On Mon, Apr 15, 2019 at 03:46:59PM +0800, Yan, Zheng wrote: > On 4/12/19 5:08 AM, jglisse@xxxxxxxxxx wrote: > > From: Jérôme Glisse <jglisse@xxxxxxxxxx> > > > > When page reference were taken through GUP (get_user_page*()) we need > > to drop them with put_user_pages(). > > > > Signed-off-by: Jérôme Glisse <jglisse@xxxxxxxxxx> > > Cc: linux-fsdevel@xxxxxxxxxxxxxxx > > Cc: linux-block@xxxxxxxxxxxxxxx > > Cc: linux-mm@xxxxxxxxx > > Cc: John Hubbard <jhubbard@xxxxxxxxxx> > > Cc: Jan Kara <jack@xxxxxxx> > > Cc: Dan Williams <dan.j.williams@xxxxxxxxx> > > Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> > > Cc: Johannes Thumshirn <jthumshirn@xxxxxxx> > > Cc: Christoph Hellwig <hch@xxxxxx> > > Cc: Jens Axboe <axboe@xxxxxxxxx> > > Cc: Ming Lei <ming.lei@xxxxxxxxxx> > > Cc: Dave Chinner <david@xxxxxxxxxxxxx> > > Cc: Jason Gunthorpe <jgg@xxxxxxxx> > > Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> > > Cc: Yan Zheng <zyan@xxxxxxxxxx> > > Cc: Sage Weil <sage@xxxxxxxxxx> > > Cc: Ilya Dryomov <idryomov@xxxxxxxxx> > > Cc: ceph-devel@xxxxxxxxxxxxxxx > > --- > > fs/ceph/file.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/fs/ceph/file.c b/fs/ceph/file.c > > index 6c5b85f01721..5842ad3a4218 100644 > > --- a/fs/ceph/file.c > > +++ b/fs/ceph/file.c > > @@ -667,7 +667,8 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to, > > } else { > > iov_iter_advance(to, 0); > > } > > - ceph_put_page_vector(pages, num_pages, false); > > + /* iov_iter_get_pages_alloc() did call GUP */ > > + put_user_pages(pages, num_pages); > > pages in pipe were not from get_user_pages(). Am I missing anything? Oh my mistake i miss-read iov_iter_is_pipe() and iov_iter_get_pages_alloc() missed the special case for pipe before iterate_all_kinds() Thanks for catching that. Cheers, Jérôme