pmcraid: fix lock imbalance in pmcraid_reset_reload()

From: Christoph Hellwig
Date: Sun Apr 23 2017 - 04:33:23 EST


sparse found a bug that has always been present since the driver was
merged:

drivers/scsi/pmcraid.c:2353:12: warning: context imbalance in 'pmcraid_reset_reload' - different lock contexts for basic block

Fix this by using a common unlock goto label, and also reduce the
indentation level in the function.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/scsi/pmcraid.c | 59 ++++++++++++++++++++++++--------------------------
1 file changed, 28 insertions(+), 31 deletions(-)

diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c
index 49e70a383afa..3cc858f45838 100644
--- a/drivers/scsi/pmcraid.c
+++ b/drivers/scsi/pmcraid.c
@@ -2373,46 +2373,43 @@ static int pmcraid_reset_reload(
spin_lock_irqsave(pinstance->host->host_lock, lock_flags);

if (pinstance->ioa_state == IOA_STATE_DEAD) {
- spin_unlock_irqrestore(pinstance->host->host_lock,
- lock_flags);
pmcraid_info("reset_reload: IOA is dead\n");
- return reset;
- } else if (pinstance->ioa_state == target_state) {
+ goto out_unlock;
+ }
+
+ if (pinstance->ioa_state == target_state) {
reset = 0;
+ goto out_unlock;
}
}

- if (reset) {
- pmcraid_info("reset_reload: proceeding with reset\n");
- scsi_block_requests(pinstance->host);
- reset_cmd = pmcraid_get_free_cmd(pinstance);
-
- if (reset_cmd == NULL) {
- pmcraid_err("no free cmnd for reset_reload\n");
- spin_unlock_irqrestore(pinstance->host->host_lock,
- lock_flags);
- return reset;
- }
+ pmcraid_info("reset_reload: proceeding with reset\n");
+ scsi_block_requests(pinstance->host);
+ reset_cmd = pmcraid_get_free_cmd(pinstance);
+ if (reset_cmd == NULL) {
+ pmcraid_err("no free cmnd for reset_reload\n");
+ goto out_unlock;
+ }

- if (shutdown_type == SHUTDOWN_NORMAL)
- pinstance->ioa_bringdown = 1;
+ if (shutdown_type == SHUTDOWN_NORMAL)
+ pinstance->ioa_bringdown = 1;

- pinstance->ioa_shutdown_type = shutdown_type;
- pinstance->reset_cmd = reset_cmd;
- pinstance->force_ioa_reset = reset;
- pmcraid_info("reset_reload: initiating reset\n");
- pmcraid_ioa_reset(reset_cmd);
- spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
- pmcraid_info("reset_reload: waiting for reset to complete\n");
- wait_event(pinstance->reset_wait_q,
- !pinstance->ioa_reset_in_progress);
+ pinstance->ioa_shutdown_type = shutdown_type;
+ pinstance->reset_cmd = reset_cmd;
+ pinstance->force_ioa_reset = reset;
+ pmcraid_info("reset_reload: initiating reset\n");
+ pmcraid_ioa_reset(reset_cmd);
+ spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
+ pmcraid_info("reset_reload: waiting for reset to complete\n");
+ wait_event(pinstance->reset_wait_q,
+ !pinstance->ioa_reset_in_progress);

- pmcraid_info("reset_reload: reset is complete !!\n");
- scsi_unblock_requests(pinstance->host);
- if (pinstance->ioa_state == target_state)
- reset = 0;
- }
+ pmcraid_info("reset_reload: reset is complete !!\n");
+ scsi_unblock_requests(pinstance->host);
+ return pinstance->ioa_state != target_state;

+out_unlock:
+ spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
return reset;
}

--
2.11.0