patch-2.3.43 linux/fs/adfs/inode.c

• Lines: 537
• Date: Thu Feb 10 12:16:57 2000
• Orig file: v2.3.42/linux/fs/adfs/inode.c
• Orig date: Sun Nov 7 16:37:34 1999

diff -u --recursive --new-file v2.3.42/linux/fs/adfs/inode.c linux/fs/adfs/inode.c
@@ -1,9 +1,9 @@
 /*
  *  linux/fs/adfs/inode.c
  *
- * Copyright (C) 1997 Russell King
+ * Copyright (C) 1997-1999 Russell King
  */
-
+#include <linux/version.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/adfs_fs.h>
@@ -13,210 +13,367 @@
 #include <linux/locks.h>
 #include <linux/mm.h>
 
+#include "adfs.h"
+
 /*
- * Old Inode numbers:
- *  bit 30 - 16		FragID of parent object
- *  bit 15		0			1
- *  bit 14 - 0		FragID of object	Offset into parent FragID
- *
- * New Inode numbers:
- *  Inode = Frag ID of parent (14) + Frag Offset (8) + (index into directory + 1)(8)
+ * 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.
  */
-#define inode_frag(ino)		((ino) >> 8)
-#define inode_idx(ino)		((ino) & 0xff)
-#define inode_dirindex(idx)	(((idx) & 0xff) * 26 - 21)
-
-#define frag_id(x)		(((x) >> 8) & 0x7fff)
-#define off(x)			(((x) & 0xff) ? (((x) & 0xff) - 1) << sb->u.adfs_sb.s_dr->log2sharesize : 0)
-
-static inline int adfs_inode_validate_no (struct super_block *sb, unsigned int inode_no)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
+int
+adfs_get_block(struct inode *inode, long block, struct buffer_head *bh, int create)
 {
-	unsigned long max_frag_id;
+	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) {
+			bh->b_dev = inode->i_dev;
+			bh->b_blocknr = block;
+			bh->b_state |= (1UL << BH_Mapped);
+		}
+		return 0;
+	}
+	/* don't support allocation of blocks yet */
+	return -EIO;
 
-	max_frag_id = sb->u.adfs_sb.s_map_size * sb->u.adfs_sb.s_ids_per_zone;
+abort_negative:
+	adfs_error(inode->i_sb, "block %d < 0", block);
+	return -EIO;
 
-	return (inode_no & 0x800000ff) ||
-	       (frag_id (inode_frag (inode_no)) > max_frag_id) ||
-	       (frag_id (inode_frag (inode_no)) < 2);
+abort_toobig:
+	return 0;
 }
-
-int adfs_inode_validate (struct inode *inode)
+static int adfs_writepage(struct dentry *dentry, struct page *page)
 {
-	struct super_block *sb = inode->i_sb;
+	return block_write_full_page(page,adfs_get_block);
+}
+static int adfs_readpage(struct dentry *dentry, struct page *page)
+{
+	return block_read_full_page(page,adfs_get_block);
+}
+static int adfs_prepare_write(struct page *page, unsigned from, unsigned to)
+{
+	return cont_prepare_write(page,from,to,adfs_get_block,
+		&((struct inode*)page->mapping->host)->u.adfs_i.mmu_private);
+}
+static int _adfs_bmap(struct address_space *mapping, long block)
+{
+	return generic_block_bmap(mapping,block,adfs_get_block);
+}
+struct address_space_operations adfs_aops = {
+	readpage: adfs_readpage,
+	writepage: adfs_writepage,
+	prepare_write: adfs_prepare_write,
+	commit_write: generic_commit_write,
+	bmap: _adfs_bmap
+};
+#else
+int adfs_bmap(struct inode *inode, int block)
+{
+	if (block >= inode->i_blocks)
+		return 0;
 
-	return adfs_inode_validate_no (sb, inode->i_ino & 0xffffff00) ||
-	       adfs_inode_validate_no (sb, inode->u.adfs_i.file_id << 8);
+	return __adfs_block_map(inode->i_sb, inode->i_ino, block);
 }
+#endif
 
-unsigned long adfs_inode_generate (unsigned long parent_id, int diridx)
+static inline unsigned int
+adfs_filetype(struct inode *inode)
 {
-	if (!parent_id)
-		return -1;
+	unsigned int type;
 
-	if (diridx)
-		diridx = (diridx + 21) / 26;
+	if (inode->u.adfs_i.stamped)
+		type = (inode->u.adfs_i.loadaddr >> 8) & 0xfff;
+	else
+		type = (unsigned int) -1;
 
