scsi: sd: Fix TCG OPAL unlock on system resume

Commit 3cc2ffe5c16d ("scsi: sd: Differentiate system and runtime start/stop
management") introduced the manage_system_start_stop scsi_device flag to
allow libata to indicate to the SCSI disk driver that nothing should be
done when resuming a disk on system resume. This change turned the
execution of sd_resume() into a no-op for ATA devices on system
resume. While this solved deadlock issues during device resume, this change
also wrongly removed the execution of opal_unlock_from_suspend(). As a
result, devices with TCG OPAL locking enabled remain locked and
inaccessible after a system resume from sleep.

To fix this issue, introduce the SCSI driver resume method and implement it
with the sd_resume() function calling opal_unlock_from_suspend(). The
former sd_resume() function is renamed to sd_resume_common() and modified
to call the new sd_resume() function. For non-ATA devices, this result in
no functional changes.

In order for libata to explicitly execute sd_resume() when a device is
resumed during system restart, the function scsi_resume_device() is
introduced. libata calls this function from the revalidation work executed
on devie resume, a state that is indicated with the new device flag
ATA_DFLAG_RESUMING. Doing so, locked TCG OPAL enabled devices are unlocked
on resume, allowing normal operation.

Fixes: 3cc2ffe5c16d ("scsi: sd: Differentiate system and runtime start/stop management")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218538
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240319071209.1179257-1-dlemoal@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Constify the struct device_type usage

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the
scsi_host_type, scsi_target_type and scsi_dev_type variables to be constant
structures as well, placing it into read-only memory which can not be
modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240219-device_cleanup-scsi-v1-1-c5edf2afe178@marliere.net
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Have SCSI midlayer retry scsi_report_lun_scan() errors

This has scsi_report_lun_scan() have the SCSI midlayer retry errors instead
of driving them itself.

There is one behavior change where we no longer retry when
scsi_execute_cmd() returns < 0, but we should be ok. We don't need to retry
for failures like the queue being removed, and for the case where there are
no tags/reqs the block layer waits/retries for us. For possible memory
allocation failures from blk_rq_map_kern() we use GFP_NOIO, so retrying
will probably not help.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20240123002220.129141-14-michael.christie@oracle.com
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Retry INQUIRY after timeout

Description from: Martin Wilck <mwilck@suse.com>:

The SCSI mid layer doesn't retry commands after DID_TIME_OUT (see
scsi_noretry_cmd()). Packet loss in the fabric can cause spurious timeouts
during SCSI device probing, causing device probing to fail. This has been
observed in FCoE uplink failover tests, for example.

This patch fixes the issue by retrying the INQUIRY.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20240123002220.129141-4-michael.christie@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Have midlayer retry scsi_probe_lun() errors

This has scsi_probe_lun() ask the SCSI midlayer to retry UAs instead of
driving them itself.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20240123002220.129141-3-michael.christie@oracle.com
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: pass a queue_limits argument to blk_mq_init_queue

Pass a queue_limits to blk_mq_init_queue and apply it if non-NULL. This
will allow allocating queues with valid queue limits instead of setting
the values one at a time later.

Also rename the function to blk_mq_alloc_queue as that is a much better
name for a function that allocates a queue and always pass the queuedata
argument instead of having a separate version for the extra argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240213073425.1621680-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: Do not rescan devices with a suspended queue

Commit ff48b37802e5 ("scsi: Do not attempt to rescan suspended devices")
modified scsi_rescan_device() to avoid attempting rescanning a suspended
device. However, the modification added a check to verify that a SCSI
device is in the running state without checking if the device request
queue (in the case of block device) is also running, thus allowing the
exectuion of internal requests. Without checking the device request
queue, commit ff48b37802e5 fix is incomplete and deadlocks on resume can
still happen. Use blk_queue_pm_only() to check if the device request
queue allows executing commands in addition to checking the SCSI device
state.

Reported-by: Petr Tesarik <petr@tesarici.cz>
Fixes: ff48b37802e5 ("scsi: Do not attempt to rescan suspended devices")
Cc: stable@vger.kernel.org
Tested-by: Petr Tesarik <petr@tesarici.cz>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

scsi: Do not attempt to rescan suspended devices

scsi_rescan_device() takes a scsi device lock before executing a device
handler and device driver rescan methods. Waiting for the completion of
any command issued to the device by these methods will thus be done with
the device lock held. As a result, there is a risk of deadlocking within
the power management code if scsi_rescan_device() is called to handle a
device resume with the associated scsi device not yet resumed.

Avoid such situation by checking that the target scsi device is in the
running state, that is, fully capable of executing commands, before
proceeding with the rescan and bailout returning -EWOULDBLOCK otherwise.
With this error return, the caller can retry rescaning the device after
a delay.

The state check is done with the device lock held and is thus safe
against incoming suspend power management operations.

Fixes: 6aa0365a3c85 ("ata: libata-scsi: Avoid deadlock on rescan after device resume")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>

scsi: core: ata: Do no try to probe for CDL on old drives

Some old drives (e.g. an Ultra320 SCSI disk as reported by John) do not
seem to execute MAINTENANCE_IN / MI_REPORT_SUPPORTED_OPERATION_CODES
commands correctly and hang when a non-zero service action is specified
(one command format with service action case in scsi_report_opcode()).

Currently, CDL probing with scsi_cdl_check_cmd() is the only caller using a
non zero service action for scsi_report_opcode(). To avoid issues with
these old drives, do not attempt CDL probe if the device reports support
for an SPC version lower than 5 (CDL was introduced in SPC-5). To keep
things working with ATA devices which probe for the CDL T2A and T2B pages
introduced with SPC-6, modify ata_scsiop_inq_std() to claim SPC-6 version
compatibility for ATA drives supporting CDL.

SPC-6 standard version number is defined as Dh (= 13) in SPC-6 r09. Fix
scsi_probe_lun() to correctly capture this value by changing the bit mask
for the second byte of the INQUIRY response from 0x7 to 0xf.
include/scsi/scsi.h is modified to add the definition SCSI_SPC_6 with the
value 14 (Dh + 1). The missing definitions for the SCSI_SPC_4 and
SCSI_SPC_5 versions are also added.

Reported-by: John David Anglin <dave.anglin@bell.net>
Fixes: 624885209f31 ("scsi: core: Detect support for command duration limits")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230915022034.678121-1-dlemoal@kernel.org
Tested-by: David Gow <david@davidgow.net>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Improve type safety of scsi_rescan_device()

Most callers of scsi_rescan_device() have the scsi_device pointer readily
available. Pass a struct scsi_device pointer to scsi_rescan_device()
instead of a struct device pointer. This change prevents that a pointer to
another struct device would be passed accidentally to scsi_rescan_device().

Remove the scsi_rescan_device() declaration from the scsi_priv.h header
file since it duplicates the declaration in <scsi/scsi_host.h>.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230822153043.4046244-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Detect support for command duration limits

Introduce the function scsi_cdl_check() to detect if a device supports
command duration limits (CDL). Support for the READ 16, WRITE 16, READ 32
and WRITE 32 commands are checked using the function scsi_report_opcode()
to probe the rwcdlp and cdlp bits as they indicate the mode page defining
the command duration limits descriptors that apply to the command being
tested.

If any of these commands support CDL, the field cdl_supported of struct
scsi_device is set to 1 to indicate that the device supports CDL.

Support for CDL for a device is advertizes through sysfs using the new
cdl_supported device attribute. This attribute value is 1 for a device
supporting CDL and 0 otherwise.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-9-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Add BLIST_NO_VPD_SIZE for some VDASD

Some storage, such as AIX VDASD (virtual storage) and IBM 2076 (front
end), fail as a result of commit c92a6b5d6335 ("scsi: core: Query VPD
size before getting full page").

That commit changed getting SCSI VPD pages so that we now read just
enough of the page to get the actual page size, then read the whole
page in a second read. The problem is that the above mentioned
hardware returns zero for the page size, because of a firmware
error. In such cases, until the firmware is fixed, this new blacklist
flag says to revert to the original method of reading the VPD pages,
i.e. try to read a whole buffer's worth on the first try.

[mkp: reworked somewhat]

Fixes: c92a6b5d6335 ("scsi: core: Query VPD size before getting full page")
Reported-by: Martin Wilck <mwilck@suse.com>
Suggested-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Lee Duncan <lduncan@suse.com>
Link: https://lore.kernel.org/r/20220928181350.9948-1-leeman.duncan@gmail.com
Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Convert to scsi_execute_cmd()

scsi_execute_req() is going to be removed. Convert SCSI midlayer to
scsi_execute_cmd().

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Revert "scsi: core: map PQ=1, PDT=other values to SCSI_SCAN_TARGET_PRESENT"

This reverts commit 948e922fc44611ee2de0c89583ca958cb5307d36.

Not all targets that return PQ=1 and PDT=0 should be ignored. While
the SCSI spec is vague in this department, there appears to be a
critical mass of devices which rely on devices being accessible with
this combination of reported values.

Fixes: 948e922fc446 ("scsi: core: map PQ=1, PDT=other values to SCSI_SCAN_TARGET_PRESENT")
Link: https://lore.kernel.org/r/yq1lelrleqr.fsf@ca-mkp.ca.oracle.com
Acked-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Martin Wilck <mwilck@suse.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Use SCSI_SCAN_INITIAL in do_scsi_scan_host()

Instead of using hardcoded '0' as the do_scsi_scan_host() ->
scsi_scan_host_selected() rescan arg, use proper macro SCSI_SCAN_INITIAL.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20221121121725.1910795-3-john.g.garry@oracle.com
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Use SCSI_SCAN_RESCAN in __scsi_add_device()

Instead of using hardcoded '1' as the __scsi_add_device() ->
scsi_probe_and_add_lun() rescan arg, use proper macro SCSI_SCAN_RESCAN.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20221121121725.1910795-2-john.g.garry@oracle.com
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: remove an extra queue reference

Now that blk_mq_destroy_queue does not release the queue reference, there
is no need for a second queue reference to be held by the scsi_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20221018135720.670094-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: core: Fix a use-after-free

There are two .exit_cmd_priv implementations. Both implementations use
resources associated with the SCSI host. Make sure that these resources are
still available when .exit_cmd_priv is called by waiting inside
scsi_remove_host() until the tag set has been freed.

This commit fixes the following use-after-free:

==================================================================
BUG: KASAN: use-after-free in srp_exit_cmd_priv+0x27/0xd0 [ib_srp]
Read of size 8 at addr ffff888100337000 by task multipathd/16727
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
print_report.cold+0x5e/0x5db
kasan_report+0xab/0x120
srp_exit_cmd_priv+0x27/0xd0 [ib_srp]
scsi_mq_exit_request+0x4d/0x70
blk_mq_free_rqs+0x143/0x410
__blk_mq_free_map_and_rqs+0x6e/0x100
blk_mq_free_tag_set+0x2b/0x160
scsi_host_dev_release+0xf3/0x1a0
device_release+0x54/0xe0
kobject_put+0xa5/0x120
device_release+0x54/0xe0
kobject_put+0xa5/0x120
scsi_device_dev_release_usercontext+0x4c1/0x4e0
execute_in_process_context+0x23/0x90
device_release+0x54/0xe0
kobject_put+0xa5/0x120
scsi_disk_release+0x3f/0x50
device_release+0x54/0xe0
kobject_put+0xa5/0x120
disk_release+0x17f/0x1b0
device_release+0x54/0xe0
kobject_put+0xa5/0x120
dm_put_table_device+0xa3/0x160 [dm_mod]
dm_put_device+0xd0/0x140 [dm_mod]
free_priority_group+0xd8/0x110 [dm_multipath]
free_multipath+0x94/0xe0 [dm_multipath]
dm_table_destroy+0xa2/0x1e0 [dm_mod]
__dm_destroy+0x196/0x350 [dm_mod]
dev_remove+0x10c/0x160 [dm_mod]
ctl_ioctl+0x2c2/0x590 [dm_mod]
dm_ctl_ioctl+0x5/0x10 [dm_mod]
__x64_sys_ioctl+0xb4/0xf0
dm_ctl_ioctl+0x5/0x10 [dm_mod]
__x64_sys_ioctl+0xb4/0xf0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x46/0xb0

Link: https://lore.kernel.org/r/20220826002635.919423-1-bvanassche@acm.org
Fixes: 65ca846a5314 ("scsi: core: Introduce {init,exit}_cmd_priv()")
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.garry@huawei.com>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Reported-by: Li Zhijian <lizhijian@fujitsu.com>
Tested-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Revert "Make sure that targets outlive devices"

Revert the patch series "Call blk_mq_free_tag_set() earlier" because it
introduces a deadlock if the scsi_remove_host() caller holds a reference on
a device, target or host.

Link: https://lore.kernel.org/r/20220821220502.13685-5-bvanassche@acm.org
Fixes: fe442604199e ("scsi: core: Make sure that targets outlive devices")
Reported-by: syzbot+bafeb834708b1bb750bc@syzkaller.appspotmail.com
Tested-by: Kenneth R. Crudup <kenny@panix.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Revert "Make sure that hosts outlive targets"

Revert the patch series "Call blk_mq_free_tag_set() earlier" because it
introduces a deadlock if the scsi_remove_host() caller holds a reference on
a device, target or host.

Link: https://lore.kernel.org/r/20220821220502.13685-4-bvanassche@acm.org
Fixes: 16728aaba62e ("scsi: core: Make sure that hosts outlive targets")
Reported-by: syzbot+bafeb834708b1bb750bc@syzkaller.appspotmail.com
Tested-by: Kenneth R. Crudup <kenny@panix.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Make sure that hosts outlive targets

Fix the race conditions between SCSI LLD kernel module unloading and SCSI
device and target removal by making sure that SCSI hosts are destroyed
after all associated target and device objects have been freed.

Link: https://lore.kernel.org/r/20220728221851.1822295-3-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.garry@huawei.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
[ bvanassche: Reworked Ming's patch and split it ]
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Make sure that targets outlive devices

This commit prevents that the following sequence triggers a kernel crash:

- Deletion of a SCSI device is requested via sysfs. Device removal takes
some time because blk_cleanup_queue() is waiting for the SCSI error
handler.

- The SCSI target associated with that SCSI device is removed.

- scsi_remove_target() returns and its caller frees the resources
associated with the SCSI target.

- The error handler makes progress and invokes an LLD callback that
dereferences the SCSI target pointer.

Link: https://lore.kernel.org/r/20220728221851.1822295-2-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.garry@huawei.com>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Reported-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Do not truncate INQUIRY data on modern devices

Low-level device drivers have had the ability to limit the size of an
INQUIRY for many years. This made sense for a wide variety of legacy
devices. However, we are unnecessarily truncating the INQUIRY response for
many modern devices. This prevents us from consulting fields beyond the
first 36 bytes.

If a device reports that it supports a larger INQUIRY response, and the
device also reports that it implements SPC-4 or newer, allow the larger
INQUIRY to proceed.

Link: https://lore.kernel.org/r/20220302053559.32147-4-martin.petersen@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Fix sbitmap depth in scsi_realloc_sdev_budget_map()

In commit edb854a3680b ("scsi: core: Reallocate device's budget map on
queue depth change"), the sbitmap for the device budget map may be
reallocated after the slave device depth is configured.

When the sbitmap is reallocated we use the result from
scsi_device_max_queue_depth() for the sbitmap size, but don't resize to
match the actual device queue depth.

Fix by resizing the sbitmap after reallocating the budget sbitmap. We do
this instead of init'ing the sbitmap to the device queue depth as the user
may want to change the queue depth later via sysfs or other.

Link: https://lore.kernel.org/r/1647423870-143867-1-git-send-email-john.garry@huawei.com
Fixes: edb854a3680b ("scsi: core: Reallocate device's budget map on queue depth change")
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Reallocate device's budget map on queue depth change

We currently use ->cmd_per_lun as initial queue depth for setting up the
budget_map. Martin Wilck reported that it is common for the queue_depth to
be subsequently updated in slave_configure() based on detected hardware
characteristics.

As a result, for some drivers, the static host template settings for
cmd_per_lun and can_queue won't actually get used in practice. And if the
default values are used to allocate the budget_map, memory may be consumed
unnecessarily.

