From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: [PATCH 1/6] new helper: dup_iter() Date: Sat, 7 Feb 2015 05:48:41 +0000 Message-ID: <1423288126-31119-1-git-send-email-viro@ZenIV.linux.org.uk> References: <20150207054419.GY29656@ZenIV.linux.org.uk> Cc: Christoph Hellwig , Miklos Szeredi , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, Felipe Balbi , linux-usb@vger.kernel.org To: Alan Stern Return-path: In-Reply-To: <20150207054419.GY29656@ZenIV.linux.org.uk> Sender: owner-linux-aio@kvack.org List-Id: linux-fsdevel.vger.kernel.org From: Al Viro Copy iter and kmemdup the underlying array for the copy. Returns a pointer to result of kmemdup() to be kfree()'d later. Signed-off-by: Al Viro --- include/linux/uio.h | 2 ++ mm/iov_iter.c | 15 +++++++++++++++ 2 files changed, 17 insertions(+) diff --git a/include/linux/uio.h b/include/linux/uio.h index b447402..e325cb1 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -98,6 +98,8 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start); int iov_iter_npages(const struct iov_iter *i, int maxpages); +const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags); + static inline size_t iov_iter_count(struct iov_iter *i) { return i->count; diff --git a/mm/iov_iter.c b/mm/iov_iter.c index 8277320..9d96e283 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -751,3 +751,18 @@ int iov_iter_npages(const struct iov_iter *i, int maxpages) return npages; } EXPORT_SYMBOL(iov_iter_npages); + +const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags) +{ + *new = *old; + if (new->type & ITER_BVEC) + return new->bvec = kmemdup(new->bvec, + new->nr_segs * sizeof(struct bio_vec), + flags); + else + /* iovec and kvec have identical layout */ + return new->iov = kmemdup(new->iov, + new->nr_segs * sizeof(struct iovec), + flags); +} +EXPORT_SYMBOL(dup_iter); -- 2.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: aart@kvack.org