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 */
433 static gc_level_t inode_block_level(struct logfs_block *block)
435 BUG_ON(block->inode->i_ino == LOGFS_INO_MASTER);
436 return GC_LEVEL(LOGFS_MAX_LEVELS);
439 static gc_level_t indirect_block_level(struct logfs_block *block)
447 inode = page->mapping->host;
448 logfs_unpack_index(page->index, &bix, &level);
449 return expand_level(inode->i_ino, level);
453 * This silences a false, yet annoying gcc warning. I hate it when my editor
454 * jumps into bitops.h each time I recompile this file.
455 * TODO: Complain to gcc folks about this and upgrade compiler.
457 static unsigned long fnb(const unsigned long *addr,
458 unsigned long size, unsigned long offset)
460 return find_next_bit(addr, size, offset);
463 static __be64 inode_val0(struct inode *inode)
465 struct logfs_inode *li = logfs_inode(inode);
469 * Explicit shifting generates good code, but must match the format
470 * of the structure. Add some paranoia just in case.
472 BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_mode) != 0);
473 BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_height) != 2);
474 BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_flags) != 4);
476 val = (u64)inode->i_mode << 48 |
477 (u64)li->li_height << 40 |
479 return cpu_to_be64(val);
482 static int inode_write_alias(struct super_block *sb,
483 struct logfs_block *block, write_alias_t *write_one_alias)
485 struct inode *inode = block->inode;
486 struct logfs_inode *li = logfs_inode(inode);
493 for (pos = 0; ; pos++) {
494 pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos);
495 if (pos >= LOGFS_EMBEDDED_FIELDS + INODE_POINTER_OFS)
499 case INODE_HEIGHT_OFS:
500 val = inode_val0(inode);
503 val = cpu_to_be64(li->li_used_bytes);;
506 val = cpu_to_be64(i_size_read(inode));
508 case INODE_POINTER_OFS ... INODE_POINTER_OFS + LOGFS_EMBEDDED_FIELDS - 1:
509 val = cpu_to_be64(li->li_data[pos - INODE_POINTER_OFS]);
515 ino = LOGFS_INO_MASTER;
518 err = write_one_alias(sb, ino, bix, level, pos, val);
524 static int indirect_write_alias(struct super_block *sb,
525 struct logfs_block *block, write_alias_t *write_one_alias)
528 struct page *page = block->page;
534 for (pos = 0; ; pos++) {
535 pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos);
536 if (pos >= LOGFS_BLOCK_FACTOR)
539 ino = page->mapping->host->i_ino;
540 logfs_unpack_index(page->index, &bix, &level);
541 child = kmap_atomic(page, KM_USER0);
543 kunmap_atomic(child, KM_USER0);
544 err = write_one_alias(sb, ino, bix, level, pos, val);
550 int logfs_write_obj_aliases_pagecache(struct super_block *sb)
552 struct logfs_super *super = logfs_super(sb);
553 struct logfs_block *block;
556 list_for_each_entry(block, &super->s_object_alias, alias_list) {
557 err = block->ops->write_alias(sb, block, write_alias_journal);
564 void __free_block(struct super_block *sb, struct logfs_block *block)
566 BUG_ON(!list_empty(&block->item_list));
567 list_del(&block->alias_list);
568 mempool_free(block, logfs_super(sb)->s_block_pool);
571 static void inode_free_block(struct super_block *sb, struct logfs_block *block)
573 struct inode *inode = block->inode;
575 logfs_inode(inode)->li_block = NULL;
576 __free_block(sb, block);
579 static void indirect_free_block(struct super_block *sb,
580 struct logfs_block *block)
582 ClearPagePrivate(block->page);
583 block->page->private = 0;
584 __free_block(sb, block);
588 static struct logfs_block_ops inode_block_ops = {
589 .write_block = inode_write_block,
590 .block_level = inode_block_level,
591 .free_block = inode_free_block,
592 .write_alias = inode_write_alias,
595 struct logfs_block_ops indirect_block_ops = {
596 .write_block = indirect_write_block,
597 .block_level = indirect_block_level,
598 .free_block = indirect_free_block,
599 .write_alias = indirect_write_alias,
602 struct logfs_block *__alloc_block(struct super_block *sb,
603 u64 ino, u64 bix, level_t level)
605 struct logfs_super *super = logfs_super(sb);
606 struct logfs_block *block;
608 block = mempool_alloc(super->s_block_pool, GFP_NOFS);
609 memset(block, 0, sizeof(*block));
610 INIT_LIST_HEAD(&block->alias_list);
611 INIT_LIST_HEAD(&block->item_list);
615 block->level = level;
619 static void alloc_inode_block(struct inode *inode)
621 struct logfs_inode *li = logfs_inode(inode);
622 struct logfs_block *block;
627 block = __alloc_block(inode->i_sb, LOGFS_INO_MASTER, inode->i_ino, 0);
628 block->inode = inode;
629 li->li_block = block;
630 block->ops = &inode_block_ops;
633 void initialize_block_counters(struct page *page, struct logfs_block *block,
634 __be64 *array, int page_is_empty)
642 if (page->index < first_indirect_block()) {
643 /* Counters are pointless on level 0 */
646 if (page->index == first_indirect_block()) {
647 /* Skip unused pointers */
649 block->full = I0_BLOCKS;
651 if (!page_is_empty) {
652 for (i = start; i < LOGFS_BLOCK_FACTOR; i++) {
653 ptr = be64_to_cpu(array[i]);
656 if (ptr & LOGFS_FULLY_POPULATED)
662 static void alloc_data_block(struct inode *inode, struct page *page)
664 struct logfs_block *block;
668 if (PagePrivate(page))
671 logfs_unpack_index(page->index, &bix, &level);
672 block = __alloc_block(inode->i_sb, inode->i_ino, bix, level);
674 SetPagePrivate(page);
675 page->private = (unsigned long)block;
676 block->ops = &indirect_block_ops;
679 static void alloc_indirect_block(struct inode *inode, struct page *page,
682 struct logfs_block *block;
685 if (PagePrivate(page))
688 alloc_data_block(inode, page);
