From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: [PATCH 09/11] block: iov_count_pages() Date: Tue, 3 Dec 2013 14:00:15 -0800 Message-ID: <1386108017-27964-10-git-send-email-kmo@daterainc.com> References: <1386108017-27964-1-git-send-email-kmo@daterainc.com> Cc: hch@infradead.org, clm@fb.com, viro@zeniv.linux.org.uk, zab@redhat.com, shaggy@kernel.org, Kent Overstreet To: axboe@kernel.dk, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Return-path: Received: from mail-pd0-f172.google.com ([209.85.192.172]:33109 "EHLO mail-pd0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755396Ab3LCWAs (ORCPT ); Tue, 3 Dec 2013 17:00:48 -0500 Received: by mail-pd0-f172.google.com with SMTP id g10so21048027pdj.3 for ; Tue, 03 Dec 2013 14:00:47 -0800 (PST) In-Reply-To: <1386108017-27964-1-git-send-email-kmo@daterainc.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Signed-off-by: Kent Overstreet --- fs/bio.c | 42 ++++++------------------------------------ include/linux/uio.h | 2 ++ lib/iovec.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 38 insertions(+), 36 deletions(-) diff --git a/fs/bio.c b/fs/bio.c index a7e5789..a660e3f 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -1095,23 +1095,9 @@ struct bio *bio_copy_user_iov(struct request_queue *q, unsigned int len; unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0; - for (i = 0; i < iter->nr_segs; i++) { - unsigned long uaddr; - unsigned long end; - unsigned long start; - - uaddr = (unsigned long) iter->iov[i].iov_base; - end = (uaddr + iter->iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; - start = uaddr >> PAGE_SHIFT; - - /* - * Overflow, abort - */ - if (end < start) - return ERR_PTR(-EINVAL); - - nr_pages += end - start; - } + nr_pages = iov_count_pages(iter, 0); + if (nr_pages < 0) + return ERR_PTR(nr_pages); if (offset) nr_pages++; @@ -1241,25 +1227,9 @@ static struct bio *__bio_map_user_iov(struct request_queue *q, struct iov_iter i; struct iovec iov; - iov_for_each(iov, i, *iter) { - unsigned long uaddr = (unsigned long) iov.iov_base; - unsigned long len = iov.iov_len; - unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; - unsigned long start = uaddr >> PAGE_SHIFT; - - /* - * Overflow, abort - */ - if (end < start) - return ERR_PTR(-EINVAL); - - nr_pages += end - start; - /* - * buffer must be aligned to at least hardsector size for now - */ - if (uaddr & queue_dma_alignment(q)) - return ERR_PTR(-EINVAL); - } + nr_pages = iov_count_pages(iter, queue_dma_alignment(q)); + if (nr_pages < 0) + return ERR_PTR(nr_pages); if (!nr_pages) return ERR_PTR(-EINVAL); diff --git a/include/linux/uio.h b/include/linux/uio.h index d653fee..d74c3451 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -60,6 +60,8 @@ static inline struct iovec iov_iter_iovec(const struct iov_iter *iter) unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to); +int iov_count_pages(const struct iov_iter *iter, unsigned align); + size_t iov_iter_copy_from_user_atomic(struct page *page, struct iov_iter *i, unsigned long offset, size_t bytes); size_t iov_iter_copy_from_user(struct page *page, diff --git a/lib/iovec.c b/lib/iovec.c index 454baa8..fa2c050 100644 --- a/lib/iovec.c +++ b/lib/iovec.c @@ -1,5 +1,7 @@ #include #include +#include +#include #include /* @@ -51,3 +53,31 @@ int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len) return 0; } EXPORT_SYMBOL(memcpy_toiovec); + +int iov_count_pages(const struct iov_iter *iter, unsigned align) +{ + struct iov_iter i = *iter; + int nr_pages = 0; + + while (iov_iter_count(&i)) { + unsigned long uaddr = (unsigned long) i.iov->iov_base + + i.iov_offset; + unsigned long len = i.iov->iov_len - i.iov_offset; + + if ((uaddr & align) || (len & align)) + return -EINVAL; + + /* + * Overflow, abort + */ + if (uaddr + len < uaddr) + return -EINVAL; + + nr_pages += DIV_ROUND_UP(len + offset_in_page(uaddr), + PAGE_SIZE); + iov_iter_advance(&i, len); + } + + return nr_pages; +} +EXPORT_SYMBOL(iov_count_pages); -- 1.8.4.4