scsi: libsas: Delete struct scsi_core

Since commit 79855d178557 ("libsas: remove task_collector mode"), struct
scsi_core only contains a reference to the shost. struct scsi_core is only
used in sas_

scsi: libsas: Delete struct scsi_core

Since commit 79855d178557 ("libsas: remove task_collector mode"), struct
scsi_core only contains a reference to the shost. struct scsi_core is only
used in sas_ha_struct.core, so delete scsi_core and replace with a
reference to the shost there.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230815115156.343535-5-john.g.garry@oracle.com
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: Delete enum sas_class

enum sas_class prob would have been useful if function sas_show_class() was
ever implemented, which it wasn't.

enum sas_class is used as asd_sas_port.class and a

scsi: libsas: Delete enum sas_class

enum sas_class prob would have been useful if function sas_show_class() was
ever implemented, which it wasn't.

enum sas_class is used as asd_sas_port.class and asd_sas_phy.class, which
are only ever set, so delete these members and the enum.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230815115156.343535-3-john.g.garry@oracle.com
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: Clean up sas_form_port()

Sparse throws a warning about context imbalance ("different lock contexts
for basic block") in sas_form_port() as it gets confused with the fact that
a port is

scsi: libsas: Clean up sas_form_port()

Sparse throws a warning about context imbalance ("different lock contexts
for basic block") in sas_form_port() as it gets confused with the fact that
a port is locked within one of the two search loops and unlocked afterward
outside of the search loops once the phy is added to the port. Since this
code is not easy to follow, improve it by factoring out the code adding the
phy to the port once the port is locked into the helper function
sas_form_port_add_phy(). This helper can then be called directly within the
port search loops, avoiding confusion and clearing the sparse warning.

Link: https://lore.kernel.org/r/20220228094857.557329-1-damien.lemoal@opensource.wdc.com
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: Allow libsas to include SCSI header files directly

libsas needs to include some header files in the scsi directory. However
these are currently hardcoded with the path "../" in the C f

scsi: libsas: Allow libsas to include SCSI header files directly

libsas needs to include some header files in the scsi directory. However
these are currently hardcoded with the path "../" in the C files. Do this
in the Makefile to avoid hardcoding the path.

Link: https://lore.kernel.org/r/20210716074551.771312-1-yanaijie@huawei.com
Cc: John Garry <john.garry@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: Use _safe() loop in sas_resume_port()

If sas_notify_lldd_dev_found() fails then this code calls:

sas_unregister_dev(port, dev);

which removes "dev", our list iterator, from the list

scsi: libsas: Use _safe() loop in sas_resume_port()

If sas_notify_lldd_dev_found() fails then this code calls:

sas_unregister_dev(port, dev);

which removes "dev", our list iterator, from the list. This could lead to
an endless loop. We need to use list_for_each_entry_safe().

Link: https://lore.kernel.org/r/YKUeq6gwfGcvvhty@mwanda
Fixes: 303694eeee5e ("[SCSI] libsas: suspend / resume support")
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: Use _safe() loop in sas_resume_port()

[ Upstream commit 8c7e7b8486cda21269d393245883c5e4737d5ee7 ]

If sas_notify_lldd_dev_found() fails then this code calls:

sas_unregister_dev(port

scsi: libsas: Use _safe() loop in sas_resume_port()

[ Upstream commit 8c7e7b8486cda21269d393245883c5e4737d5ee7 ]

If sas_notify_lldd_dev_found() fails then this code calls:

sas_unregister_dev(port, dev);

which removes "dev", our list iterator, from the list. This could lead to
an endless loop. We need to use list_for_each_entry_safe().

Link: https://lore.kernel.org/r/YKUeq6gwfGcvvhty@mwanda
Fixes: 303694eeee5e ("[SCSI] libsas: suspend / resume support")
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

scsi: libsas: Tidy SAS address print format

Currently we use a mixture of %016llx, %llx, and %16llx when printing a SAS
address.

Since the most significant nibble of the SAS address is always 5 - a

scsi: libsas: Tidy SAS address print format

Currently we use a mixture of %016llx, %llx, and %16llx when printing a SAS
address.

Since the most significant nibble of the SAS address is always 5 - as per
standard - this formatting is not so important; but some fake SAS addresses
for SATA devices may not be. And we have mangled/invalid address to
consider also. And it's better to be consistent in the code, so use a fixed
format.

The SAS address is a fixed size at 64b, so we want to 0 byte extend to 16
nibbles, so use %016llx globally.

Also make some prints to be explicitly hex, and tidy some whitespace issue.

