scsi: device_handler: rdac: Have midlayer retry send_mode_select() errors

This has rdac have the SCSI midlayer retry errors instead of driving them
itself.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20240123002220.129141-8-michael.christie@oracle.com
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: rdac: Fix sshdr use

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-6-michael.christie@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: rdac: Fix send_mode_select retry handling

If send_mode_select retries scsi_execute_cmd it will leave err set to
SCSI_DH_RETRY/SCSI_DH_IMM_RETRY. If on the retry, the command is
successful, then SCSI_DH_RETRY/SCSI_DH_IMM_RETRY will be returned to the
scsi_dh activation caller. On the retry, we will then detect the previous
MODE SELECT had worked, and so we will return success.

This patch has us return the correct return value, so we can avoid the
extra scsi_dh activation call and to avoid failures if the caller had hit
its activation retry limit and does not end up retrying.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-5-michael.christie@oracle.com
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh: Convert to scsi_execute_cmd()

scsi_execute() is going to be removed. Convert the scsi_dh users 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/device_handlers: Use the new blk_opf_t type

Improve static type checking by using the new blk_opf_t type for variables
that represent request flags.

Cc: Hannes Reinecke <hare@suse.com>
Cc: Martin Wilck <mwilck@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-43-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: scsi_dh_rdac: Avoid crash during rdac_bus_attach()

The following BUG_ON() was observed during RDAC scan:

[595952.944297] kernel BUG at drivers/scsi/device_handler/scsi_dh_rdac.c:427!
[595952.951143] Internal error: Oops - BUG: 0 [#1] SMP
......
[595953.251065] Call trace:
[595953.259054] check_ownership+0xb0/0x118
[595953.269794] rdac_bus_attach+0x1f0/0x4b0
[595953.273787] scsi_dh_handler_attach+0x3c/0xe8
[595953.278211] scsi_dh_add_device+0xc4/0xe8
[595953.282291] scsi_sysfs_add_sdev+0x8c/0x2a8
[595953.286544] scsi_probe_and_add_lun+0x9fc/0xd00
[595953.291142] __scsi_scan_target+0x598/0x630
[595953.295395] scsi_scan_target+0x120/0x130
[595953.299481] fc_user_scan+0x1a0/0x1c0 [scsi_transport_fc]
[595953.304944] store_scan+0xb0/0x108
[595953.308420] dev_attr_store+0x44/0x60
[595953.312160] sysfs_kf_write+0x58/0x80
[595953.315893] kernfs_fop_write+0xe8/0x1f0
[595953.319888] __vfs_write+0x60/0x190
[595953.323448] vfs_write+0xac/0x1c0
[595953.326836] ksys_write+0x74/0xf0
[595953.330221] __arm64_sys_write+0x24/0x30

Code is in check_ownership:

list_for_each_entry_rcu(tmp, &h->ctlr->dh_list, node) {
/* h->sdev should always be valid */
BUG_ON(!tmp->sdev);
tmp->sdev->access_state = access_state;
}

rdac_bus_attach
initialize_controller
list_add_rcu(&h->node, &h->ctlr->dh_list);
h->sdev = sdev;

rdac_bus_detach
list_del_rcu(&h->node);
h->sdev = NULL;

Fix the race between rdac_bus_attach() and rdac_bus_detach() where h->sdev
is NULL when processing the RDAC attach.

Link: https://lore.kernel.org/r/20210113063103.2698953-1-yebin10@huawei.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Introduce enum scsi_disposition

Improve readability of the code in the SCSI core by introducing an
enumeration type for the values used internally that decide how to continue
processing a SCSI command. The eh_*_handler return values have not been
changed because that would involve modifying all SCSI drivers.

The output of the following command has been inspected to verify that no
out-of-range values are assigned to a variable of type enum
scsi_disposition:

KCFLAGS=-Wassign-enum make CC=clang W=1 drivers/scsi/

Link: https://lore.kernel.org/r/20210415220826.29438-6-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh_rdac: zero cdb in send_mode_select()

cdb in send_mode_select() is not zeroed and is only partially filled in
rdac_failover_get(), which leads to some random data getting to the
device. Users have reported storage responding to such commands with
INVALID FIELD IN CDB. Code before commit 327825574132 was not affected, as
it called blk_rq_set_block_pc().

