libsas power management routines to suspend and recover the sas domain
based on a model where the lldd is allowed and expected to be
"forgetful".
sas_suspend_ha - disable event processing allowing the lldd to take down
links without concern for causing hotplug events.
Regardless of whether the lldd actually posts link down
messages libsas notifies the lldd that all
domain_devices are gone.
sas_prep_resume_ha - on the way back up before the lldd starts link
training clean out any spurious events that were
generated on the way down, and re-enable event
processing
sas_resume_ha - after the lldd has started and decided that all phys
have posted link-up events this routine is called to let
libsas start it's own timeout of any phys that did not
resume. After the timeout an lldd can cancel the
phy teardown by posting a link-up event.
Storage for ex_change_count (u16) and phy_change_count (u8) are changed
to int so they can be set to -1 to indicate 'invalidated'.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jacek Danecki <jacek.danecki@intel.com>
Tested-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
When managing shost->host_eh_scheduled libata assumes that there is a
1:1 shost-to-ata_port relationship. libsas creates a 1:N relationship
so it needs to manage host_eh_scheduled cumulatively at the host level.
The sched_eh and end_eh port port ops allow libsas to track when domain
devices enter/leave the "eh-pending" state under ha->lock (previously
named ha->state_lock, but it is no longer just a lock for ha->state
changes).
Since host_eh_scheduled indicates eh without backing commands pinning
the device it can be deallocated at any time. Move the taking of the
domain_device reference under the port_lock to guarantee that the
ata_port stays around for the duration of eh.
Reviewed-by: Jacek Danecki <jacek.danecki@intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This changes the ordering of initialization and probing events from:
1/ allocate rphy in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
2/ allocate ata_port and schedule port probe in DISCE_PROBE
...to:
1/ allocate ata_port in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
2/ allocate rphy in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
3/ schedule port probe in DISCE_PROBE
This ordering prevents PHYE_SIGNAL_LOSS_EVENTS from sneaking in to
destrory ata devices before they have been fully initialized:
BUG: unable to handle kernel paging request at 0000000000003b10
IP: [<ffffffffa0053d7e>] sas_ata_end_eh+0x12/0x5e [libsas]
...
[<ffffffffa004d1af>] sas_unregister_common_dev+0x78/0xc9 [libsas]
[<ffffffffa004d4d4>] sas_unregister_dev+0x4f/0xad [libsas]
[<ffffffffa004d5b1>] sas_unregister_domain_devices+0x7f/0xbf [libsas]
[<ffffffffa004c487>] sas_deform_port+0x61/0x1b8 [libsas]
[<ffffffffa004bed0>] sas_phye_loss_of_signal+0x29/0x2b [libsas]
...and kills the awkward "sata domain_device briefly existing in the
domain without an ata_port" state.
Reported-by: Michal Kosciowski <michal.kosciowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
libsas ata error handling is already async but this does not help the
scan case. Move initial link recovery out from under host->scan_mutex,
and delay synchronization with eh until after all port probe/recovery
work has been queued.
Device ordering is maintained with scan order by still calling
sas_rphy_add() in order of domain discovery.
Since we now scan the domain list when invoking libata-eh we need to be
careful to check for fully initialized ata ports.
Acked-by: Jack Wang <jack_wang@usish.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
ata devices are always scanned after ssp. Prior to the ata error
handling reworks libsas would tend to scan devices in ascending expander
phy order. Restore this ordering by deferring ssp discovery to a
DISCE_PROBE event, and keep the probe order consistent with the
discovery order, not the placement of sata devices.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
libsas fails to discover all sata devices in the domain. If a device fails
negotiation and does not transmit a signature fis the link needs recovery.
libata already understands how to manage slow to come up links, so treat these
conditions as ata device attach events for the purposes of creating an
ata_port. This allows libata to manage retrying link bring up.
Rediscovery is modified to be careful about checking changes in dev_type. It
looks like libsas leaks old devices if the sas address changes, but that's a
fix for another patch.
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
If we have a domain with sas and sata devices there may still be sas
recovery actions to take after peeling off the commands to send to
libata.
Reported-by: Andrzej Jakowski <andrzej.jakowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Link resets leave ata affiliations intact, so arrange for libsas to make
an effort to avoid dropping the device due to a slow-to-recover link.
Towards this end carry out reset in the host workqueue so that it can
check for ata devices and kick the reset request to libata. Hard
resets, in contrast, bypass libata since they are meant for associating
an ata device with another initiator in the domain (tears down
affiliations).
