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1#include <linux/err.h>
2#include <linux/slab.h>
3#include <linux/module.h>
4#include <linux/spinlock.h>
5#include <linux/hardirq.h>
6#include "ctree.h"
7#include "extent_map.h"
8
9
10static struct kmem_cache *extent_map_cache;
11
12int __init extent_map_init(void)
13{
14 extent_map_cache = kmem_cache_create("extent_map",
15 sizeof(struct extent_map), 0,
16 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
17 if (!extent_map_cache)
18 return -ENOMEM;
19 return 0;
20}
21
22void extent_map_exit(void)
23{
24 if (extent_map_cache)
25 kmem_cache_destroy(extent_map_cache);
26}
27
28/**
29 * extent_map_tree_init - initialize extent map tree
30 * @tree: tree to initialize
31 *
32 * Initialize the extent tree @tree. Should be called for each new inode
33 * or other user of the extent_map interface.
34 */
35void extent_map_tree_init(struct extent_map_tree *tree)
36{
37 tree->map = RB_ROOT;
38 rwlock_init(&tree->lock);
39}
40
41/**
42 * alloc_extent_map - allocate new extent map structure
43 *
44 * Allocate a new extent_map structure. The new structure is
45 * returned with a reference count of one and needs to be
46 * freed using free_extent_map()
47 */
48struct extent_map *alloc_extent_map(void)
49{
50 struct extent_map *em;
51 em = kmem_cache_alloc(extent_map_cache, GFP_NOFS);
52 if (!em)
53 return NULL;
54 em->in_tree = 0;
55 em->flags = 0;
56 em->compress_type = BTRFS_COMPRESS_NONE;
57 atomic_set(&em->refs, 1);
58 return em;
59}
60
61/**
62 * free_extent_map - drop reference count of an extent_map
63 * @em: extent map beeing releasead
64 *
65 * Drops the reference out on @em by one and free the structure
66 * if the reference count hits zero.
67 */
68void free_extent_map(struct extent_map *em)
69{
70 if (!em)
71 return;
72 WARN_ON(atomic_read(&em->refs) == 0);
73 if (atomic_dec_and_test(&em->refs)) {
74 WARN_ON(em->in_tree);
75 kmem_cache_free(extent_map_cache, em);
76 }
77}
78
79static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
80 struct rb_node *node)
81{
82 struct rb_node **p = &root->rb_node;
83 struct rb_node *parent = NULL;
84 struct extent_map *entry;
85
86 while (*p) {
87 parent = *p;
88 entry = rb_entry(parent, struct extent_map, rb_node);
89
90 WARN_ON(!entry->in_tree);
91
92 if (offset < entry->start)
93 p = &(*p)->rb_left;
94 else if (offset >= extent_map_end(entry))
95 p = &(*p)->rb_right;
96 else
97 return parent;
98 }
99
100 entry = rb_entry(node, struct extent_map, rb_node);
101 entry->in_tree = 1;
102 rb_link_node(node, parent, p);
103 rb_insert_color(node, root);
104 return NULL;
105}
106
107/*
108 * search through the tree for an extent_map with a given offset. If
109 * it can't be found, try to find some neighboring extents
110 */
111static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
112 struct rb_node **prev_ret,
113 struct rb_node **next_ret)
114{
115 struct rb_node *n = root->rb_node;
116 struct rb_node *prev = NULL;
117 struct rb_node *orig_prev = NULL;
118 struct extent_map *entry;
119 struct extent_map *prev_entry = NULL;
120
121 while (n) {
122 entry = rb_entry(n, struct extent_map, rb_node);
123 prev = n;
124 prev_entry = entry;
125
126 WARN_ON(!entry->in_tree);
127
128 if (offset < entry->start)
129 n = n->rb_left;
