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5db53f3e JE |
1 | /* |
2 | * fs/logfs/readwrite.c | |
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 | * | |
9 | * Actually contains five sets of very similar functions: | |
10 | * read read blocks from a file | |
11 | * seek_hole find next hole | |
12 | * seek_data find next data block | |
13 | * valid check whether a block still belongs to a file | |
14 | * write write blocks to a file | |
15 | * delete delete a block (for directories and ifile) | |
16 | * rewrite move existing blocks of a file to a new location (gc helper) | |
17 | * truncate truncate a file | |
18 | */ | |
19 | #include "logfs.h" | |
20 | #include <linux/sched.h> | |
5a0e3ad6 | 21 | #include <linux/slab.h> |
5db53f3e JE |
22 | |
23 | static u64 adjust_bix(u64 bix, level_t level) | |
24 | { | |
25 | switch (level) { | |
26 | case 0: | |
27 | return bix; | |
28 | case LEVEL(1): | |
29 | return max_t(u64, bix, I0_BLOCKS); | |
30 | case LEVEL(2): | |
31 | return max_t(u64, bix, I1_BLOCKS); | |
32 | case LEVEL(3): | |
33 | return max_t(u64, bix, I2_BLOCKS); | |
34 | case LEVEL(4): | |
35 | return max_t(u64, bix, I3_BLOCKS); | |
36 | case LEVEL(5): | |
37 | return max_t(u64, bix, I4_BLOCKS); | |
38 | default: | |
39 | WARN_ON(1); | |
40 | return bix; | |
41 | } | |
42 | } | |
43 | ||
44 | static inline u64 maxbix(u8 height) | |
45 | { | |
46 | return 1ULL << (LOGFS_BLOCK_BITS * height); | |
47 | } | |
48 | ||
49 | /** | |
50 | * The inode address space is cut in two halves. Lower half belongs to data | |
51 | * pages, upper half to indirect blocks. If the high bit (INDIRECT_BIT) is | |
52 | * set, the actual block index (bix) and level can be derived from the page | |
53 | * index. | |
54 | * | |
55 | * The lowest three bits of the block index are set to 0 after packing and | |
56 | * unpacking. Since the lowest n bits (9 for 4KiB blocksize) are ignored | |
57 | * anyway this is harmless. | |
58 | */ | |
59 | #define ARCH_SHIFT (BITS_PER_LONG - 32) | |
60 | #define INDIRECT_BIT (0x80000000UL << ARCH_SHIFT) | |
61 | #define LEVEL_SHIFT (28 + ARCH_SHIFT) | |
62 | static inline pgoff_t first_indirect_block(void) | |
63 | { | |
64 | return INDIRECT_BIT | (1ULL << LEVEL_SHIFT); | |
65 | } | |
66 | ||
67 | pgoff_t logfs_pack_index(u64 bix, level_t level) | |
68 | { | |
69 | pgoff_t index; | |
70 | ||
71 | BUG_ON(bix >= INDIRECT_BIT); | |
72 | if (level == 0) | |
73 | return bix; | |
74 | ||
75 | index = INDIRECT_BIT; | |
76 | index |= (__force long)level << LEVEL_SHIFT; | |
77 | index |= bix >> ((__force u8)level * LOGFS_BLOCK_BITS); | |
78 | return index; | |
79 | } | |
80 | ||
81 | void logfs_unpack_index(pgoff_t index, u64 *bix, level_t *level) | |
82 | { | |
83 | u8 __level; | |
84 | ||
85 | if (!(index & INDIRECT_BIT)) { | |
86 | *bix = index; | |
87 | *level = 0; | |
88 | return; | |
89 | } | |
90 | ||
91 | __level = (index & ~INDIRECT_BIT) >> LEVEL_SHIFT; | |
92 | *level = LEVEL(__level); | |
93 | *bix = (index << (__level * LOGFS_BLOCK_BITS)) & ~INDIRECT_BIT; | |
94 | *bix = adjust_bix(*bix, *level); | |
95 | return; | |
96 | } | |
97 | #undef ARCH_SHIFT | |
98 | #undef INDIRECT_BIT | |
99 | #undef LEVEL_SHIFT | |
100 | ||
101 | /* | |
102 | * Time is stored as nanoseconds since the epoch. | |
103 | */ | |
104 | static struct timespec be64_to_timespec(__be64 betime) | |
105 | { | |
106 | return ns_to_timespec(be64_to_cpu(betime)); | |
107 | } | |
108 | ||
109 | static __be64 timespec_to_be64(struct timespec tsp) | |
110 | { | |
111 | return cpu_to_be64((u64)tsp.tv_sec * NSEC_PER_SEC + tsp.tv_nsec); | |
112 | } | |
113 | ||
114 | static void logfs_disk_to_inode(struct logfs_disk_inode *di, struct inode*inode) | |
115 | { | |
116 | struct logfs_inode *li = logfs_inode(inode); | |
117 | int i; | |
118 | ||
119 | inode->i_mode = be16_to_cpu(di->di_mode); | |
120 | li->li_height = di->di_height; | |
121 | li->li_flags = be32_to_cpu(di->di_flags); | |
122 | inode->i_uid = be32_to_cpu(di->di_uid); | |
123 | inode->i_gid = be32_to_cpu(di->di_gid); | |
124 | inode->i_size = be64_to_cpu(di->di_size); | |
125 | logfs_set_blocks(inode, be64_to_cpu(di->di_used_bytes)); | |
126 | inode->i_atime = be64_to_timespec(di->di_atime); | |
127 | inode->i_ctime = be64_to_timespec(di->di_ctime); | |
128 | inode->i_mtime = be64_to_timespec(di->di_mtime); | |
129 | inode->i_nlink = be32_to_cpu(di->di_refcount); | |
130 | inode->i_generation = be32_to_cpu(di->di_generation); | |
131 | ||
132 | switch (inode->i_mode & S_IFMT) { | |
133 | case S_IFSOCK: /* fall through */ | |
134 | case S_IFBLK: /* fall through */ | |
135 | case S_IFCHR: /* fall through */ | |
136 | case S_IFIFO: | |
137 | inode->i_rdev = be64_to_cpu(di->di_data[0]); | |
138 | break; | |
139 | case S_IFDIR: /* fall through */ | |
140 | case S_IFREG: /* fall through */ | |
141 | case S_IFLNK: | |
142 | for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++) | |
143 | li->li_data[i] = be64_to_cpu(di->di_data[i]); | |
144 | break; | |
145 | default: | |
146 | BUG(); | |
147 | } | |
148 | } | |
149 | ||
150 | static void logfs_inode_to_disk(struct inode *inode, struct logfs_disk_inode*di) | |
151 | { | |
152 | struct logfs_inode *li = logfs_inode(inode); | |
153 | int i; | |
154 | ||
155 | di->di_mode = cpu_to_be16(inode->i_mode); | |
156 | di->di_height = li->li_height; | |
157 | di->di_pad = 0; | |
158 | di->di_flags = cpu_to_be32(li->li_flags); | |
159 | di->di_uid = cpu_to_be32(inode->i_uid); | |
160 | di->di_gid = cpu_to_be32(inode->i_gid); | |
161 | di->di_size = cpu_to_be64(i_size_read(inode)); | |
162 | di->di_used_bytes = cpu_to_be64(li->li_used_bytes); | |
163 | di->di_atime = timespec_to_be64(inode->i_atime); | |
164 | di->di_ctime = timespec_to_be64(inode->i_ctime); | |
165 | di->di_mtime = timespec_to_be64(inode->i_mtime); | |
166 | di->di_refcount = cpu_to_be32(inode->i_nlink); | |
167 | di->di_generation = cpu_to_be32(inode->i_generation); | |
168 | ||
169 | switch (inode->i_mode & S_IFMT) { | |
170 | case S_IFSOCK: /* fall through */ | |
171 | case S_IFBLK: /* fall through */ | |
172 | case S_IFCHR: /* fall through */ | |
173 | case S_IFIFO: | |
174 | di->di_data[0] = cpu_to_be64(inode->i_rdev); | |
175 | break; | |
176 | case S_IFDIR: /* fall through */ | |
177 | case S_IFREG: /* fall through */ | |
178 | case S_IFLNK: | |
179 | for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++) | |
180 | di->di_data[i] = cpu_to_be64(li->li_data[i]); | |
181 | break; | |
182 | default: | |
183 | BUG(); | |
184 | } | |
185 | } | |
186 | ||
187 | static void __logfs_set_blocks(struct inode *inode) | |
188 | { | |
189 | struct super_block *sb = inode->i_sb; | |
190 | struct logfs_inode *li = logfs_inode(inode); | |
191 | ||
192 | inode->i_blocks = ULONG_MAX; | |
193 | if (li->li_used_bytes >> sb->s_blocksize_bits < ULONG_MAX) | |
194 | inode->i_blocks = ALIGN(li->li_used_bytes, 512) >> 9; | |
195 | } | |
196 | ||
197 | void logfs_set_blocks(struct inode *inode, u64 bytes) | |
198 | { | |
199 | struct logfs_inode *li = logfs_inode(inode); | |
200 | ||
201 | li->li_used_bytes = bytes; | |
202 | __logfs_set_blocks(inode); | |
203 | } | |
204 | ||
205 | static void prelock_page(struct super_block *sb, struct page *page, int lock) | |
206 | { | |
207 | struct logfs_super *super = logfs_super(sb); | |
208 | ||
209 | BUG_ON(!PageLocked(page)); | |
210 | if (lock) { | |
211 | BUG_ON(PagePreLocked(page)); | |
212 | SetPagePreLocked(page); | |
213 | } else { | |
214 | /* We are in GC path. */ | |
215 | if (PagePreLocked(page)) | |
216 | super->s_lock_count++; | |
217 | else | |
218 | SetPagePreLocked(page); | |
219 | } | |
220 | } | |
221 | ||
222 | static void preunlock_page(struct super_block *sb, struct page *page, int lock) | |
223 | { | |
224 | struct logfs_super *super = logfs_super(sb); | |
225 | ||
226 | BUG_ON(!PageLocked(page)); | |
227 | if (lock) | |
228 | ClearPagePreLocked(page); | |
229 | else { | |
230 | /* We are in GC path. */ | |
231 | BUG_ON(!PagePreLocked(page)); | |
232 | if (super->s_lock_count) | |
233 | super->s_lock_count--; | |
234 | else | |
235 | ClearPagePreLocked(page); | |
236 | } | |
237 | } | |
238 | ||
239 | /* | |
240 | * Logfs is prone to an AB-BA deadlock where one task tries to acquire | |
241 | * s_write_mutex with a locked page and GC tries to get that page while holding | |
242 | * s_write_mutex. | |
243 | * To solve this issue logfs will ignore the page lock iff the page in question | |
244 | * is waiting for s_write_mutex. We annotate this fact by setting PG_pre_locked | |
245 | * in addition to PG_locked. | |
246 | */ | |
247 | static void logfs_get_wblocks(struct super_block *sb, struct page *page, | |
248 | int lock) | |
249 | { | |
250 | struct logfs_super *super = logfs_super(sb); | |
251 | ||
252 | if (page) | |
253 | prelock_page(sb, page, lock); | |
254 | ||
255 | if (lock) { | |
256 | mutex_lock(&super->s_write_mutex); | |
257 | logfs_gc_pass(sb); | |
258 | /* FIXME: We also have to check for shadowed space | |
259 | * and mempool fill grade */ | |
260 | } | |
261 | } | |
262 | ||
263 | static void logfs_put_wblocks(struct super_block *sb, struct page *page, | |
264 | int lock) | |
265 | { | |
266 | struct logfs_super *super = logfs_super(sb); | |
267 | ||
268 | if (page) | |
269 | preunlock_page(sb, page, lock); | |
270 | /* Order matters - we must clear PG_pre_locked before releasing | |
271 | * s_write_mutex or we could race against another task. */ | |
272 | if (lock) | |
273 | mutex_unlock(&super->s_write_mutex); | |
274 | } | |
275 | ||
276 | static struct page *logfs_get_read_page(struct inode *inode, u64 bix, | |
277 | level_t level) | |
