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: NKent 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 enums have been separate since the dawn of SAS, mainly because the
latter is a procotol only enum and the former includes additional state
for libsas.  The dichotomy causes endless confusion about which one you
should use where and leads to pointless warnings like this:

drivers/scsi/mvsas/mv_sas.c: In function 'mvs_update_phyinfo':
drivers/scsi/mvsas/mv_sas.c:1162:34: warning: comparison between 'enum sas_device_type' and 'enum sas_dev_type' [-Wenum-compare]

Fix by eliminating one of them.  The one kept is effectively the sas.h
one, but call it sas_device_type and make sure the enums are all
properly namespaced with the SAS_ prefix.
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

If a result of the SMP discover function is PHY VACANT,
the content of discover response structure (dr) is not valid.
It sometimes happens that dr->attached_sas_addr can contain
even SAS address of other phy. In such case an invalid phy
is created, what causes NULL pointer dereference during
destruction of expander's phys.

So if a result of SMP function is PHY VACANT, the content of discover
response structure (dr) must not be copied to phy structure.

This patch fixes the following bug:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
IP: [<ffffffff811c9002>] sysfs_find_dirent+0x12/0x90
Call Trace:
  [<ffffffff811c95f5>] sysfs_get_dirent+0x35/0x80
  [<ffffffff811cb55e>] sysfs_unmerge_group+0x1e/0xb0
  [<ffffffff813329f4>] dpm_sysfs_remove+0x24/0x90
  [<ffffffff8132b0f4>] device_del+0x44/0x1d0
  [<ffffffffa016fc59>] sas_rphy_delete+0x9/0x20 [scsi_transport_sas]
  [<ffffffffa01a16f6>] sas_destruct_devices+0xe6/0x110 [libsas]
  [<ffffffff8107ac7c>] process_one_work+0x16c/0x350
  [<ffffffff8107d84a>] worker_thread+0x17a/0x410
  [<ffffffff81081b76>] kthread+0x96/0xa0
  [<ffffffff81464944>] kernel_thread_helper+0x4/0x10
Signed-off-by: NLukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: NPawel Baldysiak <pawel.baldysiak@intel.com>
Reviewed-by: NMaciej Patelczyk <maciej.patelczyk@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

In fact the disc_resp buffer will be overwrite by smp response, so we never
found this typo, correct it by using the right one.
Signed-off-by: NJohn Gong <john_gong@usish.com>
Signed-off-by: NJack Wang <jack_wang@usish.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

More prep work for immutable bvecs/effecient bio splitting - usage of
bi_vcnt has to be auditing, so getting rid of all the unnecessary usage
makes that easier.

Plus, bio_segments() is really what this code wanted, as it respects the
current value of bi_idx.
Signed-off-by: NKent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Eric Moore <Eric.Moore@lsi.com>
CC: "James E.J. Bottomley" <JBottomley@parallels.com>
CC: linux-scsi@vger.kernel.org

Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The timer and the completion are only used for slow path tasks (smp, and
lldd tmfs), yet we incur the allocation space and cpu setup time for
every fast path task.

Cc: Xiangliang Yu <yuxiangl@marvell.com>
Acked-by: NJack Wang <jack_wang@usish.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

commit 198439e4 [SCSI] libsas: do not set res = 0 in sas_ex_discover_dev()
commit 19252de6 [SCSI] libsas: fix wide port hotplug issues

The above commits seem to have confused the return value of
sas_ex_discover_dev which is non-zero on failure and
sas_ex_join_wide_port which just indicates short circuiting discovery on
already established ports.  The result is random discovery failures
depending on configuration.

Calls to sas_ex_join_wide_port are the source of the trouble as its
return value is errantly assigned to 'res'.  Convert it to bool and stop
returning its result up the stack.

Cc: <stable@vger.kernel.org>
Tested-by: NDan Melnic <dan.melnic@amd.com>
Reported-by: NDan Melnic <dan.melnic@amd.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NJack Wang <jack_wang@usish.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Continue running revalidation until no more broadcast devices are
discovered.  Fixes cases where re-discovery completes too early in a
domain with multiple expanders with pending re-discovery events.
Servicing BCNs can get backed up behind error recovery.

