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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" | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
5db53f3e JE |
14 | |
15 | static int logfs_mark_segment_bad(struct super_block *sb, u32 segno) | |
16 | { | |
17 | struct logfs_super *super = logfs_super(sb); | |
18 | struct btree_head32 *head = &super->s_reserved_segments; | |
19 | int err; | |
20 | ||
21 | err = btree_insert32(head, segno, (void *)1, GFP_NOFS); | |
22 | if (err) | |
23 | return err; | |
24 | logfs_super(sb)->s_bad_segments++; | |
25 | /* FIXME: write to journal */ | |
26 | return 0; | |
27 | } | |
28 | ||
9421502b | 29 | int logfs_erase_segment(struct super_block *sb, u32 segno, int ensure_erase) |
5db53f3e JE |
30 | { |
31 | struct logfs_super *super = logfs_super(sb); | |
32 | ||
33 | super->s_gec++; | |
34 | ||
35 | return super->s_devops->erase(sb, (u64)segno << super->s_segshift, | |
9421502b | 36 | super->s_segsize, ensure_erase); |
5db53f3e JE |
37 | } |
38 | ||
39 | static s64 logfs_get_free_bytes(struct logfs_area *area, size_t bytes) | |
40 | { | |
41 | s32 ofs; | |
42 | ||
43 | logfs_open_area(area, bytes); | |
44 | ||
45 | ofs = area->a_used_bytes; | |
46 | area->a_used_bytes += bytes; | |
47 | BUG_ON(area->a_used_bytes >= logfs_super(area->a_sb)->s_segsize); | |
48 | ||
49 | return dev_ofs(area->a_sb, area->a_segno, ofs); | |
50 | } | |
51 | ||
52 | static struct page *get_mapping_page(struct super_block *sb, pgoff_t index, | |
53 | int use_filler) | |
54 | { | |
55 | struct logfs_super *super = logfs_super(sb); | |
56 | struct address_space *mapping = super->s_mapping_inode->i_mapping; | |
57 | filler_t *filler = super->s_devops->readpage; | |
58 | struct page *page; | |
59 | ||
60 | BUG_ON(mapping_gfp_mask(mapping) & __GFP_FS); | |
61 | if (use_filler) | |
62 | page = read_cache_page(mapping, index, filler, sb); | |
63 | else { | |
64 | page = find_or_create_page(mapping, index, GFP_NOFS); | |
65 | unlock_page(page); | |
66 | } | |
67 | return page; | |
68 | } | |
69 | ||
70 | void __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len, | |
71 | int use_filler) | |
72 | { | |
73 | pgoff_t index = ofs >> PAGE_SHIFT; | |
74 | struct page *page; | |
75 | long offset = ofs & (PAGE_SIZE-1); | |
76 | long copylen; | |
77 | ||
78 | /* Only logfs_wbuf_recover may use len==0 */ | |
79 | BUG_ON(!len && !use_filler); | |
80 | do { | |
81 | copylen = min((ulong)len, PAGE_SIZE - offset); | |
82 | ||
83 | page = get_mapping_page(area->a_sb, index, use_filler); | |
84 | SetPageUptodate(page); | |
85 | BUG_ON(!page); /* FIXME: reserve a pool */ | |
86 | memcpy(page_address(page) + offset, buf, copylen); | |
87 | SetPagePrivate(page); | |
88 | page_cache_release(page); | |
89 | ||
90 | buf += copylen; | |
91 | len -= copylen; | |
92 | offset = 0; | |
93 | index++; | |
94 | } while (len); | |
95 | } | |
96 | ||
97 | /* | |
98 | * bdev_writeseg will write full pages. Memset the tail to prevent data leaks. | |
99 | */ | |
100 | static void pad_wbuf(struct logfs_area *area, int final) | |
101 | { | |
102 | struct super_block *sb = area->a_sb; | |
103 | struct logfs_super *super = logfs_super(sb); | |
104 | struct page *page; | |
105 | u64 ofs = dev_ofs(sb, area->a_segno, area->a_used_bytes); | |
106 | pgoff_t index = ofs >> PAGE_SHIFT; | |
107 | long offset = ofs & (PAGE_SIZE-1); | |
108 | u32 len = PAGE_SIZE - offset; | |
109 | ||
110 | if (len == PAGE_SIZE) { | |
111 | /* The math in this function can surely use some love */ | |
112 | len = 0; | |
113 | } | |
114 | if (len) { | |
115 | BUG_ON(area->a_used_bytes >= super->s_segsize); | |
116 | ||
117 | page = get_mapping_page(area->a_sb, index, 0); | |
118 | BUG_ON(!page); /* FIXME: reserve a pool */ | |
119 | memset(page_address(page) + offset, 0xff, len); | |
120 | SetPagePrivate(page); | |
121 | page_cache_release(page); | |
122 | } | |
123 | ||
124 | if (!final) | |
125 | return; | |
126 | ||
127 | area->a_used_bytes += len; | |