278 | { | |
279 | return find_or_create_page(inode->i_mapping, | |
280 | logfs_pack_index(bix, level), GFP_NOFS); | |
281 | } | |
282 | ||
283 | static void logfs_put_read_page(struct page *page) | |
284 | { | |
285 | unlock_page(page); | |
286 | page_cache_release(page); | |
287 | } | |
288 | ||
289 | static void logfs_lock_write_page(struct page *page) | |
290 | { | |
291 | int loop = 0; | |
292 | ||
293 | while (unlikely(!trylock_page(page))) { | |
294 | if (loop++ > 0x1000) { | |
295 | /* Has been observed once so far... */ | |
296 | printk(KERN_ERR "stack at %p\n", &loop); | |
297 | BUG(); | |
298 | } | |
299 | if (PagePreLocked(page)) { | |
300 | /* Holder of page lock is waiting for us, it | |
301 | * is safe to use this page. */ | |
302 | break; | |
303 | } | |
304 | /* Some other process has this page locked and has | |
305 | * nothing to do with us. Wait for it to finish. | |
306 | */ | |
307 | schedule(); | |
308 | } | |
309 | BUG_ON(!PageLocked(page)); | |
310 | } | |
311 | ||
312 | static struct page *logfs_get_write_page(struct inode *inode, u64 bix, | |
313 | level_t level) | |
314 | { | |
315 | struct address_space *mapping = inode->i_mapping; | |
316 | pgoff_t index = logfs_pack_index(bix, level); | |
317 | struct page *page; | |
318 | int err; | |
319 | ||
320 | repeat: | |
321 | page = find_get_page(mapping, index); | |
322 | if (!page) { | |
323 | page = __page_cache_alloc(GFP_NOFS); | |
324 | if (!page) | |
325 | return NULL; | |
326 | err = add_to_page_cache_lru(page, mapping, index, GFP_NOFS); | |
327 | if (unlikely(err)) { | |
328 | page_cache_release(page); | |
329 | if (err == -EEXIST) | |
330 | goto repeat; | |
331 | return NULL; | |
332 | } | |
333 | } else logfs_lock_write_page(page); | |
334 | BUG_ON(!PageLocked(page)); | |
335 | return page; | |
336 | } | |
337 | ||
338 | static void logfs_unlock_write_page(struct page *page) | |
339 | { | |
340 | if (!PagePreLocked(page)) | |
341 | unlock_page(page); | |
342 | } | |
343 | ||
344 | static void logfs_put_write_page(struct page *page) | |
345 | { | |
346 | logfs_unlock_write_page(page); | |
347 | page_cache_release(page); | |
348 | } | |
349 | ||
350 | static struct page *logfs_get_page(struct inode *inode, u64 bix, level_t level, | |
351 | int rw) | |
352 | { | |
353 | if (rw == READ) | |
354 | return logfs_get_read_page(inode, bix, level); | |
355 | else | |
356 | return logfs_get_write_page(inode, bix, level); | |
357 | } | |
358 | ||
359 | static void logfs_put_page(struct page *page, int rw) | |
360 | { | |
361 | if (rw == READ) | |
362 | logfs_put_read_page(page); | |
363 | else | |
364 | logfs_put_write_page(page); | |
365 | } | |
366 | ||
367 | static unsigned long __get_bits(u64 val, int skip, int no) | |
368 | { | |
369 | u64 ret = val; | |
370 | ||
371 | ret >>= skip * no; | |
372 | ret <<= 64 - no; | |
373 | ret >>= 64 - no; | |
374 | return ret; | |
375 | } | |
376 | ||
377 | static unsigned long get_bits(u64 val, level_t skip) | |
378 | { | |
379 | return __get_bits(val, (__force int)skip, LOGFS_BLOCK_BITS); | |
380 | } | |
381 | ||
382 | static inline void init_shadow_tree(struct super_block *sb, | |
383 | struct shadow_tree *tree) | |
384 | { | |
385 | struct logfs_super *super = logfs_super(sb); | |
386 | ||
387 | btree_init_mempool64(&tree->new, super->s_btree_pool); | |
388 | btree_init_mempool64(&tree->old, super->s_btree_pool); | |
389 | } | |
390 | ||
391 | static void indirect_write_block(struct logfs_block *block) | |
392 | { | |
393 | struct page *page; | |
394 | struct inode *inode; | |
395 | int ret; | |
396 | ||
397 | page = block->page; | |
398 | inode = page->mapping->host; | |
399 | logfs_lock_write_page(page); | |
400 | ret = logfs_write_buf(inode, page, 0); | |
401 | logfs_unlock_write_page(page); | |
402 | /* | |
403 | * This needs some rework. Unless you want your filesystem to run | |
404 | * completely synchronously (you don't), the filesystem will always | |
405 | * report writes as 'successful' before the actual work has been | |
406 | * done. The actual work gets done here and this is where any errors | |
407 | * will show up. And there isn't much we can do about it, really. | |
408 | * | |
409 | * Some attempts to fix the errors (move from bad blocks, retry io,...) | |
410 | * have already been done, so anything left should be either a broken | |
411 | * device or a bug somewhere in logfs itself. Being relatively new, | |
412 | * the odds currently favor a bug, so for now the line below isn't | |
413 | * entirely tasteles. | |
414 | */ | |
415 | BUG_ON(ret); | |
416 | } | |
417 | ||
418 | static void inode_write_block(struct logfs_block *block) | |
419 | { | |
420 | struct inode *inode; | |
421 | int ret; | |
422 | ||
423 | inode = block->inode; | |
424 | if (inode->i_ino == LOGFS_INO_MASTER) | |
c6d38301 | 425 | logfs_write_anchor(inode->i_sb); |
5db53f3e JE |
426 | else { |
427 | ret = __logfs_write_inode(inode, 0); | |
428 | /* see indirect_write_block comment */ | |
429 | BUG_ON(ret); | |
430 | } | |
431 | } | |
432 | ||
433 | static gc_level_t inode_block_level(struct logfs_block *block) | |
434 | { | |
435 | BUG_ON(block->inode->i_ino == LOGFS_INO_MASTER); | |
436 | return GC_LEVEL(LOGFS_MAX_LEVELS); | |
437 | } | |
438 | ||
439 | static gc_level_t indirect_block_level(struct logfs_block *block) | |
440 | { | |
441 | struct page *page; | |
442 | struct inode *inode; | |
443 | u64 bix; | |
444 | level_t level; | |
445 | ||
446 | page = block->page; | |
447 | inode = page->mapping->host; | |
448 | logfs_unpack_index(page->index, &bix, &level); | |
449 | return expand_level(inode->i_ino, level); | |
450 | } | |
451 | ||
452 | /* | |
453 | * This silences a false, yet annoying gcc warning. I hate it when my editor | |
454 | * jumps into bitops.h each time I recompile this file. | |
455 | * TODO: Complain to gcc folks about this and upgrade compiler. | |
456 | */ | |
457 | static unsigned long fnb(const unsigned long *addr, | |
458 | unsigned long size, unsigned long offset) | |
459 | { | |
460 | return find_next_bit(addr, size, offset); | |
461 | } | |
462 | ||
463 | static __be64 inode_val0(struct inode *inode) | |
464 | { | |
465 | struct logfs_inode *li = logfs_inode(inode); | |
466 | u64 val; | |
467 | ||
468 | /* | |
469 | * Explicit shifting generates good code, but must match the format | |
470 | * of the structure. Add some paranoia just in case. | |
471 | */ | |
472 | BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_mode) != 0); | |
473 | BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_height) != 2); | |
474 | BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_flags) != 4); | |
475 | ||
476 | val = (u64)inode->i_mode << 48 | | |
477 | (u64)li->li_height << 40 | | |
478 | (u64)li->li_flags; | |
479 | return cpu_to_be64(val); | |
480 | } | |
481 | ||
482 | static int inode_write_alias(struct super_block *sb, | |
483 | struct logfs_block *block, write_alias_t *write_one_alias) | |
484 | { | |
485 | struct inode *inode = block->inode; | |
486 | struct logfs_inode *li = logfs_inode(inode); | |
487 | unsigned long pos; | |
488 | u64 ino , bix; | |
489 | __be64 val; | |
490 | level_t level; | |
491 | int err; | |
492 | ||
493 | for (pos = 0; ; pos++) { | |
494 | pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos); | |
495 | if (pos >= LOGFS_EMBEDDED_FIELDS + INODE_POINTER_OFS) | |
496 | return 0; | |
497 | ||
498 | switch (pos) { | |
499 | case INODE_HEIGHT_OFS: | |
500 | val = inode_val0(inode); | |
501 | break; | |
502 | case INODE_USED_OFS: | |
503 | val = cpu_to_be64(li->li_used_bytes);; | |
504 | break; | |
505 | case INODE_SIZE_OFS: | |
506 | val = cpu_to_be64(i_size_read(inode)); | |
507 | break; | |
508 | case INODE_POINTER_OFS ... INODE_POINTER_OFS + LOGFS_EMBEDDED_FIELDS - 1: | |
509 | val = cpu_to_be64(li->li_data[pos - INODE_POINTER_OFS]); | |
510 | break; | |
511 | default: | |
512 | BUG(); | |
513 | } | |
514 | ||
515 | ino = LOGFS_INO_MASTER; | |
516 | bix = inode->i_ino; | |
517 | level = LEVEL(0); | |
518 | err = write_one_alias(sb, ino, bix, level, pos, val); | |
519 | if (err) | |
520 | return err; | |
521 | } | |
522 | } | |
523 | ||
524 | static int indirect_write_alias(struct super_block *sb, | |
525 | struct logfs_block *block, write_alias_t *write_one_alias) | |
526 | { | |
527 | unsigned long pos; | |
528 | struct page *page = block->page; | |
529 | u64 ino , bix; | |
530 | __be64 *child, val; | |
531 | level_t level; | |
532 | int err; | |
533 | ||
534 | for (pos = 0; ; pos++) { | |
535 | pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos); | |
536 | if (pos >= LOGFS_BLOCK_FACTOR) | |
537 | return 0; | |
538 | ||
539 | ino = page->mapping->host->i_ino; | |
540 | logfs_unpack_index(page->index, &bix, &level); | |
541 | child = kmap_atomic(page, KM_USER0); | |
542 | val = child[pos]; | |
543 | kunmap_atomic(child, KM_USER0); | |
544 | err = write_one_alias(sb, ino, bix, level, pos, val); | |
545 | if (err) | |
546 | return err; | |
547 | } | |
548 | } | |
549 | ||
550 | int logfs_write_obj_aliases_pagecache(struct super_block *sb) | |
551 | { | |
552 | struct logfs_super *super = logfs_super(sb); | |
553 | struct logfs_block *block; | |
554 | int err; | |
555 | ||
556 | list_for_each_entry(block, &super->s_object_alias, alias_list) { | |
557 | err = block->ops->write_alias(sb, block, write_alias_journal); | |
558 | if (err) | |
559 | return err; | |
560 | } | |
561 | return 0; | |
562 | } | |
563 | ||
564 | void __free_block(struct super_block *sb, struct logfs_block *block) | |
565 | { | |
566 | BUG_ON(!list_empty(&block->item_list)); | |
567 | list_del(&block->alias_list); | |