Cc: <stable@vger.kernel.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The discovery function "sas_rediscover_dev" had two bugs: 1) it did
not pay attention to the return status from the SMP task execution;
2) the stack variable used for the returned SAS address was compared
against 0 without being initialized.
Signed-off-by: NJeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Normalize phy->attached_sas_addr to return a zero-address in the case
when device-type == NO_DEVICE or the linkrate is invalid to handle
expanders that put non-zero sas addresses in the discovery response:

 sas: ex 5001b4da000f903f phy02:U:0 attached: 0100000000000000 (no device)
 sas: ex 5001b4da000f903f phy01:U:0 attached: 0100000000000000 (no device)
 sas: ex 5001b4da000f903f phy03:U:0 attached: 0100000000000000 (no device)
 sas: ex 5001b4da000f903f phy00:U:0 attached: 0100000000000000 (no device)
Reported-by: NAndrzej Jakowski <andrzej.jakowski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJames 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: NMichal Kosciowski <michal.kosciowski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NJeff Garzik <jgarzik@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The check_ready implementation in the expander-attached ata device case
polls on sas_ex_phy_discover().  The effect is that the ex_phy fields
(critically ->attached_sas_addr) can change.  When ata_eh ends and
libsas comes along to revalidate the domain
sas_unregister_devs_sas_addr() can fail to lookup devices to remove, or
fail to re-add an ata device that ata_eh marked as disabled.  So change
the code to skip the sas_address and change count updates when ata_eh is
active.

Cc: Jack Wang <jack_wang@usish.com>
Tested-by: NMaciej Patelczyk <maciej.patelczyk@intel.com>
Tested-by: NBartek Nowakowski <bartek.nowakowski@intel.com>
Tested-by: NJacek Danecki <jacek.danecki@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Since the domain_device can out live the scsi_target we need the rphy to
follow suit otherwise we run into issues like:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
  IP: [<ffffffffa011561b>] sas_ata_printk+0x43/0x6f [libsas]
  PGD 0
  Oops: 0000 [#1] SMP
  CPU 1
  Modules linked in: ses enclosure isci libsas scsi_transport_sas fuse sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf microcode pcspkr igb joydev iTCO_wdt ioatdma iTCO_vendor_support i2c_i801 i2c_core dca wmi hed ipv6 pata_acpi ata_generic [last unloaded: scsi_wait_scan]

  Pid: 129, comm: kworker/u:3 Not tainted 3.3.0-rc5-isci+ #1 Intel Corporation SandyBridge Platform/To be filled by O.E.M.
  RIP: 0010:[<ffffffffa011561b>] [<ffffffffa011561b>] sas_ata_printk+0x43/0x6f [libsas]
  RSP: 0018:ffff88042232dd70 EFLAGS: 00010282
  RAX: 0000000000000000 RBX: ffff8804283165b8 RCX: ffff88042232dda0
  RDX: ffff88042232dd78 RSI: ffff8804283165b8 RDI: ffffffffa01188d7
  RBP: ffff88042232ddd0 R08: ffff880388454000 R09: ffff8803edfde1f8
  R10: ffff8803edfde1f8 R11: ffff8803edfde1f8 R12: ffff880428316750
  R13: ffff880388454000 R14: ffff8803f88b31d0 R15: ffff8803f8b21d50
  FS: 0000000000000000(0000) GS:ffff88042ee20000(0000) knlGS:0000000000000000
  CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 0000000000000050 CR3: 0000000001a05000 CR4: 00000000000406e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process kworker/u:3 (pid: 129, threadinfo ffff88042232c000, task ffff88042230c920)
  Stack:
  0000000000000000 ffff880400000018 ffff88042232dde0 ffff88042232dda0
  ffffffffa01188c4 ffff88042ee93af0 ffff88042232ddb0 ffffffff8100e047
  ffff88042232de10 ffff880420e5a2c8 ffff8803f8b21d50 ffff8803edfde1f8
  Call Trace:
  [<ffffffff8100e047>] ? load_TLS+0xb/0xf
  [<ffffffffa01156ad>] async_sas_ata_eh+0x66/0x95 [libsas]
  [<ffffffff810655e1>] async_run_entry_fn+0x9e/0x131
Reported-by: NTom Jackson <thomas.p.jackson@intel.com>
Tested-by: NTom Jackson <thomas.p.jackson@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

If an expander reports 'PHY VACANT' for a phy index prior to the one
that generated a BCN libsas fails rediscovery.  Since a vacant phy is
defined as a valid phy index that will never have an attached device
just continue the search.