128 | for ( ; area->a_used_bytes < super->s_segsize; | |
129 | area->a_used_bytes += PAGE_SIZE) { | |
130 | /* Memset another page */ | |
131 | index++; | |
132 | page = get_mapping_page(area->a_sb, index, 0); | |
133 | BUG_ON(!page); /* FIXME: reserve a pool */ | |
134 | memset(page_address(page), 0xff, PAGE_SIZE); | |
135 | SetPagePrivate(page); | |
136 | page_cache_release(page); | |
137 | } | |
138 | } | |
139 | ||
140 | /* | |
141 | * We have to be careful with the alias tree. Since lookup is done by bix, | |
142 | * it needs to be normalized, so 14, 15, 16, etc. all match when dealing with | |
143 | * indirect blocks. So always use it through accessor functions. | |
144 | */ | |
145 | static void *alias_tree_lookup(struct super_block *sb, u64 ino, u64 bix, | |
146 | level_t level) | |
147 | { | |
148 | struct btree_head128 *head = &logfs_super(sb)->s_object_alias_tree; | |
149 | pgoff_t index = logfs_pack_index(bix, level); | |
150 | ||
151 | return btree_lookup128(head, ino, index); | |
152 | } | |
153 | ||
154 | static int alias_tree_insert(struct super_block *sb, u64 ino, u64 bix, | |
155 | level_t level, void *val) | |
156 | { | |
157 | struct btree_head128 *head = &logfs_super(sb)->s_object_alias_tree; | |
158 | pgoff_t index = logfs_pack_index(bix, level); | |
159 | ||
160 | return btree_insert128(head, ino, index, val, GFP_NOFS); | |
161 | } | |
162 | ||
163 | static int btree_write_alias(struct super_block *sb, struct logfs_block *block, | |
164 | write_alias_t *write_one_alias) | |
165 | { | |
166 | struct object_alias_item *item; | |
167 | int err; | |
168 | ||
169 | list_for_each_entry(item, &block->item_list, list) { | |
170 | err = write_alias_journal(sb, block->ino, block->bix, | |
171 | block->level, item->child_no, item->val); | |
172 | if (err) | |
173 | return err; | |
174 | } | |
175 | return 0; | |
176 | } | |
177 | ||
178 | static gc_level_t btree_block_level(struct logfs_block *block) | |
179 | { | |
180 | return expand_level(block->ino, block->level); | |
181 | } | |
182 | ||
183 | static struct logfs_block_ops btree_block_ops = { | |
184 | .write_block = btree_write_block, | |
185 | .block_level = btree_block_level, | |
186 | .free_block = __free_block, | |
187 | .write_alias = btree_write_alias, | |
188 | }; | |
189 | ||
190 | int logfs_load_object_aliases(struct super_block *sb, | |
191 | struct logfs_obj_alias *oa, int count) | |
192 | { | |
193 | struct logfs_super *super = logfs_super(sb); | |
194 | struct logfs_block *block; | |
195 | struct object_alias_item *item; | |
196 | u64 ino, bix; | |
197 | level_t level; | |
198 | int i, err; | |
199 | ||
200 | super->s_flags |= LOGFS_SB_FLAG_OBJ_ALIAS; | |
201 | count /= sizeof(*oa); | |
202 | for (i = 0; i < count; i++) { | |
203 | item = mempool_alloc(super->s_alias_pool, GFP_NOFS); | |
204 | if (!item) | |
205 | return -ENOMEM; | |
206 | memset(item, 0, sizeof(*item)); | |
207 | ||
208 | super->s_no_object_aliases++; | |
209 | item->val = oa[i].val; | |
210 | item->child_no = be16_to_cpu(oa[i].child_no); | |
211 | ||
212 | ino = be64_to_cpu(oa[i].ino); | |
213 | bix = be64_to_cpu(oa[i].bix); | |
214 | level = LEVEL(oa[i].level); | |
215 | ||
216 | log_aliases("logfs_load_object_aliases(%llx, %llx, %x, %x) %llx\n", | |
217 | ino, bix, level, item->child_no, | |
218 | be64_to_cpu(item->val)); | |
219 | block = alias_tree_lookup(sb, ino, bix, level); | |
220 | if (!block) { | |
221 | block = __alloc_block(sb, ino, bix, level); | |
222 | block->ops = &btree_block_ops; | |
223 | err = alias_tree_insert(sb, ino, bix, level, block); | |
224 | BUG_ON(err); /* mempool empty */ | |
225 | } | |
226 | if (test_and_set_bit(item->child_no, block->alias_map)) { | |
227 | printk(KERN_ERR"LogFS: Alias collision detected\n"); | |
228 | return -EIO; | |
229 | } | |
230 | list_move_tail(&block->alias_list, &super->s_object_alias); | |
231 | list_add(&item->list, &block->item_list); | |
232 | } | |
233 | return 0; | |
234 | } | |
235 | ||
