/* * linux/fs/adfs/inode.c * * Copyright (C) 1997-1999 Russell King * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/errno.h> #include <linux/fs.h> #include <linux/adfs_fs.h> #include <linux/time.h> #include <linux/stat.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/smp_lock.h> #include <linux/module.h> #include <linux/buffer_head.h> #include "adfs.h" /* * Lookup/Create a block at offset 'block' into 'inode'. We currently do * not support creation of new blocks, so we return -EIO for this case. */ static int adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh, int create) { if (block < 0) goto abort_negative; if (!create) { if (block >= inode->i_blocks) goto abort_toobig; block = __adfs_block_map(inode->i_sb, inode->i_ino, block); if (block) map_bh(bh, inode->i_sb, block); return 0; } /* don't support allocation of blocks yet */ return -EIO; abort_negative: adfs_error(inode->i_sb, "block %d < 0", block); return -EIO; abort_toobig: return 0; } static int adfs_writepage(struct page *page, struct writeback_control *wbc) { return block_write_full_page(page, adfs_get_block, wbc); } static int adfs_readpage(struct file *file, struct page *page) { return block_read_full_page(page, adfs_get_block); } static int adfs_prepare_write(struct file *file, struct page *page, unsigned int from, unsigned int to) { return cont_prepare_write(page, from, to, adfs_get_block, &ADFS_I(page->mapping->host)->mmu_private); } static sector_t _adfs_bmap(struct address_space *mapping, sector_t block) { return generic_block_bmap(mapping, block, adfs_get_block); } static const struct address_space_operations adfs_aops = { .readpage = adfs_readpage, .writepage = adfs_writepage, .sync_page = block_sync_page, .prepare_write = adfs_prepare_write, .commit_write = generic_commit_write, .bmap = _adfs_bmap }; static inline unsigned int adfs_filetype(struct inode *inode) { unsigned int type; if (ADFS_I(inode)->stamped) type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff; else type = (unsigned int) -1; return type; } /* * Convert ADFS attributes and filetype to Linux permission. */ static umode_t adfs_atts2mode(struct super_block *sb, struct inode *inode) { unsigned int filetype, attr = ADFS_I(inode)->attr; umode_t mode, rmask; struct adfs_sb_info *asb = ADFS_SB(sb); if (attr & ADFS_NDA_DIRECTORY) { mode = S_IRUGO & asb->s_owner_mask; return S_IFDIR | S_IXUGO | mode; } filetype = adfs_filetype(inode); switch (filetype) { case 0xfc0: /* LinkFS */ return S_IFLNK|S_IRWXUGO; case 0xfe6: /* UnixExec */ rmask = S_IRUGO | S_IXUGO; break; default: rmask = S_IRUGO; } mode = S_IFREG; if (attr & ADFS_NDA_OWNER_READ) mode |= rmask & asb->s_owner_mask; if (attr & ADFS_NDA_OWNER_WRITE) mode |= S_IWUGO & asb->s_owner_mask; if (attr & ADFS_NDA_PUBLIC_READ) mode |= rmask & asb->s_other_mask; if (attr & ADFS_NDA_PUBLIC_WRITE) mode |= S_IWUGO & asb->s_other_mask; return mode; } /* * Convert Linux permission to ADFS attribute. We try to do the reverse * of atts2mode, but there is not a 1:1 translation. */ static int adfs_mode2atts(struct super_block *sb, struct inode *inode) { umode_t mode; int attr; struct adfs_sb_info *asb = ADFS_SB(sb); /* FIXME: should we be able to alter a link? */ if (S_ISLNK(inode->i_mode)) return ADFS_I(inode)->attr; if (S_ISDIR(inode->i_mode)) attr = ADFS_NDA_DIRECTORY; else attr = 0; mode = inode->i_mode & asb->s_owner_mask; if (mode & S_IRUGO) attr |= ADFS_NDA_OWNER_READ; if (mode & S_IWUGO) attr |= ADFS_NDA_OWNER_WRITE; mode = inode->i_mode & asb->s_other_mask; mode &= ~asb->s_owner_mask; if (mode & S_IRUGO) attr |= ADFS_NDA_PUBLIC_READ; if (mode & S_IWUGO) attr |= ADFS_NDA_PUBLIC_WRITE; return attr; } /* * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time * referenced to 1 Jan 1900 (til 2248) */ static void adfs_adfs2unix_time(struct timespec *tv, struct inode *inode) { unsigned int high, low; if (ADFS_I(inode)->stamped == 0) goto cur_time; high = ADFS_I(inode)->loadaddr << 24; low = ADFS_I(inode)->execaddr; high |= low >> 8; low &= 255; /* Files dated pre 01 Jan 1970 00:00:00. */ if (high < 0x336e996a) goto too_early; /* Files dated post 18 Jan 2038 03:14:05. */ if (high >= 0x656e9969) goto too_late; /* discard 2208988800 (0x336e996a00) seconds of time */ high -= 0x336e996a; /* convert 40-bit centi-seconds to 32-bit seconds */ tv->tv_sec = (((high % 100) << 8) + low) / 100 + (high / 100 << 8); tv->tv_nsec = 0; return; cur_time: *tv = CURRENT_TIME_SEC; return; too_early: tv->tv_sec = tv->tv_nsec = 