Commit | Line | Data |
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654598be ZL |
1 | /* |
2 | * fs/ext4/extents_status.c | |
3 | * | |
4 | * Written by Yongqiang Yang <xiaoqiangnk@gmail.com> | |
5 | * Modified by | |
6 | * Allison Henderson <achender@linux.vnet.ibm.com> | |
7 | * Hugh Dickins <hughd@google.com> | |
8 | * Zheng Liu <wenqing.lz@taobao.com> | |
9 | * | |
10 | * Ext4 extents status tree core functions. | |
11 | */ | |
d3922a77 | 12 | #include <linux/list_sort.h> |
eb68d0e2 ZL |
13 | #include <linux/proc_fs.h> |
14 | #include <linux/seq_file.h> | |
654598be | 15 | #include "ext4.h" |
654598be | 16 | |
992e9fdd ZL |
17 | #include <trace/events/ext4.h> |
18 | ||
654598be ZL |
19 | /* |
20 | * According to previous discussion in Ext4 Developer Workshop, we | |
21 | * will introduce a new structure called io tree to track all extent | |
22 | * status in order to solve some problems that we have met | |
23 | * (e.g. Reservation space warning), and provide extent-level locking. | |
24 | * Delay extent tree is the first step to achieve this goal. It is | |
25 | * original built by Yongqiang Yang. At that time it is called delay | |
06b0c886 | 26 | * extent tree, whose goal is only track delayed extents in memory to |
654598be ZL |
27 | * simplify the implementation of fiemap and bigalloc, and introduce |
28 | * lseek SEEK_DATA/SEEK_HOLE support. That is why it is still called | |
06b0c886 ZL |
29 | * delay extent tree at the first commit. But for better understand |
30 | * what it does, it has been rename to extent status tree. | |
654598be | 31 | * |
06b0c886 ZL |
32 | * Step1: |
33 | * Currently the first step has been done. All delayed extents are | |
34 | * tracked in the tree. It maintains the delayed extent when a delayed | |
35 | * allocation is issued, and the delayed extent is written out or | |
654598be ZL |
36 | * invalidated. Therefore the implementation of fiemap and bigalloc |
37 | * are simplified, and SEEK_DATA/SEEK_HOLE are introduced. | |
38 | * | |
39 | * The following comment describes the implemenmtation of extent | |
40 | * status tree and future works. | |
06b0c886 ZL |
41 | * |
42 | * Step2: | |
43 | * In this step all extent status are tracked by extent status tree. | |
44 | * Thus, we can first try to lookup a block mapping in this tree before | |
45 | * finding it in extent tree. Hence, single extent cache can be removed | |
46 | * because extent status tree can do a better job. Extents in status | |
47 | * tree are loaded on-demand. Therefore, the extent status tree may not | |
48 | * contain all of the extents in a file. Meanwhile we define a shrinker | |
49 | * to reclaim memory from extent status tree because fragmented extent | |
50 | * tree will make status tree cost too much memory. written/unwritten/- | |
51 | * hole extents in the tree will be reclaimed by this shrinker when we | |
52 | * are under high memory pressure. Delayed extents will not be | |
53 | * reclimed because fiemap, bigalloc, and seek_data/hole need it. | |
654598be ZL |
54 | */ |
55 | ||
56 | /* | |
06b0c886 | 57 | * Extent status tree implementation for ext4. |
654598be ZL |
58 | * |
59 | * | |
60 | * ========================================================================== | |
06b0c886 | 61 | * Extent status tree tracks all extent status. |
654598be | 62 | * |
06b0c886 | 63 | * 1. Why we need to implement extent status tree? |
654598be | 64 | * |
06b0c886 | 65 | * Without extent status tree, ext4 identifies a delayed extent by looking |
654598be ZL |
66 | * up page cache, this has several deficiencies - complicated, buggy, |
67 | * and inefficient code. | |
68 | * | |
06b0c886 ZL |
69 | * FIEMAP, SEEK_HOLE/DATA, bigalloc, and writeout all need to know if a |
70 | * block or a range of blocks are belonged to a delayed extent. | |
654598be | 71 | * |
06b0c886 | 72 | * Let us have a look at how they do without extent status tree. |
654598be ZL |
73 | * -- FIEMAP |
74 | * FIEMAP looks up page cache to identify delayed allocations from holes. | |
75 | * | |
76 | * -- SEEK_HOLE/DATA | |
77 | * SEEK_HOLE/DATA has the same problem as FIEMAP. | |
78 | * | |
79 | * -- bigalloc | |
80 | * bigalloc looks up page cache to figure out if a block is | |
81 | * already under delayed allocation or not to determine whether | |
82 | * quota reserving is needed for the cluster. | |
83 | * | |
654598be ZL |
84 | * -- writeout |
85 | * Writeout looks up whole page cache to see if a buffer is | |
86 | * mapped, If there are not very many delayed buffers, then it is | |
87 | * time comsuming. | |
88 | * | |
06b0c886 | 89 | * With extent status tree implementation, FIEMAP, SEEK_HOLE/DATA, |
654598be ZL |
90 | * bigalloc and writeout can figure out if a block or a range of |
91 | * blocks is under delayed allocation(belonged to a delayed extent) or | |
06b0c886 | 92 | * not by searching the extent tree. |
654598be ZL |
93 | * |
94 | * | |
95 | * ========================================================================== | |
06b0c886 ZL |
96 | * 2. Ext4 extent status tree impelmentation |
97 | * | |
98 | * -- extent | |
99 | * A extent is a range of blocks which are contiguous logically and | |
100 | * physically. Unlike extent in extent tree, this extent in ext4 is | |
101 | * a in-memory struct, there is no corresponding on-disk data. There | |
102 | * is no limit on length of extent, so an extent can contain as many | |
103 | * blocks as they are contiguous logically and physically. | |
654598be | 104 | * |
06b0c886 ZL |
105 | * -- extent status tree |
106 | * Every inode has an extent status tree and all allocation blocks | |
107 | * are added to the tree with different status. The extent in the | |
108 | * tree are ordered by logical block no. | |
654598be | 109 | * |
06b0c886 ZL |
110 | * -- operations on a extent status tree |
111 | * There are three important operations on a delayed extent tree: find | |
112 | * next extent, adding a extent(a range of blocks) and removing a extent. | |
654598be | 113 | * |
06b0c886 ZL |
114 | * -- race on a extent status tree |
115 | * Extent status tree is protected by inode->i_es_lock. | |
654598be | 116 | * |
06b0c886 ZL |
117 | * -- memory consumption |
