Merge git://git.infradead.org/mtd-2.6

* git://git.infradead.org/mtd-2.6: (53 commits)
  [MTD] struct device - replace bus_id with dev_name(), dev_set_name()
  [MTD] [NOR] Fixup for Numonyx M29W128 chips
  [MTD] mtdpart: Make ecc_stats more realistic.
  powerpc/85xx: TQM8548: Update DTS file for multi-chip support
  powerpc: NAND: FSL UPM: document new bindings
  [MTD] [NAND] FSL-UPM: Add wait flags to support board/chip specific delays
  [MTD] [NAND] FSL-UPM: add multi chip support
  [MTD] [NOR] Add device parent info to physmap_of
  [MTD] [NAND] Add support for NAND on the Socrates board
  [MTD] [NAND] Add support for 4KiB pages.
  [MTD] sysfs support should not depend on CONFIG_PROC_FS
  [MTD] [NAND] Add parent info for CAFÉ controller
  [MTD] support driver model updates
  [MTD] driver model updates (part 2)
  [MTD] driver model updates
  [MTD] [NAND] move gen_nand's probe function to .devinit.text
  [MTD] [MAPS] move sa1100 flash's probe function to .devinit.text
  [MTD] fix use after free in register_mtd_blktrans
  [MTD] [MAPS] Drop now unused sharpsl-flash map
  [MTD] ofpart: Check name property to determine partition nodes.
  ...

Manually fix trivial conflict in drivers/mtd/maps/Makefile

9 files changed, 1089 insertions, 674 deletions

diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
index 77ccf8cb0823..043740dde20c 100644
--- a/fs/jffs2/acl.c
+++ b/fs/jffs2/acl.c
@@ -38,12 +38,12 @@ static int jffs2_acl_count(size_t size)
 	size_t s;
 
 	size -= sizeof(struct jffs2_acl_header);
-	s = size - 4 * sizeof(struct jffs2_acl_entry_short);
-	if (s < 0) {
+	if (size < 4 * sizeof(struct jffs2_acl_entry_short)) {
 		if (size % sizeof(struct jffs2_acl_entry_short))
 			return -1;
 		return size / sizeof(struct jffs2_acl_entry_short);
 	} else {
+		s = size - 4 * sizeof(struct jffs2_acl_entry_short);
 		if (s % sizeof(struct jffs2_acl_entry))
 			return -1;
 		return s / sizeof(struct jffs2_acl_entry) + 4;
diff --git a/fs/jffs2/malloc.c b/fs/jffs2/malloc.c
index f9211252b5f1..9eff2bdae8a7 100644
--- a/fs/jffs2/malloc.c
+++ b/fs/jffs2/malloc.c
@@ -284,10 +284,9 @@ void jffs2_free_inode_cache(struct jffs2_inode_cache *x)
 struct jffs2_xattr_datum *jffs2_alloc_xattr_datum(void)
 {
 	struct jffs2_xattr_datum *xd;
-	xd = kmem_cache_alloc(xattr_datum_cache, GFP_KERNEL);
+	xd = kmem_cache_zalloc(xattr_datum_cache, GFP_KERNEL);
 	dbg_memalloc("%p\n", xd);
 
-	memset(xd, 0, sizeof(struct jffs2_xattr_datum));
 	xd->class = RAWNODE_CLASS_XATTR_DATUM;
 	xd->node = (void *)xd;
 	INIT_LIST_HEAD(&xd->xindex);
@@ -303,10 +302,9 @@ void jffs2_free_xattr_datum(struct jffs2_xattr_datum *xd)
 struct jffs2_xattr_ref *jffs2_alloc_xattr_ref(void)
 {
 	struct jffs2_xattr_ref *ref;
-	ref = kmem_cache_alloc(xattr_ref_cache, GFP_KERNEL);
+	ref = kmem_cache_zalloc(xattr_ref_cache, GFP_KERNEL);
 	dbg_memalloc("%p\n", ref);
 
-	memset(ref, 0, sizeof(struct jffs2_xattr_ref));
 	ref->class = RAWNODE_CLASS_XATTR_REF;
 	ref->node = (void *)ref;
 	return ref;
diff --git a/fs/romfs/Kconfig b/fs/romfs/Kconfig
index 1a17020f9faf..ce2d6bcc6266 100644
--- a/fs/romfs/Kconfig
+++ b/fs/romfs/Kconfig
@@ -1,6 +1,6 @@
 config ROMFS_FS
 	tristate "ROM file system support"
-	depends on BLOCK
+	depends on BLOCK || MTD
 	---help---
 	  This is a very small read-only file system mainly intended for
 	  initial ram disks of installation disks, but it could be used for
@@ -14,3 +14,49 @@ config ROMFS_FS
 
 	  If you don't know whether you need it, then you don't need it:
 	  answer N.
+
+#
+# Select the backing stores to be supported
+#
+choice
+	prompt "RomFS backing stores"
+	depends on ROMFS_FS
+	default ROMFS_BACKED_BY_BLOCK
+	help
+	  Select the backing stores to be supported.
+
+config ROMFS_BACKED_BY_BLOCK
+	bool "Block device-backed ROM file system support"
+	depends on BLOCK
+	help
+	  This permits ROMFS to use block devices buffered through the page
+	  cache as the medium from which to retrieve data.  It does not allow
+	  direct mapping of the medium.
+
+	  If unsure, answer Y.
+
+config ROMFS_BACKED_BY_MTD
+	bool "MTD-backed ROM file system support"
+	depends on MTD=y || (ROMFS_FS=m && MTD)
+	help
+	  This permits ROMFS to use MTD based devices directly, without the
+	  intercession of the block layer (which may have been disabled).  It
+	  also allows direct mapping of MTD devices through romfs files under
+	  NOMMU conditions if the underlying device is directly addressable by
+	  the CPU.
+
+	  If unsure, answer Y.
+
+config ROMFS_BACKED_BY_BOTH
+	bool "Both the above"
+	depends on BLOCK && (MTD=y || (ROMFS_FS=m && MTD))
+endchoice
+
+
+config ROMFS_ON_BLOCK
+	bool
+	default y if ROMFS_BACKED_BY_BLOCK || ROMFS_BACKED_BY_BOTH
+
+config ROMFS_ON_MTD
+	bool
+	default y if ROMFS_BACKED_BY_MTD || ROMFS_BACKED_BY_BOTH
diff --git a/fs/romfs/Makefile b/fs/romfs/Makefile
index c95b21cf49a3..420beb7d495c 100644
--- a/fs/romfs/Makefile
+++ b/fs/romfs/Makefile
@@ -1,7 +1,12 @@
 #
-# Makefile for the linux romfs filesystem routines.
+# Makefile for the linux RomFS filesystem routines.