Fix the issue by reallocating the budget_map after ->slave_configure()
returns. At that time the device queue_depth should accurately reflect what
the hardware needs.

Link: https://lore.kernel.org/r/20220127153733.409132-1-ming.lei@redhat.com
Cc: Bart Van Assche <bvanassche@acm.org>
Reported-by: Martin Wilck <martin.wilck@suse.com>
Suggested-by: Martin Wilck <martin.wilck@suse.com>
Tested-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Declare 'scsi_scan_type' static

'scsi_scan_type' is only used in one source file. Hence declare it static.

Link: https://lore.kernel.org/r/20211129194609.3466071-3-bvanassche@acm.org
Fixes: a19a93e4c6a9 ("scsi: core: pm: Rely on the device driver core for async power management")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Suppress a kernel-doc warning

Suppress the following kernel-doc warning:

drivers/scsi/scsi_scan.c:129: warning: Function parameter or member 'dev' not described in 'scsi_enable_async_suspend'

Link: https://lore.kernel.org/r/20211129194609.3466071-2-bvanassche@acm.org
Fixes: a19a93e4c6a9 ("scsi: core: pm: Rely on the device driver core for async power management")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: pm: Rely on the device driver core for async power management

Instead of implementing asynchronous resume support in the SCSI core, rely
on the device driver core for resuming SCSI devices asynchronously.
Instead of only supporting asynchronous resumes, also support asynchronous
suspends.

Link: https://lore.kernel.org/r/20211006215453.3318929-2-bvanassche@acm.org
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Delete scsi_{get,free}_host_dev()

Since commit 0653c358d2dc ("scsi: Drop gdth driver"), functions
scsi_{get,free}_host_dev() no longer have any in-tree users, so delete
them.

Link: https://lore.kernel.org/r/1631528047-30150-1-git-send-email-john.garry@huawei.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Nacked-by: Hannes Reinecke <hare@suse.de>

block: remove QUEUE_FLAG_SCSI_PASSTHROUGH

Export scsi_device_from_queue for use with pktcdvd and use that instead
of the otherwise unused QUEUE_FLAG_SCSI_PASSTHROUGH queue flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20211021060607.264371-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: block: Remove the remaining SG_IO-related fields from struct request_queue

Move the sg_timeout and sg_reserved_size fields into the bsg_device and
scsi_device structures as they have nothing to do with generic block I/O.
Note that these values are now separate for bsg vs. SCSI device node
access, but that just matches how /dev/sg vs the other nodes has always
behaved.

Link: https://lore.kernel.org/r/20210729064845.1044147-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Add new flag BLIST_IGN_MEDIA_CHANGE

Add a new flag for devices that erroneously establish MEDIUM MAY HAVE
CHANGED unit attentions. Drivers can set this flag to make the SCSI
layer ignore media change events during resume.

[mkp: add "ignore" and add corresponding flag to struct scsi_device]

Link: https://lore.kernel.org/r/20210704075403.147114-2-martin.kepplinger@puri.sm
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Avoid printing an error if target_alloc() returns -ENXIO

Avoid printing a 'target allocation failed' error if the driver
target_alloc() callback function returns -ENXIO. This return value
indicates that the corresponding H:C:T:L entry is empty.

Removing this error reduces the scan time if the user issues SCAN_WILD_CARD
scan operation through sysfs parameter on a host with a lot of empty
H:C:T:L entries.

Avoiding the printk on -ENXIO matches the behavior of the other callback
functions during scanning.

Link: https://lore.kernel.org/r/20210726115402.1936-1-sreekanth.reddy@broadcom.com
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Inline scsi_mq_alloc_queue()

Since scsi_mq_alloc_queue() only has one caller, inline it. This change was
suggested by Christoph Hellwig.

Link: https://lore.kernel.org/r/20210622024654.12543-1-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Ed Tsai <ed.tsai@mediatek.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Kill DRIVER_SENSE

Replace the check for DRIVER_SENSE with a check for
scsi_status_is_check_condition().

Audit all callsites to ensure the SAM status is set correctly. For
backwards compability move the DRIVER_SENSE definition to sg.h, and update
sg, bsg, and scsi_ioctl to set the DRIVER_SENSE driver_status whenever
SAM_STAT_CHECK_CONDITION is present.

[mkp: fix zeroday srp warning]

Link: https://lore.kernel.org/r/20210427083046.31620-10-hare@suse.de
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

fix

scsi: core: Stop using DRIVER_ERROR

Return the actual error code in __scsi_execute() (which, according to the
documentation, should have happened anyway). And audit all callers to cope
with negative return values from __scsi_execute() and friends.

[mkp: resolve conflict and return bool]

Link: https://lore.kernel.org/r/20210427083046.31620-7-hare@suse.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: remove the unchecked_isa_dma flag

Remove the unchecked_isa_dma now that all users are gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210331073001.46776-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: core: Replace sdev->device_busy with sbitmap

SCSI currently uses an atomic variable to track queue depth for each
attached device. The queue depth depends on many factors such as transport
type and device implementation. In addition, the SCSI device queue depth is
not a static entity but changes over time as a result of congestion
management.

While blk-mq currently tracks queue depth for each hctx, it can't easily be
changed to accommodate the SCSI per-device requirement.

The current approach of using an atomic variable doesn't scale well when
there are lots of CPU cores and the disk is very fast. IOPS can be
substantially impacted by the atomic in the hot path.

Replace the atomic variable sdev->device_busy with an sbitmap for tracking
the SCSI device queue depth.

It has been observed that IOPS is improved ~30% by this patchset in the
following test:

1) test machine(32 logical CPU cores)
Thread(s) per core: 2
Core(s) per socket: 8
Socket(s): 2
NUMA node(s): 2
Model name: Intel(R) Xeon(R) Silver 4110 CPU @ 2.10GHz

2) setup scsi_debug:
modprobe scsi_debug virtual_gb=128 max_luns=1 submit_queues=32 delay=0 max_queue=256

3) fio script:
fio --rw=randread --size=128G --direct=1 --ioengine=libaio --iodepth=2048 \
--numjobs=32 --bs=4k --group_reporting=1 --group_reporting=1 --runtime=60 \
--loops=10000 --name=job1 --filename=/dev/sdN

[mkp: fix device_busy reference in mpt3sas]

Link: https://lore.kernel.org/r/20210122023317.687987-14-ming.lei@redhat.com
Link: https://lore.kernel.org/linux-block/20200119071432.18558-6-ming.lei@redhat.com/
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Don't start concurrent async scan on same host

The current scanning mechanism is supposed to fall back to a synchronous
host scan if an asynchronous scan is in progress. However, this rule isn't
strictly respected, scsi_prep_async_scan() doesn't hold scan_mutex when
checking shost->async_scan. When scsi_scan_host() is called concurrently,
two async scans on same host can be started and a hang in do_scan_async()
is observed.

Fixes this issue by checking & setting shost->async_scan atomically with
shost->scan_mutex.

Link: https://lore.kernel.org/r/20201010032539.426615-1-ming.lei@redhat.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Remove cmd_list functionality

Remove cmd_list functionality; no users left. With that the
scsi_put_command() becomes empty, so remove that one, too.

Link: https://lore.kernel.org/r/20200228075318.91255-14-hare@suse.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart van Assche <bvanassche@acm.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: map PQ=1, PDT=other values to SCSI_SCAN_TARGET_PRESENT

commit 84961f28e9d1 ("[SCSI] Don't add scsi_device for devices that return
PQ=1, PDT=0x1f") returns SCSI_SCAN_TARGET_PRESENT if inquiry returns PQ=1,
and PDT = 0x1f. However, from the scsi spec, it seemed setting PQ=1, and
PDT to the type it is capable to support, can also mean the device is not
connected. E.g. we see an IBM/2145 returns PQ=1 and PDT=0 for a non-mapped
lun (details attached at the end).

This patch changes the check condition a bit, so the check don't require
PTD to be 0x1f when PQ=1.

$ echo 0 0 1 > /sys/class/scsi_host/host1/scan
[ 2483.722186] scsi 1:0:0:1: scsi scan: INQUIRY pass 1 length 36
[ 2483.725687] scsi 1:0:0:1: scsi scan: INQUIRY successful with code 0x0
[ 2483.729171] scsi 1:0:0:1: scsi scan: INQUIRY pass 2 length 109
[ 2483.732481] scsi 1:0:0:1: scsi scan: INQUIRY successful with code 0x0
[ 2483.735911] scsi 1:0:0:1: Direct-Access IBM 2145 0000 PQ: 1 ANSI: 6
[ 2483.741282] scsi 1:0:0:1: Attached scsi generic sg2 type 0

$ tail /proc/scsi/scsi
Attached devices:
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: IBM Model: 2145 Rev: 0000
Type: Direct-Access ANSI SCSI revision: 06
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: IBM Model: 2145 Rev: 0000
Type: Direct-Access ANSI SCSI revision: 06
Host: scsi1 Channel: 00 Id: 00 Lun: 01
Vendor: IBM Model: 2145 Rev: 0000
Type: Direct-Access ANSI SCSI revision: 06

$ lsscsi
[0:0:0:0] disk IBM 2145 0000 /dev/sdb
[1:0:0:0] disk IBM 2145 0000 /dev/sda
[1:0:0:1] disk IBM 2145 0000 -

Signed-off-by: Li Zhong <lizhongfs@gmail.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: replace GFP_ATOMIC with GFP_KERNEL in scsi_scan.c

We had a test-report where, under memory pressure, adding LUNs to the
systems would fail (the tests add LUNs strictly in sequence):

[ 5525.853432] scsi 0:0:1:1088045124: Direct-Access IBM 2107900 .148 PQ: 0 ANSI: 5
[ 5525.853826] scsi 0:0:1:1088045124: alua: supports implicit TPGS
[ 5525.853830] scsi 0:0:1:1088045124: alua: device naa.6005076303ffd32700000000000044da port group 0 rel port 43
[ 5525.853931] sd 0:0:1:1088045124: Attached scsi generic sg10 type 0
[ 5525.854075] sd 0:0:1:1088045124: [sdk] Disabling DIF Type 1 protection
[ 5525.855495] sd 0:0:1:1088045124: [sdk] 2097152 512-byte logical blocks: (1.07 GB/1.00 GiB)
[ 5525.855606] sd 0:0:1:1088045124: [sdk] Write Protect is off
[ 5525.855609] sd 0:0:1:1088045124: [sdk] Mode Sense: ed 00 00 08
[ 5525.855795] sd 0:0:1:1088045124: [sdk] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 5525.857838] sdk: sdk1
[ 5525.859468] sd 0:0:1:1088045124: [sdk] Attached SCSI disk
[ 5525.865073] sd 0:0:1:1088045124: alua: transition timeout set to 60 seconds
[ 5525.865078] sd 0:0:1:1088045124: alua: port group 00 state A preferred supports tolusnA
[ 5526.015070] sd 0:0:1:1088045124: alua: port group 00 state A preferred supports tolusnA
[ 5526.015213] sd 0:0:1:1088045124: alua: port group 00 state A preferred supports tolusnA
[ 5526.587439] scsi_alloc_sdev: Allocation failure during SCSI scanning, some SCSI devices might not be configured
[ 5526.588562] scsi_alloc_sdev: Allocation failure during SCSI scanning, some SCSI devices might not be configured

Looking at the code of scsi_alloc_sdev(), and all the calling contexts,
there seems to be no reason to use GFP_ATMOIC here. All the different
call-contexts use a mutex at some point, and nothing in between that
requires no sleeping, as far as I could see. Additionally, the code that
later allocates the block queue for the device (scsi_mq_alloc_queue())
already uses GFP_KERNEL.

There are similar allocations in two other functions:
scsi_probe_and_add_lun(), and scsi_add_lun(),; that can also be done with
GFP_KERNEL.

Here is the contexts for the three functions so far:

scsi_alloc_sdev()
scsi_probe_and_add_lun()
scsi_sequential_lun_scan()
__scsi_scan_target()
scsi_scan_target()
mutex_lock()
scsi_scan_channel()
scsi_scan_host_selected()
mutex_lock()
scsi_report_lun_scan()
__scsi_scan_target()
...
__scsi_add_device()
mutex_lock()
__scsi_scan_target()
...
scsi_report_lun_scan()
...
scsi_get_host_dev()
mutex_lock()

scsi_probe_and_add_lun()
...

scsi_add_lun()
scsi_probe_and_add_lun()
...

So replace all these, and give them a bit of a better chance to succeed,
with more chances of reclaim.

Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: kill off the legacy IO path

This removes the legacy (non-mq) IO path for SCSI.

Cc: linux-scsi@vger.kernel.org
Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: core: check for equality of result byte values

When evaluating a SCSI command's result using the field access macros,
check for equality of the fields and not if a specific bit is set.

This is a preparation patch, for reworking the results field in the
SCSI command.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Use blist_flags_t consistently

Use the type blist_flags_t for all variables that represent blacklist
flags. Additionally, suppress recently introduced sparse warnings
related to blacklist flags.

[mkp: fixed commit id]

Fixes: 5ebde4694e3b ("scsi: Use 'blist_flags_t' for scsi_devinfo flags")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Use 'blist_flags_t' for scsi_devinfo flags

As per recommendation from Linus we should be using a distinct type for
blacklist flags.

[mkp: was cut against an older kernel, applied by hand]

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: scsi: Export blacklist flags to sysfs

Each scsi device is scanned according to the found blacklist flags, but
this information is never presented to sysfs. This makes it quite hard
to figure out if blacklisting worked as expected. With this patch we're
exporting an additional attribute 'blacklist' containing the blacklist
flags for this device.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: sd: Implement blacklist option for WRITE SAME w/ UNMAP

SBC-4 states:

"A MAXIMUM UNMAP LBA COUNT field set to a non-zero value indicates the
maximum number of LBAs that may be unmapped by an UNMAP command"

"A MAXIMUM WRITE SAME LENGTH field set to a non-zero value indicates
the maximum number of contiguous logical blocks that the device server
allows to be unmapped or written in a single WRITE SAME command."

Despite the spec being clear on the topic, some devices incorrectly
expect WRITE SAME commands with the UNMAP bit set to be limited to the
value reported in MAXIMUM UNMAP LBA COUNT in the Block Limits VPD.

Implement a blacklist option that can be used to accommodate devices
with this behavior.

Cc: <stable@vger.kernel.org>
Reported-by: Bill Kuzeja <William.Kuzeja@stratus.com>
Reported-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Document which queue type a function is intended for

Rename several functions to make it easy to see which queue type a
function is intended for.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Add STARGET_CREATED_REMOVE state to scsi_target_state

The addition of the STARGET_REMOVE state had the side effect of
introducing a race condition that can cause a crash.

scsi_target_reap_ref_release() checks the starget->state to
see if it still in STARGET_CREATED, and if so, skips calling
transport_remove_device() and device_del(), because the starget->state
is only set to STARGET_RUNNING after scsi_target_add() has called
device_add() and transport_add_device().

