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5db53f3e JE |
1 | /* |
2 | * fs/logfs/segment.c - Handling the Object Store | |
3 | * | |
4 | * As should be obvious for Linux kernel code, license is GPLv2 | |
5 | * | |
6 | * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> | |
7 | * | |
8 | * Object store or ostore makes up the complete device with exception of | |
9 | * the superblock and journal areas. Apart from its own metadata it stores | |
10 | * three kinds of objects: inodes, dentries and blocks, both data and indirect. | |
11 | */ | |
12 | #include "logfs.h" | |
13 | ||
14 | static int logfs_mark_segment_bad(struct super_block *sb, u32 segno) | |
15 | { | |
16 | struct logfs_super *super = logfs_super(sb); | |
17 | struct btree_head32 *head = &super->s_reserved_segments; | |
18 | int err; | |
19 | ||
20 | err = btree_insert32(head, segno, (void *)1, GFP_NOFS); | |
21 | if (err) | |
22 | return err; | |
23 | logfs_super(sb)->s_bad_segments++; | |
24 | /* FIXME: write to journal */ | |
25 | return 0; | |
26 | } | |
27 | ||
28 | int logfs_erase_segment(struct super_block *sb, u32 segno) | |
29 | { | |
30 | struct logfs_super *super = logfs_super(sb); | |
31 | ||
32 | super->s_gec++; | |
33 | ||
34 | return super->s_devops->erase(sb, (u64)segno << super->s_segshift, | |
35 | super->s_segsize); | |
36 | } | |
37 | ||
38 | static s64 logfs_get_free_bytes(struct logfs_area *area, size_t bytes) | |
39 | { | |
40 | s32 ofs; | |
41 | ||
42 | logfs_open_area(area, bytes); | |
43 | ||
44 | ofs = area->a_used_bytes; | |
45 | area->a_used_bytes += bytes; | |
46 | BUG_ON(area->a_used_bytes >= logfs_super(area->a_sb)->s_segsize); | |
47 | ||
48 | return dev_ofs(area->a_sb, area->a_segno, ofs); | |
49 | } | |
50 | ||
51 | static struct page *get_mapping_page(struct super_block *sb, pgoff_t index, | |
52 | int use_filler) | |
53 | { | |
54 | struct logfs_super *super = logfs_super(sb); | |
55 | struct address_space *mapping = super->s_mapping_inode->i_mapping; | |
56 | filler_t *filler = super->s_devops->readpage; | |
57 | struct page *page; | |
58 | ||
59 | BUG_ON(mapping_gfp_mask(mapping) & __GFP_FS); | |
60 | if (use_filler) | |
61 | page = read_cache_page(mapping, index, filler, sb); | |
62 | else { | |
63 | page = find_or_create_page(mapping, index, GFP_NOFS); | |
64 | unlock_page(page); | |
65 | } | |
66 | return page; | |
67 | } | |
68 | ||
69 | void __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len, | |
70 | int use_filler) | |
71 | { | |
72 | pgoff_t index = ofs >> PAGE_SHIFT; | |
73 | struct page *page; | |
74 | long offset = ofs & (PAGE_SIZE-1); | |
75 | long copylen; | |
76 | ||
77 | /* Only logfs_wbuf_recover may use len==0 */ | |
78 | BUG_ON(!len && !use_filler); | |
79 | do { | |
80 | copylen = min((ulong)len, PAGE_SIZE - offset); | |
81 | ||
82 | page = get_mapping_page(area->a_sb, index, use_filler); | |
83 | SetPageUptodate(page); | |
84 | BUG_ON(!page); /* FIXME: reserve a pool */ | |
85 | memcpy(page_address(page) + offset, buf, copylen); | |
86 | SetPagePrivate(page); | |
87 | page_cache_release(page); | |
88 | ||
89 | buf += copylen; | |
90 | len -= copylen; | |
91 | offset = 0; | |
92 | index++; | |
93 | } while (len); | |
94 | } | |
95 | ||
96 | /* | |
97 | * bdev_writeseg will write full pages. Memset the tail to prevent data leaks. | |
98 | */ | |
99 | static void pad_wbuf(struct logfs_area *area, int final) | |
100 | { | |
101 | struct super_block *sb = area->a_sb; | |
102 | struct logfs_super *super = logfs_super(sb); | |
103 | struct page *page; | |
104 | u64 ofs = dev_ofs(sb, area->a_segno, area->a_used_bytes); | |
105 | pgoff_t index = ofs >> PAGE_SHIFT; | |
106 | long offset = ofs & (PAGE_SIZE-1); | |
107 | u32 len = PAGE_SIZE - offset; | |
108 | ||
109 | if (len == PAGE_SIZE) { | |
110 | /* The math in this function can surely use some love */ | |
111 | len = 0; | |
112 | } | |
113 | if (len) { | |
114 | BUG_ON(area->a_used_bytes >= super->s_segsize); | |
115 | ||