 #
 
 obj-$(CONFIG_ROMFS_FS) += romfs.o
 
-romfs-objs := inode.o
+romfs-y := storage.o super.o
+
+ifneq ($(CONFIG_MMU),y)
+romfs-$(CONFIG_ROMFS_ON_MTD) += mmap-nommu.o
+endif
+
diff --git a/fs/romfs/inode.c b/fs/romfs/inode.c
deleted file mode 100644
index 98a232f7196b..000000000000
--- a/fs/romfs/inode.c
+++ /dev/null
@@ -1,665 +0,0 @@
-/*
- * ROMFS file system, Linux implementation
- *
- * Copyright (C) 1997-1999  Janos Farkas <chexum@shadow.banki.hu>
- *
- * Using parts of the minix filesystem
- * Copyright (C) 1991, 1992  Linus Torvalds
- *
- * and parts of the affs filesystem additionally
- * Copyright (C) 1993  Ray Burr
- * Copyright (C) 1996  Hans-Joachim Widmaier
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- * Changes
- *					Changed for 2.1.19 modules
- *	Jan 1997			Initial release
- *	Jun 1997			2.1.43+ changes
- *					Proper page locking in readpage
- *					Changed to work with 2.1.45+ fs
- *	Jul 1997			Fixed follow_link
- *			2.1.47
- *					lookup shouldn't return -ENOENT
- *					from Horst von Brand:
- *					  fail on wrong checksum
- *					  double unlock_super was possible
- *					  correct namelen for statfs
- *					spotted by Bill Hawes:
- *					  readlink shouldn't iput()
- *	Jun 1998	2.1.106		from Avery Pennarun: glibc scandir()
- *					  exposed a problem in readdir
- *			2.1.107		code-freeze spellchecker run
- *	Aug 1998			2.1.118+ VFS changes
- *	Sep 1998	2.1.122		another VFS change (follow_link)
- *	Apr 1999	2.2.7		no more EBADF checking in
- *					  lookup/readdir, use ERR_PTR
- *	Jun 1999	2.3.6		d_alloc_root use changed
- *			2.3.9		clean up usage of ENOENT/negative
- *					  dentries in lookup
- *					clean up page flags setting
- *					  (error, uptodate, locking) in
- *					  in readpage
- *					use init_special_inode for
- *					  fifos/sockets (and streamline) in
- *					  read_inode, fix _ops table order
- *	Aug 1999	2.3.16		__initfunc() => __init change
- *	Oct 1999	2.3.24		page->owner hack obsoleted
- *	Nov 1999	2.3.27		2.3.25+ page->offset => index change
- */
-
-/* todo:
- *	- see Documentation/filesystems/romfs.txt
- *	- use allocated, not stack memory for file names?
- *	- considering write access...
- *	- network (tftp) files?
- *	- merge back some _op tables
- */
-
-/*
- * Sorry about some optimizations and for some goto's.  I just wanted
- * to squeeze some more bytes out of this code.. :)
- */
-
-#include <linux/module.h>
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/romfs_fs.h>
-#include <linux/fs.h>
-#include <linux/init.h>
-#include <linux/pagemap.h>
-#include <linux/smp_lock.h>
-#include <linux/buffer_head.h>
-#include <linux/vfs.h>
-
-#include <asm/uaccess.h>
-
-struct romfs_inode_info {
-	unsigned long i_metasize;	/* size of non-data area */
-	unsigned long i_dataoffset;	/* from the start of fs */
-	struct inode vfs_inode;
-};
-
-static struct inode *romfs_iget(struct super_block *, unsigned long);
-
-/* instead of private superblock data */
-static inline unsigned long romfs_maxsize(struct super_block *sb)
-{
-	return (unsigned long)sb->s_fs_info;
-}
-
-static inline struct romfs_inode_info *ROMFS_I(struct inode *inode)
-{
-	return container_of(inode, struct romfs_inode_info, vfs_inode);
-}
-
-static __u32
-romfs_checksum(void *data, int size)
-{
-	__u32 sum;
-	__be32 *ptr;
-
-	sum = 0; ptr = data;
-	size>>=2;
-	while (size>0) {
-		sum += be32_to_cpu(*ptr++);
-		size--;
-	}
-	return sum;
-}
-
-static const struct super_operations romfs_ops;
-
-static int romfs_fill_super(struct super_block *s, void *data, int silent)
-{
-	struct buffer_head *bh;
-	struct romfs_super_block *rsb;
-	struct inode *root;
-	int sz, ret = -EINVAL;
-
-	/* I would parse the options here, but there are none.. :) */
-
-	sb_set_blocksize(s, ROMBSIZE);
-	s->s_maxbytes = 0xFFFFFFFF;
-
-	bh = sb_bread(s, 0);
-	if (!bh) {
-		/* XXX merge with other printk? */
-                printk ("romfs: unable to read superblock\n");
-		goto outnobh;
-	}
-
-	rsb = (struct romfs_super_block *)bh->b_data;
-	sz = be32_to_cpu(rsb->size);
-	if (rsb->word0 != ROMSB_WORD0 || rsb->word1 != ROMSB_WORD1
-	   || sz < ROMFH_SIZE) {
-		if (!silent)
-			printk ("VFS: Can't find a romfs filesystem on dev "
-				"%s.\n", s->s_id);
-		goto out;
-	}
-	if (romfs_checksum(rsb, min_t(int, sz, 512))) {
-		printk ("romfs: bad initial checksum on dev "
-			"%s.\n", s->s_id);
-		goto out;
-	}
-
-	s->s_magic = ROMFS_MAGIC;
-	s->s_fs_info = (void *)(long)sz;
-
-	s->s_flags |= MS_RDONLY;
-
-	/* Find the start of the fs */
-	sz = (ROMFH_SIZE +
-	      strnlen(rsb->name, ROMFS_MAXFN) + 1 + ROMFH_PAD)
-	     & ROMFH_MASK;
-
-	s->s_op	= &romfs_ops;
-	root = romfs_iget(s, sz);
-	if (IS_ERR(root)) {
-		ret = PTR_ERR(root);
-		goto out;
-	}
-
-	ret = -ENOMEM;
-	s->s_root = d_alloc_root(root);
-	if (!s->s_root)
-		goto outiput;
-
-	brelse(bh);
-	return 0;
-
-outiput:
-	iput(root);
-out:
-	brelse(bh);
-outnobh:
-	return ret;
-}
-
-/* That's simple too. */
-
-static int
-romfs_statfs(struct dentry *dentry, struct kstatfs *buf)
-{
-	buf->f_type = ROMFS_MAGIC;
-	buf->f_bsize = ROMBSIZE;
-	buf->f_bfree = buf->f_bavail = buf->f_ffree;
-	buf->f_blocks = (romfs_maxsize(dentry->d_sb)+ROMBSIZE-1)>>ROMBSBITS;
-	buf->f_namelen = ROMFS_MAXFN;
-	return 0;
-}
-
-/* some helper routines */
-
-static int
-romfs_strnlen(struct inode *i, unsigned long offset, unsigned long count)
