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authorPaulo Alcantara <pc@manguebit.com>2023-03-29 23:14:21 +0300
committerSteve French <stfrench@microsoft.com>2023-03-31 01:55:55 +0300
commit6cc041e90c178955219dcee4030bd5423f800f10 (patch)
tree9ea36548928928da57f325235771f1211230c92f /fs/cifs
parent179a88a8558bbf42991d361595281f3e45d7edfc (diff)
downloadlinux-6cc041e90c178955219dcee4030bd5423f800f10.tar.xz
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>
Diffstat (limited to 'fs/cifs')
-rw-r--r--fs/cifs/cifssmb.c21
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);