Loading...
Note: File does not exist in v3.5.6.
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fs/ext4/extents_status.c
4 *
5 * Written by Yongqiang Yang <xiaoqiangnk@gmail.com>
6 * Modified by
7 * Allison Henderson <achender@linux.vnet.ibm.com>
8 * Hugh Dickins <hughd@google.com>
9 * Zheng Liu <wenqing.lz@taobao.com>
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
18#include <trace/events/ext4.h>
19
20/*
21 * According to previous discussion in Ext4 Developer Workshop, we
22 * will introduce a new structure called io tree to track all extent
23 * status in order to solve some problems that we have met
24 * (e.g. Reservation space warning), and provide extent-level locking.
25 * Delay extent tree is the first step to achieve this goal. It is
26 * original built by Yongqiang Yang. At that time it is called delay
27 * extent tree, whose goal is only track delayed extents in memory to
28 * simplify the implementation of fiemap and bigalloc, and introduce
29 * lseek SEEK_DATA/SEEK_HOLE support. That is why it is still called
30 * delay extent tree at the first commit. But for better understand
31 * what it does, it has been rename to extent status tree.
32 *
33 * Step1:
34 * Currently the first step has been done. All delayed extents are
35 * tracked in the tree. It maintains the delayed extent when a delayed
36 * allocation is issued, and the delayed extent is written out or
37 * invalidated. Therefore the implementation of fiemap and bigalloc
38 * are simplified, and SEEK_DATA/SEEK_HOLE are introduced.
39 *
40 * The following comment describes the implemenmtation of extent
41 * status tree and future works.
42 *
43 * Step2:
44 * In this step all extent status are tracked by extent status tree.
45 * Thus, we can first try to lookup a block mapping in this tree before
46 * finding it in extent tree. Hence, single extent cache can be removed
47 * because extent status tree can do a better job. Extents in status
48 * tree are loaded on-demand. Therefore, the extent status tree may not
49 * contain all of the extents in a file. Meanwhile we define a shrinker
50 * to reclaim memory from extent status tree because fragmented extent
51 * tree will make status tree cost too much memory. written/unwritten/-
52 * hole extents in the tree will be reclaimed by this shrinker when we
53 * are under high memory pressure. Delayed extents will not be
54 * reclimed because fiemap, bigalloc, and seek_data/hole need it.
55 */
56
57/*
58 * Extent status tree implementation for ext4.
59 *
60 *
61 * ==========================================================================
62 * Extent status tree tracks all extent status.
63 *
64 * 1. Why we need to implement extent status tree?
65 *
66 * Without extent status tree, ext4 identifies a delayed extent by looking
67 * up page cache, this has several deficiencies - complicated, buggy,
68 * and inefficient code.
69 *
70 * FIEMAP, SEEK_HOLE/DATA, bigalloc, and writeout all need to know if a
71 * block or a range of blocks are belonged to a delayed extent.
72 *
73 * Let us have a look at how they do without extent status tree.
74 * -- FIEMAP
75 * FIEMAP looks up page cache to identify delayed allocations from holes.
76 *
77 * -- SEEK_HOLE/DATA
78 * SEEK_HOLE/DATA has the same problem as FIEMAP.
79 *
80 * -- bigalloc
81 * bigalloc looks up page cache to figure out if a block is
82 * already under delayed allocation or not to determine whether
83 * quota reserving is needed for the cluster.
84 *
85 * -- writeout
86 * Writeout looks up whole page cache to see if a buffer is
87 * mapped, If there are not very many delayed buffers, then it is
88 * time consuming.
89 *
90 * With extent status tree implementation, FIEMAP, SEEK_HOLE/DATA,
91 * bigalloc and writeout can figure out if a block or a range of
92 * blocks is under delayed allocation(belonged to a delayed extent) or
93 * not by searching the extent tree.
94 *
95 *
96 * ==========================================================================
97 * 2. Ext4 extent status tree impelmentation
98 *
99 * -- extent
100 * A extent is a range of blocks which are contiguous logically and
101 * physically. Unlike extent in extent tree, this extent in ext4 is
102 * a in-memory struct, there is no corresponding on-disk data. There
103 * is no limit on length of extent, so an extent can contain as many
104 * blocks as they are contiguous logically and physically.
105 *
106 * -- extent status tree
107 * Every inode has an extent status tree and all allocation blocks
108 * are added to the tree with different status. The extent in the
109 * tree are ordered by logical block no.
110 *
111 * -- operations on a extent status tree
112 * There are three important operations on a delayed extent tree: find
113 * next extent, adding a extent(a range of blocks) and removing a extent.
114 *
115 * -- race on a extent status tree
116 * Extent status tree is protected by inode->i_es_lock.
117 *
118 * -- memory consumption
119 * Fragmented extent tree will make extent status tree cost too much
120 * memory. Hence, we will reclaim written/unwritten/hole extents from
121 * the tree under a heavy memory pressure.
122 *
123 *
124 * ==========================================================================
125 * 3. Performance analysis
126 *
127 * -- overhead
128 * 1. There is a cache extent for write access, so if writes are
129 * not very random, adding space operaions are in O(1) time.
130 *
131 * -- gain
132 * 2. Code is much simpler, more readable, more maintainable and
133 * more efficient.
134 *
135 *
136 * ==========================================================================
137 * 4. TODO list
138 *
139 * -- Refactor delayed space reservation
140 *
141 * -- Extent-level locking
142 */
143
144static struct kmem_cache *ext4_es_cachep;
145static struct kmem_cache *ext4_pending_cachep;
146
147static int __es_insert_extent(struct inode *inode, struct extent_status *newes);
148static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
149 ext4_lblk_t end, int *reserved);
150static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan);
151static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
152 struct ext4_inode_info *locked_ei);
153static void __revise_pending(struct inode *inode, ext4_lblk_t lblk,
154 ext4_lblk_t len);
155
156int __init ext4_init_es(void)
157{
158 ext4_es_cachep = kmem_cache_create("ext4_extent_status",
159 sizeof(struct extent_status),
160 0, (SLAB_RECLAIM_ACCOUNT), NULL);
161 if (ext4_es_cachep == NULL)
162 return -ENOMEM;
163 return 0;
164}
165
166void ext4_exit_es(void)
167{
168 kmem_cache_destroy(ext4_es_cachep);
169}
170
171void ext4_es_init_tree(struct ext4_es_tree *tree)
172{
173 tree->root = RB_ROOT;
174 tree->cache_es = NULL;
175}
176
177#ifdef ES_DEBUG__
178static void ext4_es_print_tree(struct inode *inode)
179{
180 struct ext4_es_tree *tree;
181 struct rb_node *node;
182
183 printk(KERN_DEBUG "status extents for inode %lu:", inode->i_ino);
184 tree = &EXT4_I(inode)->i_es_tree;
185 node = rb_first(&tree->root);
186 while (node) {
187 struct extent_status *es;
188 es = rb_entry(node, struct extent_status, rb_node);
189 printk(KERN_DEBUG " [%u/%u) %llu %x",
190 es->es_lblk, es->es_len,
191 ext4_es_pblock(es), ext4_es_status(es));
192 node = rb_next(node);
193 }
194 printk(KERN_DEBUG "\n");
195}
196#else
197#define ext4_es_print_tree(inode)
198#endif
199
200static inline ext4_lblk_t ext4_es_end(struct extent_status *es)
201{
202 BUG_ON(es->es_lblk + es->es_len < es->es_lblk);
203 return es->es_lblk + es->es_len - 1;
204}
205
206/*
207 * search through the tree for an delayed extent with a given offset. If
208 * it can't be found, try to find next extent.
209 */
210static struct extent_status *__es_tree_search(struct rb_root *root,
211 ext4_lblk_t lblk)
212{
213 struct rb_node *node = root->rb_node;
214 struct extent_status *es = NULL;
215
216 while (node) {
217 es = rb_entry(node, struct extent_status, rb_node);
218 if (lblk < es->es_lblk)
219 node = node->rb_left;
220 else if (lblk > ext4_es_end(es))
221 node = node->rb_right;
222 else
223 return es;
224 }
225
226 if (es && lblk < es->es_lblk)
227 return es;
228
229 if (es && lblk > ext4_es_end(es)) {
230 node = rb_next(&es->rb_node);
231 return node ? rb_entry(node, struct extent_status, rb_node) :
232 NULL;
233 }
234
235 return NULL;
236}
237
238/*
239 * ext4_es_find_extent_range - find extent with specified status within block
240 * range or next extent following block range in
241 * extents status tree
242 *
243 * @inode - file containing the range
244 * @matching_fn - pointer to function that matches extents with desired status
245 * @lblk - logical block defining start of range
246 * @end - logical block defining end of range
247 * @es - extent found, if any
248 *
249 * Find the first extent within the block range specified by @lblk and @end
250 * in the extents status tree that satisfies @matching_fn. If a match
251 * is found, it's returned in @es. If not, and a matching extent is found
252 * beyond the block range, it's returned in @es. If no match is found, an
253 * extent is returned in @es whose es_lblk, es_len, and es_pblk components
254 * are 0.