130 else if (offset >= extent_map_end(entry))
131 n = n->rb_right;
132 else
133 return n;
134 }
135
136 if (prev_ret) {
137 orig_prev = prev;
138 while (prev && offset >= extent_map_end(prev_entry)) {
139 prev = rb_next(prev);
140 prev_entry = rb_entry(prev, struct extent_map, rb_node);
141 }
142 *prev_ret = prev;
143 prev = orig_prev;
144 }
145
146 if (next_ret) {
147 prev_entry = rb_entry(prev, struct extent_map, rb_node);
148 while (prev && offset < prev_entry->start) {
149 prev = rb_prev(prev);
150 prev_entry = rb_entry(prev, struct extent_map, rb_node);
151 }
152 *next_ret = prev;
153 }
154 return NULL;
155}
156
157/* check to see if two extent_map structs are adjacent and safe to merge */
158static int mergable_maps(struct extent_map *prev, struct extent_map *next)
159{
160 if (test_bit(EXTENT_FLAG_PINNED, &prev->flags))
161 return 0;
162
163 /*
164 * don't merge compressed extents, we need to know their
165 * actual size
166 */
167 if (test_bit(EXTENT_FLAG_COMPRESSED, &prev->flags))
168 return 0;
169
170 if (extent_map_end(prev) == next->start &&
171 prev->flags == next->flags &&
172 prev->bdev == next->bdev &&
173 ((next->block_start == EXTENT_MAP_HOLE &&
174 prev->block_start == EXTENT_MAP_HOLE) ||
175 (next->block_start == EXTENT_MAP_INLINE &&
176 prev->block_start == EXTENT_MAP_INLINE) ||
177 (next->block_start == EXTENT_MAP_DELALLOC &&
178 prev->block_start == EXTENT_MAP_DELALLOC) ||
179 (next->block_start < EXTENT_MAP_LAST_BYTE - 1 &&
180 next->block_start == extent_map_block_end(prev)))) {
181 return 1;
182 }
183 return 0;
184}
185
186static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
187{
188 struct extent_map *merge = NULL;
189 struct rb_node *rb;
190
191 if (em->start != 0) {
192 rb = rb_prev(&em->rb_node);
193 if (rb)
194 merge = rb_entry(rb, struct extent_map, rb_node);
195 if (rb && mergable_maps(merge, em)) {
196 em->start = merge->start;
197 em->len += merge->len;
198 em->block_len += merge->block_len;
199 em->block_start = merge->block_start;
200 merge->in_tree = 0;
201 rb_erase(&merge->rb_node, &tree->map);
202 free_extent_map(merge);
203 }
204 }
205
206 rb = rb_next(&em->rb_node);
207 if (rb)
208 merge = rb_entry(rb, struct extent_map, rb_node);
209 if (rb && mergable_maps(em, merge)) {
210 em->len += merge->len;
211 em->block_len += merge->len;
212 rb_erase(&merge->rb_node, &tree->map);
213 merge->in_tree = 0;
214 free_extent_map(merge);
215 }
216}
217
218int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len)
219{
220 int ret = 0;
221 struct extent_map *em;
222
223 write_lock(&tree->lock);
224 em = lookup_extent_mapping(tree, start, len);
225
226 WARN_ON(!em || em->start != start);
227
228 if (!em)
229 goto out;
230
231 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
232
233 try_merge_map(tree, em);
234
235 free_extent_map(em);
236out:
237 write_unlock(&tree->lock);
238 return ret;
239
240}
241
242/**
243 * add_extent_mapping - add new extent map to the extent tree
244 * @tree: tree to insert new map in
245 * @em: map to insert
246 *
247 * Insert @em into @tree or perform a simple forward/backward merge with
248 * existing mappings. The extent_map struct passed in will be inserted
249 * into the tree directly, with an additional reference taken, or a
250 * reference dropped if the merge attempt was successful.