Link: https://lore.kernel.org/r/1576758957-227350-1-git-send-email-john.garry@huawei.com
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: aic94xx: hisi_sas: mvsas: pm8001: Use dev_is_expander()

Many times in libsas, and in LLDDs which use libsas, the check for an
expander device is re-implemented or open coded.

Use dev_

scsi: libsas: aic94xx: hisi_sas: mvsas: pm8001: Use dev_is_expander()

Many times in libsas, and in LLDDs which use libsas, the check for an
expander device is re-implemented or open coded.

Use dev_is_expander() instead. We rename this from
sas_dev_type_is_expander() to not spill so many lines in referencing.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: switch remaining files to SPDX tags

Use the the GPLv2 SPDX tag instead of verbose boilerplate text.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@su

scsi: libsas: switch remaining files to SPDX tags

Use the the GPLv2 SPDX tag instead of verbose boilerplate text.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: Inject revalidate event for root port event

According to the SAS spec, an expander device shall transmit BROADCAST
(CHANGE) from at least one phy in each expander port other than the
e

scsi: libsas: Inject revalidate event for root port event

According to the SAS spec, an expander device shall transmit BROADCAST
(CHANGE) from at least one phy in each expander port other than the
expander port that is the cause for transmitting BROADCAST (CHANGE).

As such, for when the link is lost for a root PHY attached to an expander
PHY, we get no broadcast event.

This causes an issue for libsas, in that we will not revalidate the domain
for these events.

As a solution, for when a root PHY is formed or deformed from a root port,
insert a broadcast event to trigger a domain revalidation.

Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: Drop SAS_DPRINTK() and revise logs levels

Like sas_printk() did previously, SAS_DPRINTK() offers little value now
that libsas logs already have the "sas" prefix through pr_fmt(fmt). So

scsi: libsas: Drop SAS_DPRINTK() and revise logs levels

Like sas_printk() did previously, SAS_DPRINTK() offers little value now
that libsas logs already have the "sas" prefix through pr_fmt(fmt). So it
can be dropped.

However, after reviewing some logs in libsas, it is noticed that debug
level is too low in many instances.

So this change drops SAS_DPRINTK() and revises some logs to a more
appropriate level. However many stay at debug level, although some
are significantly promoted.

We add -DDEBUG for compilation so that we keep the debug messages by
default, as before.

All the pre-existing checkpatch errors for spanning messages across
multiple lines are also fixed.

Finally, all other references to printk() [apart from special formatting
in sas_ata.c] are removed and replaced with appropriate pr_xxx().

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: Fix kernel-doc headers

Avoid that building with W=1 causes the kernel-doc tool to complain
about function arguments that have not been documented in the libsas
kernel-doc headers. Avoi

scsi: libsas: Fix kernel-doc headers

Avoid that building with W=1 causes the kernel-doc tool to complain
about function arguments that have not been documented in the libsas
kernel-doc headers. Avoid that the short description starts with a
hyphen by changing "--" into "-" in the first line of the kernel-doc
headers.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: John Garry <john.garry@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: direct call probe and destruct

In commit 87c8331fcf72 ("[SCSI] libsas: prevent domain rediscovery
competing with ata error handling") introduced disco mutex to prevent
rediscovery comp

scsi: libsas: direct call probe and destruct

In commit 87c8331fcf72 ("[SCSI] libsas: prevent domain rediscovery
competing with ata error handling") introduced disco mutex to prevent
rediscovery competing with ata error handling and put the whole
revalidation in the mutex. But the rphy add/remove needs to wait for the
error handling which also grabs the disco mutex. This may leads to dead
lock.So the probe and destruct event were introduce to do the rphy
add/remove asynchronously and out of the lock.

The asynchronously processed workers makes the whole discovery process
not atomic, the other events may interrupt the process. For example,
if a loss of signal event inserted before the probe event, the
sas_deform_port() is called and the port will be deleted.

