Until all sas_tasks are known to no longer be in-flight this flag gates late
completions from colliding with error handling. However, it must be cleared
prior to the submission of scsi_send_eh_cmnd() requests, otherwise those
commands will never be completed correctly.
This was spotted by slub debug:
=============================================================================
BUG sas_task: Objects remaining on kmem_cache_close()
-----------------------------------------------------------------------------
INFO: Slab 0xffffea001f0eba00 objects=34 used=1 fp=0xffff8807c3aecb00 flags=0x8000000000004080
Pid: 22919, comm: modprobe Not tainted 3.2.0-isci+ #2
Call Trace:
[<ffffffff810fcdcd>] slab_err+0xb0/0xd2
[<ffffffff810e1c50>] ? free_percpu+0x31/0x117
[<ffffffff81100122>] ? kzalloc+0x14/0x16
[<ffffffff81100122>] ? kzalloc+0x14/0x16
[<ffffffff81100486>] kmem_cache_destroy+0x11d/0x270
[<ffffffffa0112bdc>] sas_class_exit+0x10/0x12 [libsas]
[<ffffffff81078fba>] sys_delete_module+0x1c4/0x23c
[<ffffffff814797ba>] ? sysret_check+0x2e/0x69
[<ffffffff8126479e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff81479782>] system_call_fastpath+0x16/0x1b
INFO: Object 0xffff8807c3aed280 @offset=21120
INFO: Allocated in sas_alloc_task+0x22/0x90 [libsas] age=4615311 cpu=2 pid=12966
__slab_alloc.clone.3+0x1d1/0x234
kmem_cache_alloc+0x52/0x10d
sas_alloc_task+0x22/0x90 [libsas]
sas_queuecommand+0x20e/0x230 [libsas]
scsi_send_eh_cmnd+0xd1/0x30c
scsi_eh_try_stu+0x4f/0x6b
scsi_eh_ready_devs+0xba/0x6ef
sas_scsi_recover_host+0xa35/0xab1 [libsas]
scsi_error_handler+0x14b/0x5fa
kthread+0x9d/0xa5
kernel_thread_helper+0x4/0x10
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/scsi/libsas/sas_scsi_host.c | 13 +++++++------
1 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 3701ff7..fd32913 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -521,8 +521,7 @@ try_bus_reset:
return FAILED;
}
-static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
- struct list_head *work_q)
+static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
{
struct scsi_cmnd *cmd, *n;
enum task_disposition res = TASK_IS_DONE;
@@ -658,7 +657,7 @@ static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
out:
list_splice_tail(&done, work_q);
list_splice_tail_init(&ha->eh_ata_q, work_q);
- return list_empty(work_q);
+ return;
clear_q:
SAS_DPRINTK("--- Exit %s -- clear_q\n", __func__);
@@ -682,10 +681,13 @@ void sas_scsi_recover_host(struct Scsi_Host *shost)
__func__, shost->host_busy, shost->host_failed);
/*
* Deal with commands that still have SAS tasks (i.e. they didn't
- * complete via the normal sas_task completion mechanism)
+ * complete via the normal sas_task completion mechanism),
+ * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
*/
set_bit(SAS_HA_FROZEN, &ha->state);
- if (sas_eh_handle_sas_errors(shost, &eh_work_q))
+ sas_eh_handle_sas_errors(shost, &eh_work_q);
+ clear_bit(SAS_HA_FROZEN, &ha->state);
+ if (list_empty(&eh_work_q))
goto out;
/*
@@ -699,7 +701,6 @@ void sas_scsi_recover_host(struct Scsi_Host *shost)
scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
out:
- clear_bit(SAS_HA_FROZEN, &ha->state);
if (ha->lldd_max_execute_num > 1)
wake_up_process(ha->core.queue_thread);
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