690 block = logfs_block(page);
691 array = kmap_atomic(page, KM_USER0);
692 initialize_block_counters(page, block, array, page_is_empty);
693 kunmap_atomic(array, KM_USER0);
696 static void block_set_pointer(struct page *page, int index, u64 ptr)
698 struct logfs_block *block = logfs_block(page);
703 array = kmap_atomic(page, KM_USER0);
704 oldptr = be64_to_cpu(array[index]);
705 array[index] = cpu_to_be64(ptr);
706 kunmap_atomic(array, KM_USER0);
707 SetPageUptodate(page);
709 block->full += !!(ptr & LOGFS_FULLY_POPULATED)
710 - !!(oldptr & LOGFS_FULLY_POPULATED);
711 block->partial += !!ptr - !!oldptr;
714 static u64 block_get_pointer(struct page *page, int index)
719 block = kmap_atomic(page, KM_USER0);
720 ptr = be64_to_cpu(block[index]);
721 kunmap_atomic(block, KM_USER0);
725 static int logfs_read_empty(struct page *page)
727 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
731 static int logfs_read_direct(struct inode *inode, struct page *page)
733 struct logfs_inode *li = logfs_inode(inode);
734 pgoff_t index = page->index;
737 block = li->li_data[index];
739 return logfs_read_empty(page);
741 return logfs_segment_read(inode, page, block, index, 0);
744 static int logfs_read_loop(struct inode *inode, struct page *page,
747 struct logfs_inode *li = logfs_inode(inode);
748 u64 bix, bofs = li->li_data[INDIRECT_INDEX];
749 level_t level, target_level;
753 logfs_unpack_index(page->index, &bix, &target_level);
755 return logfs_read_empty(page);
757 if (bix >= maxbix(li->li_height))
758 return logfs_read_empty(page);
760 for (level = LEVEL(li->li_height);
761 (__force u8)level > (__force u8)target_level;
762 level = SUBLEVEL(level)){
763 ipage = logfs_get_page(inode, bix, level, rw_context);
767 ret = logfs_segment_read(inode, ipage, bofs, bix, level);
769 logfs_put_read_page(ipage);
773 bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level)));
774 logfs_put_page(ipage, rw_context);
776 return logfs_read_empty(page);
779 return logfs_segment_read(inode, page, bofs, bix, 0);
782 static int logfs_read_block(struct inode *inode, struct page *page,
785 pgoff_t index = page->index;
787 if (index < I0_BLOCKS)
788 return logfs_read_direct(inode, page);
789 return logfs_read_loop(inode, page, rw_context);
792 static int logfs_exist_loop(struct inode *inode, u64 bix)
794 struct logfs_inode *li = logfs_inode(inode);
795 u64 bofs = li->li_data[INDIRECT_INDEX];
802 if (bix >= maxbix(li->li_height))
805 for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) {
806 ipage = logfs_get_read_page(inode, bix, level);
810 ret = logfs_segment_read(inode, ipage, bofs, bix, level);
812 logfs_put_read_page(ipage);
816 bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level)));
817 logfs_put_read_page(ipage);
825 int logfs_exist_block(struct inode *inode, u64 bix)
827 struct logfs_inode *li = logfs_inode(inode);
830 return !!li->li_data[bix];
831 return logfs_exist_loop(inode, bix);
834 static u64 seek_holedata_direct(struct inode *inode, u64 bix, int data)
836 struct logfs_inode *li = logfs_inode(inode);
838 for (; bix < I0_BLOCKS; bix++)
839 if (data ^ (li->li_data[bix] == 0))
844 static u64 seek_holedata_loop(struct inode *inode, u64 bix, int data)
846 struct logfs_inode *li = logfs_inode(inode);
848 u64 increment, bofs = li->li_data[INDIRECT_INDEX];
855 for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) {
856 increment = 1 << (LOGFS_BLOCK_BITS * ((__force u8)level-1));
857 page = logfs_get_read_page(inode, bix, level);
861 ret = logfs_segment_read(inode, page, bofs, bix, level);
863 logfs_put_read_page(page);
867 slot = get_bits(bix, SUBLEVEL(level));
868 rblock = kmap_atomic(page, KM_USER0);
869 while (slot < LOGFS_BLOCK_FACTOR) {
870 if (data && (rblock[slot] != 0))
872 if (!data && !(be64_to_cpu(rblock[slot]) & LOGFS_FULLY_POPULATED))
876 bix &= ~(increment - 1);
878 if (slot >= LOGFS_BLOCK_FACTOR) {
879 kunmap_atomic(rblock, KM_USER0);
880 logfs_put_read_page(page);
883 bofs = be64_to_cpu(rblock[slot]);
884 kunmap_atomic(rblock, KM_USER0);
885 logfs_put_read_page(page);
895 * logfs_seek_hole - find next hole starting at a given block index
896 * @inode: inode to search in
897 * @bix: block index to start searching
899 * Returns next hole. If the file doesn't contain any further holes, the
900 * block address next to eof is returned instead.
902 u64 logfs_seek_hole(struct inode *inode, u64 bix)
904 struct logfs_inode *li = logfs_inode(inode);
906 if (bix < I0_BLOCKS) {
907 bix = seek_holedata_direct(inode, bix, 0);
912 if (!li->li_data[INDIRECT_INDEX])
914 else if (li->li_data[INDIRECT_INDEX] & LOGFS_FULLY_POPULATED)
915 bix = maxbix(li->li_height);
917 bix = seek_holedata_loop(inode, bix, 0);
918 if (bix < maxbix(li->li_height))
920 /* Should not happen anymore. But if some port writes semi-
921 * corrupt images (as this one used to) we might run into it.
923 WARN_ON_ONCE(bix == maxbix(li->li_height));
929 static u64 __logfs_seek_data(struct inode *inode, u64 bix)
931 struct logfs_inode *li = logfs_inode(inode);
933 if (bix < I0_BLOCKS) {
934 bix = seek_holedata_direct(inode, bix, 1);
939 if (bix < maxbix(li->li_height)) {
940 if (!li->li_data[INDIRECT_INDEX])
941 bix = maxbix(li->li_height);
943 return seek_holedata_loop(inode, bix, 1);
950 * logfs_seek_data - find next data block after a given block index
951 * @inode: inode to search in
952 * @bix: block index to start searching
954 * Returns next data block. If the file doesn't contain any further data
955 * blocks, the last block in the file is returned instead.
