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  1. 27 Feb, 2019 1 commit
    • Bart Van Assche's avatar
      scsi: core: Avoid that system resume triggers a kernel warning · 388b4e6a
      Bart Van Assche authored 
      scsi_device_quiesce() and scsi_device_resume() are called during
system-wide suspend and resume. scsi_device_quiesce() only succeeds for
SCSI devices that are in one of the RUNNING, OFFLINE or TRANSPORT_OFFLINE
states (see also scsi_set_device_state()).  This patch avoids that the
following warning is triggered when resuming a system for which quiescing a
SCSI device failed:

WARNING: CPU: 2 PID: 11303 at drivers/scsi/scsi_lib.c:2600 scsi_device_resume+0x4f/0x58
CPU: 2 PID: 11303 Comm: kworker/u8:70 Not tainted 5.0.0-rc1+ #50
Hardware name: LENOVO 80E3/Lancer 5B2, BIOS A2CN45WW(V2.13) 08/04/2016
Workqueue: events_unbound async_run_entry_fn
Call Trace:
 scsi_dev_type_resume+0x2e/0x60
 async_run_entry_fn+0x32/0xd8
 process_one_work+0x1f4/0x420
 worker_thread+0x28/0x3c0
 kthread+0x118/0x130
 ret_from_fork+0x22/0x40

Cc: Przemek Socha <soprwa@gmail.com>
Reported-by: default avatarPrzemek Socha <soprwa@gmail.com>
Fixes: 3a0a5299 ("block, scsi: Make SCSI quiesce and resume work reliably") # v4.15
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      388b4e6a
  3. 26 Feb, 2019 8 commits
  5. 16 Feb, 2019 4 commits
    • Martin Wilck's avatar
      scsi: core: reset host byte in DID_NEXUS_FAILURE case · 4a067cf8
      Martin Wilck authored 
      Up to 4.12, __scsi_error_from_host_byte() would reset the host byte to
DID_OK for various cases including DID_NEXUS_FAILURE.  Commit
2a842aca ("block: introduce new block status code type") replaced this
function with scsi_result_to_blk_status() and removed the host-byte
resetting code for the DID_NEXUS_FAILURE case.  As the line
set_host_byte(cmd, DID_OK) was preserved for the other cases, I suppose
this was an editing mistake.

The fact that the host byte remains set after 4.13 is causing problems with
the sg_persist tool, which now returns success rather then exit status 24
when a RESERVATION CONFLICT error is encountered.

Fixes: 2a842aca "block: introduce new block status code type"
Signed-off-by: default avatarMartin Wilck <mwilck@suse.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      4a067cf8
    • John Garry's avatar
      scsi: libsas: Fix rphy phy_identifier for PHYs with end devices attached · ffeafdd2
      John Garry authored 
      The sysfs phy_identifier attribute for a sas_end_device comes from the rphy
phy_identifier value.

Currently this is not being set for rphys with an end device attached, so
we see incorrect symlinks from systemd disk/by-path:

root@localhost:~# ls -l /dev/disk/by-path/
total 0
lrwxrwxrwx 1 root root  9 Feb 13 12:26 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy0-lun-0 -> ../../sdb
lrwxrwxrwx 1 root root 10 Feb 13 12:26 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy0-lun-0-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 10 Feb 13 12:26 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy0-lun-0-part2 -> ../../sdb2
lrwxrwxrwx 1 root root 10 Feb 13 12:26 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy0-lun-0-part3 -> ../../sdc3

Indeed, each sas_end_device phy_identifier value is 0:

root@localhost:/# more sys/class/sas_device/end_device-0\:0\:2/phy_identifier
0
root@localhost:/# more sys/class/sas_device/end_device-0\:0\:10/phy_identifier
0

This patch fixes the discovery code to set the phy_identifier.  With this,
we now get proper symlinks:

root@localhost:~# ls -l /dev/disk/by-path/
total 0
lrwxrwxrwx 1 root root  9 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy10-lun-0 -> ../../sdg
lrwxrwxrwx 1 root root  9 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy11-lun-0 -> ../../sdh
lrwxrwxrwx 1 root root  9 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy2-lun-0 -> ../../sda
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy2-lun-0-part1 -> ../../sda1
lrwxrwxrwx 1 root root  9 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy3-lun-0 -> ../../sdb
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy3-lun-0-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy3-lun-0-part2 -> ../../sdb2
lrwxrwxrwx 1 root root  9 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy4-lun-0 -> ../../sdc
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy4-lun-0-part1 -> ../../sdc1
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy4-lun-0-part2 -> ../../sdc2
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy4-lun-0-part3 -> ../../sdc3
lrwxrwxrwx 1 root root  9 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy5-lun-0 -> ../../sdd
lrwxrwxrwx 1 root root  9 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy7-lun-0 -> ../../sde
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy7-lun-0-part1 -> ../../sde1
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy7-lun-0-part2 -> ../../sde2
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy7-lun-0-part3 -> ../../sde3
lrwxrwxrwx 1 root root  9 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy8-lun-0 -> ../../sdf
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy8-lun-0-part1 -> ../../sdf1
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy8-lun-0-part2 -> ../../sdf2
lrwxrwxrwx 1 root root 10 Feb 13 11:53 platform-HISI0162:01-sas-exp0x500e004aaaaaaa1f-phy8-lun-0-part3 -> ../../sdf3

Fixes: 2908d778 ("[SCSI] aic94xx: new driver")
Reported-by: default avatardann frazier <dann.frazier@canonical.com>
Signed-off-by: default avatarJohn Garry <john.garry@huawei.com>
Reviewed-by: default avatarJason Yan <yanaijie@huawei.com>
Tested-by: default avatardann frazier <dann.frazier@canonical.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      ffeafdd2
    • Masato Suzuki's avatar
      scsi: sd_zbc: Fix sd_zbc_report_zones() buffer allocation · 515ce606
      Masato Suzuki authored 
      The function sd_zbc_do_report_zones() issues a REPORT ZONES command with a
buffer size calculated based on the number of zones requested by the
caller. This value should however not exceed the capabilities of the
hardware maximum command size, that is, should not exceed the
max_hw_sectors limit of the device. This problem leads to failures of
report zones commands when re-validating disks with some SAS HBAs.

Fix this by limiting a report zone command buffer size to the minimum of
the device max_hw_sectors and calculated value based on the requested
number of zones. This does not change the semantic of the report_zones file
operation as report zones can always return less zone reports than
requested. Short reports are handled using a loop execution of the
report_zones file operation in the function blk_report_zones().

[Damien]
Before patch 'e76239a3 ("block: add a report_zones method")', report
zones buffer allocation was limited to max_sectors when allocated in
blk_report_zones(). This however does not consider the actual format of the
device reply which is interface dependent.  Limiting the allocation based
on the size of the expected reply format rather than the size of the array
of generic sturct blkzone passed by blk_report_zones() makes more sense.

Fixes: e76239a3 ("block: add a report_zones method")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarMasato Suzuki <masato.suzuki@wdc.com>
Signed-off-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      515ce606
    • Anoob Soman's avatar
      scsi: libiscsi: Fix race between iscsi_xmit_task and iscsi_complete_task · 79edd00d
      Anoob Soman authored 
      When a target sends Check Condition, whilst initiator is busy xmiting
re-queued data, could lead to race between iscsi_complete_task() and
iscsi_xmit_task() and eventually crashing with the following kernel
backtrace.