568 | mempool_free(block, logfs_super(sb)->s_block_pool); | |
569 | } | |
570 | ||
571 | static void inode_free_block(struct super_block *sb, struct logfs_block *block) | |
572 | { | |
573 | struct inode *inode = block->inode; | |
574 | ||
575 | logfs_inode(inode)->li_block = NULL; | |
576 | __free_block(sb, block); | |
577 | } | |
578 | ||
579 | static void indirect_free_block(struct super_block *sb, | |
580 | struct logfs_block *block) | |
581 | { | |
582 | ClearPagePrivate(block->page); | |
583 | block->page->private = 0; | |
584 | __free_block(sb, block); | |
585 | } | |
586 | ||
587 | ||
588 | static struct logfs_block_ops inode_block_ops = { | |
589 | .write_block = inode_write_block, | |
590 | .block_level = inode_block_level, | |
591 | .free_block = inode_free_block, | |
592 | .write_alias = inode_write_alias, | |
593 | }; | |
594 | ||
595 | struct logfs_block_ops indirect_block_ops = { | |
596 | .write_block = indirect_write_block, | |
597 | .block_level = indirect_block_level, | |
598 | .free_block = indirect_free_block, | |
599 | .write_alias = indirect_write_alias, | |
600 | }; | |
601 | ||
602 | struct logfs_block *__alloc_block(struct super_block *sb, | |
603 | u64 ino, u64 bix, level_t level) | |
604 | { | |
605 | struct logfs_super *super = logfs_super(sb); | |
606 | struct logfs_block *block; | |
607 | ||
608 | block = mempool_alloc(super->s_block_pool, GFP_NOFS); | |
609 | memset(block, 0, sizeof(*block)); | |
610 | INIT_LIST_HEAD(&block->alias_list); | |
611 | INIT_LIST_HEAD(&block->item_list); | |
612 | block->sb = sb; | |
613 | block->ino = ino; | |
614 | block->bix = bix; | |
615 | block->level = level; | |
616 | return block; | |
617 | } | |
618 | ||
619 | static void alloc_inode_block(struct inode *inode) | |
620 | { | |
621 | struct logfs_inode *li = logfs_inode(inode); | |
622 | struct logfs_block *block; | |
623 | ||
624 | if (li->li_block) | |
625 | return; | |
626 | ||
627 | block = __alloc_block(inode->i_sb, LOGFS_INO_MASTER, inode->i_ino, 0); | |
628 | block->inode = inode; | |
629 | li->li_block = block; | |
630 | block->ops = &inode_block_ops; | |
631 | } | |
632 | ||
633 | void initialize_block_counters(struct page *page, struct logfs_block *block, | |
634 | __be64 *array, int page_is_empty) | |
635 | { | |
636 | u64 ptr; | |
637 | int i, start; | |
638 | ||
639 | block->partial = 0; | |
640 | block->full = 0; | |
641 | start = 0; | |
642 | if (page->index < first_indirect_block()) { | |
643 | /* Counters are pointless on level 0 */ | |
644 | return; | |
645 | } | |
646 | if (page->index == first_indirect_block()) { | |
647 | /* Skip unused pointers */ | |
648 | start = I0_BLOCKS; | |
649 | block->full = I0_BLOCKS; | |
650 | } | |
651 | if (!page_is_empty) { | |
652 | for (i = start; i < LOGFS_BLOCK_FACTOR; i++) { | |
653 | ptr = be64_to_cpu(array[i]); | |
654 | if (ptr) | |
655 | block->partial++; | |
656 | if (ptr & LOGFS_FULLY_POPULATED) | |
657 | block->full++; | |
658 | } | |
659 | } | |
660 | } | |
661 | ||
662 | static void alloc_data_block(struct inode *inode, struct page *page) | |
663 | { | |
664 | struct logfs_block *block; | |
665 | u64 bix; | |
666 | level_t level; | |
667 | ||
668 | if (PagePrivate(page)) | |
669 | return; | |
670 | ||
671 | logfs_unpack_index(page->index, &bix, &level); | |
672 | block = __alloc_block(inode->i_sb, inode->i_ino, bix, level); | |
673 | block->page = page; | |
674 | SetPagePrivate(page); | |
675 | page->private = (unsigned long)block; | |
676 | block->ops = &indirect_block_ops; | |
677 | } | |
678 | ||
679 | static void alloc_indirect_block(struct inode *inode, struct page *page, | |
680 | int page_is_empty) | |
681 | { | |
682 | struct logfs_block *block; | |
683 | __be64 *array; | |
684 | ||
685 | if (PagePrivate(page)) | |
686 | return; | |
687 | ||
688 | alloc_data_block(inode, page); | |
689 | ||
690 | block = logfs_block(page); | |
691 | array = kmap_atomic(page, KM_USER0); | |
692 | initialize_block_counters(page, block, array, page_is_empty); | |
693 | kunmap_atomic(array, KM_USER0); | |
694 | } | |
695 | ||
696 | static void block_set_pointer(struct page *page, int index, u64 ptr) | |
697 | { | |
698 | struct logfs_block *block = logfs_block(page); | |
699 | __be64 *array; | |
700 | u64 oldptr; | |
701 | ||
702 | BUG_ON(!block); | |
703 | array = kmap_atomic(page, KM_USER0); | |
704 | oldptr = be64_to_cpu(array[index]); | |
705 | array[index] = cpu_to_be64(ptr); | |
706 | kunmap_atomic(array, KM_USER0); | |
707 | SetPageUptodate(page); | |
708 | ||
709 | block->full += !!(ptr & LOGFS_FULLY_POPULATED) | |
710 | - !!(oldptr & LOGFS_FULLY_POPULATED); | |
711 | block->partial += !!ptr - !!oldptr; | |
712 | } | |
713 | ||
714 | static u64 block_get_pointer(struct page *page, int index) | |
715 | { | |
716 | __be64 *block; | |
717 | u64 ptr; | |
718 | ||
719 | block = kmap_atomic(page, KM_USER0); | |
720 | ptr = be64_to_cpu(block[index]); | |
721 | kunmap_atomic(block, KM_USER0); | |
722 | return ptr; | |
723 | } | |
724 | ||
725 | static int logfs_read_empty(struct page *page) | |
726 | { | |
727 | zero_user_segment(page, 0, PAGE_CACHE_SIZE); | |
728 | return 0; | |
729 | } | |
730 | ||
731 | static int logfs_read_direct(struct inode *inode, struct page *page) | |
732 | { | |
733 | struct logfs_inode *li = logfs_inode(inode); | |
734 | pgoff_t index = page->index; | |
735 | u64 block; | |
736 | ||
737 | block = li->li_data[index]; | |
738 | if (!block) | |
739 | return logfs_read_empty(page); | |
740 | ||
741 | return logfs_segment_read(inode, page, block, index, 0); | |
742 | } | |
743 | ||
744 | static int logfs_read_loop(struct inode *inode, struct page *page, | |
745 | int rw_context) | |
746 | { | |
747 | struct logfs_inode *li = logfs_inode(inode); | |
748 | u64 bix, bofs = li->li_data[INDIRECT_INDEX]; | |
749 | level_t level, target_level; | |
750 | int ret; | |
751 | struct page *ipage; | |
752 | ||
753 | logfs_unpack_index(page->index, &bix, &target_level); | |
754 | if (!bofs) | |
755 | return logfs_read_empty(page); | |
756 | ||
757 | if (bix >= maxbix(li->li_height)) | |
758 | return logfs_read_empty(page); | |
759 | ||
760 | for (level = LEVEL(li->li_height); | |
761 | (__force u8)level > (__force u8)target_level; | |
762 | level = SUBLEVEL(level)){ | |
763 | ipage = logfs_get_page(inode, bix, level, rw_context); | |
764 | if (!ipage) | |
765 | return -ENOMEM; | |
766 | ||
767 | ret = logfs_segment_read(inode, ipage, bofs, bix, level); | |
768 | if (ret) { | |
769 | logfs_put_read_page(ipage); | |
770 | return ret; | |
771 | } | |
772 | ||
773 | bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level))); | |
774 | logfs_put_page(ipage, rw_context); | |
775 | if (!bofs) | |
776 | return logfs_read_empty(page); | |
777 | } | |
778 | ||
779 | return logfs_segment_read(inode, page, bofs, bix, 0); | |
780 | } | |
781 | ||
782 | static int logfs_read_block(struct inode *inode, struct page *page, | |
783 | int rw_context) | |
784 | { | |
785 | pgoff_t index = page->index; | |
786 | ||
787 | if (index < I0_BLOCKS) | |
788 | return logfs_read_direct(inode, page); | |
789 | return logfs_read_loop(inode, page, rw_context); | |
790 | } | |
791 | ||
792 | static int logfs_exist_loop(struct inode *inode, u64 bix) | |
793 | { | |
794 | struct logfs_inode *li = logfs_inode(inode); | |
795 | u64 bofs = li->li_data[INDIRECT_INDEX]; | |
796 | level_t level; | |
797 | int ret; | |
798 | struct page *ipage; | |
799 | ||
800 | if (!bofs) | |
801 | return 0; | |
802 | if (bix >= maxbix(li->li_height)) | |
803 | return 0; | |
804 | ||
805 | for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) { | |
806 | ipage = logfs_get_read_page(inode, bix, level); | |
807 | if (!ipage) | |
808 | return -ENOMEM; | |
809 | ||
810 | ret = logfs_segment_read(inode, ipage, bofs, bix, level); | |
811 | if (ret) { | |
812 | logfs_put_read_page(ipage); | |
813 | return ret; | |
814 | } | |
815 | ||
816 | bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level))); | |
817 | logfs_put_read_page(ipage); | |
818 | if (!bofs) | |
819 | return 0; | |
820 | } | |
821 | ||
822 | return 1; | |
823 | } | |
824 | ||
825 | int logfs_exist_block(struct inode *inode, u64 bix) | |
826 | { | |
827 | struct logfs_inode *li = logfs_inode(inode); | |
828 | ||
829 | if (bix < I0_BLOCKS) | |
830 | return !!li->li_data[bix]; | |
831 | return logfs_exist_loop(inode, bix); | |
832 | } | |
833 | ||
834 | static u64 seek_holedata_direct(struct inode *inode, u64 bix, int data) | |
835 | { | |
836 | struct logfs_inode *li = logfs_inode(inode); | |
837 | ||
838 | for (; bix < I0_BLOCKS; bix++) | |
839 | if (data ^ (li->li_data[bix] == 0)) | |
840 | return bix; | |
841 | return I0_BLOCKS; | |
842 | } | |
843 | ||
844 | static u64 seek_holedata_loop(struct inode *inode, u64 bix, int data) | |
845 | { | |
846 | struct logfs_inode *li = logfs_inode(inode); | |
847 | __be64 *rblock; | |
848 | u64 increment, bofs = li->li_data[INDIRECT_INDEX]; | |
849 | level_t level; | |
850 | int ret, slot; | |
851 | struct page *page; | |
852 | ||
853 | BUG_ON(!bofs); | |
854 | ||
855 | for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) { | |
856 | increment = 1 << (LOGFS_BLOCK_BITS * ((__force u8)level-1)); | |
857 | page = logfs_get_read_page(inode, bix, level); | |
858 | if (!page) | |
859 | return bix; | |
860 | ||
861 | ret = logfs_segment_read(inode, page, bofs, bix, level); | |
862 | if (ret) { | |
863 | logfs_put_read_page(page); | |
864 | return bix; | |
865 | } | |
866 | ||
867 | slot = get_bits(bix, SUBLEVEL(level)); | |
868 | rblock = kmap_atomic(page, KM_USER0); | |
869 | while (slot < LOGFS_BLOCK_FACTOR) { | |
870 | if (data && (rblock[slot] != 0)) | |
