Commit graph

539 commits

Author SHA1 Message Date
Bart Van Assche
80647a89ea scsi: target: core: Release SPC-2 reservations when closing a session
The SCSI specs require releasing SPC-2 reservations when a session is
closed. Make sure that the target core does this.

Running the libiscsi tests triggers the KASAN complaint shown below.  This
patch fixes that use-after-free.

BUG: KASAN: use-after-free in target_check_reservation+0x171/0x980 [target_core_mod]
Read of size 8 at addr ffff88802ecd1878 by task iscsi_trx/17200

CPU: 0 PID: 17200 Comm: iscsi_trx Not tainted 5.4.0-rc1-dbg+ #1
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
 dump_stack+0x8a/0xd6
 print_address_description.constprop.0+0x40/0x60
 __kasan_report.cold+0x1b/0x34
 kasan_report+0x16/0x20
 __asan_load8+0x58/0x90
 target_check_reservation+0x171/0x980 [target_core_mod]
 __target_execute_cmd+0xb1/0xf0 [target_core_mod]
 target_execute_cmd+0x22d/0x4d0 [target_core_mod]
 transport_generic_new_cmd+0x31f/0x5b0 [target_core_mod]
 transport_handle_cdb_direct+0x6f/0x90 [target_core_mod]
 iscsit_execute_cmd+0x381/0x3f0 [iscsi_target_mod]
 iscsit_sequence_cmd+0x13b/0x1f0 [iscsi_target_mod]
 iscsit_process_scsi_cmd+0x4c/0x130 [iscsi_target_mod]
 iscsit_get_rx_pdu+0x8e8/0x15f0 [iscsi_target_mod]
 iscsi_target_rx_thread+0x105/0x1b0 [iscsi_target_mod]
 kthread+0x1bc/0x210
 ret_from_fork+0x24/0x30

Allocated by task 1079:
 save_stack+0x23/0x90
 __kasan_kmalloc.constprop.0+0xcf/0xe0
 kasan_slab_alloc+0x12/0x20
 kmem_cache_alloc+0xfe/0x3a0
 transport_alloc_session+0x29/0x80 [target_core_mod]
 iscsi_target_login_thread+0xceb/0x1920 [iscsi_target_mod]
 kthread+0x1bc/0x210
 ret_from_fork+0x24/0x30

Freed by task 17193:
 save_stack+0x23/0x90
 __kasan_slab_free+0x13a/0x190
 kasan_slab_free+0x12/0x20
 kmem_cache_free+0xc8/0x3e0
 transport_free_session+0x179/0x2f0 [target_core_mod]
 transport_deregister_session+0x121/0x170 [target_core_mod]
 iscsit_close_session+0x12c/0x350 [iscsi_target_mod]
 iscsit_logout_post_handler+0x136/0x380 [iscsi_target_mod]
 iscsit_response_queue+0x8fa/0xc00 [iscsi_target_mod]
 iscsi_target_tx_thread+0x28e/0x390 [iscsi_target_mod]
 kthread+0x1bc/0x210
 ret_from_fork+0x24/0x30

The buggy address belongs to the object at ffff88802ecd1860
 which belongs to the cache se_sess_cache of size 352
The buggy address is located 24 bytes inside of
 352-byte region [ffff88802ecd1860, ffff88802ecd19c0)
The buggy address belongs to the page:
page:ffffea0000bb3400 refcount:1 mapcount:0 mapping:ffff8880bef2ed00 index:0x0 compound_mapcount: 0
flags: 0x1000000000010200(slab|head)
raw: 1000000000010200 dead000000000100 dead000000000122 ffff8880bef2ed00
raw: 0000000000000000 0000000080270027 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88802ecd1700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802ecd1780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802ecd1800: fb fb fb fb fc fc fc fc fc fc fc fc fb fb fb fb
                                                                ^
 ffff88802ecd1880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802ecd1900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Cc: Mike Christie <mchristi@redhat.com>
Link: https://lore.kernel.org/r/20191113220508.198257-2-bvanassche@acm.org
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-11-19 21:37:35 -05:00
Bart Van Assche
11bf1d14b2 scsi: target: core: Document target_cmd_size_check()
Since it is nontrivial to derive the meaning of the size argument from the
code, add a documentation header above target_cmd_size_check().

Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Link: https://lore.kernel.org/r/20191107215458.64242-1-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-11-19 21:37:34 -05:00
Thomas Gleixner
1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00
Bart Van Assche
94ebb47160 scsi: target/core: Add target_send_busy()
Introduce a function that sends the SCSI status "BUSY" back to the
initiator. The next patch will add a call to this function in the srpt
target driver.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-02-04 21:28:48 -05:00
Bart Van Assche
83f85b8ec3 scsi: target/core: Inline transport_lun_remove_cmd()
Remove the code that clears .se_lun from transport_cmd_check_stop_to_fabric()
such that the transport_lun_remove_cmd() call can be moved into
target_release_cmd_kref(). Because this guarantees that
transport_lun_remove_cmd() will be called exactly once, it is safe to change
the cmpxchg() call into a test of se_cmd.lun_ref_active. Inline
transport_lun_remove_cmd() because it is not worth to keep it as a separate
function.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-02-04 21:27:20 -05:00
Bart Van Assche
3f0661a492 scsi: target/core: Remove several state tests from the TMF code
Whether or not a session is being torn down does not affect whether or not
SCSI commands are in the task set. Hence remove the "tearing down" checks
from the TMF code. The TRANSPORT_ISTATE_PROCESSING check is left out
because it is now safe to wait for a command that is in that state. The
CMD_T_PRE_EXECUTE is left out because abort processing is postponed until
after commands have left the pre-execute state since the patch that makes
TMF processing synchronous.

See also commit 1c21a48055 ("target: Avoid early CMD_T_PRE_EXECUTE
failures during ABORT_TASK").

