13 files changed, 57 insertions, 107 deletions

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 7516957273ed..6b946bae11cf 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -448,6 +448,12 @@ ino_t ext2_inode_by_name(struct inode *dir, struct qstr *child)
         return res;
 }
 
+static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len)
+{
+        return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0,
+                                          &page, NULL, ext2_get_block);
+}
+
 /* Releases the page */
 void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
                    struct page *page, struct inode *inode, int update_times)
@@ -458,8 +464,7 @@ void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
         int err;
 
         lock_page(page);
-        err = __ext2_write_begin(NULL, page->mapping, pos, len,
-                                AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = ext2_prepare_chunk(page, pos, len);
         BUG_ON(err);
         de->inode = cpu_to_le32(inode->i_ino);
         ext2_set_de_type(de, inode);
@@ -542,8 +547,7 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode)
 got_it:
         pos = page_offset(page) +
                 (char*)de - (char*)page_address(page);
-        err = __ext2_write_begin(NULL, page->mapping, pos, rec_len, 0,
-                                                        &page, NULL);
+        err = ext2_prepare_chunk(page, pos, rec_len);
         if (err)
                 goto out_unlock;
         if (de->inode) {
@@ -576,8 +580,7 @@ out_unlock:
  */
 int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
 {
-        struct address_space *mapping = page->mapping;
-        struct inode *inode = mapping->host;
+        struct inode *inode = page->mapping->host;
         char *kaddr = page_address(page);
         unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1);
         unsigned to = ((char *)dir - kaddr) +
@@ -601,8 +604,7 @@ int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
                 from = (char*)pde - (char*)page_address(page);
         pos = page_offset(page) + from;
         lock_page(page);
-        err = __ext2_write_begin(NULL, page->mapping, pos, to - from, 0,
-                                                        &page, NULL);
+        err = ext2_prepare_chunk(page, pos, to - from);
         BUG_ON(err);
         if (pde)
                 pde->rec_len = ext2_rec_len_to_disk(to - from);
@@ -621,8 +623,7 @@ out:
  */
 int ext2_make_empty(struct inode *inode, struct inode *parent)
 {
-        struct address_space *mapping = inode->i_mapping;
-        struct page *page = grab_cache_page(mapping, 0);
+        struct page *page = grab_cache_page(inode->i_mapping, 0);
         unsigned chunk_size = ext2_chunk_size(inode);
         struct ext2_dir_entry_2 * de;
         int err;
@@ -631,8 +632,7 @@ int ext2_make_empty(struct inode *inode, struct inode *parent)
         if (!page)
                 return -ENOMEM;
 
-        err = __ext2_write_begin(NULL, page->mapping, 0, chunk_size, 0,
-                                                        &page, NULL);
+        err = ext2_prepare_chunk(page, 0, chunk_size);
         if (err) {
                 unlock_page(page);
                 goto fail;
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index 52b34f1d2738..8f53d11bf957 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -127,9 +127,6 @@ extern void ext2_set_inode_flags(struct inode *inode);
 extern void ext2_get_inode_flags(struct ext2_inode_info *);
 extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                        u64 start, u64 len);
-int __ext2_write_begin(struct file *file, struct address_space *mapping,
-                loff_t pos, unsigned len, unsigned flags,
-                struct page **pagep, void **fsdata);
 
 /* ioctl.c */
 extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 348805cd4109..2f4dfbcd7696 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -765,14 +765,6 @@ ext2_readpages(struct file *file, struct address_space *mapping,
         return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
 }
 
-int __ext2_write_begin(struct file *file, struct address_space *mapping,
-                loff_t pos, unsigned len, unsigned flags,
-                struct page **pagep, void **fsdata)
-{
-        return block_write_begin_newtrunc(file, mapping, pos, len, flags,
-                                        pagep, fsdata, ext2_get_block);
-}
-
 static int
 ext2_write_begin(struct file *file, struct address_space *mapping,
                 loff_t pos, unsigned len, unsigned flags,
@@ -781,7 +773,8 @@ ext2_write_begin(struct file *file, struct address_space *mapping,
         int ret;
 
