diff options
| author | Paulo Alcantara <pc@manguebit.com> | 2023-03-29 17:14:21 -0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2023-03-30 17:55:55 -0500 |
| commit | 6cc041e90c178955219dcee4030bd5423f800f10 (patch) | |
| tree | 9ea36548928928da57f325235771f1211230c92f | |
| parent | 179a88a8558bbf42991d361595281f3e45d7edfc (diff) | |
cifs: avoid races in parallel reconnects in smb1
Prevent multiple threads of doing negotiate, session setup and tree
connect by holding @ses->session_mutex in cifs_reconnect_tcon() while
reconnecting session and tcon.
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
| -rw-r--r-- | fs/cifs/cifssmb.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 38a697eca305..c9d57ba84be4 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -71,7 +71,7 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command) int rc; struct cifs_ses *ses; struct TCP_Server_Info *server; - struct nls_table *nls_codepage; + struct nls_table *nls_codepage = NULL; /* * SMBs NegProt, SessSetup, uLogoff do not have tcon yet so check for @@ -99,6 +99,7 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command) } spin_unlock(&tcon->tc_lock); +again: rc = cifs_wait_for_server_reconnect(server, tcon->retry); if (rc) return rc; @@ -110,8 +111,7 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command) } spin_unlock(&ses->chan_lock); - nls_codepage = load_nls_default(); - + mutex_lock(&ses->session_mutex); /* * Recheck after acquire mutex. If another thread is negotiating * and the server never sends an answer the socket will be closed @@ -120,29 +120,38 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command) spin_lock(&server->srv_lock); if (server->tcpStatus == CifsNeedReconnect) { spin_unlock(&server->srv_lock); + mutex_lock(&ses->session_mutex); + + if (tcon->retry) + goto again; rc = -EHOSTDOWN; goto out; } spin_unlock(&server->srv_lock); + nls_codepage = load_nls_default(); + /* * need to prevent multiple threads trying to simultaneously * reconnect the same SMB session */ + spin_lock(&ses->ses_lock); spin_lock(&ses->chan_lock); - if (!cifs_chan_needs_reconnect(ses, server)) { + if (!cifs_chan_needs_reconnect(ses, server) && + ses->ses_status == SES_GOOD) { spin_unlock(&ses->chan_lock); + spin_unlock(&ses->ses_lock); /* this means that we only need to tree connect */ if (tcon->need_reconnect) goto skip_sess_setup; - rc = -EHOSTDOWN; + mutex_unlock(&ses->session_mutex); goto out; } spin_unlock(&ses->chan_lock); + spin_unlock(&ses->ses_lock); - mutex_lock(&ses->session_mutex); rc = cifs_negotiate_protocol(0, ses, server); if (!rc) rc = cifs_setup_session(0, ses, server, nls_codepage); |