871 | break; | |
872 | if (!data && !(be64_to_cpu(rblock[slot]) & LOGFS_FULLY_POPULATED)) | |
873 | break; | |
874 | slot++; | |
875 | bix += increment; | |
876 | bix &= ~(increment - 1); | |
877 | } | |
878 | if (slot >= LOGFS_BLOCK_FACTOR) { | |
879 | kunmap_atomic(rblock, KM_USER0); | |
880 | logfs_put_read_page(page); | |
881 | return bix; | |
882 | } | |
883 | bofs = be64_to_cpu(rblock[slot]); | |
884 | kunmap_atomic(rblock, KM_USER0); | |
885 | logfs_put_read_page(page); | |
886 | if (!bofs) { | |
887 | BUG_ON(data); | |
888 | return bix; | |
889 | } | |
890 | } | |
891 | return bix; | |
892 | } | |
893 | ||
894 | /** | |
895 | * logfs_seek_hole - find next hole starting at a given block index | |
896 | * @inode: inode to search in | |
897 | * @bix: block index to start searching | |
898 | * | |
899 | * Returns next hole. If the file doesn't contain any further holes, the | |
900 | * block address next to eof is returned instead. | |
901 | */ | |
902 | u64 logfs_seek_hole(struct inode *inode, u64 bix) | |
903 | { | |
904 | struct logfs_inode *li = logfs_inode(inode); | |
905 | ||
906 | if (bix < I0_BLOCKS) { | |
907 | bix = seek_holedata_direct(inode, bix, 0); | |
908 | if (bix < I0_BLOCKS) | |
909 | return bix; | |
910 | } | |
911 | ||
912 | if (!li->li_data[INDIRECT_INDEX]) | |
913 | return bix; | |
914 | else if (li->li_data[INDIRECT_INDEX] & LOGFS_FULLY_POPULATED) | |
915 | bix = maxbix(li->li_height); | |
916 | else { | |
917 | bix = seek_holedata_loop(inode, bix, 0); | |
918 | if (bix < maxbix(li->li_height)) | |
919 | return bix; | |
920 | /* Should not happen anymore. But if some port writes semi- | |
921 | * corrupt images (as this one used to) we might run into it. | |
922 | */ | |
923 | WARN_ON_ONCE(bix == maxbix(li->li_height)); | |
924 | } | |
925 | ||
926 | return bix; | |
927 | } | |
928 | ||
929 | static u64 __logfs_seek_data(struct inode *inode, u64 bix) | |
930 | { | |
931 | struct logfs_inode *li = logfs_inode(inode); | |
932 | ||
933 | if (bix < I0_BLOCKS) { | |
934 | bix = seek_holedata_direct(inode, bix, 1); | |
935 | if (bix < I0_BLOCKS) | |
936 | return bix; | |
937 | } | |
938 | ||
939 | if (bix < maxbix(li->li_height)) { | |
940 | if (!li->li_data[INDIRECT_INDEX]) | |
941 | bix = maxbix(li->li_height); | |
942 | else | |
943 | return seek_holedata_loop(inode, bix, 1); | |
944 | } | |
945 | ||
946 | return bix; | |
947 | } | |
948 | ||
949 | /** | |
950 | * logfs_seek_data - find next data block after a given block index | |
951 | * @inode: inode to search in | |
952 | * @bix: block index to start searching | |
953 | * | |
954 | * Returns next data block. If the file doesn't contain any further data | |
955 | * blocks, the last block in the file is returned instead. | |
956 | */ | |
957 | u64 logfs_seek_data(struct inode *inode, u64 bix) | |
958 | { | |
959 | struct super_block *sb = inode->i_sb; | |
960 | u64 ret, end; | |
961 | ||
962 | ret = __logfs_seek_data(inode, bix); | |
963 | end = i_size_read(inode) >> sb->s_blocksize_bits; | |
964 | if (ret >= end) | |
965 | ret = max(bix, end); | |
966 | return ret; | |
967 | } | |
968 | ||
969 | static int logfs_is_valid_direct(struct logfs_inode *li, u64 bix, u64 ofs) | |
970 | { | |
971 | return pure_ofs(li->li_data[bix]) == ofs; | |
972 | } | |
973 | ||
974 | static int __logfs_is_valid_loop(struct inode *inode, u64 bix, | |
975 | u64 ofs, u64 bofs) | |
976 | { | |
977 | struct logfs_inode *li = logfs_inode(inode); | |
978 | level_t level; | |
979 | int ret; | |
980 | struct page *page; | |
981 | ||
982 | for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)){ | |
983 | page = logfs_get_write_page(inode, bix, level); | |
984 | BUG_ON(!page); | |
985 | ||
986 | ret = logfs_segment_read(inode, page, bofs, bix, level); | |
987 | if (ret) { | |
988 | logfs_put_write_page(page); | |
989 | return 0; | |
990 | } | |
991 | ||
992 | bofs = block_get_pointer(page, get_bits(bix, SUBLEVEL(level))); | |
993 | logfs_put_write_page(page); | |
994 | if (!bofs) | |
995 | return 0; | |
996 | ||
997 | if (pure_ofs(bofs) == ofs) | |
998 | return 1; | |
999 | } | |
1000 | return 0; | |
1001 | } | |
1002 | ||
1003 | static int logfs_is_valid_loop(struct inode *inode, u64 bix, u64 ofs) | |
1004 | { | |
1005 | struct logfs_inode *li = logfs_inode(inode); | |
1006 | u64 bofs = li->li_data[INDIRECT_INDEX]; | |
1007 | ||
1008 | if (!bofs) | |
1009 | return 0; | |
1010 | ||
1011 | if (bix >= maxbix(li->li_height)) | |
1012 | return 0; | |
1013 | ||
1014 | if (pure_ofs(bofs) == ofs) | |
1015 | return 1; | |
1016 | ||
1017 | return __logfs_is_valid_loop(inode, bix, ofs, bofs); | |
1018 | } | |
1019 | ||
1020 | static int __logfs_is_valid_block(struct inode *inode, u64 bix, u64 ofs) | |
1021 | { | |
1022 | struct logfs_inode *li = logfs_inode(inode); | |
1023 | ||
1024 | if ((inode->i_nlink == 0) && atomic_read(&inode->i_count) == 1) | |
1025 | return 0; | |
1026 | ||
1027 | if (bix < I0_BLOCKS) | |
1028 | return logfs_is_valid_direct(li, bix, ofs); | |
1029 | return logfs_is_valid_loop(inode, bix, ofs); | |
1030 | } | |
1031 | ||
1032 | /** | |
1033 | * logfs_is_valid_block - check whether this block is still valid | |
1034 | * | |
1035 | * @sb - superblock | |
1036 | * @ofs - block physical offset | |
1037 | * @ino - block inode number | |
1038 | * @bix - block index | |
1039 | * @level - block level | |
1040 | * | |
1041 | * Returns 0 if the block is invalid, 1 if it is valid and 2 if it will | |
1042 | * become invalid once the journal is written. | |
1043 | */ | |
1044 | int logfs_is_valid_block(struct super_block *sb, u64 ofs, u64 ino, u64 bix, | |
1045 | gc_level_t gc_level) | |
1046 | { | |
1047 | struct logfs_super *super = logfs_super(sb); | |
1048 | struct inode *inode; | |
1049 | int ret, cookie; | |
1050 | ||
1051 | /* Umount closes a segment with free blocks remaining. Those | |
1052 | * blocks are by definition invalid. */ | |
1053 | if (ino == -1) | |
1054 | return 0; | |
1055 | ||
1056 | LOGFS_BUG_ON((u64)(u_long)ino != ino, sb); | |
1057 | ||
1058 | inode = logfs_safe_iget(sb, ino, &cookie); | |
1059 | if (IS_ERR(inode)) | |
1060 | goto invalid; | |
1061 | ||
1062 | ret = __logfs_is_valid_block(inode, bix, ofs); | |
1063 | logfs_safe_iput(inode, cookie); | |
1064 | if (ret) | |
1065 | return ret; | |
1066 | ||
1067 | invalid: | |
1068 | /* Block is nominally invalid, but may still sit in the shadow tree, | |
1069 | * waiting for a journal commit. | |
1070 | */ | |
1071 | if (btree_lookup64(&super->s_shadow_tree.old, ofs)) | |
1072 | return 2; | |
1073 | return 0; | |
1074 | } | |
1075 | ||
1076 | int logfs_readpage_nolock(struct page *page) | |
1077 | { | |
1078 | struct inode *inode = page->mapping->host; | |
1079 | int ret = -EIO; | |
1080 | ||
1081 | ret = logfs_read_block(inode, page, READ); | |
1082 | ||
1083 | if (ret) { | |
1084 | ClearPageUptodate(page); | |
1085 | SetPageError(page); | |
1086 | } else { | |
1087 | SetPageUptodate(page); | |
1088 | ClearPageError(page); | |
1089 | } | |
1090 | flush_dcache_page(page); | |
1091 | ||
1092 | return ret; | |
1093 | } | |
1094 | ||
1095 | static int logfs_reserve_bytes(struct inode *inode, int bytes) | |
1096 | { | |
1097 | struct logfs_super *super = logfs_super(inode->i_sb); | |
1098 | u64 available = super->s_free_bytes + super->s_dirty_free_bytes | |
1099 | - super->s_dirty_used_bytes - super->s_dirty_pages; | |
1100 | ||
1101 | if (!bytes) | |
1102 | return 0; | |
1103 | ||
1104 | if (available < bytes) | |
1105 | return -ENOSPC; | |
1106 | ||
1107 | if (available < bytes + super->s_root_reserve && | |
1108 | !capable(CAP_SYS_RESOURCE)) | |
1109 | return -ENOSPC; | |
1110 | ||
1111 | return 0; | |
1112 | } | |
1113 | ||
1114 | int get_page_reserve(struct inode *inode, struct page *page) | |
1115 | { | |
1116 | struct logfs_super *super = logfs_super(inode->i_sb); | |
1117 | int ret; | |
1118 | ||
1119 | if (logfs_block(page) && logfs_block(page)->reserved_bytes) | |
1120 | return 0; | |
1121 | ||
1122 | logfs_get_wblocks(inode->i_sb, page, WF_LOCK); | |
1123 | ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE); | |
1124 | if (!ret) { | |
1125 | alloc_data_block(inode, page); | |
1126 | logfs_block(page)->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE; | |
1127 | super->s_dirty_pages += 6 * LOGFS_MAX_OBJECTSIZE; | |
1128 | } | |
1129 | logfs_put_wblocks(inode->i_sb, page, WF_LOCK); | |
1130 | return ret; | |
1131 | } | |
1132 | ||
1133 | /* | |
1134 | * We are protected by write lock. Push victims up to superblock level | |
1135 | * and release transaction when appropriate. | |
1136 | */ | |
1137 | /* FIXME: This is currently called from the wrong spots. */ | |
1138 | static void logfs_handle_transaction(struct inode *inode, | |
1139 | struct logfs_transaction *ta) | |
1140 | { | |
1141 | struct logfs_super *super = logfs_super(inode->i_sb); | |
1142 | ||
1143 | if (!ta) | |
1144 | return; | |
1145 | logfs_inode(inode)->li_block->ta = NULL; | |
1146 | ||
1147 | if (inode->i_ino != LOGFS_INO_MASTER) { | |
1148 | BUG(); /* FIXME: Yes, this needs more thought */ | |
1149 | /* just remember the transaction until inode is written */ | |
1150 | //BUG_ON(logfs_inode(inode)->li_transaction); | |
1151 | //logfs_inode(inode)->li_transaction = ta; | |
1152 | return; | |
1153 | } | |
1154 | ||
1155 | switch (ta->state) { | |
1156 | case CREATE_1: /* fall through */ | |
1157 | case UNLINK_1: | |
1158 | BUG_ON(super->s_victim_ino); | |
1159 | super->s_victim_ino = ta->ino; | |
1160 | break; | |
1161 | case CREATE_2: /* fall through */ | |
1162 | case UNLINK_2: | |
1163 | BUG_ON(super->s_victim_ino != ta->ino); | |
