Commit Graph

241 Commits

Author SHA1 Message Date
scameron@beardog.cce.hp.com
67c99a72e3 [SCSI] hpsa: fix NULL dereference in hpsa_put_ctlr_into_performant_mode()
Initialize local variable trans_support before it is used rather
than after.  It is supposed to contain the value of a register on the
controller containing bits that describe which transport modes the
controller supports (e.g. "performant", "ioaccel1",  "ioaccel2").  A
NULL pointer dereference will almost certainly occur if trans_support
is not initialized at the right point.  If for example the uninitialized
trans_support value does not have the bit set for ioaccel2 support when it
should be, then ioaccel2_alloc_cmds_and_bft() will not get called as it
should be and the h->ioaccel2_blockFetchTable array will remain NULL
instead of being allocated.  Too late, trans_support finally gets
initialized with the correct value with ioaccel2 mode bit set,
which later causes calc_bucket_map() to be called to fill in
h->ioaccel2_blockFetchTable[].  However h->ioaccel2_blockFetchTable
is NULL because it didn't get allocated because earlier trans_support
wasn't initialized at the right point.

Fixes: e1f7de0cdd
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reported-by: Baoquan He <bhe@redhat.com>
Tested-by: Baoquan He <bhe@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-04-21 07:56:53 -07:00
Stephen M. Cameron
9a993302cc [SCSI] hpsa: update driver version to 3.4.4-1
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-19 15:16:07 -07:00
Stephen M. Cameron
000ff7c25a [SCSI] hpsa: fix bad endif placement in RAID 5 mapper code
It caused the i/o request to always be counted as ineligible for
the accelerated i/o path on 32 bit systems and negatively affected
performance.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-19 15:16:06 -07:00
Stephen M. Cameron
df03c3f628 [SCSI] hpsa: Do not zero fields of ioaccel2 command structure twice
Structure was already memset to zero at the top
of hpsa_scsi_ioaccel2_queue_command

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:24 -07:00
Stephen M. Cameron
316b221a37 [SCSI] hpsa: Add hba mode to the hpsa driver
This allows exposing physical disks behind Smart
Array controllers to the OS (if the controller
has the right firmware and is in "hba" mode)

Signed-off-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:23 -07:00
Tomas Henzl
8919358e3d [SCSI] hpsa: increase the probability of a reported success after a device reset
rc is set in the loop, and it isn't set back to zero anywhere
this patch fixes it

Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:23 -07:00
Stephen M. Cameron
9846590eda [SCSI] hpsa: bring format-in-progress drives online when ready
Do not expose drives that are undergoing a format immediately
to the OS, instead wait until they are ready before bringing
them online.  This is so that logical drives created with
"rapid parity initialization" do not get immediately kicked
off the system for being unresponsive.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:23 -07:00
Stephen M. Cameron
9f02e5bc60 [SCSI] hpsa: remove unused kthread.h header
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:23 -07:00
Stephen M. Cameron
8e616a5ee6 [SCSI] hpsa: Add support for a few HP Storage controllers
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:10 -07:00
Stephen M. Cameron
2ba8bfc82e [SCSI] hpsa add sysfs debug switch for raid map debugging messages
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:09 -07:00
Stephen M. Cameron
d1e8beac49 [SCSI] hpsa: improve error messages for driver initiated commands
On encountering unexpected error conditions from driver initiated
commands, print something useful like CDB and sense data rather than
something useless like the kernel virtual address of the command buffer.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:09 -07:00
Stephen M. Cameron
faff6ee053 [SCSI] hpsa: only do device rescan for certain events
Do no rescan on every events -- way too many rescans are
triggered if we don't filter the events.  Limit rescans
to be triggered by the following set of events:

 * controller state change
 * enclosure hot plug
 * physical drive state change
 * logical drive state change
 * redundant controller state change
 * accelerated io enabled/disabled
 * accelerated io configuration change

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:09 -07:00
Stephen M. Cameron
23100dd96a [SCSI] hpsa: when switching out of accel mode await only accel command completions
Don't wait for *all* commands to complete, only for accelerated mode
commands.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:08 -07:00
Scott Teel
dd0e19f3ce [SCSI] hpsa: add controller base data-at-rest encryption compatibility ioaccel2
Add controller-based data-at-rest encryption compatibility
to ioaccel2 path (HP SSD Smart Path).

