Tejun Heo wrote:
Implement SCSI part of hotplug.
This must be done in a separate context as SCSI makes use of EH during
probing. Unfortunately, SCSI probing fails silently if EH is active.
ata_eh_scsi_hotplug() does its best to avoid such conditions but,
theoretically, it may fail to associate SCSI device to newly found ATA
device; however, the chance is very slim and I haven't experienced any
such event during testing.
Device removal synchronization is somewhat complex but I think I've
got it right and haven't seen it malfunction.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/scsi/libata-core.c | 1 +
drivers/scsi/libata-eh.c | 70 +++++++++++++++++++++++++++++++++++++++++++-
drivers/scsi/libata-scsi.c | 59 +++++++++++++++++++++++++++++++++++++
drivers/scsi/libata.h | 2 +
include/linux/libata.h | 2 +
5 files changed, 132 insertions(+), 2 deletions(-)
6a1cd6180ac9e13e29446378bd15245c4c7efd5d
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 1809f98..7600b5f 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -5347,6 +5347,7 @@ static void ata_host_init(struct ata_por
ap->last_ctl = 0xFF;
INIT_WORK(&ap->port_task, NULL, NULL);
+ INIT_WORK(&ap->hotplug_task, ata_eh_scsi_hotplug, ap);
INIT_LIST_HEAD(&ap->eh_done_q);
/* set cable type */
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index fff93d9..0ab7d52 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -286,9 +286,13 @@ void ata_scsi_error(struct Scsi_Host *ho
/* clean up */
spin_lock_irqsave(hs_lock, flags);
+ if (ap->flags & ATA_FLAG_SCSI_HOTPLUG)
+ queue_work(ata_hotplug_wq, &ap->hotplug_task);
+
if (ap->flags & ATA_FLAG_RECOVERED)
ata_port_printk(ap, KERN_INFO, "EH complete\n");
- ap->flags &= ~ATA_FLAG_RECOVERED;
+
+ ap->flags &= ~(ATA_FLAG_SCSI_HOTPLUG | ATA_FLAG_RECOVERED);
spin_unlock_irqrestore(hs_lock, flags);
@@ -1736,6 +1740,70 @@ static void ata_eh_finish(struct ata_por
}
/**
+ * ata_eh_scsi_hotplug - SCSI part of hotplug
+ * @data: Pointer to ATA port to perform SCSI hotplug on
+ *
+ * Perform SCSI part of hotplug. It's executed from a separate
+ * workqueue after EH completes. This is necessary because SCSI
+ * hot plugging requires working EH and hot unplugging is
+ * synchronized with hot plugging with a mutex.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep).
+ */
+void ata_eh_scsi_hotplug(void *data)
Would prefer ata_eh_scsi_hotplug() to be in libata-scsi. Otherwise ACK.
Jeff
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