However, if an rport loss occurs while a target is being scanned,
it can happen that scsi_remove_target() will be called while the
starget is still in the STARGET_CREATED state. In this case, the
starget->state will be set to STARGET_REMOVE, and as a result,
scsi_target_reap_ref_release() will take the wrong path. The end
result is a panic:

[ 1255.356653] Oops: 0000 [#1] SMP
[ 1255.360154] Modules linked in: x86_pkg_temp_thermal kvm_intel kvm irqbypass crc32c_intel ghash_clmulni_i
[ 1255.393234] CPU: 5 PID: 149 Comm: kworker/u96:4 Tainted: G W 4.11.0+ #8
[ 1255.401879] Hardware name: Dell Inc. PowerEdge R320/08VT7V, BIOS 2.0.22 11/19/2013
[ 1255.410327] Workqueue: scsi_wq_6 fc_scsi_scan_rport [scsi_transport_fc]
[ 1255.417720] task: ffff88060ca8c8c0 task.stack: ffffc900048a8000
[ 1255.424331] RIP: 0010:kernfs_find_ns+0x13/0xc0
[ 1255.429287] RSP: 0018:ffffc900048abbf0 EFLAGS: 00010246
[ 1255.435123] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 1255.443083] RDX: 0000000000000000 RSI: ffffffff8188d659 RDI: 0000000000000000
[ 1255.451043] RBP: ffffc900048abc10 R08: 0000000000000000 R09: 0000012433fe0025
[ 1255.459005] R10: 0000000025e5a4b5 R11: 0000000025e5a4b5 R12: ffffffff8188d659
[ 1255.466972] R13: 0000000000000000 R14: ffff8805f55e5088 R15: 0000000000000000
[ 1255.474931] FS: 0000000000000000(0000) GS:ffff880616b40000(0000) knlGS:0000000000000000
[ 1255.483959] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1255.490370] CR2: 0000000000000068 CR3: 0000000001c09000 CR4: 00000000000406e0
[ 1255.498332] Call Trace:
[ 1255.501058] kernfs_find_and_get_ns+0x31/0x60
[ 1255.505916] sysfs_unmerge_group+0x1d/0x60
[ 1255.510498] dpm_sysfs_remove+0x22/0x60
[ 1255.514783] device_del+0xf4/0x2e0
[ 1255.518577] ? device_remove_file+0x19/0x20
[ 1255.523241] attribute_container_class_device_del+0x1a/0x20
[ 1255.529457] transport_remove_classdev+0x4e/0x60
[ 1255.534607] ? transport_add_class_device+0x40/0x40
[ 1255.540046] attribute_container_device_trigger+0xb0/0xc0
[ 1255.546069] transport_remove_device+0x15/0x20
[ 1255.551025] scsi_target_reap_ref_release+0x25/0x40
[ 1255.556467] scsi_target_reap+0x2e/0x40
[ 1255.560744] __scsi_scan_target+0xaa/0x5b0
[ 1255.565312] scsi_scan_target+0xec/0x100
[ 1255.569689] fc_scsi_scan_rport+0xb1/0xc0 [scsi_transport_fc]
[ 1255.576099] process_one_work+0x14b/0x390
[ 1255.580569] worker_thread+0x4b/0x390
[ 1255.584651] kthread+0x109/0x140
[ 1255.588251] ? rescuer_thread+0x330/0x330
[ 1255.592730] ? kthread_park+0x60/0x60
[ 1255.596815] ret_from_fork+0x29/0x40
[ 1255.600801] Code: 24 08 48 83 42 40 01 5b 41 5c 5d c3 66 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90
[ 1255.621876] RIP: kernfs_find_ns+0x13/0xc0 RSP: ffffc900048abbf0
[ 1255.628479] CR2: 0000000000000068
[ 1255.632756] ---[ end trace 34a69ba0477d036f ]---

Fix this by adding another scsi_target state STARGET_CREATED_REMOVE
to distinguish this case.

Fixes: f05795d3d771 ("scsi: Add intermediate STARGET_REMOVE state to scsi_target_state")
Reported-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: remove various unused blist flags

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Protect SCSI device state changes with a mutex

Serializing SCSI device state changes avoids that two state changes can
occur concurrently, e.g. the state changes in scsi_target_block() and
__scsi_remove_device(). This serialization is essential to make patch
"Make __scsi_remove_device go straight from BLOCKED to DEL" work
reliably.

Enable this mechanism for all scsi_target_*block() callers but not for
the scsi_internal_device_unblock() calls from the mpt3sas driver because
that driver can call scsi_internal_device_unblock() from atomic context.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: fix some kernel-doc markups

Sphinx is very pedantic with regards to ident/spacing.
Fix some kernel-doc markups in order to solve those
errors/warnings:

./drivers/scsi/scsicam.c:121: WARNING: Inline emphasis start-string without end-string.
./drivers/scsi/scsicam.c:121: WARNING: Inline emphasis start-string without end-string.
./drivers/scsi/scsicam.c:121: WARNING: Inline emphasis start-string without end-string.
./drivers/scsi/scsi_scan.c:1056: ERROR: Unexpected indentation.
./drivers/scsi/scsi_scan.c:1057: WARNING: Block quote ends without a blank line; unexpected unindent.
./drivers/scsi/scsi_transport_fc.c:2918: ERROR: Unexpected indentation.
./drivers/scsi/scsi_transport_fc.c:2921: WARNING: Block quote ends without a blank line; unexpected unindent.
./drivers/scsi/scsi_transport_fc.c:2922: WARNING: Enumerated list ends without a blank line; unexpected unindent.

No functional changes.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

scsi: Remove one useless stack variable

The local variable of 'devname' in scsi_report_lun_scan() isn't used any
more, so remove it.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Fix use-after-free

This patch fixes one use-after-free report[1] by KASAN.

In __scsi_scan_target(), when a type 31 device is probed,
SCSI_SCAN_TARGET_PRESENT is returned and the target will be scanned
again.

Inside the following scsi_report_lun_scan(), one new scsi_device
instance is allocated, and scsi_probe_and_add_lun() is called again to
probe the target and still see type 31 device, finally
__scsi_remove_device() is called to remove & free the device at the end
of scsi_probe_and_add_lun(), so cause use-after-free in
scsi_report_lun_scan().

And the following SCSI log can be observed:

scsi 0:0:2:0: scsi scan: INQUIRY pass 1 length 36
scsi 0:0:2:0: scsi scan: INQUIRY successful with code 0x0
scsi 0:0:2:0: scsi scan: peripheral device type of 31, no device added
scsi 0:0:2:0: scsi scan: Sending REPORT LUNS to (try 0)
scsi 0:0:2:0: scsi scan: REPORT LUNS successful (try 0) result 0x0
scsi 0:0:2:0: scsi scan: REPORT LUN scan
scsi 0:0:2:0: scsi scan: INQUIRY pass 1 length 36
scsi 0:0:2:0: scsi scan: INQUIRY successful with code 0x0
scsi 0:0:2:0: scsi scan: peripheral device type of 31, no device added
BUG: KASAN: use-after-free in __scsi_scan_target+0xbf8/0xe40 at addr ffff88007b44a104

This patch fixes the issue by moving the putting reference at
the end of scsi_report_lun_scan().

[1] KASAN report
==================================================================
[ 3.274597] PM: Adding info for serio:serio1
[ 3.275127] BUG: KASAN: use-after-free in __scsi_scan_target+0xd87/0xdf0 at addr ffff880254d8c304
[ 3.275653] Read of size 4 by task kworker/u10:0/27
[ 3.275903] CPU: 3 PID: 27 Comm: kworker/u10:0 Not tainted 4.8.0 #2121
[ 3.276258] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 3.276797] Workqueue: events_unbound async_run_entry_fn
[ 3.277083] ffff880254d8c380 ffff880259a37870 ffffffff94bbc6c1 ffff880078402d80
[ 3.277532] ffff880254d8bb80 ffff880259a37898 ffffffff9459fec1 ffff880259a37930
[ 3.277989] ffff880254d8bb80 ffff880078402d80 ffff880259a37920 ffffffff945a0165
[ 3.278436] Call Trace:
[ 3.278528] [<ffffffff94bbc6c1>] dump_stack+0x65/0x84
[ 3.278797] [<ffffffff9459fec1>] kasan_object_err+0x21/0x70
[ 3.279063] device: 'psaux': device_add
[ 3.279616] [<ffffffff945a0165>] kasan_report_error+0x205/0x500
[ 3.279651] PM: Adding info for No Bus:psaux
[ 3.280202] [<ffffffff944ecd22>] ? kfree_const+0x22/0x30
[ 3.280486] [<ffffffff94bc2dc9>] ? kobject_release+0x119/0x370
[ 3.280805] [<ffffffff945a0543>] __asan_report_load4_noabort+0x43/0x50
[ 3.281170] [<ffffffff9507e1f7>] ? __scsi_scan_target+0xd87/0xdf0
[ 3.281506] [<ffffffff9507e1f7>] __scsi_scan_target+0xd87/0xdf0
[ 3.281848] [<ffffffff9507d470>] ? scsi_add_device+0x30/0x30
[ 3.282156] [<ffffffff94f7f660>] ? pm_runtime_autosuspend_expiration+0x60/0x60
[ 3.282570] [<ffffffff956ddb07>] ? _raw_spin_lock+0x17/0x40
[ 3.282880] [<ffffffff9507e505>] scsi_scan_channel+0x105/0x160
[ 3.283200] [<ffffffff9507e8a2>] scsi_scan_host_selected+0x212/0x2f0
[ 3.283563] [<ffffffff9507eb3c>] do_scsi_scan_host+0x1bc/0x250
[ 3.283882] [<ffffffff9507efc1>] do_scan_async+0x41/0x450
[ 3.284173] [<ffffffff941c1fee>] async_run_entry_fn+0xfe/0x610
[ 3.284492] [<ffffffff941a8954>] ? pwq_dec_nr_in_flight+0x124/0x2a0
[ 3.284876] [<ffffffff941d1770>] ? preempt_count_add+0x130/0x160
[ 3.285207] [<ffffffff941a9a84>] process_one_work+0x544/0x12d0
[ 3.285526] [<ffffffff941aa8e9>] worker_thread+0xd9/0x12f0
[ 3.285844] [<ffffffff941aa810>] ? process_one_work+0x12d0/0x12d0
[ 3.286182] [<ffffffff941bb365>] kthread+0x1c5/0x260
[ 3.286443] [<ffffffff940855cd>] ? __switch_to+0x88d/0x1430
[ 3.286745] [<ffffffff941bb1a0>] ? kthread_worker_fn+0x5a0/0x5a0
[ 3.287085] [<ffffffff956dde9f>] ret_from_fork+0x1f/0x40
[ 3.287368] [<ffffffff941bb1a0>] ? kthread_worker_fn+0x5a0/0x5a0
[ 3.287697] Object at ffff880254d8bb80, in cache kmalloc-2048 size: 2048
[ 3.288064] Allocated:
[ 3.288147] PID = 27
[ 3.288218] [<ffffffff940b27ab>] save_stack_trace+0x2b/0x50
[ 3.288531] [<ffffffff9459f246>] save_stack+0x46/0xd0
[ 3.288806] [<ffffffff9459f4bd>] kasan_kmalloc+0xad/0xe0
[ 3.289098] [<ffffffff9459c07e>] __kmalloc+0x13e/0x250
[ 3.289378] [<ffffffff95078e5a>] scsi_alloc_sdev+0xea/0xcf0
[ 3.289701] [<ffffffff9507de76>] __scsi_scan_target+0xa06/0xdf0
[ 3.290034] [<ffffffff9507e505>] scsi_scan_channel+0x105/0x160
[ 3.290362] [<ffffffff9507e8a2>] scsi_scan_host_selected+0x212/0x2f0
[ 3.290724] [<ffffffff9507eb3c>] do_scsi_scan_host+0x1bc/0x250
[ 3.291055] [<ffffffff9507efc1>] do_scan_async+0x41/0x450
[ 3.291354] [<ffffffff941c1fee>] async_run_entry_fn+0xfe/0x610
[ 3.291695] [<ffffffff941a9a84>] process_one_work+0x544/0x12d0
[ 3.292022] [<ffffffff941aa8e9>] worker_thread+0xd9/0x12f0
[ 3.292325] [<ffffffff941bb365>] kthread+0x1c5/0x260
[ 3.292594] [<ffffffff956dde9f>] ret_from_fork+0x1f/0x40
[ 3.292886] Freed:
[ 3.292945] PID = 27
[ 3.293016] [<ffffffff940b27ab>] save_stack_trace+0x2b/0x50
[ 3.293327] [<ffffffff9459f246>] save_stack+0x46/0xd0
[ 3.293600] [<ffffffff9459fa61>] kasan_slab_free+0x71/0xb0
[ 3.293916] [<ffffffff9459bac2>] kfree+0xa2/0x1f0
[ 3.294168] [<ffffffff9508158a>] scsi_device_dev_release_usercontext+0x50a/0x730
[ 3.294598] [<ffffffff941ace9a>] execute_in_process_context+0xda/0x130
[ 3.294974] [<ffffffff9508107c>] scsi_device_dev_release+0x1c/0x20
[ 3.295322] [<ffffffff94f566f6>] device_release+0x76/0x1e0
[ 3.295626] [<ffffffff94bc2db7>] kobject_release+0x107/0x370
[ 3.295942] [<ffffffff94bc29ce>] kobject_put+0x4e/0xa0
[ 3.296222] [<ffffffff94f56e17>] put_device+0x17/0x20
[ 3.296497] [<ffffffff9505201c>] scsi_device_put+0x7c/0xa0
[ 3.296801] [<ffffffff9507e1bc>] __scsi_scan_target+0xd4c/0xdf0
[ 3.297132] [<ffffffff9507e505>] scsi_scan_channel+0x105/0x160
[ 3.297458] [<ffffffff9507e8a2>] scsi_scan_host_selected+0x212/0x2f0
[ 3.297829] [<ffffffff9507eb3c>] do_scsi_scan_host+0x1bc/0x250
[ 3.298156] [<ffffffff9507efc1>] do_scan_async+0x41/0x450
[ 3.298453] [<ffffffff941c1fee>] async_run_entry_fn+0xfe/0x610
[ 3.298777] [<ffffffff941a9a84>] process_one_work+0x544/0x12d0
[ 3.299105] [<ffffffff941aa8e9>] worker_thread+0xd9/0x12f0
[ 3.299408] [<ffffffff941bb365>] kthread+0x1c5/0x260
[ 3.299676] [<ffffffff956dde9f>] ret_from_fork+0x1f/0x40
[ 3.299967] Memory state around the buggy address:
[ 3.300209] ffff880254d8c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 3.300608] ffff880254d8c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 3.300986] >ffff880254d8c300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 3.301408] ^
[ 3.301550] ffff880254d8c380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 3.301987] ffff880254d8c400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 3.302396]
==================================================================

Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: move function declarations to scsi_priv.h

We get 2 warnings about global functions without a declaration in the
scsi driver when building with W=1:

drivers/scsi/scsi_lib.c:467:6: warning: no previous prototype for 'scsi_requeue_run_queue' [-Wmissing-prototypes]
drivers/scsi/scsi_lib.c:2609:6: warning: no previous prototype for 'scsi_evt_thread' [-Wmissing-prototypes]

In fact, both functions are declared in drivers/scsi/scsi_scan.c but
need to move them into scsi_priv.h.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Add intermediate STARGET_REMOVE state to scsi_target_state

Add intermediate STARGET_REMOVE state to scsi_target_state to avoid
running into the BUG_ON() in scsi_target_reap(). The STARGET_REMOVE
state is only valid in the path from scsi_remove_target() to
scsi_target_destroy() indicating this target is going to be removed.

This re-fixes the problem introduced in commits bc3f02a795d3 ("[SCSI]
scsi_remove_target: fix softlockup regression on hot remove") and
40998193560d ("scsi: restart list search after unlock in
scsi_remove_target") in a more comprehensive way.

[mkp: Included James' fix for scsi_target_destroy()]

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Fixes: 40998193560dab6c3ce8d25f4fa58a23e252ef38
Cc: stable@vger.kernel.org
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: James Bottomley <jejb@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: disable automatic target scan

On larger installations it is useful to disable automatic LUN scanning,
and only add the required LUNs via udev rules. This can speed up bootup
dramatically.

This patch introduces a new scan module parameter value 'manual', which
works like 'none', but can be overridden by setting the 'rescan' value
from scsi_scan_target to 'SCSI_SCAN_MANUAL'. And it updates all
relevant callers to set the 'rescan' value to 'SCSI_SCAN_MANUAL' if
invoked via the 'scan' option in sysfs.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh: add 'rescan' callback

If a device needs to be rescanned the device_handler might need
to be rechecked, too.
So add a 'rescan' callback to the device handler and call it
upon scsi_rescan_device(). The rescan callback will be invoked
from the Unit Attention handling of ASC/ASCQ 3F 03
(INQUIRY DATA HAS CHANGED).

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

scsi_dh_alua: Add new blacklist flag 'BLIST_SYNC_ALUA'

Add a new blacklist flag BLIST_SYNC_ALUA to instruct the
alua device handler to use synchronous command submission
for ALUA commands.

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

scsi: Export function scsi_scan.c:sanitize_inquiry_string

The hpsa driver uses this function to cleanup inquiry data. Our new pqi
driver will also use this function. This function was copied into both
drivers.

This patch exports sanitize_inquiry_string so the hpsa and the pqi
drivers can use this function directly.

