iov_iter_init()用来初始化iov_iter 接着就是调用call_read_iter函数,如下,其实就是调用ext4_file_operations中的 ext4_file_read_iter。 static inline ssize_t call_read_iter(struct file *file, struct kiocb *kio, struct iov_iter *iter) { return file->f_op->read_iter(kio, iter); } ext4_fi...
(sk, &msg, &iov, 1, copy) 其次降级为内核发送消息 iov_iter_kvec sock_sendmsg(sock, msg) memalloc_noreclaim_restore iscsi_tcp_get_curr_r2t conn->session->tt->alloc_pdu iscsi_prep_data_out_pdu -> 初始化 Data-Out hdr->ttt = r2t->ttt hdr->opcode = ISCSI_OP_SCSI_DATA_OUT rc ...
struct iov_iter { @@ -39,6 +41,7 @@ struct iov_iter { const struct iovec *iov; const struct kvec *kvec; const struct bio_vec *bvec; struct xarray *xarray; struct pipe_inode_info *pipe; }; union { @@ -47,6 +50,7 @@ struct iov_iter { unsigned int head; unsigned int star...
const struct iovec *iov = iter_iov(from); int ret; unsigned long count = 0; ret = hfi1_user_sdma_process_request( fd, (struct iovec *)(from->iov + done), fd, (struct iovec *)(iov + done), dim, &count); if (ret) { reqs = ret;2...
xfs_file_write_iter->xfs_file_buffered_write->iomap_file_buffered_write->iomap_iter->.iomap_begin->xfs_buffered_write_iomap_begin->xfs_iread_extents->xfs_btree_visit_blocks->xfs_btree_readahead_ptr->xfs_buf_readahead->xfs_buf_readahead_map->xfs_buf_read_map->xfs_buf_read->xfs_buf_sub...
read_iter和read的区别是, read_iter一次性可以读取多个文件片段 new_sync_read的实现如下: fs/read_write.c ksys_read-> vfs_read->new_sync_read static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) { struct iovec iov = { .iov_base = buf, ...
static size_t __copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { if (likely(iter_is_iovec(i))) return copy_page_to_iter_iovec(page, offset, bytes, i); if (iov_iter_is_bvec(i) || iov_iter_is_kvec(i) || iov_iter_is_xarray(i))...
static int myserver(void *data){ struct socket *sock,*client_sock; struct sockaddr_in s_addr; unsigned short portnum=8888; int ret=0; char recvbuf[1024]; char sendbuf[4096]; char *result; struct msghdr recvmsg,sendmsg; struct kvec send_vec,recv_vec; //sendbuf = kmalloc(1024,GFP_KE...
if (iov_iter_is_kvec(iter)) { memcpy(&ctx->iter, iter, sizeof(*iter)); ctx->len = count; iov_iter_advance(iter, count); return 0; } if (array_size(max_pages, sizeof(*bv)) <= CIFS_AIO_KMALLOC_LIMIT) bv = kmalloc_array(max_pages, sizeof(*bv), GFP_KERNEL...
Linux内核模块使用SOCK_RAW实现CAN接口不接收数据所以，通过一些试验和错误，我能够以一种有效的方式更改...