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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,
148 struct extent_status *prealloc);
149static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
150 ext4_lblk_t end, int *reserved,
151 struct extent_status *prealloc);
152static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan);
153static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
154 struct ext4_inode_info *locked_ei);
155static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
156 ext4_lblk_t len,
157 struct pending_reservation **prealloc);
158
159int __init ext4_init_es(void)
160{
161 ext4_es_cachep = KMEM_CACHE(extent_status, SLAB_RECLAIM_ACCOUNT);
162 if (ext4_es_cachep == NULL)
163 return -ENOMEM;
164 return 0;
165}
166
167void ext4_exit_es(void)
168{
169 kmem_cache_destroy(ext4_es_cachep);
170}
171
172void ext4_es_init_tree(struct ext4_es_tree *tree)
173{
174 tree->root = RB_ROOT;
175 tree->cache_es = NULL;
176}
177
178#ifdef ES_DEBUG__
179static void ext4_es_print_tree(struct inode *inode)
180{
181 struct ext4_es_tree *tree;
182 struct rb_node *node;
183
184 printk(KERN_DEBUG "status extents for inode %lu:", inode->i_ino);
185 tree = &EXT4_I(inode)->i_es_tree;
186 node = rb_first(&tree->root);
187 while (node) {
188 struct extent_status *es;
189 es = rb_entry(node, struct extent_status, rb_node);
190 printk(KERN_DEBUG " [%u/%u) %llu %x",
191 es->es_lblk, es->es_len,
192 ext4_es_pblock(es), ext4_es_status(es));
193 node = rb_next(node);
194 }
195 printk(KERN_DEBUG "\n");
196}
197#else
198#define ext4_es_print_tree(inode)
199#endif
200
201static inline ext4_lblk_t ext4_es_end(struct extent_status *es)
202{
203 BUG_ON(es->es_lblk + es->es_len < es->es_lblk);
204 return es->es_lblk + es->es_len - 1;
205}
206
207/*
208 * search through the tree for an delayed extent with a given offset. If
209 * it can't be found, try to find next extent.
210 */
211static struct extent_status *__es_tree_search(struct rb_root *root,
212 ext4_lblk_t lblk)
213{
214 struct rb_node *node = root->rb_node;
215 struct extent_status *es = NULL;
216
217 while (node) {
218 es = rb_entry(node, struct extent_status, rb_node);
219 if (lblk < es->es_lblk)
220 node = node->rb_left;
221 else if (lblk > ext4_es_end(es))
222 node = node->rb_right;
223 else
224 return es;
225 }
226
227 if (es && lblk < es->es_lblk)
228 return es;
229
230 if (es && lblk > ext4_es_end(es)) {
231 node = rb_next(&es->rb_node);
232 return node ? rb_entry(node, struct extent_status, rb_node) :
233 NULL;
234 }
235
236 return NULL;
237}
238
239/*
240 * ext4_es_find_extent_range - find extent with specified status within block
241 * range or next extent following block range in
242 * extents status tree
243 *
244 * @inode - file containing the range
245 * @matching_fn - pointer to function that matches extents with desired status
246 * @lblk - logical block defining start of range
247 * @end - logical block defining end of range
248 * @es - extent found, if any
249 *
250 * Find the first extent within the block range specified by @lblk and @end
251 * in the extents status tree that satisfies @matching_fn. If a match
252 * is found, it's returned in @es. If not, and a matching extent is found
253 * beyond the block range, it's returned in @es. If no match is found, an
254 * extent is returned in @es whose es_lblk, es_len, and es_pblk components
255 * are 0.
256 */
257static void __es_find_extent_range(struct inode *inode,
258 int (*matching_fn)(struct extent_status *es),
259 ext4_lblk_t lblk, ext4_lblk_t end,
260 struct extent_status *es)
261{
262 struct ext4_es_tree *tree = NULL;
263 struct extent_status *es1 = NULL;
264 struct rb_node *node;
265
266 WARN_ON(es == NULL);
267 WARN_ON(end < lblk);
268
269 tree = &EXT4_I(inode)->i_es_tree;
270
271 /* see if the extent has been cached */
272 es->es_lblk = es->es_len = es->es_pblk = 0;
273 es1 = READ_ONCE(tree->cache_es);
274 if (es1 && 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 es1 = __es_tree_search(&tree->root, lblk);
282
283out:
284 if (es1 && !matching_fn(es1)) {
285 while ((node = rb_next(&es1->rb_node)) != NULL) {
286 es1 = rb_entry(node, struct extent_status, rb_node);
287 if (es1->es_lblk > end) {
288 es1 = NULL;
289 break;
290 }
291 if (matching_fn(es1))
292 break;
293 }
294 }
295
296 if (es1 && matching_fn(es1)) {
297 WRITE_ONCE(tree->cache_es, es1);
298 es->es_lblk = es1->es_lblk;
299 es->es_len = es1->es_len;
300 es->es_pblk = es1->es_pblk;
301 }
302
303}
304
305/*
306 * Locking for __es_find_extent_range() for external use
307 */
308void ext4_es_find_extent_range(struct inode *inode,
309 int (*matching_fn)(struct extent_status *es),
310 ext4_lblk_t lblk, ext4_lblk_t end,
311 struct extent_status *es)
312{
313 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
314 return;
315
316 trace_ext4_es_find_extent_range_enter(inode, lblk);
317
318 read_lock(&EXT4_I(inode)->i_es_lock);
319 __es_find_extent_range(inode, matching_fn, lblk, end, es);
320 read_unlock(&EXT4_I(inode)->i_es_lock);
321
322 trace_ext4_es_find_extent_range_exit(inode, es);
323}
324
325/*
326 * __es_scan_range - search block range for block with specified status
327 * in extents status tree
328 *
329 * @inode - file containing the range
330 * @matching_fn - pointer to function that matches extents with desired status
331 * @lblk - logical block defining start of range
332 * @end - logical block defining end of range
333 *
334 * Returns true if at least one block in the specified block range satisfies
335 * the criterion specified by @matching_fn, and false if not. If at least
336 * one extent has the specified status, then there is at least one block
337 * in the cluster with that status. Should only be called by code that has
338 * taken i_es_lock.
339 */
340static bool __es_scan_range(struct inode *inode,
341 int (*matching_fn)(struct extent_status *es),
342 ext4_lblk_t start, ext4_lblk_t end)
343{
344 struct extent_status es;
345
346 __es_find_extent_range(inode, matching_fn, start, end, &es);
347 if (es.es_len == 0)
348 return false; /* no matching extent in the tree */
349 else if (es.es_lblk <= start &&
350 start < es.es_lblk + es.es_len)
351 return true;
352 else if (start <= es.es_lblk && es.es_lblk <= end)
353 return true;
354 else
355 return false;
356}
357/*
358 * Locking for __es_scan_range() for external use
359 */
360bool ext4_es_scan_range(struct inode *inode,
361 int (*matching_fn)(struct extent_status *es),
362 ext4_lblk_t lblk, ext4_lblk_t end)
363{
364 bool ret;
365
366 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
367 return false;
368
369 read_lock(&EXT4_I(inode)->i_es_lock);
370 ret = __es_scan_range(inode, matching_fn, lblk, end);
371 read_unlock(&EXT4_I(inode)->i_es_lock);
372
373 return ret;
374}
375
376/*
377 * __es_scan_clu - search cluster for block with specified status in
378 * extents status tree
379 *
380 * @inode - file containing the cluster
381 * @matching_fn - pointer to function that matches extents with desired status
382 * @lblk - logical block in cluster to be searched
383 *
384 * Returns true if at least one extent in the cluster containing @lblk
385 * satisfies the criterion specified by @matching_fn, and false if not. If at
386 * least one extent has the specified status, then there is at least one block
387 * in the cluster with that status. Should only be called by code that has
388 * taken i_es_lock.
389 */
390static bool __es_scan_clu(struct inode *inode,
391 int (*matching_fn)(struct extent_status *es),
392 ext4_lblk_t lblk)
393{
394 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
395 ext4_lblk_t lblk_start, lblk_end;
396
397 lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
398 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
399
400 return __es_scan_range(inode, matching_fn, lblk_start, lblk_end);
401}
402
403/*
404 * Locking for __es_scan_clu() for external use
405 */
406bool ext4_es_scan_clu(struct inode *inode,
407 int (*matching_fn)(struct extent_status *es),
408 ext4_lblk_t lblk)
409{
410 bool ret;
411
412 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
413 return false;
414
415 read_lock(&EXT4_I(inode)->i_es_lock);
416 ret = __es_scan_clu(inode, matching_fn, lblk);
417 read_unlock(&EXT4_I(inode)->i_es_lock);
418
419 return ret;
420}
421
422static void ext4_es_list_add(struct inode *inode)
423{
424 struct ext4_inode_info *ei = EXT4_I(inode);
425 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
426
427 if (!list_empty(&ei->i_es_list))
428 return;
429
430 spin_lock(&sbi->s_es_lock);
431 if (list_empty(&ei->i_es_list)) {
432 list_add_tail(&ei->i_es_list, &sbi->s_es_list);
433 sbi->s_es_nr_inode++;
434 }
435 spin_unlock(&sbi->s_es_lock);
436}
437
438static void ext4_es_list_del(struct inode *inode)
439{
440 struct ext4_inode_info *ei = EXT4_I(inode);
441 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
442
443 spin_lock(&sbi->s_es_lock);
444 if (!list_empty(&ei->i_es_list)) {
445 list_del_init(&ei->i_es_list);
446 sbi->s_es_nr_inode--;
447 WARN_ON_ONCE(sbi->s_es_nr_inode < 0);
448 }
449 spin_unlock(&sbi->s_es_lock);
450}
451
452static inline struct pending_reservation *__alloc_pending(bool nofail)
453{
454 if (!nofail)
455 return kmem_cache_alloc(ext4_pending_cachep, GFP_ATOMIC);
456
457 return kmem_cache_zalloc(ext4_pending_cachep, GFP_KERNEL | __GFP_NOFAIL);
458}
459
460static inline void __free_pending(struct pending_reservation *pr)
461{
462 kmem_cache_free(ext4_pending_cachep, pr);
463}
464
465/*
466 * Returns true if we cannot fail to allocate memory for this extent_status
467 * entry and cannot reclaim it until its status changes.
