rename libdde_linux26 into libdde-linux26 to make dpkg-source happy

3 files changed, 0 insertions, 5468 deletions

diff --git a/libdde_linux26/lib/src/fs/block_dev.c b/libdde_linux26/lib/src/fs/block_dev.c
deleted file mode 100644
index 4c4c2f64..00000000
--- a/libdde_linux26/lib/src/fs/block_dev.c
+++ /dev/null
@@ -1,1422 +0,0 @@
-/*
- *  linux/fs/block_dev.c
- *
- *  Copyright (C) 1991, 1992  Linus Torvalds
- *  Copyright (C) 2001  Andrea Arcangeli <andrea@suse.de> SuSE
- */
-
-#include <linux/init.h>
-#include <linux/mm.h>
-#include <linux/fcntl.h>
-#include <linux/slab.h>
-#include <linux/kmod.h>
-#include <linux/major.h>
-#include <linux/smp_lock.h>
-#include <linux/device_cgroup.h>
-#include <linux/highmem.h>
-#include <linux/blkdev.h>
-#include <linux/module.h>
-#include <linux/blkpg.h>
-#include <linux/buffer_head.h>
-#include <linux/writeback.h>
-#include <linux/mpage.h>
-#include <linux/mount.h>
-#include <linux/uio.h>
-#include <linux/namei.h>
-#include <linux/log2.h>
-#include <asm/uaccess.h>
-#include "internal.h"
-
-#ifdef DDE_LINUX
-#include "local.h"
-#endif
-
-struct bdev_inode {
-	struct block_device bdev;
-	struct inode vfs_inode;
-};
-
-static const struct address_space_operations def_blk_aops;
-
-static inline struct bdev_inode *BDEV_I(struct inode *inode)
-{
-	return container_of(inode, struct bdev_inode, vfs_inode);
-}
-
-inline struct block_device *I_BDEV(struct inode *inode)
-{
-	return &BDEV_I(inode)->bdev;
-}
-
-EXPORT_SYMBOL(I_BDEV);
-
-static sector_t max_block(struct block_device *bdev)
-{
-	sector_t retval = ~((sector_t)0);
-	loff_t sz = i_size_read(bdev->bd_inode);
-
-	if (sz) {
-		unsigned int size = block_size(bdev);
-		unsigned int sizebits = blksize_bits(size);
-		retval = (sz >> sizebits);
-	}
-	return retval;
-}
-
-/* Kill _all_ buffers and pagecache , dirty or not.. */
-static void kill_bdev(struct block_device *bdev)
-{
-	if (bdev->bd_inode->i_mapping->nrpages == 0)
-		return;
-	invalidate_bh_lrus();
-	truncate_inode_pages(bdev->bd_inode->i_mapping, 0);
-}	
-
-int set_blocksize(struct block_device *bdev, int size)
-{
-	/* Size must be a power of two, and between 512 and PAGE_SIZE */
-	if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size))
-		return -EINVAL;
-
-	/* Size cannot be smaller than the size supported by the device */
-	if (size < bdev_hardsect_size(bdev))
-		return -EINVAL;
-
-	/* Don't change the size if it is same as current */
-	if (bdev->bd_block_size != size) {
-		sync_blockdev(bdev);
-		bdev->bd_block_size = size;
-		bdev->bd_inode->i_blkbits = blksize_bits(size);
-		kill_bdev(bdev);
-	}
-	return 0;
-}
-
-EXPORT_SYMBOL(set_blocksize);
-
-int sb_set_blocksize(struct super_block *sb, int size)
-{
-	if (set_blocksize(sb->s_bdev, size))
-		return 0;
-	/* If we get here, we know size is power of two
-	 * and it's value is between 512 and PAGE_SIZE */
-	sb->s_blocksize = size;
-	sb->s_blocksize_bits = blksize_bits(size);
-	return sb->s_blocksize;
-}
-
-EXPORT_SYMBOL(sb_set_blocksize);
-
-int sb_min_blocksize(struct super_block *sb, int size)
-{
-	int minsize = bdev_hardsect_size(sb->s_bdev);
-	if (size < minsize)
-		size = minsize;
-	return sb_set_blocksize(sb, size);
-}
-
-EXPORT_SYMBOL(sb_min_blocksize);
-
-static int
-blkdev_get_block(struct inode *inode, sector_t iblock,
-		struct buffer_head *bh, int create)
-{
-	if (iblock >= max_block(I_BDEV(inode))) {
-		if (create)
-			return -EIO;
-
-		/*
-		 * for reads, we're just trying to fill a partial page.
-		 * return a hole, they will have to call get_block again
-		 * before they can fill it, and they will get -EIO at that
-		 * time
-		 */
-		return 0;
-	}
-	bh->b_bdev = I_BDEV(inode);
-	bh->b_blocknr = iblock;
-	set_buffer_mapped(bh);
-	return 0;
-}
-
-static int
-blkdev_get_blocks(struct inode *inode, sector_t iblock,
-		struct buffer_head *bh, int create)
-{
-	sector_t end_block = max_block(I_BDEV(inode));
-	unsigned long max_blocks = bh->b_size >> inode->i_blkbits;
-
-	if ((iblock + max_blocks) > end_block) {
-		max_blocks = end_block - iblock;
-		if ((long)max_blocks <= 0) {
-			if (create)
-				return -EIO;	/* write fully beyond EOF */
-			/*
-			 * It is a read which is fully beyond EOF.  We return
-			 * a !buffer_mapped buffer
-			 */
-			max_blocks = 0;
-		}
-	}
-
-	bh->b_bdev = I_BDEV(inode);
-	bh->b_blocknr = iblock;
-	bh->b_size = max_blocks << inode->i_blkbits;
-	if (max_blocks)
-		set_buffer_mapped(bh);
-	return 0;
-}
-
-static ssize_t
-blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
-			loff_t offset, unsigned long nr_segs)
-{
-	struct file *file = iocb->ki_filp;
-	struct inode *inode = file->f_mapping->host;
-
-#ifndef DDE_LINUX
-	return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode),
-				iov, offset, nr_segs, blkdev_get_blocks, NULL);
-#else
-	WARN_UNIMPL;
-	return 0;
-#endif /* DDE_LINUX */
-}
-
-static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
-{
-	return block_write_full_page(page, blkdev_get_block, wbc);
-}
-
-static int blkdev_readpage(struct file * file, struct page * page)
-{
-	return block_read_full_page(page, blkdev_get_block);
-}
-
-static int blkdev_write_begin(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned flags,
-			struct page **pagep, void **fsdata)
-{
-	*pagep = NULL;
-	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-				blkdev_get_block);
-}
-
-static int blkdev_write_end(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned copied,
-			struct page *page, void *fsdata)
-{
-	int ret;
-	ret = block_write_end(file, mapping, pos, len, copied, page, fsdata);
-
-	unlock_page(page);
-	page_cache_release(page);
-
-	return ret;
-}
-
-/*
- * private llseek:
- * for a block special file file->f_path.dentry->d_inode->i_size is zero
- * so we compute the size by hand (just as in block_read/write above)
- */
-static loff_t block_llseek(struct file *file, loff_t offset, int origin)
-{
-	struct inode *bd_inode = file->f_mapping->host;
-	loff_t size;
-	loff_t retval;
-
-	mutex_lock(&bd_inode->i_mutex);
-	size = i_size_read(bd_inode);
-
-	switch (origin) {
-		case 2:
-			offset += size;
-			break;
-		case 1:
-			offset += file->f_pos;
-	}
-	retval = -EINVAL;
-	if (offset >= 0 && offset <= size) {
-		if (offset != file->f_pos) {
-			file->f_pos = offset;
-		}
-		retval = offset;
-	}
-	mutex_unlock(&bd_inode->i_mutex);
-	return retval;
-}
-	
-/*
- *	Filp is never NULL; the only case when ->fsync() is called with
- *	NULL first argument is nfsd_sync_dir() and that's not a directory.
- */
- 
-static int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
-{
-	return sync_blockdev(I_BDEV(filp->f_mapping->host));
-}
-
-/*
- * pseudo-fs
- */
-
-static  __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock);
-static struct kmem_cache * bdev_cachep __read_mostly;
-
-static struct inode *bdev_alloc_inode(struct super_block *sb)
-{
-	struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
-	if (!ei)
-		return NULL;
-	return &ei->vfs_inode;
-}
-
-static void bdev_destroy_inode(struct inode *inode)
-{
-	struct bdev_inode *bdi = BDEV_I(inode);
-
-	bdi->bdev.bd_inode_backing_dev_info = NULL;
-	kmem_cache_free(bdev_cachep, bdi);
-}
-
-static void init_once(void *foo)
-{
-	struct bdev_inode *ei = (struct bdev_inode *) foo;
-	struct block_device *bdev = &ei->bdev;
-
-	memset(bdev, 0, sizeof(*bdev));
-	mutex_init(&bdev->bd_mutex);
-	sema_init(&bdev->bd_mount_sem, 1);
-	INIT_LIST_HEAD(&bdev->bd_inodes);
-	INIT_LIST_HEAD(&bdev->bd_list);
-#ifdef CONFIG_SYSFS
-	INIT_LIST_HEAD(&bdev->bd_holder_list);
-#endif
-	inode_init_once(&ei->vfs_inode);
-	/* Initialize mutex for freeze. */
-	mutex_init(&bdev->bd_fsfreeze_mutex);
-}
-
-static inline void __bd_forget(struct inode *inode)
-{
-	list_del_init(&inode->i_devices);
-	inode->i_bdev = NULL;
-	inode->i_mapping = &inode->i_data;
-}
-
-static void bdev_clear_inode(struct inode *inode)
-{
-	struct block_device *bdev = &BDEV_I(inode)->bdev;
-	struct list_head *p;
-	spin_lock(&bdev_lock);
-	while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) {
-		__bd_forget(list_entry(p, struct inode, i_devices));
-	}
-	list_del_init(&bdev->bd_list);
-	spin_unlock(&bdev_lock);
-}
-
-static const struct super_operations bdev_sops = {
-	.statfs = simple_statfs,
-	.alloc_inode = bdev_alloc_inode,
-	.destroy_inode = bdev_destroy_inode,
-	.drop_inode = generic_delete_inode,
-	.clear_inode = bdev_clear_inode,
-};
-
-static int bd_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
-{
-	return get_sb_pseudo(fs_type, "bdev:", &bdev_sops, 0x62646576, mnt);
-}
-
-static struct file_system_type bd_type = {
-	.name		= "bdev",
-	.get_sb		= bd_get_sb,
-	.kill_sb	= kill_anon_super,
-};
-
-struct super_block *blockdev_superblock __read_mostly;
-
-void __init bdev_cache_init(void)
-{
-	int err;
-	struct vfsmount *bd_mnt;
-
-	bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode),
-			0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
-				SLAB_MEM_SPREAD|SLAB_PANIC),
-			init_once);
-	err = register_filesystem(&bd_type);
-	if (err)
-		panic("Cannot register bdev pseudo-fs");
-	bd_mnt = kern_mount(&bd_type);
-	if (IS_ERR(bd_mnt))
-		panic("Cannot create bdev pseudo-fs");
-	blockdev_superblock = bd_mnt->mnt_sb;	/* For writeback */
-}
-
-/*
- * Most likely _very_ bad one - but then it's hardly critical for small
- * /dev and can be fixed when somebody will need really large one.
- * Keep in mind that it will be fed through icache hash function too.
- */
-static inline unsigned long hash(dev_t dev)
-{
-	return MAJOR(dev)+MINOR(dev);
-}
-
-static int bdev_test(struct inode *inode, void *data)
-{
-	return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data;
-}
-
-static int bdev_set(struct inode *inode, void *data)
-{
-	BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data;
-	return 0;
-}
-
-static LIST_HEAD(all_bdevs);
-
-struct block_device *bdget(dev_t dev)
-{
-	struct block_device *bdev;
-	struct inode *inode;
-
-	printk_all_partitions();
-
-	inode = iget5_locked(blockdev_superblock, hash(dev),
-			bdev_test, bdev_set, &dev);
-
-	if (!inode)
-		return NULL;
-
-	bdev = &BDEV_I(inode)->bdev;
-
-	if (inode->i_state & I_NEW) {
-		bdev->bd_contains = NULL;
-		bdev->bd_inode = inode;
-		bdev->bd_block_size = (1 << inode->i_blkbits);
-		bdev->bd_part_count = 0;
-		bdev->bd_invalidated = 0;
-		inode->i_mode = S_IFBLK;
-		inode->i_rdev = dev;
-		inode->i_bdev = bdev;
-		inode->i_data.a_ops = &def_blk_aops;
-		mapping_set_gfp_mask(&inode->i_data, GFP_USER);
-		inode->i_data.backing_dev_info = &default_backing_dev_info;
-		spin_lock(&bdev_lock);
-		list_add(&bdev->bd_list, &all_bdevs);
-		spin_unlock(&bdev_lock);
-		unlock_new_inode(inode);
-	}
-	return bdev;
-}
-
-EXPORT_SYMBOL(bdget);
-
-long nr_blockdev_pages(void)
-{
-	struct block_device *bdev;
-	long ret = 0;
-	spin_lock(&bdev_lock);
-	list_for_each_entry(bdev, &all_bdevs, bd_list) {
-		ret += bdev->bd_inode->i_mapping->nrpages;
-	}
-	spin_unlock(&bdev_lock);
-	return ret;
-}
-
-void bdput(struct block_device *bdev)
-{
-	iput(bdev->bd_inode);
-}
-
-EXPORT_SYMBOL(bdput);
- 
-static struct block_device *bd_acquire(struct inode *inode)
-{
-	struct block_device *bdev;
-
-	spin_lock(&bdev_lock);
-	bdev = inode->i_bdev;
-	if (bdev) {
-		atomic_inc(&bdev->bd_inode->i_count);
-		spin_unlock(&bdev_lock);
-		return bdev;
-	}
-	spin_unlock(&bdev_lock);
-
-	bdev = bdget(inode->i_rdev);
-	if (bdev) {
-		spin_lock(&bdev_lock);
-		if (!inode->i_bdev) {
-			/*
-			 * We take an additional bd_inode->i_count for inode,
-			 * and it's released in clear_inode() of inode.
-			 * So, we can access it via ->i_mapping always
-			 * without igrab().
-			 */
-			atomic_inc(&bdev->bd_inode->i_count);
-			inode->i_bdev = bdev;
-			inode->i_mapping = bdev->bd_inode->i_mapping;
-			list_add(&inode->i_devices, &bdev->bd_inodes);
-		}
-		spin_unlock(&bdev_lock);
-	}
-	return bdev;
-}
-
-/* Call when you free inode */
-
-void bd_forget(struct inode *inode)
-{
-	struct block_device *bdev = NULL;
-
-	spin_lock(&bdev_lock);
-	if (inode->i_bdev) {
-		if (!sb_is_blkdev_sb(inode->i_sb))
-			bdev = inode->i_bdev;
-		__bd_forget(inode);
-	}
-	spin_unlock(&bdev_lock);
-
-	if (bdev)
-		iput(bdev->bd_inode);
-}
-
-int bd_claim(struct block_device *bdev, void *holder)
-{
-	int res;
-	spin_lock(&bdev_lock);
-
-	/* first decide result */
-	if (bdev->bd_holder == holder)
-		res = 0;	 /* already a holder */
-	else if (bdev->bd_holder != NULL)
-		res = -EBUSY; 	 /* held by someone else */
-	else if (bdev->bd_contains == bdev)
-		res = 0;  	 /* is a whole device which isn't held */
-
-	else if (bdev->bd_contains->bd_holder == bd_claim)
-		res = 0; 	 /* is a partition of a device that is being partitioned */
-	else if (bdev->bd_contains->bd_holder != NULL)
-		res = -EBUSY;	 /* is a partition of a held device */
-	else
-		res = 0;	 /* is a partition of an un-held device */
-
-	/* now impose change */
-	if (res==0) {
-		/* note that for a whole device bd_holders
-		 * will be incremented twice, and bd_holder will
-		 * be set to bd_claim before being set to holder
-		 */
-		bdev->bd_contains->bd_holders ++;
-		bdev->bd_contains->bd_holder = bd_claim;
-		bdev->bd_holders++;
-		bdev->bd_holder = holder;
-	}
-	spin_unlock(&bdev_lock);
-	return res;
-}
-
-EXPORT_SYMBOL(bd_claim);
-
-void bd_release(struct block_device *bdev)
-{
-	spin_lock(&bdev_lock);
-	if (!--bdev->bd_contains->bd_holders)
-		bdev->bd_contains->bd_holder = NULL;
-	if (!--bdev->bd_holders)
-		bdev->bd_holder = NULL;
-	spin_unlock(&bdev_lock);
-}
-
-EXPORT_SYMBOL(bd_release);
-
-#ifdef CONFIG_SYSFS
-/*
- * Functions for bd_claim_by_kobject / bd_release_from_kobject
- *
- *     If a kobject is passed to bd_claim_by_kobject()
- *     and the kobject has a parent directory,
- *     following symlinks are created:
- *        o from the kobject to the claimed bdev
- *        o from "holders" directory of the bdev to the parent of the kobject
- *     bd_release_from_kobject() removes these symlinks.
- *
- *     Example:
- *        If /dev/dm-0 maps to /dev/sda, kobject corresponding to
- *        /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then:
- *           /sys/block/dm-0/slaves/sda --> /sys/block/sda
- *           /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
- */
-
-static int add_symlink(struct kobject *from, struct kobject *to)
-{
-	if (!from || !to)
-		return 0;
-	return sysfs_create_link(from, to, kobject_name(to));
-}
-
-static void del_symlink(struct kobject *from, struct kobject *to)
-{
-	if (!from || !to)
-		return;
-	sysfs_remove_link(from, kobject_name(to));
-}
-
-/*
- * 'struct bd_holder' contains pointers to kobjects symlinked by
- * bd_claim_by_kobject.
- * It's connected to bd_holder_list which is protected by bdev->bd_sem.
- */
-struct bd_holder {
-	struct list_head list;	/* chain of holders of the bdev */
-	int count;		/* references from the holder */
-	struct kobject *sdir;	/* holder object, e.g. "/block/dm-0/slaves" */
-	struct kobject *hdev;	/* e.g. "/block/dm-0" */
-	struct kobject *hdir;	/* e.g. "/block/sda/holders" */
-	struct kobject *sdev;	/* e.g. "/block/sda" */
-};
-
-/*
- * Get references of related kobjects at once.
- * Returns 1 on success. 0 on failure.
- *
- * Should call bd_holder_release_dirs() after successful use.
- */
-static int bd_holder_grab_dirs(struct block_device *bdev,
-			struct bd_holder *bo)
-{
-	if (!bdev || !bo)
-		return 0;
-
-	bo->sdir = kobject_get(bo->sdir);
-	if (!bo->sdir)
-		return 0;
-
-	bo->hdev = kobject_get(bo->sdir->parent);
-	if (!bo->hdev)
-		goto fail_put_sdir;
-
-	bo->sdev = kobject_get(&part_to_dev(bdev->bd_part)->kobj);
-	if (!bo->sdev)
-		goto fail_put_hdev;
-
-	bo->hdir = kobject_get(bdev->bd_part->holder_dir);
-	if (!bo->hdir)
-		goto fail_put_sdev;
-
-	return 1;
-
-fail_put_sdev:
-	kobject_put(bo->sdev);
-fail_put_hdev:
-	kobject_put(bo->hdev);
-fail_put_sdir:
-	kobject_put(bo->sdir);
-
-	return 0;
-}
-
-/* Put references of related kobjects at once. */
-static void bd_holder_release_dirs(struct bd_holder *bo)
-{
-	kobject_put(bo->hdir);
-	kobject_put(bo->sdev);
-	kobject_put(bo->hdev);
-	kobject_put(bo->sdir);
-}
-
-static struct bd_holder *alloc_bd_holder(struct kobject *kobj)
-{
-	struct bd_holder *bo;
-
-	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
-	if (!bo)
-		return NULL;
-
-	bo->count = 1;
-	bo->sdir = kobj;
-
-	return bo;
-}
-
-static void free_bd_holder(struct bd_holder *bo)
-{
-	kfree(bo);
-}
-
-/**
- * find_bd_holder - find matching struct bd_holder from the block device
- *
- * @bdev:	struct block device to be searched
- * @bo:		target struct bd_holder
- *
- * Returns matching entry with @bo in @bdev->bd_holder_list.
- * If found, increment the reference count and return the pointer.
- * If not found, returns NULL.
- */
-static struct bd_holder *find_bd_holder(struct block_device *bdev,
-					struct bd_holder *bo)
-{
-	struct bd_holder *tmp;
-
-	list_for_each_entry(tmp, &bdev->bd_holder_list, list)
-		if (tmp->sdir == bo->sdir) {
-			tmp->count++;
-			return tmp;
-		}
-
-	return NULL;
-}
-
-/**
- * add_bd_holder - create sysfs symlinks for bd_claim() relationship
- *
- * @bdev:	block device to be bd_claimed
- * @bo:		preallocated and initialized by alloc_bd_holder()
- *
- * Add @bo to @bdev->bd_holder_list, create symlinks.
- *
- * Returns 0 if symlinks are created.
- * Returns -ve if something fails.
