From: Al Viro Date: Fri, 13 Nov 2015 07:36:04 +0000 (-0500) Subject: cifs: quit playing games with draining iovecs X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3ab3f2a1fee45f5788ddccd8b3ece6f74ae905bd;p=linux-beck.git cifs: quit playing games with draining iovecs ... and use ITER_BVEC for the page part of request to send Signed-off-by: Al Viro --- diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index d9b4f444fdf9..7d5f53a01922 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -37,8 +37,6 @@ extern void cifs_buf_release(void *); extern struct smb_hdr *cifs_small_buf_get(void); extern void cifs_small_buf_release(void *); extern void free_rsp_buf(int, void *); -extern void cifs_rqst_page_to_kvec(struct smb_rqst *rqst, unsigned int idx, - struct kvec *iov); extern int smb_send(struct TCP_Server_Info *, struct smb_hdr *, unsigned int /* length */); extern unsigned int _get_xid(void); diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 87abe8ed074c..206a597b2293 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -124,41 +124,32 @@ cifs_delete_mid(struct mid_q_entry *mid) /* * smb_send_kvec - send an array of kvecs to the server * @server: Server to send the data to - * @iov: Pointer to array of kvecs - * @n_vec: length of kvec array + * @smb_msg: Message to send * @sent: amount of data sent on socket is stored here * * Our basic "send data to server" function. Should be called with srv_mutex * held. The caller is responsible for handling the results. */ static int -smb_send_kvec(struct TCP_Server_Info *server, struct kvec *iov, size_t n_vec, - size_t *sent) +smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg, + size_t *sent) { int rc = 0; - int i = 0; - struct msghdr smb_msg; - unsigned int remaining; - size_t first_vec = 0; + int retries = 0; struct socket *ssocket = server->ssocket; *sent = 0; - smb_msg.msg_name = (struct sockaddr *) &server->dstaddr; - smb_msg.msg_namelen = sizeof(struct sockaddr); - smb_msg.msg_control = NULL; - smb_msg.msg_controllen = 0; + smb_msg->msg_name = (struct sockaddr *) &server->dstaddr; + smb_msg->msg_namelen = sizeof(struct sockaddr); + smb_msg->msg_control = NULL; + smb_msg->msg_controllen = 0; if (server->noblocksnd) - smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL; + smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL; else - smb_msg.msg_flags = MSG_NOSIGNAL; - - remaining = 0; - for (i = 0; i < n_vec; i++) - remaining += iov[i].iov_len; + smb_msg->msg_flags = MSG_NOSIGNAL; - i = 0; - while (remaining) { + while (msg_data_left(smb_msg)) { /* * If blocking send, we try 3 times, since each can block * for 5 seconds. For nonblocking we have to try more @@ -177,35 +168,21 @@ smb_send_kvec(struct TCP_Server_Info *server, struct kvec *iov, size_t n_vec, * after the retries we will kill the socket and * reconnect which may clear the network problem. */ - rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec], - n_vec - first_vec, remaining); + rc = sock_sendmsg(ssocket, smb_msg); if (rc == -EAGAIN) { - i++; - if (i >= 14 || (!server->noblocksnd && (i > 2))) { + retries++; + if (retries >= 14 || + (!server->noblocksnd && (retries > 2))) { cifs_dbg(VFS, "sends on sock %p stuck for 15 seconds\n", ssocket); - rc = -EAGAIN; - break; + return -EAGAIN; } - msleep(1 << i); + msleep(1 << retries); continue; } if (rc < 0) - break; - - /* send was at least partially successful */ - *sent += rc; - - if (rc == remaining) { - remaining = 0; - break; - } - - if (rc > remaining) { - cifs_dbg(VFS, "sent %d requested %d\n", rc, remaining); - break; - } + return rc; if (rc == 0) { /* should never happen, letting socket clear before @@ -215,59 +192,11 @@ smb_send_kvec(struct TCP_Server_Info *server, struct kvec *iov, size_t n_vec, continue; } - remaining -= rc; - - /* the line below resets i */ - for (i = first_vec; i < n_vec; i++) { - if (iov[i].iov_len) { - if (rc > iov[i].iov_len) { - rc -= iov[i].iov_len; - iov[i].iov_len = 0; - } else { - iov[i].iov_base += rc; - iov[i].iov_len -= rc; - first_vec = i; - break; - } - } - } - - i = 0; /* in case we get ENOSPC on the next send */ - rc = 0; + /* send was at least partially successful */ + *sent += rc; + retries = 0; /* in case we get ENOSPC on the next send */ } - return rc; -} - -/** - * rqst_page_to_kvec - Turn a slot in the smb_rqst page array into a kvec - * @rqst: pointer to smb_rqst - * @idx: index into the array of the page - * @iov: pointer to struct kvec that will hold the result - * - * Helper function to convert a slot in the rqst->rq_pages array into a kvec. - * The page will be kmapped and the address placed into iov_base. The length - * will then be adjusted according to the ptailoff. - */ -void -cifs_rqst_page_to_kvec(struct smb_rqst *rqst, unsigned int idx, - struct kvec *iov) -{ - /* - * FIXME: We could avoid this kmap altogether if we used - * kernel_sendpage instead of kernel_sendmsg. That will only - * work if signing is disabled though as sendpage inlines the - * page directly into the fraglist. If userspace modifies the - * page after we calculate the signature, then the server will - * reject it and may break the connection. kernel_sendmsg does - * an extra copy of the data and avoids that issue. - */ - iov->iov_base = kmap(rqst->rq_pages[idx]); - - /* if last page, don't send beyond this offset into page */ - if (idx == (rqst->rq_npages - 1)) - iov->iov_len = rqst->rq_tailsz; - else - iov->iov_len = rqst->rq_pagesz; + return 0; } static unsigned long @@ -299,8 +228,9 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst) unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base); unsigned long send_length; unsigned int i; - size_t total_len = 0, sent; + size_t total_len = 0, sent, size; struct socket *ssocket = server->ssocket; + struct msghdr smb_msg; int val = 1; if (ssocket == NULL) @@ -321,7 +251,13 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst) kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK, (char *)&val, sizeof(val)); - rc = smb_send_kvec(server, iov, n_vec, &sent); + size = 0; + for (i = 0; i < n_vec; i++) + size += iov[i].iov_len; + + iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC, iov, n_vec, size); + + rc = smb_send_kvec(server, &smb_msg, &sent); if (rc < 0) goto uncork; @@ -329,11 +265,16 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst) /* now walk the page array and send each page in it */ for (i = 0; i < rqst->rq_npages; i++) { - struct kvec p_iov; - - cifs_rqst_page_to_kvec(rqst, i, &p_iov); - rc = smb_send_kvec(server, &p_iov, 1, &sent); - kunmap(rqst->rq_pages[i]); + size_t len = i == rqst->rq_npages - 1 + ? rqst->rq_tailsz + : rqst->rq_pagesz; + struct bio_vec bvec = { + .bv_page = rqst->rq_pages[i], + .bv_len = len + }; + iov_iter_bvec(&smb_msg.msg_iter, WRITE | ITER_BVEC, + &bvec, 1, len); + rc = smb_send_kvec(server, &smb_msg, &sent); if (rc < 0) break;