If you don't know whether you need it, then you don't need it:
answer N.
+
+config ROMFS_ON_BLOCK
+ bool "Block device-backed ROM file system support" if (ROMFS_ON_MTD && EMBEDDED)
+ depends on ROMFS_FS && 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_ON_MTD
+ bool "MTD-backed ROM file system support"
+ depends on ROMFS_FS
+ 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.
+
#
-# 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
+
+++ /dev/null
-/*
- * 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");
--- /dev/null
+/* 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);
--- /dev/null
+/* 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,
+};
--- /dev/null
+/* 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;
+}
--- /dev/null
+/* 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 */
projects / linux-2.6-omap-h63xx.git / commitdiff