fs: convert simple fs to new truncate

Convert simple filesystems: ramfs, configfs, sysfs, block_dev to new truncate
sequence.

Cc: Christoph Hellwig <[e-mail]>
Signed-off-by: Nick Piggin <[e-mail]>
Signed-off-by: Al Viro <[e-mail]>

fs/block_dev.c

···
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file->f_mapping->host;
 
-	return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode),
-				iov, offset, nr_segs, blkdev_get_blocks, NULL);
+	return blockdev_direct_IO_no_locking_newtrunc(rw, iocb, inode,
+				I_BDEV(inode), iov, offset, nr_segs,
+				blkdev_get_blocks, NULL);
 }
 
 int __sync_blockdev(struct block_device *bdev, int wait)
···
 			struct page **pagep, void **fsdata)
 {
 	*pagep = NULL;
-	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-				blkdev_get_block);
+	return block_write_begin_newtrunc(file, mapping, pos, len, flags,
+				pagep, fsdata, blkdev_get_block);
 }
 
 static int blkdev_write_end(struct file *file, struct address_space *mapping,

fs/configfs/inode.c

···
 	if (!sd)
 		return -EINVAL;
 
+	error = simple_setattr(dentry, iattr);
+	if (error)
+		return error;
+
 	sd_iattr = sd->s_iattr;
-
-	error = inode_change_ok(inode, iattr);
-	if (error)
-		return error;
-
-	error = inode_setattr(inode, iattr);
-	if (error)
-		return error;
-
 	if (!sd_iattr) {
 		/* setting attributes for the first time, allocate now */
 		sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);

fs/ramfs/file-mmu.c

···
 };
 
 const struct inode_operations ramfs_file_inode_operations = {
+	.setattr	= simple_setattr,
 	.getattr	= simple_getattr,
 };

fs/ramfs/file-nommu.c

···
 			return ret;
 	}
 
-	ret = vmtruncate(inode, newsize);
+	ret = simple_setsize(inode, newsize);
 
 	return ret;
 }
···
 
 	/* pick out size-changing events */
 	if (ia->ia_valid & ATTR_SIZE) {
-		loff_t size = i_size_read(inode);
+		loff_t size = inode->i_size;
+
 		if (ia->ia_size != size) {
 			ret = ramfs_nommu_resize(inode, ia->ia_size, size);
 			if (ret < 0 || ia->ia_valid == ATTR_SIZE)
···
 		}
 	}
 
-	ret = inode_setattr(inode, ia);
+	generic_setattr(inode, ia);
  out:
 	ia->ia_valid = old_ia_valid;
 	return ret;

fs/sysfs/inode.c

···
 	if (error)
 		goto out;
 
-	iattr->ia_valid &= ~ATTR_SIZE; /* ignore size changes */
-
-	error = inode_setattr(inode, iattr);
-	if (error)
-		goto out;
+	/* this ignores size changes */
+	generic_setattr(inode, iattr);
 
 	error = sysfs_sd_setattr(sd, iattr);
+
 out:
 	mutex_unlock(&sysfs_mutex);
 	return error;