-	return (parent_id << 8) | diridx;
+	return type;
 }
 
-unsigned long adfs_inode_objid (struct inode *inode)
+/*
+ * Convert ADFS attributes and filetype to Linux permission.
+ */
+static umode_t
+adfs_atts2mode(struct super_block *sb, struct inode *inode)
 {
-	if (adfs_inode_validate (inode)) {
-		adfs_error (inode->i_sb, "adfs_inode_objid",
-			    "bad inode number: %lu (%X,%X)",
-			    inode->i_ino, inode->i_ino, inode->u.adfs_i.file_id);
-		return 0;
+	unsigned int filetype, attr = inode->u.adfs_i.attr;
+	umode_t mode, rmask;
+
+	if (attr & ADFS_NDA_DIRECTORY) {
+		mode = S_IRUGO & sb->u.adfs_sb.s_owner_mask;
+		return S_IFDIR | S_IXUGO | mode;
 	}
 
-	return inode->u.adfs_i.file_id;
-}
+	filetype = adfs_filetype(inode);
 
-int adfs_bmap (struct inode *inode, int block)
-{
-	struct super_block *sb = inode->i_sb;
-	unsigned int blk;
+	switch (filetype) {
+	case 0xfc0:	/* LinkFS */
+		return S_IFLNK|S_IRWXUGO;
+
+	case 0xfe6:	/* UnixExec */
+		rmask = S_IRUGO | S_IXUGO;
+		break;
 
-	if (adfs_inode_validate (inode)) {
-		adfs_error (sb, "adfs_bmap",
-			    "bad inode number: %lu (%X,%X)",
-			    inode->i_ino, inode->i_ino, inode->u.adfs_i.file_id);
-		return 0;
+	default:
+		rmask = S_IRUGO;
 	}
 
-	if (block < 0) {
-		adfs_error(sb, "adfs_bmap", "block(%d) < 0", block);
-		return 0;
-	}
+	mode = S_IFREG;
 
-	if (block > inode->i_blocks)
-		return 0;
+	if (attr & ADFS_NDA_OWNER_READ)
+		mode |= rmask & sb->u.adfs_sb.s_owner_mask;
 
-	block += off(inode->u.adfs_i.file_id);
+	if (attr & ADFS_NDA_OWNER_WRITE)
+		mode |= S_IWUGO & sb->u.adfs_sb.s_owner_mask;
 
-	if (frag_id(inode->u.adfs_i.file_id) == ADFS_ROOT_FRAG)
-		blk = sb->u.adfs_sb.s_map_block + block;
-	else
-		blk = adfs_map_lookup (sb, frag_id(inode->u.adfs_i.file_id), block);
-	return blk;
+	if (attr & ADFS_NDA_PUBLIC_READ)
+		mode |= rmask & sb->u.adfs_sb.s_other_mask;
+
+	if (attr & ADFS_NDA_PUBLIC_WRITE)
+		mode |= S_IWUGO & sb->u.adfs_sb.s_other_mask;
+	return mode;
 }
 
-unsigned int adfs_parent_bmap (struct inode *inode, int block)
+/*
+ * 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)
 {
-	struct super_block *sb = inode->i_sb;
-	unsigned int blk, fragment;
+	umode_t mode;
+	int attr;
 
-	if (adfs_inode_validate_no (sb, inode->i_ino & 0xffffff00)) {
-		adfs_error (sb, "adfs_parent_bmap",
-			    "bad inode number: %lu (%X,%X)",
-			    inode->i_ino, inode->i_ino, inode->u.adfs_i.file_id);
-		return 0;
-	}
+	/* FIXME: should we be able to alter a link? */
+	if (S_ISLNK(inode->i_mode))
+		return inode->u.adfs_i.attr;
 
-	fragment = inode_frag (inode->i_ino);
-	if (frag_id (fragment) == ADFS_ROOT_FRAG)
-		blk = sb->u.adfs_sb.s_map_block + off(fragment) + block;
+	if (S_ISDIR(inode->i_mode))
+		attr = ADFS_NDA_DIRECTORY;
 	else
-		blk = adfs_map_lookup (sb, frag_id (fragment), off(fragment) + block);
-	return blk;	
+		attr = 0;
+
+	mode = inode->i_mode & sb->u.adfs_sb.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 & sb->u.adfs_sb.s_other_mask;
+	mode &= ~sb->u.adfs_sb.s_owner_mask;
+	if (mode & S_IRUGO)
+		attr |= ADFS_NDA_PUBLIC_READ;
+	if (mode & S_IWUGO)
+		attr |= ADFS_NDA_PUBLIC_WRITE;
+
+	return attr;
 }
 
