CIFS: SMBD: Support page offset in RDMA recv

RDMA recv function needs to place data to the correct place starting at
page offset.

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 11 insertions, 7 deletions

diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index 6141e3ce3442..ba53c5257bbc 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -2004,10 +2004,12 @@ read_rfc1002_done:
  * return value: actual data read
  */
 static int smbd_recv_page(struct smbd_connection *info,
-                struct page *page, unsigned int to_read)
+                struct page *page, unsigned int page_offset,
+                unsigned int to_read)
 {
         int ret;
         char *to_address;
+        void *page_address;
 
         /* make sure we have the page ready for read */
         ret = wait_event_interruptible(
@@ -2015,16 +2017,17 @@ static int smbd_recv_page(struct smbd_connection *info,
                 info->reassembly_data_length >= to_read ||
                         info->transport_status != SMBD_CONNECTED);
         if (ret)
-                return 0;
+                return ret;
 
         /* now we can read from reassembly queue and not sleep */
-        to_address = kmap_atomic(page);
+        page_address = kmap_atomic(page);
+        to_address = (char *) page_address + page_offset;
 
         log_read(INFO, "reading from page=%p address=%p to_read=%d\n",
                 page, to_address, to_read);
 
         ret = smbd_recv_buf(info, to_address, to_read);
-        kunmap_atomic(to_address);
+        kunmap_atomic(page_address);
 
         return ret;
 }
@@ -2038,7 +2041,7 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
 {
         char *buf;
         struct page *page;
-        unsigned int to_read;
+        unsigned int to_read, page_offset;
         int rc;
 
         info->smbd_recv_pending++;
@@ -2052,15 +2055,16 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
 
         case READ | ITER_BVEC:
                 page = msg->msg_iter.bvec->bv_page;
+                page_offset = msg->msg_iter.bvec->bv_offset;
                 to_read = msg->msg_iter.bvec->bv_len;
-                rc = smbd_recv_page(info, page, to_read);
+                rc = smbd_recv_page(info, page, page_offset, to_read);
                 break;
 
         default:
                 /* It's a bug in upper layer to get there */
                 cifs_dbg(VFS, "CIFS: invalid msg type %d\n",
                         msg->msg_iter.type);
-                rc = -EIO;
+                rc = -EINVAL;
         }
 
         info->smbd_recv_pending--;