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-rw-r--r--fs/logfs/readwrite.c2267
1 files changed, 2267 insertions, 0 deletions
diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
new file mode 100644
index 000000000000..3159db6958e5
--- /dev/null
+++ b/fs/logfs/readwrite.c
@@ -0,0 +1,2267 @@
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>
21#include <linux/slab.h>
22
23static 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
44static 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)
62static inline pgoff_t first_indirect_block(void)
63{
64 return INDIRECT_BIT | (1ULL << LEVEL_SHIFT);
65}
66
67pgoff_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
81void 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 */
104static struct timespec be64_to_timespec(__be64 betime)
105{
106 return ns_to_timespec(be64_to_cpu(betime));
107}
108
109static __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
114static 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
150static 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
187static 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
197void 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
205static 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
222static 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 */
247static 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
263static 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
276static 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
283static void logfs_put_read_page(struct page *page)
284{
285 unlock_page(page);
286 page_cache_release(page);
287}
288
289static 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
312static 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
320repeat:
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
338static void logfs_unlock_write_page(struct page *page)
339{
340 if (!PagePreLocked(page))
341 unlock_page(page);
342}
343
344static void logfs_put_write_page(struct page *page)
345{
346 logfs_unlock_write_page(page);
347 page_cache_release(page);
348}
349
350static 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
359static 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
367static 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
377static unsigned long get_bits(u64 val, level_t skip)
378{
379 return __get_bits(val, (__force int)skip, LOGFS_BLOCK_BITS);
380}
381
382static 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
391static 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
418static 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)
425 logfs_write_anchor(inode->i_sb);
426 else {
427 ret = __logfs_write_inode(inode, 0);
428 /* see indirect_write_block comment */
429 BUG_ON(ret);
430 }
431}
432
433/*
434 * This silences a false, yet annoying gcc warning. I hate it when my editor
435 * jumps into bitops.h each time I recompile this file.
436 * TODO: Complain to gcc folks about this and upgrade compiler.
437 */
438static unsigned long fnb(const unsigned long *addr,
439 unsigned long size, unsigned long offset)
440{
441 return find_next_bit(addr, size, offset);
442}
443
444static __be64 inode_val0(struct inode *inode)
445{
446 struct logfs_inode *li = logfs_inode(inode);
447 u64 val;
448
449 /*
450 * Explicit shifting generates good code, but must match the format
451 * of the structure. Add some paranoia just in case.
452 */
453 BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_mode) != 0);
454 BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_height) != 2);
455 BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_flags) != 4);
456
457 val = (u64)inode->i_mode << 48 |
458 (u64)li->li_height << 40 |
459 (u64)li->li_flags;
460 return cpu_to_be64(val);
461}
462
463static int inode_write_alias(struct super_block *sb,
464 struct logfs_block *block, write_alias_t *write_one_alias)
465{
466 struct inode *inode = block->inode;
467 struct logfs_inode *li = logfs_inode(inode);
468 unsigned long pos;
469 u64 ino , bix;
470 __be64 val;
471 level_t level;
472 int err;
473
474 for (pos = 0; ; pos++) {
475 pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos);
476 if (pos >= LOGFS_EMBEDDED_FIELDS + INODE_POINTER_OFS)
477 return 0;
478
479 switch (pos) {
480 case INODE_HEIGHT_OFS:
481 val = inode_val0(inode);
482 break;
483 case INODE_USED_OFS:
484 val = cpu_to_be64(li->li_used_bytes);;
485 break;
486 case INODE_SIZE_OFS:
487 val = cpu_to_be64(i_size_read(inode));
488 break;
489 case INODE_POINTER_OFS ... INODE_POINTER_OFS + LOGFS_EMBEDDED_FIELDS - 1:
490 val = cpu_to_be64(li->li_data[pos - INODE_POINTER_OFS]);
491 break;
492 default:
493 BUG();
494 }
495
496 ino = LOGFS_INO_MASTER;
497 bix = inode->i_ino;
498 level = LEVEL(0);
499 err = write_one_alias(sb, ino, bix, level, pos, val);
500 if (err)
501 return err;
502 }
503}
504
505static int indirect_write_alias(struct super_block *sb,
506 struct logfs_block *block, write_alias_t *write_one_alias)
507{
508 unsigned long pos;
509 struct page *page = block->page;
510 u64 ino , bix;
511 __be64 *child, val;
512 level_t level;
513 int err;
514
515 for (pos = 0; ; pos++) {
516 pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos);
517 if (pos >= LOGFS_BLOCK_FACTOR)
518 return 0;
519
520 ino = page->mapping->host->i_ino;
521 logfs_unpack_index(page->index, &bix, &level);
522 child = kmap_atomic(page, KM_USER0);
523 val = child[pos];
524 kunmap_atomic(child, KM_USER0);
525 err = write_one_alias(sb, ino, bix, level, pos, val);
526 if (err)
527 return err;
528 }
529}
530
531int logfs_write_obj_aliases_pagecache(struct super_block *sb)
532{
533 struct logfs_super *super = logfs_super(sb);
534 struct logfs_block *block;
535 int err;
536
537 list_for_each_entry(block, &super->s_object_alias, alias_list) {
538 err = block->ops->write_alias(sb, block, write_alias_journal);
539 if (err)
540 return err;
541 }
542 return 0;
543}
544
545void __free_block(struct super_block *sb, struct logfs_block *block)
546{
547 BUG_ON(!list_empty(&block->item_list));
548 list_del(&block->alias_list);
549 mempool_free(block, logfs_super(sb)->s_block_pool);
550}
551
552static void inode_free_block(struct super_block *sb, struct logfs_block *block)
553{
554 struct inode *inode = block->inode;
555
556 logfs_inode(inode)->li_block = NULL;
557 __free_block(sb, block);
558}
559
560static void indirect_free_block(struct super_block *sb,
561 struct logfs_block *block)
562{
563 ClearPagePrivate(block->page);
564 block->page->private = 0;
565 __free_block(sb, block);
566}
567
568
569static struct logfs_block_ops inode_block_ops = {
570 .write_block = inode_write_block,
571 .free_block = inode_free_block,
572 .write_alias = inode_write_alias,
573};
574
575struct logfs_block_ops indirect_block_ops = {
576 .write_block = indirect_write_block,
577 .free_block = indirect_free_block,
578 .write_alias = indirect_write_alias,
579};
580
581struct logfs_block *__alloc_block(struct super_block *sb,
582 u64 ino, u64 bix, level_t level)
583{
584 struct logfs_super *super = logfs_super(sb);
585 struct logfs_block *block;
586
587 block = mempool_alloc(super->s_block_pool, GFP_NOFS);
588 memset(block, 0, sizeof(*block));
589 INIT_LIST_HEAD(&block->alias_list);
590 INIT_LIST_HEAD(&block->item_list);
591 block->sb = sb;
592 block->ino = ino;
593 block->bix = bix;
594 block->level = level;
595 return block;
596}
597
598static void alloc_inode_block(struct inode *inode)
599{
600 struct logfs_inode *li = logfs_inode(inode);
601 struct logfs_block *block;
602
603 if (li->li_block)
604 return;
605
606 block = __alloc_block(inode->i_sb, LOGFS_INO_MASTER, inode->i_ino, 0);