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-02-04 21:25:13 -05:00
Linus Torvalds
938edb8a31 SCSI misc on 20181224
This is mostly update of the usual drivers: smarpqi, lpfc, qedi,
 megaraid_sas, libsas, zfcp, mpt3sas, hisi_sas.  Additionally, we have
 a pile of annotation, unused variable and minor updates.  The big API
 change is the updates for Christoph's DMA rework which include
 removing the DISABLE_CLUSTERING flag.  And finally there are a couple
 of target tree updates.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
 -----BEGIN PGP SIGNATURE-----
 
 iJwEABMIAEQWIQTnYEDbdso9F2cI+arnQslM7pishQUCXCEUNiYcamFtZXMuYm90
 dG9tbGV5QGhhbnNlbnBhcnRuZXJzaGlwLmNvbQAKCRDnQslM7pishdjKAP9vrTTv
 qFaYmAoRSbPq9ZiixaXLMy0K/6o76Uay0gnBqgD/fgn3jg/KQ6alNaCjmfeV3wAj
 u1j3H7tha9j1it+4pUw=
 =GDa+
 -----END PGP SIGNATURE-----

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

Pull SCSI updates from James Bottomley:
 "This is mostly update of the usual drivers: smarpqi, lpfc, qedi,
  megaraid_sas, libsas, zfcp, mpt3sas, hisi_sas.

  Additionally, we have a pile of annotation, unused variable and minor
  updates.

  The big API change is the updates for Christoph's DMA rework which
  include removing the DISABLE_CLUSTERING flag.

  And finally there are a couple of target tree updates"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (259 commits)
  scsi: isci: request: mark expected switch fall-through
  scsi: isci: remote_node_context: mark expected switch fall-throughs
  scsi: isci: remote_device: Mark expected switch fall-throughs
  scsi: isci: phy: Mark expected switch fall-through
  scsi: iscsi: Capture iscsi debug messages using tracepoints
  scsi: myrb: Mark expected switch fall-throughs
  scsi: megaraid: fix out-of-bound array accesses
  scsi: mpt3sas: mpt3sas_scsih: Mark expected switch fall-through
  scsi: fcoe: remove set but not used variable 'port'
  scsi: smartpqi: call pqi_free_interrupts() in pqi_shutdown()
  scsi: smartpqi: fix build warnings
  scsi: smartpqi: update driver version
  scsi: smartpqi: add ofa support
  scsi: smartpqi: increase fw status register read timeout
  scsi: smartpqi: bump driver version
  scsi: smartpqi: add smp_utils support
  scsi: smartpqi: correct lun reset issues
  scsi: smartpqi: correct volume status
  scsi: smartpqi: do not offline disks for transient did no connect conditions
  scsi: smartpqi: allow for larger raid maps
  ...
2018-12-28 14:48:06 -08:00
Wei Yongjun
8b2db98e81 scsi: target/core: Use kmem_cache_free() instead of kfree()
memory allocated by kmem_cache_alloc() should be freed using
kmem_cache_free(), not kfree().

Fixes: ad669505c4 ("scsi: target/core: Make sure that target_wait_for_sess_cmds() waits long enough")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-18 22:52:14 -05:00
Bart Van Assche
3ad9800231 scsi: target/core: Reduce the amount of code executed with a spinlock held
Due to the "make ABORT and LUN RESET handling synchronous" patch, cmd->work
is only modified from the regular command execution path and no longer
asynchronously by the code that executes task management functions. Since
the regular command execution code is sequential per command, no locking is
required to manipulate cmd->work. Hence stop protecting cmd->work
manipulations with locking.

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 21:22:55 -05:00
Bart Van Assche
2c9fa49e10 scsi: target/core: Make ABORT and LUN RESET handling synchronous
Instead of invoking target driver callback functions from the context that
handles an abort or LUN RESET task management function, only set the abort
flag from that context and perform the actual abort handling from the
context of the regular command processing flow. This approach has the
advantage that the task management code becomes much easier to read and to
verify since the number of potential race conditions against the command
processing flow is strongly reduced.

This patch has been tested by running the following two shell commands
concurrently for about ten minutes for both the iSCSI and the SRP target
drivers ($dev is an initiator device node connected with storage provided
by the target driver under test):

 * fio with data verification enabled on a filesystem mounted on top of
   $dev.

 * while true; do sg_reset -d $dev; echo -n .; sleep .1; done

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 21:22:55 -05:00
Bart Van Assche
aaa00cc93c scsi: target/core: Fix TAS handling for aborted commands
The TASK ABORTED STATUS (TAS) bit is defined as follows in SAM:
"TASK_ABORTED: this status shall be returned if a command is aborted by a
command or task management function on another I_T nexus and the control
mode page TAS bit is set to one". TAS handling is spread over the target
core and the iSCSI target driver. If a LUN RESET is received, the target
core will send the TASK_ABORTED response for all commands for which such a
response has to be sent. If an ABORT TASK is received, only the iSCSI
target driver will send the TASK_ABORTED response for the commands for
which that response has to be sent.  That is a bug since all target drivers
have to honor the TAS bit. Fix this by moving the code that handles TAS
from the iSCSI target driver into the target core. Additionally, if a
command has been aborted, instead of sending the TASK_ABORTED status from
the context that processes the SCSI command send it from the context of the
ABORT TMF.  The core_tmr_abort_task() change in this patch causes the
CMD_T_TAS flag to be set if a TASK_ABORTED status has to be sent back to
the initiator that submitted the command. If that flag has been set
transport_cmd_finish_abort() will send the TASK_ABORTED response.

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 21:22:15 -05:00
Bart Van Assche
fbbd492355 scsi: target/core: Simplify the code for aborting SCSI commands
Instead of allowing the code that aborts a SCSI command to finish before
all iSCSI data frames have been received, make that code wait until all
iSCSI data frames have been received. Introduce a new member variable in
the target driver template to communicate that information from the iSCSI
target driver to the target core. This change allows to leave out the check
whether or not it is already safe to send the TASK_ABORTED reply from
transport_send_task_abort().

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 21:20:07 -05:00
Bart Van Assche
a014c3647a scsi: target/core: Make it possible to wait from more than one context for command completion
This patch does not change any functionality but makes the patch that makes
TMF handling synchronous easier to read.

