Commit Graph

946 Commits

Author SHA1 Message Date
Linus Torvalds
1a0b6abaea Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull first round of SCSI updates from James Bottomley:
 "This patch consists of the usual driver updates (megaraid_sas,
  scsi_debug, qla2xxx, qla4xxx, lpfc, bnx2fc, be2iscsi, hpsa, ipr) plus
  an assortment of minor fixes and the first precursors of SCSI-MQ (the
  code path simplifications) and the bug fix for the USB oops on remove
  (which involves an infrastructure change, so is sent via the main tree
  with a delayed backport after a cycle in which it is shown to
  introduce no new bugs)"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (196 commits)
  [SCSI] sd: Quiesce mode sense error messages
  [SCSI] add support for per-host cmd pools
  [SCSI] simplify command allocation and freeing a bit
  [SCSI] megaraid: simplify internal command handling
  [SCSI] ses: Use vpd information from scsi_device
  [SCSI] Add EVPD page 0x83 and 0x80 to sysfs
  [SCSI] Return VPD page length in scsi_vpd_inquiry()
  [SCSI] scsi_sysfs: Implement 'is_visible' callback
  [SCSI] hpsa: update driver version to 3.4.4-1
  [SCSI] hpsa: fix bad endif placement in RAID 5 mapper code
  [SCSI] qla2xxx: Fix build errors related to invalid print fields on some architectures.
  [SCSI] bfa: Replace large udelay() with mdelay()
  [SCSI] vmw_pvscsi: Some improvements in pvscsi driver.
  [SCSI] vmw_pvscsi: Add support for I/O requests coalescing.
  [SCSI] vmw_pvscsi: Fix pvscsi_abort() function.
  [SCSI] remove deprecated IRQF_DISABLED from SCSI
  [SCSI] bfa: Updating Maintainers email ids
  [SCSI] ipr: Add new CCIN definition for Grand Canyon support
  [SCSI] ipr: Format HCAM overlay ID 0x21
  [SCSI] ipr: Use pci_enable_msi_range() and pci_enable_msix_range()
  ...
2014-04-01 18:49:04 -07:00
Christoph Hellwig
89d9a56795 [SCSI] add support for per-host cmd pools
This allows drivers to specify the size of their per-command private
data in the host template and then get extra memory allocated for
each command instead of needing another allocation in ->queuecommand.

With the current SCSI code that already does multiple allocations for
each command this probably doesn't make a big performance impact, but
it allows to clean up the drivers, and prepare them for using the
blk-mq infrastructure where the common allocation will make a difference.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-27 08:26:33 -07:00
Christoph Hellwig
0f2bb84d2a [SCSI] megaraid: simplify internal command handling
We don't use the passed in scsi command for anything, so just add a adapter-
wide internal status to go along with the internal scb that is used unter
int_mtx to pass back the return value and get rid of all the complexities
and abuse of the scsi_cmnd structure.

This gets rid of the only user of scsi_allocate_command/scsi_free_command,
which can now be removed.

[jejb: checkpatch fixes]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-27 08:26:31 -07:00
Hannes Reinecke
b3ae8780b4 [SCSI] Add EVPD page 0x83 and 0x80 to sysfs
EVPD page 0x83 is used to uniquely identify the device.
So instead of having each and every program issue a separate
SG_IO call to retrieve this information it does make far more
sense to display it in sysfs.

Some older devices (most notably tapes) will only report reliable
information in page 0x80 (Unit Serial Number). So export this
in the sysfs attribute 'vpd_pg80'.

[jejb: checkpatch fix]
[hare: attach after transport configure]
[fengguang.wu@intel.com: spotted problems with the original now fixed]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-27 08:25:33 -07:00
Dan Williams
bc6e7c4b0d libata, libsas: kill pm_result and related cleanup
Tejun says:
  "At least for libata, worrying about suspend/resume failures don't make
   whole lot of sense.  If suspend failed, just proceed with suspend.  If
   the device can't be woken up afterwards, that's that.  There isn't
   anything we could have done differently anyway.  The same for resume, if
   spinup fails, the device is dud and the following commands will invoke
   EH actions and will eventually fail.  Again, there really isn't any
   *choice* to make.  Just making sure the errors are handled gracefully
   (ie. don't crash) and the following commands are handled correctly
   should be enough."

