4 * As should be obvious for Linux kernel code, license is GPLv2
6 * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
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
20 #include <linux/sched.h>
21 #include <linux/slab.h>
23 static u64 adjust_bix(u64 bix, level_t level)
29 return max_t(u64, bix, I0_BLOCKS);
31 return max_t(u64, bix, I1_BLOCKS);
33 return max_t(u64, bix, I2_BLOCKS);
35 return max_t(u64, bix, I3_BLOCKS);
37 return max_t(u64, bix, I4_BLOCKS);
44 static inline u64 maxbix(u8 height)
46 return 1ULL << (LOGFS_BLOCK_BITS * height);
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
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.
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)
64 return INDIRECT_BIT | (1ULL << LEVEL_SHIFT);
67 pgoff_t logfs_pack_index(u64 bix, level_t level)
71 BUG_ON(bix >= INDIRECT_BIT);
76 index |= (__force long)level << LEVEL_SHIFT;
77 index |= bix >> ((__force u8)level * LOGFS_BLOCK_BITS);
81 void logfs_unpack_index(pgoff_t index, u64 *bix, level_t *level)
85 if (!(index & INDIRECT_BIT)) {
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);
102 * Time is stored as nanoseconds since the epoch.
104 static struct timespec be64_to_timespec(__be64 betime)
106 return ns_to_timespec(be64_to_cpu(betime));
109 static __be64 timespec_to_be64(struct timespec tsp)
111 return cpu_to_be64((u64)tsp.tv_sec * NSEC_PER_SEC + tsp.tv_nsec);
114 static void logfs_disk_to_inode(struct logfs_disk_inode *di, struct inode*inode)
116 struct logfs_inode *li = logfs_inode(inode);
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);
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 */
137 inode->i_rdev = be64_to_cpu(di->di_data[0]);
139 case S_IFDIR: /* fall through */
140 case S_IFREG: /* fall through */
142 for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++)
143 li->li_data[i] = be64_to_cpu(di->di_data[i]);
150 static void logfs_inode_to_disk(struct inode *inode, struct logfs_disk_inode*di)
152 struct logfs_inode *li = logfs_inode(inode);
155 di->di_mode = cpu_to_be16(inode->i_mode);
156 di->di_height = li->li_height;
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);
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 */
174 di->di_data[0] = cpu_to_be64(inode->i_rdev);
176 case S_IFDIR: /* fall through */
177 case S_IFREG: /* fall through */
179 for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++)
180 di->di_data[i] = cpu_to_be64(li->li_data[i]);
187 static void __logfs_set_blocks(struct inode *inode)
189 struct super_block *sb = inode->i_sb;
190 struct logfs_inode *li = logfs_inode(inode);
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;
197 void logfs_set_blocks(struct inode *inode, u64 bytes)
199 struct logfs_inode *li = logfs_inode(inode);
201 li->li_used_bytes = bytes;
202 __logfs_set_blocks(inode);
205 static void prelock_page(struct super_block *sb, struct page *page, int lock)
207 struct logfs_super *super = logfs_super(sb);
209 BUG_ON(!PageLocked(page));
211 BUG_ON(PagePreLocked(page));
212 SetPagePreLocked(page);
214 /* We are in GC path. */
215 if (PagePreLocked(page))
216 super->s_lock_count++;
218 SetPagePreLocked(page);
222 static void preunlock_page(struct super_block *sb, struct page *page, int lock)
224 struct logfs_super *super = logfs_super(sb);
226 BUG_ON(!PageLocked(page));
228 ClearPagePreLocked(page);
230 /* We are in GC path. */
231 BUG_ON(!PagePreLocked(page));
232 if (super->s_lock_count)
233 super->s_lock_count--;
235 ClearPagePreLocked(page);
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
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.
247 static void logfs_get_wblocks(struct super_block *sb, struct page *page,
250 struct logfs_super *super = logfs_super(sb);
253 prelock_page(sb, page, lock);
256 mutex_lock(&super->s_write_mutex);
258 /* FIXME: We also have to check for shadowed space
259 * and mempool fill grade */
263 static void logfs_put_wblocks(struct super_block *sb, struct page *page,
266 struct logfs_super *super = logfs_super(sb);
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. */
273 mutex_unlock(&super->s_write_mutex);
276 static struct page *logfs_get_read_page(struct inode *inode, u64 bix,
279 return find_or_create_page(inode->i_mapping,
280 logfs_pack_index(bix, level), GFP_NOFS);
283 static void logfs_put_read_page(struct page *page)
286 page_cache_release(page);
289 static void logfs_lock_write_page(struct page *page)
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);
299 if (PagePreLocked(page)) {
300 /* Holder of page lock is waiting for us, it
301 * is safe to use this page. */
304 /* Some other process has this page locked and has
305 * nothing to do with us. Wait for it to finish.
309 BUG_ON(!PageLocked(page));
312 static struct page *logfs_get_write_page(struct inode *inode, u64 bix,
315 struct address_space *mapping = inode->i_mapping;
316 pgoff_t index = logfs_pack_index(bix, level);
321 page = find_get_page(mapping, index);
323 page = __page_cache_alloc(GFP_NOFS);
326 err = add_to_page_cache_lru(page, mapping, index, GFP_NOFS);
328 page_cache_release(page);
333 } else logfs_lock_write_page(page);
334 BUG_ON(!PageLocked(page));
338 static void logfs_unlock_write_page(struct page *page)
340 if (!PagePreLocked(page))
344 static void logfs_put_write_page(struct page *page)
346 logfs_unlock_write_page(page);
347 page_cache_release(page);
350 static struct page *logfs_get_page(struct inode *inode, u64 bix, level_t level,
354 return logfs_get_read_page(inode, bix, level);
356 return logfs_get_write_page(inode, bix, level);
359 static void logfs_put_page(struct page *page, int rw)
362 logfs_put_read_page(page);
364 logfs_put_write_page(page);
367 static unsigned long __get_bits(u64 val, int skip, int no)
377 static unsigned long get_bits(u64 val, level_t skip)
379 return __get_bits(val, (__force int)skip, LOGFS_BLOCK_BITS);
382 static inline void init_shadow_tree(struct super_block *sb,
383 struct shadow_tree *tree)
385 struct logfs_super *super = logfs_super(sb);
387 btree_init_mempool64(&tree->new, super->s_btree_pool);
388 btree_init_mempool64(&tree->old, super->s_btree_pool);
391 static void indirect_write_block(struct logfs_block *block)
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);
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.
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
418 static void inode_write_block(struct logfs_block *block)
423 inode = block->inode;
424 if (inode->i_ino == LOGFS_INO_MASTER)
425 logfs_write_anchor(inode->i_sb);
427 ret = __logfs_write_inode(inode, 0);
428 /* see indirect_write_block comment */
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.