607 block->inode = inode;
608 li->li_block = block;
609 block->ops = &inode_block_ops;
610}
611
612void initialize_block_counters(struct page *page, struct logfs_block *block,
613 __be64 *array, int page_is_empty)
614{
615 u64 ptr;
616 int i, start;
617
618 block->partial = 0;
619 block->full = 0;
620 start = 0;
621 if (page->index < first_indirect_block()) {
622 /* Counters are pointless on level 0 */
623 return;
624 }
625 if (page->index == first_indirect_block()) {
626 /* Skip unused pointers */
627 start = I0_BLOCKS;
628 block->full = I0_BLOCKS;
629 }
630 if (!page_is_empty) {
631 for (i = start; i < LOGFS_BLOCK_FACTOR; i++) {
632 ptr = be64_to_cpu(array[i]);
633 if (ptr)
634 block->partial++;
635 if (ptr & LOGFS_FULLY_POPULATED)
636 block->full++;
637 }
638 }
639}
640
641static void alloc_data_block(struct inode *inode, struct page *page)
642{
643 struct logfs_block *block;
644 u64 bix;
645 level_t level;
646
647 if (PagePrivate(page))
648 return;
649
650 logfs_unpack_index(page->index, &bix, &level);
651 block = __alloc_block(inode->i_sb, inode->i_ino, bix, level);
652 block->page = page;
653 SetPagePrivate(page);
654 page->private = (unsigned long)block;
655 block->ops = &indirect_block_ops;
656}
657
658static void alloc_indirect_block(struct inode *inode, struct page *page,
659 int page_is_empty)
660{
661 struct logfs_block *block;
662 __be64 *array;
663
664 if (PagePrivate(page))
665 return;
666
667 alloc_data_block(inode, page);
668
669 block = logfs_block(page);
670 array = kmap_atomic(page, KM_USER0);
671 initialize_block_counters(page, block, array, page_is_empty);
672 kunmap_atomic(array, KM_USER0);
673}
674
675static void block_set_pointer(struct page *page, int index, u64 ptr)
676{
677 struct logfs_block *block = logfs_block(page);
678 __be64 *array;
679 u64 oldptr;
680
681 BUG_ON(!block);
682 array = kmap_atomic(page, KM_USER0);
683 oldptr = be64_to_cpu(array[index]);
684 array[index] = cpu_to_be64(ptr);
685 kunmap_atomic(array, KM_USER0);
686 SetPageUptodate(page);
687
688 block->full += !!(ptr & LOGFS_FULLY_POPULATED)
689 - !!(oldptr & LOGFS_FULLY_POPULATED);
690 block->partial += !!ptr - !!oldptr;
691}
692
693static u64 block_get_pointer(struct page *page, int index)
694{
695 __be64 *block;
696 u64 ptr;
697
698 block = kmap_atomic(page, KM_USER0);
699 ptr = be64_to_cpu(block[index]);
700 kunmap_atomic(block, KM_USER0);
701 return ptr;
702}
703
704static int logfs_read_empty(struct page *page)
705{
706 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
707 return 0;
708}
709
710static int logfs_read_direct(struct inode *inode, struct page *page)
711{
712 struct logfs_inode *li = logfs_inode(inode);
713 pgoff_t index = page->index;
714 u64 block;
715
716 block = li->li_data[index];
717 if (!block)
718 return logfs_read_empty(page);
719
720 return logfs_segment_read(inode, page, block, index, 0);
721}
722
723static int logfs_read_loop(struct inode *inode, struct page *page,
724 int rw_context)
725{
726 struct logfs_inode *li = logfs_inode(inode);
727 u64 bix, bofs = li->li_data[INDIRECT_INDEX];
728 level_t level, target_level;
729 int ret;
730 struct page *ipage;
731
732 logfs_unpack_index(page->index, &bix, &target_level);
733 if (!bofs)
734 return logfs_read_empty(page);
735
736 if (bix >= maxbix(li->li_height))
737 return logfs_read_empty(page);
738
739 for (level = LEVEL(li->li_height);
740 (__force u8)level > (__force u8)target_level;
741 level = SUBLEVEL(level)){
742 ipage = logfs_get_page(inode, bix, level, rw_context);
743 if (!ipage)
744 return -ENOMEM;
745
746 ret = logfs_segment_read(inode, ipage, bofs, bix, level);
747 if (ret) {
748 logfs_put_read_page(ipage);
749 return ret;
750 }
751
752 bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level)));
753 logfs_put_page(ipage, rw_context);
754 if (!bofs)
755 return logfs_read_empty(page);
756 }
757
758 return logfs_segment_read(inode, page, bofs, bix, 0);
759}
760
761static int logfs_read_block(struct inode *inode, struct page *page,
762 int rw_context)
763{
764 pgoff_t index = page->index;
765
766 if (index < I0_BLOCKS)
767 return logfs_read_direct(inode, page);
768 return logfs_read_loop(inode, page, rw_context);
769}
770
771static int logfs_exist_loop(struct inode *inode, u64 bix)
772{
773 struct logfs_inode *li = logfs_inode(inode);
774 u64 bofs = li->li_data[INDIRECT_INDEX];
775 level_t level;
776 int ret;
777 struct page *ipage;
778
779 if (!bofs)
780 return 0;
781 if (bix >= maxbix(li->li_height))
782 return 0;
783
784 for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) {
785 ipage = logfs_get_read_page(inode, bix, level);
786 if (!ipage)
787 return -ENOMEM;
788
789 ret = logfs_segment_read(inode, ipage, bofs, bix, level);
790 if (ret) {
791 logfs_put_read_page(ipage);
792 return ret;
793 }
794
795 bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level)));
796 logfs_put_read_page(ipage);
797 if (!bofs)
798 return 0;
799 }
800
801 return 1;
802}
803
804int logfs_exist_block(struct inode *inode, u64 bix)
805{
806 struct logfs_inode *li = logfs_inode(inode);
807
808 if (bix < I0_BLOCKS)
809 return !!li->li_data[bix];
810 return logfs_exist_loop(inode, bix);
811}
812
813static u64 seek_holedata_direct(struct inode *inode, u64 bix, int data)
814{
815 struct logfs_inode *li = logfs_inode(inode);
816
817 for (; bix < I0_BLOCKS; bix++)
818 if (data ^ (li->li_data[bix] == 0))
819 return bix;
820 return I0_BLOCKS;
821}
822
823static u64 seek_holedata_loop(struct inode *inode, u64 bix, int data)
824{
825 struct logfs_inode *li = logfs_inode(inode);
826 __be64 *rblock;
827 u64 increment, bofs = li->li_data[INDIRECT_INDEX];
828 level_t level;
829 int ret, slot;
830 struct page *page;
831
832 BUG_ON(!bofs);
833
834 for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) {
835 increment = 1 << (LOGFS_BLOCK_BITS * ((__force u8)level-1));
836 page = logfs_get_read_page(inode, bix, level);
837 if (!page)
838 return bix;
839
840 ret = logfs_segment_read(inode, page, bofs, bix, level);
841 if (ret) {
842 logfs_put_read_page(page);
843 return bix;
844 }
845
846 slot = get_bits(bix, SUBLEVEL(level));
847 rblock = kmap_atomic(page, KM_USER0);
848 while (slot < LOGFS_BLOCK_FACTOR) {
849 if (data && (rblock[slot] != 0))
850 break;
851 if (!data && !(be64_to_cpu(rblock[slot]) & LOGFS_FULLY_POPULATED))
852 break;
853 slot++;
854 bix += increment;
855 bix &= ~(increment - 1);
856 }
857 if (slot >= LOGFS_BLOCK_FACTOR) {
858 kunmap_atomic(rblock, KM_USER0);
859 logfs_put_read_page(page);
860 return bix;
861 }
862 bofs = be64_to_cpu(rblock[slot]);
863 kunmap_atomic(rblock, KM_USER0);
864 logfs_put_read_page(page);
865 if (!bofs) {
866 BUG_ON(data);
867 return bix;
868 }
869 }
870 return bix;
871}
872
873/**
874 * logfs_seek_hole - find next hole starting at a given block index
875 * @inode: inode to search in
876 * @bix: block index to start searching
877 *
878 * Returns next hole. If the file doesn't contain any further holes, the
879 * block address next to eof is returned instead.
880 */
881u64 logfs_seek_hole(struct inode *inode, u64 bix)
882{
883 struct logfs_inode *li = logfs_inode(inode);
884
885 if (bix < I0_BLOCKS) {
886 bix = seek_holedata_direct(inode, bix, 0);
887 if (bix < I0_BLOCKS)
888 return bix;
889 }
890
891 if (!li->li_data[INDIRECT_INDEX])
892 return bix;
893 else if (li->li_data[INDIRECT_INDEX] & LOGFS_FULLY_POPULATED)
894 bix = maxbix(li->li_height);
895 else {
896 bix = seek_holedata_loop(inode, bix, 0);
897 if (bix < maxbix(li->li_height))
898 return bix;
899 /* Should not happen anymore. But if some port writes semi-
900 * corrupt images (as this one used to) we might run into it.
