[PATCH 4.2.y-ckt 35/98] CIFS: Fix SMB2+ interim response processing for read requests

Kamal Mostafa
2016-03-15T23:30:29Z

From: Pavel Shilovsky <pshilovsky@samba.org>

commit 6cc3b24235929b54acd5ecc987ef11a425bd209e upstream.

For interim responses we only need to parse a header and update
a number credits. Now it is done for all SMB2+ command except
SMB2_READ which is wrong. Fix this by adding such processing.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Tested-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
fs/cifs/cifssmb.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 672ef35..5a6f639 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1394,11 +1394,10 @@ openRetry:
* current bigbuf.
*/
static int
-cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
+discard_remaining_data(struct TCP_Server_Info *server)
{
unsigned int rfclen = get_rfc1002_length(server->smallbuf);
int remaining = rfclen + 4 - server->total_read;
- struct cifs_readdata *rdata = mid->callback_data;

while (remaining > 0) {
int length;
@@ -1412,10 +1411,20 @@ cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
remaining -= length;
}

- dequeue_mid(mid, rdata->result);
return 0;
}

+static int
+cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
+{
+ int length;
+ struct cifs_readdata *rdata = mid->callback_data;
+
+ length = discard_remaining_data(server);
+ dequeue_mid(mid, rdata->result);
+ return length;
+}
+
int
cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
{
@@ -1444,6 +1453,12 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
return length;
server->total_read += length;

+ if (server->ops->is_status_pending &&
+ server->ops->is_status_pending(buf, server, 0)) {
+ discard_remaining_data(server);
+ return -1;
+ }
+
/* Was the SMB read successful? */
rdata->result = server->ops->map_error(buf, false);
if (rdata->result != 0) {
--
2.7.0