1164 | super->s_victim_ino = 0; | |
1165 | /* transaction ends here - free it */ | |
1166 | kfree(ta); | |
1167 | break; | |
1168 | case CROSS_RENAME_1: | |
1169 | BUG_ON(super->s_rename_dir); | |
1170 | BUG_ON(super->s_rename_pos); | |
1171 | super->s_rename_dir = ta->dir; | |
1172 | super->s_rename_pos = ta->pos; | |
1173 | break; | |
1174 | case CROSS_RENAME_2: | |
1175 | BUG_ON(super->s_rename_dir != ta->dir); | |
1176 | BUG_ON(super->s_rename_pos != ta->pos); | |
1177 | super->s_rename_dir = 0; | |
1178 | super->s_rename_pos = 0; | |
1179 | kfree(ta); | |
1180 | break; | |
1181 | case TARGET_RENAME_1: | |
1182 | BUG_ON(super->s_rename_dir); | |
1183 | BUG_ON(super->s_rename_pos); | |
1184 | BUG_ON(super->s_victim_ino); | |
1185 | super->s_rename_dir = ta->dir; | |
1186 | super->s_rename_pos = ta->pos; | |
1187 | super->s_victim_ino = ta->ino; | |
1188 | break; | |
1189 | case TARGET_RENAME_2: | |
1190 | BUG_ON(super->s_rename_dir != ta->dir); | |
1191 | BUG_ON(super->s_rename_pos != ta->pos); | |
1192 | BUG_ON(super->s_victim_ino != ta->ino); | |
1193 | super->s_rename_dir = 0; | |
1194 | super->s_rename_pos = 0; | |
1195 | break; | |
1196 | case TARGET_RENAME_3: | |
1197 | BUG_ON(super->s_rename_dir); | |
1198 | BUG_ON(super->s_rename_pos); | |
1199 | BUG_ON(super->s_victim_ino != ta->ino); | |
1200 | super->s_victim_ino = 0; | |
1201 | kfree(ta); | |
1202 | break; | |
1203 | default: | |
1204 | BUG(); | |
1205 | } | |
1206 | } | |
1207 | ||
1208 | /* | |
1209 | * Not strictly a reservation, but rather a check that we still have enough | |
1210 | * space to satisfy the write. | |
1211 | */ | |
1212 | static int logfs_reserve_blocks(struct inode *inode, int blocks) | |
1213 | { | |
1214 | return logfs_reserve_bytes(inode, blocks * LOGFS_MAX_OBJECTSIZE); | |
1215 | } | |
1216 | ||
1217 | struct write_control { | |
1218 | u64 ofs; | |
1219 | long flags; | |
1220 | }; | |
1221 | ||
1222 | static struct logfs_shadow *alloc_shadow(struct inode *inode, u64 bix, | |
1223 | level_t level, u64 old_ofs) | |
1224 | { | |
1225 | struct logfs_super *super = logfs_super(inode->i_sb); | |
1226 | struct logfs_shadow *shadow; | |
1227 | ||
1228 | shadow = mempool_alloc(super->s_shadow_pool, GFP_NOFS); | |
1229 | memset(shadow, 0, sizeof(*shadow)); | |
1230 | shadow->ino = inode->i_ino; | |
1231 | shadow->bix = bix; | |
1232 | shadow->gc_level = expand_level(inode->i_ino, level); | |
1233 | shadow->old_ofs = old_ofs & ~LOGFS_FULLY_POPULATED; | |
1234 | return shadow; | |
1235 | } | |
1236 | ||
1237 | static void free_shadow(struct inode *inode, struct logfs_shadow *shadow) | |
1238 | { | |
1239 | struct logfs_super *super = logfs_super(inode->i_sb); | |
1240 | ||
1241 | mempool_free(shadow, super->s_shadow_pool); | |
1242 | } | |
1243 | ||
1244 | /** | |
1245 | * fill_shadow_tree - Propagate shadow tree changes due to a write | |
1246 | * @inode: Inode owning the page | |
1247 | * @page: Struct page that was written | |
1248 | * @shadow: Shadow for the current write | |
1249 | * | |
1250 | * Writes in logfs can result in two semi-valid objects. The old object | |
1251 | * is still valid as long as it can be reached by following pointers on | |
1252 | * the medium. Only when writes propagate all the way up to the journal | |
1253 | * has the new object safely replaced the old one. | |
1254 | * | |
1255 | * To handle this problem, a struct logfs_shadow is used to represent | |
1256 | * every single write. It is attached to the indirect block, which is | |
1257 | * marked dirty. When the indirect block is written, its shadows are | |
1258 | * handed up to the next indirect block (or inode). Untimately they | |
1259 | * will reach the master inode and be freed upon journal commit. | |
1260 | * | |
1261 | * This function handles a single step in the propagation. It adds the | |
1262 | * shadow for the current write to the tree, along with any shadows in | |
1263 | * the page's tree, in case it was an indirect block. If a page is | |
1264 | * written, the inode parameter is left NULL, if an inode is written, | |
1265 | * the page parameter is left NULL. | |
1266 | */ | |
1267 | static void fill_shadow_tree(struct inode *inode, struct page *page, | |
1268 | struct logfs_shadow *shadow) | |
1269 | { | |
1270 | struct logfs_super *super = logfs_super(inode->i_sb); | |
1271 | struct logfs_block *block = logfs_block(page); | |
1272 | struct shadow_tree *tree = &super->s_shadow_tree; | |
1273 | ||
1274 | if (PagePrivate(page)) { | |
1275 | if (block->alias_map) | |
1276 | super->s_no_object_aliases -= bitmap_weight( | |
1277 | block->alias_map, LOGFS_BLOCK_FACTOR); | |
1278 | logfs_handle_transaction(inode, block->ta); | |
1279 | block->ops->free_block(inode->i_sb, block); | |
1280 | } | |
1281 | if (shadow) { | |
1282 | if (shadow->old_ofs) | |
1283 | btree_insert64(&tree->old, shadow->old_ofs, shadow, | |
1284 | GFP_NOFS); | |
1285 | else | |
1286 | btree_insert64(&tree->new, shadow->new_ofs, shadow, | |
1287 | GFP_NOFS); | |
1288 | ||
1289 | super->s_dirty_used_bytes += shadow->new_len; | |
1290 | super->s_dirty_free_bytes += shadow->old_len; | |
1291 | } | |
1292 | } | |
1293 | ||
1294 | static void logfs_set_alias(struct super_block *sb, struct logfs_block *block, | |
1295 | long child_no) | |
1296 | { | |
1297 | struct logfs_super *super = logfs_super(sb); | |
1298 | ||
1299 | if (block->inode && block->inode->i_ino == LOGFS_INO_MASTER) { | |
1300 | /* Aliases in the master inode are pointless. */ | |
1301 | return; | |
1302 | } | |
1303 | ||
1304 | if (!test_bit(child_no, block->alias_map)) { | |
1305 | set_bit(child_no, block->alias_map); | |
1306 | super->s_no_object_aliases++; | |
1307 | } | |
1308 | list_move_tail(&block->alias_list, &super->s_object_alias); | |
1309 | } | |
1310 | ||
1311 | /* | |
1312 | * Object aliases can and often do change the size and occupied space of a | |
1313 | * file. So not only do we have to change the pointers, we also have to | |
1314 | * change inode->i_size and li->li_used_bytes. Which is done by setting | |
1315 | * another two object aliases for the inode itself. | |
1316 | */ | |
1317 | static void set_iused(struct inode *inode, struct logfs_shadow *shadow) | |
1318 | { | |
1319 | struct logfs_inode *li = logfs_inode(inode); | |
1320 | ||
1321 | if (shadow->new_len == shadow->old_len) | |
1322 | return; | |
1323 | ||
1324 | alloc_inode_block(inode); | |
1325 | li->li_used_bytes += shadow->new_len - shadow->old_len; | |
1326 | __logfs_set_blocks(inode); | |
1327 | logfs_set_alias(inode->i_sb, li->li_block, INODE_USED_OFS); | |
1328 | logfs_set_alias(inode->i_sb, li->li_block, INODE_SIZE_OFS); | |
1329 | } | |
1330 | ||
1331 | static int logfs_write_i0(struct inode *inode, struct page *page, | |
1332 | struct write_control *wc) | |
1333 | { | |
1334 | struct logfs_shadow *shadow; | |
1335 | u64 bix; | |
1336 | level_t level; | |
1337 | int full, err = 0; | |
1338 | ||
1339 | logfs_unpack_index(page->index, &bix, &level); | |
1340 | if (wc->ofs == 0) | |
1341 | if (logfs_reserve_blocks(inode, 1)) | |
1342 | return -ENOSPC; | |
1343 | ||
1344 | shadow = alloc_shadow(inode, bix, level, wc->ofs); | |
1345 | if (wc->flags & WF_WRITE) | |
1346 | err = logfs_segment_write(inode, page, shadow); | |
1347 | if (wc->flags & WF_DELETE) | |
1348 | logfs_segment_delete(inode, shadow); | |
1349 | if (err) { | |
1350 | free_shadow(inode, shadow); | |
1351 | return err; | |
1352 | } | |
1353 | ||
1354 | set_iused(inode, shadow); | |
1355 | full = 1; | |
1356 | if (level != 0) { | |
1357 | alloc_indirect_block(inode, page, 0); | |
1358 | full = logfs_block(page)->full == LOGFS_BLOCK_FACTOR; | |
1359 | } | |
1360 | fill_shadow_tree(inode, page, shadow); | |
1361 | wc->ofs = shadow->new_ofs; | |
1362 | if (wc->ofs && full) | |
1363 | wc->ofs |= LOGFS_FULLY_POPULATED; | |
1364 | return 0; | |
1365 | } | |
1366 | ||
1367 | static int logfs_write_direct(struct inode *inode, struct page *page, | |
1368 | long flags) | |
1369 | { | |
1370 | struct logfs_inode *li = logfs_inode(inode); | |
1371 | struct write_control wc = { | |
1372 | .ofs = li->li_data[page->index], | |
1373 | .flags = flags, | |
1374 | }; | |
1375 | int err; | |
1376 | ||
1377 | alloc_inode_block(inode); | |
1378 | ||
1379 | err = logfs_write_i0(inode, page, &wc); | |
1380 | if (err) | |
1381 | return err; | |
1382 | ||
1383 | li->li_data[page->index] = wc.ofs; | |
1384 | logfs_set_alias(inode->i_sb, li->li_block, | |
1385 | page->index + INODE_POINTER_OFS); | |
1386 | return 0; | |
1387 | } | |
1388 | ||
1389 | static int ptr_change(u64 ofs, struct page *page) | |
1390 | { | |
1391 | struct logfs_block *block = logfs_block(page); | |
1392 | int empty0, empty1, full0, full1; | |
1393 | ||
1394 | empty0 = ofs == 0; | |
1395 | empty1 = block->partial == 0; | |
1396 | if (empty0 != empty1) | |
1397 | return 1; | |
1398 | ||
1399 | /* The !! is necessary to shrink result to int */ | |
1400 | full0 = !!(ofs & LOGFS_FULLY_POPULATED); | |
1401 | full1 = block->full == LOGFS_BLOCK_FACTOR; | |
1402 | if (full0 != full1) | |
1403 | return 1; | |
1404 | return 0; | |
1405 | } | |
1406 | ||
1407 | static int __logfs_write_rec(struct inode *inode, struct page *page, | |
1408 | struct write_control *this_wc, | |
1409 | pgoff_t bix, level_t target_level, level_t level) | |
1410 | { | |
1411 | int ret, page_empty = 0; | |
1412 | int child_no = get_bits(bix, SUBLEVEL(level)); | |
1413 | struct page *ipage; | |
1414 | struct write_control child_wc = { | |
1415 | .flags = this_wc->flags, | |
1416 | }; | |
1417 | ||
1418 | ipage = logfs_get_write_page(inode, bix, level); | |
1419 | if (!ipage) | |
1420 | return -ENOMEM; | |