901 */
902 WARN_ON_ONCE(bix == maxbix(li->li_height));
903 }
904
905 return bix;
906}
907
908static u64 __logfs_seek_data(struct inode *inode, u64 bix)
909{
910 struct logfs_inode *li = logfs_inode(inode);
911
912 if (bix < I0_BLOCKS) {
913 bix = seek_holedata_direct(inode, bix, 1);
914 if (bix < I0_BLOCKS)
915 return bix;
916 }
917
918 if (bix < maxbix(li->li_height)) {
919 if (!li->li_data[INDIRECT_INDEX])
920 bix = maxbix(li->li_height);
921 else
922 return seek_holedata_loop(inode, bix, 1);
923 }
924
925 return bix;
926}
927
928/**
929 * logfs_seek_data - find next data block after a given block index
930 * @inode: inode to search in
931 * @bix: block index to start searching
932 *
933 * Returns next data block. If the file doesn't contain any further data
934 * blocks, the last block in the file is returned instead.
935 */
936u64 logfs_seek_data(struct inode *inode, u64 bix)
937{
938 struct super_block *sb = inode->i_sb;
939 u64 ret, end;
940
941 ret = __logfs_seek_data(inode, bix);
942 end = i_size_read(inode) >> sb->s_blocksize_bits;
943 if (ret >= end)
944 ret = max(bix, end);
945 return ret;
946}
947
948static int logfs_is_valid_direct(struct logfs_inode *li, u64 bix, u64 ofs)
949{
950 return pure_ofs(li->li_data[bix]) == ofs;
951}
952
953static int __logfs_is_valid_loop(struct inode *inode, u64 bix,
954 u64 ofs, u64 bofs)
955{
956 struct logfs_inode *li = logfs_inode(inode);
957 level_t level;
958 int ret;
959 struct page *page;
960
961 for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)){
962 page = logfs_get_write_page(inode, bix, level);
963 BUG_ON(!page);
964
965 ret = logfs_segment_read(inode, page, bofs, bix, level);
966 if (ret) {
967 logfs_put_write_page(page);
968 return 0;
969 }
970
971 bofs = block_get_pointer(page, get_bits(bix, SUBLEVEL(level)));
972 logfs_put_write_page(page);
973 if (!bofs)
974 return 0;
975
976 if (pure_ofs(bofs) == ofs)
977 return 1;
978 }
979 return 0;
980}
981
982static int logfs_is_valid_loop(struct inode *inode, u64 bix, u64 ofs)
983{
984 struct logfs_inode *li = logfs_inode(inode);
985 u64 bofs = li->li_data[INDIRECT_INDEX];
986
987 if (!bofs)
988 return 0;
989
990 if (bix >= maxbix(li->li_height))
991 return 0;
992
993 if (pure_ofs(bofs) == ofs)
994 return 1;
995
996 return __logfs_is_valid_loop(inode, bix, ofs, bofs);
997}
998
999static int __logfs_is_valid_block(struct inode *inode, u64 bix, u64 ofs)
1000{
1001 struct logfs_inode *li = logfs_inode(inode);
1002
1003 if ((inode->i_nlink == 0) && atomic_read(&inode->i_count) == 1)
1004 return 0;
1005
1006 if (bix < I0_BLOCKS)
1007 return logfs_is_valid_direct(li, bix, ofs);
1008 return logfs_is_valid_loop(inode, bix, ofs);
1009}
1010
1011/**
1012 * logfs_is_valid_block - check whether this block is still valid
1013 *
1014 * @sb - superblock
1015 * @ofs - block physical offset
1016 * @ino - block inode number
1017 * @bix - block index
1018 * @level - block level
1019 *
1020 * Returns 0 if the block is invalid, 1 if it is valid and 2 if it will
1021 * become invalid once the journal is written.
1022 */
1023int logfs_is_valid_block(struct super_block *sb, u64 ofs, u64 ino, u64 bix,
1024 gc_level_t gc_level)
1025{
1026 struct logfs_super *super = logfs_super(sb);
1027 struct inode *inode;
1028 int ret, cookie;
1029
1030 /* Umount closes a segment with free blocks remaining. Those
1031 * blocks are by definition invalid. */
1032 if (ino == -1)
1033 return 0;
1034
1035 LOGFS_BUG_ON((u64)(u_long)ino != ino, sb);
1036
1037 inode = logfs_safe_iget(sb, ino, &cookie);
1038 if (IS_ERR(inode))
1039 goto invalid;
1040
1041 ret = __logfs_is_valid_block(inode, bix, ofs);
1042 logfs_safe_iput(inode, cookie);
1043 if (ret)
1044 return ret;
1045
1046invalid:
1047 /* Block is nominally invalid, but may still sit in the shadow tree,
1048 * waiting for a journal commit.
1049 */
1050 if (btree_lookup64(&super->s_shadow_tree.old, ofs))
1051 return 2;
1052 return 0;
1053}
1054
1055int logfs_readpage_nolock(struct page *page)
1056{
1057 struct inode *inode = page->mapping->host;
1058 int ret = -EIO;
1059
1060 ret = logfs_read_block(inode, page, READ);
1061
1062 if (ret) {
1063 ClearPageUptodate(page);
1064 SetPageError(page);
1065 } else {
1066 SetPageUptodate(page);
1067 ClearPageError(page);
1068 }
1069 flush_dcache_page(page);
1070
1071 return ret;
1072}
1073
1074static int logfs_reserve_bytes(struct inode *inode, int bytes)
1075{
1076 struct logfs_super *super = logfs_super(inode->i_sb);
1077 u64 available = super->s_free_bytes + super->s_dirty_free_bytes
1078 - super->s_dirty_used_bytes - super->s_dirty_pages;
1079
1080 if (!bytes)
1081 return 0;
1082
1083 if (available < bytes)
1084 return -ENOSPC;
1085
1086 if (available < bytes + super->s_root_reserve &&
1087 !capable(CAP_SYS_RESOURCE))
1088 return -ENOSPC;
1089
1090 return 0;
1091}
1092
1093int get_page_reserve(struct inode *inode, struct page *page)
1094{
1095 struct logfs_super *super = logfs_super(inode->i_sb);
1096 int ret;
1097
1098 if (logfs_block(page) && logfs_block(page)->reserved_bytes)
1099 return 0;
1100
1101 logfs_get_wblocks(inode->i_sb, page, WF_LOCK);
1102 ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE);
1103 if (!ret) {
1104 alloc_data_block(inode, page);
1105 logfs_block(page)->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE;
1106 super->s_dirty_pages += 6 * LOGFS_MAX_OBJECTSIZE;
1107 }
1108 logfs_put_wblocks(inode->i_sb, page, WF_LOCK);
1109 return ret;
1110}
1111
1112/*
1113 * We are protected by write lock. Push victims up to superblock level
1114 * and release transaction when appropriate.