Cc: <stable@vger.kernel.org>
Signed-off-by: NThomas Jackson <thomas.p.jackson@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

If discovery returns 0 for target_port_protocols but shows an attached
sata device, just report SAS_PROTOCOL_SATA in the identify data so
userspace can reliably search for sata devices in the domain.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames 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: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

If the phy is attached to a new sas address unregister the first address
before processing the new attachment.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames 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: NJack Wang <jack_wang@usish.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

It's difficult to determine which domain_device is triggering error recovery,
so convert messages like:

  sas: ex 5001b4da000e703f phy08:T attached: 5001b4da000e7028
  sas: ex 5001b4da000e703f phy09:T attached: 5001b4da000e7029
  ...
  ata7: sas eh calling libata port error handler
  ata8: sas eh calling libata port error handler

...into:

  sas: ex 5001517e85cfefff phy05:T:9 attached: 5001517e85cfefe5 (stp)
  sas: ex 5001517e3b0af0bf phy11:T:8 attached: 5001517e3b0af0ab (stp)
  ...
  sas: ata7: end_device-21:1: dev error handler
  sas: ata8: end_device-20:0:5: dev error handler

which shows attached link rate, device type, and associates a
domain_device with its ata_port id to correlate messages emitted from
libata-eh.

As Doug notes, we can also take the opportunity to clarify expander phy
routing capabilities.

[dgilbert@interlog.com: clarify table2table with 'U']
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

In the direct-attached case this routine returns the phy on which this
device was first discovered.  Which is broken if we want to support
wide-targets, as this phy reference can become stale even though the
port is still active.

In the expander-attached case this routine tries to lookup the phy by
scanning the attached sas addresses of the parent expander, and BUG_ONs
if it can't find it.  However since eh and the libsas workqueue run
independently we can still be attempting device recovery via eh after
libsas has recorded the device as detached.  This is even easier to hit
now that eh is blocked while device domain rediscovery takes place, and
that libata is fed more timed out commands increasing the chances that
it will try to recover the ata device.

Arrange for dev->phy to always point to a last known good phy, it may be
stale after the port is torn down, but it will catch up for wide port
reconfigurations, and never be NULL.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

No sense in issuing or retrying commands to an expander that has been
removed.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Commit 56dd2c06 "[SCSI] libsas: Don't issue commands to devices that
have been hot-removed" marked the parent device of an end-device as gone
when all the phys to the end device have been deleted.

The expander device is still present until its parent is removed.  This
is a benign change until the smp_execute_task() path is taught to check
->gone.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Use ata_wait_after_reset() to poll for link recovery after a reset.
This combined with sas_ha->eh_mutex prevents expander rediscovery from
probing phys in an intermediate state.  Local discovery does not have a
mechanism to filter link status changes during this timeout, so it
remains the responsibility of lldds to prevent premature port teardown.
Although once all lldd's support ->lldd_ata_check_ready() that could be
used as a gate to local port teardown.

The signature fis is re-transmitted when the link comes back so we
should be revalidating the ata device class, but that is left to a future
patch.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

SAS does not tag SMP requests, and at least one lldd (isci) does not permit
more than one in-flight request at a time.

[jejb: fix sas_init_dev tab issues while we're at it]
Signed-off-by: NJeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames 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: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames 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: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames 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: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

In preparation for adding tracking of another device state "destroy".
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Arrange for the deallocation of a struct domain_device object when it no
longer has:
1/ any children
2/ references by any scsi_targets
3/ references by a lldd

The comment about domain_device lifetime in
Documentation/scsi/libsas.txt is stale as it appears mainline never had
a version of a struct domain_device that was registered as a kobject.
We now manage domain_device reference counts on behalf of external
agents.
Reviewed-by: NJack Wang <jack_wang@usish.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

port->dev_list maintains a list of devices attached to a given sas root port.
It needs to be mutated under a lock as contexts outside of the
single-threaded-libsas-workqueue access the list via sas_find_dev_by_rphy().
Fixup locations where the list was being mutated without a lock.

