diff options
| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-09-07 07:46:50 +0400 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-09-11 03:48:54 +0400 |
| commit | d5705c4ab5035be618a34c95505727acac2e70ec (patch) | |
| tree | 512bd3f2a432db2e1ae147a46950927ce2cb0502 /drivers/target | |
| parent | 0105c257be8bfb7370631e442eff3213adbfdcb7 (diff) | |
| download | linux-d5705c4ab5035be618a34c95505727acac2e70ec.tar.xz | |
iscsi-target: Fix race with thread_pre_handler flush_signals + ISCSI_THREAD_SET_DIE
This patch addresses an long standing race in iscsi_[rx,tx]_thread_pre_handler()
use of flush_signals(), and between iscsi_deallocate_extra_thread_sets() setting
ISCSI_THREAD_SET_DIE before calling kthread_stop().
It addresses the issue by both holding ts_state_lock before calling send_sig()
in iscsi_deallocate_extra_thread_sets(), as well as only calling flush_signals()
when ts->status != ISCSI_THREAD_SET_DIE within iscsi_[rx,tx]_thread_pre_handler()
code.
v2 changes:
- Add explicit complete(&ts->[rx,tx]_start_comp); before kthread_stop() in
iscsi_deallocate_extra_thread_sets()
- Drop left-over send_sig() calls in iscsi_deallocate_extra_thread_sets()
- Add kthread_should_stop() check in iscsi_signal_thread_pre_handler()
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
| -rw-r--r-- | drivers/target/iscsi/iscsi_target_tq.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/target/iscsi/iscsi_target_tq.c b/drivers/target/iscsi/iscsi_target_tq.c index 81289520f96b..1a5bbec03f3e 100644 --- a/drivers/target/iscsi/iscsi_target_tq.c +++ b/drivers/target/iscsi/iscsi_target_tq.c @@ -189,16 +189,20 @@ static void iscsi_deallocate_extra_thread_sets(void) spin_lock_bh(&ts->ts_state_lock); ts->status = ISCSI_THREAD_SET_DIE; - spin_unlock_bh(&ts->ts_state_lock); if (ts->rx_thread) { - send_sig(SIGINT, ts->rx_thread, 1); + complete(&ts->rx_start_comp); + spin_unlock_bh(&ts->ts_state_lock); kthread_stop(ts->rx_thread); + spin_lock_bh(&ts->ts_state_lock); } if (ts->tx_thread) { - send_sig(SIGINT, ts->tx_thread, 1); + complete(&ts->tx_start_comp); + spin_unlock_bh(&ts->ts_state_lock); kthread_stop(ts->tx_thread); + spin_lock_bh(&ts->ts_state_lock); } + spin_unlock_bh(&ts->ts_state_lock); /* * Release this thread_id in the thread_set_bitmap */ @@ -400,7 +404,8 @@ static void iscsi_check_to_add_additional_sets(void) static int iscsi_signal_thread_pre_handler(struct iscsi_thread_set *ts) { spin_lock_bh(&ts->ts_state_lock); - if ((ts->status == ISCSI_THREAD_SET_DIE) || signal_pending(current)) { + if (ts->status == ISCSI_THREAD_SET_DIE || kthread_should_stop() || + signal_pending(current)) { spin_unlock_bh(&ts->ts_state_lock); return -1; } @@ -419,7 +424,8 @@ struct iscsi_conn *iscsi_rx_thread_pre_handler(struct iscsi_thread_set *ts) goto sleep; } - flush_signals(current); + if (ts->status != ISCSI_THREAD_SET_DIE) + flush_signals(current); if (ts->delay_inactive && (--ts->thread_count == 0)) { spin_unlock_bh(&ts->ts_state_lock); @@ -472,7 +478,8 @@ struct iscsi_conn *iscsi_tx_thread_pre_handler(struct iscsi_thread_set *ts) goto sleep; } - flush_signals(current); + if (ts->status != ISCSI_THREAD_SET_DIE) + flush_signals(current); if (ts->delay_inactive && (--ts->thread_count == 0)) { spin_unlock_bh(&ts->ts_state_lock); |