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authorVenkateswararao Jujjuri (JV) <jvrao@linux.vnet.ibm.com>2011-02-01 20:04:59 -0800
committerEric Van Hensbergen <ericvh@gmail.com>2011-03-15 09:57:36 -0500
commitca41bb3e21d7b3cb2079e225e3a7e62e6c776518 (patch)
treefa65d03bf9d4e8839631ae4a295ab3f1b7ba3e06 /net/9p/client.c
parent2c66523fd290edeea26cbe8cedd0af167d0f7e5f (diff)
downloadlinux-ca41bb3e21d7b3cb2079e225e3a7e62e6c776518.tar.bz2
[net/9p] Handle Zero Copy TREAD/RERROR case in !dotl case.
This takes care of copying out error buffers from user buffer payloads when we are using zero copy. This happens because the only payload buffer the server has to respond to the request is the user buffer given for the zero copy read. Because we only use zerocopy when the amount of data to transfer is greater than a certain size (currently 4K) and error strings are limited to ERRMAX (currently 128) we don't need to worry about there being sufficient space for the error to fit in the payload. Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'net/9p/client.c')
-rw-r--r--net/9p/client.c64
1 files changed, 41 insertions, 23 deletions
diff --git a/net/9p/client.c b/net/9p/client.c
index 6e07ef494ff2..251abb1699c4 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -443,6 +443,7 @@ static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
{
int8_t type;
int err;
+ int ecode;
err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
if (err) {
@@ -450,36 +451,53 @@ static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
return err;
}
- if (type == P9_RERROR || type == P9_RLERROR) {
- int ecode;
-
- if (!p9_is_proto_dotl(c)) {
- char *ename;
+ if (type != P9_RERROR && type != P9_RLERROR)
+ return 0;
- err = p9pdu_readf(req->rc, c->proto_version, "s?d",
- &ename, &ecode);
- if (err)
- goto out_err;
+ if (!p9_is_proto_dotl(c)) {
+ char *ename;
+
+ if (req->tc->pbuf_size) {
+ /* Handle user buffers */
+ size_t len = req->rc->size - req->rc->offset;
+ if (req->tc->pubuf) {
+ /* User Buffer */
+ err = copy_from_user(
+ &req->rc->sdata[req->rc->offset],
+ req->tc->pubuf, len);
+ if (err) {
+ err = -EFAULT;
+ goto out_err;
+ }
+ } else {
+ /* Kernel Buffer */
+ memmove(&req->rc->sdata[req->rc->offset],
+ req->tc->pkbuf, len);
+ }
+ }
+ err = p9pdu_readf(req->rc, c->proto_version, "s?d",
+ &ename, &ecode);
+ if (err)
+ goto out_err;
- if (p9_is_proto_dotu(c))
- err = -ecode;
+ if (p9_is_proto_dotu(c))
+ err = -ecode;
- if (!err || !IS_ERR_VALUE(err)) {
- err = p9_errstr2errno(ename, strlen(ename));
+ if (!err || !IS_ERR_VALUE(err)) {
+ err = p9_errstr2errno(ename, strlen(ename));
- P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
+ P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode,
+ ename);
- kfree(ename);
- }
- } else {
- err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
- err = -ecode;
-
- P9_DPRINTK(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
+ kfree(ename);
}
+ } else {
+ err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
+ err = -ecode;
+
+ P9_DPRINTK(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
+ }
- } else
- err = 0;
return err;