236 | static void kill_alias(void *_block, unsigned long ignore0, | |
237 | u64 ignore1, u64 ignore2, size_t ignore3) | |
238 | { | |
239 | struct logfs_block *block = _block; | |
240 | struct super_block *sb = block->sb; | |
241 | struct logfs_super *super = logfs_super(sb); | |
242 | struct object_alias_item *item; | |
243 | ||
244 | while (!list_empty(&block->item_list)) { | |
245 | item = list_entry(block->item_list.next, typeof(*item), list); | |
246 | list_del(&item->list); | |
247 | mempool_free(item, super->s_alias_pool); | |
248 | } | |
249 | block->ops->free_block(sb, block); | |
250 | } | |
251 | ||
252 | static int obj_type(struct inode *inode, level_t level) | |
253 | { | |
254 | if (level == 0) { | |
255 | if (S_ISDIR(inode->i_mode)) | |
256 | return OBJ_DENTRY; | |
257 | if (inode->i_ino == LOGFS_INO_MASTER) | |
258 | return OBJ_INODE; | |
259 | } | |
260 | return OBJ_BLOCK; | |
261 | } | |
262 | ||
263 | static int obj_len(struct super_block *sb, int obj_type) | |
264 | { | |
265 | switch (obj_type) { | |
266 | case OBJ_DENTRY: | |
267 | return sizeof(struct logfs_disk_dentry); | |
268 | case OBJ_INODE: | |
269 | return sizeof(struct logfs_disk_inode); | |
270 | case OBJ_BLOCK: | |
271 | return sb->s_blocksize; | |
272 | default: | |
273 | BUG(); | |
274 | } | |
275 | } | |
276 | ||
277 | static int __logfs_segment_write(struct inode *inode, void *buf, | |
278 | struct logfs_shadow *shadow, int type, int len, int compr) | |
279 | { | |
280 | struct logfs_area *area; | |
281 | struct super_block *sb = inode->i_sb; | |
282 | s64 ofs; | |
283 | struct logfs_object_header h; | |
284 | int acc_len; | |
285 | ||
286 | if (shadow->gc_level == 0) | |
287 | acc_len = len; | |
288 | else | |
289 | acc_len = obj_len(sb, type); | |
290 | ||
291 | area = get_area(sb, shadow->gc_level); | |
292 | ofs = logfs_get_free_bytes(area, len + LOGFS_OBJECT_HEADERSIZE); | |
293 | LOGFS_BUG_ON(ofs <= 0, sb); | |
294 | /* | |
295 | * Order is important. logfs_get_free_bytes(), by modifying the | |
296 | * segment file, may modify the content of the very page we're about | |
297 | * to write now. Which is fine, as long as the calculated crc and | |
298 | * written data still match. So do the modifications _before_ | |
299 | * calculating the crc. | |
300 | */ | |
301 | ||
302 | h.len = cpu_to_be16(len); | |
303 | h.type = type; | |
304 | h.compr = compr; | |
305 | h.ino = cpu_to_be64(inode->i_ino); | |
306 | h.bix = cpu_to_be64(shadow->bix); | |
307 | h.crc = logfs_crc32(&h, sizeof(h) - 4, 4); | |
308 | h.data_crc = logfs_crc32(buf, len, 0); | |
309 | ||
310 | logfs_buf_write(area, ofs, &h, sizeof(h)); | |
311 | logfs_buf_write(area, ofs + LOGFS_OBJECT_HEADERSIZE, buf, len); | |
312 | ||
313 | shadow->new_ofs = ofs; | |
314 | shadow->new_len = acc_len + LOGFS_OBJECT_HEADERSIZE; | |
315 | ||
316 | return 0; | |
317 | } | |
318 | ||
319 | static s64 logfs_segment_write_compress(struct inode *inode, void *buf, | |
320 | struct logfs_shadow *shadow, int type, int len) | |
321 | { | |
322 | struct super_block *sb = inode->i_sb; | |
323 | void *compressor_buf = logfs_super(sb)->s_compressed_je; | |
324 | ssize_t compr_len; | |
325 | int ret; | |
326 | ||
327 | mutex_lock(&logfs_super(sb)->s_journal_mutex); | |
328 | compr_len = logfs_compress(buf, compressor_buf, len, len); | |
329 | ||
330 | if (compr_len >= 0) { | |
331 | ret = __logfs_segment_write(inode, compressor_buf, shadow, | |
332 | type, compr_len, COMPR_ZLIB); | |
333 | } else { | |
334 | ret = __logfs_segment_write(inode, buf, shadow, type, len, | |
335 | COMPR_NONE); | |
336 | } | |
337 | mutex_unlock(&logfs_super(sb)->s_journal_mutex); | |
338 | return ret; | |
339 | } | |
340 | ||
341 | /** | |
342 | * logfs_segment_write - write data block to object store | |
343 | * @inode: inode containing data | |
344 | * | |
345 | * Returns an errno or zero. | |
346 | */ | |
347 | int logfs_segment_write(struct inode *inode, struct page *page, | |
348 | struct logfs_shadow *shadow) | |
349 | { | |