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 21:20:07 -05:00
Bart Van Assche
db5b21a24e scsi: target/core: Use system workqueues for TMF
A quote from SAM-5: "The order in which task management requests are
processed is not specified by the SCSI architecture model.  The SCSI
architecture model does not require in-order delivery of such task
management requests or processing by the task manager in the order
received. To guarantee the processing order of task management requests
referencing sent to a specific logical unit, an application client should
not have more than one such task management request pending to that logical
unit." This means that it is safe to use the system workqueues instead of
tmr_wq for processing TMFs. An intended side effect of this patch is that
it enables concurrent processing of TMFs.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 21:20:07 -05:00
Bart Van Assche
ad669505c4 scsi: target/core: Make sure that target_wait_for_sess_cmds() waits long enough
A session must only be released after all code that accesses the session
structure has finished. Make sure that this is the case by introducing a
new command counter per session that is only decremented after the
.release_cmd() callback has finished. This patch fixes the following crash:

BUG: KASAN: use-after-free in do_raw_spin_lock+0x1c/0x130
Read of size 4 at addr ffff8801534b16e4 by task rmdir/14805
CPU: 16 PID: 14805 Comm: rmdir Not tainted 4.18.0-rc2-dbg+ #5
Call Trace:
dump_stack+0xa4/0xf5
print_address_description+0x6f/0x270
kasan_report+0x241/0x360
__asan_load4+0x78/0x80
do_raw_spin_lock+0x1c/0x130
_raw_spin_lock_irqsave+0x52/0x60
srpt_set_ch_state+0x27/0x70 [ib_srpt]
srpt_disconnect_ch+0x1b/0xc0 [ib_srpt]
srpt_close_session+0xa8/0x260 [ib_srpt]
target_shutdown_sessions+0x170/0x180 [target_core_mod]
core_tpg_del_initiator_node_acl+0xf3/0x200 [target_core_mod]
target_fabric_nacl_base_release+0x25/0x30 [target_core_mod]
config_item_release+0x9c/0x110 [configfs]
config_item_put+0x26/0x30 [configfs]
configfs_rmdir+0x3b8/0x510 [configfs]
vfs_rmdir+0xb3/0x1e0
do_rmdir+0x262/0x2c0
do_syscall_64+0x77/0x230
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 21:20:07 -05:00
Bart Van Assche
a95be3842c scsi: target/core: Simplify transport_clear_lun_ref()
Since transport_clear_lun_ref() already waits until the percpu-refcount
.release() method is called, it is not necessary to wait first until
percpu_ref_kill_and_confirm() has finished transitioning the refcount into
atomic mode. Remove the code that waits for percpu_ref_kill_and_confirm()
to complete and also the completion object that is used by that code.  This
patch does not change the behavior of the SCSI target code.

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 21:20:07 -05:00
Bart Van Assche
5d6cd9fe31 scsi: target/core: Use kvcalloc() instead of open-coding it
This patch does not change any functionality. Note: the code that frees
sess_cmd_map already uses kvfree() so that code does not need to be
modified.

Reviewed-by: David Disseldorp <ddiss@suse.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 21:20:07 -05:00
David Disseldorp
30c7ca9350 scsi: target: drop unnecessary get_fabric_name() accessor from fabric_ops
All fabrics return a const string. In all cases *except* iSCSI the
get_fabric_name() string matches fabric_ops.name.

Both fabric_ops.get_fabric_name() and fabric_ops.name are user-facing, with
the former being used for PR/ALUA state and the latter for ConfigFS
(config/target/$name), so we unfortunately need to keep both strings around
for now.  Replace the useless .get_fabric_name() accessor function with a
const string fabric_name member variable.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-28 18:50:58 -05:00
Bart Van Assche
5841734fa6 scsi: target/core: Avoid that a kernel oops is triggered when COMPARE AND WRITE fails
Fixes: aa73237dcb ("scsi: target/core: Always call transport_complete_callback() upon failure")
Reviewed-by: David Disseldorp <ddiss@suse.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-05 22:16:00 -05:00
Roland Dreier
6110f37fb3 scsi: target: Don't request modules that aren't even built
If, for example, I don't enable CONFIG_TCM_PSCSI, then every time I load
the target subsystem, I get an annoying

    Unable to load target_core_pscsi

kernel log message.  Instead let's only request_module() on things if
that code is enabled.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-10-23 21:19:20 -04:00
Bart Van Assche
aa73237dcb scsi: target/core: Always call transport_complete_callback() upon failure
COMPARE AND WRITE command execution starts with a call of
sbc_compare_and_write(). That function locks the caw_sem member in the
backend device data structure and submits a read request to the backend
driver. Upon successful completion of the read compare_and_write_callback()
gets called. That last function compares the data that has been read. If it
matches transport_complete_callback is set to compare_and_write_post and a
write request is submitted. compare_and_write_post() submits a write request
to the backend driver.

XDWRITEREAD command execution starts with sbc_execute_rw() submitting a
read to the backend device. Upon successful completion of the read the
xdreadwrite_callback() gets called. That function xors the data that has
been read with the data in the data-out buffer and stores the result in
the data-in buffer.

Call transport_complete_callback() not only if COMPARE AND WRITE fails but
also if XDWRITEREAD fails. This makes the code more systematic. Make sure
that the callback functions handle (cmd, false, NULL) argument triples fine.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-10-16 01:13:35 -04:00
Bart Van Assche
4240d448a4 scsi: target/core: Fix spelling in two source code comments
Change one occurrence of "aleady" into "already" and one occurrence of
"is" into "if".

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-10-16 01:13:35 -04:00
Nicholas Bellinger
38fe73cc2c scsi: target: Fix target_wait_for_sess_cmds breakage with active signals
With the addition of commit 00d909a107 ("scsi: target: Make the session
shutdown code also wait for commands that are being aborted") in v4.19-rc, it
incorrectly assumes no signals will be pending for task_struct executing the
normal session shutdown and I/O quiesce code-path.

For example, iscsi-target and iser-target issue SIGINT to all kthreads as part
of session shutdown.  This has been the behaviour since day one.

