1 /*
2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
3 *
4 * Copyright (C) 2002-2011 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
6 *
7 * Created by Charles Manning <charles@aleph1.co.uk>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14 #include "yaffs_allocator.h"
15 #include "yaffs_guts.h"
16 #include "yaffs_trace.h"
17 #include "yportenv.h"
18
19 /*
20 * Each entry in yaffs_tnode_list and yaffs_obj_list hold blocks
21 * of approx 100 objects that are themn allocated singly.
22 * This is basically a simplified slab allocator.
23 *
24 * We don't use the Linux slab allocator because slab does not allow
25 * us to dump all the objects in one hit when we do a umount and tear
26 * down all the tnodes and objects. slab requires that we first free
27 * the individual objects.
28 *
29 * Once yaffs has been mainlined I shall try to motivate for a change
30 * to slab to provide the extra features we need here.
31 */
32
33 struct yaffs_tnode_list {
34 struct yaffs_tnode_list *next;
35 struct yaffs_tnode *tnodes;
36 };
37
38 struct yaffs_obj_list {
39 struct yaffs_obj_list *next;
40 struct yaffs_obj *objects;
41 };
42
43 struct yaffs_allocator {
44 int n_tnodes_created;
45 struct yaffs_tnode *free_tnodes;
46 int n_free_tnodes;
47 struct yaffs_tnode_list *alloc_tnode_list;
48
49 int n_obj_created;
50 struct list_head free_objs;
51 int n_free_objects;
52
53 struct yaffs_obj_list *allocated_obj_list;
54 };
55
yaffs_deinit_raw_tnodes(struct yaffs_dev * dev)56 static void yaffs_deinit_raw_tnodes(struct yaffs_dev *dev)
57 {
58 struct yaffs_allocator *allocator =
59 (struct yaffs_allocator *)dev->allocator;
60 struct yaffs_tnode_list *tmp;
61
62 if (!allocator) {
63 BUG();
64 return;
65 }
66
67 while (allocator->alloc_tnode_list) {
68 tmp = allocator->alloc_tnode_list->next;
69
70 kfree(allocator->alloc_tnode_list->tnodes);
71 kfree(allocator->alloc_tnode_list);
72 allocator->alloc_tnode_list = tmp;
73 }
74
75 allocator->free_tnodes = NULL;
76 allocator->n_free_tnodes = 0;
77 allocator->n_tnodes_created = 0;
78 }
79
yaffs_init_raw_tnodes(struct yaffs_dev * dev)80 static void yaffs_init_raw_tnodes(struct yaffs_dev *dev)
81 {
82 struct yaffs_allocator *allocator = dev->allocator;
83
84 if (!allocator) {
85 BUG();
86 return;
87 }
88
89 allocator->alloc_tnode_list = NULL;
90 allocator->free_tnodes = NULL;
91 allocator->n_free_tnodes = 0;
92 allocator->n_tnodes_created = 0;
93 }
94
yaffs_create_tnodes(struct yaffs_dev * dev,int n_tnodes)95 static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
96 {
97 struct yaffs_allocator *allocator =
98 (struct yaffs_allocator *)dev->allocator;
99 int i;
100 struct yaffs_tnode *new_tnodes;
101 u8 *mem;
102 struct yaffs_tnode *curr;
103 struct yaffs_tnode *next;
104 struct yaffs_tnode_list *tnl;
105
106 if (!allocator) {
107 BUG();
108 return YAFFS_FAIL;
109 }
110
111 if (n_tnodes < 1)
112 return YAFFS_OK;
113
114 /* make these things */
115 new_tnodes = kmalloc(n_tnodes * dev->tnode_size, GFP_NOFS);
116 mem = (u8 *) new_tnodes;
117
118 if (!new_tnodes) {
119 yaffs_trace(YAFFS_TRACE_ERROR,
120 "yaffs: Could not allocate Tnodes");
121 return YAFFS_FAIL;
122 }
123
124 /* New hookup for wide tnodes */
125 for (i = 0; i < n_tnodes - 1; i++) {
126 curr = (struct yaffs_tnode *)&mem[i * dev->tnode_size];
127 next = (struct yaffs_tnode *)&mem[(i + 1) * dev->tnode_size];
128 curr->internal[0] = next;
129 }
130
131 curr = (struct yaffs_tnode *)&mem[(n_tnodes - 1) * dev->tnode_size];
132 curr->internal[0] = allocator->free_tnodes;
133 allocator->free_tnodes = (struct yaffs_tnode *)mem;
134
135 allocator->n_free_tnodes += n_tnodes;
136 allocator->n_tnodes_created += n_tnodes;
137
138 /* Now add this bunch of tnodes to a list for freeing up.