         *pagep = NULL;
-        ret = __ext2_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
+        ret = block_write_begin_newtrunc(file, mapping, pos, len, flags,
+                                         pagep, fsdata, ext2_get_block);
         if (ret < 0)
                 ext2_write_failed(mapping, pos + len);
         return ret;
diff --git a/fs/minix/dir.c b/fs/minix/dir.c
index 1dbf921ca44b..085a9262c692 100644
--- a/fs/minix/dir.c
+++ b/fs/minix/dir.c
@@ -271,8 +271,7 @@ int minix_add_link(struct dentry *dentry, struct inode *inode)
 
 got_it:
         pos = page_offset(page) + p - (char *)page_address(page);
-        err = __minix_write_begin(NULL, page->mapping, pos, sbi->s_dirsize,
-                                        AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
         if (err)
                 goto out_unlock;
         memcpy (namx, name, namelen);
@@ -297,8 +296,7 @@ out_unlock:
 
 int minix_delete_entry(struct minix_dir_entry *de, struct page *page)
 {
-        struct address_space *mapping = page->mapping;
-        struct inode *inode = (struct inode*)mapping->host;
+        struct inode *inode = page->mapping->host;
         char *kaddr = page_address(page);
         loff_t pos = page_offset(page) + (char*)de - kaddr;
         struct minix_sb_info *sbi = minix_sb(inode->i_sb);
@@ -306,8 +304,7 @@ int minix_delete_entry(struct minix_dir_entry *de, struct page *page)
         int err;
 
         lock_page(page);
-        err = __minix_write_begin(NULL, mapping, pos, len,
-                                        AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = minix_prepare_chunk(page, pos, len);
         if (err == 0) {
                 if (sbi->s_version == MINIX_V3)
                         ((minix3_dirent *) de)->inode = 0;
@@ -325,16 +322,14 @@ int minix_delete_entry(struct minix_dir_entry *de, struct page *page)
 
 int minix_make_empty(struct inode *inode, struct inode *dir)
 {
-        struct address_space *mapping = inode->i_mapping;
-        struct page *page = grab_cache_page(mapping, 0);
+        struct page *page = grab_cache_page(inode->i_mapping, 0);
         struct minix_sb_info *sbi = minix_sb(inode->i_sb);
         char *kaddr;
         int err;
 
         if (!page)
                 return -ENOMEM;
-        err = __minix_write_begin(NULL, mapping, 0, 2 * sbi->s_dirsize,
-                                        AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = minix_prepare_chunk(page, 0, 2 * sbi->s_dirsize);
         if (err) {
                 unlock_page(page);
                 goto fail;
@@ -425,8 +420,7 @@ not_empty:
 void minix_set_link(struct minix_dir_entry *de, struct page *page,
         struct inode *inode)
 {
-        struct address_space *mapping = page->mapping;
-        struct inode *dir = mapping->host;
+        struct inode *dir = page->mapping->host;
         struct minix_sb_info *sbi = minix_sb(dir->i_sb);
         loff_t pos = page_offset(page) +
                         (char *)de-(char*)page_address(page);
@@ -434,8 +428,7 @@ void minix_set_link(struct minix_dir_entry *de, struct page *page,
 
         lock_page(page);
 
-        err = __minix_write_begin(NULL, mapping, pos, sbi->s_dirsize,
-                                        AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
         if (err == 0) {
                 if (sbi->s_version == MINIX_V3)
                         ((minix3_dirent *) de)->inode = inode->i_ino;
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 756f8c93780c..f4abe45229bb 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -357,12 +357,10 @@ static int minix_readpage(struct file *file, struct page *page)
         return block_read_full_page(page,minix_get_block);
 }
 
-int __minix_write_begin(struct file *file, struct address_space *mapping,
-                        loff_t pos, unsigned len, unsigned flags,
-                        struct page **pagep, void **fsdata)
+int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len)
 {
-        return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-                                minix_get_block);
+        return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0,
+                                          &page, NULL, minix_get_block);
 }
 
 static int minix_write_begin(struct file *file, struct address_space *mapping,
@@ -370,7 +368,8 @@ static int minix_write_begin(struct file *file, struct address_space *mapping,
                         struct page **pagep, void **fsdata)
 {
         *pagep = NULL;
-        return __minix_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
+        return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+                                minix_get_block);
 }
 
