| Message ID | 20160409205129.GI25498@ZenIV.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, 2016-04-09 at 21:51 +0100, Al Viro wrote: > ... and use ITER_BVEC for the page part of request to send > > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> > --- > fs/cifs/cifsproto.h | 2 - > fs/cifs/transport.c | 141 +++++++++++++++--------------------------- > ---------- > 2 files changed, 41 insertions(+), 102 deletions(-) > > diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h > index d9b4f44..7d5f53a 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 87abe8e..206a597 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; > What's the advantage of using iov_iter_bvec over iov_iter_kvec ? That said... Acked-by: Jeff Layton <jlayton@poochiereds.net> -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Apr 19, 2016 at 01:53:17PM -0400, Jeff Layton wrote:
> What's the advantage of using iov_iter_bvec over iov_iter_kvec ?
No need to screw with kmap() in the caller; moreover, when it comes to actual
copying it gets away with kmap_atomic() just around the memcpy(), which is
considerably cheaper.
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diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index d9b4f44..7d5f53a 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 87abe8e..206a597 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;
... and use ITER_BVEC for the page part of request to send Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- fs/cifs/cifsproto.h | 2 - fs/cifs/transport.c | 141 +++++++++++++++------------------------------------- 2 files changed, 41 insertions(+), 102 deletions(-)