118 | * Fragmented extent tree will make extent status tree cost too much | |
119 | * memory. Hence, we will reclaim written/unwritten/hole extents from | |
120 | * the tree under a heavy memory pressure. | |
654598be ZL |
121 | * |
122 | * | |
123 | * ========================================================================== | |
06b0c886 ZL |
124 | * 3. Performance analysis |
125 | * | |
654598be ZL |
126 | * -- overhead |
127 | * 1. There is a cache extent for write access, so if writes are | |
128 | * not very random, adding space operaions are in O(1) time. | |
129 | * | |
130 | * -- gain | |
131 | * 2. Code is much simpler, more readable, more maintainable and | |
132 | * more efficient. | |
133 | * | |
134 | * | |
135 | * ========================================================================== | |
136 | * 4. TODO list | |
654598be | 137 | * |
06b0c886 | 138 | * -- Refactor delayed space reservation |
654598be ZL |
139 | * |
140 | * -- Extent-level locking | |
141 | */ | |
142 | ||
143 | static struct kmem_cache *ext4_es_cachep; | |
144 | ||
bdedbb7b ZL |
145 | static int __es_insert_extent(struct inode *inode, struct extent_status *newes); |
146 | static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk, | |
06b0c886 | 147 | ext4_lblk_t end); |
dd475925 | 148 | static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan); |
edaa53ca ZL |
149 | static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan, |
150 | struct ext4_inode_info *locked_ei); | |
06b0c886 | 151 | |
654598be ZL |
152 | int __init ext4_init_es(void) |
153 | { | |
24630774 TT |
154 | ext4_es_cachep = kmem_cache_create("ext4_extent_status", |
155 | sizeof(struct extent_status), | |
156 | 0, (SLAB_RECLAIM_ACCOUNT), NULL); | |
654598be ZL |
157 | if (ext4_es_cachep == NULL) |
158 | return -ENOMEM; | |
159 | return 0; | |
160 | } | |
161 | ||
162 | void ext4_exit_es(void) | |
163 | { | |
164 | if (ext4_es_cachep) | |
165 | kmem_cache_destroy(ext4_es_cachep); | |
166 | } | |
167 | ||
168 | void ext4_es_init_tree(struct ext4_es_tree *tree) | |
169 | { | |
170 | tree->root = RB_ROOT; | |
171 | tree->cache_es = NULL; | |
172 | } | |
173 | ||
174 | #ifdef ES_DEBUG__ | |
175 | static void ext4_es_print_tree(struct inode *inode) | |
176 | { | |
177 | struct ext4_es_tree *tree; | |
178 | struct rb_node *node; | |
179 | ||
180 | printk(KERN_DEBUG "status extents for inode %lu:", inode->i_ino); | |
181 | tree = &EXT4_I(inode)->i_es_tree; | |
182 | node = rb_first(&tree->root); | |
183 | while (node) { | |
184 | struct extent_status *es; | |
185 | es = rb_entry(node, struct extent_status, rb_node); | |
ce140cdd | 186 | printk(KERN_DEBUG " [%u/%u) %llu %x", |
fdc0212e ZL |
187 | es->es_lblk, es->es_len, |
188 | ext4_es_pblock(es), ext4_es_status(es)); | |
654598be ZL |
189 | node = rb_next(node); |
190 | } | |
191 | printk(KERN_DEBUG "\n"); | |
192 | } | |
193 | #else | |
194 | #define ext4_es_print_tree(inode) | |
195 | #endif | |
196 | ||
06b0c886 | 197 | static inline ext4_lblk_t ext4_es_end(struct extent_status *es) |
654598be | 198 | { |
06b0c886 ZL |
199 | BUG_ON(es->es_lblk + es->es_len < es->es_lblk); |
200 | return es->es_lblk + es->es_len - 1; | |
654598be ZL |
201 | } |
202 | ||
203 | /* | |
204 | * search through the tree for an delayed extent with a given offset. If | |
205 | * it can't be found, try to find next extent. | |
206 | */ | |
207 | static struct extent_status *__es_tree_search(struct rb_root *root, | |
06b0c886 | 208 | ext4_lblk_t lblk) |
654598be ZL |
209 | { |
210 | struct rb_node *node = root->rb_node; | |
211 | struct extent_status *es = NULL; | |
212 | ||
213 | while (node) { | |
214 | es = rb_entry(node, struct extent_status, rb_node); | |
06b0c886 | 215 | if (lblk < es->es_lblk) |
654598be | 216 | node = node->rb_left; |
06b0c886 | 217 | else if (lblk > ext4_es_end(es)) |
654598be ZL |
218 | node = node->rb_right; |
219 | else | |
220 | return es; | |
221 | } | |
222 | ||
06b0c886 | 223 | if (es && lblk < es->es_lblk) |
654598be ZL |
224 | return es; |
225 | ||
06b0c886 | 226 | if (es && lblk > ext4_es_end(es)) { |
654598be ZL |
227 | node = rb_next(&es->rb_node); |
228 | return node ? rb_entry(node, struct extent_status, rb_node) : | |
229 | NULL; | |
230 | } | |
231 | ||
232 | return NULL; | |
233 | } | |
234 | ||
235 | /* | |
e30b5dca YZ |
236 | * ext4_es_find_delayed_extent_range: find the 1st delayed extent covering |
237 | * @es->lblk if it exists, otherwise, the next extent after @es->lblk. | |
654598be ZL |
238 | * |
239 | * @inode: the inode which owns delayed extents | |
be401363 | 240 | * @lblk: the offset where we start to search |
e30b5dca | 241 | * @end: the offset where we stop to search |
654598be | 242 | * @es: delayed extent that we found |
654598be | 243 | */ |
e30b5dca YZ |
244 | void ext4_es_find_delayed_extent_range(struct inode *inode, |
245 | ext4_lblk_t lblk, ext4_lblk_t end, | |
be401363 | 246 | struct extent_status *es) |
654598be ZL |
247 | { |
248 | struct ext4_es_tree *tree = NULL; | |
249 | struct extent_status *es1 = NULL; | |
250 | struct rb_node *node; | |
654598be | 251 | |
be401363 | 252 | BUG_ON(es == NULL); |
e30b5dca YZ |
253 | BUG_ON(end < lblk); |
254 | trace_ext4_es_find_delayed_extent_range_enter(inode, lblk); | |
992e9fdd | 255 | |
654598be ZL |
256 | read_lock(&EXT4_I(inode)->i_es_lock); |
257 | tree = &EXT4_I(inode)->i_es_tree; | |
258 | ||
fdc0212e | 259 | /* find extent in cache firstly */ |
be401363 | 260 | es->es_lblk = es->es_len = es->es_pblk = 0; |
654598be ZL |
261 | if (tree->cache_es) { |
262 | es1 = tree->cache_es; | |
be401363 | 263 | if (in_range(lblk, es1->es_lblk, es1->es_len)) { |
3be78c73 | 264 | es_debug("%u cached by [%u/%u) %llu %x\n", |
be401363 | 265 | lblk, es1->es_lblk, es1->es_len, |
fdc0212e | 266 | ext4_es_pblock(es1), ext4_es_status(es1)); |
654598be ZL |
267 | goto out; |
268 | } | |
269 | } | |
270 | ||
be401363 | 271 | es1 = __es_tree_search(&tree->root, lblk); |
654598be ZL |
272 | |
273 | out: | |
be401363 ZL |
274 | if (es1 && !ext4_es_is_delayed(es1)) { |
275 | while ((node = rb_next(&es1->rb_node)) != NULL) { | |
276 | es1 = rb_entry(node, struct extent_status, rb_node); | |
