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| author | Bart Van Assche <bvanassche@acm.org> | 2019-01-25 21:34:56 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-23 22:11:20 +0300 |
| commit | 7d6d14a119c861d349257e3c3f2c84a18580413c (patch) | |
| tree | d00a6381fbf0ec0f7285e7fbb6e5774cb1f23fd7 | |
| parent | 6c922faf889a49ef95120ae700398f30941e9466 (diff) | |
| download | linux-7d6d14a119c861d349257e3c3f2c84a18580413c.tar.xz | |
scsi: target/iscsi: Avoid iscsit_release_commands_from_conn() deadlock
commit 32e36bfbcf31452a854263e7c7f32fbefc4b44d8 upstream.
When using SCSI passthrough in combination with the iSCSI target driver
then cmd->t_state_lock may be obtained from interrupt context. Hence, all
code that obtains cmd->t_state_lock from thread context must disable
interrupts first. This patch avoids that lockdep reports the following:
WARNING: inconsistent lock state
4.18.0-dbg+ #1 Not tainted
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
iscsi_ttx/1800 [HC1[1]:SC0[2]:HE0:SE0] takes:
000000006e7b0ceb (&(&cmd->t_state_lock)->rlock){?...}, at: target_complete_cmd+0x47/0x2c0 [target_core_mod]
{HARDIRQ-ON-W} state was registered at:
lock_acquire+0xd2/0x260
_raw_spin_lock+0x32/0x50
iscsit_close_connection+0x97e/0x1020 [iscsi_target_mod]
iscsit_take_action_for_connection_exit+0x108/0x200 [iscsi_target_mod]
iscsi_target_rx_thread+0x180/0x190 [iscsi_target_mod]
kthread+0x1cf/0x1f0
ret_from_fork+0x24/0x30
irq event stamp: 1281
hardirqs last enabled at (1279): [<ffffffff970ade79>] __local_bh_enable_ip+0xa9/0x160
hardirqs last disabled at (1281): [<ffffffff97a008a5>] interrupt_entry+0xb5/0xd0
softirqs last enabled at (1278): [<ffffffff977cd9a1>] lock_sock_nested+0x51/0xc0
softirqs last disabled at (1280): [<ffffffffc07a6e04>] ip6_finish_output2+0x124/0xe40 [ipv6]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(&cmd->t_state_lock)->rlock);
<Interrupt>
lock(&(&cmd->t_state_lock)->rlock);
| -rw-r--r-- | drivers/target/iscsi/iscsi_target.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index bd15a564fe24..3ad2659630e8 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -4040,9 +4040,9 @@ static void iscsit_release_commands_from_conn(struct iscsi_conn *conn) struct se_cmd *se_cmd = &cmd->se_cmd; if (se_cmd->se_tfo != NULL) { - spin_lock(&se_cmd->t_state_lock); + spin_lock_irq(&se_cmd->t_state_lock); se_cmd->transport_state |= CMD_T_FABRIC_STOP; - spin_unlock(&se_cmd->t_state_lock); + spin_unlock_irq(&se_cmd->t_state_lock); } } spin_unlock_bh(&conn->cmd_lock); |