto out;
  1238. /* Simply invalidate cache_es. */
  1239. tree->cache_es = NULL;
  1240. if (count_reserved)
  1241. init_rsvd(inode, lblk, es, &rc);
  1242. orig_es.es_lblk = es->es_lblk;
  1243. orig_es.es_len = es->es_len;
  1244. orig_es.es_pblk = es->es_pblk;
  1245. len1 = lblk > es->es_lblk ? lblk - es->es_lblk : 0;
  1246. len2 = ext4_es_end(es) > end ? ext4_es_end(es) - end : 0;
  1247. if (len1 > 0)
  1248. es->es_len = len1;
  1249. if (len2 > 0) {
  1250. if (len1 > 0) {
  1251. struct extent_status newes;
  1252. newes.es_lblk = end + 1;
  1253. newes.es_len = len2;
  1254. block = 0x7FDEADBEEFULL;
  1255. if (ext4_es_is_written(&orig_es) ||
  1256. ext4_es_is_unwritten(&orig_es))
  1257. block = ext4_es_pblock(&orig_es) +
  1258. orig_es.es_len - len2;
  1259. ext4_es_store_pblock_status(&newes, block,
  1260. ext4_es_status(&orig_es));
  1261. err = __es_insert_extent(inode, &newes, prealloc);
  1262. if (err) {
  1263. if (!ext4_es_must_keep(&newes))
  1264. return 0;
  1265. es->es_lblk = orig_es.es_lblk;
  1266. es->es_len = orig_es.es_len;
  1267. goto out;
  1268. }
  1269. } else {
  1270. es->es_lblk = end + 1;
  1271. es->es_len = len2;
  1272. if (ext4_es_is_written(es) ||
  1273. ext4_es_is_unwritten(es)) {
  1274. block = orig_es.es_pblk + orig_es.es_len - len2;
  1275. ext4_es_store_pblock(es, block);
  1276. }
  1277. }
  1278. if (count_reserved)
  1279. count_rsvd(inode, orig_es.es_lblk + len1,
  1280. orig_es.es_len - len1 - len2, &orig_es, &rc);
  1281. goto out_get_reserved;
  1282. }
  1283. if (len1 > 0) {
  1284. if (count_reserved)
  1285. count_rsvd(inode, lblk, orig_es.es_len - len1,
  1286. &orig_es, &rc);
  1287. node = rb_next(&es->rb_node);
  1288. if (node)
  1289. es = rb_entry(node, struct extent_status, rb_node);
  1290. else
  1291. es = NULL;
  1292. }
  1293. while (es && ext4_es_end(es) <= end) {
  1294. if (count_reserved)
  1295. count_rsvd(inode, es->es_lblk, es->es_len, es, &rc);
  1296. node = rb_next(&es->rb_node);
  1297. rb_erase(&es->rb_node, &tree->root);
  1298. ext4_es_free_extent(inode, es);
  1299. if (!node) {
  1300. es = NULL;
  1301. break;
  1302. }
  1303. es = rb_entry(node, struct extent_status, rb_node);
  1304. }
  1305. if (es && es->es_lblk < end + 1) {
  1306. ext4_lblk_t orig_len = es->es_len;
  1307. len1 = ext4_es_end(es) - end;
  1308. if (count_reserved)
  1309. count_rsvd(inode, es->es_lblk, orig_len - len1,
  1310. es, &rc);
  1311. es->es_lblk = end + 1;
  1312. es->es_len = len1;
  1313. if (ext4_es_is_written(es) || ext4_es_is_unwritten(es)) {
  1314. block = es->es_pblk + orig_len - len1;
  1315. ext4_es_store_pblock(es, block);
  1316. }
  1317. }
  1318. out_get_reserved:
  1319. if (count_reserved)
  1320. *reserved = get_rsvd(inode, end, es, &rc);
  1321. out:
  1322. return err;
  1323. }
  1324. /*
  1325. * ext4_es_remove_extent - removes block range from extent status tree
  1326. *
  1327. * @inode - file containing range
  1328. * @lblk - first block in range
  1329. * @len - number of blocks to remove
  1330. *
  1331. * Reduces block/cluster reservation count and for bigalloc cancels pending
  1332. * reservations as needed. Returns 0 on success, error code on failure.
