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libata: perform port detach in EH

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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@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
Tejun Heo 2008-11-03 20:04:37 +09:00 committed by Jeff Garzik
parent ad74e4c18d
commit ece180d1cf
3 changed files with 37 additions and 21 deletions
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23
drivers/ata/libata-core.c
View File

@ -6107,8 +6107,6 @@ int ata_host_activate(struct ata_host *host, int irq,
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;
@ -6116,28 +6114,15 @@ static void ata_port_detach(struct ata_port *ap)
/* 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 & 0xff0);
ata_for_each_dev(dev, link, ALL)
ata_dev_disable(dev);
}
/* it better be dead now */
WARN_ON(!(ap->pflags & ATA_PFLAG_UNLOADED));
/* 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);
ata_port_wait_eh(ap);
cancel_rearming_delayed_work(&ap->hotplug_task);
skip_eh:

32
drivers/ata/libata-eh.c
View File

@ -491,6 +491,31 @@ enum blk_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
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
@ -618,8 +643,13 @@ void ata_scsi_error(struct Scsi_Host *host)
/* 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);

3
include/linux/libata.h
View File

@ -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 */