sas_device objects can be referenced concurrently throughout the driver.
We need a way to make sure threads can't delete them out from under each
other. This patch adds the refcount and refactors the code to use it.
Additionally, we cannot iterate over the sas_device_list without holding
the lock or we risk corrupting random memory if items are added or
deleted as we iterate. This patch refactors _scsih_probe_sas() to use
the sas_device_list in a safe way.
This patch is ported from the following mpt2sas driver commit
d224fe0d60 ("mpt2sas: Refcount sas_device objects and fix unsafe list
usage").
Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Added dma_mapping_error() API after mapping an address with dma_map_single()
API. Otherwise when CONFIG_DMA_API_DEBUG is enabled in the kernel, then it
complains about mpt3sas driver not calling dma_mapping_error after mapping an
address with dma_map_single
Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
During hot-plugging of a disk(having a flaky link), the disk addition
stops and any further disk addition or removal doesn't happen on that
controller.
This is because, when driver receives DELAY_NOT_RESPONDING event for a disk
while it is undergoing addition at the SCSI Transport layer, the driver
would block the I/O to that disk resulting in a deadlock. i.e the disk
addition work couldn't be completed at the SCSI Transport Layer as it
can't send any I/Os (such as Inquiry, Report LUNs etc) to the disk as
I/Os are blocked to this drive. Also any subsequent device removal
(TARGET_NOT_RESPONDING) or link update(RC_PHY_CHANGED) event couldn't be
processed as they are in the queue to get processed after disk addition
event.
Description of Change:
Don't block the drive when drive addition is under the control of SML.
So that SML won't be blocked of issuing the device dicovery commands
(such as Inquiry, Report LUNs etc).
Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Copyright, Trademark & Confidentiality legal statements throughout the
source code changed from LSI to Avago.
Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This reverts commit 963ba22b90
("mpt3sas: Remove phys on topology change")
Reverting the previous mpt3sas drives patch changes,
since we will observe below issue
Issue:
Drives connected Enclosure/Expander will unregister with
SCSI Transport Layer, if any one remove and add expander
cable with in DMD (Device Missing Delay) time period or
even any one power-off and power-on the Enclosure with in
the DMD period.
Cc: <stable@vger.kernel.org>
Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When we start sharing biovecs, keeping bi_vcnt accurate for splits is
going to be error prone - and unnecessary, if we refactor some code.
So bio_segments() has to go - but most of the existing users just needed
to know if the bio had multiple segments, which is easier - add a
bio_multiple_segments() for them.
(Two of the current uses of bio_segments() are going to go away in a
couple patches, but the current implementation of bio_segments() is
unsafe as soon as we start doing driver conversions for immutable
biovecs - so implement a dumb version for bisectability, it'll go away
in a couple patches)
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
These driver files are initially, substantially similar to mpt2sas but,
because mpt2sas is going into maintenance mode and mp3sas will become heavily
developed, we elected to keep the code bases separate.
Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Reviewed-by: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