As-is when signals are pending with se_cmds active in se_sess->sess_cmd_list,
wait_event_interruptible_lock_irq_timeout() returns a negative number and
immediately kills the machine because of the do while (ret <= 0) loop that was
added in commit 00d909a107 to spin while backend I/O is taking any amount of
extended time (say 30 seconds) to complete.

Here's what it looks like in action with debug plus delayed backend I/O
completion:

[ 4951.909951] se_sess: 000000003e7e08fa before target_wait_for_sess_cmds
[ 4951.914600] target_wait_for_sess_cmds: signal_pending: 1
[ 4951.918015] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 0
[ 4951.921639] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 1
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 2
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 3
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 4
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 5
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 6
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 7
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 8
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 9

... followed by the usual RCU CPU stalls and deadlock.

There was never a case pre commit 00d909a107 where
wait_for_complete(&se_cmd->cmd_wait_comp) was able to be interrupted, so to
address this for v4.19+ moving forward go ahead and use
wait_event_lock_irq_timeout() instead so new code works with all fabric
drivers.

Also for commit 00d909a107, fix a minor regression in
target_release_cmd_kref() to only wake_up the new se_sess->cmd_list_wq only
when shutdown has actually been triggered via se_sess->sess_tearing_down.

Fixes: 00d909a107 ("scsi: target: Make the session shutdown code also wait for commands that are being aborted")
Cc: <stable@vger.kernel.org> # v4.19+
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Bryant G. Ly <bly@catalogicsoftware.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-10-16 00:11:13 -04:00
Mike Christie
fb7c70f2d7 scsi: target: add session removal function
This adds a function to remove a session which should be used by drivers
that use target_setup_session. The next patches will convert the target
drivers to use this new function.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Chris Boot <bootc@bootc.net>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Cc: <qla2xxx-upstream@qlogic.com>
Cc: Johannes Thumshirn <jth@kernel.org>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-08-02 15:29:31 -04:00
Mike Christie
fa83428730 scsi: target: rename target_alloc_session
Rename target_alloc_session to target_setup_session to avoid confusion with
the other transport session allocation function that only allocates the
session and because the target_alloc_session does so much more. It
allocates the session, sets up the nacl and registers the session.

The next patch will then add a remove function to match the setup in this
one, so it should make sense for all drivers, except iscsi, to just call
those 2 functions to setup and remove a session.

iscsi will continue to be the odd driver.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Chris Boot <bootc@bootc.net>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Cc: <qla2xxx-upstream@qlogic.com>
Cc: Johannes Thumshirn <jth@kernel.org>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-08-02 15:29:31 -04:00
Mike Christie
3cd14285a1 scsi: target: make transport_init_session_tags static
transport_init_session_tags is only called from target_core_transport.c so
make it static.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-08-02 15:29:31 -04:00
Mike Christie
6a64f6e159 scsi: target: fix __transport_register_session locking
When __transport_register_session is called from transport_register_session
irqs will already have been disabled, so we do not want the unlock irq call
to enable them until the higher level has done the final
spin_unlock_irqrestore/ spin_unlock_irq.

This has __transport_register_session use the save/restore call.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-08-02 15:29:31 -04:00
Bart Van Assche
325c1e8b24 scsi: target: Fix handling of removed LUNs
Send a valid ASC / ASCQ combination back to the initiator if a SCSI command
is received after a LUN has been removed. This patch fixes the following
call trace:

WARNING: CPU: 0 PID: 4 at drivers/target/target_core_transport.c:3131 translate_sense_reason+0x164/0x190 [target_core_mod]
Workqueue: ib-comp-wq ib_cq_poll_work [ib_core]
RIP: 0010:translate_sense_reason+0x164/0x190 [target_core_mod]
Call Trace:
transport_send_check_condition_and_sense+0x95/0x1c0 [target_core_mod]
transport_generic_request_failure+0x102/0x270 [target_core_mod]
transport_generic_new_cmd+0x138/0x340 [target_core_mod]
transport_handle_cdb_direct+0x2f/0x80 [target_core_mod]
target_submit_cmd_map_sgls+0x212/0x2a0 [target_core_mod]
srpt_handle_new_iu+0x244/0x680 [ib_srpt]
__ib_process_cq+0x6d/0xc0 [ib_core]
ib_cq_poll_work+0x18/0x50 [ib_core]
process_one_work+0x20b/0x6a0
worker_thread+0x35/0x380
kthread+0x117/0x130
ret_from_fork+0x24/0x30

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:32 -04:00
Bart Van Assche
17e391dd09 scsi: target: Send unit attention condition even if the sense buffer is too small
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:32 -04:00
Bart Van Assche
89a104ed4f scsi: target: Do not duplicate the code that marks that a command has sense data
This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:32 -04:00
Bart Van Assche
7b2cc7dc0d scsi: target: Simplify the code for waiting for command completion
Instead of embedding the completion that is used for waiting for command
completion in struct se_cmd, let the context that waits for command
completion allocate it. This makes it possible to have a single code path
for non-aborted and aborted commands in target_release_cmd_kref() and
avoids that transport_generic_free_cmd() has to call
cmd->se_tfo->release_cmd() directly. This patch does not change any
functionality. Note: transport_generic_free_cmd() only waits until the
se_cmd reference count has reached zero after it has set both
CMD_T_FABRIC_STOP and CMD_T_ABORTED.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:31 -04:00
Bart Van Assche
edf46eee59 scsi: target: Simplify transport_generic_free_cmd() (2/2)
Since target_wait_free_cmd() skips TMFs with no associated LUN, it is safe
to call that function for such commands. Use this to simplify
transport_generic_free_cmd(). The only functional change in this patch is
that CMD_T_FABRIC_STOP gets set for TMFs with no associated LUN by
transport_generic_free_cmd().