957 u64 logfs_seek_data(struct inode *inode, u64 bix)
959 struct super_block *sb = inode->i_sb;
962 ret = __logfs_seek_data(inode, bix);
963 end = i_size_read(inode) >> sb->s_blocksize_bits;
969 static int logfs_is_valid_direct(struct logfs_inode *li, u64 bix, u64 ofs)
971 return pure_ofs(li->li_data[bix]) == ofs;
974 static int __logfs_is_valid_loop(struct inode *inode, u64 bix,
977 struct logfs_inode *li = logfs_inode(inode);
982 for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)){
983 page = logfs_get_write_page(inode, bix, level);
986 ret = logfs_segment_read(inode, page, bofs, bix, level);
988 logfs_put_write_page(page);
992 bofs = block_get_pointer(page, get_bits(bix, SUBLEVEL(level)));
993 logfs_put_write_page(page);
997 if (pure_ofs(bofs) == ofs)
1003 static int logfs_is_valid_loop(struct inode *inode, u64 bix, u64 ofs)
1005 struct logfs_inode *li = logfs_inode(inode);
1006 u64 bofs = li->li_data[INDIRECT_INDEX];
1011 if (bix >= maxbix(li->li_height))
1014 if (pure_ofs(bofs) == ofs)
1017 return __logfs_is_valid_loop(inode, bix, ofs, bofs);
1020 static int __logfs_is_valid_block(struct inode *inode, u64 bix, u64 ofs)
1022 struct logfs_inode *li = logfs_inode(inode);
1024 if ((inode->i_nlink == 0) && atomic_read(&inode->i_count) == 1)
1027 if (bix < I0_BLOCKS)
1028 return logfs_is_valid_direct(li, bix, ofs);
1029 return logfs_is_valid_loop(inode, bix, ofs);
1033 * logfs_is_valid_block - check whether this block is still valid
1036 * @ofs - block physical offset
1037 * @ino - block inode number
1038 * @bix - block index
1039 * @level - block level
1041 * Returns 0 if the block is invalid, 1 if it is valid and 2 if it will
1042 * become invalid once the journal is written.
1044 int logfs_is_valid_block(struct super_block *sb, u64 ofs, u64 ino, u64 bix,
1045 gc_level_t gc_level)
1047 struct logfs_super *super = logfs_super(sb);
1048 struct inode *inode;
1051 /* Umount closes a segment with free blocks remaining. Those
1052 * blocks are by definition invalid. */
1056 LOGFS_BUG_ON((u64)(u_long)ino != ino, sb);
1058 inode = logfs_safe_iget(sb, ino, &cookie);
1062 ret = __logfs_is_valid_block(inode, bix, ofs);
1063 logfs_safe_iput(inode, cookie);
1068 /* Block is nominally invalid, but may still sit in the shadow tree,
1069 * waiting for a journal commit.
1071 if (btree_lookup64(&super->s_shadow_tree.old, ofs))
1076 int logfs_readpage_nolock(struct page *page)
1078 struct inode *inode = page->mapping->host;
1081 ret = logfs_read_block(inode, page, READ);
1084 ClearPageUptodate(page);
1087 SetPageUptodate(page);
1088 ClearPageError(page);
1090 flush_dcache_page(page);
1095 static int logfs_reserve_bytes(struct inode *inode, int bytes)
1097 struct logfs_super *super = logfs_super(inode->i_sb);
1098 u64 available = super->s_free_bytes + super->s_dirty_free_bytes
1099 - super->s_dirty_used_bytes - super->s_dirty_pages;
1104 if (available < bytes)
1107 if (available < bytes + super->s_root_reserve &&
1108 !capable(CAP_SYS_RESOURCE))
1114 int get_page_reserve(struct inode *inode, struct page *page)
1116 struct logfs_super *super = logfs_super(inode->i_sb);
1119 if (logfs_block(page) && logfs_block(page)->reserved_bytes)
1122 logfs_get_wblocks(inode->i_sb, page, WF_LOCK);
1123 ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE);
1125 alloc_data_block(inode, page);
1126 logfs_block(page)->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE;
1127 super->s_dirty_pages += 6 * LOGFS_MAX_OBJECTSIZE;
1129 logfs_put_wblocks(inode->i_sb, page, WF_LOCK);
1134 * We are protected by write lock. Push victims up to superblock level
1135 * and release transaction when appropriate.
1137 /* FIXME: This is currently called from the wrong spots. */
1138 static void logfs_handle_transaction(struct inode *inode,
1139 struct logfs_transaction *ta)
1141 struct logfs_super *super = logfs_super(inode->i_sb);
1145 logfs_inode(inode)->li_block->ta = NULL;
1147 if (inode->i_ino != LOGFS_INO_MASTER) {
1148 BUG(); /* FIXME: Yes, this needs more thought */
1149 /* just remember the transaction until inode is written */
1150 //BUG_ON(logfs_inode(inode)->li_transaction);
1151 //logfs_inode(inode)->li_transaction = ta;
1155 switch (ta->state) {
1156 case CREATE_1: /* fall through */
1158 BUG_ON(super->s_victim_ino);
1159 super->s_victim_ino = ta->ino;
1161 case CREATE_2: /* fall through */
1163 BUG_ON(super->s_victim_ino != ta->ino);
1164 super->s_victim_ino = 0;
1165 /* transaction ends here - free it */
1168 case CROSS_RENAME_1:
1169 BUG_ON(super->s_rename_dir);
1170 BUG_ON(super->s_rename_pos);
1171 super->s_rename_dir = ta->dir;
1172 super->s_rename_pos = ta->pos;
1174 case CROSS_RENAME_2:
1175 BUG_ON(super->s_rename_dir != ta->dir);
1176 BUG_ON(super->s_rename_pos != ta->pos);
1177 super->s_rename_dir = 0;
1178 super->s_rename_pos = 0;
1181 case TARGET_RENAME_1:
1182 BUG_ON(super->s_rename_dir);
1183 BUG_ON(super->s_rename_pos);
1184 BUG_ON(super->s_victim_ino);
1185 super->s_rename_dir = ta->dir;
1186 super->s_rename_pos = ta->pos;
1187 super->s_victim_ino = ta->ino;
1189 case TARGET_RENAME_2:
1190 BUG_ON(super->s_rename_dir != ta->dir);
1191 BUG_ON(super->s_rename_pos != ta->pos);
1192 BUG_ON(super->s_victim_ino != ta->ino);
1193 super->s_rename_dir = 0;
1194 super->s_rename_pos = 0;
1196 case TARGET_RENAME_3:
1197 BUG_ON(super->s_rename_dir);
1198 BUG_ON(super->s_rename_pos);
1199 BUG_ON(super->s_victim_ino != ta->ino);
1200 super->s_victim_ino = 0;
1209 * Not strictly a reservation, but rather a check that we still have enough
1210 * space to satisfy the write.