255 */
256static void __es_find_extent_range(struct inode *inode,
257 int (*matching_fn)(struct extent_status *es),
258 ext4_lblk_t lblk, ext4_lblk_t end,
259 struct extent_status *es)
260{
261 struct ext4_es_tree *tree = NULL;
262 struct extent_status *es1 = NULL;
263 struct rb_node *node;
264
265 WARN_ON(es == NULL);
266 WARN_ON(end < lblk);
267
268 tree = &EXT4_I(inode)->i_es_tree;
269
270 /* see if the extent has been cached */
271 es->es_lblk = es->es_len = es->es_pblk = 0;
272 if (tree->cache_es) {
273 es1 = tree->cache_es;
274 if (in_range(lblk, es1->es_lblk, es1->es_len)) {
275 es_debug("%u cached by [%u/%u) %llu %x\n",
276 lblk, es1->es_lblk, es1->es_len,
277 ext4_es_pblock(es1), ext4_es_status(es1));
278 goto out;
279 }
280 }
281
282 es1 = __es_tree_search(&tree->root, lblk);
283
284out:
285 if (es1 && !matching_fn(es1)) {
286 while ((node = rb_next(&es1->rb_node)) != NULL) {
287 es1 = rb_entry(node, struct extent_status, rb_node);
288 if (es1->es_lblk > end) {
289 es1 = NULL;
290 break;
291 }
292 if (matching_fn(es1))
293 break;
294 }
295 }
296
297 if (es1 && matching_fn(es1)) {
298 tree->cache_es = es1;
299 es->es_lblk = es1->es_lblk;
300 es->es_len = es1->es_len;
301 es->es_pblk = es1->es_pblk;
302 }
303
304}
305
306/*
307 * Locking for __es_find_extent_range() for external use
308 */
309void ext4_es_find_extent_range(struct inode *inode,
310 int (*matching_fn)(struct extent_status *es),
311 ext4_lblk_t lblk, ext4_lblk_t end,
312 struct extent_status *es)
313{
314 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
315 return;
316
317 trace_ext4_es_find_extent_range_enter(inode, lblk);
318
319 read_lock(&EXT4_I(inode)->i_es_lock);
320 __es_find_extent_range(inode, matching_fn, lblk, end, es);
321 read_unlock(&EXT4_I(inode)->i_es_lock);
322
323 trace_ext4_es_find_extent_range_exit(inode, es);
324}
325
326/*
327 * __es_scan_range - search block range for block with specified status
328 * in extents status tree
329 *
330 * @inode - file containing the range
331 * @matching_fn - pointer to function that matches extents with desired status
332 * @lblk - logical block defining start of range
333 * @end - logical block defining end of range
334 *
335 * Returns true if at least one block in the specified block range satisfies
336 * the criterion specified by @matching_fn, and false if not. If at least
337 * one extent has the specified status, then there is at least one block
338 * in the cluster with that status. Should only be called by code that has
339 * taken i_es_lock.
340 */
341static bool __es_scan_range(struct inode *inode,
342 int (*matching_fn)(struct extent_status *es),
343 ext4_lblk_t start, ext4_lblk_t end)
344{
345 struct extent_status es;
346
347 __es_find_extent_range(inode, matching_fn, start, end, &es);
348 if (es.es_len == 0)
349 return false; /* no matching extent in the tree */
350 else if (es.es_lblk <= start &&
351 start < es.es_lblk + es.es_len)
352 return true;
353 else if (start <= es.es_lblk && es.es_lblk <= end)
354 return true;
355 else
356 return false;
357}
358/*
359 * Locking for __es_scan_range() for external use
360 */
361bool ext4_es_scan_range(struct inode *inode,
362 int (*matching_fn)(struct extent_status *es),
363 ext4_lblk_t lblk, ext4_lblk_t end)
364{
365 bool ret;
366
367 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
368 return false;
369
370 read_lock(&EXT4_I(inode)->i_es_lock);
371 ret = __es_scan_range(inode, matching_fn, lblk, end);
372 read_unlock(&EXT4_I(inode)->i_es_lock);
373
374 return ret;
375}
376
377/*
378 * __es_scan_clu - search cluster for block with specified status in
379 * extents status tree
380 *
381 * @inode - file containing the cluster
382 * @matching_fn - pointer to function that matches extents with desired status
383 * @lblk - logical block in cluster to be searched
384 *
385 * Returns true if at least one extent in the cluster containing @lblk
386 * satisfies the criterion specified by @matching_fn, and false if not. If at
387 * least one extent has the specified status, then there is at least one block
388 * in the cluster with that status. Should only be called by code that has
389 * taken i_es_lock.
390 */
391static bool __es_scan_clu(struct inode *inode,
392 int (*matching_fn)(struct extent_status *es),
393 ext4_lblk_t lblk)
394{
395 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
396 ext4_lblk_t lblk_start, lblk_end;
397
398 lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
399 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
400
401 return __es_scan_range(inode, matching_fn, lblk_start, lblk_end);
402}
403
404/*
405 * Locking for __es_scan_clu() for external use
406 */
407bool ext4_es_scan_clu(struct inode *inode,
408 int (*matching_fn)(struct extent_status *es),
409 ext4_lblk_t lblk)
410{
411 bool ret;
412
413 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
414 return false;
415
416 read_lock(&EXT4_I(inode)->i_es_lock);
417 ret = __es_scan_clu(inode, matching_fn, lblk);
418 read_unlock(&EXT4_I(inode)->i_es_lock);
419
420 return ret;
421}
422
423static void ext4_es_list_add(struct inode *inode)
424{
425 struct ext4_inode_info *ei = EXT4_I(inode);
426 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
427
428 if (!list_empty(&ei->i_es_list))
429 return;
430
431 spin_lock(&sbi->s_es_lock);
432 if (list_empty(&ei->i_es_list)) {
433 list_add_tail(&ei->i_es_list, &sbi->s_es_list);
434 sbi->s_es_nr_inode++;
435 }
436 spin_unlock(&sbi->s_es_lock);
437}
438
439static void ext4_es_list_del(struct inode *inode)
440{
441 struct ext4_inode_info *ei = EXT4_I(inode);
442 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
443
444 spin_lock(&sbi->s_es_lock);
445 if (!list_empty(&ei->i_es_list)) {
446 list_del_init(&ei->i_es_list);
447 sbi->s_es_nr_inode--;
448 WARN_ON_ONCE(sbi->s_es_nr_inode < 0);
449 }
450 spin_unlock(&sbi->s_es_lock);
451}
452
453static struct extent_status *
454ext4_es_alloc_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len,
455 ext4_fsblk_t pblk)
456{
457 struct extent_status *es;
458 es = kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC);
459 if (es == NULL)
460 return NULL;
461 es->es_lblk = lblk;
462 es->es_len = len;
463 es->es_pblk = pblk;
464
465 /*
466 * We don't count delayed extent because we never try to reclaim them
467 */
468 if (!ext4_es_is_delayed(es)) {
469 if (!EXT4_I(inode)->i_es_shk_nr++)
470 ext4_es_list_add(inode);
471 percpu_counter_inc(&EXT4_SB(inode->i_sb)->
472 s_es_stats.es_stats_shk_cnt);
473 }
474
475 EXT4_I(inode)->i_es_all_nr++;
476 percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
477
478 return es;
479}
480
481static void ext4_es_free_extent(struct inode *inode, struct extent_status *es)
482{
483 EXT4_I(inode)->i_es_all_nr--;
484 percpu_counter_dec(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
485
486 /* Decrease the shrink counter when this es is not delayed */
487 if (!ext4_es_is_delayed(es)) {
488 BUG_ON(EXT4_I(inode)->i_es_shk_nr == 0);
489 if (!--EXT4_I(inode)->i_es_shk_nr)
490 ext4_es_list_del(inode);
491 percpu_counter_dec(&EXT4_SB(inode->i_sb)->
492 s_es_stats.es_stats_shk_cnt);
493 }
494
495 kmem_cache_free(ext4_es_cachep, es);
496}
497
498/*
499 * Check whether or not two extents can be merged
500 * Condition:
501 * - logical block number is contiguous
502 * - physical block number is contiguous
503 * - status is equal
504 */
505static int ext4_es_can_be_merged(struct extent_status *es1,
506 struct extent_status *es2)
507{
508 if (ext4_es_type(es1) != ext4_es_type(es2))
509 return 0;
510
511 if (((__u64) es1->es_len) + es2->es_len > EXT_MAX_BLOCKS) {
512 pr_warn("ES assertion failed when merging extents. "
513 "The sum of lengths of es1 (%d) and es2 (%d) "
514 "is bigger than allowed file size (%d)\n",
515 es1->es_len, es2->es_len, EXT_MAX_BLOCKS);
516 WARN_ON(1);
517 return 0;
518 }
519
520 if (((__u64) es1->es_lblk) + es1->es_len != es2->es_lblk)
521 return 0;
522
523 if ((ext4_es_is_written(es1) || ext4_es_is_unwritten(es1)) &&
524 (ext4_es_pblock(es1) + es1->es_len == ext4_es_pblock(es2)))
525 return 1;
526
527 if (ext4_es_is_hole(es1))
528 return 1;
529
530 /* we need to check delayed extent is without unwritten status */
531 if (ext4_es_is_delayed(es1) && !ext4_es_is_unwritten(es1))
532 return 1;
533
534 return 0;
535}
536
537static struct extent_status *
538ext4_es_try_to_merge_left(struct inode *inode, struct extent_status *es)
539{
540 struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
541 struct extent_status *es1;
542 struct rb_node *node;
543
544 node = rb_prev(&es->rb_node);
545 if (!node)
546 return es;
547
548 es1 = rb_entry(node, struct extent_status, rb_node);
549 if (ext4_es_can_be_merged(es1, es)) {
550 es1->es_len += es->es_len;
551 if (ext4_es_is_referenced(es))
552 ext4_es_set_referenced(es1);
553 rb_erase(&es->rb_node, &tree->root);
554 ext4_es_free_extent(inode, es);
555 es = es1;
556 }
557
558 return es;
559}
560
561static struct extent_status *
562ext4_es_try_to_merge_right(struct inode *inode, struct extent_status *es)
563{
564 struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
565 struct extent_status *es1;
566 struct rb_node *node;
567
568 node = rb_next(&es->rb_node);
569 if (!node)
570 return es;
571
572 es1 = rb_entry(node, struct extent_status, rb_node);
573 if (ext4_es_can_be_merged(es, es1)) {
574 es->es_len += es1->es_len;
575 if (ext4_es_is_referenced(es1))
576 ext4_es_set_referenced(es);
577 rb_erase(node, &tree->root);
578 ext4_es_free_extent(inode, es1);
579 }
580
581 return es;
582}
583
584#ifdef ES_AGGRESSIVE_TEST
585#include "ext4_extents.h" /* Needed when ES_AGGRESSIVE_TEST is defined */
586
587static void ext4_es_insert_extent_ext_check(struct inode *inode,
588 struct extent_status *es)
589{
590 struct ext4_ext_path *path = NULL;
591 struct ext4_extent *ex;
592 ext4_lblk_t ee_block;
593 ext4_fsblk_t ee_start;
594 unsigned short ee_len;
595 int depth, ee_status, es_status;
596
597 path = ext4_find_extent(inode, es->es_lblk, NULL, EXT4_EX_NOCACHE);
598 if (IS_ERR(path))
599 return;
600
601 depth = ext_depth(inode);
602 ex = path[depth].p_ext;
603
604 if (ex) {
605
606 ee_block = le32_to_cpu(ex->ee_block);
607 ee_start = ext4_ext_pblock(ex);
608 ee_len = ext4_ext_get_actual_len(ex);
609
610 ee_status = ext4_ext_is_unwritten(ex) ? 1 : 0;
611 es_status = ext4_es_is_unwritten(es) ? 1 : 0;
612
613 /*
614 * Make sure ex and es are not overlap when we try to insert
615 * a delayed/hole extent.