e30b5dca YZ |
277 | if (es1->es_lblk > end) { |
278 | es1 = NULL; | |
279 | break; | |
280 | } | |
be401363 ZL |
281 | if (ext4_es_is_delayed(es1)) |
282 | break; | |
283 | } | |
284 | } | |
285 | ||
286 | if (es1 && ext4_es_is_delayed(es1)) { | |
654598be | 287 | tree->cache_es = es1; |
06b0c886 ZL |
288 | es->es_lblk = es1->es_lblk; |
289 | es->es_len = es1->es_len; | |
fdc0212e | 290 | es->es_pblk = es1->es_pblk; |
654598be ZL |
291 | } |
292 | ||
293 | read_unlock(&EXT4_I(inode)->i_es_lock); | |
992e9fdd | 294 | |
e30b5dca | 295 | trace_ext4_es_find_delayed_extent_range_exit(inode, es); |
654598be ZL |
296 | } |
297 | ||
b0dea4c1 | 298 | static void ext4_es_list_add(struct inode *inode) |
edaa53ca ZL |
299 | { |
300 | struct ext4_inode_info *ei = EXT4_I(inode); | |
301 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); | |
302 | ||
303 | if (!list_empty(&ei->i_es_list)) | |
304 | return; | |
305 | ||
306 | spin_lock(&sbi->s_es_lock); | |
307 | if (list_empty(&ei->i_es_list)) { | |
308 | list_add_tail(&ei->i_es_list, &sbi->s_es_list); | |
309 | sbi->s_es_nr_inode++; | |
310 | } | |
311 | spin_unlock(&sbi->s_es_lock); | |
312 | } | |
313 | ||
b0dea4c1 | 314 | static void ext4_es_list_del(struct inode *inode) |
edaa53ca ZL |
315 | { |
316 | struct ext4_inode_info *ei = EXT4_I(inode); | |
317 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); | |
318 | ||
319 | spin_lock(&sbi->s_es_lock); | |
320 | if (!list_empty(&ei->i_es_list)) { | |
321 | list_del_init(&ei->i_es_list); | |
322 | sbi->s_es_nr_inode--; | |
323 | WARN_ON_ONCE(sbi->s_es_nr_inode < 0); | |
324 | } | |
325 | spin_unlock(&sbi->s_es_lock); | |
326 | } | |
327 | ||
654598be | 328 | static struct extent_status * |
bdedbb7b ZL |
329 | ext4_es_alloc_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len, |
330 | ext4_fsblk_t pblk) | |
654598be ZL |
331 | { |
332 | struct extent_status *es; | |
333 | es = kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC); | |
334 | if (es == NULL) | |
335 | return NULL; | |
06b0c886 ZL |
336 | es->es_lblk = lblk; |
337 | es->es_len = len; | |
fdc0212e | 338 | es->es_pblk = pblk; |
74cd15cd ZL |
339 | |
340 | /* | |
341 | * We don't count delayed extent because we never try to reclaim them | |
342 | */ | |
24630774 | 343 | if (!ext4_es_is_delayed(es)) { |
b0dea4c1 JK |
344 | if (!EXT4_I(inode)->i_es_shk_nr++) |
345 | ext4_es_list_add(inode); | |
eb68d0e2 | 346 | percpu_counter_inc(&EXT4_SB(inode->i_sb)-> |
edaa53ca | 347 | s_es_stats.es_stats_shk_cnt); |
24630774 | 348 | } |
74cd15cd | 349 | |
eb68d0e2 ZL |
350 | EXT4_I(inode)->i_es_all_nr++; |
351 | percpu_counter_inc(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt); | |
352 | ||
654598be ZL |
353 | return es; |
354 | } | |
355 | ||
bdedbb7b | 356 | static void ext4_es_free_extent(struct inode *inode, struct extent_status *es) |
654598be | 357 | { |
eb68d0e2 ZL |
358 | EXT4_I(inode)->i_es_all_nr--; |
359 | percpu_counter_dec(&EXT4_SB(inode->i_sb)->s_es_stats.es_stats_all_cnt); | |
360 | ||
edaa53ca | 361 | /* Decrease the shrink counter when this es is not delayed */ |
74cd15cd | 362 | if (!ext4_es_is_delayed(es)) { |
edaa53ca | 363 | BUG_ON(EXT4_I(inode)->i_es_shk_nr == 0); |
b0dea4c1 JK |
364 | if (!--EXT4_I(inode)->i_es_shk_nr) |
365 | ext4_es_list_del(inode); | |
eb68d0e2 | 366 | percpu_counter_dec(&EXT4_SB(inode->i_sb)-> |
edaa53ca | 367 | s_es_stats.es_stats_shk_cnt); |
74cd15cd ZL |
368 | } |
369 | ||
654598be ZL |
370 | kmem_cache_free(ext4_es_cachep, es); |
371 | } | |
372 | ||
06b0c886 ZL |
373 | /* |
374 | * Check whether or not two extents can be merged | |
375 | * Condition: | |
376 | * - logical block number is contiguous | |
fdc0212e ZL |
377 | * - physical block number is contiguous |
378 | * - status is equal | |
06b0c886 ZL |
379 | */ |
380 | static int ext4_es_can_be_merged(struct extent_status *es1, | |
381 | struct extent_status *es2) | |
382 | { | |
2be12de9 | 383 | if (ext4_es_type(es1) != ext4_es_type(es2)) |
06b0c886 ZL |
384 | return 0; |
385 | ||
0baaea64 LC |
386 | if (((__u64) es1->es_len) + es2->es_len > EXT_MAX_BLOCKS) { |
387 | pr_warn("ES assertion failed when merging extents. " | |
388 | "The sum of lengths of es1 (%d) and es2 (%d) " | |
389 | "is bigger than allowed file size (%d)\n", | |
390 | es1->es_len, es2->es_len, EXT_MAX_BLOCKS); | |
391 | WARN_ON(1); | |
fdc0212e | 392 | return 0; |
0baaea64 | 393 | } |
fdc0212e | 394 | |
bd384364 | 395 | if (((__u64) es1->es_lblk) + es1->es_len != es2->es_lblk) |
fdc0212e ZL |
396 | return 0; |
397 | ||
bd384364 ZL |
398 | if ((ext4_es_is_written(es1) || ext4_es_is_unwritten(es1)) && |
399 | (ext4_es_pblock(es1) + es1->es_len == ext4_es_pblock(es2))) | |
400 | return 1; | |
401 | ||
402 | if (ext4_es_is_hole(es1)) | |
403 | return 1; | |
404 | ||
405 | /* we need to check delayed extent is without unwritten status */ | |
406 | if (ext4_es_is_delayed(es1) && !ext4_es_is_unwritten(es1)) | |
407 | return 1; | |
408 | ||
409 | return 0; | |
06b0c886 ZL |
410 | } |
411 | ||
654598be | 412 | static struct extent_status * |
bdedbb7b | 413 | ext4_es_try_to_merge_left(struct inode *inode, struct extent_status *es) |
654598be | 414 | { |
bdedbb7b | 415 | struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree; |
654598be ZL |
416 | struct extent_status *es1; |
417 | struct rb_node *node; | |
418 | ||
419 | node = rb_prev(&es->rb_node); | |
420 | if (!node) | |
421 | return es; | |
422 | ||
423 | es1 = rb_entry(node, struct extent_status, rb_node); | |
06b0c886 ZL |
424 | if (ext4_es_can_be_merged(es1, es)) { |
425 | es1->es_len += es->es_len; | |
2be12de9 JK |
426 | if (ext4_es_is_referenced(es)) |
427 | ext4_es_set_referenced(es1); | |
654598be | 428 | rb_erase(&es->rb_node, &tree->root); |
bdedbb7b | 429 | ext4_es_free_extent(inode, es); |
654598be ZL |
430 | es = es1; |
431 | } | |
432 | ||
433 | return es; | |
434 | } | |
435 | ||
436 | static struct extent_status * | |
bdedbb7b | 437 | ext4_es_try_to_merge_right(struct inode *inode, struct extent_status *es) |
654598be | 438 | { |
bdedbb7b | 439 | struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree; |
654598be ZL |
440 | struct extent_status *es1; |
441 | struct rb_node *node; | |