1421 | ||
1422 | if (this_wc->ofs) { | |
1423 | ret = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level); | |
1424 | if (ret) | |
1425 | goto out; | |
1426 | } else if (!PageUptodate(ipage)) { | |
1427 | page_empty = 1; | |
1428 | logfs_read_empty(ipage); | |
1429 | } | |
1430 | ||
1431 | child_wc.ofs = block_get_pointer(ipage, child_no); | |
1432 | ||
1433 | if ((__force u8)level-1 > (__force u8)target_level) | |
1434 | ret = __logfs_write_rec(inode, page, &child_wc, bix, | |
1435 | target_level, SUBLEVEL(level)); | |
1436 | else | |
1437 | ret = logfs_write_i0(inode, page, &child_wc); | |
1438 | ||
1439 | if (ret) | |
1440 | goto out; | |
1441 | ||
1442 | alloc_indirect_block(inode, ipage, page_empty); | |
1443 | block_set_pointer(ipage, child_no, child_wc.ofs); | |
1444 | /* FIXME: first condition seems superfluous */ | |
1445 | if (child_wc.ofs || logfs_block(ipage)->partial) | |
1446 | this_wc->flags |= WF_WRITE; | |
1447 | /* the condition on this_wc->ofs ensures that we won't consume extra | |
1448 | * space for indirect blocks in the future, which we cannot reserve */ | |
1449 | if (!this_wc->ofs || ptr_change(this_wc->ofs, ipage)) | |
1450 | ret = logfs_write_i0(inode, ipage, this_wc); | |
1451 | else | |
1452 | logfs_set_alias(inode->i_sb, logfs_block(ipage), child_no); | |
1453 | out: | |
1454 | logfs_put_write_page(ipage); | |
1455 | return ret; | |
1456 | } | |
1457 | ||
1458 | static int logfs_write_rec(struct inode *inode, struct page *page, | |
1459 | pgoff_t bix, level_t target_level, long flags) | |
1460 | { | |
1461 | struct logfs_inode *li = logfs_inode(inode); | |
1462 | struct write_control wc = { | |
1463 | .ofs = li->li_data[INDIRECT_INDEX], | |
1464 | .flags = flags, | |
1465 | }; | |
1466 | int ret; | |
1467 | ||
1468 | alloc_inode_block(inode); | |
1469 | ||
1470 | if (li->li_height > (__force u8)target_level) | |
1471 | ret = __logfs_write_rec(inode, page, &wc, bix, target_level, | |
1472 | LEVEL(li->li_height)); | |
1473 | else | |
1474 | ret = logfs_write_i0(inode, page, &wc); | |
1475 | if (ret) | |
1476 | return ret; | |
1477 | ||
1478 | if (li->li_data[INDIRECT_INDEX] != wc.ofs) { | |
1479 | li->li_data[INDIRECT_INDEX] = wc.ofs; | |
1480 | logfs_set_alias(inode->i_sb, li->li_block, | |
1481 | INDIRECT_INDEX + INODE_POINTER_OFS); | |
1482 | } | |
1483 | return ret; | |
1484 | } | |
1485 | ||
1486 | void logfs_add_transaction(struct inode *inode, struct logfs_transaction *ta) | |
1487 | { | |
1488 | alloc_inode_block(inode); | |
1489 | logfs_inode(inode)->li_block->ta = ta; | |
1490 | } | |
1491 | ||
1492 | void logfs_del_transaction(struct inode *inode, struct logfs_transaction *ta) | |
1493 | { | |
1494 | struct logfs_block *block = logfs_inode(inode)->li_block; | |
1495 | ||
1496 | if (block && block->ta) | |
1497 | block->ta = NULL; | |
1498 | } | |
1499 | ||
1500 | static int grow_inode(struct inode *inode, u64 bix, level_t level) | |
1501 | { | |
1502 | struct logfs_inode *li = logfs_inode(inode); | |
1503 | u8 height = (__force u8)level; | |
1504 | struct page *page; | |
1505 | struct write_control wc = { | |
1506 | .flags = WF_WRITE, | |
1507 | }; | |
1508 | int err; | |
1509 | ||
1510 | BUG_ON(height > 5 || li->li_height > 5); | |
1511 | while (height > li->li_height || bix >= maxbix(li->li_height)) { | |
1512 | page = logfs_get_write_page(inode, I0_BLOCKS + 1, | |
1513 | LEVEL(li->li_height + 1)); | |
1514 | if (!page) | |
1515 | return -ENOMEM; | |
1516 | logfs_read_empty(page); | |
1517 | alloc_indirect_block(inode, page, 1); | |
1518 | block_set_pointer(page, 0, li->li_data[INDIRECT_INDEX]); | |
1519 | err = logfs_write_i0(inode, page, &wc); | |
1520 | logfs_put_write_page(page); | |
1521 | if (err) | |
1522 | return err; | |
1523 | li->li_data[INDIRECT_INDEX] = wc.ofs; | |
1524 | wc.ofs = 0; | |
1525 | li->li_height++; | |
1526 | logfs_set_alias(inode->i_sb, li->li_block, INODE_HEIGHT_OFS); | |
1527 | } | |
1528 | return 0; | |
1529 | } | |
1530 | ||
1531 | static int __logfs_write_buf(struct inode *inode, struct page *page, long flags) | |
1532 | { | |
1533 | struct logfs_super *super = logfs_super(inode->i_sb); | |
1534 | pgoff_t index = page->index; | |
1535 | u64 bix; | |
1536 | level_t level; | |
1537 | int err; | |
1538 | ||
1539 | flags |= WF_WRITE | WF_DELETE; | |
1540 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; | |
1541 | ||
1542 | logfs_unpack_index(index, &bix, &level); | |
1543 | if (logfs_block(page) && logfs_block(page)->reserved_bytes) | |
1544 | super->s_dirty_pages -= logfs_block(page)->reserved_bytes; | |
1545 | ||
1546 | if (index < I0_BLOCKS) | |
1547 | return logfs_write_direct(inode, page, flags); | |
1548 | ||
1549 | bix = adjust_bix(bix, level); | |
1550 | err = grow_inode(inode, bix, level); | |
1551 | if (err) | |
1552 | return err; | |
1553 | return logfs_write_rec(inode, page, bix, level, flags); | |
1554 | } | |
1555 | ||
1556 | int logfs_write_buf(struct inode *inode, struct page *page, long flags) | |
1557 | { | |
1558 | struct super_block *sb = inode->i_sb; | |
1559 | int ret; | |
1560 | ||
1561 | logfs_get_wblocks(sb, page, flags & WF_LOCK); | |
1562 | ret = __logfs_write_buf(inode, page, flags); | |
1563 | logfs_put_wblocks(sb, page, flags & WF_LOCK); | |
1564 | return ret; | |
1565 | } | |
1566 | ||
1567 | static int __logfs_delete(struct inode *inode, struct page *page) | |
1568 | { | |
1569 | long flags = WF_DELETE; | |
1570 | ||
1571 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; | |
1572 | ||
1573 | if (page->index < I0_BLOCKS) | |
1574 | return logfs_write_direct(inode, page, flags); | |
1575 | return logfs_write_rec(inode, page, page->index, 0, flags); | |
1576 | } | |
1577 | ||
1578 | int logfs_delete(struct inode *inode, pgoff_t index, | |
1579 | struct shadow_tree *shadow_tree) | |
1580 | { | |
1581 | struct super_block *sb = inode->i_sb; | |
1582 | struct page *page; | |
1583 | int ret; | |
1584 | ||
1585 | page = logfs_get_read_page(inode, index, 0); | |
1586 | if (!page) | |
1587 | return -ENOMEM; | |
1588 | ||
1589 | logfs_get_wblocks(sb, page, 1); | |
1590 | ret = __logfs_delete(inode, page); | |
1591 | logfs_put_wblocks(sb, page, 1); | |
1592 | ||
1593 | logfs_put_read_page(page); | |
1594 | ||
1595 | return ret; | |
1596 | } | |
1597 | ||
5db53f3e JE |
1598 | int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs, |
1599 | gc_level_t gc_level, long flags) | |
1600 | { | |
1601 | level_t level = shrink_level(gc_level); | |
1602 | struct page *page; | |
1603 | int err; | |
1604 | ||
1605 | page = logfs_get_write_page(inode, bix, level); | |
1606 | if (!page) | |
1607 | return -ENOMEM; | |
1608 | ||
1609 | err = logfs_segment_read(inode, page, ofs, bix, level); | |
1610 | if (!err) { | |
1611 | if (level != 0) | |
1612 | alloc_indirect_block(inode, page, 0); | |
1613 | err = logfs_write_buf(inode, page, flags); | |
19321917 JE |
1614 | if (!err && shrink_level(gc_level) == 0) { |
1615 | /* Rewrite cannot mark the inode dirty but has to | |
1616 | * write it immediatly. | |
1617 | * Q: Can't we just create an alias for the inode | |
1618 | * instead? And if not, why not? | |
1619 | */ | |
1620 | if (inode->i_ino == LOGFS_INO_MASTER) | |
1621 | logfs_write_anchor(inode->i_sb); | |
1622 | else { | |
1623 | err = __logfs_write_inode(inode, flags); | |
1624 | } | |
1625 | } | |
5db53f3e JE |
1626 | } |
1627 | logfs_put_write_page(page); | |
1628 | return err; | |
1629 | } | |
1630 | ||
1631 | static int truncate_data_block(struct inode *inode, struct page *page, | |
1632 | u64 ofs, struct logfs_shadow *shadow, u64 size) | |
1633 | { | |
1634 | loff_t pageofs = page->index << inode->i_sb->s_blocksize_bits; | |
1635 | u64 bix; | |
1636 | level_t level; | |
1637 | int err; | |
1638 | ||
1639 | /* Does truncation happen within this page? */ | |
1640 | if (size <= pageofs || size - pageofs >= PAGE_SIZE) | |
1641 | return 0; | |
1642 | ||
1643 | logfs_unpack_index(page->index, &bix, &level); | |
1644 | BUG_ON(level != 0); | |
1645 | ||
1646 | err = logfs_segment_read(inode, page, ofs, bix, level); | |
1647 | if (err) | |
1648 | return err; | |
1649 | ||
1650 | zero_user_segment(page, size - pageofs, PAGE_CACHE_SIZE); | |
1651 | return logfs_segment_write(inode, page, shadow); | |
1652 | } | |
1653 | ||
1654 | static int logfs_truncate_i0(struct inode *inode, struct page *page, | |
1655 | struct write_control *wc, u64 size) | |
1656 | { | |
1657 | struct logfs_shadow *shadow; | |
1658 | u64 bix; | |
1659 | level_t level; | |
1660 | int err = 0; | |
1661 | ||
1662 | logfs_unpack_index(page->index, &bix, &level); | |
1663 | BUG_ON(level != 0); | |
1664 | shadow = alloc_shadow(inode, bix, level, wc->ofs); | |
1665 | ||
1666 | err = truncate_data_block(inode, page, wc->ofs, shadow, size); | |
1667 | if (err) { | |
1668 | free_shadow(inode, shadow); | |
1669 | return err; | |
1670 | } | |
1671 | ||
1672 | logfs_segment_delete(inode, shadow); | |
1673 | set_iused(inode, shadow); | |
1674 | fill_shadow_tree(inode, page, shadow); | |
1675 | wc->ofs = shadow->new_ofs; | |
1676 | return 0; | |
1677 | } | |
1678 | ||
1679 | static int logfs_truncate_direct(struct inode *inode, u64 size) | |
1680 | { | |
1681 | struct logfs_inode *li = logfs_inode(inode); | |
1682 | struct write_control wc; | |
1683 | struct page *page; | |
1684 | int e; | |
1685 | int err; | |
1686 | ||
1687 | alloc_inode_block(inode); | |
1688 | ||
1689 | for (e = I0_BLOCKS - 1; e >= 0; e--) { | |
1690 | if (size > (e+1) * LOGFS_BLOCKSIZE) | |
1691 | break; | |
1692 | ||
1693 | wc.ofs = li->li_data[e]; | |
1694 | if (!wc.ofs) | |
1695 | continue; | |
1696 | ||
1697 | page = logfs_get_write_page(inode, e, 0); | |
