linux.git/drivers/scsi/ipr.c, branch v4.12

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2017-05-04T19:19:44+00:00

Pull SCSI updates from James Bottomley:
 "This update includes the usual round of major driver updates
  (hisi_sas, ufs, fnic, cxlflash, be2iscsi, ipr, stex). There's also the
  usual amount of cosmetic and spelling stuff"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (155 commits)
  scsi: qla4xxx: fix spelling mistake: "Tempalate" -> "Template"
  scsi: stex: make S6flag static
  scsi: mac_esp: fix to pass correct device identity to free_irq()
  scsi: aacraid: pci_alloc_consistent() failures on ARM64
  scsi: ufs: make ufshcd_get_lists_status() register operation obvious
  scsi: ufs: use MASK_EE_STATUS
  scsi: mac_esp: Replace bogus memory barrier with spinlock
  scsi: fcoe: make fcoe_e_d_tov and fcoe_r_a_tov static
  scsi: sd_zbc: Do not write lock zones for reset
  scsi: sd_zbc: Remove superfluous assignments
  scsi: sd: sd_zbc: Rename sd_zbc_setup_write_cmnd
  scsi: Improve scsi_get_sense_info_fld
  scsi: sd: Cleanup sd_done sense data handling
  scsi: sd: Improve sd_completed_bytes
  scsi: sd: Fix function descriptions
  scsi: mpt3sas: remove redundant wmb
  scsi: mpt: Move scsi_remove_host() out of mptscsih_remove_host()
  scsi: sg: reset 'res_in_use' after unlinking reserved array
  scsi: mvumi: remove code handling zero scsi_sg_count(scmd) case
  scsi: fusion: fix spelling mistake: "Persistancy" -> "Persistency"
  ...

Merge remote-tracking branch 'mkp-scsi/4.11/scsi-fixes' into fixes

2017-04-12T14:29:17+00:00

scsi: ipr: do not set DID_PASSTHROUGH on CHECK CONDITION

2017-04-12T01:40:19+00:00

On a dual controller setup with multipath enabled, some MEDIUM ERRORs
caused both paths to be failed, thus I/O got queued/blocked since the
'queue_if_no_path' feature is enabled by default on IPR controllers.

This example disabled 'queue_if_no_path' so the I/O failure is seen at
the sg_dd program.  Notice that after the sg_dd test-case, both paths
are in 'failed' state, and both path/priority groups are in 'enabled'
state (not 'active') -- which would block I/O with 'queue_if_no_path'.

    # sg_dd if=/dev/dm-2 bs=4096 count=1 dio=1 verbose=4 blk_sgio=0
    <...>
    read(unix): count=4096, res=-1
    sg_dd: reading, skip=0 : Input/output error
    <...>

    # dmesg
    [...] sd 2:2:16:0: [sds] FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
    [...] sd 2:2:16:0: [sds] Sense Key : Medium Error [current]
    [...] sd 2:2:16:0: [sds] Add. Sense: Unrecovered read error - recommend rewrite the data
    [...] sd 2:2:16:0: [sds] CDB: Read(10) 28 00 00 00 00 00 00 00 20 00
    [...] blk_update_request: I/O error, dev sds, sector 0
    [...] device-mapper: multipath: Failing path 65:32.
    <...>
    [...] device-mapper: multipath: Failing path 65:224.

    # multipath -l
    1IBM_IPR-0_59C2AE0000001F80 dm-2 IBM     ,IPR-0   59C2AE00
    size=5.2T features='0' hwhandler='1 alua' wp=rw
    |-+- policy='service-time 0' prio=0 status=enabled
    | `- 2:2:16:0 sds  65:32  failed undef running
    `-+- policy='service-time 0' prio=0 status=enabled
      `- 1:2:7:0  sdae 65:224 failed undef running

This is not the desired behavior. The dm-multipath explicitly checks
for the MEDIUM ERROR case (and a few others) so not to fail the path
(e.g., I/O to other sectors could potentially happen without problems).
See dm-mpath.c :: do_end_io_bio() -> noretry_error() !->! fail_path().