-static int adfs_atts2mode(struct super_block *sb, unsigned char mode, unsigned int filetype)
+/*
+ * Convert an ADFS time to Unix time.  ADFS has a 40-bit centi-second time
+ * referenced to 1 Jan 1900 (til 2248)
+ */
+static unsigned int
+adfs_adfs2unix_time(struct inode *inode)
 {
-	int omode = 0;
+	unsigned int high, low;
 
-	if (filetype == 0xfc0 /* LinkFS */) {
-		omode = S_IFLNK|S_IRUSR|S_IWUSR|S_IXUSR|
-				S_IRGRP|S_IWGRP|S_IXGRP|
-				S_IROTH|S_IWOTH|S_IXOTH;
-	} else {
-		if (mode & ADFS_NDA_DIRECTORY) {
-			omode |= S_IRUGO & sb->u.adfs_sb.s_owner_mask;
-			omode |= S_IFDIR|S_IXUSR|S_IXGRP|S_IXOTH;
-		} else
-			omode |= S_IFREG;
-
-		if (mode & ADFS_NDA_OWNER_READ) {
-			omode |= S_IRUGO & sb->u.adfs_sb.s_owner_mask;
-			if (filetype == 0xfe6 /* UnixExec */)
-				omode |= S_IXUGO & sb->u.adfs_sb.s_owner_mask;
-		}
+	if (inode->u.adfs_i.stamped == 0)
+		return CURRENT_TIME;
 
-		if (mode & ADFS_NDA_OWNER_WRITE)
-			omode |= S_IWUGO & sb->u.adfs_sb.s_owner_mask;
+	high = inode->u.adfs_i.loadaddr << 24;
+	low  = inode->u.adfs_i.execaddr;
 
-		if (mode & ADFS_NDA_PUBLIC_READ) {
-			omode |= S_IRUGO & sb->u.adfs_sb.s_other_mask;
-			if (filetype == 0xfe6 /* UnixExec */)
-				omode |= S_IXUGO & sb->u.adfs_sb.s_other_mask;
-		}
+	high |= low >> 8;
+	low  &= 255;
 
-		if (mode & ADFS_NDA_PUBLIC_WRITE)
-			omode |= S_IWUGO & sb->u.adfs_sb.s_other_mask;
-	}
-	return omode;
+	/* Files dated pre  01 Jan 1970 00:00:00. */
+	if (high < 0x336e996a)
+		return 0;
+
+	/* Files dated post 18 Jan 2038 03:14:05. */
+	if (high >= 0x656e9969)
+		return 0x7ffffffd;
+
+	/* discard 2208988800 (0x336e996a00) seconds of time */
+	high -= 0x336e996a;
+
+	/* convert 40-bit centi-seconds to 32-bit seconds */
+	return (((high % 100) << 8) + low) / 100 + (high / 100 << 8);
 }
 
-void adfs_read_inode (struct inode *inode)
+/*
+ * 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)
 {
-	struct super_block *sb;
-	struct buffer_head *bh[4];
-	struct adfs_idir_entry ide;
-	int buffers;
+	unsigned int high, low;
 
-	sb = inode->i_sb;
-	inode->i_uid = sb->u.adfs_sb.s_uid;
-	inode->i_gid = sb->u.adfs_sb.s_gid;
-	inode->i_version = ++event;
+	if (inode->u.adfs_i.stamped) {
+		/* convert 32-bit seconds to 40-bit centi-seconds */
+		low  = (secs & 255) * 100;
+		high = (secs / 256) * 100 + (low << 8) + 0x336e996a;
+
+		inode->u.adfs_i.loadaddr = (high >> 24) |
+				(inode->u.adfs_i.loadaddr & ~0xff);
+		inode->u.adfs_i.execaddr = (low & 255) | (high << 8);
+	}
+}
 