  1333. */
  1334. int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
  1335. ext4_lblk_t len)
  1336. {
  1337. ext4_lblk_t end;
  1338. int err = 0;
  1339. int reserved = 0;
  1340. struct extent_status *es = NULL;
  1341. if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
  1342. return 0;
  1343. trace_ext4_es_remove_extent(inode, lblk, len);
  1344. es_debug("remove [%u/%u) from extent status tree of inode %lu\n",
  1345. lblk, len, inode->i_ino);
  1346. if (!len)
  1347. return err;
  1348. end = lblk + len - 1;
  1349. BUG_ON(end < lblk);
  1350. retry:
  1351. if (err && !es)
  1352. es = __es_alloc_extent(true);
  1353. /*
  1354. * ext4_clear_inode() depends on us taking i_es_lock unconditionally
  1355. * so that we are sure __es_shrink() is done with the inode before it
  1356. * is reclaimed.
  1357. */
  1358. write_lock(&EXT4_I(inode)->i_es_lock);
  1359. err = __es_remove_extent(inode, lblk, end, &reserved, es);
  1360. /* Free preallocated extent if it didn't get used. */
  1361. if (es) {
  1362. if (!es->es_len)
  1363. __es_free_extent(es);
  1364. es = NULL;
  1365. }
  1366. write_unlock(&EXT4_I(inode)->i_es_lock);
  1367. if (err)
  1368. goto retry;
  1369. ext4_es_print_tree(inode);
  1370. ext4_da_release_space(inode, reserved);
  1371. return 0;
  1372. }
  1373. static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
  1374. struct ext4_inode_info *locked_ei)
  1375. {
  1376. struct ext4_inode_info *ei;
  1377. struct ext4_es_stats *es_stats;
  1378. ktime_t start_time;
  1379. u64 scan_time;
  1380. int nr_to_walk;
  1381. int nr_shrunk = 0;
  1382. int retried = 0, nr_skipped = 0;
  1383. es_stats = &sbi->s_es_stats;
  1384. start_time = ktime_get();
  1385. retry:
  1386. spin_lock(&sbi->s_es_lock);
  1387. nr_to_walk = sbi->s_es_nr_inode;
  1388. while (nr_to_walk-- > 0) {
  1389. if (list_empty(&sbi->s_es_list)) {
  1390. spin_unlock(&sbi->s_es_lock);
  1391. goto out;
  1392. }
  1393. ei = list_first_entry(&sbi->s_es_list, struct ext4_inode_info,
  1394. i_es_list);
  1395. /* Move the inode to the tail */
  1396. list_move_tail(&ei->i_es_list, &sbi->s_es_list);
  1397. /*
  1398. * Normally we try hard to avoid shrinking precached inodes,
  1399. * but we will as a last resort.
  1400. */
  1401. if (!retried && ext4_test_inode_state(&ei->vfs_inode,
  1402. EXT4_STATE_EXT_PRECACHED)) {
  1403. nr_skipped++;
  1404. continue;
  1405. }
  1406. if (ei == locked_ei || !write_trylock(&ei->i_es_lock)) {
  1407. nr_skipped++;
  1408. continue;
  1409. }
  1410. /*
  1411. * Now we hold i_es_lock which protects us from inode reclaim
  1412. * freeing inode under us
  1413. */
  1414. spin_unlock(&sbi->s_es_lock);
  1415. nr_shrunk += es_reclaim_extents(ei, &nr_to_scan);
  1416. write_unlock(&ei->i_es_lock);
  1417. if (nr_to_scan <= 0)
  1418. goto out;
  1419. spin_lock(&sbi->s_es_lock);
  1420. }
  1421. spin_unlock(&sbi->s_es_lock);
  1422. /*
  1423. * If we skipped any inodes, and we weren't able to make any
  1424. * forward progress, try again to scan precached inodes.