350 | struct super_block *sb = inode->i_sb; | |
351 | struct logfs_super *super = logfs_super(sb); | |
352 | int do_compress, type, len; | |
353 | int ret; | |
354 | void *buf; | |
355 | ||
c6d38301 JE |
356 | super->s_flags |= LOGFS_SB_FLAG_DIRTY; |
357 | BUG_ON(super->s_flags & LOGFS_SB_FLAG_SHUTDOWN); | |
5db53f3e JE |
358 | do_compress = logfs_inode(inode)->li_flags & LOGFS_IF_COMPRESSED; |
359 | if (shadow->gc_level != 0) { | |
360 | /* temporarily disable compression for indirect blocks */ | |
361 | do_compress = 0; | |
362 | } | |
363 | ||
364 | type = obj_type(inode, shrink_level(shadow->gc_level)); | |
365 | len = obj_len(sb, type); | |
366 | buf = kmap(page); | |
367 | if (do_compress) | |
368 | ret = logfs_segment_write_compress(inode, buf, shadow, type, | |
369 | len); | |
370 | else | |
371 | ret = __logfs_segment_write(inode, buf, shadow, type, len, | |
372 | COMPR_NONE); | |
373 | kunmap(page); | |
374 | ||
375 | log_segment("logfs_segment_write(%llx, %llx, %x) %llx->%llx %x->%x\n", | |
376 | shadow->ino, shadow->bix, shadow->gc_level, | |
377 | shadow->old_ofs, shadow->new_ofs, | |
378 | shadow->old_len, shadow->new_len); | |
379 | /* this BUG_ON did catch a locking bug. useful */ | |
380 | BUG_ON(!(shadow->new_ofs & (super->s_segsize - 1))); | |
381 | return ret; | |
382 | } | |
383 | ||
384 | int wbuf_read(struct super_block *sb, u64 ofs, size_t len, void *buf) | |
385 | { | |
386 | pgoff_t index = ofs >> PAGE_SHIFT; | |
387 | struct page *page; | |
388 | long offset = ofs & (PAGE_SIZE-1); | |
389 | long copylen; | |
390 | ||
391 | while (len) { | |
392 | copylen = min((ulong)len, PAGE_SIZE - offset); | |
393 | ||
394 | page = get_mapping_page(sb, index, 1); | |
395 | if (IS_ERR(page)) | |
396 | return PTR_ERR(page); | |
397 | memcpy(buf, page_address(page) + offset, copylen); | |
398 | page_cache_release(page); | |
399 | ||
400 | buf += copylen; | |
401 | len -= copylen; | |
402 | offset = 0; | |
403 | index++; | |
404 | } | |
405 | return 0; | |
406 | } | |
407 | ||
408 | /* | |
409 | * The "position" of indirect blocks is ambiguous. It can be the position | |
410 | * of any data block somewhere behind this indirect block. So we need to | |
411 | * normalize the positions through logfs_block_mask() before comparing. | |
412 | */ | |
413 | static int check_pos(struct super_block *sb, u64 pos1, u64 pos2, level_t level) | |
414 | { | |
415 | return (pos1 & logfs_block_mask(sb, level)) != | |
416 | (pos2 & logfs_block_mask(sb, level)); | |
417 | } | |
418 | ||
419 | #if 0 | |
420 | static int read_seg_header(struct super_block *sb, u64 ofs, | |
421 | struct logfs_segment_header *sh) | |
422 | { | |
423 | __be32 crc; | |
424 | int err; | |
425 | ||
426 | err = wbuf_read(sb, ofs, sizeof(*sh), sh); | |
427 | if (err) | |
428 | return err; | |
429 | crc = logfs_crc32(sh, sizeof(*sh), 4); | |
430 | if (crc != sh->crc) { | |
431 | printk(KERN_ERR"LOGFS: header crc error at %llx: expected %x, " | |
432 | "got %x\n", ofs, be32_to_cpu(sh->crc), | |
433 | be32_to_cpu(crc)); | |
434 | return -EIO; | |
435 | } | |
436 | return 0; | |
437 | } | |
438 | #endif | |
439 | ||
440 | static int read_obj_header(struct super_block *sb, u64 ofs, | |
441 | struct logfs_object_header *oh) | |
442 | { | |
443 | __be32 crc; | |
444 | int err; | |
445 | ||
446 | err = wbuf_read(sb, ofs, sizeof(*oh), oh); | |
447 | if (err) | |
448 | return err; | |
449 | crc = logfs_crc32(oh, sizeof(*oh) - 4, 4); | |
450 | if (crc != oh->crc) { | |
451 | printk(KERN_ERR"LOGFS: header crc error at %llx: expected %x, " | |
452 | "got %x\n", ofs, be32_to_cpu(oh->crc), | |
453 | be32_to_cpu(crc)); | |
454 | return -EIO; | |
455 | } | |
456 | return 0; | |
457 | } | |
458 | ||
459 | static void move_btree_to_page(struct inode *inode, struct page *page, | |
460 | __be64 *data) | |
461 | { | |
462 | struct super_block *sb = inode->i_sb; | |
463 | struct logfs_super *super = logfs_super(sb); | |
464 | struct btree_head128 *head = &super->s_object_alias_tree; | |
