Commit 511c54a2f691 ("CIFS: Reconnect expired SMB sessions") upstream.
According to the MS-SMB2 spec (3.2.5.1.6) once the client receives
STATUS_NETWORK_SESSION_EXPIRED error code from a server it should
reconnect the current SMB session. Currently the client doesn't do
that. This can result in subsequent client requests failing by
the server. The patch adds an additional logic to the demultiplex
thread to identify expired sessions and reconnect them.
Cc: <stable@xxxxxxxxxxxxxxx> # 3.16.x-3.18.x
Signed-off-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
---
fs/cifs/cifsglob.h | 2 ++
fs/cifs/cifssmb.c | 7 +++++++
fs/cifs/connect.c | 7 +++++++
fs/cifs/smb2ops.c | 15 +++++++++++++++
4 files changed, 31 insertions(+)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 99745da..0a359af 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -347,6 +347,8 @@ struct smb_version_operations {
unsigned int (*calc_smb_size)(void *);
/* check for STATUS_PENDING and process it in a positive case */
bool (*is_status_pending)(char *, struct TCP_Server_Info *, int);
+ /* check for STATUS_NETWORK_SESSION_EXPIRED */
+ bool (*is_session_expired)(char *);
/* send oplock break response */
int (*oplock_response)(struct cifs_tcon *, struct cifs_fid *,
struct cifsInodeInfo *);
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 8e1a17c..b2218b7 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1458,6 +1458,13 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
return length;
server->total_read += length;
+ if (server->ops->is_session_expired &&
+ server->ops->is_session_expired(buf)) {
+ cifs_reconnect(server);
+ wake_up(&server->response_q);
+ return -1;
+ }
+
if (server->ops->is_status_pending &&
server->ops->is_status_pending(buf, server, 0)) {
discard_remaining_data(server);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 43df8c3..43bb9e2 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -839,6 +839,13 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
cifs_dump_mem("Bad SMB: ", buf,
min_t(unsigned int, server->total_read, 48));
+ if (server->ops->is_session_expired &&
+ server->ops->is_session_expired(buf)) {
+ cifs_reconnect(server);
+ wake_up(&server->response_q);
+ return -1;
+ }
+
if (server->ops->is_status_pending &&
server->ops->is_status_pending(buf, server, length))
return -1;
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 881af94..d23a416 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -896,6 +896,18 @@ smb2_is_status_pending(char *buf, struct TCP_Server_Info *server, int length)
return true;
}
+static bool
+smb2_is_session_expired(char *buf)
+{
+ struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
+
+ if (hdr->Status != STATUS_NETWORK_SESSION_EXPIRED)
+ return false;
+
+ cifs_dbg(FYI, "Session expired\n");
+ return true;
+}
+
static int
smb2_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid,
struct cifsInodeInfo *cinode)
@@ -1424,6 +1436,7 @@ struct smb_version_operations smb20_operations = {
.close_dir = smb2_close_dir,
.calc_smb_size = smb2_calc_size,
.is_status_pending = smb2_is_status_pending,
+ .is_session_expired = smb2_is_session_expired,
.oplock_response = smb2_oplock_response,
.queryfs = smb2_queryfs,
.mand_lock = smb2_mand_lock,
@@ -1505,6 +1518,7 @@ struct smb_version_operations smb21_operations = {
.close_dir = smb2_close_dir,
.calc_smb_size = smb2_calc_size,
.is_status_pending = smb2_is_status_pending,
+ .is_session_expired = smb2_is_session_expired,
.oplock_response = smb2_oplock_response,
.queryfs = smb2_queryfs,
.mand_lock = smb2_mand_lock,
@@ -1587,6 +1601,7 @@ struct smb_version_operations smb30_operations = {
.close_dir = smb2_close_dir,
.calc_smb_size = smb2_calc_size,
.is_status_pending = smb2_is_status_pending,
+ .is_session_expired = smb2_is_session_expired,
.oplock_response = smb2_oplock_response,
.queryfs = smb2_queryfs,
.mand_lock = smb2_mand_lock,
--
2.7.4