struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len) { struct rds_message *rm; unsigned int i; int num_sgs = ceil(total_len, PAGE_SIZE); int extra_bytes = num_sgs * sizeof(struct scatterlist); rm = rds_message_alloc(extra_bytes, GFP_NOWAIT); if (!rm) return ERR_PTR(-ENOMEM); set_bit(RDS_MSG_PAGEVEC, &rm->m_flags); rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len); rm->data.op_nents = ceil(total_len, PAGE_SIZE); rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs); if (!rm->data.op_sg) { rds_message_put(rm); return ERR_PTR(-ENOMEM); } for (i = 0; i < rm->data.op_nents; ++i) { sg_set_page(&rm->data.op_sg[i], virt_to_page(page_addrs[i]), PAGE_SIZE, 0); } return rm; }
struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len) { struct rds_message *rm; unsigned int i; rm = rds_message_alloc(ceil(total_len, PAGE_SIZE), GFP_KERNEL); if (rm == NULL) return ERR_PTR(-ENOMEM); set_bit(RDS_MSG_PAGEVEC, &rm->m_flags); rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len); rm->m_nents = ceil(total_len, PAGE_SIZE); for (i = 0; i < rm->m_nents; ++i) { sg_set_page(&rm->m_sg[i], virt_to_page(page_addrs[i]), PAGE_SIZE, 0); } return rm; }
struct rds_message *rds_message_copy_from_user(struct iovec *first_iov, size_t total_len) { unsigned long to_copy; unsigned long iov_off; unsigned long sg_off; struct rds_message *rm; struct iovec *iov; struct scatterlist *sg; int ret; rm = rds_message_alloc(ceil(total_len, PAGE_SIZE), GFP_KERNEL); if (rm == NULL) { ret = -ENOMEM; goto out; } rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len); /* * now allocate and copy in the data payload. */ sg = rm->m_sg; iov = first_iov; iov_off = 0; sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */ while (total_len) { if (sg_page(sg) == NULL) { ret = rds_page_remainder_alloc(sg, total_len, GFP_HIGHUSER); if (ret) goto out; rm->m_nents++; sg_off = 0; } while (iov_off == iov->iov_len) { iov_off = 0; iov++; } to_copy = min(iov->iov_len - iov_off, sg->length - sg_off); to_copy = min_t(size_t, to_copy, total_len); rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to " "sg [%p, %u, %u] + %lu\n", to_copy, iov->iov_base, iov->iov_len, iov_off, (void *)sg_page(sg), sg->offset, sg->length, sg_off); ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off, iov->iov_base + iov_off, to_copy); if (ret) goto out; iov_off += to_copy; total_len -= to_copy; sg_off += to_copy; if (sg_off == sg->length) sg++; } ret = 0; out: if (ret) { if (rm) rds_message_put(rm); rm = ERR_PTR(ret); } return rm; }