1212 static int logfs_reserve_blocks(struct inode *inode, int blocks)
1214 return logfs_reserve_bytes(inode, blocks * LOGFS_MAX_OBJECTSIZE);
1217 struct write_control {
1222 static struct logfs_shadow *alloc_shadow(struct inode *inode, u64 bix,
1223 level_t level, u64 old_ofs)
1225 struct logfs_super *super = logfs_super(inode->i_sb);
1226 struct logfs_shadow *shadow;
1228 shadow = mempool_alloc(super->s_shadow_pool, GFP_NOFS);
1229 memset(shadow, 0, sizeof(*shadow));
1230 shadow->ino = inode->i_ino;
1232 shadow->gc_level = expand_level(inode->i_ino, level);
1233 shadow->old_ofs = old_ofs & ~LOGFS_FULLY_POPULATED;
1237 static void free_shadow(struct inode *inode, struct logfs_shadow *shadow)
1239 struct logfs_super *super = logfs_super(inode->i_sb);
1241 mempool_free(shadow, super->s_shadow_pool);
1245 * fill_shadow_tree - Propagate shadow tree changes due to a write
1246 * @inode: Inode owning the page
1247 * @page: Struct page that was written
1248 * @shadow: Shadow for the current write
1250 * Writes in logfs can result in two semi-valid objects. The old object
1251 * is still valid as long as it can be reached by following pointers on
1252 * the medium. Only when writes propagate all the way up to the journal
1253 * has the new object safely replaced the old one.
1255 * To handle this problem, a struct logfs_shadow is used to represent
1256 * every single write. It is attached to the indirect block, which is
1257 * marked dirty. When the indirect block is written, its shadows are
1258 * handed up to the next indirect block (or inode). Untimately they
1259 * will reach the master inode and be freed upon journal commit.
1261 * This function handles a single step in the propagation. It adds the
1262 * shadow for the current write to the tree, along with any shadows in
1263 * the page's tree, in case it was an indirect block. If a page is
1264 * written, the inode parameter is left NULL, if an inode is written,
1265 * the page parameter is left NULL.
1267 static void fill_shadow_tree(struct inode *inode, struct page *page,
1268 struct logfs_shadow *shadow)
1270 struct logfs_super *super = logfs_super(inode->i_sb);
1271 struct logfs_block *block = logfs_block(page);
1272 struct shadow_tree *tree = &super->s_shadow_tree;
1274 if (PagePrivate(page)) {
1275 if (block->alias_map)
1276 super->s_no_object_aliases -= bitmap_weight(
1277 block->alias_map, LOGFS_BLOCK_FACTOR);
1278 logfs_handle_transaction(inode, block->ta);
1279 block->ops->free_block(inode->i_sb, block);
1282 if (shadow->old_ofs)
1283 btree_insert64(&tree->old, shadow->old_ofs, shadow,
1286 btree_insert64(&tree->new, shadow->new_ofs, shadow,
1289 super->s_dirty_used_bytes += shadow->new_len;
1290 super->s_dirty_free_bytes += shadow->old_len;
1294 static void logfs_set_alias(struct super_block *sb, struct logfs_block *block,
1297 struct logfs_super *super = logfs_super(sb);
1299 if (block->inode && block->inode->i_ino == LOGFS_INO_MASTER) {
1300 /* Aliases in the master inode are pointless. */
1304 if (!test_bit(child_no, block->alias_map)) {
1305 set_bit(child_no, block->alias_map);
1306 super->s_no_object_aliases++;
1308 list_move_tail(&block->alias_list, &super->s_object_alias);
1312 * Object aliases can and often do change the size and occupied space of a
1313 * file. So not only do we have to change the pointers, we also have to
1314 * change inode->i_size and li->li_used_bytes. Which is done by setting
1315 * another two object aliases for the inode itself.
