linux.git/drivers/scsi/libiscsi.c, branch v5.12

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

2021-04-18T03:25:33+00:00

Pull SCSI fixes from James Bottomley:
 "Two fixes: the libsas fix is for a problem that occurs when trying to
  change the cache type of an ATA device and the libiscsi one is a
  regression fix from this merge window"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: libsas: Reset num_scatter if libata marks qc as NODATA
  scsi: iscsi: Fix iSCSI cls conn state

scsi: iscsi: Fix iSCSI cls conn state

2021-04-08T01:30:59+00:00

In commit 9e67600ed6b8 ("scsi: iscsi: Fix race condition between login and
sync thread") I missed that libiscsi was now setting the iSCSI class state,
and that patch ended up resetting the state during conn stoppage and using
the wrong state value during ep_disconnect. This patch moves the setting of
the class state to the class module and then fixes the two issues above.

Link: https://lore.kernel.org/r/20210406171746.5016-1-michael.christie@oracle.com
Fixes: 9e67600ed6b8 ("scsi: iscsi: Fix race condition between login and sync thread")
Cc: Gulam Mohamed 
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: iscsi: Ensure sysfs attributes are limited to PAGE_SIZE

2021-03-05T01:09:51+00:00

As the iSCSI parameters are exported back through sysfs, it should be
enforcing that they never are more than PAGE_SIZE (which should be more
than enough) before accepting updates through netlink.

Change all iSCSI sysfs attributes to use sysfs_emit().

Cc: stable@vger.kernel.org
Reported-by: Adam Nichols 
Reviewed-by: Lee Duncan 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Mike Christie 
Signed-off-by: Chris Leech 
Signed-off-by: Martin K. Petersen

scsi: libiscsi: Reset max/exp cmdsn during recovery

2021-02-09T03:39:04+00:00

If we lose the session then relogin, but the new cmdsn window has shrunk
(due to something like an admin changing a setting) we will have the old
exp/max_cmdsn values and will never be able to update them. For example,
max_cmdsn would be 64, but if on the target the user set the window to be
smaller then the target could try to return the max_cmdsn as 32. We will
see that new max_cmdsn in the rsp but because it's lower than the old
max_cmdsn when the window was larger we will not update it.

So this patch has us reset the window values during session cleanup so they
can be updated after a new login.

Link: https://lore.kernel.org/r/20210207044608.27585-8-michael.christie@oracle.com
Reviewed-by: Lee Duncan 
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: libiscsi: Add helper to calculate max SCSI cmds per session

2021-02-09T03:39:04+00:00

This patch just breaks out the code that calculates the number of SCSI cmds
that will be used for a SCSI session. It also adds a check that we don't go
over the host's can_queue value.

Link: https://lore.kernel.org/r/20210207044608.27585-6-michael.christie@oracle.com
Reviewed-by: Lee Duncan 
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: libiscsi: Fix iSCSI host workq destruction

2021-02-09T03:39:04+00:00

We allocate the iSCSI host workq in iscsi_host_alloc() so iscsi_host_free()
should do the destruction. Drivers can then do their error/goto handling
and call iscsi_host_free() to clean up what has been allocated in
iscsi_host_alloc().

Link: https://lore.kernel.org/r/20210207044608.27585-5-michael.christie@oracle.com
Reviewed-by: Lee Duncan 
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: libiscsi: Fix iscsi_task use after free()

2021-02-09T03:39:03+00:00

The following bug was reported and debugged by wubo40@huawei.com:

When testing kernel 4.18 version, NULL pointer dereference problem occurs
in iscsi_eh_cmd_timed_out() function.

I think this bug in the upstream is still exists.

The analysis reasons are as follows:

1) For some reason, I/O command did not complete within the timeout
   period. The block layer timer works, call scsi_times_out() to handle I/O
   timeout logic.  At the same time the command just completes.

2) scsi_times_out() call iscsi_eh_cmd_timed_out() to process timeout logic.
   Although there is an NULL judgment for the task, the task has not been
   released yet now.

3) iscsi_complete_task() calls __iscsi_put_task(). The task reference count
   reaches zero, the conditions for free task is met, then
   iscsi_free_task() frees the task, and sets sc->SCp.ptr = NULL. After
   iscsi_eh_cmd_timed_out() passes the task judgment check, there can still
   be NULL dereference scenarios.