The only libata user that actually cares about the result from a suspend
operation is libsas.  However, it only cares about whether queuing a new
operation collides with an in-flight one.  All libsas does with the
error is retry, but we can just let libata wait for the previous
operation before continuing.

Other cleanups include:
1/ Unifying all ata port pm operations on an ata_port_pm_ prefix
2/ Marking all ata port pm helper routines as returning void, only
   ata_port_pm_ entry points need to fake a 0 return value.
3/ Killing ata_port_{suspend|resume}_common() in favor of calling
   ata_port_request_pm() directly
4/ Killing the wrappers that just do a to_ata_port() conversion
5/ Clearly marking the entry points that do async operations with an
  _async suffix.

Reference: http://marc.info/?l=linux-scsi&m=138995409532286&w=2

Cc: Phillip Susi <psusi@ubuntu.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Todd Brandt <todd.e.brandt@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-03-18 16:08:38 -04:00
Christoph Hellwig
0479633686 [SCSI] do not manipulate device reference counts in scsi_get/put_command
Many callers won't need this and we can optimize them away.  In addition
the handling in the __-prefixed variants was inconsistant to start with.

Based on an earlier patch from Bart Van Assche.

[jejb: fix kerneldoc probelm picked up by Fengguang Wu]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:24 -07:00
Shlomo Pongratz
659743b02c [SCSI] libiscsi: Reduce locking contention in fast path
Replace the session lock with two locks, a forward lock and
a backwards lock named frwd_lock and back_lock respectively.

The forward lock protects resources that change while sending a
request to the target, such as cmdsn, queued_cmdsn, and allocating
task from the commands' pool with kfifo_out.

The backward lock protects resources that change while processing
a response or in error path, such as cmdsn_exp, cmdsn_max, and
returning tasks to the commands' pool with kfifo_in.

Under a steady state fast-path situation, that is when one
or more processes/threads submit IO to an iscsi device and
a single kernel upcall (e.g softirq) is dealing with processing
of responses without errors, this patch eliminates the contention
between the queuecommand()/request response/scsi_done() flows
associated with iscsi sessions.

Between the forward and the backward locks exists a strict locking
hierarchy. The mutual exclusion zone protected by the forward lock can
enclose the mutual exclusion zone protected by the backward lock but not
vice versa.

For example, in iscsi_conn_teardown or in iscsi_xmit_data when there is
a failure and __iscsi_put_task is called, the backward lock is taken while
the forward lock is still taken. On the other hand, if in the RX path a nop
is to be sent, for example in iscsi_handle_reject or __iscsi_complete_pdu
than the forward lock is released and the backward lock is taken for the
duration of iscsi_send_nopout, later the backward lock is released and the
forward lock is retaken.

libiscsi_tcp uses two kernel fifos the r2t pool and the r2t queue.

The insertion and deletion from these queues didn't corespond to the
assumption taken by the new forward/backwards session locking paradigm.

That is, in iscsi_tcp_clenup_task which belongs to the RX (backwards)
path, r2t is taken out from r2t queue and inserted to the r2t pool.
In iscsi_tcp_get_curr_r2t which belong to the TX (forward) path, r2t
is also inserted to the r2t pool and another r2t is pulled from r2t
queue.

Only in iscsi_tcp_r2t_rsp which is called in the RX path but can requeue
to the TX path, r2t is taken from the r2t pool and inserted to the r2t
queue.

In order to cope with this situation, two spin locks were added,
pool2queue and queue2pool. The former protects extracting from the
r2t pool and inserting to the r2t queue, and the later protects the
extracing from the r2t queue and inserting to the r2t pool.

Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
[minor fix up to apply cleanly and compile fix]
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:19:18 -07:00
James Bottomley
e63ed0d7a9 [SCSI] fix our current target reap infrastructure
This patch eliminates the reap_ref and replaces it with a proper kref.
On last put of this kref, the target is removed from visibility in
sysfs.  The final call to scsi_target_reap() for the device is done from
__scsi_remove_device() and only if the device was made visible.  This
ensures that the target disappears as soon as the last device is gone
rather than waiting until final release of the device (which is often
too long).

Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org # delay backport by 2 months for field testing
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:18:59 -07:00
Dan Williams
3af74a3c07 [SCSI] libsas: introduce scmd_dbg() to quiet false positive "timeout" messages
libsas sometimes short circuits timeouts to force commands into error
recovery.  It is misleading to log that the command timed-out in
sas_scsi_timed_out() when in fact it was just queued for error handling.
It's also redundant in the case of a true timeout as libata eh will
detect and report timeouts via it's AC_ERR_TIMEOUT facility.

Given that some environments consider "timeout" errors to be indicative
of impending device failure demote the sas_scsi_timed_out() timeout
message to be disabled by default.  This parallels ata_scsi_timed_out().

[jejb: checkpatch fix]
Reported-by: Xun Ni <xun.ni@intel.com>
Tested-by: Nelson Cheng <nelson.cheng@intel.com>
Acked-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:18:53 -07:00
Chad Dupuis
624f28be81 [SCSI] scsi_transport_fc: Add 32Gbps speed definition.
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15 10:17:50 -07:00
Linus Torvalds
4e13c5d021 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "The highlights this round include:

  - add support for SCSI Referrals (Hannes)
  - add support for T10 DIF into target core (nab + mkp)
  - add support for T10 DIF emulation in FILEIO + RAMDISK backends (Sagi + nab)
  - add support for T10 DIF -> bio_integrity passthrough in IBLOCK backend (nab)
  - prep changes to iser-target for >= v3.15 T10 DIF support (Sagi)
  - add support for qla2xxx N_Port ID Virtualization - NPIV (Saurav + Quinn)
  - allow percpu_ida_alloc() to receive task state bitmask (Kent)
  - fix >= v3.12 iscsi-target session reset hung task regression (nab)
  - fix >= v3.13 percpu_ref se_lun->lun_ref_active race (nab)
  - fix a long-standing network portal creation race (Andy)"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (51 commits)
  target: Fix percpu_ref_put race in transport_lun_remove_cmd
  target/iscsi: Fix network portal creation race
  target: Report bad sector in sense data for DIF errors
  iscsi-target: Convert gfp_t parameter to task state bitmask
  iscsi-target: Fix connection reset hang with percpu_ida_alloc
  percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask
  iscsi-target: Pre-allocate more tags to avoid ack starvation
  qla2xxx: Configure NPIV fc_vport via tcm_qla2xxx_npiv_make_lport
  qla2xxx: Enhancements to enable NPIV support for QLOGIC ISPs with TCM/LIO.
  qla2xxx: Fix scsi_host leak on qlt_lport_register callback failure
  IB/isert: pass scatterlist instead of cmd to fast_reg_mr routine
  IB/isert: Move fastreg descriptor creation to a function
  IB/isert: Avoid frwr notation, user fastreg
  IB/isert: seperate connection protection domains and dma MRs
  tcm_loop: Enable DIF/DIX modes in SCSI host LLD
  target/rd: Add DIF protection into rd_execute_rw
  target/rd: Add support for protection SGL setup + release
  target/rd: Refactor rd_build_device_space + rd_release_device_space
  target/file: Add DIF protection support to fd_execute_rw
  target/file: Add DIF protection init/format support
  ...
2014-01-31 15:31:23 -08:00
Linus Torvalds
08d21b5f93 Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd
Pull exofs and ore fixes from Boaz Harrosh:
 "The main fix here, the first patch, is also destined for -stable.  The
  rest is small trivia and cosmetics.  The ORE patches effect both exofs
  and pnfs-objects very reproducible bugs"

[ ORE is "object raid engine", used by exofs and pnfs  - Linus ]

* 'for-linus' of git://git.open-osd.org/linux-open-osd:
  exofs: Print less in r4w
  exofs: Allow corrupted directory entry to be empty file
  exofs: Allow O_DIRECT open
  ore: Don't crash on NULL bio in _clear_bio
  ore: Fix wrong math in allocation of per device BIO
2014-01-28 10:57:14 -08:00
Linus Torvalds
8e585a6c4a Merge tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband
Pull infiniband updates from Roland Dreier:
 "Main batch of InfiniBand/RDMA changes for 3.14:
   - Flow steering for InfiniBand UD traffic
   - IP-based addressing for IBoE aka RoCE
   - Pass SRP submaintainership from Dave to Bart
   - SRP transport fixes from Bart
   - Add the new Cisco usNIC low-level device driver
   - Various other fixes"

* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: (75 commits)
  IB/mlx5: Verify reserved fields are cleared
  IB/mlx5: Remove old field for create mkey mailbox
  IB/mlx5: Abort driver cleanup if teardown hca fails
  IB/mlx5: Allow creation of QPs with zero-length work queues
  mlx5_core: Fix PowerPC support
  mlx5_core: Improve debugfs readability
  IB/mlx5: Add support for resize CQ
  IB/mlx5: Implement modify CQ
  IB/mlx5: Make sure doorbell record is visible before doorbell
  mlx5_core: Use mlx5 core style warning
  IB/mlx5: Clear out struct before create QP command
  mlx5_core: Fix out arg size in access_register command
  RDMA/nes: Slight optimization of Ethernet address compare
  IB/qib: Fix QP check when looping back to/from QP1
  RDMA/cxgb4: Fix gcc warning on 32-bit arch
  IB/usnic: Remove unused includes of <linux/version.h>
  RDMA/amso1100: Add check if cache memory was allocated before freeing it
  IPoIB: Report operstate consistently when brought up without a link
  IB/core: Fix unused variable warning
  RDMA/cma: Handle global/non-linklocal IPv6 addresses in cma_check_linklocal()
  ...
2014-01-24 17:18:32 -08:00
Boaz Harrosh
aad560b7f6 ore: Fix wrong math in allocation of per device BIO
At IO preparation we calculate the max pages at each device and
allocate a BIO per device of that size. The calculation was wrong
on some unaligned corner cases offset/length combination and would
make prepare return with -ENOMEM. This would be bad for pnfs-objects
that would in that case IO through MDS. And fatal for exofs were it
would fail writes with EIO.

Fix it by doing the proper math, that will work in all cases. (I
ran a test with all possible offset/length combinations this time
round).

Also when reading we do not need to allocate for the parity units
since we jump over them.

Also lower the max_io_length to take into account the parity pages
so not to allocate BIOs bigger than PAGE_SIZE

CC: Stable Kernel <stable@vger.kernel.org>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2014-01-23 10:55:03 +02:00
Bart Van Assche
0c7f82189d scsi_transport_srp: Fix kernel-doc warnings
The following command has been used to verify that the kernel-doc
tool no longer complains about undocumented fields:

    scripts/kernel-doc -html drivers/scsi/scsi_transport_srp.c \
      include/scsi/scsi_transport_srp.h >srp-transport-doc.html

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-01-21 10:46:17 -08:00
Bart Van Assche
93079162bf scsi_transport_srp: Fix a race condition
The rport timers must be stopped before the SRP initiator destroys the
resources associated with the SCSI host. This is necessary because
otherwise the callback functions invoked from the SRP transport layer
could trigger a use-after-free. Stopping the rport timers before
invoking scsi_remove_host() can trigger long delays in the SCSI error
handler if a transport layer failure occurs while scsi_remove_host()
is in progress. Hence move the code for stopping the rport timers from
srp_rport_release() into a new function and invoke that function after
scsi_remove_host() has finished. This patch fixes the following
sporadic kernel crash:

     kernel BUG at include/asm-generic/dma-mapping-common.h:64!
     invalid opcode: 0000 [#1] SMP
     RIP: 0010:[<ffffffffa03b20b1>]  [<ffffffffa03b20b1>] srp_unmap_data+0x121/0x130 [ib_srp]
     Call Trace:
     [<ffffffffa03b20fc>] srp_free_req+0x3c/0x80 [ib_srp]
     [<ffffffffa03b2188>] srp_finish_req+0x48/0x70 [ib_srp]
     [<ffffffffa03b21fb>] srp_terminate_io+0x4b/0x60 [ib_srp]
     [<ffffffffa03a6fb5>] __rport_fail_io_fast+0x75/0x80 [scsi_transport_srp]
     [<ffffffffa03a7438>] rport_fast_io_fail_timedout+0x88/0xc0 [scsi_transport_srp]
     [<ffffffff8108b370>] worker_thread+0x170/0x2a0
     [<ffffffff81090876>] kthread+0x96/0xa0
     [<ffffffff8100c0ca>] child_rip+0xa/0x20