-{
-	struct buffer_head *bh;
-	unsigned long avail, maxsize, res;
-
-	maxsize = romfs_maxsize(i->i_sb);
-	if (offset >= maxsize)
-		return -1;
-
-	/* strnlen is almost always valid */
-	if (count > maxsize || offset+count > maxsize)
-		count = maxsize-offset;
-
-	bh = sb_bread(i->i_sb, offset>>ROMBSBITS);
-	if (!bh)
-		return -1;		/* error */
-
-	avail = ROMBSIZE - (offset & ROMBMASK);
-	maxsize = min_t(unsigned long, count, avail);
-	res = strnlen(((char *)bh->b_data)+(offset&ROMBMASK), maxsize);
-	brelse(bh);
-
-	if (res < maxsize)
-		return res;		/* found all of it */
-
-	while (res < count) {
-		offset += maxsize;
-
-		bh = sb_bread(i->i_sb, offset>>ROMBSBITS);
-		if (!bh)
-			return -1;
-		maxsize = min_t(unsigned long, count - res, ROMBSIZE);
-		avail = strnlen(bh->b_data, maxsize);
-		res += avail;
-		brelse(bh);
-		if (avail < maxsize)
-			return res;
-	}
-	return res;
-}
-
-static int
-romfs_copyfrom(struct inode *i, void *dest, unsigned long offset, unsigned long count)
-{
-	struct buffer_head *bh;
-	unsigned long avail, maxsize, res;
-
-	maxsize = romfs_maxsize(i->i_sb);
-	if (offset >= maxsize || count > maxsize || offset+count>maxsize)
-		return -1;
-
-	bh = sb_bread(i->i_sb, offset>>ROMBSBITS);
-	if (!bh)
-		return -1;		/* error */
-
-	avail = ROMBSIZE - (offset & ROMBMASK);
-	maxsize = min_t(unsigned long, count, avail);
-	memcpy(dest, ((char *)bh->b_data) + (offset & ROMBMASK), maxsize);
-	brelse(bh);
-
-	res = maxsize;			/* all of it */
-
-	while (res < count) {
-		offset += maxsize;
-		dest += maxsize;
-
-		bh = sb_bread(i->i_sb, offset>>ROMBSBITS);
-		if (!bh)
-			return -1;
-		maxsize = min_t(unsigned long, count - res, ROMBSIZE);
-		memcpy(dest, bh->b_data, maxsize);
-		brelse(bh);
-		res += maxsize;
-	}
-	return res;
-}
-
-static unsigned char romfs_dtype_table[] = {
-	DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_SOCK, DT_FIFO
-};
-
-static int
-romfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
-{
-	struct inode *i = filp->f_path.dentry->d_inode;
-	struct romfs_inode ri;
-	unsigned long offset, maxoff;
-	int j, ino, nextfh;
-	int stored = 0;
-	char fsname[ROMFS_MAXFN];	/* XXX dynamic? */
-
-	lock_kernel();
-
-	maxoff = romfs_maxsize(i->i_sb);
-
-	offset = filp->f_pos;
-	if (!offset) {
-		offset = i->i_ino & ROMFH_MASK;
-		if (romfs_copyfrom(i, &ri, offset, ROMFH_SIZE) <= 0)
-			goto out;
-		offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
-	}
-
-	/* Not really failsafe, but we are read-only... */
-	for(;;) {
-		if (!offset || offset >= maxoff) {
-			offset = maxoff;
-			filp->f_pos = offset;
-			goto out;
-		}
-		filp->f_pos = offset;
-
-		/* Fetch inode info */
-		if (romfs_copyfrom(i, &ri, offset, ROMFH_SIZE) <= 0)
-			goto out;
-
-		j = romfs_strnlen(i, offset+ROMFH_SIZE, sizeof(fsname)-1);
-		if (j < 0)
-			goto out;
-
-		fsname[j]=0;
-		romfs_copyfrom(i, fsname, offset+ROMFH_SIZE, j);
-
-		ino = offset;
-		nextfh = be32_to_cpu(ri.next);
-		if ((nextfh & ROMFH_TYPE) == ROMFH_HRD)
-			ino = be32_to_cpu(ri.spec);
-		if (filldir(dirent, fsname, j, offset, ino,
-			    romfs_dtype_table[nextfh & ROMFH_TYPE]) < 0) {
-			goto out;
-		}
-		stored++;
-		offset = nextfh & ROMFH_MASK;
-	}
-out:
-	unlock_kernel();
-	return stored;
-}
-
-static struct dentry *
-romfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
-{
-	unsigned long offset, maxoff;
-	long res;
-	int fslen;
-	struct inode *inode = NULL;
-	char fsname[ROMFS_MAXFN];	/* XXX dynamic? */
-	struct romfs_inode ri;
-	const char *name;		/* got from dentry */
-	int len;
-
-	res = -EACCES;			/* placeholder for "no data here" */
-	offset = dir->i_ino & ROMFH_MASK;
-	lock_kernel();
-	if (romfs_copyfrom(dir, &ri, offset, ROMFH_SIZE) <= 0)
-		goto error;
-
-	maxoff = romfs_maxsize(dir->i_sb);
-	offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
-
-	/* OK, now find the file whose name is in "dentry" in the
-	 * directory specified by "dir".  */
-
-	name = dentry->d_name.name;
-	len = dentry->d_name.len;
-
-	for(;;) {
-		if (!offset || offset >= maxoff)
-			goto success; /* negative success */
-		if (romfs_copyfrom(dir, &ri, offset, ROMFH_SIZE) <= 0)
-			goto error;
-
-		/* try to match the first 16 bytes of name */
-		fslen = romfs_strnlen(dir, offset+ROMFH_SIZE, ROMFH_SIZE);
-		if (len < ROMFH_SIZE) {
-			if (len == fslen) {
-				/* both are shorter, and same size */
-				romfs_copyfrom(dir, fsname, offset+ROMFH_SIZE, len+1);
-				if (strncmp (name, fsname, len) == 0)
-					break;
-			}
-		} else if (fslen >= ROMFH_SIZE) {
-			/* both are longer; XXX optimize max size */
-			fslen = romfs_strnlen(dir, offset+ROMFH_SIZE, sizeof(fsname)-1);
-			if (len == fslen) {
-				romfs_copyfrom(dir, fsname, offset+ROMFH_SIZE, len+1);
-				if (strncmp(name, fsname, len) == 0)
-					break;
-			}
-		}
-		/* next entry */
-		offset = be32_to_cpu(ri.next) & ROMFH_MASK;
-	}
-
-	/* Hard link handling */
-	if ((be32_to_cpu(ri.next) & ROMFH_TYPE) == ROMFH_HRD)
-		offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
-
-	inode = romfs_iget(dir->i_sb, offset);
-	if (IS_ERR(inode)) {
-		res = PTR_ERR(inode);
-		goto error;
-	}
-
-success:
-	d_add(dentry, inode);
-	res = 0;
-error:
-	unlock_kernel();
-	return ERR_PTR(res);
-}
-
-/*
- * Ok, we do readpage, to be able to execute programs.  Unfortunately,
- * we can't use bmap, since we may have looser alignments.
