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: 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>
This commit is contained in:
Wen Xiong 2018-09-20 19:32:12 -05:00 committed by Martin K. Petersen
parent 8c39e2699f
commit 318ddb34b2
2 changed files with 64 additions and 47 deletions

View File

@ -3335,64 +3335,19 @@ static void ipr_release_dump(struct kref *kref)
LEAVE;
}
/**
* ipr_worker_thread - Worker thread
* @work: ioa config struct
*
* Called at task level from a work thread. This function takes care
* of adding and removing device from the mid-layer as configuration
* changes are detected by the adapter.
*
* Return value:
* nothing
**/
static void ipr_worker_thread(struct work_struct *work)
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_dump *dump;
struct ipr_ioa_cfg *ioa_cfg =
container_of(work, struct ipr_ioa_cfg, work_q);
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);
if (ioa_cfg->sdt_state == READ_DUMP) {
dump = ioa_cfg->dump;
if (!dump) {
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
return;
}
kref_get(&dump->kref);
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
ipr_get_ioa_dump(ioa_cfg, dump);
kref_put(&dump->kref, ipr_release_dump);
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
if (ioa_cfg->sdt_state == DUMP_OBTAINED && !ioa_cfg->dump_timeout)
ipr_initiate_ioa_reset(ioa_cfg, IPR_SHUTDOWN_NONE);
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
return;
}
if (ioa_cfg->scsi_unblock) {
ioa_cfg->scsi_unblock = 0;
ioa_cfg->scsi_blocked = 0;
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
scsi_unblock_requests(ioa_cfg->host);
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
if (ioa_cfg->scsi_blocked)
scsi_block_requests(ioa_cfg->host);
}
if (!ioa_cfg->scan_enabled) {
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
return;
}
restart:
do {
did_work = 0;
@ -3439,6 +3394,66 @@ restart:
LEAVE;
}
/**
* ipr_worker_thread - Worker thread
* @work: ioa config struct
*
* Called at task level from a work thread. This function takes care
* of adding and removing device from the mid-layer as configuration
* changes are detected by the adapter.
*
* Return value:
* nothing
**/
static void ipr_worker_thread(struct work_struct *work)
{
unsigned long lock_flags;
struct ipr_dump *dump;
struct ipr_ioa_cfg *ioa_cfg =
container_of(work, struct ipr_ioa_cfg, work_q);
ENTER;
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
if (ioa_cfg->sdt_state == READ_DUMP) {
dump = ioa_cfg->dump;
if (!dump) {
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
return;
}
kref_get(&dump->kref);
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
ipr_get_ioa_dump(ioa_cfg, dump);
kref_put(&dump->kref, ipr_release_dump);
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
if (ioa_cfg->sdt_state == DUMP_OBTAINED && !ioa_cfg->dump_timeout)
ipr_initiate_ioa_reset(ioa_cfg, IPR_SHUTDOWN_NONE);
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
return;
}
if (ioa_cfg->scsi_unblock) {
ioa_cfg->scsi_unblock = 0;
ioa_cfg->scsi_blocked = 0;
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
scsi_unblock_requests(ioa_cfg->host);
spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
if (ioa_cfg->scsi_blocked)
scsi_block_requests(ioa_cfg->host);
}
if (!ioa_cfg->scan_enabled) {
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
return;
}
schedule_work(&ioa_cfg->scsi_add_work_q);
spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
LEAVE;
}
#ifdef CONFIG_SCSI_IPR_TRACE
/**
* ipr_read_trace - Dump the adapter trace
@ -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);

View File

@ -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;