The problem trace is:

1) ipr_scsi_done()  // SENSE KEY/CHECK CONDITION detected, go to..
2) ipr_erp_start()  // ipr_is_gscsi() and masked_ioasc OK, go to..
3) ipr_gen_sense()  // masked_ioasc is IPR_IOASC_MED_DO_NOT_REALLOC,
                    // so set DID_PASSTHROUGH.

4) scsi_decide_disposition()  // check for DID_PASSTHROUGH and return
                              // early on, faking a DID_OK.. *instead*
                              // of reaching scsi_check_sense().

                              // Had it reached the latter, that would
                              // set host_byte to DID_MEDIUM_ERROR.

5) scsi_finish_command()
6) scsi_io_completion()
7) __scsi_error_from_host_byte()  // That would be converted to -ENODATA
<...>
8) dm_softirq_done()
9) multipath_end_io()
10) do_end_io()
11) noretry_error()  // And that is checked in dm-mpath :: noretry_error()
                     // which would cause fail_path() not to be called.

With this patch applied, the I/O is failed but the paths are not.  This
multipath device continues accepting more I/O requests without blocking.
(and notice the different host byte/driver byte handling per SCSI layer).

    # dmesg
    [...] sd 2:2:7:0: [sdaf] Done: SUCCESS Result: hostbyte=0x13 driverbyte=DRIVER_OK
    [...] sd 2:2:7:0: [sdaf] CDB: Read(10) 28 00 00 00 00 00 00 00 40 00
    [...] sd 2:2:7:0: [sdaf] Sense Key : Medium Error [current]
    [...] sd 2:2:7:0: [sdaf] Add. Sense: Unrecovered read error - recommend rewrite the data
    [...] blk_update_request: critical medium error, dev sdaf, sector 0
    [...] blk_update_request: critical medium error, dev dm-6, sector 0
    [...] sd 2:2:7:0: [sdaf] Done: SUCCESS Result: hostbyte=0x13 driverbyte=DRIVER_OK
    [...] sd 2:2:7:0: [sdaf] CDB: Read(10) 28 00 00 00 00 00 00 00 10 00
    [...] sd 2:2:7:0: [sdaf] Sense Key : Medium Error [current]
    [...] sd 2:2:7:0: [sdaf] Add. Sense: Unrecovered read error - recommend rewrite the data
    [...] blk_update_request: critical medium error, dev sdaf, sector 0
    [...] blk_update_request: critical medium error, dev dm-6, sector 0
    [...] Buffer I/O error on dev dm-6, logical block 0, async page read

    # multipath -l 1IBM_IPR-0_59C2AE0000001F80
    1IBM_IPR-0_59C2AE0000001F80 dm-6 IBM     ,IPR-0   59C2AE00
    size=5.2T features='1 queue_if_no_path' hwhandler='1 alua' wp=rw
    |-+- policy='service-time 0' prio=0 status=active
    | `- 2:2:7:0  sdaf 65:240 active undef running
    `-+- policy='service-time 0' prio=0 status=enabled
      `- 1:2:7:0  sdh  8:112  active undef running

Signed-off-by: Mauricio Faria de Oliveira 
Acked-by: Brian King 
Signed-off-by: Martin K. Petersen

scsi: ipr: Fix SATA EH hang

2017-03-23T16:04:05+00:00

This patch fixes a hang that can occur in ATA EH with ipr. With ipr's
usage of libata, commands should never end up on ap->eh_done_q. The
timeout function we use for ipr, even for SATA devices, is
scsi_times_out, so ATA_QCFLAG_EH_SCHEDULED never gets set for ipr and EH
is driven completely by ipr and SCSI. The SCSI EH thread ends up calling
ipr's eh_device_reset_handler, which then calls
ata_std_error_handler. This ends up calling ipr_sata_reset, which issues
a reset to the device. This should result in all pending commands
getting failed back and having ata_qc_complete called for them, which
should end up clearing ATA_QCFLAG_FAILED as qc->flags gets zeroed in
ata_qc_free.  This ensures that when we end up in ata_eh_finish, we
don't do anything more with the command.

On adapters that only support a single interrupt and when running with
two MSI-X vectors or less, the adapter firmware guarantees that
responses to all outstanding commands are sent back prior to sending the
response to the SATA reset command.  On newer adapters supporting
multiple HRRQs, however, this can no longer be guaranteed, since the
command responses and reset response may be processed on different
HRRQs.