468 */
469static inline bool ext4_es_must_keep(struct extent_status *es)
470{
471 /* fiemap, bigalloc, and seek_data/hole need to use it. */
472 if (ext4_es_is_delayed(es))
473 return true;
474
475 return false;
476}
477
478static inline struct extent_status *__es_alloc_extent(bool nofail)
479{
480 if (!nofail)
481 return kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC);
482
483 return kmem_cache_zalloc(ext4_es_cachep, GFP_KERNEL | __GFP_NOFAIL);
484}
485
486static void ext4_es_init_extent(struct inode *inode, struct extent_status *es,
487 ext4_lblk_t lblk, ext4_lblk_t len, ext4_fsblk_t pblk)
488{
489 es->es_lblk = lblk;
490 es->es_len = len;
491 es->es_pblk = pblk;
492
493 /* We never try to reclaim a must kept extent, so we don't count it. */
494 if (!ext4_es_must_keep(es)) {
495 if (!EXT4_I(inode)->i_es_shk_nr++)
496 ext4_es_list_add(inode);
497 percpu_counter_inc(&EXT4_SB(inode->i_sb)->
498 s_es_stats.es_stats_shk_cnt);
499 }
500
501 EXT4_I(inode)->i_es_all_nr++;
502 percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
503}
504
505static inline void __es_free_extent(struct extent_status *es)
506{
507 kmem_cache_free(ext4_es_cachep, es);
508}
509
510static void ext4_es_free_extent(struct inode *inode, struct extent_status *es)
511{
512 EXT4_I(inode)->i_es_all_nr--;
513 percpu_counter_dec(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt);
514
515 /* Decrease the shrink counter when we can reclaim the extent. */
516 if (!ext4_es_must_keep(es)) {
517 BUG_ON(EXT4_I(inode)->i_es_shk_nr == 0);
518 if (!--EXT4_I(inode)->i_es_shk_nr)
519 ext4_es_list_del(inode);
520 percpu_counter_dec(&EXT4_SB(inode->i_sb)->
521 s_es_stats.es_stats_shk_cnt);
522 }
523
524 __es_free_extent(es);
525}
526
527/*
528 * Check whether or not two extents can be merged
529 * Condition:
530 * - logical block number is contiguous
531 * - physical block number is contiguous
532 * - status is equal
533 */
534static int ext4_es_can_be_merged(struct extent_status *es1,
535 struct extent_status *es2)
536{
537 if (ext4_es_type(es1) != ext4_es_type(es2))
538 return 0;
539
540 if (((__u64) es1->es_len) + es2->es_len > EXT_MAX_BLOCKS) {
541 pr_warn("ES assertion failed when merging extents. "
542 "The sum of lengths of es1 (%d) and es2 (%d) "
543 "is bigger than allowed file size (%d)\n",
544 es1->es_len, es2->es_len, EXT_MAX_BLOCKS);
545 WARN_ON(1);
546 return 0;
547 }
548
549 if (((__u64) es1->es_lblk) + es1->es_len != es2->es_lblk)
550 return 0;
551
552 if ((ext4_es_is_written(es1) || ext4_es_is_unwritten(es1)) &&
553 (ext4_es_pblock(es1) + es1->es_len == ext4_es_pblock(es2)))
554 return 1;
555
556 if (ext4_es_is_hole(es1))
557 return 1;
558
559 /* we need to check delayed extent is without unwritten status */
560 if (ext4_es_is_delayed(es1) && !ext4_es_is_unwritten(es1))
561 return 1;
562
563 return 0;
564}
565
566static struct extent_status *
567ext4_es_try_to_merge_left(struct inode *inode, struct extent_status *es)
568{
569 struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
570 struct extent_status *es1;
571 struct rb_node *node;
572
573 node = rb_prev(&es->rb_node);
574 if (!node)
575 return es;
576
577 es1 = rb_entry(node, struct extent_status, rb_node);
578 if (ext4_es_can_be_merged(es1, es)) {
579 es1->es_len += es->es_len;
580 if (ext4_es_is_referenced(es))
581 ext4_es_set_referenced(es1);
582 rb_erase(&es->rb_node, &tree->root);
583 ext4_es_free_extent(inode, es);
584 es = es1;
585 }
586
587 return es;
588}
589
590static struct extent_status *
591ext4_es_try_to_merge_right(struct inode *inode, struct extent_status *es)
592{
593 struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
594 struct extent_status *es1;
595 struct rb_node *node;
596
597 node = rb_next(&es->rb_node);
598 if (!node)
599 return es;
600
601 es1 = rb_entry(node, struct extent_status, rb_node);
602 if (ext4_es_can_be_merged(es, es1)) {
603 es->es_len += es1->es_len;
604 if (ext4_es_is_referenced(es1))
605 ext4_es_set_referenced(es);
606 rb_erase(node, &tree->root);
607 ext4_es_free_extent(inode, es1);
608 }
609
610 return es;
611}
612
613#ifdef ES_AGGRESSIVE_TEST
614#include "ext4_extents.h" /* Needed when ES_AGGRESSIVE_TEST is defined */
615
616static void ext4_es_insert_extent_ext_check(struct inode *inode,
617 struct extent_status *es)
618{
619 struct ext4_ext_path *path = NULL;
620 struct ext4_extent *ex;
621 ext4_lblk_t ee_block;
622 ext4_fsblk_t ee_start;
623 unsigned short ee_len;
624 int depth, ee_status, es_status;
625
626 path = ext4_find_extent(inode, es->es_lblk, NULL, EXT4_EX_NOCACHE);
627 if (IS_ERR(path))
628 return;
629
630 depth = ext_depth(inode);
631 ex = path[depth].p_ext;
632
633 if (ex) {
634
635 ee_block = le32_to_cpu(ex->ee_block);
636 ee_start = ext4_ext_pblock(ex);
637 ee_len = ext4_ext_get_actual_len(ex);
638
639 ee_status = ext4_ext_is_unwritten(ex) ? 1 : 0;
640 es_status = ext4_es_is_unwritten(es) ? 1 : 0;
641
642 /*
643 * Make sure ex and es are not overlap when we try to insert
644 * a delayed/hole extent.
645 */
646 if (!ext4_es_is_written(es) && !ext4_es_is_unwritten(es)) {
647 if (in_range(es->es_lblk, ee_block, ee_len)) {
648 pr_warn("ES insert assertion failed for "
649 "inode: %lu we can find an extent "
650 "at block [%d/%d/%llu/%c], but we "
651 "want to add a delayed/hole extent "
652 "[%d/%d/%llu/%x]\n",
653 inode->i_ino, ee_block, ee_len,
654 ee_start, ee_status ? 'u' : 'w',
655 es->es_lblk, es->es_len,
656 ext4_es_pblock(es), ext4_es_status(es));
657 }
658 goto out;
659 }
660
661 /*
662 * We don't check ee_block == es->es_lblk, etc. because es
663 * might be a part of whole extent, vice versa.
664 */
665 if (es->es_lblk < ee_block ||
666 ext4_es_pblock(es) != ee_start + es->es_lblk - ee_block) {
667 pr_warn("ES insert assertion failed for inode: %lu "
668 "ex_status [%d/%d/%llu/%c] != "
669 "es_status [%d/%d/%llu/%c]\n", inode->i_ino,
670 ee_block, ee_len, ee_start,
671 ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
672 ext4_es_pblock(es), es_status ? 'u' : 'w');
673 goto out;
674 }
675
676 if (ee_status ^ es_status) {
677 pr_warn("ES insert assertion failed for inode: %lu "
678 "ex_status [%d/%d/%llu/%c] != "
679 "es_status [%d/%d/%llu/%c]\n", inode->i_ino,
680 ee_block, ee_len, ee_start,
681 ee_status ? 'u' : 'w', es->es_lblk, es->es_len,
682 ext4_es_pblock(es), es_status ? 'u' : 'w');
683 }
684 } else {
685 /*
686 * We can't find an extent on disk. So we need to make sure
687 * that we don't want to add an written/unwritten extent.
688 */
689 if (!ext4_es_is_delayed(es) && !ext4_es_is_hole(es)) {
690 pr_warn("ES insert assertion failed for inode: %lu "
691 "can't find an extent at block %d but we want "
692 "to add a written/unwritten extent "
693 "[%d/%d/%llu/%x]\n", inode->i_ino,
694 es->es_lblk, es->es_lblk, es->es_len,
695 ext4_es_pblock(es), ext4_es_status(es));
696 }
697 }
698out:
699 ext4_free_ext_path(path);
700}
701
702static void ext4_es_insert_extent_ind_check(struct inode *inode,
703 struct extent_status *es)
704{
705 struct ext4_map_blocks map;
706 int retval;
707
708 /*
709 * Here we call ext4_ind_map_blocks to lookup a block mapping because
710 * 'Indirect' structure is defined in indirect.c. So we couldn't
711 * access direct/indirect tree from outside. It is too dirty to define
712 * this function in indirect.c file.
