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libiscsi: Fix iscsi_check_transport_timeouts possible infinite loop

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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 <arieln@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
This commit is contained in:
Ariel Nahum 2015-09-03 19:49:55 +03:00 committed by James Bottomley
parent 6ff33f3902
commit 52f5664a87
1 changed files with 11 additions and 6 deletions
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17
drivers/scsi/libiscsi.c
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@ -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;