-	if (adfs_inode_validate_no (sb, inode->i_ino & 0xffffff00)) {
-		adfs_error (sb, "adfs_read_inode",
-			    "bad inode number: %lu", inode->i_ino);
-		goto bad;
-	}
-
-	if (frag_id(inode_frag (inode->i_ino)) == ADFS_ROOT_FRAG &&
-	    inode_idx (inode->i_ino) == 0) {
-		/* root dir */
-		inode->i_mode	 = S_IRWXUGO | S_IFDIR;
-		inode->i_nlink	 = 2;
-		inode->i_size	 = ADFS_NEWDIR_SIZE;
-		inode->i_blksize = PAGE_SIZE;
-		inode->i_blocks  = inode->i_size >> sb->s_blocksize_bits;
-		inode->i_mtime   =
-		inode->i_atime   =
-		inode->i_ctime   = 0;
-		inode->u.adfs_i.file_id = inode_frag (inode->i_ino);
-	} else {
-		if (!(buffers = adfs_dir_read_parent (inode, bh)))
-			goto bad;
-
-		if (adfs_dir_check (inode, bh, buffers, NULL)) {
-			adfs_dir_free (bh, buffers);
-			goto bad;
-		}
+/*
+ * 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;
 
-		if (!adfs_dir_find_entry (sb, bh, buffers, inode_dirindex (inode->i_ino), &ide)) {
-			adfs_dir_free (bh, buffers);
-			goto bad;
-		}
-		adfs_dir_free (bh, buffers);
-		inode->i_mode	 = adfs_atts2mode(sb, ide.mode, ide.filetype);
-		inode->i_nlink	 = 2;
-		inode->i_size    = ide.size;
-		inode->i_blksize = PAGE_SIZE;
-		inode->i_blocks	 = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
-		inode->i_mtime	 =
-		inode->i_atime   =
-		inode->i_ctime   = ide.mtime;
-		inode->u.adfs_i.file_id = ide.file_id;
-	}
+	inode = get_empty_inode();
+	if (!inode)
+		goto out;
+
+	inode->i_version = ++event;
+	inode->i_sb	 = sb;
+	inode->i_dev	 = sb->s_dev;
+	inode->i_uid	 = sb->u.adfs_sb.s_uid;
+	inode->i_gid	 = sb->u.adfs_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.
+	 */
+	inode->u.adfs_i.parent_id = obj->parent_id;
+	inode->u.adfs_i.loadaddr  = obj->loadaddr;
+	inode->u.adfs_i.execaddr  = obj->execaddr;
+	inode->u.adfs_i.attr      = obj->attr;
+	inode->u.adfs_i.stamped	  = ((obj->loadaddr & 0xfff00000) == 0xfff00000);
+
+	inode->i_mode	 = adfs_atts2mode(sb, inode);
+	inode->i_mtime	 =
+	inode->i_atime	 =
+	inode->i_ctime	 = adfs_adfs2unix_time(inode);
 
 	if (S_ISDIR(inode->i_mode))
-		inode->i_op	 = &adfs_dir_inode_operations;
-	else if (S_ISREG(inode->i_mode))
+		inode->i_op	= &adfs_dir_inode_operations;
+	else if (S_ISREG(inode->i_mode)) {
 		inode->i_op	 = &adfs_file_inode_operations;
-	return;
+		inode->i_mapping->a_ops = &adfs_aops;
+		inode->u.adfs_i.mmu_private = inode->i_size;
+	}
+
+	insert_inode_hash(inode);
+
+out:
+	return inode;
+}
 
-bad:
+/*
+ * This is no longer a valid way to obtain the metadata associated with the
+ * inode number on this filesystem.  This means that this filesystem cannot
+ * be shared via NFS.
+ */
+void adfs_read_inode(struct inode *inode)
+{
+	adfs_error(inode->i_sb, "unsupported method of reading inode");
 	make_bad_inode(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;
+
+	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 != sb->u.adfs_sb.s_uid) ||
+	    (ia_valid & ATTR_GID && attr->ia_gid != sb->u.adfs_sb.s_gid))
+		error = -EPERM;
+
+	if (error)
+		goto out;
+
+	if (ia_valid & ATTR_SIZE)
+		inode->i_size = attr->ia_size;
+	if (ia_valid & ATTR_MTIME) {
+		inode->i_mtime = attr->ia_mtime;
+		adfs_unix2adfs_time(inode, attr->ia_mtime);
+	}
+	/*
+	 * 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) {
+		inode->u.adfs_i.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:
+	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()
+ */
+void adfs_write_inode(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct object_info obj;
+
+	obj.file_id	= inode->i_ino;
+	obj.name_len	= 0;
+	obj.parent_id	= inode->u.adfs_i.parent_id;
+	obj.loadaddr	= inode->u.adfs_i.loadaddr;
+	obj.execaddr	= inode->u.adfs_i.execaddr;
+	obj.attr	= inode->u.adfs_i.attr;
+	obj.size	= inode->i_size;
+
+	adfs_dir_update(sb, &obj);
 }