From d2fee58a3bb15b2b8f1eaff14aa3432cf0f35d8c Mon Sep 17 00:00:00 2001
From: Bob Peterson <rpeterso@redhat.com>
Date: Mon, 10 Oct 2016 09:19:52 -0400
Subject: dlm: remove lock_sock to avoid scheduling while atomic
Before this patch, functions save_callbacks and restore_callbacks
called function lock_sock and release_sock to prevent other processes
from messing with the struct sock while the callbacks were saved and
restored. However, function add_sock calls write_lock_bh prior to
calling it save_callbacks, which disables preempts. So the call to
lock_sock would try to schedule when we can't schedule.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
---
fs/dlm/lowcomms.c | 4 ----
1 file changed, 4 deletions(-)
(limited to 'fs/dlm/lowcomms.c')
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 485494e5a28e..df680a26141b 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -519,24 +519,20 @@ out:
/* Note: sk_callback_lock must be locked before calling this function. */
static void save_callbacks(struct connection *con, struct sock *sk)
{
- lock_sock(sk);
con->orig_data_ready = sk->sk_data_ready;
con->orig_state_change = sk->sk_state_change;
con->orig_write_space = sk->sk_write_space;
con->orig_error_report = sk->sk_error_report;
- release_sock(sk);
}
static void restore_callbacks(struct connection *con, struct sock *sk)
{
write_lock_bh(&sk->sk_callback_lock);
- lock_sock(sk);
sk->sk_user_data = NULL;
sk->sk_data_ready = con->orig_data_ready;
sk->sk_state_change = con->orig_state_change;
sk->sk_write_space = con->orig_write_space;
sk->sk_error_report = con->orig_error_report;
- release_sock(sk);
write_unlock_bh(&sk->sk_callback_lock);
}
--
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