116 | page = get_mapping_page(area->a_sb, index, 0); | |
117 | BUG_ON(!page); /* FIXME: reserve a pool */ | |
118 | memset(page_address(page) + offset, 0xff, len); | |
119 | SetPagePrivate(page); | |
120 | page_cache_release(page); | |
121 | } | |
122 | ||
123 | if (!final) | |
124 | return; | |
125 | ||
126 | area->a_used_bytes += len; | |
127 | for ( ; area->a_used_bytes < super->s_segsize; | |
128 | area->a_used_bytes += PAGE_SIZE) { | |
129 | /* Memset another page */ | |
130 | index++; | |
131 | page = get_mapping_page(area->a_sb, index, 0); | |
132 | BUG_ON(!page); /* FIXME: reserve a pool */ | |
133 | memset(page_address(page), 0xff, PAGE_SIZE); | |
134 | SetPagePrivate(page); | |
135 | page_cache_release(page); | |
136 | } | |
137 | } | |
138 | ||
139 | /* | |
140 | * We have to be careful with the alias tree. Since lookup is done by bix, | |
141 | * it needs to be normalized, so 14, 15, 16, etc. all match when dealing with | |
142 | * indirect blocks. So always use it through accessor functions. | |
143 | */ | |
144 | static void *alias_tree_lookup(struct super_block *sb, u64 ino, u64 bix, | |
145 | level_t level) | |
146 | { | |
147 | struct btree_head128 *head = &logfs_super(sb)->s_object_alias_tree; | |
148 | pgoff_t index = logfs_pack_index(bix, level); | |
149 | ||
150 | return btree_lookup128(head, ino, index); | |
151 | } | |
152 | ||
153 | static int alias_tree_insert(struct super_block *sb, u64 ino, u64 bix, | |
154 | level_t level, void *val) | |
155 | { | |
156 | struct btree_head128 *head = &logfs_super(sb)->s_object_alias_tree; | |
157 | pgoff_t index = logfs_pack_index(bix, level); | |
158 | ||
159 | return btree_insert128(head, ino, index, val, GFP_NOFS); | |
160 | } | |
161 | ||
162 | static int btree_write_alias(struct super_block *sb, struct logfs_block *block, | |
163 | write_alias_t *write_one_alias) | |
164 | { | |
165 | struct object_alias_item *item; | |
166 | int err; | |
167 | ||
168 | list_for_each_entry(item, &block->item_list, list) { | |
169 | err = write_alias_journal(sb, block->ino, block->bix, | |
170 | block->level, item->child_no, item->val); | |
171 | if (err) | |
172 | return err; | |
173 | } | |
174 | return 0; | |
175 | } | |
176 | ||
177 | static gc_level_t btree_block_level(struct logfs_block *block) | |
178 | { | |
179 | return expand_level(block->ino, block->level); | |
180 | } | |
181 | ||
182 | static struct logfs_block_ops btree_block_ops = { | |
183 | .write_block = btree_write_block, | |
184 | .block_level = btree_block_level, | |
185 | .free_block = __free_block, | |
186 | .write_alias = btree_write_alias, | |
187 | }; | |
188 | ||
189 | int logfs_load_object_aliases(struct super_block *sb, | |
190 | struct logfs_obj_alias *oa, int count) | |
191 | { | |
192 | struct logfs_super *super = logfs_super(sb); | |
193 | struct logfs_block *block; | |
194 | struct object_alias_item *item; | |
195 | u64 ino, bix; | |
196 | level_t level; | |
197 | int i, err; | |
198 | ||
199 | super->s_flags |= LOGFS_SB_FLAG_OBJ_ALIAS; | |
200 | count /= sizeof(*oa); | |
201 | for (i = 0; i < count; i++) { | |
202 | item = mempool_alloc(super->s_alias_pool, GFP_NOFS); | |
203 | if (!item) | |
204 | return -ENOMEM; | |
205 | memset(item, 0, sizeof(*item)); | |
206 | ||
207 | super->s_no_object_aliases++; | |
208 | item->val = oa[i].val; | |
209 | item->child_no = be16_to_cpu(oa[i].child_no); | |
210 | ||
211 | ino = be64_to_cpu(oa[i].ino); | |
212 | bix = be64_to_cpu(oa[i].bix); | |
213 | level = LEVEL(oa[i].level); | |
214 | ||
215 | log_aliases("logfs_load_object_aliases(%llx, %llx, %x, %x) %llx\n", | |
216 | ino, bix, level, item->child_no, | |
217 | be64_to_cpu(item->val)); | |
218 | block = alias_tree_lookup(sb, ino, bix, level); | |
219 | if (!block) { | |
220 | block = __alloc_block(sb, ino, bix, level); | |
221 | block->ops = &btree_block_ops; | |
222 | err = alias_tree_insert(sb, ino, bix, level, block); | |
223 | BUG_ON(err); /* mempool empty */ | |
224 | } | |
225 | if (test_and_set_bit(item->child_no, block->alias_map)) { | |
