| /* |
| * 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> |
| |
| 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); |
| inode->i_nlink = 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. |
| */ |
| static 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 */ |
| } |
| } |
| |
| static 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); |
| else { |
| ret = __logfs_write_inode(inode, 0); |
| /* see indirect_write_block comment */ |
| BUG_ON(ret); |
| } |
| } |
| |
| static gc_level_t inode_block_level(struct logfs_block *block) |
| { |
| BUG_ON(block->inode->i_ino == LOGFS_INO_MASTER); |
| return GC_LEVEL(LOGFS_MAX_LEVELS); |
| } |
| |
| static gc_level_t indirect_block_level(struct logfs_block *block) |
| { |
| struct page *page; |
| struct inode *inode; |
| u64 bix; |
| level_t level; |
| |
| page = block->page; |
| inode = page->mapping->host; |
| logfs_unpack_index(page->index, &bix, &level); |
| return expand_level(inode->i_ino, level); |
| } |
| |
| /* |
| * 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, KM_USER0); |
| val = child[pos]; |
| kunmap_atomic(child, KM_USER0); |
| 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) |
| { |
| ClearPagePrivate(block->page); |
| block->page->private = 0; |
| __free_block(sb, block); |
| } |
| |
| |
| static struct logfs_block_ops inode_block_ops = { |
| .write_block = inode_write_block, |
| .block_level = inode_block_level, |
| .free_block = inode_free_block, |
| .write_alias = inode_write_alias, |
| }; |
| |
| struct logfs_block_ops indirect_block_ops = { |
| .write_block = indirect_write_block, |
| .block_level = indirect_block_level, |
| .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->private = (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, KM_USER0); |
| initialize_block_counters(page, block, array, page_is_empty); |
| kunmap_atomic(array, KM_USER0); |
| } |
| |
| 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, KM_USER0); |
| oldptr = be64_to_cpu(array[index]); |
| array[index] = cpu_to_be64(ptr); |
| kunmap_atomic(array, KM_USER0); |
| 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, KM_USER0); |
| ptr = be64_to_cpu(block[index]); |
| kunmap_atomic(block, KM_USER0); |
| 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, KM_USER0); |
| 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, KM_USER0); |
| logfs_put_read_page(page); |
| return bix; |
| } |
| bofs = be64_to_cpu(rblock[slot]); |
| kunmap_atomic(rblock, KM_USER0); |
| 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 { |
| 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); |
| int ret; |
| |
| if (logfs_block(page) && logfs_block(page)->reserved_bytes) |
| return 0; |
| |
| logfs_get_wblocks(inode->i_sb, page, WF_LOCK); |
| ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE); |
| if (!ret) { |
| alloc_data_block(inode, page); |
| logfs_block(page)->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE; |
| super->s_dirty_pages += 6 * LOGFS_MAX_OBJECTSIZE; |
| } |
| 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); |
| } |
| |
| /** |
| * 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; |
| } |
| } |
| |
| 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; |
| |
| inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
| |
| if (page->index < I0_BLOCKS) |
| return logfs_write_direct(inode, page, flags); |
| 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; |
| } |
| |
| /* Rewrite cannot mark the inode dirty but has to write it immediatly. */ |
| 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); |
| } |
| 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); |
| } |
| |
| int logfs_truncate(struct inode *inode, u64 size) |
| { |
| struct super_block *sb = inode->i_sb; |
| int err; |
| |
| logfs_get_wblocks(sb, NULL, 1); |
| err = __logfs_truncate(inode, size); |
| if (!err) |
| err = __logfs_write_inode(inode, 0); |
| logfs_put_wblocks(sb, NULL, 1); |
| |
| if (!err) |
| err = vmtruncate(inode, size); |
| |
| /* 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; |
| page->private = 0; |
| ClearPagePrivate(page); |
| } |
| |
| 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; |
| page->private = (unsigned long)block; |
| SetPagePrivate(page); |
| |
| 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, KM_USER0); |
| logfs_disk_to_inode(di, inode); |
| kunmap_atomic(di, KM_USER0); |
| 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, KM_USER0); |
| logfs_inode_to_disk(inode, di); |
| kunmap_atomic(di, KM_USER0); |
| move_inode_to_page(page, inode); |
| return page; |
| } |
| |
| /* Cheaper version of write_inode. All changes are concealed in |
| * aliases, which are moved back. No write to the medium happens. |
| */ |
| void logfs_clear_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; |
| |
| /* 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); |
| } |
| |
| 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); |
| 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, KM_USER0); |
| 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, KM_USER0); |
| |
| 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, long flags) |
| { |
| struct super_block *sb = inode->i_sb; |
| int ret; |
| |
| logfs_get_wblocks(sb, NULL, flags & WF_LOCK); |
| ret = do_write_inode(inode); |
| logfs_put_wblocks(sb, NULL, 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_delete_inode(struct inode *inode) |
| { |
| struct logfs_inode *li = logfs_inode(inode); |
| |
| 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); |
| clear_inode(inode); |
| } |
| |
| 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, KM_USER0); |
| memcpy(pagebuf, buf, count); |
| flush_dcache_page(page); |
| kunmap_atomic(pagebuf, KM_USER0); |
| |
| 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); |
| 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); |
| |
| destroy_meta_inode(super->s_segfile_inode); |
| if (super->s_block_pool) |
| mempool_destroy(super->s_block_pool); |
| if (super->s_shadow_pool) |
| mempool_destroy(super->s_shadow_pool); |
| } |