- */
-
-static int
-romfs_readpage(struct file *file, struct page * page)
-{
-	struct inode *inode = page->mapping->host;
-	loff_t offset, size;
-	unsigned long filled;
-	void *buf;
-	int result = -EIO;
-
-	page_cache_get(page);
-	lock_kernel();
-	buf = kmap(page);
-	if (!buf)
-		goto err_out;
-
-	/* 32 bit warning -- but not for us :) */
-	offset = page_offset(page);
-	size = i_size_read(inode);
-	filled = 0;
-	result = 0;
-	if (offset < size) {
-		unsigned long readlen;
-
-		size -= offset;
-		readlen = size > PAGE_SIZE ? PAGE_SIZE : size;
-
-		filled = romfs_copyfrom(inode, buf, ROMFS_I(inode)->i_dataoffset+offset, readlen);
-
-		if (filled != readlen) {
-			SetPageError(page);
-			filled = 0;
-			result = -EIO;
-		}
-	}
-
-	if (filled < PAGE_SIZE)
-		memset(buf + filled, 0, PAGE_SIZE-filled);
-
-	if (!result)
-		SetPageUptodate(page);
-	flush_dcache_page(page);
-
-	unlock_page(page);
-
-	kunmap(page);
-err_out:
-	page_cache_release(page);
-	unlock_kernel();
-
-	return result;
-}
-
-/* Mapping from our types to the kernel */
-
-static const struct address_space_operations romfs_aops = {
-	.readpage = romfs_readpage
-};
-
-static const struct file_operations romfs_dir_operations = {
-	.read		= generic_read_dir,
-	.readdir	= romfs_readdir,
-};
-
-static const struct inode_operations romfs_dir_inode_operations = {
-	.lookup		= romfs_lookup,
-};
-
-static mode_t romfs_modemap[] =
-{
-	0, S_IFDIR+0644, S_IFREG+0644, S_IFLNK+0777,
-	S_IFBLK+0600, S_IFCHR+0600, S_IFSOCK+0644, S_IFIFO+0644
-};
-
-static struct inode *
-romfs_iget(struct super_block *sb, unsigned long ino)
-{
-	int nextfh, ret;
-	struct romfs_inode ri;
-	struct inode *i;
-
-	ino &= ROMFH_MASK;
-	i = iget_locked(sb, ino);
-	if (!i)
-		return ERR_PTR(-ENOMEM);
-	if (!(i->i_state & I_NEW))
-		return i;
-
-	i->i_mode = 0;
-
-	/* Loop for finding the real hard link */
-	for(;;) {
-		if (romfs_copyfrom(i, &ri, ino, ROMFH_SIZE) <= 0) {
-			printk(KERN_ERR "romfs: read error for inode 0x%lx\n",
-				ino);
-			iget_failed(i);
-			return ERR_PTR(-EIO);
-		}
-		/* XXX: do romfs_checksum here too (with name) */
-
-		nextfh = be32_to_cpu(ri.next);
-		if ((nextfh & ROMFH_TYPE) != ROMFH_HRD)
-			break;
-
-		ino = be32_to_cpu(ri.spec) & ROMFH_MASK;
-	}
-
-	i->i_nlink = 1;		/* Hard to decide.. */
-	i->i_size = be32_to_cpu(ri.size);
-	i->i_mtime.tv_sec = i->i_atime.tv_sec = i->i_ctime.tv_sec = 0;
-	i->i_mtime.tv_nsec = i->i_atime.tv_nsec = i->i_ctime.tv_nsec = 0;
-
-        /* Precalculate the data offset */
-	ret = romfs_strnlen(i, ino + ROMFH_SIZE, ROMFS_MAXFN);
-	if (ret >= 0)
-		ino = (ROMFH_SIZE + ret + 1 + ROMFH_PAD) & ROMFH_MASK;
-	else
-		ino = 0;
-
-        ROMFS_I(i)->i_metasize = ino;
-        ROMFS_I(i)->i_dataoffset = ino+(i->i_ino&ROMFH_MASK);
-
-        /* Compute permissions */
-        ino = romfs_modemap[nextfh & ROMFH_TYPE];
-	/* only "normal" files have ops */
-	switch (nextfh & ROMFH_TYPE) {
-		case 1:
-			i->i_size = ROMFS_I(i)->i_metasize;
-			i->i_op = &romfs_dir_inode_operations;
-			i->i_fop = &romfs_dir_operations;
-			if (nextfh & ROMFH_EXEC)
-				ino |= S_IXUGO;
-			i->i_mode = ino;
-			break;
-		case 2:
-			i->i_fop = &generic_ro_fops;
-			i->i_data.a_ops = &romfs_aops;
-			if (nextfh & ROMFH_EXEC)
-				ino |= S_IXUGO;
-			i->i_mode = ino;
-			break;
-		case 3:
-			i->i_op = &page_symlink_inode_operations;
-			i->i_data.a_ops = &romfs_aops;
-			i->i_mode = ino | S_IRWXUGO;
-			break;
-		default:
-			/* depending on MBZ for sock/fifos */
-			nextfh = be32_to_cpu(ri.spec);
-			init_special_inode(i, ino,
-					MKDEV(nextfh>>16,nextfh&0xffff));
-	}
-	unlock_new_inode(i);
-	return i;
-}
-
-static struct kmem_cache * romfs_inode_cachep;
-
-static struct inode *romfs_alloc_inode(struct super_block *sb)
-{
-	struct romfs_inode_info *ei;
-	ei = kmem_cache_alloc(romfs_inode_cachep, GFP_KERNEL);
-	if (!ei)
-		return NULL;
-	return &ei->vfs_inode;
-}
-
-static void romfs_destroy_inode(struct inode *inode)
-{
-	kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode));
-}
-
-static void init_once(void *foo)
-{
-	struct romfs_inode_info *ei = foo;
-
-	inode_init_once(&ei->vfs_inode);
-}
-
-static int init_inodecache(void)
-{
-	romfs_inode_cachep = kmem_cache_create("romfs_inode_cache",
-					     sizeof(struct romfs_inode_info),
-					     0, (SLAB_RECLAIM_ACCOUNT|
-						SLAB_MEM_SPREAD),
-					     init_once);
-	if (romfs_inode_cachep == NULL)
-		return -ENOMEM;
-	return 0;
-}
-
-static void destroy_inodecache(void)
-{
-	kmem_cache_destroy(romfs_inode_cachep);
-}
-
-static int romfs_remount(struct super_block *sb, int *flags, char *data)
-{
-	*flags |= MS_RDONLY;
-	return 0;
-}
-
-static const struct super_operations romfs_ops = {
-	.alloc_inode	= romfs_alloc_inode,
-	.destroy_inode	= romfs_destroy_inode,
-	.statfs		= romfs_statfs,
-	.remount_fs	= romfs_remount,
-};
-
-static int romfs_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
-{
-	return get_sb_bdev(fs_type, flags, dev_name, data, romfs_fill_super,
-			   mnt);
-}
-
-static struct file_system_type romfs_fs_type = {
-	.owner		= THIS_MODULE,
-	.name		= "romfs",
-	.get_sb		= romfs_get_sb,
-	.kill_sb	= kill_block_super,
-	.fs_flags	= FS_REQUIRES_DEV,
-};
-
-static int __init init_romfs_fs(void)
-{
-	int err = init_inodecache();
-	if (err)
-		goto out1;
-        err = register_filesystem(&romfs_fs_type);
-	if (err)
-		goto out;
-	return 0;
-out:
-	destroy_inodecache();
-out1:
-	return err;
-}
-
-static void __exit exit_romfs_fs(void)
-{
-	unregister_filesystem(&romfs_fs_type);
-	destroy_inodecache();
-}
-
-/* Yes, works even as a module... :) */
-
-module_init(init_romfs_fs)
-module_exit(exit_romfs_fs)
-MODULE_LICENSE("GPL");
diff --git a/fs/romfs/internal.h b/fs/romfs/internal.h
new file mode 100644
index 000000000000..06044a9dc62d
--- /dev/null
+++ b/fs/romfs/internal.h
@@ -0,0 +1,47 @@
+/* RomFS internal definitions
+ *
+ * Copyright © 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/romfs_fs.h>
+
+struct romfs_inode_info {
+	struct inode	vfs_inode;
+	unsigned long	i_metasize;	/* size of non-data area */
