/* * fs/logfs/readwrite.c * * As should be obvious for Linux kernel code, license is GPLv2 * * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> * * * Actually contains five sets of very similar functions: * read read blocks from a file * seek_hole find next hole * seek_data find next data block * valid check whether a block still belongs to a file * write write blocks to a file * delete delete a block (for directories and ifile) * rewrite move existing blocks of a file to a new location (gc helper) * truncate truncate a file */ #include "logfs.h" #include <linux/sched.h> #include <linux/slab.h> static u64 adjust_bix(u64 bix, level_t level) { switch (level) { case 0: return bix; case LEVEL(1): return max_t(u64, bix, I0_BLOCKS); case LEVEL(2): return max_t(u64, bix, I1_BLOCKS); case LEVEL(3): return max_t(u64, bix, I2_BLOCKS); case LEVEL(4): return max_t(u64, bix, I3_BLOCKS); case LEVEL(5): return max_t(u64, bix, I4_BLOCKS); default: WARN_ON(1); return bix; } } static inline u64 maxbix(u8 height) { return 1ULL << (LOGFS_BLOCK_BITS * height); } /** * The inode address space is cut in two halves. Lower half belongs to data * pages, upper half to indirect blocks. If the high bit (INDIRECT_BIT) is * set, the actual block index (bix) and level can be derived from the page * index. * * The lowest three bits of the block index are set to 0 after packing and * unpacking. Since the lowest n bits (9 for 4KiB blocksize) are ignored * anyway this is harmless. */ #define ARCH_SHIFT (BITS_PER_LONG - 32) #define INDIRECT_BIT (0x80000000UL << ARCH_SHIFT) #define LEVEL_SHIFT (28 + ARCH_SHIFT) static inline pgoff_t first_indirect_block(void) { return INDIRECT_BIT | (1ULL << LEVEL_SHIFT); } pgoff_t logfs_pack_index(u64 bix, level_t level) { pgoff_t index; BUG_ON(bix >= INDIRECT_BIT); if (level == 0) return bix; index = INDIRECT_BIT; index |= (__force long)level << LEVEL_SHIFT; index |= bix >> ((__force u8)level * LOGFS_BLOCK_BITS); return index; } void logfs_unpack_index(pgoff_t index, u64 *bix, level_t *level) { u8 __level; if (!(index & INDIRECT_BIT)) { *bix = index; *level = 0; return; } __level = (index & ~INDIRECT_BIT) >> LEVEL_SHIFT; *level = LEVEL(__level); *bix = (index << (__level * LOGFS_BLOCK_BITS)) & ~INDIRECT_BIT; *bix = adjust_bix(*bix, *level); return; } #undef ARCH_SHIFT #undef INDIRECT_BIT #undef LEVEL_SHIFT /* * Time is stored as nanoseconds since the epoch. */ static struct timespec be64_to_timespec(__be64 betime) { return ns_to_timespec(be64_to_cpu(betime)); } static __be64 timespec_to_be64(struct timespec tsp) { return cpu_to_be64((u64)tsp.tv_sec * NSEC_PER_SEC + tsp.tv_nsec); } static void logfs_disk_to_inode(struct logfs_disk_inode *di, struct inode*inode) { struct logfs_inode *li = logfs_inode(inode); int i; inode->i_mode = be16_to_cpu(di->di_mode); li->li_height = di->di_height; li->li_flags = be32_to_cpu(di->di_flags); inode->i_uid = be32_to_cpu(di->di_uid); inode->i_gid = be32_to_cpu(di->di_gid); inode->i_size = be64_to_cpu(di->di_size); logfs_set_blocks(inode, be64_to_cpu(di->di_used_bytes)); inode->i_atime = be64_to_timespec(di->di_atime); inode->i_ctime = be64_to_timespec(di->di_ctime); inode->i_mtime = be64_to_timespec(di->di_mtime); set_nlink(inode, be32_to_cpu(di->di_refcount)); inode->i_generation = be32_to_cpu(di->di_generation); switch (inode->i_mode & S_IFMT) { case S_IFSOCK: /* fall through */ case S_IFBLK: /* fall through */ case S_IFCHR: /* fall through */ case S_IFIFO: inode->i_rdev = be64_to_cpu(di->di_data[0]); break; case S_IFDIR: /* fall through */ case S_IFREG: /* fall through */ case S_IFLNK: for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++) li->li_data[i] = be64_to_cpu(di->di_data[i]); break; default: BUG(); } } static void logfs_inode_to_disk(struct inode *inode, struct logfs_disk_inode*di) { struct logfs_inode *li = logfs_inode(inode); int i; di->di_mode = cpu_to_be16(inode->i_mode); di->di_height = li->li_height; di->di_pad = 0; di->di_flags = cpu_to_be32(li->li_flags); di->di_uid = cpu_to_be32(inode->i_uid); di->di_gid = cpu_to_be32(inode->i_gid); di->di_size = cpu_to_be64(i_size_read(inode)); di->di_used_bytes = cpu_to_be64(li->li_used_bytes); di->di_atime = timespec_to_be64(inode->i_atime); di->di_ctime = timespec_to_be64(inode->i_ctime); di->di_mtime = timespec_to_be64(inode->i_mtime); di->di_refcount = cpu_to_be32(inode->i_nlink); di->di_generation = cpu_to_be32(inode->i_generation); switch (inode->i_mode & S_IFMT) { case S_IFSOCK: /* fall through */ case S_IFBLK: /* fall through */ case S_IFCHR: /* fall through */ case S_IFIFO: di->di_data[0] = cpu_to_be64(inode->i_rdev); break; case S_IFDIR: /* fall through */ case S_IFREG: /* fall through */ case S_IFLNK: for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++) di->di_data[i] = cpu_to_be64(li->li_data[i]); break; default: BUG(); } } static void __logfs_set_blocks(struct inode *inode) { struct super_block *sb = inode->i_sb; struct logfs_inode *li = logfs_inode(inode); inode->i_blocks = ULONG_MAX; if (li->li_used_bytes >> sb->s_blocksize_bits < ULONG_MAX) inode->i_blocks = ALIGN(li->li_used_bytes, 512) >> 9; } void logfs_set_blocks(struct inode *inode, u64 bytes) { struct logfs_inode *li = logfs_inode(inode); li->li_used_bytes = bytes; __logfs_set_blocks(inode); } static void prelock_page(struct super_block *sb, struct page *page, int lock) { struct logfs_super *super = logfs_super(sb); BUG_ON(!PageLocked(page)); if (lock) { BUG_ON(PagePreLocked(page)); SetPagePreLocked(page); } else { /* We are in GC path. */ if (PagePreLocked(page)) super->s_lock_count++; else SetPagePreLocked(page); } } static void preunlock_page(struct super_block *sb, struct page *page, int lock) { struct logfs_super *super = logfs_super(sb); BUG_ON(!PageLocked(page)); if (lock) ClearPagePreLocked(page); else { /* We are in GC path. */ BUG_ON(!PagePreLocked(page)); if (super->s_lock_count) super->s_lock_count--; else ClearPagePreLocked(page); } } /* * Logfs is prone to an AB-BA deadlock where one task tries to acquire * s_write_mutex with a locked page and GC tries to get that page while holding * s_write_mutex. * To solve this issue logfs will ignore the page lock iff the page in question * is waiting for s_write_mutex. We annotate this fact by setting PG_pre_locked * in addition to PG_locked. */ void logfs_get_wblocks(struct super_block *sb, struct page *page, int lock) { struct logfs_super *super = logfs_super(sb); if (page) prelock_page(sb, page, lock); if (lock) { mutex_lock(&super->s_write_mutex); logfs_gc_pass(sb); /* FIXME: We also have to check for shadowed space * and mempool fill grade */ } } void logfs_put_wblocks(struct super_block *sb, struct page *page, int lock) { struct logfs_super *super = logfs_super(sb); if (page) preunlock_page(sb, page, lock); /* Order matters - we must clear PG_pre_locked