442 | ||
443 | node = rb_next(&es->rb_node); | |
444 | if (!node) | |
445 | return es; | |
446 | ||
447 | es1 = rb_entry(node, struct extent_status, rb_node); | |
06b0c886 ZL |
448 | if (ext4_es_can_be_merged(es, es1)) { |
449 | es->es_len += es1->es_len; | |
2be12de9 JK |
450 | if (ext4_es_is_referenced(es1)) |
451 | ext4_es_set_referenced(es); | |
654598be | 452 | rb_erase(node, &tree->root); |
bdedbb7b | 453 | ext4_es_free_extent(inode, es1); |
654598be ZL |
454 | } |
455 | ||
456 | return es; | |
457 | } | |
458 | ||
921f266b | 459 | #ifdef ES_AGGRESSIVE_TEST |
d7b2a00c ZL |
460 | #include "ext4_extents.h" /* Needed when ES_AGGRESSIVE_TEST is defined */ |
461 | ||
921f266b DM |
462 | static void ext4_es_insert_extent_ext_check(struct inode *inode, |
463 | struct extent_status *es) | |
464 | { | |
465 | struct ext4_ext_path *path = NULL; | |
466 | struct ext4_extent *ex; | |
467 | ext4_lblk_t ee_block; | |
468 | ext4_fsblk_t ee_start; | |
469 | unsigned short ee_len; | |
470 | int depth, ee_status, es_status; | |
471 | ||
ed8a1a76 | 472 | path = ext4_find_extent(inode, es->es_lblk, NULL, EXT4_EX_NOCACHE); |
921f266b DM |
473 | if (IS_ERR(path)) |
474 | return; | |
475 | ||
476 | depth = ext_depth(inode); | |
477 | ex = path[depth].p_ext; | |
478 | ||
479 | if (ex) { | |
480 | ||
481 | ee_block = le32_to_cpu(ex->ee_block); | |
482 | ee_start = ext4_ext_pblock(ex); | |
483 | ee_len = ext4_ext_get_actual_len(ex); | |
484 | ||
556615dc | 485 | ee_status = ext4_ext_is_unwritten(ex) ? 1 : 0; |
921f266b DM |
486 | es_status = ext4_es_is_unwritten(es) ? 1 : 0; |
487 | ||
488 | /* | |
489 | * Make sure ex and es are not overlap when we try to insert | |
490 | * a delayed/hole extent. | |
491 | */ | |
492 | if (!ext4_es_is_written(es) && !ext4_es_is_unwritten(es)) { | |
493 | if (in_range(es->es_lblk, ee_block, ee_len)) { | |
bdafe42a | 494 | pr_warn("ES insert assertion failed for " |
921f266b DM |
495 | "inode: %lu we can find an extent " |
496 | "at block [%d/%d/%llu/%c], but we " | |
ce140cdd EW |
497 | "want to add a delayed/hole extent " |
498 | "[%d/%d/%llu/%x]\n", | |
921f266b DM |
499 | inode->i_ino, ee_block, ee_len, |
500 | ee_start, ee_status ? 'u' : 'w', | |
501 | es->es_lblk, es->es_len, | |
502 | ext4_es_pblock(es), ext4_es_status(es)); | |
503 | } | |
504 | goto out; | |
505 | } | |
506 | ||
507 | /* | |
508 | * We don't check ee_block == es->es_lblk, etc. because es | |
509 | * might be a part of whole extent, vice versa. | |
510 | */ | |
511 | if (es->es_lblk < ee_block || | |
512 | ext4_es_pblock(es) != ee_start + es->es_lblk - ee_block) { | |
bdafe42a | 513 | pr_warn("ES insert assertion failed for inode: %lu " |
921f266b DM |
514 | "ex_status [%d/%d/%llu/%c] != " |
515 | "es_status [%d/%d/%llu/%c]\n", inode->i_ino, | |
516 | ee_block, ee_len, ee_start, | |
517 | ee_status ? 'u' : 'w', es->es_lblk, es->es_len, | |
518 | ext4_es_pblock(es), es_status ? 'u' : 'w'); | |
519 | goto out; | |
520 | } | |
521 | ||
522 | if (ee_status ^ es_status) { | |
bdafe42a | 523 | pr_warn("ES insert assertion failed for inode: %lu " |
921f266b DM |
524 | "ex_status [%d/%d/%llu/%c] != " |
525 | "es_status [%d/%d/%llu/%c]\n", inode->i_ino, | |
526 | ee_block, ee_len, ee_start, | |
527 | ee_status ? 'u' : 'w', es->es_lblk, es->es_len, | |
528 | ext4_es_pblock(es), es_status ? 'u' : 'w'); | |
529 | } | |
530 | } else { | |
531 | /* | |
532 | * We can't find an extent on disk. So we need to make sure | |
533 | * that we don't want to add an written/unwritten extent. | |
534 | */ | |
535 | if (!ext4_es_is_delayed(es) && !ext4_es_is_hole(es)) { | |
bdafe42a | 536 | pr_warn("ES insert assertion failed for inode: %lu " |
921f266b | 537 | "can't find an extent at block %d but we want " |
ce140cdd EW |
538 | "to add a written/unwritten extent " |
539 | "[%d/%d/%llu/%x]\n", inode->i_ino, | |
921f266b DM |
540 | es->es_lblk, es->es_lblk, es->es_len, |
541 | ext4_es_pblock(es), ext4_es_status(es)); | |
542 | } | |
543 | } | |
544 | out: | |
b7ea89ad TT |
545 | ext4_ext_drop_refs(path); |
546 | kfree(path); | |
921f266b DM |
547 | } |
548 | ||
549 | static void ext4_es_insert_extent_ind_check(struct inode *inode, | |
550 | struct extent_status *es) | |
551 | { | |
552 | struct ext4_map_blocks map; | |
553 | int retval; | |
554 | ||
555 | /* | |
556 | * Here we call ext4_ind_map_blocks to lookup a block mapping because | |
557 | * 'Indirect' structure is defined in indirect.c. So we couldn't | |
558 | * access direct/indirect tree from outside. It is too dirty to define | |
559 | * this function in indirect.c file. | |
560 | */ | |
561 | ||
562 | map.m_lblk = es->es_lblk; | |
563 | map.m_len = es->es_len; | |
564 | ||
565 | retval = ext4_ind_map_blocks(NULL, inode, &map, 0); | |
566 | if (retval > 0) { | |
567 | if (ext4_es_is_delayed(es) || ext4_es_is_hole(es)) { | |
568 | /* | |
569 | * We want to add a delayed/hole extent but this | |
570 | * block has been allocated. | |
571 | */ | |
bdafe42a | 572 | pr_warn("ES insert assertion failed for inode: %lu " |
921f266b | 573 | "We can find blocks but we want to add a " |
ce140cdd | 574 | "delayed/hole extent [%d/%d/%llu/%x]\n", |
921f266b DM |
575 | inode->i_ino, es->es_lblk, es->es_len, |
576 | ext4_es_pblock(es), ext4_es_status(es)); | |
577 | return; | |
578 | } else if (ext4_es_is_written(es)) { | |
579 | if (retval != es->es_len) { | |
bdafe42a | 580 | pr_warn("ES insert assertion failed for " |
921f266b DM |
581 | "inode: %lu retval %d != es_len %d\n", |
582 | inode->i_ino, retval, es->es_len); | |
583 | return; | |
584 | } | |
585 | if (map.m_pblk != ext4_es_pblock(es)) { | |
bdafe42a | 586 | pr_warn("ES insert assertion failed for " |
921f266b DM |
587 | "inode: %lu m_pblk %llu != " |
588 | "es_pblk %llu\n", | |
589 | inode->i_ino, map.m_pblk, | |
590 | ext4_es_pblock(es)); | |
591 | return; | |
592 | } | |
593 | } else { | |
594 | /* | |
595 | * We don't need to check unwritten extent because | |
596 | * indirect-based file doesn't have it. | |
597 | */ | |
598 | BUG_ON(1); | |
599 | } | |
600 | } else if (retval == 0) { | |
601 | if (ext4_es_is_written(es)) { | |
bdafe42a | 602 | pr_warn("ES insert assertion failed for inode: %lu " |