Fix this by zeroing out the cdb first.

Identified & fix proposed by HPE.

Fixes: 327825574132 ("scsi_dh_rdac: switch to scsi_execute_req_flags()")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20190904155205.1666-1-martin.wilck@suse.com
Signed-off-by: Martin Wilck <mwilck@suse.com>
Acked-by: Ales Novak <alnovak@suse.cz>
Reviewed-by: Shane Seymour <shane.seymour@hpe.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: return blk_status_t from device handler ->prep_fn

Remove the last use of the old BLKPREP_* values, which get converted
to BLK_STS_* later anyway.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: device_handler: remove VLAs

In preparation to enabling -Wvla, remove VLAs and replace them with
fixed-length arrays instead.

scsi_dh_{alua,emc,rdac} use variable-length array declarations to store
command blocks, with the appropriate size as determined by
COMMAND_SIZE. This patch replaces these with fixed-sized arrays using
MAX_COMMAND_SIZE, so that the array size can be determined at compile
time.

This was prompted by https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Stephen Kitt <steve@sk2.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_dh: Return SCSI_DH_XX error code from ->attach()

Rather than having each device handler implementing their own error
mapping, have the ->attach() call return a SCSI_DH_XXX error code and
implement the mapping in scsi_dh_handler_attach().

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

scsi: scsi_dh_rdac: Use ctlr directly in rdac_failover_get()

rdac_failover_get references struct rdac_controller as
ctlr->ms_sdev->handler_data->ctlr for no apparent reason. Besides being
inefficient this also introduces a null-pointer dereference as
send_mode_select() sets ctlr->ms_sdev to NULL before calling
rdac_failover_get():

[ 18.432550] device-mapper: multipath service-time: version 0.3.0 loaded
[ 18.436124] BUG: unable to handle kernel NULL pointer dereference at 0000000000000790
[ 18.436129] IP: send_mode_select+0xca/0x560
[ 18.436129] PGD 0
[ 18.436130] P4D 0
[ 18.436130]
[ 18.436132] Oops: 0000 [#1] SMP
[ 18.436133] Modules linked in: dm_service_time sd_mod dm_multipath amdkfd amd_iommu_v2 radeon(+) i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm qla2xxx drm serio_raw scsi_transport_fc bnx2 i2c_core dm_mirror dm_region_hash dm_log dm_mod
[ 18.436143] CPU: 4 PID: 443 Comm: kworker/u16:2 Not tainted 4.12.0-rc1.1.el7.test.x86_64 #1
[ 18.436144] Hardware name: IBM BladeCenter LS22 -[79013SG]-/Server Blade, BIOS -[L8E164AUS-1.07]- 05/25/2011
[ 18.436145] Workqueue: kmpath_rdacd send_mode_select
[ 18.436146] task: ffff880225116a40 task.stack: ffffc90002bd8000
[ 18.436148] RIP: 0010:send_mode_select+0xca/0x560
[ 18.436148] RSP: 0018:ffffc90002bdbda8 EFLAGS: 00010246
[ 18.436149] RAX: 0000000000000000 RBX: ffffc90002bdbe08 RCX: ffff88017ef04a80
[ 18.436150] RDX: ffffc90002bdbe08 RSI: ffff88017ef04a80 RDI: ffff8802248e4388
[ 18.436151] RBP: ffffc90002bdbe48 R08: 0000000000000000 R09: ffffffff81c104c0
[ 18.436151] R10: 00000000000001ff R11: 000000000000035a R12: ffffc90002bdbdd8
[ 18.436152] R13: ffff8802248e4390 R14: ffff880225152800 R15: ffff8802248e4400
[ 18.436153] FS: 0000000000000000(0000) GS:ffff880227d00000(0000) knlGS:0000000000000000
[ 18.436154] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 18.436154] CR2: 0000000000000790 CR3: 000000042535b000 CR4: 00000000000006e0
[ 18.436155] Call Trace:
[ 18.436159] ? rdac_activate+0x14e/0x150
[ 18.436161] ? refcount_dec_and_test+0x11/0x20
[ 18.436162] ? kobject_put+0x1c/0x50
[ 18.436165] ? scsi_dh_activate+0x6f/0xd0
[ 18.436168] process_one_work+0x149/0x360
[ 18.436170] worker_thread+0x4d/0x3c0
[ 18.436172] kthread+0x109/0x140
[ 18.436173] ? rescuer_thread+0x380/0x380
[ 18.436174] ? kthread_park+0x60/0x60
[ 18.436176] ret_from_fork+0x2c/0x40
[ 18.436177] Code: 49 c7 46 20 00 00 00 00 4c 89 ef c6 07 00 0f 1f 40 00 45 31 ed c7 45 b0 05 00 00 00 44 89 6d b4 4d 89 f5 4c 8b 75 a8 49 8b 45 20 <48> 8b b0 90 07 00 00 48 8b 56 10 8b 42 10 48 8d 7a 28 85 c0 0f
[ 18.436192] RIP: send_mode_select+0xca/0x560 RSP: ffffc90002bdbda8
[ 18.436192] CR2: 0000000000000790
[ 18.436198] ---[ end trace 40f3e4dca1ffabdd ]---
[ 18.436199] Kernel panic - not syncing: Fatal exception
[ 18.436222] Kernel Offset: disabled
[-- MARK -- Thu May 18 11:45:00 2017]