And sas_port_delete() may run before the destruct event, but the
port-x:x is the top parent of end device or expander. This leads to
a kernel WARNING such as:

[ 82.042979] sysfs group 'power' not found for kobject 'phy-1:0:22'
[ 82.042983] ------------[ cut here ]------------
[ 82.042986] WARNING: CPU: 54 PID: 1714 at fs/sysfs/group.c:237
sysfs_remove_group+0x94/0xa0
[ 82.043059] Call trace:
[ 82.043082] [<ffff0000082e7624>] sysfs_remove_group+0x94/0xa0
[ 82.043085] [<ffff00000864e320>] dpm_sysfs_remove+0x60/0x70
[ 82.043086] [<ffff00000863ee10>] device_del+0x138/0x308
[ 82.043089] [<ffff00000869a2d0>] sas_phy_delete+0x38/0x60
[ 82.043091] [<ffff00000869a86c>] do_sas_phy_delete+0x6c/0x80
[ 82.043093] [<ffff00000863dc20>] device_for_each_child+0x58/0xa0
[ 82.043095] [<ffff000008696f80>] sas_remove_children+0x40/0x50
[ 82.043100] [<ffff00000869d1bc>] sas_destruct_devices+0x64/0xa0
[ 82.043102] [<ffff0000080e93bc>] process_one_work+0x1fc/0x4b0
[ 82.043104] [<ffff0000080e96c0>] worker_thread+0x50/0x490
[ 82.043105] [<ffff0000080f0364>] kthread+0xfc/0x128
[ 82.043107] [<ffff0000080836c0>] ret_from_fork+0x10/0x50

Make probe and destruct a direct call in the disco and revalidate function,
but put them outside the lock. The whole discovery or revalidate won't
be interrupted by other events. And the DISCE_PROBE and DISCE_DESTRUCT
event are deleted as a result of the direct call.

Introduce a new list to destruct the sas_port and put the port delete after
the destruct. This makes sure the right order of destroying the sysfs
kobject and fix the warning above.

In sas_ex_revalidate_domain() have a loop to find all broadcasted
device, and sometimes we have a chance to find the same expander twice.
Because the sas_port will be deleted at the end of the whole revalidate
process, sas_port with the same name cannot be added before this.
Otherwise the sysfs will complain of creating duplicate filename. Since
the LLDD will send broadcast for every device change, we can only
process one expander's revalidation.

[mkp: kbuild test robot warning]

Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: use flush_workqueue to process disco events synchronously

Now we are processing sas event and discover event in different
workqueues. It's safe to wait the discover event done in the

scsi: libsas: use flush_workqueue to process disco events synchronously

Now we are processing sas event and discover event in different
workqueues. It's safe to wait the discover event done in the sas event
work. Use flush_workqueue() to insure the disco and revalidate events
processed synchronously so that the whole discover and revalidate
process will not be interrupted by other events.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: Use dynamic alloced work to avoid sas event lost

Now libsas hotplug work is static, every sas event type has its own
static work, LLDD driver queues the hotplug work into shost->work_q

scsi: libsas: Use dynamic alloced work to avoid sas event lost

Now libsas hotplug work is static, every sas event type has its own
static work, LLDD driver queues the hotplug work into shost->work_q. If
LLDD driver burst posts lots hotplug events to libsas, the hotplug
events may pending in the workqueue like

shost->work_q
new work[PORTE_BYTES_DMAED] --> |[PHYE_LOSS_OF_SIGNAL][PORTE_BYTES_DMAED] -> processing
|<-------wait worker to process-------->|

In this case, a new PORTE_BYTES_DMAED event coming, libsas try to queue
it to shost->work_q, but this work is already pending, so it would be
lost. Finally, libsas delete the related sas port and sas devices, but
LLDD driver expect libsas add the sas port and devices(last sas event).

This patch use dynamic allocated work to avoid this issue.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

[SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type

These enums have been separate since the dawn of SAS, mainly because the
latter is a procotol only enum and the for

[SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type

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: James Bottomley <JBottomley@Parallels.com>

show more ...

[SCSI] libsas: suspend / resume support

libsas power management routines to suspend and recover the sas domain
based on a model where the lldd is allowed and expected to be
"forgetful".

sas_suspend

[SCSI] libsas: suspend / resume support

libsas power management routines to suspend and recover the sas domain
based on a model where the lldd is allowed and expected to be
"forgetful".

sas_suspend_ha - disable event processing allowing the lldd to take down
links without concern for causing hotplug events.
Regardless of whether the lldd actually posts link down
messages libsas notifies the lldd that all
domain_devices are gone.

sas_prep_resume_ha - on the way back up before the lldd starts link
training clean out any spurious events that were
generated on the way down, and re-enable event
processing

sas_resume_ha - after the lldd has started and decided that all phys
have posted link-up events this routine is called to let
libsas start it's own timeout of any phys that did not
resume. After the timeout an lldd can cancel the
phy teardown by posting a link-up event.

Storage for ex_change_count (u16) and phy_change_count (u8) are changed
to int so they can be set to -1 to indicate 'invalidated'.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jacek Danecki <jacek.danecki@intel.com>
Tested-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

show more ...