1115 */
1116/* FIXME: This is currently called from the wrong spots. */
1117static void logfs_handle_transaction(struct inode *inode,
1118 struct logfs_transaction *ta)
1119{
1120 struct logfs_super *super = logfs_super(inode->i_sb);
1121
1122 if (!ta)
1123 return;
1124 logfs_inode(inode)->li_block->ta = NULL;
1125
1126 if (inode->i_ino != LOGFS_INO_MASTER) {
1127 BUG(); /* FIXME: Yes, this needs more thought */
1128 /* just remember the transaction until inode is written */
1129 //BUG_ON(logfs_inode(inode)->li_transaction);
1130 //logfs_inode(inode)->li_transaction = ta;
1131 return;
1132 }
1133
1134 switch (ta->state) {
1135 case CREATE_1: /* fall through */
1136 case UNLINK_1:
1137 BUG_ON(super->s_victim_ino);
1138 super->s_victim_ino = ta->ino;
1139 break;
1140 case CREATE_2: /* fall through */
1141 case UNLINK_2:
1142 BUG_ON(super->s_victim_ino != ta->ino);
1143 super->s_victim_ino = 0;
1144 /* transaction ends here - free it */
1145 kfree(ta);
1146 break;
1147 case CROSS_RENAME_1:
1148 BUG_ON(super->s_rename_dir);
1149 BUG_ON(super->s_rename_pos);
1150 super->s_rename_dir = ta->dir;
1151 super->s_rename_pos = ta->pos;
1152 break;
1153 case CROSS_RENAME_2:
1154 BUG_ON(super->s_rename_dir != ta->dir);
1155 BUG_ON(super->s_rename_pos != ta->pos);
1156 super->s_rename_dir = 0;
1157 super->s_rename_pos = 0;
1158 kfree(ta);
1159 break;
1160 case TARGET_RENAME_1:
1161 BUG_ON(super->s_rename_dir);
1162 BUG_ON(super->s_rename_pos);
1163 BUG_ON(super->s_victim_ino);
1164 super->s_rename_dir = ta->dir;
1165 super->s_rename_pos = ta->pos;
1166 super->s_victim_ino = ta->ino;
1167 break;
1168 case TARGET_RENAME_2:
1169 BUG_ON(super->s_rename_dir != ta->dir);
1170 BUG_ON(super->s_rename_pos != ta->pos);
1171 BUG_ON(super->s_victim_ino != ta->ino);
1172 super->s_rename_dir = 0;
1173 super->s_rename_pos = 0;
1174 break;
1175 case TARGET_RENAME_3:
1176 BUG_ON(super->s_rename_dir);
1177 BUG_ON(super->s_rename_pos);
1178 BUG_ON(super->s_victim_ino != ta->ino);
1179 super->s_victim_ino = 0;
1180 kfree(ta);
1181 break;
1182 default:
1183 BUG();
1184 }
1185}
1186
1187/*
1188 * Not strictly a reservation, but rather a check that we still have enough
1189 * space to satisfy the write.
1190 */
1191static int logfs_reserve_blocks(struct inode *inode, int blocks)
1192{
1193 return logfs_reserve_bytes(inode, blocks * LOGFS_MAX_OBJECTSIZE);
1194}
1195
1196struct write_control {
1197 u64 ofs;
1198 long flags;
1199};
1200
1201static struct logfs_shadow *alloc_shadow(struct inode *inode, u64 bix,
1202 level_t level, u64 old_ofs)
1203{
1204 struct logfs_super *super = logfs_super(inode->i_sb);
1205 struct logfs_shadow *shadow;
1206
1207 shadow = mempool_alloc(super->s_shadow_pool, GFP_NOFS);
1208 memset(shadow, 0, sizeof(*shadow));
1209 shadow->ino = inode->i_ino;
1210 shadow->bix = bix;
1211 shadow->gc_level = expand_level(inode->i_ino, level);
1212 shadow->old_ofs = old_ofs & ~LOGFS_FULLY_POPULATED;
1213 return shadow;
1214}
1215
1216static void free_shadow(struct inode *inode, struct logfs_shadow *shadow)
1217{
1218 struct logfs_super *super = logfs_super(inode->i_sb);
1219
1220 mempool_free(shadow, super->s_shadow_pool);
1221}
1222
1223static void mark_segment(struct shadow_tree *tree, u32 segno)
1224{
1225 int err;
1226
1227 if (!btree_lookup32(&tree->segment_map, segno)) {
1228 err = btree_insert32(&tree->segment_map, segno, (void *)1,
1229 GFP_NOFS);
1230 BUG_ON(err);
1231 tree->no_shadowed_segments++;
1232 }
1233}
1234
1235/**
1236 * fill_shadow_tree - Propagate shadow tree changes due to a write
1237 * @inode: Inode owning the page
1238 * @page: Struct page that was written
1239 * @shadow: Shadow for the current write
1240 *
1241 * Writes in logfs can result in two semi-valid objects. The old object
1242 * is still valid as long as it can be reached by following pointers on
1243 * the medium. Only when writes propagate all the way up to the journal
1244 * has the new object safely replaced the old one.
1245 *
1246 * To handle this problem, a struct logfs_shadow is used to represent
1247 * every single write. It is attached to the indirect block, which is
1248 * marked dirty. When the indirect block is written, its shadows are
1249 * handed up to the next indirect block (or inode). Untimately they
1250 * will reach the master inode and be freed upon journal commit.
1251 *
1252 * This function handles a single step in the propagation. It adds the
1253 * shadow for the current write to the tree, along with any shadows in
1254 * the page's tree, in case it was an indirect block. If a page is
1255 * written, the inode parameter is left NULL, if an inode is written,
1256 * the page parameter is left NULL.
1257 */
1258static void fill_shadow_tree(struct inode *inode, struct page *page,
1259 struct logfs_shadow *shadow)
1260{
1261 struct logfs_super *super = logfs_super(inode->i_sb);
1262 struct logfs_block *block = logfs_block(page);
1263 struct shadow_tree *tree = &super->s_shadow_tree;
1264
1265 if (PagePrivate(page)) {
1266 if (block->alias_map)
1267 super->s_no_object_aliases -= bitmap_weight(
1268 block->alias_map, LOGFS_BLOCK_FACTOR);
1269 logfs_handle_transaction(inode, block->ta);
1270 block->ops->free_block(inode->i_sb, block);
1271 }
1272 if (shadow) {
1273 if (shadow->old_ofs)
1274 btree_insert64(&tree->old, shadow->old_ofs, shadow,
1275 GFP_NOFS);
1276 else
1277 btree_insert64(&tree->new, shadow->new_ofs, shadow,
1278 GFP_NOFS);
1279
1280 super->s_dirty_used_bytes += shadow->new_len;
1281 super->s_dirty_free_bytes += shadow->old_len;
1282 mark_segment(tree, shadow->old_ofs >> super->s_segshift);
1283 mark_segment(tree, shadow->new_ofs >> super->s_segshift);
1284 }
1285}
1286
1287static void logfs_set_alias(struct super_block *sb, struct logfs_block *block,
1288 long child_no)
1289{
1290 struct logfs_super *super = logfs_super(sb);
1291
1292 if (block->inode && block->inode->i_ino == LOGFS_INO_MASTER) {
1293 /* Aliases in the master inode are pointless. */
1294 return;
1295 }
1296
1297 if (!test_bit(child_no, block->alias_map)) {
1298 set_bit(child_no, block->alias_map);
1299 super->s_no_object_aliases++;
1300 }
1301 list_move_tail(&block->alias_list, &super->s_object_alias);
1302}
1303
1304/*
1305 * Object aliases can and often do change the size and occupied space of a
1306 * file. So not only do we have to change the pointers, we also have to
1307 * change inode->i_size and li->li_used_bytes. Which is done by setting
1308 * another two object aliases for the inode itself.