Fixes: 327825574132 scsi_dh_rdac: switch to scsi_execute_req_flags()
Cc: stable@vger.kernel.org
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: remove scsi_execute_req_flags

And switch all callers to use scsi_execute instead.

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

scsi_dh_rdac: switch to scsi_execute_req_flags()

Switch to scsi_execute_req_flags() and scsi_get_vpd_page() instead of
open-coding it. Using scsi_execute_req_flags() will set REQ_QUIET and
REQ_PREEMPT, but this is okay as we're evaluating the errors anyway and
should be able to send the command even if the device is quiesced.

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

block: split out request-only flags into a new namespace

A lot of the REQ_* flags are only used on struct requests, and only of
use to the block layer and a few drivers that dig into struct request
internals.

This patch adds a new req_flags_t rq_flags field to struct request for
them, and thus dramatically shrinks the number of common requests. It
also removes the unfortunate situation where we have to fit the fields
from the same enum into 32 bits for struct bio and 64 bits for
struct request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

scsi_dh_rdac: update 'access_state' field

Track attached SCSI devices and update the 'access_state' whenever the
path state of the device changes.

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

scsi_dh_rdac: always retry MODE SELECT on command lock violation

If MODE SELECT returns with sense '05/91/36' (command lock violation)
it should always be retried without counting the number of retries.
During an HBA upgrade or similar circumstances one might see a flood
of MODE SELECT command from various HBAs, which will easily trigger
the sense code and exceed the retry count.

Cc: <stable@vger.kernel.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh: kill struct scsi_dh_data

Add a ->handler and a ->handler_data field to struct scsi_device and kill
this indirection. Also move struct scsi_device_handler to scsi_dh.h so that
changes to it don't require rebuilding every SCSI LLDD.

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

scsi_dh: move device matching to the core code

Add a single list of devices that need non-ALUA device handlers to the core
scsi_dh code so that we can autoload the modules for them at probe time.

While this is a little ugly in terms of architecture it actually
significantly simplifies the code in addition to the new autoloading
functionality.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: handle more device handler setup/teardown in common code

Move all code to set up and tear down sdev->scsi_dh_data to common code.

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

scsi: remove struct scsi_dh_devlist

All drivers now do their own matching, so there is no more need to expose
a device list as part of the interface.

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

scsi: use container_of to get at device handler private data

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

scsi_dh: get module reference outside of device handler

We need to grab a reference to the module before calling the attach
routines to avoid a small race vs module removal. It also cleans up
the code significantly as a side effect.

