[PATCH net-next 1/4] scsi_tcp: block BH in TCP callbacks
From: Eric Dumazet <edumazet@google.com>
Date: 2016-05-18 00:44:20
Subsystem:
iscsi, scsi subsystem, the rest · Maintainers:
Lee Duncan, Chris Leech, Mike Christie, "James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds
iscsi_sw_tcp_data_ready() and iscsi_sw_tcp_state_change() were
using read_lock(&sk->sk_callback_lock) which is fine if caller
disabled BH.
TCP stack no longer has this requirement and can run from
process context.
Use read_lock_bh() variant to restore previous assumption.
Ideally this code could use RCU instead...
Fixes: 5413d1babe8f ("net: do not block BH while processing socket backlog")
Fixes: d41a69f1d390 ("tcp: make tcp_sendmsg() aware of socket backlog")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mike Christie <redacted>
Cc: Venkatesh Srinivas <redacted>
---
drivers/scsi/iscsi_tcp.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 2e4c82f8329c..ace4f1f41b8e 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c@@ -131,10 +131,10 @@ static void iscsi_sw_tcp_data_ready(struct sock *sk) struct iscsi_tcp_conn *tcp_conn; read_descriptor_t rd_desc; - read_lock(&sk->sk_callback_lock); + read_lock_bh(&sk->sk_callback_lock); conn = sk->sk_user_data; if (!conn) { - read_unlock(&sk->sk_callback_lock); + read_unlock_bh(&sk->sk_callback_lock); return; } tcp_conn = conn->dd_data;
@@ -154,7 +154,7 @@ static void iscsi_sw_tcp_data_ready(struct sock *sk) /* If we had to (atomically) map a highmem page, * unmap it now. */ iscsi_tcp_segment_unmap(&tcp_conn->in.segment); - read_unlock(&sk->sk_callback_lock); + read_unlock_bh(&sk->sk_callback_lock); } static void iscsi_sw_tcp_state_change(struct sock *sk)
@@ -165,10 +165,10 @@ static void iscsi_sw_tcp_state_change(struct sock *sk) struct iscsi_session *session; void (*old_state_change)(struct sock *); - read_lock(&sk->sk_callback_lock); + read_lock_bh(&sk->sk_callback_lock); conn = sk->sk_user_data; if (!conn) { - read_unlock(&sk->sk_callback_lock); + read_unlock_bh(&sk->sk_callback_lock); return; } session = conn->session;
@@ -179,7 +179,7 @@ static void iscsi_sw_tcp_state_change(struct sock *sk) tcp_sw_conn = tcp_conn->dd_data; old_state_change = tcp_sw_conn->old_state_change; - read_unlock(&sk->sk_callback_lock); + read_unlock_bh(&sk->sk_callback_lock); old_state_change(sk); }
--
2.8.0.rc3.226.g39d4020