438 static unsigned long fnb(const unsigned long *addr,
439 unsigned long size, unsigned long offset)
441 return find_next_bit(addr, size, offset);
444 static __be64 inode_val0(struct inode *inode)
446 struct logfs_inode *li = logfs_inode(inode);
450 * Explicit shifting generates good code, but must match the format
451 * of the structure. Add some paranoia just in case.
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);
457 val = (u64)inode->i_mode << 48 |
458 (u64)li->li_height << 40 |
460 return cpu_to_be64(val);
463 static int inode_write_alias(struct super_block *sb,
464 struct logfs_block *block, write_alias_t *write_one_alias)
466 struct inode *inode = block->inode;
467 struct logfs_inode *li = logfs_inode(inode);
474 for (pos = 0; ; pos++) {
475 pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos);
476 if (pos >= LOGFS_EMBEDDED_FIELDS + INODE_POINTER_OFS)
480 case INODE_HEIGHT_OFS:
481 val = inode_val0(inode);
484 val = cpu_to_be64(li->li_used_bytes);;
487 val = cpu_to_be64(i_size_read(inode));
489 case INODE_POINTER_OFS ... INODE_POINTER_OFS + LOGFS_EMBEDDED_FIELDS - 1:
490 val = cpu_to_be64(li->li_data[pos - INODE_POINTER_OFS]);
496 ino = LOGFS_INO_MASTER;
499 err = write_one_alias(sb, ino, bix, level, pos, val);
505 static int indirect_write_alias(struct super_block *sb,
506 struct logfs_block *block, write_alias_t *write_one_alias)
509 struct page *page = block->page;
515 for (pos = 0; ; pos++) {
516 pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos);
517 if (pos >= LOGFS_BLOCK_FACTOR)
520 ino = page->mapping->host->i_ino;
521 logfs_unpack_index(page->index, &bix, &level);
522 child = kmap_atomic(page, KM_USER0);
524 kunmap_atomic(child, KM_USER0);
525 err = write_one_alias(sb, ino, bix, level, pos, val);
531 int logfs_write_obj_aliases_pagecache(struct super_block *sb)
533 struct logfs_super *super = logfs_super(sb);
534 struct logfs_block *block;
537 list_for_each_entry(block, &super->s_object_alias, alias_list) {
538 err = block->ops->write_alias(sb, block, write_alias_journal);
545 void __free_block(struct super_block *sb, struct logfs_block *block)
547 BUG_ON(!list_empty(&block->item_list));
548 list_del(&block->alias_list);
549 mempool_free(block, logfs_super(sb)->s_block_pool);
552 static void inode_free_block(struct super_block *sb, struct logfs_block *block)
554 struct inode *inode = block->inode;
556 logfs_inode(inode)->li_block = NULL;
557 __free_block(sb, block);
560 static void indirect_free_block(struct super_block *sb,
561 struct logfs_block *block)
563 ClearPagePrivate(block->page);
564 block->page->private = 0;
565 __free_block(sb, block);
569 static 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,
575 struct logfs_block_ops indirect_block_ops = {
576 .write_block = indirect_write_block,
577 .free_block = indirect_free_block,
578 .write_alias = indirect_write_alias,
581 struct logfs_block *__alloc_block(struct super_block *sb,
582 u64 ino, u64 bix, level_t level)
584 struct logfs_super *super = logfs_super(sb);
585 struct logfs_block *block;
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);
594 block->level = level;
598 static void alloc_inode_block(struct inode *inode)
600 struct logfs_inode *li = logfs_inode(inode);
601 struct logfs_block *block;
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;
612 void initialize_block_counters(struct page *page, struct logfs_block *block,
613 __be64 *array, int page_is_empty)
621 if (page->index < first_indirect_block()) {
622 /* Counters are pointless on level 0 */
625 if (page->index == first_indirect_block()) {
626 /* Skip unused pointers */
628 block->full = I0_BLOCKS;
630 if (!page_is_empty) {
631 for (i = start; i < LOGFS_BLOCK_FACTOR; i++) {
632 ptr = be64_to_cpu(array[i]);
635 if (ptr & LOGFS_FULLY_POPULATED)
641 static void alloc_data_block(struct inode *inode, struct page *page)
643 struct logfs_block *block;
647 if (PagePrivate(page))
650 logfs_unpack_index(page->index, &bix, &level);
651 block = __alloc_block(inode->i_sb, inode->i_ino, bix, level);
653 SetPagePrivate(page);
654 page->private = (unsigned long)block;
655 block->ops = &indirect_block_ops;
658 static void alloc_indirect_block(struct inode *inode, struct page *page,
661 struct logfs_block *block;
664 if (PagePrivate(page))
667 alloc_data_block(inode, page);
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);
675 static void block_set_pointer(struct page *page, int index, u64 ptr)
677 struct logfs_block *block = logfs_block(page);
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);
688 block->full += !!(ptr & LOGFS_FULLY_POPULATED)
689 - !!(oldptr & LOGFS_FULLY_POPULATED);
690 block->partial += !!ptr - !!oldptr;
693 static u64 block_get_pointer(struct page *page, int index)
698 block = kmap_atomic(page, KM_USER0);
699 ptr = be64_to_cpu(block[index]);
700 kunmap_atomic(block, KM_USER0);
704 static int logfs_read_empty(struct page *page)
706 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
710 static int logfs_read_direct(struct inode *inode, struct page *page)
712 struct logfs_inode *li = logfs_inode(inode);
713 pgoff_t index = page->index;
716 block = li->li_data[index];
718 return logfs_read_empty(page);
720 return logfs_segment_read(inode, page, block, index, 0);
723 static int logfs_read_loop(struct inode *inode, struct page *page,
726 struct logfs_inode *li = logfs_inode(inode);
727 u64 bix, bofs = li->li_data[INDIRECT_INDEX];
728 level_t level, target_level;
732 logfs_unpack_index(page->index, &bix, &target_level);
734 return logfs_read_empty(page);
736 if (bix >= maxbix(li->li_height))
737 return logfs_read_empty(page);
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);
746 ret = logfs_segment_read(inode, ipage, bofs, bix, level);
748 logfs_put_read_page(ipage);
752 bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level)));
753 logfs_put_page(ipage, rw_context);
755 return logfs_read_empty(page);
758 return logfs_segment_read(inode, page, bofs, bix, 0);
761 static int logfs_read_block(struct inode *inode, struct page *page,
764 pgoff_t index = page->index;
766 if (index < I0_BLOCKS)
767 return logfs_read_direct(inode, page);
768 return logfs_read_loop(inode, page, rw_context);
771 static int logfs_exist_loop(struct inode *inode, u64 bix)
773 struct logfs_inode *li = logfs_inode(inode);
774 u64 bofs = li->li_data[INDIRECT_INDEX];
781 if (bix >= maxbix(li->li_height))
784 for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) {
785 ipage = logfs_get_read_page(inode, bix, level);
789 ret = logfs_segment_read(inode, ipage, bofs, bix, level);
791 logfs_put_read_page(ipage);
795 bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level)));
796 logfs_put_read_page(ipage);
804 int logfs_exist_block(struct inode *inode, u64 bix)
806 struct logfs_inode *li = logfs_inode(inode);
809 return !!li->li_data[bix];
810 return logfs_exist_loop(inode, bix);
813 static u64 seek_holedata_direct(struct inode *inode, u64 bix, int data)
815 struct logfs_inode *li = logfs_inode(inode);
817 for (; bix < I0_BLOCKS; bix++)
818 if (data ^ (li->li_data[bix] == 0))
823 static u64 seek_holedata_loop(struct inode *inode, u64 bix, int data)
825 struct logfs_inode *li = logfs_inode(inode);
827 u64 increment, bofs = li->li_data[INDIRECT_INDEX];
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);
840 ret = logfs_segment_read(inode, page, bofs, bix, level);
842 logfs_put_read_page(page);
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))
851 if (!data && !(be64_to_cpu(rblock[slot]) & LOGFS_FULLY_POPULATED))
855 bix &= ~(increment - 1);
857 if (slot >= LOGFS_BLOCK_FACTOR) {
858 kunmap_atomic(rblock, KM_USER0);
859 logfs_put_read_page(page);
862 bofs = be64_to_cpu(rblock[slot]);
863 kunmap_atomic(rblock, KM_USER0);
864 logfs_put_read_page(page);
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
878 * Returns next hole. If the file doesn't contain any further holes, the
879 * block address next to eof is returned instead.