713 */
714
715 map.m_lblk = es->es_lblk;
716 map.m_len = es->es_len;
717
718 retval = ext4_ind_map_blocks(NULL, inode, &map, 0);
719 if (retval > 0) {
720 if (ext4_es_is_delayed(es) || ext4_es_is_hole(es)) {
721 /*
722 * We want to add a delayed/hole extent but this
723 * block has been allocated.
724 */
725 pr_warn("ES insert assertion failed for inode: %lu "
726 "We can find blocks but we want to add a "
727 "delayed/hole extent [%d/%d/%llu/%x]\n",
728 inode->i_ino, es->es_lblk, es->es_len,
729 ext4_es_pblock(es), ext4_es_status(es));
730 return;
731 } else if (ext4_es_is_written(es)) {
732 if (retval != es->es_len) {
733 pr_warn("ES insert assertion failed for "
734 "inode: %lu retval %d != es_len %d\n",
735 inode->i_ino, retval, es->es_len);
736 return;
737 }
738 if (map.m_pblk != ext4_es_pblock(es)) {
739 pr_warn("ES insert assertion failed for "
740 "inode: %lu m_pblk %llu != "
741 "es_pblk %llu\n",
742 inode->i_ino, map.m_pblk,
743 ext4_es_pblock(es));
744 return;
745 }
746 } else {
747 /*
748 * We don't need to check unwritten extent because
749 * indirect-based file doesn't have it.
750 */
751 BUG();
752 }
753 } else if (retval == 0) {
754 if (ext4_es_is_written(es)) {
755 pr_warn("ES insert assertion failed for inode: %lu "
756 "We can't find the block but we want to add "
757 "a written extent [%d/%d/%llu/%x]\n",
758 inode->i_ino, es->es_lblk, es->es_len,
759 ext4_es_pblock(es), ext4_es_status(es));
760 return;
761 }
762 }
763}
764
765static inline void ext4_es_insert_extent_check(struct inode *inode,
766 struct extent_status *es)
767{
768 /*
769 * We don't need to worry about the race condition because
770 * caller takes i_data_sem locking.
771 */
772 BUG_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
773 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
774 ext4_es_insert_extent_ext_check(inode, es);
775 else
776 ext4_es_insert_extent_ind_check(inode, es);
777}
778#else
779static inline void ext4_es_insert_extent_check(struct inode *inode,
780 struct extent_status *es)
781{
782}
783#endif
784
785static int __es_insert_extent(struct inode *inode, struct extent_status *newes,
786 struct extent_status *prealloc)
787{
788 struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
789 struct rb_node **p = &tree->root.rb_node;
790 struct rb_node *parent = NULL;
791 struct extent_status *es;
792
793 while (*p) {
794 parent = *p;
795 es = rb_entry(parent, struct extent_status, rb_node);
796
797 if (newes->es_lblk < es->es_lblk) {
798 if (ext4_es_can_be_merged(newes, es)) {
799 /*
800 * Here we can modify es_lblk directly
801 * because it isn't overlapped.
802 */
803 es->es_lblk = newes->es_lblk;
804 es->es_len += newes->es_len;
805 if (ext4_es_is_written(es) ||
806 ext4_es_is_unwritten(es))
807 ext4_es_store_pblock(es,
808 newes->es_pblk);
809 es = ext4_es_try_to_merge_left(inode, es);
810 goto out;
811 }
812 p = &(*p)->rb_left;
813 } else if (newes->es_lblk > ext4_es_end(es)) {
814 if (ext4_es_can_be_merged(es, newes)) {
815 es->es_len += newes->es_len;
816 es = ext4_es_try_to_merge_right(inode, es);
817 goto out;
818 }
819 p = &(*p)->rb_right;
820 } else {
821 BUG();
822 return -EINVAL;
823 }
824 }
825
826 if (prealloc)
827 es = prealloc;
828 else
829 es = __es_alloc_extent(false);
830 if (!es)
831 return -ENOMEM;
832 ext4_es_init_extent(inode, es, newes->es_lblk, newes->es_len,
833 newes->es_pblk);
834
835 rb_link_node(&es->rb_node, parent, p);
836 rb_insert_color(&es->rb_node, &tree->root);
837
838out:
839 tree->cache_es = es;
840 return 0;
841}
842
843/*
844 * ext4_es_insert_extent() adds information to an inode's extent
845 * status tree.
846 */
847void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
848 ext4_lblk_t len, ext4_fsblk_t pblk,
849 unsigned int status)
850{
851 struct extent_status newes;
852 ext4_lblk_t end = lblk + len - 1;
853 int err1 = 0, err2 = 0, err3 = 0;
854 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
855 struct extent_status *es1 = NULL;
856 struct extent_status *es2 = NULL;
857 struct pending_reservation *pr = NULL;
858 bool revise_pending = false;
859
860 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
861 return;
862
863 es_debug("add [%u/%u) %llu %x to extent status tree of inode %lu\n",
864 lblk, len, pblk, status, inode->i_ino);
865
866 if (!len)
867 return;
868
869 BUG_ON(end < lblk);
870
871 if ((status & EXTENT_STATUS_DELAYED) &&
872 (status & EXTENT_STATUS_WRITTEN)) {
873 ext4_warning(inode->i_sb, "Inserting extent [%u/%u] as "
874 " delayed and written which can potentially "
875 " cause data loss.", lblk, len);
876 WARN_ON(1);
877 }
878
879 newes.es_lblk = lblk;
880 newes.es_len = len;
881 ext4_es_store_pblock_status(&newes, pblk, status);
882 trace_ext4_es_insert_extent(inode, &newes);
883
884 ext4_es_insert_extent_check(inode, &newes);
885
886 revise_pending = sbi->s_cluster_ratio > 1 &&
887 test_opt(inode->i_sb, DELALLOC) &&
888 (status & (EXTENT_STATUS_WRITTEN |
889 EXTENT_STATUS_UNWRITTEN));
890retry:
891 if (err1 && !es1)
892 es1 = __es_alloc_extent(true);
893 if ((err1 || err2) && !es2)
894 es2 = __es_alloc_extent(true);
895 if ((err1 || err2 || err3) && revise_pending && !pr)
896 pr = __alloc_pending(true);
897 write_lock(&EXT4_I(inode)->i_es_lock);
898
899 err1 = __es_remove_extent(inode, lblk, end, NULL, es1);
900 if (err1 != 0)
901 goto error;
902 /* Free preallocated extent if it didn't get used. */
903 if (es1) {
904 if (!es1->es_len)
905 __es_free_extent(es1);
906 es1 = NULL;
907 }
908
909 err2 = __es_insert_extent(inode, &newes, es2);
910 if (err2 == -ENOMEM && !ext4_es_must_keep(&newes))
911 err2 = 0;
912 if (err2 != 0)
913 goto error;
914 /* Free preallocated extent if it didn't get used. */
915 if (es2) {
916 if (!es2->es_len)
917 __es_free_extent(es2);
918 es2 = NULL;
919 }
920
921 if (revise_pending) {
922 err3 = __revise_pending(inode, lblk, len, &pr);
923 if (err3 != 0)
924 goto error;
925 if (pr) {
926 __free_pending(pr);
927 pr = NULL;
928 }
929 }
930error:
931 write_unlock(&EXT4_I(inode)->i_es_lock);
932 if (err1 || err2 || err3)
933 goto retry;
934
935 ext4_es_print_tree(inode);
936 return;
937}
938
939/*
940 * ext4_es_cache_extent() inserts information into the extent status
941 * tree if and only if there isn't information about the range in
942 * question already.
943 */
944void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
945 ext4_lblk_t len, ext4_fsblk_t pblk,
946 unsigned int status)
947{
948 struct extent_status *es;
949 struct extent_status newes;
950 ext4_lblk_t end = lblk + len - 1;
951
952 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
953 return;
954
955 newes.es_lblk = lblk;
956 newes.es_len = len;
957 ext4_es_store_pblock_status(&newes, pblk, status);
958 trace_ext4_es_cache_extent(inode, &newes);
959
960 if (!len)
961 return;
962
963 BUG_ON(end < lblk);
964
965 write_lock(&EXT4_I(inode)->i_es_lock);
966
967 es = __es_tree_search(&EXT4_I(inode)->i_es_tree.root, lblk);
968 if (!es || es->es_lblk > end)
969 __es_insert_extent(inode, &newes, NULL);
970 write_unlock(&EXT4_I(inode)->i_es_lock);
971}
972
973/*
974 * ext4_es_lookup_extent() looks up an extent in extent status tree.
975 *
976 * ext4_es_lookup_extent is called by ext4_map_blocks/ext4_da_map_blocks.