226 | printk(KERN_ERR"LogFS: Alias collision detected\n"); | |
227 | return -EIO; | |
228 | } | |
229 | list_move_tail(&block->alias_list, &super->s_object_alias); | |
230 | list_add(&item->list, &block->item_list); | |
231 | } | |
232 | return 0; | |
233 | } | |
234 | ||
235 | static void kill_alias(void *_block, unsigned long ignore0, | |
236 | u64 ignore1, u64 ignore2, size_t ignore3) | |
237 | { | |
238 | struct logfs_block *block = _block; | |
239 | struct super_block *sb = block->sb; | |
240 | struct logfs_super *super = logfs_super(sb); | |
241 | struct object_alias_item *item; | |
242 | ||
243 | while (!list_empty(&block->item_list)) { | |
244 | item = list_entry(block->item_list.next, typeof(*item), list); | |
245 | list_del(&item->list); | |
246 | mempool_free(item, super->s_alias_pool); | |
247 | } | |
248 | block->ops->free_block(sb, block); | |
249 | } | |
250 | ||
251 | static int obj_type(struct inode *inode, level_t level) | |
252 | { | |
253 | if (level == 0) { | |
254 | if (S_ISDIR(inode->i_mode)) | |
255 | return OBJ_DENTRY; | |
256 | if (inode->i_ino == LOGFS_INO_MASTER) | |
257 | return OBJ_INODE; | |
258 | } | |
259 | return OBJ_BLOCK; | |
260 | } | |
261 | ||
262 | static int obj_len(struct super_block *sb, int obj_type) | |
263 | { | |
264 | switch (obj_type) { | |
265 | case OBJ_DENTRY: | |
266 | return sizeof(struct logfs_disk_dentry); | |
267 | case OBJ_INODE: | |
268 | return sizeof(struct logfs_disk_inode); | |
269 | case OBJ_BLOCK: | |
270 | return sb->s_blocksize; | |
271 | default: | |
272 | BUG(); | |
273 | } | |
274 | } | |
275 | ||
276 | static int __logfs_segment_write(struct inode *inode, void *buf, | |
277 | struct logfs_shadow *shadow, int type, int len, int compr) | |
278 | { | |
279 | struct logfs_area *area; | |
280 | struct super_block *sb = inode->i_sb; | |
281 | s64 ofs; | |
282 | struct logfs_object_header h; | |
283 | int acc_len; | |
284 | ||
285 | if (shadow->gc_level == 0) | |
286 | acc_len = len; | |
287 | else | |
288 | acc_len = obj_len(sb, type); | |
289 | ||
290 | area = get_area(sb, shadow->gc_level); | |
291 | ofs = logfs_get_free_bytes(area, len + LOGFS_OBJECT_HEADERSIZE); | |
292 | LOGFS_BUG_ON(ofs <= 0, sb); | |
293 | /* | |
294 | * Order is important. logfs_get_free_bytes(), by modifying the | |
295 | * segment file, may modify the content of the very page we're about | |
296 | * to write now. Which is fine, as long as the calculated crc and | |
297 | * written data still match. So do the modifications _before_ | |
298 | * calculating the crc. | |
299 | */ | |
300 | ||
301 | h.len = cpu_to_be16(len); | |
302 | h.type = type; | |
303 | h.compr = compr; | |
304 | h.ino = cpu_to_be64(inode->i_ino); | |
305 | h.bix = cpu_to_be64(shadow->bix); | |
306 | h.crc = logfs_crc32(&h, sizeof(h) - 4, 4); | |
307 | h.data_crc = logfs_crc32(buf, len, 0); | |
308 | ||
309 | logfs_buf_write(area, ofs, &h, sizeof(h)); | |
310 | logfs_buf_write(area, ofs + LOGFS_OBJECT_HEADERSIZE, buf, len); | |
311 | ||
312 | shadow->new_ofs = ofs; | |
313 | shadow->new_len = acc_len + LOGFS_OBJECT_HEADERSIZE; | |
314 | ||
315 | return 0; | |
316 | } | |
317 | ||
318 | static s64 logfs_segment_write_compress(struct inode *inode, void *buf, | |
319 | struct logfs_shadow *shadow, int type, int len) | |
320 | { | |
321 | struct super_block *sb = inode->i_sb; | |
322 | void *compressor_buf = logfs_super(sb)->s_compressed_je; | |
323 | ssize_t compr_len; | |
324 | int ret; | |
325 | ||
326 | mutex_lock(&logfs_super(sb)->s_journal_mutex); | |
327 | compr_len = logfs_compress(buf, compressor_buf, len, len); | |
328 | ||
329 | if (compr_len >= 0) { | |
330 | ret = __logfs_segment_write(inode, compressor_buf, shadow, | |
331 | type, compr_len, COMPR_ZLIB); | |
332 | } else { | |
333 | ret = __logfs_segment_write(inode, buf, shadow, type, len, | |
334 | COMPR_NONE); | |
335 | } | |
336 | mutex_unlock(&logfs_super(sb)->s_journal_mutex); | |
337 | return ret; | |
338 | } | |
339 | ||
340 | /** | |