If ipr returns from ipr_sata_reset before the outstanding command was
returned, this sends us down the path of __ata_eh_qc_complete which then
moves the associated scsi_cmd from the work_q in
scsi_eh_bus_device_reset to ap->eh_done_q, which then will sit there
forever and we will be wedged.

This patch fixes this up by ensuring that any outstanding commands are
flushed before returning from eh_device_reset_handler for a SATA device.

Reported-by: David Jeffery 
Signed-off-by: Brian King 
Reviewed-by: Wendy Xiong 
Tested-by: Wendy Xiong 
Signed-off-by: Martin K. Petersen

scsi: ipr: Error path locking fixes

2017-03-23T16:04:05+00:00

This patch closes up some potential race conditions observed in the
error handling paths in ipr while debugging an issue resulting in a hang
with SATA error handling. These patches ensure we are holding the
correct lock when adding and removing commands from the free and pending
queues in some error scenarios.

Signed-off-by: Brian King 
Reviewed-by: Wendy Xiong 
Tested-by: Wendy Xiong 
Signed-off-by: Martin K. Petersen

scsi: ipr: Fix abort path race condition

2017-03-23T16:04:05+00:00

This fixes a race condition in the error handlomg paths of ipr. While a
command is outstanding to the adapter, it is placed on a pending queue
for the hrrq it is associated with, while holding the HRRQ lock. When a
command is completed, it is removed from the pending queue, under HRRQ
lock, and placed on a local list.  This list is then iterated through
without any locks and each command's done function is invoked, inside of
which, the command gets returned to the free list while grabbing the
HRRQ lock. This fixes two race conditions when commands have been
removed from the pending list but have not yet been added to the free
list. Both of these changes fix race conditions that could result in
returning success from eh_abort_handler and then later calling scsi_done
for the same request.

The first race condition is in ipr_cancel_op. It looks through each
pending queue to see if the command to be aborted is still outstanding
or not. Rather than looking on the pending queue, reverse the logic to
check to look for commands that are NOT on the free queue.  The second
race condition can occur when in ipr_wait_for_ops where we are waiting
for responses for commands we've aborted.

Signed-off-by: Brian King 
Reviewed-by: Wendy Xiong 
Tested-by: Wendy Xiong 
Signed-off-by: Martin K. Petersen

scsi: ipr: Remove redundant initialization

2017-03-23T16:04:05+00:00

Removes some code in __ipr_eh_dev_reset which was modifying the ipr_cmd
done function. This should have already been setup at command allocation
time and if its since been changed, it means we are in the ipr_erp*
functions and need to wait for them to complete and don't want to
override that here.

Signed-off-by: Brian King 
Reviewed-by: Wendy Xiong 
Tested-by: Wendy Xiong 
Signed-off-by: Martin K. Petersen

scsi: ipr: Fix missed EH wakeup

2017-03-23T16:04:05+00:00

Following a command abort or device reset, ipr's EH handlers wait for
the commands getting aborted to get sent back from the adapter prior to
returning from the EH handler. This fixes up some cases where the
completion handler was not getting called, which would have resulted in
the EH thread waiting until it timed out, greatly extending EH time.

Signed-off-by: Brian King 
Reviewed-by: Wendy Xiong 
Tested-by: Wendy Xiong 
Signed-off-by: Martin K. Petersen

scripts/spelling.txt: add "intialization" pattern and fix typo instances

2017-02-28T02:43:47+00:00

Fix typos and add the following to the scripts/spelling.txt:

  intialization||initialization

The "inintialization" in drivers/acpi/spcr.c is a different pattern but
I fixed it as well in this commit.

Link: http://lkml.kernel.org/r/1481573103-11329-16-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scsi: ipr: Fix runaway IRQs when falling back from MSI to LSI

2016-12-01T00:58:04+00:00

LSIs must be ack'ed with an MMIO otherwise they remain asserted
forever. This is controlled by the "clear_isr" flag.

While we set that flag properly when deciding initially whether to use
LSIs or MSIs, we fail to set it if we first chose MSIs, the test fails,
then fallback to LSIs.

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Brian King 
Signed-off-by: Martin K. Petersen