+	unsigned long	i_dataoffset;	/* from the start of fs */
+};
+
+static inline size_t romfs_maxsize(struct super_block *sb)
+{
+	return (size_t) (unsigned long) sb->s_fs_info;
+}
+
+static inline struct romfs_inode_info *ROMFS_I(struct inode *inode)
+{
+	return container_of(inode, struct romfs_inode_info, vfs_inode);
+}
+
+/*
+ * mmap-nommu.c
+ */
+#if !defined(CONFIG_MMU) && defined(CONFIG_ROMFS_ON_MTD)
+extern const struct file_operations romfs_ro_fops;
+#else
+#define romfs_ro_fops	generic_ro_fops
+#endif
+
+/*
+ * storage.c
+ */
+extern int romfs_dev_read(struct super_block *sb, unsigned long pos,
+			  void *buf, size_t buflen);
+extern ssize_t romfs_dev_strnlen(struct super_block *sb,
+				 unsigned long pos, size_t maxlen);
+extern int romfs_dev_strncmp(struct super_block *sb, unsigned long pos,
+			     const char *str, size_t size);
diff --git a/fs/romfs/mmap-nommu.c b/fs/romfs/mmap-nommu.c
new file mode 100644
index 000000000000..f0511e816967
--- /dev/null
+++ b/fs/romfs/mmap-nommu.c
@@ -0,0 +1,75 @@
+/* NOMMU mmap support for RomFS on MTD devices
+ *
+ * Copyright © 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/mm.h>
+#include <linux/mtd/super.h>
+#include "internal.h"
+
+/*
+ * try to determine where a shared mapping can be made
+ * - only supported for NOMMU at the moment (MMU can't doesn't copy private
+ *   mappings)
+ * - attempts to map through to the underlying MTD device
+ */
+static unsigned long romfs_get_unmapped_area(struct file *file,
+					     unsigned long addr,
+					     unsigned long len,
+					     unsigned long pgoff,
+					     unsigned long flags)
+{
+	struct inode *inode = file->f_mapping->host;
+	struct mtd_info *mtd = inode->i_sb->s_mtd;
+	unsigned long isize, offset;
+
+	if (!mtd)
+		goto cant_map_directly;
+
+	isize = i_size_read(inode);
+	offset = pgoff << PAGE_SHIFT;
+	if (offset > isize || len > isize || offset > isize - len)
+		return (unsigned long) -EINVAL;
+
+	/* we need to call down to the MTD layer to do the actual mapping */
+	if (mtd->get_unmapped_area) {
+		if (addr != 0)
+			return (unsigned long) -EINVAL;
+
+		if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
+			return (unsigned long) -EINVAL;
+
+		offset += ROMFS_I(inode)->i_dataoffset;
+		if (offset > mtd->size - len)
+			return (unsigned long) -EINVAL;
+
+		return mtd->get_unmapped_area(mtd, len, offset, flags);
+	}
+
+cant_map_directly:
+	return (unsigned long) -ENOSYS;
+}
+
+/*
+ * permit a R/O mapping to be made directly through onto an MTD device if
+ * possible
+ */
+static int romfs_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -ENOSYS;
+}
+
+const struct file_operations romfs_ro_fops = {
+	.llseek			= generic_file_llseek,
+	.read			= do_sync_read,
+	.aio_read		= generic_file_aio_read,
+	.splice_read		= generic_file_splice_read,
+	.mmap			= romfs_mmap,
+	.get_unmapped_area	= romfs_get_unmapped_area,
+};
diff --git a/fs/romfs/storage.c b/fs/romfs/storage.c
new file mode 100644
index 000000000000..7e3e1e12a081
--- /dev/null
+++ b/fs/romfs/storage.c
@@ -0,0 +1,261 @@
+/* RomFS storage access routines
+ *
+ * Copyright © 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/fs.h>
+#include <linux/mtd/super.h>
+#include <linux/buffer_head.h>
+#include "internal.h"
+
+#if !defined(CONFIG_ROMFS_ON_MTD) && !defined(CONFIG_ROMFS_ON_BLOCK)
+#error no ROMFS backing store interface configured
+#endif
+
+#ifdef CONFIG_ROMFS_ON_MTD
+#define ROMFS_MTD_READ(sb, ...) ((sb)->s_mtd->read((sb)->s_mtd, ##__VA_ARGS__))
+
+/*
+ * read data from an romfs image on an MTD device
+ */
+static int romfs_mtd_read(struct super_block *sb, unsigned long pos,
+			  void *buf, size_t buflen)
+{
+	size_t rlen;
+	int ret;
+
+	ret = ROMFS_MTD_READ(sb, pos, buflen, &rlen, buf);
+	return (ret < 0 || rlen != buflen) ? -EIO : 0;
+}
+
+/*
+ * determine the length of a string in a romfs image on an MTD device
+ */
+static ssize_t romfs_mtd_strnlen(struct super_block *sb,
+				 unsigned long pos, size_t maxlen)
+{
+	ssize_t n = 0;
+	size_t segment;
+	u_char buf[16], *p;
+	size_t len;
+	int ret;
+
+	/* scan the string up to 16 bytes at a time */
+	while (maxlen > 0) {
+		segment = min_t(size_t, maxlen, 16);
+		ret = ROMFS_MTD_READ(sb, pos, segment, &len, buf);
+		if (ret < 0)
+			return ret;
+		p = memchr(buf, 0, len);
+		if (p)
+			return n + (p - buf);
+		maxlen -= len;
+		pos += len;
+		n += len;
+	}
+
+	return n;
+}
+
+/*
+ * compare a string to one in a romfs image on MTD
+ * - return 1 if matched, 0 if differ, -ve if error
+ */
+static int romfs_mtd_strncmp(struct super_block *sb, unsigned long pos,
+			     const char *str, size_t size)
+{
+	u_char buf[16];
+	size_t len, segment;
+	int ret;
+
+	/* scan the string up to 16 bytes at a time */
+	while (size > 0) {
+		segment = min_t(size_t, size, 16);
+		ret = ROMFS_MTD_READ(sb, pos, segment, &len, buf);
+		if (ret < 0)
+			return ret;
+		if (memcmp(buf, str, len) != 0)
+			return 0;
+		size -= len;
+		pos += len;
+		str += len;
+	}
+
+	return 1;
+}
+#endif /* CONFIG_ROMFS_ON_MTD */
+
+#ifdef CONFIG_ROMFS_ON_BLOCK
+/*
+ * read data from an romfs image on a block device
+ */
+static int romfs_blk_read(struct super_block *sb, unsigned long pos,
+			  void *buf, size_t buflen)
+{
+	struct buffer_head *bh;
+	unsigned long offset;
+	size_t segment;
+
+	/* copy the string up to blocksize bytes at a time */
+	while (buflen > 0) {
+		offset = pos & (ROMBSIZE - 1);
+		segment = min_t(size_t, buflen, ROMBSIZE - offset);
+		bh = sb_bread(sb, pos >> ROMBSBITS);
+		if (!bh)
+			return -EIO;
+		memcpy(buf, bh->b_data + offset, segment);
+		brelse(bh);
+		buflen -= segment;
+		pos += segment;
+	}
+
+	return 0;
+}
+
+/*
+ * determine the length of a string in romfs on a block device
+ */
+static ssize_t romfs_blk_strnlen(struct super_block *sb,
+				 unsigned long pos, size_t limit)
+{
+	struct buffer_head *bh;
+	unsigned long offset;
+	ssize_t n = 0;
+	size_t segment;
+	u_char *buf, *p;
+
+	/* scan the string up to blocksize bytes at a time */
+	while (limit > 0) {
+		offset = pos & (ROMBSIZE - 1);