before releasing * s_write_mutex or we could race against another task. */ if (lock) mutex_unlock(&super->s_write_mutex); } static struct page *logfs_get_read_page(struct inode *inode, u64 bix, level_t level) { return find_or_create_page(inode->i_mapping, logfs_pack_index(bix, level), GFP_NOFS); } static void logfs_put_read_page(struct page *page) { unlock_page(page); page_cache_release(page); } static void logfs_lock_write_page(struct page *page) { int loop = 0; while (unlikely(!trylock_page(page))) { if (loop++ > 0x1000) { /* Has been observed once so far... */ printk(KERN_ERR "stack at %p\n", &loop); BUG(); } if (PagePreLocked(page)) { /* Holder of page lock is waiting for us, it * is safe to use this page. */ break; } /* Some other process has this page locked and has * nothing to do with us. Wait for it to finish. */ schedule(); } BUG_ON(!PageLocked(page)); } static struct page *logfs_get_write_page(struct inode *inode, u64 bix, level_t level) { struct address_space *mapping = inode->i_mapping; pgoff_t index = logfs_pack_index(bix, level); struct page *page; int err; repeat: page = find_get_page(mapping, index); if (!page) { page = __page_cache_alloc(GFP_NOFS); if (!page) return NULL; err = add_to_page_cache_lru(page, mapping, index, GFP_NOFS); if (unlikely(err)) { page_cache_release(page); if (err == -EEXIST) goto repeat; return NULL; } } else logfs_lock_write_page(page); BUG_ON(!PageLocked(page)); return page; } static void logfs_unlock_write_page(struct page *page) { if (!PagePreLocked(page)) unlock_page(page); } static void logfs_put_write_page(struct page *page) { logfs_unlock_write_page(page); page_cache_release(page); } static struct page *logfs_get_page(struct inode *inode, u64 bix, level_t level, int rw) { if (rw == READ) return logfs_get_read_page(inode, bix, level); else return logfs_get_write_page(inode, bix, level); } static void logfs_put_page(struct page *page, int rw) { if (rw == READ) logfs_put_read_page(page); else logfs_put_write_page(page); } static unsigned long __get_bits(u64 val, int skip, int no) { u64 ret = val; ret >>= skip * no; ret <<= 64 - no; ret >>= 64 - no; return ret; } static unsigned long get_bits(u64 val, level_t skip) { return __get_bits(val, (__force int)skip, LOGFS_BLOCK_BITS); } static inline void init_shadow_tree(struct super_block *sb, struct shadow_tree *tree) { struct logfs_super *super = logfs_super(sb); btree_init_mempool64(&tree->new, super->s_btree_pool); btree_init_mempool64(&tree->old, super->s_btree_pool); } static void indirect_write_block(struct logfs_block *block) { struct page *page; struct inode *inode; int ret; page = block->page; inode = page->mapping->host; logfs_lock_write_page(page); ret = logfs_write_buf(inode, page, 0); logfs_unlock_write_page(page); /* * This needs some rework. Unless you want your filesystem to run * completely synchronously (you don't), the filesystem will always * report writes as 'successful' before the actual work has been * done. The actual work gets done here and this is where any errors * will show up. And there isn't much we can do about it, really. * * Some attempts to fix the errors (move from bad blocks, retry io,...) * have already been done, so anything left should be either a broken * device or a bug somewhere in logfs itself. Being relatively new, * the odds currently favor a bug, so for now the line below isn't * entirely tasteles. */ BUG_ON(ret); } static void inode_write_block(struct logfs_block *block) { struct inode *inode; int ret; inode = block->inode; if (inode->i_ino == LOGFS_INO_MASTER) logfs_write_anchor(inode->i_sb); else { ret = __logfs_write_inode(inode, NULL, 0); /* see indirect_write_block comment */ BUG_ON(ret); } } /* * This silences a false, yet annoying gcc warning. I hate it when my editor * jumps into bitops.h each time I recompile this file. * TODO: Complain to gcc folks about this and upgrade compiler. */ static unsigned long fnb(const unsigned long *addr, unsigned long size, unsigned long offset) { return find_next_bit(addr, size, offset); } static __be64 inode_val0(struct inode *inode) { struct logfs_inode *li = logfs_inode(inode); u64 val; /* * Explicit shifting generates good code, but must match the format * of the structure. Add some paranoia just in case. */ BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_mode) != 0); BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_height) != 2); BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_flags) != 4); val = (u64)inode->i_mode << 48 | (u64)li->li_height << 40 | (u64)li->li_flags; return cpu_to_be64(val); } static int inode_write_alias(struct super_block *sb, struct logfs_block *block, write_alias_t *write_one_alias) { struct inode *inode = block->inode; struct logfs_inode *li = logfs_inode(inode); unsigned long pos; u64 ino , bix; __be64 val; level_t level; int err; for (pos = 0; ; pos++) { pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos); if (pos >= LOGFS_EMBEDDED_FIELDS + INODE_POINTER_OFS) return 0; switch (pos) { case INODE_HEIGHT_OFS: val = inode_val0(inode); break; case INODE_USED_OFS: val = cpu_to_be64(li->li_used_bytes); break; case INODE_SIZE_OFS: val = cpu_to_be64(i_size_read(inode)); break; case INODE_POINTER_OFS ... INODE_POINTER_OFS + LOGFS_EMBEDDED_FIELDS - 1: val = cpu_to_be64(li->li_data[pos - INODE_POINTER_OFS]); break; default: BUG(); } ino = LOGFS_INO_MASTER; bix = inode->i_ino; level = LEVEL(0); err = write_one_alias(sb, ino, bix, level, pos, val); if (err) return err; } } static int indirect_write_alias(struct super_block *sb, struct logfs_block *block, write_alias_t *write_one_alias) { unsigned long pos; struct page *page = block->page; u64 ino , bix; __be64 *child, val; level_t level; int err; for (pos = 0; ; pos++) { pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos); if (pos >= LOGFS_BLOCK_FACTOR) return 0; ino = page->mapping->host->i_ino; logfs_unpack_index(page->index, &bix, &level); child = kmap_atomic(page); val = child[pos]; kunmap_atomic(child); err = write_one_alias(sb, ino, bix, level, pos, val); if (err) return err; } } int logfs_write_obj_aliases_pagecache(struct super_block *sb) { struct logfs_super *super = logfs_super(sb); struct logfs_block *block; int err; list_for_each_entry(block, &super->s_object_alias, alias_list) { err = block->ops->write_alias(sb, block, write_alias_journal); if (err) return err; } return 0; } void __free_block(struct super_block *sb, struct logfs_block *block) { BUG_ON(!list_empty(&block->item_list)); list_del(&block->alias_list); mempool_free(block, logfs_super(sb)->s_block_pool); } static void inode_free_block(struct super_block *sb, struct logfs_block *block) { struct inode *inode = block->inode; logfs_inode(inode)->li_block = NULL; __free_block(sb, block); } static void indirect_free_block(struct super_block *sb, struct logfs_block *block) { struct page *page = block->page; if (PagePrivate(page)) { ClearPagePrivate(page); page_cache_release(page); set_page_private(page, 0); } __free_block(sb, block); } static struct logfs_block_ops inode_block_ops = { .write_block = inode_write_block, .free_block = inode_free_block, .write_alias = inode_write_alias, }; struct logfs_block_ops indirect_block_ops = { .write_block = indirect_write_block, .free_block = indirect_free_block, .write_alias = indirect_write_alias, }; struct logfs_block *__alloc_block(struct super_block *sb, u64 ino, u64 bix, level_t level) { struct logfs_super *super = logfs_super(sb); struct logfs_block *block; block = mempool_alloc(super->s_block_pool, GFP_NOFS); memset(block, 0, sizeof(*block)); INIT_LIST_HEAD(&block->alias_list); INIT_LIST_HEAD(&block->item_list); block->sb = sb; block->ino = ino; block->bix = bix; block->level = level; return block; } static void alloc_inode_block(struct inode *inode) { struct logfs_inode *li = logfs_inode(inode); struct logfs_block *block; if (li->li_block) return; block = __alloc_block(inode->i_sb, LOGFS_INO_MASTER, inode->i_ino, 0); block->inode = inode; li->li_block = block; block->ops = &inode_block_ops; } void initialize_block_counters(struct page *page, struct logfs_block *block, __be64 *array, int page_is_empty) { u64 ptr; int i, start; block->partial = 0; block->full = 0; start = 0; if (page->index < first_indirect_block()) { /* Counters are pointless on level 0 */ return; } if (page->index == first_indirect_block()) { /* Skip unused pointers */ start = I0_BLOCKS; block->full = I0_BLOCKS; } if (!page_is_empty) { for (i = start; i < LOGFS_BLOCK_FACTOR; i++) { ptr = be64_to_cpu(array[i]); if (ptr) block->partial++; if (ptr & LOGFS_FULLY_POPULATED) block->full++; } } } static void alloc_data_block(struct inode *inode, struct page *page) { struct logfs_block *block; u64 bix; level_t level; if (PagePrivate(page)) return; logfs_unpack_index(page->index, &bix, &level); block = __alloc_block(inode->i_sb, inode->i_ino, bix, level); block->page = page; SetPagePrivate(page); page_cache_get(page); set_page_private(page, (unsigned long) block); block->ops = &indirect_block_ops; } static void alloc_indirect_block(struct inode *inode, struct page *page, int page_is_empty) { struct logfs_block *block; __be64 *array; if (PagePrivate(page)) return; alloc_data_block(inode, page); block = logfs_block(page); array = kmap_atomic(page); initialize_block_counters(page, block, array, page_is_empty); kunmap_atomic(array); } static void block_set_pointer(struct page *page, int index, u64 ptr) { struct logfs_block *block = logfs_block(page); __be64 *array; u64 oldptr; BUG_ON(!block); array = kmap_atomic(page); oldptr = be64_to_cpu(array[index]); array[index] = cpu_to_be64(ptr); kunmap_atomic(array); SetPageUptodate(page); block->full += !!(ptr & LOGFS_FULLY_POPULATED) - !!(oldptr & LOGFS_FULLY_POPULATED); block->partial += !!ptr - !!oldptr; } static u64 block_get_pointer(struct page *page, int index) { __be64 *block; u64 ptr; block = kmap_atomic(page); ptr = be64_to_cpu(block[index]); kunmap_atomic(block); return ptr; } static int logfs_read_empty(struct page *page) { zero_user_segment(page, 0, PAGE_CACHE_SIZE); return 0; } static int logfs_read_direct(struct inode *inode, struct page *page) { struct logfs_inode *li = logfs_inode(inode); pgoff_t index = page->index; u64 block; block = li->li_data[index]; if (!block) return logfs_read_empty(page); return logfs_segment_read(inode, page, block, index, 0); } static int logfs_read_loop(struct inode *inode, struct page *page, int rw_context) { struct logfs_inode *li = logfs_inode(inode); u64 bix, bofs = li->li_data[INDIRECT_INDEX]; level_t level, target_level; int ret; struct page *ipage; logfs_unpack_index(page->index, &bix, &target_level); if (!bofs) return logfs_read_empty(page); if (bix >= maxbix(li->li_height)) return logfs_read_empty(page); for (level = LEVEL(li->li_height); (__force u8)level > (__force u8)target_level; level = SUBLEVEL(level)){ ipage = logfs_get_page(inode, bix, level, rw_context); if (!ipage) return -ENOMEM; ret = logfs_segment_read(inode, ipage, bofs, bix, level); if (ret) { logfs_put_read_page(ipage); return ret; } bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level))); logfs_put_page(ipage, rw_context); if (!bofs) return logfs_read_empty(page); } return logfs_segment_read(inode, page, bofs, bix, 0); } static int logfs_read_block(struct inode *inode, struct page *page, int rw_context) { pgoff_t index = page->index; if (index < I0_BLOCKS) return logfs_read_direct(inode, page); return logfs_read_loop(inode, page, rw_context); } static int logfs_exist_loop(struct inode *inode, u64 bix) { struct logfs_inode *li = logfs_inode(inode); u64 bofs = li->li_data[INDIRECT_INDEX]; level_t level; int ret; struct page *ipage; if (!bofs) return 0; if (bix >= maxbix(li->li_height)) return 0; for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) { ipage = logfs_get_read_page(inode, bix, level); if (!ipage) return -ENOMEM; ret = logfs_segment_read(inode, ipage, bofs, bix, level); if (ret) { logfs_put_read_page(ipage); return ret; } bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level))); logfs_put_read_page(ipage); if (!bofs) return 0; } return 1; } int logfs_exist_block(struct inode *inode, u64 bix) { struct logfs_inode *li = logfs_inode(inode); if (bix < I0_BLOCKS) return !!li->li_data[bix]; return logfs_exist_loop(inode, bix); } static u64 seek_holedata_direct(struct inode *inode, u64 bix, int data) { struct logfs_inode *li = logfs_inode(inode); for (; bix < I0_BLOCKS; bix++) if (data ^ (li->li_data[bix] == 0)) return bix; return I0_BLOCKS; } static u64 seek_holedata_loop(struct inode *inode, u64 bix, int data) { struct logfs_inode *li = logfs_inode(inode); __be64 *rblock; u64 increment, bofs = li->li_data[INDIRECT_INDEX]; level_t level; int ret, slot; struct page *page; BUG_ON(!bofs); for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) { increment = 1 << (LOGFS_BLOCK_BITS * ((__force u8)level-1)); page = logfs_get_read_page(inode, bix, level); if (!page) return bix; ret = logfs_segment_read(inode, page, bofs, bix, level); if (ret) { logfs_put_read_page(page); return bix; } slot = get_bits(bix, SUBLEVEL(level)); rblock = kmap_atomic(page); while (slot < LOGFS_BLOCK_FACTOR) { if (data && (rblock[slot] != 0)) break; if (!data && !