提交 8064ab4d 编写于 作者: S Steve French

[CIFS] cifs truncate missing a fix for private map COW race

vmtruncate had added the same fix to handle the case of private pages
being Copy on writed while truncate_inode_pages is going on
Signed-off-by: NSteve French <sfrench@us.ibm.com>
上级 cb00e99c
......@@ -1377,8 +1377,17 @@ static int cifs_vmtruncate(struct inode *inode, loff_t offset)
}
i_size_write(inode, offset);
spin_unlock(&inode->i_lock);
/*
* unmap_mapping_range is called twice, first simply for efficiency
* so that truncate_inode_pages does fewer single-page unmaps. However
* after this first call, and before truncate_inode_pages finishes,
* it is possible for private pages to be COWed, which remain after
* truncate_inode_pages finishes, hence the second unmap_mapping_range
* call must be made for correctness.
*/
unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
truncate_inode_pages(mapping, offset);
unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
goto out_truncate;
do_expand:
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册