1317 static void set_iused(struct inode *inode, struct logfs_shadow *shadow)
1319 struct logfs_inode *li = logfs_inode(inode);
1321 if (shadow->new_len == shadow->old_len)
1324 alloc_inode_block(inode);
1325 li->li_used_bytes += shadow->new_len - shadow->old_len;
1326 __logfs_set_blocks(inode);
1327 logfs_set_alias(inode->i_sb, li->li_block, INODE_USED_OFS);
1328 logfs_set_alias(inode->i_sb, li->li_block, INODE_SIZE_OFS);
1331 static int logfs_write_i0(struct inode *inode, struct page *page,
1332 struct write_control *wc)
1334 struct logfs_shadow *shadow;
1339 logfs_unpack_index(page->index, &bix, &level);
1341 if (logfs_reserve_blocks(inode, 1))
1344 shadow = alloc_shadow(inode, bix, level, wc->ofs);
1345 if (wc->flags & WF_WRITE)
1346 err = logfs_segment_write(inode, page, shadow);
1347 if (wc->flags & WF_DELETE)
1348 logfs_segment_delete(inode, shadow);
1350 free_shadow(inode, shadow);
1354 set_iused(inode, shadow);
1357 alloc_indirect_block(inode, page, 0);
1358 full = logfs_block(page)->full == LOGFS_BLOCK_FACTOR;
1360 fill_shadow_tree(inode, page, shadow);
1361 wc->ofs = shadow->new_ofs;
1362 if (wc->ofs && full)
1363 wc->ofs |= LOGFS_FULLY_POPULATED;
1367 static int logfs_write_direct(struct inode *inode, struct page *page,
1370 struct logfs_inode *li = logfs_inode(inode);
1371 struct write_control wc = {
1372 .ofs = li->li_data[page->index],
1377 alloc_inode_block(inode);
1379 err = logfs_write_i0(inode, page, &wc);
1383 li->li_data[page->index] = wc.ofs;
1384 logfs_set_alias(inode->i_sb, li->li_block,
1385 page->index + INODE_POINTER_OFS);
1389 static int ptr_change(u64 ofs, struct page *page)
1391 struct logfs_block *block = logfs_block(page);
1392 int empty0, empty1, full0, full1;
1395 empty1 = block->partial == 0;
1396 if (empty0 != empty1)
1399 /* The !! is necessary to shrink result to int */
1400 full0 = !!(ofs & LOGFS_FULLY_POPULATED);
1401 full1 = block->full == LOGFS_BLOCK_FACTOR;
1407 static int __logfs_write_rec(struct inode *inode, struct page *page,
1408 struct write_control *this_wc,
1409 pgoff_t bix, level_t target_level, level_t level)
1411 int ret, page_empty = 0;
1412 int child_no = get_bits(bix, SUBLEVEL(level));
1414 struct write_control child_wc = {
1415 .flags = this_wc->flags,
1418 ipage = logfs_get_write_page(inode, bix, level);
1423 ret = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level);
1426 } else if (!PageUptodate(ipage)) {
1428 logfs_read_empty(ipage);
1431 child_wc.ofs = block_get_pointer(ipage, child_no);
1433 if ((__force u8)level-1 > (__force u8)target_level)
1434 ret = __logfs_write_rec(inode, page, &child_wc, bix,
1435 target_level, SUBLEVEL(level));
1437 ret = logfs_write_i0(inode, page, &child_wc);
1442 alloc_indirect_block(inode, ipage, page_empty);
1443 block_set_pointer(ipage, child_no, child_wc.ofs);
1444 /* FIXME: first condition seems superfluous */
1445 if (child_wc.ofs || logfs_block(ipage)->partial)
1446 this_wc->flags |= WF_WRITE;
1447 /* the condition on this_wc->ofs ensures that we won't consume extra
1448 * space for indirect blocks in the future, which we cannot reserve */
1449 if (!this_wc->ofs || ptr_change(this_wc->ofs, ipage))
1450 ret = logfs_write_i0(inode, ipage, this_wc);
1452 logfs_set_alias(inode->i_sb, logfs_block(ipage), child_no);
1454 logfs_put_write_page(ipage);
1458 static int logfs_write_rec(struct inode *inode, struct page *page,
1459 pgoff_t bix, level_t target_level, long flags)
1461 struct logfs_inode *li = logfs_inode(inode);
1462 struct write_control wc = {
1463 .ofs = li->li_data[INDIRECT_INDEX],
1468 alloc_inode_block(inode);
1470 if (li->li_height > (__force u8)target_level)
1471 ret = __logfs_write_rec(inode, page, &wc, bix, target_level,
1472 LEVEL(li->li_height));
1474 ret = logfs_write_i0(inode, page, &wc);
1478 if (li->li_data[INDIRECT_INDEX] != wc.ofs) {
1479 li->li_data[INDIRECT_INDEX] = wc.ofs;
1480 logfs_set_alias(inode->i_sb, li->li_block,
1481 INDIRECT_INDEX + INODE_POINTER_OFS);
1486 void logfs_add_transaction(struct inode *inode, struct logfs_transaction *ta)
1488 alloc_inode_block(inode);
1489 logfs_inode(inode)->li_block->ta = ta;
1492 void logfs_del_transaction(struct inode *inode, struct logfs_transaction *ta)
1494 struct logfs_block *block = logfs_inode(inode)->li_block;
1496 if (block && block->ta)
1500 static int grow_inode(struct inode *inode, u64 bix, level_t level)
1502 struct logfs_inode *li = logfs_inode(inode);
1503 u8 height = (__force u8)level;
1505 struct write_control wc = {
1510 BUG_ON(height > 5 || li->li_height > 5);
1511 while (height > li->li_height || bix >= maxbix(li->li_height)) {
1512 page = logfs_get_write_page(inode, I0_BLOCKS + 1,
1513 LEVEL(li->li_height + 1));
1516 logfs_read_empty(page);
1517 alloc_indirect_block(inode, page, 1);
1518 block_set_pointer(page, 0, li->li_data[INDIRECT_INDEX]);
1519 err = logfs_write_i0(inode, page, &wc);
1520 logfs_put_write_page(page);
1523 li->li_data[INDIRECT_INDEX] = wc.ofs;
1526 logfs_set_alias(inode->i_sb, li->li_block, INODE_HEIGHT_OFS);
1531 static int __logfs_write_buf(struct inode *inode, struct page *page, long flags)
1533 struct logfs_super *super = logfs_super(inode->i_sb);
1534 pgoff_t index = page->index;
1539 flags |= WF_WRITE | WF_DELETE;
1540 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
1542 logfs_unpack_index(index, &bix, &level);
1543 if (logfs_block(page) && logfs_block(page)->reserved_bytes)
1544 super->s_dirty_pages -= logfs_block(page)->reserved_bytes;
1546 if (index < I0_BLOCKS)
1547 return logfs_write_direct(inode, page, flags);
1549 bix = adjust_bix(bix, level);
1550 err = grow_inode(inode, bix, level);
1553 return logfs_write_rec(inode, page, bix, level, flags);
1556 int logfs_write_buf(struct inode *inode, struct page *page, long flags)
1558 struct super_block *sb = inode->i_sb;
1561 logfs_get_wblocks(sb, page, flags & WF_LOCK);
1562 ret = __logfs_write_buf(inode, page, flags);
1563 logfs_put_wblocks(sb, page, flags & WF_LOCK);
1567 static int __logfs_delete(struct inode *inode, struct page *page)
1569 long flags = WF_DELETE;
1571 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
1573 if (page->index < I0_BLOCKS)
1574 return logfs_write_direct(inode, page, flags);
1575 return logfs_write_rec(inode, page, page->index, 0, flags);
1578 int logfs_delete(struct inode *inode, pgoff_t index,
1579 struct shadow_tree *shadow_tree)
1581 struct super_block *sb = inode->i_sb;
1585 page = logfs_get_read_page(inode, index, 0);
1589 logfs_get_wblocks(sb, page, 1);
1590 ret = __logfs_delete(inode, page);
1591 logfs_put_wblocks(sb, page, 1);
1593 logfs_put_read_page(page);
1598 int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs,
1599 gc_level_t gc_level, long flags)
1601 level_t level = shrink_level(gc_level);
1605 page = logfs_get_write_page(inode, bix, level);
1609 err = logfs_segment_read(inode, page, ofs, bix, level);
1612 alloc_indirect_block(inode, page, 0);
1613 err = logfs_write_buf(inode, page, flags);
1614 if (!err && shrink_level(gc_level) == 0) {
1615 /* Rewrite cannot mark the inode dirty but has to
1616 * write it immediatly.