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

block,scsi: fixup blk_get_request dead queue scenarios

The blk_get_request function may fail in low-memory conditions or during
device removal (even if __GFP_WAIT is set). To distinguish between these
errors, modify the blk_get_request call stack to return the appropriate
ERR_PTR. Verify that all callers check the return status and consider
IS_ERR instead of a simple NULL pointer check.

For consistency, make a similar change to the blk_mq_alloc_request leg
of blk_get_request. It may fail if the queue is dead, or the caller was
unwilling to wait.

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Jiri Kosina <jkosina@suse.cz> [for pktdvd]
Acked-by: Boaz Harrosh <bharrosh@panasas.com> [for osd]
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

block: add blk_rq_set_block_pc()

With the optimizations around not clearing the full request at alloc
time, we are leaving some of the needed init for REQ_TYPE_BLOCK_PC
up to the user allocating the request.

Add a blk_rq_set_block_pc() that sets the command type to
REQ_TYPE_BLOCK_PC, and properly initializes the members associated
with this type of request. Update callers to use this function instead
of manipulating rq->cmd_type directly.

Includes fixes from Christoph Hellwig <hch@lst.de> for my half-assed
attempt.

Signed-off-by: Jens Axboe <axboe@fb.com>

[SCSI] scsi_dh_rdac: Add new IBM 1813 product id to rdac devlist

Signed-off-by: Sean Stewart <Sean.Stewart@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_rdac : minor return fix for rdac

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_rdac : Consolidate rdac strings together

This patch consolidates the strings together. Purpose is to remove minor product strings extensions.
That way the future products with similar strings should not require change here.

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_rdac: Add a new netapp vendor/product string

This patch adds a new vendor/product strings for netapp E series product.
Also consolidated the strings together with similar names.

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_rdac: Fix for unbalanced reference count

This patch fixes an unbalanced refcount issue.

Elevating the lock for both kref_put and also for controller node deletion.
Previously, controller deletion was protected but the not the kref_put. This
was causing the other thread to pick up the controller structure which was
already kref'd zero.

This was causing the following WARN_ON and also sometimes panic.

WARNING: at lib/kref.c:43 kref_get+0x2d/0x30() (Not tainted)
Hardware name: IBM System x3655 -[7985AC1]-
Modules linked in: fuse scsi_dh_rdac autofs4 nfs lockd fscache nfs_acl
auth_rpcgss sunrpc 8021q garp stp llc ipv6 ib_srp(U) scsi_transport_srp
scsi_tgt ib_cm(U) ib_sa(U) ib_uverbs(U) ib_umad(U) mlx4_ib(U) mlx4_core(U)
ib_mthca(U) ib_mad(U) ib_core(U) dm_mirror dm_region_hash dm_log dm_round_robin
dm_multipath uinput bnx2 ses enclosure sg ibmpex ibmaem ipmi_msghandler
serio_raw k8temp hwmon amd64_edac_mod edac_core edac_mce_amd shpchp i2c_piix4
ext4 mbcache jbd2 sr_mod cdrom sd_mod crc_t10dif sata_svw pata_acpi ata_generic
pata_serverworks aacraid radeon ttm drm_kms_helper drm i2c_algo_bit i2c_core
dm_mod [last unloaded: freq_table]
Pid: 13735, comm: srp_daemon Not tainted 2.6.32-71.el6.x86_64 #1
Call Trace:
[<ffffffff8106b857>] warn_slowpath_common+0x87/0xc0
[<ffffffff8106b8aa>] warn_slowpath_null+0x1a/0x20
[<ffffffff8125c39d>] kref_get+0x2d/0x30
[<ffffffffa01b4029>] rdac_bus_attach+0x459/0x580 [scsi_dh_rdac]
[<ffffffff8135232a>] scsi_dh_handler_attach+0x2a/0x80
[<ffffffff81352c7b>] scsi_dh_notifier+0x9b/0xa0
[<ffffffff814cd7a5>] notifier_call_chain+0x55/0x80
[<ffffffff8109711a>] __blocking_notifier_call_chain+0x5a/0x80
[<ffffffff81097156>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff8132bec5>] device_add+0x515/0x640
[<ffffffff813329e4>] ? attribute_container_device_trigger+0xc4/0xe0
[<ffffffff8134f659>] scsi_sysfs_add_sdev+0x89/0x2c0
[<ffffffff8134d096>] scsi_probe_and_add_lun+0xea6/0xed0
[<ffffffff8134beb2>] ? scsi_alloc_target+0x292/0x2d0
[<ffffffff8134d1e1>] __scsi_scan_target+0x121/0x750
[<ffffffff811df806>] ? sysfs_create_file+0x26/0x30
[<ffffffff8132b759>] ? device_create_file+0x19/0x20
[<ffffffff81332838>] ? attribute_container_add_attrs+0x78/0x90
[<ffffffff814b008c>] ? klist_next+0x4c/0xf0
[<ffffffff81332e30>] ? transport_configure+0x0/0x20
[<ffffffff813329e4>] ? attribute_container_device_trigger+0xc4/0xe0
[<ffffffff8134df40>] scsi_scan_target+0xd0/0xe0
[<ffffffffa02f053a>] srp_create_target+0x75a/0x890 [ib_srp]
[<ffffffff8132a130>] dev_attr_store+0x20/0x30
[<ffffffff811df145>] sysfs_write_file+0xe5/0x170
[<ffffffff8116c818>] vfs_write+0xb8/0x1a0
[<ffffffff810d40a2>] ? audit_syscall_entry+0x272/0x2a0
[<ffffffff8116d251>] sys_write+0x51/0x90
[<ffffffff81013172>] system_call_fastpath+0x16/0x1b

