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[nbd] pass iov_iter to nbd_xmit()

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... and don't mess with kmap() - just use BVEC_ITER for those parts.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2015-11-12 05:09:35 -05:00
parent c1696cab70
commit c9f2b6aeb9
1 changed files with 27 additions and 39 deletions
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66
drivers/block/nbd.c
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@ -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);