465 | struct logfs_block *block; | |
466 | struct object_alias_item *item, *next; | |
467 | ||
468 | if (!(super->s_flags & LOGFS_SB_FLAG_OBJ_ALIAS)) | |
469 | return; | |
470 | ||
471 | block = btree_remove128(head, inode->i_ino, page->index); | |
472 | if (!block) | |
473 | return; | |
474 | ||
475 | log_blockmove("move_btree_to_page(%llx, %llx, %x)\n", | |
476 | block->ino, block->bix, block->level); | |
477 | list_for_each_entry_safe(item, next, &block->item_list, list) { | |
478 | data[item->child_no] = item->val; | |
479 | list_del(&item->list); | |
480 | mempool_free(item, super->s_alias_pool); | |
481 | } | |
482 | block->page = page; | |
483 | SetPagePrivate(page); | |
484 | page->private = (unsigned long)block; | |
485 | block->ops = &indirect_block_ops; | |
486 | initialize_block_counters(page, block, data, 0); | |
487 | } | |
488 | ||
489 | /* | |
490 | * This silences a false, yet annoying gcc warning. I hate it when my editor | |
491 | * jumps into bitops.h each time I recompile this file. | |
492 | * TODO: Complain to gcc folks about this and upgrade compiler. | |
493 | */ | |
494 | static unsigned long fnb(const unsigned long *addr, | |
495 | unsigned long size, unsigned long offset) | |
496 | { | |
497 | return find_next_bit(addr, size, offset); | |
498 | } | |
499 | ||
500 | void move_page_to_btree(struct page *page) | |
501 | { | |
502 | struct logfs_block *block = logfs_block(page); | |
503 | struct super_block *sb = block->sb; | |
504 | struct logfs_super *super = logfs_super(sb); | |
505 | struct object_alias_item *item; | |
506 | unsigned long pos; | |
507 | __be64 *child; | |
508 | int err; | |
509 | ||
510 | if (super->s_flags & LOGFS_SB_FLAG_SHUTDOWN) { | |
511 | block->ops->free_block(sb, block); | |
512 | return; | |
513 | } | |
514 | log_blockmove("move_page_to_btree(%llx, %llx, %x)\n", | |
515 | block->ino, block->bix, block->level); | |
516 | super->s_flags |= LOGFS_SB_FLAG_OBJ_ALIAS; | |
517 | ||
518 | for (pos = 0; ; pos++) { | |
519 | pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos); | |
520 | if (pos >= LOGFS_BLOCK_FACTOR) | |
521 | break; | |
522 | ||
523 | item = mempool_alloc(super->s_alias_pool, GFP_NOFS); | |
524 | BUG_ON(!item); /* mempool empty */ | |
525 | memset(item, 0, sizeof(*item)); | |
526 | ||
527 | child = kmap_atomic(page, KM_USER0); | |
528 | item->val = child[pos]; | |
529 | kunmap_atomic(child, KM_USER0); | |
530 | item->child_no = pos; | |
531 | list_add(&item->list, &block->item_list); | |
532 | } | |
533 | block->page = NULL; | |
534 | ClearPagePrivate(page); | |
535 | page->private = 0; | |
536 | block->ops = &btree_block_ops; | |
537 | err = alias_tree_insert(block->sb, block->ino, block->bix, block->level, | |
538 | block); | |
539 | BUG_ON(err); /* mempool empty */ | |
540 | ClearPageUptodate(page); | |
541 | } | |
542 | ||
543 | static int __logfs_segment_read(struct inode *inode, void *buf, | |
544 | u64 ofs, u64 bix, level_t level) | |
545 | { | |
546 | struct super_block *sb = inode->i_sb; | |
547 | void *compressor_buf = logfs_super(sb)->s_compressed_je; | |
548 | struct logfs_object_header oh; | |
549 | __be32 crc; | |
550 | u16 len; | |
551 | int err, block_len; | |
552 | ||
553 | block_len = obj_len(sb, obj_type(inode, level)); | |
554 | err = read_obj_header(sb, ofs, &oh); | |
555 | if (err) | |
556 | goto out_err; | |
557 | ||
558 | err = -EIO; | |
559 | if (be64_to_cpu(oh.ino) != inode->i_ino | |
560 | || check_pos(sb, be64_to_cpu(oh.bix), bix, level)) { | |
561 | printk(KERN_ERR"LOGFS: (ino, bix) don't match at %llx: " | |
562 | "expected (%lx, %llx), got (%llx, %llx)\n", | |
563 | ofs, inode->i_ino, bix, | |
564 | be64_to_cpu(oh.ino), be64_to_cpu(oh.bix)); | |
565 | goto out_err; | |
566 | } | |
567 | ||
568 | len = be16_to_cpu(oh.len); | |
569 | ||
570 | switch (oh.compr) { | |
571 | case COMPR_NONE: | |
572 | err = wbuf_read(sb, ofs + LOGFS_OBJECT_HEADERSIZE, len, buf); | |
573 | if (err) | |
574 | goto out_err; | |