Suggested-by: Hannes Reinecke <hare@suse.de>
Suggested-by: Matthew R. Ochs mrochs@linux.vnet.ibm.com
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Justin Lindley <justin.lindley@pmcs.com>
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: rescan VPD attributes

The VPD page information might change, so we need to be able to update
it. This patch implements a VPD page rescan whenever the 'rescan' sysfs
attribute is triggered.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Shane Seymour <shane.seymour@hpe.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: report 'INQUIRY result too short' once per host

Some host adapters (e.g. Hyper-V storvsc) are known for not respecting
the SPC-2/3/4 requirement for 'INQUIRY data (see table ...) shall
contain at least 36 bytes'. As a result we get tons on 'scsi 0:7:1:1:
scsi scan: INQUIRY result too short (5), using 36' messages on
console. This can be problematic for slow consoles. Introduce
short_inquiry flag in struct Scsi_Host to print the message once per
host.

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

scsi_scan: don't dump trace when scsi_prep_async_scan() is called twice

The only user of scsi_prep_async_scan() is scsi_scan_host() and it
handles the situation correctly. Move 'called twice' reporting to debug
level as well.

The issue is observed on Hyper-V: on any device add/remove event storvsc
driver calls scsi_scan_host() and in case previous scan is still running
we get the message and stack dump on console.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: use host wide tags by default

This patch changes the !blk-mq path to the same defaults as the blk-mq
I/O path by always enabling block tagging, and always using host wide
tags. We've had blk-mq available for a few releases so bugs with
this mode should have been ironed out, and this ensures we get better
coverage of over tagging setup over different configs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

SCSI: Increase REPORT_LUNS timeout

This patch fixes an issue seen with an IBM 2145 (SVC) where, following an error
injection test which results in paths going offline, when they came
back online, the path would timeout the REPORT_LUNS issued during the
scan. This timeout situation continued until retries were expired, resulting in
falling back to a sequential LUN scan. Then, since the target responds
with PQ=1, PDT=0 for all possible LUNs, due to the way the sequential
LUN scan code works, we end up adding 512 LUNs for each target, when there
is really only a small handful of LUNs that are actually present.

This patch increases the timeout used on the REPORT_LUNS to 30 seconds.
This patch solves the issue of 512 non existent LUNs showing up after
this event.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Move code that is used both by initiator and target drivers

Move the functions that are used by both the initiator and target
subsystems into scsi_common.c/.h. This change will allow to remove
the initiator SCSI header include directives from most SCSI target
source files in a later patch.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi_scan: fix queue depth initialisation problem

Currently we blindly use the value of cmd_per_lun as the initial setting for
queue_depth. This fails miserably (hangs the system) if it is zero, which is
the default value for anything uninitialised in the template. The net result
is that every host template has to set a value for cmd_per_lun. Instead, use
a default value of 1 if the actual value is unset. This should pave the way
for removing cmd_per_lun from all the templates and eventually from SCSI
itself.

Signed-off-by: James Bottomley <JBottomley@Odin.com>

SCSI: add 1024 max sectors black list flag

This works around a issue with qnap iscsi targets not handling large IOs
very well.

The target returns:

VPD INQUIRY: Block limits page (SBC)
Maximum compare and write length: 1 blocks
Optimal transfer length granularity: 1 blocks
Maximum transfer length: 4294967295 blocks
Optimal transfer length: 4294967295 blocks
Maximum prefetch, xdread, xdwrite transfer length: 0 blocks
Maximum unmap LBA count: 8388607
Maximum unmap block descriptor count: 1
Optimal unmap granularity: 16383
Unmap granularity alignment valid: 0
Unmap granularity alignment: 0
Maximum write same length: 0xffffffff blocks
Maximum atomic transfer length: 0
Atomic alignment: 0
Atomic transfer length granularity: 0

and it is *sometimes* able to handle at least one IO of size up to 8 MB. We
have seen in traces where it will sometimes work, but other times it
looks like it fails and it looks like it returns failures if we send
multiple large IOs sometimes. Also it looks like it can return 2 different
errors. It will sometimes send iscsi reject errors indicating out of
resources or it will send invalid cdb illegal requests check conditions.
And then when it sends iscsi rejects it does not seem to handle retries
when there are command sequence holes, so I could not just add code to
try and gracefully handle that error code.

The problem is that we do not have a good contact for the company,
so we are not able to determine under what conditions it returns
which error and why it sometimes works.

So, this patch just adds a new black list flag to set targets like this to
the old max safe sectors of 1024. The max_hw_sectors changes added in 3.19
caused this regression, so I also ccing stable.

Reported-by: Christian Hesse <list@eworm.de>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: serialize ->rescan against ->remove

Lock the device embedded in the scsi_device to protect against
concurrent calls to ->remove.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

block: support different tag allocation policy

The libata tag allocation is using a round-robin policy. Next patch will
make libata use block generic tag allocation, so let's add a policy to
tag allocation.

Currently two policies: FIFO (default) and round-robin.

Cc: Jens Axboe <axboe@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

scsi: retry report-luns when reported LU count requres more memory

Update scsi_report_lun_scan to initially always report up to 511 LUs,
as the previous default max_report_luns did. Retry in a loop if not
enough memory is available for the number of LUs reported. Parameter
max_report_luns is removed as it is no longer used.

Signed-off-by: Rob Evers <revers@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: use set/get_unaligned_be32 in report_luns

Signed-off-by: Rob Evers <revers@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: avoid unnecessary GFP_ATOMIC allocation in scsi_report_lun_scan

Signed-off-by: Rob Evers <revers@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: remove scsi_driver owner field

The driver core driver structure has grown an owner field and now
requires it to be set for all modular drivers. Set it up for
all scsi_driver instances and get rid of the now superflous
scsi_driver owner field.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Shane M Seymour <shane.seymour@hp.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: drop reason argument from ->change_queue_depth

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth. For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway. The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

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

scsi: always assign block layer tags if enabled

Allow a driver to ask for block layer tags by setting .use_blk_tags in the
host template, in which case it will always see a valid value in
request->tag, similar to the behavior when using blk-mq. This means even
SCSI "untagged" commands will now have a tag, which is especially useful
when using a host-wide tag map.

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

scsi: fix off-by-one LUN check in scsi_scan_host_selected()

The Scsi_Host structure max_lun field is the maximum allowed LUN plus 1. So
a LUN value is invalid if >= max_lun.

Signed-off-by: Mark Knibbs <markk@clara.co.uk>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: fix trivial typos in scsi_scan.c comment

Signed-off-by: Mark Knibbs <markk@clara.co.uk>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: don't add scsi_device if its already visible

If LLD has added scsi device (by calling scsi_add_device) before scheduling
async scsi_scan_host then scsi_finish_async_scan() will end up calling
scsi_sysfs_add_sdev for scsi device which was already added by LLD.
This patch fixes this issue by skipping the call to scsi_sysfs_add_sdev()
if it's already visible to rest of the kernel.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: fix the type for well known LUs

Some devices may respond with wrong type for well-known logical units.
This patch forces well-known type for devices which doesn't report it
correct.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: don't store LUN bits in CDB[1] for USB mass-storage devices

The SCSI specification requires that the second Command Data Byte
should contain the LUN value in its high-order bits if the recipient
device reports SCSI level 2 or below. Nevertheless, some USB
mass-storage devices use those bits for other purposes in
vendor-specific commands. Currently Linux has no way to send such
commands, because the SCSI stack always overwrites the LUN bits.

Testing shows that Windows 7 and XP do not store the LUN bits in the
CDB when sending commands to a USB device. This doesn't matter if the
device uses the Bulk-Only or UAS transports (which virtually all
modern USB mass-storage devices do), as these have a separate
mechanism for sending the LUN value.

Therefore this patch introduces a flag in the Scsi_Host structure to
inform the SCSI midlayer that a transport does not require the LUN
bits to be stored in the CDB, and it makes usb-storage set this flag
for all devices using the Bulk-Only transport. (UAS is handled by a
separate driver, but it doesn't really matter because no SCSI-2 or
lower device is at all likely to use UAS.)

The patch also cleans up the code responsible for storing the LUN
value by adding a bitflag to the scsi_device structure. The test for
whether to stick the LUN value in the CDB can be made when the device
is probed, and stored for future use rather than being made over and
over in the fast path.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Tiziano Bacocco <tiziano.bacocco@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: do not issue SCSI RSOC command to Promise Vtrak E610f

Some devices don't like REPORT SUPPORTED OPERATION CODES and will
simply timeout causing sd_mod init to take a very very long time.
Introduce BLIST_NO_RSOC scsi scan flag, that stops RSOC from being
issued. Add it to Promise Vtrak E610f entry in scsi scan
blacklist. Fixes bug #79901 reported at
https://bugzilla.kernel.org/show_bug.cgi?id=79901

Fixes: 98dcc2946adb ("SCSI: sd: Update WRITE SAME heuristics")

Signed-off-by: Janusz Dziemidowicz <rraptorr@nails.eu.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: add a blacklist flag which enables VPD page inquiries

Despite supporting modern SCSI features some storage devices continue to
claim conformance to an older version of the SPC spec. This is done for
compatibility with legacy operating systems.

Linux by default will not attempt to read VPD pages on devices that
claim SPC-2 or older. Introduce a blacklist flag that can be used to
trigger VPD page inquiries on devices that are known to support them.

Reported-by: KY Srinivasan <kys@microsoft.com>
Tested-by: KY Srinivasan <kys@microsoft.com>
Reviewed-by: KY Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: move the writeable field from struct scsi_device to struct scsi_cd

We currently set the field in common code based on the device type,
but then only use it in the cdrom driver which also overrides the
value previously set in the generic code.

Just leave this entirely to the CDROM driver to make everyones life
simpler.

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

scsi: add support for a blk-mq based I/O path.

This patch adds support for an alternate I/O path in the scsi midlayer
which uses the blk-mq infrastructure instead of the legacy request code.

Use of blk-mq is fully transparent to drivers, although for now a host
template field is provided to opt out of blk-mq usage in case any unforseen
incompatibilities arise.

In general replacing the legacy request code with blk-mq is a simple and
mostly mechanical transformation. The biggest exception is the new code
that deals with the fact the I/O submissions in blk-mq must happen from
process context, which slightly complicates the I/O completion handler.
The second biggest differences is that blk-mq is build around the concept
of preallocated requests that also include driver specific data, which
in SCSI context means the scsi_cmnd structure. This completely avoids
dynamic memory allocations for the fast path through I/O submission.

Due the preallocated requests the MQ code path exclusively uses the
host-wide shared tag allocator instead of a per-LUN one. This only
affects drivers actually using the block layer provided tag allocator
instead of their own. Unlike the old path blk-mq always provides a tag,
although drivers don't have to use it.

For now the blk-mq path is disable by defauly and must be enabled using
the "use_blk_mq" module parameter. Once the remaining work in the block
layer to make blk-mq more suitable for slow devices is complete I hope
to make it the default and eventually even remove the old code path.

Based on the earlier scsi-mq prototype by Nicholas Bellinger.

Thanks to Bart Van Assche and Robert Elliot for testing, benchmarking and
various sugestions and code contributions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>

scsi: use dev_printk variants where possible

Using dev_printk variants prefixes the logging message with
the originating device, which makes debugging easier.

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

scsi_scan: Fixup scsilun_to_int()

scsilun_to_int() has an error which prevents it from generating
correct LUN numbers for 64bit values.
Also we should remove the misleading comment about portions of
the LUN being ignored; the initiator should treat the LUN as
an opaque value.
And, finally, the example given should use the correct
prefix (here: extended flat space addressing scheme).

This patch includes the modifications suggested by
Bart van Assche.

Cc: Bart van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: James Bottomley <jbottomley@parallels.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: use 64-bit value for 'max_luns'

Now that we're using 64-bit LUNs internally we need to increase
the size of max_luns to 64 bits, too.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: use 64-bit LUNs

The SCSI standard defines 64-bit values for LUNs, and large arrays
employing large or hierarchical LUN numbers become more and more
common.

So update the linux SCSI stack to use 64-bit LUN numbers.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi_scan: Restrict sequential scan to 256 LUNs

Sequential scan for more than 256 LUNs is very fragile as
LUNs might not be numbered sequentially after that point.

SAM revisions later than SCSI-3 impose a structure on
LUNs larger than 256, making LUN numbers between 256
and 16384 illegal.
SCSI-3, however allows for plain 64-bit numbers with
no internal structure.

So restrict sequential LUN scan to 256 LUNs and add a
new blacklist flag 'BLIST_SCSI3LUN' to scan up to
max_lun devices.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: Remove CONFIG_SCSI_MULTI_LUN

Obsolete; either use 'max_lun' if the host supports only a
limited number of LUNs or BLIST_NOLUN if the target has
problems addressing more than one LUN.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: async sd resume

async_schedule() sd resume work to allow disks and other devices to
resume in parallel.

This moves the entirety of scsi_device resume to an async context to
ensure that scsi_device_resume() remains ordered with respect to the
completion of the start/stop command. For the duration of the resume,
new command submissions (that do not originate from the scsi-core) will
be deferred (BLKPREP_DEFER).

It adds a new ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain) as a container
of these operations. Like scsi_sd_probe_domain it is flushed at
sd_remove() time to ensure async ops do not continue past the
end-of-life of the sdev. The implementation explicitly refrains from
reusing scsi_sd_probe_domain directly for this purpose as it is flushed
at the end of dpm_resume(), potentially defeating some of the benefit.
Given sdevs are quiesced it is permissible for these resume operations
to bleed past the async_synchronize_full() calls made by the driver
core.

We defer the resolution of which pm callback to call until
scsi_dev_type_{suspend|resume} time and guarantee that the callback
parameter is never NULL. With this in place the type of resume
operation is encoded in the async function identifier.

There is a concern that async resume could trigger PSU overload. In the
enterprise, storage enclosures enforce staggered spin-up regardless of
what the kernel does making async scanning safe by default. Outside of
that context a user can disable asynchronous scanning via a kernel
command line or CONFIG_SCSI_SCAN_ASYNC. Honor that setting when
deciding whether to do resume asynchronously.

Inspired by Todd's analysis and initial proposal [2]:
https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach

Cc: Len Brown <len.brown@intel.com>
Cc: Phillip Susi <psusi@ubuntu.com>
[alan: bug fix and clean up suggestion]
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
[djbw: kick all resume work to the async queue]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

[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>

[SCSI] dual scan thread bug fix

In the highly unusual case where two threads are running concurrently through
the scanning code scanning the same target, we run into the situation where
one may allocate the target while the other is still using it. In this case,
because the reap checks for STARGET_CREATED and kills the target without
reference counting, the second thread will do the wrong thing on reap.

Fix this by reference counting even creates and doing the STARGET_CREATED
check in the final put.

Tested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org # delay backport for 2 months for field testing
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[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>

[SCSI] Workaround for disks that report bad optimal transfer length

Not all disks fill out the VPD pages correctly. Add a blacklist flag
that allows us ignore the SBC-3 VPD pages for a given device. The
BLIST_SKIP_VPD_PAGES flag triggers our existing skip_vpd_pages
scsi_device parameter to bypass VPD scanning.

Also blacklist the offending Seagate drive model.

Reported-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Allow error handling timeout to be specified

Introduce eh_timeout which can be used for error handling purposes. This
was previously hardcoded to 10 seconds in the SCSI error handling
code. However, for some fast-fail scenarios it is necessary to be able
to tune this as it can take several iterations (bus device, target, bus,
controller) before we give up.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Disable DIF on Hitachi Ultrastar 15K300

Hitachi Ultrastar 15K300 is quirky. Disable T10 PI (DIF).

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Fix 'Device not ready' issue on mpt2sas

This is a particularly nasty SCSI ATA Translation Layer (SATL) problem.

SAT-2 says (section 8.12.2)

if the device is in the stopped state as the result of
processing a START STOP UNIT command (see 9.11), then the SATL
shall terminate the TEST UNIT READY command with CHECK CONDITION
status with the sense key set to NOT READY and the additional
sense code of LOGICAL UNIT NOT READY, INITIALIZING COMMAND
REQUIRED;

mpt2sas internal SATL seems to implement this. The result is very confusing
standby behaviour (using hdparm -y). If you suspend a drive and then send
another command, usually it wakes up. However, if the next command is a TEST
UNIT READY, the SATL sees that the drive is suspended and proceeds to follow
the SATL rules for this, returning NOT READY to all subsequent commands. This
means that the ordering of TEST UNIT READY is crucial: if you send TUR and
then a command, you get a NOT READY to both back. If you send a command and
then a TUR, you get GOOD status because the preceeding command woke the drive.

