1 files changed, 395 insertions, 0 deletions
diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c
new file mode 100644
index 0000000..a02802a
--- /dev/null
+++ b/fs/adfs/inode.c
@@ -0,0 +1,395 @@
+/*
+ *  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 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");