921f266b | 603 | "We can't find the block but we want to add " |
ce140cdd | 604 | "a written extent [%d/%d/%llu/%x]\n", |
921f266b DM |
605 | inode->i_ino, es->es_lblk, es->es_len, |
606 | ext4_es_pblock(es), ext4_es_status(es)); | |
607 | return; | |
608 | } | |
609 | } | |
610 | } | |
611 | ||
612 | static inline void ext4_es_insert_extent_check(struct inode *inode, | |
613 | struct extent_status *es) | |
614 | { | |
615 | /* | |
616 | * We don't need to worry about the race condition because | |
617 | * caller takes i_data_sem locking. | |
618 | */ | |
619 | BUG_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem)); | |
620 | if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) | |
621 | ext4_es_insert_extent_ext_check(inode, es); | |
622 | else | |
623 | ext4_es_insert_extent_ind_check(inode, es); | |
624 | } | |
625 | #else | |
626 | static inline void ext4_es_insert_extent_check(struct inode *inode, | |
627 | struct extent_status *es) | |
628 | { | |
629 | } | |
630 | #endif | |
631 | ||
bdedbb7b | 632 | static int __es_insert_extent(struct inode *inode, struct extent_status *newes) |
654598be | 633 | { |
bdedbb7b | 634 | struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree; |
654598be ZL |
635 | struct rb_node **p = &tree->root.rb_node; |
636 | struct rb_node *parent = NULL; | |
637 | struct extent_status *es; | |
654598be ZL |
638 | |
639 | while (*p) { | |
640 | parent = *p; | |
641 | es = rb_entry(parent, struct extent_status, rb_node); | |
642 | ||
06b0c886 ZL |
643 | if (newes->es_lblk < es->es_lblk) { |
644 | if (ext4_es_can_be_merged(newes, es)) { | |
645 | /* | |
646 | * Here we can modify es_lblk directly | |
647 | * because it isn't overlapped. | |
648 | */ | |
649 | es->es_lblk = newes->es_lblk; | |
650 | es->es_len += newes->es_len; | |
fdc0212e ZL |
651 | if (ext4_es_is_written(es) || |
652 | ext4_es_is_unwritten(es)) | |
653 | ext4_es_store_pblock(es, | |
654 | newes->es_pblk); | |
bdedbb7b | 655 | es = ext4_es_try_to_merge_left(inode, es); |
654598be ZL |
656 | goto out; |
657 | } | |
658 | p = &(*p)->rb_left; | |
06b0c886 ZL |
659 | } else if (newes->es_lblk > ext4_es_end(es)) { |
660 | if (ext4_es_can_be_merged(es, newes)) { | |
661 | es->es_len += newes->es_len; | |
bdedbb7b | 662 | es = ext4_es_try_to_merge_right(inode, es); |
654598be ZL |
663 | goto out; |
664 | } | |
665 | p = &(*p)->rb_right; | |
666 | } else { | |
06b0c886 ZL |
667 | BUG_ON(1); |
668 | return -EINVAL; | |
654598be ZL |
669 | } |
670 | } | |
671 | ||
bdedbb7b | 672 | es = ext4_es_alloc_extent(inode, newes->es_lblk, newes->es_len, |
fdc0212e | 673 | newes->es_pblk); |
654598be ZL |
674 | if (!es) |
675 | return -ENOMEM; | |
676 | rb_link_node(&es->rb_node, parent, p); | |
677 | rb_insert_color(&es->rb_node, &tree->root); | |
678 | ||
679 | out: | |
680 | tree->cache_es = es; | |
681 | return 0; | |
682 | } | |
683 | ||
684 | /* | |
bdafe42a TT |
685 | * ext4_es_insert_extent() adds information to an inode's extent |
686 | * status tree. | |
654598be ZL |
687 | * |
688 | * Return 0 on success, error code on failure. | |
689 | */ | |
06b0c886 | 690 | int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk, |
fdc0212e | 691 | ext4_lblk_t len, ext4_fsblk_t pblk, |
3be78c73 | 692 | unsigned int status) |
654598be | 693 | { |
06b0c886 ZL |
694 | struct extent_status newes; |
695 | ext4_lblk_t end = lblk + len - 1; | |
654598be ZL |
696 | int err = 0; |
697 | ||
3be78c73 | 698 | es_debug("add [%u/%u) %llu %x to extent status tree of inode %lu\n", |
fdc0212e | 699 | lblk, len, pblk, status, inode->i_ino); |
06b0c886 | 700 | |
d4381472 EG |
701 | if (!len) |
702 | return 0; | |
703 | ||
06b0c886 ZL |
704 | BUG_ON(end < lblk); |
705 | ||
d2dc317d LC |
706 | if ((status & EXTENT_STATUS_DELAYED) && |
707 | (status & EXTENT_STATUS_WRITTEN)) { | |
708 | ext4_warning(inode->i_sb, "Inserting extent [%u/%u] as " | |
709 | " delayed and written which can potentially " | |
8d2ae1cb | 710 | " cause data loss.", lblk, len); |
d2dc317d LC |
711 | WARN_ON(1); |
712 | } | |
713 | ||
06b0c886 ZL |
714 | newes.es_lblk = lblk; |
715 | newes.es_len = len; | |
9a6633b1 | 716 | ext4_es_store_pblock_status(&newes, pblk, status); |
fdc0212e | 717 | trace_ext4_es_insert_extent(inode, &newes); |
654598be | 718 | |
921f266b DM |
719 | ext4_es_insert_extent_check(inode, &newes); |
720 | ||
654598be | 721 | write_lock(&EXT4_I(inode)->i_es_lock); |
bdedbb7b | 722 | err = __es_remove_extent(inode, lblk, end); |
06b0c886 ZL |
723 | if (err != 0) |
724 | goto error; | |
e15f742c | 725 | retry: |
bdedbb7b | 726 | err = __es_insert_extent(inode, &newes); |
edaa53ca | 727 | if (err == -ENOMEM && __es_shrink(EXT4_SB(inode->i_sb), |
dd475925 | 728 | 128, EXT4_I(inode))) |
e15f742c TT |
729 | goto retry; |
730 | if (err == -ENOMEM && !ext4_es_is_delayed(&newes)) | |
731 | err = 0; | |
06b0c886 ZL |
732 | |
733 | error: | |
654598be ZL |
734 | write_unlock(&EXT4_I(inode)->i_es_lock); |
735 | ||
736 | ext4_es_print_tree(inode); | |
737 | ||
738 | return err; | |
739 | } | |
740 | ||
107a7bd3 TT |
741 | /* |
742 | * ext4_es_cache_extent() inserts information into the extent status | |
743 | * tree if and only if there isn't information about the range in | |
744 | * question already. | |
745 | */ | |
746 | void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk, | |
747 | ext4_lblk_t len, ext4_fsblk_t pblk, | |
748 | unsigned int status) | |
749 | { | |
750 | struct extent_status *es; | |
751 | struct extent_status newes; | |
752 | ext4_lblk_t end = lblk + len - 1; | |
753 | ||
754 | newes.es_lblk = lblk; | |
755 | newes.es_len = len; | |
9a6633b1 | 756 | ext4_es_store_pblock_status(&newes, pblk, status); |
107a7bd3 TT |
757 | trace_ext4_es_cache_extent(inode, &newes); |
758 | ||
759 | if (!len) | |
760 | return; | |
761 | ||
762 | BUG_ON(end < lblk); | |
763 | ||
764 | write_lock(&EXT4_I(inode)->i_es_lock); | |
765 | ||
766 | es = __es_tree_search(&EXT4_I(inode)->i_es_tree.root, lblk); | |
7869a4a6 TT |
767 | if (!es || es->es_lblk > end) |
768 | __es_insert_extent(inode, &newes); | |
107a7bd3 TT |
769 | write_unlock(&EXT4_I(inode)->i_es_lock); |
770 | } | |
771 | ||
d100eef2 ZL |
772 | /* |