1309 */
1310static void set_iused(struct inode *inode, struct logfs_shadow *shadow)
1311{
1312 struct logfs_inode *li = logfs_inode(inode);
1313
1314 if (shadow->new_len == shadow->old_len)
1315 return;
1316
1317 alloc_inode_block(inode);
1318 li->li_used_bytes += shadow->new_len - shadow->old_len;
1319 __logfs_set_blocks(inode);
1320 logfs_set_alias(inode->i_sb, li->li_block, INODE_USED_OFS);
1321 logfs_set_alias(inode->i_sb, li->li_block, INODE_SIZE_OFS);
1322}
1323
1324static int logfs_write_i0(struct inode *inode, struct page *page,
1325 struct write_control *wc)
1326{
1327 struct logfs_shadow *shadow;
1328 u64 bix;
1329 level_t level;
1330 int full, err = 0;
1331
1332 logfs_unpack_index(page->index, &bix, &level);
1333 if (wc->ofs == 0)
1334 if (logfs_reserve_blocks(inode, 1))
1335 return -ENOSPC;
1336
1337 shadow = alloc_shadow(inode, bix, level, wc->ofs);
1338 if (wc->flags & WF_WRITE)
1339 err = logfs_segment_write(inode, page, shadow);
1340 if (wc->flags & WF_DELETE)
1341 logfs_segment_delete(inode, shadow);
1342 if (err) {
1343 free_shadow(inode, shadow);
1344 return err;
1345 }
1346
1347 set_iused(inode, shadow);
1348 full = 1;
1349 if (level != 0) {
1350 alloc_indirect_block(inode, page, 0);
1351 full = logfs_block(page)->full == LOGFS_BLOCK_FACTOR;
1352 }
1353 fill_shadow_tree(inode, page, shadow);
1354 wc->ofs = shadow->new_ofs;
1355 if (wc->ofs && full)
1356 wc->ofs |= LOGFS_FULLY_POPULATED;
1357 return 0;
1358}
1359
1360static int logfs_write_direct(struct inode *inode, struct page *page,
1361 long flags)
1362{
1363 struct logfs_inode *li = logfs_inode(inode);
1364 struct write_control wc = {
1365 .ofs = li->li_data[page->index],
1366 .flags = flags,
1367 };
1368 int err;
1369
1370 alloc_inode_block(inode);
1371
1372 err = logfs_write_i0(inode, page, &wc);
1373 if (err)
1374 return err;
1375
1376 li->li_data[page->index] = wc.ofs;
1377 logfs_set_alias(inode->i_sb, li->li_block,
1378 page->index + INODE_POINTER_OFS);
1379 return 0;
1380}
1381
1382static int ptr_change(u64 ofs, struct page *page)
1383{
1384 struct logfs_block *block = logfs_block(page);
1385 int empty0, empty1, full0, full1;
1386
1387 empty0 = ofs == 0;
1388 empty1 = block->partial == 0;
1389 if (empty0 != empty1)
1390 return 1;
1391
1392 /* The !! is necessary to shrink result to int */
1393 full0 = !!(ofs & LOGFS_FULLY_POPULATED);
1394 full1 = block->full == LOGFS_BLOCK_FACTOR;
1395 if (full0 != full1)
1396 return 1;
1397 return 0;
1398}
1399
1400static int __logfs_write_rec(struct inode *inode, struct page *page,
1401 struct write_control *this_wc,
1402 pgoff_t bix, level_t target_level, level_t level)
1403{
1404 int ret, page_empty = 0;
1405 int child_no = get_bits(bix, SUBLEVEL(level));
1406 struct page *ipage;
1407 struct write_control child_wc = {
1408 .flags = this_wc->flags,
1409 };
1410
1411 ipage = logfs_get_write_page(inode, bix, level);
1412 if (!ipage)
1413 return -ENOMEM;
1414
1415 if (this_wc->ofs) {
1416 ret = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level);
1417 if (ret)
1418 goto out;
1419 } else if (!PageUptodate(ipage)) {
1420 page_empty = 1;
1421 logfs_read_empty(ipage);
1422 }
1423
1424 child_wc.ofs = block_get_pointer(ipage, child_no);
1425
1426 if ((__force u8)level-1 > (__force u8)target_level)
1427 ret = __logfs_write_rec(inode, page, &child_wc, bix,
1428 target_level, SUBLEVEL(level));
1429 else
1430 ret = logfs_write_i0(inode, page, &child_wc);
1431
1432 if (ret)
1433 goto out;
1434
1435 alloc_indirect_block(inode, ipage, page_empty);
1436 block_set_pointer(ipage, child_no, child_wc.ofs);
1437 /* FIXME: first condition seems superfluous */
1438 if (child_wc.ofs || logfs_block(ipage)->partial)
1439 this_wc->flags |= WF_WRITE;
1440 /* the condition on this_wc->ofs ensures that we won't consume extra
1441 * space for indirect blocks in the future, which we cannot reserve */
1442 if (!this_wc->ofs || ptr_change(this_wc->ofs, ipage))
1443 ret = logfs_write_i0(inode, ipage, this_wc);
1444 else
1445 logfs_set_alias(inode->i_sb, logfs_block(ipage), child_no);
1446out:
1447 logfs_put_write_page(ipage);
1448 return ret;
1449}
1450
1451static int logfs_write_rec(struct inode *inode, struct page *page,
1452 pgoff_t bix, level_t target_level, long flags)
1453{
1454 struct logfs_inode *li = logfs_inode(inode);
1455 struct write_control wc = {
1456 .ofs = li->li_data[INDIRECT_INDEX],
1457 .flags = flags,
1458 };
1459 int ret;
1460
1461 alloc_inode_block(inode);
1462
1463 if (li->li_height > (__force u8)target_level)
1464 ret = __logfs_write_rec(inode, page, &wc, bix, target_level,
1465 LEVEL(li->li_height));
1466 else
1467 ret = logfs_write_i0(inode, page, &wc);
1468 if (ret)
1469 return ret;
1470
1471 if (li->li_data[INDIRECT_INDEX] != wc.ofs) {
1472 li->li_data[INDIRECT_INDEX] = wc.ofs;
1473 logfs_set_alias(inode->i_sb, li->li_block,
1474 INDIRECT_INDEX + INODE_POINTER_OFS);
1475 }
1476 return ret;
1477}
1478
1479void logfs_add_transaction(struct inode *inode, struct logfs_transaction *ta)
1480{
1481 alloc_inode_block(inode);
1482 logfs_inode(inode)->li_block->ta = ta;
1483}
1484
1485void logfs_del_transaction(struct inode *inode, struct logfs_transaction *ta)
1486{
1487 struct logfs_block *block = logfs_inode(inode)->li_block;
1488
1489 if (block && block->ta)
1490 block->ta = NULL;
1491}
1492
1493static int grow_inode(struct inode *inode, u64 bix, level_t level)
1494{
1495 struct logfs_inode *li = logfs_inode(inode);
1496 u8 height = (__force u8)level;
1497 struct page *page;
1498 struct write_control wc = {
1499 .flags = WF_WRITE,
1500 };
1501 int err;
1502
1503 BUG_ON(height > 5 || li->li_height > 5);
1504 while (height > li->li_height || bix >= maxbix(li->li_height)) {
1505 page = logfs_get_write_page(inode, I0_BLOCKS + 1,
1506 LEVEL(li->li_height + 1));
1507 if (!page)
1508 return -ENOMEM;
1509 logfs_read_empty(page);
1510 alloc_indirect_block(inode, page, 1);
1511 block_set_pointer(page, 0, li->li_data[INDIRECT_INDEX]);
1512 err = logfs_write_i0(inode, page, &wc);
1513 logfs_put_write_page(page);
1514 if (err)
1515 return err;
1516 li->li_data[INDIRECT_INDEX] = wc.ofs;
1517 wc.ofs = 0;
1518 li->li_height++;
1519 logfs_set_alias(inode->i_sb, li->li_block, INODE_HEIGHT_OFS);
1520 }
1521 return 0;
1522}
1523
1524static int __logfs_write_buf(struct inode *inode, struct page *page, long flags)
1525{
1526 struct logfs_super *super = logfs_super(inode->i_sb);
1527 pgoff_t index = page->index;
1528 u64 bix;
1529 level_t level;
1530 int err;
1531
1532 flags |= WF_WRITE | WF_DELETE;
1533 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
1534
1535 logfs_unpack_index(index, &bix, &level);
1536 if (logfs_block(page) && logfs_block(page)->reserved_bytes)
1537 super->s_dirty_pages -= logfs_block(page)->reserved_bytes;
1538
1539 if (index < I0_BLOCKS)
1540 return logfs_write_direct(inode, page, flags);
1541
1542 bix = adjust_bix(bix, level);
1543 err = grow_inode(inode, bix, level);
1544 if (err)
1545 return err;
1546 return logfs_write_rec(inode, page, bix, level, flags);
1547}
1548
1549int logfs_write_buf(struct inode *inode, struct page *page, long flags)
1550{
1551 struct super_block *sb = inode->i_sb;
1552 int ret;
1553
1554 logfs_get_wblocks(sb, page, flags & WF_LOCK);
1555 ret = __logfs_write_buf(inode, page, flags);
1556 logfs_put_wblocks(sb, page, flags & WF_LOCK);
1557 return ret;
1558}
1559
1560static int __logfs_delete(struct inode *inode, struct page *page)
1561{
1562 long flags = WF_DELETE;
1563
1564 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
1565
1566 if (page->index < I0_BLOCKS)
1567 return logfs_write_direct(inode, page, flags);
1568 return logfs_write_rec(inode, page, page->index, 0, flags);
1569}
1570
1571int logfs_delete(struct inode *inode, pgoff_t index,
1572 struct shadow_tree *shadow_tree)
1573{
1574 struct super_block *sb = inode->i_sb;
1575 struct page *page;
1576 int ret;
1577
1578 page = logfs_get_read_page(inode, index, 0);
1579 if (!page)
1580 return -ENOMEM;
1581
1582 logfs_get_wblocks(sb, page, 1);
1583 ret = __logfs_delete(inode, page);
1584 logfs_put_wblocks(sb, page, 1);
1585
1586 logfs_put_read_page(page);
1587
1588 return ret;
1589}
1590
1591int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs,
1592 gc_level_t gc_level, long flags)
1593{
1594 level_t level = shrink_level(gc_level);
1595 struct page *page;
1596 int err;
1597
1598 page = logfs_get_write_page(inode, bix, level);
1599 if (!page)
1600 return -ENOMEM;
1601
1602 err = logfs_segment_read(inode, page, ofs, bix, level);
1603 if (!err) {
1604 if (level != 0)
1605 alloc_indirect_block(inode, page, 0);
1606 err = logfs_write_buf(inode, page, flags);
1607 if (!err && shrink_level(gc_level) == 0) {
1608 /* Rewrite cannot mark the inode dirty but has to
1609 * write it immediatly.