616 */
617 if (!ext4_es_is_written(es) && !ext4_es_is_unwritten(es)) {
618 if (in_range(es->es_lblk, ee_block, ee_len)) {
619 pr_warn("ES insert assertion failed for "
620 "inode: %lu we can find an extent "
621 "at block [%d/%d/%llu/%c], but we "
622 "want to add a delayed/hole extent "
623 "[%d/%d/%llu/%x]\n",
624 inode->i_ino, ee_block, ee_len,
625 ee_start, ee_status ? 'u' : 'w',
626 es->es_lblk, es->es_len,
627 ext4_es_pblock(es), ext4_es_status(es));
628 }
629 goto out;
630 }
631
632 /*
633 * We don't check ee_block == es->es_lblk, etc. because es
634 * might be a part of whole extent, vice versa.
635 */
636 if (es->es_lblk < ee_block ||
637 ext4_es_pblock(es) != ee_start + es->es_lblk - ee_block) {
638 pr_warn("ES insert assertion failed for inode: %lu "
639 "ex_status [%d/%d/%llu/%c] != "
640 "es_status [%d/%d/%llu/%c]\n", inode->i_ino,
641 ee_block, ee_len, ee_start,
642 ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
643 ext4_es_pblock(es), es_status ? 'u' : 'w');
644 goto out;
645 }
646
647 if (ee_status ^ es_status) {
648 pr_warn("ES insert assertion failed for inode: %lu "
649 "ex_status [%d/%d/%llu/%c] != "
650 "es_status [%d/%d/%llu/%c]\n", inode->i_ino,
651 ee_block, ee_len, ee_start,
652 ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
653 ext4_es_pblock(es), es_status ? 'u' : 'w');
654 }
655 } else {
656 /*
657 * We can't find an extent on disk. So we need to make sure
658 * that we don't want to add an written/unwritten extent.
659 */
660 if (!ext4_es_is_delayed(es) && !ext4_es_is_hole(es)) {
661 pr_warn("ES insert assertion failed for inode: %lu "
662 "can't find an extent at block %d but we want "
663 "to add a written/unwritten extent "
664 "[%d/%d/%llu/%x]\n", inode->i_ino,
665 es->es_lblk, es->es_lblk, es->es_len,
666 ext4_es_pblock(es), ext4_es_status(es));
667 }
668 }
669out:
670 ext4_ext_drop_refs(path);
671 kfree(path);
672}
673
674static void ext4_es_insert_extent_ind_check(struct inode *inode,
675 struct extent_status *es)
676{
677 struct ext4_map_blocks map;
678 int retval;
679
680 /*
681 * Here we call ext4_ind_map_blocks to lookup a block mapping because
682 * 'Indirect' structure is defined in indirect.c. So we couldn't
683 * access direct/indirect tree from outside. It is too dirty to define
684 * this function in indirect.c file.
685 */
686
687 map.m_lblk = es->es_lblk;
688 map.m_len = es->es_len;
689
690 retval = ext4_ind_map_blocks(NULL, inode, &map, 0);
691 if (retval > 0) {
692 if (ext4_es_is_delayed(es) || ext4_es_is_hole(es)) {
693 /*
694 * We want to add a delayed/hole extent but this
695 * block has been allocated.
696 */
697 pr_warn("ES insert assertion failed for inode: %lu "
698 "We can find blocks but we want to add a "
699 "delayed/hole extent [%d/%d/%llu/%x]\n",
700 inode->i_ino, es->es_lblk, es->es_len,
701 ext4_es_pblock(es), ext4_es_status(es));
702 return;
703 } else if (ext4_es_is_written(es)) {
704 if (retval != es->es_len) {
705 pr_warn("ES insert assertion failed for "
706 "inode: %lu retval %d != es_len %d\n",
707 inode->i_ino, retval, es->es_len);
708 return;
709 }
710 if (map.m_pblk != ext4_es_pblock(es)) {
711 pr_warn("ES insert assertion failed for "
712 "inode: %lu m_pblk %llu != "
713 "es_pblk %llu\n",
714 inode->i_ino, map.m_pblk,
715 ext4_es_pblock(es));
716 return;
717 }
718 } else {
719 /*
720 * We don't need to check unwritten extent because
721 * indirect-based file doesn't have it.
722 */
723 BUG();
724 }
725 } else if (retval == 0) {
726 if (ext4_es_is_written(es)) {
727 pr_warn("ES insert assertion failed for inode: %lu "
728 "We can't find the block but we want to add "
729 "a written extent [%d/%d/%llu/%x]\n",
730 inode->i_ino, es->es_lblk, es->es_len,
731 ext4_es_pblock(es), ext4_es_status(es));
732 return;
733 }
734 }
735}
736
737static inline void ext4_es_insert_extent_check(struct inode *inode,
738 struct extent_status *es)
739{
740 /*
741 * We don't need to worry about the race condition because
742 * caller takes i_data_sem locking.
743 */
744 BUG_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
745 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
746 ext4_es_insert_extent_ext_check(inode, es);
747 else
748 ext4_es_insert_extent_ind_check(inode, es);
749}
750#else
751static inline void ext4_es_insert_extent_check(struct inode *inode,
752 struct extent_status *es)
753{
754}
755#endif
756
757static int __es_insert_extent(struct inode *inode, struct extent_status *newes)
758{
759 struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
760 struct rb_node **p = &tree->root.rb_node;
761 struct rb_node *parent = NULL;
762 struct extent_status *es;
763
764 while (*p) {
765 parent = *p;
766 es = rb_entry(parent, struct extent_status, rb_node);
767
768 if (newes->es_lblk < es->es_lblk) {
769 if (ext4_es_can_be_merged(newes, es)) {
770 /*
771 * Here we can modify es_lblk directly
772 * because it isn't overlapped.
773 */
774 es->es_lblk = newes->es_lblk;
775 es->es_len += newes->es_len;
776 if (ext4_es_is_written(es) ||
777 ext4_es_is_unwritten(es))
778 ext4_es_store_pblock(es,
779 newes->es_pblk);
780 es = ext4_es_try_to_merge_left(inode, es);
781 goto out;
782 }
783 p = &(*p)->rb_left;
784 } else if (newes->es_lblk > ext4_es_end(es)) {
785 if (ext4_es_can_be_merged(es, newes)) {
786 es->es_len += newes->es_len;
787 es = ext4_es_try_to_merge_right(inode, es);
788 goto out;
789 }
790 p = &(*p)->rb_right;
791 } else {
792 BUG();
793 return -EINVAL;
794 }
795 }
796
797 es = ext4_es_alloc_extent(inode, newes->es_lblk, newes->es_len,
798 newes->es_pblk);
799 if (!es)
800 return -ENOMEM;
801 rb_link_node(&es->rb_node, parent, p);
802 rb_insert_color(&es->rb_node, &tree->root);
803
804out:
805 tree->cache_es = es;
806 return 0;
807}
808
809/*
810 * ext4_es_insert_extent() adds information to an inode's extent
811 * status tree.
812 *
813 * Return 0 on success, error code on failure.