251 */
252int add_extent_mapping(struct extent_map_tree *tree,
253 struct extent_map *em)
254{
255 int ret = 0;
256 struct rb_node *rb;
257 struct extent_map *exist;
258
259 exist = lookup_extent_mapping(tree, em->start, em->len);
260 if (exist) {
261 free_extent_map(exist);
262 ret = -EEXIST;
263 goto out;
264 }
265 rb = tree_insert(&tree->map, em->start, &em->rb_node);
266 if (rb) {
267 ret = -EEXIST;
268 goto out;
269 }
270 atomic_inc(&em->refs);
271
272 try_merge_map(tree, em);
273out:
274 return ret;
275}
276
277/* simple helper to do math around the end of an extent, handling wrap */
278static u64 range_end(u64 start, u64 len)
279{
280 if (start + len < start)
281 return (u64)-1;
282 return start + len;
283}
284
285struct extent_map *__lookup_extent_mapping(struct extent_map_tree *tree,
286 u64 start, u64 len, int strict)
287{
288 struct extent_map *em;
289 struct rb_node *rb_node;
290 struct rb_node *prev = NULL;
291 struct rb_node *next = NULL;
292 u64 end = range_end(start, len);
293
294 rb_node = __tree_search(&tree->map, start, &prev, &next);
295 if (!rb_node) {
296 if (prev)
297 rb_node = prev;
298 else if (next)
299 rb_node = next;
300 else
301 return NULL;
302 }
303
304 em = rb_entry(rb_node, struct extent_map, rb_node);
305
306 if (strict && !(end > em->start && start < extent_map_end(em)))
307 return NULL;
308
309 atomic_inc(&em->refs);
310 return em;
311}
312
313/**
314 * lookup_extent_mapping - lookup extent_map
315 * @tree: tree to lookup in
316 * @start: byte offset to start the search
317 * @len: length of the lookup range
318 *
319 * Find and return the first extent_map struct in @tree that intersects the
320 * [start, len] range. There may be additional objects in the tree that
321 * intersect, so check the object returned carefully to make sure that no
322 * additional lookups are needed.
323 */
324struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
325 u64 start, u64 len)
326{
327 return __lookup_extent_mapping(tree, start, len, 1);
328}
329
330/**
331 * search_extent_mapping - find a nearby extent map
332 * @tree: tree to lookup in
333 * @start: byte offset to start the search
334 * @len: length of the lookup range
335 *
336 * Find and return the first extent_map struct in @tree that intersects the
337 * [start, len] range.
338 *
339 * If one can't be found, any nearby extent may be returned
340 */
341struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
342 u64 start, u64 len)
343{
344 return __lookup_extent_mapping(tree, start, len, 0);
345}
346
347/**
348 * remove_extent_mapping - removes an extent_map from the extent tree
349 * @tree: extent tree to remove from
350 * @em: extent map beeing removed
351 *
352 * Removes @em from @tree. No reference counts are dropped, and no checks
353 * are done to see if the range is in use
354 */
355int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
356{
357 int ret = 0;
358
359 WARN_ON(test_bit(EXTENT_FLAG_PINNED, &em->flags));
360 rb_erase(&em->rb_node, &tree->map);
361 em->in_tree = 0;
362 return ret;
363}
1#include <linux/err.h>
2#include <linux/slab.h>
3#include <linux/spinlock.h>
4#include <linux/hardirq.h>
5#include "ctree.h"
6#include "extent_map.h"
7
8
9static struct kmem_cache *extent_map_cache;
10
11int __init extent_map_init(void)
12{
13 extent_map_cache = kmem_cache_create("btrfs_extent_map",
14 sizeof(struct extent_map), 0,
15 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
16 if (!extent_map_cache)
17 return -ENOMEM;
18 return 0;
19}
20
21void extent_map_exit(void)
22{
23 if (extent_map_cache)
24 kmem_cache_destroy(extent_map_cache);
25}
26
27/**
28 * extent_map_tree_init - initialize extent map tree
29 * @tree: tree to initialize
30 *
31 * Initialize the extent tree @tree. Should be called for each new inode
32 * or other user of the extent_map interface.
33 */
34void extent_map_tree_init(struct extent_map_tree *tree)
35{
36 tree->map = RB_ROOT;
37 INIT_LIST_HEAD(&tree->modified_extents);
38 rwlock_init(&tree->lock);
39}
40
41/**
42 * alloc_extent_map - allocate new extent map structure
43 *
44 * Allocate a new extent_map structure. The new structure is
45 * returned with a reference count of one and needs to be
46 * freed using free_extent_map()
47 */
48struct extent_map *alloc_extent_map(void)
49{
50 struct extent_map *em;
51 em = kmem_cache_zalloc(extent_map_cache, GFP_NOFS);
52 if (!em)
53 return NULL;
54 RB_CLEAR_NODE(&em->rb_node);
55 em->flags = 0;
56 em->compress_type = BTRFS_COMPRESS_NONE;
57 em->generation = 0;
58 atomic_set(&em->refs, 1);
59 INIT_LIST_HEAD(&em->list);
60 return em;
61}
62
63/**
64 * free_extent_map - drop reference count of an extent_map
65 * @em: extent map beeing releasead
66 *
67 * Drops the reference out on @em by one and free the structure
68 * if the reference count hits zero.
