linux.git/include/target, branch v4.4.20

target: Fix ordered task CHECK_CONDITION early exception handling

2016-08-20T16:09:26+00:00

commit 410c29dfbfdf73d0d0b5d14a21868ab038eca703 upstream.

If a Simple command is sent with a failure, target_setup_cmd_from_cdb
returns with TCM_UNSUPPORTED_SCSI_OPCODE or TCM_INVALID_CDB_FIELD.

So in the cases where target_setup_cmd_from_cdb returns an error, we
never get far enough to call target_execute_cmd to increment simple_cmds.
Since simple_cmds isn't incremented, the result of the failure from
target_setup_cmd_from_cdb causes transport_generic_request_failure to
decrement simple_cmds, due to call to transport_complete_task_attr.

With this dev->simple_cmds or dev->dev_ordered_sync is now -1, not 0.
So when a subsequent command with an Ordered Task is sent, it causes
a hang, since dev->simple_cmds is at -1.

Tested-by: Bryant G. Ly 
Signed-off-by: Bryant G. Ly 
Tested-by: Michael Cyr 
Signed-off-by: Michael Cyr 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix max_unmap_lba_count calc overflow

2016-08-20T16:09:26+00:00

commit ea263c7fada4af8ec7fe5fcfd6e7d7705a89351b upstream.

max_discard_sectors only 32bits, and some non scsi backend
devices will set this to the max 0xffffffff, so we can end up
overflowing during the max_unmap_lba_count calculation.

This fixes a regression caused by my patch:

commit 8a9ebe717a133ba7bc90b06047f43cc6b8bcb8b3
Author: Mike Christie 
Date:   Mon Jan 18 14:09:27 2016 -0600

    target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors

which can result in extra discards being sent to due the overflow
causing max_unmap_lba_count to be smaller than what the backing
device can actually support.

Signed-off-by: Mike Christie 
Reviewed-by: Bart Van Assche 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix ordered task target_setup_cmd_from_cdb exception hang

2016-08-20T16:09:26+00:00

commit dff0ca9ea7dc8be2181a62df4a722c32ce68ff4a upstream.

If a command with a Simple task attribute is failed due to a Unit
Attention, then a subsequent command with an Ordered task attribute
will hang forever.  The reason for this is that the Unit Attention
status is checked for in target_setup_cmd_from_cdb, before the call
to target_execute_cmd, which calls target_handle_task_attr, which
in turn increments dev->simple_cmds.

However, transport_generic_request_failure still calls
transport_complete_task_attr, which will decrement dev->simple_cmds.
In this case, simple_cmds is now -1.  So when a command with the
Ordered task attribute is sent, target_handle_task_attr sees that
dev->simple_cmds is not 0, so it decides it can't execute the
command until all the (nonexistent) Simple commands have completed.

Reported-by: Michael Cyr 
Tested-by: Michael Cyr 
Reported-by: Bryant G. Ly 
Tested-by: Bryant G. Ly 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors

2016-03-09T23:34:51+00:00

commit 8a9ebe717a133ba7bc90b06047f43cc6b8bcb8b3 upstream.

In a couple places we are not converting to/from the Linux
block layer 512 bytes sectors.

1.

The request queue values and what we do are a mismatch of
things:

max_discard_sectors - This is in linux block layer 512 byte
sectors. We are just copying this to max_unmap_lba_count.

discard_granularity - This is in bytes. We are converting it
to Linux block layer 512 byte sectors.

discard_alignment - This is in bytes. We are just copying
this over.

The problem is that the core LIO code exports these values in
spc_emulate_evpd_b0 and we use them to test request arguments
in sbc_execute_unmap, but we never convert to the block size
we export to the initiator. If we are not using 512 byte sectors
then we are exporting the wrong values or are checks are off.
And, for the discard_alignment/bytes case we are just plain messed
up.

2.

blkdev_issue_discard's start and number of sector arguments
are supposed to be in linux block layer 512 byte sectors. We are
currently passing in the values we get from the initiator which
might be based on some other sector size.