- */
-static int add_bd_holder(struct block_device *bdev, struct bd_holder *bo)
-{
-	int err;
-
-	if (!bo)
-		return -EINVAL;
-
-	if (!bd_holder_grab_dirs(bdev, bo))
-		return -EBUSY;
-
-	err = add_symlink(bo->sdir, bo->sdev);
-	if (err)
-		return err;
-
-	err = add_symlink(bo->hdir, bo->hdev);
-	if (err) {
-		del_symlink(bo->sdir, bo->sdev);
-		return err;
-	}
-
-	list_add_tail(&bo->list, &bdev->bd_holder_list);
-	return 0;
-}
-
-/**
- * del_bd_holder - delete sysfs symlinks for bd_claim() relationship
- *
- * @bdev:	block device to be bd_claimed
- * @kobj:	holder's kobject
- *
- * If there is matching entry with @kobj in @bdev->bd_holder_list
- * and no other bd_claim() from the same kobject,
- * remove the struct bd_holder from the list, delete symlinks for it.
- *
- * Returns a pointer to the struct bd_holder when it's removed from the list
- * and ready to be freed.
- * Returns NULL if matching claim isn't found or there is other bd_claim()
- * by the same kobject.
- */
-static struct bd_holder *del_bd_holder(struct block_device *bdev,
-					struct kobject *kobj)
-{
-	struct bd_holder *bo;
-
-	list_for_each_entry(bo, &bdev->bd_holder_list, list) {
-		if (bo->sdir == kobj) {
-			bo->count--;
-			BUG_ON(bo->count < 0);
-			if (!bo->count) {
-				list_del(&bo->list);
-				del_symlink(bo->sdir, bo->sdev);
-				del_symlink(bo->hdir, bo->hdev);
-				bd_holder_release_dirs(bo);
-				return bo;
-			}
-			break;
-		}
-	}
-
-	return NULL;
-}
-
-/**
- * bd_claim_by_kobject - bd_claim() with additional kobject signature
- *
- * @bdev:	block device to be claimed
- * @holder:	holder's signature
- * @kobj:	holder's kobject
- *
- * Do bd_claim() and if it succeeds, create sysfs symlinks between
- * the bdev and the holder's kobject.
- * Use bd_release_from_kobject() when relesing the claimed bdev.
- *
- * Returns 0 on success. (same as bd_claim())
- * Returns errno on failure.
- */
-static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
-				struct kobject *kobj)
-{
-	int err;
-	struct bd_holder *bo, *found;
-
-	if (!kobj)
-		return -EINVAL;
-
-	bo = alloc_bd_holder(kobj);
-	if (!bo)
-		return -ENOMEM;
-
-	mutex_lock(&bdev->bd_mutex);
-
-	err = bd_claim(bdev, holder);
-	if (err)
-		goto fail;
-
-	found = find_bd_holder(bdev, bo);
-	if (found)
-		goto fail;
-
-	err = add_bd_holder(bdev, bo);
-	if (err)
-		bd_release(bdev);
-	else
-		bo = NULL;
-fail:
-	mutex_unlock(&bdev->bd_mutex);
-	free_bd_holder(bo);
-	return err;
-}
-
-/**
- * bd_release_from_kobject - bd_release() with additional kobject signature
- *
- * @bdev:	block device to be released
- * @kobj:	holder's kobject
- *
- * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject().
- */
-static void bd_release_from_kobject(struct block_device *bdev,
-					struct kobject *kobj)
-{
-	if (!kobj)
-		return;
-
-	mutex_lock(&bdev->bd_mutex);
-	bd_release(bdev);
-	free_bd_holder(del_bd_holder(bdev, kobj));
-	mutex_unlock(&bdev->bd_mutex);
-}
-
-/**
- * bd_claim_by_disk - wrapper function for bd_claim_by_kobject()
- *
- * @bdev:	block device to be claimed
- * @holder:	holder's signature
- * @disk:	holder's gendisk
- *
- * Call bd_claim_by_kobject() with getting @disk->slave_dir.
- */
-int bd_claim_by_disk(struct block_device *bdev, void *holder,
-			struct gendisk *disk)
-{
-	return bd_claim_by_kobject(bdev, holder, kobject_get(disk->slave_dir));
-}
-EXPORT_SYMBOL_GPL(bd_claim_by_disk);
-
-/**
- * bd_release_from_disk - wrapper function for bd_release_from_kobject()
- *
- * @bdev:	block device to be claimed
- * @disk:	holder's gendisk
- *
- * Call bd_release_from_kobject() and put @disk->slave_dir.
- */
-void bd_release_from_disk(struct block_device *bdev, struct gendisk *disk)
-{
-	bd_release_from_kobject(bdev, disk->slave_dir);
-	kobject_put(disk->slave_dir);
-}
-EXPORT_SYMBOL_GPL(bd_release_from_disk);
-#endif
-
-/*
- * Tries to open block device by device number.  Use it ONLY if you
- * really do not have anything better - i.e. when you are behind a
- * truly sucky interface and all you are given is a device number.  _Never_
- * to be used for internal purposes.  If you ever need it - reconsider
- * your API.
- */
-struct block_device *open_by_devnum(dev_t dev, fmode_t mode)
-{
-	struct block_device *bdev = bdget(dev);
-	int err = -ENOMEM;
-	if (bdev)
-		err = blkdev_get(bdev, mode);
-	return err ? ERR_PTR(err) : bdev;
-}
-
-EXPORT_SYMBOL(open_by_devnum);
-
-/**
- * flush_disk - invalidates all buffer-cache entries on a disk
- *
- * @bdev:      struct block device to be flushed
- *
- * Invalidates all buffer-cache entries on a disk. It should be called
- * when a disk has been changed -- either by a media change or online
- * resize.
- */
-static void flush_disk(struct block_device *bdev)
-{
-	if (__invalidate_device(bdev)) {
-		char name[BDEVNAME_SIZE] = "";
-
-		if (bdev->bd_disk)
-			disk_name(bdev->bd_disk, 0, name);
-		printk(KERN_WARNING "VFS: busy inodes on changed media or "
-		       "resized disk %s\n", name);
-	}
-
-	if (!bdev->bd_disk)
-		return;
-	if (disk_partitionable(bdev->bd_disk))
-		bdev->bd_invalidated = 1;
-}
-
-/**
- * check_disk_size_change - checks for disk size change and adjusts bdev size.
- * @disk: struct gendisk to check
- * @bdev: struct bdev to adjust.
- *
- * This routine checks to see if the bdev size does not match the disk size
- * and adjusts it if it differs.
- */
-void check_disk_size_change(struct gendisk *disk, struct block_device *bdev)
-{
-	loff_t disk_size, bdev_size;
-
-	disk_size = (loff_t)get_capacity(disk) << 9;
-	bdev_size = i_size_read(bdev->bd_inode);
-	if (disk_size != bdev_size) {
-		char name[BDEVNAME_SIZE];
-
-		disk_name(disk, 0, name);
-		printk(KERN_INFO
-		       "%s: detected capacity change from %lld to %lld\n",
-		       name, bdev_size, disk_size);
-		i_size_write(bdev->bd_inode, disk_size);
-		flush_disk(bdev);
-	}
-}
-EXPORT_SYMBOL(check_disk_size_change);
-
-/**
- * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
- * @disk: struct gendisk to be revalidated
- *
- * This routine is a wrapper for lower-level driver's revalidate_disk
- * call-backs.  It is used to do common pre and post operations needed
- * for all revalidate_disk operations.
- */
-int revalidate_disk(struct gendisk *disk)
-{
-	struct block_device *bdev;
-	int ret = 0;
-
-	if (disk->fops->revalidate_disk)
-		ret = disk->fops->revalidate_disk(disk);
-
-	bdev = bdget_disk(disk, 0);
-	if (!bdev)
-		return ret;
-
-	mutex_lock(&bdev->bd_mutex);
-	check_disk_size_change(disk, bdev);
-	mutex_unlock(&bdev->bd_mutex);
-	bdput(bdev);
-	return ret;
-}
-EXPORT_SYMBOL(revalidate_disk);
-
-/*
- * This routine checks whether a removable media has been changed,
- * and invalidates all buffer-cache-entries in that case. This
- * is a relatively slow routine, so we have to try to minimize using
- * it. Thus it is called only upon a 'mount' or 'open'. This
- * is the best way of combining speed and utility, I think.
- * People changing diskettes in the middle of an operation deserve
- * to lose :-)
- */
-int check_disk_change(struct block_device *bdev)
-{
-	struct gendisk *disk = bdev->bd_disk;
-	struct block_device_operations * bdops = disk->fops;
-
-	if (!bdops->media_changed)
-		return 0;
-	if (!bdops->media_changed(bdev->bd_disk))
-		return 0;
-
-	flush_disk(bdev);
-	if (bdops->revalidate_disk)
-		bdops->revalidate_disk(bdev->bd_disk);
-	return 1;
-}
-
-EXPORT_SYMBOL(check_disk_change);
-
-void bd_set_size(struct block_device *bdev, loff_t size)
-{
-	unsigned bsize = bdev_hardsect_size(bdev);
-
-	bdev->bd_inode->i_size = size;
-	while (bsize < PAGE_CACHE_SIZE) {
-		if (size & bsize)
-			break;
-		bsize <<= 1;
-	}
-	bdev->bd_block_size = bsize;
-	bdev->bd_inode->i_blkbits = blksize_bits(bsize);
-}
-EXPORT_SYMBOL(bd_set_size);
-
-static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
-
-/*
- * bd_mutex locking:
- *
- *  mutex_lock(part->bd_mutex)
- *    mutex_lock_nested(whole->bd_mutex, 1)
- */
-
-static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
-{
-	struct gendisk *disk;
-	int ret;
-	int partno;
-	int perm = 0;
-
-	if (mode & FMODE_READ)
-		perm |= MAY_READ;
-	if (mode & FMODE_WRITE)
-		perm |= MAY_WRITE;
-	/*
-	 * hooks: /n/, see "layering violations".
-	 */
-	ret = devcgroup_inode_permission(bdev->bd_inode, perm);
-	if (ret != 0) {
-		bdput(bdev);
-		return ret;
-	}
-
-	lock_kernel();
- restart:
-
-	ret = -ENXIO;
-	disk = get_gendisk(bdev->bd_dev, &partno);
-	if (!disk)
-		goto out_unlock_kernel;
-
-	mutex_lock_nested(&bdev->bd_mutex, for_part);
-	if (!bdev->bd_openers) {
-		bdev->bd_disk = disk;
-		bdev->bd_contains = bdev;
-		if (!partno) {
-			struct backing_dev_info *bdi;
-
-			ret = -ENXIO;
-			bdev->bd_part = disk_get_part(disk, partno);
-			if (!bdev->bd_part)
-				goto out_clear;
-
-			if (disk->fops->open) {
-				ret = disk->fops->open(bdev, mode);
-				if (ret == -ERESTARTSYS) {
-					/* Lost a race with 'disk' being
-					 * deleted, try again.
-					 * See md.c
-					 */
-					disk_put_part(bdev->bd_part);
-					bdev->bd_part = NULL;
-					module_put(disk->fops->owner);
-					put_disk(disk);
-					bdev->bd_disk = NULL;
-					mutex_unlock(&bdev->bd_mutex);
-					goto restart;
-				}
-				if (ret)
-					goto out_clear;
-			}
-			if (!bdev->bd_openers) {
-				bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
-				bdi = blk_get_backing_dev_info(bdev);
-				if (bdi == NULL)
-					bdi = &default_backing_dev_info;
-				bdev->bd_inode->i_data.backing_dev_info = bdi;
-			}
-			if (bdev->bd_invalidated)
-				rescan_partitions(disk, bdev);
-		} else {
-			struct block_device *whole;
-			whole = bdget_disk(disk, 0);
-			ret = -ENOMEM;
-			if (!whole)
-				goto out_clear;
-			BUG_ON(for_part);
-			ret = __blkdev_get(whole, mode, 1);
-			if (ret)
-				goto out_clear;
-			bdev->bd_contains = whole;
-			bdev->bd_inode->i_data.backing_dev_info =
-			   whole->bd_inode->i_data.backing_dev_info;
-			bdev->bd_part = disk_get_part(disk, partno);
-			if (!(disk->flags & GENHD_FL_UP) ||
-			    !bdev->bd_part || !bdev->bd_part->nr_sects) {
-				ret = -ENXIO;
-				goto out_clear;
-			}
-			bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
-		}
-	} else {
-		put_disk(disk);
-		module_put(disk->fops->owner);
-		disk = NULL;
-		if (bdev->bd_contains == bdev) {
-			if (bdev->bd_disk->fops->open) {
-				ret = bdev->bd_disk->fops->open(bdev, mode);
-				if (ret)
-					goto out_unlock_bdev;
-			}
-			if (bdev->bd_invalidated)
-				rescan_partitions(bdev->bd_disk, bdev);
-		}
-	}
-	bdev->bd_openers++;
-	if (for_part)
-		bdev->bd_part_count++;
-	mutex_unlock(&bdev->bd_mutex);
-	unlock_kernel();
-	return 0;
-
- out_clear:
-	disk_put_part(bdev->bd_part);
-	bdev->bd_disk = NULL;
-	bdev->bd_part = NULL;
-	bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
-	if (bdev != bdev->bd_contains)
-		__blkdev_put(bdev->bd_contains, mode, 1);
-	bdev->bd_contains = NULL;
- out_unlock_bdev:
-	mutex_unlock(&bdev->bd_mutex);
- out_unlock_kernel:
-	unlock_kernel();
-
-	if (disk)
-		module_put(disk->fops->owner);
-	put_disk(disk);
-	bdput(bdev);
-
-	return ret;
-}
-
-int blkdev_get(struct block_device *bdev, fmode_t mode)
-{
-	return __blkdev_get(bdev, mode, 0);
-}
-EXPORT_SYMBOL(blkdev_get);
-
-static int blkdev_open(struct inode * inode, struct file * filp)
-{
-	struct block_device *bdev;
-	int res;
-
-	/*
-	 * Preserve backwards compatibility and allow large file access
-	 * even if userspace doesn't ask for it explicitly. Some mkfs
-	 * binary needs it. We might want to drop this workaround
-	 * during an unstable branch.
-	 */
-	filp->f_flags |= O_LARGEFILE;
-
-	if (filp->f_flags & O_NDELAY)
-		filp->f_mode |= FMODE_NDELAY;
-	if (filp->f_flags & O_EXCL)
-		filp->f_mode |= FMODE_EXCL;
-	if ((filp->f_flags & O_ACCMODE) == 3)
-		filp->f_mode |= FMODE_WRITE_IOCTL;
-
-	bdev = bd_acquire(inode);
-	if (bdev == NULL)
-		return -ENOMEM;
-
-	filp->f_mapping = bdev->bd_inode->i_mapping;
-
-	res = blkdev_get(bdev, filp->f_mode);
-	if (res)
-		return res;
-
-	if (filp->f_mode & FMODE_EXCL) {
-		res = bd_claim(bdev, filp);
-		if (res)
-			goto out_blkdev_put;
-	}
-
-	return 0;
-
- out_blkdev_put:
-	blkdev_put(bdev, filp->f_mode);
-	return res;
-}
-
-static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
-{
-	int ret = 0;
-	struct gendisk *disk = bdev->bd_disk;
-	struct block_device *victim = NULL;
-
-	mutex_lock_nested(&bdev->bd_mutex, for_part);
-	lock_kernel();
-	if (for_part)
-		bdev->bd_part_count--;
-
-	if (!--bdev->bd_openers) {
-		sync_blockdev(bdev);
-		kill_bdev(bdev);
-	}
-	if (bdev->bd_contains == bdev) {
-		if (disk->fops->release)
-			ret = disk->fops->release(disk, mode);
-	}
-	if (!bdev->bd_openers) {
-		struct module *owner = disk->fops->owner;
-
-		put_disk(disk);
-		module_put(owner);
-		disk_put_part(bdev->bd_part);
-		bdev->bd_part = NULL;
-		bdev->bd_disk = NULL;
-		bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
-		if (bdev != bdev->bd_contains)
-			victim = bdev->bd_contains;
-		bdev->bd_contains = NULL;
-	}
-	unlock_kernel();
-	mutex_unlock(&bdev->bd_mutex);
-	bdput(bdev);
-	if (victim)
-		__blkdev_put(victim, mode, 1);
-	return ret;
-}
-
-int blkdev_put(struct block_device *bdev, fmode_t mode)
-{
-	return __blkdev_put(bdev, mode, 0);
-}
-EXPORT_SYMBOL(blkdev_put);
-
-static int blkdev_close(struct inode * inode, struct file * filp)
-{
-	struct block_device *bdev = I_BDEV(filp->f_mapping->host);
-	if (bdev->bd_holder == filp)
-		bd_release(bdev);
-	return blkdev_put(bdev, filp->f_mode);
-}
-
-static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
-{
-	struct block_device *bdev = I_BDEV(file->f_mapping->host);
-	fmode_t mode = file->f_mode;
-
-	/*
-	 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
-	 * to updated it before every ioctl.
-	 */
-	if (file->f_flags & O_NDELAY)
-		mode |= FMODE_NDELAY;
-	else
-		mode &= ~FMODE_NDELAY;
-
-	return blkdev_ioctl(bdev, mode, cmd, arg);
-}
-
-/*
- * Try to release a page associated with block device when the system
- * is under memory pressure.
- */
-static int blkdev_releasepage(struct page *page, gfp_t wait)
-{
-	struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super;
-
-	if (super && super->s_op->bdev_try_to_free_page)
-		return super->s_op->bdev_try_to_free_page(super, page, wait);
-
-	return try_to_free_buffers(page);
-}
-
-static const struct address_space_operations def_blk_aops = {
-	.readpage	= blkdev_readpage,
-	.writepage	= blkdev_writepage,
-	.sync_page	= block_sync_page,
-	.write_begin	= blkdev_write_begin,
-	.write_end	= blkdev_write_end,
-	.writepages	= generic_writepages,
-	.releasepage	= blkdev_releasepage,
-	.direct_IO	= blkdev_direct_IO,
-};
-
-const struct file_operations def_blk_fops = {
-	.open		= blkdev_open,
-	.release	= blkdev_close,
-#ifndef DDE_LINUX
-	.llseek		= block_llseek,
-	.read		= do_sync_read,
-	.write		= do_sync_write,
-  	.aio_read	= generic_file_aio_read,
-  	.aio_write	= generic_file_aio_write_nolock,
-	.mmap		= generic_file_mmap,
-	.fsync		= block_fsync,
-	.unlocked_ioctl	= block_ioctl,
-#ifdef CONFIG_COMPAT
-	.compat_ioctl	= compat_blkdev_ioctl,
-#endif
-	.splice_read	= generic_file_splice_read,
-	.splice_write	= generic_file_splice_write,
-#endif /* DDE_LINUX */
-};
-
-int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
-{
-	int res;
-	mm_segment_t old_fs = get_fs();
-	set_fs(KERNEL_DS);
-	res = blkdev_ioctl(bdev, 0, cmd, arg);
-	set_fs(old_fs);
-	return res;
-}
-
-EXPORT_SYMBOL(ioctl_by_bdev);
-
-/**
- * lookup_bdev  - lookup a struct block_device by name
- * @pathname:	special file representing the block device
- *
- * Get a reference to the blockdevice at @pathname in the current
- * namespace if possible and return it.  Return ERR_PTR(error)
- * otherwise.
- */
-struct block_device *lookup_bdev(const char *pathname)
-{
-	struct block_device *bdev;
-	struct inode *inode;
-	struct path path;
-	int error;
-
-	if (!pathname || !*pathname)
-		return ERR_PTR(-EINVAL);
-
-	error = kern_path(pathname, LOOKUP_FOLLOW, &path);
-	if (error)
-		return ERR_PTR(error);
-
-	inode = path.dentry->d_inode;
-	error = -ENOTBLK;
-	if (!S_ISBLK(inode->i_mode))
-		goto fail;
-	error = -EACCES;
-	if (path.mnt->mnt_flags & MNT_NODEV)
-		goto fail;
-	error = -ENOMEM;
-	bdev = bd_acquire(inode);
-	if (!bdev)
-		goto fail;
-out:
-	path_put(&path);
-	return bdev;
-fail:
-	bdev = ERR_PTR(error);
-	goto out;
-}
-EXPORT_SYMBOL(lookup_bdev);
-
-/**
- * open_bdev_exclusive  -  open a block device by name and set it up for use
- *
- * @path:	special file representing the block device
- * @mode:	FMODE_... combination to pass be used
- * @holder:	owner for exclusion
- *
- * Open the blockdevice described by the special file at @path, claim it
- * for the @holder.
- */
-struct block_device *open_bdev_exclusive(const char *path, fmode_t mode, void *holder)
-{
-	struct block_device *bdev;
-	int error = 0;
-
-	bdev = lookup_bdev(path);
-	if (IS_ERR(bdev))
-		return bdev;
-
-	error = blkdev_get(bdev, mode);
-	if (error)
-		return ERR_PTR(error);
-	error = -EACCES;
-	if ((mode & FMODE_WRITE) && bdev_read_only(bdev))
-		goto blkdev_put;
-	error = bd_claim(bdev, holder);
-	if (error)
-		goto blkdev_put;
-
-	return bdev;
-	
-blkdev_put:
-	blkdev_put(bdev, mode);
-	return ERR_PTR(error);
-}
-
-EXPORT_SYMBOL(open_bdev_exclusive);
-
-/**
- * close_bdev_exclusive  -  close a blockdevice opened by open_bdev_exclusive()
- *
- * @bdev:	blockdevice to close
- * @mode:	mode, must match that used to open.
- *
- * This is the counterpart to open_bdev_exclusive().
- */
-void close_bdev_exclusive(struct block_device *bdev, fmode_t mode)
-{
-	bd_release(bdev);
-	blkdev_put(bdev, mode);
-}
-
-EXPORT_SYMBOL(close_bdev_exclusive);
-
-int __invalidate_device(struct block_device *bdev)
-{
-	struct super_block *sb = get_super(bdev);
-	int res = 0;
-
-	if (sb) {
-		/*
-		 * no need to lock the super, get_super holds the
-		 * read mutex so the filesystem cannot go away
-		 * under us (->put_super runs with the write lock
-		 * hold).