(be64_to_cpu(rblock[slot]) & LOGFS_FULLY_POPULATED)) break; slot++; bix += increment; bix &= ~(increment - 1); } if (slot >= LOGFS_BLOCK_FACTOR) { kunmap_atomic(rblock); logfs_put_read_page(page); return bix; } bofs = be64_to_cpu(rblock[slot]); kunmap_atomic(rblock); logfs_put_read_page(page); if (!bofs) { BUG_ON(data); return bix; } } return bix; } /** * logfs_seek_hole - find next hole starting at a given block index * @inode: inode to search in * @bix: block index to start searching * * Returns next hole. If the file doesn't contain any further holes, the * block address next to eof is returned instead. */ u64 logfs_seek_hole(struct inode *inode, u64 bix) { struct logfs_inode *li = logfs_inode(inode); if (bix < I0_BLOCKS) { bix = seek_holedata_direct(inode, bix, 0); if (bix < I0_BLOCKS) return bix; } if (!li->li_data[INDIRECT_INDEX]) return bix; else if (li->li_data[INDIRECT_INDEX] & LOGFS_FULLY_POPULATED) bix = maxbix(li->li_height); else if (bix >= maxbix(li->li_height)) return bix; else { bix = seek_holedata_loop(inode, bix, 0); if (bix < maxbix(li->li_height)) return bix; /* Should not happen anymore. But if some port writes semi- * corrupt images (as this one used to) we might run into it. */ WARN_ON_ONCE(bix == maxbix(li->li_height)); } return bix; } static u64 __logfs_seek_data(struct inode *inode, u64 bix) { struct logfs_inode *li = logfs_inode(inode); if (bix < I0_BLOCKS) { bix = seek_holedata_direct(inode, bix, 1); if (bix < I0_BLOCKS) return bix; } if (bix < maxbix(li->li_height)) { if (!li->li_data[INDIRECT_INDEX]) bix = maxbix(li->li_height); else return seek_holedata_loop(inode, bix, 1); } return bix; } /** * logfs_seek_data - find next data block after a given block index * @inode: inode to search in * @bix: block index to start searching * * Returns next data block. If the file doesn't contain any further data * blocks, the last block in the file is returned instead. */ u64 logfs_seek_data(struct inode *inode, u64 bix) { struct super_block *sb = inode->i_sb; u64 ret, end; ret = __logfs_seek_data(inode, bix); end = i_size_read(inode) >> sb->s_blocksize_bits; if (ret >= end) ret = max(bix, end); return ret; } static int logfs_is_valid_direct(struct logfs_inode *li, u64 bix, u64 ofs) { return pure_ofs(li->li_data[bix]) == ofs; } static int __logfs_is_valid_loop(struct inode *inode, u64 bix, u64 ofs, u64 bofs) { struct logfs_inode *li = logfs_inode(inode); level_t level; int ret; struct page *page; for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)){ page = logfs_get_write_page(inode, bix, level); BUG_ON(!page); ret = logfs_segment_read(inode, page, bofs, bix, level); if (ret) { logfs_put_write_page(page); return 0; } bofs = block_get_pointer(page, get_bits(bix, SUBLEVEL(level))); logfs_put_write_page(page); if (!bofs) return 0; if (pure_ofs(bofs) == ofs) return 1; } return 0; } static int logfs_is_valid_loop(struct inode *inode, u64 bix, u64 ofs) { struct logfs_inode *li = logfs_inode(inode); u64 bofs = li->li_data[INDIRECT_INDEX]; if (!bofs) return 0; if (bix >= maxbix(li->li_height)) return 0; if (pure_ofs(bofs) == ofs) return 1; return __logfs_is_valid_loop(inode, bix, ofs, bofs); } static int __logfs_is_valid_block(struct inode *inode, u64 bix, u64 ofs) { struct logfs_inode *li = logfs_inode(inode); if ((inode->i_nlink == 0) && atomic_read(&inode->i_count) == 1) return 0; if (bix < I0_BLOCKS) return logfs_is_valid_direct(li, bix, ofs); return logfs_is_valid_loop(inode, bix, ofs); } /** * logfs_is_valid_block - check whether this block is still valid * * @sb - superblock * @ofs - block physical offset * @ino - block inode number * @bix - block index * @level - block level * * Returns 0 if the block is invalid, 1 if it is valid and 2 if it will * become invalid once the journal is written. */ int logfs_is_valid_block(struct super_block *sb, u64 ofs, u64 ino, u64 bix, gc_level_t gc_level) { struct logfs_super *super = logfs_super(sb); struct inode *inode; int ret, cookie; /* Umount closes a segment with free blocks remaining. Those * blocks are by definition invalid. */ if (ino == -1) return 0; LOGFS_BUG_ON((u64)(u_long)ino != ino, sb); inode = logfs_safe_iget(sb, ino, &cookie); if (IS_ERR(inode)) goto invalid; ret = __logfs_is_valid_block(inode, bix, ofs); logfs_safe_iput(inode, cookie); if (ret) return ret; invalid: /* Block is nominally invalid, but may still sit in the shadow tree, * waiting for a journal commit. */ if (btree_lookup64(&super->s_shadow_tree.old, ofs)) return 2; return 0; } int logfs_readpage_nolock(struct page *page) { struct inode *inode = page->mapping->host; int ret = -EIO; ret = logfs_read_block(inode, page, READ); if (ret) { ClearPageUptodate(page); SetPageError(page); } else { SetPageUptodate(page); ClearPageError(page); } flush_dcache_page(page); return ret; } static int logfs_reserve_bytes(struct inode *inode, int bytes) { struct logfs_super *super = logfs_super(inode->i_sb); u64 available = super->s_free_bytes + super->s_dirty_free_bytes - super->s_dirty_used_bytes - super->s_dirty_pages; if (!bytes) return 0; if (available < bytes) return -ENOSPC; if (available < bytes + super->s_root_reserve && !capable(CAP_SYS_RESOURCE)) return -ENOSPC; return 0; } int get_page_reserve(struct inode *inode, struct page *page) { struct logfs_super *super = logfs_super(inode->i_sb); struct logfs_block *block = logfs_block(page); int ret; if (block && block->reserved_bytes) return 0; logfs_get_wblocks(inode->i_sb, page, WF_LOCK); while ((ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE)) && !list_empty(&super->s_writeback_list)) { block = list_entry(super->s_writeback_list.next, struct logfs_block, alias_list); block->ops->write_block(block); } if (!ret) { alloc_data_block(inode, page); block = logfs_block(page); block->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE; super->s_dirty_pages += 6 * LOGFS_MAX_OBJECTSIZE; list_move_tail(&block->alias_list, &super->s_writeback_list); } logfs_put_wblocks(inode->i_sb, page, WF_LOCK); return ret; } /* * We are protected by write lock. Push victims up to superblock level * and release transaction when appropriate. */ /* FIXME: This is currently called from the wrong spots. */ static void logfs_handle_transaction(struct inode *inode, struct logfs_transaction *ta) { struct logfs_super *super = logfs_super(inode->i_sb); if (!ta) return; logfs_inode(inode)->li_block->ta = NULL; if (inode->i_ino != LOGFS_INO_MASTER) { BUG(); /* FIXME: Yes, this needs more thought */ /* just remember the transaction until inode is written */ //BUG_ON(logfs_inode(inode)->li_transaction); //logfs_inode(inode)->li_transaction = ta; return; } switch (ta->state) { case CREATE_1: /* fall through */ case UNLINK_1: BUG_ON(super->s_victim_ino); super->s_victim_ino = ta->ino; break; case CREATE_2: /* fall through */ case UNLINK_2: BUG_ON(super->s_victim_ino != ta->ino); super->s_victim_ino = 0; /* transaction ends here - free it */ kfree(ta); break; case CROSS_RENAME_1: BUG_ON(super->s_rename_dir); BUG_ON(super->s_rename_pos); super->s_rename_dir = ta->dir; super->s_rename_pos = ta->pos; break; case CROSS_RENAME_2: BUG_ON(super->s_rename_dir != ta->dir); BUG_ON(super->s_rename_pos != ta->pos); super->s_rename_dir = 