[PATCH 5.17 229/343] cifs: fix potential race with cifsd thread

From: Greg Kroah-Hartman
Date: Tue Apr 12 2022 - 05:29:32 EST


From: Paulo Alcantara <pc@xxxxxx>

[ Upstream commit 687127c81ad32c8900a3fedbc7ed8f686ca95855 ]

To avoid racing with demultiplex thread while it is handling data on
socket, use cifs_signal_cifsd_for_reconnect() helper for marking
current server to reconnect and let the demultiplex thread handle the
rest.

Fixes: dca65818c80c ("cifs: use a different reconnect helper for non-cifsd threads")
Reviewed-by: Enzo Matsumiya <ematsumiya@xxxxxxx>
Reviewed-by: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/cifs/connect.c | 2 +-
fs/cifs/netmisc.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index d6f8ccc7bfe2..0270b412f801 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -4465,7 +4465,7 @@ static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tco
*/
if (rc && server->current_fullpath != server->origin_fullpath) {
server->current_fullpath = server->origin_fullpath;
- cifs_reconnect(tcon->ses->server, true);
+ cifs_signal_cifsd_for_reconnect(server, true);
}

dfs_cache_free_tgts(tl);
diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c
index ebe236b9d9f5..235aa1b395eb 100644
--- a/fs/cifs/netmisc.c
+++ b/fs/cifs/netmisc.c
@@ -896,7 +896,7 @@ map_and_check_smb_error(struct mid_q_entry *mid, bool logErr)
if (class == ERRSRV && code == ERRbaduid) {
cifs_dbg(FYI, "Server returned 0x%x, reconnecting session...\n",
code);
- cifs_reconnect(mid->server, false);
+ cifs_signal_cifsd_for_reconnect(mid->server, false);
}
}

--
2.35.1