cifs: Fix negotiate retry functionality

[ Upstream commit e94e882a6d69525c07589222cf3a6ff57ad12b5b ]

SMB negotiate retry functionality in cifs_negotiate() is currently broken
and does not work when doing socket reconnect. Caller of this function,
which is cifs_negotiate_protocol() requires that tcpStatus after successful
execution of negotiate callback stay in CifsInNegotiate. But if the
CIFSSMBNegotiate() called from cifs_negotiate() fails due to connection
issues then tcpStatus is changed as so repeated CIFSSMBNegotiate() call
does not help.

Fix this problem by moving retrying code from negotiate callback (which is
either cifs_negotiate() or smb2_negotiate()) to cifs_negotiate_protocol()
which is caller of those callbacks. This allows to properly handle and
implement correct transistions between tcpStatus states as function
cifs_negotiate_protocol() already handles it.

With this change, cifs_negotiate_protocol() now handles also -EAGAIN error
set by the RFC1002_NEGATIVE_SESSION_RESPONSE processing after reconnecting
with NetBIOS session.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index cc9c912db8def904ee27582520ac63ae8d0bb044..92685fc675b59d739b4ac03df693039b9c31d361 100644 (file)
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -3922,11 +3922,13 @@ int
 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
                        struct TCP_Server_Info *server)
 {
+       bool in_retry = false;
        int rc = 0;
 
        if (!server->ops->need_neg || !server->ops->negotiate)
                return -ENOSYS;
 
+retry:
        /* only send once per connect */
        spin_lock(&server->srv_lock);
        if (server->tcpStatus != CifsGood &&
@@ -3946,6 +3948,14 @@ cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
        spin_unlock(&server->srv_lock);
 
        rc = server->ops->negotiate(xid, ses, server);
+       if (rc == -EAGAIN) {
+               /* Allow one retry attempt */
+               if (!in_retry) {
+                       in_retry = true;
+                       goto retry;
+               }
+               rc = -EHOSTDOWN;
+       }
        if (rc == 0) {
                spin_lock(&server->srv_lock);
                if (server->tcpStatus == CifsInNegotiate)

diff --git a/fs/smb/client/smb1ops.c b/fs/smb/client/smb1ops.c
index 808970e4a7142fd84a3080c1e4e197cbdb6517a7..e28cdaca47e1204bd4fc79fc57c262890cee2ddd 100644 (file)
--- a/fs/smb/client/smb1ops.c
+++ b/fs/smb/client/smb1ops.c
@@ -426,13 +426,6 @@ cifs_negotiate(const unsigned int xid,
 {
        int rc;
        rc = CIFSSMBNegotiate(xid, ses, server);
-       if (rc == -EAGAIN) {
-               /* retry only once on 1st time connection */
-               set_credits(server, 1);
-               rc = CIFSSMBNegotiate(xid, ses, server);
-               if (rc == -EAGAIN)
-                       rc = -EHOSTDOWN;
-       }
        return rc;
 }
 

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index 7aeac8dd9a1d137f4e5404f1635b055789f554c4..6f89e087629fe67e198808d65df5db966d32f2a4 100644 (file)
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -464,9 +464,6 @@ smb2_negotiate(const unsigned int xid,
        server->CurrentMid = 0;
        spin_unlock(&server->mid_lock);
        rc = SMB2_negotiate(xid, ses, server);
-       /* BB we probably don't need to retry with modern servers */
-       if (rc == -EAGAIN)
-               rc = -EHOSTDOWN;
        return rc;
 }