1610 * Q: Can't we just create an alias for the inode
1611 * instead? And if not, why not?
1612 */
1613 if (inode->i_ino == LOGFS_INO_MASTER)
1614 logfs_write_anchor(inode->i_sb);
1615 else {
1616 err = __logfs_write_inode(inode, flags);
1617 }
1618 }
1619 }
1620 logfs_put_write_page(page);
1621 return err;
1622}
1623
1624static int truncate_data_block(struct inode *inode, struct page *page,
1625 u64 ofs, struct logfs_shadow *shadow, u64 size)
1626{
1627 loff_t pageofs = page->index << inode->i_sb->s_blocksize_bits;
1628 u64 bix;
1629 level_t level;
1630 int err;
1631
1632 /* Does truncation happen within this page? */
1633 if (size <= pageofs || size - pageofs >= PAGE_SIZE)
1634 return 0;
1635
1636 logfs_unpack_index(page->index, &bix, &level);
1637 BUG_ON(level != 0);
1638
1639 err = logfs_segment_read(inode, page, ofs, bix, level);
1640 if (err)
1641 return err;
1642
1643 zero_user_segment(page, size - pageofs, PAGE_CACHE_SIZE);
1644 return logfs_segment_write(inode, page, shadow);
1645}
1646
1647static int logfs_truncate_i0(struct inode *inode, struct page *page,
1648 struct write_control *wc, u64 size)
1649{
1650 struct logfs_shadow *shadow;
1651 u64 bix;
1652 level_t level;
1653 int err = 0;
1654
1655 logfs_unpack_index(page->index, &bix, &level);
1656 BUG_ON(level != 0);
1657 shadow = alloc_shadow(inode, bix, level, wc->ofs);
1658
1659 err = truncate_data_block(inode, page, wc->ofs, shadow, size);
1660 if (err) {
1661 free_shadow(inode, shadow);
1662 return err;
1663 }
1664
1665 logfs_segment_delete(inode, shadow);
1666 set_iused(inode, shadow);
1667 fill_shadow_tree(inode, page, shadow);
1668 wc->ofs = shadow->new_ofs;
1669 return 0;
1670}
1671
1672static int logfs_truncate_direct(struct inode *inode, u64 size)
1673{
1674 struct logfs_inode *li = logfs_inode(inode);
1675 struct write_control wc;
1676 struct page *page;
1677 int e;
1678 int err;
1679
1680 alloc_inode_block(inode);
1681
1682 for (e = I0_BLOCKS - 1; e >= 0; e--) {
1683 if (size > (e+1) * LOGFS_BLOCKSIZE)
1684 break;
1685
1686 wc.ofs = li->li_data[e];
1687 if (!wc.ofs)
1688 continue;
1689
1690 page = logfs_get_write_page(inode, e, 0);
1691 if (!page)
1692 return -ENOMEM;
1693 err = logfs_segment_read(inode, page, wc.ofs, e, 0);
1694 if (err) {
1695 logfs_put_write_page(page);
1696 return err;
1697 }
1698 err = logfs_truncate_i0(inode, page, &wc, size);
1699 logfs_put_write_page(page);
1700 if (err)
1701 return err;
1702
1703 li->li_data[e] = wc.ofs;
1704 }
1705 return 0;
1706}
1707
1708/* FIXME: these need to become per-sb once we support different blocksizes */
1709static u64 __logfs_step[] = {
1710 1,
1711 I1_BLOCKS,
1712 I2_BLOCKS,
1713 I3_BLOCKS,
1714};
1715
1716static u64 __logfs_start_index[] = {
1717 I0_BLOCKS,
1718 I1_BLOCKS,
1719 I2_BLOCKS,
1720 I3_BLOCKS
1721};
1722
1723static inline u64 logfs_step(level_t level)
1724{
1725 return __logfs_step[(__force u8)level];
1726}
1727
1728static inline u64 logfs_factor(u8 level)
1729{
1730 return __logfs_step[level] * LOGFS_BLOCKSIZE;
1731}
1732
1733static inline u64 logfs_start_index(level_t level)
1734{
1735 return __logfs_start_index[(__force u8)level];
1736}
1737
1738static void logfs_unpack_raw_index(pgoff_t index, u64 *bix, level_t *level)
1739{
1740 logfs_unpack_index(index, bix, level);
1741 if (*bix <= logfs_start_index(SUBLEVEL(*level)))
1742 *bix = 0;
1743}
1744
1745static int __logfs_truncate_rec(struct inode *inode, struct page *ipage,
1746 struct write_control *this_wc, u64 size)
1747{
1748 int truncate_happened = 0;
1749 int e, err = 0;
1750 u64 bix, child_bix, next_bix;
1751 level_t level;
1752 struct page *page;
1753 struct write_control child_wc = { /* FIXME: flags */ };
1754
1755 logfs_unpack_raw_index(ipage->index, &bix, &level);
1756 err = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level);
1757 if (err)
1758 return err;
1759
1760 for (e = LOGFS_BLOCK_FACTOR - 1; e >= 0; e--) {
1761 child_bix = bix + e * logfs_step(SUBLEVEL(level));
1762 next_bix = child_bix + logfs_step(SUBLEVEL(level));
1763 if (size > next_bix * LOGFS_BLOCKSIZE)
1764 break;
1765
1766 child_wc.ofs = pure_ofs(block_get_pointer(ipage, e));
1767 if (!child_wc.ofs)
1768 continue;
1769
1770 page = logfs_get_write_page(inode, child_bix, SUBLEVEL(level));
1771 if (!page)
1772 return -ENOMEM;
1773
1774 if ((__force u8)level > 1)
1775 err = __logfs_truncate_rec(inode, page, &child_wc, size);
1776 else
1777 err = logfs_truncate_i0(inode, page, &child_wc, size);
1778 logfs_put_write_page(page);
1779 if (err)
1780 return err;
1781
1782 truncate_happened = 1;
1783 alloc_indirect_block(inode, ipage, 0);
1784 block_set_pointer(ipage, e, child_wc.ofs);
1785 }
1786
1787 if (!truncate_happened) {
1788 printk("ineffectual truncate (%lx, %lx, %llx)\n", inode->i_ino, ipage->index, size);
1789 return 0;
1790 }
1791
1792 this_wc->flags = WF_DELETE;
1793 if (logfs_block(ipage)->partial)
1794 this_wc->flags |= WF_WRITE;
1795
1796 return logfs_write_i0(inode, ipage, this_wc);
1797}
1798
1799static int logfs_truncate_rec(struct inode *inode, u64 size)
1800{
1801 struct logfs_inode *li = logfs_inode(inode);
1802 struct write_control wc = {
1803 .ofs = li->li_data[INDIRECT_INDEX],
1804 };
1805 struct page *page;
1806 int err;
1807
1808 alloc_inode_block(inode);
1809
1810 if (!wc.ofs)
1811 return 0;
1812
1813 page = logfs_get_write_page(inode, 0, LEVEL(li->li_height));
1814 if (!page)
1815 return -ENOMEM;
1816
1817 err = __logfs_truncate_rec(inode, page, &wc, size);
1818 logfs_put_write_page(page);
1819 if (err)
1820 return err;
1821
1822 if (li->li_data[INDIRECT_INDEX] != wc.ofs)
1823 li->li_data[INDIRECT_INDEX] = wc.ofs;
1824 return 0;
1825}
1826
1827static int __logfs_truncate(struct inode *inode, u64 size)
1828{
1829 int ret;
1830
1831 if (size >= logfs_factor(logfs_inode(inode)->li_height))
1832 return 0;
1833
1834 ret = logfs_truncate_rec(inode, size);
1835 if (ret)
1836 return ret;
1837
1838 return logfs_truncate_direct(inode, size);
1839}
1840
1841/*
1842 * Truncate, by changing the segment file, can consume a fair amount
1843 * of resources. So back off from time to time and do some GC.