0; super->s_rename_pos = 0; kfree(ta); break; case TARGET_RENAME_1: BUG_ON(super->s_rename_dir); BUG_ON(super->s_rename_pos); BUG_ON(super->s_victim_ino); super->s_rename_dir = ta->dir; super->s_rename_pos = ta->pos; super->s_victim_ino = ta->ino; break; case TARGET_RENAME_2: BUG_ON(super->s_rename_dir != ta->dir); BUG_ON(super->s_rename_pos != ta->pos); BUG_ON(super->s_victim_ino != ta->ino); super->s_rename_dir = 0; super->s_rename_pos = 0; break; case TARGET_RENAME_3: BUG_ON(super->s_rename_dir); BUG_ON(super->s_rename_pos); BUG_ON(super->s_victim_ino != ta->ino); super->s_victim_ino = 0; kfree(ta); break; default: BUG(); } } /* * Not strictly a reservation, but rather a check that we still have enough * space to satisfy the write. */ static int logfs_reserve_blocks(struct inode *inode, int blocks) { return logfs_reserve_bytes(inode, blocks * LOGFS_MAX_OBJECTSIZE); } struct write_control { u64 ofs; long flags; }; static struct logfs_shadow *alloc_shadow(struct inode *inode, u64 bix, level_t level, u64 old_ofs) { struct logfs_super *super = logfs_super(inode->i_sb); struct logfs_shadow *shadow; shadow = mempool_alloc(super->s_shadow_pool, GFP_NOFS); memset(shadow, 0, sizeof(*shadow)); shadow->ino = inode->i_ino; shadow->bix = bix; shadow->gc_level = expand_level(inode->i_ino, level); shadow->old_ofs = old_ofs & ~LOGFS_FULLY_POPULATED; return shadow; } static void free_shadow(struct inode *inode, struct logfs_shadow *shadow) { struct logfs_super *super = logfs_super(inode->i_sb); mempool_free(shadow, super->s_shadow_pool); } static void mark_segment(struct shadow_tree *tree, u32 segno) { int err; if (!btree_lookup32(&tree->segment_map, segno)) { err = btree_insert32(&tree->segment_map, segno, (void *)1, GFP_NOFS); BUG_ON(err); tree->no_shadowed_segments++; } } /** * fill_shadow_tree - Propagate shadow tree changes due to a write * @inode: Inode owning the page * @page: Struct page that was written * @shadow: Shadow for the current write * * Writes in logfs can result in two semi-valid objects. The old object * is still valid as long as it can be reached by following pointers on * the medium. Only when writes propagate all the way up to the journal * has the new object safely replaced the old one. * * To handle this problem, a struct logfs_shadow is used to represent * every single write. It is attached to the indirect block, which is * marked dirty. When the indirect block is written, its shadows are * handed up to the next indirect block (or inode). Untimately they * will reach the master inode and be freed upon journal commit. * * This function handles a single step in the propagation. It adds the * shadow for the current write to the tree, along with any shadows in * the page's tree, in case it was an indirect block. If a page is * written, the inode parameter is left NULL, if an inode is written, * the page parameter is left NULL. */ static void fill_shadow_tree(struct inode *inode, struct page *page, struct logfs_shadow *shadow) { struct logfs_super *super = logfs_super(inode->i_sb); struct logfs_block *block = logfs_block(page); struct shadow_tree *tree = &super->s_shadow_tree; if (PagePrivate(page)) { if (block->alias_map) super->s_no_object_aliases -= bitmap_weight( block->alias_map, LOGFS_BLOCK_FACTOR); logfs_handle_transaction(inode, block->ta); block->ops->free_block(inode->i_sb, block); } if (shadow) { if (shadow->old_ofs) btree_insert64(&tree->old, shadow->old_ofs, shadow, GFP_NOFS); else btree_insert64(&tree->new, shadow->new_ofs, shadow, GFP_NOFS); super->s_dirty_used_bytes += shadow->new_len; super->s_dirty_free_bytes += shadow->old_len; mark_segment(tree, shadow->old_ofs >> super->s_segshift); mark_segment(tree, shadow->new_ofs >> super->s_segshift); } } static void logfs_set_alias(struct super_block *sb, struct logfs_block *block, long child_no) { struct logfs_super *super = logfs_super(sb); if (block->inode && block->inode->i_ino == LOGFS_INO_MASTER) { /* Aliases in the master inode are pointless. */ return; } if (!test_bit(child_no, block->alias_map)) { set_bit(child_no, block->alias_map); super->s_no_object_aliases++; } list_move_tail(&block->alias_list, &super->s_object_alias); } /* * Object aliases can and often do change the size and occupied space of a * file. So not only do we have to change the pointers, we also have to * change inode->i_size and li->li_used_bytes. Which is done by setting * another two object aliases for the inode itself. */ static void set_iused(struct inode *inode, struct logfs_shadow *shadow) { struct logfs_inode *li = logfs_inode(inode); if (shadow->new_len == shadow->old_len) return; alloc_inode_block(inode); li->li_used_bytes += shadow->new_len - shadow->old_len; __logfs_set_blocks(inode); logfs_set_alias(inode->i_sb, li->li_block, INODE_USED_OFS); logfs_set_alias(inode->i_sb, li->li_block, INODE_SIZE_OFS); } static int logfs_write_i0(struct inode *inode, struct page *page, struct write_control *wc) { struct logfs_shadow *shadow; u64 bix; level_t level; int full, err = 0; logfs_unpack_index(page->index, &bix, &level); if (wc->ofs == 0) if (logfs_reserve_blocks(inode, 1)) return -ENOSPC; shadow = alloc_shadow(inode, bix, level, wc->ofs); if (wc->flags & WF_WRITE) err = logfs_segment_write(inode, page, shadow); if (wc->flags & WF_DELETE) logfs_segment_delete(inode, shadow); if (err) { free_shadow(inode, shadow); return err; } set_iused(inode, shadow); full = 1; if (level != 0) { alloc_indirect_block(inode, page, 0); full = logfs_block(page)->full == LOGFS_BLOCK_FACTOR; } fill_shadow_tree(inode, page, shadow); wc->ofs = shadow->new_ofs; if (wc->ofs && full) wc->ofs |= LOGFS_FULLY_POPULATED; return 0; } static int logfs_write_direct(struct inode *inode, struct page *page, long flags) { struct logfs_inode *li = logfs_inode(inode); struct write_control wc = { .ofs = li->li_data[page->index], .flags = flags, }; int err; alloc_inode_block(inode); err = logfs_write_i0(inode, page, &wc); if (err) return err; li->li_data[page->index] = wc.ofs; logfs_set_alias(inode->i_sb, li->li_block, page->index + INODE_POINTER_OFS); return 0; } static int ptr_change(u64 ofs, struct page *page) { struct logfs_block *block = logfs_block(page); int empty0, empty1, full0, full1; empty0 = ofs == 0; empty1 = block->partial == 0; if (empty0 != empty1) return 1; /* The !! is necessary to shrink result to int */ full0 = !!