881 u64 logfs_seek_hole(struct inode *inode, u64 bix)
883 struct logfs_inode *li = logfs_inode(inode);
885 if (bix < I0_BLOCKS) {
886 bix = seek_holedata_direct(inode, bix, 0);
891 if (!li->li_data[INDIRECT_INDEX])
893 else if (li->li_data[INDIRECT_INDEX] & LOGFS_FULLY_POPULATED)
894 bix = maxbix(li->li_height);
895 else if (bix >= maxbix(li->li_height))
898 bix = seek_holedata_loop(inode, bix, 0);
899 if (bix < maxbix(li->li_height))
901 /* Should not happen anymore. But if some port writes semi-
902 * corrupt images (as this one used to) we might run into it.
904 WARN_ON_ONCE(bix == maxbix(li->li_height));
910 static u64 __logfs_seek_data(struct inode *inode, u64 bix)
912 struct logfs_inode *li = logfs_inode(inode);
914 if (bix < I0_BLOCKS) {
915 bix = seek_holedata_direct(inode, bix, 1);
920 if (bix < maxbix(li->li_height)) {
921 if (!li->li_data[INDIRECT_INDEX])
922 bix = maxbix(li->li_height);
924 return seek_holedata_loop(inode, bix, 1);
931 * logfs_seek_data - find next data block after a given block index
932 * @inode: inode to search in
933 * @bix: block index to start searching
935 * Returns next data block. If the file doesn't contain any further data
936 * blocks, the last block in the file is returned instead.
938 u64 logfs_seek_data(struct inode *inode, u64 bix)
940 struct super_block *sb = inode->i_sb;
943 ret = __logfs_seek_data(inode, bix);
944 end = i_size_read(inode) >> sb->s_blocksize_bits;
950 static int logfs_is_valid_direct(struct logfs_inode *li, u64 bix, u64 ofs)
952 return pure_ofs(li->li_data[bix]) == ofs;
955 static int __logfs_is_valid_loop(struct inode *inode, u64 bix,
958 struct logfs_inode *li = logfs_inode(inode);
963 for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)){
964 page = logfs_get_write_page(inode, bix, level);
967 ret = logfs_segment_read(inode, page, bofs, bix, level);
969 logfs_put_write_page(page);
973 bofs = block_get_pointer(page, get_bits(bix, SUBLEVEL(level)));
974 logfs_put_write_page(page);
978 if (pure_ofs(bofs) == ofs)
984 static int logfs_is_valid_loop(struct inode *inode, u64 bix, u64 ofs)
986 struct logfs_inode *li = logfs_inode(inode);
987 u64 bofs = li->li_data[INDIRECT_INDEX];
992 if (bix >= maxbix(li->li_height))
995 if (pure_ofs(bofs) == ofs)
998 return __logfs_is_valid_loop(inode, bix, ofs, bofs);
1001 static int __logfs_is_valid_block(struct inode *inode, u64 bix, u64 ofs)
1003 struct logfs_inode *li = logfs_inode(inode);
1005 if ((inode->i_nlink == 0) && atomic_read(&inode->i_count) == 1)
1008 if (bix < I0_BLOCKS)
1009 return logfs_is_valid_direct(li, bix, ofs);
1010 return logfs_is_valid_loop(inode, bix, ofs);
1014 * logfs_is_valid_block - check whether this block is still valid
1017 * @ofs - block physical offset
1018 * @ino - block inode number
1019 * @bix - block index
1020 * @level - block level
1022 * Returns 0 if the block is invalid, 1 if it is valid and 2 if it will
1023 * become invalid once the journal is written.
1025 int logfs_is_valid_block(struct super_block *sb, u64 ofs, u64 ino, u64 bix,
1026 gc_level_t gc_level)
1028 struct logfs_super *super = logfs_super(sb);
1029 struct inode *inode;
1032 /* Umount closes a segment with free blocks remaining. Those
1033 * blocks are by definition invalid. */
1037 LOGFS_BUG_ON((u64)(u_long)ino != ino, sb);
1039 inode = logfs_safe_iget(sb, ino, &cookie);
1043 ret = __logfs_is_valid_block(inode, bix, ofs);
1044 logfs_safe_iput(inode, cookie);
1049 /* Block is nominally invalid, but may still sit in the shadow tree,
1050 * waiting for a journal commit.
1052 if (btree_lookup64(&super->s_shadow_tree.old, ofs))
1057 int logfs_readpage_nolock(struct page *page)
1059 struct inode *inode = page->mapping->host;
1062 ret = logfs_read_block(inode, page, READ);
1065 ClearPageUptodate(page);
1068 SetPageUptodate(page);
1069 ClearPageError(page);
1071 flush_dcache_page(page);
1076 static int logfs_reserve_bytes(struct inode *inode, int bytes)
1078 struct logfs_super *super = logfs_super(inode->i_sb);
1079 u64 available = super->s_free_bytes + super->s_dirty_free_bytes
1080 - super->s_dirty_used_bytes - super->s_dirty_pages;
1085 if (available < bytes)
1088 if (available < bytes + super->s_root_reserve &&
1089 !capable(CAP_SYS_RESOURCE))
1095 int get_page_reserve(struct inode *inode, struct page *page)
1097 struct logfs_super *super = logfs_super(inode->i_sb);
1100 if (logfs_block(page) && logfs_block(page)->reserved_bytes)
1103 logfs_get_wblocks(inode->i_sb, page, WF_LOCK);
1104 ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE);
1106 alloc_data_block(inode, page);
1107 logfs_block(page)->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE;
1108 super->s_dirty_pages += 6 * LOGFS_MAX_OBJECTSIZE;
1110 logfs_put_wblocks(inode->i_sb, page, WF_LOCK);
1115 * We are protected by write lock. Push victims up to superblock level
1116 * and release transaction when appropriate.