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_rdac: Fix error path

If create_singlethread_workqueue() failes, rdac_init should fail too.

Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: "Moger, Babu" <Babu.Moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_rdac: Adding the match function for rdac device handler

This patch introduces the match function for rdac device handler. Without
this, sometimes handler attach fails during the device_add. Included check for
TPGS bit before proceeding further. The match function was introduced by
commit 6c3633d08acf514e2e89aa95d2346ce9d64d719a

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

scsi: Fix up files implicitly depending on module.h inclusion

The module.h header was implicitly present everywhere, so files
with no explicit include of the module infrastructure would build
anyway. We are now removing the implicit include, and so we need
to call out the module.h file that we need explicitly.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

[SCSI] scsi_dh_rdac: Adding NetApp as a brand name for rdac

Signed-off-by: Vijay Chauhan <Vijay.chauhan@netapp.com>
Reviewed-by: Bob Stankey <Robert.stankey@netapp.com>
Reviewed-by: Babu Moger <Babu.moger@netapp.com>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_rdac: Adding couple more vendor product ids

This patch adds couple more Vendor/Product IDs for RDAC.. There are no
functional changes.

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] dh_rdac: Associate HBA and storage in rdac_controller to support partitions in storage

rdac hardware handler assumes that there is one-to-one relation ship
between the host and the controller w.r.t lun. IOW, it does not
support "multiple storage partitions" within a storage.

Example:
HBA1 and HBA2 see lun 0 and 1 in storage A (1)
HBA3 and HBA4 see lun 0 and 1 in storage A (2)
HBA5 and HBA6 see lun 0 and 1 in storage A (3)

luns 0 and 1 in (1), (2) and (3) are totally different.

But, rdac handler treats the lun 0s (and lun 1s) as the same when
sending a mode select to the controller, which is wrong.

This patch makes the rdac hardware handler associate HBA and the
storage w.r.t lun (and not the host itself).

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] dh_rdac: Use WWID from C8 page instead of Subsystem id from C4 page to identify storage

rdac hardware handler uses "Subsystem Identifier" from C4 inquiry page
to uniquely identify a storage. The problem with that is that if any
any of the bytes are non-ascii, subsys_id will all be spaces (hex
0x20). This creates lot of problems especially when there are multiple
rdac storages are connected to the server.