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:31 -04:00
Bart Van Assche
a8864d861d scsi: target: Simplify transport_generic_free_cmd() (1/2)
Move identical code outside an if/else statement. This patch does not
change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:31 -04:00
Bart Van Assche
65422d705f scsi: target: Fold core_tmr_handle_tas_abort() into transport_cmd_finish_abort()
For the two calls to transport_cmd_finish_abort() outside
core_tmr_handle_tas_abort() it is guaranteed that CMD_T_TAS is not set. Use
this property to fold core_tmr_handle_tas_abort() into
transport_cmd_finish_abort(). This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:31 -04:00
Bart Van Assche
953bcf7ad1 scsi: target: Document when CMD_T_STOP and CMD_T_COMPLETE are set
Document those aspects of transport_cmd_check_stop_to_fabric() and
transport_generic_free_cmd() of which it is nontrivial to derive these from
their implementation.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:31 -04:00
Bart Van Assche
00d909a107 scsi: target: Make the session shutdown code also wait for commands that are being aborted
Target drivers must call target_sess_cmd_list_set_waiting() and
target_wait_for_sess_cmds() before freeing a session. Since freeing a
session is only safe after all commands that are associated with a session
have finished, make target_wait_for_sess_cmds() also wait for commands that
are being aborted. Instead of setting a flag in each pending command from
target_sess_cmd_list_set_waiting() and waiting in
target_wait_for_sess_cmds() on a per-command completion, only set a
per-session flag in the former function and wait on a per-session
completion in the latter function. This change is safe because once a SCSI
initiator system has submitted a command a target system is always allowed
to execute it to completion. See also commit 0f4a943168 ("target: Fix
remote-port TMR ABORT + se_cmd fabric stop").

This patch is based on the following two patches:

* Bart Van Assche, target: Simplify session shutdown code, February 19, 2015
  (8df5463d7d).

* Christoph Hellwig, target: Rework session shutdown code, December 7, 2015
  (http://thread.gmane.org/gmane.linux.scsi.target.devel/10695).

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:31 -04:00
Bart Van Assche
d1bff07f38 scsi: target: Introduce transport_init_session()
Other than initializing xcopy_pt_sess.sess_wait_list, this patch does not
change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:31 -04:00
Bart Van Assche
317f89712d scsi: target: Rename transport_init_session() into transport_alloc_session()
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:31 -04:00
Bart Van Assche
3eeff19840 scsi: target: Move a list_del_init() statement
This patch does not change any functionality but makes the next patch
easier to read.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-07-02 16:44:30 -04:00
Matthew Wilcox
10e9cbb6b5 scsi: target: Convert target drivers to use sbitmap
The sbitmap and the percpu_ida perform essentially the same task,
allocating tags for commands.  The sbitmap outperforms the percpu_ida as
documented here: https://lkml.org/lkml/2014/4/22/553

The sbitmap interface is a little harder to use, but being able to remove
the percpu_ida code and getting better performance justifies the additional
complexity.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>	# f_tcm
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-06-19 22:02:25 -04:00
Kees Cook
fad953ce0b treewide: Use array_size() in vzalloc()
The vzalloc() function has no 2-factor argument form, so multiplication
factors need to be wrapped in array_size(). This patch replaces cases of:

        vzalloc(a * b)

with:
        vzalloc(array_size(a, b))

as well as handling cases of:

        vzalloc(a * b * c)

with:

        vzalloc(array3_size(a, b, c))

This does, however, attempt to ignore constant size factors like:

        vzalloc(4 * 1024)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  vzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  vzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  vzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
  vzalloc(
-	sizeof(TYPE) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * COUNT_ID
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(THING) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * COUNT_ID
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

  vzalloc(
-	SIZE * COUNT
+	array_size(COUNT, SIZE)
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  vzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  vzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  vzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  vzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  vzalloc(C1 * C2 * C3, ...)
|
  vzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants.
@@
expression E1, E2;
constant C1, C2;
@@

(
  vzalloc(C1 * C2, ...)
|
  vzalloc(
-	E1 * E2
+	array_size(E1, E2)
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Kees Cook
6396bb2215 treewide: kzalloc() -> kcalloc()
The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

        kzalloc(a * b, gfp)

with:
        kcalloc(a * b, gfp)

as well as handling cases of:

        kzalloc(a * b * c, gfp)

with:

        kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kzalloc(sizeof(THING) * C2, ...)
|
  kzalloc(sizeof(TYPE) * C2, ...)
|
  kzalloc(C1 * C2 * C3, ...)
|
  kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kzalloc
+ kcalloc
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Colin Ian King
c167828088 scsi: target: fix spelling mistake "Uknown" -> "Unknown"
Trivial fix to spelling mistake in pr_err message text.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-28 21:32:19 -04:00
Lee Duncan
bd81372065 scsi: target: transport should handle st FM/EOM/ILI reads
When a tape drive is exported via LIO using the pscsi module, a read
that requests more bytes per block than the tape can supply returns an
empty buffer. This is because the pscsi pass-through target module sees
the "ILI" illegal length bit set and thinks there is no reason to return
the data.

This is a long-standing transport issue, since it assumes that no data
need be returned under a check condition, which isn't always the case
for tape.

Add in a check for tape reads with the ILI, EOM, or FM bits set, with a
sense code of NO_SENSE, treating such cases as if the read
succeeded. The layered tape driver then "does the right thing" when it
gets such a response.

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-05-18 12:22:48 -04:00
Randy Dunlap
9ad97b8b40 scsi: target: target_core_transport.c: enable+fix kernel-doc
For exported functions that already have near-kernel-doc notation,
fix them to begin with "/**" and make a few corrections so that they
don't have any kernel-doc warnings.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
To: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: linux-scsi@vger.kernel.org
Cc: target-devel@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-04-20 19:14:38 -04:00
Randy Dunlap
1e74aff12d scsi: target: target_core_transport.c: fix kernel-doc warnings
Correct a function parameter's name to eliminate kernel-doc warnings
in drivers/target/target_core_transport.c.