[3326150.987523] ALERT: BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
[3326150.987549] ALERT: IP: [<ffffffffa05ce70d>] iscsi_xmit_task+0x2d/0xc0 [libiscsi]
[3326150.987571] WARN: PGD 569c8067 PUD 569c9067 PMD 0
[3326150.987582] WARN: Oops: 0002 [#1] SMP
[3326150.987593] WARN: Modules linked in: tun nfsv3 nfs fscache dm_round_robin
[3326150.987762] WARN: CPU: 2 PID: 8399 Comm: kworker/u32:1 Tainted: G O 4.4.0+2 #1
[3326150.987774] WARN: Hardware name: Dell Inc. PowerEdge R720/0W7JN5, BIOS 2.5.4 01/22/2016
[3326150.987790] WARN: Workqueue: iscsi_q_13 iscsi_xmitworker [libiscsi]
[3326150.987799] WARN: task: ffff8801d50f3800 ti: ffff8801f5458000 task.ti: ffff8801f5458000
[3326150.987810] WARN: RIP: e030:[<ffffffffa05ce70d>] [<ffffffffa05ce70d>] iscsi_xmit_task+0x2d/0xc0 [libiscsi]
[3326150.987825] WARN: RSP: e02b:ffff8801f545bdb0 EFLAGS: 00010246
[3326150.987831] WARN: RAX: 00000000ffffffc3 RBX: ffff880282d2ab20 RCX: ffff88026b6ac480
[3326150.987842] WARN: RDX: 0000000000000000 RSI: 00000000fffffe01 RDI: ffff880282d2ab20
[3326150.987852] WARN: RBP: ffff8801f545bdc8 R08: 0000000000000000 R09: 0000000000000008
[3326150.987862] WARN: R10: 0000000000000000 R11: 000000000000fe88 R12: 0000000000000000
[3326150.987872] WARN: R13: ffff880282d2abe8 R14: ffff880282d2abd8 R15: ffff880282d2ac08
[3326150.987890] WARN: FS: 00007f5a866b4840(0000) GS:ffff88028a640000(0000) knlGS:0000000000000000
[3326150.987900] WARN: CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033
[3326150.987907] WARN: CR2: 0000000000000078 CR3: 0000000070244000 CR4: 0000000000042660
[3326150.987918] WARN: Stack:
[3326150.987924] WARN: ffff880282d2ad58 ffff880282d2ab20 ffff880282d2abe8 ffff8801f545be18
[3326150.987938] WARN: ffffffffa05cea90 ffff880282d2abf8 ffff88026b59cc80 ffff88026b59cc00
[3326150.987951] WARN: ffff88022acf32c0 ffff880289491800 ffff880255a80800 0000000000000400
[3326150.987964] WARN: Call Trace:
[3326150.987975] WARN: [<ffffffffa05cea90>] iscsi_xmitworker+0x2f0/0x360 [libiscsi]
[3326150.987988] WARN: [<ffffffff8108862c>] process_one_work+0x1fc/0x3b0
[3326150.987997] WARN: [<ffffffff81088f95>] worker_thread+0x2a5/0x470
[3326150.988006] WARN: [<ffffffff8159cad8>] ? __schedule+0x648/0x870
[3326150.988015] WARN: [<ffffffff81088cf0>] ? rescuer_thread+0x300/0x300
[3326150.988023] WARN: [<ffffffff8108ddf5>] kthread+0xd5/0xe0
[3326150.988031] WARN: [<ffffffff8108dd20>] ? kthread_stop+0x110/0x110
[3326150.988040] WARN: [<ffffffff815a0bcf>] ret_from_fork+0x3f/0x70
[3326150.988048] WARN: [<ffffffff8108dd20>] ? kthread_stop+0x110/0x110
[3326150.988127] ALERT: RIP [<ffffffffa05ce70d>] iscsi_xmit_task+0x2d/0xc0 [libiscsi]
[3326150.988138] WARN: RSP <ffff8801f545bdb0>
[3326150.988144] WARN: CR2: 0000000000000078
[3326151.020366] WARN: ---[ end trace 1c60974d4678d81b ]---

Commit 6f8830f5 ("scsi: libiscsi: add lock around task lists to fix
list corruption regression") introduced "taskqueuelock" to fix list
corruption during the race, but this wasn't enough.

Re-setting of conn->task to NULL, could race with iscsi_xmit_task().
iscsi_complete_task()
{
    ....
    if (conn->task == task)
        conn->task = NULL;
}

conn->task in iscsi_xmit_task() could be NULL and so will be task.
__iscsi_get_task(task) will crash (NullPtr de-ref), trying to access
refcount.

iscsi_xmit_task()
{
    struct iscsi_task *task = conn->task;

    __iscsi_get_task(task);
}

This commit will take extra conn->session->back_lock in iscsi_xmit_task()
to ensure iscsi_xmit_task() waits for iscsi_complete_task(), if
iscsi_complete_task() wins the race.  If iscsi_xmit_task() wins the race,
iscsi_xmit_task() increments task->refcount
(__iscsi_get_task) ensuring iscsi_complete_task() will not iscsi_free_task().
Signed-off-by: default avatarAnoob Soman <anoob.soman@citrix.com>
Signed-off-by: default avatarBob Liu <bob.liu@oracle.com>
Acked-by: default avatarLee Duncan <lduncan@suse.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      79edd00d
  7. 13 Feb, 2019 2 commits
  9. 05 Feb, 2019 4 commits
    • Vaibhav Jain's avatar
      scsi: cxlflash: Prevent deadlock when adapter probe fails · bb61b843
      Vaibhav Jain authored 
      Presently when an error is encountered during probe of the cxlflash
adapter, a deadlock is seen with cpu thread stuck inside
cxlflash_remove(). Below is the trace of the deadlock as logged by
khungtaskd:

cxlflash 0006:00:00.0: cxlflash_probe: init_afu failed rc=-16
INFO: task kworker/80:1:890 blocked for more than 120 seconds.
       Not tainted 5.0.0-rc4-capi2-kexec+ #2
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/80:1    D    0   890      2 0x00000808
Workqueue: events work_for_cpu_fn