   CPU0                                                CPU3

    |- scsi_times_out()                                 |-
iscsi_complete_task()
    |                                                   |
    |- iscsi_eh_cmd_timed_out()                         |-
__iscsi_put_task()
    |                                                   |
    |- task=sc->SCp.ptr, task is not NUL, check passed  |-
iscsi_free_task(task)
    |                                                   |
    |                                                   |-> sc->SCp.ptr
= NULL
    |                                                   |
    |- task is NULL now, NULL pointer dereference       |
    |                                                   |
   \|/                                                 \|/

Calltrace:
[380751.840862] BUG: unable to handle kernel NULL pointer dereference at
0000000000000138
[380751.843709] PGD 0 P4D 0
[380751.844770] Oops: 0000 [#1] SMP PTI
[380751.846283] CPU: 0 PID: 403 Comm: kworker/0:1H Kdump: loaded
Tainted: G
[380751.851467] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
[380751.856521] Workqueue: kblockd blk_mq_timeout_work
[380751.858527] RIP: 0010:iscsi_eh_cmd_timed_out+0x15e/0x2e0 [libiscsi]
[380751.861129] Code: 83 ea 01 48 8d 74 d0 08 48 8b 10 48 8b 4a 50 48 85
c9 74 2c 48 39 d5 74
[380751.868811] RSP: 0018:ffffc1e280a5fd58 EFLAGS: 00010246
[380751.870978] RAX: ffff9fd1e84e15e0 RBX: ffff9fd1e84e6dd0 RCX:
0000000116acc580
[380751.873791] RDX: ffff9fd1f97a9400 RSI: ffff9fd1e84e1800 RDI:
ffff9fd1e4d6d420
[380751.876059] RBP: ffff9fd1e4d49000 R08: 0000000116acc580 R09:
0000000116acc580
[380751.878284] R10: 0000000000000000 R11: 0000000000000000 R12:
ffff9fd1e6e931e8
[380751.880500] R13: ffff9fd1e84e6ee0 R14: 0000000000000010 R15:
0000000000000003
[380751.882687] FS:  0000000000000000(0000) GS:ffff9fd1fac00000(0000)
knlGS:0000000000000000
[380751.885236] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[380751.887059] CR2: 0000000000000138 CR3: 000000011860a001 CR4:
00000000003606f0
[380751.889308] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[380751.891523] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[380751.893738] Call Trace:
[380751.894639]  scsi_times_out+0x60/0x1c0
[380751.895861]  blk_mq_check_expired+0x144/0x200
[380751.897302]  ? __switch_to_asm+0x35/0x70
[380751.898551]  blk_mq_queue_tag_busy_iter+0x195/0x2e0
[380751.900091]  ? __blk_mq_requeue_request+0x100/0x100
[380751.901611]  ? __switch_to_asm+0x41/0x70
[380751.902853]  ? __blk_mq_requeue_request+0x100/0x100
[380751.904398]  blk_mq_timeout_work+0x54/0x130
[380751.905740]  process_one_work+0x195/0x390
[380751.907228]  worker_thread+0x30/0x390
[380751.908713]  ? process_one_work+0x390/0x390
[380751.910350]  kthread+0x10d/0x130
[380751.911470]  ? kthread_flush_work_fn+0x10/0x10
[380751.913007]  ret_from_fork+0x35/0x40

crash> dis -l iscsi_eh_cmd_timed_out+0x15e
xxxxx/drivers/scsi/libiscsi.c: 2062

1970 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd
*sc)
{
...
1984         spin_lock_bh(&session->frwd_lock);
1985         task = (struct iscsi_task *)sc->SCp.ptr;
1986         if (!task) {
1987                 /*
1988                  * Raced with completion. Blk layer has taken
ownership
1989                  * so let timeout code complete it now.
1990                  */
1991                 rc = BLK_EH_DONE;
1992                 goto done;
1993         }

...

2052         for (i = 0; i < conn->session->cmds_max; i++) {
2053                 running_task = conn->session->cmds[i];
2054                 if (!running_task->sc || running_task == task ||
2055                      running_task->state != ISCSI_TASK_RUNNING)
2056                         continue;
2057
2058                 /*
2059                  * Only check if cmds started before this one have
made
2060                  * progress, or this could never fail
2061                  */
2062                 if (time_after(running_task->sc->jiffies_at_alloc,
2063                                task->sc->jiffies_at_alloc))    <---
2064                         continue;
2065
...
}

carsh> struct scsi_cmnd ffff9fd1e6e931e8
struct scsi_cmnd {
  ...
  SCp = {
    ptr = 0x0,   <--- iscsi_task
    this_residual = 0,
    ...
  },
}

To prevent this, we take a ref to the cmd under the back (completion) lock
so if the completion side were to call iscsi_complete_task() on the task
while the timer/eh paths are not holding the back_lock it will not be freed
from under us.