977 *
978 * Return: 1 on found, 0 on not
979 */
980int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
981 ext4_lblk_t *next_lblk,
982 struct extent_status *es)
983{
984 struct ext4_es_tree *tree;
985 struct ext4_es_stats *stats;
986 struct extent_status *es1 = NULL;
987 struct rb_node *node;
988 int found = 0;
989
990 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
991 return 0;
992
993 trace_ext4_es_lookup_extent_enter(inode, lblk);
994 es_debug("lookup extent in block %u\n", lblk);
995
996 tree = &EXT4_I(inode)->i_es_tree;
997 read_lock(&EXT4_I(inode)->i_es_lock);
998
999 /* find extent in cache firstly */
1000 es->es_lblk = es->es_len = es->es_pblk = 0;
1001 es1 = READ_ONCE(tree->cache_es);
1002 if (es1 && in_range(lblk, es1->es_lblk, es1->es_len)) {
1003 es_debug("%u cached by [%u/%u)\n",
1004 lblk, es1->es_lblk, es1->es_len);
1005 found = 1;
1006 goto out;
1007 }
1008
1009 node = tree->root.rb_node;
1010 while (node) {
1011 es1 = rb_entry(node, struct extent_status, rb_node);
1012 if (lblk < es1->es_lblk)
1013 node = node->rb_left;
1014 else if (lblk > ext4_es_end(es1))
1015 node = node->rb_right;
1016 else {
1017 found = 1;
1018 break;
1019 }
1020 }
1021
1022out:
1023 stats = &EXT4_SB(inode->i_sb)->s_es_stats;
1024 if (found) {
1025 BUG_ON(!es1);
1026 es->es_lblk = es1->es_lblk;
1027 es->es_len = es1->es_len;
1028 es->es_pblk = es1->es_pblk;
1029 if (!ext4_es_is_referenced(es1))
1030 ext4_es_set_referenced(es1);
1031 percpu_counter_inc(&stats->es_stats_cache_hits);
1032 if (next_lblk) {
1033 node = rb_next(&es1->rb_node);
1034 if (node) {
1035 es1 = rb_entry(node, struct extent_status,
1036 rb_node);
1037 *next_lblk = es1->es_lblk;
1038 } else
1039 *next_lblk = 0;
1040 }
1041 } else {
1042 percpu_counter_inc(&stats->es_stats_cache_misses);
1043 }
1044
1045 read_unlock(&EXT4_I(inode)->i_es_lock);
1046
1047 trace_ext4_es_lookup_extent_exit(inode, es, found);
1048 return found;
1049}
1050
1051struct rsvd_count {
1052 int ndelonly;
1053 bool first_do_lblk_found;
1054 ext4_lblk_t first_do_lblk;
1055 ext4_lblk_t last_do_lblk;
1056 struct extent_status *left_es;
1057 bool partial;
1058 ext4_lblk_t lclu;
1059};
1060
1061/*
1062 * init_rsvd - initialize reserved count data before removing block range
1063 * in file from extent status tree
1064 *
1065 * @inode - file containing range
1066 * @lblk - first block in range
1067 * @es - pointer to first extent in range
1068 * @rc - pointer to reserved count data
1069 *
1070 * Assumes es is not NULL
1071 */
1072static void init_rsvd(struct inode *inode, ext4_lblk_t lblk,
1073 struct extent_status *es, struct rsvd_count *rc)
1074{
1075 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1076 struct rb_node *node;
1077
1078 rc->ndelonly = 0;
1079
1080 /*
1081 * for bigalloc, note the first delonly block in the range has not
1082 * been found, record the extent containing the block to the left of
1083 * the region to be removed, if any, and note that there's no partial
1084 * cluster to track
1085 */
1086 if (sbi->s_cluster_ratio > 1) {
1087 rc->first_do_lblk_found = false;
1088 if (lblk > es->es_lblk) {
1089 rc->left_es = es;
1090 } else {
1091 node = rb_prev(&es->rb_node);
1092 rc->left_es = node ? rb_entry(node,
1093 struct extent_status,
1094 rb_node) : NULL;
1095 }
1096 rc->partial = false;
1097 }
1098}
1099
1100/*
1101 * count_rsvd - count the clusters containing delayed and not unwritten
1102 * (delonly) blocks in a range within an extent and add to
1103 * the running tally in rsvd_count
1104 *
1105 * @inode - file containing extent
1106 * @lblk - first block in range
1107 * @len - length of range in blocks
1108 * @es - pointer to extent containing clusters to be counted
1109 * @rc - pointer to reserved count data
1110 *
1111 * Tracks partial clusters found at the beginning and end of extents so
1112 * they aren't overcounted when they span adjacent extents
1113 */
1114static void count_rsvd(struct inode *inode, ext4_lblk_t lblk, long len,
1115 struct extent_status *es, struct rsvd_count *rc)
1116{
1117 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1118 ext4_lblk_t i, end, nclu;
1119
1120 if (!ext4_es_is_delonly(es))
1121 return;
1122
1123 WARN_ON(len <= 0);
1124
1125 if (sbi->s_cluster_ratio == 1) {
1126 rc->ndelonly += (int) len;
1127 return;
1128 }
1129
1130 /* bigalloc */
1131
1132 i = (lblk < es->es_lblk) ? es->es_lblk : lblk;
1133 end = lblk + (ext4_lblk_t) len - 1;
1134 end = (end > ext4_es_end(es)) ? ext4_es_end(es) : end;
1135
1136 /* record the first block of the first delonly extent seen */
1137 if (!rc->first_do_lblk_found) {
1138 rc->first_do_lblk = i;
1139 rc->first_do_lblk_found = true;
1140 }
1141
1142 /* update the last lblk in the region seen so far */
1143 rc->last_do_lblk = end;
1144
1145 /*
1146 * if we're tracking a partial cluster and the current extent
1147 * doesn't start with it, count it and stop tracking
1148 */
1149 if (rc->partial && (rc->lclu != EXT4_B2C(sbi, i))) {
1150 rc->ndelonly++;
1151 rc->partial = false;
1152 }
1153
1154 /*
1155 * if the first cluster doesn't start on a cluster boundary but
1156 * ends on one, count it
1157 */
1158 if (EXT4_LBLK_COFF(sbi, i) != 0) {
1159 if (end >= EXT4_LBLK_CFILL(sbi, i)) {
1160 rc->ndelonly++;
1161 rc->partial = false;
1162 i = EXT4_LBLK_CFILL(sbi, i) + 1;
1163 }
1164 }
1165
1166 /*
1167 * if the current cluster starts on a cluster boundary, count the
1168 * number of whole delonly clusters in the extent
1169 */
1170 if ((i + sbi->s_cluster_ratio - 1) <= end) {
1171 nclu = (end - i + 1) >> sbi->s_cluster_bits;
1172 rc->ndelonly += nclu;
1173 i += nclu << sbi->s_cluster_bits;
1174 }
1175
1176 /*
1177 * start tracking a partial cluster if there's a partial at the end
1178 * of the current extent and we're not already tracking one
1179 */
1180 if (!rc->partial && i <= end) {
1181 rc->partial = true;
1182 rc->lclu = EXT4_B2C(sbi, i);
1183 }
1184}
1185
1186/*
1187 * __pr_tree_search - search for a pending cluster reservation
1188 *
1189 * @root - root of pending reservation tree
1190 * @lclu - logical cluster to search for
1191 *
1192 * Returns the pending reservation for the cluster identified by @lclu
1193 * if found. If not, returns a reservation for the next cluster if any,
1194 * and if not, returns NULL.
1195 */
1196static struct pending_reservation *__pr_tree_search(struct rb_root *root,
1197 ext4_lblk_t lclu)
1198{
1199 struct rb_node *node = root->rb_node;
1200 struct pending_reservation *pr = NULL;
1201
1202 while (node) {
1203 pr = rb_entry(node, struct pending_reservation, rb_node);
1204 if (lclu < pr->lclu)
1205 node = node->rb_left;
1206 else if (lclu > pr->lclu)
1207 node = node->rb_right;
1208 else
1209 return pr;
1210 }
1211 if (pr && lclu < pr->lclu)
1212 return pr;
1213 if (pr && lclu > pr->lclu) {
1214 node = rb_next(&pr->rb_node);
1215 return node ? rb_entry(node, struct pending_reservation,
1216 rb_node) : NULL;
1217 }
1218 return NULL;
1219}
1220
1221/*
1222 * get_rsvd - calculates and returns the number of cluster reservations to be
1223 * released when removing a block range from the extent status tree
1224 * and releases any pending reservations within the range
1225 *
1226 * @inode - file containing block range
1227 * @end - last block in range
1228 * @right_es - pointer to extent containing next block beyond end or NULL
1229 * @rc - pointer to reserved count data
1230 *
1231 * The number of reservations to be released is equal to the number of
1232 * clusters containing delayed and not unwritten (delonly) blocks within
1233 * the range, minus the number of clusters still containing delonly blocks
1234 * at the ends of the range, and minus the number of pending reservations
1235 * within the range.