Call Trace:
 0x4d72136320 (unreliable)
 __switch_to+0x2cc/0x460
 __schedule+0x2bc/0xac0
 schedule+0x40/0xb0
 cxlflash_remove+0xec/0x640 [cxlflash]
 cxlflash_probe+0x370/0x8f0 [cxlflash]
 local_pci_probe+0x6c/0x140
 work_for_cpu_fn+0x38/0x60
 process_one_work+0x260/0x530
 worker_thread+0x280/0x5d0
 kthread+0x1a8/0x1b0
 ret_from_kernel_thread+0x5c/0x80
INFO: task systemd-udevd:5160 blocked for more than 120 seconds.

The deadlock occurs as cxlflash_remove() is called from cxlflash_probe()
without setting 'cxlflash_cfg->state' to STATE_PROBED and the probe thread
starts to wait on 'cxlflash_cfg->reset_waitq'. Since the device was never
successfully probed the 'cxlflash_cfg->state' never changes from
STATE_PROBING hence the deadlock occurs.

We fix this deadlock by setting the variable 'cxlflash_cfg->state' to
STATE_PROBED in case an error occurs during cxlflash_probe() and just
before calling cxlflash_remove().

Cc: stable@vger.kernel.org
Fixes: c21e0bbf("cxlflash: Base support for IBM CXL Flash Adapter")
Signed-off-by: default avatarVaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      bb61b843
    • Ross Lagerwall's avatar
      Revert "scsi: libfc: Add WARN_ON() when deleting rports" · d8f6382a
      Ross Lagerwall authored 
      This reverts commit bbc0f8bd.

It added a warning whose intent was to check whether the rport was still
linked into the peer list. It doesn't work as intended and gives false
positive warnings for two reasons:

1) If the rport is never linked into the peer list it will not be
considered empty since the list_head is never initialized.

2) If the rport is deleted from the peer list using list_del_rcu(), then
the list_head is in an undefined state and it is not considered empty.
Signed-off-by: default avatarRoss Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      d8f6382a
    • Damien Le Moal's avatar
      scsi: sd_zbc: Fix zone information messages · 88fc41c4
      Damien Le Moal authored 
      Commit bf505456 ("block: Introduce blk_revalidate_disk_zones()")
inadvertently broke the message output of sd_zbc_print_zones() because the
zone information initialization of the scsi disk structure was moved to the
second scan run while sd_zbc_print_zones() is called on the first
scan. This leads to the following incorrect message to be printed for any
ZBC or ZAC zoned disks.

"...[sdX] 4294967295 zones of 0 logical blocks + 1 runt zone"

Fix this by initializing sdkp zone size and number of zones early on the
first scan. This does not impact the execution of
blk_revalidate_zones(). This functions is still called only once the block
device capacity is set on the second revalidate run on boot, or if the disk
zone configuration changed (i.e. the disk changed).

Fixes: bf505456 ("block: Introduce blk_revalidate_disk_zones()")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      88fc41c4
    • David Disseldorp's avatar
      scsi: target: make the pi_prot_format ConfigFS path readable · b6cd7f34
      David Disseldorp authored 
      pi_prot_format conversion to write-only caused userspace breakage. Make the
ConfigFS path readable again and hardcode the "0\n" content, matching
previous output.

Fixes: 6baca760 ("scsi: target: drop unused pi_prot_format attribute storage")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1667505Reported-by: default avatarLee Duncan <lduncan@suse.com>
Reported-by: default avatarLaura Abbott <labbott@redhat.com>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarDavid Disseldorp <ddiss@suse.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      b6cd7f34
  11. 01 Feb, 2019 1 commit
    • James Bottomley's avatar
      scsi: aic94xx: fix module loading · 42caa0ed
      James Bottomley authored 
      The aic94xx driver is currently failing to load with errors like

sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:03.0/0000:02:00.3/0000:07:02.0/revision'

Because the PCI code had recently added a file named 'revision' to every
PCI device.  Fix this by renaming the aic94xx revision file to
aic_revision.  This is safe to do for us because as far as I can tell,
there's nothing in userspace relying on the current aic94xx revision file
so it can be renamed without breaking anything.