Need to add a new transport_sas_phy_reset() since the current
sas_phy_reset() is a utility function to libsas lldds. They are not
prepared for it to loop back into eh.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Since sata devices can take several seconds to recover the link on reset
the 0.5 seconds that libsas currently waits may not be enough. Instead
if we are rediscovering a phy that was previously attached to a sata
device let libata handle any resets to encourage the device to transmit
the initial fis.
Once sas_ata_hard_reset() and lldds learn how to honor 'deadline' libsas
should stop encountering phys in an intermediate state, until then this
will loop until the fis is transmitted or ->attached_sas_addr gets
cleared, but in the more likely initial discovery case we keep existing
behavior.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Until we have told the lldd to forget a task a timed out operation can
return from the hardware at any time. Since completion frees the task
we need to make sure that no tasks run their normal completion handler
once eh has decided to manage the task. Similar to
ata_scsi_cmd_error_handler() freeze completions to let eh judge the
outcome of the race.
Task collector mode is problematic because it presents a situation where
a task can be timed out and aborted before the lldd has even seen it.
For this case we need to guarantee that a task that an lldd has been
told to forget does not get queued after the lldd says "never seen it".
With sas_scsi_timed_out we achieve this with the ->task_queue_flush
mutex, rather than adding more time.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
libata error handling provides for a timeout for link recovery. libsas
must not rescan for previously known devices in this interval otherwise
it may remove a device that is simply waiting for its link to recover.
Let libata-eh make the determination of when the link is stable and
prevent libsas (host workqueue) from taking action while this
determination is pending.
Using a mutex (ha->disco_mutex) to flush and disable revalidation while
eh is running requires any discovery action that may block on eh be
moved to its own context outside the lock. Probing ATA devices
explicitly waits on ata-eh and the cache-flush-io issued during device
removal may also pend awaiting eh completion. Essentially any rphy
add/remove activity needs to run outside the lock.
This adds two new cleanup states for sas_unregister_domain_devices()
'allocated-but-not-probed', and 'flagged-for-destruction'. In the
'allocated-but-not-probed' state dev->rphy points to a rphy that is
known to have not been through a sas_rphy_add() event. At domain
teardown check if this device is still pending probe and cleanup
accordingly. Similarly if a device has already been queued for removal
then sas_unregister_domain_devices has nothing to do.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
These are never freed in the nominal path. A domain_device has a
different lifetime than a sas_rphy we need a dev->rphy independent way
of identifying sata devices.
Reviewed-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
The conversion is quite complex given that the libata new error
handler has to be hooked into the current libsas timeout and error
handling. The way this is done is to process all the failed commands
via libsas first, but if they have no underlying sas task (and they're
on a sata device) assume they are destined for the libata error
handler and send them accordingly.
Finally, activate the port recovery of the libata error handler for
each port known to the host. This is somewhat suboptimal, since that
port may not need recovering, but given the current architecture of
the libata error handler, it's the only way; and the spurious
activation is harmless.
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Two functions in include/scsi/sas_ata.h don't have static inlines
leading to problems if they're built in:
On Thu, 2008-04-03 at 14:06 +0200, Toralf Förster wrote:
> drivers/scsi/mvsas.o: In function `sas_ata_init_host_and_port':
> mvsas.c:(.text+0x0): multiple definition of `sas_ata_init_host_and_port'
> drivers/scsi/libsas/built-in.o:(.text+0x37f4): first defined here
> drivers/scsi/mvsas.o: In function `sas_ata_task_abort':
> mvsas.c:(.text+0x7): multiple definition of `sas_ata_task_abort'
> drivers/scsi/libsas/built-in.o:(.text+0x37fb): first defined here
> make[2]: *** [drivers/scsi/built-in.o] Error 1
> make[1]: *** [drivers/scsi] Error 2
> make: *** [drivers] Error 2
Add the correct static inline modifiers.
Tested-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Not everyone wants libsas automatically to pull in libata. This patch
makes the behaviour configurable, so you can build libsas with or
without ATA support.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
ATA devices need special handling for sas_task_abort. If the ATA command
came from SCSI, then we merely need to tell SCSI to abort the scsi_cmnd.
However, internal commands require a bit more work--we need to fill the qc
with the appropriate error status and complete the command, and eventually
post_internal will issue the actual ABORT TASK.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This is a respin of my earlier patch that migrates the ATA support code
into a separate file. For now, the controversial linking bits have
been removed per James Bottomley's request for a patch that contains
only the migration diffs, which means that libsas continues to require
libata. I intend to address that problem in a separate patch.
This patch is against the aic94xx-sas-2.6 git tree, and it has been
sanity tested on my x206m with Seagate SATA and SAS disks without
uncovering any new problems.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Dan Williams