There is a similar problem in iblock_execute_write_same where
the bio functions want values in 512 byte sectors but we are
passing in what we got from the initiator.

Signed-off-by: Mike Christie 
Signed-off-by: Nicholas Bellinger 
[ kamal: backport to 4.4-stable: no unmap_zeroes_data ]
Signed-off-by: Kamal Mostafa 
Signed-off-by: Greg Kroah-Hartman

target: Fix remote-port TMR ABORT + se_cmd fabric stop

2016-03-03T23:07:27+00:00

commit 0f4a943168f31d29a1701908931acaba518b131a upstream.

To address the bug where fabric driver level shutdown
of se_cmd occurs at the same time when TMR CMD_T_ABORTED
is happening resulting in a -1 ->cmd_kref, this patch
adds a CMD_T_FABRIC_STOP bit that is used to determine
when TMR + driver I_T nexus shutdown is happening
concurrently.

It changes target_sess_cmd_list_set_waiting() to obtain
se_cmd->cmd_kref + set CMD_T_FABRIC_STOP, and drop local
reference in target_wait_for_sess_cmds() and invoke extra
target_put_sess_cmd() during Task Aborted Status (TAS)
when necessary.

Also, it adds a new target_wait_free_cmd() wrapper around
transport_wait_for_tasks() for the special case within
transport_generic_free_cmd() to set CMD_T_FABRIC_STOP,
and is now aware of CMD_T_ABORTED + CMD_T_TAS status
bits to know when an extra transport_put_cmd() during
TAS is required.

Note transport_generic_free_cmd() is expected to block on
cmd->cmd_wait_comp in order to follow what iscsi-target
expects during iscsi_conn context se_cmd shutdown.

Cc: Quinn Tran 
Cc: Himanshu Madhani 
Cc: Sagi Grimberg 
Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Andy Grover 
Cc: Mike Christie 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix LUN_RESET active I/O handling for ACK_KREF

2016-03-03T23:07:27+00:00

commit febe562c20dfa8f33bee7d419c6b517986a5aa33 upstream.

This patch fixes a NULL pointer se_cmd->cmd_kref < 0
refcount bug during TMR LUN_RESET with active se_cmd
I/O, that can be triggered during se_cmd descriptor
shutdown + release via core_tmr_drain_state_list() code.

To address this bug, add common __target_check_io_state()
helper for ABORT_TASK + LUN_RESET w/ CMD_T_COMPLETE
checking, and set CMD_T_ABORTED + obtain ->cmd_kref for
both cases ahead of last target_put_sess_cmd() after
TFO->aborted_task() -> transport_cmd_finish_abort()
callback has completed.

It also introduces SCF_ACK_KREF to determine when
transport_cmd_finish_abort() needs to drop the second
extra reference, ahead of calling target_put_sess_cmd()
for the final kref_put(&se_cmd->cmd_kref).

It also updates transport_cmd_check_stop() to avoid
holding se_cmd->t_state_lock while dropping se_cmd
device state via target_remove_from_state_list(), now
that core_tmr_drain_state_list() is holding the
se_device lock while checking se_cmd state from
within TMR logic.

Finally, move transport_put_cmd() release of SGL +
TMR + extended CDB memory into target_free_cmd_mem()
in order to avoid potential resource leaks in TMR
ABORT_TASK + LUN_RESET code-paths.  Also update
target_release_cmd_kref() accordingly.

Reviewed-by: Quinn Tran 
Cc: Himanshu Madhani 
Cc: Sagi Grimberg 
Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Andy Grover 
Cc: Mike Christie 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix race for SCF_COMPARE_AND_WRITE_POST checking

2015-11-29T03:33:15+00:00

This patch addresses a race + use after free where the first
stage of COMPARE_AND_WRITE in compare_and_write_callback()
is rescheduled after the backend sends the secondary WRITE,
resulting in second stage compare_and_write_post() callback
completing in target_complete_ok_work() before the first
can return.

Because current code depends on checking se_cmd->se_cmd_flags
after return from se_cmd->transport_complete_callback(),
this results in first stage having SCF_COMPARE_AND_WRITE_POST
set, which incorrectly falls through into second stage CAW
processing code, eventually triggering a NULL pointer
dereference due to use after free.

