net/9p: switch the guts of p9_client_{read,write}() to iov_iter
[linux-drm-fsl-dcu.git] / net / 9p / client.c
index e86a9bea1d160ccc1a739eee576d0bdbf0483956..9ef5d85f082f5716651f66a8309ffd6680af8e9b 100644 (file)
@@ -34,6 +34,7 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/uaccess.h>
+#include <linux/uio.h>
 #include <net/9p/9p.h>
 #include <linux/parser.h>
 #include <net/9p/client.h>
@@ -555,7 +556,7 @@ out_err:
  */
 
 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
-                             char *uidata, int in_hdrlen, int kern_buf)
+                             struct iov_iter *uidata, int in_hdrlen)
 {
        int err;
        int ecode;
@@ -591,16 +592,11 @@ static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
                ename = &req->rc->sdata[req->rc->offset];
                if (len > inline_len) {
                        /* We have error in external buffer */
-                       if (kern_buf) {
-                               memcpy(ename + inline_len, uidata,
-                                      len - inline_len);
-                       } else {
-                               err = copy_from_user(ename + inline_len,
-                                                    uidata, len - inline_len);
-                               if (err) {
-                                       err = -EFAULT;
-                                       goto out_err;
-                               }
+                       err = copy_from_iter(ename + inline_len,
+                                            len - inline_len, uidata);
+                       if (err != len - inline_len) {
+                               err = -EFAULT;
+                               goto out_err;
                        }
                }
                ename = NULL;
@@ -806,8 +802,8 @@ reterr:
  * p9_client_zc_rpc - issue a request and wait for a response
  * @c: client session
  * @type: type of request
- * @uidata: user bffer that should be ued for zero copy read
- * @uodata: user buffer that shoud be user for zero copy write
+ * @uidata: destination for zero copy read
+ * @uodata: source for zero copy write
  * @inlen: read buffer size
  * @olen: write buffer size
  * @hdrlen: reader header size, This is the size of response protocol data
@@ -816,9 +812,10 @@ reterr:
  * Returns request structure (which client must free using p9_free_req)
  */
 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
-                                        char *uidata, char *uodata,
+                                        struct iov_iter *uidata,
+                                        struct iov_iter *uodata,
                                         int inlen, int olen, int in_hdrlen,
-                                        int kern_buf, const char *fmt, ...)
+                                        const char *fmt, ...)
 {
        va_list ap;
        int sigpending, err;
@@ -841,12 +838,8 @@ static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
        } else
                sigpending = 0;
 
-       /* If we are called with KERNEL_DS force kern_buf */
-       if (segment_eq(get_fs(), KERNEL_DS))
-               kern_buf = 1;
-
        err = c->trans_mod->zc_request(c, req, uidata, uodata,
-                                      inlen, olen, in_hdrlen, kern_buf);
+                                      inlen, olen, in_hdrlen);
        if (err < 0) {
                if (err == -EIO)
                        c->status = Disconnected;
@@ -876,7 +869,7 @@ static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
        if (err < 0)
                goto reterr;
 
-       err = p9_check_zc_errors(c, req, uidata, in_hdrlen, kern_buf);
+       err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
        trace_9p_client_res(c, type, req->rc->tag, err);
        if (!err)
                return req;
@@ -1545,11 +1538,24 @@ p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
                                                                u32 count)
 {
        char *dataptr;
-       int kernel_buf = 0;
        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);
+       }
 
        p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
                   fid->fid, (unsigned long long) offset, count);
@@ -1565,18 +1571,12 @@ p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
 
        /* Don't bother zerocopy for small IO (< 1024) */
        if (clnt->trans_mod->zc_request && rsize > 1024) {
-               char *indata;
-               if (data) {
-                       kernel_buf = 1;
-                       indata = data;
-               } else
-                       indata = (__force char *)udata;
                /*
                 * response header len is 11
                 * PDU Header(7) + IO Size (4)
                 */
-               req = p9_client_zc_rpc(clnt, P9_TREAD, indata, NULL, rsize, 0,
-                                      11, kernel_buf, "dqd", fid->fid,
+               req = p9_client_zc_rpc(clnt, P9_TREAD, &to, NULL, rsize, 0,
+                                      11, "dqd", fid->fid,
                                       offset, rsize);
        } else {
                non_zc = 1;
@@ -1596,16 +1596,9 @@ p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
 
        p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
 
-       if (non_zc) {
-               if (data) {
-                       memmove(data, dataptr, count);
-               } else {
-                       err = copy_to_user(udata, dataptr, count);
-                       if (err) {
-                               err = -EFAULT;
-                               goto free_and_error;
-                       }
-               }
+       if (non_zc && copy_to_iter(dataptr, count, &to) != count) {
+               err = -EFAULT;
+               goto free_and_error;
        }
        p9_free_req(clnt, req);
        return count;
@@ -1622,9 +1615,23 @@ p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
                                                        u64 offset, u32 count)
 {
        int err, rsize;
-       int kernel_buf = 0;
        struct p9_client *clnt;
        struct p9_req_t *req;
+       struct iov_iter from;
+       union {
+               struct kvec kv;
+               struct iovec iov;
+       } v;
+
+       if (data) {
+               v.kv.iov_base = data;
+               v.kv.iov_len = count;
+               iov_iter_kvec(&from, ITER_KVEC | WRITE, &v.kv, 1, count);
+       } else {
+               v.iov.iov_base = udata;
+               v.iov.iov_len = count;
+               iov_iter_init(&from, WRITE, &v.iov, 1, count);
+       }
 
        p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
                                fid->fid, (unsigned long long) offset, count);
@@ -1640,22 +1647,12 @@ p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
 
        /* Don't bother zerocopy for small IO (< 1024) */
        if (clnt->trans_mod->zc_request && rsize > 1024) {
-               char *odata;
-               if (data) {
-                       kernel_buf = 1;
-                       odata = data;
-               } else
-                       odata = (char *)udata;
-               req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, odata, 0, rsize,
-                                      P9_ZC_HDR_SZ, kernel_buf, "dqd",
+               req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, &from, 0, rsize,
+                                      P9_ZC_HDR_SZ, "dqd",
                                       fid->fid, offset, rsize);
        } else {
-               if (data)
-                       req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
-                                           offset, rsize, data);
-               else
-                       req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
-                                           offset, rsize, udata);
+               req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
+                                           offset, rsize, &from);
        }
        if (IS_ERR(req)) {
                err = PTR_ERR(req);
@@ -2068,6 +2065,10 @@ int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
        struct p9_client *clnt;
        struct p9_req_t *req;
        char *dataptr;
+       struct kvec kv = {.iov_base = data, .iov_len = count};
+       struct iov_iter to;
+
+       iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
 
        p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
                                fid->fid, (unsigned long long) offset, count);
@@ -2088,8 +2089,8 @@ int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
                 * response header len is 11
                 * PDU Header(7) + IO Size (4)
                 */
-               req = p9_client_zc_rpc(clnt, P9_TREADDIR, data, NULL, rsize, 0,
-                                      11, 1, "dqd", fid->fid, offset, rsize);
+               req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
+                                      11, "dqd", fid->fid, offset, rsize);
        } else {
                non_zc = 1;
                req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,