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 54aba8d642ee75c17465ddb62111aa3348237659..267fba234c12d78f3edd97979e46ce8dbc73216f 100644 (file)
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -3946,11 +3946,13 @@ 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 &&
@@ -3970,6 +3972,14 @@ 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 caa1d852ece49c0bd8a9970987f70aa3eb851bdd..280885dd6bf080e670a1b403d66ce92e64c7b349 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 b809a616728f27c796197d332709832d9d6f1858..cead96454bb3ddc25380731cfd2c43fd064a30cd 100644 (file)
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -428,9 +428,6 @@ 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;
 }