int hfs_extend_file(struct inode *inode) { struct super_block *sb = inode->i_sb; u32 start, len, goal; int res; mutex_lock(&HFS_I(inode)->extents_lock); if (HFS_I(inode)->alloc_blocks == HFS_I(inode)->first_blocks) goal = hfs_ext_lastblock(HFS_I(inode)->first_extents); else { res = hfs_ext_read_extent(inode, HFS_I(inode)->alloc_blocks); if (res) goto out; goal = hfs_ext_lastblock(HFS_I(inode)->cached_extents); } len = HFS_I(inode)->clump_blocks; start = hfs_vbm_search_free(sb, goal, &len); if (!len) { res = -ENOSPC; goto out; } dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len); if (HFS_I(inode)->alloc_blocks == HFS_I(inode)->first_blocks) { if (!HFS_I(inode)->first_blocks) { dprint(DBG_EXTENT, "first extents\n"); /* no extents yet */ HFS_I(inode)->first_extents[0].block = cpu_to_be16(start); HFS_I(inode)->first_extents[0].count = cpu_to_be16(len); res = 0; } else { /* try to append to extents in inode */ res = hfs_add_extent(HFS_I(inode)->first_extents, HFS_I(inode)->alloc_blocks, start, len); if (res == -ENOSPC) goto insert_extent; } if (!res) { hfs_dump_extent(HFS_I(inode)->first_extents); HFS_I(inode)->first_blocks += len; } } else { res = hfs_add_extent(HFS_I(inode)->cached_extents, HFS_I(inode)->alloc_blocks - HFS_I(inode)->cached_start, start, len); if (!res) { hfs_dump_extent(HFS_I(inode)->cached_extents); HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY; HFS_I(inode)->cached_blocks += len; } else if (res == -ENOSPC) goto insert_extent; } out: mutex_unlock(&HFS_I(inode)->extents_lock); if (!res) { HFS_I(inode)->alloc_blocks += len; mark_inode_dirty(inode); if (inode->i_ino < HFS_FIRSTUSER_CNID) set_bit(HFS_FLG_ALT_MDB_DIRTY, &HFS_SB(sb)->flags); set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags); mark_sb_dirty(sb); } return res; insert_extent: dprint(DBG_EXTENT, "insert new extent\n"); hfs_ext_write_extent(inode); memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec)); HFS_I(inode)->cached_extents[0].block = cpu_to_be16(start); HFS_I(inode)->cached_extents[0].count = cpu_to_be16(len); hfs_dump_extent(HFS_I(inode)->cached_extents); HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW; HFS_I(inode)->cached_start = HFS_I(inode)->alloc_blocks; HFS_I(inode)->cached_blocks = len; res = 0; goto out; }
/* * grow_fork() * * Try to add enough allocation blocks to 'fork' * so that it is 'ablock' allocation blocks long. */ static int grow_fork(struct hfs_fork *fork, int ablocks) { struct hfs_cat_entry *entry = fork->entry; struct hfs_mdb *mdb = entry->mdb; struct hfs_extent *ext; int i, start, err; hfs_u16 need, len=0; hfs_u32 ablksz = mdb->alloc_blksz; hfs_u32 blocks, clumpablks; blocks = fork->psize; need = ablocks - blocks/ablksz; if (need < 1) { /* no need to grow the fork */ return 0; } /* round up to clumpsize */ if (entry->u.file.clumpablks) { clumpablks = entry->u.file.clumpablks; } else { clumpablks = mdb->clumpablks; } need = ((need + clumpablks - 1) / clumpablks) * clumpablks; /* find last extent record and try to extend it */ if (!(ext = find_ext(fork, blocks/ablksz - 1))) { /* somehow we couldn't find the end of the file! */ return -1; } /* determine which is the last used extent in the record */ /* then try to allocate the blocks immediately following it */ for (i=2; (i>=0) && !ext->length[i]; --i) {}; if (i>=0) { /* try to extend the last extent */ start = ext->block[i] + ext->length[i]; err = 0; lock_bitmap(mdb); len = hfs_vbm_count_free(mdb, start); if (!len) { unlock_bitmap(mdb); goto more_extents; } if (need < len) { len = need; } err = hfs_set_vbm_bits(mdb, start, len); unlock_bitmap(mdb); if (err) { relse_ext(ext); return -1; } zero_blocks(mdb, start, len); ext->length[i] += len; ext->end += len; blocks = (fork->psize += len * ablksz); need -= len; update_ext(fork, ext); } more_extents: /* add some more extents */ while (need) { len = need; err = 0; lock_bitmap(mdb); start = hfs_vbm_search_free(mdb, &len); if (need < len) { len = need; } err = hfs_set_vbm_bits(mdb, start, len); unlock_bitmap(mdb); if (!len || err) { relse_ext(ext); return -1; } zero_blocks(mdb, start, len); /* determine which is the first free extent in the record */ for (i=0; (i<3) && ext->length[i]; ++i) {}; if (i < 3) { ext->block[i] = start; ext->length[i] = len; ext->end += len; update_ext(fork, ext); } else { if (!(ext = new_extent(fork, ext, blocks/ablksz, start, len, ablksz))) { lock_bitmap(mdb); hfs_clear_vbm_bits(mdb, start, len); unlock_bitmap(mdb); return -1; } } blocks = (fork->psize += len * ablksz); need -= len; } set_cache(fork, ext); relse_ext(ext); return 0; }