814 */
815int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
816 ext4_lblk_t len, ext4_fsblk_t pblk,
817 unsigned int status)
818{
819 struct extent_status newes;
820 ext4_lblk_t end = lblk + len - 1;
821 int err = 0;
822 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
823
824 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
825 return 0;
826
827 es_debug("add [%u/%u) %llu %x to extent status tree of inode %lu\n",
828 lblk, len, pblk, status, inode->i_ino);
829
830 if (!len)
831 return 0;
832
833 BUG_ON(end < lblk);
834
835 if ((status & EXTENT_STATUS_DELAYED) &&
836 (status & EXTENT_STATUS_WRITTEN)) {
837 ext4_warning(inode->i_sb, "Inserting extent [%u/%u] as "
838 " delayed and written which can potentially "
839 " cause data loss.", lblk, len);
840 WARN_ON(1);
841 }
842
843 newes.es_lblk = lblk;
844 newes.es_len = len;
845 ext4_es_store_pblock_status(&newes, pblk, status);
846 trace_ext4_es_insert_extent(inode, &newes);
847
848 ext4_es_insert_extent_check(inode, &newes);
849
850 write_lock(&EXT4_I(inode)->i_es_lock);
851 err = __es_remove_extent(inode, lblk, end, NULL);
852 if (err != 0)
853 goto error;
854retry:
855 err = __es_insert_extent(inode, &newes);
856 if (err == -ENOMEM && __es_shrink(EXT4_SB(inode->i_sb),
857 128, EXT4_I(inode)))
858 goto retry;
859 if (err == -ENOMEM && !ext4_es_is_delayed(&newes))
860 err = 0;
861
862 if (sbi->s_cluster_ratio > 1 && test_opt(inode->i_sb, DELALLOC) &&
863 (status & EXTENT_STATUS_WRITTEN ||
864 status & EXTENT_STATUS_UNWRITTEN))
865 __revise_pending(inode, lblk, len);
866
867error:
868 write_unlock(&EXT4_I(inode)->i_es_lock);
869
870 ext4_es_print_tree(inode);
871
872 return err;
873}
874
875/*
876 * ext4_es_cache_extent() inserts information into the extent status
877 * tree if and only if there isn't information about the range in
878 * question already.
879 */
880void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
881 ext4_lblk_t len, ext4_fsblk_t pblk,
882 unsigned int status)
883{
884 struct extent_status *es;
885 struct extent_status newes;
886 ext4_lblk_t end = lblk + len - 1;
887
888 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
889 return;
890
891 newes.es_lblk = lblk;
892 newes.es_len = len;
893 ext4_es_store_pblock_status(&newes, pblk, status);
894 trace_ext4_es_cache_extent(inode, &newes);
895
896 if (!len)
897 return;
898
899 BUG_ON(end < lblk);
900
901 write_lock(&EXT4_I(inode)->i_es_lock);
902
903 es = __es_tree_search(&EXT4_I(inode)->i_es_tree.root, lblk);
904 if (!es || es->es_lblk > end)
905 __es_insert_extent(inode, &newes);
906 write_unlock(&EXT4_I(inode)->i_es_lock);
907}
908
909/*
910 * ext4_es_lookup_extent() looks up an extent in extent status tree.
911 *
912 * ext4_es_lookup_extent is called by ext4_map_blocks/ext4_da_map_blocks.
913 *
914 * Return: 1 on found, 0 on not
915 */
916int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
917 ext4_lblk_t *next_lblk,
918 struct extent_status *es)
919{
920 struct ext4_es_tree *tree;
921 struct ext4_es_stats *stats;
922 struct extent_status *es1 = NULL;
923 struct rb_node *node;
924 int found = 0;
925
926 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
927 return 0;
928
929 trace_ext4_es_lookup_extent_enter(inode, lblk);
930 es_debug("lookup extent in block %u\n", lblk);
931
932 tree = &EXT4_I(inode)->i_es_tree;
933 read_lock(&EXT4_I(inode)->i_es_lock);
934
935 /* find extent in cache firstly */
936 es->es_lblk = es->es_len = es->es_pblk = 0;
937 if (tree->cache_es) {
938 es1 = tree->cache_es;
939 if (in_range(lblk, es1->es_lblk, es1->es_len)) {
940 es_debug("%u cached by [%u/%u)\n",
941 lblk, es1->es_lblk, es1->es_len);
942 found = 1;
943 goto out;
944 }
945 }
946
947 node = tree->root.rb_node;
948 while (node) {
949 es1 = rb_entry(node, struct extent_status, rb_node);
950 if (lblk < es1->es_lblk)
951 node = node->rb_left;
952 else if (lblk > ext4_es_end(es1))
953 node = node->rb_right;
954 else {
955 found = 1;
956 break;
957 }
958 }
959
960out:
961 stats = &EXT4_SB(inode->i_sb)->s_es_stats;
962 if (found) {
963 BUG_ON(!es1);
964 es->es_lblk = es1->es_lblk;
965 es->es_len = es1->es_len;
966 es->es_pblk = es1->es_pblk;
967 if (!ext4_es_is_referenced(es1))
968 ext4_es_set_referenced(es1);
969 percpu_counter_inc(&stats->es_stats_cache_hits);
970 if (next_lblk) {
971 node = rb_next(&es1->rb_node);
972 if (node) {
973 es1 = rb_entry(node, struct extent_status,
974 rb_node);
975 *next_lblk = es1->es_lblk;
976 } else
977 *next_lblk = 0;
978 }
979 } else {
980 percpu_counter_inc(&stats->es_stats_cache_misses);
981 }
982
983 read_unlock(&EXT4_I(inode)->i_es_lock);
984
985 trace_ext4_es_lookup_extent_exit(inode, es, found);
986 return found;
987}
988
989struct rsvd_count {
990 int ndelonly;
991 bool first_do_lblk_found;
992 ext4_lblk_t first_do_lblk;
993 ext4_lblk_t last_do_lblk;
994 struct extent_status *left_es;
995 bool partial;
996 ext4_lblk_t lclu;
997};
998
999/*
1000 * init_rsvd - initialize reserved count data before removing block range
1001 * in file from extent status tree
1002 *
1003 * @inode - file containing range
1004 * @lblk - first block in range
1005 * @es - pointer to first extent in range
1006 * @rc - pointer to reserved count data
1007 *
1008 * Assumes es is not NULL
1009 */
1010static void init_rsvd(struct inode *inode, ext4_lblk_t lblk,
1011 struct extent_status *es, struct rsvd_count *rc)
1012{
1013 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1014 struct rb_node *node;
1015
1016 rc->ndelonly = 0;
1017
1018 /*
1019 * for bigalloc, note the first delonly block in the range has not
1020 * been found, record the extent containing the block to the left of
1021 * the region to be removed, if any, and note that there's no partial
1022 * cluster to track
1023 */
1024 if (sbi->s_cluster_ratio > 1) {
1025 rc->first_do_lblk_found = false;
1026 if (lblk > es->es_lblk) {
1027 rc->left_es = es;
1028 } else {
1029 node = rb_prev(&es->rb_node);
1030 rc->left_es = node ? rb_entry(node,
1031 struct extent_status,
1032 rb_node) : NULL;
1033 }
1034 rc->partial = false;
1035 }
1036}
1037
1038/*
1039 * count_rsvd - count the clusters containing delayed and not unwritten
1040 * (delonly) blocks in a range within an extent and add to
1041 * the running tally in rsvd_count
1042 *
1043 * @inode - file containing extent
1044 * @lblk - first block in range
1045 * @len - length of range in blocks
1046 * @es - pointer to extent containing clusters to be counted
1047 * @rc - pointer to reserved count data
1048 *
1049 * Tracks partial clusters found at the beginning and end of extents so
1050 * they aren't overcounted when they span adjacent extents
1051 */
1052static void count_rsvd(struct inode *inode, ext4_lblk_t lblk, long len,
1053 struct extent_status *es, struct rsvd_count *rc)
1054{
1055 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1056 ext4_lblk_t i, end, nclu;
1057
1058 if (!ext4_es_is_delonly(es))
1059 return;
1060
1061 WARN_ON(len <= 0);
1062
1063 if (sbi->s_cluster_ratio == 1) {
1064 rc->ndelonly += (int) len;
1065 return;
1066 }
1067
1068 /* bigalloc */
1069
1070 i = (lblk < es->es_lblk) ? es->es_lblk : lblk;
1071 end = lblk + (ext4_lblk_t) len - 1;
1072 end = (end > ext4_es_end(es)) ? ext4_es_end(es) : end;
1073
1074 /* record the first block of the first delonly extent seen */
1075 if (!rc->first_do_lblk_found) {
1076 rc->first_do_lblk = i;
1077 rc->first_do_lblk_found = true;
1078 }
1079
1080 /* update the last lblk in the region seen so far */
1081 rc->last_do_lblk = end;
1082
1083 /*
1084 * if we're tracking a partial cluster and the current extent
1085 * doesn't start with it, count it and stop tracking
1086 */
1087 if (rc->partial && (rc->lclu != EXT4_B2C(sbi, i))) {
1088 rc->ndelonly++;
1089 rc->partial = false;
1090 }
1091
1092 /*
1093 * if the first cluster doesn't start on a cluster boundary but
1094 * ends on one, count it
1095 */
1096 if (EXT4_LBLK_COFF(sbi, i) != 0) {
1097 if (end >= EXT4_LBLK_CFILL(sbi, i)) {
1098 rc->ndelonly++;
1099 rc->partial = false;
1100 i = EXT4_LBLK_CFILL(sbi, i) + 1;
1101 }
1102 }
1103
1104 /*
1105 * if the current cluster starts on a cluster boundary, count the
1106 * number of whole delonly clusters in the extent
1107 */
1108 if ((i + sbi->s_cluster_ratio - 1) <= end) {
1109 nclu = (end - i + 1) >> sbi->s_cluster_bits;
1110 rc->ndelonly += nclu;
1111 i += nclu << sbi->s_cluster_bits;
1112 }
1113
1114 /*
1115 * start tracking a partial cluster if there's a partial at the end
1116 * of the current extent and we're not already tracking one
1117 */
1118 if (!rc->partial && i <= end) {
1119 rc->partial = true;
1120 rc->lclu = EXT4_B2C(sbi, i);
1121 }
1122}
1123
1124/*
1125 * __pr_tree_search - search for a pending cluster reservation
1126 *
1127 * @root - root of pending reservation tree
1128 * @lclu - logical cluster to search for
1129 *
1130 * Returns the pending reservation for the cluster identified by @lclu
1131 * if found. If not, returns a reservation for the next cluster if any,
1132 * and if not, returns NULL.