341 | * logfs_segment_write - write data block to object store | |
342 | * @inode: inode containing data | |
343 | * | |
344 | * Returns an errno or zero. | |
345 | */ | |
346 | int logfs_segment_write(struct inode *inode, struct page *page, | |
347 | struct logfs_shadow *shadow) | |
348 | { | |
349 | struct super_block *sb = inode->i_sb; | |
350 | struct logfs_super *super = logfs_super(sb); | |
351 | int do_compress, type, len; | |
352 | int ret; | |
353 | void *buf; | |
354 | ||
355 | BUG_ON(logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN); | |
356 | do_compress = logfs_inode(inode)->li_flags & LOGFS_IF_COMPRESSED; | |
357 | if (shadow->gc_level != 0) { | |
358 | /* temporarily disable compression for indirect blocks */ | |
359 | do_compress = 0; | |
360 | } | |
361 | ||
362 | type = obj_type(inode, shrink_level(shadow->gc_level)); | |
363 | len = obj_len(sb, type); | |
364 | buf = kmap(page); | |
365 | if (do_compress) | |
366 | ret = logfs_segment_write_compress(inode, buf, shadow, type, | |
367 | len); | |
368 | else | |
369 | ret = __logfs_segment_write(inode, buf, shadow, type, len, | |
370 | COMPR_NONE); | |
371 | kunmap(page); | |
372 | ||
373 | log_segment("logfs_segment_write(%llx, %llx, %x) %llx->%llx %x->%x\n", | |
374 | shadow->ino, shadow->bix, shadow->gc_level, | |
375 | shadow->old_ofs, shadow->new_ofs, | |
376 | shadow->old_len, shadow->new_len); | |
377 | /* this BUG_ON did catch a locking bug. useful */ | |
378 | BUG_ON(!(shadow->new_ofs & (super->s_segsize - 1))); | |
379 | return ret; | |
380 | } | |
381 | ||
382 | int wbuf_read(struct super_block *sb, u64 ofs, size_t len, void *buf) | |
383 | { | |
384 | pgoff_t index = ofs >> PAGE_SHIFT; | |
385 | struct page *page; | |
386 | long offset = ofs & (PAGE_SIZE-1); | |
387 | long copylen; | |
388 | ||
389 | while (len) { | |
390 | copylen = min((ulong)len, PAGE_SIZE - offset); | |
391 | ||
392 | page = get_mapping_page(sb, index, 1); | |
393 | if (IS_ERR(page)) | |
394 | return PTR_ERR(page); | |
395 | memcpy(buf, page_address(page) + offset, copylen); | |
396 | page_cache_release(page); | |
397 | ||
398 | buf += copylen; | |
399 | len -= copylen; | |
400 | offset = 0; | |
401 | index++; | |
402 | } | |
403 | return 0; | |
404 | } | |
405 | ||
406 | /* | |
407 | * The "position" of indirect blocks is ambiguous. It can be the position | |
408 | * of any data block somewhere behind this indirect block. So we need to | |
409 | * normalize the positions through logfs_block_mask() before comparing. | |
410 | */ | |
411 | static int check_pos(struct super_block *sb, u64 pos1, u64 pos2, level_t level) | |
412 | { | |
413 | return (pos1 & logfs_block_mask(sb, level)) != | |
414 | (pos2 & logfs_block_mask(sb, level)); | |
415 | } | |
416 | ||
417 | #if 0 | |
418 | static int read_seg_header(struct super_block *sb, u64 ofs, | |
419 | struct logfs_segment_header *sh) | |
420 | { | |
421 | __be32 crc; | |
422 | int err; | |
423 | ||
424 | err = wbuf_read(sb, ofs, sizeof(*sh), sh); | |
425 | if (err) | |
426 | return err; | |
427 | crc = logfs_crc32(sh, sizeof(*sh), 4); | |
428 | if (crc != sh->crc) { | |
429 | printk(KERN_ERR"LOGFS: header crc error at %llx: expected %x, " | |
430 | "got %x\n", ofs, be32_to_cpu(sh->crc), | |
431 | be32_to_cpu(crc)); | |
432 | return -EIO; | |
433 | } | |
434 | return 0; | |
435 | } | |
436 | #endif | |
437 | ||
438 | static int read_obj_header(struct super_block *sb, u64 ofs, | |
439 | struct logfs_object_header *oh) | |
440 | { | |
441 | __be32 crc; | |
442 | int err; | |
443 | ||
444 | err = wbuf_read(sb, ofs, sizeof(*oh), oh); | |
445 | if (err) | |
446 | return err; | |
447 | crc = logfs_crc32(oh, sizeof(*oh) - 4, 4); | |
448 | if (crc != oh->crc) { | |
449 | printk(KERN_ERR"LOGFS: header crc error at %llx: expected %x, " | |
450 | "got %x\n", ofs, be32_to_cpu(oh->crc), | |
451 | be32_to_cpu(crc)); | |
452 | return -EIO; | |
453 | } | |
454 | return 0; | |
455 | } | |
456 | ||
457 | static void move_btree_to_page(struct inode *inode, struct page *page, | |