  1425. */
  1426. if ((nr_shrunk == 0) && nr_skipped && !retried) {
  1427. retried++;
  1428. goto retry;
  1429. }
  1430. if (locked_ei && nr_shrunk == 0)
  1431. nr_shrunk = es_reclaim_extents(locked_ei, &nr_to_scan);
  1432. out:
  1433. scan_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
  1434. if (likely(es_stats->es_stats_scan_time))
  1435. es_stats->es_stats_scan_time = (scan_time +
  1436. es_stats->es_stats_scan_time*3) / 4;
  1437. else
  1438. es_stats->es_stats_scan_time = scan_time;
  1439. if (scan_time > es_stats->es_stats_max_scan_time)
  1440. es_stats->es_stats_max_scan_time = scan_time;
  1441. if (likely(es_stats->es_stats_shrunk))
  1442. es_stats->es_stats_shrunk = (nr_shrunk +
  1443. es_stats->es_stats_shrunk*3) / 4;
  1444. else
  1445. es_stats->es_stats_shrunk = nr_shrunk;
  1446. trace_ext4_es_shrink(sbi->s_sb, nr_shrunk, scan_time,
  1447. nr_skipped, retried);
  1448. return nr_shrunk;
  1449. }
  1450. static unsigned long ext4_es_count(struct shrinker *shrink,
  1451. struct shrink_control *sc)
  1452. {
  1453. unsigned long nr;
  1454. struct ext4_sb_info *sbi;
  1455. sbi = container_of(shrink, struct ext4_sb_info, s_es_shrinker);
  1456. nr = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
  1457. trace_ext4_es_shrink_count(sbi->s_sb, sc->nr_to_scan, nr);
  1458. return nr;
  1459. }
  1460. static unsigned long ext4_es_scan(struct shrinker *shrink,
  1461. struct shrink_control *sc)
  1462. {
  1463. struct ext4_sb_info *sbi = container_of(shrink,
  1464. struct ext4_sb_info, s_es_shrinker);
  1465. int nr_to_scan = sc->nr_to_scan;
  1466. int ret, nr_shrunk;
  1467. ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
  1468. trace_ext4_es_shrink_scan_enter(sbi->s_sb, nr_to_scan, ret);
  1469. nr_shrunk = __es_shrink(sbi, nr_to_scan, NULL);
  1470. ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
  1471. trace_ext4_es_shrink_scan_exit(sbi->s_sb, nr_shrunk, ret);
  1472. return nr_shrunk;
  1473. }
  1474. int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v)
  1475. {
  1476. struct ext4_sb_info *sbi = EXT4_SB((struct super_block *) seq->private);
  1477. struct ext4_es_stats *es_stats = &sbi->s_es_stats;
  1478. struct ext4_inode_info *ei, *max = NULL;
  1479. unsigned int inode_cnt = 0;
  1480. if (v != SEQ_START_TOKEN)
  1481. return 0;
  1482. /* here we just find an inode that has the max nr. of objects */
  1483. spin_lock(&sbi->s_es_lock);
  1484. list_for_each_entry(ei, &sbi->s_es_list, i_es_list) {
  1485. inode_cnt++;
  1486. if (max && max->i_es_all_nr < ei->i_es_all_nr)
  1487. max = ei;
  1488. else if (!max)
  1489. max = ei;
  1490. }
  1491. spin_unlock(&sbi->s_es_lock);
  1492. seq_printf(seq, "stats:\n %lld objects\n %lld reclaimable objects\n",
  1493. percpu_counter_sum_positive(&es_stats->es_stats_all_cnt),
  1494. percpu_counter_sum_positive(&es_stats->es_stats_shk_cnt));
  1495. seq_printf(seq, " %lld/%lld cache hits/misses\n",
  1496. percpu_counter_sum_positive(&es_stats->es_stats_cache_hits),
  1497. percpu_counter_sum_positive(&es_stats->es_stats_cache_misses));
  1498. if (inode_cnt)
  1499. seq_printf(seq, " %d inodes on list\n", inode_cnt);
  1500. seq_printf(seq, "average:\n %llu us scan time\n",
  1501. div_u64(es_stats->es_stats_scan_time, 1000));
  1502. seq_printf(seq, " %lu shrunk objects\n", es_stats->es_stats_shrunk);
  1503. if (inode_cnt)
  1504. seq_printf(seq,
  1505. "maximum:\n %lu inode (%u objects, %u reclaimable)\n"
  1506. " %llu us max scan time\n",
  1507. max->vfs_inode.i_ino, max->i_es_all_nr, max->i_es_shk_nr,
  1508. div_u64(es_stats->es_stats_max_scan_time, 1000));
  1509. return 0;
  1510. }
  1511. int ext4_es_register_shrinker(struct ext4_sb_info *sbi)
  1512. {
  1513. int err;
  1514. /* Make sure we have enough bits for physical block number */
  1515. BUILD_BUG_ON(ES_SHIFT < 48);
  1516. INIT_LIST_HEAD(&sbi->s_es_list);
  1517. sbi->s_es_nr_inode = 0;
  1518. spin_lock_init(&sbi->s_es_lock);
  1519. sbi->s_es_stats.es_stats_shrunk = 0;
  1520. err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_hits, 0,
  1521. GFP_KERNEL);
