On 2 July 2018 at 14:52, Christoph Hellwig <hch@xxxxxx> wrote: > On Sun, Jul 01, 2018 at 11:43:43PM +0200, Andreas Gruenbacher wrote: >> > + WARN_ON_ONCE(plen != PAGE_SIZE); >> >> Inline mappings only extend to the end of the file (iomap->offset == 0 >> && iomap->length == inode->i_size), so length and plen will be >> inode->i_size here. This assertion should just be removed. > > But we should generally still return PAGE_SIZE from iomap_begin > because we cover the whole page and zero the rest, don't we? iomap_begin doesn't know when it's being called for readpage. Direct I/O reads don't pad to the page size, for example, so handling the padding in the caller seems reasonable. If you compare with regular block-based mappings, those are also block but not necessarily page aligned. For stuffed files, iomap_begin will return an IOMAP_HOLE mapping for offsets beyond the end of the file, so iterating beyond the end of the file is fine (even if readpage doesn't do that). > Either way, I can remove the assert from now. Yes, thanks. Andreas