1617 * Q: Can't we just create an alias for the inode
1618 * instead? And if not, why not?
1620 if (inode->i_ino == LOGFS_INO_MASTER)
1621 logfs_write_anchor(inode->i_sb);
1623 err = __logfs_write_inode(inode, flags);
1627 logfs_put_write_page(page);
1631 static int truncate_data_block(struct inode *inode, struct page *page,
1632 u64 ofs, struct logfs_shadow *shadow, u64 size)
1634 loff_t pageofs = page->index << inode->i_sb->s_blocksize_bits;
1639 /* Does truncation happen within this page? */
1640 if (size <= pageofs || size - pageofs >= PAGE_SIZE)
1643 logfs_unpack_index(page->index, &bix, &level);
1646 err = logfs_segment_read(inode, page, ofs, bix, level);
1650 zero_user_segment(page, size - pageofs, PAGE_CACHE_SIZE);
1651 return logfs_segment_write(inode, page, shadow);
1654 static int logfs_truncate_i0(struct inode *inode, struct page *page,
1655 struct write_control *wc, u64 size)
1657 struct logfs_shadow *shadow;
1662 logfs_unpack_index(page->index, &bix, &level);
1664 shadow = alloc_shadow(inode, bix, level, wc->ofs);
1666 err = truncate_data_block(inode, page, wc->ofs, shadow, size);
1668 free_shadow(inode, shadow);
1672 logfs_segment_delete(inode, shadow);
1673 set_iused(inode, shadow);
1674 fill_shadow_tree(inode, page, shadow);
1675 wc->ofs = shadow->new_ofs;
1679 static int logfs_truncate_direct(struct inode *inode, u64 size)
1681 struct logfs_inode *li = logfs_inode(inode);
1682 struct write_control wc;
1687 alloc_inode_block(inode);
1689 for (e = I0_BLOCKS - 1; e >= 0; e--) {
1690 if (size > (e+1) * LOGFS_BLOCKSIZE)
1693 wc.ofs = li->li_data[e];
1697 page = logfs_get_write_page(inode, e, 0);
1700 err = logfs_segment_read(inode, page, wc.ofs, e, 0);
1702 logfs_put_write_page(page);
1705 err = logfs_truncate_i0(inode, page, &wc, size);
1706 logfs_put_write_page(page);
1710 li->li_data[e] = wc.ofs;
1715 /* FIXME: these need to become per-sb once we support different blocksizes */
1716 static u64 __logfs_step[] = {
1723 static u64 __logfs_start_index[] = {
1730 static inline u64 logfs_step(level_t level)
1732 return __logfs_step[(__force u8)level];
1735 static inline u64 logfs_factor(u8 level)
1737 return __logfs_step[level] * LOGFS_BLOCKSIZE;
1740 static inline u64 logfs_start_index(level_t level)
1742 return __logfs_start_index[(__force u8)level];
1745 static void logfs_unpack_raw_index(pgoff_t index, u64 *bix, level_t *level)
1747 logfs_unpack_index(index, bix, level);
1748 if (*bix <= logfs_start_index(SUBLEVEL(*level)))
1752 static int __logfs_truncate_rec(struct inode *inode, struct page *ipage,
1753 struct write_control *this_wc, u64 size)
1755 int truncate_happened = 0;
1757 u64 bix, child_bix, next_bix;
1760 struct write_control child_wc = { /* FIXME: flags */ };
1762 logfs_unpack_raw_index(ipage->index, &bix, &level);
1763 err = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level);
1767 for (e = LOGFS_BLOCK_FACTOR - 1; e >= 0; e--) {
1768 child_bix = bix + e * logfs_step(SUBLEVEL(level));
1769 next_bix = child_bix + logfs_step(SUBLEVEL(level));
1770 if (size > next_bix * LOGFS_BLOCKSIZE)
1773 child_wc.ofs = pure_ofs(block_get_pointer(ipage, e));
1777 page = logfs_get_write_page(inode, child_bix, SUBLEVEL(level));
1781 if ((__force u8)level > 1)
1782 err = __logfs_truncate_rec(inode, page, &child_wc, size);
1784 err = logfs_truncate_i0(inode, page, &child_wc, size);
1785 logfs_put_write_page(page);
1789 truncate_happened = 1;
1790 alloc_indirect_block(inode, ipage, 0);
1791 block_set_pointer(ipage, e, child_wc.ofs);
1794 if (!truncate_happened) {
1795 printk("ineffectual truncate (%lx, %lx, %llx)\n", inode->i_ino, ipage->index, size);
1799 this_wc->flags = WF_DELETE;
1800 if (logfs_block(ipage)->partial)
1801 this_wc->flags |= WF_WRITE;
1803 return logfs_write_i0(inode, ipage, this_wc);
1806 static int logfs_truncate_rec(struct inode *inode, u64 size)
1808 struct logfs_inode *li = logfs_inode(inode);
1809 struct write_control wc = {
1810 .ofs = li->li_data[INDIRECT_INDEX],
1815 alloc_inode_block(inode);
1820 page = logfs_get_write_page(inode, 0, LEVEL(li->li_height));
1824 err = __logfs_truncate_rec(inode, page, &wc, size);
1825 logfs_put_write_page(page);
1829 if (li->li_data[INDIRECT_INDEX] != wc.ofs)
1830 li->li_data[INDIRECT_INDEX] = wc.ofs;
1834 static int __logfs_truncate(struct inode *inode, u64 size)
1838 if (size >= logfs_factor(logfs_inode(inode)->li_height))
1841 ret = logfs_truncate_rec(inode, size);
1845 return logfs_truncate_direct(inode, size);
1848 int logfs_truncate(struct inode *inode, u64 size)
1850 struct super_block *sb = inode->i_sb;
1853 logfs_get_wblocks(sb, NULL, 1);
1854 err = __logfs_truncate(inode, size);
1856 err = __logfs_write_inode(inode, 0);
1857 logfs_put_wblocks(sb, NULL, 1);
1860 err = vmtruncate(inode, size);
1862 /* I don't trust error recovery yet. */
1867 static void move_page_to_inode(struct inode *inode, struct page *page)