This bit us badly because

commit 85ef06d1d252f6a2e73b678591ab71caad4667bb
Author: Tejun Heo <tj@kernel.org>
Date: Fri Jul 1 16:17:47 2011 +0200

block: flush MEDIA_CHANGE from drivers on close(2)

Changed our ordering on TEST UNIT READY commands meaning that SATA drives
connected to an mpt2sas now suspend and refuse to wake (because the mpt2sas
SATL sees the suspend *before* the drives get awoken by the next ATA command)
resulting in lots of failed commands.

The standard is completely nuts forcing this inconsistent behaviour, but we
have to work around it.

The fix for this is twofold:

1. Set the allow_restart flag so we wake the drive when we see it has been
suspended

2. Return all TEST UNIT READY status directly to the mid layer without any
further error handling which prevents us causing error handling which
may offline the device just because of a media check TUR.

Reported-by: Matthias Prager <linux@matthiasprager.de>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Revert "[SCSI] fix async probe regression"

This reverts commit 43a8d39d0137612c336aa8bbb2cb886a79772ffb.

Commit 43a8d39d fixed the fact that wait_for_device_probe() was unable
to flush sd probe work. Now that sd probe work is once again flushable
via wait_for_device_probe() this workaround is no longer needed.

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

[SCSI] cleanup usages of scsi_complete_async_scans

Now that scsi registers its async scan work with the async subsystem,
wait_for_device_probe() is sufficient for ensuring all scanning is
complete.

[jejb: fix merge problems with eea03c20ae38 Make wait_for_device_probe() also do scsi_complete_async_scans()]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] queue async scan work to an async_schedule domain

This is preparation to enable async_synchronize_full() to be used as a
replacement for scsi_complete_async_scans(), i.e. to stop leaking scsi
internal details where they are not needed.

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

[SCSI] fix hot unplug vs async scan race

The following crash results from cases where the end_device has been
removed before scsi_sysfs_add_sdev has had a chance to run.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
IP: [<ffffffff8115e100>] sysfs_create_dir+0x32/0xb6
...
Call Trace:
[<ffffffff8125e4a8>] kobject_add_internal+0x120/0x1e3
[<ffffffff81075149>] ? trace_hardirqs_on+0xd/0xf
[<ffffffff8125e641>] kobject_add_varg+0x41/0x50
[<ffffffff8125e70b>] kobject_add+0x64/0x66
[<ffffffff8131122b>] device_add+0x12d/0x63a
[<ffffffff814b65ea>] ? _raw_spin_unlock_irqrestore+0x47/0x56
[<ffffffff8107de15>] ? module_refcount+0x89/0xa0
[<ffffffff8132f348>] scsi_sysfs_add_sdev+0x4e/0x28a
[<ffffffff8132dcbb>] do_scan_async+0x9c/0x145

...teach scsi_sysfs_add_devices() to check for deleted devices() before
trying to add them, and teach scsi_remove_target() how to remove targets
that have not been added via device_add().

Cc: <stable@vger.kernel.org>
Reported-by: Dariusz Majchrzak <dariusz.majchrzak@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] fix async probe regression

Commit a7a20d1 "[SCSI] sd: limit the scope of the async probe domain"
moved sd probe work out of reach of wait_for_device_probe(). Allow it
to be synced via scsi_complete_async_scans().

Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_scan: Fix 'Poison overwritten' warning caused by using freed 'shost'

In do_scan_async(), calling scsi_autopm_put_host(shost) may reference
freed shost, and cause Posison overwitten warning.
Yes, this case can happen, for example, an USB is disconnected just
when do_scan_async() thread starts to run, then scsi_host_put() called
in scsi_finish_async_scan() will lead to shost be freed(because the
refcount of shost->shost_gendev decreases to 1 after USB disconnects),
at this point, if references shost again, system will show following
warning msg.

To make scsi_autopm_put_host(shost) always reference a valid shost,
put it just before scsi_host_put() in function
scsi_finish_async_scan().

[ 299.281565] =============================================================================
[ 299.281634] BUG kmalloc-4096 (Tainted: G I ): Poison overwritten
[ 299.281682] -----------------------------------------------------------------------------
[ 299.281684]
[ 299.281752] INFO: 0xffff880056c305d0-0xffff880056c305d0. First byte
0x6a instead of 0x6b
[ 299.281816] INFO: Allocated in scsi_host_alloc+0x4a/0x490 age=1688
cpu=1 pid=2004
[ 299.281870] __slab_alloc+0x617/0x6c1
[ 299.281901] __kmalloc+0x28c/0x2e0
[ 299.281931] scsi_host_alloc+0x4a/0x490
[ 299.281966] usb_stor_probe1+0x5b/0xc40 [usb_storage]
[ 299.282010] storage_probe+0xa4/0xe0 [usb_storage]
[ 299.282062] usb_probe_interface+0x172/0x330 [usbcore]
[ 299.282105] driver_probe_device+0x257/0x3b0
[ 299.282138] __driver_attach+0x103/0x110
[ 299.282171] bus_for_each_dev+0x8e/0xe0
[ 299.282201] driver_attach+0x26/0x30
[ 299.282230] bus_add_driver+0x1c4/0x430
[ 299.282260] driver_register+0xb6/0x230
[ 299.282298] usb_register_driver+0xe5/0x270 [usbcore]
[ 299.282337] 0xffffffffa04ab03d
[ 299.282364] do_one_initcall+0x47/0x230
[ 299.282396] sys_init_module+0xa0f/0x1fe0
[ 299.282429] INFO: Freed in scsi_host_dev_release+0x18a/0x1d0 age=85
cpu=0 pid=2008
[ 299.282482] __slab_free+0x3c/0x2a1
[ 299.282510] kfree+0x296/0x310
[ 299.282536] scsi_host_dev_release+0x18a/0x1d0
[ 299.282574] device_release+0x74/0x100
[ 299.282606] kobject_release+0xc7/0x2a0
[ 299.282637] kobject_put+0x54/0xa0
[ 299.282668] put_device+0x27/0x40
[ 299.282694] scsi_host_put+0x1d/0x30
[ 299.282723] do_scan_async+0x1fc/0x2b0
[ 299.282753] kthread+0xdf/0xf0
[ 299.282782] kernel_thread_helper+0x4/0x10
[ 299.282817] INFO: Slab 0xffffea00015b0c00 objects=7 used=7 fp=0x
(null) flags=0x100000000004080
[ 299.282882] INFO: Object 0xffff880056c30000 @offset=0 fp=0x (null)
[ 299.282884]
...

Signed-off-by: Huajun Li <huajun.li.lee@gmail.com>
Cc: stable@kernel.org
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

SCSI & usb-storage: add flags for VPD pages and REPORT LUNS

This patch (as1507) adds a skip_vpd_pages flag to struct scsi_device
and a no_report_luns flag to struct scsi_target. The first is used to
control whether sd will look at VPD pages for information on block
provisioning, limits, and characteristics. The second prevents
scsi_report_lun_scan() from issuing a REPORT LUNS command.

The patch also modifies usb-storage to set the new flag bits for all
USB devices and targets, and to stop adjusting the scsi_level value.

Historically we have seen that USB mass-storage devices often don't
support VPD pages or REPORT LUNS properly. Until now we have avoided
these things by setting the scsi_level to SCSI_2 for all USB devices.
But this has the side effect of storing the LUN bits into the second
byte of each CDB, and now we have a report of a device which doesn't
like that. The best solution is to stop abusing scsi_level and
instead have separate flags for VPD pages and REPORT LUNS.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Perry Wagle <wagle@mac.com>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

block: misc updates to blk_get_queue()

* blk_get_queue() is peculiar in that it returns 0 on success and 1 on
failure instead of 0 / -errno or boolean. Update it such that it
returns %true on success and %false on failure.

* Make sure the caller checks for the return value.

* Separate out __blk_get_queue() which doesn't check whether @q is
dead and put it in blk.h. This will be used later.

This patch doesn't introduce any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

[SCSI] fix WARNING: at drivers/scsi/scsi_lib.c:1704

On Mon, 2011-11-07 at 17:24 +1100, Stephen Rothwell wrote:
> Hi all,
>
> Starting some time last week I am getting the following during boot on
> our PPC970 blade:
>
> calling .ipr_init+0x0/0x68 @ 1
> ipr: IBM Power RAID SCSI Device Driver version: 2.5.2 (April 27, 2011)
> ipr 0000:01:01.0: Found IOA with IRQ: 26
> ipr 0000:01:01.0: Starting IOA initialization sequence.
> ipr 0000:01:01.0: Adapter firmware version: 06160039
> ipr 0000:01:01.0: IOA initialized.
> scsi0 : IBM 572E Storage Adapter
> ------------[ cut here ]------------
> WARNING: at drivers/scsi/scsi_lib.c:1704
> Modules linked in:
> NIP: c00000000053b3d4 LR: c00000000053e5b0 CTR: c000000000541d70
> REGS: c0000000783c2f60 TRAP: 0700 Not tainted (3.1.0-autokern1)
> MSR: 8000000000029032 <EE,ME,CE,IR,DR> CR: 24002024 XER: 20000002
> TASK = c0000000783b8000[1] 'swapper' THREAD: c0000000783c0000 CPU: 0
> GPR00: 0000000000000001 c0000000783c31e0 c000000000cf38b0 c00000000239a9d0
> GPR04: c000000000cbe8f8 0000000000000000 c0000000783c3040 0000000000000000
> GPR08: c000000075daf488 c000000078a3b7ff c000000000bcacc8 0000000000000000
> GPR12: 0000000044002028 c000000007ffb000 0000000002e40000 000000000099b800
> GPR16: 0000000000000000 c000000000bba5fc c000000000a61db8 0000000000000000
> GPR20: 0000000001b77200 0000000000000000 c000000078990000 0000000000000001
> GPR24: c000000002396828 0000000000000000 0000000000000000 c000000078a3b938
> GPR28: fffffffffffffffa c0000000008ad2c0 c000000000c7faa8 c00000000239a9d0
> NIP [c00000000053b3d4] .scsi_free_queue+0x24/0x90
> LR [c00000000053e5b0] .scsi_alloc_sdev+0x280/0x2e0
> Call Trace:
> [c0000000783c31e0] [c000000000c7faa8] wireless_seq_fops+0x278d0/0x2eb88 (unreliable)
> [c0000000783c3270] [c00000000053e5b0] .scsi_alloc_sdev+0x280/0x2e0
> [c0000000783c3330] [c00000000053eba0] .scsi_probe_and_add_lun+0x390/0xb40
> [c0000000783c34a0] [c00000000053f7ec] .__scsi_scan_target+0x16c/0x650
> [c0000000783c35f0] [c00000000053fd90] .scsi_scan_channel+0xc0/0x100
> [c0000000783c36a0] [c00000000053fefc] .scsi_scan_host_selected+0x12c/0x1c0
> [c0000000783c3750] [c00000000083dcb4] .ipr_probe+0x2c0/0x390
> [c0000000783c3830] [c0000000003f50b4] .local_pci_probe+0x34/0x50
> [c0000000783c38a0] [c0000000003f5f78] .pci_device_probe+0x148/0x150
> [c0000000783c3950] [c0000000004e1e8c] .driver_probe_device+0xdc/0x210
> [c0000000783c39f0] [c0000000004e20cc] .__driver_attach+0x10c/0x110
> [c0000000783c3a80] [c0000000004e1228] .bus_for_each_dev+0x98/0xf0
> [c0000000783c3b30] [c0000000004e1bf8] .driver_attach+0x28/0x40
> [c0000000783c3bb0] [c0000000004e07d8] .bus_add_driver+0x218/0x340
> [c0000000783c3c60] [c0000000004e2a2c] .driver_register+0x9c/0x1b0
> [c0000000783c3d00] [c0000000003f62d4] .__pci_register_driver+0x64/0x140
> [c0000000783c3da0] [c000000000b99f88] .ipr_init+0x4c/0x68
> [c0000000783c3e20] [c00000000000ad24] .do_one_initcall+0x1a4/0x1e0
> [c0000000783c3ee0] [c000000000b512d0] .kernel_init+0x14c/0x1fc
> [c0000000783c3f90] [c000000000022468] .kernel_thread+0x54/0x70
> Instruction dump:
> ebe1fff8 7c0803a6 4e800020 7c0802a6 fba1ffe8 fbe1fff8 7c7f1b78 f8010010
> f821ff71 e8030398 3120ffff 7c090110 <0b000000> e86303b0 482de065 60000000
> ---[ end trace 759bed76a85e8dec ]---
> scsi 0:0:1:0: Direct-Access IBM-ESXS MAY2036RC T106 PQ: 0 ANSI: 5
> ------------[ cut here ]------------
>
> I get lots more of these. The obvious commit to point the finger at
> is 3308511c93e6 ("[SCSI] Make scsi_free_queue() kill pending SCSI
> commands") but the root cause may be something different.

Caused by

commit f7c9c6bb14f3104608a3a83cadea10a6943d2804
Author: Anton Blanchard <anton@samba.org>
Date: Thu Nov 3 08:56:22 2011 +1100

[SCSI] Fix block queue and elevator memory leak in scsi_alloc_sdev

Doesn't completely do the teardown. The true fix is to do a proper
teardown instead of hand rolling it

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: stable@kernel.org #2.6.38+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Fix block queue and elevator memory leak in scsi_alloc_sdev

When looking at memory consumption issues I noticed quite a
lot of memory in the kmalloc-2048 bucket:

OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
6561 6471 98% 2.30K 243 27 15552K kmalloc-2048

Over 15MB. slub debug shows that cfq is responsible for almost
all of it:

# sort -nr /sys/kernel/slab/kmalloc-2048/alloc_calls
6402 .cfq_init_queue+0xec/0x460 age=43423/43564/43655 pid=1 cpus=4,11,13

In scsi_alloc_sdev we do scsi_alloc_queue but if slave_alloc
fails we don't free it with scsi_free_queue.

The patch below fixes the issue:

OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
135 72 53% 2.30K 5 27 320K kmalloc-2048

# cat /sys/kernel/slab/kmalloc-2048/alloc_calls
3 .cfq_init_queue+0xec/0x460 age=3811/3876/3925 pid=1 cpus=4,11,13

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org> #2.6.38+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Fix oops caused by queue refcounting failure

In certain circumstances, we can get an oops from a torn down device.
Most notably this is from CD roms trying to call scsi_ioctl. The root
cause of the problem is the fact that after scsi_remove_device() has
been called, the queue is fully torn down. This is actually wrong
since the queue can be used until the sdev release function is called.
Therefore, we add an extra reference to the queue which is released in
sdev->release, so the queue always exists.

Reported-by: Parag Warudkar <parag.lkml@gmail.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <jbottomley@parallels.com>

scsi: remove performance regression due to async queue run

Commit c21e6beb removed our queue request_fn re-enter
protection, and defaulted to always running the queues from
kblockd to be safe. This was a known potential slow down,
but should be safe.

Unfortunately this is causing big performance regressions for
some, so we need to improve this logic. Looking into the details
of the re-enter, the real issue is on requeue of requests.

Requeue of requests upon seeing a BUSY condition from the device
ends up re-running the queue, causing traces like this:

scsi_request_fn()
scsi_dispatch_cmd()
scsi_queue_insert()
__scsi_queue_insert()
scsi_run_queue()
scsi_request_fn()
...

potentially causing the issue we want to avoid. So special
case the requeue re-run of the queue, but improve it to offload
the entire run of local queue and starved queue from a single
workqueue callback. This is a lot better than potentially
kicking off a workqueue run for each device seen.

This also fixes the issue of the local device going into recursion,
since the above mentioned commit never moved that queue run out
of line.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

driver core: remove CONFIG_SYSFS_DEPRECATED_V2 but keep it for block devices

This patch removes the old CONFIG_SYSFS_DEPRECATED_V2 config option,
but it keeps the logic around to handle block devices in the old manner
as some people like to run new kernel versions on old (pre 2007/2008)
distros.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[SCSI] implement runtime Power Management

This patch (as1398b) adds runtime PM support to the SCSI layer. Only
the machanism is provided; use of it is up to the various high-level
drivers, and the patch doesn't change any of them. Except for sg --
the patch expicitly prevents a device from being runtime-suspended
while its sg device file is open.