-		 */
-		shrink_dcache_sb(sb);
-		res = invalidate_inodes(sb);
-		drop_super(sb);
-	}
-	invalidate_bdev(bdev);
-	return res;
-}
-EXPORT_SYMBOL(__invalidate_device);
diff --git a/libdde_linux26/lib/src/fs/buffer.c b/libdde_linux26/lib/src/fs/buffer.c
deleted file mode 100644
index d3b1c445..00000000
--- a/libdde_linux26/lib/src/fs/buffer.c
+++ /dev/null
@@ -1,3474 +0,0 @@
-/*
- *  linux/fs/buffer.c
- *
- *  Copyright (C) 1991, 1992, 2002  Linus Torvalds
- */
-
-/*
- * Start bdflush() with kernel_thread not syscall - Paul Gortmaker, 12/95
- *
- * Removed a lot of unnecessary code and simplified things now that
- * the buffer cache isn't our primary cache - Andrew Tridgell 12/96
- *
- * Speed up hash, lru, and free list operations.  Use gfp() for allocating
- * hash table, use SLAB cache for buffer heads. SMP threading.  -DaveM
- *
- * Added 32k buffer block sizes - these are required older ARM systems. - RMK
- *
- * async buffer flushing, 1999 Andrea Arcangeli <andrea@suse.de>
- */
-
-#include <linux/kernel.h>
-#include <linux/syscalls.h>
-#include <linux/fs.h>
-#include <linux/mm.h>
-#include <linux/percpu.h>
-#include <linux/slab.h>
-#include <linux/capability.h>
-#include <linux/blkdev.h>
-#include <linux/file.h>
-#include <linux/quotaops.h>
-#include <linux/highmem.h>
-#include <linux/module.h>
-#include <linux/writeback.h>
-#include <linux/hash.h>
-#include <linux/suspend.h>
-#include <linux/buffer_head.h>
-#include <linux/task_io_accounting_ops.h>
-#include <linux/bio.h>
-#include <linux/notifier.h>
-#include <linux/cpu.h>
-#include <linux/bitops.h>
-#include <linux/mpage.h>
-#include <linux/bit_spinlock.h>
-
-static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
-
-#define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers)
-
-inline void
-init_buffer(struct buffer_head *bh, bh_end_io_t *handler, void *private)
-{
-	bh->b_end_io = handler;
-	bh->b_private = private;
-}
-
-static int sync_buffer(void *word)
-{
-	struct block_device *bd;
-	struct buffer_head *bh
-		= container_of(word, struct buffer_head, b_state);
-
-	smp_mb();
-	bd = bh->b_bdev;
-	if (bd)
-		blk_run_address_space(bd->bd_inode->i_mapping);
-	io_schedule();
-	return 0;
-}
-
-void __lock_buffer(struct buffer_head *bh)
-{
-	wait_on_bit_lock(&bh->b_state, BH_Lock, sync_buffer,
-							TASK_UNINTERRUPTIBLE);
-}
-EXPORT_SYMBOL(__lock_buffer);
-
-void unlock_buffer(struct buffer_head *bh)
-{
-	clear_bit_unlock(BH_Lock, &bh->b_state);
-	smp_mb__after_clear_bit();
-	wake_up_bit(&bh->b_state, BH_Lock);
-}
-
-/*
- * Block until a buffer comes unlocked.  This doesn't stop it
- * from becoming locked again - you have to lock it yourself
- * if you want to preserve its state.
- */
-void __wait_on_buffer(struct buffer_head * bh)
-{
-	wait_on_bit(&bh->b_state, BH_Lock, sync_buffer, TASK_UNINTERRUPTIBLE);
-}
-
-static void
-__clear_page_buffers(struct page *page)
-{
-	ClearPagePrivate(page);
-	set_page_private(page, 0);
-	page_cache_release(page);
-}
-
-
-static int quiet_error(struct buffer_head *bh)
-{
-	if (!test_bit(BH_Quiet, &bh->b_state) && printk_ratelimit())
-		return 0;
-	return 1;
-}
-
-
-static void buffer_io_error(struct buffer_head *bh)
-{
-	char b[BDEVNAME_SIZE];
-	printk(KERN_ERR "Buffer I/O error on device %s, logical block %Lu\n",
-			bdevname(bh->b_bdev, b),
-			(unsigned long long)bh->b_blocknr);
-}
-
-/*
- * End-of-IO handler helper function which does not touch the bh after
- * unlocking it.
- * Note: unlock_buffer() sort-of does touch the bh after unlocking it, but
- * a race there is benign: unlock_buffer() only use the bh's address for
- * hashing after unlocking the buffer, so it doesn't actually touch the bh
- * itself.
- */
-static void __end_buffer_read_notouch(struct buffer_head *bh, int uptodate)
-{
-	if (uptodate) {
-		set_buffer_uptodate(bh);
-	} else {
-		/* This happens, due to failed READA attempts. */
-		clear_buffer_uptodate(bh);
-	}
-	unlock_buffer(bh);
-}
-
-/*
- * Default synchronous end-of-IO handler..  Just mark it up-to-date and
- * unlock the buffer. This is what ll_rw_block uses too.
- */
-void end_buffer_read_sync(struct buffer_head *bh, int uptodate)
-{
-	__end_buffer_read_notouch(bh, uptodate);
-	put_bh(bh);
-}
-
-void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
-{
-	char b[BDEVNAME_SIZE];
-
-	if (uptodate) {
-		set_buffer_uptodate(bh);
-	} else {
-		if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) {
-			buffer_io_error(bh);
-			printk(KERN_WARNING "lost page write due to "
-					"I/O error on %s\n",
-				       bdevname(bh->b_bdev, b));
-		}
-		set_buffer_write_io_error(bh);
-		clear_buffer_uptodate(bh);
-	}
-	unlock_buffer(bh);
-	put_bh(bh);
-}
-
-/*
- * Write out and wait upon all the dirty data associated with a block
- * device via its mapping.  Does not take the superblock lock.
- */
-int sync_blockdev(struct block_device *bdev)
-{
-#ifndef DDE_LINUX
-	int ret = 0;
-
-	if (bdev)
-		ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
-	return ret;
-#else
-	WARN_UNIMPL;
-	return 0;
-#endif /* DDE_LINUX */
-}
-EXPORT_SYMBOL(sync_blockdev);
-
-/*
- * Write out and wait upon all dirty data associated with this
- * device.   Filesystem data as well as the underlying block
- * device.  Takes the superblock lock.
- */
-int fsync_bdev(struct block_device *bdev)
-{
-#ifndef DDE_LINUX
-	struct super_block *sb = get_super(bdev);
-	if (sb) {
-		int res = fsync_super(sb);
-		drop_super(sb);
-		return res;
-	}
-	return sync_blockdev(bdev);
-#else
-	WARN_UNIMPL;
-	return -1;
-#endif
-}
-
-/**
- * freeze_bdev  --  lock a filesystem and force it into a consistent state
- * @bdev:	blockdevice to lock
- *
- * This takes the block device bd_mount_sem to make sure no new mounts
- * happen on bdev until thaw_bdev() is called.
- * If a superblock is found on this device, we take the s_umount semaphore
- * on it to make sure nobody unmounts until the snapshot creation is done.
- * The reference counter (bd_fsfreeze_count) guarantees that only the last
- * unfreeze process can unfreeze the frozen filesystem actually when multiple
- * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
- * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
- * actually.
- */
-struct super_block *freeze_bdev(struct block_device *bdev)
-{
-	struct super_block *sb;
-	int error = 0;
-
-	mutex_lock(&bdev->bd_fsfreeze_mutex);
-	if (bdev->bd_fsfreeze_count > 0) {
-		bdev->bd_fsfreeze_count++;
-		sb = get_super(bdev);
-		mutex_unlock(&bdev->bd_fsfreeze_mutex);
-		return sb;
-	}
-	bdev->bd_fsfreeze_count++;
-
-	down(&bdev->bd_mount_sem);
-	sb = get_super(bdev);
-	if (sb && !(sb->s_flags & MS_RDONLY)) {
-		sb->s_frozen = SB_FREEZE_WRITE;
-		smp_wmb();
-
-		__fsync_super(sb);
-
-		sb->s_frozen = SB_FREEZE_TRANS;
-		smp_wmb();
-
-		sync_blockdev(sb->s_bdev);
-
-		if (sb->s_op->freeze_fs) {
-			error = sb->s_op->freeze_fs(sb);
-			if (error) {
-				printk(KERN_ERR
-					"VFS:Filesystem freeze failed\n");
-				sb->s_frozen = SB_UNFROZEN;
-				drop_super(sb);
-				up(&bdev->bd_mount_sem);
-				bdev->bd_fsfreeze_count--;
-				mutex_unlock(&bdev->bd_fsfreeze_mutex);
-				return ERR_PTR(error);
-			}
-		}
-	}
-
-	sync_blockdev(bdev);
-	mutex_unlock(&bdev->bd_fsfreeze_mutex);
-
-	return sb;	/* thaw_bdev releases s->s_umount and bd_mount_sem */
-}
-EXPORT_SYMBOL(freeze_bdev);
-
-/**
- * thaw_bdev  -- unlock filesystem
- * @bdev:	blockdevice to unlock
- * @sb:		associated superblock
- *
- * Unlocks the filesystem and marks it writeable again after freeze_bdev().
- */
-int thaw_bdev(struct block_device *bdev, struct super_block *sb)
-{
-	int error = 0;
-
-	mutex_lock(&bdev->bd_fsfreeze_mutex);
-	if (!bdev->bd_fsfreeze_count) {
-		mutex_unlock(&bdev->bd_fsfreeze_mutex);
-		return -EINVAL;
-	}
-
-	bdev->bd_fsfreeze_count--;
-	if (bdev->bd_fsfreeze_count > 0) {
-		if (sb)
-			drop_super(sb);
-		mutex_unlock(&bdev->bd_fsfreeze_mutex);
-		return 0;
-	}
-
-	if (sb) {
-		BUG_ON(sb->s_bdev != bdev);
-		if (!(sb->s_flags & MS_RDONLY)) {
-			if (sb->s_op->unfreeze_fs) {
-				error = sb->s_op->unfreeze_fs(sb);
-				if (error) {
-					printk(KERN_ERR
-						"VFS:Filesystem thaw failed\n");
-					sb->s_frozen = SB_FREEZE_TRANS;
-					bdev->bd_fsfreeze_count++;
-					mutex_unlock(&bdev->bd_fsfreeze_mutex);
-					return error;
-				}
-			}
-			sb->s_frozen = SB_UNFROZEN;
-			smp_wmb();
-			wake_up(&sb->s_wait_unfrozen);
-		}
-		drop_super(sb);
-	}
-
-	up(&bdev->bd_mount_sem);
-	mutex_unlock(&bdev->bd_fsfreeze_mutex);
-	return 0;
-}
-EXPORT_SYMBOL(thaw_bdev);
-
-/*
- * Various filesystems appear to want __find_get_block to be non-blocking.
- * But it's the page lock which protects the buffers.  To get around this,
- * we get exclusion from try_to_free_buffers with the blockdev mapping's
- * private_lock.
- *
- * Hack idea: for the blockdev mapping, i_bufferlist_lock contention
- * may be quite high.  This code could TryLock the page, and if that
- * succeeds, there is no need to take private_lock. (But if
- * private_lock is contended then so is mapping->tree_lock).
- */
-static struct buffer_head *
-__find_get_block_slow(struct block_device *bdev, sector_t block)
-{
-	struct inode *bd_inode = bdev->bd_inode;
-	struct address_space *bd_mapping = bd_inode->i_mapping;
-	struct buffer_head *ret = NULL;
-	pgoff_t index;
-	struct buffer_head *bh;
-	struct buffer_head *head;
-	struct page *page;
-	int all_mapped = 1;
-
-	index = block >> (PAGE_CACHE_SHIFT - bd_inode->i_blkbits);
-	page = find_get_page(bd_mapping, index);
-	if (!page)
-		goto out;
-
-	spin_lock(&bd_mapping->private_lock);
-	if (!page_has_buffers(page))
-		goto out_unlock;
-	head = page_buffers(page);
-	bh = head;
-	do {
-		if (bh->b_blocknr == block) {
-			ret = bh;
-			get_bh(bh);
-			goto out_unlock;
-		}
-		if (!buffer_mapped(bh))
-			all_mapped = 0;
-		bh = bh->b_this_page;
-	} while (bh != head);
-
-	/* we might be here because some of the buffers on this page are
-	 * not mapped.  This is due to various races between
-	 * file io on the block device and getblk.  It gets dealt with
-	 * elsewhere, don't buffer_error if we had some unmapped buffers
-	 */
-	if (all_mapped) {
-		printk("__find_get_block_slow() failed. "
-			"block=%llu, b_blocknr=%llu\n",
-			(unsigned long long)block,
-			(unsigned long long)bh->b_blocknr);
-		printk("b_state=0x%08lx, b_size=%zu\n",
-			bh->b_state, bh->b_size);
-		printk("device blocksize: %d\n", 1 << bd_inode->i_blkbits);
-	}
-out_unlock:
-	spin_unlock(&bd_mapping->private_lock);
-	page_cache_release(page);
-out:
-	return ret;
-}
-
-/* If invalidate_buffers() will trash dirty buffers, it means some kind
-   of fs corruption is going on. Trashing dirty data always imply losing
-   information that was supposed to be just stored on the physical layer
-   by the user.
-
-   Thus invalidate_buffers in general usage is not allwowed to trash
-   dirty buffers. For example ioctl(FLSBLKBUF) expects dirty data to
-   be preserved.  These buffers are simply skipped.
-  
-   We also skip buffers which are still in use.  For example this can
-   happen if a userspace program is reading the block device.
-
-   NOTE: In the case where the user removed a removable-media-disk even if
-   there's still dirty data not synced on disk (due a bug in the device driver
-   or due an error of the user), by not destroying the dirty buffers we could
-   generate corruption also on the next media inserted, thus a parameter is
-   necessary to handle this case in the most safe way possible (trying
-   to not corrupt also the new disk inserted with the data belonging to
-   the old now corrupted disk). Also for the ramdisk the natural thing
-   to do in order to release the ramdisk memory is to destroy dirty buffers.
-
-   These are two special cases. Normal usage imply the device driver
-   to issue a sync on the device (without waiting I/O completion) and
-   then an invalidate_buffers call that doesn't trash dirty buffers.
-
-   For handling cache coherency with the blkdev pagecache the 'update' case
-   is been introduced. It is needed to re-read from disk any pinned
-   buffer. NOTE: re-reading from disk is destructive so we can do it only
-   when we assume nobody is changing the buffercache under our I/O and when
-   we think the disk contains more recent information than the buffercache.
-   The update == 1 pass marks the buffers we need to update, the update == 2
-   pass does the actual I/O. */
-void invalidate_bdev(struct block_device *bdev)
-{
-	struct address_space *mapping = bdev->bd_inode->i_mapping;
-
-	if (mapping->nrpages == 0)
-		return;
-
-#ifndef DDE_LINUX
-	invalidate_bh_lrus();
-	invalidate_mapping_pages(mapping, 0, -1);
-#endif
-}
-
-/*
- * Kick pdflush then try to free up some ZONE_NORMAL memory.
- */
-static void free_more_memory(void)
-{
-	struct zone *zone;
-	int nid;
-
-#ifndef DDE_LINUX
-	wakeup_pdflush(1024);
-	yield();
-
-	for_each_online_node(nid) {
-		(void)first_zones_zonelist(node_zonelist(nid, GFP_NOFS),
-						gfp_zone(GFP_NOFS), NULL,
-						&zone);
-		if (zone)
-			try_to_free_pages(node_zonelist(nid, GFP_NOFS), 0,
-						GFP_NOFS);
-	}
-#else
-	WARN_UNIMPL;
-#endif
-}
-
-/*
- * I/O completion handler for block_read_full_page() - pages
- * which come unlocked at the end of I/O.
- */
-static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
-{
-	unsigned long flags;
-	struct buffer_head *first;
-	struct buffer_head *tmp;
-	struct page *page;
-	int page_uptodate = 1;
-
-	BUG_ON(!buffer_async_read(bh));
-
-	page = bh->b_page;
-	if (uptodate) {
-		set_buffer_uptodate(bh);
-	} else {
-		clear_buffer_uptodate(bh);
-		if (!quiet_error(bh))
-			buffer_io_error(bh);
-		SetPageError(page);
-	}
-
-	/*
-	 * Be _very_ careful from here on. Bad things can happen if
-	 * two buffer heads end IO at almost the same time and both
-	 * decide that the page is now completely done.
-	 */
-	first = page_buffers(page);
-	local_irq_save(flags);
-	bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
-	clear_buffer_async_read(bh);
-	unlock_buffer(bh);
-	tmp = bh;
-	do {
-		if (!buffer_uptodate(tmp))
-			page_uptodate = 0;
-		if (buffer_async_read(tmp)) {
-			BUG_ON(!buffer_locked(tmp));
-			goto still_busy;
-		}
-		tmp = tmp->b_this_page;
-	} while (tmp != bh);
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
-
-	/*
-	 * If none of the buffers had errors and they are all
-	 * uptodate then we can set the page uptodate.
-	 */
-	if (page_uptodate && !PageError(page))
-		SetPageUptodate(page);
-	unlock_page(page);
-	return;
-
-still_busy:
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
-	return;
-}
-
-/*
- * Completion handler for block_write_full_page() - pages which are unlocked
- * during I/O, and which have PageWriteback cleared upon I/O completion.
- */
-static void end_buffer_async_write(struct buffer_head *bh, int uptodate)
-{
-	char b[BDEVNAME_SIZE];
-	unsigned long flags;
-	struct buffer_head *first;
-	struct buffer_head *tmp;
-	struct page *page;
-
-	BUG_ON(!buffer_async_write(bh));
-
-	page = bh->b_page;
-	if (uptodate) {
-		set_buffer_uptodate(bh);
-	} else {
-		if (!quiet_error(bh)) {
-			buffer_io_error(bh);
-			printk(KERN_WARNING "lost page write due to "
-					"I/O error on %s\n",
-			       bdevname(bh->b_bdev, b));
-		}
-		set_bit(AS_EIO, &page->mapping->flags);
-		set_buffer_write_io_error(bh);
-		clear_buffer_uptodate(bh);
-		SetPageError(page);
-	}
-
-	first = page_buffers(page);
-	local_irq_save(flags);
-	bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
-
-	clear_buffer_async_write(bh);
-	unlock_buffer(bh);
-	tmp = bh->b_this_page;
-	while (tmp != bh) {
-		if (buffer_async_write(tmp)) {
-			BUG_ON(!buffer_locked(tmp));
-			goto still_busy;
-		}
-		tmp = tmp->b_this_page;
-	}
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
-	end_page_writeback(page);
-	return;
-
-still_busy:
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
-	return;
-}
-
-/*
- * If a page's buffers are under async readin (end_buffer_async_read
- * completion) then there is a possibility that another thread of
- * control could lock one of the buffers after it has completed
- * but while some of the other buffers have not completed.  This
- * locked buffer would confuse end_buffer_async_read() into not unlocking
- * the page.  So the absence of BH_Async_Read tells end_buffer_async_read()
- * that this buffer is not under async I/O.
- *
- * The page comes unlocked when it has no locked buffer_async buffers
- * left.
- *
- * PageLocked prevents anyone starting new async I/O reads any of
- * the buffers.
- *
- * PageWriteback is used to prevent simultaneous writeout of the same
- * page.
- *
- * PageLocked prevents anyone from starting writeback of a page which is
- * under read I/O (PageWriteback is only ever set against a locked page).
- */
-static void mark_buffer_async_read(struct buffer_head *bh)
-{
-	bh->b_end_io = end_buffer_async_read;
-	set_buffer_async_read(bh);
-}
-
-void mark_buffer_async_write(struct buffer_head *bh)
-{
-	bh->b_end_io = end_buffer_async_write;
-	set_buffer_async_write(bh);
-}
-EXPORT_SYMBOL(mark_buffer_async_write);
-
-
-/*
- * fs/buffer.c contains helper functions for buffer-backed address space's
- * fsync functions.  A common requirement for buffer-based filesystems is
- * that certain data from the backing blockdev needs to be written out for
- * a successful fsync().  For example, ext2 indirect blocks need to be
- * written back and waited upon before fsync() returns.
- *
- * The functions mark_buffer_inode_dirty(), fsync_inode_buffers(),
- * inode_has_buffers() and invalidate_inode_buffers() are provided for the
- * management of a list of dependent buffers at ->i_mapping->private_list.
- *
- * Locking is a little subtle: try_to_free_buffers() will remove buffers
- * from their controlling inode's queue when they are being freed.  But
- * try_to_free_buffers() will be operating against the *blockdev* mapping
- * at the time, not against the S_ISREG file which depends on those buffers.
- * So the locking for private_list is via the private_lock in the address_space
- * which backs the buffers.  Which is different from the address_space 
- * against which the buffers are listed.  So for a particular address_space,
- * mapping->private_lock does *not* protect mapping->private_list!  In fact,
- * mapping->private_list will always be protected by the backing blockdev's
- * ->private_lock.
- *
- * Which introduces a requirement: all buffers on an address_space's
- * ->private_list must be from the same address_space: the blockdev's.
- *
- * address_spaces which do not place buffers at ->private_list via these
- * utility functions are free to use private_lock and private_list for
- * whatever they want.  The only requirement is that list_empty(private_list)
- * be true at clear_inode() time.
