From c9f2b6aeb92286f15ffc80d2ba16bc24e530f560 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 12 Nov 2015 05:09:35 -0500 Subject: [PATCH] [nbd] pass iov_iter to nbd_xmit() ... and don't mess with kmap() - just use BVEC_ITER for those parts. Signed-off-by: Al Viro --- drivers/block/nbd.c | 66 ++++++++++++++++++++++------------------------------- 1 file changed, 27 insertions(+), 39 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 8e63cae..3c2dbe4 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -209,13 +209,12 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, /* * Send or receive packet. */ -static int sock_xmit(struct nbd_device *nbd, int index, int send, void *buf, - int size, int msg_flags) +static int sock_xmit(struct nbd_device *nbd, int index, int send, + struct iov_iter *iter, int msg_flags) { struct socket *sock = nbd->socks[index]->sock; int result; struct msghdr msg; - struct kvec iov = {.iov_base = buf, .iov_len = size}; unsigned long pflags = current->flags; if (unlikely(!sock)) { @@ -225,8 +224,7 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send, void *buf, return -EINVAL; } - iov_iter_kvec(&msg.msg_iter, (send ? WRITE : READ) | ITER_KVEC, - &iov, 1, size); + msg.msg_iter = *iter; current->flags |= PF_MEMALLOC; do { @@ -254,28 +252,21 @@ static int sock_xmit(struct nbd_device *nbd, int index, int send, void *buf, return result; } -static inline int sock_send_bvec(struct nbd_device *nbd, int index, - struct bio_vec *bvec, int flags) -{ - int result; - void *kaddr = kmap(bvec->bv_page); - result = sock_xmit(nbd, index, 1, kaddr + bvec->bv_offset, - bvec->bv_len, flags); - kunmap(bvec->bv_page); - return result; -} - /* always call with the tx_lock held */ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) { struct request *req = blk_mq_rq_from_pdu(cmd); int result, flags; - struct nbd_request request; + struct nbd_request request = {.magic = htonl(NBD_REQUEST_MAGIC)}; + struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)}; + struct iov_iter from; unsigned long size = blk_rq_bytes(req); struct bio *bio; u32 type; u32 tag = blk_mq_unique_tag(req); + iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request)); + if (req_op(req) == REQ_OP_DISCARD) type = NBD_CMD_TRIM; else if (req_op(req) == REQ_OP_FLUSH) @@ -285,8 +276,6 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) else type = NBD_CMD_READ; - memset(&request, 0, sizeof(request)); - request.magic = htonl(NBD_REQUEST_MAGIC); request.type = htonl(type); if (type != NBD_CMD_FLUSH) { request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); @@ -297,7 +286,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n", cmd, nbdcmd_to_ascii(type), (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req)); - result = sock_xmit(nbd, index, 1, &request, sizeof(request), + result = sock_xmit(nbd, index, 1, &from, (type == NBD_CMD_WRITE) ? MSG_MORE : 0); if (result <= 0) { dev_err_ratelimited(disk_to_dev(nbd->disk), @@ -322,7 +311,9 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) flags = MSG_MORE; dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n", cmd, bvec.bv_len); - result = sock_send_bvec(nbd, index, &bvec, flags); + iov_iter_bvec(&from, ITER_BVEC | WRITE, + &bvec, 1, bvec.bv_len); + result = sock_xmit(nbd, index, 1, &from, flags); if (result <= 0) { dev_err(disk_to_dev(nbd->disk), "Send data failed (result %d)\n", @@ -343,17 +334,6 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) return 0; } -static inline int sock_recv_bvec(struct nbd_device *nbd, int index, - struct bio_vec *bvec) -{ - int result; - void *kaddr = kmap(bvec->bv_page); - result = sock_xmit(nbd, index, 0, kaddr + bvec->bv_offset, - bvec->bv_len, MSG_WAITALL); - kunmap(bvec->bv_page); - return result; -} - /* NULL returned = something went wrong, inform userspace */ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) { @@ -363,9 +343,12 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) struct request *req = NULL; u16 hwq; u32 tag; + struct kvec iov = {.iov_base = &reply, .iov_len = sizeof(reply)}; + struct iov_iter to; reply.magic = 0; - result = sock_xmit(nbd, index, 0, &reply, sizeof(reply), MSG_WAITALL); + iov_iter_kvec(&to, READ | ITER_KVEC, &iov, 1, sizeof(reply)); + result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL); if (result <= 0) { if (!test_bit(NBD_DISCONNECTED, &nbd->runtime_flags) && !test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) @@ -405,7 +388,9 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) struct bio_vec bvec; rq_for_each_segment(bvec, req, iter) { - result = sock_recv_bvec(nbd, index, &bvec); + iov_iter_bvec(&to, ITER_BVEC | READ, + &bvec, 1, bvec.bv_len); + result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL); if (result <= 0) { dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", result); @@ -645,14 +630,17 @@ static void nbd_parse_flags(struct nbd_device *nbd, struct block_device *bdev) static void send_disconnects(struct nbd_device *nbd) { - struct nbd_request request = {}; + struct nbd_request request = { + .magic = htonl(NBD_REQUEST_MAGIC), + .type = htonl(NBD_CMD_DISC), + }; + struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)}; + struct iov_iter from; int i, ret; - request.magic = htonl(NBD_REQUEST_MAGIC); - request.type = htonl(NBD_CMD_DISC); - for (i = 0; i < nbd->num_connections; i++) { - ret = sock_xmit(nbd, i, 1, &request, sizeof(request), 0); + iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request)); + ret = sock_xmit(nbd, i, 1, &from, 0); if (ret <= 0) dev_err(disk_to_dev(nbd->disk), "Send disconnect failed %d\n", ret); -- 2.7.4