4.18-stable review patch. If anyone has any objections, please let me know.
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From: Wen Xiong wenxiong@linux.vnet.ibm.com
[ Upstream commit 318ddb34b2052f838aa243d07173e2badf3e630e ]
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: Wen Xiong wenxiong@linux.vnet.ibm.com Acked-by: Brian King brking@linux.vnet.ibm.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/scsi/ipr.c | 106 ++++++++++++++++++++++++++++++----------------------- drivers/scsi/ipr.h | 1 2 files changed, 62 insertions(+), 45 deletions(-)
--- a/drivers/scsi/ipr.c +++ b/drivers/scsi/ipr.c @@ -3310,6 +3310,65 @@ static void ipr_release_dump(struct 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 @@ -3324,13 +3383,9 @@ static void ipr_release_dump(struct 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); @@ -3368,49 +3423,9 @@ static void ipr_worker_thread(struct wor 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; }
@@ -9908,6 +9923,7 @@ static void ipr_init_ioa_cfg(struct ipr_ 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); --- a/drivers/scsi/ipr.h +++ b/drivers/scsi/ipr.h @@ -1568,6 +1568,7 @@ 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;