SCSI EH locks door if sdev->locked is set. Sometimes door lock
command fails continuously (e.g. when medium is not present) and as
libata uses EH to acquire sense data, this easily creates a loop where
a failed lock door invokes EH and EH issues lock door on completion.
This patch clears sdev->locked on door lock failure to break this
loop. This problem has been spotted and diagnosed by Unicorn Chang
<uchang@tw.ibm.com>.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Reimplement per-dev PM. The original implementation directly put the
device into suspended mode and didn't synchronize w/ EH operations
including hotplug. This patch reimplements ata_scsi_device_suspend()
and ata_scsi_device_resume() such that they request EH to perform the
respective operations. Both functions synchronize with hotplug such
that it doesn't operate on detached devices.
Suspend waits for completion but resume just issues request and
returns. This allows parallel wake up of devices and thus speeds up
system resume.
Due to sdev detach synchronization, it's not feasible to separate out
EH requesting from sdev handling; thus, ata_device_suspend/resume()
are removed and everything is implemented in the respective
libata-scsi functions.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Implement ATA_EHI_RESUME_LINK, which indicates that the link needs to
be resumed. This used to be implied by ATA_EHI_HOTPLUGGED. However,
hotplug isn't the only event which requires link resume and separating
this out allows other places to request link resume. This
differentiation also allows better debounce timing selection.
This patch converts user scan to use ATA_EHI_RESUME_LINK.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ap->flags is way too clamped. Separate out core dynamic flags to
ap->pflags. ATA_FLAG_DISABLED is a dynamic flag but left alone as
it's referenced by a lot of LLDs and it's gonna be removed once all
LLDs are converted to new EH.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Separate out parts of ata_scsi_find_dev to be reused in
future SAS/SATA patches.
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Prepare for changes required to support SATA devices
attached to SAS HBAs. For these devices we don't want to
use host_set at all, since libata will not be the owner
of struct scsi_host.
Signed-off-by: Brian King <brking@us.ibm.com>
(with slight merge modifications made by...)
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Depending on timing, ata_scsi_dev_rescan() might encounter a device
which is enabled but not yet attached to sdev. On such cases, the
original code caused oops. This patch makes ata_scsi_dev_rescan()
rescan only device which are attached to sdevs.
While at it, properly indent leading comment and add description about
how it's synchronized with sdev attach/detach.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
With Achim patch the last user (gdth) is switched away from scsi_request
so we an kill it now. Also disables some code in i2o_scsi that was
broken since the sg driver stopped using scsi_requests.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Various scsi drivers use scsi_cmnd.buffer and scsi_cmnd.bufflen in their
queuecommand functions. Those fields are internal storage for the
midlayer only and are used to restore the original payload after
request_buffer and request_bufflen have been overwritten for EH. Using
the buffer and bufflen fields means they do very broken things in error
handling.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Implement warmplug. User-initiated unplug can be detected by
hostt->slave_destroy() and plug by transportt->user_scan(). This
patch only implements the two callbacks. The next function will hook
them.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Implement SCSI part of hotplug.
This must be done in a separate context as SCSI makes use of EH during
probing. SCSI scan fails silently if EH is in progress. In such
cases, libata pauses briefly and retries until every device is
attached.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Implement ata_eh_detach_dev(). This function is responsible for
detaching an ATA device and offlining the associated SCSI device
atomically so that the detached device is not accessed after ATA
detach is complete.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Add device persistent field dev->sdev and store the attached SCSI
device. With hotplug, libata needs to know the attached SCSI device
to offline and detach it, but scsi_device_lookup() cannot be used
because libata will reuse SCSI ID numbers - dead but not gone devices
(due to zombie opens, etc...) interfere with the lookup.
dev->sdev doesn't hold reference to the SCSI device. It's cleared
when the SCSI device goes away.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Separate out ata_find_dev() and __ata_scsi_find_dev() from
ata_scsi_find_dev(). These will be used by later hotplug
implementation.
Signed-off-by: Tejun Heo <htejun@gmail.com>
The upstream tree has the ATA_DFLAG_PIO bug fixed but does not have the
pass throuugh bug fix
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
libata implemented a feature to schedule EH without an associated EH
by manipulating shost->host_eh_scheduled in ata_scsi_schedule_eh()
directly. Move this function to scsi_error.c and rename it to
scsi_schedule_eh(). It is now an exported API for SCSI transports and
exported via new header file drivers/scsi/scsi_transport_api.h
This patch also de-export scsi_eh_wakeup() which was exported
specifically for ata_scsi_schedule_eh().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Now that all NCQ related stuff are in place, implement NCQ device
configuration and bump ATA_MAX_QUEUE to 32 thus activating NCQ
support.
Original implementation is from Jens Axboe.