1133 */
1134static struct pending_reservation *__pr_tree_search(struct rb_root *root,
1135 ext4_lblk_t lclu)
1136{
1137 struct rb_node *node = root->rb_node;
1138 struct pending_reservation *pr = NULL;
1139
1140 while (node) {
1141 pr = rb_entry(node, struct pending_reservation, rb_node);
1142 if (lclu < pr->lclu)
1143 node = node->rb_left;
1144 else if (lclu > pr->lclu)
1145 node = node->rb_right;
1146 else
1147 return pr;
1148 }
1149 if (pr && lclu < pr->lclu)
1150 return pr;
1151 if (pr && lclu > pr->lclu) {
1152 node = rb_next(&pr->rb_node);
1153 return node ? rb_entry(node, struct pending_reservation,
1154 rb_node) : NULL;
1155 }
1156 return NULL;
1157}
1158
1159/*
1160 * get_rsvd - calculates and returns the number of cluster reservations to be
1161 * released when removing a block range from the extent status tree
1162 * and releases any pending reservations within the range
1163 *
1164 * @inode - file containing block range
1165 * @end - last block in range
1166 * @right_es - pointer to extent containing next block beyond end or NULL
1167 * @rc - pointer to reserved count data
1168 *
1169 * The number of reservations to be released is equal to the number of
1170 * clusters containing delayed and not unwritten (delonly) blocks within
1171 * the range, minus the number of clusters still containing delonly blocks
1172 * at the ends of the range, and minus the number of pending reservations
1173 * within the range.
1174 */
1175static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
1176 struct extent_status *right_es,
1177 struct rsvd_count *rc)
1178{
1179 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1180 struct pending_reservation *pr;
1181 struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
1182 struct rb_node *node;
1183 ext4_lblk_t first_lclu, last_lclu;
1184 bool left_delonly, right_delonly, count_pending;
1185 struct extent_status *es;
1186
1187 if (sbi->s_cluster_ratio > 1) {
1188 /* count any remaining partial cluster */
1189 if (rc->partial)
1190 rc->ndelonly++;
1191
1192 if (rc->ndelonly == 0)
1193 return 0;
1194
1195 first_lclu = EXT4_B2C(sbi, rc->first_do_lblk);
1196 last_lclu = EXT4_B2C(sbi, rc->last_do_lblk);
1197
1198 /*
1199 * decrease the delonly count by the number of clusters at the
1200 * ends of the range that still contain delonly blocks -
1201 * these clusters still need to be reserved
1202 */
1203 left_delonly = right_delonly = false;
1204
1205 es = rc->left_es;
1206 while (es && ext4_es_end(es) >=
1207 EXT4_LBLK_CMASK(sbi, rc->first_do_lblk)) {
1208 if (ext4_es_is_delonly(es)) {
1209 rc->ndelonly--;
1210 left_delonly = true;
1211 break;
1212 }
1213 node = rb_prev(&es->rb_node);
1214 if (!node)
1215 break;
1216 es = rb_entry(node, struct extent_status, rb_node);
1217 }
1218 if (right_es && (!left_delonly || first_lclu != last_lclu)) {
1219 if (end < ext4_es_end(right_es)) {
1220 es = right_es;
1221 } else {
1222 node = rb_next(&right_es->rb_node);
1223 es = node ? rb_entry(node, struct extent_status,
1224 rb_node) : NULL;
1225 }
1226 while (es && es->es_lblk <=
1227 EXT4_LBLK_CFILL(sbi, rc->last_do_lblk)) {
1228 if (ext4_es_is_delonly(es)) {
1229 rc->ndelonly--;
1230 right_delonly = true;
1231 break;
1232 }
1233 node = rb_next(&es->rb_node);
1234 if (!node)
1235 break;
1236 es = rb_entry(node, struct extent_status,
1237 rb_node);
1238 }
1239 }
1240
1241 /*
1242 * Determine the block range that should be searched for
1243 * pending reservations, if any. Clusters on the ends of the
1244 * original removed range containing delonly blocks are
1245 * excluded. They've already been accounted for and it's not
1246 * possible to determine if an associated pending reservation
1247 * should be released with the information available in the
1248 * extents status tree.
1249 */
1250 if (first_lclu == last_lclu) {
1251 if (left_delonly | right_delonly)
1252 count_pending = false;
1253 else
1254 count_pending = true;
1255 } else {
1256 if (left_delonly)
1257 first_lclu++;
1258 if (right_delonly)
1259 last_lclu--;
1260 if (first_lclu <= last_lclu)
1261 count_pending = true;
1262 else
1263 count_pending = false;
1264 }
1265
1266 /*
1267 * a pending reservation found between first_lclu and last_lclu
1268 * represents an allocated cluster that contained at least one
1269 * delonly block, so the delonly total must be reduced by one
1270 * for each pending reservation found and released
1271 */
1272 if (count_pending) {
1273 pr = __pr_tree_search(&tree->root, first_lclu);
1274 while (pr && pr->lclu <= last_lclu) {
1275 rc->ndelonly--;
1276 node = rb_next(&pr->rb_node);
1277 rb_erase(&pr->rb_node, &tree->root);
1278 kmem_cache_free(ext4_pending_cachep, pr);
1279 if (!node)
1280 break;
1281 pr = rb_entry(node, struct pending_reservation,
1282 rb_node);
1283 }
1284 }
1285 }
1286 return rc->ndelonly;
1287}
1288
1289
1290/*
1291 * __es_remove_extent - removes block range from extent status tree
1292 *
1293 * @inode - file containing range
1294 * @lblk - first block in range
1295 * @end - last block in range
1296 * @reserved - number of cluster reservations released
1297 *
1298 * If @reserved is not NULL and delayed allocation is enabled, counts
1299 * block/cluster reservations freed by removing range and if bigalloc
1300 * enabled cancels pending reservations as needed. Returns 0 on success,
1301 * error code on failure.
1302 */
1303static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
1304 ext4_lblk_t end, int *reserved)
1305{
1306 struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
1307 struct rb_node *node;
1308 struct extent_status *es;
1309 struct extent_status orig_es;
1310 ext4_lblk_t len1, len2;
1311 ext4_fsblk_t block;
1312 int err;
1313 bool count_reserved = true;
1314 struct rsvd_count rc;
1315
1316 if (reserved == NULL || !test_opt(inode->i_sb, DELALLOC))
1317 count_reserved = false;
1318retry:
1319 err = 0;
1320
1321 es = __es_tree_search(&tree->root, lblk);
1322 if (!es)
1323 goto out;
1324 if (es->es_lblk > end)
1325 goto out;
1326
1327 /* Simply invalidate cache_es. */
1328 tree->cache_es = NULL;
1329 if (count_reserved)
1330 init_rsvd(inode, lblk, es, &rc);
1331
1332 orig_es.es_lblk = es->es_lblk;
1333 orig_es.es_len = es->es_len;
1334 orig_es.es_pblk = es->es_pblk;
1335
1336 len1 = lblk > es->es_lblk ? lblk - es->es_lblk : 0;
1337 len2 = ext4_es_end(es) > end ? ext4_es_end(es) - end : 0;
1338 if (len1 > 0)
1339 es->es_len = len1;
1340 if (len2 > 0) {
1341 if (len1 > 0) {
1342 struct extent_status newes;
1343
1344 newes.es_lblk = end + 1;
1345 newes.es_len = len2;
1346 block = 0x7FDEADBEEFULL;
1347 if (ext4_es_is_written(&orig_es) ||
1348 ext4_es_is_unwritten(&orig_es))
1349 block = ext4_es_pblock(&orig_es) +
1350 orig_es.es_len - len2;
1351 ext4_es_store_pblock_status(&newes, block,
1352 ext4_es_status(&orig_es));
1353 err = __es_insert_extent(inode, &newes);
1354 if (err) {
1355 es->es_lblk = orig_es.es_lblk;
1356 es->es_len = orig_es.es_len;
1357 if ((err == -ENOMEM) &&
1358 __es_shrink(EXT4_SB(inode->i_sb),
1359 128, EXT4_I(inode)))
1360 goto retry;
1361 goto out;
1362 }
1363 } else {
1364 es->es_lblk = end + 1;
1365 es->es_len = len2;
1366 if (ext4_es_is_written(es) ||
1367 ext4_es_is_unwritten(es)) {
1368 block = orig_es.es_pblk + orig_es.es_len - len2;
1369 ext4_es_store_pblock(es, block);
1370 }
1371 }
1372 if (count_reserved)
1373 count_rsvd(inode, lblk, orig_es.es_len - len1 - len2,
1374 &orig_es, &rc);
1375 goto out;
1376 }
1377
1378 if (len1 > 0) {
1379 if (count_reserved)
1380 count_rsvd(inode, lblk, orig_es.es_len - len1,
1381 &orig_es, &rc);
1382 node = rb_next(&es->rb_node);
1383 if (node)
1384 es = rb_entry(node, struct extent_status, rb_node);
1385 else
1386 es = NULL;
1387 }
1388
1389 while (es && ext4_es_end(es) <= end) {
1390 if (count_reserved)
1391 count_rsvd(inode, es->es_lblk, es->es_len, es, &rc);
1392 node = rb_next(&es->rb_node);
1393 rb_erase(&es->rb_node, &tree->root);
1394 ext4_es_free_extent(inode, es);
1395 if (!node) {
1396 es = NULL;
1397 break;
1398 }
1399 es = rb_entry(node, struct extent_status, rb_node);
1400 }
1401
1402 if (es && es->es_lblk < end + 1) {
1403 ext4_lblk_t orig_len = es->es_len;
1404
1405 len1 = ext4_es_end(es) - end;
1406 if (count_reserved)
1407 count_rsvd(inode, es->es_lblk, orig_len - len1,
1408 es, &rc);
1409 es->es_lblk = end + 1;
1410 es->es_len = len1;
1411 if (ext4_es_is_written(es) || ext4_es_is_unwritten(es)) {
1412 block = es->es_pblk + orig_len - len1;
1413 ext4_es_store_pblock(es, block);
1414 }
1415 }
1416
1417 if (count_reserved)
1418 *reserved = get_rsvd(inode, end, es, &rc);
1419out:
1420 return err;
1421}
1422
1423/*
1424 * ext4_es_remove_extent - removes block range from extent status tree
1425 *
1426 * @inode - file containing range
1427 * @lblk - first block in range
1428 * @len - number of blocks to remove
1429 *
1430 * Reduces block/cluster reservation count and for bigalloc cancels pending
1431 * reservations as needed. Returns 0 on success, error code on failure.