Use "Storage Array Unique Identifier" from C8 inquiry page, which is the
world wide unique identifier for the storage array, to uniquely identify
the storage.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

treewide: fix potentially dangerous trailing ';' in #defined values/expressions

All these are instances of
#define NAME value;
or
#define NAME(params_opt) value;

These of course fail to build when used in contexts like
if(foo $OP NAME)
while(bar $OP NAME)
and may silently generate the wrong code in contexts such as
foo = NAME + 1; /* foo = value; + 1; */
bar = NAME - 1; /* bar = value; - 1; */
baz = NAME & quux; /* baz = value; & quux; */

Reported on comp.lang.c,
Message-ID: <ab0d55fe-25e5-482b-811e-c475aa6065c3@c29g2000yqd.googlegroups.com>
Initial analysis of the dangers provided by Keith Thompson in that thread.

There are many more instances of more complicated macros having unnecessary
trailing semicolons, but this pile seems to be all of the cases of simple
values suffering from the problem. (Thus things that are likely to be found
in one of the contexts above, more complicated ones aren't.)

Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

[SCSI] scsi_dh_rdac : decide whether to send mode select based on operating mode

Based on the operating modes, handler decides whether to send mode
select or not. Purpose here is to reduce io-shipping as much as
possible whenever there is an option.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Reviewed-by: Yanling Qi <yanling.qi@lsi.com>
Reviewed-by: Sudhir Dachepalli <Sudhir.Dachepalli@lis.com>
Reviewed-by: Somasundaram Krishnasamy <Somasundaram.Krishnasamy@lsi.com>
Reviewed-by: Bob Stankey <Robert.Stankey@lsi.com>
Reviewed-by: Vijay Chauhan <Vijay.Chauhan@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac : Detect the different RDAC operating modes

This patch detects different operating RDAC modes during the
discovery. It also collects the information about the preferred path.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Reviewed-by: Yanling Qi <yanling.qi@lsi.com>
Reviewed-by: Sudhir Dachepalli <Sudhir.Dachepalli@lis.com>
Reviewed-by: Somasundaram Krishnasamy <Somasundaram.Krishnasamy@lsi.com>
Reviewed-by: Bob Stankey <Robert.Stankey@lsi.com>
Reviewed-by: Vijay Chauhan <Vijay.Chauhan@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac : Add definitions for different RDAC operating modes

This patch adds definitions to support for different operating modes
for LSI rdac storage. Currently, rdac support 3 operation modes.

1. RDAC mode(legacy)
2. AVT mode
3. IOSHIP mode

These definitions are used while activating the path(rdac_activate).

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Reviewed-by: Yanling Qi <yanling.qi@lsi.com>
Reviewed-by: Sudhir Dachepalli <Sudhir.Dachepalli@lis.com>
Reviewed-by: Somasundaram Krishnasamy <Somasundaram.Krishnasamy@lsi.com>
Reviewed-by: Bob Stankey <Robert.Stankey@lsi.com>
Reviewed-by: Vijay Chauhan <Vijay.Chauhan@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: Add MD36xxf into device list

This patch is to add Dell MD36xxf array into the RDAC handler device list.

Singed-off-by: Yanqing Liu <Yanqing_Liu@Dell.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac : Adding MODULE VERSION for rdac device handler

Adding MODULE_VERSION for scsi_dh_rdac. This will be helpful sometimes
to get the code level without looking at the code.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh: cosmetic change to sizeof()

instead of doing sizeof(struct X) it's better to do sizeof(*v) where v
is the variable pointing to struct X.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Babu Moger <babu.moger@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: fix for lun_table update for rdac device handler

During one of our testing, we noticed that mode select command sent
from the host did not have the lun_table updated.

Problem is root caused to the way lun table is updated. Lun table
update was done after the call to blk_rq_map_kern is made. This was
causing problem because kernel uses bounce buffer(bio_copy_kern) if
the address is not aligned. The command buffer updated after the
call(blk_rq_map_kern) was not going on the wire. Moved the code to
update the lun_table before the call to fix the problem.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Signed-off-by: Somasundaram Krishnasamy <Somasundaram.Krishnasamy@lsi.com>
Signed-off-by: Yanling Qi <Yanling.Qi@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: Add two new SUN devices to rdac_dev_list

Signed-off-by: Vijay Chauhan <vijay.chauhan@lsi.com>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: Add Dell MD36xxi controller into RDAC device list

This patch is to add next generation of Dell iSCSI PowerVault
controller MD36xxi into RDAC device list.