1118 /* FIXME: This is currently called from the wrong spots. */
1119 static void logfs_handle_transaction(struct inode *inode,
1120 struct logfs_transaction *ta)
1122 struct logfs_super *super = logfs_super(inode->i_sb);
1126 logfs_inode(inode)->li_block->ta = NULL;
1128 if (inode->i_ino != LOGFS_INO_MASTER) {
1129 BUG(); /* FIXME: Yes, this needs more thought */
1130 /* just remember the transaction until inode is written */
1131 //BUG_ON(logfs_inode(inode)->li_transaction);
1132 //logfs_inode(inode)->li_transaction = ta;
1136 switch (ta->state) {
1137 case CREATE_1: /* fall through */
1139 BUG_ON(super->s_victim_ino);
1140 super->s_victim_ino = ta->ino;
1142 case CREATE_2: /* fall through */
1144 BUG_ON(super->s_victim_ino != ta->ino);
1145 super->s_victim_ino = 0;
1146 /* transaction ends here - free it */
1149 case CROSS_RENAME_1:
1150 BUG_ON(super->s_rename_dir);
1151 BUG_ON(super->s_rename_pos);
1152 super->s_rename_dir = ta->dir;
1153 super->s_rename_pos = ta->pos;
1155 case CROSS_RENAME_2:
1156 BUG_ON(super->s_rename_dir != ta->dir);
1157 BUG_ON(super->s_rename_pos != ta->pos);
1158 super->s_rename_dir = 0;
1159 super->s_rename_pos = 0;
1162 case TARGET_RENAME_1:
1163 BUG_ON(super->s_rename_dir);
1164 BUG_ON(super->s_rename_pos);
1165 BUG_ON(super->s_victim_ino);
1166 super->s_rename_dir = ta->dir;
1167 super->s_rename_pos = ta->pos;
1168 super->s_victim_ino = ta->ino;
1170 case TARGET_RENAME_2:
1171 BUG_ON(super->s_rename_dir != ta->dir);
1172 BUG_ON(super->s_rename_pos != ta->pos);
1173 BUG_ON(super->s_victim_ino != ta->ino);
1174 super->s_rename_dir = 0;
1175 super->s_rename_pos = 0;
1177 case TARGET_RENAME_3:
1178 BUG_ON(super->s_rename_dir);
1179 BUG_ON(super->s_rename_pos);
1180 BUG_ON(super->s_victim_ino != ta->ino);
1181 super->s_victim_ino = 0;
1190 * Not strictly a reservation, but rather a check that we still have enough
1191 * space to satisfy the write.
1193 static int logfs_reserve_blocks(struct inode *inode, int blocks)
1195 return logfs_reserve_bytes(inode, blocks * LOGFS_MAX_OBJECTSIZE);
1198 struct write_control {
1203 static struct logfs_shadow *alloc_shadow(struct inode *inode, u64 bix,
1204 level_t level, u64 old_ofs)
1206 struct logfs_super *super = logfs_super(inode->i_sb);
1207 struct logfs_shadow *shadow;
1209 shadow = mempool_alloc(super->s_shadow_pool, GFP_NOFS);
1210 memset(shadow, 0, sizeof(*shadow));
1211 shadow->ino = inode->i_ino;
1213 shadow->gc_level = expand_level(inode->i_ino, level);
1214 shadow->old_ofs = old_ofs & ~LOGFS_FULLY_POPULATED;
1218 static void free_shadow(struct inode *inode, struct logfs_shadow *shadow)
1220 struct logfs_super *super = logfs_super(inode->i_sb);
1222 mempool_free(shadow, super->s_shadow_pool);
1225 static void mark_segment(struct shadow_tree *tree, u32 segno)
1229 if (!btree_lookup32(&tree->segment_map, segno)) {
1230 err = btree_insert32(&tree->segment_map, segno, (void *)1,
1233 tree->no_shadowed_segments++;
1238 * fill_shadow_tree - Propagate shadow tree changes due to a write
1239 * @inode: Inode owning the page
1240 * @page: Struct page that was written
1241 * @shadow: Shadow for the current write
1243 * Writes in logfs can result in two semi-valid objects. The old object
1244 * is still valid as long as it can be reached by following pointers on
1245 * the medium. Only when writes propagate all the way up to the journal
1246 * has the new object safely replaced the old one.
1248 * To handle this problem, a struct logfs_shadow is used to represent
1249 * every single write. It is attached to the indirect block, which is
1250 * marked dirty. When the indirect block is written, its shadows are
1251 * handed up to the next indirect block (or inode). Untimately they
1252 * will reach the master inode and be freed upon journal commit.
1254 * This function handles a single step in the propagation. It adds the
1255 * shadow for the current write to the tree, along with any shadows in
1256 * the page's tree, in case it was an indirect block. If a page is
1257 * written, the inode parameter is left NULL, if an inode is written,
1258 * the page parameter is left NULL.
1260 static void fill_shadow_tree(struct inode *inode, struct page *page,
1261 struct logfs_shadow *shadow)
1263 struct logfs_super *super = logfs_super(inode->i_sb);
1264 struct logfs_block *block = logfs_block(page);
1265 struct shadow_tree *tree = &super->s_shadow_tree;
1267 if (PagePrivate(page)) {
1268 if (block->alias_map)
1269 super->s_no_object_aliases -= bitmap_weight(
1270 block->alias_map, LOGFS_BLOCK_FACTOR);
1271 logfs_handle_transaction(inode, block->ta);
1272 block->ops->free_block(inode->i_sb, block);
1275 if (shadow->old_ofs)
1276 btree_insert64(&tree->old, shadow->old_ofs, shadow,
1279 btree_insert64(&tree->new, shadow->new_ofs, shadow,
1282 super->s_dirty_used_bytes += shadow->new_len;
1283 super->s_dirty_free_bytes += shadow->old_len;
1284 mark_segment(tree, shadow->old_ofs >> super->s_segshift);
1285 mark_segment(tree, shadow->new_ofs >> super->s_segshift);
1289 static void logfs_set_alias(struct super_block *sb, struct logfs_block *block,
1292 struct logfs_super *super = logfs_super(sb);
1294 if (block->inode && block->inode->i_ino == LOGFS_INO_MASTER) {
1295 /* Aliases in the master inode are pointless. */
1299 if (!test_bit(child_no, block->alias_map)) {
1300 set_bit(child_no, block->alias_map);
1301 super->s_no_object_aliases++;
1303 list_move_tail(&block->alias_list, &super->s_object_alias);
1307 * Object aliases can and often do change the size and occupied space of a
1308 * file. So not only do we have to change the pointers, we also have to
1309 * change inode->i_size and li->li_used_bytes. Which is done by setting
1310 * another two object aliases for the inode itself.