1844 * 8 or 2048 blocks should be well within safety limits even if
1845 * every single block resided in a different segment.
1846 */
1847#define TRUNCATE_STEP (8 * 1024 * 1024)
1848int logfs_truncate(struct inode *inode, u64 target)
1849{
1850 struct super_block *sb = inode->i_sb;
1851 u64 size = i_size_read(inode);
1852 int err = 0;
1853
1854 size = ALIGN(size, TRUNCATE_STEP);
1855 while (size > target) {
1856 if (size > TRUNCATE_STEP)
1857 size -= TRUNCATE_STEP;
1858 else
1859 size = 0;
1860 if (size < target)
1861 size = target;
1862
1863 logfs_get_wblocks(sb, NULL, 1);
1864 err = __logfs_truncate(inode, target);
1865 if (!err)
1866 err = __logfs_write_inode(inode, 0);
1867 logfs_put_wblocks(sb, NULL, 1);
1868 }
1869
1870 if (!err)
1871 err = vmtruncate(inode, target);
1872
1873 /* I don't trust error recovery yet. */
1874 WARN_ON(err);
1875 return err;
1876}
1877
1878static void move_page_to_inode(struct inode *inode, struct page *page)
1879{
1880 struct logfs_inode *li = logfs_inode(inode);
1881 struct logfs_block *block = logfs_block(page);
1882
1883 if (!block)
1884 return;
1885
1886 log_blockmove("move_page_to_inode(%llx, %llx, %x)\n",
1887 block->ino, block->bix, block->level);
1888 BUG_ON(li->li_block);
1889 block->ops = &inode_block_ops;
1890 block->inode = inode;
1891 li->li_block = block;
1892
1893 block->page = NULL;
1894 page->private = 0;
1895 ClearPagePrivate(page);
1896}
1897
1898static void move_inode_to_page(struct page *page, struct inode *inode)
1899{
1900 struct logfs_inode *li = logfs_inode(inode);
1901 struct logfs_block *block = li->li_block;
1902
1903 if (!block)
1904 return;
1905
1906 log_blockmove("move_inode_to_page(%llx, %llx, %x)\n",
1907 block->ino, block->bix, block->level);
1908 BUG_ON(PagePrivate(page));
1909 block->ops = &indirect_block_ops;
1910 block->page = page;
1911 page->private = (unsigned long)block;
1912 SetPagePrivate(page);
1913
1914 block->inode = NULL;
1915 li->li_block = NULL;
1916}
1917
1918int logfs_read_inode(struct inode *inode)
1919{
1920 struct super_block *sb = inode->i_sb;
1921 struct logfs_super *super = logfs_super(sb);
1922 struct inode *master_inode = super->s_master_inode;
1923 struct page *page;
1924 struct logfs_disk_inode *di;
1925 u64 ino = inode->i_ino;
1926
1927 if (ino << sb->s_blocksize_bits > i_size_read(master_inode))
1928 return -ENODATA;
1929 if (!logfs_exist_block(master_inode, ino))
1930 return -ENODATA;
1931
1932 page = read_cache_page(master_inode->i_mapping, ino,
1933 (filler_t *)logfs_readpage, NULL);
1934 if (IS_ERR(page))
1935 return PTR_ERR(page);
1936
1937 di = kmap_atomic(page, KM_USER0);
1938 logfs_disk_to_inode(di, inode);
1939 kunmap_atomic(di, KM_USER0);
1940 move_page_to_inode(inode, page);
1941 page_cache_release(page);
1942 return 0;
1943}
1944
1945/* Caller must logfs_put_write_page(page); */
1946static struct page *inode_to_page(struct inode *inode)
1947{
1948 struct inode *master_inode = logfs_super(inode->i_sb)->s_master_inode;
1949 struct logfs_disk_inode *di;
1950 struct page *page;
1951
1952 BUG_ON(inode->i_ino == LOGFS_INO_MASTER);
1953
1954 page = logfs_get_write_page(master_inode, inode->i_ino, 0);
1955 if (!page)
1956 return NULL;
1957
1958 di = kmap_atomic(page, KM_USER0);
1959 logfs_inode_to_disk(inode, di);
1960 kunmap_atomic(di, KM_USER0);
1961 move_inode_to_page(page, inode);
1962 return page;
1963}
1964
1965/* Cheaper version of write_inode. All changes are concealed in
1966 * aliases, which are moved back. No write to the medium happens.
1967 */
1968void logfs_clear_inode(struct inode *inode)
1969{
1970 struct super_block *sb = inode->i_sb;
1971 struct logfs_inode *li = logfs_inode(inode);
1972 struct logfs_block *block = li->li_block;
1973 struct page *page;
1974
1975 /* Only deleted files may be dirty at this point */
1976 BUG_ON(inode->i_state & I_DIRTY && inode->i_nlink);
1977 if (!block)
1978 return;
1979 if ((logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN)) {
1980 block->ops->free_block(inode->i_sb, block);
1981 return;
1982 }
1983
1984 BUG_ON(inode->i_ino < LOGFS_RESERVED_INOS);
1985 page = inode_to_page(inode);
1986 BUG_ON(!page); /* FIXME: Use emergency page */
1987 logfs_put_write_page(page);
1988}
1989
1990static int do_write_inode(struct inode *inode)
1991{
1992 struct super_block *sb = inode->i_sb;
1993 struct inode *master_inode = logfs_super(sb)->s_master_inode;
1994 loff_t size = (inode->i_ino + 1) << inode->i_sb->s_blocksize_bits;
1995 struct page *page;
1996 int err;
1997
1998 BUG_ON(inode->i_ino == LOGFS_INO_MASTER);
1999 /* FIXME: lock inode */
2000
2001 if (i_size_read(master_inode) < size)
2002 i_size_write(master_inode, size);
2003
2004 /* TODO: Tell vfs this inode is clean now */
2005
2006 page = inode_to_page(inode);
2007 if (!page)
2008 return -ENOMEM;
2009
2010 /* FIXME: transaction is part of logfs_block now. Is that enough? */
2011 err = logfs_write_buf(master_inode, page, 0);
2012 logfs_put_write_page(page);
2013 return err;
2014}
2015
2016static void logfs_mod_segment_entry(struct super_block *sb, u32 segno,
2017 int write,
2018 void (*change_se)(struct logfs_segment_entry *, long),
2019 long arg)
2020{
2021 struct logfs_super *super = logfs_super(sb);
2022 struct inode *inode;
2023 struct page *page;
2024 struct logfs_segment_entry *se;
2025 pgoff_t page_no;
2026 int child_no;
2027
2028 page_no = segno >> (sb->s_blocksize_bits - 3);
2029 child_no = segno & ((sb->s_blocksize >> 3) - 1);
2030
2031 inode = super->s_segfile_inode;
2032 page = logfs_get_write_page(inode, page_no, 0);
2033 BUG_ON(!page); /* FIXME: We need some reserve page for this case */
2034 if (!PageUptodate(page))
2035 logfs_read_block(inode, page, WRITE);
2036
2037 if (write)
2038 alloc_indirect_block(inode, page, 0);
2039 se = kmap_atomic(page, KM_USER0);
2040 change_se(se + child_no, arg);
2041 if (write) {
2042 logfs_set_alias(sb, logfs_block(page), child_no);
2043 BUG_ON((int)be32_to_cpu(se[child_no].valid) > super->s_segsize);
2044 }
2045 kunmap_atomic(se, KM_USER0);
2046
2047 logfs_put_write_page(page);
2048}
2049
2050static void __get_segment_entry(struct logfs_segment_entry *se, long _target)
2051{
2052 struct logfs_segment_entry *target = (void *)_target;
2053
2054 *target = *se;
2055}
2056
2057void logfs_get_segment_entry(struct super_block *sb, u32 segno,