  1522. if (err)
  1523. return err;
  1524. err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_misses, 0,
  1525. GFP_KERNEL);
  1526. if (err)
  1527. goto err1;
  1528. sbi->s_es_stats.es_stats_scan_time = 0;
  1529. sbi->s_es_stats.es_stats_max_scan_time = 0;
  1530. err = percpu_counter_init(&sbi->s_es_stats.es_stats_all_cnt, 0, GFP_KERNEL);
  1531. if (err)
  1532. goto err2;
  1533. err = percpu_counter_init(&sbi->s_es_stats.es_stats_shk_cnt, 0, GFP_KERNEL);
  1534. if (err)
  1535. goto err3;
  1536. sbi->s_es_shrinker.scan_objects = ext4_es_scan;
  1537. sbi->s_es_shrinker.count_objects = ext4_es_count;
  1538. sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
  1539. err = register_shrinker(&sbi->s_es_shrinker, "ext4-es:%s",
  1540. sbi->s_sb->s_id);
  1541. if (err)
  1542. goto err4;
  1543. return 0;
  1544. err4:
  1545. percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
  1546. err3:
  1547. percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
  1548. err2:
  1549. percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
  1550. err1:
  1551. percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits);
  1552. return err;
  1553. }
  1554. void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi)
  1555. {
  1556. percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits);
  1557. percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
  1558. percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
  1559. percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
  1560. unregister_shrinker(&sbi->s_es_shrinker);
  1561. }
  1562. /*
  1563. * Shrink extents in given inode from ei->i_es_shrink_lblk till end. Scan at
  1564. * most *nr_to_scan extents, update *nr_to_scan accordingly.
  1565. *
  1566. * Return 0 if we hit end of tree / interval, 1 if we exhausted nr_to_scan.
  1567. * Increment *nr_shrunk by the number of reclaimed extents. Also update
  1568. * ei->i_es_shrink_lblk to where we should continue scanning.
  1569. */
  1570. static int es_do_reclaim_extents(struct ext4_inode_info *ei, ext4_lblk_t end,
  1571. int *nr_to_scan, int *nr_shrunk)
  1572. {
  1573. struct inode *inode = &ei->vfs_inode;
  1574. struct ext4_es_tree *tree = &ei->i_es_tree;
  1575. struct extent_status *es;
  1576. struct rb_node *node;
  1577. es = __es_tree_search(&tree->root, ei->i_es_shrink_lblk);
  1578. if (!es)
  1579. goto out_wrap;
  1580. while (*nr_to_scan > 0) {
  1581. if (es->es_lblk > end) {
  1582. ei->i_es_shrink_lblk = end + 1;
  1583. return 0;
  1584. }
  1585. (*nr_to_scan)--;
  1586. node = rb_next(&es->rb_node);
  1587. if (ext4_es_must_keep(es))
  1588. goto next;
  1589. if (ext4_es_is_referenced(es)) {
  1590. ext4_es_clear_referenced(es);
  1591. goto next;
  1592. }
  1593. rb_erase(&es->rb_node, &tree->root);
  1594. ext4_es_free_extent(inode, es);
  1595. (*nr_shrunk)++;
  1596. next:
  1597. if (!node)
  1598. goto out_wrap;
  1599. es = rb_entry(node, struct extent_status, rb_node);
  1600. }
  1601. ei->i_es_shrink_lblk = es->es_lblk;
  1602. return 1;
  1603. out_wrap:
  1604. ei->i_es_shrink_lblk = 0;
  1605. return 0;
  1606. }
  1607. static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan)
  1608. {
  1609. struct inode *inode = &ei->vfs_inode;
  1610. int nr_shrunk = 0;
  1611. ext4_lblk_t start = ei->i_es_shrink_lblk;
  1612. static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
  1613. DEFAULT_RATELIMIT_BURST);
  1614. if (ei->i_es_shk_nr == 0)
  1615. return 0;
  1616. if (ext4_test_inode_state(inode, EXT4_STATE_EXT_PRECACHED) &&
  1617. __ratelimit(&_rs))
  1618. ext4_warning(inode->i_sb, "forced shrink of precached extents");
  1619. if (!es_do_reclaim_extents(ei, EXT_MAX_BLOCKS, nr_to_scan, &nr_shrunk) &&
  1620. start != 0)
  1621. es_do_reclaim_extents(ei, start - 1, nr_to_scan, &nr_shrunk);
  1622. ei->i_es_tree.cache_es = NULL;
  1623. return nr_shrunk;
  1624. }
  1625. /*
  1626. * Called to support EXT4_IOC_CLEAR_ES_CACHE. We can only remove
  1627. * discretionary entries from the extent status cache. (Some entries
  1628. * must be present for proper operations.)