1312 static void set_iused(struct inode *inode, struct logfs_shadow *shadow)
1314 struct logfs_inode *li = logfs_inode(inode);
1316 if (shadow->new_len == shadow->old_len)
1319 alloc_inode_block(inode);
1320 li->li_used_bytes += shadow->new_len - shadow->old_len;
1321 __logfs_set_blocks(inode);
1322 logfs_set_alias(inode->i_sb, li->li_block, INODE_USED_OFS);
1323 logfs_set_alias(inode->i_sb, li->li_block, INODE_SIZE_OFS);
1326 static int logfs_write_i0(struct inode *inode, struct page *page,
1327 struct write_control *wc)
1329 struct logfs_shadow *shadow;
1334 logfs_unpack_index(page->index, &bix, &level);
1336 if (logfs_reserve_blocks(inode, 1))
1339 shadow = alloc_shadow(inode, bix, level, wc->ofs);
1340 if (wc->flags & WF_WRITE)
1341 err = logfs_segment_write(inode, page, shadow);
1342 if (wc->flags & WF_DELETE)
1343 logfs_segment_delete(inode, shadow);
1345 free_shadow(inode, shadow);
1349 set_iused(inode, shadow);
1352 alloc_indirect_block(inode, page, 0);
1353 full = logfs_block(page)->full == LOGFS_BLOCK_FACTOR;
1355 fill_shadow_tree(inode, page, shadow);
1356 wc->ofs = shadow->new_ofs;
1357 if (wc->ofs && full)
1358 wc->ofs |= LOGFS_FULLY_POPULATED;
1362 static int logfs_write_direct(struct inode *inode, struct page *page,
1365 struct logfs_inode *li = logfs_inode(inode);
1366 struct write_control wc = {
1367 .ofs = li->li_data[page->index],
1372 alloc_inode_block(inode);
1374 err = logfs_write_i0(inode, page, &wc);
1378 li->li_data[page->index] = wc.ofs;
1379 logfs_set_alias(inode->i_sb, li->li_block,
1380 page->index + INODE_POINTER_OFS);
1384 static int ptr_change(u64 ofs, struct page *page)
1386 struct logfs_block *block = logfs_block(page);
1387 int empty0, empty1, full0, full1;
1390 empty1 = block->partial == 0;
1391 if (empty0 != empty1)
1394 /* The !! is necessary to shrink result to int */
1395 full0 = !!(ofs & LOGFS_FULLY_POPULATED);
1396 full1 = block->full == LOGFS_BLOCK_FACTOR;
1402 static int __logfs_write_rec(struct inode *inode, struct page *page,
1403 struct write_control *this_wc,
1404 pgoff_t bix, level_t target_level, level_t level)
1406 int ret, page_empty = 0;
1407 int child_no = get_bits(bix, SUBLEVEL(level));
1409 struct write_control child_wc = {
1410 .flags = this_wc->flags,
1413 ipage = logfs_get_write_page(inode, bix, level);
1418 ret = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level);
1421 } else if (!PageUptodate(ipage)) {
1423 logfs_read_empty(ipage);
1426 child_wc.ofs = block_get_pointer(ipage, child_no);
1428 if ((__force u8)level-1 > (__force u8)target_level)
1429 ret = __logfs_write_rec(inode, page, &child_wc, bix,
1430 target_level, SUBLEVEL(level));
1432 ret = logfs_write_i0(inode, page, &child_wc);
1437 alloc_indirect_block(inode, ipage, page_empty);
1438 block_set_pointer(ipage, child_no, child_wc.ofs);
1439 /* FIXME: first condition seems superfluous */
1440 if (child_wc.ofs || logfs_block(ipage)->partial)
1441 this_wc->flags |= WF_WRITE;
1442 /* the condition on this_wc->ofs ensures that we won't consume extra
1443 * space for indirect blocks in the future, which we cannot reserve */
1444 if (!this_wc->ofs || ptr_change(this_wc->ofs, ipage))
1445 ret = logfs_write_i0(inode, ipage, this_wc);
1447 logfs_set_alias(inode->i_sb, logfs_block(ipage), child_no);
1449 logfs_put_write_page(ipage);
1453 static int logfs_write_rec(struct inode *inode, struct page *page,
1454 pgoff_t bix, level_t target_level, long flags)
1456 struct logfs_inode *li = logfs_inode(inode);
1457 struct write_control wc = {
1458 .ofs = li->li_data[INDIRECT_INDEX],
1463 alloc_inode_block(inode);
1465 if (li->li_height > (__force u8)target_level)
1466 ret = __logfs_write_rec(inode, page, &wc, bix, target_level,
1467 LEVEL(li->li_height));
1469 ret = logfs_write_i0(inode, page, &wc);
1473 if (li->li_data[INDIRECT_INDEX] != wc.ofs) {
1474 li->li_data[INDIRECT_INDEX] = wc.ofs;
1475 logfs_set_alias(inode->i_sb, li->li_block,
1476 INDIRECT_INDEX + INODE_POINTER_OFS);
1481 void logfs_add_transaction(struct inode *inode, struct logfs_transaction *ta)
1483 alloc_inode_block(inode);
1484 logfs_inode(inode)->li_block->ta = ta;
1487 void logfs_del_transaction(struct inode *inode, struct logfs_transaction *ta)
1489 struct logfs_block *block = logfs_inode(inode)->li_block;
1491 if (block && block->ta)
1495 static int grow_inode(struct inode *inode, u64 bix, level_t level)
1497 struct logfs_inode *li = logfs_inode(inode);
1498 u8 height = (__force u8)level;
1500 struct write_control wc = {
1505 BUG_ON(height > 5 || li->li_height > 5);
1506 while (height > li->li_height || bix >= maxbix(li->li_height)) {
1507 page = logfs_get_write_page(inode, I0_BLOCKS + 1,
1508 LEVEL(li->li_height + 1));
1511 logfs_read_empty(page);
1512 alloc_indirect_block(inode, page, 1);
1513 block_set_pointer(page, 0, li->li_data[INDIRECT_INDEX]);
1514 err = logfs_write_i0(inode, page, &wc);
1515 logfs_put_write_page(page);
1518 li->li_data[INDIRECT_INDEX] = wc.ofs;
1521 logfs_set_alias(inode->i_sb, li->li_block, INODE_HEIGHT_OFS);
1526 static int __logfs_write_buf(struct inode *inode, struct page *page, long flags)
1528 struct logfs_super *super = logfs_super(inode->i_sb);
1529 pgoff_t index = page->index;
1534 flags |= WF_WRITE | WF_DELETE;
1535 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
1537 logfs_unpack_index(index, &bix, &level);
1538 if (logfs_block(page) && logfs_block(page)->reserved_bytes)
1539 super->s_dirty_pages -= logfs_block(page)->reserved_bytes;
1541 if (index < I0_BLOCKS)
1542 return logfs_write_direct(inode, page, flags);
1544 bix = adjust_bix(bix, level);
1545 err = grow_inode(inode, bix, level);
1548 return logfs_write_rec(inode, page, bix, level, flags);
1551 int logfs_write_buf(struct inode *inode, struct page *page, long flags)
1553 struct super_block *sb = inode->i_sb;
1556 logfs_get_wblocks(sb, page, flags & WF_LOCK);