[SCSI] Revert "[SCSI] libsas: fix sas port naming"

This reverts commit a692b0eec5efae382dfa800e8b4b083f172921a7.

Tom reports:

[ 8.741033] ------------[ cut here ]------------
[ 8.741038] WAR

[SCSI] Revert "[SCSI] libsas: fix sas port naming"

This reverts commit a692b0eec5efae382dfa800e8b4b083f172921a7.

Tom reports:

[ 8.741033] ------------[ cut here ]------------
[ 8.741038] WARNING: at fs/sysfs/dir.c:508 sysfs_add_one+0xc1/0xf0()
[ 8.741040] Hardware name: To Be Filled By O.E.M.
[ 8.741041] sysfs: cannot create duplicate filename

...and missing 2 out of 4 drives connected to mvsas. Commit a692b0ee
made the assumption that all the phy ids an lldd registers to libsas are
unique. However, in the "multi-chip" case mvsas does a rather annoying
duplication of phy ids in the array passed to libsas. So, for example,
chip0 has phy0-3 at ha phy index 0-3 and chip1 has its phy0-3 at ha phy
index 4-7. The more natural model would be to create a scsi_host (and
sas_ha) per chip (controller), but for now revert the naming fix which
unfortunately means dealing with unpredictable end-device names for a
bit longer.

Cc: Xiangliang Yu <yuxiangl@marvell.com>
Cc: Patrick Thomson <patrick.s.thomson@intel.com>
Reported-by: Tom Rini <trini@ti.com>
Tested-by: Tom Rini <trini@ti.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

show more ...

[SCSI] libsas: introduce sas_work to fix sas_drain_work vs sas_queue_work

When requeuing work to a draining workqueue the last work instance may
not be idle, so sas_queue_work() must not touch work-

[SCSI] libsas: introduce sas_work to fix sas_drain_work vs sas_queue_work

When requeuing work to a draining workqueue the last work instance may
not be idle, so sas_queue_work() must not touch work->entry. Introduce
sas_work with a drain_node list_head to have a private list for
collecting work deferred due to drain collision.

Fixes reports like:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff810410d4>] process_one_work+0x2e/0x338

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

show more ...

[SCSI] libsas: set attached device type and target protocols for local phys

Before:
$ cat /sys/class/sas_phy/phy-6\:3/device_type
none
$ cat /sys/class/sas_phy/phy-6\:3/target_port_protocols
none

A

[SCSI] libsas: set attached device type and target protocols for local phys

Before:
$ cat /sys/class/sas_phy/phy-6\:3/device_type
none
$ cat /sys/class/sas_phy/phy-6\:3/target_port_protocols
none

After:
$ cat /sys/class/sas_phy/phy-6\:3/device_type
end device
$ cat /sys/class/sas_phy/phy-6\:3/target_port_protocols
sata

Also downgrade the phy_list_lock to _irq instead of _irqsave since
libsas will never call sas_get_port_device with interrupts disbled.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

show more ...

[SCSI] libsas: fix sas port naming

Make sas-port naming consistent with the expander-attached case whereby
the phy-id is the last digit in the port name. Otherwise we get the
random behavior of the

[SCSI] libsas: fix sas port naming

Make sas-port naming consistent with the expander-attached case whereby
the phy-id is the last digit in the port name. Otherwise we get the
random behavior of the allocation order.

Reported-by: Patrick Thomson <patrick.s.thomson@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

show more ...

[SCSI] libsas: mark all domain devices gone if root port disappears

If the top level expander is hot removed, mark all child devices as gone
before unregistration to short circuit futile recovery.

[SCSI] libsas: mark all domain devices gone if root port disappears

If the top level expander is hot removed, mark all child devices as gone
before unregistration to short circuit futile recovery.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

show more ...

[SCSI] libsas: fix sas_find_local_phy(), take phy references

In the direct-attached case this routine returns the phy on which this
device was first discovered. Which is broken if we want to suppor

[SCSI] libsas: fix sas_find_local_phy(), take phy references

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: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

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[SCSI] libsas: prevent domain rediscovery competing with ata error handling

libata error handling provides for a timeout for link recovery. libsas
must not rescan for previously known devices in th

[SCSI] libsas: prevent domain rediscovery competing with ata error handling

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: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

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[SCSI] libsas: convert dev->gone to flags

In preparation for adding tracking of another device state "destroy".

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley

[SCSI] libsas: convert dev->gone to flags

In preparation for adding tracking of another device state "destroy".

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

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