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-01-21 10:46:17 -08:00
Hannes Reinecke
c66094bf32 target_core_alua: Referrals infrastructure
Add infrastructure for referrals.

v2 changes:

 - Fix unsigned long long division in core_alua_state_lba_dependent on
   32-bit  (Fengguang + Chen + Hannes)
 - Fix compile warning in core_alua_state_lba_dependent (nab)
 - Convert segment_* + sectors variables in core_alua_state_lba_dependent
   to u64 (Hannes)

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-01-09 21:48:17 -08:00
Adheer Chandravanshi
ae56ff4084 [SCSI] libiscsi: Add local_ipaddr parameter in iscsi_conn struct
Add local_ipaddr param and support get/set operations on it.

Signed-off-by: Adheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 20:56:26 -08:00
Adheer Chandravanshi
5af62f240b [SCSI] scsi_transport_iscsi: Export ISCSI_PARAM_LOCAL_IPADDR attr for iscsi_connection
This attribute specifies the local IP address used to establish connection.

Signed-off-by: Adheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 20:56:26 -08:00
Lalit Chandivade
6fa7c55438 [SCSI] scsi_transport_iscsi: Add host statistics support
Add transport_iscsi hooks to get aggregate host statistics.
The statistics include MAC, TCP/IP & iSCSI statistics.

Signed-off-by: Lalit Chandivade <lalit.chandivade@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 20:56:25 -08:00
Hannes Reinecke
e494f6a728 [SCSI] improved eh timeout handler
When a command runs into a timeout we need to send an 'ABORT TASK'
TMF. This is typically done by the 'eh_abort_handler' LLDD callback.

Conceptually, however, this function is a normal SCSI command, so
there is no need to enter the error handler.

This patch implements a new scsi_abort_command() function which
invokes an asynchronous function scsi_eh_abort_handler() to
abort the commands via the usual 'eh_abort_handler'.

If abort succeeds the command is either retried or terminated,
depending on the number of allowed retries. However, 'eh_eflags'
records the abort, so if the retry would fail again the
command is pushed onto the error handler without trying to
abort it (again); it'll be cleared up from SCSI EH.

[hare: smatch detected stray switch fixed]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 07:39:02 -08:00
James Bottomley
2451079bc2 [SCSI] Fix erratic device offline during EH
Commit 18a4d0a22e
(Handle disk devices which can not process medium access commands)
was introduced to offline any device which cannot process medium
access commands.
However, commit 3eef6257de
(Reduce error recovery time by reducing use of TURs) reduced
the number of TURs by sending it only on the first failing
command, which might or might not be a medium access command.
So in combination this results in an erratic device offlining
during EH; if the command where the TUR was sent upon happens
to be a medium access command the device will be set offline,
if not everything proceeds as normal.

This patch moves the check to the final test, eliminating
this problem.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19 07:39:02 -08:00
Harish Zunjarrao
3e0f65b34c [SCSI] iscsi_transport: Additional parameters for network settings
Added support to display and update additional network parameters
through iscsiadm.

Signed-off-by: Harish Zunjarrao <harish.zunjarrao@qlogic.com>
Signed-off-by: Adheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-16 10:57:50 -08:00
Harish Zunjarrao
b867cda44e [SCSI] iscsi_transport: Remove net param enum values
Remove explicit values assignment for net param enums.

Signed-off-by: Harish Zunjarrao <harish.zunjarrao@qlogic.com>
Signed-off-by: Adheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-16 10:57:50 -08:00
Martin K. Petersen
54b2b50c20 [SCSI] Disable WRITE SAME for RAID and virtual host adapter drivers
Some host adapters do not pass commands through to the target disk
directly. Instead they provide an emulated target which may or may not
accurately report its capabilities. In some cases the physical device
characteristics are reported even when the host adapter is processing
commands on the device's behalf. This can lead to adapter firmware hangs
or excessive I/O errors.

This patch disables WRITE SAME for devices connected to host adapters
that provide an emulated target. Driver writers can disable WRITE SAME
by setting the no_write_same flag in the host adapter template.

[jejb: fix up rejections due to eh_deadline patch]
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-11-29 08:48:39 +04:00