1236 */
1237static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
1238 struct extent_status *right_es,
1239 struct rsvd_count *rc)
1240{
1241 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1242 struct pending_reservation *pr;
1243 struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
1244 struct rb_node *node;
1245 ext4_lblk_t first_lclu, last_lclu;
1246 bool left_delonly, right_delonly, count_pending;
1247 struct extent_status *es;
1248
1249 if (sbi->s_cluster_ratio > 1) {
1250 /* count any remaining partial cluster */
1251 if (rc->partial)
1252 rc->ndelonly++;
1253
1254 if (rc->ndelonly == 0)
1255 return 0;
1256
1257 first_lclu = EXT4_B2C(sbi, rc->first_do_lblk);
1258 last_lclu = EXT4_B2C(sbi, rc->last_do_lblk);
1259
1260 /*
1261 * decrease the delonly count by the number of clusters at the
1262 * ends of the range that still contain delonly blocks -
1263 * these clusters still need to be reserved
1264 */
1265 left_delonly = right_delonly = false;
1266
1267 es = rc->left_es;
1268 while (es && ext4_es_end(es) >=
1269 EXT4_LBLK_CMASK(sbi, rc->first_do_lblk)) {
1270 if (ext4_es_is_delonly(es)) {
1271 rc->ndelonly--;
1272 left_delonly = true;
1273 break;
1274 }
1275 node = rb_prev(&es->rb_node);
1276 if (!node)
1277 break;
1278 es = rb_entry(node, struct extent_status, rb_node);
1279 }
1280 if (right_es && (!left_delonly || first_lclu != last_lclu)) {
1281 if (end < ext4_es_end(right_es)) {
1282 es = right_es;
1283 } else {
1284 node = rb_next(&right_es->rb_node);
1285 es = node ? rb_entry(node, struct extent_status,
1286 rb_node) : NULL;
1287 }
1288 while (es && es->es_lblk <=
1289 EXT4_LBLK_CFILL(sbi, rc->last_do_lblk)) {
1290 if (ext4_es_is_delonly(es)) {
1291 rc->ndelonly--;
1292 right_delonly = true;
1293 break;
1294 }
1295 node = rb_next(&es->rb_node);
1296 if (!node)
1297 break;
1298 es = rb_entry(node, struct extent_status,
1299 rb_node);
1300 }
1301 }
1302
1303 /*
1304 * Determine the block range that should be searched for
1305 * pending reservations, if any. Clusters on the ends of the
1306 * original removed range containing delonly blocks are
1307 * excluded. They've already been accounted for and it's not
1308 * possible to determine if an associated pending reservation
1309 * should be released with the information available in the
1310 * extents status tree.
1311 */
1312 if (first_lclu == last_lclu) {
1313 if (left_delonly | right_delonly)
1314 count_pending = false;
1315 else
1316 count_pending = true;
1317 } else {
1318 if (left_delonly)
1319 first_lclu++;
1320 if (right_delonly)
1321 last_lclu--;
1322 if (first_lclu <= last_lclu)
1323 count_pending = true;
1324 else
1325 count_pending = false;
1326 }
1327
1328 /*
1329 * a pending reservation found between first_lclu and last_lclu
1330 * represents an allocated cluster that contained at least one
1331 * delonly block, so the delonly total must be reduced by one
1332 * for each pending reservation found and released
1333 */
1334 if (count_pending) {
1335 pr = __pr_tree_search(&tree->root, first_lclu);
1336 while (pr && pr->lclu <= last_lclu) {
1337 rc->ndelonly--;
1338 node = rb_next(&pr->rb_node);
1339 rb_erase(&pr->rb_node, &tree->root);
1340 __free_pending(pr);
1341 if (!node)
1342 break;
1343 pr = rb_entry(node, struct pending_reservation,
1344 rb_node);
1345 }
1346 }
1347 }
1348 return rc->ndelonly;
1349}
1350
1351
1352/*
1353 * __es_remove_extent - removes block range from extent status tree
1354 *
1355 * @inode - file containing range
1356 * @lblk - first block in range
1357 * @end - last block in range
1358 * @reserved - number of cluster reservations released
1359 * @prealloc - pre-allocated es to avoid memory allocation failures
1360 *
1361 * If @reserved is not NULL and delayed allocation is enabled, counts
1362 * block/cluster reservations freed by removing range and if bigalloc
1363 * enabled cancels pending reservations as needed. Returns 0 on success,
1364 * error code on failure.
1365 */
1366static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
1367 ext4_lblk_t end, int *reserved,
1368 struct extent_status *prealloc)
1369{
1370 struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
1371 struct rb_node *node;
1372 struct extent_status *es;
1373 struct extent_status orig_es;
1374 ext4_lblk_t len1, len2;
1375 ext4_fsblk_t block;
1376 int err = 0;
1377 bool count_reserved = true;
1378 struct rsvd_count rc;
1379
1380 if (reserved == NULL || !test_opt(inode->i_sb, DELALLOC))
1381 count_reserved = false;
1382
1383 es = __es_tree_search(&tree->root, lblk);
1384 if (!es)
1385 goto out;
1386 if (es->es_lblk > end)
1387 goto out;
1388
1389 /* Simply invalidate cache_es. */
1390 tree->cache_es = NULL;
1391 if (count_reserved)
1392 init_rsvd(inode, lblk, es, &rc);
1393
1394 orig_es.es_lblk = es->es_lblk;
1395 orig_es.es_len = es->es_len;
1396 orig_es.es_pblk = es->es_pblk;
1397
1398 len1 = lblk > es->es_lblk ? lblk - es->es_lblk : 0;
1399 len2 = ext4_es_end(es) > end ? ext4_es_end(es) - end : 0;
1400 if (len1 > 0)
1401 es->es_len = len1;
1402 if (len2 > 0) {
1403 if (len1 > 0) {
1404 struct extent_status newes;
1405
1406 newes.es_lblk = end + 1;
1407 newes.es_len = len2;
1408 block = 0x7FDEADBEEFULL;
1409 if (ext4_es_is_written(&orig_es) ||
1410 ext4_es_is_unwritten(&orig_es))
1411 block = ext4_es_pblock(&orig_es) +
1412 orig_es.es_len - len2;
1413 ext4_es_store_pblock_status(&newes, block,
1414 ext4_es_status(&orig_es));
1415 err = __es_insert_extent(inode, &newes, prealloc);
1416 if (err) {
1417 if (!ext4_es_must_keep(&newes))
1418 return 0;
1419
1420 es->es_lblk = orig_es.es_lblk;
1421 es->es_len = orig_es.es_len;
1422 goto out;
1423 }
1424 } else {
1425 es->es_lblk = end + 1;
1426 es->es_len = len2;
1427 if (ext4_es_is_written(es) ||
1428 ext4_es_is_unwritten(es)) {
1429 block = orig_es.es_pblk + orig_es.es_len - len2;
1430 ext4_es_store_pblock(es, block);
1431 }
1432 }
1433 if (count_reserved)
1434 count_rsvd(inode, orig_es.es_lblk + len1,
1435 orig_es.es_len - len1 - len2, &orig_es, &rc);
1436 goto out_get_reserved;
1437 }
1438
1439 if (len1 > 0) {
1440 if (count_reserved)
1441 count_rsvd(inode, lblk, orig_es.es_len - len1,
1442 &orig_es, &rc);
1443 node = rb_next(&es->rb_node);
1444 if (node)
1445 es = rb_entry(node, struct extent_status, rb_node);
1446 else
1447 es = NULL;
1448 }
1449
1450 while (es && ext4_es_end(es) <= end) {
1451 if (count_reserved)
1452 count_rsvd(inode, es->es_lblk, es->es_len, es, &rc);
1453 node = rb_next(&es->rb_node);
1454 rb_erase(&es->rb_node, &tree->root);
1455 ext4_es_free_extent(inode, es);
1456 if (!node) {
1457 es = NULL;
1458 break;
1459 }
1460 es = rb_entry(node, struct extent_status, rb_node);
1461 }
1462
1463 if (es && es->es_lblk < end + 1) {
1464 ext4_lblk_t orig_len = es->es_len;
1465
1466 len1 = ext4_es_end(es) - end;
1467 if (count_reserved)
1468 count_rsvd(inode, es->es_lblk, orig_len - len1,
1469 es, &rc);
1470 es->es_lblk = end + 1;
1471 es->es_len = len1;
1472 if (ext4_es_is_written(es) || ext4_es_is_unwritten(es)) {
1473 block = es->es_pblk + orig_len - len1;
1474 ext4_es_store_pblock(es, block);
1475 }
1476 }
1477
1478out_get_reserved:
1479 if (count_reserved)
1480 *reserved = get_rsvd(inode, end, es, &rc);
1481out:
1482 return err;
1483}
1484
1485/*
1486 * ext4_es_remove_extent - removes block range from extent status tree
1487 *
1488 * @inode - file containing range
1489 * @lblk - first block in range
1490 * @len - number of blocks to remove
1491 *
1492 * Reduces block/cluster reservation count and for bigalloc cancels pending
1493 * reservations as needed.
1494 */
1495void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
1496 ext4_lblk_t len)
1497{
1498 ext4_lblk_t end;
1499 int err = 0;
1500 int reserved = 0;
1501 struct extent_status *es = NULL;
1502
1503 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
1504 return;
1505
1506 trace_ext4_es_remove_extent(inode, lblk, len);
1507 es_debug("remove [%u/%u) from extent status tree of inode %lu\n",
1508 lblk, len, inode->i_ino);
1509
1510 if (!len)
1511 return;
1512
1513 end = lblk + len - 1;
1514 BUG_ON(end < lblk);
1515
1516retry:
1517 if (err && !es)
1518 es = __es_alloc_extent(true);
1519 /*
1520 * ext4_clear_inode() depends on us taking i_es_lock unconditionally
1521 * so that we are sure __es_shrink() is done with the inode before it
1522 * is reclaimed.