 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/minix/minix.h b/fs/minix/minix.h
index 111f34ee9e3b..407b1c84911e 100644
--- a/fs/minix/minix.h
+++ b/fs/minix/minix.h
@@ -53,9 +53,7 @@ extern int minix_new_block(struct inode * inode);
 extern void minix_free_block(struct inode *inode, unsigned long block);
 extern unsigned long minix_count_free_blocks(struct minix_sb_info *sbi);
 extern int minix_getattr(struct vfsmount *, struct dentry *, struct kstat *);
-extern int __minix_write_begin(struct file *file, struct address_space *mapping,
-                        loff_t pos, unsigned len, unsigned flags,
-                        struct page **pagep, void **fsdata);
+extern int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len);
 
 extern void V1_minix_truncate(struct inode *);
 extern void V2_minix_truncate(struct inode *);
diff --git a/fs/nilfs2/dir.c b/fs/nilfs2/dir.c
index 85c89dfc71f0..fc2bcfa599a3 100644
--- a/fs/nilfs2/dir.c
+++ b/fs/nilfs2/dir.c
@@ -80,23 +80,11 @@ static unsigned nilfs_last_byte(struct inode *inode, unsigned long page_nr)
         return last_byte;
 }
 
-static int nilfs_prepare_chunk_uninterruptible(struct page *page,
-                                               struct address_space *mapping,
-                                               unsigned from, unsigned to)
+static int nilfs_prepare_chunk(struct page *page, unsigned from, unsigned to)
 {
         loff_t pos = page_offset(page) + from;
-        return block_write_begin(NULL, mapping, pos, to - from,
-                                 AOP_FLAG_UNINTERRUPTIBLE, &page,
-                                 NULL, nilfs_get_block);
-}
-
-static int nilfs_prepare_chunk(struct page *page,
-                               struct address_space *mapping,
-                               unsigned from, unsigned to)
-{
-        loff_t pos = page_offset(page) + from;
-        return block_write_begin(NULL, mapping, pos, to - from, 0, &page,
-                                 NULL, nilfs_get_block);
+        return block_write_begin_newtrunc(NULL, page->mapping, pos, to - from,
+                                          0, &page, NULL, nilfs_get_block);
 }
 
 static void nilfs_commit_chunk(struct page *page,
@@ -449,7 +437,7 @@ void nilfs_set_link(struct inode *dir, struct nilfs_dir_entry *de,
         int err;
 
         lock_page(page);
-        err = nilfs_prepare_chunk_uninterruptible(page, mapping, from, to);
+        err = nilfs_prepare_chunk(page, from, to);
         BUG_ON(err);
         de->inode = cpu_to_le64(inode->i_ino);
         nilfs_set_de_type(de, inode);
@@ -530,7 +518,7 @@ int nilfs_add_link(struct dentry *dentry, struct inode *inode)
 got_it:
         from = (char *)de - (char *)page_address(page);
         to = from + rec_len;
-        err = nilfs_prepare_chunk(page, page->mapping, from, to);
+        err = nilfs_prepare_chunk(page, from, to);
         if (err)
                 goto out_unlock;
         if (de->inode) {
@@ -587,7 +575,7 @@ int nilfs_delete_entry(struct nilfs_dir_entry *dir, struct page *page)
         if (pde)
                 from = (char *)pde - (char *)page_address(page);
         lock_page(page);
-        err = nilfs_prepare_chunk(page, mapping, from, to);
+        err = nilfs_prepare_chunk(page, from, to);
         BUG_ON(err);
         if (pde)
                 pde->rec_len = cpu_to_le16(to - from);
@@ -615,7 +603,7 @@ int nilfs_make_empty(struct inode *inode, struct inode *parent)
         if (!page)
                 return -ENOMEM;
 