(ofs & LOGFS_FULLY_POPULATED); full1 = block->full == LOGFS_BLOCK_FACTOR; if (full0 != full1) return 1; return 0; } static int __logfs_write_rec(struct inode *inode, struct page *page, struct write_control *this_wc, pgoff_t bix, level_t target_level, level_t level) { int ret, page_empty = 0; int child_no = get_bits(bix, SUBLEVEL(level)); struct page *ipage; struct write_control child_wc = { .flags = this_wc->flags, }; ipage = logfs_get_write_page(inode, bix, level); if (!ipage) return -ENOMEM; if (this_wc->ofs) { ret = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level); if (ret) goto out; } else if (!PageUptodate(ipage)) { page_empty = 1; logfs_read_empty(ipage); } child_wc.ofs = block_get_pointer(ipage, child_no); if ((__force u8)level-1 > (__force u8)target_level) ret = __logfs_write_rec(inode, page, &child_wc, bix, target_level, SUBLEVEL(level)); else ret = logfs_write_i0(inode, page, &child_wc); if (ret) goto out; alloc_indirect_block(inode, ipage, page_empty); block_set_pointer(ipage, child_no, child_wc.ofs); /* FIXME: first condition seems superfluous */ if (child_wc.ofs || logfs_block(ipage)->partial) this_wc->flags |= WF_WRITE; /* the condition on this_wc->ofs ensures that we won't consume extra * space for indirect blocks in the future, which we cannot reserve */ if (!this_wc->ofs || ptr_change(this_wc->ofs, ipage)) ret = logfs_write_i0(inode, ipage, this_wc); else logfs_set_alias(inode->i_sb, logfs_block(ipage), child_no); out: logfs_put_write_page(ipage); return ret; } static int logfs_write_rec(struct inode *inode, struct page *page, pgoff_t bix, level_t target_level, long flags) { struct logfs_inode *li = logfs_inode(inode); struct write_control wc = { .ofs = li->li_data[INDIRECT_INDEX], .flags = flags, }; int ret; alloc_inode_block(inode); if (li->li_height > (__force u8)target_level) ret = __logfs_write_rec(inode, page, &wc, bix, target_level, LEVEL(li->li_height)); else ret = logfs_write_i0(inode, page, &wc); if (ret) return ret; if (li->li_data[INDIRECT_INDEX] != wc.ofs) { li->li_data[INDIRECT_INDEX] = wc.ofs; logfs_set_alias(inode->i_sb, li->li_block, INDIRECT_INDEX + INODE_POINTER_OFS); } return ret; } void logfs_add_transaction(struct inode *inode, struct logfs_transaction *ta) { alloc_inode_block(inode); logfs_inode(inode)->li_block->ta = ta; } void logfs_del_transaction(struct inode *inode, struct logfs_transaction *ta) { struct logfs_block *block = logfs_inode(inode)->li_block; if (block && block->ta) block->ta = NULL; } static int grow_inode(struct inode *inode, u64 bix, level_t level) { struct logfs_inode *li = logfs_inode(inode); u8 height = (__force u8)level; struct page *page; struct write_control wc = { .flags = WF_WRITE, }; int err; BUG_ON(height > 5 || li->li_height > 5); while (height > li->li_height || bix >= maxbix(li->li_height)) { page = logfs_get_write_page(inode, I0_BLOCKS + 1, LEVEL(li->li_height + 1)); if (!page) return -ENOMEM; logfs_read_empty(page); alloc_indirect_block(inode, page, 1); block_set_pointer(page, 0, li->li_data[INDIRECT_INDEX]); err = logfs_write_i0(inode, page, &wc); logfs_put_write_page(page); if (err) return err; li->li_data[INDIRECT_INDEX] = wc.ofs; wc.ofs = 0; li->li_height++; logfs_set_alias(inode->i_sb, li->li_block, INODE_HEIGHT_OFS); } return 0; } static int __logfs_write_buf(struct inode *inode, struct page *page, long flags) { struct logfs_super *super = logfs_super(inode->i_sb); pgoff_t index = page->index; u64 bix; level_t level; int err; flags |= WF_WRITE | WF_DELETE; inode->i_ctime = inode->i_mtime = CURRENT_TIME; logfs_unpack_index(index, &bix, &level); if (logfs_block(page) && logfs_block(page)->reserved_bytes) super->s_dirty_pages -= logfs_block(page)->reserved_bytes; if (index < I0_BLOCKS) return logfs_write_direct(inode, page, flags); bix = adjust_bix(bix, level); err = grow_inode(inode, bix, level); if (err) return err; return logfs_write_rec(inode, page, bix, level, flags); } int logfs_write_buf(struct inode *inode, struct page *page, long flags) { struct super_block *sb = inode->i_sb; int ret; logfs_get_wblocks(sb, page, flags & WF_LOCK); ret = __logfs_write_buf(inode, page, flags); logfs_put_wblocks(sb, page, flags & WF_LOCK); return ret; } static int __logfs_delete(struct inode *inode, struct page *page) { long flags = WF_DELETE; int err; inode->i_ctime = inode->i_mtime = CURRENT_TIME; if (page->index < I0_BLOCKS) return logfs_write_direct(inode, page, flags); err = grow_inode(inode, page->index, 0); if (err) return err; return logfs_write_rec(inode, page, page->index, 0, flags); } int logfs_delete(struct inode *inode, pgoff_t index, struct shadow_tree *shadow_tree) { struct super_block *sb = inode->i_sb; struct page *page; int ret; page = logfs_get_read_page(inode, index, 0); if (!page) return -ENOMEM; logfs_get_wblocks(sb, page, 1); ret = __logfs_delete(inode, page); logfs_put_wblocks(sb, page, 1); logfs_put_read_page(page); return ret; } int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs, gc_level_t gc_level, long flags) { level_t level = shrink_level(gc_level); struct page *page; int err; page = logfs_get_write_page(inode, bix, level); if (!page) return -ENOMEM; err = logfs_segment_read(inode, page, ofs, bix, level); if (!err) { if (level != 0) alloc_indirect_block(inode, page, 0); err = logfs_write_buf(inode, page, flags); if (!err && shrink_level(gc_level) == 0) { /* Rewrite cannot mark the inode dirty but has to * write it immediately. * Q: Can't we just create an alias for the inode * instead? And if not, why not? */ if (inode->i_ino == LOGFS_INO_MASTER) logfs_write_anchor(inode->i_sb); else { err = __logfs_write_inode(inode, page, flags); } } } logfs_put_write_page(page); return err; } static int truncate_data_block(struct inode *inode, struct page *page, u64 ofs, struct logfs_shadow *shadow, u64 size) { loff_t pageofs = page->index << inode->i_sb->s_blocksize_bits; u64 bix; level_t level; int err; /* Does truncation happen within this page? */ if (size <= pageofs || size - pageofs >= PAGE_SIZE) return 0; logfs_unpack_index(page->index, &bix, &level); BUG_ON(level != 0); err = logfs_segment_read(inode, page, ofs, bix, level); if (err) return err; zero_user_segment(page, size - pageofs, PAGE_CACHE_SIZE); return logfs_segment_write(inode, page, shadow); } static int logfs_truncate_i0(struct inode *inode, struct page *page, struct write_control *wc, u64 size) { struct logfs_shadow *shadow; u64 bix; level_t level; int err = 0; logfs_unpack_index(page->index, &bix, &level); BUG_ON(level != 0); shadow = alloc_shadow(inode, bix, level, wc->ofs); err = truncate_data_block(inode, page, wc->ofs, shadow, size); if (err) { free_shadow(inode, shadow); return err; } logfs_segment_delete(inode, shadow); set_iused(inode, shadow); fill_shadow_tree(inode, page, shadow); wc->ofs = shadow->new_ofs; return 0; } static int logfs_truncate_direct(struct inode *inode, u64 size) { struct logfs_inode *li = logfs_inode(inode); struct write_control wc; struct page *page; int e; int err; alloc_inode_block(inode); for (e = I0_BLOCKS - 1; e >= 0; e--) { if (size > (e+1) * LOGFS_BLOCKSIZE) break; wc.ofs = li->li_data[e]; if (!wc.ofs) continue; page = logfs_get_write_page(inode, e, 0); if (!page) return -ENOMEM; err = logfs_segment_read(inode, page, wc.ofs, e, 