1432 */
1433int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
1434 ext4_lblk_t len)
1435{
1436 ext4_lblk_t end;
1437 int err = 0;
1438 int reserved = 0;
1439
1440 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
1441 return 0;
1442
1443 trace_ext4_es_remove_extent(inode, lblk, len);
1444 es_debug("remove [%u/%u) from extent status tree of inode %lu\n",
1445 lblk, len, inode->i_ino);
1446
1447 if (!len)
1448 return err;
1449
1450 end = lblk + len - 1;
1451 BUG_ON(end < lblk);
1452
1453 /*
1454 * ext4_clear_inode() depends on us taking i_es_lock unconditionally
1455 * so that we are sure __es_shrink() is done with the inode before it
1456 * is reclaimed.
1457 */
1458 write_lock(&EXT4_I(inode)->i_es_lock);
1459 err = __es_remove_extent(inode, lblk, end, &reserved);
1460 write_unlock(&EXT4_I(inode)->i_es_lock);
1461 ext4_es_print_tree(inode);
1462 ext4_da_release_space(inode, reserved);
1463 return err;
1464}
1465
1466static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
1467 struct ext4_inode_info *locked_ei)
1468{
1469 struct ext4_inode_info *ei;
1470 struct ext4_es_stats *es_stats;
1471 ktime_t start_time;
1472 u64 scan_time;
1473 int nr_to_walk;
1474 int nr_shrunk = 0;
1475 int retried = 0, nr_skipped = 0;
1476
1477 es_stats = &sbi->s_es_stats;
1478 start_time = ktime_get();
1479
1480retry:
1481 spin_lock(&sbi->s_es_lock);
1482 nr_to_walk = sbi->s_es_nr_inode;
1483 while (nr_to_walk-- > 0) {
1484 if (list_empty(&sbi->s_es_list)) {
1485 spin_unlock(&sbi->s_es_lock);
1486 goto out;
1487 }
1488 ei = list_first_entry(&sbi->s_es_list, struct ext4_inode_info,
1489 i_es_list);
1490 /* Move the inode to the tail */
1491 list_move_tail(&ei->i_es_list, &sbi->s_es_list);
1492
1493 /*
1494 * Normally we try hard to avoid shrinking precached inodes,
1495 * but we will as a last resort.
1496 */
1497 if (!retried && ext4_test_inode_state(&ei->vfs_inode,
1498 EXT4_STATE_EXT_PRECACHED)) {
1499 nr_skipped++;
1500 continue;
1501 }
1502
1503 if (ei == locked_ei || !write_trylock(&ei->i_es_lock)) {
1504 nr_skipped++;
1505 continue;
1506 }
1507 /*
1508 * Now we hold i_es_lock which protects us from inode reclaim
1509 * freeing inode under us
1510 */
1511 spin_unlock(&sbi->s_es_lock);
1512
1513 nr_shrunk += es_reclaim_extents(ei, &nr_to_scan);
1514 write_unlock(&ei->i_es_lock);
1515
1516 if (nr_to_scan <= 0)
1517 goto out;
1518 spin_lock(&sbi->s_es_lock);
1519 }
1520 spin_unlock(&sbi->s_es_lock);
1521
1522 /*
1523 * If we skipped any inodes, and we weren't able to make any
1524 * forward progress, try again to scan precached inodes.
1525 */
1526 if ((nr_shrunk == 0) && nr_skipped && !retried) {
1527 retried++;
1528 goto retry;
1529 }
1530
1531 if (locked_ei && nr_shrunk == 0)
1532 nr_shrunk = es_reclaim_extents(locked_ei, &nr_to_scan);
1533
1534out:
1535 scan_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1536 if (likely(es_stats->es_stats_scan_time))
1537 es_stats->es_stats_scan_time = (scan_time +
1538 es_stats->es_stats_scan_time*3) / 4;
1539 else
1540 es_stats->es_stats_scan_time = scan_time;
1541 if (scan_time > es_stats->es_stats_max_scan_time)
1542 es_stats->es_stats_max_scan_time = scan_time;
1543 if (likely(es_stats->es_stats_shrunk))
1544 es_stats->es_stats_shrunk = (nr_shrunk +
1545 es_stats->es_stats_shrunk*3) / 4;
1546 else
1547 es_stats->es_stats_shrunk = nr_shrunk;
1548
1549 trace_ext4_es_shrink(sbi->s_sb, nr_shrunk, scan_time,
1550 nr_skipped, retried);
1551 return nr_shrunk;
1552}
1553
1554static unsigned long ext4_es_count(struct shrinker *shrink,
1555 struct shrink_control *sc)
1556{
1557 unsigned long nr;
1558 struct ext4_sb_info *sbi;
1559
1560 sbi = container_of(shrink, struct ext4_sb_info, s_es_shrinker);
1561 nr = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
1562 trace_ext4_es_shrink_count(sbi->s_sb, sc->nr_to_scan, nr);
1563 return nr;
1564}
1565
1566static unsigned long ext4_es_scan(struct shrinker *shrink,
1567 struct shrink_control *sc)
1568{
1569 struct ext4_sb_info *sbi = container_of(shrink,
1570 struct ext4_sb_info, s_es_shrinker);
1571 int nr_to_scan = sc->nr_to_scan;
1572 int ret, nr_shrunk;
1573
1574 ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
1575 trace_ext4_es_shrink_scan_enter(sbi->s_sb, nr_to_scan, ret);
1576
1577 nr_shrunk = __es_shrink(sbi, nr_to_scan, NULL);
1578
1579 ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
1580 trace_ext4_es_shrink_scan_exit(sbi->s_sb, nr_shrunk, ret);
1581 return nr_shrunk;
1582}
1583
1584int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v)
1585{
1586 struct ext4_sb_info *sbi = EXT4_SB((struct super_block *) seq->private);
1587 struct ext4_es_stats *es_stats = &sbi->s_es_stats;
1588 struct ext4_inode_info *ei, *max = NULL;
1589 unsigned int inode_cnt = 0;
1590
1591 if (v != SEQ_START_TOKEN)
1592 return 0;
1593
1594 /* here we just find an inode that has the max nr. of objects */
1595 spin_lock(&sbi->s_es_lock);
1596 list_for_each_entry(ei, &sbi->s_es_list, i_es_list) {
1597 inode_cnt++;
1598 if (max && max->i_es_all_nr < ei->i_es_all_nr)
1599 max = ei;
1600 else if (!max)
1601 max = ei;
1602 }
1603 spin_unlock(&sbi->s_es_lock);
1604
1605 seq_printf(seq, "stats:\n %lld objects\n %lld reclaimable objects\n",
1606 percpu_counter_sum_positive(&es_stats->es_stats_all_cnt),
1607 percpu_counter_sum_positive(&es_stats->es_stats_shk_cnt));
1608 seq_printf(seq, " %lld/%lld cache hits/misses\n",
1609 percpu_counter_sum_positive(&es_stats->es_stats_cache_hits),
1610 percpu_counter_sum_positive(&es_stats->es_stats_cache_misses));
1611 if (inode_cnt)
1612 seq_printf(seq, " %d inodes on list\n", inode_cnt);
1613
1614 seq_printf(seq, "average:\n %llu us scan time\n",
1615 div_u64(es_stats->es_stats_scan_time, 1000));
1616 seq_printf(seq, " %lu shrunk objects\n", es_stats->es_stats_shrunk);
1617 if (inode_cnt)
1618 seq_printf(seq,
1619 "maximum:\n %lu inode (%u objects, %u reclaimable)\n"
1620 " %llu us max scan time\n",
1621 max->vfs_inode.i_ino, max->i_es_all_nr, max->i_es_shk_nr,
1622 div_u64(es_stats->es_stats_max_scan_time, 1000));
1623
1624 return 0;
1625}
1626
1627int ext4_es_register_shrinker(struct ext4_sb_info *sbi)
1628{
1629 int err;
1630
1631 /* Make sure we have enough bits for physical block number */
1632 BUILD_BUG_ON(ES_SHIFT < 48);
1633 INIT_LIST_HEAD(&sbi->s_es_list);
1634 sbi->s_es_nr_inode = 0;
1635 spin_lock_init(&sbi->s_es_lock);
1636 sbi->s_es_stats.es_stats_shrunk = 0;
1637 err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_hits, 0,
1638 GFP_KERNEL);
1639 if (err)
1640 return err;
1641 err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_misses, 0,
1642 GFP_KERNEL);
1643 if (err)
1644 goto err1;
1645 sbi->s_es_stats.es_stats_scan_time = 0;
1646 sbi->s_es_stats.es_stats_max_scan_time = 0;
1647 err = percpu_counter_init(&sbi->s_es_stats.es_stats_all_cnt, 0, GFP_KERNEL);
1648 if (err)
1649 goto err2;
1650 err = percpu_counter_init(&sbi->s_es_stats.es_stats_shk_cnt, 0, GFP_KERNEL);
1651 if (err)
1652 goto err3;
1653
1654 sbi->s_es_shrinker.scan_objects = ext4_es_scan;
1655 sbi->s_es_shrinker.count_objects = ext4_es_count;
1656 sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
1657 err = register_shrinker(&sbi->s_es_shrinker);
1658 if (err)
1659 goto err4;
1660
1661 return 0;
1662err4:
1663 percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
1664err3:
1665 percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
1666err2:
1667 percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
1668err1:
1669 percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits);
1670 return err;
1671}
1672
1673void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi)
1674{
1675 percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits);
1676 percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
1677 percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
1678 percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
1679 unregister_shrinker(&sbi->s_es_shrinker);
1680}
1681
1682/*
1683 * Shrink extents in given inode from ei->i_es_shrink_lblk till end. Scan at
1684 * most *nr_to_scan extents, update *nr_to_scan accordingly.