Fixes these kernel-doc warnings: (tested by adding these files to a new
target.rst documentation file)

../drivers/target/target_core_transport.c:1671: warning: No description found for parameter 'fabric_tmr_ptr'
../drivers/target/target_core_transport.c:1671: warning: Excess function parameter 'fabric_context' description in 'target_submit_tmr'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
To: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: linux-scsi@vger.kernel.org
Cc: target-devel@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-04-20 19:14:38 -04:00
Linus Torvalds
858f45bff3 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "The highlights include:

   - numerous target-core-user improvements related to queue full and
     timeout handling. (MNC)

   - prevent target-core-user corruption when invalid data page is
     requested. (MNC)

   - add target-core device action configfs attributes to allow
     user-space to trigger events separate from existing attributes
     exposed to end-users. (MNC)

   - fix iscsi-target NULL pointer dereference 4.6+ regression in CHAP
     error path. (David Disseldorp)

   - avoid target-core backend UNMAP callbacks if range is zero. (Andrei
     Vagin)

   - fix a iscsi-target 4.14+ regression related multiple PDU logins,
     that was exposed due to removal of TCP prequeue support. (Florian
     Westphal + MNC)

  Also, there is a iser-target bug still being worked on for post -rc1
  code to address a long standing issue resulting in persistent
  ib_post_send() failures, for RNICs with small max_send_sge"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (36 commits)
  iscsi-target: make sure to wake up sleeping login worker
  tcmu: Fix trailing semicolon
  tcmu: fix cmd user after free
  target: fix destroy device in target_configure_device
  tcmu: allow userspace to reset ring
  target core: add device action configfs files
  tcmu: fix error return code in tcmu_configure_device()
  target_core_user: add cmd id to broken ring message
  target: add SAM_STAT_BUSY sense reason
  tcmu: prevent corruption when invalid data page requested
  target: don't call an unmap callback if a range length is zero
  target/iscsi: avoid NULL dereference in CHAP auth error path
  cxgbit: call neigh_event_send() to update MAC address
  target: tcm_loop: Use seq_puts() in tcm_loop_show_info()
  target: tcm_loop: Delete an unnecessary return statement in tcm_loop_submission_work()
  target: tcm_loop: Delete two unnecessary variable initialisations in tcm_loop_issue_tmr()
  target: tcm_loop: Combine substrings for 26 messages
  target: tcm_loop: Improve a size determination in two functions
  target: tcm_loop: Delete an error message for a failed memory allocation in four functions
  sbp-target: Delete an error message for a failed memory allocation in three functions
  ...
2018-02-09 14:49:46 -08:00
Bart Van Assche
8c7a8d1c4b lib/scatterlist: Fix chaining support in sgl_alloc_order()
This patch avoids that workloads with large block sizes (megabytes)
can trigger the following call stack with the ib_srpt driver (that
driver is the only driver that chains scatterlists allocated by
sgl_alloc_order()):

BUG: Bad page state in process kworker/0:1H  pfn:2423a78
page:fffffb03d08e9e00 count:-3 mapcount:0 mapping:          (null) index:0x0
flags: 0x57ffffc0000000()
raw: 0057ffffc0000000 0000000000000000 0000000000000000 fffffffdffffffff
raw: dead000000000100 dead000000000200 0000000000000000 0000000000000000
page dumped because: nonzero _count
CPU: 0 PID: 733 Comm: kworker/0:1H Tainted: G          I      4.15.0-rc7.bart+ #1
Hardware name: HP ProLiant DL380 G7, BIOS P67 08/16/2015
Workqueue: ib-comp-wq ib_cq_poll_work [ib_core]
Call Trace:
 dump_stack+0x5c/0x83
 bad_page+0xf5/0x10f
 get_page_from_freelist+0xa46/0x11b0
 __alloc_pages_nodemask+0x103/0x290
 sgl_alloc_order+0x101/0x180
 target_alloc_sgl+0x2c/0x40 [target_core_mod]
 srpt_alloc_rw_ctxs+0x173/0x2d0 [ib_srpt]
 srpt_handle_new_iu+0x61e/0x7f0 [ib_srpt]
 __ib_process_cq+0x55/0xa0 [ib_core]
 ib_cq_poll_work+0x1b/0x60 [ib_core]
 process_one_work+0x141/0x340
 worker_thread+0x47/0x3e0
 kthread+0xf5/0x130
 ret_from_fork+0x1f/0x30

Fixes: e80a0af475 ("lib/scatterlist: Introduce sgl_alloc() and sgl_free()")
Reported-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-19 12:31:03 -07:00
Mike Christie
d120c7083f target: add SAM_STAT_BUSY sense reason
Add SAM_STAT_BUSY sense_reason. The next patch will have
target_core_user return this value while it is temporarily
blocked and restarting.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2018-01-12 15:07:30 -08:00
Bart Van Assche
14db491726 target: Use sgl_alloc_order() and sgl_free()
Use the sgl_alloc_order() and sgl_free() functions instead of open
coding these functions.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-06 09:18:00 -07:00
Nicholas Bellinger
1c21a48055 target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK
This patch fixes bug where early se_cmd exceptions that occur
before backend execution can result in use-after-free if/when
a subsequent ABORT_TASK occurs for the same tag.

Since an early se_cmd exception will have had se_cmd added to
se_session->sess_cmd_list via target_get_sess_cmd(), it will
not have CMD_T_COMPLETE set by the usual target_complete_cmd()
backend completion path.

This causes a subsequent ABORT_TASK + __target_check_io_state()
to signal ABORT_TASK should proceed.  As core_tmr_abort_task()
executes, it will bring the outstanding se_cmd->cmd_kref count
down to zero releasing se_cmd, after se_cmd has already been
queued with error status into fabric driver response path code.

To address this bug, introduce a CMD_T_PRE_EXECUTE bit that is
set at target_get_sess_cmd() time, and cleared immediately before
backend driver dispatch in target_execute_cmd() once CMD_T_ACTIVE
is set.

Then, check CMD_T_PRE_EXECUTE within __target_check_io_state() to
determine when an early exception has occured, and avoid aborting
this se_cmd since it will have already been queued into fabric
driver response path code.