This is a follow-up to commit 5911e963 "[SCSI] libsas: remove expander
from dev list on error", where Luben noted [1]:

    > 2/ We have unlocked list manipulations in sas_ex_discover_end_dev(),
    > sas_unregister_common_dev(), and sas_ex_discover_end_dev()

    Yes, I can see that and that is very unfortunate.

[1]: http://marc.info/?l=linux-scsi&m=131480962006471&w=2Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

When a wide port is being utilized to a target, if one disables only one
of the
phys, we get an OS crash:

BUG: unable to handle kernel NULL pointer dereference at
0000000000000238
IP: [<ffffffff814ca9b1>] mutex_lock+0x21/0x50
PGD 4103f5067 PUD 41dba9067 PMD 0
Oops: 0002 [#1] SMP
last sysfs file: /sys/bus/pci/slots/5/address
CPU 0
Modules linked in: pm8001(U) ses enclosure fuse nfsd exportfs autofs4
ipmi_devintf ipmi_si ipmi_msghandler nfs lockd fscache nfs_acl
auth_rpcgss 8021q fcoe libfcoe garp libfc scsi_transport_fc stp scsi_tgt
llc sunrpc cpufreq_ondemand acpi_cpufreq freq_table ipv6 sr_mod cdrom
dm_mirror dm_region_hash dm_log uinput sg i2c_i801 i2c_core iTCO_wdt
iTCO_vendor_support e1000e mlx4_ib ib_mad ib_core mlx4_en mlx4_core ext3
jbd mbcache sd_mod crc_t10dif usb_storage ata_generic pata_acpi ata_piix
libsas(U) scsi_transport_sas dm_mod [last unloaded: pm8001]

Modules linked in: pm8001(U) ses enclosure fuse nfsd exportfs autofs4
ipmi_devintf ipmi_si ipmi_msghandler nfs lockd fscache nfs_acl
auth_rpcgss 8021q fcoe libfcoe garp libfc scsi_transport_fc stp scsi_tgt
llc sunrpc cpufreq_ondemand acpi_cpufreq freq_table ipv6 sr_mod cdrom
dm_mirror dm_region_hash dm_log uinput sg i2c_i801 i2c_core iTCO_wdt
iTCO_vendor_support e1000e mlx4_ib ib_mad ib_core mlx4_en mlx4_core ext3
jbd mbcache sd_mod crc_t10dif usb_storage ata_generic pata_acpi ata_piix
libsas(U) scsi_transport_sas dm_mod [last unloaded: pm8001]
Pid: 5146, comm: scsi_wq_5 Not tainted
2.6.32-71.29.1.el6.lustre.7.x86_64 #1 Storage Server
RIP: 0010:[<ffffffff814ca9b1>]  [<ffffffff814ca9b1>]
mutex_lock+0x21/0x50
RSP: 0018:ffff8803e4e33d30  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000238 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8803e664c800 RDI: 0000000000000238
RBP: ffff8803e4e33d40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000238 R14: ffff88041acb7200 R15: ffff88041c51ada0
FS:  0000000000000000(0000) GS:ffff880028200000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000238 CR3: 0000000410143000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process scsi_wq_5 (pid: 5146, threadinfo ffff8803e4e32000, task
ffff8803e4e294a0)
Stack:
 ffff8803e664c800 0000000000000000 ffff8803e4e33d70 ffffffffa001f06e
<0> ffff8803e4e33d60 ffff88041c51ada0 ffff88041acb7200 ffff88041bc0aa00
<0> ffff8803e4e33d90 ffffffffa0032b6c 0000000000000014 ffff88041acb7200
Call Trace:
 [<ffffffffa001f06e>] sas_port_delete_phy+0x2e/0xa0 [scsi_transport_sas]
 [<ffffffffa0032b6c>] sas_unregister_devs_sas_addr+0xac/0xe0 [libsas]
 [<ffffffffa0034914>] sas_ex_revalidate_domain+0x204/0x330 [libsas]
 [<ffffffffa00307f0>] ? sas_revalidate_domain+0x0/0x90 [libsas]
 [<ffffffffa0030855>] sas_revalidate_domain+0x65/0x90 [libsas]
 [<ffffffff8108c7d0>] worker_thread+0x170/0x2a0
 [<ffffffff81091ea0>] ? autoremove_wake_function+0x0/0x40
 [<ffffffff8108c660>] ? worker_thread+0x0/0x2a0
 [<ffffffff81091b36>] kthread+0x96/0xa0
 [<ffffffff810141ca>] child_rip+0xa/0x20
 [<ffffffff81091aa0>] ? kthread+0x0/0xa0
 [<ffffffff810141c0>] ? child_rip+0x0/0x20
Code: ff ff 85 c0 75 ed eb d6 66 90 55 48 89 e5 48 83 ec 10 48 89 1c 24
4c 89 64 24 08 0f 1f 44 00 00 48 89 fb e8 92 f4 ff ff 48 89 df <f0> ff
0f 79 05 e8 25 00 00 00 65 48 8b 04 25 08 cc 00 00 48 2d
RIP  [<ffffffff814ca9b1>] mutex_lock+0x21/0x50
 RSP <ffff8803e4e33d30>
CR2: 0000000000000238

