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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>
This commit is contained in:
Bob Peterson 2016-10-10 09:19:52 -04:00 committed by David Teigland
parent 3735b4b9f1
commit d2fee58a3b
1 changed files with 0 additions and 4 deletions
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4
fs/dlm/lowcomms.c
View File

@ -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);
}