From 4b8164b91d9fdff4dbac0a742d076bdff7fda21b Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 31 Jan 2015 20:08:47 -0500 Subject: new helper: dup_iter() 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 --- mm/iov_iter.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'mm') diff --git a/mm/iov_iter.c b/mm/iov_iter.c index 827732047da1..9d96e283520c 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); -- cgit v1.2.3-59-g8ed1b