/* * linux/fs/hfsplus/extents.c * * Copyright (C) 2001 * Brad Boyer (flar@allandria.com) * (C) 2003 Ardis Technologies <roman@ardistech.com> * * Handling of Extents both in catalog and extents overflow trees */ #include <linux/errno.h> #include <linux/fs.h> #include <linux/pagemap.h> #include "hfsplus_fs.h" #include "hfsplus_raw.h" /* Compare two extents keys, returns 0 on same, pos/neg for difference */ int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1, const hfsplus_btree_key *k2) { __be32 k1id, k2id; __be32 k1s, k2s; k1id = k1->ext.cnid; k2id = k2->ext.cnid; if (k1id != k2id) return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1; if (k1->ext.fork_type != k2->ext.fork_type) return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1; k1s = k1->ext.start_block; k2s = k2->ext.start_block; if (k1s == k2s) return 0; return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1; } static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid, u32 block, u8 type) { key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2); key->ext.cnid = cpu_to_be32(cnid); key->ext.start_block = cpu_to_be32(block); key->ext.fork_type = type; key->ext.pad = 0; } static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off) { int i; u32 count; for (i = 0; i < 8; ext++, i++) { count = be32_to_cpu(ext->block_count); if (off < count) return be32_to_cpu(ext->start_block) + off; off -= count; } /* panic? */ return 0; } static int hfsplus_ext_block_count(struct hfsplus_extent *ext) { int i; u32 count = 0; for (i = 0; i < 8; ext++, i++) count += be32_to_cpu(ext->block_count); return count; } static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext) { int i; ext += 7; for (i = 0; i < 7; ext--, i++) if (ext->block_count) break; return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count); } static void __hfsplus_ext_write_extent(struct inode *inode, struct hfs_find_data *fd) { struct hfsplus_inode_info *hip = HFSPLUS_I(inode); int res; WARN_ON(!mutex_is_locked(&hip->extents_lock)); hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start, HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA); res = hfs_brec_find(fd); if (hip->extent_state & HFSPLUS_EXT_NEW) { if (res != -ENOENT) return; hfs_brec_insert(fd, hip->cached_extents, sizeof(hfsplus_extent_rec)); hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW); } else { if (res) return; hfs_bnode_write(fd->bnode, hip->cached_extents, fd->entryoffset, fd->entrylength); hip->extent_state &= ~HFSPLUS_EXT_DIRTY; } /* * We can't just use hfsplus_mark_inode_dirty here, because we * also get called from hfsplus_write_inode, which should not * redirty the inode. Instead the callers have to be careful * to explicily mark the inode dirty, too. */ set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags); } static void hfsplus_ext_write_extent_locked(struct inode *inode) { if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) { struct hfs_find_data fd; hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd); __hfsplus_ext_write_extent(inode, &fd); hfs_find_exit(&fd); } } void hfsplus_ext_write_extent(struct inode *inode) { mutex_lock(&HFSPLUS_I(inode)->extents_lock); hfsplus_ext_write_extent_locked(inode); mutex_unlock(&HFSPLUS_I(inode)->extents_lock); } static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd, struct hfsplus_extent *extent, u32 cnid, u32 block, u8 type) { int res; hfsplus_ext_build_key(fd->search_key, cnid, block, type); fd->key->ext.cnid = 0; res = hfs_brec_find(fd); if (res && res != -ENOENT) return res; if (fd->key->ext.cnid != fd->search_key->ext.cnid || fd->key->ext.fork_type != fd->search_key->ext.fork_type) return -ENOENT; if (fd->entrylength != sizeof(hfsplus_extent_rec)) return -EIO; hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec)); return 0; } static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block) { struct hfsplus_inode_info *hip = HFSPLUS_I(inode); int res; WARN_ON(!mutex_is_locked(&hip->extents_lock)); if (hip->extent_state & HFSPLUS_EXT_DIRTY) __hfsplus_ext_write_extent(inode, fd); res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino, block, HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA); if (!res) { hip->cached_start = be32_to_cpu(fd->key->ext.start_block); hip->cached_blocks = hfsplus_ext_block_count(hip->cached_extents); } else { hip->cached_start = hip->cached_blocks = 0; hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW); } return res; } static int hfsplus_ext_read_extent(struct