458 | __be64 *data) | |
459 | { | |
460 | struct super_block *sb = inode->i_sb; | |
461 | struct logfs_super *super = logfs_super(sb); | |
462 | struct btree_head128 *head = &super->s_object_alias_tree; | |
463 | struct logfs_block *block; | |
464 | struct object_alias_item *item, *next; | |
465 | ||
466 | if (!(super->s_flags & LOGFS_SB_FLAG_OBJ_ALIAS)) | |
467 | return; | |
468 | ||
469 | block = btree_remove128(head, inode->i_ino, page->index); | |
470 | if (!block) | |
471 | return; | |
472 | ||
473 | log_blockmove("move_btree_to_page(%llx, %llx, %x)\n", | |
474 | block->ino, block->bix, block->level); | |
475 | list_for_each_entry_safe(item, next, &block->item_list, list) { | |
476 | data[item->child_no] = item->val; | |
477 | list_del(&item->list); | |
478 | mempool_free(item, super->s_alias_pool); | |
479 | } | |
480 | block->page = page; | |
481 | SetPagePrivate(page); | |
482 | page->private = (unsigned long)block; | |
483 | block->ops = &indirect_block_ops; | |
484 | initialize_block_counters(page, block, data, 0); | |
485 | } | |
486 | ||
487 | /* | |
488 | * This silences a false, yet annoying gcc warning. I hate it when my editor | |
489 | * jumps into bitops.h each time I recompile this file. | |
490 | * TODO: Complain to gcc folks about this and upgrade compiler. | |
491 | */ | |
492 | static unsigned long fnb(const unsigned long *addr, | |
493 | unsigned long size, unsigned long offset) | |
494 | { | |
495 | return find_next_bit(addr, size, offset); | |
496 | } | |
497 | ||
498 | void move_page_to_btree(struct page *page) | |
499 | { | |
500 | struct logfs_block *block = logfs_block(page); | |
501 | struct super_block *sb = block->sb; | |
502 | struct logfs_super *super = logfs_super(sb); | |
503 | struct object_alias_item *item; | |
504 | unsigned long pos; | |
505 | __be64 *child; | |
506 | int err; | |
507 | ||
508 | if (super->s_flags & LOGFS_SB_FLAG_SHUTDOWN) { | |
509 | block->ops->free_block(sb, block); | |
510 | return; | |
511 | } | |
512 | log_blockmove("move_page_to_btree(%llx, %llx, %x)\n", | |
513 | block->ino, block->bix, block->level); | |
514 | super->s_flags |= LOGFS_SB_FLAG_OBJ_ALIAS; | |
515 | ||
516 | for (pos = 0; ; pos++) { | |
517 | pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos); | |
518 | if (pos >= LOGFS_BLOCK_FACTOR) | |
519 | break; | |
520 | ||
521 | item = mempool_alloc(super->s_alias_pool, GFP_NOFS); | |
522 | BUG_ON(!item); /* mempool empty */ | |
523 | memset(item, 0, sizeof(*item)); | |
524 | ||
525 | child = kmap_atomic(page, KM_USER0); | |
526 | item->val = child[pos]; | |
527 | kunmap_atomic(child, KM_USER0); | |
528 | item->child_no = pos; | |
529 | list_add(&item->list, &block->item_list); | |
530 | } | |
531 | block->page = NULL; | |
532 | ClearPagePrivate(page); | |
533 | page->private = 0; | |
534 | block->ops = &btree_block_ops; | |
535 | err = alias_tree_insert(block->sb, block->ino, block->bix, block->level, | |
536 | block); | |
537 | BUG_ON(err); /* mempool empty */ | |
538 | ClearPageUptodate(page); | |
539 | } | |
540 | ||
541 | static int __logfs_segment_read(struct inode *inode, void *buf, | |
542 | u64 ofs, u64 bix, level_t level) | |
543 | { | |
544 | struct super_block *sb = inode->i_sb; | |
545 | void *compressor_buf = logfs_super(sb)->s_compressed_je; | |
546 | struct logfs_object_header oh; | |
547 | __be32 crc; | |
548 | u16 len; | |
549 | int err, block_len; | |
550 | ||
551 | block_len = obj_len(sb, obj_type(inode, level)); | |
552 | err = read_obj_header(sb, ofs, &oh); | |
553 | if (err) | |
554 | goto out_err; | |
555 | ||
556 | err = -EIO; | |
557 | if (be64_to_cpu(oh.ino) != inode->i_ino | |
558 | || check_pos(sb, be64_to_cpu(oh.bix), bix, level)) { | |
559 | printk(KERN_ERR"LOGFS: (ino, bix) don't match at %llx: " | |
560 | "expected (%lx, %llx), got (%llx, %llx)\n", | |
561 | ofs, inode->i_ino, bix, | |
562 | be64_to_cpu(oh.ino), be64_to_cpu(oh.bix)); | |
563 | goto out_err; | |
564 | } | |
565 | ||
