[SCSI] libata: fix locking for sas paths

For historical reasons, libsas uses the scsi host lock as the ata port lock, and libata always uses the ata host. For the old eh, this was largely irrelevant since the two locks were never mixed inside the code. However, the new eh has a case where it nests acquisition of the host lock inside the port lock (this does look rather deadlock prone). Obviously this would be an instant deadlock if the port lock were the host lock, so switch the libsas paths to use the ata host lock as well. Cc: Tejun Heo <tj@kernel.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libata: fix locking for sas paths
For historical reasons, libsas uses the scsi host lock as the ata port lock, and libata always uses the ata host. For the old eh, this was largely irrelevant since the two locks were never mixed inside the code. However, the new eh has a case where it nests acquisition of the host lock inside the port lock (this does look rather deadlock prone). Obviously this would be an instant deadlock if the port lock were the host lock, so switch the libsas paths to use the ata host lock as well. Cc: Tejun Heo <tj@kernel.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
James Bottomley
1 parent 1f723867e6
Showing 1 changed file with 1 additions and 1 deletions Side-by-side Diff
drivers/ata/libata-scsi.c
@@ -3747,7 +3747,7 @@
 		return NULL;
  
 	ap->port_no = 0;
-	ap->lock = shost->host_lock;
+	ap->lock = &host->lock;
 	ap->pio_mask = port_info->pio_mask;
 	ap->mwdma_mask = port_info->mwdma_mask;
 	ap->udma_mask = port_info->udma_mask;
...	...	@@ -3747,7 +3747,7 @@
3747	3747	return NULL;
3748	3748
3749	3749	ap->port_no = 0;
3750		- ap->lock = shost->host_lock;
	3750	+ ap->lock = &host->lock;
3751	3751	ap->pio_mask = port_info->pio_mask;
3752	3752	ap->mwdma_mask = port_info->mwdma_mask;
3753	3753	ap->udma_mask = port_info->udma_mask;