Encryption feature requires driver to supply additional fields
for encryption enable, tweak index, and data encryption key index
in the ioaccel2 request structure.

Encryption enable flag and data encryption key index come from
raid_map data structure from raid offload command.

During ioaccel2 submission, check device structure's raid map to see if
encryption is enabled for the device. If so, call new function below.

Add function set_encrypt_ioaccel2 to set encryption flag, data encryption key
index, and calculate tweak value from request's logical block address.

Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:08 -07:00
Scott Teel
51c35139e1 [SCSI] hpsa: update source file copyrights
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:08 -07:00
Scott Teel
a09c1441e4 [SCSI] hpsa: retry certain ioaccel error cases on the RAID path
Change the handling of HP SSD Smart Path errors with status:
  0x02 CHECK CONDITION
  0x08 BUSY
  0x18 RESERVATION CONFLICT
  0x40 TASK ABORTED
So that they get retried on the RAID Path.

Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:08 -07:00
Stephen M. Cameron
1b70150af5 [SCSI] hpsa: do not inquire for unsupported ioaccel status vpd page
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:07 -07:00
Stephen M. Cameron
b7bb24eb4e [SCSI] hpsa: allow VPD page zero to be queried
Code was confused and assumed that page zero was not
VPD page and all non-zero pages were VPD pages.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:07 -07:00
Scott Teel
e863d68e48 [SCSI] hpsa: rescan devices on ioaccel2 error
Allow driver to schedule a rescan whenever a request fails on the ioaccel2 path.
This eliminates the possibility of driver getting stuck in non-ioaccel mode.

IOaccel mode (HP SSD Smart Path) is disabled by driver upon error detection.
Driver relied on idea that request would be retried through normal path, and a
subsequent error would occur on that path, and be processed by controller
firmware.  As part of that process, controller disables ioaccel mode and later
reinstates it, signalling driver to change modes.

In some error cases, the error will not duplicate on the standard path,
so the driver could get stuck in non-ioaccel mode.
To avoid that, we allow driver to request a rescan during the next run of the
rescan thread.

Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:07 -07:00
Scott Teel
da0697bd30 [SCSI] hpsa: allow user to disable accelerated i/o path
Allow SSD Smart Path for a controller to be disabled by
the user, regardless of settings in controller firmware
or array configuration.

To disable:     echo 0 > /sys/class/scsi_host/host<id>/acciopath_status
To re-enable:   echo 1 > /sys/class/scsi_host/host<id>/acciopath_status
To check state: cat /sys/class/scsi_host/host<id>/acciopath_status

Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:07 -07:00
Scott Teel
6b80b18fe5 [SCSI] hpsa: complete the ioaccel raidmap code
Load balance across members of a N-way mirror set, and
handle the meta-RAID levels: R10, R50, R60.

Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:07 -07:00
Stephen M. Cameron
9fb0de2d12 [SCSI] hpsa: make device update copy the raid map also
Otherwise we could wind up using incorrect raid map data, and
then very bad things would likely happen.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:06 -07:00
Scott Teel
54b6e9e97a [SCSI] hpsa: add task management for ioaccel mode 2
Underlying firmware cannot handle task abort on accelerated path (SSD Smart Path).
Change abort requests for accelerated path commands to physical target reset.
Send reset request on normal IO path.

Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:06 -07:00
Scott Teel
bf711ac654 [SCSI] hpsa: teach hpsa_device_reset to do either target or lun reset
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:06 -07:00
Scott Teel
c349775e4c [SCSI] hpsa: get ioaccel mode 2 i/o working
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Joe Handzik <Joseph.T.Handzik@hp.com>
Signed-off-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:06 -07:00
Stephen M. Cameron
b9af4937e6 [SCSI] hpsa: initialize controller to perform io accelerator mode 2
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:05 -07:00
Mike MIller
317d4adfd3 [SCSI] hpsa: get physical device handles for io accel mode 2 as well as mode 1
Signed-off-by: Mike MIller <michael.miller@canonical.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:05 -07:00
Stephen M. Cameron
aca9012a41 [SCSI] hpsa: do ioaccel mode 2 resource allocations
Signed-off-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:05 -07:00
Stephen M. Cameron
1f7cee8c7d [SCSI] hpsa: Acknowledge controller events in ioaccell mode 2 as well as mode 1
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:05 -07:00
Mike Miller
b66cc250ee [SCSI] hpsa: add ioaccel mode 2 structure definitions
Signed-off-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:04 -07:00
Scott Teel
0e7a7fcea0 [SCSI] hpsa: complain if physical or logical aborts are not supported
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:04 -07:00
Scott Teel
c1988684bb [SCSI] hpsa: add hp_ssd_smart_path_enabled sysfs attribute
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:04 -07:00
Stephen M. Cameron
5f38936055 [SCSI] hpsa: do not rescan controllers known to be locked up
* Do not check event bits on locked up controllers to
  see if they need to be rescanned.
* Do not initiate any device rescans on controllers
  which are known to be locked up.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:04 -07:00
Stephen M. Cameron
76438d087f [SCSI] hpsa: poll controller to detect device change event
For shared SAS configurations, hosts need to poll Smart Arrays
periodically in order to be able to detect configuration changes
such as logical drives being added or removed from remote hosts.
A register on the controller indicates when such events have
occurred, and the driver polls the register via a workqueue
and kicks off a rescan of devices if such an event is detected.
Additionally, changes to logical drive raid offload eligibility
are autodetected in this way.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:04 -07:00
Stephen M. Cameron
250fb125ff [SCSI] hpsa: update raid offload status on device rescan
When rescanning for logical drives, store information about whather
raid offload is enabled for each logical drive, and update the driver's
internal record of this.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:03 -07:00
Stephen M. Cameron
283b4a9b98 [SCSI] hpsa: add ioaccell mode 1 RAID offload support.
This enables sending i/o's destined for RAID logical drives
which can be serviced by a single physical disk down a different,
faster i/o path directly to physical drives for certain logical
volumes on SSDs bypassing the Smart Array RAID stack for a
performance improvement.

Signed-off-by: Matt Gates <matthew.gates@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Don Brace <brace@beardog.cce.hp.com>
Signed-off-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:03 -07:00
Scott Teel
17eb87d216 [SCSI] hpsa: fix task management for mode-1 ioaccell path
For "mode 1" io accelerated commands, the command tag is in
a different location than for commands that go down the normal
RAID path, so the abort handler needs to take this into account.

Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:03 -07:00
Stephen M. Cameron
2f6ae5cd24 [SCSI] hpsa: only allow REQ_TYPE_FS to use fast path
When commands sent down the "fast path" fail, they must be re-tried down the
normal RAID path.  We do this by kicking i/o's back to the scsi mid layer with
a DID_SOFT_ERROR status, which causes them to be retried.  This won't work for
SG_IO's and other non REQ_TYPE_FS i/o's which could get kicked all the way back
to the application, which may have no idea that the command needs resubmitting
and likely no way to resubmit it in such a way the that driver can recognize it
as a resubmit and send it down the normal RAID path.  So we just always send
non REQ_TYPE_FS i/o's down the normal RAID path, never down the "fast path".

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:03 -07:00
Matt Gates
e1f7de0cdd [SCSI] hpsa: add support for 'fastpath' i/o
For certain i/o's to certain devices (unmasked physical disks) we
can bypass the RAID stack firmware and do the i/o to the device
directly and it will be faster.

Signed-off-by: Matt Gates <matthew.gates@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:02 -07:00
Matt Gates
e1d9cbfa09 [SCSI] hpsa: mark last scatter gather element as the last
This is normally optional, but for SSD Smart Path support (in
subsequent patches) it is required.