0); if (err) { logfs_put_write_page(page); return err; } err = logfs_truncate_i0(inode, page, &wc, size); logfs_put_write_page(page); if (err) return err; li->li_data[e] = wc.ofs; } return 0; } /* FIXME: these need to become per-sb once we support different blocksizes */ static u64 __logfs_step[] = { 1, I1_BLOCKS, I2_BLOCKS, I3_BLOCKS, }; static u64 __logfs_start_index[] = { I0_BLOCKS, I1_BLOCKS, I2_BLOCKS, I3_BLOCKS }; static inline u64 logfs_step(level_t level) { return __logfs_step[(__force u8)level]; } static inline u64 logfs_factor(u8 level) { return __logfs_step[level] * LOGFS_BLOCKSIZE; } static inline u64 logfs_start_index(level_t level) { return __logfs_start_index[(__force u8)level]; } static void logfs_unpack_raw_index(pgoff_t index, u64 *bix, level_t *level) { logfs_unpack_index(index, bix, level); if (*bix <= logfs_start_index(SUBLEVEL(*level))) *bix = 0; } static int __logfs_truncate_rec(struct inode *inode, struct page *ipage, struct write_control *this_wc, u64 size) { int truncate_happened = 0; int e, err = 0; u64 bix, child_bix, next_bix; level_t level; struct page *page; struct write_control child_wc = { /* FIXME: flags */ }; logfs_unpack_raw_index(ipage->index, &bix, &level); err = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level); if (err) return err; for (e = LOGFS_BLOCK_FACTOR - 1; e >= 0; e--) { child_bix = bix + e * logfs_step(SUBLEVEL(level)); next_bix = child_bix + logfs_step(SUBLEVEL(level)); if (size > next_bix * LOGFS_BLOCKSIZE) break; child_wc.ofs = pure_ofs(block_get_pointer(ipage, e)); if (!child_wc.ofs) continue; page = logfs_get_write_page(inode, child_bix, SUBLEVEL(level)); if (!page) return -ENOMEM; if ((__force u8)level > 1) err = __logfs_truncate_rec(inode, page, &child_wc, size); else err = logfs_truncate_i0(inode, page, &child_wc, size); logfs_put_write_page(page); if (err) return err; truncate_happened = 1; alloc_indirect_block(inode, ipage, 0); block_set_pointer(ipage, e, child_wc.ofs); } if (!truncate_happened) { printk("ineffectual truncate (%lx, %lx, %llx)\n", inode->i_ino, ipage->index, size); return 0; } this_wc->flags = WF_DELETE; if (logfs_block(ipage)->partial) this_wc->flags |= WF_WRITE; return logfs_write_i0(inode, ipage, this_wc); } static int logfs_truncate_rec(struct inode *inode, u64 size) { struct logfs_inode *li = logfs_inode(inode); struct write_control wc = { .ofs = li->li_data[INDIRECT_INDEX], }; struct page *page; int err; alloc_inode_block(inode); if (!wc.ofs) return 0; page = logfs_get_write_page(inode, 0, LEVEL(li->li_height)); if (!page) return -ENOMEM; err = __logfs_truncate_rec(inode, page, &wc, size); logfs_put_write_page(page); if (err) return err; if (li->li_data[INDIRECT_INDEX] != wc.ofs) li->li_data[INDIRECT_INDEX] = wc.ofs; return 0; } static int __logfs_truncate(struct inode *inode, u64 size) { int ret; if (size >= logfs_factor(logfs_inode(inode)->li_height)) return 0; ret = logfs_truncate_rec(inode, size); if (ret) return ret; return logfs_truncate_direct(inode, size); } /* * Truncate, by changing the segment file, can consume a fair amount * of resources. So back off from time to time and do some GC. * 8 or 2048 blocks should be well within safety limits even if * every single block resided in a different segment. */ #define TRUNCATE_STEP (8 * 1024 * 1024) int logfs_truncate(struct inode *inode, u64 target) { struct super_block *sb = inode->i_sb; u64 size = i_size_read(inode); int err = 0; size = ALIGN(size, TRUNCATE_STEP); while (size > target) { if (size > TRUNCATE_STEP) size -= TRUNCATE_STEP; else size = 0; if (size < target) size = target; logfs_get_wblocks(sb, NULL, 1); err = __logfs_truncate(inode, size); if (!err) err = __logfs_write_inode(inode, NULL, 0); logfs_put_wblocks(sb, NULL, 1); } if (!err) err = vmtruncate(inode, target); /* I don't trust error recovery yet. */ WARN_ON(err); return err; } static void move_page_to_inode(struct inode *inode, struct page *page) { struct logfs_inode *li = logfs_inode(inode); struct logfs_block *block = logfs_block(page); if (!block) return; log_blockmove("move_page_to_inode(%llx, %llx, %x)\n", block->ino, block->bix, block->level); BUG_ON(li->li_block); block->ops = &inode_block_ops; block->inode = inode; li->li_block = block; block->page = NULL; if (PagePrivate(page)) { ClearPagePrivate(page); page_cache_release(page); set_page_private(page, 0); } } static void move_inode_to_page(struct page *page, struct inode *inode) { struct logfs_inode *li = logfs_inode(inode); struct logfs_block *block = li->li_block; if (!block) return; log_blockmove("move_inode_to_page(%llx, %llx, %x)\n", block->ino, block->bix, block->level); BUG_ON(PagePrivate(page)); block->ops = &indirect_block_ops; block->page = page; if (!PagePrivate(page)) { SetPagePrivate(page); page_cache_get(page); set_page_private(page, (unsigned long) block); } block->inode = NULL; li->li_block = NULL; } int logfs_read_inode(struct inode *inode) { struct super_block *sb = inode->i_sb; struct logfs_super *super = logfs_super(sb); struct inode *master_inode = super->s_master_inode; struct page *page; struct logfs_disk_inode *di; u64 ino = inode->i_ino; if (ino << sb->s_blocksize_bits > i_size_read(master_inode)) return -ENODATA; if (!logfs_exist_block(master_inode, ino)) return -ENODATA; page = read_cache_page(master_inode->i_mapping, ino, (filler_t *)logfs_readpage, NULL); if (IS_ERR(page)) return PTR_ERR(page); di = kmap_atomic(page); logfs_disk_to_inode(di, inode); kunmap_atomic(di); move_page_to_inode(inode, page); page_cache_release(page); return 0; } /* Caller must logfs_put_write_page(page); */ static struct page *inode_to_page(struct inode *inode) { struct inode *master_inode = logfs_super(inode->i_sb)->s_master_inode; struct logfs_disk_inode *di; struct page *page; BUG_ON(inode->i_ino == LOGFS_INO_MASTER); page = logfs_get_write_page(master_inode, inode->i_ino, 0); if (!page) return NULL; di = kmap_atomic(page); logfs_inode_to_disk(inode, di); kunmap_atomic(di); move_inode_to_page(page, inode); return page; } static int do_write_inode(struct inode *inode) { struct super_block *sb = inode->i_sb; struct inode *master_inode = logfs_super(sb)->s_master_inode; loff_t size = (inode->i_ino + 1) << inode->i_sb->s_blocksize_bits; struct page *page; int err; BUG_ON(inode->i_ino == LOGFS_INO_MASTER); /* FIXME: lock inode */ if (i_size_read(master_inode) < size) i_size_write(master_inode, size); /* TODO: Tell vfs this inode is clean now */ page = inode_to_page(inode); if (!page) return -ENOMEM; /* FIXME: transaction is part of logfs_block now. Is that enough? */ err = logfs_write_buf(master_inode, page, 0); if (err) move_page_to_inode(inode, page); logfs_put_write_page(page); return err; } static void logfs_mod_segment_entry(struct super_block *sb, u32 segno, int write, void (*change_se)(struct