1557 ret = __logfs_write_buf(inode, page, flags);
1558 logfs_put_wblocks(sb, page, flags & WF_LOCK);
1562 static int __logfs_delete(struct inode *inode, struct page *page)
1564 long flags = WF_DELETE;
1566 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
1568 if (page->index < I0_BLOCKS)
1569 return logfs_write_direct(inode, page, flags);
1570 return logfs_write_rec(inode, page, page->index, 0, flags);
1573 int logfs_delete(struct inode *inode, pgoff_t index,
1574 struct shadow_tree *shadow_tree)
1576 struct super_block *sb = inode->i_sb;
1580 page = logfs_get_read_page(inode, index, 0);
1584 logfs_get_wblocks(sb, page, 1);
1585 ret = __logfs_delete(inode, page);
1586 logfs_put_wblocks(sb, page, 1);
1588 logfs_put_read_page(page);
1593 int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs,
1594 gc_level_t gc_level, long flags)
1596 level_t level = shrink_level(gc_level);
1600 page = logfs_get_write_page(inode, bix, level);
1604 err = logfs_segment_read(inode, page, ofs, bix, level);
1607 alloc_indirect_block(inode, page, 0);
1608 err = logfs_write_buf(inode, page, flags);
1609 if (!err && shrink_level(gc_level) == 0) {
1610 /* Rewrite cannot mark the inode dirty but has to
1611 * write it immediatly.
1612 * Q: Can't we just create an alias for the inode
1613 * instead? And if not, why not?
1615 if (inode->i_ino == LOGFS_INO_MASTER)
1616 logfs_write_anchor(inode->i_sb);
1618 err = __logfs_write_inode(inode, flags);
1622 logfs_put_write_page(page);
1626 static int truncate_data_block(struct inode *inode, struct page *page,
1627 u64 ofs, struct logfs_shadow *shadow, u64 size)
1629 loff_t pageofs = page->index << inode->i_sb->s_blocksize_bits;
1634 /* Does truncation happen within this page? */
1635 if (size <= pageofs || size - pageofs >= PAGE_SIZE)
1638 logfs_unpack_index(page->index, &bix, &level);
1641 err = logfs_segment_read(inode, page, ofs, bix, level);
1645 zero_user_segment(page, size - pageofs, PAGE_CACHE_SIZE);
1646 return logfs_segment_write(inode, page, shadow);
1649 static int logfs_truncate_i0(struct inode *inode, struct page *page,
1650 struct write_control *wc, u64 size)
1652 struct logfs_shadow *shadow;
1657 logfs_unpack_index(page->index, &bix, &level);
1659 shadow = alloc_shadow(inode, bix, level, wc->ofs);
1661 err = truncate_data_block(inode, page, wc->ofs, shadow, size);
1663 free_shadow(inode, shadow);
1667 logfs_segment_delete(inode, shadow);
1668 set_iused(inode, shadow);
1669 fill_shadow_tree(inode, page, shadow);
1670 wc->ofs = shadow->new_ofs;
1674 static int logfs_truncate_direct(struct inode *inode, u64 size)
1676 struct logfs_inode *li = logfs_inode(inode);
1677 struct write_control wc;
1682 alloc_inode_block(inode);
1684 for (e = I0_BLOCKS - 1; e >= 0; e--) {
1685 if (size > (e+1) * LOGFS_BLOCKSIZE)
1688 wc.ofs = li->li_data[e];
1692 page = logfs_get_write_page(inode, e, 0);
1695 err = logfs_segment_read(inode, page, wc.ofs, e, 0);
1697 logfs_put_write_page(page);
1700 err = logfs_truncate_i0(inode, page, &wc, size);
1701 logfs_put_write_page(page);
1705 li->li_data[e] = wc.ofs;
1710 /* FIXME: these need to become per-sb once we support different blocksizes */
1711 static u64 __logfs_step[] = {
1718 static u64 __logfs_start_index[] = {
1725 static inline u64 logfs_step(level_t level)
1727 return __logfs_step[(__force u8)level];
1730 static inline u64 logfs_factor(u8 level)
1732 return __logfs_step[level] * LOGFS_BLOCKSIZE;
1735 static inline u64 logfs_start_index(level_t level)
1737 return __logfs_start_index[(__force u8)level];
1740 static void logfs_unpack_raw_index(pgoff_t index, u64 *bix, level_t *level)
1742 logfs_unpack_index(index, bix, level);
1743 if (*bix <= logfs_start_index(SUBLEVEL(*level)))
1747 static int __logfs_truncate_rec(struct inode *inode, struct page *ipage,
1748 struct write_control *this_wc, u64 size)
1750 int truncate_happened = 0;
1752 u64 bix, child_bix, next_bix;
1755 struct write_control child_wc = { /* FIXME: flags */ };
1757 logfs_unpack_raw_index(ipage->index, &bix, &level);
1758 err = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level);
1762 for (e = LOGFS_BLOCK_FACTOR - 1; e >= 0; e--) {
1763 child_bix = bix + e * logfs_step(SUBLEVEL(level));
1764 next_bix = child_bix + logfs_step(SUBLEVEL(level));
1765 if (size > next_bix * LOGFS_BLOCKSIZE)
1768 child_wc.ofs = pure_ofs(block_get_pointer(ipage, e));
1772 page = logfs_get_write_page(inode, child_bix, SUBLEVEL(level));
1776 if ((__force u8)level > 1)
1777 err = __logfs_truncate_rec(inode, page, &child_wc, size);
1779 err = logfs_truncate_i0(inode, page, &child_wc, size);
1780 logfs_put_write_page(page);
1784 truncate_happened = 1;
1785 alloc_indirect_block(inode, ipage, 0);
1786 block_set_pointer(ipage, e, child_wc.ofs);
1789 if (!truncate_happened) {
1790 printk("ineffectual truncate (%lx, %lx, %llx)\n", inode->i_ino, ipage->index, size);
1794 this_wc->flags = WF_DELETE;
1795 if (logfs_block(ipage)->partial)
1796 this_wc->flags |= WF_WRITE;
1798 return logfs_write_i0(inode, ipage, this_wc);
1801 static int logfs_truncate_rec(struct inode *inode, u64 size)
1803 struct logfs_inode *li = logfs_inode(inode);
1804 struct write_control wc = {
1805 .ofs = li->li_data[INDIRECT_INDEX],
1810 alloc_inode_block(inode);
1815 page = logfs_get_write_page(inode, 0, LEVEL(li->li_height));
1819 err = __logfs_truncate_rec(inode, page, &wc, size);
1820 logfs_put_write_page(page);
1824 if (li->li_data[INDIRECT_INDEX] != wc.ofs)
1825 li->li_data[INDIRECT_INDEX] = wc.ofs;
1829 static int __logfs_truncate(struct inode *inode, u64 size)
1833 if (size >= logfs_factor(logfs_inode(inode)->li_height))
1836 ret = logfs_truncate_rec(inode, size);
1840 return logfs_truncate_direct(inode, size);
1844 * Truncate, by changing the segment file, can consume a fair amount
1845 * of resources. So back off from time to time and do some GC.