566 | len = be16_to_cpu(oh.len); | |
567 | ||
568 | switch (oh.compr) { | |
569 | case COMPR_NONE: | |
570 | err = wbuf_read(sb, ofs + LOGFS_OBJECT_HEADERSIZE, len, buf); | |
571 | if (err) | |
572 | goto out_err; | |
573 | crc = logfs_crc32(buf, len, 0); | |
574 | if (crc != oh.data_crc) { | |
575 | printk(KERN_ERR"LOGFS: uncompressed data crc error at " | |
576 | "%llx: expected %x, got %x\n", ofs, | |
577 | be32_to_cpu(oh.data_crc), | |
578 | be32_to_cpu(crc)); | |
579 | goto out_err; | |
580 | } | |
581 | break; | |
582 | case COMPR_ZLIB: | |
583 | mutex_lock(&logfs_super(sb)->s_journal_mutex); | |
584 | err = wbuf_read(sb, ofs + LOGFS_OBJECT_HEADERSIZE, len, | |
585 | compressor_buf); | |
586 | if (err) { | |
587 | mutex_unlock(&logfs_super(sb)->s_journal_mutex); | |
588 | goto out_err; | |
589 | } | |
590 | crc = logfs_crc32(compressor_buf, len, 0); | |
591 | if (crc != oh.data_crc) { | |
592 | printk(KERN_ERR"LOGFS: compressed data crc error at " | |
593 | "%llx: expected %x, got %x\n", ofs, | |
594 | be32_to_cpu(oh.data_crc), | |
595 | be32_to_cpu(crc)); | |
596 | mutex_unlock(&logfs_super(sb)->s_journal_mutex); | |
597 | goto out_err; | |
598 | } | |
599 | err = logfs_uncompress(compressor_buf, buf, len, block_len); | |
600 | mutex_unlock(&logfs_super(sb)->s_journal_mutex); | |
601 | if (err) { | |
602 | printk(KERN_ERR"LOGFS: uncompress error at %llx\n", ofs); | |
603 | goto out_err; | |
604 | } | |
605 | break; | |
606 | default: | |
607 | LOGFS_BUG(sb); | |
608 | err = -EIO; | |
609 | goto out_err; | |
610 | } | |
611 | return 0; | |
612 | ||
613 | out_err: | |
614 | logfs_set_ro(sb); | |
615 | printk(KERN_ERR"LOGFS: device is read-only now\n"); | |
616 | LOGFS_BUG(sb); | |
617 | return err; | |
618 | } | |
619 | ||
620 | /** | |
621 | * logfs_segment_read - read data block from object store | |
622 | * @inode: inode containing data | |
623 | * @buf: data buffer | |
624 | * @ofs: physical data offset | |
625 | * @bix: block index | |
626 | * @level: block level | |
627 | * | |
628 | * Returns 0 on success or a negative errno. | |
629 | */ | |
630 | int logfs_segment_read(struct inode *inode, struct page *page, | |
631 | u64 ofs, u64 bix, level_t level) | |
632 | { | |
633 | int err; | |
634 | void *buf; | |
635 | ||
636 | if (PageUptodate(page)) | |
637 | return 0; | |
638 | ||
639 | ofs &= ~LOGFS_FULLY_POPULATED; | |
640 | ||
641 | buf = kmap(page); | |
642 | err = __logfs_segment_read(inode, buf, ofs, bix, level); | |
643 | if (!err) { | |
644 | move_btree_to_page(inode, page, buf); | |
645 | SetPageUptodate(page); | |
646 | } | |
647 | kunmap(page); | |
648 | log_segment("logfs_segment_read(%lx, %llx, %x) %llx (%d)\n", | |
649 | inode->i_ino, bix, level, ofs, err); | |
650 | return err; | |
651 | } | |
652 | ||
653 | int logfs_segment_delete(struct inode *inode, struct logfs_shadow *shadow) | |
654 | { | |
655 | struct super_block *sb = inode->i_sb; | |
656 | struct logfs_object_header h; | |
657 | u16 len; | |
658 | int err; | |
659 | ||
660 | BUG_ON(logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN); | |
661 | BUG_ON(shadow->old_ofs & LOGFS_FULLY_POPULATED); | |
662 | if (!shadow->old_ofs) | |
663 | return 0; | |
664 | ||
665 | log_segment("logfs_segment_delete(%llx, %llx, %x) %llx->%llx %x->%x\n", | |
666 | shadow->ino, shadow->bix, shadow->gc_level, | |
667 | shadow->old_ofs, shadow->new_ofs, | |
668 | shadow->old_len, shadow->new_len); | |
669 | err = read_obj_header(sb, shadow->old_ofs, &h); | |
670 | LOGFS_BUG_ON(err, sb); | |
671 | LOGFS_BUG_ON(be64_to_cpu(h.ino) != inode->i_ino, sb); | |
672 | LOGFS_BUG_ON(check_pos(sb, shadow->bix, be64_to_cpu(h.bix), | |
673 | shrink_level(shadow->gc_level)), sb); | |
674 | ||
675 | if (shadow->gc_level == 0) | |
676 | len = be16_to_cpu(h.len); | |
677 | else | |
678 | len = obj_len(sb, h.type); | |
679 | shadow->old_len = len + sizeof(h); | |
680 | return 0; | |
681 | } | |
682 | ||
683 | static void freeseg(struct super_block *sb, u32 segno) | |
684 | { | |