2058 struct logfs_segment_entry *se)
2059{
2060 logfs_mod_segment_entry(sb, segno, 0, __get_segment_entry, (long)se);
2061}
2062
2063static void __set_segment_used(struct logfs_segment_entry *se, long increment)
2064{
2065 u32 valid;
2066
2067 valid = be32_to_cpu(se->valid);
2068 valid += increment;
2069 se->valid = cpu_to_be32(valid);
2070}
2071
2072void logfs_set_segment_used(struct super_block *sb, u64 ofs, int increment)
2073{
2074 struct logfs_super *super = logfs_super(sb);
2075 u32 segno = ofs >> super->s_segshift;
2076
2077 if (!increment)
2078 return;
2079
2080 logfs_mod_segment_entry(sb, segno, 1, __set_segment_used, increment);
2081}
2082
2083static void __set_segment_erased(struct logfs_segment_entry *se, long ec_level)
2084{
2085 se->ec_level = cpu_to_be32(ec_level);
2086}
2087
2088void logfs_set_segment_erased(struct super_block *sb, u32 segno, u32 ec,
2089 gc_level_t gc_level)
2090{
2091 u32 ec_level = ec << 4 | (__force u8)gc_level;
2092
2093 logfs_mod_segment_entry(sb, segno, 1, __set_segment_erased, ec_level);
2094}
2095
2096static void __set_segment_reserved(struct logfs_segment_entry *se, long ignore)
2097{
2098 se->valid = cpu_to_be32(RESERVED);
2099}
2100
2101void logfs_set_segment_reserved(struct super_block *sb, u32 segno)
2102{
2103 logfs_mod_segment_entry(sb, segno, 1, __set_segment_reserved, 0);
2104}
2105
2106static void __set_segment_unreserved(struct logfs_segment_entry *se,
2107 long ec_level)
2108{
2109 se->valid = 0;
2110 se->ec_level = cpu_to_be32(ec_level);
2111}
2112
2113void logfs_set_segment_unreserved(struct super_block *sb, u32 segno, u32 ec)
2114{
2115 u32 ec_level = ec << 4;
2116
2117 logfs_mod_segment_entry(sb, segno, 1, __set_segment_unreserved,
2118 ec_level);
2119}
2120
2121int __logfs_write_inode(struct inode *inode, long flags)
2122{
2123 struct super_block *sb = inode->i_sb;
2124 int ret;
2125
2126 logfs_get_wblocks(sb, NULL, flags & WF_LOCK);
2127 ret = do_write_inode(inode);
2128 logfs_put_wblocks(sb, NULL, flags & WF_LOCK);
2129 return ret;
2130}
2131
2132static int do_delete_inode(struct inode *inode)
2133{
2134 struct super_block *sb = inode->i_sb;
2135 struct inode *master_inode = logfs_super(sb)->s_master_inode;
2136 struct page *page;
2137 int ret;
2138
2139 page = logfs_get_write_page(master_inode, inode->i_ino, 0);
2140 if (!page)
2141 return -ENOMEM;
2142
2143 move_inode_to_page(page, inode);
2144
2145 logfs_get_wblocks(sb, page, 1);
2146 ret = __logfs_delete(master_inode, page);
2147 logfs_put_wblocks(sb, page, 1);
2148
2149 logfs_put_write_page(page);
2150 return ret;
2151}
2152
2153/*
2154 * ZOMBIE inodes have already been deleted before and should remain dead,
2155 * if it weren't for valid checking. No need to kill them again here.
2156 */
2157void logfs_delete_inode(struct inode *inode)
2158{
2159 struct logfs_inode *li = logfs_inode(inode);
2160
2161 if (!(li->li_flags & LOGFS_IF_ZOMBIE)) {
2162 li->li_flags |= LOGFS_IF_ZOMBIE;
2163 if (i_size_read(inode) > 0)
2164 logfs_truncate(inode, 0);
2165 do_delete_inode(inode);
2166 }
2167 truncate_inode_pages(&inode->i_data, 0);
2168 clear_inode(inode);
2169}
2170
2171void btree_write_block(struct logfs_block *block)
2172{
2173 struct inode *inode;
2174 struct page *page;
2175 int err, cookie;
2176
2177 inode = logfs_safe_iget(block->sb, block->ino, &cookie);
2178 page = logfs_get_write_page(inode, block->bix, block->level);
2179
2180 err = logfs_readpage_nolock(page);
2181 BUG_ON(err);
2182 BUG_ON(!PagePrivate(page));
2183 BUG_ON(logfs_block(page) != block);
2184 err = __logfs_write_buf(inode, page, 0);
2185 BUG_ON(err);
2186 BUG_ON(PagePrivate(page) || page->private);
2187
2188 logfs_put_write_page(page);
2189 logfs_safe_iput(inode, cookie);
2190}
2191
2192/**
2193 * logfs_inode_write - write inode or dentry objects
2194 *
2195 * @inode: parent inode (ifile or directory)
2196 * @buf: object to write (inode or dentry)
2197 * @n: object size
2198 * @_pos: object number (file position in blocks/objects)
2199 * @flags: write flags
2200 * @lock: 0 if write lock is already taken, 1 otherwise
2201 * @shadow_tree: shadow below this inode
2202 *
2203 * FIXME: All caller of this put a 200-300 byte variable on the stack,
2204 * only to call here and do a memcpy from that stack variable. A good
2205 * example of wasted performance and stack space.
2206 */
2207int logfs_inode_write(struct inode *inode, const void *buf, size_t count,
2208 loff_t bix, long flags, struct shadow_tree *shadow_tree)
2209{
2210 loff_t pos = bix << inode->i_sb->s_blocksize_bits;
2211 int err;
2212 struct page *page;
2213 void *pagebuf;
2214
2215 BUG_ON(pos & (LOGFS_BLOCKSIZE-1));
2216 BUG_ON(count > LOGFS_BLOCKSIZE);
2217 page = logfs_get_write_page(inode, bix, 0);
2218 if (!page)
2219 return -ENOMEM;
2220
2221 pagebuf = kmap_atomic(page, KM_USER0);
2222 memcpy(pagebuf, buf, count);
2223 flush_dcache_page(page);
2224 kunmap_atomic(pagebuf, KM_USER0);
2225
2226 if (i_size_read(inode) < pos + LOGFS_BLOCKSIZE)
2227 i_size_write(inode, pos + LOGFS_BLOCKSIZE);
2228
2229 err = logfs_write_buf(inode, page, flags);
2230 logfs_put_write_page(page);
2231 return err;
2232}
2233
2234int logfs_open_segfile(struct super_block *sb)
2235{
2236 struct logfs_super *super = logfs_super(sb);
2237 struct inode *inode;
2238
2239 inode = logfs_read_meta_inode(sb, LOGFS_INO_SEGFILE);
2240 if (IS_ERR(inode))
2241 return PTR_ERR(inode);
2242 super->s_segfile_inode = inode;
2243 return 0;
2244}
2245
2246int logfs_init_rw(struct super_block *sb)
2247{
2248 struct logfs_super *super = logfs_super(sb);
2249 int min_fill = 3 * super->s_no_blocks;
2250
2251 INIT_LIST_HEAD(&super->s_object_alias);
2252 mutex_init(&super->s_write_mutex);
2253 super->s_block_pool = mempool_create_kmalloc_pool(min_fill,
2254 sizeof(struct logfs_block));
2255 super->s_shadow_pool = mempool_create_kmalloc_pool(min_fill,
2256 sizeof(struct logfs_shadow));
2257 return 0;
2258}
2259
2260void logfs_cleanup_rw(struct super_block *sb)
2261{
2262 struct logfs_super *super = logfs_super(sb);
2263
2264 destroy_meta_inode(super->s_segfile_inode);
2265 logfs_mempool_destroy(super->s_block_pool);
2266 logfs_mempool_destroy(super->s_shadow_pool);
2267}
generated by cgit v1.2.2 (git 2.25.0) at 2025-03-03 18:23:23 -0500