- *
- * FIXME: clear_inode should not call invalidate_inode_buffers().  The
- * filesystems should do that.  invalidate_inode_buffers() should just go
- * BUG_ON(!list_empty).
- *
- * FIXME: mark_buffer_dirty_inode() is a data-plane operation.  It should
- * take an address_space, not an inode.  And it should be called
- * mark_buffer_dirty_fsync() to clearly define why those buffers are being
- * queued up.
- *
- * FIXME: mark_buffer_dirty_inode() doesn't need to add the buffer to the
- * list if it is already on a list.  Because if the buffer is on a list,
- * it *must* already be on the right one.  If not, the filesystem is being
- * silly.  This will save a ton of locking.  But first we have to ensure
- * that buffers are taken *off* the old inode's list when they are freed
- * (presumably in truncate).  That requires careful auditing of all
- * filesystems (do it inside bforget()).  It could also be done by bringing
- * b_inode back.
- */
-
-/*
- * The buffer's backing address_space's private_lock must be held
- */
-static void __remove_assoc_queue(struct buffer_head *bh)
-{
-	list_del_init(&bh->b_assoc_buffers);
-	WARN_ON(!bh->b_assoc_map);
-	if (buffer_write_io_error(bh))
-		set_bit(AS_EIO, &bh->b_assoc_map->flags);
-	bh->b_assoc_map = NULL;
-}
-
-int inode_has_buffers(struct inode *inode)
-{
-	return !list_empty(&inode->i_data.private_list);
-}
-
-/*
- * osync is designed to support O_SYNC io.  It waits synchronously for
- * all already-submitted IO to complete, but does not queue any new
- * writes to the disk.
- *
- * To do O_SYNC writes, just queue the buffer writes with ll_rw_block as
- * you dirty the buffers, and then use osync_inode_buffers to wait for
- * completion.  Any other dirty buffers which are not yet queued for
- * write will not be flushed to disk by the osync.
- */
-static int osync_buffers_list(spinlock_t *lock, struct list_head *list)
-{
-	struct buffer_head *bh;
-	struct list_head *p;
-	int err = 0;
-
-	spin_lock(lock);
-repeat:
-	list_for_each_prev(p, list) {
-		bh = BH_ENTRY(p);
-		if (buffer_locked(bh)) {
-			get_bh(bh);
-			spin_unlock(lock);
-			wait_on_buffer(bh);
-			if (!buffer_uptodate(bh))
-				err = -EIO;
-			brelse(bh);
-			spin_lock(lock);
-			goto repeat;
-		}
-	}
-	spin_unlock(lock);
-	return err;
-}
-
-/**
- * sync_mapping_buffers - write out & wait upon a mapping's "associated" buffers
- * @mapping: the mapping which wants those buffers written
- *
- * Starts I/O against the buffers at mapping->private_list, and waits upon
- * that I/O.
- *
- * Basically, this is a convenience function for fsync().
- * @mapping is a file or directory which needs those buffers to be written for
- * a successful fsync().
- */
-int sync_mapping_buffers(struct address_space *mapping)
-{
-	struct address_space *buffer_mapping = mapping->assoc_mapping;
-
-	if (buffer_mapping == NULL || list_empty(&mapping->private_list))
-		return 0;
-
-	return fsync_buffers_list(&buffer_mapping->private_lock,
-					&mapping->private_list);
-}
-EXPORT_SYMBOL(sync_mapping_buffers);
-
-/*
- * Called when we've recently written block `bblock', and it is known that
- * `bblock' was for a buffer_boundary() buffer.  This means that the block at
- * `bblock + 1' is probably a dirty indirect block.  Hunt it down and, if it's
- * dirty, schedule it for IO.  So that indirects merge nicely with their data.
- */
-void write_boundary_block(struct block_device *bdev,
-			sector_t bblock, unsigned blocksize)
-{
-	struct buffer_head *bh = __find_get_block(bdev, bblock + 1, blocksize);
-	if (bh) {
-		if (buffer_dirty(bh))
-			ll_rw_block(WRITE, 1, &bh);
-		put_bh(bh);
-	}
-}
-
-void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode)
-{
-	struct address_space *mapping = inode->i_mapping;
-	struct address_space *buffer_mapping = bh->b_page->mapping;
-
-	mark_buffer_dirty(bh);
-	if (!mapping->assoc_mapping) {
-		mapping->assoc_mapping = buffer_mapping;
-	} else {
-		BUG_ON(mapping->assoc_mapping != buffer_mapping);
-	}
-	if (!bh->b_assoc_map) {
-		spin_lock(&buffer_mapping->private_lock);
-		list_move_tail(&bh->b_assoc_buffers,
-				&mapping->private_list);
-		bh->b_assoc_map = mapping;
-		spin_unlock(&buffer_mapping->private_lock);
-	}
-}
-EXPORT_SYMBOL(mark_buffer_dirty_inode);
-
-/*
- * Mark the page dirty, and set it dirty in the radix tree, and mark the inode
- * dirty.
- *
- * If warn is true, then emit a warning if the page is not uptodate and has
- * not been truncated.
- */
-static void __set_page_dirty(struct page *page,
-		struct address_space *mapping, int warn)
-{
-	spin_lock_irq(&mapping->tree_lock);
-	if (page->mapping) {	/* Race with truncate? */
-		WARN_ON_ONCE(warn && !PageUptodate(page));
-
-		if (mapping_cap_account_dirty(mapping)) {
-			__inc_zone_page_state(page, NR_FILE_DIRTY);
-			__inc_bdi_stat(mapping->backing_dev_info,
-					BDI_RECLAIMABLE);
-			task_dirty_inc(current);
-			task_io_account_write(PAGE_CACHE_SIZE);
-		}
-		radix_tree_tag_set(&mapping->page_tree,
-				page_index(page), PAGECACHE_TAG_DIRTY);
-	}
-	spin_unlock_irq(&mapping->tree_lock);
-	__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
-}
-
-/*
- * Add a page to the dirty page list.
- *
- * It is a sad fact of life that this function is called from several places
- * deeply under spinlocking.  It may not sleep.
- *
- * If the page has buffers, the uptodate buffers are set dirty, to preserve
- * dirty-state coherency between the page and the buffers.  It the page does
- * not have buffers then when they are later attached they will all be set
- * dirty.
- *
- * The buffers are dirtied before the page is dirtied.  There's a small race
- * window in which a writepage caller may see the page cleanness but not the
- * buffer dirtiness.  That's fine.  If this code were to set the page dirty
- * before the buffers, a concurrent writepage caller could clear the page dirty
- * bit, see a bunch of clean buffers and we'd end up with dirty buffers/clean
- * page on the dirty page list.
- *
- * We use private_lock to lock against try_to_free_buffers while using the
- * page's buffer list.  Also use this to protect against clean buffers being
- * added to the page after it was set dirty.
- *
- * FIXME: may need to call ->reservepage here as well.  That's rather up to the
- * address_space though.
- */
-int __set_page_dirty_buffers(struct page *page)
-{
-	int newly_dirty;
-	struct address_space *mapping = page_mapping(page);
-
-	if (unlikely(!mapping))
-		return !TestSetPageDirty(page);
-
-	spin_lock(&mapping->private_lock);
-	if (page_has_buffers(page)) {
-		struct buffer_head *head = page_buffers(page);
-		struct buffer_head *bh = head;
-
-		do {
-			set_buffer_dirty(bh);
-			bh = bh->b_this_page;
-		} while (bh != head);
-	}
-	newly_dirty = !TestSetPageDirty(page);
-	spin_unlock(&mapping->private_lock);
-
-	if (newly_dirty)
-		__set_page_dirty(page, mapping, 1);
-	return newly_dirty;
-}
-EXPORT_SYMBOL(__set_page_dirty_buffers);
-
-/*
- * Write out and wait upon a list of buffers.
- *
- * We have conflicting pressures: we want to make sure that all
- * initially dirty buffers get waited on, but that any subsequently
- * dirtied buffers don't.  After all, we don't want fsync to last
- * forever if somebody is actively writing to the file.
- *
- * Do this in two main stages: first we copy dirty buffers to a
- * temporary inode list, queueing the writes as we go.  Then we clean
- * up, waiting for those writes to complete.
- * 
- * During this second stage, any subsequent updates to the file may end
- * up refiling the buffer on the original inode's dirty list again, so
- * there is a chance we will end up with a buffer queued for write but
- * not yet completed on that list.  So, as a final cleanup we go through
- * the osync code to catch these locked, dirty buffers without requeuing
- * any newly dirty buffers for write.
- */
-static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
-{
-	struct buffer_head *bh;
-	struct list_head tmp;
-	struct address_space *mapping;
-	int err = 0, err2;
-
-	INIT_LIST_HEAD(&tmp);
-
-	spin_lock(lock);
-	while (!list_empty(list)) {
-		bh = BH_ENTRY(list->next);
-		mapping = bh->b_assoc_map;
-		__remove_assoc_queue(bh);
-		/* Avoid race with mark_buffer_dirty_inode() which does
-		 * a lockless check and we rely on seeing the dirty bit */
-		smp_mb();
-		if (buffer_dirty(bh) || buffer_locked(bh)) {
-			list_add(&bh->b_assoc_buffers, &tmp);
-			bh->b_assoc_map = mapping;
-			if (buffer_dirty(bh)) {
-				get_bh(bh);
-				spin_unlock(lock);
-				/*
-				 * Ensure any pending I/O completes so that
-				 * ll_rw_block() actually writes the current
-				 * contents - it is a noop if I/O is still in
-				 * flight on potentially older contents.
-				 */
-				ll_rw_block(SWRITE_SYNC, 1, &bh);
-				brelse(bh);
-				spin_lock(lock);
-			}
-		}
-	}
-
-	while (!list_empty(&tmp)) {
-		bh = BH_ENTRY(tmp.prev);
-		get_bh(bh);
-		mapping = bh->b_assoc_map;
-		__remove_assoc_queue(bh);
-		/* Avoid race with mark_buffer_dirty_inode() which does
-		 * a lockless check and we rely on seeing the dirty bit */
-		smp_mb();
-		if (buffer_dirty(bh)) {
-			list_add(&bh->b_assoc_buffers,
-				 &mapping->private_list);
-			bh->b_assoc_map = mapping;
-		}
-		spin_unlock(lock);
-		wait_on_buffer(bh);
-		if (!buffer_uptodate(bh))
-			err = -EIO;
-		brelse(bh);
-		spin_lock(lock);
-	}
-	
-	spin_unlock(lock);
-	err2 = osync_buffers_list(lock, list);
-	if (err)
-		return err;
-	else
-		return err2;
-}
-
-/*
- * Invalidate any and all dirty buffers on a given inode.  We are
- * probably unmounting the fs, but that doesn't mean we have already
- * done a sync().  Just drop the buffers from the inode list.
- *
- * NOTE: we take the inode's blockdev's mapping's private_lock.  Which
- * assumes that all the buffers are against the blockdev.  Not true
- * for reiserfs.
- */
-void invalidate_inode_buffers(struct inode *inode)
-{
-	if (inode_has_buffers(inode)) {
-		struct address_space *mapping = &inode->i_data;
-		struct list_head *list = &mapping->private_list;
-		struct address_space *buffer_mapping = mapping->assoc_mapping;
-
-		spin_lock(&buffer_mapping->private_lock);
-		while (!list_empty(list))
-			__remove_assoc_queue(BH_ENTRY(list->next));
-		spin_unlock(&buffer_mapping->private_lock);
-	}
-}
-EXPORT_SYMBOL(invalidate_inode_buffers);
-
-/*
- * Remove any clean buffers from the inode's buffer list.  This is called
- * when we're trying to free the inode itself.  Those buffers can pin it.
- *
- * Returns true if all buffers were removed.
- */
-int remove_inode_buffers(struct inode *inode)
-{
-	int ret = 1;
-
-	if (inode_has_buffers(inode)) {
-		struct address_space *mapping = &inode->i_data;
-		struct list_head *list = &mapping->private_list;
-		struct address_space *buffer_mapping = mapping->assoc_mapping;
-
-		spin_lock(&buffer_mapping->private_lock);
-		while (!list_empty(list)) {
-			struct buffer_head *bh = BH_ENTRY(list->next);
-			if (buffer_dirty(bh)) {
-				ret = 0;
-				break;
-			}
-			__remove_assoc_queue(bh);
-		}
-		spin_unlock(&buffer_mapping->private_lock);
-	}
-	return ret;
-}
-
-/*
- * Create the appropriate buffers when given a page for data area and
- * the size of each buffer.. Use the bh->b_this_page linked list to
- * follow the buffers created.  Return NULL if unable to create more
- * buffers.
- *
- * The retry flag is used to differentiate async IO (paging, swapping)
- * which may not fail from ordinary buffer allocations.
- */
-struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
-		int retry)
-{
-	struct buffer_head *bh, *head;
-	long offset;
-
-try_again:
-	head = NULL;
-	offset = PAGE_SIZE;
-	while ((offset -= size) >= 0) {
-		bh = alloc_buffer_head(GFP_NOFS);
-		if (!bh)
-			goto no_grow;
-
-		bh->b_bdev = NULL;
-		bh->b_this_page = head;
-		bh->b_blocknr = -1;
-		head = bh;
-
-		bh->b_state = 0;
-		atomic_set(&bh->b_count, 0);
-		bh->b_private = NULL;
-		bh->b_size = size;
-
-		/* Link the buffer to its page */
-		set_bh_page(bh, page, offset);
-
-		init_buffer(bh, NULL, NULL);
-	}
-	return head;
-/*
- * In case anything failed, we just free everything we got.
- */
-no_grow:
-	if (head) {
-		do {
-			bh = head;
-			head = head->b_this_page;
-			free_buffer_head(bh);
-		} while (head);
-	}
-
-	/*
-	 * Return failure for non-async IO requests.  Async IO requests
-	 * are not allowed to fail, so we have to wait until buffer heads
-	 * become available.  But we don't want tasks sleeping with 
-	 * partially complete buffers, so all were released above.
-	 */
-	if (!retry)
-		return NULL;
-
-	/* We're _really_ low on memory. Now we just
-	 * wait for old buffer heads to become free due to
-	 * finishing IO.  Since this is an async request and
-	 * the reserve list is empty, we're sure there are 
-	 * async buffer heads in use.
-	 */
-	free_more_memory();
-	goto try_again;
-}
-EXPORT_SYMBOL_GPL(alloc_page_buffers);
-
-static inline void
-link_dev_buffers(struct page *page, struct buffer_head *head)
-{
-	struct buffer_head *bh, *tail;
-
-	bh = head;
-	do {
-		tail = bh;
-		bh = bh->b_this_page;
-	} while (bh);
-	tail->b_this_page = head;
-	attach_page_buffers(page, head);
-}
-
-/*
- * Initialise the state of a blockdev page's buffers.
- */ 
-static void
-init_page_buffers(struct page *page, struct block_device *bdev,
-			sector_t block, int size)
-{
-	struct buffer_head *head = page_buffers(page);
-	struct buffer_head *bh = head;
-	int uptodate = PageUptodate(page);
-
-	do {
-		if (!buffer_mapped(bh)) {
-			init_buffer(bh, NULL, NULL);
-			bh->b_bdev = bdev;
-			bh->b_blocknr = block;
-			if (uptodate)
-				set_buffer_uptodate(bh);
-			set_buffer_mapped(bh);
-		}
-		block++;
-		bh = bh->b_this_page;
-	} while (bh != head);
-}
-
-/*
- * Create the page-cache page that contains the requested block.
- *
- * This is user purely for blockdev mappings.
- */
-static struct page *
-grow_dev_page(struct block_device *bdev, sector_t block,
-		pgoff_t index, int size)
-{
-	struct inode *inode = bdev->bd_inode;
-	struct page *page;
-	struct buffer_head *bh;
-
-#ifdef DDE_LINUX
-	WARN_UNIMPL;
-	return NULL;
-#endif
-
-	page = find_or_create_page(inode->i_mapping, index,
-		(mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS)|__GFP_MOVABLE);
-	if (!page)
-		return NULL;
-
-	BUG_ON(!PageLocked(page));
-
-	if (page_has_buffers(page)) {
-		bh = page_buffers(page);
-		if (bh->b_size == size) {
-			init_page_buffers(page, bdev, block, size);
-			return page;
-		}
-		if (!try_to_free_buffers(page))
-			goto failed;
-	}
-
-	/*
-	 * Allocate some buffers for this page
-	 */
-	bh = alloc_page_buffers(page, size, 0);
-	if (!bh)
-		goto failed;
-
-	/*
-	 * Link the page to the buffers and initialise them.  Take the
-	 * lock to be atomic wrt __find_get_block(), which does not
-	 * run under the page lock.
-	 */
-	spin_lock(&inode->i_mapping->private_lock);
-	link_dev_buffers(page, bh);
-	init_page_buffers(page, bdev, block, size);
-	spin_unlock(&inode->i_mapping->private_lock);
-	return page;
-
-failed:
-	BUG();
-	unlock_page(page);
-	page_cache_release(page);
-	return NULL;
-}
-
-/*
- * Create buffers for the specified block device block's page.  If
- * that page was dirty, the buffers are set dirty also.
- */
-static int
-grow_buffers(struct block_device *bdev, sector_t block, int size)
-{
-	struct page *page;
-	pgoff_t index;
-	int sizebits;
-
-	sizebits = -1;
-	do {
-		sizebits++;
-	} while ((size << sizebits) < PAGE_SIZE);
-
-	index = block >> sizebits;
-
-	/*
-	 * Check for a block which wants to lie outside our maximum possible
-	 * pagecache index.  (this comparison is done using sector_t types).
-	 */
-	if (unlikely(index != block >> sizebits)) {
-		char b[BDEVNAME_SIZE];
-
-		printk(KERN_ERR "%s: requested out-of-range block %llu for "
-			"device %s\n",
-			__func__, (unsigned long long)block,
-			bdevname(bdev, b));
-		return -EIO;
-	}
-	block = index << sizebits;
-	/* Create a page with the proper size buffers.. */
-	page = grow_dev_page(bdev, block, index, size);
-	if (!page)
-		return 0;
-	unlock_page(page);
-	page_cache_release(page);
-	return 1;
-}
-
-static struct buffer_head *
-__getblk_slow(struct block_device *bdev, sector_t block, int size)
-{
-	/* Size must be multiple of hard sectorsize */
-	if (unlikely(size & (bdev_hardsect_size(bdev)-1) ||
-			(size < 512 || size > PAGE_SIZE))) {
-		printk(KERN_ERR "getblk(): invalid block size %d requested\n",
-					size);
-		printk(KERN_ERR "hardsect size: %d\n",
-					bdev_hardsect_size(bdev));
-
-		dump_stack();
-		return NULL;
-	}
-
-	for (;;) {
-		struct buffer_head * bh;
-		int ret;
-
-		bh = __find_get_block(bdev, block, size);
-		if (bh)
-			return bh;
-
-		ret = grow_buffers(bdev, block, size);
-		if (ret < 0)
-			return NULL;
-		if (ret == 0)
-			free_more_memory();
-	}
-}
-
-/*
- * The relationship between dirty buffers and dirty pages:
- *
- * Whenever a page has any dirty buffers, the page's dirty bit is set, and
- * the page is tagged dirty in its radix tree.
- *
- * At all times, the dirtiness of the buffers represents the dirtiness of
- * subsections of the page.  If the page has buffers, the page dirty bit is
- * merely a hint about the true dirty state.
- *
- * When a page is set dirty in its entirety, all its buffers are marked dirty
- * (if the page has buffers).
- *
- * When a buffer is marked dirty, its page is dirtied, but the page's other
- * buffers are not.
- *
- * Also.  When blockdev buffers are explicitly read with bread(), they
- * individually become uptodate.  But their backing page remains not
- * uptodate - even if all of its buffers are uptodate.  A subsequent
- * block_read_full_page() against that page will discover all the uptodate
- * buffers, will set the page uptodate and will perform no I/O.
- */
-
-/**
- * mark_buffer_dirty - mark a buffer_head as needing writeout
- * @bh: the buffer_head to mark dirty
- *
- * mark_buffer_dirty() will set the dirty bit against the buffer, then set its
- * backing page dirty, then tag the page as dirty in its address_space's radix
- * tree and then attach the address_space's inode to its superblock's dirty
- * inode list.
- *
- * mark_buffer_dirty() is atomic.  It takes bh->b_page->mapping->private_lock,
- * mapping->tree_lock and the global inode_lock.
- */
-void mark_buffer_dirty(struct buffer_head *bh)
-{
-#ifndef DDE_LINUX
-	WARN_ON_ONCE(!buffer_uptodate(bh));
-
-	/*
-	 * Very *carefully* optimize the it-is-already-dirty case.
-	 *
-	 * Don't let the final "is it dirty" escape to before we
-	 * perhaps modified the buffer.
-	 */
-	if (buffer_dirty(bh)) {
-		smp_mb();
-		if (buffer_dirty(bh))
-			return;
-	}
-
-	if (!test_set_buffer_dirty(bh)) {
-		struct page *page = bh->b_page;
-		if (!TestSetPageDirty(page))
-			__set_page_dirty(page, page_mapping(page), 0);
-	}
-#else
-	WARN_UNIMPL;
-#endif
-}
-
-/*
- * Decrement a buffer_head's reference count.  If all buffers against a page
- * have zero reference count, are clean and unlocked, and if the page is clean
- * and unlocked then try_to_free_buffers() may strip the buffers from the page
- * in preparation for freeing it (sometimes, rarely, buffers are removed from
- * a page but it ends up not being freed, and buffers may later be reattached).