-        err = nilfs_prepare_chunk(page, mapping, 0, chunk_size);
+        err = nilfs_prepare_chunk(page, 0, chunk_size);
         if (unlikely(err)) {
                 unlock_page(page);
                 goto fail;
diff --git a/fs/sysv/dir.c b/fs/sysv/dir.c
index 79941e4964a4..a77c42157620 100644
--- a/fs/sysv/dir.c
+++ b/fs/sysv/dir.c
@@ -218,8 +218,7 @@ got_it:
         pos = page_offset(page) +
                         (char*)de - (char*)page_address(page);
         lock_page(page);
-        err = __sysv_write_begin(NULL, page->mapping, pos, SYSV_DIRSIZE,
-                                AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
         if (err)
                 goto out_unlock;
         memcpy (de->name, name, namelen);
@@ -239,15 +238,13 @@ out_unlock:
 
 int sysv_delete_entry(struct sysv_dir_entry *de, struct page *page)
 {
-        struct address_space *mapping = page->mapping;
-        struct inode *inode = (struct inode*)mapping->host;
+        struct inode *inode = page->mapping->host;
         char *kaddr = (char*)page_address(page);
         loff_t pos = page_offset(page) + (char *)de - kaddr;
         int err;
 
         lock_page(page);
-        err = __sysv_write_begin(NULL, mapping, pos, SYSV_DIRSIZE,
-                                AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
         BUG_ON(err);
         de->inode = 0;
         err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
@@ -259,16 +256,14 @@ int sysv_delete_entry(struct sysv_dir_entry *de, struct page *page)
 
 int sysv_make_empty(struct inode *inode, struct inode *dir)
 {
-        struct address_space *mapping = inode->i_mapping;
-        struct page *page = grab_cache_page(mapping, 0);
+        struct page *page = grab_cache_page(inode->i_mapping, 0);
         struct sysv_dir_entry * de;
         char *base;
         int err;
 
         if (!page)
                 return -ENOMEM;
-        err = __sysv_write_begin(NULL, mapping, 0, 2 * SYSV_DIRSIZE,
-                                AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = sysv_prepare_chunk(page, 0, 2 * SYSV_DIRSIZE);
         if (err) {
                 unlock_page(page);
                 goto fail;
@@ -341,15 +336,13 @@ not_empty:
 void sysv_set_link(struct sysv_dir_entry *de, struct page *page,
         struct inode *inode)
 {
-        struct address_space *mapping = page->mapping;
-        struct inode *dir = mapping->host;
+        struct inode *dir = page->mapping->host;
         loff_t pos = page_offset(page) +
                         (char *)de-(char*)page_address(page);
         int err;
 
         lock_page(page);
-        err = __sysv_write_begin(NULL, mapping, pos, SYSV_DIRSIZE,
-                                AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = sysv_prepare_chunk(page, pos, SYSV_DIRSIZE);
         BUG_ON(err);
         de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
         err = dir_commit_chunk(page, pos, SYSV_DIRSIZE);
diff --git a/fs/sysv/itree.c b/fs/sysv/itree.c
index f042eec464c2..4068f485cfd6 100644
--- a/fs/sysv/itree.c
+++ b/fs/sysv/itree.c
@@ -459,12 +459,10 @@ static int sysv_readpage(struct file *file, struct page *page)
         return block_read_full_page(page,get_block);
 }
 
-int __sysv_write_begin(struct file *file, struct address_space *mapping,
-                        loff_t pos, unsigned len, unsigned flags,
-                        struct page **pagep, void **fsdata)
+int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len)
 {
-        return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-                                get_block);
+        return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0,
+                                          &page, NULL, get_block);
 }
 
 static int sysv_write_begin(struct file *file, struct address_space *mapping,
@@ -472,7 +470,8 @@ static int sysv_write_begin(struct file *file, struct address_space *mapping,
                         struct page **pagep, void **fsdata)
 {
         *pagep = NULL;
-        return __sysv_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
+        return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+                                get_block);
 }
 
 static sector_t sysv_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/sysv/sysv.h b/fs/sysv/sysv.h
index 94cb9b4d76c2..bb55cdb394bf 100644
--- a/fs/sysv/sysv.h
+++ b/fs/sysv/sysv.h
@@ -136,9 +136,7 @@ extern unsigned long sysv_count_free_blocks(struct super_block *);
 