+		segment = min_t(size_t, limit, ROMBSIZE - offset);
+		bh = sb_bread(sb, pos >> ROMBSBITS);
+		if (!bh)
+			return -EIO;
+		buf = bh->b_data + offset;
+		p = memchr(buf, 0, segment);
+		brelse(bh);
+		if (p)
+			return n + (p - buf);
+		limit -= segment;
+		pos += segment;
+		n += segment;
+	}
+
+	return n;
+}
+
+/*
+ * compare a string to one in a romfs image on a block device
+ * - return 1 if matched, 0 if differ, -ve if error
+ */
+static int romfs_blk_strncmp(struct super_block *sb, unsigned long pos,
+			     const char *str, size_t size)
+{
+	struct buffer_head *bh;
+	unsigned long offset;
+	size_t segment;
+	bool x;
+
+	/* scan the string up to 16 bytes at a time */
+	while (size > 0) {
+		offset = pos & (ROMBSIZE - 1);
+		segment = min_t(size_t, size, ROMBSIZE - offset);
+		bh = sb_bread(sb, pos >> ROMBSBITS);
+		if (!bh)
+			return -EIO;
+		x = (memcmp(bh->b_data + offset, str, segment) != 0);
+		brelse(bh);
+		if (x)
+			return 0;
+		size -= segment;
+		pos += segment;
+		str += segment;
+	}
+
+	return 1;
+}
+#endif /* CONFIG_ROMFS_ON_BLOCK */
+
+/*
+ * read data from the romfs image
+ */
+int romfs_dev_read(struct super_block *sb, unsigned long pos,
+		   void *buf, size_t buflen)
+{
+	size_t limit;
+
+	limit = romfs_maxsize(sb);
+	if (pos >= limit)
+		return -EIO;
+	if (buflen > limit - pos)
+		buflen = limit - pos;
+
+#ifdef CONFIG_ROMFS_ON_MTD
+	if (sb->s_mtd)
+		return romfs_mtd_read(sb, pos, buf, buflen);
+#endif
+#ifdef CONFIG_ROMFS_ON_BLOCK
+	if (sb->s_bdev)
+		return romfs_blk_read(sb, pos, buf, buflen);
+#endif
+	return -EIO;
+}
+
+/*
+ * determine the length of a string in romfs
+ */
+ssize_t romfs_dev_strnlen(struct super_block *sb,
+			  unsigned long pos, size_t maxlen)
+{
+	size_t limit;
+
+	limit = romfs_maxsize(sb);
+	if (pos >= limit)
+		return -EIO;
+	if (maxlen > limit - pos)
+		maxlen = limit - pos;
+
+#ifdef CONFIG_ROMFS_ON_MTD
+	if (sb->s_mtd)
+		return romfs_mtd_strnlen(sb, pos, limit);
+#endif
+#ifdef CONFIG_ROMFS_ON_BLOCK
+	if (sb->s_bdev)
+		return romfs_blk_strnlen(sb, pos, limit);
+#endif
+	return -EIO;
+}
+
+/*
+ * compare a string to one in romfs
+ * - return 1 if matched, 0 if differ, -ve if error
+ */
+int romfs_dev_strncmp(struct super_block *sb, unsigned long pos,
+		      const char *str, size_t size)
+{
+	size_t limit;
+
+	limit = romfs_maxsize(sb);
+	if (pos >= limit)
+		return -EIO;
+	if (size > ROMFS_MAXFN)
+		return -ENAMETOOLONG;
+	if (size > limit - pos)
+		return -EIO;
+
+#ifdef CONFIG_ROMFS_ON_MTD
+	if (sb->s_mtd)
+		return romfs_mtd_strncmp(sb, pos, str, size);
+#endif
+#ifdef CONFIG_ROMFS_ON_BLOCK
+	if (sb->s_bdev)
+		return romfs_blk_strncmp(sb, pos, str, size);
+#endif
+	return -EIO;
+}
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
new file mode 100644
index 000000000000..1e548a4975ba
--- /dev/null
+++ b/fs/romfs/super.c
@@ -0,0 +1,648 @@
+/* Block- or MTD-based romfs
+ *
+ * Copyright © 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * Derived from: ROMFS file system, Linux implementation
+ *
+ * Copyright © 1997-1999  Janos Farkas <chexum@shadow.banki.hu>
+ *
+ * Using parts of the minix filesystem
+ * Copyright © 1991, 1992  Linus Torvalds
+ *
+ * and parts of the affs filesystem additionally
+ * Copyright © 1993  Ray Burr
+ * Copyright © 1996  Hans-Joachim Widmaier
+ *
+ * Changes
+ *					Changed for 2.1.19 modules
+ *	Jan 1997			Initial release
+ *	Jun 1997			2.1.43+ changes
+ *					Proper page locking in readpage
+ *					Changed to work with 2.1.45+ fs
+ *	Jul 1997			Fixed follow_link
+ *			2.1.47
+ *					lookup shouldn't return -ENOENT
+ *					from Horst von Brand:
+ *					  fail on wrong checksum
+ *					  double unlock_super was possible
+ *					  correct namelen for statfs
+ *					spotted by Bill Hawes:
+ *					  readlink shouldn't iput()
+ *	Jun 1998	2.1.106		from Avery Pennarun: glibc scandir()
+ *					  exposed a problem in readdir
+ *			2.1.107		code-freeze spellchecker run
+ *	Aug 1998			2.1.118+ VFS changes
+ *	Sep 1998	2.1.122		another VFS change (follow_link)
+ *	Apr 1999	2.2.7		no more EBADF checking in
+ *					  lookup/readdir, use ERR_PTR
+ *	Jun 1999	2.3.6		d_alloc_root use changed
+ *			2.3.9		clean up usage of ENOENT/negative
+ *					  dentries in lookup
+ *					clean up page flags setting
+ *					  (error, uptodate, locking) in
+ *					  in readpage
+ *					use init_special_inode for
+ *					  fifos/sockets (and streamline) in
+ *					  read_inode, fix _ops table order
+ *	Aug 1999	2.3.16		__initfunc() => __init change
+ *	Oct 1999	2.3.24		page->owner hack obsoleted
+ *	Nov 1999	2.3.27		2.3.25+ page->offset => index change
+ *
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/time.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/parser.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/statfs.h>
+#include <linux/mtd/super.h>
+#include <linux/ctype.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/uaccess.h>
+#include "internal.h"
+
+static struct kmem_cache *romfs_inode_cachep;
+
+static const umode_t romfs_modemap[8] = {
+	0,			/* hard link */
+	S_IFDIR  | 0644,	/* directory */
+	S_IFREG  | 0644,	/* regular file */
+	S_IFLNK  | 0777,	/* symlink */
+	S_IFBLK  | 0600,	/* blockdev */
+	S_IFCHR  | 0600,	/* chardev */
+	S_IFSOCK | 0644,	/* socket */
+	S_IFIFO  | 0644		/* FIFO */
+};
+
+static const unsigned char romfs_dtype_table[] = {
+	DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_SOCK, DT_FIFO
+};
+
+static struct inode *romfs_iget(struct super_block *sb, unsigned long pos);
+
+/*
+ * read a page worth of data from the image
+ */
+static int romfs_readpage(struct file *file, struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	loff_t offset, size;
+	unsigned long fillsize, pos;
+	void *buf;
+	int ret;
+
+	buf = kmap(page);
+	if (!buf)
+		return -ENOMEM;
+
+	/* 32 bit warning -- but not for us :) */
+	offset = page_offset(page);
+	size = i_size_read(inode);
+	fillsize = 0;
+	ret = 0;
+	if (offset < size) {
+		size -= offset;
+		fillsize = size > PAGE_SIZE ? PAGE_SIZE : size;
+
+		pos = ROMFS_I(inode)->i_dataoffset + offset;