Note that this requires the previous patch, "scsi: libiscsi: Drop
taskqueuelock" because bnx2i sleeps in its cleanup_task callout if the cmd
is aborted. If the EH/timer and completion path are racing we don't know
which path will do the last put. The previous patch moved the operations we
needed to do under the forward lock to cleanup_queued_task.  Once that has
run we can drop the forward lock for the cmd and bnx2i no longer has to
worry about if the EH, timer or completion path did the ast put and if the
forward lock is held or not since it won't be.

Link: https://lore.kernel.org/r/20210207044608.27585-4-michael.christie@oracle.com
Reported-by: Wu Bo 
Reviewed-by: Lee Duncan 
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: libiscsi: Drop taskqueuelock

2021-02-09T03:39:03+00:00

The purpose of the taskqueuelock was to handle the issue where a bad target
decides to send a R2T and before its data has been sent decides to send a
cmd response to complete the cmd. The following patches fix up the
frwd/back locks so they are taken from the queue/xmit (frwd) and completion
(back) paths again. To get there this patch removes the taskqueuelock which
for iSCSI xmit wq based drivers was taken in the queue, xmit and completion
paths.

Instead of the lock, we just make sure we have a ref to the task when we
queue a R2T, and then we always remove the task from the requeue list in
the xmit path or the forced cleanup paths.

Link: https://lore.kernel.org/r/20210207044608.27585-3-michael.christie@oracle.com
Reviewed-by: Lee Duncan 
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: libiscsi: Fix iscsi_prep_scsi_cmd_pdu() error handling

2021-02-09T03:39:03+00:00

If iscsi_prep_scsi_cmd_pdu() fails we try to add it back to the cmdqueue,
but we leave it partially setup. We don't have functions that can undo the
pdu and init task setup. We only have cleanup_task which can clean up both
parts. So this has us just fail the cmd and go through the standard cleanup
routine and then have the SCSI midlayer retry it like is done when it fails
in the queuecommand path.

Link: https://lore.kernel.org/r/20210207044608.27585-2-michael.christie@oracle.com
Reviewed-by: Lee Duncan 
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen

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

2020-12-16T21:34:31+00:00

Pull SCSI updates from James Bottomley:
 "This consists of the usual driver updates (ufs, qla2xxx, smartpqi,
  target, zfcp, fnic, mpt3sas, ibmvfc) plus a load of cleanups, a major
  power management rework and a load of assorted minor updates.

  There are a few core updates (formatting fixes being the big one) but
  nothing major this cycle"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (279 commits)
  scsi: mpt3sas: Update driver version to 36.100.00.00
  scsi: mpt3sas: Handle trigger page after firmware update
  scsi: mpt3sas: Add persistent MPI trigger page
  scsi: mpt3sas: Add persistent SCSI sense trigger page
  scsi: mpt3sas: Add persistent Event trigger page
  scsi: mpt3sas: Add persistent Master trigger page
  scsi: mpt3sas: Add persistent trigger pages support
  scsi: mpt3sas: Sync time periodically between driver and firmware
  scsi: qla2xxx: Update version to 10.02.00.104-k
  scsi: qla2xxx: Fix device loss on 4G and older HBAs
  scsi: qla2xxx: If fcport is undergoing deletion complete I/O with retry
  scsi: qla2xxx: Fix the call trace for flush workqueue
  scsi: qla2xxx: Fix flash update in 28XX adapters on big endian machines
  scsi: qla2xxx: Handle aborts correctly for port undergoing deletion
  scsi: qla2xxx: Fix N2N and NVMe connect retry failure
  scsi: qla2xxx: Fix FW initialization error on big endian machines
  scsi: qla2xxx: Fix crash during driver load on big endian machines
  scsi: qla2xxx: Fix compilation issue in PPC systems
  scsi: qla2xxx: Don't check for fw_started while posting NVMe command
  scsi: qla2xxx: Tear down session if FW say it is down
  ...