  1629. */
  1630. void ext4_clear_inode_es(struct inode *inode)
  1631. {
  1632. struct ext4_inode_info *ei = EXT4_I(inode);
  1633. struct extent_status *es;
  1634. struct ext4_es_tree *tree;
  1635. struct rb_node *node;
  1636. write_lock(&ei->i_es_lock);
  1637. tree = &EXT4_I(inode)->i_es_tree;
  1638. tree->cache_es = NULL;
  1639. node = rb_first(&tree->root);
  1640. while (node) {
  1641. es = rb_entry(node, struct extent_status, rb_node);
  1642. node = rb_next(node);
  1643. if (!ext4_es_must_keep(es)) {
  1644. rb_erase(&es->rb_node, &tree->root);
  1645. ext4_es_free_extent(inode, es);
  1646. }
  1647. }
  1648. ext4_clear_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
  1649. write_unlock(&ei->i_es_lock);
  1650. }
  1651. #ifdef ES_DEBUG__
  1652. static void ext4_print_pending_tree(struct inode *inode)
  1653. {
  1654. struct ext4_pending_tree *tree;
  1655. struct rb_node *node;
  1656. struct pending_reservation *pr;
  1657. printk(KERN_DEBUG "pending reservations for inode %lu:", inode->i_ino);
  1658. tree = &EXT4_I(inode)->i_pending_tree;
  1659. node = rb_first(&tree->root);
  1660. while (node) {
  1661. pr = rb_entry(node, struct pending_reservation, rb_node);
  1662. printk(KERN_DEBUG " %u", pr->lclu);
  1663. node = rb_next(node);
  1664. }
  1665. printk(KERN_DEBUG "\n");
  1666. }
  1667. #else
  1668. #define ext4_print_pending_tree(inode)
  1669. #endif
  1670. int __init ext4_init_pending(void)
  1671. {
  1672. ext4_pending_cachep = kmem_cache_create("ext4_pending_reservation",
  1673. sizeof(struct pending_reservation),
  1674. 0, (SLAB_RECLAIM_ACCOUNT), NULL);
  1675. if (ext4_pending_cachep == NULL)
  1676. return -ENOMEM;
  1677. return 0;
  1678. }
  1679. void ext4_exit_pending(void)
  1680. {
  1681. kmem_cache_destroy(ext4_pending_cachep);
  1682. }
  1683. void ext4_init_pending_tree(struct ext4_pending_tree *tree)
  1684. {
  1685. tree->root = RB_ROOT;
  1686. }
  1687. /*
  1688. * __get_pending - retrieve a pointer to a pending reservation
  1689. *
  1690. * @inode - file containing the pending cluster reservation
  1691. * @lclu - logical cluster of interest
  1692. *
  1693. * Returns a pointer to a pending reservation if it's a member of
  1694. * the set, and NULL if not. Must be called holding i_es_lock.
  1695. */
  1696. static struct pending_reservation *__get_pending(struct inode *inode,
  1697. ext4_lblk_t lclu)
  1698. {
  1699. struct ext4_pending_tree *tree;
  1700. struct rb_node *node;
  1701. struct pending_reservation *pr = NULL;
  1702. tree = &EXT4_I(inode)->i_pending_tree;
  1703. node = (&tree->root)->rb_node;
  1704. while (node) {
  1705. pr = rb_entry(node, struct pending_reservation, rb_node);
  1706. if (lclu < pr->lclu)
  1707. node = node->rb_left;
  1708. else if (lclu > pr->lclu)
  1709. node = node->rb_right;
  1710. else if (lclu == pr->lclu)
  1711. return pr;
  1712. }
  1713. return NULL;
  1714. }
  1715. /*
  1716. * __insert_pending - adds a pending cluster reservation to the set of
  1717. * pending reservations
  1718. *
  1719. * @inode - file containing the cluster
  1720. * @lblk - logical block in the cluster to be added
  1721. * @prealloc - preallocated pending entry
  1722. *
  1723. * Returns 0 on successful insertion and -ENOMEM on failure. If the
  1724. * pending reservation is already in the set, returns successfully.