1869 struct logfs_inode *li = logfs_inode(inode);
1870 struct logfs_block *block = logfs_block(page);
1875 log_blockmove("move_page_to_inode(%llx, %llx, %x)\n",
1876 block->ino, block->bix, block->level);
1877 BUG_ON(li->li_block);
1878 block->ops = &inode_block_ops;
1879 block->inode = inode;
1880 li->li_block = block;
1884 ClearPagePrivate(page);
1887 static void move_inode_to_page(struct page *page, struct inode *inode)
1889 struct logfs_inode *li = logfs_inode(inode);
1890 struct logfs_block *block = li->li_block;
1895 log_blockmove("move_inode_to_page(%llx, %llx, %x)\n",
1896 block->ino, block->bix, block->level);
1897 BUG_ON(PagePrivate(page));
1898 block->ops = &indirect_block_ops;
1900 page->private = (unsigned long)block;
1901 SetPagePrivate(page);
1903 block->inode = NULL;
1904 li->li_block = NULL;
1907 int logfs_read_inode(struct inode *inode)
1909 struct super_block *sb = inode->i_sb;
1910 struct logfs_super *super = logfs_super(sb);
1911 struct inode *master_inode = super->s_master_inode;
1913 struct logfs_disk_inode *di;
1914 u64 ino = inode->i_ino;
1916 if (ino << sb->s_blocksize_bits > i_size_read(master_inode))
1918 if (!logfs_exist_block(master_inode, ino))
1921 page = read_cache_page(master_inode->i_mapping, ino,
1922 (filler_t *)logfs_readpage, NULL);
1924 return PTR_ERR(page);
1926 di = kmap_atomic(page, KM_USER0);
1927 logfs_disk_to_inode(di, inode);
1928 kunmap_atomic(di, KM_USER0);
1929 move_page_to_inode(inode, page);
1930 page_cache_release(page);
1934 /* Caller must logfs_put_write_page(page); */
1935 static struct page *inode_to_page(struct inode *inode)
1937 struct inode *master_inode = logfs_super(inode->i_sb)->s_master_inode;
1938 struct logfs_disk_inode *di;
1941 BUG_ON(inode->i_ino == LOGFS_INO_MASTER);
1943 page = logfs_get_write_page(master_inode, inode->i_ino, 0);
1947 di = kmap_atomic(page, KM_USER0);
1948 logfs_inode_to_disk(inode, di);
1949 kunmap_atomic(di, KM_USER0);
1950 move_inode_to_page(page, inode);
1954 /* Cheaper version of write_inode. All changes are concealed in
1955 * aliases, which are moved back. No write to the medium happens.
1957 void logfs_clear_inode(struct inode *inode)
1959 struct super_block *sb = inode->i_sb;
1960 struct logfs_inode *li = logfs_inode(inode);
1961 struct logfs_block *block = li->li_block;
1964 /* Only deleted files may be dirty at this point */
1965 BUG_ON(inode->i_state & I_DIRTY && inode->i_nlink);
1968 if ((logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN)) {
1969 block->ops->free_block(inode->i_sb, block);
1973 BUG_ON(inode->i_ino < LOGFS_RESERVED_INOS);
1974 page = inode_to_page(inode);
1975 BUG_ON(!page); /* FIXME: Use emergency page */
1976 logfs_put_write_page(page);
1979 static int do_write_inode(struct inode *inode)
1981 struct super_block *sb = inode->i_sb;
1982 struct inode *master_inode = logfs_super(sb)->s_master_inode;
1983 loff_t size = (inode->i_ino + 1) << inode->i_sb->s_blocksize_bits;
1987 BUG_ON(inode->i_ino == LOGFS_INO_MASTER);
1988 /* FIXME: lock inode */
1990 if (i_size_read(master_inode) < size)
1991 i_size_write(master_inode, size);
1993 /* TODO: Tell vfs this inode is clean now */
1995 page = inode_to_page(inode);
1999 /* FIXME: transaction is part of logfs_block now. Is that enough? */
2000 err = logfs_write_buf(master_inode, page, 0);
2001 logfs_put_write_page(page);
2005 static void logfs_mod_segment_entry(struct super_block *sb, u32 segno,
2007 void (*change_se)(struct logfs_segment_entry *, long),
2010 struct logfs_super *super = logfs_super(sb);
2011 struct inode *inode;
2013 struct logfs_segment_entry *se;
2017 page_no = segno >> (sb->s_blocksize_bits - 3);
2018 child_no = segno & ((sb->s_blocksize >> 3) - 1);
2020 inode = super->s_segfile_inode;
2021 page = logfs_get_write_page(inode, page_no, 0);
2022 BUG_ON(!page); /* FIXME: We need some reserve page for this case */
2023 if (!PageUptodate(page))
2024 logfs_read_block(inode, page, WRITE);
2027 alloc_indirect_block(inode, page, 0);
2028 se = kmap_atomic(page, KM_USER0);
2029 change_se(se + child_no, arg);
2031 logfs_set_alias(sb, logfs_block(page), child_no);
2032 BUG_ON((int)be32_to_cpu(se[child_no].valid) > super->s_segsize);
2034 kunmap_atomic(se, KM_USER0);
2036 logfs_put_write_page(page);
2039 static void __get_segment_entry(struct logfs_segment_entry *se, long _target)
2041 struct logfs_segment_entry *target = (void *)_target;
2046 void logfs_get_segment_entry(struct super_block *sb, u32 segno,
2047 struct logfs_segment_entry *se)
2049 logfs_mod_segment_entry(sb, segno, 0, __get_segment_entry, (long)se);
2052 static void __set_segment_used(struct logfs_segment_entry *se, long increment)
2056 valid = be32_to_cpu(se->valid);
2058 se->valid = cpu_to_be32(valid);
2061 void logfs_set_segment_used(struct super_block *sb, u64 ofs, int increment)
2063 struct logfs_super *super = logfs_super(sb);