69 */
70void free_extent_map(struct extent_map *em)
71{
72 if (!em)
73 return;
74 WARN_ON(atomic_read(&em->refs) == 0);
75 if (atomic_dec_and_test(&em->refs)) {
76 WARN_ON(extent_map_in_tree(em));
77 WARN_ON(!list_empty(&em->list));
78 kmem_cache_free(extent_map_cache, em);
79 }
80}
81
82/* simple helper to do math around the end of an extent, handling wrap */
83static u64 range_end(u64 start, u64 len)
84{
85 if (start + len < start)
86 return (u64)-1;
87 return start + len;
88}
89
90static int tree_insert(struct rb_root *root, struct extent_map *em)
91{
92 struct rb_node **p = &root->rb_node;
93 struct rb_node *parent = NULL;
94 struct extent_map *entry = NULL;
95 struct rb_node *orig_parent = NULL;
96 u64 end = range_end(em->start, em->len);
97
98 while (*p) {
99 parent = *p;
100 entry = rb_entry(parent, struct extent_map, rb_node);
101
102 if (em->start < entry->start)
103 p = &(*p)->rb_left;
104 else if (em->start >= extent_map_end(entry))
105 p = &(*p)->rb_right;
106 else
107 return -EEXIST;
108 }
109
110 orig_parent = parent;
111 while (parent && em->start >= extent_map_end(entry)) {
112 parent = rb_next(parent);
113 entry = rb_entry(parent, struct extent_map, rb_node);
114 }
115 if (parent)
116 if (end > entry->start && em->start < extent_map_end(entry))
117 return -EEXIST;
118
119 parent = orig_parent;
120 entry = rb_entry(parent, struct extent_map, rb_node);
121 while (parent && em->start < entry->start) {
122 parent = rb_prev(parent);
123 entry = rb_entry(parent, struct extent_map, rb_node);
124 }
125 if (parent)
126 if (end > entry->start && em->start < extent_map_end(entry))
127 return -EEXIST;
128
129 rb_link_node(&em->rb_node, orig_parent, p);
130 rb_insert_color(&em->rb_node, root);
131 return 0;
132}
133
134/*
135 * search through the tree for an extent_map with a given offset. If
136 * it can't be found, try to find some neighboring extents
137 */
138static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
139 struct rb_node **prev_ret,
140 struct rb_node **next_ret)
141{
142 struct rb_node *n = root->rb_node;
143 struct rb_node *prev = NULL;
144 struct rb_node *orig_prev = NULL;
145 struct extent_map *entry;
146 struct extent_map *prev_entry = NULL;
147
148 while (n) {
149 entry = rb_entry(n, struct extent_map, rb_node);
150 prev = n;
151 prev_entry = entry;
152
153 if (offset < entry->start)
154 n = n->rb_left;
155 else if (offset >= extent_map_end(entry))
156 n = n->rb_right;
157 else
158 return n;
159 }
160
161 if (prev_ret) {
162 orig_prev = prev;
163 while (prev && offset >= extent_map_end(prev_entry)) {
164 prev = rb_next(prev);
165 prev_entry = rb_entry(prev, struct extent_map, rb_node);
166 }
167 *prev_ret = prev;
168 prev = orig_prev;
169 }
170
171 if (next_ret) {
172 prev_entry = rb_entry(prev, struct extent_map, rb_node);
173 while (prev && offset < prev_entry->start) {
174 prev = rb_prev(prev);
175 prev_entry = rb_entry(prev, struct extent_map, rb_node);
176 }
177 *next_ret = prev;
178 }
179 return NULL;
180}
181
182/* check to see if two extent_map structs are adjacent and safe to merge */
183static int mergable_maps(struct extent_map *prev, struct extent_map *next)
184{
185 if (test_bit(EXTENT_FLAG_PINNED, &prev->flags))
186 return 0;
187
188 /*
189 * don't merge compressed extents, we need to know their
190 * actual size
191 */
192 if (test_bit(EXTENT_FLAG_COMPRESSED, &prev->flags))
193 return 0;
194
195 if (test_bit(EXTENT_FLAG_LOGGING, &prev->flags) ||
196 test_bit(EXTENT_FLAG_LOGGING, &next->flags))
197 return 0;
198
199 /*
200 * We don't want to merge stuff that hasn't been written to the log yet
201 * since it may not reflect exactly what is on disk, and that would be
202 * bad.
