From 52f5664a87474894e7da44f3b778dbe4e4c740b7 Mon Sep 17 00:00:00 2001 From: Ariel Nahum Date: Thu, 3 Sep 2015 19:49:55 +0300 Subject: [PATCH] libiscsi: Fix iscsi_check_transport_timeouts possible infinite loop Connection last_ping is not being updated when iscsi_send_nopout fails. Not updating the last_ping will cause firing a timer to a past time (last_ping + ping_tmo < current_time) which triggers an infinite loop of iscsi_check_transport_timeouts() and hogs the cpu. Fix this issue by checking the return value of iscsi_send_nopout. If it fails set the next_timeout to one second later. Signed-off-by: Ariel Nahum Signed-off-by: Sagi Grimberg Reviewed-by: Mike Christie Signed-off-by: James Bottomley --- drivers/scsi/libiscsi.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 33c74d3436c9..6bffd91b973a 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -976,13 +976,13 @@ static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr) wake_up(&conn->ehwait); } -static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr) +static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr) { struct iscsi_nopout hdr; struct iscsi_task *task; if (!rhdr && conn->ping_task) - return; + return -EINVAL; memset(&hdr, 0, sizeof(struct iscsi_nopout)); hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE; @@ -996,13 +996,16 @@ static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr) hdr.ttt = RESERVED_ITT; task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0); - if (!task) + if (!task) { iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n"); - else if (!rhdr) { + return -EIO; + } else if (!rhdr) { /* only track our nops */ conn->ping_task = task; conn->last_ping = jiffies; } + + return 0; } static int iscsi_nop_out_rsp(struct iscsi_task *task, @@ -2092,8 +2095,10 @@ static void iscsi_check_transport_timeouts(unsigned long data) if (time_before_eq(last_recv + recv_timeout, jiffies)) { /* send a ping to try to provoke some traffic */ ISCSI_DBG_CONN(conn, "Sending nopout as ping\n"); - iscsi_send_nopout(conn, NULL); - next_timeout = conn->last_ping + (conn->ping_timeout * HZ); + if (iscsi_send_nopout(conn, NULL)) + next_timeout = jiffies + (1 * HZ); + else + next_timeout = conn->last_ping + (conn->ping_timeout * HZ); } else next_timeout = last_recv + recv_timeout; -- 2.20.1