575 | crc = logfs_crc32(buf, len, 0); | |
576 | if (crc != oh.data_crc) { | |
577 | printk(KERN_ERR"LOGFS: uncompressed data crc error at " | |
578 | "%llx: expected %x, got %x\n", ofs, | |
579 | be32_to_cpu(oh.data_crc), | |
580 | be32_to_cpu(crc)); | |
581 | goto out_err; | |
582 | } | |
583 | break; | |
584 | case COMPR_ZLIB: | |
585 | mutex_lock(&logfs_super(sb)->s_journal_mutex); | |
586 | err = wbuf_read(sb, ofs + LOGFS_OBJECT_HEADERSIZE, len, | |
587 | compressor_buf); | |
588 | if (err) { | |
589 | mutex_unlock(&logfs_super(sb)->s_journal_mutex); | |
590 | goto out_err; | |
591 | } | |
592 | crc = logfs_crc32(compressor_buf, len, 0); | |
593 | if (crc != oh.data_crc) { | |
594 | printk(KERN_ERR"LOGFS: compressed data crc error at " | |
595 | "%llx: expected %x, got %x\n", ofs, | |
596 | be32_to_cpu(oh.data_crc), | |
597 | be32_to_cpu(crc)); | |
598 | mutex_unlock(&logfs_super(sb)->s_journal_mutex); | |
599 | goto out_err; | |
600 | } | |
601 | err = logfs_uncompress(compressor_buf, buf, len, block_len); | |
602 | mutex_unlock(&logfs_super(sb)->s_journal_mutex); | |
603 | if (err) { | |
604 | printk(KERN_ERR"LOGFS: uncompress error at %llx\n", ofs); | |
605 | goto out_err; | |
606 | } | |
607 | break; | |
608 | default: | |
609 | LOGFS_BUG(sb); | |
610 | err = -EIO; | |
611 | goto out_err; | |
612 | } | |
613 | return 0; | |
614 | ||
615 | out_err: | |
616 | logfs_set_ro(sb); | |
617 | printk(KERN_ERR"LOGFS: device is read-only now\n"); | |
618 | LOGFS_BUG(sb); | |
619 | return err; | |
620 | } | |
621 | ||
622 | /** | |
623 | * logfs_segment_read - read data block from object store | |
624 | * @inode: inode containing data | |
625 | * @buf: data buffer | |
626 | * @ofs: physical data offset | |
627 | * @bix: block index | |
628 | * @level: block level | |
629 | * | |
630 | * Returns 0 on success or a negative errno. | |
631 | */ | |
632 | int logfs_segment_read(struct inode *inode, struct page *page, | |
633 | u64 ofs, u64 bix, level_t level) | |
634 | { | |
635 | int err; | |
636 | void *buf; | |
637 | ||
638 | if (PageUptodate(page)) | |
639 | return 0; | |
640 | ||
641 | ofs &= ~LOGFS_FULLY_POPULATED; | |
642 | ||
643 | buf = kmap(page); | |
644 | err = __logfs_segment_read(inode, buf, ofs, bix, level); | |
645 | if (!err) { | |
646 | move_btree_to_page(inode, page, buf); | |
647 | SetPageUptodate(page); | |
648 | } | |
649 | kunmap(page); | |
650 | log_segment("logfs_segment_read(%lx, %llx, %x) %llx (%d)\n", | |
651 | inode->i_ino, bix, level, ofs, err); | |
652 | return err; | |
653 | } | |
654 | ||
655 | int logfs_segment_delete(struct inode *inode, struct logfs_shadow *shadow) | |
656 | { | |
657 | struct super_block *sb = inode->i_sb; | |
c6d38301 | 658 | struct logfs_super *super = logfs_super(sb); |
5db53f3e JE |
659 | struct logfs_object_header h; |
660 | u16 len; | |
661 | int err; | |
662 | ||
c6d38301 JE |
663 | super->s_flags |= LOGFS_SB_FLAG_DIRTY; |
664 | BUG_ON(super->s_flags & LOGFS_SB_FLAG_SHUTDOWN); | |
5db53f3e JE |
665 | BUG_ON(shadow->old_ofs & LOGFS_FULLY_POPULATED); |
666 | if (!shadow->old_ofs) | |
667 | return 0; | |
668 | ||
669 | log_segment("logfs_segment_delete(%llx, %llx, %x) %llx->%llx %x->%x\n", | |
670 | shadow->ino, shadow->bix, shadow->gc_level, | |
671 | shadow->old_ofs, shadow->new_ofs, | |
672 | shadow->old_len, shadow->new_len); | |
673 | err = read_obj_header(sb, shadow->old_ofs, &h); | |
674 | LOGFS_BUG_ON(err, sb); | |
675 | LOGFS_BUG_ON(be64_to_cpu(h.ino) != inode->i_ino, sb); | |
676 | LOGFS_BUG_ON(check_pos(sb, shadow->bix, be64_to_cpu(h.bix), | |
677 | shrink_level(shadow->gc_level)), sb); | |
678 | ||
679 | if (shadow->gc_level == 0) | |
680 | len = be16_to_cpu(h.len); | |
681 | else | |
682 | len = obj_len(sb, h.type); | |
683 | shadow->old_len = len + sizeof(h); | |
684 | return 0; | |
685 | } | |
686 | ||
687 | static void freeseg(struct super_block *sb, u32 segno) | |
688 | { | |
689 | struct logfs_super *super = logfs_super(sb); | |
