From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Kleikamp Subject: [PATCH V9 10/33] iov_iter: let callers extract iovecs and bio_vecs Date: Wed, 16 Oct 2013 09:04:23 -0500 Message-ID: <1381932286-14978-11-git-send-email-dave.kleikamp@oracle.com> References: <1381932286-14978-1-git-send-email-dave.kleikamp@oracle.com> Cc: linux-fsdevel@vger.kernel.org, Andrew Morton , "Maxim V. Patlasov" , Zach Brown , Christoph Hellwig , Dave Kleikamp To: linux-kernel@vger.kernel.org Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:26513 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934350Ab3JPOFo (ORCPT ); Wed, 16 Oct 2013 10:05:44 -0400 In-Reply-To: <1381932286-14978-1-git-send-email-dave.kleikamp@oracle.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Zach Brown direct IO treats memory from user iovecs and memory from arrays of kernel pages very differently. User memory is pinned and worked with in batches while kernel pages are always pinned and don't require additional processing. Rather than try and provide an abstraction that includes these different behaviours we let direct IO extract the memory structs and hand them to the existing code. Signed-off-by: Zach Brown Signed-off-by: Dave Kleikamp Tested-by: Sedat Dilek --- include/linux/fs.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/include/linux/fs.h b/include/linux/fs.h index fbe02cc..e717b47 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -372,6 +372,17 @@ static inline void iov_iter_init_bvec(struct iov_iter *i, iov_iter_advance(i, written); } + +static inline int iov_iter_has_bvec(struct iov_iter *i) +{ + return i->ops == &ii_bvec_ops; +} + +static inline struct bio_vec *iov_iter_bvec(struct iov_iter *i) +{ + BUG_ON(!iov_iter_has_bvec(i)); + return (struct bio_vec *)i->data; +} #endif extern struct iov_iter_ops ii_iovec_ops; @@ -389,8 +400,14 @@ static inline void iov_iter_init(struct iov_iter *i, iov_iter_advance(i, written); } +static inline int iov_iter_has_iovec(struct iov_iter *i) +{ + return i->ops == &ii_iovec_ops; +} + static inline struct iovec *iov_iter_iovec(struct iov_iter *i) { + BUG_ON(!iov_iter_has_iovec(i)); return (struct iovec *)i->data; } -- 1.8.4