- */
-void __brelse(struct buffer_head * buf)
-{
-	if (atomic_read(&buf->b_count)) {
-		put_bh(buf);
-		return;
-	}
-	WARN(1, KERN_ERR "VFS: brelse: Trying to free free buffer\n");
-}
-
-/*
- * bforget() is like brelse(), except it discards any
- * potentially dirty data.
- */
-void __bforget(struct buffer_head *bh)
-{
-	clear_buffer_dirty(bh);
-	if (bh->b_assoc_map) {
-		struct address_space *buffer_mapping = bh->b_page->mapping;
-
-		spin_lock(&buffer_mapping->private_lock);
-		list_del_init(&bh->b_assoc_buffers);
-		bh->b_assoc_map = NULL;
-		spin_unlock(&buffer_mapping->private_lock);
-	}
-	__brelse(bh);
-}
-
-static struct buffer_head *__bread_slow(struct buffer_head *bh)
-{
-	lock_buffer(bh);
-	if (buffer_uptodate(bh)) {
-		unlock_buffer(bh);
-		return bh;
-	} else {
-		get_bh(bh);
-		bh->b_end_io = end_buffer_read_sync;
-		submit_bh(READ, bh);
-		wait_on_buffer(bh);
-		if (buffer_uptodate(bh))
-			return bh;
-	}
-	brelse(bh);
-	return NULL;
-}
-
-/*
- * Per-cpu buffer LRU implementation.  To reduce the cost of __find_get_block().
- * The bhs[] array is sorted - newest buffer is at bhs[0].  Buffers have their
- * refcount elevated by one when they're in an LRU.  A buffer can only appear
- * once in a particular CPU's LRU.  A single buffer can be present in multiple
- * CPU's LRUs at the same time.
- *
- * This is a transparent caching front-end to sb_bread(), sb_getblk() and
- * sb_find_get_block().
- *
- * The LRUs themselves only need locking against invalidate_bh_lrus.  We use
- * a local interrupt disable for that.
- */
-
-#define BH_LRU_SIZE	8
-
-struct bh_lru {
-	struct buffer_head *bhs[BH_LRU_SIZE];
-};
-
-static DEFINE_PER_CPU(struct bh_lru, bh_lrus) = {{ NULL }};
-
-#ifdef CONFIG_SMP
-#define bh_lru_lock()	local_irq_disable()
-#define bh_lru_unlock()	local_irq_enable()
-#else
-#define bh_lru_lock()	preempt_disable()
-#define bh_lru_unlock()	preempt_enable()
-#endif
-
-static inline void check_irqs_on(void)
-{
-#ifdef irqs_disabled
-	BUG_ON(irqs_disabled());
-#endif
-}
-
-/*
- * The LRU management algorithm is dopey-but-simple.  Sorry.
- */
-static void bh_lru_install(struct buffer_head *bh)
-{
-	struct buffer_head *evictee = NULL;
-	struct bh_lru *lru;
-
-	check_irqs_on();
-	bh_lru_lock();
-	lru = &__get_cpu_var(bh_lrus);
-	if (lru->bhs[0] != bh) {
-		struct buffer_head *bhs[BH_LRU_SIZE];
-		int in;
-		int out = 0;
-
-		get_bh(bh);
-		bhs[out++] = bh;
-		for (in = 0; in < BH_LRU_SIZE; in++) {
-			struct buffer_head *bh2 = lru->bhs[in];
-
-			if (bh2 == bh) {
-				__brelse(bh2);
-			} else {
-				if (out >= BH_LRU_SIZE) {
-					BUG_ON(evictee != NULL);
-					evictee = bh2;
-				} else {
-					bhs[out++] = bh2;
-				}
-			}
-		}
-		while (out < BH_LRU_SIZE)
-			bhs[out++] = NULL;
-		memcpy(lru->bhs, bhs, sizeof(bhs));
-	}
-	bh_lru_unlock();
-
-	if (evictee)
-		__brelse(evictee);
-}
-
-/*
- * Look up the bh in this cpu's LRU.  If it's there, move it to the head.
- */
-static struct buffer_head *
-lookup_bh_lru(struct block_device *bdev, sector_t block, unsigned size)
-{
-	struct buffer_head *ret = NULL;
-	struct bh_lru *lru;
-	unsigned int i;
-
-	check_irqs_on();
-	bh_lru_lock();
-	lru = &__get_cpu_var(bh_lrus);
-	for (i = 0; i < BH_LRU_SIZE; i++) {
-		struct buffer_head *bh = lru->bhs[i];
-
-		if (bh && bh->b_bdev == bdev &&
-				bh->b_blocknr == block && bh->b_size == size) {
-			if (i) {
-				while (i) {
-					lru->bhs[i] = lru->bhs[i - 1];
-					i--;
-				}
-				lru->bhs[0] = bh;
-			}
-			get_bh(bh);
-			ret = bh;
-			break;
-		}
-	}
-	bh_lru_unlock();
-	return ret;
-}
-
-/*
- * Perform a pagecache lookup for the matching buffer.  If it's there, refresh
- * it in the LRU and mark it as accessed.  If it is not present then return
- * NULL
- */
-struct buffer_head *
-__find_get_block(struct block_device *bdev, sector_t block, unsigned size)
-{
-	struct buffer_head *bh = lookup_bh_lru(bdev, block, size);
-
-	if (bh == NULL) {
-		bh = __find_get_block_slow(bdev, block);
-		if (bh)
-			bh_lru_install(bh);
-	}
-	if (bh)
-		touch_buffer(bh);
-	return bh;
-}
-EXPORT_SYMBOL(__find_get_block);
-
-/*
- * __getblk will locate (and, if necessary, create) the buffer_head
- * which corresponds to the passed block_device, block and size. The
- * returned buffer has its reference count incremented.
- *
- * __getblk() cannot fail - it just keeps trying.  If you pass it an
- * illegal block number, __getblk() will happily return a buffer_head
- * which represents the non-existent block.  Very weird.
- *
- * __getblk() will lock up the machine if grow_dev_page's try_to_free_buffers()
- * attempt is failing.  FIXME, perhaps?
- */
-struct buffer_head *
-__getblk(struct block_device *bdev, sector_t block, unsigned size)
-{
-	struct buffer_head *bh = __find_get_block(bdev, block, size);
-
-	might_sleep();
-	if (bh == NULL)
-		bh = __getblk_slow(bdev, block, size);
-	return bh;
-}
-EXPORT_SYMBOL(__getblk);
-
-/*
- * Do async read-ahead on a buffer..
- */
-void __breadahead(struct block_device *bdev, sector_t block, unsigned size)
-{
-	struct buffer_head *bh = __getblk(bdev, block, size);
-	if (likely(bh)) {
-		ll_rw_block(READA, 1, &bh);
-		brelse(bh);
-	}
-}
-EXPORT_SYMBOL(__breadahead);
-
-/**
- *  __bread() - reads a specified block and returns the bh
- *  @bdev: the block_device to read from
- *  @block: number of block
- *  @size: size (in bytes) to read
- * 
- *  Reads a specified block, and returns buffer head that contains it.
- *  It returns NULL if the block was unreadable.
- */
-struct buffer_head *
-__bread(struct block_device *bdev, sector_t block, unsigned size)
-{
-	struct buffer_head *bh = __getblk(bdev, block, size);
-
-	if (likely(bh) && !buffer_uptodate(bh))
-		bh = __bread_slow(bh);
-	return bh;
-}
-EXPORT_SYMBOL(__bread);
-
-/*
- * invalidate_bh_lrus() is called rarely - but not only at unmount.
- * This doesn't race because it runs in each cpu either in irq
- * or with preempt disabled.
- */
-static void invalidate_bh_lru(void *arg)
-{
-	struct bh_lru *b = &get_cpu_var(bh_lrus);
-	int i;
-
-	for (i = 0; i < BH_LRU_SIZE; i++) {
-		brelse(b->bhs[i]);
-		b->bhs[i] = NULL;
-	}
-	put_cpu_var(bh_lrus);
-}
-	
-void invalidate_bh_lrus(void)
-{
-#ifndef DDE_LINUX
-	on_each_cpu(invalidate_bh_lru, NULL, 1);
-#endif
-}
-EXPORT_SYMBOL_GPL(invalidate_bh_lrus);
-
-void set_bh_page(struct buffer_head *bh,
-		struct page *page, unsigned long offset)
-{
-	bh->b_page = page;
-	BUG_ON(offset >= PAGE_SIZE);
-	if (PageHighMem(page))
-		/*
-		 * This catches illegal uses and preserves the offset:
-		 */
-		bh->b_data = (char *)(0 + offset);
-	else
-		bh->b_data = page_address(page) + offset;
-}
-EXPORT_SYMBOL(set_bh_page);
-
-/*
- * Called when truncating a buffer on a page completely.
- */
-static void discard_buffer(struct buffer_head * bh)
-{
-	lock_buffer(bh);
-	clear_buffer_dirty(bh);
-	bh->b_bdev = NULL;
-	clear_buffer_mapped(bh);
-	clear_buffer_req(bh);
-	clear_buffer_new(bh);
-	clear_buffer_delay(bh);
-	clear_buffer_unwritten(bh);
-	unlock_buffer(bh);
-}
-
-/**
- * block_invalidatepage - invalidate part of all of a buffer-backed page
- *
- * @page: the page which is affected
- * @offset: the index of the truncation point
- *
- * block_invalidatepage() is called when all or part of the page has become
- * invalidatedby a truncate operation.
- *
- * block_invalidatepage() does not have to release all buffers, but it must
- * ensure that no dirty buffer is left outside @offset and that no I/O
- * is underway against any of the blocks which are outside the truncation
- * point.  Because the caller is about to free (and possibly reuse) those
- * blocks on-disk.
- */
-void block_invalidatepage(struct page *page, unsigned long offset)
-{
-	struct buffer_head *head, *bh, *next;
-	unsigned int curr_off = 0;
-
-	BUG_ON(!PageLocked(page));
-	if (!page_has_buffers(page))
-		goto out;
-
-	head = page_buffers(page);
-	bh = head;
-	do {
-		unsigned int next_off = curr_off + bh->b_size;
-		next = bh->b_this_page;
-
-		/*
-		 * is this block fully invalidated?
-		 */
-		if (offset <= curr_off)
-			discard_buffer(bh);
-		curr_off = next_off;
-		bh = next;
-	} while (bh != head);
-
-	/*
-	 * We release buffers only if the entire page is being invalidated.
-	 * The get_block cached value has been unconditionally invalidated,
-	 * so real IO is not possible anymore.
-	 */
-	if (offset == 0)
-		try_to_release_page(page, 0);
-out:
-	return;
-}
-EXPORT_SYMBOL(block_invalidatepage);
-
-/*
- * We attach and possibly dirty the buffers atomically wrt
- * __set_page_dirty_buffers() via private_lock.  try_to_free_buffers
- * is already excluded via the page lock.
- */
-void create_empty_buffers(struct page *page,
-			unsigned long blocksize, unsigned long b_state)
-{
-	struct buffer_head *bh, *head, *tail;
-
-	head = alloc_page_buffers(page, blocksize, 1);
-	bh = head;
-	do {
-		bh->b_state |= b_state;
-		tail = bh;
-		bh = bh->b_this_page;
-	} while (bh);
-	tail->b_this_page = head;
-
-	spin_lock(&page->mapping->private_lock);
-	if (PageUptodate(page) || PageDirty(page)) {
-		bh = head;
-		do {
-			if (PageDirty(page))
-				set_buffer_dirty(bh);
-			if (PageUptodate(page))
-				set_buffer_uptodate(bh);
-			bh = bh->b_this_page;
-		} while (bh != head);
-	}
-	attach_page_buffers(page, head);
-	spin_unlock(&page->mapping->private_lock);
-}
-EXPORT_SYMBOL(create_empty_buffers);
-
-/*
- * We are taking a block for data and we don't want any output from any
- * buffer-cache aliases starting from return from that function and
- * until the moment when something will explicitly mark the buffer
- * dirty (hopefully that will not happen until we will free that block ;-)
- * We don't even need to mark it not-uptodate - nobody can expect
- * anything from a newly allocated buffer anyway. We used to used
- * unmap_buffer() for such invalidation, but that was wrong. We definitely
- * don't want to mark the alias unmapped, for example - it would confuse
- * anyone who might pick it with bread() afterwards...
- *
- * Also..  Note that bforget() doesn't lock the buffer.  So there can
- * be writeout I/O going on against recently-freed buffers.  We don't
- * wait on that I/O in bforget() - it's more efficient to wait on the I/O
- * only if we really need to.  That happens here.
- */
-void unmap_underlying_metadata(struct block_device *bdev, sector_t block)
-{
-	struct buffer_head *old_bh;
-
-	might_sleep();
-
-	old_bh = __find_get_block_slow(bdev, block);
-	if (old_bh) {
-		clear_buffer_dirty(old_bh);
-		wait_on_buffer(old_bh);
-		clear_buffer_req(old_bh);
-		__brelse(old_bh);
-	}
-}
-EXPORT_SYMBOL(unmap_underlying_metadata);
-
-/*
- * NOTE! All mapped/uptodate combinations are valid:
- *
- *	Mapped	Uptodate	Meaning
- *
- *	No	No		"unknown" - must do get_block()
- *	No	Yes		"hole" - zero-filled
- *	Yes	No		"allocated" - allocated on disk, not read in
- *	Yes	Yes		"valid" - allocated and up-to-date in memory.
- *
- * "Dirty" is valid only with the last case (mapped+uptodate).
- */
-
-/*
- * While block_write_full_page is writing back the dirty buffers under
- * the page lock, whoever dirtied the buffers may decide to clean them
- * again at any time.  We handle that by only looking at the buffer
- * state inside lock_buffer().
- *
- * If block_write_full_page() is called for regular writeback
- * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
- * locked buffer.   This only can happen if someone has written the buffer
- * directly, with submit_bh().  At the address_space level PageWriteback
- * prevents this contention from occurring.
- */
-static int __block_write_full_page(struct inode *inode, struct page *page,
-			get_block_t *get_block, struct writeback_control *wbc)
-{
-	int err;
-	sector_t block;
-	sector_t last_block;
-	struct buffer_head *bh, *head;
-	const unsigned blocksize = 1 << inode->i_blkbits;
-	int nr_underway = 0;
-
-	BUG_ON(!PageLocked(page));
-
-	last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
-
-	if (!page_has_buffers(page)) {
-		create_empty_buffers(page, blocksize,
-					(1 << BH_Dirty)|(1 << BH_Uptodate));
-	}
-
-	/*
-	 * Be very careful.  We have no exclusion from __set_page_dirty_buffers
-	 * here, and the (potentially unmapped) buffers may become dirty at
-	 * any time.  If a buffer becomes dirty here after we've inspected it
-	 * then we just miss that fact, and the page stays dirty.
-	 *
-	 * Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
-	 * handle that here by just cleaning them.
-	 */
-
-	block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
-	head = page_buffers(page);
-	bh = head;
-
-	/*
-	 * Get all the dirty buffers mapped to disk addresses and
-	 * handle any aliases from the underlying blockdev's mapping.
-	 */
-	do {
-		if (block > last_block) {
-			/*
-			 * mapped buffers outside i_size will occur, because
-			 * this page can be outside i_size when there is a
-			 * truncate in progress.
-			 */
-			/*
-			 * The buffer was zeroed by block_write_full_page()
-			 */
-			clear_buffer_dirty(bh);
-			set_buffer_uptodate(bh);
-		} else if ((!buffer_mapped(bh) || buffer_delay(bh)) &&
-			   buffer_dirty(bh)) {
-			WARN_ON(bh->b_size != blocksize);
-			err = get_block(inode, block, bh, 1);
-			if (err)
-				goto recover;
-			clear_buffer_delay(bh);
-			if (buffer_new(bh)) {
-				/* blockdev mappings never come here */
-				clear_buffer_new(bh);
-				unmap_underlying_metadata(bh->b_bdev,
-							bh->b_blocknr);
-			}
-		}
-		bh = bh->b_this_page;
-		block++;
-	} while (bh != head);
-
-	do {
-		if (!buffer_mapped(bh))
-			continue;
-		/*
-		 * If it's a fully non-blocking write attempt and we cannot
-		 * lock the buffer then redirty the page.  Note that this can
-		 * potentially cause a busy-wait loop from pdflush and kswapd
-		 * activity, but those code paths have their own higher-level
-		 * throttling.
-		 */
-		if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
-			lock_buffer(bh);
-		} else if (!trylock_buffer(bh)) {
-			redirty_page_for_writepage(wbc, page);
-			continue;
-		}
-		if (test_clear_buffer_dirty(bh)) {
-			mark_buffer_async_write(bh);
-		} else {
-			unlock_buffer(bh);
-		}
-	} while ((bh = bh->b_this_page) != head);
-
-	/*
-	 * The page and its buffers are protected by PageWriteback(), so we can
-	 * drop the bh refcounts early.
-	 */
-	BUG_ON(PageWriteback(page));
-	set_page_writeback(page);
-
-	do {
-		struct buffer_head *next = bh->b_this_page;
-		if (buffer_async_write(bh)) {
-			submit_bh(WRITE, bh);
-			nr_underway++;
-		}
-		bh = next;
-	} while (bh != head);
-	unlock_page(page);
-
-	err = 0;
-done:
-	if (nr_underway == 0) {
-		/*
-		 * The page was marked dirty, but the buffers were
-		 * clean.  Someone wrote them back by hand with
-		 * ll_rw_block/submit_bh.  A rare case.
-		 */
-		end_page_writeback(page);
-
-		/*
-		 * The page and buffer_heads can be released at any time from
-		 * here on.
-		 */
-	}
-	return err;
-
-recover:
-	/*
-	 * ENOSPC, or some other error.  We may already have added some
-	 * blocks to the file, so we need to write these out to avoid
-	 * exposing stale data.
-	 * The page is currently locked and not marked for writeback
-	 */
-	bh = head;
-	/* Recovery: lock and submit the mapped buffers */
-	do {
-		if (buffer_mapped(bh) && buffer_dirty(bh) &&
-		    !buffer_delay(bh)) {
-			lock_buffer(bh);
-			mark_buffer_async_write(bh);
-		} else {
-			/*
-			 * The buffer may have been set dirty during
-			 * attachment to a dirty page.
-			 */
-			clear_buffer_dirty(bh);
-		}
-	} while ((bh = bh->b_this_page) != head);
-	SetPageError(page);
-	BUG_ON(PageWriteback(page));
-	mapping_set_error(page->mapping, err);
-	set_page_writeback(page);
-	do {
-		struct buffer_head *next = bh->b_this_page;
-		if (buffer_async_write(bh)) {
-			clear_buffer_dirty(bh);
-			submit_bh(WRITE, bh);
-			nr_underway++;
-		}
-		bh = next;
-	} while (bh != head);
-	unlock_page(page);
-	goto done;
-}
-
-/*
- * If a page has any new buffers, zero them out here, and mark them uptodate
- * and dirty so they'll be written out (in order to prevent uninitialised
- * block data from leaking). And clear the new bit.
- */
-void page_zero_new_buffers(struct page *page, unsigned from, unsigned to)
-{
-	unsigned int block_start, block_end;
-	struct buffer_head *head, *bh;
-
-	BUG_ON(!PageLocked(page));
-	if (!page_has_buffers(page))
-		return;
-
-	bh = head = page_buffers(page);
-	block_start = 0;
-	do {
-		block_end = block_start + bh->b_size;
-
-		if (buffer_new(bh)) {
-			if (block_end > from && block_start < to) {
-				if (!PageUptodate(page)) {
-					unsigned start, size;
-
-					start = max(from, block_start);
-					size = min(to, block_end) - start;
-
-					zero_user(page, start, size);
-					set_buffer_uptodate(bh);
-				}
-
-				clear_buffer_new(bh);
-				mark_buffer_dirty(bh);
-			}
-		}
-
-		block_start = block_end;
-		bh = bh->b_this_page;
-	} while (bh != head);
-}
-EXPORT_SYMBOL(page_zero_new_buffers);
-
-static int __block_prepare_write(struct inode *inode, struct page *page,
-		unsigned from, unsigned to, get_block_t *get_block)
-{
-	unsigned block_start, block_end;
-	sector_t block;
-	int err = 0;
-	unsigned blocksize, bbits;
-	struct buffer_head *bh, *head, *wait[2], **wait_bh=wait;
-
-	BUG_ON(!PageLocked(page));
-	BUG_ON(from > PAGE_CACHE_SIZE);
-	BUG_ON(to > PAGE_CACHE_SIZE);
-	BUG_ON(from > to);
-
-	blocksize = 1 << inode->i_blkbits;
-	if (!page_has_buffers(page))
-		create_empty_buffers(page, blocksize, 0);
-	head = page_buffers(page);
-
-	bbits = inode->i_blkbits;
-	block = (sector_t)page->index << (PAGE_CACHE_SHIFT - bbits);
-
-	for(bh = head, block_start = 0; bh != head || !block_start;
-	    block++, block_start=block_end, bh = bh->b_this_page) {
-		block_end = block_start + blocksize;
-		if (block_end <= from || block_start >= to) {
-			if (PageUptodate(page)) {
-				if (!buffer_uptodate(bh))
-					set_buffer_uptodate(bh);
-			}
-			continue;
-		}
-		if (buffer_new(bh))
-			clear_buffer_new(bh);
-		if (!buffer_mapped(bh)) {
-			WARN_ON(bh->b_size != blocksize);
-			err = get_block(inode, block, bh, 1);
-			if (err)
-				break;
-			if (buffer_new(bh)) {
-				unmap_underlying_metadata(bh->b_bdev,
-							bh->b_blocknr);
-				if (PageUptodate(page)) {
-					clear_buffer_new(bh);
-					set_buffer_uptodate(bh);
-					mark_buffer_dirty(bh);
-					continue;
-				}
-				if (block_end > to || block_start < from)
-					zero_user_segments(page,
-						to, block_end,
-						block_start, from);
-				continue;
-			}
-		}
-		if (PageUptodate(page)) {
-			if (!buffer_uptodate(bh))
-				set_buffer_uptodate(bh);
-			continue; 
-		}
-		if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
-		    !buffer_unwritten(bh) &&
-		     (block_start < from || block_end > to)) {
-			ll_rw_block(READ, 1, &bh);
-			*wait_bh++=bh;
-		}
-	}
-	/*
-	 * If we issued read requests - let them complete.