690 | struct address_space *mapping = super->s_mapping_inode->i_mapping; | |
691 | struct page *page; | |
692 | u64 ofs, start, end; | |
693 | ||
694 | start = dev_ofs(sb, segno, 0); | |
695 | end = dev_ofs(sb, segno + 1, 0); | |
696 | for (ofs = start; ofs < end; ofs += PAGE_SIZE) { | |
697 | page = find_get_page(mapping, ofs >> PAGE_SHIFT); | |
698 | if (!page) | |
699 | continue; | |
700 | ClearPagePrivate(page); | |
701 | page_cache_release(page); | |
702 | } | |
703 | } | |
704 | ||
705 | int logfs_open_area(struct logfs_area *area, size_t bytes) | |
706 | { | |
707 | struct super_block *sb = area->a_sb; | |
708 | struct logfs_super *super = logfs_super(sb); | |
709 | int err, closed = 0; | |
710 | ||
711 | if (area->a_is_open && area->a_used_bytes + bytes <= super->s_segsize) | |
712 | return 0; | |
713 | ||
714 | if (area->a_is_open) { | |
715 | u64 ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes); | |
716 | u32 len = super->s_segsize - area->a_written_bytes; | |
717 | ||
718 | log_gc("logfs_close_area(%x)\n", area->a_segno); | |
719 | pad_wbuf(area, 1); | |
720 | super->s_devops->writeseg(area->a_sb, ofs, len); | |
721 | freeseg(sb, area->a_segno); | |
722 | closed = 1; | |
723 | } | |
724 | ||
725 | area->a_used_bytes = 0; | |
726 | area->a_written_bytes = 0; | |
727 | again: | |
728 | area->a_ops->get_free_segment(area); | |
729 | area->a_ops->get_erase_count(area); | |
730 | ||
731 | log_gc("logfs_open_area(%x, %x)\n", area->a_segno, area->a_level); | |
732 | err = area->a_ops->erase_segment(area); | |
733 | if (err) { | |
734 | printk(KERN_WARNING "LogFS: Error erasing segment %x\n", | |
735 | area->a_segno); | |
736 | logfs_mark_segment_bad(sb, area->a_segno); | |
737 | goto again; | |
738 | } | |
739 | area->a_is_open = 1; | |
740 | return closed; | |
741 | } | |
742 | ||
743 | void logfs_sync_area(struct logfs_area *area) | |
744 | { | |
745 | struct super_block *sb = area->a_sb; | |
746 | struct logfs_super *super = logfs_super(sb); | |
747 | u64 ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes); | |
748 | u32 len = (area->a_used_bytes - area->a_written_bytes); | |
749 | ||
750 | if (super->s_writesize) | |
751 | len &= ~(super->s_writesize - 1); | |
752 | if (len == 0) | |
753 | return; | |
754 | pad_wbuf(area, 0); | |
755 | super->s_devops->writeseg(sb, ofs, len); | |
756 | area->a_written_bytes += len; | |
757 | } | |
758 | ||
759 | void logfs_sync_segments(struct super_block *sb) | |
760 | { | |
761 | struct logfs_super *super = logfs_super(sb); | |
762 | int i; | |
763 | ||
764 | for_each_area(i) | |
765 | logfs_sync_area(super->s_area[i]); | |
766 | } | |
767 | ||
768 | /* | |
769 | * Pick a free segment to be used for this area. Effectively takes a | |
770 | * candidate from the free list (not really a candidate anymore). | |
771 | */ | |
772 | static void ostore_get_free_segment(struct logfs_area *area) | |
773 | { | |
774 | struct super_block *sb = area->a_sb; | |
775 | struct logfs_super *super = logfs_super(sb); | |
776 | ||
777 | if (super->s_free_list.count == 0) { | |
778 | printk(KERN_ERR"LOGFS: ran out of free segments\n"); | |
779 | LOGFS_BUG(sb); | |
780 | } | |
781 | ||
782 | area->a_segno = get_best_cand(sb, &super->s_free_list, NULL); | |
783 | } | |
784 | ||
785 | static void ostore_get_erase_count(struct logfs_area *area) | |
786 | { | |
787 | struct logfs_segment_entry se; | |
788 | u32 ec_level; | |
789 | ||
790 | logfs_get_segment_entry(area->a_sb, area->a_segno, &se); | |
791 | BUG_ON(se.ec_level == cpu_to_be32(BADSEG) || | |
792 | se.valid == cpu_to_be32(RESERVED)); | |
793 | ||
794 | ec_level = be32_to_cpu(se.ec_level); | |
795 | area->a_erase_count = (ec_level >> 4) + 1; | |
796 | } | |
797 | ||
798 | static int ostore_erase_segment(struct logfs_area *area) | |
799 | { | |
800 | struct super_block *sb = area->a_sb; | |
801 | struct logfs_segment_header sh; | |
802 | u64 ofs; | |
803 | int err; | |
804 | ||
9421502b | 805 | err = logfs_erase_segment(sb, area->a_segno, 0); |