1846 * 8 or 2048 blocks should be well within safety limits even if
1847 * every single block resided in a different segment.
1849 #define TRUNCATE_STEP (8 * 1024 * 1024)
1850 int logfs_truncate(struct inode *inode, u64 target)
1852 struct super_block *sb = inode->i_sb;
1853 u64 size = i_size_read(inode);
1856 size = ALIGN(size, TRUNCATE_STEP);
1857 while (size > target) {
1858 if (size > TRUNCATE_STEP)
1859 size -= TRUNCATE_STEP;
1865 logfs_get_wblocks(sb, NULL, 1);
1866 err = __logfs_truncate(inode, size);
1868 err = __logfs_write_inode(inode, 0);
1869 logfs_put_wblocks(sb, NULL, 1);
1873 err = vmtruncate(inode, target);
1875 /* I don't trust error recovery yet. */
1880 static void move_page_to_inode(struct inode *inode, struct page *page)
1882 struct logfs_inode *li = logfs_inode(inode);
1883 struct logfs_block *block = logfs_block(page);
1888 log_blockmove("move_page_to_inode(%llx, %llx, %x)\n",
1889 block->ino, block->bix, block->level);
1890 BUG_ON(li->li_block);
1891 block->ops = &inode_block_ops;
1892 block->inode = inode;
1893 li->li_block = block;
1897 ClearPagePrivate(page);
1900 static void move_inode_to_page(struct page *page, struct inode *inode)
1902 struct logfs_inode *li = logfs_inode(inode);
1903 struct logfs_block *block = li->li_block;
1908 log_blockmove("move_inode_to_page(%llx, %llx, %x)\n",
1909 block->ino, block->bix, block->level);
1910 BUG_ON(PagePrivate(page));
1911 block->ops = &indirect_block_ops;
1913 page->private = (unsigned long)block;
1914 SetPagePrivate(page);
1916 block->inode = NULL;
1917 li->li_block = NULL;
1920 int logfs_read_inode(struct inode *inode)
1922 struct super_block *sb = inode->i_sb;
1923 struct logfs_super *super = logfs_super(sb);
1924 struct inode *master_inode = super->s_master_inode;
1926 struct logfs_disk_inode *di;
1927 u64 ino = inode->i_ino;
1929 if (ino << sb->s_blocksize_bits > i_size_read(master_inode))
1931 if (!logfs_exist_block(master_inode, ino))
1934 page = read_cache_page(master_inode->i_mapping, ino,
1935 (filler_t *)logfs_readpage, NULL);
1937 return PTR_ERR(page);
1939 di = kmap_atomic(page, KM_USER0);
1940 logfs_disk_to_inode(di, inode);
1941 kunmap_atomic(di, KM_USER0);
1942 move_page_to_inode(inode, page);
1943 page_cache_release(page);
1947 /* Caller must logfs_put_write_page(page); */
1948 static struct page *inode_to_page(struct inode *inode)
1950 struct inode *master_inode = logfs_super(inode->i_sb)->s_master_inode;
1951 struct logfs_disk_inode *di;
1954 BUG_ON(inode->i_ino == LOGFS_INO_MASTER);
1956 page = logfs_get_write_page(master_inode, inode->i_ino, 0);
1960 di = kmap_atomic(page, KM_USER0);
1961 logfs_inode_to_disk(inode, di);
1962 kunmap_atomic(di, KM_USER0);
1963 move_inode_to_page(page, inode);
1967 /* Cheaper version of write_inode. All changes are concealed in
1968 * aliases, which are moved back. No write to the medium happens.
1970 void logfs_clear_inode(struct inode *inode)
1972 struct super_block *sb = inode->i_sb;
1973 struct logfs_inode *li = logfs_inode(inode);
1974 struct logfs_block *block = li->li_block;
1977 /* Only deleted files may be dirty at this point */
1978 BUG_ON(inode->i_state & I_DIRTY && inode->i_nlink);
1981 if ((logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN)) {
1982 block->ops->free_block(inode->i_sb, block);
1986 BUG_ON(inode->i_ino < LOGFS_RESERVED_INOS);
1987 page = inode_to_page(inode);
1988 BUG_ON(!page); /* FIXME: Use emergency page */
1989 logfs_put_write_page(page);
1992 static int do_write_inode(struct inode *inode)
1994 struct super_block *sb = inode->i_sb;
1995 struct inode *master_inode = logfs_super(sb)->s_master_inode;
1996 loff_t size = (inode->i_ino + 1) << inode->i_sb->s_blocksize_bits;
2000 BUG_ON(inode->i_ino == LOGFS_INO_MASTER);
2001 /* FIXME: lock inode */
2003 if (i_size_read(master_inode) < size)
2004 i_size_write(master_inode, size);
2006 /* TODO: Tell vfs this inode is clean now */
2008 page = inode_to_page(inode);
2012 /* FIXME: transaction is part of logfs_block now. Is that enough? */
2013 err = logfs_write_buf(master_inode, page, 0);
2014 logfs_put_write_page(page);
2018 static void logfs_mod_segment_entry(struct super_block *sb, u32 segno,
2020 void (*change_se)(struct logfs_segment_entry *, long),
2023 struct logfs_super *super = logfs_super(sb);
2024 struct inode *inode;
2026 struct logfs_segment_entry *se;
2030 page_no = segno >> (sb->s_blocksize_bits - 3);
2031 child_no = segno & ((sb->s_blocksize >> 3) - 1);
2033 inode = super->s_segfile_inode;
2034 page = logfs_get_write_page(inode, page_no, 0);
2035 BUG_ON(!page); /* FIXME: We need some reserve page for this case */
2036 if (!PageUptodate(page))
2037 logfs_read_block(inode, page, WRITE);
2040 alloc_indirect_block(inode, page, 0);
2041 se = kmap_atomic(page, KM_USER0);
2042 change_se(se + child_no, arg);
2044 logfs_set_alias(sb, logfs_block(page), child_no);
2045 BUG_ON((int)be32_to_cpu(se[child_no].valid) > super->s_segsize);
2047 kunmap_atomic(se, KM_USER0);
2049 logfs_put_write_page(page);
2052 static void __get_segment_entry(struct logfs_segment_entry *se, long _target)
2054 struct logfs_segment_entry *target = (void *)_target;
2059 void logfs_get_segment_entry(struct super_block *sb, u32 segno,