1685 *
1686 * Return 0 if we hit end of tree / interval, 1 if we exhausted nr_to_scan.
1687 * Increment *nr_shrunk by the number of reclaimed extents. Also update
1688 * ei->i_es_shrink_lblk to where we should continue scanning.
1689 */
1690static int es_do_reclaim_extents(struct ext4_inode_info *ei, ext4_lblk_t end,
1691 int *nr_to_scan, int *nr_shrunk)
1692{
1693 struct inode *inode = &ei->vfs_inode;
1694 struct ext4_es_tree *tree = &ei->i_es_tree;
1695 struct extent_status *es;
1696 struct rb_node *node;
1697
1698 es = __es_tree_search(&tree->root, ei->i_es_shrink_lblk);
1699 if (!es)
1700 goto out_wrap;
1701
1702 while (*nr_to_scan > 0) {
1703 if (es->es_lblk > end) {
1704 ei->i_es_shrink_lblk = end + 1;
1705 return 0;
1706 }
1707
1708 (*nr_to_scan)--;
1709 node = rb_next(&es->rb_node);
1710 /*
1711 * We can't reclaim delayed extent from status tree because
1712 * fiemap, bigallic, and seek_data/hole need to use it.
1713 */
1714 if (ext4_es_is_delayed(es))
1715 goto next;
1716 if (ext4_es_is_referenced(es)) {
1717 ext4_es_clear_referenced(es);
1718 goto next;
1719 }
1720
1721 rb_erase(&es->rb_node, &tree->root);
1722 ext4_es_free_extent(inode, es);
1723 (*nr_shrunk)++;
1724next:
1725 if (!node)
1726 goto out_wrap;
1727 es = rb_entry(node, struct extent_status, rb_node);
1728 }
1729 ei->i_es_shrink_lblk = es->es_lblk;
1730 return 1;
1731out_wrap:
1732 ei->i_es_shrink_lblk = 0;
1733 return 0;
1734}
1735
1736static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan)
1737{
1738 struct inode *inode = &ei->vfs_inode;
1739 int nr_shrunk = 0;
1740 ext4_lblk_t start = ei->i_es_shrink_lblk;
1741 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
1742 DEFAULT_RATELIMIT_BURST);
1743
1744 if (ei->i_es_shk_nr == 0)
1745 return 0;
1746
1747 if (ext4_test_inode_state(inode, EXT4_STATE_EXT_PRECACHED) &&
1748 __ratelimit(&_rs))
1749 ext4_warning(inode->i_sb, "forced shrink of precached extents");
1750
1751 if (!es_do_reclaim_extents(ei, EXT_MAX_BLOCKS, nr_to_scan, &nr_shrunk) &&
1752 start != 0)
1753 es_do_reclaim_extents(ei, start - 1, nr_to_scan, &nr_shrunk);
1754
1755 ei->i_es_tree.cache_es = NULL;
1756 return nr_shrunk;
1757}
1758
1759/*
1760 * Called to support EXT4_IOC_CLEAR_ES_CACHE. We can only remove
1761 * discretionary entries from the extent status cache. (Some entries
1762 * must be present for proper operations.)
1763 */
1764void ext4_clear_inode_es(struct inode *inode)
1765{
1766 struct ext4_inode_info *ei = EXT4_I(inode);
1767 struct extent_status *es;
1768 struct ext4_es_tree *tree;
1769 struct rb_node *node;
1770
1771 write_lock(&ei->i_es_lock);
1772 tree = &EXT4_I(inode)->i_es_tree;
1773 tree->cache_es = NULL;
1774 node = rb_first(&tree->root);
1775 while (node) {
1776 es = rb_entry(node, struct extent_status, rb_node);
1777 node = rb_next(node);
1778 if (!ext4_es_is_delayed(es)) {
1779 rb_erase(&es->rb_node, &tree->root);
1780 ext4_es_free_extent(inode, es);
1781 }
1782 }
1783 ext4_clear_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
1784 write_unlock(&ei->i_es_lock);
1785}
1786
1787#ifdef ES_DEBUG__
1788static void ext4_print_pending_tree(struct inode *inode)
1789{
1790 struct ext4_pending_tree *tree;
1791 struct rb_node *node;
1792 struct pending_reservation *pr;
1793
1794 printk(KERN_DEBUG "pending reservations for inode %lu:", inode->i_ino);
1795 tree = &EXT4_I(inode)->i_pending_tree;
1796 node = rb_first(&tree->root);
1797 while (node) {
1798 pr = rb_entry(node, struct pending_reservation, rb_node);
1799 printk(KERN_DEBUG " %u", pr->lclu);
1800 node = rb_next(node);
1801 }
1802 printk(KERN_DEBUG "\n");
1803}
1804#else
1805#define ext4_print_pending_tree(inode)
1806#endif
1807
1808int __init ext4_init_pending(void)
1809{
1810 ext4_pending_cachep = kmem_cache_create("ext4_pending_reservation",
1811 sizeof(struct pending_reservation),
1812 0, (SLAB_RECLAIM_ACCOUNT), NULL);
1813 if (ext4_pending_cachep == NULL)
1814 return -ENOMEM;
1815 return 0;
1816}
1817
1818void ext4_exit_pending(void)
1819{
1820 kmem_cache_destroy(ext4_pending_cachep);
1821}
1822
1823void ext4_init_pending_tree(struct ext4_pending_tree *tree)
1824{
1825 tree->root = RB_ROOT;
1826}
1827
1828/*
1829 * __get_pending - retrieve a pointer to a pending reservation
1830 *
1831 * @inode - file containing the pending cluster reservation
1832 * @lclu - logical cluster of interest
1833 *
1834 * Returns a pointer to a pending reservation if it's a member of
1835 * the set, and NULL if not. Must be called holding i_es_lock.
1836 */
1837static struct pending_reservation *__get_pending(struct inode *inode,
1838 ext4_lblk_t lclu)
1839{
1840 struct ext4_pending_tree *tree;
1841 struct rb_node *node;
1842 struct pending_reservation *pr = NULL;
1843
1844 tree = &EXT4_I(inode)->i_pending_tree;
1845 node = (&tree->root)->rb_node;
1846
1847 while (node) {
1848 pr = rb_entry(node, struct pending_reservation, rb_node);
1849 if (lclu < pr->lclu)
1850 node = node->rb_left;
1851 else if (lclu > pr->lclu)
1852 node = node->rb_right;
1853 else if (lclu == pr->lclu)
1854 return pr;
1855 }
1856 return NULL;
1857}
1858
1859/*
1860 * __insert_pending - adds a pending cluster reservation to the set of
1861 * pending reservations
1862 *
1863 * @inode - file containing the cluster
1864 * @lblk - logical block in the cluster to be added
1865 *
1866 * Returns 0 on successful insertion and -ENOMEM on failure. If the
1867 * pending reservation is already in the set, returns successfully.
1868 */
1869static int __insert_pending(struct inode *inode, ext4_lblk_t lblk)
1870{
1871 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1872 struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
1873 struct rb_node **p = &tree->root.rb_node;
1874 struct rb_node *parent = NULL;
1875 struct pending_reservation *pr;
1876 ext4_lblk_t lclu;
1877 int ret = 0;
1878
1879 lclu = EXT4_B2C(sbi, lblk);
1880 /* search to find parent for insertion */
1881 while (*p) {
1882 parent = *p;
1883 pr = rb_entry(parent, struct pending_reservation, rb_node);
1884
1885 if (lclu < pr->lclu) {
1886 p = &(*p)->rb_left;
1887 } else if (lclu > pr->lclu) {
1888 p = &(*p)->rb_right;
1889 } else {
1890 /* pending reservation already inserted */
1891 goto out;
1892 }
1893 }
1894
1895 pr = kmem_cache_alloc(ext4_pending_cachep, GFP_ATOMIC);
1896 if (pr == NULL) {
1897 ret = -ENOMEM;
1898 goto out;
1899 }
1900 pr->lclu = lclu;
1901
1902 rb_link_node(&pr->rb_node, parent, p);
1903 rb_insert_color(&pr->rb_node, &tree->root);
1904
1905out:
1906 return ret;
1907}
1908
1909/*
1910 * __remove_pending - removes a pending cluster reservation from the set
1911 * of pending reservations
1912 *
1913 * @inode - file containing the cluster
1914 * @lblk - logical block in the pending cluster reservation to be removed
1915 *
1916 * Returns successfully if pending reservation is not a member of the set.