-	 */
-	while(wait_bh > wait) {
-		wait_on_buffer(*--wait_bh);
-		if (!buffer_uptodate(*wait_bh))
-			err = -EIO;
-	}
-	if (unlikely(err))
-		page_zero_new_buffers(page, from, to);
-	return err;
-}
-
-static int __block_commit_write(struct inode *inode, struct page *page,
-		unsigned from, unsigned to)
-{
-	unsigned block_start, block_end;
-	int partial = 0;
-	unsigned blocksize;
-	struct buffer_head *bh, *head;
-
-	blocksize = 1 << inode->i_blkbits;
-
-	for(bh = head = page_buffers(page), block_start = 0;
-	    bh != head || !block_start;
-	    block_start=block_end, bh = bh->b_this_page) {
-		block_end = block_start + blocksize;
-		if (block_end <= from || block_start >= to) {
-			if (!buffer_uptodate(bh))
-				partial = 1;
-		} else {
-			set_buffer_uptodate(bh);
-			mark_buffer_dirty(bh);
-		}
-		clear_buffer_new(bh);
-	}
-
-	/*
-	 * If this is a partial write which happened to make all buffers
-	 * uptodate then we can optimize away a bogus readpage() for
-	 * the next read(). Here we 'discover' whether the page went
-	 * uptodate as a result of this (potentially partial) write.
-	 */
-	if (!partial)
-		SetPageUptodate(page);
-	return 0;
-}
-
-/*
- * block_write_begin takes care of the basic task of block allocation and
- * bringing partial write blocks uptodate first.
- *
- * If *pagep is not NULL, then block_write_begin uses the locked page
- * at *pagep rather than allocating its own. In this case, the page will
- * not be unlocked or deallocated on failure.
- */
-int block_write_begin(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned flags,
-			struct page **pagep, void **fsdata,
-			get_block_t *get_block)
-{
-#ifndef DDE_LINUX
-	struct inode *inode = mapping->host;
-	int status = 0;
-	struct page *page;
-	pgoff_t index;
-	unsigned start, end;
-	int ownpage = 0;
-
-	index = pos >> PAGE_CACHE_SHIFT;
-	start = pos & (PAGE_CACHE_SIZE - 1);
-	end = start + len;
-
-	page = *pagep;
-	if (page == NULL) {
-		ownpage = 1;
-		page = grab_cache_page_write_begin(mapping, index, flags);
-		if (!page) {
-			status = -ENOMEM;
-			goto out;
-		}
-		*pagep = page;
-	} else
-		BUG_ON(!PageLocked(page));
-
-	status = __block_prepare_write(inode, page, start, end, get_block);
-	if (unlikely(status)) {
-		ClearPageUptodate(page);
-
-		if (ownpage) {
-			unlock_page(page);
-			page_cache_release(page);
-			*pagep = NULL;
-
-#ifndef DDE_LINUX
-			/*
-			 * prepare_write() may have instantiated a few blocks
-			 * outside i_size.  Trim these off again. Don't need
-			 * i_size_read because we hold i_mutex.
-			 */
-			if (pos + len > inode->i_size)
-				vmtruncate(inode, inode->i_size);
-#endif
-		}
-	}
-
-out:
-	return status;
-#else
-	WARN_UNIMPL;
-	return -1;
-#endif
-}
-EXPORT_SYMBOL(block_write_begin);
-
-int block_write_end(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned copied,
-			struct page *page, void *fsdata)
-{
-	struct inode *inode = mapping->host;
-	unsigned start;
-
-	start = pos & (PAGE_CACHE_SIZE - 1);
-
-	if (unlikely(copied < len)) {
-		/*
-		 * The buffers that were written will now be uptodate, so we
-		 * don't have to worry about a readpage reading them and
-		 * overwriting a partial write. However if we have encountered
-		 * a short write and only partially written into a buffer, it
-		 * will not be marked uptodate, so a readpage might come in and
-		 * destroy our partial write.
-		 *
-		 * Do the simplest thing, and just treat any short write to a
-		 * non uptodate page as a zero-length write, and force the
-		 * caller to redo the whole thing.
-		 */
-		if (!PageUptodate(page))
-			copied = 0;
-
-		page_zero_new_buffers(page, start+copied, start+len);
-	}
-	flush_dcache_page(page);
-
-	/* This could be a short (even 0-length) commit */
-	__block_commit_write(inode, page, start, start+copied);
-
-	return copied;
-}
-EXPORT_SYMBOL(block_write_end);
-
-int generic_write_end(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned copied,
-			struct page *page, void *fsdata)
-{
-	struct inode *inode = mapping->host;
-	int i_size_changed = 0;
-
-	copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
-
-	/*
-	 * No need to use i_size_read() here, the i_size
-	 * cannot change under us because we hold i_mutex.
-	 *
-	 * But it's important to update i_size while still holding page lock:
-	 * page writeout could otherwise come in and zero beyond i_size.
-	 */
-	if (pos+copied > inode->i_size) {
-		i_size_write(inode, pos+copied);
-		i_size_changed = 1;
-	}
-
-	unlock_page(page);
-	page_cache_release(page);
-
-	/*
-	 * Don't mark the inode dirty under page lock. First, it unnecessarily
-	 * makes the holding time of page lock longer. Second, it forces lock
-	 * ordering of page lock and transaction start for journaling
-	 * filesystems.
-	 */
-	if (i_size_changed)
-		mark_inode_dirty(inode);
-
-	return copied;
-}
-EXPORT_SYMBOL(generic_write_end);
-
-/*
- * block_is_partially_uptodate checks whether buffers within a page are
- * uptodate or not.
- *
- * Returns true if all buffers which correspond to a file portion
- * we want to read are uptodate.
- */
-int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,
-					unsigned long from)
-{
-	struct inode *inode = page->mapping->host;
-	unsigned block_start, block_end, blocksize;
-	unsigned to;
-	struct buffer_head *bh, *head;
-	int ret = 1;
-
-	if (!page_has_buffers(page))
-		return 0;
-
-	blocksize = 1 << inode->i_blkbits;
-	to = min_t(unsigned, PAGE_CACHE_SIZE - from, desc->count);
-	to = from + to;
-	if (from < blocksize && to > PAGE_CACHE_SIZE - blocksize)
-		return 0;
-
-	head = page_buffers(page);
-	bh = head;
-	block_start = 0;
-	do {
-		block_end = block_start + blocksize;
-		if (block_end > from && block_start < to) {
-			if (!buffer_uptodate(bh)) {
-				ret = 0;
-				break;
-			}
-			if (block_end >= to)
-				break;
-		}
-		block_start = block_end;
-		bh = bh->b_this_page;
-	} while (bh != head);
-
-	return ret;
-}
-EXPORT_SYMBOL(block_is_partially_uptodate);
-
-/*
- * Generic "read page" function for block devices that have the normal
- * get_block functionality. This is most of the block device filesystems.
- * Reads the page asynchronously --- the unlock_buffer() and
- * set/clear_buffer_uptodate() functions propagate buffer state into the
- * page struct once IO has completed.
- */
-int block_read_full_page(struct page *page, get_block_t *get_block)
-{
-	struct inode *inode = page->mapping->host;
-	sector_t iblock, lblock;
-	struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
-	unsigned int blocksize;
-	int nr, i;
-	int fully_mapped = 1;
-
-	BUG_ON(!PageLocked(page));
-	blocksize = 1 << inode->i_blkbits;
-	if (!page_has_buffers(page))
-		create_empty_buffers(page, blocksize, 0);
-	head = page_buffers(page);
-
-	iblock = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
-	lblock = (i_size_read(inode)+blocksize-1) >> inode->i_blkbits;
-	bh = head;
-	nr = 0;
-	i = 0;
-
-	do {
-		if (buffer_uptodate(bh))
-			continue;
-
-		if (!buffer_mapped(bh)) {
-			int err = 0;
-
-			fully_mapped = 0;
-			if (iblock < lblock) {
-				WARN_ON(bh->b_size != blocksize);
-				err = get_block(inode, iblock, bh, 0);
-				if (err)
-					SetPageError(page);
-			}
-			if (!buffer_mapped(bh)) {
-				zero_user(page, i * blocksize, blocksize);
-				if (!err)
-					set_buffer_uptodate(bh);
-				continue;
-			}
-			/*
-			 * get_block() might have updated the buffer
-			 * synchronously
-			 */
-			if (buffer_uptodate(bh))
-				continue;
-		}
-		arr[nr++] = bh;
-	} while (i++, iblock++, (bh = bh->b_this_page) != head);
-
-	if (fully_mapped)
-		SetPageMappedToDisk(page);
-
-	if (!nr) {
-		/*
-		 * All buffers are uptodate - we can set the page uptodate
-		 * as well. But not if get_block() returned an error.
-		 */
-		if (!PageError(page))
-			SetPageUptodate(page);
-		unlock_page(page);
-		return 0;
-	}
-
-	/* Stage two: lock the buffers */
-	for (i = 0; i < nr; i++) {
-		bh = arr[i];
-		lock_buffer(bh);
-		mark_buffer_async_read(bh);
-	}
-
-	/*
-	 * Stage 3: start the IO.  Check for uptodateness
-	 * inside the buffer lock in case another process reading
-	 * the underlying blockdev brought it uptodate (the sct fix).
-	 */
-	for (i = 0; i < nr; i++) {
-		bh = arr[i];
-		if (buffer_uptodate(bh))
-			end_buffer_async_read(bh, 1);
-		else
-			submit_bh(READ, bh);
-	}
-	return 0;
-}
-
-/* utility function for filesystems that need to do work on expanding
- * truncates.  Uses filesystem pagecache writes to allow the filesystem to
- * deal with the hole.  
- */
-int generic_cont_expand_simple(struct inode *inode, loff_t size)
-{
-	struct address_space *mapping = inode->i_mapping;
-	struct page *page;
-	void *fsdata;
-	unsigned long limit;
-	int err;
-
-	err = -EFBIG;
-        limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
-	if (limit != RLIM_INFINITY && size > (loff_t)limit) {
-		send_sig(SIGXFSZ, current, 0);
-		goto out;
-	}
-	if (size > inode->i_sb->s_maxbytes)
-		goto out;
-
-	err = pagecache_write_begin(NULL, mapping, size, 0,
-				AOP_FLAG_UNINTERRUPTIBLE|AOP_FLAG_CONT_EXPAND,
-				&page, &fsdata);
-	if (err)
-		goto out;
-
-	err = pagecache_write_end(NULL, mapping, size, 0, 0, page, fsdata);
-	BUG_ON(err > 0);
-
-out:
-	return err;
-}
-
-static int cont_expand_zero(struct file *file, struct address_space *mapping,
-			    loff_t pos, loff_t *bytes)
-{
-	struct inode *inode = mapping->host;
-	unsigned blocksize = 1 << inode->i_blkbits;
-	struct page *page;
-	void *fsdata;
-	pgoff_t index, curidx;
-	loff_t curpos;
-	unsigned zerofrom, offset, len;
-	int err = 0;
-
-	index = pos >> PAGE_CACHE_SHIFT;
-	offset = pos & ~PAGE_CACHE_MASK;
-
-	while (index > (curidx = (curpos = *bytes)>>PAGE_CACHE_SHIFT)) {
-		zerofrom = curpos & ~PAGE_CACHE_MASK;
-		if (zerofrom & (blocksize-1)) {
-			*bytes |= (blocksize-1);
-			(*bytes)++;
-		}
-		len = PAGE_CACHE_SIZE - zerofrom;
-
-		err = pagecache_write_begin(file, mapping, curpos, len,
-						AOP_FLAG_UNINTERRUPTIBLE,
-						&page, &fsdata);
-		if (err)
-			goto out;
-		zero_user(page, zerofrom, len);
-		err = pagecache_write_end(file, mapping, curpos, len, len,
-						page, fsdata);
-		if (err < 0)
-			goto out;
-		BUG_ON(err != len);
-		err = 0;
-
-		balance_dirty_pages_ratelimited(mapping);
-	}
-
-	/* page covers the boundary, find the boundary offset */
-	if (index == curidx) {
-		zerofrom = curpos & ~PAGE_CACHE_MASK;
-		/* if we will expand the thing last block will be filled */
-		if (offset <= zerofrom) {
-			goto out;
-		}
-		if (zerofrom & (blocksize-1)) {
-			*bytes |= (blocksize-1);
-			(*bytes)++;
-		}
-		len = offset - zerofrom;
-
-		err = pagecache_write_begin(file, mapping, curpos, len,
-						AOP_FLAG_UNINTERRUPTIBLE,
-						&page, &fsdata);
-		if (err)
-			goto out;
-		zero_user(page, zerofrom, len);
-		err = pagecache_write_end(file, mapping, curpos, len, len,
-						page, fsdata);
-		if (err < 0)
-			goto out;
-		BUG_ON(err != len);
-		err = 0;
-	}
-out:
-	return err;
-}
-
-/*
- * For moronic filesystems that do not allow holes in file.
- * We may have to extend the file.
- */
-int cont_write_begin(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned flags,
-			struct page **pagep, void **fsdata,
-			get_block_t *get_block, loff_t *bytes)
-{
-	struct inode *inode = mapping->host;
-	unsigned blocksize = 1 << inode->i_blkbits;
-	unsigned zerofrom;
-	int err;
-
-	err = cont_expand_zero(file, mapping, pos, bytes);
-	if (err)
-		goto out;
-
-	zerofrom = *bytes & ~PAGE_CACHE_MASK;
-	if (pos+len > *bytes && zerofrom & (blocksize-1)) {
-		*bytes |= (blocksize-1);
-		(*bytes)++;
-	}
-
-	*pagep = NULL;
-	err = block_write_begin(file, mapping, pos, len,
-				flags, pagep, fsdata, get_block);
-out:
-	return err;
-}
-
-int block_prepare_write(struct page *page, unsigned from, unsigned to,
-			get_block_t *get_block)
-{
-	struct inode *inode = page->mapping->host;
-	int err = __block_prepare_write(inode, page, from, to, get_block);
-	if (err)
-		ClearPageUptodate(page);
-	return err;
-}
-
-int block_commit_write(struct page *page, unsigned from, unsigned to)
-{
-	struct inode *inode = page->mapping->host;
-	__block_commit_write(inode,page,from,to);
-	return 0;
-}
-
-/*
- * block_page_mkwrite() is not allowed to change the file size as it gets
- * called from a page fault handler when a page is first dirtied. Hence we must
- * be careful to check for EOF conditions here. We set the page up correctly
- * for a written page which means we get ENOSPC checking when writing into
- * holes and correct delalloc and unwritten extent mapping on filesystems that
- * support these features.
- *
- * We are not allowed to take the i_mutex here so we have to play games to
- * protect against truncate races as the page could now be beyond EOF.  Because
- * vmtruncate() writes the inode size before removing pages, once we have the
- * page lock we can determine safely if the page is beyond EOF. If it is not
- * beyond EOF, then the page is guaranteed safe against truncation until we
- * unlock the page.
- */
-int
-block_page_mkwrite(struct vm_area_struct *vma, struct page *page,
-		   get_block_t get_block)
-{
-	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
-	unsigned long end;
-	loff_t size;
-	int ret = -EINVAL;
-
-	lock_page(page);
-	size = i_size_read(inode);
-	if ((page->mapping != inode->i_mapping) ||
-	    (page_offset(page) > size)) {
-		/* page got truncated out from underneath us */
-		goto out_unlock;
-	}
-
-	/* page is wholly or partially inside EOF */
-	if (((page->index + 1) << PAGE_CACHE_SHIFT) > size)
-		end = size & ~PAGE_CACHE_MASK;
-	else
-		end = PAGE_CACHE_SIZE;
-
-	ret = block_prepare_write(page, 0, end, get_block);
-	if (!ret)
-		ret = block_commit_write(page, 0, end);
-
-out_unlock:
-	unlock_page(page);
-	return ret;
-}
-
-/*
- * nobh_write_begin()'s prereads are special: the buffer_heads are freed
- * immediately, while under the page lock.  So it needs a special end_io
- * handler which does not touch the bh after unlocking it.
- */
-static void end_buffer_read_nobh(struct buffer_head *bh, int uptodate)
-{
-	__end_buffer_read_notouch(bh, uptodate);
-}
-
-/*
- * Attach the singly-linked list of buffers created by nobh_write_begin, to
- * the page (converting it to circular linked list and taking care of page
- * dirty races).
- */
-static void attach_nobh_buffers(struct page *page, struct buffer_head *head)
-{
-	struct buffer_head *bh;
-
-	BUG_ON(!PageLocked(page));
-
-	spin_lock(&page->mapping->private_lock);
-	bh = head;
-	do {
-		if (PageDirty(page))
-			set_buffer_dirty(bh);
-		if (!bh->b_this_page)
-			bh->b_this_page = head;
-		bh = bh->b_this_page;
-	} while (bh != head);
-	attach_page_buffers(page, head);
-	spin_unlock(&page->mapping->private_lock);
-}
-
-/*
- * On entry, the page is fully not uptodate.
- * On exit the page is fully uptodate in the areas outside (from,to)
- */
-int nobh_write_begin(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned flags,
-			struct page **pagep, void **fsdata,
-			get_block_t *get_block)
-{
-	struct inode *inode = mapping->host;
-	const unsigned blkbits = inode->i_blkbits;
-	const unsigned blocksize = 1 << blkbits;
-	struct buffer_head *head, *bh;
-	struct page *page;
-	pgoff_t index;
-	unsigned from, to;
-	unsigned block_in_page;
-	unsigned block_start, block_end;
-	sector_t block_in_file;
-	int nr_reads = 0;
-	int ret = 0;
-	int is_mapped_to_disk = 1;
-
-	index = pos >> PAGE_CACHE_SHIFT;
-	from = pos & (PAGE_CACHE_SIZE - 1);
-	to = from + len;
-
-	page = grab_cache_page_write_begin(mapping, index, flags);
-	if (!page)
-		return -ENOMEM;
-	*pagep = page;
-	*fsdata = NULL;
-
-	if (page_has_buffers(page)) {
-		unlock_page(page);
-		page_cache_release(page);
-		*pagep = NULL;
-		return block_write_begin(file, mapping, pos, len, flags, pagep,
-					fsdata, get_block);
-	}
-
-	if (PageMappedToDisk(page))
-		return 0;
-
-	/*
-	 * Allocate buffers so that we can keep track of state, and potentially
-	 * attach them to the page if an error occurs. In the common case of
-	 * no error, they will just be freed again without ever being attached
-	 * to the page (which is all OK, because we're under the page lock).
-	 *
-	 * Be careful: the buffer linked list is a NULL terminated one, rather
-	 * than the circular one we're used to.
-	 */
-	head = alloc_page_buffers(page, blocksize, 0);
-	if (!head) {
-		ret = -ENOMEM;
-		goto out_release;
-	}
-
-	block_in_file = (sector_t)page->index << (PAGE_CACHE_SHIFT - blkbits);
-
-	/*
-	 * We loop across all blocks in the page, whether or not they are
-	 * part of the affected region.  This is so we can discover if the
-	 * page is fully mapped-to-disk.
-	 */
-	for (block_start = 0, block_in_page = 0, bh = head;
-		  block_start < PAGE_CACHE_SIZE;
-		  block_in_page++, block_start += blocksize, bh = bh->b_this_page) {
-		int create;
-
-		block_end = block_start + blocksize;
-		bh->b_state = 0;
-		create = 1;
-		if (block_start >= to)
-			create = 0;
-		ret = get_block(inode, block_in_file + block_in_page,
-					bh, create);
-		if (ret)
-			goto failed;
-		if (!buffer_mapped(bh))
-			is_mapped_to_disk = 0;
-		if (buffer_new(bh))
-			unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
-		if (PageUptodate(page)) {
-			set_buffer_uptodate(bh);
-			continue;
-		}
-		if (buffer_new(bh) || !buffer_mapped(bh)) {
-			zero_user_segments(page, block_start, from,
-							to, block_end);
-			continue;
-		}
-		if (buffer_uptodate(bh))
-			continue;	/* reiserfs does this */
-		if (block_start < from || block_end > to) {
-			lock_buffer(bh);
-			bh->b_end_io = end_buffer_read_nobh;
-			submit_bh(READ, bh);
-			nr_reads++;
-		}
-	}
-
-	if (nr_reads) {
-		/*
-		 * The page is locked, so these buffers are protected from
-		 * any VM or truncate activity.  Hence we don't need to care
-		 * for the buffer_head refcounts.
-		 */
-		for (bh = head; bh; bh = bh->b_this_page) {
-			wait_on_buffer(bh);
-			if (!buffer_uptodate(bh))
-				ret = -EIO;
-		}
-		if (ret)
-			goto failed;
-	}
-
-	if (is_mapped_to_disk)
-		SetPageMappedToDisk(page);
-
-	*fsdata = head; /* to be released by nobh_write_end */
-
-	return 0;
-
-failed:
-	BUG_ON(!ret);
-	/*
-	 * Error recovery is a bit difficult. We need to zero out blocks that
-	 * were newly allocated, and dirty them to ensure they get written out.