2064 u32 segno = ofs >> super->s_segshift;
2069 logfs_mod_segment_entry(sb, segno, 1, __set_segment_used, increment);
2072 static void __set_segment_erased(struct logfs_segment_entry *se, long ec_level)
2074 se->ec_level = cpu_to_be32(ec_level);
2077 void logfs_set_segment_erased(struct super_block *sb, u32 segno, u32 ec,
2078 gc_level_t gc_level)
2080 u32 ec_level = ec << 4 | (__force u8)gc_level;
2082 logfs_mod_segment_entry(sb, segno, 1, __set_segment_erased, ec_level);
2085 static void __set_segment_reserved(struct logfs_segment_entry *se, long ignore)
2087 se->valid = cpu_to_be32(RESERVED);
2090 void logfs_set_segment_reserved(struct super_block *sb, u32 segno)
2092 logfs_mod_segment_entry(sb, segno, 1, __set_segment_reserved, 0);
2095 static void __set_segment_unreserved(struct logfs_segment_entry *se,
2099 se->ec_level = cpu_to_be32(ec_level);
2102 void logfs_set_segment_unreserved(struct super_block *sb, u32 segno, u32 ec)
2104 u32 ec_level = ec << 4;
2106 logfs_mod_segment_entry(sb, segno, 1, __set_segment_unreserved,
2110 int __logfs_write_inode(struct inode *inode, long flags)
2112 struct super_block *sb = inode->i_sb;
2115 logfs_get_wblocks(sb, NULL, flags & WF_LOCK);
2116 ret = do_write_inode(inode);
2117 logfs_put_wblocks(sb, NULL, flags & WF_LOCK);
2121 static int do_delete_inode(struct inode *inode)
2123 struct super_block *sb = inode->i_sb;
2124 struct inode *master_inode = logfs_super(sb)->s_master_inode;
2128 page = logfs_get_write_page(master_inode, inode->i_ino, 0);
2132 move_inode_to_page(page, inode);
2134 logfs_get_wblocks(sb, page, 1);
2135 ret = __logfs_delete(master_inode, page);
2136 logfs_put_wblocks(sb, page, 1);
2138 logfs_put_write_page(page);
2143 * ZOMBIE inodes have already been deleted before and should remain dead,
2144 * if it weren't for valid checking. No need to kill them again here.
2146 void logfs_delete_inode(struct inode *inode)
2148 struct logfs_inode *li = logfs_inode(inode);
2150 if (!(li->li_flags & LOGFS_IF_ZOMBIE)) {
2151 li->li_flags |= LOGFS_IF_ZOMBIE;
2152 if (i_size_read(inode) > 0)
2153 logfs_truncate(inode, 0);
2154 do_delete_inode(inode);
2156 truncate_inode_pages(&inode->i_data, 0);
2160 void btree_write_block(struct logfs_block *block)
2162 struct inode *inode;
2166 inode = logfs_safe_iget(block->sb, block->ino, &cookie);
2167 page = logfs_get_write_page(inode, block->bix, block->level);
2169 err = logfs_readpage_nolock(page);
2171 BUG_ON(!PagePrivate(page));
2172 BUG_ON(logfs_block(page) != block);
2173 err = __logfs_write_buf(inode, page, 0);
2175 BUG_ON(PagePrivate(page) || page->private);
2177 logfs_put_write_page(page);
2178 logfs_safe_iput(inode, cookie);
2182 * logfs_inode_write - write inode or dentry objects
2184 * @inode: parent inode (ifile or directory)
2185 * @buf: object to write (inode or dentry)
2187 * @_pos: object number (file position in blocks/objects)
2188 * @flags: write flags
2189 * @lock: 0 if write lock is already taken, 1 otherwise
2190 * @shadow_tree: shadow below this inode
2192 * FIXME: All caller of this put a 200-300 byte variable on the stack,
2193 * only to call here and do a memcpy from that stack variable. A good
2194 * example of wasted performance and stack space.
2196 int logfs_inode_write(struct inode *inode, const void *buf, size_t count,
2197 loff_t bix, long flags, struct shadow_tree *shadow_tree)
2199 loff_t pos = bix << inode->i_sb->s_blocksize_bits;
2204 BUG_ON(pos & (LOGFS_BLOCKSIZE-1));
2205 BUG_ON(count > LOGFS_BLOCKSIZE);
2206 page = logfs_get_write_page(inode, bix, 0);
2210 pagebuf = kmap_atomic(page, KM_USER0);
2211 memcpy(pagebuf, buf, count);
2212 flush_dcache_page(page);
2213 kunmap_atomic(pagebuf, KM_USER0);
2215 if (i_size_read(inode) < pos + LOGFS_BLOCKSIZE)
2216 i_size_write(inode, pos + LOGFS_BLOCKSIZE);
2218 err = logfs_write_buf(inode, page, flags);
2219 logfs_put_write_page(page);
2223 int logfs_open_segfile(struct super_block *sb)
2225 struct logfs_super *super = logfs_super(sb);
2226 struct inode *inode;
2228 inode = logfs_read_meta_inode(sb, LOGFS_INO_SEGFILE);
2230 return PTR_ERR(inode);
2231 super->s_segfile_inode = inode;
2235 int logfs_init_rw(struct super_block *sb)
2237 struct logfs_super *super = logfs_super(sb);
2238 int min_fill = 3 * super->s_no_blocks;
2240 INIT_LIST_HEAD(&super->s_object_alias);
2241 mutex_init(&super->s_write_mutex);
2242 super->s_block_pool = mempool_create_kmalloc_pool(min_fill,
2243 sizeof(struct logfs_block));
2244 super->s_shadow_pool = mempool_create_kmalloc_pool(min_fill,
2245 sizeof(struct logfs_shadow));
2249 void logfs_cleanup_rw(struct super_block *sb)
2251 struct logfs_super *super = logfs_super(sb);
2253 destroy_meta_inode(super->s_segfile_inode);
2254 if (super->s_block_pool)
2255 mempool_destroy(super->s_block_pool);
2256 if (super->s_shadow_pool)
2257 mempool_destroy(super->s_shadow_pool);