[net/9p] Read side zerocopy changes for 9P2000.L protocol.

Modify p9_client_read() to check the transport preference and act accordingly.
If the preference is P9_TRANS_PREF_PAYLOAD_SEP, send the payload
separately instead of putting it directly on PDU.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This commit is contained in:
Venkateswararao Jujjuri (JV) 2011-01-28 17:05:59 -08:00 committed by Eric Van Hensbergen
parent 6f69c395ce
commit bb2f8a5515
2 changed files with 39 additions and 8 deletions

View file

@ -1270,7 +1270,15 @@ p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
if (count < rsize)
rsize = count;
req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
/* Don't bother zerocopy form small IO (< 1024) */
if (((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
P9_TRANS_PREF_PAYLOAD_SEP) && (rsize > 1024)) {
req = p9_client_rpc(clnt, P9_TREAD, "dqE", fid->fid, offset,
rsize, data, udata);
} else {
req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
rsize);
}
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto error;
@ -1284,13 +1292,15 @@ p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
if (data) {
memmove(data, dataptr, count);
} else {
err = copy_to_user(udata, dataptr, count);
if (err) {
err = -EFAULT;
goto free_and_error;
if (!req->tc->pbuf_size) {
if (data) {
memmove(data, dataptr, count);
} else {
err = copy_to_user(udata, dataptr, count);
if (err) {
err = -EFAULT;
goto free_and_error;
}
}
}
p9_free_req(clnt, req);

View file

@ -114,6 +114,17 @@ pdu_write_u(struct p9_fcall *pdu, const char __user *udata, size_t size)
return size - len;
}
static size_t
pdu_write_urw(struct p9_fcall *pdu, const char *kdata, const char __user *udata,
size_t size)
{
BUG_ON(pdu->size > P9_IOHDRSZ);
pdu->pubuf = (char __user *)udata;
pdu->pkbuf = (char *)kdata;
pdu->pbuf_size = size;
return 0;
}
/*
b - int8_t
w - int16_t
@ -445,6 +456,16 @@ p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
errcode = -EFAULT;
}
break;
case 'E':{
int32_t cnt = va_arg(ap, int32_t);
const char *k = va_arg(ap, const void *);
const char *u = va_arg(ap, const void *);
errcode = p9pdu_writef(pdu, proto_version, "d",
cnt);
if (!errcode && pdu_write_urw(pdu, k, u, cnt))
errcode = -EFAULT;
}
break;
case 'U':{
int32_t count = va_arg(ap, int32_t);
const char __user *udata =