Commit 318ddb34 authored by Wen Xiong's avatar Wen Xiong Committed by Martin K. Petersen
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scsi: ipr: System hung while dlpar adding primary ipr adapter back



While dlpar adding primary ipr adapter back, driver goes through adapter
initialization then schedule ipr_worker_thread to start te disk scan by
dropping the host lock, calling scsi_add_device.  Then get the adapter reset
request again, so driver does scsi_block_requests, this will cause the
scsi_add_device get hung until we unblock. But we can't run ipr_worker_thread
to do the unblock because its stuck in scsi_add_device.

This patch fixes the issue.

[mkp: typo and whitespace fixes]
Signed-off-by: default avatarWen Xiong <wenxiong@linux.vnet.ibm.com>
Acked-by: default avatarBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 8c39e269
......@@ -3335,6 +3335,65 @@ static void ipr_release_dump(struct kref *kref)
LEAVE;
}
static void ipr_add_remove_thread(struct work_struct *work)
{
unsigned long lock_flags;
struct ipr_resource_entry *res;
struct scsi_device *sdev;
struct ipr_ioa_cfg *ioa_cfg =
container_of(work, struct ipr_ioa_cfg, scsi_add_work_q);
u8 bus, target, lun;
int did_work;
ENTER;
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
restart:
do {
did_work = 0;
if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].allow_cmds) {
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
return;
}
list_for_each_entry(res, &ioa_cfg->used_res_q, queue) {
if (res->del_from_ml && res->sdev) {
did_work = 1;
sdev = res->sdev;
if (!scsi_device_get(sdev)) {
if (!res->add_to_ml)
list_move_tail(&res->queue, &ioa_cfg->free_res_q);
else
res->del_from_ml = 0;
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
scsi_remove_device(sdev);
scsi_device_put(sdev);
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
}
break;
}
}
} while (did_work);
list_for_each_entry(res, &ioa_cfg->used_res_q, queue) {
if (res->add_to_ml) {
bus = res->bus;
target = res->target;
lun = res->lun;
res->add_to_ml = 0;
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
scsi_add_device(ioa_cfg->host, bus, target, lun);
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
goto restart;
}
}
ioa_cfg->scan_done = 1;
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
kobject_uevent(&ioa_cfg->host->shost_dev.kobj, KOBJ_CHANGE);
LEAVE;
}
/**
* ipr_worker_thread - Worker thread
* @work: ioa config struct
......@@ -3349,13 +3408,9 @@ static void ipr_release_dump(struct kref *kref)
static void ipr_worker_thread(struct work_struct *work)
{
unsigned long lock_flags;
struct ipr_resource_entry *res;
struct scsi_device *sdev;
struct ipr_dump *dump;
struct ipr_ioa_cfg *ioa_cfg =
container_of(work, struct ipr_ioa_cfg, work_q);
u8 bus, target, lun;
int did_work;
ENTER;
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
......@@ -3393,49 +3448,9 @@ static void ipr_worker_thread(struct work_struct *work)
return;
}
restart:
do {
did_work = 0;
if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].allow_cmds) {
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
return;
}
schedule_work(&ioa_cfg->scsi_add_work_q);
list_for_each_entry(res, &ioa_cfg->used_res_q, queue) {
if (res->del_from_ml && res->sdev) {
did_work = 1;
sdev = res->sdev;
if (!scsi_device_get(sdev)) {
if (!res->add_to_ml)
list_move_tail(&res->queue, &ioa_cfg->free_res_q);
else
res->del_from_ml = 0;
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
scsi_remove_device(sdev);
scsi_device_put(sdev);
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
}
break;
}
}
} while (did_work);
list_for_each_entry(res, &ioa_cfg->used_res_q, queue) {
if (res->add_to_ml) {
bus = res->bus;
target = res->target;
lun = res->lun;
res->add_to_ml = 0;
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
scsi_add_device(ioa_cfg->host, bus, target, lun);
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
goto restart;
}
}
ioa_cfg->scan_done = 1;
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
kobject_uevent(&ioa_cfg->host->shost_dev.kobj, KOBJ_CHANGE);
LEAVE;
}
......@@ -9933,6 +9948,7 @@ static void ipr_init_ioa_cfg(struct ipr_ioa_cfg *ioa_cfg,
INIT_LIST_HEAD(&ioa_cfg->free_res_q);
INIT_LIST_HEAD(&ioa_cfg->used_res_q);
INIT_WORK(&ioa_cfg->work_q, ipr_worker_thread);
INIT_WORK(&ioa_cfg->scsi_add_work_q, ipr_add_remove_thread);
init_waitqueue_head(&ioa_cfg->reset_wait_q);
init_waitqueue_head(&ioa_cfg->msi_wait_q);
init_waitqueue_head(&ioa_cfg->eeh_wait_q);
......
......@@ -1575,6 +1575,7 @@ struct ipr_ioa_cfg {
u8 saved_mode_page_len;
struct work_struct work_q;
struct work_struct scsi_add_work_q;
struct workqueue_struct *reset_work_q;
wait_queue_head_t reset_wait_q;
......
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