Signed-off-by: Matt Gates <matthew.gates@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:01 -07:00
Matt Gates
a93aa1fe00 [SCSI] hpsa: use extended report luns command for HP SSD SmartPath
There is an extended report luns command which contains
additional information about physical devices.  In particular
we need to get the physical device handle so we can use an
alternate i/o path for fast physical devices like SSDs so
we can speed up certain i/o's by bypassing the RAID stack
code in the controller firmware.

Signed-off-by: Matt Gates <matthew.gates@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:01 -07:00
Hannes Reinecke
eee0f03a54 [SCSI] hpsa: fixup MSI-X registration
Commit 254f796b9f updated
the driver to use 16 MSI-X vectors, despite the fact that
older controllers would provide only 4.
This was causing MSI-X registration to drop down to INTx
mode. But as the controller support performant mode, the
initialisation will become confused and cause the machine
to stall during boot.

This patch fixes up the MSI-X registration to re-issue
the pci_enable_msix() call with the correct number of
MSI-X vectors. With that the hpsa driver continues to
works on older controllers like the P200.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:01 -07:00
Matt Gates
3ce438df10 [SCSI] hpsa: allow SCSI mid layer to handle unit attention
We were clobbering the SCSI status and setting
cmd->result = DID_SOFT_ERROR << 16; to get a retry,
but better to let the mid layer handle the unit
attention.

Signed-off-by: Matt Gates <matthew.gates@hp.com>
Acked-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 20:56:30 -08:00
Stephen M. Cameron
0ddf1d7750 [SCSI] hpsa: do not require board "not ready" status after hard reset
Immediately following a hard board reset, There are some
mandatory delays during which we must not access the board
and during which we might miss the "not ready" status,
therefore it is a mistake to look for and expect to see
the "not ready" status.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 20:56:30 -08:00
Stephen M. Cameron
28e1344647 [SCSI] hpsa: enable unit attention reporting
This used to be the default, but at some point the firmware guys
changed the default and I failed to notice.  Now to get unit
attention notifications, you must twiddle a bit indicating you
want them.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 20:56:30 -08:00
Stephen M. Cameron
97a5e98c1b [SCSI] hpsa: rename scsi prefetch field
The field contains more bits than just the one
to indicate whether scsi prefetch should be turned on.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 20:56:29 -08:00
Stephen M. Cameron
8a98db7386 [SCSI] hpsa: use workqueue instead of kernel thread for lockup detection
Much simpler and avoids races starting/stopping the thread.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 20:56:29 -08:00
Mike Miller
d5747e0aa0 [SCSI] hpsa: remove P822se PCI ID
Remove PCI ID for the never shipped P822se.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 07:39:04 -08:00
Stephen M. Cameron
396883e292 [SCSI] hpsa: prevent stalled i/o
If a fifo full condition is encountered, i/o requests will stack
up in the h->reqQ queue.  The only thing which empties this queue
is start_io, which only gets called when new i/o requests come in.
If none are forthcoming, i/o in h->reqQ will be stalled.

To fix this, whenever fifo full condition is encountered, this
is recorded, and the interrupt handler examines this to see
if a fifo full condition was recently encountered when a
command completes and will call start_io to prevent i/o's in
h->reqQ from getting stuck.

I've only ever seen this problem occur when running specialized
test programs that pound on the the CCISS_PASSTHRU ioctl.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 07:38:56 -08:00
Stephen M. Cameron
0390f0c0df [SCSI] hpsa: cap CCISS_PASSTHRU at 20 concurrent commands.
Cap CCISS_BIG_PASSTHRU as well.  If an attempt is made
to exceed this, ioctl() will return -1 with errno == EAGAIN.

This is to prevent a userland program from exhausting all of
pci_alloc_consistent memory.  I've only seen this problem when
running a special test program designed to provoke it.  20
concurrent commands via the passthru ioctls (not counting SG_IO)
should be more than enough.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 07:38:56 -08:00