logfs_segment_entry *, long), long arg) { struct logfs_super *super = logfs_super(sb); struct inode *inode; struct page *page; struct logfs_segment_entry *se; pgoff_t page_no; int child_no; page_no = segno >> (sb->s_blocksize_bits - 3); child_no = segno & ((sb->s_blocksize >> 3) - 1); inode = super->s_segfile_inode; page = logfs_get_write_page(inode, page_no, 0); BUG_ON(!page); /* FIXME: We need some reserve page for this case */ if (!PageUptodate(page)) logfs_read_block(inode, page, WRITE); if (write) alloc_indirect_block(inode, page, 0); se = kmap_atomic(page); change_se(se + child_no, arg); if (write) { logfs_set_alias(sb, logfs_block(page), child_no); BUG_ON((int)be32_to_cpu(se[child_no].valid) > super->s_segsize); } kunmap_atomic(se); logfs_put_write_page(page); } static void __get_segment_entry(struct logfs_segment_entry *se, long _target) { struct logfs_segment_entry *target = (void *)_target; *target = *se; } void logfs_get_segment_entry(struct super_block *sb, u32 segno, struct logfs_segment_entry *se) { logfs_mod_segment_entry(sb, segno, 0, __get_segment_entry, (long)se); } static void __set_segment_used(struct logfs_segment_entry *se, long increment) { u32 valid; valid = be32_to_cpu(se->valid); valid += increment; se->valid = cpu_to_be32(valid); } void logfs_set_segment_used(struct super_block *sb, u64 ofs, int increment) { struct logfs_super *super = logfs_super(sb); u32 segno = ofs >> super->s_segshift; if (!increment) return; logfs_mod_segment_entry(sb, segno, 1, __set_segment_used, increment); } static void __set_segment_erased(struct logfs_segment_entry *se, long ec_level) { se->ec_level = cpu_to_be32(ec_level); } void logfs_set_segment_erased(struct super_block *sb, u32 segno, u32 ec, gc_level_t gc_level) { u32 ec_level = ec << 4 | (__force u8)gc_level; logfs_mod_segment_entry(sb, segno, 1, __set_segment_erased, ec_level); } static void __set_segment_reserved(struct logfs_segment_entry *se, long ignore) { se->valid = cpu_to_be32(RESERVED); } void logfs_set_segment_reserved(struct super_block *sb, u32 segno) { logfs_mod_segment_entry(sb, segno, 1, __set_segment_reserved, 0); } static void __set_segment_unreserved(struct logfs_segment_entry *se, long ec_level) { se->valid = 0; se->ec_level = cpu_to_be32(ec_level); } void logfs_set_segment_unreserved(struct super_block *sb, u32 segno, u32 ec) { u32 ec_level = ec << 4; logfs_mod_segment_entry(sb, segno, 1, __set_segment_unreserved, ec_level); } int __logfs_write_inode(struct inode *inode, struct page *page, long flags) { struct super_block *sb = inode->i_sb; int ret; logfs_get_wblocks(sb, page, flags & WF_LOCK); ret = do_write_inode(inode); logfs_put_wblocks(sb, page, flags & WF_LOCK); return ret; } static int do_delete_inode(struct inode *inode) { struct super_block *sb = inode->i_sb; struct inode *master_inode = logfs_super(sb)->s_master_inode; struct page *page; int ret; page = logfs_get_write_page(master_inode, inode->i_ino, 0); if (!page) return -ENOMEM; move_inode_to_page(page, inode); logfs_get_wblocks(sb, page, 1); ret = __logfs_delete(master_inode, page); logfs_put_wblocks(sb, page, 1); logfs_put_write_page(page); return ret; } /* * ZOMBIE inodes have already been deleted before and should remain dead, * if it weren't for valid checking. No need to kill them again here. */ void logfs_evict_inode(struct inode *inode) { struct super_block *sb = inode->i_sb; struct logfs_inode *li = logfs_inode(inode); struct logfs_block *block = li->li_block; struct page *page; if (!inode->i_nlink) { if (!(li->li_flags & LOGFS_IF_ZOMBIE)) { li->li_flags |= LOGFS_IF_ZOMBIE; if (i_size_read(inode) > 0) logfs_truncate(inode, 0); do_delete_inode(inode); } } truncate_inode_pages(&inode->i_data, 0); end_writeback(inode); /* Cheaper version of write_inode. All changes are concealed in * aliases, which are moved back. No write to the medium happens. */ /* Only deleted files may be dirty at this point */ BUG_ON(inode->i_state & I_DIRTY && inode->i_nlink); if (!block) return; if ((logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN)) { block->ops->free_block(inode->i_sb, block); return; } BUG_ON(inode->i_ino < LOGFS_RESERVED_INOS); page = inode_to_page(inode); BUG_ON(!page); /* FIXME: Use emergency page */ logfs_put_write_page(page); } void btree_write_block(struct logfs_block *block) { struct inode *inode; struct page *page; int err, cookie; inode = logfs_safe_iget(block->sb, block->ino, &cookie); page = logfs_get_write_page(inode, block->bix, block->level); err = logfs_readpage_nolock(page); BUG_ON(err); BUG_ON(!PagePrivate(page)); BUG_ON(logfs_block(page) != block); err = __logfs_write_buf(inode, page, 0); BUG_ON(err); BUG_ON(PagePrivate(page) || page->private); logfs_put_write_page(page); logfs_safe_iput(inode, cookie); } /** * logfs_inode_write - write inode or dentry objects * * @inode: parent inode (ifile or directory) * @buf: object to write (inode or dentry) * @n: object size * @_pos: object number (file position in blocks/objects) * @flags: write flags * @lock: 0 if write lock is already taken, 1 otherwise * @shadow_tree: shadow below this inode * * FIXME: All caller of this put a 200-300 byte variable on the stack, * only to call here and do a memcpy from that stack variable. A good * example of wasted performance and stack space. */ int logfs_inode_write(struct inode *inode, const void *buf, size_t count, loff_t bix, long flags, struct shadow_tree *shadow_tree) { loff_t pos = bix << inode->i_sb->s_blocksize_bits; int err; struct page *page; void *pagebuf; BUG_ON(pos & (LOGFS_BLOCKSIZE-1)); BUG_ON(count > LOGFS_BLOCKSIZE); page = logfs_get_write_page(inode, bix, 0); if (!page) return -ENOMEM; pagebuf = kmap_atomic(page); memcpy(pagebuf, buf, count); flush_dcache_page(page); kunmap_atomic(pagebuf); if (i_size_read(inode) < pos + LOGFS_BLOCKSIZE) i_size_write(inode, pos + LOGFS_BLOCKSIZE); err = logfs_write_buf(inode, page, flags); logfs_put_write_page(page); return err; } int logfs_open_segfile(struct super_block *sb) { struct logfs_super *super = logfs_super(sb); struct inode *inode; inode = logfs_read_meta_inode(sb, LOGFS_INO_SEGFILE); if (IS_ERR(inode)) return PTR_ERR(inode); super->s_segfile_inode = inode; return 0; } int logfs_init_rw(struct super_block *sb) { struct logfs_super *super = logfs_super(sb); int min_fill = 3 * super->s_no_blocks; INIT_LIST_HEAD(&super->s_object_alias); INIT_LIST_HEAD(&super->s_writeback_list); mutex_init(&super->s_write_mutex); super->s_block_pool = mempool_create_kmalloc_pool(min_fill, sizeof(struct logfs_block)); super->s_shadow_pool = mempool_create_kmalloc_pool(min_fill, sizeof(struct logfs_shadow)); return 0; } void logfs_cleanup_rw(struct super_block *sb) { struct logfs_super *super = logfs_super(sb); logfs_mempool_destroy(super->s_block_pool); logfs_mempool_destroy(super->s_shadow_pool); }