1523 */
1524 write_lock(&EXT4_I(inode)->i_es_lock);
1525 err = __es_remove_extent(inode, lblk, end, &reserved, es);
1526 /* Free preallocated extent if it didn't get used. */
1527 if (es) {
1528 if (!es->es_len)
1529 __es_free_extent(es);
1530 es = NULL;
1531 }
1532 write_unlock(&EXT4_I(inode)->i_es_lock);
1533 if (err)
1534 goto retry;
1535
1536 ext4_es_print_tree(inode);
1537 ext4_da_release_space(inode, reserved);
1538 return;
1539}
1540
1541static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
1542 struct ext4_inode_info *locked_ei)
1543{
1544 struct ext4_inode_info *ei;
1545 struct ext4_es_stats *es_stats;
1546 ktime_t start_time;
1547 u64 scan_time;
1548 int nr_to_walk;
1549 int nr_shrunk = 0;
1550 int retried = 0, nr_skipped = 0;
1551
1552 es_stats = &sbi->s_es_stats;
1553 start_time = ktime_get();
1554
1555retry:
1556 spin_lock(&sbi->s_es_lock);
1557 nr_to_walk = sbi->s_es_nr_inode;
1558 while (nr_to_walk-- > 0) {
1559 if (list_empty(&sbi->s_es_list)) {
1560 spin_unlock(&sbi->s_es_lock);
1561 goto out;
1562 }
1563 ei = list_first_entry(&sbi->s_es_list, struct ext4_inode_info,
1564 i_es_list);
1565 /* Move the inode to the tail */
1566 list_move_tail(&ei->i_es_list, &sbi->s_es_list);
1567
1568 /*
1569 * Normally we try hard to avoid shrinking precached inodes,
1570 * but we will as a last resort.
1571 */
1572 if (!retried && ext4_test_inode_state(&ei->vfs_inode,
1573 EXT4_STATE_EXT_PRECACHED)) {
1574 nr_skipped++;
1575 continue;
1576 }
1577
1578 if (ei == locked_ei || !write_trylock(&ei->i_es_lock)) {
1579 nr_skipped++;
1580 continue;
1581 }
1582 /*
1583 * Now we hold i_es_lock which protects us from inode reclaim
1584 * freeing inode under us
1585 */
1586 spin_unlock(&sbi->s_es_lock);
1587
1588 nr_shrunk += es_reclaim_extents(ei, &nr_to_scan);
1589 write_unlock(&ei->i_es_lock);
1590
1591 if (nr_to_scan <= 0)
1592 goto out;
1593 spin_lock(&sbi->s_es_lock);
1594 }
1595 spin_unlock(&sbi->s_es_lock);
1596
1597 /*
1598 * If we skipped any inodes, and we weren't able to make any
1599 * forward progress, try again to scan precached inodes.
1600 */
1601 if ((nr_shrunk == 0) && nr_skipped && !retried) {
1602 retried++;
1603 goto retry;
1604 }
1605
1606 if (locked_ei && nr_shrunk == 0)
1607 nr_shrunk = es_reclaim_extents(locked_ei, &nr_to_scan);
1608
1609out:
1610 scan_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1611 if (likely(es_stats->es_stats_scan_time))
1612 es_stats->es_stats_scan_time = (scan_time +
1613 es_stats->es_stats_scan_time*3) / 4;
1614 else
1615 es_stats->es_stats_scan_time = scan_time;
1616 if (scan_time > es_stats->es_stats_max_scan_time)
1617 es_stats->es_stats_max_scan_time = scan_time;
1618 if (likely(es_stats->es_stats_shrunk))
1619 es_stats->es_stats_shrunk = (nr_shrunk +
1620 es_stats->es_stats_shrunk*3) / 4;
1621 else
1622 es_stats->es_stats_shrunk = nr_shrunk;
1623
1624 trace_ext4_es_shrink(sbi->s_sb, nr_shrunk, scan_time,
1625 nr_skipped, retried);
1626 return nr_shrunk;
1627}
1628
1629static unsigned long ext4_es_count(struct shrinker *shrink,
1630 struct shrink_control *sc)
1631{
1632 unsigned long nr;
1633 struct ext4_sb_info *sbi;
1634
1635 sbi = shrink->private_data;
1636 nr = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
1637 trace_ext4_es_shrink_count(sbi->s_sb, sc->nr_to_scan, nr);
1638 return nr;
1639}
1640
1641static unsigned long ext4_es_scan(struct shrinker *shrink,
1642 struct shrink_control *sc)
1643{
1644 struct ext4_sb_info *sbi = shrink->private_data;
1645 int nr_to_scan = sc->nr_to_scan;
1646 int ret, nr_shrunk;
1647
1648 ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
1649 trace_ext4_es_shrink_scan_enter(sbi->s_sb, nr_to_scan, ret);
1650
1651 nr_shrunk = __es_shrink(sbi, nr_to_scan, NULL);
1652
1653 ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
1654 trace_ext4_es_shrink_scan_exit(sbi->s_sb, nr_shrunk, ret);
1655 return nr_shrunk;
1656}
1657
1658int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v)
1659{
1660 struct ext4_sb_info *sbi = EXT4_SB((struct super_block *) seq->private);
1661 struct ext4_es_stats *es_stats = &sbi->s_es_stats;
1662 struct ext4_inode_info *ei, *max = NULL;
1663 unsigned int inode_cnt = 0;
1664
1665 if (v != SEQ_START_TOKEN)
1666 return 0;
1667
1668 /* here we just find an inode that has the max nr. of objects */
1669 spin_lock(&sbi->s_es_lock);
1670 list_for_each_entry(ei, &sbi->s_es_list, i_es_list) {
1671 inode_cnt++;
1672 if (max && max->i_es_all_nr < ei->i_es_all_nr)
1673 max = ei;
1674 else if (!max)
1675 max = ei;
1676 }
1677 spin_unlock(&sbi->s_es_lock);
1678
1679 seq_printf(seq, "stats:\n %lld objects\n %lld reclaimable objects\n",
1680 percpu_counter_sum_positive(&es_stats->es_stats_all_cnt),
1681 percpu_counter_sum_positive(&es_stats->es_stats_shk_cnt));
1682 seq_printf(seq, " %lld/%lld cache hits/misses\n",
1683 percpu_counter_sum_positive(&es_stats->es_stats_cache_hits),
1684 percpu_counter_sum_positive(&es_stats->es_stats_cache_misses));
1685 if (inode_cnt)
1686 seq_printf(seq, " %d inodes on list\n", inode_cnt);
1687
1688 seq_printf(seq, "average:\n %llu us scan time\n",
1689 div_u64(es_stats->es_stats_scan_time, 1000));
1690 seq_printf(seq, " %lu shrunk objects\n", es_stats->es_stats_shrunk);
1691 if (inode_cnt)
1692 seq_printf(seq,
1693 "maximum:\n %lu inode (%u objects, %u reclaimable)\n"
1694 " %llu us max scan time\n",
1695 max->vfs_inode.i_ino, max->i_es_all_nr, max->i_es_shk_nr,
1696 div_u64(es_stats->es_stats_max_scan_time, 1000));
1697
1698 return 0;
1699}
1700
1701int ext4_es_register_shrinker(struct ext4_sb_info *sbi)
1702{
1703 int err;
1704
1705 /* Make sure we have enough bits for physical block number */
1706 BUILD_BUG_ON(ES_SHIFT < 48);
1707 INIT_LIST_HEAD(&sbi->s_es_list);
1708 sbi->s_es_nr_inode = 0;
1709 spin_lock_init(&sbi->s_es_lock);
1710 sbi->s_es_stats.es_stats_shrunk = 0;
1711 err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_hits, 0,
1712 GFP_KERNEL);
1713 if (err)
1714 return err;
1715 err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_misses, 0,
1716 GFP_KERNEL);
1717 if (err)
1718 goto err1;
1719 sbi->s_es_stats.es_stats_scan_time = 0;
1720 sbi->s_es_stats.es_stats_max_scan_time = 0;
1721 err = percpu_counter_init(&sbi->s_es_stats.es_stats_all_cnt, 0, GFP_KERNEL);
1722 if (err)
1723 goto err2;
1724 err = percpu_counter_init(&sbi->s_es_stats.es_stats_shk_cnt, 0, GFP_KERNEL);
1725 if (err)
1726 goto err3;
1727
1728 sbi->s_es_shrinker = shrinker_alloc(0, "ext4-es:%s", sbi->s_sb->s_id);
1729 if (!sbi->s_es_shrinker) {
1730 err = -ENOMEM;
1731 goto err4;
1732 }
1733
1734 sbi->s_es_shrinker->scan_objects = ext4_es_scan;
1735 sbi->s_es_shrinker->count_objects = ext4_es_count;
1736 sbi->s_es_shrinker->private_data = sbi;
1737
1738 shrinker_register(sbi->s_es_shrinker);
1739
1740 return 0;
1741err4:
1742 percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
1743err3:
1744 percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
1745err2:
1746 percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
1747err1:
1748 percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits);
1749 return err;
1750}
1751
1752void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi)
1753{
1754 percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits);
1755 percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
1756 percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
1757 percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
1758 shrinker_free(sbi->s_es_shrinker);
1759}
1760
1761/*
1762 * Shrink extents in given inode from ei->i_es_shrink_lblk till end. Scan at
1763 * most *nr_to_scan extents, update *nr_to_scan accordingly.
1764 *
1765 * Return 0 if we hit end of tree / interval, 1 if we exhausted nr_to_scan.
1766 * Increment *nr_shrunk by the number of reclaimed extents. Also update
1767 * ei->i_es_shrink_lblk to where we should continue scanning.