The implementation is simplistic. In general, hosts and targets are
automatically suspended when all their children are asleep, but for
them the runtime-suspend code doesn't actually do anything. (A host's
runtime PM status is propagated up the device tree, though, so a
runtime-PM-aware lower-level driver could power down the host adapter
hardware at the appropriate times.) There are comments indicating
where a transport class might be notified or some other hooks added.

LUNs are runtime-suspended by calling the drivers' existing suspend
handlers (and likewise for runtime-resume). Somewhat arbitrarily, the
implementation delays for 100 ms before suspending an eligible LUN.
This is because there typically are occasions during bootup when the
same device file is opened and closed several times in quick
succession.

The way this all works is that the SCSI core increments a device's
PM-usage count when it is registered. If a high-level driver does
nothing then the device will not be eligible for runtime-suspend
because of the elevated usage count. If a high-level driver wants to
use runtime PM then it can call scsi_autopm_put_device() in its probe
routine to decrement the usage count and scsi_autopm_get_device() in
its remove routine to restore the original count.

Hosts, targets, and LUNs are not suspended while they are being probed
or removed, or while the error handler is running. In fact, a fairly
large part of the patch consists of code to make sure that things
aren't suspended at such times.

[jejb: fix up compile issues in PM config variations]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fix race in scsi_target_reap

This patch (as1357) fixes a race in SCSI target allocation and
release. Putting a target in the STARGET_DEL state isn't protected by
the host lock, so an old target structure could be reused by a new
device even though it's about to be deleted. The cure is to change
the state while still holding the host lock.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

scsi_scan.c: fix/convert functions to use kernel-doc

scsi_scan.c: fix incorrectly formatted kernel-doc notation
& convert documentation of 2 functions into kernel-doc.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] don't kfree an initialized struct device

This patch (as1359) fixes a bug in scsi_alloc_target(). After a
device structure has been initialized (and especially after its name
has been set), it must not be freed directly. One has to call
put_device() instead.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

block: Rename blk_queue_max_sectors to blk_queue_max_hw_sectors

The block layer calling convention is blk_queue_<limit name>.
blk_queue_max_sectors predates this practice, leading to some confusion.
Rename the function to appropriately reflect that its intended use is to
set max_hw_sectors.

Also introduce a temporary wrapper for backwards compability. This can
be removed after the merge window is closed.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

[SCSI] fix refcounting bug in scsi_get_host_dev

This patch (as1334) fixes a bug in scsi_get_host_dev(). It
incorrectly calls get_device() on the new device's target.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fix memory leak in scsi_report_lun_scan

This patch (as1333) fixes a bug in scsi_report_lun_scan(). If a
newly-allocated device can't be used, it should be deleted.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] add queue_depth ramp up code

Current FC HBA queue_depth ramp up code depends on last queue
full time. The sdev already has last_queue_full_time field to
track last queue full time but stored value is truncated by
last four bits.

So this patch updates last_queue_full_time without truncating
last 4 bits to store full value and then updates its only
current usages in scsi_track_queue_full to ignore last four bits
to keep current usages same while also use this field
in added ramp up code.

Adds scsi_handle_queue_ramp_up to ramp up queue_depth on
successful completion of IO. The scsi_handle_queue_ramp_up will
do ramp up on all luns of a target, just same as ramp down done
on all luns on a target.

The ramp up is skipped in case the change_queue_depth is not
supported by LLD or already reached to added max_queue_depth.

Updates added max_queue_depth on every new update to default
queue_depth value.

The ramp up is also skipped if lapsed time since either last
queue ramp up or down is less than LLD specified
queue_ramp_up_period.

Adds queue_ramp_up_period to sysfs but only if change_queue_depth
is supported since ramp up and queue_ramp_up_period is needed only
in case change_queue_depth is supported first.

Initializes queue_ramp_up_period to 120HZ jiffies as initial
default value, it is same as used in existing lpfc and qla2xxx.

-v2
Combined all ramp code into this single patch.

-v3
Moves max_queue_depth initialization after slave_configure is
called from after slave_alloc calling done. Also adjusted
max_queue_depth check to skip ramp up if current queue_depth
is >= max_queue_depth.

-v4
Changes sdev->queue_ramp_up_period unit to ms when using sysfs i/f
to store or show its value.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Tested-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fix async scan add/remove race resulting in an oops

Async scanning introduced a very wide window where the SCSI device is
up and running but has not yet been added to sysfs. We delay the
adding until all scans have completed to retain the same ordering as
sync scanning.

This delay in visibility causes an oops if a device is removed before
we make it visible because the SCSI removal routines have an inbuilt
assumption that if a device is in SDEV_RUNNING state, it must be
visible (which is not necessarily true in the async scanning case).

Fix this by introducing an additional is_visible flag which we can use
to condition the tear down so we do the right thing for running but
not yet made visible.

Reported-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fix memory leak in initialization

The root cause of the problem is the fact that dev_set_name() now
allocates storage instead of using the original array within the kobj.
That means that the SCSI assumption that if you haven't made the
containing object or any sub objects visible, you can just destroy it
(and its component devices) lock stock and barrel becomes false.

Fix this by doing the get of sdev_dev at parent time and thus do an
extra put of it in scsi_destroy_sdev() (and all other destruction
without add paths).

Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] Increase default timeout for INQUIRY

This patch (as1224) changes the default timeout for INQUIRY commands
from 3 seconds to 20 seconds, which is the value used by Windows for
USB Mass-Storage devices. Some of these devices, like the Corsair
Flash Voyager (see Bugzilla #12188) really do need a long timeout.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] initialize max_target_blocked in scsi_alloc_target

This patch initializes the max_target_blocked field of a scsi target
structure so that a queuecommand return value of
SCSI_MLQUEUE_TARGET_BUSY will actually result in having the
scsi_queue_insert blocking the device queue before requeuing the
command and running the queue. Otherwise, can and does cause livelock
on single CPU configurations if/when open-iSCSI software initiator's
command PDU window fills.

Signed-off-by: Ed Goggin <egoggin@vmware.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

driver synchronization: make scsi_wait_scan more advanced

There is currently only one way for userspace to say "wait for my storage
device to get ready for the modules I just loaded": to load the
scsi_wait_scan module. Expectations of userspace are that once this
module is loaded, all the (storage) devices for which the drivers
were loaded before the module load are present.

Now, there are some issues with the implementation, and the async
stuff got caught in the middle of this: The existing code only
waits for the scsy async probing to finish, but it did not take
into account at all that probing might not have begun yet.
(Russell ran into this problem on his computer and the fix works for him)

This patch fixes this more thoroughly than the previous "fix", which
had some bad side effects (namely, for kernel code that wanted to wait for
the scsi scan it would also do an async sync, which would deadlock if you did
it from async context already.. there's a report about that on lkml):
The patch makes the module first wait for all device driver probes, and then it
will wait for the scsi parallel scan to finish.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] add OSD_TYPE

- Define the OSD_TYPE scsi device and let it show up in scans

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_scan: add missing interim SDEV_DEL state if slave_alloc fails

We were running i/o and performing a bunch of hba resets in a loop.
This forces a lot of target removes and then rescans. Since the
resets are occuring during scan it's causing the scan i/o to timeout,
invoking error recovery, etc. We end up getting some nasty crashing
in scsi_scan.c due to references to old sdevs that are failing
but had some lingering references that kept them around.

Fix by setting device state to SDEV_DEL if the LLD's slave_alloc
fails.

Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

fastboot: make scsi probes asynchronous

This patch makes part of the scsi probe (which is mostly device spin up and the
partition scan) asynchronous. Only the part that runs after getting the device
number allocated is asynchronous, ensuring that device numbering remains stable.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

[SCSI] struct device - replace bus_id with dev_name(), dev_set_name()

[jejb: limit ioctl to returning 20 characters to avoid overrun
on long device names and add a few more conversions]
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] retry with missing data for INQUIRY

This patch changes scsi_probe_lun() to retry INQUIRY if the device has
not actually sent back any INQUIRY data,

This enables the Thecus N2050 storage device to work better. The
firmware on that device starts up strangely; it sends no data in
response to the initial INQUIRY, and it sends the INQUIRY information
in response to the followup REQUEST SENSE. But after that it works
better, so retrying the INQUIRY is enough to get it going.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] add residual argument to scsi_execute and scsi_execute_req

scsi_execute() and scsi_execute_req() discard the residual length
information. Some callers need it. This adds residual argument
(optional) to scsi_execute and scsi_execute_req.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Add helper code so transport classes/driver can control queueing (v3)

SCSI-ml manages the queueing limits for the device and host, but
does not do so at the target level. However something something similar
can come in userful when a driver is transitioning a transport object to
the the blocked state, becuase at that time we do not want to queue
io and we do not want the queuecommand to be called again.

The patch adds code similar to the exisiting SCSI_ML_*BUSY handlers.
You can now return SCSI_MLQUEUE_TARGET_BUSY when we hit
a transport level queueing issue like the hw cannot allocate some
resource at the iscsi session/connection level, or the target has temporarily
closed or shrunk the queueing window, or if we are transitioning
to the blocked state.

bnx2i, when they rework their firmware according to netdev
developers requests, will also need to be able to limit queueing at this
level. bnx2i will hook into libiscsi, but will allocate a scsi host per
netdevice/hba, so unlike pure software iscsi/iser which is allocating
a host per session, it cannot set the scsi_host->can_queue and return
SCSI_MLQUEUE_HOST_BUSY to reflect queueing limits on the transport.

The iscsi class/driver can also set a scsi_target->can_queue value which
reflects the max commands the driver/class can support. For iscsi this
reflects the number of commands we can support for each session due to
session/connection hw limits, driver limits, and to also reflect the
session/targets's queueing window.

Changes:
v1 - initial patch.
v2 - Fix scsi_run_queue handling of multiple blocked targets.
Previously we would break from the main loop if a device was added back on
the starved list. We now run over the list and check if any target is
blocked.
v3 - Rediff for scsi-misc.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Update the SCSI state model to allow blocking in the created state

Brian King <brking@linux.vnet.ibm.com> reported that fibre channel
devices can oops during scanning if their ports block (because the
device goes from CREATED -> BLOCK -> RUNNING rather than CREATED ->
BLOCK -> CREATED).

Fix this by adding a new state: CREATED_BLOCK which can only transition
back to CREATED and disallow the CREATED -> BLOCK transition. Now both
the created and blocked states that the mid-layer recognises can include
CREATED_BLOCK.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] add inline functions for recognising created and blocked states

The created and blocked states are very shortly going to correspond to
mixed sdev_state states.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] fix check of PQ and PDT bits for WLUNs

For IBM z series certain LUNs can no longer be accessed.

This is because kernel version 2.6.19 a check was introduced not to
create a generic SCSI device for devices that return PQ=1 and
PDT=0x1f. For WLUNs (see SAM-3, p. 41ff) generic SCSI devices should
be created unconditionally without looking at the PQ bit, so add a
check for WLUNs in with this test.

Acked-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] replace __FUNCTION__ with __func__

[jejb: fixed up a ton of missed conversions.

All of you are on notice this has happened, driver trees will now
need to be rebased]

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: SCSI List <linux-scsi@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_scan.c: Release mutex in error handling code

The mutex is released on a successful return, so it would seem that it
should be released on an error return as well.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression l;
@@

mutex_lock(l);
... when != mutex_unlock(l)
when any
when strict
(
if (...) { ... when != mutex_unlock(l)
+ mutex_unlock(l);
return ...;
}
|
mutex_unlock(l);
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] make struct scsi_{host,target}_type static

Make the needlessly global struct scsi_{host,target}_type static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

Remove duplicated unlikely() in IS_ERR()

Some drivers have duplicated unlikely() macros. IS_ERR() already has
unlikely() in itself.

This patch cleans up such pointless code.

Signed-off-by: Hirofumi Nakagawa <hnakagawa@miraclelinux.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jeff Garzik <jeff@garzik.org>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] rework scsi_target allocation

The current target allocation code registeres each possible target
with sysfs; it will be deleted again if no useable LUN on this target
was found. This results in a string of 'target add/target remove' uevents.

Based on a patch by Hannes Reinecke <hare@suse.de> this patch reworks
the target allocation code so that only uevents for existing targets
are sent. The sysfs registration is split off from the existing
scsi_target_alloc() into a in a new scsi_add_target() function, which
should be called whenever an existing target is found. Only then a
uevent is sent, so we'll be generating events for existing targets
only.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] add scsi_host and scsi_target to scsi_bus

This patch implements scsi_host and scsi_target device types
and adds both to the scsi_bus.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] docbook: fix scsi source file

Fix docbook problem in SCSI source files.
These cause the generated docbook to be incorrect.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

docbook: fix scsi source file

Fix docbook problem in SCSI source files.
These cause the generated docbook to be incorrect.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] add missing transport configure points for target and host

While trying to convert the SPI transport class to attribute groups, I
discovered that we don't actually have any transport configure points
for either the target or the host. This patch adds these missing
transport class triggers. The host one is simply done after the add,
the target one tries to be more clever and add it after devices may have
been placed on the target (so the device configure will have set up the
target parameters).

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] move single_lun flag from scsi_device to scsi_target

Some SCSI tape medium changers that need the BLIST_SINGLELUN flag have
the medium changer at one LUN and the tape drive at a different LUN.
The inquiry string of the tape drive may be different from that of the
medium changer. In order for single_lun to be effective, every
scsi_device under a given scsi_target must have it set. This means that
there needs to be a blacklist entry for BOTH the medium changer AND the
tape drive, which is impractical because some medium changers may be
paired with a variety of different tape drive models. It makes more
sense to put the single_lun flag in scsi_target instead of scsi_device,
which causes every device at a given target ID to inherit the single_lun
flag from one LUN. This makes it possible to blacklist just the medium
changer and not the tape drive.

Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Add Documentation and integrate into docbook build

Add Documentation/DocBook/scsi_midlayer.tmpl, add to Makefile, and update
lots of kerneldoc comments in drivers/scsi/*.

Updated with comments from Stefan Richter, Stephen M. Cameron,
James Bottomley and Randy Dunlap.

Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

SCSI: add asynchronous event notification API

Originally based on a patch by Kristen Carlson Accardi @ Intel.
Copious input from James Bottomley.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[SCSI] scsi_scan: Cope with kthread_run failing

If kthread_run failed, we would fail to scan the host, and leak the
allocated async_scan_data. Since using a separate thread is just an
optimisation, do the scan synchronously if we fail to spawn a thread.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Fix signness of parameters in scsi module

In scsi module I've found some inconsistency between variable type
used in module_param_named and type passed to module_param_named as an
argument. Especially the inconsistency of `max_scsi_luns' parameter is
a bit serious because the description text says "last scsi LUN (should
be between 1 and 2^32-1)".

Signed-off-by: Masatake YAMATO <jet@gyve.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Fix async scanning double-add problems

Stress-testing and some thought has revealed some places where
asynchronous scanning needs some more attention to locking.

- Since async_scan is a bit, we need to hold the host_lock while
modifying it to prevent races against other CPUs modifying the word
that bit is in. This is probably a theoretical race for the moment,
but other patches may change that.
- The async_scan bit means not only that this host is being scanned
asynchronously, but that all the devices attached to this host are not
yet added to sysfs. So we must ensure that this bit is always in sync.
I've chosen to do this with the scan_mutex since it's already acquired
in most of the right places.
- If the host changes state to deleted while we're in the middle of
a scan, we'll end up with some devices on the host's list which must
be deleted. Add a check to scsi_sysfs_add_devices() to ensure the
host is still running.
- To avoid the async_scan bit being protected by three locks, the
async_scan_lock now only protects the scanning_list.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Clean up scsi_add_lun a bit

This patch tidies up scsi_add_lun a bit. I rewrote the kerneldoc to match
the actual parameters, moved the check for RBC and MMC REPORT_LUN devices
away from the switch(), changed the setup of sdev->type to account for
BLIST_ISROM, moved the check for BLIST_NO_ULD_ATTACH further down in
the function, removed a bogus comment and fixed some whitespace issues.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: Report FCP LUN to SCSI midlayer

When reporting SCSI devices to the SCSI midlayer, use the FCP LUN as
LUN reported to the SCSI layer. With this approach, zfcp does not have
to create unique LUNS, and this code can be removed.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix CONFIG_SCSI_WAIT_SCAN=m

CONFIG_MODULES=y
CONFIG_SCSI=y
CONFIG_SCSI_SCAN_ASYNC=y
CONFIG_SCSI_WAIT_SCAN=m

2.6.21-rc5-mm2 VFS panics unable to find my root on /dev/sda2, but boots
okay if I change drivers/scsi/Kconfig to "default y" instead of "default m"
for SCSI_WAIT_SCAN.