773 | * ext4_es_lookup_extent() looks up an extent in extent status tree. | |
774 | * | |
775 | * ext4_es_lookup_extent is called by ext4_map_blocks/ext4_da_map_blocks. | |
776 | * | |
777 | * Return: 1 on found, 0 on not | |
778 | */ | |
779 | int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk, | |
780 | struct extent_status *es) | |
781 | { | |
782 | struct ext4_es_tree *tree; | |
eb68d0e2 | 783 | struct ext4_es_stats *stats; |
d100eef2 ZL |
784 | struct extent_status *es1 = NULL; |
785 | struct rb_node *node; | |
786 | int found = 0; | |
787 | ||
788 | trace_ext4_es_lookup_extent_enter(inode, lblk); | |
789 | es_debug("lookup extent in block %u\n", lblk); | |
790 | ||
791 | tree = &EXT4_I(inode)->i_es_tree; | |
792 | read_lock(&EXT4_I(inode)->i_es_lock); | |
793 | ||
794 | /* find extent in cache firstly */ | |
795 | es->es_lblk = es->es_len = es->es_pblk = 0; | |
796 | if (tree->cache_es) { | |
797 | es1 = tree->cache_es; | |
798 | if (in_range(lblk, es1->es_lblk, es1->es_len)) { | |
799 | es_debug("%u cached by [%u/%u)\n", | |
800 | lblk, es1->es_lblk, es1->es_len); | |
801 | found = 1; | |
802 | goto out; | |
803 | } | |
804 | } | |
805 | ||
806 | node = tree->root.rb_node; | |
807 | while (node) { | |
808 | es1 = rb_entry(node, struct extent_status, rb_node); | |
809 | if (lblk < es1->es_lblk) | |
810 | node = node->rb_left; | |
811 | else if (lblk > ext4_es_end(es1)) | |
812 | node = node->rb_right; | |
813 | else { | |
814 | found = 1; | |
815 | break; | |
816 | } | |
817 | } | |
818 | ||
819 | out: | |
eb68d0e2 | 820 | stats = &EXT4_SB(inode->i_sb)->s_es_stats; |
d100eef2 ZL |
821 | if (found) { |
822 | BUG_ON(!es1); | |
823 | es->es_lblk = es1->es_lblk; | |
824 | es->es_len = es1->es_len; | |
825 | es->es_pblk = es1->es_pblk; | |
87d8a74b JK |
826 | if (!ext4_es_is_referenced(es1)) |
827 | ext4_es_set_referenced(es1); | |
eb68d0e2 ZL |
828 | stats->es_stats_cache_hits++; |
829 | } else { | |
830 | stats->es_stats_cache_misses++; | |
d100eef2 ZL |
831 | } |
832 | ||
833 | read_unlock(&EXT4_I(inode)->i_es_lock); | |
834 | ||
835 | trace_ext4_es_lookup_extent_exit(inode, es, found); | |
836 | return found; | |
837 | } | |
838 | ||
bdedbb7b ZL |
839 | static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk, |
840 | ext4_lblk_t end) | |
654598be | 841 | { |
bdedbb7b | 842 | struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree; |
654598be | 843 | struct rb_node *node; |
654598be ZL |
844 | struct extent_status *es; |
845 | struct extent_status orig_es; | |
06b0c886 | 846 | ext4_lblk_t len1, len2; |
fdc0212e | 847 | ext4_fsblk_t block; |
e15f742c | 848 | int err; |
654598be | 849 | |
e15f742c TT |
850 | retry: |
851 | err = 0; | |
06b0c886 | 852 | es = __es_tree_search(&tree->root, lblk); |
654598be ZL |
853 | if (!es) |
854 | goto out; | |
06b0c886 | 855 | if (es->es_lblk > end) |
654598be ZL |
856 | goto out; |
857 | ||
858 | /* Simply invalidate cache_es. */ | |
859 | tree->cache_es = NULL; | |
860 | ||
06b0c886 ZL |
861 | orig_es.es_lblk = es->es_lblk; |
862 | orig_es.es_len = es->es_len; | |
fdc0212e ZL |
863 | orig_es.es_pblk = es->es_pblk; |
864 | ||
06b0c886 ZL |
865 | len1 = lblk > es->es_lblk ? lblk - es->es_lblk : 0; |
866 | len2 = ext4_es_end(es) > end ? ext4_es_end(es) - end : 0; | |
654598be | 867 | if (len1 > 0) |
06b0c886 | 868 | es->es_len = len1; |
654598be ZL |
869 | if (len2 > 0) { |
870 | if (len1 > 0) { | |
06b0c886 ZL |
871 | struct extent_status newes; |
872 | ||
873 | newes.es_lblk = end + 1; | |
874 | newes.es_len = len2; | |
666525df | 875 | block = 0x7FDEADBEEFULL; |
fdc0212e | 876 | if (ext4_es_is_written(&orig_es) || |
9a6633b1 | 877 | ext4_es_is_unwritten(&orig_es)) |
fdc0212e ZL |
878 | block = ext4_es_pblock(&orig_es) + |
879 | orig_es.es_len - len2; | |
9a6633b1 TT |
880 | ext4_es_store_pblock_status(&newes, block, |
881 | ext4_es_status(&orig_es)); | |
bdedbb7b | 882 | err = __es_insert_extent(inode, &newes); |
654598be | 883 | if (err) { |
06b0c886 ZL |
884 | es->es_lblk = orig_es.es_lblk; |
885 | es->es_len = orig_es.es_len; | |
e15f742c | 886 | if ((err == -ENOMEM) && |
edaa53ca | 887 | __es_shrink(EXT4_SB(inode->i_sb), |
dd475925 | 888 | 128, EXT4_I(inode))) |
e15f742c | 889 | goto retry; |
654598be ZL |
890 | goto out; |
891 | } | |
892 | } else { | |
06b0c886 ZL |
893 | es->es_lblk = end + 1; |
894 | es->es_len = len2; | |
fdc0212e ZL |
895 | if (ext4_es_is_written(es) || |
896 | ext4_es_is_unwritten(es)) { | |
897 | block = orig_es.es_pblk + orig_es.es_len - len2; | |
898 | ext4_es_store_pblock(es, block); | |
899 | } | |
654598be ZL |
900 | } |
901 | goto out; | |
902 | } | |
903 | ||
904 | if (len1 > 0) { | |
905 | node = rb_next(&es->rb_node); | |
906 | if (node) | |
907 | es = rb_entry(node, struct extent_status, rb_node); | |
908 | else | |
909 | es = NULL; | |
910 | } | |
911 | ||
06b0c886 | 912 | while (es && ext4_es_end(es) <= end) { |
654598be ZL |
913 | node = rb_next(&es->rb_node); |
914 | rb_erase(&es->rb_node, &tree->root); | |
bdedbb7b | 915 | ext4_es_free_extent(inode, es); |
654598be ZL |
916 | if (!node) { |
917 | es = NULL; | |
918 | break; | |
919 | } | |
920 | es = rb_entry(node, struct extent_status, rb_node); | |
921 | } | |
922 | ||
06b0c886 | 923 | if (es && es->es_lblk < end + 1) { |
fdc0212e ZL |
924 | ext4_lblk_t orig_len = es->es_len; |
925 | ||
06b0c886 ZL |
926 | len1 = ext4_es_end(es) - end; |
927 | es->es_lblk = end + 1; | |
928 | es->es_len = len1; | |
fdc0212e ZL |
929 | if (ext4_es_is_written(es) || ext4_es_is_unwritten(es)) { |
930 | block = es->es_pblk + orig_len - len1; | |
931 | ext4_es_store_pblock(es, block); | |
932 | } | |
654598be ZL |
933 | } |
934 | ||
935 | out: | |
06b0c886 ZL |
936 | return err; |
937 | } | |
938 | ||
939 | /* | |
940 | * ext4_es_remove_extent() removes a space from a extent status tree. | |
941 | * | |
942 | * Return 0 on success, error code on failure. | |
943 | */ | |
944 | int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk, | |
945 | ext4_lblk_t len) | |
946 | { | |
06b0c886 ZL |
947 | ext4_lblk_t end; |
948 | int err = 0; | |
949 | ||
950 | trace_ext4_es_remove_extent(inode, lblk, len); | |
951 | es_debug("remove [%u/%u) from extent status tree of inode %lu\n", | |
