From 01cf30825c8729884090151ab97f1c9c5d14a8bc Mon Sep 17 00:00:00 2001 From: Steve French Date: Thu, 1 Jul 2021 12:22:47 -0500 Subject: [PATCH] cifs: make locking consistent around the server session status There were three places where we were not taking the spinlock around updates to server->tcpStatus when it was being modified. To be consistent (also removes Coverity warning) and to remove possibility of race best to lock all places where it is updated. Two of the three were in initialization of the field and can't race - but added lock around the other. Addresses-Coverity: 1399512 ("Data race condition") Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 3 ++- fs/cifs/connect.c | 5 +++++ fs/cifs/transport.c | 2 ++ 3 files changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 3100f8b66e60..921680fb7931 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -577,6 +577,7 @@ struct TCP_Server_Info { char server_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL]; struct smb_version_operations *ops; struct smb_version_values *vals; + /* updates to tcpStatus protected by GlobalMid_Lock */ enum statusEnum tcpStatus; /* what we think the status is */ char *hostname; /* hostname portion of UNC string */ struct socket *ssocket; @@ -1785,7 +1786,7 @@ require use of the stronger protocol */ * list operations on pending_mid_q and oplockQ * updates to XID counters, multiplex id and SMB sequence numbers * list operations on global DnotifyReqList - * updates to ses->status + * updates to ses->status and TCP_Server_Info->tcpStatus * updates to server->CurrentMid * tcp_ses_lock protects: * list operations on tcp and SMB session lists diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 5d269f583dac..01dc45178f66 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1403,6 +1403,11 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx) goto out_err_crypto_release; } tcp_ses->min_offload = ctx->min_offload; + /* + * at this point we are the only ones with the pointer + * to the struct since the kernel thread not created yet + * no need to spinlock this update of tcpStatus + */ tcp_ses->tcpStatus = CifsNeedNegotiate; if ((ctx->max_credits < 20) || (ctx->max_credits > 60000)) diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index f65f9a692ca2..75a95de320cf 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -431,7 +431,9 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst, * be taken as the remainder of this one. We need to kill the * socket so the server throws away the partial SMB */ + spin_lock(&GlobalMid_Lock); server->tcpStatus = CifsNeedReconnect; + spin_unlock(&GlobalMid_Lock); trace_smb3_partial_send_reconnect(server->CurrentMid, server->conn_id, server->hostname); } -- 2.30.2