0; return; too_late: tv->tv_sec = 0x7ffffffd; tv->tv_nsec = 0; return; } /* * Convert an Unix time to ADFS time. We only do this if the entry has a * time/date stamp already. */ static void adfs_unix2adfs_time(struct inode *inode, unsigned int secs) { unsigned int high, low; if (ADFS_I(inode)->stamped) { /* convert 32-bit seconds to 40-bit centi-seconds */ low = (secs & 255) * 100; high = (secs / 256) * 100 + (low >> 8) + 0x336e996a; ADFS_I(inode)->loadaddr = (high >> 24) | (ADFS_I(inode)->loadaddr & ~0xff); ADFS_I(inode)->execaddr = (low & 255) | (high << 8); } } /* * Fill in the inode information from the object information. * * Note that this is an inode-less filesystem, so we can't use the inode * number to reference the metadata on the media. Instead, we use the * inode number to hold the object ID, which in turn will tell us where * the data is held. We also save the parent object ID, and with these * two, we can locate the metadata. * * This does mean that we rely on an objects parent remaining the same at * all times - we cannot cope with a cross-directory rename (yet). */ struct inode * adfs_iget(struct super_block *sb, struct object_info *obj) { struct inode *inode; inode = new_inode(sb); if (!inode) goto out; inode->i_uid = ADFS_SB(sb)->s_uid; inode->i_gid = ADFS_SB(sb)->s_gid; inode->i_ino = obj->file_id; inode->i_size = obj->size; inode->i_nlink = 2; inode->i_blksize = PAGE_SIZE; inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits; /* * we need to save the parent directory ID so that * write_inode can update the directory information * for this file. This will need special handling * for cross-directory renames. */ ADFS_I(inode)->parent_id = obj->parent_id; ADFS_I(inode)->loadaddr = obj->loadaddr; ADFS_I(inode)->execaddr = obj->execaddr; ADFS_I(inode)->attr = obj->attr; ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000); inode->i_mode = adfs_atts2mode(sb, inode); adfs_adfs2unix_time(&inode->i_mtime, inode); inode->i_atime = inode->i_mtime; inode->i_ctime = inode->i_mtime; if (S_ISDIR(inode->i_mode)) { inode->i_op = &adfs_dir_inode_operations; inode->i_fop = &adfs_dir_operations; } else if (S_ISREG(inode->i_mode)) { inode->i_op = &adfs_file_inode_operations; inode->i_fop = &adfs_file_operations; inode->i_mapping->a_ops = &adfs_aops; ADFS_I(inode)->mmu_private = inode->i_size; } insert_inode_hash(inode); out: return inode; } /* * Validate and convert a changed access mode/time to their ADFS equivalents. * adfs_write_inode will actually write the information back to the directory * later. */ int adfs_notify_change(struct dentry *dentry, struct iattr *attr) { struct inode *inode = dentry->d_inode; struct super_block *sb = inode->i_sb; unsigned int ia_valid = attr->ia_valid; int error; lock_kernel(); error = inode_change_ok(inode, attr); /* * we can't change the UID or GID of any file - * we have a global UID/GID in the superblock */ if ((ia_valid & ATTR_UID && attr->ia_uid != ADFS_SB(sb)->s_uid) || (ia_valid & ATTR_GID && attr->ia_gid != ADFS_SB(sb)->s_gid)) error = -EPERM; if (error) goto out; if (ia_valid & ATTR_SIZE) error = vmtruncate(inode, attr->ia_size); if (error) goto out; if (ia_valid & ATTR_MTIME) { inode->i_mtime = attr->ia_mtime; adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec); } /* * FIXME: should we make these == to i_mtime since we don't * have the ability to represent them in our filesystem? */ if (ia_valid & ATTR_ATIME) inode->i_atime = attr->ia_atime; if (ia_valid & ATTR_CTIME) inode->i_ctime = attr->ia_ctime; if (ia_valid & ATTR_MODE) { ADFS_I(inode)->attr = adfs_mode2atts(sb, inode); inode->i_mode = adfs_atts2mode(sb, inode); } /* * FIXME: should we be marking this inode dirty even if * we don't have any metadata to write back? */ if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE)) mark_inode_dirty(inode); out: unlock_kernel(); return error; } /* * write an existing inode back to the directory, and therefore the disk. * The adfs-specific inode data has already been updated by * adfs_notify_change() */ int adfs_write_inode(struct inode *inode, int unused) { struct super_block *sb = inode->i_sb; struct object_info obj; int ret; lock_kernel(); obj.file_id = inode->i_ino; obj.name_len = 0; obj.parent_id = ADFS_I(inode)->parent_id; obj.loadaddr = ADFS_I(inode)->loadaddr; obj.execaddr = ADFS_I(inode)->execaddr; obj.attr = ADFS_I(inode)->attr; obj.size = inode->i_size; ret = adfs_dir_update(sb, &obj); unlock_kernel(); return ret; } MODULE_LICENSE("GPL");