  1725. */
  1726. static int __insert_pending(struct inode *inode, ext4_lblk_t lblk,
  1727. struct pending_reservation **prealloc)
  1728. {
  1729. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  1730. struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
  1731. struct rb_node **p = &tree->root.rb_node;
  1732. struct rb_node *parent = NULL;
  1733. struct pending_reservation *pr;
  1734. ext4_lblk_t lclu;
  1735. int ret = 0;
  1736. lclu = EXT4_B2C(sbi, lblk);
  1737. /* search to find parent for insertion */
  1738. while (*p) {
  1739. parent = *p;
  1740. pr = rb_entry(parent, struct pending_reservation, rb_node);
  1741. if (lclu < pr->lclu) {
  1742. p = &(*p)->rb_left;
  1743. } else if (lclu > pr->lclu) {
  1744. p = &(*p)->rb_right;
  1745. } else {
  1746. /* pending reservation already inserted */
  1747. goto out;
  1748. }
  1749. }
  1750. if (likely(*prealloc == NULL)) {
  1751. pr = __alloc_pending(false);
  1752. if (!pr) {
  1753. ret = -ENOMEM;
  1754. goto out;
  1755. }
  1756. } else {
  1757. pr = *prealloc;
  1758. *prealloc = NULL;
  1759. }
  1760. pr->lclu = lclu;
  1761. rb_link_node(&pr->rb_node, parent, p);
  1762. rb_insert_color(&pr->rb_node, &tree->root);
  1763. out:
  1764. return ret;
  1765. }
  1766. /*
  1767. * __remove_pending - removes a pending cluster reservation from the set
  1768. * of pending reservations
  1769. *
  1770. * @inode - file containing the cluster
  1771. * @lblk - logical block in the pending cluster reservation to be removed
  1772. *
  1773. * Returns successfully if pending reservation is not a member of the set.
  1774. */
  1775. static void __remove_pending(struct inode *inode, ext4_lblk_t lblk)
  1776. {
  1777. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  1778. struct pending_reservation *pr;
  1779. struct ext4_pending_tree *tree;
  1780. pr = __get_pending(inode, EXT4_B2C(sbi, lblk));
  1781. if (pr != NULL) {
  1782. tree = &EXT4_I(inode)->i_pending_tree;
  1783. rb_erase(&pr->rb_node, &tree->root);
  1784. __free_pending(pr);
  1785. }
  1786. }
  1787. /*
  1788. * ext4_remove_pending - removes a pending cluster reservation from the set
  1789. * of pending reservations
  1790. *
  1791. * @inode - file containing the cluster
  1792. * @lblk - logical block in the pending cluster reservation to be removed
  1793. *
  1794. * Locking for external use of __remove_pending.
  1795. */
  1796. void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk)
  1797. {
  1798. struct ext4_inode_info *ei = EXT4_I(inode);
  1799. write_lock(&ei->i_es_lock);
  1800. __remove_pending(inode, lblk);
  1801. write_unlock(&ei->i_es_lock);
  1802. }
  1803. /*
  1804. * ext4_is_pending - determine whether a cluster has a pending reservation
  1805. * on it
  1806. *
  1807. * @inode - file containing the cluster
  1808. * @lblk - logical block in the cluster
  1809. *
  1810. * Returns true if there's a pending reservation for the cluster in the
  1811. * set of pending reservations, and false if not.
  1812. */
  1813. bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk)
  1814. {
  1815. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  1816. struct ext4_inode_info *ei = EXT4_I(inode);
  1817. bool ret;
  1818. read_lock(&ei->i_es_lock);
  1819. ret = (bool)(__get_pending(inode, EXT4_B2C(sbi, lblk)) != NULL);
  1820. read_unlock(&ei->i_es_lock);
  1821. return ret;
  1822. }
  1823. /*
  1824. * ext4_es_insert_delayed_block - adds a delayed block to the extents status
  1825. * tree, adding a pending reservation where
  1826. * needed
  1827. *
  1828. * @inode - file containing the newly added block
  1829. * @lblk - logical block to be added
  1830. * @allocated - indicates whether a physical cluster has been allocated for
  1831. * the logical cluster that contains the block
  1832. *
  1833. * Returns 0 on success, negative error code on failure.