952 | lblk, len, inode->i_ino); | |
953 | ||
d4381472 EG |
954 | if (!len) |
955 | return err; | |
956 | ||
06b0c886 ZL |
957 | end = lblk + len - 1; |
958 | BUG_ON(end < lblk); | |
959 | ||
edaa53ca ZL |
960 | /* |
961 | * ext4_clear_inode() depends on us taking i_es_lock unconditionally | |
962 | * so that we are sure __es_shrink() is done with the inode before it | |
963 | * is reclaimed. | |
964 | */ | |
06b0c886 | 965 | write_lock(&EXT4_I(inode)->i_es_lock); |
bdedbb7b | 966 | err = __es_remove_extent(inode, lblk, end); |
654598be ZL |
967 | write_unlock(&EXT4_I(inode)->i_es_lock); |
968 | ext4_es_print_tree(inode); | |
969 | return err; | |
970 | } | |
74cd15cd | 971 | |
edaa53ca ZL |
972 | static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan, |
973 | struct ext4_inode_info *locked_ei) | |
74cd15cd | 974 | { |
74cd15cd | 975 | struct ext4_inode_info *ei; |
eb68d0e2 | 976 | struct ext4_es_stats *es_stats; |
eb68d0e2 ZL |
977 | ktime_t start_time; |
978 | u64 scan_time; | |
edaa53ca | 979 | int nr_to_walk; |
1ab6c499 | 980 | int nr_shrunk = 0; |
edaa53ca | 981 | int retried = 0, nr_skipped = 0; |
74cd15cd | 982 | |
eb68d0e2 ZL |
983 | es_stats = &sbi->s_es_stats; |
984 | start_time = ktime_get(); | |
d3922a77 | 985 | |
7869a4a6 | 986 | retry: |
edaa53ca ZL |
987 | spin_lock(&sbi->s_es_lock); |
988 | nr_to_walk = sbi->s_es_nr_inode; | |
989 | while (nr_to_walk-- > 0) { | |
edaa53ca ZL |
990 | if (list_empty(&sbi->s_es_list)) { |
991 | spin_unlock(&sbi->s_es_lock); | |
992 | goto out; | |
993 | } | |
994 | ei = list_first_entry(&sbi->s_es_list, struct ext4_inode_info, | |
995 | i_es_list); | |
996 | /* Move the inode to the tail */ | |
dd475925 | 997 | list_move_tail(&ei->i_es_list, &sbi->s_es_list); |
74cd15cd | 998 | |
7869a4a6 | 999 | /* |
edaa53ca ZL |
1000 | * Normally we try hard to avoid shrinking precached inodes, |
1001 | * but we will as a last resort. | |
7869a4a6 | 1002 | */ |
edaa53ca ZL |
1003 | if (!retried && ext4_test_inode_state(&ei->vfs_inode, |
1004 | EXT4_STATE_EXT_PRECACHED)) { | |
7869a4a6 | 1005 | nr_skipped++; |
74cd15cd ZL |
1006 | continue; |
1007 | } | |
d3922a77 | 1008 | |
edaa53ca ZL |
1009 | if (ei == locked_ei || !write_trylock(&ei->i_es_lock)) { |
1010 | nr_skipped++; | |
d3922a77 | 1011 | continue; |
edaa53ca ZL |
1012 | } |
1013 | /* | |
1014 | * Now we hold i_es_lock which protects us from inode reclaim | |
1015 | * freeing inode under us | |
1016 | */ | |
1017 | spin_unlock(&sbi->s_es_lock); | |
74cd15cd | 1018 | |
dd475925 | 1019 | nr_shrunk += es_reclaim_extents(ei, &nr_to_scan); |
74cd15cd ZL |
1020 | write_unlock(&ei->i_es_lock); |
1021 | ||
dd475925 | 1022 | if (nr_to_scan <= 0) |
edaa53ca ZL |
1023 | goto out; |
1024 | spin_lock(&sbi->s_es_lock); | |
74cd15cd | 1025 | } |
edaa53ca | 1026 | spin_unlock(&sbi->s_es_lock); |
7869a4a6 TT |
1027 | |
1028 | /* | |
1029 | * If we skipped any inodes, and we weren't able to make any | |
edaa53ca | 1030 | * forward progress, try again to scan precached inodes. |
7869a4a6 TT |
1031 | */ |
1032 | if ((nr_shrunk == 0) && nr_skipped && !retried) { | |
1033 | retried++; | |
7869a4a6 TT |
1034 | goto retry; |
1035 | } | |
1036 | ||
e15f742c | 1037 | if (locked_ei && nr_shrunk == 0) |
dd475925 | 1038 | nr_shrunk = es_reclaim_extents(locked_ei, &nr_to_scan); |
e15f742c | 1039 | |
edaa53ca | 1040 | out: |
eb68d0e2 ZL |
1041 | scan_time = ktime_to_ns(ktime_sub(ktime_get(), start_time)); |
1042 | if (likely(es_stats->es_stats_scan_time)) | |
1043 | es_stats->es_stats_scan_time = (scan_time + | |
1044 | es_stats->es_stats_scan_time*3) / 4; | |
1045 | else | |
1046 | es_stats->es_stats_scan_time = scan_time; | |
1047 | if (scan_time > es_stats->es_stats_max_scan_time) | |
1048 | es_stats->es_stats_max_scan_time = scan_time; | |
1049 | if (likely(es_stats->es_stats_shrunk)) | |
1050 | es_stats->es_stats_shrunk = (nr_shrunk + | |
1051 | es_stats->es_stats_shrunk*3) / 4; | |
1052 | else | |
1053 | es_stats->es_stats_shrunk = nr_shrunk; | |
1054 | ||
edaa53ca | 1055 | trace_ext4_es_shrink(sbi->s_sb, nr_shrunk, scan_time, |
eb68d0e2 | 1056 | nr_skipped, retried); |
e15f742c TT |
1057 | return nr_shrunk; |
1058 | } | |
1059 | ||
1ab6c499 DC |
1060 | static unsigned long ext4_es_count(struct shrinker *shrink, |
1061 | struct shrink_control *sc) | |
1062 | { | |
1063 | unsigned long nr; | |
1064 | struct ext4_sb_info *sbi; | |
1065 | ||
1066 | sbi = container_of(shrink, struct ext4_sb_info, s_es_shrinker); | |
edaa53ca | 1067 | nr = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt); |
e963bb1d | 1068 | trace_ext4_es_shrink_count(sbi->s_sb, sc->nr_to_scan, nr); |
1ab6c499 DC |
1069 | return nr; |
1070 | } | |
1071 | ||
1072 | static unsigned long ext4_es_scan(struct shrinker *shrink, | |
1073 | struct shrink_control *sc) | |
e15f742c TT |
1074 | { |
1075 | struct ext4_sb_info *sbi = container_of(shrink, | |
1076 | struct ext4_sb_info, s_es_shrinker); | |
1077 | int nr_to_scan = sc->nr_to_scan; | |
1078 | int ret, nr_shrunk; | |
1079 | ||
edaa53ca | 1080 | ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt); |
e963bb1d | 1081 | trace_ext4_es_shrink_scan_enter(sbi->s_sb, nr_to_scan, ret); |
e15f742c TT |
1082 | |
1083 | if (!nr_to_scan) | |
1084 | return ret; | |
1085 | ||
edaa53ca | 1086 | nr_shrunk = __es_shrink(sbi, nr_to_scan, NULL); |
e15f742c | 1087 | |
e963bb1d | 1088 | trace_ext4_es_shrink_scan_exit(sbi->s_sb, nr_shrunk, ret); |
1ab6c499 | 1089 | return nr_shrunk; |
74cd15cd ZL |
1090 | } |
1091 | ||
ebd173be | 1092 | int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v) |
74cd15cd | 1093 | { |
ebd173be | 1094 | struct ext4_sb_info *sbi = EXT4_SB((struct super_block *) seq->private); |
eb68d0e2 ZL |
1095 | struct ext4_es_stats *es_stats = &sbi->s_es_stats; |
1096 | struct ext4_inode_info *ei, *max = NULL; | |
1097 | unsigned int inode_cnt = 0; | |
1098 | ||
1099 | if (v != SEQ_START_TOKEN) | |
1100 | return 0; | |
1101 | ||
1102 | /* here we just find an inode that has the max nr. of objects */ | |
edaa53ca ZL |
1103 | spin_lock(&sbi->s_es_lock); |
1104 | list_for_each_entry(ei, &sbi->s_es_list, i_es_list) { | |
eb68d0e2 ZL |
1105 | inode_cnt++; |