1768 */
1769static int es_do_reclaim_extents(struct ext4_inode_info *ei, ext4_lblk_t end,
1770 int *nr_to_scan, int *nr_shrunk)
1771{
1772 struct inode *inode = &ei->vfs_inode;
1773 struct ext4_es_tree *tree = &ei->i_es_tree;
1774 struct extent_status *es;
1775 struct rb_node *node;
1776
1777 es = __es_tree_search(&tree->root, ei->i_es_shrink_lblk);
1778 if (!es)
1779 goto out_wrap;
1780
1781 while (*nr_to_scan > 0) {
1782 if (es->es_lblk > end) {
1783 ei->i_es_shrink_lblk = end + 1;
1784 return 0;
1785 }
1786
1787 (*nr_to_scan)--;
1788 node = rb_next(&es->rb_node);
1789
1790 if (ext4_es_must_keep(es))
1791 goto next;
1792 if (ext4_es_is_referenced(es)) {
1793 ext4_es_clear_referenced(es);
1794 goto next;
1795 }
1796
1797 rb_erase(&es->rb_node, &tree->root);
1798 ext4_es_free_extent(inode, es);
1799 (*nr_shrunk)++;
1800next:
1801 if (!node)
1802 goto out_wrap;
1803 es = rb_entry(node, struct extent_status, rb_node);
1804 }
1805 ei->i_es_shrink_lblk = es->es_lblk;
1806 return 1;
1807out_wrap:
1808 ei->i_es_shrink_lblk = 0;
1809 return 0;
1810}
1811
1812static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan)
1813{
1814 struct inode *inode = &ei->vfs_inode;
1815 int nr_shrunk = 0;
1816 ext4_lblk_t start = ei->i_es_shrink_lblk;
1817 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
1818 DEFAULT_RATELIMIT_BURST);
1819
1820 if (ei->i_es_shk_nr == 0)
1821 return 0;
1822
1823 if (ext4_test_inode_state(inode, EXT4_STATE_EXT_PRECACHED) &&
1824 __ratelimit(&_rs))
1825 ext4_warning(inode->i_sb, "forced shrink of precached extents");
1826
1827 if (!es_do_reclaim_extents(ei, EXT_MAX_BLOCKS, nr_to_scan, &nr_shrunk) &&
1828 start != 0)
1829 es_do_reclaim_extents(ei, start - 1, nr_to_scan, &nr_shrunk);
1830
1831 ei->i_es_tree.cache_es = NULL;
1832 return nr_shrunk;
1833}
1834
1835/*
1836 * Called to support EXT4_IOC_CLEAR_ES_CACHE. We can only remove
1837 * discretionary entries from the extent status cache. (Some entries
1838 * must be present for proper operations.)
1839 */
1840void ext4_clear_inode_es(struct inode *inode)
1841{
1842 struct ext4_inode_info *ei = EXT4_I(inode);
1843 struct extent_status *es;
1844 struct ext4_es_tree *tree;
1845 struct rb_node *node;
1846
1847 write_lock(&ei->i_es_lock);
1848 tree = &EXT4_I(inode)->i_es_tree;
1849 tree->cache_es = NULL;
1850 node = rb_first(&tree->root);
1851 while (node) {
1852 es = rb_entry(node, struct extent_status, rb_node);
1853 node = rb_next(node);
1854 if (!ext4_es_must_keep(es)) {
1855 rb_erase(&es->rb_node, &tree->root);
1856 ext4_es_free_extent(inode, es);
1857 }
1858 }
1859 ext4_clear_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
1860 write_unlock(&ei->i_es_lock);
1861}
1862
1863#ifdef ES_DEBUG__
1864static void ext4_print_pending_tree(struct inode *inode)
1865{
1866 struct ext4_pending_tree *tree;
1867 struct rb_node *node;
1868 struct pending_reservation *pr;
1869
1870 printk(KERN_DEBUG "pending reservations for inode %lu:", inode->i_ino);
1871 tree = &EXT4_I(inode)->i_pending_tree;
1872 node = rb_first(&tree->root);
1873 while (node) {
1874 pr = rb_entry(node, struct pending_reservation, rb_node);
1875 printk(KERN_DEBUG " %u", pr->lclu);
1876 node = rb_next(node);
1877 }
1878 printk(KERN_DEBUG "\n");
1879}
1880#else
1881#define ext4_print_pending_tree(inode)
1882#endif
1883
1884int __init ext4_init_pending(void)
1885{
1886 ext4_pending_cachep = KMEM_CACHE(pending_reservation, SLAB_RECLAIM_ACCOUNT);
1887 if (ext4_pending_cachep == NULL)
1888 return -ENOMEM;
1889 return 0;
1890}
1891
1892void ext4_exit_pending(void)
1893{
1894 kmem_cache_destroy(ext4_pending_cachep);
1895}
1896
1897void ext4_init_pending_tree(struct ext4_pending_tree *tree)
1898{
1899 tree->root = RB_ROOT;
1900}
1901
1902/*
1903 * __get_pending - retrieve a pointer to a pending reservation
1904 *
1905 * @inode - file containing the pending cluster reservation
1906 * @lclu - logical cluster of interest
1907 *
1908 * Returns a pointer to a pending reservation if it's a member of
1909 * the set, and NULL if not. Must be called holding i_es_lock.
1910 */
1911static struct pending_reservation *__get_pending(struct inode *inode,
1912 ext4_lblk_t lclu)
1913{
1914 struct ext4_pending_tree *tree;
1915 struct rb_node *node;
1916 struct pending_reservation *pr = NULL;
1917
1918 tree = &EXT4_I(inode)->i_pending_tree;
1919 node = (&tree->root)->rb_node;
1920
1921 while (node) {
1922 pr = rb_entry(node, struct pending_reservation, rb_node);
1923 if (lclu < pr->lclu)
1924 node = node->rb_left;
1925 else if (lclu > pr->lclu)
1926 node = node->rb_right;
1927 else if (lclu == pr->lclu)
1928 return pr;
1929 }
1930 return NULL;
1931}
1932
1933/*
1934 * __insert_pending - adds a pending cluster reservation to the set of
1935 * pending reservations
1936 *
1937 * @inode - file containing the cluster
1938 * @lblk - logical block in the cluster to be added
1939 * @prealloc - preallocated pending entry
1940 *
1941 * Returns 0 on successful insertion and -ENOMEM on failure. If the
1942 * pending reservation is already in the set, returns successfully.
1943 */
1944static int __insert_pending(struct inode *inode, ext4_lblk_t lblk,
1945 struct pending_reservation **prealloc)
1946{
1947 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1948 struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
1949 struct rb_node **p = &tree->root.rb_node;
1950 struct rb_node *parent = NULL;
1951 struct pending_reservation *pr;
1952 ext4_lblk_t lclu;
1953 int ret = 0;
1954
1955 lclu = EXT4_B2C(sbi, lblk);
1956 /* search to find parent for insertion */
1957 while (*p) {
1958 parent = *p;
1959 pr = rb_entry(parent, struct pending_reservation, rb_node);
1960
1961 if (lclu < pr->lclu) {
1962 p = &(*p)->rb_left;
1963 } else if (lclu > pr->lclu) {
1964 p = &(*p)->rb_right;
1965 } else {
1966 /* pending reservation already inserted */
1967 goto out;
1968 }
1969 }
1970
1971 if (likely(*prealloc == NULL)) {
1972 pr = __alloc_pending(false);
1973 if (!pr) {
1974 ret = -ENOMEM;
1975 goto out;
1976 }
1977 } else {
1978 pr = *prealloc;
1979 *prealloc = NULL;
1980 }
1981 pr->lclu = lclu;
1982
1983 rb_link_node(&pr->rb_node, parent, p);
1984 rb_insert_color(&pr->rb_node, &tree->root);
1985
1986out:
1987 return ret;
1988}
1989
1990/*
1991 * __remove_pending - removes a pending cluster reservation from the set
1992 * of pending reservations
1993 *
1994 * @inode - file containing the cluster
1995 * @lblk - logical block in the pending cluster reservation to be removed
1996 *
1997 * Returns successfully if pending reservation is not a member of the set.
1998 */
1999static void __remove_pending(struct inode *inode, ext4_lblk_t lblk)
2000{
2001 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2002 struct pending_reservation *pr;
2003 struct ext4_pending_tree *tree;
2004
2005 pr = __get_pending(inode, EXT4_B2C(sbi, lblk));
2006 if (pr != NULL) {
2007 tree = &EXT4_I(inode)->i_pending_tree;
2008 rb_erase(&pr->rb_node, &tree->root);
2009 __free_pending(pr);
2010 }
2011}
2012
2013/*
2014 * ext4_remove_pending - removes a pending cluster reservation from the set
2015 * of pending reservations
2016 *
2017 * @inode - file containing the cluster
2018 * @lblk - logical block in the pending cluster reservation to be removed
2019 *
2020 * Locking for external use of __remove_pending.
2021 */
2022void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk)
2023{
2024 struct ext4_inode_info *ei = EXT4_I(inode);
2025
2026 write_lock(&ei->i_es_lock);
2027 __remove_pending(inode, lblk);
2028 write_unlock(&ei->i_es_lock);
2029}
2030
2031/*
2032 * ext4_is_pending - determine whether a cluster has a pending reservation
2033 * on it
2034 *
2035 * @inode - file containing the cluster
2036 * @lblk - logical block in the cluster
2037 *
2038 * Returns true if there's a pending reservation for the cluster in the
2039 * set of pending reservations, and false if not.