  1834. */
  1835. int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
  1836. bool allocated)
  1837. {
  1838. struct extent_status newes;
  1839. int err1 = 0, err2 = 0, err3 = 0;
  1840. struct extent_status *es1 = NULL;
  1841. struct extent_status *es2 = NULL;
  1842. struct pending_reservation *pr = NULL;
  1843. if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
  1844. return 0;
  1845. es_debug("add [%u/1) delayed to extent status tree of inode %lu\n",
  1846. lblk, inode->i_ino);
  1847. newes.es_lblk = lblk;
  1848. newes.es_len = 1;
  1849. ext4_es_store_pblock_status(&newes, ~0, EXTENT_STATUS_DELAYED);
  1850. trace_ext4_es_insert_delayed_block(inode, &newes, allocated);
  1851. ext4_es_insert_extent_check(inode, &newes);
  1852. retry:
  1853. if (err1 && !es1)
  1854. es1 = __es_alloc_extent(true);
  1855. if ((err1 || err2) && !es2)
  1856. es2 = __es_alloc_extent(true);
  1857. if ((err1 || err2 || err3) && allocated && !pr)
  1858. pr = __alloc_pending(true);
  1859. write_lock(&EXT4_I(inode)->i_es_lock);
  1860. err1 = __es_remove_extent(inode, lblk, lblk, NULL, es1);
  1861. if (err1 != 0)
  1862. goto error;
  1863. /* Free preallocated extent if it didn't get used. */
  1864. if (es1) {
  1865. if (!es1->es_len)
  1866. __es_free_extent(es1);
  1867. es1 = NULL;
  1868. }
  1869. err2 = __es_insert_extent(inode, &newes, es2);
  1870. if (err2 != 0)
  1871. goto error;
  1872. /* Free preallocated extent if it didn't get used. */
  1873. if (es2) {
  1874. if (!es2->es_len)
  1875. __es_free_extent(es2);
  1876. es2 = NULL;
  1877. }
  1878. if (allocated) {
  1879. err3 = __insert_pending(inode, lblk, &pr);
  1880. if (err3 != 0)
  1881. goto error;
  1882. if (pr) {
  1883. __free_pending(pr);
  1884. pr = NULL;
  1885. }
  1886. }
  1887. error:
  1888. write_unlock(&EXT4_I(inode)->i_es_lock);
  1889. if (err1 || err2 || err3)
  1890. goto retry;
  1891. ext4_es_print_tree(inode);
  1892. ext4_print_pending_tree(inode);
  1893. return 0;
  1894. }
  1895. /*
  1896. * __es_delayed_clu - count number of clusters containing blocks that
  1897. * are delayed only
  1898. *
  1899. * @inode - file containing block range
  1900. * @start - logical block defining start of range
  1901. * @end - logical block defining end of range
  1902. *
  1903. * Returns the number of clusters containing only delayed (not delayed
  1904. * and unwritten) blocks in the range specified by @start and @end. Any
  1905. * cluster or part of a cluster within the range and containing a delayed
  1906. * and not unwritten block within the range is counted as a whole cluster.
  1907. */
  1908. static unsigned int __es_delayed_clu(struct inode *inode, ext4_lblk_t start,
  1909. ext4_lblk_t end)
  1910. {
  1911. struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
  1912. struct extent_status *es;
  1913. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  1914. struct rb_node *node;
  1915. ext4_lblk_t first_lclu, last_lclu;
  1916. unsigned long long last_counted_lclu;
  1917. unsigned int n = 0;
  1918. /* guaranteed to be unequal to any ext4_lblk_t value */
  1919. last_counted_lclu = ~0ULL;
  1920. es = __es_tree_search(&tree->root, start);
  1921. while (es && (es->es_lblk <= end)) {
  1922. if (ext4_es_is_delonly(es)) {
  1923. if (es->es_lblk <= start)
  1924. first_lclu = EXT4_B2C(sbi, start);
  1925. else
  1926. first_lclu = EXT4_B2C(sbi, es->es_lblk);
  1927. if (ext4_es_end(es) >= end)
  1928. last_lclu = EXT4_B2C(sbi, end);
  1929. else
  1930. last_lclu = EXT4_B2C(sbi, ext4_es_end(es));
  1931. if (first_lclu == last_counted_lclu)
  1932. n += last_lclu - first_lclu;
  1933. else
  1934. n += last_lclu - first_lclu + 1;
  1935. last_counted_lclu = last_lclu;
  1936. }
  1937. node = rb_next(&es->rb_node);
  1938. if (!node)
  1939. break;
  1940. es = rb_entry(node, struct extent_status, rb_node);
  1941. }
  1942. return n;
  1943. }
  1944. /*
  1945. * ext4_es_delayed_clu - count number of clusters containing blocks that
  1946. * are both delayed and unwritten
  1947. *
  1948. * @inode - file containing block range
  1949. * @lblk - logical block defining start of range
  1950. * @len - number of blocks in range
  1951. *
  1952. * Locking for external use of __es_delayed_clu().