1106 | if (max && max->i_es_all_nr < ei->i_es_all_nr) | |
1107 | max = ei; | |
1108 | else if (!max) | |
1109 | max = ei; | |
1110 | } | |
edaa53ca | 1111 | spin_unlock(&sbi->s_es_lock); |
eb68d0e2 ZL |
1112 | |
1113 | seq_printf(seq, "stats:\n %lld objects\n %lld reclaimable objects\n", | |
1114 | percpu_counter_sum_positive(&es_stats->es_stats_all_cnt), | |
edaa53ca | 1115 | percpu_counter_sum_positive(&es_stats->es_stats_shk_cnt)); |
eb68d0e2 ZL |
1116 | seq_printf(seq, " %lu/%lu cache hits/misses\n", |
1117 | es_stats->es_stats_cache_hits, | |
1118 | es_stats->es_stats_cache_misses); | |
eb68d0e2 | 1119 | if (inode_cnt) |
edaa53ca | 1120 | seq_printf(seq, " %d inodes on list\n", inode_cnt); |
eb68d0e2 ZL |
1121 | |
1122 | seq_printf(seq, "average:\n %llu us scan time\n", | |
1123 | div_u64(es_stats->es_stats_scan_time, 1000)); | |
1124 | seq_printf(seq, " %lu shrunk objects\n", es_stats->es_stats_shrunk); | |
1125 | if (inode_cnt) | |
1126 | seq_printf(seq, | |
1127 | "maximum:\n %lu inode (%u objects, %u reclaimable)\n" | |
1128 | " %llu us max scan time\n", | |
edaa53ca | 1129 | max->vfs_inode.i_ino, max->i_es_all_nr, max->i_es_shk_nr, |
eb68d0e2 ZL |
1130 | div_u64(es_stats->es_stats_max_scan_time, 1000)); |
1131 | ||
1132 | return 0; | |
1133 | } | |
1134 | ||
eb68d0e2 | 1135 | int ext4_es_register_shrinker(struct ext4_sb_info *sbi) |
74cd15cd | 1136 | { |
eb68d0e2 ZL |
1137 | int err; |
1138 | ||
624d0f1d JK |
1139 | /* Make sure we have enough bits for physical block number */ |
1140 | BUILD_BUG_ON(ES_SHIFT < 48); | |
edaa53ca ZL |
1141 | INIT_LIST_HEAD(&sbi->s_es_list); |
1142 | sbi->s_es_nr_inode = 0; | |
1143 | spin_lock_init(&sbi->s_es_lock); | |
eb68d0e2 ZL |
1144 | sbi->s_es_stats.es_stats_shrunk = 0; |
1145 | sbi->s_es_stats.es_stats_cache_hits = 0; | |
1146 | sbi->s_es_stats.es_stats_cache_misses = 0; | |
1147 | sbi->s_es_stats.es_stats_scan_time = 0; | |
1148 | sbi->s_es_stats.es_stats_max_scan_time = 0; | |
c2661b80 | 1149 | err = percpu_counter_init(&sbi->s_es_stats.es_stats_all_cnt, 0, GFP_KERNEL); |
eb68d0e2 ZL |
1150 | if (err) |
1151 | return err; | |
edaa53ca | 1152 | err = percpu_counter_init(&sbi->s_es_stats.es_stats_shk_cnt, 0, GFP_KERNEL); |
eb68d0e2 ZL |
1153 | if (err) |
1154 | goto err1; | |
1155 | ||
1ab6c499 DC |
1156 | sbi->s_es_shrinker.scan_objects = ext4_es_scan; |
1157 | sbi->s_es_shrinker.count_objects = ext4_es_count; | |
74cd15cd | 1158 | sbi->s_es_shrinker.seeks = DEFAULT_SEEKS; |
eb68d0e2 ZL |
1159 | err = register_shrinker(&sbi->s_es_shrinker); |
1160 | if (err) | |
1161 | goto err2; | |
1162 | ||
eb68d0e2 ZL |
1163 | return 0; |
1164 | ||
1165 | err2: | |
edaa53ca | 1166 | percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt); |
eb68d0e2 ZL |
1167 | err1: |
1168 | percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt); | |
1169 | return err; | |
74cd15cd ZL |
1170 | } |
1171 | ||
d3922a77 | 1172 | void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi) |
74cd15cd | 1173 | { |
eb68d0e2 | 1174 | percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt); |
edaa53ca | 1175 | percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt); |
d3922a77 | 1176 | unregister_shrinker(&sbi->s_es_shrinker); |
74cd15cd ZL |
1177 | } |
1178 | ||
dd475925 JK |
1179 | /* |
1180 | * Shrink extents in given inode from ei->i_es_shrink_lblk till end. Scan at | |
1181 | * most *nr_to_scan extents, update *nr_to_scan accordingly. | |
1182 | * | |
1183 | * Return 0 if we hit end of tree / interval, 1 if we exhausted nr_to_scan. | |
1184 | * Increment *nr_shrunk by the number of reclaimed extents. Also update | |
1185 | * ei->i_es_shrink_lblk to where we should continue scanning. | |
1186 | */ | |
1187 | static int es_do_reclaim_extents(struct ext4_inode_info *ei, ext4_lblk_t end, | |
1188 | int *nr_to_scan, int *nr_shrunk) | |
74cd15cd ZL |
1189 | { |
1190 | struct inode *inode = &ei->vfs_inode; | |
1191 | struct ext4_es_tree *tree = &ei->i_es_tree; | |
74cd15cd | 1192 | struct extent_status *es; |
dd475925 | 1193 | struct rb_node *node; |
74cd15cd | 1194 | |
dd475925 JK |
1195 | es = __es_tree_search(&tree->root, ei->i_es_shrink_lblk); |
1196 | if (!es) | |
1197 | goto out_wrap; | |
1198 | node = &es->rb_node; | |
1199 | while (*nr_to_scan > 0) { | |
1200 | if (es->es_lblk > end) { | |
1201 | ei->i_es_shrink_lblk = end + 1; | |
1202 | return 0; | |
1203 | } | |
7869a4a6 | 1204 | |
dd475925 | 1205 | (*nr_to_scan)--; |
74cd15cd ZL |
1206 | node = rb_next(&es->rb_node); |
1207 | /* | |
1208 | * We can't reclaim delayed extent from status tree because | |
1209 | * fiemap, bigallic, and seek_data/hole need to use it. | |
1210 | */ | |
2be12de9 JK |
1211 | if (ext4_es_is_delayed(es)) |
1212 | goto next; | |
1213 | if (ext4_es_is_referenced(es)) { | |
1214 | ext4_es_clear_referenced(es); | |
1215 | goto next; | |
74cd15cd | 1216 | } |
2be12de9 JK |
1217 | |
1218 | rb_erase(&es->rb_node, &tree->root); | |
1219 | ext4_es_free_extent(inode, es); | |
1220 | (*nr_shrunk)++; | |
1221 | next: | |
dd475925 JK |
1222 | if (!node) |
1223 | goto out_wrap; | |
1224 | es = rb_entry(node, struct extent_status, rb_node); | |
74cd15cd | 1225 | } |
dd475925 JK |
1226 | ei->i_es_shrink_lblk = es->es_lblk; |
1227 | return 1; | |
1228 | out_wrap: | |
1229 | ei->i_es_shrink_lblk = 0; | |
1230 | return 0; | |
1231 | } | |
1232 | ||
1233 | static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan) | |
1234 | { | |
1235 | struct inode *inode = &ei->vfs_inode; | |
1236 | int nr_shrunk = 0; | |
1237 | ext4_lblk_t start = ei->i_es_shrink_lblk; | |
1238 | static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, | |
1239 | DEFAULT_RATELIMIT_BURST); | |
1240 | ||
1241 | if (ei->i_es_shk_nr == 0) | |
1242 | return 0; | |
1243 | ||
1244 | if (ext4_test_inode_state(inode, EXT4_STATE_EXT_PRECACHED) && | |
1245 | __ratelimit(&_rs)) | |
1246 | ext4_warning(inode->i_sb, "forced shrink of precached extents"); | |
1247 | ||
1248 | if (!es_do_reclaim_extents(ei, EXT_MAX_BLOCKS, nr_to_scan, &nr_shrunk) && | |
1249 | start != 0) | |
1250 | es_do_reclaim_extents(ei, start - 1, nr_to_scan, &nr_shrunk); | |
1251 | ||
1252 | ei->i_es_tree.cache_es = NULL; | |
74cd15cd ZL |
1253 | return nr_shrunk; |
1254 | } |