-	 * Buffers need to be attached to the page at this point, otherwise
-	 * the handling of potential IO errors during writeout would be hard
-	 * (could try doing synchronous writeout, but what if that fails too?)
-	 */
-	attach_nobh_buffers(page, head);
-	page_zero_new_buffers(page, from, to);
-
-out_release:
-	unlock_page(page);
-	page_cache_release(page);
-	*pagep = NULL;
-
-	if (pos + len > inode->i_size)
-		vmtruncate(inode, inode->i_size);
-
-	return ret;
-}
-EXPORT_SYMBOL(nobh_write_begin);
-
-int nobh_write_end(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned copied,
-			struct page *page, void *fsdata)
-{
-	struct inode *inode = page->mapping->host;
-	struct buffer_head *head = fsdata;
-	struct buffer_head *bh;
-	BUG_ON(fsdata != NULL && page_has_buffers(page));
-
-	if (unlikely(copied < len) && head)
-		attach_nobh_buffers(page, head);
-	if (page_has_buffers(page))
-		return generic_write_end(file, mapping, pos, len,
-					copied, page, fsdata);
-
-	SetPageUptodate(page);
-	set_page_dirty(page);
-	if (pos+copied > inode->i_size) {
-		i_size_write(inode, pos+copied);
-		mark_inode_dirty(inode);
-	}
-
-	unlock_page(page);
-	page_cache_release(page);
-
-	while (head) {
-		bh = head;
-		head = head->b_this_page;
-		free_buffer_head(bh);
-	}
-
-	return copied;
-}
-EXPORT_SYMBOL(nobh_write_end);
-
-/*
- * nobh_writepage() - based on block_full_write_page() except
- * that it tries to operate without attaching bufferheads to
- * the page.
- */
-int nobh_writepage(struct page *page, get_block_t *get_block,
-			struct writeback_control *wbc)
-{
-	struct inode * const inode = page->mapping->host;
-	loff_t i_size = i_size_read(inode);
-	const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
-	unsigned offset;
-	int ret;
-
-	/* Is the page fully inside i_size? */
-	if (page->index < end_index)
-		goto out;
-
-	/* Is the page fully outside i_size? (truncate in progress) */
-	offset = i_size & (PAGE_CACHE_SIZE-1);
-	if (page->index >= end_index+1 || !offset) {
-		/*
-		 * The page may have dirty, unmapped buffers.  For example,
-		 * they may have been added in ext3_writepage().  Make them
-		 * freeable here, so the page does not leak.
-		 */
-#if 0
-		/* Not really sure about this  - do we need this ? */
-		if (page->mapping->a_ops->invalidatepage)
-			page->mapping->a_ops->invalidatepage(page, offset);
-#endif
-		unlock_page(page);
-		return 0; /* don't care */
-	}
-
-	/*
-	 * The page straddles i_size.  It must be zeroed out on each and every
-	 * writepage invocation because it may be mmapped.  "A file is mapped
-	 * in multiples of the page size.  For a file that is not a multiple of
-	 * the  page size, the remaining memory is zeroed when mapped, and
-	 * writes to that region are not written out to the file."
-	 */
-	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
-out:
-	ret = mpage_writepage(page, get_block, wbc);
-	if (ret == -EAGAIN)
-		ret = __block_write_full_page(inode, page, get_block, wbc);
-	return ret;
-}
-EXPORT_SYMBOL(nobh_writepage);
-
-int nobh_truncate_page(struct address_space *mapping,
-			loff_t from, get_block_t *get_block)
-{
-	pgoff_t index = from >> PAGE_CACHE_SHIFT;
-	unsigned offset = from & (PAGE_CACHE_SIZE-1);
-	unsigned blocksize;
-	sector_t iblock;
-	unsigned length, pos;
-	struct inode *inode = mapping->host;
-	struct page *page;
-	struct buffer_head map_bh;
-	int err;
-
-	blocksize = 1 << inode->i_blkbits;
-	length = offset & (blocksize - 1);
-
-	/* Block boundary? Nothing to do */
-	if (!length)
-		return 0;
-
-	length = blocksize - length;
-	iblock = (sector_t)index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
-
-	page = grab_cache_page(mapping, index);
-	err = -ENOMEM;
-	if (!page)
-		goto out;
-
-	if (page_has_buffers(page)) {
-has_buffers:
-		unlock_page(page);
-		page_cache_release(page);
-		return block_truncate_page(mapping, from, get_block);
-	}
-
-	/* Find the buffer that contains "offset" */
-	pos = blocksize;
-	while (offset >= pos) {
-		iblock++;
-		pos += blocksize;
-	}
-
-	err = get_block(inode, iblock, &map_bh, 0);
-	if (err)
-		goto unlock;
-	/* unmapped? It's a hole - nothing to do */
-	if (!buffer_mapped(&map_bh))
-		goto unlock;
-
-	/* Ok, it's mapped. Make sure it's up-to-date */
-	if (!PageUptodate(page)) {
-		err = mapping->a_ops->readpage(NULL, page);
-		if (err) {
-			page_cache_release(page);
-			goto out;
-		}
-		lock_page(page);
-		if (!PageUptodate(page)) {
-			err = -EIO;
-			goto unlock;
-		}
-		if (page_has_buffers(page))
-			goto has_buffers;
-	}
-	zero_user(page, offset, length);
-	set_page_dirty(page);
-	err = 0;
-
-unlock:
-	unlock_page(page);
-	page_cache_release(page);
-out:
-	return err;
-}
-EXPORT_SYMBOL(nobh_truncate_page);
-
-int block_truncate_page(struct address_space *mapping,
-			loff_t from, get_block_t *get_block)
-{
-	pgoff_t index = from >> PAGE_CACHE_SHIFT;
-	unsigned offset = from & (PAGE_CACHE_SIZE-1);
-	unsigned blocksize;
-	sector_t iblock;
-	unsigned length, pos;
-	struct inode *inode = mapping->host;
-	struct page *page;
-	struct buffer_head *bh;
-	int err;
-
-	blocksize = 1 << inode->i_blkbits;
-	length = offset & (blocksize - 1);
-
-	/* Block boundary? Nothing to do */
-	if (!length)
-		return 0;
-
-	length = blocksize - length;
-	iblock = (sector_t)index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
-	
-	page = grab_cache_page(mapping, index);
-	err = -ENOMEM;
-	if (!page)
-		goto out;
-
-	if (!page_has_buffers(page))
-		create_empty_buffers(page, blocksize, 0);
-
-	/* Find the buffer that contains "offset" */
-	bh = page_buffers(page);
-	pos = blocksize;
-	while (offset >= pos) {
-		bh = bh->b_this_page;
-		iblock++;
-		pos += blocksize;
-	}
-
-	err = 0;
-	if (!buffer_mapped(bh)) {
-		WARN_ON(bh->b_size != blocksize);
-		err = get_block(inode, iblock, bh, 0);
-		if (err)
-			goto unlock;
-		/* unmapped? It's a hole - nothing to do */
-		if (!buffer_mapped(bh))
-			goto unlock;
-	}
-
-	/* Ok, it's mapped. Make sure it's up-to-date */
-	if (PageUptodate(page))
-		set_buffer_uptodate(bh);
-
-	if (!buffer_uptodate(bh) && !buffer_delay(bh) && !buffer_unwritten(bh)) {
-		err = -EIO;
-		ll_rw_block(READ, 1, &bh);
-		wait_on_buffer(bh);
-		/* Uhhuh. Read error. Complain and punt. */
-		if (!buffer_uptodate(bh))
-			goto unlock;
-	}
-
-	zero_user(page, offset, length);
-	mark_buffer_dirty(bh);
-	err = 0;
-
-unlock:
-	unlock_page(page);
-	page_cache_release(page);
-out:
-	return err;
-}
-
-/*
- * The generic ->writepage function for buffer-backed address_spaces
- */
-int block_write_full_page(struct page *page, get_block_t *get_block,
-			struct writeback_control *wbc)
-{
-	struct inode * const inode = page->mapping->host;
-	loff_t i_size = i_size_read(inode);
-	const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
-	unsigned offset;
-
-	/* Is the page fully inside i_size? */
-	if (page->index < end_index)
-		return __block_write_full_page(inode, page, get_block, wbc);
-
-	/* Is the page fully outside i_size? (truncate in progress) */
-	offset = i_size & (PAGE_CACHE_SIZE-1);
-	if (page->index >= end_index+1 || !offset) {
-		/*
-		 * The page may have dirty, unmapped buffers.  For example,
-		 * they may have been added in ext3_writepage().  Make them
-		 * freeable here, so the page does not leak.
-		 */
-		do_invalidatepage(page, 0);
-		unlock_page(page);
-		return 0; /* don't care */
-	}
-
-	/*
-	 * The page straddles i_size.  It must be zeroed out on each and every
-	 * writepage invokation because it may be mmapped.  "A file is mapped
-	 * in multiples of the page size.  For a file that is not a multiple of
-	 * the  page size, the remaining memory is zeroed when mapped, and
-	 * writes to that region are not written out to the file."
-	 */
-	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
-	return __block_write_full_page(inode, page, get_block, wbc);
-}
-
-sector_t generic_block_bmap(struct address_space *mapping, sector_t block,
-			    get_block_t *get_block)
-{
-	struct buffer_head tmp;
-	struct inode *inode = mapping->host;
-	tmp.b_state = 0;
-	tmp.b_blocknr = 0;
-	tmp.b_size = 1 << inode->i_blkbits;
-	get_block(inode, block, &tmp, 0);
-	return tmp.b_blocknr;
-}
-
-static void end_bio_bh_io_sync(struct bio *bio, int err)
-{
-	struct buffer_head *bh = bio->bi_private;
-
-	if (err == -EOPNOTSUPP) {
-		set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
-		set_bit(BH_Eopnotsupp, &bh->b_state);
-	}
-
-	if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags)))
-		set_bit(BH_Quiet, &bh->b_state);
-
-	bh->b_end_io(bh, test_bit(BIO_UPTODATE, &bio->bi_flags));
-	bio_put(bio);
-}
-
-int submit_bh(int rw, struct buffer_head * bh)
-{
-	struct bio *bio;
-	int ret = 0;
-
-	BUG_ON(!buffer_locked(bh));
-	BUG_ON(!buffer_mapped(bh));
-	BUG_ON(!bh->b_end_io);
-
-	/*
-	 * Mask in barrier bit for a write (could be either a WRITE or a
-	 * WRITE_SYNC
-	 */
-	if (buffer_ordered(bh) && (rw & WRITE))
-		rw |= WRITE_BARRIER;
-
-	/*
-	 * Only clear out a write error when rewriting
-	 */
-	if (test_set_buffer_req(bh) && (rw & WRITE))
-		clear_buffer_write_io_error(bh);
-
-	/*
-	 * from here on down, it's all bio -- do the initial mapping,
-	 * submit_bio -> generic_make_request may further map this bio around
-	 */
-	bio = bio_alloc(GFP_NOIO, 1);
-
-	bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9);
-	bio->bi_bdev = bh->b_bdev;
-	bio->bi_io_vec[0].bv_page = bh->b_page;
-	bio->bi_io_vec[0].bv_len = bh->b_size;
-	bio->bi_io_vec[0].bv_offset = bh_offset(bh);
-
-	bio->bi_vcnt = 1;
-	bio->bi_idx = 0;
-	bio->bi_size = bh->b_size;
-
-	bio->bi_end_io = end_bio_bh_io_sync;
-	bio->bi_private = bh;
-
-	bio_get(bio);
-	submit_bio(rw, bio);
-
-	if (bio_flagged(bio, BIO_EOPNOTSUPP))
-		ret = -EOPNOTSUPP;
-
-	bio_put(bio);
-	return ret;
-}
-
-/**
- * ll_rw_block: low-level access to block devices (DEPRECATED)
- * @rw: whether to %READ or %WRITE or %SWRITE or maybe %READA (readahead)
- * @nr: number of &struct buffer_heads in the array
- * @bhs: array of pointers to &struct buffer_head
- *
- * ll_rw_block() takes an array of pointers to &struct buffer_heads, and
- * requests an I/O operation on them, either a %READ or a %WRITE.  The third
- * %SWRITE is like %WRITE only we make sure that the *current* data in buffers
- * are sent to disk. The fourth %READA option is described in the documentation
- * for generic_make_request() which ll_rw_block() calls.
- *
- * This function drops any buffer that it cannot get a lock on (with the
- * BH_Lock state bit) unless SWRITE is required, any buffer that appears to be
- * clean when doing a write request, and any buffer that appears to be
- * up-to-date when doing read request.  Further it marks as clean buffers that
- * are processed for writing (the buffer cache won't assume that they are
- * actually clean until the buffer gets unlocked).
- *
- * ll_rw_block sets b_end_io to simple completion handler that marks
- * the buffer up-to-date (if approriate), unlocks the buffer and wakes
- * any waiters. 
- *
- * All of the buffers must be for the same device, and must also be a
- * multiple of the current approved size for the device.
- */
-void ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
-{
-	int i;
-
-	for (i = 0; i < nr; i++) {
-		struct buffer_head *bh = bhs[i];
-
-		if (rw == SWRITE || rw == SWRITE_SYNC)
-			lock_buffer(bh);
-		else if (!trylock_buffer(bh))
-			continue;
-
-		if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC) {
-			if (test_clear_buffer_dirty(bh)) {
-				bh->b_end_io = end_buffer_write_sync;
-				get_bh(bh);
-				if (rw == SWRITE_SYNC)
-					submit_bh(WRITE_SYNC, bh);
-				else
-					submit_bh(WRITE, bh);
-				continue;
-			}
-		} else {
-			if (!buffer_uptodate(bh)) {
-				bh->b_end_io = end_buffer_read_sync;
-				get_bh(bh);
-				submit_bh(rw, bh);
-				continue;
-			}
-		}
-		unlock_buffer(bh);
-	}
-}
-
-/*
- * For a data-integrity writeout, we need to wait upon any in-progress I/O
- * and then start new I/O and then wait upon it.  The caller must have a ref on
- * the buffer_head.
- */
-int sync_dirty_buffer(struct buffer_head *bh)
-{
-	int ret = 0;
-
-	WARN_ON(atomic_read(&bh->b_count) < 1);
-	lock_buffer(bh);
-	if (test_clear_buffer_dirty(bh)) {
-		get_bh(bh);
-		bh->b_end_io = end_buffer_write_sync;
-		ret = submit_bh(WRITE, bh);
-		wait_on_buffer(bh);
-		if (buffer_eopnotsupp(bh)) {
-			clear_buffer_eopnotsupp(bh);
-			ret = -EOPNOTSUPP;
-		}
-		if (!ret && !buffer_uptodate(bh))
-			ret = -EIO;
-	} else {
-		unlock_buffer(bh);
-	}
-	return ret;
-}
-
-/*
- * try_to_free_buffers() checks if all the buffers on this particular page
- * are unused, and releases them if so.
- *
- * Exclusion against try_to_free_buffers may be obtained by either
- * locking the page or by holding its mapping's private_lock.
- *
- * If the page is dirty but all the buffers are clean then we need to
- * be sure to mark the page clean as well.  This is because the page
- * may be against a block device, and a later reattachment of buffers
- * to a dirty page will set *all* buffers dirty.  Which would corrupt
- * filesystem data on the same device.
- *
- * The same applies to regular filesystem pages: if all the buffers are
- * clean then we set the page clean and proceed.  To do that, we require
- * total exclusion from __set_page_dirty_buffers().  That is obtained with
- * private_lock.
- *
- * try_to_free_buffers() is non-blocking.
- */
-static inline int buffer_busy(struct buffer_head *bh)
-{
-	return atomic_read(&bh->b_count) |
-		(bh->b_state & ((1 << BH_Dirty) | (1 << BH_Lock)));
-}
-
-static int
-drop_buffers(struct page *page, struct buffer_head **buffers_to_free)
-{
-	struct buffer_head *head = page_buffers(page);
-	struct buffer_head *bh;
-
-	bh = head;
-	do {
-		if (buffer_write_io_error(bh) && page->mapping)
-			set_bit(AS_EIO, &page->mapping->flags);
-		if (buffer_busy(bh))
-			goto failed;
-		bh = bh->b_this_page;
-	} while (bh != head);
-
-	do {
-		struct buffer_head *next = bh->b_this_page;
-
-		if (bh->b_assoc_map)
-			__remove_assoc_queue(bh);
-		bh = next;
-	} while (bh != head);
-	*buffers_to_free = head;
-	__clear_page_buffers(page);
-	return 1;
-failed:
-	return 0;
-}
-
-int try_to_free_buffers(struct page *page)
-{
-	struct address_space * const mapping = page->mapping;
-	struct buffer_head *buffers_to_free = NULL;
-	int ret = 0;
-
-	BUG_ON(!PageLocked(page));
-	if (PageWriteback(page))
-		return 0;
-
-	if (mapping == NULL) {		/* can this still happen? */
-		ret = drop_buffers(page, &buffers_to_free);
-		goto out;
-	}
-
-	spin_lock(&mapping->private_lock);
-	ret = drop_buffers(page, &buffers_to_free);
-
-	/*
-	 * If the filesystem writes its buffers by hand (eg ext3)
-	 * then we can have clean buffers against a dirty page.  We
-	 * clean the page here; otherwise the VM will never notice
-	 * that the filesystem did any IO at all.
-	 *
-	 * Also, during truncate, discard_buffer will have marked all
-	 * the page's buffers clean.  We discover that here and clean
-	 * the page also.
-	 *
-	 * private_lock must be held over this entire operation in order
-	 * to synchronise against __set_page_dirty_buffers and prevent the
-	 * dirty bit from being lost.
-	 */
-#ifndef DDE_LINUX
-	if (ret)
-		cancel_dirty_page(page, PAGE_CACHE_SIZE);
-#endif
-	spin_unlock(&mapping->private_lock);
-out:
-	if (buffers_to_free) {
-		struct buffer_head *bh = buffers_to_free;
-
-		do {
-			struct buffer_head *next = bh->b_this_page;
-			free_buffer_head(bh);
-			bh = next;
-		} while (bh != buffers_to_free);
-	}
-	return ret;
-}
-EXPORT_SYMBOL(try_to_free_buffers);
-
-void block_sync_page(struct page *page)
-{
-	struct address_space *mapping;
-
-	smp_mb();
-	mapping = page_mapping(page);
-	if (mapping)
-		blk_run_backing_dev(mapping->backing_dev_info, page);
-}
-
-/*
- * There are no bdflush tunables left.  But distributions are
- * still running obsolete flush daemons, so we terminate them here.
- *
- * Use of bdflush() is deprecated and will be removed in a future kernel.
- * The `pdflush' kernel threads fully replace bdflush daemons and this call.
- */
-SYSCALL_DEFINE2(bdflush, int, func, long, data)
-{
-	static int msg_count;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	if (msg_count < 5) {
-		msg_count++;
-		printk(KERN_INFO
-			"warning: process `%s' used the obsolete bdflush"
-			" system call\n", current->comm);
-		printk(KERN_INFO "Fix your initscripts?\n");
-	}
-
-	if (func == 1)
-		do_exit(0);
-	return 0;
-}
-
-/*
- * Buffer-head allocation
- */
-static struct kmem_cache *bh_cachep;
-
-/*
- * Once the number of bh's in the machine exceeds this level, we start
- * stripping them in writeback.
- */
-static int max_buffer_heads;
-
-int buffer_heads_over_limit;
-
-struct bh_accounting {
-	int nr;			/* Number of live bh's */
-	int ratelimit;		/* Limit cacheline bouncing */
-};
-
-static DEFINE_PER_CPU(struct bh_accounting, bh_accounting) = {0, 0};
-
-static void recalc_bh_state(void)
-{
-	int i;
-	int tot = 0;
-
-	if (__get_cpu_var(bh_accounting).ratelimit++ < 4096)
-		return;
-	__get_cpu_var(bh_accounting).ratelimit = 0;
-	for_each_online_cpu(i)
-		tot += per_cpu(bh_accounting, i).nr;
-	buffer_heads_over_limit = (tot > max_buffer_heads);
-}
-	
-struct buffer_head *alloc_buffer_head(gfp_t gfp_flags)
-{
-	struct buffer_head *ret = kmem_cache_alloc(bh_cachep, gfp_flags);
-	if (ret) {
-		INIT_LIST_HEAD(&ret->b_assoc_buffers);
-		get_cpu_var(bh_accounting).nr++;
-		recalc_bh_state();
-		put_cpu_var(bh_accounting);
-	}
-	return ret;
-}
-EXPORT_SYMBOL(alloc_buffer_head);
-
-void free_buffer_head(struct buffer_head *bh)
-{
-	BUG_ON(!list_empty(&bh->b_assoc_buffers));
-	kmem_cache_free(bh_cachep, bh);
-	get_cpu_var(bh_accounting).nr--;
-	recalc_bh_state();
-	put_cpu_var(bh_accounting);
-}
-EXPORT_SYMBOL(free_buffer_head);
-
-static void buffer_exit_cpu(int cpu)
-{
-	int i;
-	struct bh_lru *b = &per_cpu(bh_lrus, cpu);
-
-	for (i = 0; i < BH_LRU_SIZE; i++) {
-		brelse(b->bhs[i]);
-		b->bhs[i] = NULL;
-	}
-	get_cpu_var(bh_accounting).nr += per_cpu(bh_accounting, cpu).nr;
-	per_cpu(bh_accounting, cpu).nr = 0;
-	put_cpu_var(bh_accounting);
-}
-
-static int buffer_cpu_notify(struct notifier_block *self,
-			      unsigned long action, void *hcpu)
-{
-	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
-		buffer_exit_cpu((unsigned long)hcpu);
-	return NOTIFY_OK;
-}
-
-/**
- * bh_uptodate_or_lock - Test whether the buffer is uptodate
- * @bh: struct buffer_head
- *
- * Return true if the buffer is up-to-date and false,
- * with the buffer locked, if not.