Fixes: 702ed3be (PCI: Create revision file in sysfs)
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      42caa0ed
  13. 29 Jan, 2019 5 commits
    • Dan Carpenter's avatar
      scsi: 53c700: pass correct "dev" to dma_alloc_attrs() · 8437fcf1
      Dan Carpenter authored 
      The "hostdata->dev" pointer is NULL here.  We set "hostdata->dev = dev;"
later in the function and we also use "hostdata->dev" when we call
dma_free_attrs() in NCR_700_release().

This bug predates git version control.
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      8437fcf1
    • Dan Carpenter's avatar
      scsi: bnx2fc: Fix error handling in probe() · b2d3492f
      Dan Carpenter authored 
      There are two issues here.  First if cmgr->hba is not set early enough then
it leads to a NULL dereference.  Second if we don't completely initialize
cmgr->io_bdt_pool[] then we end up dereferencing uninitialized pointers.

Fixes: 853e2bd2 ("[SCSI] bnx2fc: Broadcom FCoE offload driver")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      b2d3492f
    • Douglas Gilbert's avatar
      scsi: scsi_debug: fix write_same with virtual_gb problem · 40d07b52
      Douglas Gilbert authored 
      The WRITE SAME(10) and (16) implementations didn't take account of the
buffer wrap required when the virtual_gb parameter is greater than 0.

Fix that and rename the fake_store() function to lba2fake_store() to lessen
confusion with the global fake_storep pointer. Bump version date.
Signed-off-by: default avatarDouglas Gilbert <dgilbert@interlog.com>
Reported-by: default avatarBart Van Assche <bvanassche@acm.org>
Tested by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      40d07b52
    • Ming Lu's avatar
      scsi: libfc: free skb when receiving invalid flogi resp · 5d8fc4a9
      Ming Lu authored 
      The issue to be fixed in this commit is when libfc found it received a
invalid FLOGI response from FC switch, it would return without freeing the
fc frame, which is just the skb data. This would cause memory leak if FC
switch keeps sending invalid FLOGI responses.

This fix is just to make it execute `fc_frame_free(fp)` before returning
from function `fc_lport_flogi_resp`.
Signed-off-by: default avatarMing Lu <ming.lu@citrix.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      5d8fc4a9
    • Steffen Maier's avatar
      scsi: zfcp: fix sysfs block queue limit output for max_segment_size · b6319569
      Steffen Maier authored 
      Since v2.6.35 commit 68322984 ("[SCSI] zfcp: Report scatter-gather
limits to SCSI and block layer"), zfcp set dma_parms.max_segment_size ==
PAGE_SIZE (but without using the setter dma_set_max_seg_size()) and
scsi_host_template.dma_boundary == PAGE_SIZE - 1.

v5.0-rc1 commit 50c2e910 ("scsi: introduce a max_segment_size
host_template parameters") introduced a new field
scsi_host_template.max_segment_size. If an LLDD such as zfcp does not set
it, scsi_host_alloc() uses BLK_MAX_SEGMENT_SIZE = 65536 for
Scsi_Host.max_segment_size. __scsi_init_queue() announced the minimum of
Scsi_Host.max_segment_size and dma_parms.max_segment_size to the block
layer. For zfcp: min(65536, 4096) == 4096 which was still good.

v5.0 commit a8cf59a6 ("scsi: communicate max segment size to the DMA
mapping code") announces Scsi_Host.max_segment_size to the block layer and
overwrites dma_parms.max_segment_size with Scsi_Host.max_segment_size.  For
zfcp dma_parms.max_segment_size == Scsi_Host.max_segment_size == 65536
which is also reflected in block queue limits.

$ cd /sys/bus/ccw/drivers/zfcp
$ cd 0.0.3c40/host5/rport-5:0-4/target5:0:4/5:0:4:10/block/sdi/queue
$ cat max_segment_size
65536

Zfcp I/O still works because dma_boundary implicitly still keeps the
effective max segment size <= PAGE_SIZE.  However, dma_boundary does not
seem visible to user space, but max_segment_size is visible and shows a
misleading wrong value.  Fix it and inherit the stable tag of a8cf59a6.

Devices on our bus ccw support DMA but no DMA mapping. Of multiple device
types on the ccw bus, only zfcp needs dma_parms for SCSI limits.  So, leave
dma_parms setup in zfcp and do not move it to the bus.
Signed-off-by: default avatarSteffen Maier <maier@linux.ibm.com>
Fixes: 50c2e910 ("scsi: introduce a max_segment_size host_template parameters")
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      b6319569
  15. 23 Jan, 2019 6 commits
  17. 12 Jan, 2019 9 commits
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