139 * NB If we can't add this to the management list it isn't fatal
140 * but it just means we can't free this bunch of tnodes later.
141 */
142 tnl = kmalloc(sizeof(struct yaffs_tnode_list), GFP_NOFS);
143 if (!tnl) {
144 yaffs_trace(YAFFS_TRACE_ERROR,
145 "Could not add tnodes to management list");
146 return YAFFS_FAIL;
147 } else {
148 tnl->tnodes = new_tnodes;
149 tnl->next = allocator->alloc_tnode_list;
150 allocator->alloc_tnode_list = tnl;
151 }
152
153 yaffs_trace(YAFFS_TRACE_ALLOCATE, "Tnodes added");
154
155 return YAFFS_OK;
156 }
157
yaffs_alloc_raw_tnode(struct yaffs_dev * dev)158 struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
159 {
160 struct yaffs_allocator *allocator =
161 (struct yaffs_allocator *)dev->allocator;
162 struct yaffs_tnode *tn = NULL;
163
164 if (!allocator) {
165 BUG();
166 return NULL;
167 }
168
169 /* If there are none left make more */
170 if (!allocator->free_tnodes)
171 yaffs_create_tnodes(dev, YAFFS_ALLOCATION_NTNODES);
172
173 if (allocator->free_tnodes) {
174 tn = allocator->free_tnodes;
175 allocator->free_tnodes = allocator->free_tnodes->internal[0];
176 allocator->n_free_tnodes--;
177 }
178
179 return tn;
180 }
181
182 /* FreeTnode frees up a tnode and puts it back on the free list */
yaffs_free_raw_tnode(struct yaffs_dev * dev,struct yaffs_tnode * tn)183 void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
184 {
185 struct yaffs_allocator *allocator = dev->allocator;
186
187 if (!allocator) {
188 BUG();
189 return;
190 }
191
192 if (tn) {
193 tn->internal[0] = allocator->free_tnodes;
194 allocator->free_tnodes = tn;
195 allocator->n_free_tnodes++;
196 }
197 dev->checkpoint_blocks_required = 0; /* force recalculation */
198 }
199
200 /*--------------- yaffs_obj alloaction ------------------------
201 *
202 * Free yaffs_objs are stored in a list using obj->siblings.
203 * The blocks of allocated objects are stored in a linked list.