- */
-int bh_uptodate_or_lock(struct buffer_head *bh)
-{
-	if (!buffer_uptodate(bh)) {
-		lock_buffer(bh);
-		if (!buffer_uptodate(bh))
-			return 0;
-		unlock_buffer(bh);
-	}
-	return 1;
-}
-EXPORT_SYMBOL(bh_uptodate_or_lock);
-
-/**
- * bh_submit_read - Submit a locked buffer for reading
- * @bh: struct buffer_head
- *
- * Returns zero on success and -EIO on error.
- */
-int bh_submit_read(struct buffer_head *bh)
-{
-	BUG_ON(!buffer_locked(bh));
-
-	if (buffer_uptodate(bh)) {
-		unlock_buffer(bh);
-		return 0;
-	}
-
-	get_bh(bh);
-	bh->b_end_io = end_buffer_read_sync;
-	submit_bh(READ, bh);
-	wait_on_buffer(bh);
-	if (buffer_uptodate(bh))
-		return 0;
-	return -EIO;
-}
-EXPORT_SYMBOL(bh_submit_read);
-
-static void
-init_buffer_head(void *data)
-{
-	struct buffer_head *bh = data;
-
-	memset(bh, 0, sizeof(*bh));
-	INIT_LIST_HEAD(&bh->b_assoc_buffers);
-}
-
-void __init buffer_init(void)
-{
-	int nrpages;
-
-	bh_cachep = kmem_cache_create("buffer_head",
-			sizeof(struct buffer_head), 0,
-				(SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
-				SLAB_MEM_SPREAD),
-				init_buffer_head);
-
-	/*
-	 * Limit the bh occupancy to 10% of ZONE_NORMAL
-	 */
-	nrpages = (nr_free_buffer_pages() * 10) / 100;
-	max_buffer_heads = nrpages * (PAGE_SIZE / sizeof(struct buffer_head));
-	hotcpu_notifier(buffer_cpu_notify, 0);
-}
-
-EXPORT_SYMBOL(__bforget);
-EXPORT_SYMBOL(__brelse);
-EXPORT_SYMBOL(__wait_on_buffer);
-EXPORT_SYMBOL(block_commit_write);
-EXPORT_SYMBOL(block_prepare_write);
-EXPORT_SYMBOL(block_page_mkwrite);
-EXPORT_SYMBOL(block_read_full_page);
-EXPORT_SYMBOL(block_sync_page);
-EXPORT_SYMBOL(block_truncate_page);
-EXPORT_SYMBOL(block_write_full_page);
-EXPORT_SYMBOL(cont_write_begin);
-EXPORT_SYMBOL(end_buffer_read_sync);
-EXPORT_SYMBOL(end_buffer_write_sync);
-EXPORT_SYMBOL(file_fsync);
-EXPORT_SYMBOL(fsync_bdev);
-EXPORT_SYMBOL(generic_block_bmap);
-EXPORT_SYMBOL(generic_cont_expand_simple);
-EXPORT_SYMBOL(init_buffer);
-EXPORT_SYMBOL(invalidate_bdev);
-EXPORT_SYMBOL(ll_rw_block);
-EXPORT_SYMBOL(mark_buffer_dirty);
-EXPORT_SYMBOL(submit_bh);
-EXPORT_SYMBOL(sync_dirty_buffer);
-EXPORT_SYMBOL(unlock_buffer);
diff --git a/libdde_linux26/lib/src/fs/char_dev.c b/libdde_linux26/lib/src/fs/char_dev.c
deleted file mode 100644
index 3b8e8b3d..00000000
--- a/libdde_linux26/lib/src/fs/char_dev.c
+++ /dev/null
@@ -1,572 +0,0 @@
-/*
- *  linux/fs/char_dev.c
- *
- *  Copyright (C) 1991, 1992  Linus Torvalds
- */
-
-#include <linux/init.h>
-#include <linux/fs.h>
-#include <linux/kdev_t.h>
-#include <linux/slab.h>
-#include <linux/string.h>
-
-#include <linux/major.h>
-#include <linux/errno.h>
-#include <linux/module.h>
-#include <linux/smp_lock.h>
-#include <linux/seq_file.h>
-
-#include <linux/kobject.h>
-#include <linux/kobj_map.h>
-#include <linux/cdev.h>
-#include <linux/mutex.h>
-#include <linux/backing-dev.h>
-
-#ifdef CONFIG_KMOD
-#include <linux/kmod.h>
-#endif
-#include "internal.h"
-
-#ifdef DDE_LINUX
-#include "local.h"
-#endif
-
-/*
- * capabilities for /dev/mem, /dev/kmem and similar directly mappable character
- * devices
- * - permits shared-mmap for read, write and/or exec
- * - does not permit private mmap in NOMMU mode (can't do COW)
- * - no readahead or I/O queue unplugging required
- */
-struct backing_dev_info directly_mappable_cdev_bdi = {
-	.capabilities	= (
-#ifdef CONFIG_MMU
-		/* permit private copies of the data to be taken */
-		BDI_CAP_MAP_COPY |
-#endif
-		/* permit direct mmap, for read, write or exec */
-		BDI_CAP_MAP_DIRECT |
-		BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP),
-};
-
-static struct kobj_map *cdev_map;
-
-static DEFINE_MUTEX(chrdevs_lock);
-
-static struct char_device_struct {
-	struct char_device_struct *next;
-	unsigned int major;
-	unsigned int baseminor;
-	int minorct;
-	char name[64];
-	struct cdev *cdev;		/* will die */
-} *chrdevs[CHRDEV_MAJOR_HASH_SIZE];
-
-/* index in the above */
-static inline int major_to_index(int major)
-{
-	return major % CHRDEV_MAJOR_HASH_SIZE;
-}
-
-#ifdef CONFIG_PROC_FS
-
-void chrdev_show(struct seq_file *f, off_t offset)
-{
-	struct char_device_struct *cd;
-
-	if (offset < CHRDEV_MAJOR_HASH_SIZE) {
-		mutex_lock(&chrdevs_lock);
-		for (cd = chrdevs[offset]; cd; cd = cd->next)
-			seq_printf(f, "%3d %s\n", cd->major, cd->name);
-		mutex_unlock(&chrdevs_lock);
-	}
-}
-
-#endif /* CONFIG_PROC_FS */
-
-/*
- * Register a single major with a specified minor range.
- *
- * If major == 0 this functions will dynamically allocate a major and return
- * its number.
- *
- * If major > 0 this function will attempt to reserve the passed range of
- * minors and will return zero on success.
- *
- * Returns a -ve errno on failure.
- */
-static struct char_device_struct *
-__register_chrdev_region(unsigned int major, unsigned int baseminor,
-			   int minorct, const char *name)
-{
-	struct char_device_struct *cd, **cp;
-	int ret = 0;
-	int i;
-
-	cd = kzalloc(sizeof(struct char_device_struct), GFP_KERNEL);
-	if (cd == NULL)
-		return ERR_PTR(-ENOMEM);
-
-	mutex_lock(&chrdevs_lock);
-
-	/* temporary */
-	if (major == 0) {
-		for (i = ARRAY_SIZE(chrdevs)-1; i > 0; i--) {
-			if (chrdevs[i] == NULL)
-				break;
-		}
-
-		if (i == 0) {
-			ret = -EBUSY;
-			goto out;
-		}
-		major = i;
-		ret = major;
-	}
-
-	cd->major = major;
-	cd->baseminor = baseminor;
-	cd->minorct = minorct;
-	strlcpy(cd->name, name, sizeof(cd->name));
-
-	i = major_to_index(major);
-
-	for (cp = &chrdevs[i]; *cp; cp = &(*cp)->next)
-		if ((*cp)->major > major ||
-		    ((*cp)->major == major &&
-		     (((*cp)->baseminor >= baseminor) ||
-		      ((*cp)->baseminor + (*cp)->minorct > baseminor))))
-			break;
-
-	/* Check for overlapping minor ranges.  */
-	if (*cp && (*cp)->major == major) {
-		int old_min = (*cp)->baseminor;
-		int old_max = (*cp)->baseminor + (*cp)->minorct - 1;
-		int new_min = baseminor;
-		int new_max = baseminor + minorct - 1;
-
-		/* New driver overlaps from the left.  */
-		if (new_max >= old_min && new_max <= old_max) {
-			ret = -EBUSY;
-			goto out;
-		}
-
-		/* New driver overlaps from the right.  */
-		if (new_min <= old_max && new_min >= old_min) {
-			ret = -EBUSY;
-			goto out;
-		}
-	}
-
-	cd->next = *cp;
-	*cp = cd;
-	mutex_unlock(&chrdevs_lock);
-	return cd;
-out:
-	mutex_unlock(&chrdevs_lock);
-	kfree(cd);
-	return ERR_PTR(ret);
-}
-
-static struct char_device_struct *
-__unregister_chrdev_region(unsigned major, unsigned baseminor, int minorct)
-{
-	struct char_device_struct *cd = NULL, **cp;
-	int i = major_to_index(major);
-
-	mutex_lock(&chrdevs_lock);
-	for (cp = &chrdevs[i]; *cp; cp = &(*cp)->next)
-		if ((*cp)->major == major &&
-		    (*cp)->baseminor == baseminor &&
-		    (*cp)->minorct == minorct)
-			break;
-	if (*cp) {
-		cd = *cp;
-		*cp = cd->next;
-	}
-	mutex_unlock(&chrdevs_lock);
-	return cd;
-}
-
-/**
- * register_chrdev_region() - register a range of device numbers
- * @from: the first in the desired range of device numbers; must include
- *        the major number.
- * @count: the number of consecutive device numbers required
- * @name: the name of the device or driver.
- *
- * Return value is zero on success, a negative error code on failure.
- */
-int register_chrdev_region(dev_t from, unsigned count, const char *name)
-{
-	struct char_device_struct *cd;
-	dev_t to = from + count;
-	dev_t n, next;
-
-	for (n = from; n < to; n = next) {
-		next = MKDEV(MAJOR(n)+1, 0);
-		if (next > to)
-			next = to;
-		cd = __register_chrdev_region(MAJOR(n), MINOR(n),
-			       next - n, name);
-		if (IS_ERR(cd))
-			goto fail;
-	}
-	return 0;
-fail:
-	to = n;
-	for (n = from; n < to; n = next) {
-		next = MKDEV(MAJOR(n)+1, 0);
-		kfree(__unregister_chrdev_region(MAJOR(n), MINOR(n), next - n));
-	}
-	return PTR_ERR(cd);
-}
-
-/**
- * alloc_chrdev_region() - register a range of char device numbers
- * @dev: output parameter for first assigned number
- * @baseminor: first of the requested range of minor numbers
- * @count: the number of minor numbers required
- * @name: the name of the associated device or driver
- *
- * Allocates a range of char device numbers.  The major number will be
- * chosen dynamically, and returned (along with the first minor number)
- * in @dev.  Returns zero or a negative error code.
- */
-int alloc_chrdev_region(dev_t *dev, unsigned baseminor, unsigned count,
-			const char *name)
-{
-	struct char_device_struct *cd;
-	cd = __register_chrdev_region(0, baseminor, count, name);
-	if (IS_ERR(cd))
-		return PTR_ERR(cd);
-	*dev = MKDEV(cd->major, cd->baseminor);
-	return 0;
-}
-
-/**
- * register_chrdev() - Register a major number for character devices.
- * @major: major device number or 0 for dynamic allocation
- * @name: name of this range of devices
- * @fops: file operations associated with this devices
- *
- * If @major == 0 this functions will dynamically allocate a major and return
- * its number.
- *
- * If @major > 0 this function will attempt to reserve a device with the given
- * major number and will return zero on success.
- *
- * Returns a -ve errno on failure.
- *
- * The name of this device has nothing to do with the name of the device in
- * /dev. It only helps to keep track of the different owners of devices. If
- * your module name has only one type of devices it's ok to use e.g. the name
- * of the module here.
- *
- * This function registers a range of 256 minor numbers. The first minor number
- * is 0.
- */
-int register_chrdev(unsigned int major, const char *name,
-		    const struct file_operations *fops)
-{
-	struct char_device_struct *cd;
-	struct cdev *cdev;
-	char *s;
-	int err = -ENOMEM;
-
-	cd = __register_chrdev_region(major, 0, 256, name);
-	if (IS_ERR(cd))
-		return PTR_ERR(cd);
-	
-	cdev = cdev_alloc();
-	if (!cdev)
-		goto out2;
-
-	cdev->owner = fops->owner;
-	cdev->ops = fops;
-	kobject_set_name(&cdev->kobj, "%s", name);
-	for (s = strchr(kobject_name(&cdev->kobj),'/'); s; s = strchr(s, '/'))
-		*s = '!';
-		
-	err = cdev_add(cdev, MKDEV(cd->major, 0), 256);
-	if (err)
-		goto out;
-
-	cd->cdev = cdev;
-
-	return major ? 0 : cd->major;
-out:
-	kobject_put(&cdev->kobj);
-out2:
-	kfree(__unregister_chrdev_region(cd->major, 0, 256));
-	return err;
-}
-
-/**
- * unregister_chrdev_region() - return a range of device numbers
- * @from: the first in the range of numbers to unregister
- * @count: the number of device numbers to unregister
- *
- * This function will unregister a range of @count device numbers,
- * starting with @from.  The caller should normally be the one who
- * allocated those numbers in the first place...
- */
-void unregister_chrdev_region(dev_t from, unsigned count)
-{
-	dev_t to = from + count;
-	dev_t n, next;
-
-	for (n = from; n < to; n = next) {
-		next = MKDEV(MAJOR(n)+1, 0);
-		if (next > to)
-			next = to;
-		kfree(__unregister_chrdev_region(MAJOR(n), MINOR(n), next - n));
-	}
-}
-
-void unregister_chrdev(unsigned int major, const char *name)
-{
-	struct char_device_struct *cd;
-	cd = __unregister_chrdev_region(major, 0, 256);
-	if (cd && cd->cdev)
-		cdev_del(cd->cdev);
-	kfree(cd);
-}
-
-static DEFINE_SPINLOCK(cdev_lock);
-
-static struct kobject *cdev_get(struct cdev *p)
-{
-	struct module *owner = p->owner;
-	struct kobject *kobj;
-
-	if (owner && !try_module_get(owner))
-		return NULL;
-	kobj = kobject_get(&p->kobj);
-	if (!kobj)
-		module_put(owner);
-	return kobj;
-}
-
-void cdev_put(struct cdev *p)
-{
-	if (p) {
-		struct module *owner = p->owner;
-		kobject_put(&p->kobj);
-		module_put(owner);
-	}
-}
-
-/*
- * Called every time a character special file is opened
- */
-static int chrdev_open(struct inode *inode, struct file *filp)
-{
-	struct cdev *p;
-	struct cdev *new = NULL;
-	int ret = 0;
-
-	spin_lock(&cdev_lock);
-	p = inode->i_cdev;
-	if (!p) {
-		struct kobject *kobj;
-		int idx;
-		spin_unlock(&cdev_lock);
-		kobj = kobj_lookup(cdev_map, inode->i_rdev, &idx);
-		if (!kobj)
-			return -ENXIO;
-		new = container_of(kobj, struct cdev, kobj);
-		spin_lock(&cdev_lock);
-		/* Check i_cdev again in case somebody beat us to it while
-		   we dropped the lock. */
-		p = inode->i_cdev;
-		if (!p) {
-			inode->i_cdev = p = new;
-			inode->i_cindex = idx;
-			list_add(&inode->i_devices, &p->list);
-			new = NULL;
-		} else if (!cdev_get(p))
-			ret = -ENXIO;
-	} else if (!cdev_get(p))
-		ret = -ENXIO;
-	spin_unlock(&cdev_lock);
-	cdev_put(new);
-	if (ret)
-		return ret;
-
-	ret = -ENXIO;
-	filp->f_op = fops_get(p->ops);
-	if (!filp->f_op)
-		goto out_cdev_put;
-
-	if (filp->f_op->open) {
-		ret = filp->f_op->open(inode,filp);
-		if (ret)
-			goto out_cdev_put;
-	}
-
-	return 0;
-
- out_cdev_put:
-	cdev_put(p);
-	return ret;
-}
-
-void cd_forget(struct inode *inode)
-{
-	spin_lock(&cdev_lock);
-	list_del_init(&inode->i_devices);
-	inode->i_cdev = NULL;
-	spin_unlock(&cdev_lock);
-}
-
-static void cdev_purge(struct cdev *cdev)
-{
-	spin_lock(&cdev_lock);
-	while (!list_empty(&cdev->list)) {
-		struct inode *inode;
-		inode = container_of(cdev->list.next, struct inode, i_devices);
-		list_del_init(&inode->i_devices);
-		inode->i_cdev = NULL;
-	}
-	spin_unlock(&cdev_lock);
-}
-
-/*
- * Dummy default file-operations: the only thing this does
- * is contain the open that then fills in the correct operations
- * depending on the special file...
- */
-const struct file_operations def_chr_fops = {
-	.open = chrdev_open,
-};
-
-static struct kobject *exact_match(dev_t dev, int *part, void *data)
-{
-	struct cdev *p = data;
-	return &p->kobj;
-}
-
-static int exact_lock(dev_t dev, void *data)
-{
-	struct cdev *p = data;
-	return cdev_get(p) ? 0 : -1;
-}
-
-/**
- * cdev_add() - add a char device to the system
- * @p: the cdev structure for the device
- * @dev: the first device number for which this device is responsible
- * @count: the number of consecutive minor numbers corresponding to this
- *         device
- *
- * cdev_add() adds the device represented by @p to the system, making it
- * live immediately.  A negative error code is returned on failure.
- */
-int cdev_add(struct cdev *p, dev_t dev, unsigned count)
-{
-	p->dev = dev;
-	p->count = count;
-	return kobj_map(cdev_map, dev, count, NULL, exact_match, exact_lock, p);
-}
-
-static void cdev_unmap(dev_t dev, unsigned count)
-{
-	kobj_unmap(cdev_map, dev, count);
-}
-
-/**
- * cdev_del() - remove a cdev from the system
- * @p: the cdev structure to be removed
- *
- * cdev_del() removes @p from the system, possibly freeing the structure
- * itself.
- */
-void cdev_del(struct cdev *p)
-{
-	cdev_unmap(p->dev, p->count);
-	kobject_put(&p->kobj);
-}
-
-
-static void cdev_default_release(struct kobject *kobj)
-{
-	struct cdev *p = container_of(kobj, struct cdev, kobj);
-	cdev_purge(p);
-}
-
-static void cdev_dynamic_release(struct kobject *kobj)
-{
-	struct cdev *p = container_of(kobj, struct cdev, kobj);
-	cdev_purge(p);
-	kfree(p);
-}
-
-static struct kobj_type ktype_cdev_default = {
-	.release	= cdev_default_release,
-};
-
-static struct kobj_type ktype_cdev_dynamic = {
-	.release	= cdev_dynamic_release,
-};
-
-/**
- * cdev_alloc() - allocate a cdev structure
- *
- * Allocates and returns a cdev structure, or NULL on failure.
- */
-struct cdev *cdev_alloc(void)
-{
-	struct cdev *p = kzalloc(sizeof(struct cdev), GFP_KERNEL);
-	if (p) {
-		INIT_LIST_HEAD(&p->list);
-		kobject_init(&p->kobj, &ktype_cdev_dynamic);
-	}
-	return p;
-}
-
-/**
- * cdev_init() - initialize a cdev structure
- * @cdev: the structure to initialize
- * @fops: the file_operations for this device
- *
- * Initializes @cdev, remembering @fops, making it ready to add to the
- * system with cdev_add().
- */
-void cdev_init(struct cdev *cdev, const struct file_operations *fops)
-{
-	memset(cdev, 0, sizeof *cdev);
-	INIT_LIST_HEAD(&cdev->list);
-	kobject_init(&cdev->kobj, &ktype_cdev_default);
-	cdev->ops = fops;
-}
-
-static struct kobject *base_probe(dev_t dev, int *part, void *data)
-{
-	if (request_module("char-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
-		/* Make old-style 2.4 aliases work */
-		request_module("char-major-%d", MAJOR(dev));
-	return NULL;
-}
-
-void __init chrdev_init(void)
-{
-	cdev_map = kobj_map_init(base_probe, &chrdevs_lock);
-	bdi_init(&directly_mappable_cdev_bdi);
-}
-
-#ifndef LIBINPUT
-core_initcall(chrdev_init);
-#endif
-
-/* Let modules do char dev stuff */
-EXPORT_SYMBOL(register_chrdev_region);
-EXPORT_SYMBOL(unregister_chrdev_region);
-EXPORT_SYMBOL(alloc_chrdev_region);
-EXPORT_SYMBOL(cdev_init);
-EXPORT_SYMBOL(cdev_alloc);
-EXPORT_SYMBOL(cdev_del);
-EXPORT_SYMBOL(cdev_add);
-EXPORT_SYMBOL(register_chrdev);
-EXPORT_SYMBOL(unregister_chrdev);
-EXPORT_SYMBOL(directly_mappable_cdev_bdi);