Signed-off-by: Yanqing Liu <Yanqing_Liu@Dell.com>
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>

[SCSI] scsi_dh_rdac: Add two new IBM devices to rdac_dev_list

This patch adds two new IBM storage devices which can use rdac device handlers.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh: Make rdac hardware handler's activate() async

Batch up MODE_SELECT in rdac device handler.

LSI RDAC storage has the capability of handling mode selects for
multiple luns in a same command. Make use of that ability to send
as few MODE SELECTs as possible to the storage controller as possible.

This patch creates a work queue and queues up activate requests
when a MODE SELECT is sent down the wire. When that MODE SELECT
completes, it compiles queued up activate requests for multiple
luns into a single MODE SELECT.

This reduces the time to do failover/failback of large number of LUNS.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh: Change the scsidh_activate interface to be asynchronous

Make scsi_dh_activate() function asynchronous, by taking in two additional
parameters, one is the callback function and the other is the data to call
the callback function with.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: Fix for returning correct mode select cmd return info

The function mode_select_handle_sense returns SCSI_DH_OK even when there is a sense code which is incorrect. Removing it so that it returns SCSI_DH_IO when there is sense that is not handled by this function.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Reviewed-by: Vijay Chauhan <vijay.chauhan@lsi.com>
Reviewed-by: Bob Stankey <Robert.stankey@lsi.com>
Reviewed-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: changes for rdac debug logging

Patch to add debugging stuff for rdac device handler.
- Added a bit mask "module parameter" rdac_logging with 2 bits for each type
of logging.
- currently defined only two types of logging(failover and sense logging). Can
be enhanced later if required.
- By default only failover logging is enabled which is equivalent of current
logging.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Reviewed-by: Vijay Chauhan <vijay.chauhan@lsi.com>
Reviewed-by: Bob Stankey <Robert.stankey@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: changes to collect the rdac debug information during the initialization

Adding the code to read the debug information during initialization. This
patch collects the information about storage and controllers during
rdac_activate.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Reviewed-by: Vijay Chauhan <vijay.chauhan@lsi.com>
Reviewed-by: Bob Stankey <Robert.stankey@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: move the init code from rdac_activate to rdac_bus_attach

Moving the initialization code from rdac_activate to rdac_bus_attach which is
more efficient. We don't have to collect all the information during every
activate.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Reviewed-by: Vijay Chauhan <vijay.chauhan@lsi.com>
Reviewed-by: Bob Stankey <Robert.stankey@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: Add support for Sun StorageTek ST2500, ST2510 and ST2530

These storage arrays can use RDAC when configured with 'linux' as the
initiator.

http://www.sun.com/storage/disk_systems/workgroup/2500/
http://www.sun.com/storage/disk_systems/workgroup/2510/
http://www.sun.com/storage/disk_systems/workgroup/2530/

Signed-off-by: Charlie Brady <charlieb@budge.apana.org.au>
Reviewed-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: add support for next generation of Dell PV array

This patch is to add DM support for next generation of Dell PowerVault
storage array.

Signed-off-by: Yanqing Liu <Yanqing_Liu@Dell.com>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh: add two SUN devices to the list of devices supported by default

Reported-by: Rice Brown <rick.brown@oit.gatech.edu>
Signed-Off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh_rdac: Retry for NOT_READY(02/04/01) in rdac device handler

During device discovery read capacity fails with 0x020401 and sets the
device size to 0. As a reason any I/O submitted to this path gets
killed at sd_prep_fn with BLKPREP_KILL. This patch is to retry for
0x020401. NEED_RETRY in scsi_decide_disposition does not give
sufficient time for the device to become ready.