  1953. */
  1954. unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
  1955. ext4_lblk_t len)
  1956. {
  1957. struct ext4_inode_info *ei = EXT4_I(inode);
  1958. ext4_lblk_t end;
  1959. unsigned int n;
  1960. if (len == 0)
  1961. return 0;
  1962. end = lblk + len - 1;
  1963. WARN_ON(end < lblk);
  1964. read_lock(&ei->i_es_lock);
  1965. n = __es_delayed_clu(inode, lblk, end);
  1966. read_unlock(&ei->i_es_lock);
  1967. return n;
  1968. }
  1969. /*
  1970. * __revise_pending - makes, cancels, or leaves unchanged pending cluster
  1971. * reservations for a specified block range depending
  1972. * upon the presence or absence of delayed blocks
  1973. * outside the range within clusters at the ends of the
  1974. * range
  1975. *
  1976. * @inode - file containing the range
  1977. * @lblk - logical block defining the start of range
  1978. * @len - length of range in blocks
  1979. * @prealloc - preallocated pending entry
  1980. *
  1981. * Used after a newly allocated extent is added to the extents status tree.
  1982. * Requires that the extents in the range have either written or unwritten
  1983. * status. Must be called while holding i_es_lock.
  1984. */
  1985. static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
  1986. ext4_lblk_t len,
  1987. struct pending_reservation **prealloc)
  1988. {
  1989. struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  1990. ext4_lblk_t end = lblk + len - 1;
  1991. ext4_lblk_t first, last;
  1992. bool f_del = false, l_del = false;
  1993. int ret = 0;
  1994. if (len == 0)
  1995. return 0;
  1996. /*
  1997. * Two cases - block range within single cluster and block range
  1998. * spanning two or more clusters. Note that a cluster belonging
  1999. * to a range starting and/or ending on a cluster boundary is treated
  2000. * as if it does not contain a delayed extent. The new range may
  2001. * have allocated space for previously delayed blocks out to the
  2002. * cluster boundary, requiring that any pre-existing pending
  2003. * reservation be canceled. Because this code only looks at blocks
  2004. * outside the range, it should revise pending reservations
  2005. * correctly even if the extent represented by the range can't be
  2006. * inserted in the extents status tree due to ENOSPC.
  2007. */
  2008. if (EXT4_B2C(sbi, lblk) == EXT4_B2C(sbi, end)) {
  2009. first = EXT4_LBLK_CMASK(sbi, lblk);
  2010. if (first != lblk)
  2011. f_del = __es_scan_range(inode, &ext4_es_is_delonly,
  2012. first, lblk - 1);
  2013. if (f_del) {
  2014. ret = __insert_pending(inode, first, prealloc);
  2015. if (ret < 0)
  2016. goto out;
  2017. } else {
  2018. last = EXT4_LBLK_CMASK(sbi, end) +
  2019. sbi->s_cluster_ratio - 1;
  2020. if (last != end)
  2021. l_del = __es_scan_range(inode,
  2022. &ext4_es_is_delonly,
  2023. end + 1, last);
  2024. if (l_del) {
  2025. ret = __insert_pending(inode, last, prealloc);
  2026. if (ret < 0)
  2027. goto out;
  2028. } else
  2029. __remove_pending(inode, last);
  2030. }
  2031. } else {
  2032. first = EXT4_LBLK_CMASK(sbi, lblk);
  2033. if (first != lblk)
  2034. f_del = __es_scan_range(inode, &ext4_es_is_delonly,
  2035. first, lblk - 1);
  2036. if (f_del) {
  2037. ret = __insert_pending(inode, first, prealloc);
  2038. if (ret < 0)
  2039. goto out;
  2040. } else
  2041. __remove_pending(inode, first);
  2042. last = EXT4_LBLK_CMASK(sbi, end) + sbi->s_cluster_ratio - 1;
  2043. if (last != end)
  2044. l_del = __es_scan_range(inode, &ext4_es_is_delonly,
  2045. end + 1, last);
  2046. if (l_del) {
  2047. ret = __insert_pending(inode, last, prealloc);
  2048. if (ret < 0)
  2049. goto out;
  2050. } else
  2051. __remove_pending(inode, last);
  2052. }
  2053. out:
  2054. return ret;
  2055. }