+
+		ret = romfs_dev_read(inode->i_sb, pos, buf, fillsize);
+		if (ret < 0) {
+			SetPageError(page);
+			fillsize = 0;
+			ret = -EIO;
+		}
+	}
+
+	if (fillsize < PAGE_SIZE)
+		memset(buf + fillsize, 0, PAGE_SIZE - fillsize);
+	if (ret == 0)
+		SetPageUptodate(page);
+
+	flush_dcache_page(page);
+	kunmap(page);
+	unlock_page(page);
+	return ret;
+}
+
+static const struct address_space_operations romfs_aops = {
+	.readpage	= romfs_readpage
+};
+
+/*
+ * read the entries from a directory
+ */
+static int romfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+	struct inode *i = filp->f_dentry->d_inode;
+	struct romfs_inode ri;
+	unsigned long offset, maxoff;
+	int j, ino, nextfh;
+	int stored = 0;
+	char fsname[ROMFS_MAXFN];	/* XXX dynamic? */
+	int ret;
+
+	maxoff = romfs_maxsize(i->i_sb);
+
+	offset = filp->f_pos;
+	if (!offset) {
+		offset = i->i_ino & ROMFH_MASK;
+		ret = romfs_dev_read(i->i_sb, offset, &ri, ROMFH_SIZE);
+		if (ret < 0)
+			goto out;
+		offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
+	}
+
+	/* Not really failsafe, but we are read-only... */
+	for (;;) {
+		if (!offset || offset >= maxoff) {
+			offset = maxoff;
+			filp->f_pos = offset;
+			goto out;
+		}
+		filp->f_pos = offset;
+
+		/* Fetch inode info */
+		ret = romfs_dev_read(i->i_sb, offset, &ri, ROMFH_SIZE);
+		if (ret < 0)
+			goto out;
+
+		j = romfs_dev_strnlen(i->i_sb, offset + ROMFH_SIZE,
+				      sizeof(fsname) - 1);
+		if (j < 0)
+			goto out;
+
+		ret = romfs_dev_read(i->i_sb, offset + ROMFH_SIZE, fsname, j);
+		if (ret < 0)
+			goto out;
+		fsname[j] = '\0';
+
+		ino = offset;
+		nextfh = be32_to_cpu(ri.next);
+		if ((nextfh & ROMFH_TYPE) == ROMFH_HRD)
+			ino = be32_to_cpu(ri.spec);
+		if (filldir(dirent, fsname, j, offset, ino,
+			    romfs_dtype_table[nextfh & ROMFH_TYPE]) < 0)
+			goto out;
+
+		stored++;
+		offset = nextfh & ROMFH_MASK;
+	}
+
+out:
+	return stored;
+}
+
+/*
+ * look up an entry in a directory
+ */
+static struct dentry *romfs_lookup(struct inode *dir, struct dentry *dentry,
+				   struct nameidata *nd)
+{
+	unsigned long offset, maxoff;
+	struct inode *inode;
+	struct romfs_inode ri;
+	const char *name;		/* got from dentry */
+	int len, ret;
+
+	offset = dir->i_ino & ROMFH_MASK;
+	ret = romfs_dev_read(dir->i_sb, offset, &ri, ROMFH_SIZE);
+	if (ret < 0)
+		goto error;
+
+	/* search all the file entries in the list starting from the one
+	 * pointed to by the directory's special data */
+	maxoff = romfs_maxsize(dir->i_sb);
+	offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
+
+	name = dentry->d_name.name;
+	len = dentry->d_name.len;
+
+	for (;;) {
+		if (!offset || offset >= maxoff)
+			goto out0;
+
+		ret = romfs_dev_read(dir->i_sb, offset, &ri, sizeof(ri));
+		if (ret < 0)
+			goto error;
+
+		/* try to match the first 16 bytes of name */
+		ret = romfs_dev_strncmp(dir->i_sb, offset + ROMFH_SIZE, name,
+					len);
+		if (ret < 0)
+			goto error;
+		if (ret == 1)
+			break;
+
+		/* next entry */
+		offset = be32_to_cpu(ri.next) & ROMFH_MASK;
+	}
+
+	/* Hard link handling */
+	if ((be32_to_cpu(ri.next) & ROMFH_TYPE) == ROMFH_HRD)
+		offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
+
+	inode = romfs_iget(dir->i_sb, offset);
+	if (IS_ERR(inode)) {
+		ret = PTR_ERR(inode);
+		goto error;
+	}
+	goto outi;
+
+	/*
+	 * it's a bit funky, _lookup needs to return an error code
+	 * (negative) or a NULL, both as a dentry.  ENOENT should not
+	 * be returned, instead we need to create a negative dentry by
+	 * d_add(dentry, NULL); and return 0 as no error.
+	 * (Although as I see, it only matters on writable file
+	 * systems).
+	 */
+out0:
+	inode = NULL;
+outi:
+	d_add(dentry, inode);
+	ret = 0;
+error:
+	return ERR_PTR(ret);
+}
+
+static const struct file_operations romfs_dir_operations = {
+	.read		= generic_read_dir,
+	.readdir	= romfs_readdir,
+};
+
+static struct inode_operations romfs_dir_inode_operations = {
+	.lookup		= romfs_lookup,
+};
+
+/*
+ * get a romfs inode based on its position in the image (which doubles as the
+ * inode number)
+ */
+static struct inode *romfs_iget(struct super_block *sb, unsigned long pos)
+{
+	struct romfs_inode_info *inode;
+	struct romfs_inode ri;
+	struct inode *i;
+	unsigned long nlen;
+	unsigned nextfh, ret;
+	umode_t mode;
+
+	/* we might have to traverse a chain of "hard link" file entries to get
+	 * to the actual file */
+	for (;;) {
+		ret = romfs_dev_read(sb, pos, &ri, sizeof(ri));
+		if (ret < 0)
+			goto error;
+
+		/* XXX: do romfs_checksum here too (with name) */
+
+		nextfh = be32_to_cpu(ri.next);
+		if ((nextfh & ROMFH_TYPE) != ROMFH_HRD)
+			break;
+
+		pos = be32_to_cpu(ri.spec) & ROMFH_MASK;
+	}
+
+	/* determine the length of the filename */
+	nlen = romfs_dev_strnlen(sb, pos + ROMFH_SIZE, ROMFS_MAXFN);
+	if (IS_ERR_VALUE(nlen))
+		goto eio;
+
+	/* get an inode for this image position */
+	i = iget_locked(sb, pos);
+	if (!i)
+		return ERR_PTR(-ENOMEM);
+
+	if (!(i->i_state & I_NEW))
+		return i;
+
+	/* precalculate the data offset */
+	inode = ROMFS_I(i);
+	inode->i_metasize = (ROMFH_SIZE + nlen + 1 + ROMFH_PAD) & ROMFH_MASK;
+	inode->i_dataoffset = pos + inode->i_metasize;
+
+	i->i_nlink = 1;		/* Hard to decide.. */
+	i->i_size = be32_to_cpu(ri.size);
+	i->i_mtime.tv_sec = i->i_atime.tv_sec = i->i_ctime.tv_sec = 0;
+	i->i_mtime.tv_nsec = i->i_atime.tv_nsec = i->i_ctime.tv_nsec = 0;
+
+	/* set up mode and ops */
+	mode = romfs_modemap[nextfh & ROMFH_TYPE];
+
+	switch (nextfh & ROMFH_TYPE) {
+	case ROMFH_DIR:
+		i->i_size = ROMFS_I(i)->i_metasize;
+		i->i_op = &romfs_dir_inode_operations;
+		i->i_fop = &romfs_dir_operations;
+		if (nextfh & ROMFH_EXEC)
+			mode |= S_IXUGO;
+		break;
+	case ROMFH_REG:
+		i->i_fop = &romfs_ro_fops;
+		i->i_data.a_ops = &romfs_aops;
+		if (i->i_sb->s_mtd)
+			i->i_data.backing_dev_info =
+				i->i_sb->s_mtd->backing_dev_info;
+		if (nextfh & ROMFH_EXEC)
+			mode |= S_IXUGO;
+		break;
+	case ROMFH_SYM:
+		i->i_op = &page_symlink_inode_operations;
+		i->i_data.a_ops = &romfs_aops;
+		mode |= S_IRWXUGO;