1917 */
1918static void __remove_pending(struct inode *inode, ext4_lblk_t lblk)
1919{
1920 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1921 struct pending_reservation *pr;
1922 struct ext4_pending_tree *tree;
1923
1924 pr = __get_pending(inode, EXT4_B2C(sbi, lblk));
1925 if (pr != NULL) {
1926 tree = &EXT4_I(inode)->i_pending_tree;
1927 rb_erase(&pr->rb_node, &tree->root);
1928 kmem_cache_free(ext4_pending_cachep, pr);
1929 }
1930}
1931
1932/*
1933 * ext4_remove_pending - removes a pending cluster reservation from the set
1934 * of pending reservations
1935 *
1936 * @inode - file containing the cluster
1937 * @lblk - logical block in the pending cluster reservation to be removed
1938 *
1939 * Locking for external use of __remove_pending.
1940 */
1941void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk)
1942{
1943 struct ext4_inode_info *ei = EXT4_I(inode);
1944
1945 write_lock(&ei->i_es_lock);
1946 __remove_pending(inode, lblk);
1947 write_unlock(&ei->i_es_lock);
1948}
1949
1950/*
1951 * ext4_is_pending - determine whether a cluster has a pending reservation
1952 * on it
1953 *
1954 * @inode - file containing the cluster
1955 * @lblk - logical block in the cluster
1956 *
1957 * Returns true if there's a pending reservation for the cluster in the
1958 * set of pending reservations, and false if not.
1959 */
1960bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk)
1961{
1962 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1963 struct ext4_inode_info *ei = EXT4_I(inode);
1964 bool ret;
1965
1966 read_lock(&ei->i_es_lock);
1967 ret = (bool)(__get_pending(inode, EXT4_B2C(sbi, lblk)) != NULL);
1968 read_unlock(&ei->i_es_lock);
1969
1970 return ret;
1971}
1972
1973/*
1974 * ext4_es_insert_delayed_block - adds a delayed block to the extents status
1975 * tree, adding a pending reservation where
1976 * needed
1977 *
1978 * @inode - file containing the newly added block
1979 * @lblk - logical block to be added
1980 * @allocated - indicates whether a physical cluster has been allocated for
1981 * the logical cluster that contains the block
1982 *
1983 * Returns 0 on success, negative error code on failure.
1984 */
1985int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
1986 bool allocated)
1987{
1988 struct extent_status newes;
1989 int err = 0;
1990
1991 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
1992 return 0;
1993
1994 es_debug("add [%u/1) delayed to extent status tree of inode %lu\n",
1995 lblk, inode->i_ino);
1996
1997 newes.es_lblk = lblk;
1998 newes.es_len = 1;
1999 ext4_es_store_pblock_status(&newes, ~0, EXTENT_STATUS_DELAYED);
2000 trace_ext4_es_insert_delayed_block(inode, &newes, allocated);
2001
2002 ext4_es_insert_extent_check(inode, &newes);
2003
2004 write_lock(&EXT4_I(inode)->i_es_lock);
2005
2006 err = __es_remove_extent(inode, lblk, lblk, NULL);
2007 if (err != 0)
2008 goto error;
2009retry:
2010 err = __es_insert_extent(inode, &newes);
2011 if (err == -ENOMEM && __es_shrink(EXT4_SB(inode->i_sb),
2012 128, EXT4_I(inode)))
2013 goto retry;
2014 if (err != 0)
2015 goto error;
2016
2017 if (allocated)
2018 __insert_pending(inode, lblk);
2019
2020error:
2021 write_unlock(&EXT4_I(inode)->i_es_lock);
2022
2023 ext4_es_print_tree(inode);
2024 ext4_print_pending_tree(inode);
2025
2026 return err;
2027}
2028
2029/*
2030 * __es_delayed_clu - count number of clusters containing blocks that
2031 * are delayed only
2032 *
2033 * @inode - file containing block range
2034 * @start - logical block defining start of range
2035 * @end - logical block defining end of range
2036 *
2037 * Returns the number of clusters containing only delayed (not delayed
2038 * and unwritten) blocks in the range specified by @start and @end. Any
2039 * cluster or part of a cluster within the range and containing a delayed
2040 * and not unwritten block within the range is counted as a whole cluster.
2041 */
2042static unsigned int __es_delayed_clu(struct inode *inode, ext4_lblk_t start,
2043 ext4_lblk_t end)
2044{
2045 struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
2046 struct extent_status *es;
2047 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2048 struct rb_node *node;
2049 ext4_lblk_t first_lclu, last_lclu;
2050 unsigned long long last_counted_lclu;
2051 unsigned int n = 0;
2052
2053 /* guaranteed to be unequal to any ext4_lblk_t value */
2054 last_counted_lclu = ~0ULL;
2055
2056 es = __es_tree_search(&tree->root, start);
2057
2058 while (es && (es->es_lblk <= end)) {
2059 if (ext4_es_is_delonly(es)) {
2060 if (es->es_lblk <= start)
2061 first_lclu = EXT4_B2C(sbi, start);
2062 else
2063 first_lclu = EXT4_B2C(sbi, es->es_lblk);
2064
2065 if (ext4_es_end(es) >= end)
2066 last_lclu = EXT4_B2C(sbi, end);
2067 else
2068 last_lclu = EXT4_B2C(sbi, ext4_es_end(es));
2069
2070 if (first_lclu == last_counted_lclu)
2071 n += last_lclu - first_lclu;
2072 else
2073 n += last_lclu - first_lclu + 1;
2074 last_counted_lclu = last_lclu;
2075 }
2076 node = rb_next(&es->rb_node);
2077 if (!node)
2078 break;
2079 es = rb_entry(node, struct extent_status, rb_node);
2080 }
2081
2082 return n;
2083}
2084
2085/*
2086 * ext4_es_delayed_clu - count number of clusters containing blocks that
2087 * are both delayed and unwritten
2088 *
2089 * @inode - file containing block range
2090 * @lblk - logical block defining start of range
2091 * @len - number of blocks in range
2092 *
2093 * Locking for external use of __es_delayed_clu().
2094 */
2095unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
2096 ext4_lblk_t len)
2097{
2098 struct ext4_inode_info *ei = EXT4_I(inode);
2099 ext4_lblk_t end;
2100 unsigned int n;
2101
2102 if (len == 0)
2103 return 0;
2104
2105 end = lblk + len - 1;
2106 WARN_ON(end < lblk);
2107
2108 read_lock(&ei->i_es_lock);
2109
2110 n = __es_delayed_clu(inode, lblk, end);
2111
2112 read_unlock(&ei->i_es_lock);
2113
2114 return n;
2115}
2116
2117/*
2118 * __revise_pending - makes, cancels, or leaves unchanged pending cluster
2119 * reservations for a specified block range depending
2120 * upon the presence or absence of delayed blocks
2121 * outside the range within clusters at the ends of the
2122 * range
2123 *
2124 * @inode - file containing the range
2125 * @lblk - logical block defining the start of range
2126 * @len - length of range in blocks
2127 *
2128 * Used after a newly allocated extent is added to the extents status tree.
2129 * Requires that the extents in the range have either written or unwritten
2130 * status. Must be called while holding i_es_lock.
2131 */
2132static void __revise_pending(struct inode *inode, ext4_lblk_t lblk,
2133 ext4_lblk_t len)
2134{
2135 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2136 ext4_lblk_t end = lblk + len - 1;
2137 ext4_lblk_t first, last;
2138 bool f_del = false, l_del = false;
2139
2140 if (len == 0)
2141 return;
2142
2143 /*
2144 * Two cases - block range within single cluster and block range
2145 * spanning two or more clusters. Note that a cluster belonging
2146 * to a range starting and/or ending on a cluster boundary is treated
2147 * as if it does not contain a delayed extent. The new range may
2148 * have allocated space for previously delayed blocks out to the
2149 * cluster boundary, requiring that any pre-existing pending
2150 * reservation be canceled. Because this code only looks at blocks
2151 * outside the range, it should revise pending reservations
2152 * correctly even if the extent represented by the range can't be
2153 * inserted in the extents status tree due to ENOSPC.
2154 */
2155
2156 if (EXT4_B2C(sbi, lblk) == EXT4_B2C(sbi, end)) {
2157 first = EXT4_LBLK_CMASK(sbi, lblk);
2158 if (first != lblk)
2159 f_del = __es_scan_range(inode, &ext4_es_is_delonly,
2160 first, lblk - 1);
2161 if (f_del) {
2162 __insert_pending(inode, first);
2163 } else {
2164 last = EXT4_LBLK_CMASK(sbi, end) +
2165 sbi->s_cluster_ratio - 1;
2166 if (last != end)
2167 l_del = __es_scan_range(inode,
2168 &ext4_es_is_delonly,
2169 end + 1, last);
2170 if (l_del)
2171 __insert_pending(inode, last);
2172 else
2173 __remove_pending(inode, last);
2174 }
2175 } else {
2176 first = EXT4_LBLK_CMASK(sbi, lblk);
2177 if (first != lblk)
2178 f_del = __es_scan_range(inode, &ext4_es_is_delonly,
2179 first, lblk - 1);
2180 if (f_del)
2181 __insert_pending(inode, first);
2182 else
2183 __remove_pending(inode, first);
2184
2185 last = EXT4_LBLK_CMASK(sbi, end) + sbi->s_cluster_ratio - 1;
2186 if (last != end)
2187 l_del = __es_scan_range(inode, &ext4_es_is_delonly,
2188 end + 1, last);
2189 if (l_del)
2190 __insert_pending(inode, last);
2191 else
2192 __remove_pending(inode, last);
2193 }
2194}