Maxim Patlasov <[email protected]> writes: > The patch allows fuse_req to refer to array of iovec-s describing > layout of user-data over req->pages. fuse_copy_pages() is re-worked to > support both cased: former layout where pages[] corresponded to <buf, len> > and newer one where pages[] corresponds to iovec[]. > > Signed-off-by: Maxim Patlasov <[email protected]> > --- > fs/fuse/dev.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++--- > fs/fuse/fuse_i.h | 12 ++++++++++-- > 2 files changed, 59 insertions(+), 5 deletions(-) > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c > index 7df2b5e..cdae525 100644 > --- a/fs/fuse/dev.c > +++ b/fs/fuse/dev.c > @@ -850,9 +850,9 @@ static int fuse_copy_page(struct fuse_copy_state *cs, > struct page **pagep, > return 0; > } > > -/* Copy pages in the request to/from userspace buffer */ > -static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes, > - int zeroing) > +/* Start from addr(pages[0]) + page_offset. No holes in the middle. */ > +static int fuse_copy_pages_for_buf(struct fuse_copy_state *cs, unsigned > nbytes, > + int zeroing) > { > unsigned i; > struct fuse_req *req = cs->req; > @@ -874,6 +874,52 @@ static int fuse_copy_pages(struct fuse_copy_state *cs, > unsigned nbytes, > return 0; > } > > +/* Take iov_offset as offset in iovec[0]. Iterate based on iovec[].iov_len */ > +static int fuse_copy_pages_for_iovec(struct fuse_copy_state *cs, > + unsigned nbytes, int zeroing) > +{ > + unsigned i; > + struct fuse_req *req = cs->req; > + const struct iovec *iov = req->iovec; > + unsigned iov_offset = req->iov_offset; > + > + for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) { > + int err; > + unsigned long user_addr = (unsigned long)iov->iov_base + > + iov_offset; > + unsigned offset = user_addr & ~PAGE_MASK; > + unsigned count = min_t(size_t, PAGE_SIZE - offset, > + iov->iov_len - iov_offset);
It would be much cleaner if we didn't have to deal with the original iovec here, but only offset and length relative to the page. I understand that that would mean allocating an array for these. In the other thread I mentioned the possibility of allocating the page array. Instead of a page array, we could have an array of (pageptr, offset, len) which would simplify the whole thing. Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