Reported-by: Donald White <dew@datera.io>
Cc: Donald White <dew@datera.io>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-07 19:50:24 -08:00
Nicholas Bellinger
9574a497df target: Fix quiese during transport_write_pending_qf endless loop
This patch fixes a potential end-less loop during QUEUE_FULL,
where cmd->se_tfo->write_pending() callback fails repeatedly
but __transport_wait_for_tasks() has already been invoked to
quiese the outstanding se_cmd descriptor.

To address this bug, this patch adds a CMD_T_STOP|CMD_T_ABORTED
check within transport_write_pending_qf() and invokes the
existing se_cmd->t_transport_stop_comp to signal quiese
completion back to __transport_wait_for_tasks().

Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Cc: Potnuri Bharat Teja <bharat@chelsio.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: stable@vger.kernel.org # 4.11+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-07 19:45:28 -08:00
Nicholas Bellinger
fd2f928b0d target: Fix caw_sem leak in transport_generic_request_failure
With the recent addition of transport_check_aborted_status() within
transport_generic_request_failure() to avoid sending a SCSI status
exception after CMD_T_ABORTED w/ TAS=1 has occured, it introduced
a COMPARE_AND_WRITE early failure regression.

Namely when COMPARE_AND_WRITE fails and se_device->caw_sem has
been taken by sbc_compare_and_write(), if the new check for
transport_check_aborted_status() returns true and exits,
cmd->transport_complete_callback() -> compare_and_write_post()
is skipped never releasing se_device->caw_sem.

This regression was originally introduced by:

  commit e3b88ee95b
  Author: Bart Van Assche <bart.vanassche@sandisk.com>
  Date:   Tue Feb 14 16:25:45 2017 -0800

      target: Fix handling of aborted failed commands

To address this bug, move the transport_check_aborted_status()
call after transport_complete_task_attr() and
cmd->transport_complete_callback().

Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: stable@vger.kernel.org # 4.11+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-07 19:43:55 -08:00
Nicholas Bellinger
1c79df1f34 target: Fix QUEUE_FULL + SCSI task attribute handling
This patch fixes a bug during QUEUE_FULL where transport_complete_qf()
calls transport_complete_task_attr() after it's already been invoked
by target_complete_ok_work() or transport_generic_request_failure()
during initial completion, preceeding QUEUE_FULL.

This will result in se_device->simple_cmds, se_device->dev_cur_ordered_id
and/or se_device->dev_ordered_sync being updated multiple times for
a single se_cmd.

To address this bug, clear SCF_TASK_ATTR_SET after the first call
to transport_complete_task_attr(), and avoid updating SCSI task
attribute related counters for any subsequent calls.

Also, when a se_cmd is deferred due to ordered tags and executed
via target_restart_delayed_cmds(), set CMD_T_SENT before execution
matching what target_execute_cmd() does.

Cc: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-07 19:41:37 -08:00
Bart Van Assche
c017069823 target: Inline transport_put_cmd()
Since all transput_put_cmd() does is to call target_put_sess_cmd(),
inline transport_put_cmd() into its callers. Leave out the BUG_ON()
statement because if cmd->se_tfo == NULL then cmd->cmd_kref is 0
and kref_put() will complain anyway. Notes:
- transport_init_se_cmd() initializes both .se_tfo and .cmd_kref.
- The only target driver that does not call transport_init_se_cmd()
  for all commands is the iSCSI target driver. See also
  iscsi_target_rx_opcode().

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-04 15:15:41 -07:00
Bart Van Assche
d7e595ddd5 target: Suppress gcc 7 fallthrough warnings
Avoid that gcc 7 reports the following warning when building with W=1:

warning: this statement may fall through [-Wimplicit-fallthrough=]

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Varun Prakash <varun@chelsio.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-04 15:15:35 -07:00
Mike Christie
a271eac46a target: return SAM_STAT_TASK_SET_FULL for TCM_OUT_OF_RESOURCES
TCM_OUT_OF_RESOURCES is getting translated to
TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE which seems like a heavy
error when we just cannot allocate a resource that may be
allocatable later. This has us translate TCM_OUT_OF_RESOURCES
to SAM_STAT_TASK_SET_FULL instead.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-04 15:01:49 -07:00
tangwenji
79dd6f2fd1 target: add sense code INSUFFICIENT REGISTRATION RESOURCES
If a PERSISTENT RESERVE OUT command with a REGISTER service action or a
REGISTER AND IGNORE EXISTING KEY service action or REGISTER AND MOVE
service action is attempted, but there are insufficient device server
resources to complete the operation, then the command shall be terminated
with CHECK CONDITION status, with the sense key set to ILLEGAL REQUEST,and
the additonal sense code set to INSUFFICIENT REGISTRATION RESOURCES.

Signed-off-by: tangwenji <tang.wenji@zte.com.cn>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-11-04 14:45:23 -07:00
Nicholas Bellinger
6f48655fac target: Fix node_acl demo-mode + uncached dynamic shutdown regression
This patch fixes a generate_node_acls = 1 + cache_dynamic_acls = 0
regression, that was introduced by

  commit 01d4d67355
  Author: Nicholas Bellinger <nab@linux-iscsi.org>
  Date:   Wed Dec 7 12:55:54 2016 -0800

which originally had the proper list_del_init() usage, but was
dropped during list review as it was thought unnecessary by HCH.

However, list_del_init() usage is required during the special
generate_node_acls = 1 + cache_dynamic_acls = 0 case when
transport_free_session() does a list_del(&se_nacl->acl_list),
followed by target_complete_nacl() doing the same thing.