204 */
205
yaffs_init_raw_objs(struct yaffs_dev * dev)206 static void yaffs_init_raw_objs(struct yaffs_dev *dev)
207 {
208 struct yaffs_allocator *allocator = dev->allocator;
209
210 if (!allocator) {
211 BUG();
212 return;
213 }
214
215 allocator->allocated_obj_list = NULL;
216 INIT_LIST_HEAD(&allocator->free_objs);
217 allocator->n_free_objects = 0;
218 }
219
yaffs_deinit_raw_objs(struct yaffs_dev * dev)220 static void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
221 {
222 struct yaffs_allocator *allocator = dev->allocator;
223 struct yaffs_obj_list *tmp;
224
225 if (!allocator) {
226 BUG();
227 return;
228 }
229
230 while (allocator->allocated_obj_list) {
231 tmp = allocator->allocated_obj_list->next;
232 kfree(allocator->allocated_obj_list->objects);
233 kfree(allocator->allocated_obj_list);
234 allocator->allocated_obj_list = tmp;
235 }
236
237 INIT_LIST_HEAD(&allocator->free_objs);
238 allocator->n_free_objects = 0;
239 allocator->n_obj_created = 0;
240 }
241
yaffs_create_free_objs(struct yaffs_dev * dev,int n_obj)242 static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj)
243 {
244 struct yaffs_allocator *allocator = dev->allocator;
245 int i;
246 struct yaffs_obj *new_objs;
247 struct yaffs_obj_list *list;
248
249 if (!allocator) {
250 BUG();
251 return YAFFS_FAIL;
252 }
253
254 if (n_obj < 1)
255 return YAFFS_OK;
256
257 /* make these things */
258 new_objs = kmalloc(n_obj * sizeof(struct yaffs_obj), GFP_NOFS);
259 list = kmalloc(sizeof(struct yaffs_obj_list), GFP_NOFS);
260
261 if (!new_objs || !list) {
262 kfree(new_objs);
263 new_objs = NULL;
264 kfree(list);
265 list = NULL;
266 yaffs_trace(YAFFS_TRACE_ALLOCATE,
267 "Could not allocate more objects");
268 return YAFFS_FAIL;
269 }
270
271 /* Hook them into the free list */
272 for (i = 0; i < n_obj; i++)
273 list_add(&new_objs[i].siblings, &allocator->free_objs);
274
275 allocator->n_free_objects += n_obj;
276 allocator->n_obj_created += n_obj;
277
278 /* Now add this bunch of Objects to a list for freeing up. */
279
280 list->objects = new_objs;
281 list->next = allocator->allocated_obj_list;
282 allocator->allocated_obj_list = list;
283
284 return YAFFS_OK;
285 }
286
yaffs_alloc_raw_obj(struct yaffs_dev * dev)287 struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
288 {
289 struct yaffs_obj *obj = NULL;
290 struct list_head *lh;
291 struct yaffs_allocator *allocator = dev->allocator;
292
293 if (!allocator) {
294 BUG();
295 return obj;
296 }
297
298 /* If there are none left make more */
299 if (list_empty(&allocator->free_objs))
300 yaffs_create_free_objs(dev, YAFFS_ALLOCATION_NOBJECTS);
301
302 if (!list_empty(&allocator->free_objs)) {
303 lh = allocator->free_objs.next;
304 obj = list_entry(lh, struct yaffs_obj, siblings);
305 list_del_init(lh);
306 allocator->n_free_objects--;
307 }
308
309 return obj;
310 }
311
yaffs_free_raw_obj(struct yaffs_dev * dev,struct yaffs_obj * obj)312 void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
313 {
314
315 struct yaffs_allocator *allocator = dev->allocator;
316
317 if (!allocator) {
318 BUG();
319 return;
320 }
321
322 /* Link into the free list. */
323 list_add(&obj->siblings, &allocator->free_objs);
324 allocator->n_free_objects++;
325 }
326
yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev * dev)327 void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
328 {
329
330 if (!dev->allocator) {
331 BUG();
332 return;
333 }
334
335 yaffs_deinit_raw_tnodes(dev);
336 yaffs_deinit_raw_objs(dev);
337 kfree(dev->allocator);
338 dev->allocator = NULL;
339 }
340
yaffs_init_raw_tnodes_and_objs(struct yaffs_dev * dev)341 void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
342 {
343 struct yaffs_allocator *allocator;
344
345 if (dev->allocator) {
346 BUG();
347 return;
348 }
349
350 allocator = kmalloc(sizeof(struct yaffs_allocator), GFP_NOFS);
351 if (allocator) {
352 dev->allocator = allocator;
353 yaffs_init_raw_tnodes(dev);
354 yaffs_init_raw_objs(dev);
355 }
356 }
357