1698 | if (!page) | |
1699 | return -ENOMEM; | |
1700 | err = logfs_segment_read(inode, page, wc.ofs, e, 0); | |
1701 | if (err) { | |
1702 | logfs_put_write_page(page); | |
1703 | return err; | |
1704 | } | |
1705 | err = logfs_truncate_i0(inode, page, &wc, size); | |
1706 | logfs_put_write_page(page); | |
1707 | if (err) | |
1708 | return err; | |
1709 | ||
1710 | li->li_data[e] = wc.ofs; | |
1711 | } | |
1712 | return 0; | |
1713 | } | |
1714 | ||
1715 | /* FIXME: these need to become per-sb once we support different blocksizes */ | |
1716 | static u64 __logfs_step[] = { | |
1717 | 1, | |
1718 | I1_BLOCKS, | |
1719 | I2_BLOCKS, | |
1720 | I3_BLOCKS, | |
1721 | }; | |
1722 | ||
1723 | static u64 __logfs_start_index[] = { | |
1724 | I0_BLOCKS, | |
1725 | I1_BLOCKS, | |
1726 | I2_BLOCKS, | |
1727 | I3_BLOCKS | |
1728 | }; | |
1729 | ||
1730 | static inline u64 logfs_step(level_t level) | |
1731 | { | |
1732 | return __logfs_step[(__force u8)level]; | |
1733 | } | |
1734 | ||
1735 | static inline u64 logfs_factor(u8 level) | |
1736 | { | |
1737 | return __logfs_step[level] * LOGFS_BLOCKSIZE; | |
1738 | } | |
1739 | ||
1740 | static inline u64 logfs_start_index(level_t level) | |
1741 | { | |
1742 | return __logfs_start_index[(__force u8)level]; | |
1743 | } | |
1744 | ||
1745 | static void logfs_unpack_raw_index(pgoff_t index, u64 *bix, level_t *level) | |
1746 | { | |
1747 | logfs_unpack_index(index, bix, level); | |
1748 | if (*bix <= logfs_start_index(SUBLEVEL(*level))) | |
1749 | *bix = 0; | |
1750 | } | |
1751 | ||
1752 | static int __logfs_truncate_rec(struct inode *inode, struct page *ipage, | |
1753 | struct write_control *this_wc, u64 size) | |
1754 | { | |
1755 | int truncate_happened = 0; | |
1756 | int e, err = 0; | |
1757 | u64 bix, child_bix, next_bix; | |
1758 | level_t level; | |
1759 | struct page *page; | |
1760 | struct write_control child_wc = { /* FIXME: flags */ }; | |
1761 | ||
1762 | logfs_unpack_raw_index(ipage->index, &bix, &level); | |
1763 | err = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level); | |
1764 | if (err) | |
1765 | return err; | |
1766 | ||
1767 | for (e = LOGFS_BLOCK_FACTOR - 1; e >= 0; e--) { | |
1768 | child_bix = bix + e * logfs_step(SUBLEVEL(level)); | |
1769 | next_bix = child_bix + logfs_step(SUBLEVEL(level)); | |
1770 | if (size > next_bix * LOGFS_BLOCKSIZE) | |
1771 | break; | |
1772 | ||
1773 | child_wc.ofs = pure_ofs(block_get_pointer(ipage, e)); | |
1774 | if (!child_wc.ofs) | |
1775 | continue; | |
1776 | ||
1777 | page = logfs_get_write_page(inode, child_bix, SUBLEVEL(level)); | |
1778 | if (!page) | |
1779 | return -ENOMEM; | |
1780 | ||
1781 | if ((__force u8)level > 1) | |
1782 | err = __logfs_truncate_rec(inode, page, &child_wc, size); | |
1783 | else | |
1784 | err = logfs_truncate_i0(inode, page, &child_wc, size); | |
1785 | logfs_put_write_page(page); | |
1786 | if (err) | |
1787 | return err; | |
1788 | ||
1789 | truncate_happened = 1; | |
1790 | alloc_indirect_block(inode, ipage, 0); | |
1791 | block_set_pointer(ipage, e, child_wc.ofs); | |
1792 | } | |
1793 | ||
1794 | if (!truncate_happened) { | |
1795 | printk("ineffectual truncate (%lx, %lx, %llx)\n", inode->i_ino, ipage->index, size); | |
1796 | return 0; | |
1797 | } | |
1798 | ||
1799 | this_wc->flags = WF_DELETE; | |
1800 | if (logfs_block(ipage)->partial) | |
1801 | this_wc->flags |= WF_WRITE; | |
1802 | ||
1803 | return logfs_write_i0(inode, ipage, this_wc); | |
1804 | } | |
1805 | ||
1806 | static int logfs_truncate_rec(struct inode *inode, u64 size) | |
1807 | { | |
1808 | struct logfs_inode *li = logfs_inode(inode); | |
1809 | struct write_control wc = { | |
1810 | .ofs = li->li_data[INDIRECT_INDEX], | |
1811 | }; | |
1812 | struct page *page; | |
1813 | int err; | |
1814 | ||
1815 | alloc_inode_block(inode); | |
1816 | ||
1817 | if (!wc.ofs) | |
1818 | return 0; | |
1819 | ||
1820 | page = logfs_get_write_page(inode, 0, LEVEL(li->li_height)); | |
1821 | if (!page) | |
1822 | return -ENOMEM; | |
1823 | ||
1824 | err = __logfs_truncate_rec(inode, page, &wc, size); | |
1825 | logfs_put_write_page(page); | |
1826 | if (err) | |
1827 | return err; | |
1828 | ||
1829 | if (li->li_data[INDIRECT_INDEX] != wc.ofs) | |
1830 | li->li_data[INDIRECT_INDEX] = wc.ofs; | |
1831 | return 0; | |
1832 | } | |
1833 | ||
1834 | static int __logfs_truncate(struct inode *inode, u64 size) | |
1835 | { | |
1836 | int ret; | |
1837 | ||
1838 | if (size >= logfs_factor(logfs_inode(inode)->li_height)) | |
1839 | return 0; | |
1840 | ||
1841 | ret = logfs_truncate_rec(inode, size); | |
1842 | if (ret) | |
1843 | return ret; | |
1844 | ||
1845 | return logfs_truncate_direct(inode, size); | |
1846 | } | |
1847 | ||
1848 | int logfs_truncate(struct inode *inode, u64 size) | |
1849 | { | |
1850 | struct super_block *sb = inode->i_sb; | |
1851 | int err; | |
1852 | ||
1853 | logfs_get_wblocks(sb, NULL, 1); | |
1854 | err = __logfs_truncate(inode, size); | |
1855 | if (!err) | |
1856 | err = __logfs_write_inode(inode, 0); | |
1857 | logfs_put_wblocks(sb, NULL, 1); | |
1858 | ||
1859 | if (!err) | |
1860 | err = vmtruncate(inode, size); | |
1861 | ||
1862 | /* I don't trust error recovery yet. */ | |
1863 | WARN_ON(err); | |
1864 | return err; | |
1865 | } | |
1866 | ||
1867 | static void move_page_to_inode(struct inode *inode, struct page *page) | |
1868 | { | |
1869 | struct logfs_inode *li = logfs_inode(inode); | |
1870 | struct logfs_block *block = logfs_block(page); | |
1871 | ||
1872 | if (!block) | |
1873 | return; | |
1874 | ||
1875 | log_blockmove("move_page_to_inode(%llx, %llx, %x)\n", | |
1876 | block->ino, block->bix, block->level); | |
1877 | BUG_ON(li->li_block); | |
1878 | block->ops = &inode_block_ops; | |
1879 | block->inode = inode; | |
1880 | li->li_block = block; | |
1881 | ||
1882 | block->page = NULL; | |
1883 | page->private = 0; | |
1884 | ClearPagePrivate(page); | |
1885 | } | |
1886 | ||
1887 | static void move_inode_to_page(struct page *page, struct inode *inode) | |
1888 | { | |
1889 | struct logfs_inode *li = logfs_inode(inode); | |
1890 | struct logfs_block *block = li->li_block; | |
1891 | ||
1892 | if (!block) | |
1893 | return; | |
1894 | ||
1895 | log_blockmove("move_inode_to_page(%llx, %llx, %x)\n", | |
1896 | block->ino, block->bix, block->level); | |
1897 | BUG_ON(PagePrivate(page)); | |
1898 | block->ops = &indirect_block_ops; | |
1899 | block->page = page; | |
1900 | page->private = (unsigned long)block; | |
1901 | SetPagePrivate(page); | |
1902 | ||
1903 | block->inode = NULL; | |
1904 | li->li_block = NULL; | |
1905 | } | |
1906 | ||
1907 | int logfs_read_inode(struct inode *inode) | |
1908 | { | |
1909 | struct super_block *sb = inode->i_sb; | |
1910 | struct logfs_super *super = logfs_super(sb); | |
1911 | struct inode *master_inode = super->s_master_inode; | |
1912 | struct page *page; | |
1913 | struct logfs_disk_inode *di; | |
1914 | u64 ino = inode->i_ino; | |
1915 | ||
1916 | if (ino << sb->s_blocksize_bits > i_size_read(master_inode)) | |
1917 | return -ENODATA; | |
1918 | if (!logfs_exist_block(master_inode, ino)) | |
1919 | return -ENODATA; | |
1920 | ||
1921 | page = read_cache_page(master_inode->i_mapping, ino, | |
1922 | (filler_t *)logfs_readpage, NULL); | |
1923 | if (IS_ERR(page)) | |
1924 | return PTR_ERR(page); | |
1925 | ||
1926 | di = kmap_atomic(page, KM_USER0); | |
1927 | logfs_disk_to_inode(di, inode); | |
1928 | kunmap_atomic(di, KM_USER0); | |
1929 | move_page_to_inode(inode, page); | |
1930 | page_cache_release(page); | |
1931 | return 0; | |
1932 | } | |
1933 | ||
1934 | /* Caller must logfs_put_write_page(page); */ | |
1935 | static struct page *inode_to_page(struct inode *inode) | |
1936 | { | |
1937 | struct inode *master_inode = logfs_super(inode->i_sb)->s_master_inode; | |
1938 | struct logfs_disk_inode *di; | |
1939 | struct page *page; | |
1940 | ||
1941 | BUG_ON(inode->i_ino == LOGFS_INO_MASTER); | |
1942 | ||
1943 | page = logfs_get_write_page(master_inode, inode->i_ino, 0); | |
1944 | if (!page) | |
1945 | return NULL; | |
1946 | ||
1947 | di = kmap_atomic(page, KM_USER0); | |
1948 | logfs_inode_to_disk(inode, di); | |
1949 | kunmap_atomic(di, KM_USER0); | |
1950 | move_inode_to_page(page, inode); | |
1951 | return page; | |
1952 | } | |
1953 | ||
1954 | /* Cheaper version of write_inode. All changes are concealed in | |
1955 | * aliases, which are moved back. No write to the medium happens. | |
1956 | */ | |
1957 | void logfs_clear_inode(struct inode *inode) | |
1958 | { | |
1959 | struct super_block *sb = inode->i_sb; | |
1960 | struct logfs_inode *li = logfs_inode(inode); | |
1961 | struct logfs_block *block = li->li_block; | |
1962 | struct page *page; | |
1963 | ||
1964 | /* Only deleted files may be dirty at this point */ | |
1965 | BUG_ON(inode->i_state & I_DIRTY && inode->i_nlink); | |
1966 | if (!block) | |
1967 | return; | |
1968 | if ((logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN)) { | |
1969 | block->ops->free_block(inode->i_sb, block); | |
1970 | return; | |
1971 | } | |
1972 | ||
1973 | BUG_ON(inode->i_ino < LOGFS_RESERVED_INOS); | |
1974 | page = inode_to_page(inode); | |
1975 | BUG_ON(!page); /* FIXME: Use emergency page */ | |
1976 | logfs_put_write_page(page); | |
1977 | } | |
1978 | ||
1979 | static int do_write_inode(struct inode *inode) | |
1980 | { | |
1981 | struct super_block *sb = inode->i_sb; | |
1982 | struct inode *master_inode = logfs_super(sb)->s_master_inode; | |
1983 | loff_t size = (inode->i_ino + 1) << inode->i_sb->s_blocksize_bits; | |
1984 | struct page *page; | |
1985 | int err; | |
1986 | ||
1987 | BUG_ON(inode->i_ino == LOGFS_INO_MASTER); | |