Make sure there's a late_initcall to scsi_complete_async_scans when it's
built in, so a monolithic SCSI_SCAN_ASYNC kernel can rely on the scans
being completed before trying to mount root, even if they're slow.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix scsi_wait_scan build problem

The #ifdef MODULE around the export of scsi_complete_async_scans()
which is the API the scsi_wait_scan module uses is incorrect and
causes the symbol to be undefined in certain circumstances leading to
a build failure. Remove the defines.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Replace remaining references to "driverfs" with "sysfs".

Globally, s/driverfs/sysfs/g.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[SCSI] SCSI core: better initialization for sdev->scsi_level

This patch will affect the CDB in INQUIRY commands sent to LUNs above 0
when LUN-0 reports a scsi_level of 0; the LUN bits will no longer be set
in the second byte of the CDB. This is as it should be. Nevertheless,
it's possible that some wacky device might be adversely affected. I doubt
anyone will complain...

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] scsi_scan.c: handle bad inquiry responses

A particular USB device has been reporting short inquiry lengths. The
SCSI code cannot operate properly unless we get an inquiry length of
36 or above (because of the way we parse vendor and product), so
assume at least 36 bytes are valid even if the device reports fewer.
This is wrong, but it's no worse than what we're doing now (using the
garbage beyond the last reported valid byte).

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Fix scsi_add_device() for async scanning

I had thought that all drivers which didn't call scsi_scan_host()
called scsi_scan_target(). Some, such as sbp2, mptsas and libata-scsi,
call scsi_add_device() or __scsi_add_device(). We just need to wait
for the currently executing async scans to complete first. This is the
same code that's in scsi_scan_target(), except that we have to return
an error instead of void when we're declining to scan at all.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] scsi_scan message cosmetic error

Hi,

Minor typo ...
In my first iteration of patches (that got merged), the
BLIST_ATTACH_PQ3 actually had the value 0x800000, but that
got changed later to avoid conflicts. This piece must have
been overlooked.
You could obviously do something like %x and then add the
bitflags, but that looks overkill for something that does
not tend to change.

Please merge.
(Patch applied against latest 2.6.20rc version that I tested.)

From: Kurt Garloff <kurt@garloff.de>
Subject: [SCSI SCAN] Fix logging message for PQ3 devices

The blacklist flags BLIST_ATTACH_PQ3 has value 0x1000000,
not 0x800000.

Signed-off-by: Kurt Garloff <garloff@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] scsi_scan: fix report lun problems with CDROM or RBC devices

Apparently no ATAPI CD/DVD actually supports REPORT LUNS (in spite of
claiming scsi-3 compliance, where it's mandatory) and worse, some
crash or flake out on being sent the command. This may actually be
due to a conflict between SPC and MMC with MMC not listing REPORT LUNS
as mandatory. The same standards conflict exists for RBC as well.

Fix all of this by reversing the blacklists for CDROM and RBC devices
(i.e. now they have to have the BLIST_REPORTLUNS2 flag set even if the
inquiry data returns scsi-3 compliance).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Add missing completion to scsi_complete_async_scans()

If either scsi_complete_async_scans() is called a second time
before the first call has finished, or a host scan is started while
scsi_complete_async_scans() is still sleeping, it would fail to wake up
the other task, which would sleep forever.

I've changed the kernel-doc to make it clear that
scsi_complete_async_scans() only guarantees that scans which started
before it was called are guaranteed to have finished when it returns.
I considered making it wait until all scans are completed, but it can't
guarantee that no more scans will start before it returns anyway, and it
runs the risk of confusing other callers of scsi_complete_async_scans()
for hosts actually scanning.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Make scsi_scan_host work for drivers which find their own targets

If a driver can find its own targets, it can now fill in scan_finished and
(optionally) scan_start in the scsi_host_template. Then, when it calls
scsi_scan_host(), it will be called back (from a thread if asynchronous
discovery is enabled), first to start the scan, and then at intervals to
check if the scan is completed.

Also make scsi_prep_async_scan and scsi_finish_async_scan static.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix missing check for no scanning

Drivers that called scsi_scan_target() instead of scsi_scan_host() were
still adding devices; this needs to be under the control of userspace,
not the driver.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Add Kconfig option for asynchronous SCSI scanning

Without this patch, the user has to add a kernel command line parameter
to get asynchronous SCSI scanning. Now they can select the default at
compile time and still override it at boot time if they need to.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

WorkStruct: Pass the work_struct pointer instead of context data

Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.

For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.

To make this work, an extra flag is introduced into the management side of the
work_struct. This governs auto-release of the structure upon execution.

Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function. This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated.. This is a
problem if the auxiliary data is taken away (as done by the last patch).

However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems. But then the work function must itself release the
work_struct by calling work_release().

In most cases, automatic release is fine, so this is the default. Special
initiators exist for the non-auto-release case (ending in _NAR).


Signed-Off-By: David Howells <dhowells@redhat.com>

[PATCH] SCSI core: always store >= 36 bytes of INQUIRY data

This patch (as810c) copies a minimum of 36 bytes of INQUIRY data, even if
the device claims that not all of them are valid. Often badly behaved
devices put plausible data in the Vendor, Product, and Revision strings but
set the Additional Length byte to a small value. Using potentially valid
data is certainly better than allocating a short buffer and then reading
beyond the end of it, which is what we do now.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[SCSI] Add ability to scan scsi busses asynchronously

Since it often takes around 20-30 seconds to scan a scsi bus, it's
highly advantageous to do this in parallel with other things. The bulk
of this patch is ensuring that devices don't change numbering, and that
all devices are discovered prior to trying to start init. For those
who build SCSI as modules, there's a new scsi_wait_scan module that will
ensure all bus scans are finished.

This patch only handles drivers which call scsi_scan_host. Fibre Channel,
SAS, SATA, USB and Firewire all need additional work.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Fix refcount breakage with 'echo "1" > scan' when target already present

Spotted by: Dan Aloni <da-xx@monatomic.org>

The problem is there's inconsistent locking semantic usage of
scsi_alloc_target(). Two callers assume the target comes back with
reference unincremented and the third assumes its incremented. Fix by
always making the reference incremented on return. Also fix path in
target alloc that could consistently increment the parent lock.
Finally document scsi_alloc_target() so its callers know what the
expectations are.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] SCSI: sanitize INQUIRY strings

Sanitize the Vendor, Product, and Revision strings contained in an
INQUIRY result by setting all non-graphic or non-ASCII characters to ' '.
Since the standard disallows such characters, this will affect
only non-compliant devices.

To help maintain backward compatibility, NUL characters are treated
specially. They are taken as string terminators; they and all the
following characters are set to ' '. If some valid characters get
erased as a result... well, we weren't seeing them before so we haven't
lost anything.

The primary purpose of this change is to allow blacklist entries to
match devices with illegal Vendor or Product strings.

In addition, the patch updates a couple of function prototypes, giving
inq_result its correct type (unsigned char *).

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Don't add scsi_device for devices that return PQ=1, PDT=0x1f

Some targets may return slight variations of PQ and PDT to indicate
no LUN mapped. USB UFI setting PDT=0x1f but having reserved bits for
PQ is one example, and NetApp targets returning PQ=1 and PDT=0x1f is
another. Both instances seem like reasonable responses according to
SPC-3 and UFI specs.

The current scsi_probe_and_add_lun() code adds a scsi_device
for targets that return PQ=1 and PDT=0x1f. This causes LUNs of type
"UNKNOWN" to show up in /proc/scsi/scsi when no LUNs are mapped.
In addition, subsequent rescans fail to recognize LUNs that may be
added on the target, unless preceded by a write to the delete attribute
of the "UNKNOWN" LUN.

This patch addresses this problem by skipping over the scsi_add_lun()
when PQ=1,PDT=0x1f is encountered, and just returns
SCSI_SCAN_TARGET_PRESENT.

Signed-off-by: Dave Wysochanski <davidw@netapp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix up short inquiry printing

A recent drivers base commit:

3e95637a48820ff8bedb33e6439def96ccff1de5

Caused the bus to be added to dev_printk, so now our SCSI inquiry short
messages print like this:

scsiscsi 2:0:0:0: Direct access IBM-ESXS ST973401SS B519 PQ: 0 ANSI: 5

Just remove the "scsi" from the sdev_printk to compensate.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Improve inquiry printing

- Replace scsi_device_types array API with scsi_device_type function API.
Gets rid of a lot of common code, as well as being easier to use.
- Add the new device types in SPC4 r05a, and rename some of the older ones.
- Reformat the printing of inquiry data; now fits on one line and
includes PQ.

I think I've addressed all the feedback from the previous versions. My
current test box prints:

scsi 2:0:1:0: Direct access HP 18.2G ATLAS10K3_18_SCA HP05 PQ: 0 ANSI: 2

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[SCSI] scsi: Device scanning oops for offlined devices (resend)

If a device gets offlined as a result of the Inquiry sent
during scanning, the following oops can occur. After the
disk gets put into the SDEV_OFFLINE state, the error handler
sends back the failed inquiry, which wakes the thread doing
the scan. This starts a race between the scanning thread
freeing the scsi device and the error handler calling
scsi_run_host_queues to restart the host. Since the disk
is in the SDEV_OFFLINE state, scsi_device_get will still
work, which results in __scsi_iterate_devices getting
a reference to the scsi disk when it shouldn't.

The following execution thread causes the oops:

CPU 0 (scan) CPU 1 (eh)

---------------------------------------------------------
scsi_probe_and_add_lun
....
scsi_eh_offline_sdevs
scsi_eh_flush_done_q
scsi_destroy_sdev
scsi_device_dev_release
scsi_restart_operations
scsi_run_host_queues
__scsi_iterate_devices
get_device
scsi_device_dev_release_usercontext
scsi_run_queue
<---OOPS--->

The patch fixes this by changing the state of the sdev to SDEV_DEL
before doing the final put_device, which should prevent the race
from occurring.

Original oops follows:

Badness in kref_get at lib/kref.c:32
Call Trace:
[C00000002F4476D0] [C00000000000EE20] .show_stack+0x68/0x1b0 (unreliable)
[C00000002F447770] [C00000000037515C] .program_check_exception+0x1cc/0x5a8
[C00000002F447840] [C00000000000446C] program_check_common+0xec/0x100
Exception: 700 at .kref_get+0x10/0x28
LR = .kobject_get+0x20/0x3c
[C00000002F447B30] [C00000002F447BC0] 0xc00000002f447bc0 (unreliable)
[C00000002F447BB0] [C000000000254BDC] .get_device+0x20/0x3c
[C00000002F447C30] [D000000000063188] .scsi_device_get+0x34/0xdc [scsi_mod]
[C00000002F447CC0] [D0000000000633EC] .__scsi_iterate_devices+0x50/0xbc [scsi_mod]
[C00000002F447D60] [D00000000006A910] .scsi_run_host_queues+0x34/0x5c [scsi_mod]
[C00000002F447DF0] [D000000000069054] .scsi_error_handler+0xdb4/0xe44 [scsi_mod]
[C00000002F447EE0] [C00000000007B4E0] .kthread+0x128/0x178
[C00000002F447F90] [C000000000025E84] .kernel_thread+0x4c/0x68
Unable to handle kernel paging request for <7>PCI: Enabling device: (0002:41:01.1), cmd 143
data at address 0x000001b8
Faulting instruction address: 0xd0000000000698e4
sym1: <1010-66> rev 0x1 at pci 0002:41:01.1 irq 216
sym1: No NVRAM, ID 7, Fast-80, LVD, parity checking
sym1: SCSI BUS has been reset.
scsi2 : sym-2.2.2
cpu 0x0: Vector: 300 (Data Access) at [c00000002f447a30]
pc: d0000000000698e4: .scsi_run_queue+0x2c/0x218 [scsi_mod]
lr: d00000000006a904: .scsi_run_host_queues+0x28/0x5c [scsi_mod]
sp: c00000002f447cb0
msr: 9000000000009032
dar: 1b8
dsisr: 40000000
current = 0xc0000000045fecd0
paca = 0xc00000000048ee80
pid = 1123, comm = scsi_eh_1
enter ? for help
[c00000002f447d60] d00000000006a904 .scsi_run_host_queues+0x28/0x5c [scsi_mod]
[c00000002f447df0] d000000000069054 .scsi_error_handler+0xdb4/0xe44 [scsi_mod]
[c00000002f447ee0] c00000000007b4e0 .kthread+0x128/0x178
[c00000002f447f90] c000000000025e84 .kernel_thread+0x4c/0x68

Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] remove scsi_request infrastructure

With Achim patch the last user (gdth) is switched away from scsi_request
so we an kill it now. Also disables some code in i2o_scsi that was
broken since the sg driver stopped using scsi_requests.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Return -EINVAL when "id == max_id" in scsi_scan_host_selected()

The scsi_scan_host_selected() should return -EINVAL when the id is equal
to the max_id. Currently it uses ">" when comparing with max_id, and
hence leaves the border case when "id==max_id".
The channel and lun have values valid from 0 up to,
and including, max_channel or max_lun. But, the valid values for id
range from 0 to max_id-1. This patch fixes the problem.

Signed-off-by: Amit Arora <aarora@in.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] scsi_scan.c: fix compile warnings

drivers/scsi/scsi_scan.c: In function `scsi_probe_and_add_lun':
drivers/scsi/scsi_scan.c:926: warning: unused variable `vend'
drivers/scsi/scsi_scan.c:926: warning: unused variable `mod'
drivers/scsi/scsi_scan.c: At top level:
drivers/scsi/scsi_scan.c:829: warning: `scsi_inq_str' defined but not used

Fix those, tighten up the (somewhat poorly-designed) logging macro and fix
some coding-style warts.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] BLIST_ATTACH_PQ3 flags

Some devices report a peripheral qualifier of 3 for LUN 0; with the original
code, we would still try a REPORT_LUNS scan (if SCSI level is >= 3 or if we
have the BLIST_REPORTLUNS2 passed in), but NOT any sequential scan.
Also, the device at LUN 0 (which is not connected according to the PQ) is not
registered with the OS.

Unfortunately, SANs exist that are SCSI-2 and do NOT support REPORT_LUNS, but
report a unknown device with PQ 3 on LUN 0. We still need to scan them, and
most probably we even need BLIST_SPARSELUN (and BLIST_LARGELUN). See the bug
reference for an infamous example.

This is patch 3/3:
3. Implement the blacklist flag BLIST_ATTACH_PQ3 that makes the scsi
scanning code register PQ3 devices and continues scanning; only sg
will attach thanks to scsi_bus_match().

Signed-off-by: Kurt Garloff <garloff@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Better log messages for PQ3 devs

Some devices report a peripheral qualifier of 3 for LUN 0; with the original
code, we would still try a REPORT_LUNS scan (if SCSI level is >= 3 or if we
have the BLIST_REPORTLUNS2 passed in), but NOT any sequential scan.
Also, the device at LUN 0 (which is not connected according to the PQ) is not
registered with the OS.

Unfortunately, SANs exist that are SCSI-2 and do NOT support REPORT_LUNS, but
report a unknown device with PQ 3 on LUN 0. We still need to scan them, and
most probably we even need BLIST_SPARSELUN (and BLIST_LARGELUN). See the bug
reference for an infamous example.

This patch 2/3:
If a PQ3 device is found, log a message that describes the device
(INQUIRY DATA and C:B:T:U tuple) and make a suggestion for blacklisting
it.