To address this bug, pass in a new *post_ret parameter into
se_cmd->transport_complete_callback(), and depend upon this
value instead of ->se_cmd_flags to determine when to return
or fall through into ->queue_status() code for CAW.

Cc: Sagi Grimberg 
Cc:  # v3.12+
Signed-off-by: Nicholas Bellinger

Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

2015-11-14T04:04:17+00:00

Pull SCSI target updates from Nicholas Bellinger:
 "This series contains HCH's changes to absorb configfs attribute
  ->show() + ->store() function pointer usage from it's original
  tree-wide consumers, into common configfs code.

  It includes usb-gadget, target w/ drivers, netconsole and ocfs2
  changes to realize the improved simplicity, that now renders the
  original include/target/configfs_macros.h CPP magic for fabric drivers
  and others, unnecessary and obsolete.

  And with common code in place, new configfs attributes can be added
  easier than ever before.

  Note, there are further improvements in-flight from other folks for
  v4.5 code in configfs land, plus number of target fixes for post -rc1
  code"

In the meantime, a new user of the now-removed old configfs API came in
through the char/misc tree in commit 7bd1d4093c2f ("stm class: Introduce
an abstraction for System Trace Module devices").

This merge resolution comes from Alexander Shishkin, who updated his stm
class tracing abstraction to account for the removal of the old
show_attribute and store_attribute methods in commit 517982229f78
("configfs: remove old API") from this pull.  As Alexander says about
that patch:

 "There's no need to keep an extra wrapper structure per item and the
  awkward show_attribute/store_attribute item ops are no longer needed.

  This patch converts policy code to the new api, all the while making
  the code quite a bit smaller and easier on the eyes.

  Signed-off-by: Alexander Shishkin "

That patch was folded into the merge so that the tree should be fully
bisectable.

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (23 commits)
  configfs: remove old API
  ocfs2/cluster: use per-attribute show and store methods
  ocfs2/cluster: move locking into attribute store methods
  netconsole: use per-attribute show and store methods
  target: use per-attribute show and store methods
  spear13xx_pcie_gadget: use per-attribute show and store methods
  dlm: use per-attribute show and store methods
  usb-gadget/f_serial: use per-attribute show and store methods
  usb-gadget/f_phonet: use per-attribute show and store methods
  usb-gadget/f_obex: use per-attribute show and store methods
  usb-gadget/f_uac2: use per-attribute show and store methods
  usb-gadget/f_uac1: use per-attribute show and store methods
  usb-gadget/f_mass_storage: use per-attribute show and store methods
  usb-gadget/f_sourcesink: use per-attribute show and store methods
  usb-gadget/f_printer: use per-attribute show and store methods
  usb-gadget/f_midi: use per-attribute show and store methods
  usb-gadget/f_loopback: use per-attribute show and store methods
  usb-gadget/ether: use per-attribute show and store methods
  usb-gadget/f_acm: use per-attribute show and store methods
  usb-gadget/f_hid: use per-attribute show and store methods
  ...

target: use per-attribute show and store methods

2015-10-14T05:17:49+00:00

This also allows to remove the target-specific old configfs macros, and
gets rid of the target_core_fabric_configfs.h header which only had one
function declaration left that could be moved to a better place.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Nicholas Bellinger 
Acked-by: Nicholas Bellinger 
Signed-off-by: Nicholas Bellinger

target: Propigate backend read-only to core_tpg_add_lun

2015-09-25T06:17:21+00:00

This patch adds a DF_READ_ONLY flag that is used by IBLOCK to
signal when a backend has been set to read-only mode, in order
to propigate read-only status up to core_tpg_add_lun() for all
future LUN fabric exports.

With this is place, existing emulation for reporting read-only
in spc_emulate_modesense() and normal transport_lookup_cmd_lun()
TCM_WRITE_PROTECTED status checking just works as expected.

Reported-by: Joeue Deng 
Reported-by: Andy Grover 
Signed-off-by: Nicholas Bellinger