5db53f3e JE |
806 | if (err) |
807 | return err; | |
808 | ||
809 | sh.pad = 0; | |
810 | sh.type = SEG_OSTORE; | |
811 | sh.level = (__force u8)area->a_level; | |
812 | sh.segno = cpu_to_be32(area->a_segno); | |
813 | sh.ec = cpu_to_be32(area->a_erase_count); | |
814 | sh.gec = cpu_to_be64(logfs_super(sb)->s_gec); | |
815 | sh.crc = logfs_crc32(&sh, sizeof(sh), 4); | |
816 | ||
817 | logfs_set_segment_erased(sb, area->a_segno, area->a_erase_count, | |
818 | area->a_level); | |
819 | ||
820 | ofs = dev_ofs(sb, area->a_segno, 0); | |
821 | area->a_used_bytes = sizeof(sh); | |
822 | logfs_buf_write(area, ofs, &sh, sizeof(sh)); | |
823 | return 0; | |
824 | } | |
825 | ||
826 | static const struct logfs_area_ops ostore_area_ops = { | |
827 | .get_free_segment = ostore_get_free_segment, | |
828 | .get_erase_count = ostore_get_erase_count, | |
829 | .erase_segment = ostore_erase_segment, | |
830 | }; | |
831 | ||
832 | static void free_area(struct logfs_area *area) | |
833 | { | |
834 | if (area) | |
835 | freeseg(area->a_sb, area->a_segno); | |
836 | kfree(area); | |
837 | } | |
838 | ||
839 | static struct logfs_area *alloc_area(struct super_block *sb) | |
840 | { | |
841 | struct logfs_area *area; | |
842 | ||
843 | area = kzalloc(sizeof(*area), GFP_KERNEL); | |
844 | if (!area) | |
845 | return NULL; | |
846 | ||
847 | area->a_sb = sb; | |
848 | return area; | |
849 | } | |
850 | ||
851 | static void map_invalidatepage(struct page *page, unsigned long l) | |
852 | { | |
853 | BUG(); | |
854 | } | |
855 | ||
856 | static int map_releasepage(struct page *page, gfp_t g) | |
857 | { | |
858 | /* Don't release these pages */ | |
859 | return 0; | |
860 | } | |
861 | ||
862 | static const struct address_space_operations mapping_aops = { | |
863 | .invalidatepage = map_invalidatepage, | |
864 | .releasepage = map_releasepage, | |
865 | .set_page_dirty = __set_page_dirty_nobuffers, | |
866 | }; | |
867 | ||
868 | int logfs_init_mapping(struct super_block *sb) | |
869 | { | |
870 | struct logfs_super *super = logfs_super(sb); | |
871 | struct address_space *mapping; | |
872 | struct inode *inode; | |
873 | ||
874 | inode = logfs_new_meta_inode(sb, LOGFS_INO_MAPPING); | |
875 | if (IS_ERR(inode)) | |
876 | return PTR_ERR(inode); | |
877 | super->s_mapping_inode = inode; | |
878 | mapping = inode->i_mapping; | |
879 | mapping->a_ops = &mapping_aops; | |
880 | /* Would it be possible to use __GFP_HIGHMEM as well? */ | |
881 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
882 | return 0; | |
883 | } | |
884 | ||
885 | int logfs_init_areas(struct super_block *sb) | |
886 | { | |
887 | struct logfs_super *super = logfs_super(sb); | |
888 | int i = -1; | |
889 | ||
890 | super->s_alias_pool = mempool_create_kmalloc_pool(600, | |
891 | sizeof(struct object_alias_item)); | |
892 | if (!super->s_alias_pool) | |
893 | return -ENOMEM; | |
894 | ||
895 | super->s_journal_area = alloc_area(sb); | |
896 | if (!super->s_journal_area) | |
897 | goto err; | |
898 | ||
899 | for_each_area(i) { | |
900 | super->s_area[i] = alloc_area(sb); | |
901 | if (!super->s_area[i]) | |
902 | goto err; | |
903 | super->s_area[i]->a_level = GC_LEVEL(i); | |
904 | super->s_area[i]->a_ops = &ostore_area_ops; | |
905 | } | |
906 | btree_init_mempool128(&super->s_object_alias_tree, | |
907 | super->s_btree_pool); | |
908 | return 0; | |
909 | ||
910 | err: | |
911 | for (i--; i >= 0; i--) | |
912 | free_area(super->s_area[i]); | |
913 | free_area(super->s_journal_area); | |
914 | mempool_destroy(super->s_alias_pool); | |
915 | return -ENOMEM; | |
916 | } | |
917 | ||
918 | void logfs_cleanup_areas(struct super_block *sb) | |
919 | { | |
920 | struct logfs_super *super = logfs_super(sb); | |
921 | int i; | |
922 | ||
923 | btree_grim_visitor128(&super->s_object_alias_tree, 0, kill_alias); | |
924 | for_each_area(i) | |
925 | free_area(super->s_area[i]); | |
926 | free_area(super->s_journal_area); | |
927 | destroy_meta_inode(super->s_mapping_inode); | |
928 | } |