The following patch is admittedly a band-aid, and does not solve the
root cause, but it still is a good candidate for hardening as a pointer
check before reference.
Signed-off-by: NMark Salyzyn <mark_salyzyn@us.xyratex.com>
Tested-by: NJack Wang <jack_wang@usish.com>
Cc: stable@kernel.org
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Libsas forget to set the sas_address and device type of rphy lead to file
under /sys/class/sas_x show wrong value, fix that.
Signed-off-by: NJack Wang <jack_wang@usish.com>
Tested-by: NCrystal Yu <crystal_yu@usish.com>
Cc: stable@kernel.org
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Allow expander table-to-table attachments for
expanders that support it.
Signed-off-by: NLuben Tuikov <ltuikov@yahoo.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

In an enclosure model where there are chaining expanders to a large body
of storage, it was discovered that libsas, responding to a broadcast
event change, would only revalidate the domain of first child expander
in the list.

The issue is that the pointer value to the discovered source device was
used to break out of the loop, rather than the content of the pointer.

This still remains non-compliant as the revalidate domain code is
supposed to loop through all child expanders, and not stop at the first
one it finds that reports a change count. However, the design of this
routine does not allow multiple device discoveries and that would be a
more complicated set of patches reserved for another day. We are fixing
the glaring bug rather than refactoring the code.
Signed-off-by: NMark Salyzyn <msalyzyn@us.xyratex.com>
Cc: stable@kernel.org
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

If expander discovery fails (sas_discover_expander()), remove the
expander from the port device list (sas_ex_discover_expander()),
before freeing it. Else the list is corrupted and, e.g., when we
attempt to send SMP commands to other devices, the kernel oopses.
Signed-off-by: NLuben Tuikov <ltuikov@yahoo.com>
Cc: stable@kernel.org
Reviewed-by: NJack Wang <jack_wang@usish.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

In some test envirenment, there is loopback topology test. We should
handle this during discovery.
Signed-off-by: NJack Wang <jack_wang@usish.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

This patch fix bug reported by Chuck. And this new version incorporate comments
from Hannes. Please consider to include it into mainline.
Signed-off-by: NJack Wang <jack_wang@usish.com>
Signed-off-by: NLindar Liu <lindar_liu@usish.com>
Tested-by: NChuck Tuffli <Chuck_Tuffli@pmc-sierra.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

sd will get hung up issuing commands to flush write cache if a SAS
device behind the expander is unplugged without warning.  Change libsas
to reject commands to domain devices that have already gone away.

[maciej.trela@intel.com: removed setting ->gone in sas_deform_port() to
 permit sync cache commands at module removal]
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Tested-by: NHaipao Fan <haipao.fan@intel.com>
Signed-off-by: NMaciej Trela <maciej.trela@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>