On Fri, 24 Oct 2014 17:20:41 -0400 Matthew Wilcox <matthew.r.wilcox@xxxxxxxxx> wrote: > It takes a get_block parameter just like nobh_truncate_page() and > block_truncate_page() > > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -458,3 +458,47 @@ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, > return result; > } > EXPORT_SYMBOL_GPL(dax_fault); > + > +/** > + * dax_truncate_page - handle a partial page being truncated in a DAX file > + * @inode: The file being truncated > + * @from: The file offset that is being truncated to > + * @get_block: The filesystem method used to translate file offsets to blocks > + * > + * Similar to block_truncate_page(), this function can be called by a > + * filesystem when it is truncating an DAX file to handle the partial page. > + * > + * We work in terms of PAGE_CACHE_SIZE here for commonality with > + * block_truncate_page(), but we could go down to PAGE_SIZE if the filesystem > + * took care of disposing of the unnecessary blocks. But PAGE_SIZE==PAGE_CACHE_SIZE. Unclear what you're saying here. > + Even if the filesystem > + * block size is smaller than PAGE_SIZE, we have to zero the rest of the page > + * since the file might be mmaped. > + */ > > ... > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>