Signed-off-by: Tejun Heo <htejun@gmail.com>
This patch implements NCQ command translation and exclusion. Note
that NCQ commands don't use ata_rwcmd_protocol() to choose ATA
command. This is because, unlike non-NCQ RW commands, NCQ commands
can only be used for NCQ protocol and FUA handling is done with a flag
rather than separate command.
NCQ enabled device will have queue depth larger than one but no two
non-NCQ commands can be issued simultaneously, neither can a non-NCQ
command and NCQ commands. This patch makes ata_scsi_translate()
return SCSI_MLQUEUE_DEVICE_BUSY if such exclusion is necessary. SCSI
midlayer will retry the command later.
As SCSI midlayer always retries once a command completes, this doesn't
incur unnecessary delays and as most commands will be NCQ ones for NCQ
device, so the overhead should be negligible.
Initial implementation is from Jens Axboe and using
SCSI_MLQUEUE_DEVICE_BUSY for exclusion is suggested by Jeff Garzik.
Signed-off-by: Tejun Heo <htejun@gmail.com>
ata_scsi_translate() will need to return SCSI_ML_QUEUE_DEVICE_BUSY to
achieve exlusion between NCQ and non-NCQ commands or among non-NCQ
commands. Pass its return value upward to SCSI midlayer.
Signed-off-by: Tejun Heo <htejun@gmail.com>
SCSI command completion path used to do some part of EH including
printing messages and obtaining sense data. With new EH, all these
are responsibilities of the EH, update SCSI command completion path to
reflect this.
Signed-off-by: Tejun Heo <htejun@gmail.com>
ata_port_schedule_eh() directly schedules EH for @ap without
associated qc. Once EH scheduled, no further qc is allowed and EH
kicks in as soon as all currently active qc's are drained.
ata_port_abort() schedules all currently active commands for EH by
qc_completing them with ATA_QCFLAG_FAILED set. If ata_port_abort()
doesn't find any qc to abort, it directly schedule EH using
ata_port_schedule_eh().
These two functions provide ways to invoke EH for conditions which
aren't directly related to any specfic qc.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Add qc->result_tf and ATA_QCFLAG_RESULT_TF. This moves the
responsibility of loading result TF from post-compltion path to qc
execution path. qc->result_tf is loaded if explicitly requested or
the qc failsa. This allows more efficient completion implementation
and correct handling of result TF for controllers which don't have
global TF representation such as sil3124/32.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Overriding the whole EH code is a per-transport, not per-host thing.
Move ->eh_strategy_handler to the transport class, same as
->eh_timed_out.
Downside is that scsi_host_alloc can't check for the total lack of EH
anymore, but the transition period from old EH where we needed it is
long gone already.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Convert the ATAPI_ENABLE_DMADIR compile time option needed
by some SATA-PATA bridge to runtime module parameter.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
A lot of EH codes are about to be added to libata. Separate out
libata-eh.c. ata_scsi_timed_out(), ata_scsi_error(),
ata_qc_timeout(), ata_eng_timeout(), ata_eh_qc_complete() and
ata_eh_qc_retry() are moved. No code is changed by this patch.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
qcs might get retried because of unrelated failure. e.g. NCQ command
failure causes the whole command set to be aborted. Decrement
scmd->retries for such retrials to avoid unnecessarily failing
commands. Note that scmd->retries will be incremented the first time.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
TF register might not be directly accessible depending on errors.
e.g. TF of failed NCQ command is in log page 10h. Make reading TF
responsibility of error handlers. For the current EH, simply push TF
reading into qc completion functions as they are practically part of
EH. New EH will fill qc->tf with status registers before complting
qcs.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Current sense generation code does not generate sense error if status
register value doesn't indicate error condition. However, LLDD's may
indicate errors which 't show up in status register. Completing such
qc's without generating sense results in successful completion of
failed commands.
Invoke ata_to_sense_error() regardless of status register if
qc->err_mask is not zero such that ata_to_sense_error() generates
default sense error.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Add a new qc flag ATA_QCFLAG_IO. This flag gets set for normal IO
commands originating from SCSI midlayer. This information will be
used by EH to determine transfer speed reconfiguration.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Rename ATA_FLAG_PORT_DISABLED to ATA_FLAG_DISABLED for consistency.
(ATA_FLAG_* are always about ports).
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch renames ata_dev_present() to ata_dev_enabled() and adds
ata_dev_disabled(). This is to discern the state where a device is
present but disabled from not-present state. This disctinction is
necessary when configuring transfer mode because device selection
timing must not be violated even if a device fails to configure.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
There is no reason for the issuer to diddle with a failed qc as the
issuer has complete control over when a qc gets freed (usually in
->complete_fn). Make ata_qc_issue() responsible for completing qcs
which failed to issue.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
In preparation for SAS, kill some unnecessary code in ata_scsi_ioctl
to find the ATA port and device given the scsi_device. Neither local
is used in the function.
Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Encapsulate part of ata_scsi_queuecmd so that it can be
reused by future SAS patches.
Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