+		break;
+	default:
+		/* depending on MBZ for sock/fifos */
+		nextfh = be32_to_cpu(ri.spec);
+		init_special_inode(i, mode, MKDEV(nextfh >> 16,
+						  nextfh & 0xffff));
+		break;
+	}
+
+	i->i_mode = mode;
+
+	unlock_new_inode(i);
+	return i;
+
+eio:
+	ret = -EIO;
+error:
+	printk(KERN_ERR "ROMFS: read error for inode 0x%lx\n", pos);
+	return ERR_PTR(ret);
+}
+
+/*
+ * allocate a new inode
+ */
+static struct inode *romfs_alloc_inode(struct super_block *sb)
+{
+	struct romfs_inode_info *inode;
+	inode = kmem_cache_alloc(romfs_inode_cachep, GFP_KERNEL);
+	return inode ? &inode->vfs_inode : NULL;
+}
+
+/*
+ * return a spent inode to the slab cache
+ */
+static void romfs_destroy_inode(struct inode *inode)
+{
+	kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode));
+}
+
+/*
+ * get filesystem statistics
+ */
+static int romfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	buf->f_type = ROMFS_MAGIC;
+	buf->f_namelen = ROMFS_MAXFN;
+	buf->f_bsize = ROMBSIZE;
+	buf->f_bfree = buf->f_bavail = buf->f_ffree;
+	buf->f_blocks =
+		(romfs_maxsize(dentry->d_sb) + ROMBSIZE - 1) >> ROMBSBITS;
+	return 0;
+}
+
+/*
+ * remounting must involve read-only
+ */
+static int romfs_remount(struct super_block *sb, int *flags, char *data)
+{
+	*flags |= MS_RDONLY;
+	return 0;
+}
+
+static const struct super_operations romfs_super_ops = {
+	.alloc_inode	= romfs_alloc_inode,
+	.destroy_inode	= romfs_destroy_inode,
+	.statfs		= romfs_statfs,
+	.remount_fs	= romfs_remount,
+};
+
+/*
+ * checksum check on part of a romfs filesystem
+ */
+static __u32 romfs_checksum(const void *data, int size)
+{
+	const __be32 *ptr = data;
+	__u32 sum;
+
+	sum = 0;
+	size >>= 2;
+	while (size > 0) {
+		sum += be32_to_cpu(*ptr++);
+		size--;
+	}
+	return sum;
+}
+
+/*
+ * fill in the superblock
+ */
+static int romfs_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct romfs_super_block *rsb;
+	struct inode *root;
+	unsigned long pos, img_size;
+	const char *storage;
+	size_t len;
+	int ret;
+
+#ifdef CONFIG_BLOCK
+	if (!sb->s_mtd) {
+		sb_set_blocksize(sb, ROMBSIZE);
+	} else {
+		sb->s_blocksize = ROMBSIZE;
+		sb->s_blocksize_bits = blksize_bits(ROMBSIZE);
+	}
+#endif
+
+	sb->s_maxbytes = 0xFFFFFFFF;
+	sb->s_magic = ROMFS_MAGIC;
+	sb->s_flags |= MS_RDONLY | MS_NOATIME;
+	sb->s_op = &romfs_super_ops;
+
+	/* read the image superblock and check it */
+	rsb = kmalloc(512, GFP_KERNEL);
+	if (!rsb)
+		return -ENOMEM;
+
+	sb->s_fs_info = (void *) 512;
+	ret = romfs_dev_read(sb, 0, rsb, 512);
+	if (ret < 0)
+		goto error_rsb;
+
+	img_size = be32_to_cpu(rsb->size);
+
+	if (sb->s_mtd && img_size > sb->s_mtd->size)
+		goto error_rsb_inval;
+
+	sb->s_fs_info = (void *) img_size;
+
+	if (rsb->word0 != ROMSB_WORD0 || rsb->word1 != ROMSB_WORD1 ||
+	    img_size < ROMFH_SIZE) {
+		if (!silent)
+			printk(KERN_WARNING "VFS:"
+			       " Can't find a romfs filesystem on dev %s.\n",
+			       sb->s_id);
+		goto error_rsb_inval;
+	}
+
+	if (romfs_checksum(rsb, min_t(size_t, img_size, 512))) {
+		printk(KERN_ERR "ROMFS: bad initial checksum on dev %s.\n",
+		       sb->s_id);
+		goto error_rsb_inval;
+	}
+
+	storage = sb->s_mtd ? "MTD" : "the block layer";
+
+	len = strnlen(rsb->name, ROMFS_MAXFN);
+	if (!silent)
+		printk(KERN_NOTICE "ROMFS: Mounting image '%*.*s' through %s\n",
+		       (unsigned) len, (unsigned) len, rsb->name, storage);
+
+	kfree(rsb);
+	rsb = NULL;
+
+	/* find the root directory */
+	pos = (ROMFH_SIZE + len + 1 + ROMFH_PAD) & ROMFH_MASK;
+
+	root = romfs_iget(sb, pos);
+	if (!root)
+		goto error;
+
+	sb->s_root = d_alloc_root(root);
+	if (!sb->s_root)
+		goto error_i;
+
+	return 0;
+
+error_i:
+	iput(root);
+error:
+	return -EINVAL;
+error_rsb_inval:
+	ret = -EINVAL;
+error_rsb:
+	return ret;
+}
+
+/*
+ * get a superblock for mounting
+ */
+static int romfs_get_sb(struct file_system_type *fs_type,
+			int flags, const char *dev_name,
+			void *data, struct vfsmount *mnt)
+{
+	int ret = -EINVAL;
+
+#ifdef CONFIG_ROMFS_ON_MTD
+	ret = get_sb_mtd(fs_type, flags, dev_name, data, romfs_fill_super,
+			 mnt);
+#endif
+#ifdef CONFIG_ROMFS_ON_BLOCK
+	if (ret == -EINVAL)
+		ret = get_sb_bdev(fs_type, flags, dev_name, data,
+				  romfs_fill_super, mnt);
+#endif
+	return ret;
+}
+
+/*
+ * destroy a romfs superblock in the appropriate manner
+ */
+static void romfs_kill_sb(struct super_block *sb)
+{
+#ifdef CONFIG_ROMFS_ON_MTD
+	if (sb->s_mtd) {
+		kill_mtd_super(sb);
+		return;
+	}
+#endif
+#ifdef CONFIG_ROMFS_ON_BLOCK
+	if (sb->s_bdev) {
+		kill_block_super(sb);
+		return;
+	}
+#endif
+}
+
+static struct file_system_type romfs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "romfs",
+	.get_sb		= romfs_get_sb,
+	.kill_sb	= romfs_kill_sb,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+
+/*
+ * inode storage initialiser
+ */
+static void romfs_i_init_once(void *_inode)
+{
+	struct romfs_inode_info *inode = _inode;
+
+	inode_init_once(&inode->vfs_inode);
+}
+
+/*
+ * romfs module initialisation
+ */
+static int __init init_romfs_fs(void)
+{
+	int ret;
+
+	printk(KERN_INFO "ROMFS MTD (C) 2007 Red Hat, Inc.\n");
+
+	romfs_inode_cachep =
+		kmem_cache_create("romfs_i",
+				  sizeof(struct romfs_inode_info), 0,
+				  SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
+				  romfs_i_init_once);
+
+	if (!romfs_inode_cachep) {
+		printk(KERN_ERR
+		       "ROMFS error: Failed to initialise inode cache\n");
+		return -ENOMEM;
+	}
+	ret = register_filesystem(&romfs_fs_type);
+	if (ret) {
+		printk(KERN_ERR "ROMFS error: Failed to register filesystem\n");
+		goto error_register;
+	}
+	return 0;
+
+error_register:
+	kmem_cache_destroy(romfs_inode_cachep);
+	return ret;
+}
+
+/*
+ * romfs module removal
+ */
+static void __exit exit_romfs_fs(void)
+{
+	unregister_filesystem(&romfs_fs_type);
+	kmem_cache_destroy(romfs_inode_cachep);
+}
+
+module_init(init_romfs_fs);
+module_exit(exit_romfs_fs);
+
+MODULE_DESCRIPTION("Direct-MTD Capable RomFS");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL"); /* Actually dual-licensed, but it doesn't matter for */