Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933214AbaLDU1j (ORCPT ); Thu, 4 Dec 2014 15:27:39 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:50293 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754737AbaLDUXT (ORCPT ); Thu, 4 Dec 2014 15:23:19 -0500 From: Al Viro To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org Subject: [RFC][PATCH 08/13] iov_iter.c: convert copy_from_iter() to iterate_and_advance Date: Thu, 4 Dec 2014 20:23:12 +0000 Message-Id: <1417724597-17099-8-git-send-email-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <20141204202011.GO29748@ZenIV.linux.org.uk> References: <20141204202011.GO29748@ZenIV.linux.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro Signed-off-by: Al Viro --- mm/iov_iter.c | 106 +++++++++------------------------------------------------- 1 file changed, 15 insertions(+), 91 deletions(-) diff --git a/mm/iov_iter.c b/mm/iov_iter.c index 17b7144..791429d 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -142,51 +142,6 @@ static size_t copy_to_iter_iovec(void *from, size_t bytes, struct iov_iter *i) return wanted - bytes; } -static size_t copy_from_iter_iovec(void *to, size_t bytes, struct iov_iter *i) -{ - size_t skip, copy, left, wanted; - const struct iovec *iov; - char __user *buf; - - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - wanted = bytes; - iov = i->iov; - skip = i->iov_offset; - buf = iov->iov_base + skip; - copy = min(bytes, iov->iov_len - skip); - - left = __copy_from_user(to, buf, copy); - copy -= left; - skip += copy; - to += copy; - bytes -= copy; - while (unlikely(!left && bytes)) { - iov++; - buf = iov->iov_base; - copy = min(bytes, iov->iov_len); - left = __copy_from_user(to, buf, copy); - copy -= left; - skip = copy; - to += copy; - bytes -= copy; - } - - if (skip == iov->iov_len) { - iov++; - skip = 0; - } - i->count -= wanted - bytes; - i->nr_segs -= iov - i->iov; - i->iov = iov; - i->iov_offset = skip; - return wanted - bytes; -} - static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { @@ -444,48 +399,6 @@ static size_t copy_to_iter_bvec(void *from, size_t bytes, struct iov_iter *i) return wanted - bytes; } -static size_t copy_from_iter_bvec(void *to, size_t bytes, struct iov_iter *i) -{ - size_t skip, copy, wanted; - const struct bio_vec *bvec; - - if (unlikely(bytes > i->count)) - bytes = i->count; - - if (unlikely(!bytes)) - return 0; - - wanted = bytes; - bvec = i->bvec; - skip = i->iov_offset; - - copy = min(bytes, bvec->bv_len - skip); - - memcpy_from_page(to, bvec->bv_page, bvec->bv_offset + skip, copy); - - to += copy; - skip += copy; - bytes -= copy; - - while (bytes) { - bvec++; - copy = min(bytes, (size_t)bvec->bv_len); - memcpy_from_page(to, bvec->bv_page, bvec->bv_offset, copy); - skip = copy; - to += copy; - bytes -= copy; - } - if (skip == bvec->bv_len) { - bvec++; - skip = 0; - } - i->count -= wanted; - i->nr_segs -= bvec - i->bvec; - i->bvec = bvec; - i->iov_offset = skip; - return wanted; -} - size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i) { if (i->type & ITER_BVEC) @@ -497,10 +410,21 @@ EXPORT_SYMBOL(copy_to_iter); size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) { - if (i->type & ITER_BVEC) - return copy_from_iter_bvec(addr, bytes, i); - else - return copy_from_iter_iovec(addr, bytes, i); + char *to = addr; + if (unlikely(bytes > i->count)) + bytes = i->count; + + if (unlikely(!bytes)) + return 0; + + iterate_and_advance(i, bytes, v, + __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base, + v.iov_len), + memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, + v.bv_offset, v.bv_len) + ) + + return bytes; } EXPORT_SYMBOL(copy_from_iter); -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/