1988 | /* FIXME: lock inode */ | |
1989 | ||
1990 | if (i_size_read(master_inode) < size) | |
1991 | i_size_write(master_inode, size); | |
1992 | ||
1993 | /* TODO: Tell vfs this inode is clean now */ | |
1994 | ||
1995 | page = inode_to_page(inode); | |
1996 | if (!page) | |
1997 | return -ENOMEM; | |
1998 | ||
1999 | /* FIXME: transaction is part of logfs_block now. Is that enough? */ | |
2000 | err = logfs_write_buf(master_inode, page, 0); | |
2001 | logfs_put_write_page(page); | |
2002 | return err; | |
2003 | } | |
2004 | ||
2005 | static void logfs_mod_segment_entry(struct super_block *sb, u32 segno, | |
2006 | int write, | |
2007 | void (*change_se)(struct logfs_segment_entry *, long), | |
2008 | long arg) | |
2009 | { | |
2010 | struct logfs_super *super = logfs_super(sb); | |
2011 | struct inode *inode; | |
2012 | struct page *page; | |
2013 | struct logfs_segment_entry *se; | |
2014 | pgoff_t page_no; | |
2015 | int child_no; | |
2016 | ||
2017 | page_no = segno >> (sb->s_blocksize_bits - 3); | |
2018 | child_no = segno & ((sb->s_blocksize >> 3) - 1); | |
2019 | ||
2020 | inode = super->s_segfile_inode; | |
2021 | page = logfs_get_write_page(inode, page_no, 0); | |
2022 | BUG_ON(!page); /* FIXME: We need some reserve page for this case */ | |
2023 | if (!PageUptodate(page)) | |
2024 | logfs_read_block(inode, page, WRITE); | |
2025 | ||
2026 | if (write) | |
2027 | alloc_indirect_block(inode, page, 0); | |
2028 | se = kmap_atomic(page, KM_USER0); | |
2029 | change_se(se + child_no, arg); | |
2030 | if (write) { | |
2031 | logfs_set_alias(sb, logfs_block(page), child_no); | |
2032 | BUG_ON((int)be32_to_cpu(se[child_no].valid) > super->s_segsize); | |
2033 | } | |
2034 | kunmap_atomic(se, KM_USER0); | |
2035 | ||
2036 | logfs_put_write_page(page); | |
2037 | } | |
2038 | ||
2039 | static void __get_segment_entry(struct logfs_segment_entry *se, long _target) | |
2040 | { | |
2041 | struct logfs_segment_entry *target = (void *)_target; | |
2042 | ||
2043 | *target = *se; | |
2044 | } | |
2045 | ||
2046 | void logfs_get_segment_entry(struct super_block *sb, u32 segno, | |
2047 | struct logfs_segment_entry *se) | |
2048 | { | |
2049 | logfs_mod_segment_entry(sb, segno, 0, __get_segment_entry, (long)se); | |
2050 | } | |
2051 | ||
2052 | static void __set_segment_used(struct logfs_segment_entry *se, long increment) | |
2053 | { | |
2054 | u32 valid; | |
2055 | ||
2056 | valid = be32_to_cpu(se->valid); | |
2057 | valid += increment; | |
2058 | se->valid = cpu_to_be32(valid); | |
2059 | } | |
2060 | ||
2061 | void logfs_set_segment_used(struct super_block *sb, u64 ofs, int increment) | |
2062 | { | |
2063 | struct logfs_super *super = logfs_super(sb); | |
2064 | u32 segno = ofs >> super->s_segshift; | |
2065 | ||
2066 | if (!increment) | |
2067 | return; | |
2068 | ||
2069 | logfs_mod_segment_entry(sb, segno, 1, __set_segment_used, increment); | |
2070 | } | |
2071 | ||
2072 | static void __set_segment_erased(struct logfs_segment_entry *se, long ec_level) | |
2073 | { | |
2074 | se->ec_level = cpu_to_be32(ec_level); | |
2075 | } | |
2076 | ||
2077 | void logfs_set_segment_erased(struct super_block *sb, u32 segno, u32 ec, | |
2078 | gc_level_t gc_level) | |
2079 | { | |
2080 | u32 ec_level = ec << 4 | (__force u8)gc_level; | |
2081 | ||
2082 | logfs_mod_segment_entry(sb, segno, 1, __set_segment_erased, ec_level); | |
2083 | } | |
2084 | ||
2085 | static void __set_segment_reserved(struct logfs_segment_entry *se, long ignore) | |
2086 | { | |
2087 | se->valid = cpu_to_be32(RESERVED); | |
2088 | } | |
2089 | ||
2090 | void logfs_set_segment_reserved(struct super_block *sb, u32 segno) | |
2091 | { | |
2092 | logfs_mod_segment_entry(sb, segno, 1, __set_segment_reserved, 0); | |
2093 | } | |
2094 | ||
2095 | static void __set_segment_unreserved(struct logfs_segment_entry *se, | |
2096 | long ec_level) | |
2097 | { | |
2098 | se->valid = 0; | |
2099 | se->ec_level = cpu_to_be32(ec_level); | |
2100 | } | |
2101 | ||
2102 | void logfs_set_segment_unreserved(struct super_block *sb, u32 segno, u32 ec) | |
2103 | { | |
2104 | u32 ec_level = ec << 4; | |
2105 | ||
2106 | logfs_mod_segment_entry(sb, segno, 1, __set_segment_unreserved, | |
2107 | ec_level); | |
2108 | } | |
2109 | ||
2110 | int __logfs_write_inode(struct inode *inode, long flags) | |
2111 | { | |
2112 | struct super_block *sb = inode->i_sb; | |
2113 | int ret; | |
2114 | ||
2115 | logfs_get_wblocks(sb, NULL, flags & WF_LOCK); | |
2116 | ret = do_write_inode(inode); | |
2117 | logfs_put_wblocks(sb, NULL, flags & WF_LOCK); | |
2118 | return ret; | |
2119 | } | |
2120 | ||
2121 | static int do_delete_inode(struct inode *inode) | |
2122 | { | |
2123 | struct super_block *sb = inode->i_sb; | |
2124 | struct inode *master_inode = logfs_super(sb)->s_master_inode; | |
2125 | struct page *page; | |
2126 | int ret; | |
2127 | ||
2128 | page = logfs_get_write_page(master_inode, inode->i_ino, 0); | |
2129 | if (!page) | |
2130 | return -ENOMEM; | |
2131 | ||
2132 | move_inode_to_page(page, inode); | |
2133 | ||
2134 | logfs_get_wblocks(sb, page, 1); | |
2135 | ret = __logfs_delete(master_inode, page); | |
2136 | logfs_put_wblocks(sb, page, 1); | |
2137 | ||
2138 | logfs_put_write_page(page); | |
2139 | return ret; | |
2140 | } | |
2141 | ||
2142 | /* | |
2143 | * ZOMBIE inodes have already been deleted before and should remain dead, | |
2144 | * if it weren't for valid checking. No need to kill them again here. | |
2145 | */ | |
2146 | void logfs_delete_inode(struct inode *inode) | |
2147 | { | |
2148 | struct logfs_inode *li = logfs_inode(inode); | |
2149 | ||
2150 | if (!(li->li_flags & LOGFS_IF_ZOMBIE)) { | |
2151 | li->li_flags |= LOGFS_IF_ZOMBIE; | |
2152 | if (i_size_read(inode) > 0) | |
2153 | logfs_truncate(inode, 0); | |
2154 | do_delete_inode(inode); | |
2155 | } | |
2156 | truncate_inode_pages(&inode->i_data, 0); | |
2157 | clear_inode(inode); | |
2158 | } | |
2159 | ||
2160 | void btree_write_block(struct logfs_block *block) | |
2161 | { | |
2162 | struct inode *inode; | |
2163 | struct page *page; | |
2164 | int err, cookie; | |
2165 | ||
2166 | inode = logfs_safe_iget(block->sb, block->ino, &cookie); | |
2167 | page = logfs_get_write_page(inode, block->bix, block->level); | |
2168 | ||
2169 | err = logfs_readpage_nolock(page); | |
2170 | BUG_ON(err); | |
2171 | BUG_ON(!PagePrivate(page)); | |
2172 | BUG_ON(logfs_block(page) != block); | |
2173 | err = __logfs_write_buf(inode, page, 0); | |
2174 | BUG_ON(err); | |
2175 | BUG_ON(PagePrivate(page) || page->private); | |
2176 | ||
2177 | logfs_put_write_page(page); | |
2178 | logfs_safe_iput(inode, cookie); | |
2179 | } | |
2180 | ||
2181 | /** | |
2182 | * logfs_inode_write - write inode or dentry objects | |
2183 | * | |
2184 | * @inode: parent inode (ifile or directory) | |
2185 | * @buf: object to write (inode or dentry) | |
2186 | * @n: object size | |
2187 | * @_pos: object number (file position in blocks/objects) | |
2188 | * @flags: write flags | |
2189 | * @lock: 0 if write lock is already taken, 1 otherwise | |
2190 | * @shadow_tree: shadow below this inode | |
2191 | * | |
2192 | * FIXME: All caller of this put a 200-300 byte variable on the stack, | |
2193 | * only to call here and do a memcpy from that stack variable. A good | |
2194 | * example of wasted performance and stack space. | |
2195 | */ | |
2196 | int logfs_inode_write(struct inode *inode, const void *buf, size_t count, | |
2197 | loff_t bix, long flags, struct shadow_tree *shadow_tree) | |
2198 | { | |
2199 | loff_t pos = bix << inode->i_sb->s_blocksize_bits; | |
2200 | int err; | |
2201 | struct page *page; | |
2202 | void *pagebuf; | |
2203 | ||
2204 | BUG_ON(pos & (LOGFS_BLOCKSIZE-1)); | |
2205 | BUG_ON(count > LOGFS_BLOCKSIZE); | |
2206 | page = logfs_get_write_page(inode, bix, 0); | |
2207 | if (!page) | |
2208 | return -ENOMEM; | |
2209 | ||
2210 | pagebuf = kmap_atomic(page, KM_USER0); | |
2211 | memcpy(pagebuf, buf, count); | |
2212 | flush_dcache_page(page); | |
2213 | kunmap_atomic(pagebuf, KM_USER0); | |
2214 | ||
2215 | if (i_size_read(inode) < pos + LOGFS_BLOCKSIZE) | |
2216 | i_size_write(inode, pos + LOGFS_BLOCKSIZE); | |
2217 | ||
2218 | err = logfs_write_buf(inode, page, flags); | |
2219 | logfs_put_write_page(page); | |
2220 | return err; | |
2221 | } | |
2222 | ||
2223 | int logfs_open_segfile(struct super_block *sb) | |
2224 | { | |
2225 | struct logfs_super *super = logfs_super(sb); | |
2226 | struct inode *inode; | |
2227 | ||
2228 | inode = logfs_read_meta_inode(sb, LOGFS_INO_SEGFILE); | |
2229 | if (IS_ERR(inode)) | |
2230 | return PTR_ERR(inode); | |
2231 | super->s_segfile_inode = inode; | |
2232 | return 0; | |
2233 | } | |
2234 | ||
2235 | int logfs_init_rw(struct super_block *sb) | |
2236 | { | |
2237 | struct logfs_super *super = logfs_super(sb); | |
2238 | int min_fill = 3 * super->s_no_blocks; | |
2239 | ||
2240 | INIT_LIST_HEAD(&super->s_object_alias); | |
2241 | mutex_init(&super->s_write_mutex); | |
2242 | super->s_block_pool = mempool_create_kmalloc_pool(min_fill, | |
2243 | sizeof(struct logfs_block)); | |
2244 | super->s_shadow_pool = mempool_create_kmalloc_pool(min_fill, | |
2245 | sizeof(struct logfs_shadow)); | |
2246 | return 0; | |
2247 | } | |
2248 | ||
2249 | void logfs_cleanup_rw(struct super_block *sb) | |
2250 | { | |
2251 | struct logfs_super *super = logfs_super(sb); | |
2252 | ||
2253 | destroy_meta_inode(super->s_segfile_inode); | |
2254 | if (super->s_block_pool) | |
2255 | mempool_destroy(super->s_block_pool); | |
2256 | if (super->s_shadow_pool) | |
2257 | mempool_destroy(super->s_shadow_pool); | |
2258 | } |