Signed-off-by: Kurt Garloff <garloff@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Try LUN 1 and use bflags

Some devices report a peripheral qualifier of 3 for LUN 0; with the original
code, we would still try a REPORT_LUNS scan (if SCSI level is >= 3 or if we
have the BLIST_REPORTLUNS2 passed in), but NOT any sequential scan.
Also, the device at LUN 0 (which is not connected according to the PQ) is not
registered with the OS.

Unfortunately, SANs exist that are SCSI-2 and do NOT support REPORT_LUNS, but
report a unknown device with PQ 3 on LUN 0. We still need to scan them, and
most probably we even need BLIST_SPARSELUN (and BLIST_LARGELUN). See the bug
reference for an infamous example.

This is patch 1/3:
If we end up in sequential scan, at least try LUN 1 for devices
that reported a PQ of 3 for LUN 0.
Also return blacklist flags, even for PQ3 devices.

Signed-off-by: Kurt Garloff <garloff@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] add SCSI_UNKNOWN and LUN transfer limit restrictions

Original From: Ingo Flaschberger <if@xip.at>

To support the RA4100 array from Compaq.

This patch now correctly handles SCSI_UNKNOWN types with regard to
BLIST_REPORTLUNS2 (allow it) and cdb[1] LUN inclusion (don't).

It also allows a BLIST_MAX_512 flag to restrict the maximum transfer
length to 512 blocks (apparently this is an RA4100 problem).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] scsi: move target_destroy call

This patch moves the calling of target_destroy next to the list_del. This
closed a race being seen while doing a device add on the aic7xxx.

Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix two leaks in scsi_alloc_sdev failure paths

If the scsi_alloc_queue or the slave_alloc calls in scsi_alloc_device fail,
we forget to release the locally allocated sdev on the failure path.

Coverity #609

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] scsi: Handle device_add failure in scsi_alloc_target

Fixes scsi to handle device_add failure in scsi_alloc_target.
Without this patch, if this call were to fail, we can oops
when we free the target.

Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix scsi process problems and clean up the target reap issues

In order to use the new execute_in_process_context() API, you have to
provide it with the work storage, which I do in SCSI in scsi_device and
scsi_target, but which also means that we can no longer queue up the
target reaps, so instead I moved the target to a state model which
allows target_alloc to detect if we've received a dying target and wait
for it to be gone. Hopefully, this should also solve the target
namespace race.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Recognize missing LUNs for non-standard devices

Some non-standard SCSI targets or protocols, such as USB UFI, report "no
LUN present" by setting the Peripheral Device Type to 0x1f and the
Peripheral Qualifier to 0 (not 3 as the standard requires) in the INQUIRY
response. This patch (as650b) adds a new target flag and code to
accomodate such targets.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix uninitialized variable error

in __scsi_add_device, sdev may be uninitialised if
scsi_host_scan_allowed() returns false. Fix by initialising at the
top of the routine. Also rely on the fact that
scsi_probe_and_add_lun() only actually fills in the sdev pointer if
the SCSI_SCAN_LUN_PRESENT case (so no need to check the return value).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Remove devfs support from the SCSI subsystem

As devfs has been disabled from the kernel tree for a number of months
now (5 to be exact), here's a patch against 2.6.16-rc1-git1 that removes
support for it from the SCSI subsystem.

The patch also removes the scsi_disk devfs_name field as it's no longer
needed.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] SCSI core kmalloc2kzalloc

Change the core SCSI code to use kzalloc rather than kmalloc+memset
where possible.

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] scsi: handle ->slave_configure return value

When �>slave_configure fails the scsi midlayer should handle it.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix wrong context bugs in SCSI

There's a bug in releasing scsi_device where the release function
actually frees the block queue. However, the block queue release
calls flush_work(), which requires process context (the scsi_device
structure may release from irq context). Update the release function
to invoke via the execute_in_process_context() API.

Also clean up the scsi_target structure releasing via this API.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] remove target parent limitiation

When James Smart fixed the issue of the userspace scan atributes
crashing the system with the FC transport class he added a patch to
let the transport class check if the parent is valid for a given
transport class.

When adding support for the integrated raid of fusion sas devices
we ran into a problem with that, as it didn't allow adding virtual
raid volumes without the transport class knowing about it.

So this patch adds a user_scan attribute instead, that takes over from
scsi_scan_host_selected if the transport class sets it and thus lets
the transport class control the user-initiated scanning. As this
plugs the hole about user-initiated scanning the target_parent hook
goes away and we rely on callers of the scanning routines to do
something sensible.

For SAS this meant I had to switch from a spinlock to a mutex to
synchronize the topology linked lists, in FC they were completely
unsynchronized which seems wrong.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] turn most scsi semaphores into mutexes

the scsi layer is using semaphores in a mutex way, this patch converts
these into using mutexes instead

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] Fix Fibre Channel boot oops

The oops is characteristic of the underlying device being removed from
visibility before the class device, and sure enough we do device_del()
before transport_unregister() in the scsi_target_reap() routines. I've
no idea why this is suddenly showing up, since the code has been in
there since that function was first invented. However, I've confirmed
this fixes Andrew Vasquez's boot oops.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[SCSI] fix scsi_reap_target() device_del from atomic context

scsi_reap_target() was desgined to be called from any context.
However it must do a device_del() of the target device, which may only
be called from user context. Thus we have to reimplement
scsi_reap_target() via a workqueue.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Mark some core scsi data structures const

patch below marks a few scsi core datastructures as const, so that they end up
in the .rodata section and don't cacheline share with things that get dirtied

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] Fix SCSI scanning slab corruption

There is a double free in the scsi scan code if a LLDD's slave_alloc()
call fails. There is a direct call to scsi_free_queue and then the
following put_device calls the release function, which also frees the
queue.

Remove the redundant scsi_free_queue.

Signed-off-by: Brian King <brking@us.ibm.com>
Tested-by: Nathan Lynch <ntl@pobox.com>
[ Also removed some strange whitespace artifacts in that area ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[SCSI] fix double free of scsi request queue

Current scsi scanning code appears to have a use after free
bug is a LLDD's slave_alloc fails. Remove the redundant
scsi_free_queue.

Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] remove Scsi_Device typedef

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Fix refcount leak in scsi_report_lun_scan

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] use {sdev,scmd,starget,shost}_printk in generic code

rejections fixed and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] kill unused scsi_scan_single_target()

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] move the mid-layer printk's over to shost/starget/sdev_printk

This should eliminate (at least in the mid layer) to make numeric
assumptions about any of the enumeration variables. As a side effect,
it will also make all the messages consistent and line us up nicely for
the error logging strategy (if it ever shows itself again).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] allow REPORT LUN scanning even for LUN 0 PQ of 3

Currently we just ignore the device, which means there are a few
arrays out there that we don't find.

This patch updates the scsi_report_lun_scan() to take a target instead
of a device so it can be called on a return of
SCSI_SCAN_TARGET_PRESENT, which is what a PQ 3 device returns.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] SCSI scanning and removal fixes

This patch (as545) fixes the list traversals in __scsi_remove_target and
scsi_forget_host. In each case the existing code list_for_each_entry_safe
in an _unsafe_ manner, because the list was not protected from outside
modification while the iteration was running.

The new scsi_forget_host routine takes the moderately controversial step
of iterating over devices for removal rather than iterating over targets.
This makes more sense to me because the current scheme treats targets as
second-class citizens, created and removed on demand, rather than as
objects corresponding to actual hardware. (Also I couldn't figure out any
safe way to iterate over the target list, since it's not so easy to tell
when a target has already been removed.)

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Alter the scsi_add_device() API to conform to what users expect

The original API returned either an ERR_PTR() or a refcounted sdev.
Unfortunately, if it's successful, you need to do a scsi_device_put() on
the sdev otherwise the refcounting is wrong.

Everyone seems to expect that scsi_add_device() should be callable
without doing the ref put, so alter the API so it is (we still have
__scsi_add_device with the original behaviour).

The only actual caller that needs altering is the one in firewire ...
not because it gets this right, but because it acts on the error if one
is returned.

Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Fix module removal/device add race

This patch (as546) fixes an oops-causing failure to check the return code
from scsi_device_get. The call can return an error if the LLD is being
unloaded from memory.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] add missing scan mutex to scsi_scan_target()

This patch (as543) adds a private entry point to scsi_scan_target, for use
when the caller already owns the scan_mutex, and updates the kerneldoc for
that routine (which was badly out-of-date). It converts scsi_scan_channel
to use the new entry point. Lastly, it modifies scsi_get_host_dev to make
it acquire the scan_mutex, necessary since the routine adds a new
scsi_device even if it doesn't do any actual scanning.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] convert sd to scsi_execute_req (and update the scsi_execute_req API)

This one removes struct scsi_request entirely from sd. In the process,
I noticed we have no callers of scsi_wait_req who don't immediately
normalise the sense, so I updated the API to make it take a struct
scsi_sense_hdr instead of simply a big sense buffer.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] use scatter lists for all block pc requests and simplify hw handlers

Original From: Mike Christie <michaelc@cs.wisc.edu>

Add scsi_execute_req() as a replacement for scsi_wait_req()

Fixed up various pieces (added REQ_SPECIAL and caught req use after
free)

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix target scanning oops with fc transport class

We have some nasty issues with 2.6.12-rc6. Any request to scan on
the lpfc or qla2xxx FC adapters will oops. What is happening is the
system is defaulting to non-transport registered targets, which
inherit the parent of the scan. On this second scan, performed by
the attribute, the parent becomes the shost instead of the rport.
The slave functions in the 2 FC adapters use starget_to_rport()
routines, which incorrectly map the shost as an rport pointer.

Additionally, this pointed out other weaknesses:
- If the target structure is torn down outside of the transport,
we have no method for it to be regenerated at the proper parent.
- We have race conditions on the target being allocated by both
the midlayer scan (parent=shost) and by the fc transport
(parent=rport).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] host state model update: mediate host add/remove race

Add support to not allow additions to a host when it is being removed.

Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] scsi_scan: check return code from scsi_sysfs_add_sdev

Adds a missing check for an error return code from scsi_sysfs_add_sdev.
This resolves entry #4863 in the OSDL bugzilla. Although in that bug
report the failure occurred because of a confusion over scanning vs.
rescanning, in general add_sdev can fail for a number of reasons (the
simplest being insufficient memory) and the caller should cope properly.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[SCSI] add int_to_scsilun() function

One of the issues we had was reverting the midlayers lun value
into the 8byte lun value that we wanted to send to the device.
Historically, there's been some combination of byte swapping,
setting high/low, etc. There's also been no common thread between
how our driver did it and others. I also got very confused as
to why byteswap routines were being used.

Anyway, this patch is a LLDD-callable function that reverts the
midlayer's lun value, stored in an int, to the 8-byte quantity
(note: this is not the real 8byte quantity, just the same amount
that scsilun_to_int() was able to convert and store originally).

This also solves the dilemma of the thread:
http://marc.theaimsgroup.com/?l=linux-kernel&m=112116767118981&w=2

A patch for the lpfc driver to use this function will be along
in a few days (batched with other patches).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix slab corruption during ipr probe

With CONFIG_DEBUG_SLAB=y I see slab corruption messages during boot on
pSeries machines with IPR adapters with any 2.6.12-rc kernel.

The change which seems to have introduced the problem is "SCSI: revamp
target scanning routines" and may be found at:
http://marc.theaimsgroup.com/?l=bk-commits-head&m=111093946426333&w=2

In order to revert that in a 2.6.12-rc1 tree, I had to revert "target
code updates to support scanned targets" first:
http://marc.theaimsgroup.com/?l=bk-commits-head&m=111094132524649&w=2

With both patches reverted, the corruption messages go away.

ipr: IBM Power RAID SCSI Device Driver version: 2.0.13 (February 21,
2005)
ipr 0001:d0:01.0: Found IOA with IRQ: 167
ipr 0001:d0:01.0: Starting IOA initialization sequence.
ipr 0001:d0:01.0: Adapter firmware version: 020A005C
ipr 0001:d0:01.0: IOA initialized.
scsi0 : IBM 570B Storage Adapter
Vendor: IBM Model: VSBPD4E1 U4SCSI Rev: 4770
Type: Enclosure ANSI SCSI revision: 02
Vendor: IBM H0 Model: HUS103036FL3800 Rev: RPQF
Type: Direct-Access ANSI SCSI revision: 04
Vendor: IBM H0 Model: HUS103036FL3800 Rev: RPQF
Type: Direct-Access ANSI SCSI revision: 04
Vendor: IBM H0 Model: HUS103036FL3800 Rev: RPQF
Type: Direct-Access ANSI SCSI revision: 04
Vendor: IBM H0 Model: HUS103036FL3800 Rev: RPQF
Type: Direct-Access ANSI SCSI revision: 04
Vendor: IBM Model: VSBPD4E1 U4SCSI Rev: 4770
Type: Enclosure ANSI SCSI revision: 02
Slab corruption: start=c0000001e8de5268, len=512
Redzone: 0x5a2cf071/0x5a2cf071.
Last user: [<c00000000029c3a0>](.scsi_target_dev_release+0x28/0x50)
080: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6a
Prev obj: start=c0000001e8de5050, len=512
Redzone: 0x5a2cf071/0x5a2cf071.
Last user: [<0000000000000000>](0x0)
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
Next obj: start=c0000001e8de5480, len=512
Redzone: 0x170fc2a5/0x170fc2a5.
Last user: [<c000000000228d7c>](.as_init_queue+0x5c/0x228)
000: c0 00 00 01 e8 83 26 08 00 00 00 00 00 00 00 00
010: 00 00 00 00 00 00 00 00 c0 00 00 01 e8 de 54 98
Slab corruption: start=c0000001e8de5268, len=512
Redzone: 0x5a2cf071/0x5a2cf071.
Last user: [<c00000000029c3a0>](.scsi_target_dev_release+0x28/0x50)
080: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6a
Prev obj: start=c0000001e8de5050, len=512
Redzone: 0x5a2cf071/0x5a2cf071.
Last user: [<0000000000000000>](0x0)
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
Next obj: start=c0000001e8de5480, len=512
Redzone: 0x170fc2a5/0x170fc2a5.
Last user: [<c000000000228d7c>](.as_init_queue+0x5c/0x228)
000: c0 00 00 01 e8 83 26 08 00 00 00 00 00 00 00 00
010: 00 00 00 00 00 00 00 00 c0 00 00 01 e8 de 54 98
...

I did some digging and the problem seems to be a refcounting issue in
__scsi_add_device. The target gets freed in scsi_target_reap, and
then __scsi_add_device tries to do another device_put on it.

Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Add target alloc/destroy callbacks to the host template

This gives the HBA driver notice when a target is created and
destroyed to allow it to manage its own target based allocations
accordingly.

This is a much reduced verson of the original patch sent in by
James.Smart@Emulex.com

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] TYPE_RBC cache fixes (sbp2.c affected)

a) TYPE_SDAD renamed to TYPE_RBC and taken to scsi.h
b) in sbp2.c remapping of TYPE_RPB to TYPE_DISK turned off
c) relevant places in midlayer and sd.c taught to accept TYPE_RBC
d) sd.c::sd_read_cache_type() looks into page 6 when dealing with
TYPE_RBC - these guys have writeback cache flag there and are not guaranteed
to have page 8 at all.
e) sd_read_cache_type() got an extra sanity check - it checks that
it got the page it asked for before using its contents. And screams if
mismatch had happened. Rationale: there are broken devices out there that
are "helpful" enough to go for "I don't have a page you've asked for, here,
have another one". For example, PL3507 had been caught doing just that...
f) sbp2 sets sdev->use_10_for_rw and sdev->use_10_for_ms instead
of bothering to remap READ6/WRITE6/MOD_SENSE, so most of the conversions
in there are gone now.

Incidentally, I wonder if USB storage devices that have no
mode page 8 are simply RBC ones. I haven't touched that, but it might
be interesting to check...

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] SCSI GFP fixes

Somebody forgot that | has higher priority than ?:. As the result,
allocation is done with bogus flags - instead of GFP_ATOMIC + possibly
GFP_DMA we always get GFP_DMA and no GFP_ATOMIC.

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] fix NMI lockup with CFQ scheduler

The current problem seen is that the queue lock is actually in the
SCSI device structure, so when that structure is freed on device
release, we go boom if the queue tries to access the lock again.

The fix here is to move the lock from the scsi_device to the queue.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!