inode *inode, u32 block) { struct hfsplus_inode_info *hip = HFSPLUS_I(inode); struct hfs_find_data fd; int res; if (block >= hip->cached_start && block < hip->cached_start + hip->cached_blocks) return 0; hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd); res = __hfsplus_ext_cache_extent(&fd, inode, block); hfs_find_exit(&fd); return res; } /* Get a block at iblock for inode, possibly allocating if create */ int hfsplus_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { struct super_block *sb = inode->i_sb; struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); struct hfsplus_inode_info *hip = HFSPLUS_I(inode); int res = -EIO; u32 ablock, dblock, mask; int was_dirty = 0; int shift; /* Convert inode block to disk allocation block */ shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits; ablock = iblock >> sbi->fs_shift; if (iblock >= hip->fs_blocks) { if (iblock > hip->fs_blocks || !create) return -EIO; if (ablock >= hip->alloc_blocks) { res = hfsplus_file_extend(inode); if (res) return res; } } else create = 0; if (ablock < hip->first_blocks) { dblock = hfsplus_ext_find_block(hip->first_extents, ablock); goto done; } if (inode->i_ino == HFSPLUS_EXT_CNID) return -EIO; mutex_lock(&hip->extents_lock); /* * hfsplus_ext_read_extent will write out a cached extent into * the extents btree. In that case we may have to mark the inode * dirty even for a pure read of an extent here. */ was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY); res = hfsplus_ext_read_extent(inode, ablock); if (res) { mutex_unlock(&hip->extents_lock); return -EIO; } dblock = hfsplus_ext_find_block(hip->cached_extents, ablock - hip->cached_start); mutex_unlock(&hip->extents_lock); done: dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock); mask = (1 << sbi->fs_shift) - 1; map_bh(bh_result, sb, (dblock << sbi->fs_shift) + sbi->blockoffset + (iblock & mask)); if (create) { set_buffer_new(bh_result); hip->phys_size += sb->s_blocksize; hip->fs_blocks++; inode_add_bytes(inode, sb->s_blocksize); } if (create || was_dirty) mark_inode_dirty(inode); return 0; } static void hfsplus_dump_extent(struct hfsplus_extent *extent) { int i; dprint(DBG_EXTENT, " "); for (i = 0; i < 8; i++) dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block), be32_to_cpu(extent[i].block_count)); dprint(DBG_EXTENT, "\n"); } static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset, u32 alloc_block, u32 block_count) { u32 count, start; int i; hfsplus_dump_extent(extent); for (i = 0; i < 8; extent++, i++) { count = be32_to_cpu(extent->block_count); if (offset == count) { start = be32_to_cpu(extent->start_block); if (alloc_block != start + count) { if (++i >= 8) return -ENOSPC; extent++; extent->start_block = cpu_to_be32(alloc_block); } else block_count += count; extent->block_count = cpu_to_be32(block_count); return 0; } else if (offset < count) break; offset -= count; } /* panic? */ return -EIO; } static int hfsplus_free_extents(struct super_block *sb, struct hfsplus_extent *extent, u32 offset, u32 block_nr) { u32 count, start; int i; hfsplus_dump_extent(extent); for (i = 0; i < 8; extent++, i++) { count = be32_to_cpu(extent->block_count); if (offset == count) goto found; else if (offset < count) break; offset -= count; } /* panic? */ return -EIO; found: for (;;) { start = be32_to_cpu(extent->start_block); if (count <= block_nr) { hfsplus_block_free(sb, start, count); extent->block_count = 0; extent->start_block = 0; block_nr -= count; } else { count -= block_nr; hfsplus_block_free(sb, start + count, block_nr); extent->block_count = cpu_to_be32(count); block_nr = 0; } if (!block_nr || !i) return 0; i--; extent--; count = be32_to_cpu(extent->block_count); } } int hfsplus_free_fork(struct super_block *sb, u32 cnid, struct hfsplus_fork_raw *fork, int type) { struct hfs_find_data fd; hfsplus_extent_rec ext_entry; u32 total_blocks, blocks, start; int res, i; total_blocks = be32_to_cpu(fork->total_blocks); if (!total_blocks) return 0; blocks = 0; for (i = 0; i < 8; i++) blocks += be32_to_cpu(fork->extents[i].block_count); res = hfsplus_free_extents(sb, fork->extents, blocks, blocks); if (res) return res; if (total_blocks == blocks) return 0; hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd); do { res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid, total_blocks, type); if (res) break; start = be32_to_cpu(fd.key->ext.start_block); hfsplus_free_extents(sb, ext_entry, total_blocks - start, total_blocks); hfs_brec_remove(&fd); total_blocks = start; } while (total_blocks > blocks); hfs_find_exit(&fd); return res; } int hfsplus_file_extend(struct inode *inode) { struct super_block *sb = inode->i_sb; struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); struct hfsplus_inode_info *hip = HFSPLUS_I(inode); u32 start, len, goal; int res; if (sbi->alloc_file->i_size * 8 < sbi->total_blocks - sbi->free_blocks + 8) { /* extend alloc file */ printk(KERN_ERR "hfs: extend alloc file! " "(%llu,%u,%u)\n", sbi->alloc_file->i_size * 8, sbi->total_blocks, sbi->free_blocks); return -ENOSPC; } mutex_lock(&hip->extents_lock); if (hip->alloc_blocks == hip->first_blocks) goal = hfsplus_ext_lastblock(hip->first_extents); else { res = hfsplus_ext_read_extent(inode, hip->alloc_blocks); if (res) goto out; goal = hfsplus_ext_lastblock(hip->cached_extents); } len = hip->clump_blocks; start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len); if (start >= sbi->total_blocks) { start = hfsplus_block_allocate(sb, goal, 0, &len); if (start >= goal) { res = -ENOSPC; goto out; } } dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len); if (hip->alloc_blocks <= hip->first_blocks) { if (!hip->first_blocks) { dprint(DBG_EXTENT, "first extents\n"); /* no extents yet */ hip->first_extents[0].start_block = cpu_to_be32(start); hip->first_extents[0].block_count = cpu_to_be32(len); res = 0; } else { /* try to append to extents in inode */ res = hfsplus_add_extent(hip->first_extents, hip->alloc_blocks, start, len); if (res == -ENOSPC) goto insert_extent; } if (!res) { hfsplus_dump_extent(hip->first_extents); hip->first_blocks += len; } } else { res = hfsplus_add_extent(hip->cached_extents, hip->alloc_blocks - hip->cached_start, start, len); if (!res) { hfsplus_dump_extent(hip->cached_extents); hip->extent_state |= HFSPLUS_EXT_DIRTY; hip->cached_blocks += len; } else if (res == -ENOSPC) goto insert_extent; } out: mutex_unlock(&hip->extents_lock); if (!res) { hip->alloc_blocks += len; hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY); } return res; insert_extent: dprint(DBG_EXTENT, "insert new extent\n"); hfsplus_ext_write_extent_locked(inode); memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec)); hip->cached_extents[0].start_block = cpu_to_be32(start); hip->cached_extents[0].block_count = cpu_to_be32(len); hfsplus_dump_extent(hip->cached_extents); hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW; hip->cached_start = hip->alloc_blocks; hip->cached_blocks = len; res = 0; goto out; } void hfsplus_file_truncate(struct inode *inode) { struct super_block *sb = inode->i_sb; struct hfsplus_inode_info *hip = HFSPLUS_I(inode); struct hfs_find_data fd; u32 alloc_cnt, blk_cnt, start; int res; dprint(DBG_INODE, "truncate: %lu, %llu -> %llu\n", inode->i_ino, (long long)hip->phys_size, inode->i_size); if (inode->i_size > hip->phys_size) { struct address_space *mapping = inode->i_mapping; struct page *page; void *fsdata; u32 size = inode->i_size; int res; res = pagecache_write_begin(NULL, mapping, size, 0, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata); if (res) return; res = pagecache_write_end(NULL, mapping, size, 0, 0, page, fsdata); if (res < 0) return; mark_inode_dirty(inode); return; } else if (inode->i_size == hip->phys_size) return; blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >> HFSPLUS_SB(sb)->alloc_blksz_shift; alloc_cnt = hip->alloc_blocks; if (blk_cnt == alloc_cnt) goto out; mutex_lock(&hip->extents_lock); hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd); while (1) { if (alloc_cnt == hip->first_blocks) { hfsplus_free_extents(sb, hip->first_extents, alloc_cnt, alloc_cnt - blk_cnt); hfsplus_dump_extent(hip->first_extents); hip->first_blocks = blk_cnt; break; } res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt); if (res) break; start = hip->cached_start; hfsplus_free_extents(sb, hip->cached_extents, alloc_cnt - start, alloc_cnt - blk_cnt); hfsplus_dump_extent(hip->cached_extents); if (blk_cnt > start) { hip->extent_state |= HFSPLUS_EXT_DIRTY; break; } alloc_cnt = start; hip->cached_start = hip->cached_blocks = 0; hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW); hfs_brec_remove(&fd); } hfs_find_exit(&fd); mutex_unlock(&hip->extents_lock); hip->alloc_blocks = blk_cnt; out: hip->phys_size = inode->i_size; hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits; inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits); hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY); }