ata_port_detach() first made sure EH saw ATA_PFLAG_UNLOADING and then
assumed EH context belongs to it and performed detach operation
itself. However, UNLOADING doesn't disable all of EH and this could
lead to problems including triggering WARN_ON()'s in EH path.
This patch makes port detach behave more like other EH actions such
that ata_port_detach() requests EH to detach and waits for completion.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
drivers/ata/libata-core.c | 23 ++++-------------------
drivers/ata/libata-eh.c | 32 +++++++++++++++++++++++++++++++-
include/linux/libata.h | 3 ++-
3 files changed, 37 insertions(+), 21 deletions(-)
Index: work/drivers/ata/libata-eh.c
===================================================================
--- work.orig/drivers/ata/libata-eh.c
+++ work/drivers/ata/libata-eh.c
@@ -491,6 +491,31 @@ enum blk_eh_timer_return ata_scsi_timed_
return ret;
}
+static void ata_eh_unload(struct ata_port *ap)
+{
+ struct ata_link *link;
+ struct ata_device *dev;
+ unsigned long flags;
+
+ /* Restore SControl IPM and SPD for the next driver and
+ * disable attached devices.
+ */
+ ata_for_each_link(link, ap, PMP_FIRST) {
+ sata_scr_write(link, SCR_CONTROL, link->saved_scontrol & 0xff0);
+ ata_for_each_dev(dev, link, ALL)
+ ata_dev_disable(dev);
+ }
+
+ /* freeze and set UNLOADED */
+ spin_lock_irqsave(ap->lock, flags);
+
+ ata_port_freeze(ap); /* won't be thawed */
+ ap->pflags &= ~ATA_PFLAG_EH_PENDING; /* clear pending from freeze */
+ ap->pflags |= ATA_PFLAG_UNLOADED;
+
+ spin_unlock_irqrestore(ap->lock, flags);
+}
+
/**
* ata_scsi_error - SCSI layer error handler callback
* @host: SCSI host on which error occurred
@@ -621,8 +646,13 @@ void ata_scsi_error(struct Scsi_Host *ho
/* invoke EH, skip if unloading or suspended */
if (!(ap->pflags & (ATA_PFLAG_UNLOADING | ATA_PFLAG_SUSPENDED)))
ap->ops->error_handler(ap);
- else
+ else {
+ /* if unloading, commence suicide */
+ if ((ap->pflags & ATA_PFLAG_UNLOADING) &&
+ !(ap->pflags & ATA_PFLAG_UNLOADED))
+ ata_eh_unload(ap);
ata_eh_finish(ap);
+ }
/* process port suspend request */
ata_eh_handle_port_suspend(ap);
Index: work/include/linux/libata.h
===================================================================
--- work.orig/include/linux/libata.h
+++ work/include/linux/libata.h
@@ -213,10 +213,11 @@ enum {
ATA_PFLAG_FROZEN = (1 << 2), /* port is frozen */
ATA_PFLAG_RECOVERED = (1 << 3), /* recovery action performed */
ATA_PFLAG_LOADING = (1 << 4), /* boot/loading probe */
- ATA_PFLAG_UNLOADING = (1 << 5), /* module is unloading */
ATA_PFLAG_SCSI_HOTPLUG = (1 << 6), /* SCSI hotplug scheduled */
ATA_PFLAG_INITIALIZING = (1 << 7), /* being initialized, don't touch */
ATA_PFLAG_RESETTING = (1 << 8), /* reset in progress */
+ ATA_PFLAG_UNLOADING = (1 << 9), /* driver is being unloaded */
+ ATA_PFLAG_UNLOADED = (1 << 10), /* driver is unloaded */
ATA_PFLAG_SUSPENDED = (1 << 17), /* port is suspended (power) */
ATA_PFLAG_PM_PENDING = (1 << 18), /* PM operation pending */
Index: work/drivers/ata/libata-core.c
===================================================================
--- work.orig/drivers/ata/libata-core.c
+++ work/drivers/ata/libata-core.c
@@ -6019,8 +6019,6 @@ int ata_host_activate(struct ata_host *h
static void ata_port_detach(struct ata_port *ap)
{
unsigned long flags;
- struct ata_link *link;
- struct ata_device *dev;
if (!ap->ops->error_handler)
goto skip_eh;
@@ -6028,28 +6026,15 @@ static void ata_port_detach(struct ata_p
/* tell EH we're leaving & flush EH */
spin_lock_irqsave(ap->lock, flags);
ap->pflags |= ATA_PFLAG_UNLOADING;
+ ata_port_schedule_eh(ap);
spin_unlock_irqrestore(ap->lock, flags);
+ /* wait till EH commits suicide */
ata_port_wait_eh(ap);
- /* EH is now guaranteed to see UNLOADING - EH context belongs
- * to us. Restore SControl and disable all existing devices.
- */
- ata_for_each_link(link, ap, PMP_FIRST) {
- sata_scr_write(link, SCR_CONTROL, link->saved_scontrol);
- ata_for_each_dev(dev, link, ALL)
- ata_dev_disable(dev);
- }
-
- /* Final freeze & EH. All in-flight commands are aborted. EH
- * will be skipped and retrials will be terminated with bad
- * target.
- */
- spin_lock_irqsave(ap->lock, flags);
- ata_port_freeze(ap); /* won't be thawed */
- spin_unlock_irqrestore(ap->lock, flags);
+ /* it better be dead now */
+ WARN_ON(!(ap->pflags & ATA_PFLAG_UNLOADED));
- ata_port_wait_eh(ap);
cancel_rearming_delayed_work(&ap->hotplug_task);
skip_eh:
--
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