For pages that were retained via get_user_pages*(), release those pages
via the new put_user_page*() routines, instead of via put_page() or
release_pages().
This is part a tree-wide conversion, as described in commit 
fc1d8e7cca2d
("mm: introduce put_user_page*(), placeholder versions").
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-block@vger.kernel.org
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
                struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
 
                for (j = 0; j < imu->nr_bvecs; j++)
-                       put_page(imu->bvec[j].bv_page);
+                       put_user_page(imu->bvec[j].bv_page);
 
                if (ctx->account_mem)
                        io_unaccount_mem(ctx->user, imu->nr_bvecs);
                         * if we did partial map, or found file backed vmas,
                         * release any pages we did get
                         */
-                       if (pret > 0) {
-                               for (j = 0; j < pret; j++)
-                                       put_page(pages[j]);
-                       }
+                       if (pret > 0)
+                               put_user_pages(pages, pret);
                        if (ctx->account_mem)
                                io_unaccount_mem(ctx->user, nr_pages);
                        kvfree(imu->bvec);