get rid of cont_write_begin_newtrunc

Move the call to vmtruncate to get rid of accessive blocks to the callers
in preparation of the new truncate sequence and rename the non-truncating
version to cont_write_begin.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/adfs/inode.c

@@ -50,10 +50,19 @@ static int adfs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				adfs_get_block,
 				&ADFS_I(mapping->host)->mmu_private);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)

fs/affs/file.c

@@ -406,10 +406,19 @@ static int affs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				affs_get_block,
 				&AFFS_I(mapping->host)->mmu_private);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)

fs/buffer.c

@@ -2351,7 +2351,7 @@ static int cont_expand_zero(struct file *file, struct address_space *mapping,
  * For moronic filesystems that do not allow holes in file.
  * We may have to extend the file.
  */
-int cont_write_begin_newtrunc(struct file *file, struct address_space *mapping,
+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)
@@ -2377,25 +2377,6 @@ int cont_write_begin_newtrunc(struct file *file, struct address_space *mapping,
 out:
 	return err;
 }
-EXPORT_SYMBOL(cont_write_begin_newtrunc);
-
-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)
-{
-	int ret;
-
-	ret = cont_write_begin_newtrunc(file, mapping, pos, len, flags,
-					pagep, fsdata, get_block, bytes);
-	if (unlikely(ret)) {
-		loff_t isize = mapping->host->i_size;
-		if (pos + len > isize)
-			vmtruncate(mapping->host, isize);
-	}
-
-	return ret;
-}
 EXPORT_SYMBOL(cont_write_begin);
 
 int block_prepare_write(struct page *page, unsigned from, unsigned to,

fs/fat/inode.c

@@ -159,7 +159,7 @@ static int fat_write_begin(struct file *file, struct address_space *mapping,
 	int err;
 
 	*pagep = NULL;
-	err = cont_write_begin_newtrunc(file, mapping, pos, len, flags,
+	err = cont_write_begin(file, mapping, pos, len, flags,
 				pagep, fsdata, fat_get_block,
 				&MSDOS_I(mapping->host)->mmu_private);
 	if (err < 0)

fs/hfs/inode.c

@@ -39,10 +39,19 @@ static int hfs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				hfs_get_block,
 				&HFS_I(mapping->host)->phys_size);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t hfs_bmap(struct address_space *mapping, sector_t block)

fs/hfsplus/inode.c

@@ -31,10 +31,19 @@ static int hfsplus_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				hfsplus_get_block,
 				&HFSPLUS_I(mapping->host).phys_size);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t hfsplus_bmap(struct address_space *mapping, sector_t block)

fs/hpfs/file.c

@@ -97,10 +97,19 @@ static int hpfs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				hpfs_get_block,
 				&hpfs_i(mapping->host)->mmu_private);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)

fs/qnx4/inode.c

@@ -320,10 +320,19 @@ static int qnx4_write_begin(struct file *file, struct address_space *mapping,
 			struct page **pagep, void **fsdata)
 {
 	struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				qnx4_get_block,
 				&qnx4_inode->mmu_private);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
 {

include/linux/buffer_head.h

@@ -217,9 +217,6 @@ int generic_write_end(struct file *, struct address_space *,
 				struct page *, void *);
 void page_zero_new_buffers(struct page *page, unsigned from, unsigned to);
 int block_prepare_write(struct page*, unsigned, unsigned, get_block_t*);
-int cont_write_begin_newtrunc(struct file *, struct address_space *, loff_t,
-			unsigned, unsigned, struct page **, void **,
-			get_block_t *, loff_t *);
 int cont_write_begin(struct file *, struct address_space *, loff_t,
 			unsigned, unsigned, struct page **, void **,
 			get_block_t *, loff_t *);