9p: switch p9_client_read() to passing struct iov_iter *
... and make it loop
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/net/9p/client.c b/net/9p/client.c
index aa38cfe..18583bb 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1534,79 +1534,77 @@
EXPORT_SYMBOL(p9_client_unlinkat);
int
-p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
- u32 count)
+p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
{
- char *dataptr;
+ struct p9_client *clnt = fid->clnt;
struct p9_req_t *req;
- struct p9_client *clnt;
- int err, rsize, non_zc = 0;
- struct iov_iter to;
- union {
- struct kvec kv;
- struct iovec iov;
- } v;
-
- if (data) {
- v.kv.iov_base = data;
- v.kv.iov_len = count;
- iov_iter_kvec(&to, ITER_KVEC | READ, &v.kv, 1, count);
- } else {
- v.iov.iov_base = udata;
- v.iov.iov_len = count;
- iov_iter_init(&to, READ, &v.iov, 1, count);
- }
+ int total = 0;
p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
- fid->fid, (unsigned long long) offset, count);
- err = 0;
- clnt = fid->clnt;
+ fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
- rsize = fid->iounit;
- if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
- rsize = clnt->msize - P9_IOHDRSZ;
+ while (iov_iter_count(to)) {
+ int count = iov_iter_count(to);
+ int rsize, non_zc = 0;
+ char *dataptr;
+
+ rsize = fid->iounit;
+ if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
+ rsize = clnt->msize - P9_IOHDRSZ;
- if (count < rsize)
- rsize = count;
+ if (count < rsize)
+ rsize = count;
- /* Don't bother zerocopy for small IO (< 1024) */
- if (clnt->trans_mod->zc_request && rsize > 1024) {
- /*
- * response header len is 11
- * PDU Header(7) + IO Size (4)
- */
- req = p9_client_zc_rpc(clnt, P9_TREAD, &to, NULL, rsize, 0,
- 11, "dqd", fid->fid,
- offset, rsize);
- } else {
- non_zc = 1;
- req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
- rsize);
+ /* Don't bother zerocopy for small IO (< 1024) */
+ if (clnt->trans_mod->zc_request && rsize > 1024) {
+ /*
+ * response header len is 11
+ * PDU Header(7) + IO Size (4)
+ */
+ req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
+ 0, 11, "dqd", fid->fid,
+ offset, rsize);
+ } else {
+ non_zc = 1;
+ req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
+ rsize);
+ }
+ if (IS_ERR(req)) {
+ *err = PTR_ERR(req);
+ break;
+ }
+
+ *err = p9pdu_readf(req->rc, clnt->proto_version,
+ "D", &count, &dataptr);
+ if (*err) {
+ trace_9p_protocol_dump(clnt, req->rc);
+ p9_free_req(clnt, req);
+ break;
+ }
+
+ p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
+ if (!count) {
+ p9_free_req(clnt, req);
+ break;
+ }
+
+ if (non_zc) {
+ int n = copy_to_iter(dataptr, count, to);
+ total += n;
+ offset += n;
+ if (n != count) {
+ *err = -EFAULT;
+ p9_free_req(clnt, req);
+ break;
+ }
+ } else {
+ iov_iter_advance(to, count);
+ total += count;
+ offset += count;
+ }
+ p9_free_req(clnt, req);
}
- if (IS_ERR(req)) {
- err = PTR_ERR(req);
- goto error;
- }
-
- err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
- if (err) {
- trace_9p_protocol_dump(clnt, req->rc);
- goto free_and_error;
- }
-
- p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
-
- if (non_zc && copy_to_iter(dataptr, count, &to) != count) {
- err = -EFAULT;
- goto free_and_error;
- }
- p9_free_req(clnt, req);
- return count;
-
-free_and_error:
- p9_free_req(clnt, req);
-error:
- return err;
+ return total;
}
EXPORT_SYMBOL(p9_client_read);