 /* itree.c */
 extern void sysv_truncate(struct inode *);
-extern int __sysv_write_begin(struct file *file, struct address_space *mapping,
-                        loff_t pos, unsigned len, unsigned flags,
-                        struct page **pagep, void **fsdata);
+extern int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len);
 
 /* inode.c */
 extern struct inode *sysv_iget(struct super_block *, unsigned int);
diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c
index ec784756dc65..dbc90994715a 100644
--- a/fs/ufs/dir.c
+++ b/fs/ufs/dir.c
@@ -95,8 +95,7 @@ void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
         int err;
 
         lock_page(page);
-        err = __ufs_write_begin(NULL, page->mapping, pos, len,
-                                AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = ufs_prepare_chunk(page, pos, len);
         BUG_ON(err);
 
         de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
@@ -381,8 +380,7 @@ int ufs_add_link(struct dentry *dentry, struct inode *inode)
 got_it:
         pos = page_offset(page) +
                         (char*)de - (char*)page_address(page);
-        err = __ufs_write_begin(NULL, page->mapping, pos, rec_len,
-                                AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = ufs_prepare_chunk(page, pos, rec_len);
         if (err)
                 goto out_unlock;
         if (de->d_ino) {
@@ -518,7 +516,6 @@ int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
                      struct page * page)
 {
         struct super_block *sb = inode->i_sb;
-        struct address_space *mapping = page->mapping;
         char *kaddr = page_address(page);
         unsigned from = ((char*)dir - kaddr) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
         unsigned to = ((char*)dir - kaddr) + fs16_to_cpu(sb, dir->d_reclen);
@@ -549,8 +546,7 @@ int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
 
         pos = page_offset(page) + from;
         lock_page(page);
-        err = __ufs_write_begin(NULL, mapping, pos, to - from,
-                                AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = ufs_prepare_chunk(page, pos, to - from);
         BUG_ON(err);
         if (pde)
                 pde->d_reclen = cpu_to_fs16(sb, to - from);
@@ -577,8 +573,7 @@ int ufs_make_empty(struct inode * inode, struct inode *dir)
         if (!page)
                 return -ENOMEM;
 
-        err = __ufs_write_begin(NULL, mapping, 0, chunk_size,
-                                AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        err = ufs_prepare_chunk(page, 0, chunk_size);
         if (err) {
                 unlock_page(page);
                 goto fail;
diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index 73fe773aa034..a9555b1ffd28 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -558,12 +558,10 @@ static int ufs_readpage(struct file *file, struct page *page)
         return block_read_full_page(page,ufs_getfrag_block);
 }
 
-int __ufs_write_begin(struct file *file, struct address_space *mapping,
-                        loff_t pos, unsigned len, unsigned flags,
-                        struct page **pagep, void **fsdata)
+int ufs_prepare_chunk(struct page *page, loff_t pos, unsigned len)
 {
-        return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-                                ufs_getfrag_block);
+        return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0,
+                                          &page, NULL, ufs_getfrag_block);
 }
 
 static int ufs_write_begin(struct file *file, struct address_space *mapping,
@@ -571,7 +569,8 @@ static int ufs_write_begin(struct file *file, struct address_space *mapping,
                         struct page **pagep, void **fsdata)
 {
         *pagep = NULL;
-        return __ufs_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
+        return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+                                ufs_getfrag_block);
 }
 
 static sector_t ufs_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/ufs/util.h b/fs/ufs/util.h
index 23ceed8c8fb9..0466036912f1 100644
--- a/fs/ufs/util.h
+++ b/fs/ufs/util.h
@@ -257,9 +257,7 @@ ufs_set_inode_gid(struct super_block *sb, struct ufs_inode *inode, u32 value)
 
 extern dev_t ufs_get_inode_dev(struct super_block *, struct ufs_inode_info *);
 extern void ufs_set_inode_dev(struct super_block *, struct ufs_inode_info *, dev_t);
-extern int __ufs_write_begin(struct file *file, struct address_space *mapping,
-                loff_t pos, unsigned len, unsigned flags,
-                struct page **pagep, void **fsdata);
+extern int ufs_prepare_chunk(struct page *page, loff_t pos, unsigned len);
 
 /*
  * These functions manipulate ufs buffers