cifs: don't bother with kmap on read_pages side

just do ITER_BVEC recvmsg

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 35 insertions, 30 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index eb426658566d..e33c5e0ecfd0 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -501,39 +501,34 @@ server_unresponsive(struct TCP_Server_Info *server)
         return false;
 }
 
-int
-cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
-                       unsigned int nr_segs, unsigned int to_read)
+static int
+cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 {
         int length = 0;
         int total_read;
-        struct msghdr smb_msg;
 
-        smb_msg.msg_control = NULL;
-        smb_msg.msg_controllen = 0;
-        iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC,
-                      iov_orig, nr_segs, to_read);
+        smb_msg->msg_control = NULL;
+        smb_msg->msg_controllen = 0;
 
-        for (total_read = 0; msg_data_left(&smb_msg); total_read += length) {
+        for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
                 try_to_freeze();
 
-                if (server_unresponsive(server)) {
-                        total_read = -ECONNABORTED;
-                        break;
-                }
+                if (server_unresponsive(server))
+                        return -ECONNABORTED;
 
-                length = sock_recvmsg(server->ssocket, &smb_msg, 0);
+                length = sock_recvmsg(server->ssocket, smb_msg, 0);
 
-                if (server->tcpStatus == CifsExiting) {
-                        total_read = -ESHUTDOWN;
-                        break;
-                } else if (server->tcpStatus == CifsNeedReconnect) {
+                if (server->tcpStatus == CifsExiting)
+                        return -ESHUTDOWN;
+
+                if (server->tcpStatus == CifsNeedReconnect) {
                         cifs_reconnect(server);
-                        total_read = -ECONNABORTED;
-                        break;
-                } else if (length == -ERESTARTSYS ||
-                           length == -EAGAIN ||
-                           length == -EINTR) {
+                        return -ECONNABORTED;
+                }
+
+                if (length == -ERESTARTSYS ||
+                    length == -EAGAIN ||
+                    length == -EINTR) {
                         /*
                          * Minimum sleep to prevent looping, allowing socket
                          * to clear and app threads to set tcpStatus
@@ -542,11 +537,12 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
                         usleep_range(1000, 2000);
                         length = 0;
                         continue;
-                } else if (length <= 0) {
+                }
+
+                if (length <= 0) {
                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
                         cifs_reconnect(server);
-                        total_read = -ECONNABORTED;
-                        break;
+                        return -ECONNABORTED;
                 }
         }
         return total_read;
@@ -556,12 +552,21 @@ int
 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
                       unsigned int to_read)
 {
-        struct kvec iov;
+        struct msghdr smb_msg;
+        struct kvec iov = {.iov_base = buf, .iov_len = to_read};
+        iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC, &iov, 1, to_read);
 
-        iov.iov_base = buf;
-        iov.iov_len = to_read;
+        return cifs_readv_from_socket(server, &smb_msg);
+}
 
-        return cifs_readv_from_socket(server, &iov, 1, to_read);
+int
+cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
+                      unsigned int to_read)
+{
+        struct msghdr smb_msg;
+        struct bio_vec bv = {.bv_page = page, .bv_len = to_read};
+        iov_iter_bvec(&smb_msg.msg_iter, READ | ITER_BVEC, &bv, 1, to_read);
+        return cifs_readv_from_socket(server, &smb_msg);
 }
 
 static bool