685 | struct logfs_super *super = logfs_super(sb); | |
686 | struct address_space *mapping = super->s_mapping_inode->i_mapping; | |
687 | struct page *page; | |
688 | u64 ofs, start, end; | |
689 | ||
690 | start = dev_ofs(sb, segno, 0); | |
691 | end = dev_ofs(sb, segno + 1, 0); | |
692 | for (ofs = start; ofs < end; ofs += PAGE_SIZE) { | |
693 | page = find_get_page(mapping, ofs >> PAGE_SHIFT); | |
694 | if (!page) | |
695 | continue; | |
696 | ClearPagePrivate(page); | |
697 | page_cache_release(page); | |
698 | } | |
699 | } | |
700 | ||
701 | int logfs_open_area(struct logfs_area *area, size_t bytes) | |
702 | { | |
703 | struct super_block *sb = area->a_sb; | |
704 | struct logfs_super *super = logfs_super(sb); | |
705 | int err, closed = 0; | |
706 | ||
707 | if (area->a_is_open && area->a_used_bytes + bytes <= super->s_segsize) | |
708 | return 0; | |
709 | ||
710 | if (area->a_is_open) { | |
711 | u64 ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes); | |
712 | u32 len = super->s_segsize - area->a_written_bytes; | |
713 | ||
714 | log_gc("logfs_close_area(%x)\n", area->a_segno); | |
715 | pad_wbuf(area, 1); | |
716 | super->s_devops->writeseg(area->a_sb, ofs, len); | |
717 | freeseg(sb, area->a_segno); | |
718 | closed = 1; | |
719 | } | |
720 | ||
721 | area->a_used_bytes = 0; | |
722 | area->a_written_bytes = 0; | |
723 | again: | |
724 | area->a_ops->get_free_segment(area); | |
725 | area->a_ops->get_erase_count(area); | |
726 | ||
727 | log_gc("logfs_open_area(%x, %x)\n", area->a_segno, area->a_level); | |
728 | err = area->a_ops->erase_segment(area); | |
729 | if (err) { | |
730 | printk(KERN_WARNING "LogFS: Error erasing segment %x\n", | |
731 | area->a_segno); | |
732 | logfs_mark_segment_bad(sb, area->a_segno); | |
733 | goto again; | |
734 | } | |
735 | area->a_is_open = 1; | |
736 | return closed; | |
737 | } | |
738 | ||
739 | void logfs_sync_area(struct logfs_area *area) | |
740 | { | |
741 | struct super_block *sb = area->a_sb; | |
742 | struct logfs_super *super = logfs_super(sb); | |
743 | u64 ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes); | |
744 | u32 len = (area->a_used_bytes - area->a_written_bytes); | |
745 | ||
746 | if (super->s_writesize) | |
747 | len &= ~(super->s_writesize - 1); | |
748 | if (len == 0) | |
749 | return; | |
750 | pad_wbuf(area, 0); | |
751 | super->s_devops->writeseg(sb, ofs, len); | |
752 | area->a_written_bytes += len; | |
753 | } | |
754 | ||
755 | void logfs_sync_segments(struct super_block *sb) | |
756 | { | |
757 | struct logfs_super *super = logfs_super(sb); | |
758 | int i; | |
759 | ||
760 | for_each_area(i) | |
761 | logfs_sync_area(super->s_area[i]); | |
762 | } | |
763 | ||
764 | /* | |
765 | * Pick a free segment to be used for this area. Effectively takes a | |
766 | * candidate from the free list (not really a candidate anymore). | |
767 | */ | |
768 | static void ostore_get_free_segment(struct logfs_area *area) | |
769 | { | |
770 | struct super_block *sb = area->a_sb; | |
771 | struct logfs_super *super = logfs_super(sb); | |
772 | ||
773 | if (super->s_free_list.count == 0) { | |
774 | printk(KERN_ERR"LOGFS: ran out of free segments\n"); | |
775 | LOGFS_BUG(sb); | |
776 | } | |
777 | ||
778 | area->a_segno = get_best_cand(sb, &super->s_free_list, NULL); | |
779 | } | |
780 | ||
781 | static void ostore_get_erase_count(struct logfs_area *area) | |
782 | { | |
783 | struct logfs_segment_entry se; | |
784 | u32 ec_level; | |
785 | ||
786 | logfs_get_segment_entry(area->a_sb, area->a_segno, &se); | |
787 | BUG_ON(se.ec_level == cpu_to_be32(BADSEG) || | |
788 | se.valid == cpu_to_be32(RESERVED)); | |
789 | ||
790 | ec_level = be32_to_cpu(se.ec_level); | |
791 | area->a_erase_count = (ec_level >> 4) + 1; | |
792 | } | |
793 | ||
794 | static int ostore_erase_segment(struct logfs_area *area) | |
795 | { | |
796 | struct super_block *sb = area->a_sb; | |
797 | struct logfs_segment_header sh; | |
798 | u64 ofs; | |
799 | int err; | |
800 | ||
801 | err = logfs_erase_segment(sb, area->a_segno); | |