Signed-off-by: Vijay Chauhan <vijay.chauhan@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh_rdac: Retry for NOT_READY check condition

This patch adds retry for NOT_READY check condition - Quiesce in
progress (02/A1/02)

Signed-off-by: Vijay Chauhan<vijay.chauhan@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh_rdac: Retry mode select for NO_SENSE, ABORTED_COMMAND, UNIT_ATTENTION, NOT_READY(02/04/01)

This patch is to add retry for mode select if mode select command is
returned with sense NO_SENSE, UNIT_ATTENTION, ABORTED_COMMAND,
NOT_READY(02/04/01). This patch reorganise the sense keys from if-else
to switch-case format for better maintainability.

Signed-off-by: Vijay Chauhan <vijay.chauhan@lsi.com>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh_rdac: Retry for Quiescence in Progress in rdac device handler

During device discovery read capacity fails with 0x068b02 and sets the
device size to 0. As a reason any I/O submitted to this path gets
killed at sd_prep_fn with BLKPREP_KILL. This patch is to retry for
0x068b02

Signed-off-by: Vijay Chauhan <vijay.chauhan@lsi.com>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh_rdac: Add LSI vendor and product ids in rdac device list

[jejb: fixed whitespace damage]
Signed-off-by: Babu Moger <Babu.Moger@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: Retry mode select in rdac device handler

When the mode select sent to the controller fails with the retryable
error, it is better to retry the mode_select from the hardware handler
itself, instead of propagating the failure to dm-multipath.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: Make sure the state of a path is set properly when controller is swapped from passive to active

When the controller ownership is changed (from passive to active),
check_ownership() doesn't set the state of the device to ACTIVE.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reported-by: "Moger, Babu" <Babu.Moger@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: Initialize path state to be passive when path is not owned

Set the path state to be passive when we learn that the controller does
not own the path to the LUN.

This will avoid sending even a single i/o thru the passive path at the
probe time.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] block: separate failfast into multiple bits.

Multipath is best at handling transport errors. If it gets a device
error then there is not much the multipath layer can do. It will just
access the same device but from a different path.

This patch breaks up failfast into device, transport and driver errors.
The multipath layers (md and dm mutlipath) only ask the lower levels to
fast fail transport errors. The user of failfast, read ahead, will ask
to fast fail on all errors.

Note that blk_noretry_request will return true if any failfast bit
is set. This allows drivers that do not support the multipath failfast
bits to continue to fail on any failfast error like before. Drivers
like scsi that are able to fail fast specific errors can check
for the specific fail fast type. In the next patch I will convert
scsi.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: add Dell product information into rdac device handler

Add Dell Powervault storage arrays into device list of rdac device
handler.

Signed-off-by: Yanqing Liu <yanqing_liu@dell.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: no need to initialize rq->cmd with blk_get_request

blk_get_request initializes rq->cmd (rq_init does) so the users don't
need to do that.

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

[SCSI] scsi_dh: make check_sense return ADD_TO_MLQUEUE

Change scsi_dh check_sense functions to return ADD_TO_MLQUEUE
to allow retries to occur without restriction of blk_noretry_request
check.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: Initialize lun_state in check_ownership()

lun_state need to be initialized inside check_ownership().

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: Do not use scsilun in rdac hardware handler

RDAC storage controller doesn't seem to use the scsilun format. It uses
only the last byte for LUN.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

make struct scsi_dh_devlist's static

This patch makes several needlessly global struct scsi_dh_devlist's
static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] scsi_dh: Update RDAC device handler

This patch updates the RDAC device handler to
refuse to attach to devices not supporting the
RDAC vpd pages.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: Implement common device table handling

Instead of having each and every driver implement its own
device table scanning code we should rather implement a common
routine and scan the device tables there.
This allows us also to implement a general notifier chain
callback for all device handler instead for one per handler.

[sekharan: Fix rejections caused by conflicting bug fix]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

scsi_dh: Verify "dev" is a sdev before accessing it.

Before accessing the device data structure in hardware handlers,
make sure it is a indeed a sdev device.

Yinghai Lu <yhlu.kernel@gmail.com> found the bug on Jul 16, 2008,
and later tested/verified the following fix.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] scsi_dh: add lsi rdac device handler

This patch provides the device handler to support the LSI RDAC SCSI
based storage devices.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>