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authorNicholas Bellinger <nab@linux-iscsi.org>2016-01-11 21:53:05 -0800
committerNicholas Bellinger <nab@linux-iscsi.org>2016-02-03 14:09:47 -0800
commita6d9bb1c9605cd4f44e2d8290dc4d0e88f20292d (patch)
tree451fc518e71e8c51e983785c90d690b98a6cd098 /drivers/target/target_core_tmr.c
parentfebe562c20dfa8f33bee7d419c6b517986a5aa33 (diff)
downloadlinux-a6d9bb1c9605cd4f44e2d8290dc4d0e88f20292d.tar.gz
target: Fix LUN_RESET active TMR descriptor handling
This patch fixes a NULL pointer se_cmd->cmd_kref < 0 refcount bug during TMR LUN_RESET with active TMRs, triggered during se_cmd + se_tmr_req descriptor shutdown + release via core_tmr_drain_tmr_list(). To address this bug, go ahead and obtain a local kref_get_unless_zero(&se_cmd->cmd_kref) for active I/O to set CMD_T_ABORTED, and transport_wait_for_tasks() followed by the final target_put_sess_cmd() to drop the local ->cmd_kref. Also add two new checks within target_tmr_work() to avoid CMD_T_ABORTED -> TFO->queue_tm_rsp() callbacks ahead of invoking the backend -> fabric put in transport_cmd_check_stop_to_fabric(). For good measure, also change core_tmr_release_req() to use list_del_init() ahead of se_tmr_req memory free. Reviewed-by: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/target_core_tmr.c')
-rw-r--r--drivers/target/target_core_tmr.c22
1 files changed, 21 insertions, 1 deletions
diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index fb3decc28589..072af07bd2ff 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -68,7 +68,7 @@ void core_tmr_release_req(struct se_tmr_req *tmr)
if (dev) {
spin_lock_irqsave(&dev->se_tmr_lock, flags);
- list_del(&tmr->tmr_list);
+ list_del_init(&tmr->tmr_list);
spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
}
@@ -194,9 +194,11 @@ static void core_tmr_drain_tmr_list(
struct list_head *preempt_and_abort_list)
{
LIST_HEAD(drain_tmr_list);
+ struct se_session *sess;
struct se_tmr_req *tmr_p, *tmr_pp;
struct se_cmd *cmd;
unsigned long flags;
+ bool rc;
/*
* Release all pending and outgoing TMRs aside from the received
* LUN_RESET tmr..
@@ -222,17 +224,31 @@ static void core_tmr_drain_tmr_list(
if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd))
continue;
+ sess = cmd->se_sess;
+ if (WARN_ON_ONCE(!sess))
+ continue;
+
+ spin_lock(&sess->sess_cmd_lock);
spin_lock(&cmd->t_state_lock);
if (!(cmd->transport_state & CMD_T_ACTIVE)) {
spin_unlock(&cmd->t_state_lock);
+ spin_unlock(&sess->sess_cmd_lock);
continue;
}
if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
spin_unlock(&cmd->t_state_lock);
+ spin_unlock(&sess->sess_cmd_lock);
continue;
}
+ cmd->transport_state |= CMD_T_ABORTED;
spin_unlock(&cmd->t_state_lock);
+ rc = kref_get_unless_zero(&cmd->cmd_kref);
+ spin_unlock(&sess->sess_cmd_lock);
+ if (!rc) {
+ printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n");
+ continue;
+ }
list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
}
spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
@@ -246,7 +262,11 @@ static void core_tmr_drain_tmr_list(
(preempt_and_abort_list) ? "Preempt" : "", tmr_p,
tmr_p->function, tmr_p->response, cmd->t_state);
+ cancel_work_sync(&cmd->work);
+ transport_wait_for_tasks(cmd);
+
transport_cmd_finish_abort(cmd, 1);
+ target_put_sess_cmd(cmd);
}
}