203 */
204 if (!list_empty(&prev->list) || !list_empty(&next->list))
205 return 0;
206
207 if (extent_map_end(prev) == next->start &&
208 prev->flags == next->flags &&
209 prev->bdev == next->bdev &&
210 ((next->block_start == EXTENT_MAP_HOLE &&
211 prev->block_start == EXTENT_MAP_HOLE) ||
212 (next->block_start == EXTENT_MAP_INLINE &&
213 prev->block_start == EXTENT_MAP_INLINE) ||
214 (next->block_start == EXTENT_MAP_DELALLOC &&
215 prev->block_start == EXTENT_MAP_DELALLOC) ||
216 (next->block_start < EXTENT_MAP_LAST_BYTE - 1 &&
217 next->block_start == extent_map_block_end(prev)))) {
218 return 1;
219 }
220 return 0;
221}
222
223static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
224{
225 struct extent_map *merge = NULL;
226 struct rb_node *rb;
227
228 if (em->start != 0) {
229 rb = rb_prev(&em->rb_node);
230 if (rb)
231 merge = rb_entry(rb, struct extent_map, rb_node);
232 if (rb && mergable_maps(merge, em)) {
233 em->start = merge->start;
234 em->orig_start = merge->orig_start;
235 em->len += merge->len;
236 em->block_len += merge->block_len;
237 em->block_start = merge->block_start;
238 em->mod_len = (em->mod_len + em->mod_start) - merge->mod_start;
239 em->mod_start = merge->mod_start;
240 em->generation = max(em->generation, merge->generation);
241
242 rb_erase(&merge->rb_node, &tree->map);
243 RB_CLEAR_NODE(&merge->rb_node);
244 free_extent_map(merge);
245 }
246 }
247
248 rb = rb_next(&em->rb_node);
249 if (rb)
250 merge = rb_entry(rb, struct extent_map, rb_node);
251 if (rb && mergable_maps(em, merge)) {
252 em->len += merge->len;
253 em->block_len += merge->block_len;
254 rb_erase(&merge->rb_node, &tree->map);
255 RB_CLEAR_NODE(&merge->rb_node);
256 em->mod_len = (merge->mod_start + merge->mod_len) - em->mod_start;
257 em->generation = max(em->generation, merge->generation);
258 free_extent_map(merge);
259 }
260}
261
262/**
263 * unpin_extent_cache - unpin an extent from the cache
264 * @tree: tree to unpin the extent in
265 * @start: logical offset in the file
266 * @len: length of the extent
267 * @gen: generation that this extent has been modified in
268 *
269 * Called after an extent has been written to disk properly. Set the generation
270 * to the generation that actually added the file item to the inode so we know
271 * we need to sync this extent when we call fsync().
272 */
273int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len,
274 u64 gen)
275{
276 int ret = 0;
277 struct extent_map *em;
278 bool prealloc = false;
279
280 write_lock(&tree->lock);
281 em = lookup_extent_mapping(tree, start, len);
282
283 WARN_ON(!em || em->start != start);
284
285 if (!em)
286 goto out;
287
288 if (!test_bit(EXTENT_FLAG_LOGGING, &em->flags))
289 list_move(&em->list, &tree->modified_extents);
290 em->generation = gen;
291 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
292 em->mod_start = em->start;
293 em->mod_len = em->len;
294
295 if (test_bit(EXTENT_FLAG_FILLING, &em->flags)) {
296 prealloc = true;
297 clear_bit(EXTENT_FLAG_FILLING, &em->flags);
298 }
299
300 try_merge_map(tree, em);
301
302 if (prealloc) {
303 em->mod_start = em->start;
304 em->mod_len = em->len;
305 }
306
307 free_extent_map(em);
308out:
309 write_unlock(&tree->lock);
310 return ret;
311
312}
313
314void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em)
315{
316 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
317 if (extent_map_in_tree(em))
318 try_merge_map(tree, em);
319}
320
321static inline void setup_extent_mapping(struct extent_map_tree *tree,
322 struct extent_map *em,
323 int modified)
324{
325 atomic_inc(&em->refs);
326 em->mod_start = em->start;
327 em->mod_len = em->len;
328
329 if (modified)
330 list_move(&em->list, &tree->modified_extents);
331 else
332 try_merge_map(tree, em);
333}
334
335/**
336 * add_extent_mapping - add new extent map to the extent tree
337 * @tree: tree to insert new map in
338 * @em: map to insert
339 *
340 * Insert @em into @tree or perform a simple forward/backward merge with
341 * existing mappings. The extent_map struct passed in will be inserted
342 * into the tree directly, with an additional reference taken, or a
343 * reference dropped if the merge attempt was successful.