2060 struct logfs_segment_entry *se)
2062 logfs_mod_segment_entry(sb, segno, 0, __get_segment_entry, (long)se);
2065 static void __set_segment_used(struct logfs_segment_entry *se, long increment)
2069 valid = be32_to_cpu(se->valid);
2071 se->valid = cpu_to_be32(valid);
2074 void logfs_set_segment_used(struct super_block *sb, u64 ofs, int increment)
2076 struct logfs_super *super = logfs_super(sb);
2077 u32 segno = ofs >> super->s_segshift;
2082 logfs_mod_segment_entry(sb, segno, 1, __set_segment_used, increment);
2085 static void __set_segment_erased(struct logfs_segment_entry *se, long ec_level)
2087 se->ec_level = cpu_to_be32(ec_level);
2090 void logfs_set_segment_erased(struct super_block *sb, u32 segno, u32 ec,
2091 gc_level_t gc_level)
2093 u32 ec_level = ec << 4 | (__force u8)gc_level;
2095 logfs_mod_segment_entry(sb, segno, 1, __set_segment_erased, ec_level);
2098 static void __set_segment_reserved(struct logfs_segment_entry *se, long ignore)
2100 se->valid = cpu_to_be32(RESERVED);
2103 void logfs_set_segment_reserved(struct super_block *sb, u32 segno)
2105 logfs_mod_segment_entry(sb, segno, 1, __set_segment_reserved, 0);
2108 static void __set_segment_unreserved(struct logfs_segment_entry *se,
2112 se->ec_level = cpu_to_be32(ec_level);
2115 void logfs_set_segment_unreserved(struct super_block *sb, u32 segno, u32 ec)
2117 u32 ec_level = ec << 4;
2119 logfs_mod_segment_entry(sb, segno, 1, __set_segment_unreserved,
2123 int __logfs_write_inode(struct inode *inode, long flags)
2125 struct super_block *sb = inode->i_sb;
2128 logfs_get_wblocks(sb, NULL, flags & WF_LOCK);
2129 ret = do_write_inode(inode);
2130 logfs_put_wblocks(sb, NULL, flags & WF_LOCK);
2134 static int do_delete_inode(struct inode *inode)
2136 struct super_block *sb = inode->i_sb;
2137 struct inode *master_inode = logfs_super(sb)->s_master_inode;
2141 page = logfs_get_write_page(master_inode, inode->i_ino, 0);
2145 move_inode_to_page(page, inode);
2147 logfs_get_wblocks(sb, page, 1);
2148 ret = __logfs_delete(master_inode, page);
2149 logfs_put_wblocks(sb, page, 1);
2151 logfs_put_write_page(page);
2156 * ZOMBIE inodes have already been deleted before and should remain dead,
2157 * if it weren't for valid checking. No need to kill them again here.
2159 void logfs_delete_inode(struct inode *inode)
2161 struct logfs_inode *li = logfs_inode(inode);
2163 if (!(li->li_flags & LOGFS_IF_ZOMBIE)) {
2164 li->li_flags |= LOGFS_IF_ZOMBIE;
2165 if (i_size_read(inode) > 0)
2166 logfs_truncate(inode, 0);
2167 do_delete_inode(inode);
2169 truncate_inode_pages(&inode->i_data, 0);
2173 void btree_write_block(struct logfs_block *block)
2175 struct inode *inode;
2179 inode = logfs_safe_iget(block->sb, block->ino, &cookie);
2180 page = logfs_get_write_page(inode, block->bix, block->level);
2182 err = logfs_readpage_nolock(page);
2184 BUG_ON(!PagePrivate(page));
2185 BUG_ON(logfs_block(page) != block);
2186 err = __logfs_write_buf(inode, page, 0);
2188 BUG_ON(PagePrivate(page) || page->private);
2190 logfs_put_write_page(page);
2191 logfs_safe_iput(inode, cookie);
2195 * logfs_inode_write - write inode or dentry objects
2197 * @inode: parent inode (ifile or directory)
2198 * @buf: object to write (inode or dentry)
2200 * @_pos: object number (file position in blocks/objects)
2201 * @flags: write flags
2202 * @lock: 0 if write lock is already taken, 1 otherwise
2203 * @shadow_tree: shadow below this inode
2205 * FIXME: All caller of this put a 200-300 byte variable on the stack,
2206 * only to call here and do a memcpy from that stack variable. A good
2207 * example of wasted performance and stack space.
2209 int logfs_inode_write(struct inode *inode, const void *buf, size_t count,
2210 loff_t bix, long flags, struct shadow_tree *shadow_tree)
2212 loff_t pos = bix << inode->i_sb->s_blocksize_bits;
2217 BUG_ON(pos & (LOGFS_BLOCKSIZE-1));
2218 BUG_ON(count > LOGFS_BLOCKSIZE);
2219 page = logfs_get_write_page(inode, bix, 0);
2223 pagebuf = kmap_atomic(page, KM_USER0);
2224 memcpy(pagebuf, buf, count);
2225 flush_dcache_page(page);
2226 kunmap_atomic(pagebuf, KM_USER0);
2228 if (i_size_read(inode) < pos + LOGFS_BLOCKSIZE)
2229 i_size_write(inode, pos + LOGFS_BLOCKSIZE);
2231 err = logfs_write_buf(inode, page, flags);
2232 logfs_put_write_page(page);
2236 int logfs_open_segfile(struct super_block *sb)
2238 struct logfs_super *super = logfs_super(sb);
2239 struct inode *inode;
2241 inode = logfs_read_meta_inode(sb, LOGFS_INO_SEGFILE);
2243 return PTR_ERR(inode);
2244 super->s_segfile_inode = inode;
2248 int logfs_init_rw(struct super_block *sb)
2250 struct logfs_super *super = logfs_super(sb);
2251 int min_fill = 3 * super->s_no_blocks;
2253 INIT_LIST_HEAD(&super->s_object_alias);
2254 mutex_init(&super->s_write_mutex);
2255 super->s_block_pool = mempool_create_kmalloc_pool(min_fill,
2256 sizeof(struct logfs_block));
2257 super->s_shadow_pool = mempool_create_kmalloc_pool(min_fill,
2258 sizeof(struct logfs_shadow));
2262 void logfs_cleanup_rw(struct super_block *sb)
2264 struct logfs_super *super = logfs_super(sb);
2266 destroy_meta_inode(super->s_segfile_inode);
2267 logfs_mempool_destroy(super->s_block_pool);
2268 logfs_mempool_destroy(super->s_shadow_pool);