2040 */
2041bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk)
2042{
2043 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2044 struct ext4_inode_info *ei = EXT4_I(inode);
2045 bool ret;
2046
2047 read_lock(&ei->i_es_lock);
2048 ret = (bool)(__get_pending(inode, EXT4_B2C(sbi, lblk)) != NULL);
2049 read_unlock(&ei->i_es_lock);
2050
2051 return ret;
2052}
2053
2054/*
2055 * ext4_es_insert_delayed_block - adds a delayed block to the extents status
2056 * tree, adding a pending reservation where
2057 * needed
2058 *
2059 * @inode - file containing the newly added block
2060 * @lblk - logical block to be added
2061 * @allocated - indicates whether a physical cluster has been allocated for
2062 * the logical cluster that contains the block
2063 */
2064void ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
2065 bool allocated)
2066{
2067 struct extent_status newes;
2068 int err1 = 0, err2 = 0, err3 = 0;
2069 struct extent_status *es1 = NULL;
2070 struct extent_status *es2 = NULL;
2071 struct pending_reservation *pr = NULL;
2072
2073 if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
2074 return;
2075
2076 es_debug("add [%u/1) delayed to extent status tree of inode %lu\n",
2077 lblk, inode->i_ino);
2078
2079 newes.es_lblk = lblk;
2080 newes.es_len = 1;
2081 ext4_es_store_pblock_status(&newes, ~0, EXTENT_STATUS_DELAYED);
2082 trace_ext4_es_insert_delayed_block(inode, &newes, allocated);
2083
2084 ext4_es_insert_extent_check(inode, &newes);
2085
2086retry:
2087 if (err1 && !es1)
2088 es1 = __es_alloc_extent(true);
2089 if ((err1 || err2) && !es2)
2090 es2 = __es_alloc_extent(true);
2091 if ((err1 || err2 || err3) && allocated && !pr)
2092 pr = __alloc_pending(true);
2093 write_lock(&EXT4_I(inode)->i_es_lock);
2094
2095 err1 = __es_remove_extent(inode, lblk, lblk, NULL, es1);
2096 if (err1 != 0)
2097 goto error;
2098 /* Free preallocated extent if it didn't get used. */
2099 if (es1) {
2100 if (!es1->es_len)
2101 __es_free_extent(es1);
2102 es1 = NULL;
2103 }
2104
2105 err2 = __es_insert_extent(inode, &newes, es2);
2106 if (err2 != 0)
2107 goto error;
2108 /* Free preallocated extent if it didn't get used. */
2109 if (es2) {
2110 if (!es2->es_len)
2111 __es_free_extent(es2);
2112 es2 = NULL;
2113 }
2114
2115 if (allocated) {
2116 err3 = __insert_pending(inode, lblk, &pr);
2117 if (err3 != 0)
2118 goto error;
2119 if (pr) {
2120 __free_pending(pr);
2121 pr = NULL;
2122 }
2123 }
2124error:
2125 write_unlock(&EXT4_I(inode)->i_es_lock);
2126 if (err1 || err2 || err3)
2127 goto retry;
2128
2129 ext4_es_print_tree(inode);
2130 ext4_print_pending_tree(inode);
2131 return;
2132}
2133
2134/*
2135 * __es_delayed_clu - count number of clusters containing blocks that
2136 * are delayed only
2137 *
2138 * @inode - file containing block range
2139 * @start - logical block defining start of range
2140 * @end - logical block defining end of range
2141 *
2142 * Returns the number of clusters containing only delayed (not delayed
2143 * and unwritten) blocks in the range specified by @start and @end. Any
2144 * cluster or part of a cluster within the range and containing a delayed
2145 * and not unwritten block within the range is counted as a whole cluster.
2146 */
2147static unsigned int __es_delayed_clu(struct inode *inode, ext4_lblk_t start,
2148 ext4_lblk_t end)
2149{
2150 struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
2151 struct extent_status *es;
2152 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2153 struct rb_node *node;
2154 ext4_lblk_t first_lclu, last_lclu;
2155 unsigned long long last_counted_lclu;
2156 unsigned int n = 0;
2157
2158 /* guaranteed to be unequal to any ext4_lblk_t value */
2159 last_counted_lclu = ~0ULL;
2160
2161 es = __es_tree_search(&tree->root, start);
2162
2163 while (es && (es->es_lblk <= end)) {
2164 if (ext4_es_is_delonly(es)) {
2165 if (es->es_lblk <= start)
2166 first_lclu = EXT4_B2C(sbi, start);
2167 else
2168 first_lclu = EXT4_B2C(sbi, es->es_lblk);
2169
2170 if (ext4_es_end(es) >= end)
2171 last_lclu = EXT4_B2C(sbi, end);
2172 else
2173 last_lclu = EXT4_B2C(sbi, ext4_es_end(es));
2174
2175 if (first_lclu == last_counted_lclu)
2176 n += last_lclu - first_lclu;
2177 else
2178 n += last_lclu - first_lclu + 1;
2179 last_counted_lclu = last_lclu;
2180 }
2181 node = rb_next(&es->rb_node);
2182 if (!node)
2183 break;
2184 es = rb_entry(node, struct extent_status, rb_node);
2185 }
2186
2187 return n;
2188}
2189
2190/*
2191 * ext4_es_delayed_clu - count number of clusters containing blocks that
2192 * are both delayed and unwritten
2193 *
2194 * @inode - file containing block range
2195 * @lblk - logical block defining start of range
2196 * @len - number of blocks in range
2197 *
2198 * Locking for external use of __es_delayed_clu().
2199 */
2200unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
2201 ext4_lblk_t len)
2202{
2203 struct ext4_inode_info *ei = EXT4_I(inode);
2204 ext4_lblk_t end;
2205 unsigned int n;
2206
2207 if (len == 0)
2208 return 0;
2209
2210 end = lblk + len - 1;
2211 WARN_ON(end < lblk);
2212
2213 read_lock(&ei->i_es_lock);
2214
2215 n = __es_delayed_clu(inode, lblk, end);
2216
2217 read_unlock(&ei->i_es_lock);
2218
2219 return n;
2220}
2221
2222/*
2223 * __revise_pending - makes, cancels, or leaves unchanged pending cluster
2224 * reservations for a specified block range depending
2225 * upon the presence or absence of delayed blocks
2226 * outside the range within clusters at the ends of the
2227 * range
2228 *
2229 * @inode - file containing the range
2230 * @lblk - logical block defining the start of range
2231 * @len - length of range in blocks
2232 * @prealloc - preallocated pending entry
2233 *
2234 * Used after a newly allocated extent is added to the extents status tree.
2235 * Requires that the extents in the range have either written or unwritten
2236 * status. Must be called while holding i_es_lock.
2237 */
2238static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
2239 ext4_lblk_t len,
2240 struct pending_reservation **prealloc)
2241{
2242 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2243 ext4_lblk_t end = lblk + len - 1;
2244 ext4_lblk_t first, last;
2245 bool f_del = false, l_del = false;
2246 int ret = 0;
2247
2248 if (len == 0)
2249 return 0;
2250
2251 /*
2252 * Two cases - block range within single cluster and block range
2253 * spanning two or more clusters. Note that a cluster belonging
2254 * to a range starting and/or ending on a cluster boundary is treated
2255 * as if it does not contain a delayed extent. The new range may
2256 * have allocated space for previously delayed blocks out to the
2257 * cluster boundary, requiring that any pre-existing pending
2258 * reservation be canceled. Because this code only looks at blocks
2259 * outside the range, it should revise pending reservations
2260 * correctly even if the extent represented by the range can't be
2261 * inserted in the extents status tree due to ENOSPC.
2262 */
2263
2264 if (EXT4_B2C(sbi, lblk) == EXT4_B2C(sbi, end)) {
2265 first = EXT4_LBLK_CMASK(sbi, lblk);
2266 if (first != lblk)
2267 f_del = __es_scan_range(inode, &ext4_es_is_delonly,
2268 first, lblk - 1);
2269 if (f_del) {
2270 ret = __insert_pending(inode, first, prealloc);
2271 if (ret < 0)
2272 goto out;
2273 } else {
2274 last = EXT4_LBLK_CMASK(sbi, end) +
2275 sbi->s_cluster_ratio - 1;
2276 if (last != end)
2277 l_del = __es_scan_range(inode,
2278 &ext4_es_is_delonly,
2279 end + 1, last);
2280 if (l_del) {
2281 ret = __insert_pending(inode, last, prealloc);
2282 if (ret < 0)
2283 goto out;
2284 } else
2285 __remove_pending(inode, last);
2286 }
2287 } else {
2288 first = EXT4_LBLK_CMASK(sbi, lblk);
2289 if (first != lblk)
2290 f_del = __es_scan_range(inode, &ext4_es_is_delonly,
2291 first, lblk - 1);
2292 if (f_del) {
2293 ret = __insert_pending(inode, first, prealloc);
2294 if (ret < 0)
2295 goto out;
2296 } else
2297 __remove_pending(inode, first);
2298
2299 last = EXT4_LBLK_CMASK(sbi, end) + sbi->s_cluster_ratio - 1;
2300 if (last != end)
2301 l_del = __es_scan_range(inode, &ext4_es_is_delonly,
2302 end + 1, last);
2303 if (l_del) {
2304 ret = __insert_pending(inode, last, prealloc);
2305 if (ret < 0)
2306 goto out;
2307 } else
2308 __remove_pending(inode, last);
2309 }
2310out:
2311 return ret;
2312}