802 | if (err) | |
803 | return err; | |
804 | ||
805 | sh.pad = 0; | |
806 | sh.type = SEG_OSTORE; | |
807 | sh.level = (__force u8)area->a_level; | |
808 | sh.segno = cpu_to_be32(area->a_segno); | |
809 | sh.ec = cpu_to_be32(area->a_erase_count); | |
810 | sh.gec = cpu_to_be64(logfs_super(sb)->s_gec); | |
811 | sh.crc = logfs_crc32(&sh, sizeof(sh), 4); | |
812 | ||
813 | logfs_set_segment_erased(sb, area->a_segno, area->a_erase_count, | |
814 | area->a_level); | |
815 | ||
816 | ofs = dev_ofs(sb, area->a_segno, 0); | |
817 | area->a_used_bytes = sizeof(sh); | |
818 | logfs_buf_write(area, ofs, &sh, sizeof(sh)); | |
819 | return 0; | |
820 | } | |
821 | ||
822 | static const struct logfs_area_ops ostore_area_ops = { | |
823 | .get_free_segment = ostore_get_free_segment, | |
824 | .get_erase_count = ostore_get_erase_count, | |
825 | .erase_segment = ostore_erase_segment, | |
826 | }; | |
827 | ||
828 | static void free_area(struct logfs_area *area) | |
829 | { | |
830 | if (area) | |
831 | freeseg(area->a_sb, area->a_segno); | |
832 | kfree(area); | |
833 | } | |
834 | ||
835 | static struct logfs_area *alloc_area(struct super_block *sb) | |
836 | { | |
837 | struct logfs_area *area; | |
838 | ||
839 | area = kzalloc(sizeof(*area), GFP_KERNEL); | |
840 | if (!area) | |
841 | return NULL; | |
842 | ||
843 | area->a_sb = sb; | |
844 | return area; | |
845 | } | |
846 | ||
847 | static void map_invalidatepage(struct page *page, unsigned long l) | |
848 | { | |
849 | BUG(); | |
850 | } | |
851 | ||
852 | static int map_releasepage(struct page *page, gfp_t g) | |
853 | { | |
854 | /* Don't release these pages */ | |
855 | return 0; | |
856 | } | |
857 | ||
858 | static const struct address_space_operations mapping_aops = { | |
859 | .invalidatepage = map_invalidatepage, | |
860 | .releasepage = map_releasepage, | |
861 | .set_page_dirty = __set_page_dirty_nobuffers, | |
862 | }; | |
863 | ||
864 | int logfs_init_mapping(struct super_block *sb) | |
865 | { | |
866 | struct logfs_super *super = logfs_super(sb); | |
867 | struct address_space *mapping; | |
868 | struct inode *inode; | |
869 | ||
870 | inode = logfs_new_meta_inode(sb, LOGFS_INO_MAPPING); | |
871 | if (IS_ERR(inode)) | |
872 | return PTR_ERR(inode); | |
873 | super->s_mapping_inode = inode; | |
874 | mapping = inode->i_mapping; | |
875 | mapping->a_ops = &mapping_aops; | |
876 | /* Would it be possible to use __GFP_HIGHMEM as well? */ | |
877 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
878 | return 0; | |
879 | } | |
880 | ||
881 | int logfs_init_areas(struct super_block *sb) | |
882 | { | |
883 | struct logfs_super *super = logfs_super(sb); | |
884 | int i = -1; | |
885 | ||
886 | super->s_alias_pool = mempool_create_kmalloc_pool(600, | |
887 | sizeof(struct object_alias_item)); | |
888 | if (!super->s_alias_pool) | |
889 | return -ENOMEM; | |
890 | ||
891 | super->s_journal_area = alloc_area(sb); | |
892 | if (!super->s_journal_area) | |
893 | goto err; | |
894 | ||
895 | for_each_area(i) { | |
896 | super->s_area[i] = alloc_area(sb); | |
897 | if (!super->s_area[i]) | |
898 | goto err; | |
899 | super->s_area[i]->a_level = GC_LEVEL(i); | |
900 | super->s_area[i]->a_ops = &ostore_area_ops; | |
901 | } | |
902 | btree_init_mempool128(&super->s_object_alias_tree, | |
903 | super->s_btree_pool); | |
904 | return 0; | |
905 | ||
906 | err: | |
907 | for (i--; i >= 0; i--) | |
908 | free_area(super->s_area[i]); | |
909 | free_area(super->s_journal_area); | |
910 | mempool_destroy(super->s_alias_pool); | |
911 | return -ENOMEM; | |
912 | } | |
913 | ||
914 | void logfs_cleanup_areas(struct super_block *sb) | |
915 | { | |
916 | struct logfs_super *super = logfs_super(sb); | |
917 | int i; | |
918 | ||
919 | btree_grim_visitor128(&super->s_object_alias_tree, 0, kill_alias); | |
920 | for_each_area(i) | |
921 | free_area(super->s_area[i]); | |
922 | free_area(super->s_journal_area); | |
923 | destroy_meta_inode(super->s_mapping_inode); | |
924 | } |