CIFS: Optimize cifs_user_read() in a short read case on reconnects
by filling the output buffer with a data got from a partially received
response and requesting the remaining data from the server. This is
suitable for non-signed connections.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 57d447c..66f6500 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1561,6 +1561,12 @@
case MID_REQUEST_SUBMITTED:
case MID_RETRY_NEEDED:
rdata->result = -EAGAIN;
+ if (server->sign && rdata->got_bytes)
+ /* reset bytes number since we can not check a sign */
+ rdata->got_bytes = 0;
+ /* FIXME: should this be counted toward the initiating task? */
+ task_io_account_read(rdata->got_bytes);
+ cifs_stats_bytes_read(tcon, rdata->got_bytes);
break;
default:
rdata->result = -EIO;
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index e170128..5d2501d 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3030,13 +3030,30 @@
else if (rdata->result == -EAGAIN) {
/* resend call if it's a retryable error */
struct list_head tmp_list;
+ unsigned int got_bytes = rdata->got_bytes;
list_del_init(&rdata->list);
INIT_LIST_HEAD(&tmp_list);
- rc = cifs_send_async_read(rdata->offset,
- rdata->bytes, rdata->cfile,
- cifs_sb, &tmp_list);
+ /*
+ * Got a part of data and then reconnect has
+ * happened -- fill the buffer and continue
+ * reading.
+ */
+ if (got_bytes && got_bytes < rdata->bytes) {
+ rc = cifs_readdata_to_iov(rdata, to);
+ if (rc) {
+ kref_put(&rdata->refcount,
+ cifs_uncached_readdata_release);
+ continue;
+ }
+ }
+
+ rc = cifs_send_async_read(
+ rdata->offset + got_bytes,
+ rdata->bytes - got_bytes,
+ rdata->cfile, cifs_sb,
+ &tmp_list);
list_splice(&tmp_list, &rdata_list);
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index c66ae41..cde943d 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1729,6 +1729,12 @@
case MID_REQUEST_SUBMITTED:
case MID_RETRY_NEEDED:
rdata->result = -EAGAIN;
+ if (server->sign && rdata->got_bytes)
+ /* reset bytes number since we can not check a sign */
+ rdata->got_bytes = 0;
+ /* FIXME: should this be counted toward the initiating task? */
+ task_io_account_read(rdata->got_bytes);
+ cifs_stats_bytes_read(tcon, rdata->got_bytes);
break;
default:
if (rdata->result != -ENODATA)