344 */
345int add_extent_mapping(struct extent_map_tree *tree,
346 struct extent_map *em, int modified)
347{
348 int ret = 0;
349
350 ret = tree_insert(&tree->map, em);
351 if (ret)
352 goto out;
353
354 setup_extent_mapping(tree, em, modified);
355out:
356 return ret;
357}
358
359static struct extent_map *
360__lookup_extent_mapping(struct extent_map_tree *tree,
361 u64 start, u64 len, int strict)
362{
363 struct extent_map *em;
364 struct rb_node *rb_node;
365 struct rb_node *prev = NULL;
366 struct rb_node *next = NULL;
367 u64 end = range_end(start, len);
368
369 rb_node = __tree_search(&tree->map, start, &prev, &next);
370 if (!rb_node) {
371 if (prev)
372 rb_node = prev;
373 else if (next)
374 rb_node = next;
375 else
376 return NULL;
377 }
378
379 em = rb_entry(rb_node, struct extent_map, rb_node);
380
381 if (strict && !(end > em->start && start < extent_map_end(em)))
382 return NULL;
383
384 atomic_inc(&em->refs);
385 return em;
386}
387
388/**
389 * lookup_extent_mapping - lookup extent_map
390 * @tree: tree to lookup in
391 * @start: byte offset to start the search
392 * @len: length of the lookup range
393 *
394 * Find and return the first extent_map struct in @tree that intersects the
395 * [start, len] range. There may be additional objects in the tree that
396 * intersect, so check the object returned carefully to make sure that no
397 * additional lookups are needed.
398 */
399struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
400 u64 start, u64 len)
401{
402 return __lookup_extent_mapping(tree, start, len, 1);
403}
404
405/**
406 * search_extent_mapping - find a nearby extent map
407 * @tree: tree to lookup in
408 * @start: byte offset to start the search
409 * @len: length of the lookup range
410 *
411 * Find and return the first extent_map struct in @tree that intersects the
412 * [start, len] range.
413 *
414 * If one can't be found, any nearby extent may be returned
415 */
416struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
417 u64 start, u64 len)
418{
419 return __lookup_extent_mapping(tree, start, len, 0);
420}
421
422/**
423 * remove_extent_mapping - removes an extent_map from the extent tree
424 * @tree: extent tree to remove from
425 * @em: extent map beeing removed
426 *
427 * Removes @em from @tree. No reference counts are dropped, and no checks
428 * are done to see if the range is in use
429 */
430int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
431{
432 int ret = 0;
433
434 WARN_ON(test_bit(EXTENT_FLAG_PINNED, &em->flags));
435 rb_erase(&em->rb_node, &tree->map);
436 if (!test_bit(EXTENT_FLAG_LOGGING, &em->flags))
437 list_del_init(&em->list);
438 RB_CLEAR_NODE(&em->rb_node);
439 return ret;
440}
441
442void replace_extent_mapping(struct extent_map_tree *tree,
443 struct extent_map *cur,
444 struct extent_map *new,
445 int modified)
446{
447 WARN_ON(test_bit(EXTENT_FLAG_PINNED, &cur->flags));
448 ASSERT(extent_map_in_tree(cur));
449 if (!test_bit(EXTENT_FLAG_LOGGING, &cur->flags))
450 list_del_init(&cur->list);
451 rb_replace_node(&cur->rb_node, &new->rb_node, &tree->map);
452 RB_CLEAR_NODE(&cur->rb_node);
453
454 setup_extent_mapping(tree, new, modified);
455}