This was manifesting as a general protection fault as reported
by Justin:

kernel: general protection fault: 0000 [#1] SMP
kernel: Modules linked in:
kernel: CPU: 0 PID: 11047 Comm: iscsi_ttx Not tainted 4.13.0-rc2.x86_64.1+ #20
kernel: Hardware name: Intel Corporation S5500BC/S5500BC, BIOS S5500.86B.01.00.0064.050520141428 05/05/2014
kernel: task: ffff88026939e800 task.stack: ffffc90007884000
kernel: RIP: 0010:target_put_nacl+0x49/0xb0
kernel: RSP: 0018:ffffc90007887d70 EFLAGS: 00010246
kernel: RAX: dead000000000200 RBX: ffff8802556ca000 RCX: 0000000000000000
kernel: RDX: dead000000000100 RSI: 0000000000000246 RDI: ffff8802556ce028
kernel: RBP: ffffc90007887d88 R08: 0000000000000001 R09: 0000000000000000
kernel: R10: ffffc90007887df8 R11: ffffea0009986900 R12: ffff8802556ce020
kernel: R13: ffff8802556ce028 R14: ffff8802556ce028 R15: ffffffff88d85540
kernel: FS:  0000000000000000(0000) GS:ffff88027fc00000(0000) knlGS:0000000000000000
kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
kernel: CR2: 00007fffe36f5f94 CR3: 0000000009209000 CR4: 00000000003406f0
kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
kernel: Call Trace:
kernel:  transport_free_session+0x67/0x140
kernel:  transport_deregister_session+0x7a/0xc0
kernel:  iscsit_close_session+0x92/0x210
kernel:  iscsit_close_connection+0x5f9/0x840
kernel:  iscsit_take_action_for_connection_exit+0xfe/0x110
kernel:  iscsi_target_tx_thread+0x140/0x1e0
kernel:  ? wait_woken+0x90/0x90
kernel:  kthread+0x124/0x160
kernel:  ? iscsit_thread_get_cpumask+0x90/0x90
kernel:  ? kthread_create_on_node+0x40/0x40
kernel:  ret_from_fork+0x22/0x30
kernel: Code: 00 48 89 fb 4c 8b a7 48 01 00 00 74 68 4d 8d 6c 24 08 4c
89 ef e8 e8 28 43 00 48 8b 93 20 04 00 00 48 8b 83 28 04 00 00 4c 89
ef <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 83 20
kernel: RIP: target_put_nacl+0x49/0xb0 RSP: ffffc90007887d70
kernel: ---[ end trace f12821adbfd46fed ]---

To address this, go ahead and use proper list_del_list() for all
cases of se_nacl->acl_list deletion.

Reported-by: Justin Maggard <jmaggard01@gmail.com>
Tested-by: Justin Maggard <jmaggard01@gmail.com>
Cc: Justin Maggard <jmaggard01@gmail.com>
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-08-09 20:55:19 -07:00
Linus Torvalds
48ea2cedde Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "It's been usually busy for summer, with most of the efforts centered
  around TCMU developments and various target-core + fabric driver bug
  fixing activities. Not particularly large in terms of LoC, but lots of
  smaller patches from many different folks.

  The highlights include:

   - ibmvscsis logical partition manager support (Michael Cyr + Bryant
     Ly)

   - Convert target/iblock WRITE_SAME to blkdev_issue_zeroout (hch +
     nab)

   - Add support for TMR percpu LUN reference counting (nab)

   - Fix a potential deadlock between EXTENDED_COPY and iscsi shutdown
     (Bart)

   - Fix COMPARE_AND_WRITE caw_sem leak during se_cmd quiesce (Jiang Yi)

   - Fix TMCU module removal (Xiubo Li)

   - Fix iser-target OOPs during login failure (Andrea Righi + Sagi)

   - Breakup target-core free_device backend driver callback (mnc)

   - Perform TCMU add/delete/reconfig synchronously (mnc)

   - Fix TCMU multiple UIO open/close sequences (mnc)

   - Fix TCMU CHECK_CONDITION sense handling (mnc)

   - Fix target-core SAM_STAT_BUSY + TASK_SET_FULL handling (mnc + nab)

   - Introduce TYPE_ZBC support in PSCSI (Damien Le Moal)

   - Fix possible TCMU memory leak + OOPs when recalculating cmd base
     size (Xiubo Li + Bryant Ly + Damien Le Moal + mnc)

   - Add login_keys_workaround attribute for non RFC initiators (Robert
     LeBlanc + Arun Easi + nab)"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (68 commits)
  iscsi-target: Add login_keys_workaround attribute for non RFC initiators
  Revert "qla2xxx: Fix incorrect tcm_qla2xxx_free_cmd use during TMR ABORT"
  tcmu: clean up the code and with one small fix
  tcmu: Fix possbile memory leak / OOPs when recalculating cmd base size
  target: export lio pgr/alua support as device attr
  target: Fix return sense reason in target_scsi3_emulate_pr_out
  target: Fix cmd size for PR-OUT in passthrough_parse_cdb
  tcmu: Fix dev_config_store
  target: pscsi: Introduce TYPE_ZBC support
  target: Use macro for WRITE_VERIFY_32 operation codes
  target: fix SAM_STAT_BUSY/TASK_SET_FULL handling
  target: remove transport_complete
  pscsi: finish cmd processing from pscsi_req_done
  tcmu: fix sense handling during completion
  target: add helper to copy sense to se_cmd buffer
  target: do not require a transport_complete for SCF_TRANSPORT_TASK_SENSE
  target: make device_mutex and device_list static
  tcmu: Fix flushing cmd entry dcache page
  tcmu: fix multiple uio open/close sequences
  tcmu: drop configured check in destroy
  ...
2017-07-13 14:27:32 -07:00
Michal Hocko
dcda9b0471 mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semantic
__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to
the page allocator.  This has been true but only for allocations
requests larger than PAGE_ALLOC_COSTLY_ORDER.  It has been always
ignored for smaller sizes.  This is a bit unfortunate because there is
no way to express the same semantic for those requests and they are
considered too important to fail so they might end up looping in the
page allocator for ever, similarly to GFP_NOFAIL requests.

Now that the whole tree has been cleaned up and accidental or misled
usage of __GFP_REPEAT flag has been removed for !costly requests we can
give the original flag a better name and more importantly a more useful
semantic.  Let's rename it to __GFP_RETRY_MAYFAIL which tells the user
that the allocator would try really hard but there is no promise of a
success.  This will work independent of the order and overrides the
default allocator behavior.  Page allocator users have several levels of
guarantee vs.  cost options (take GFP_KERNEL as an example)

 - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_
   attempt to free memory at all. The most light weight mode which even
   doesn't kick the background reclaim. Should be used carefully because
   it might deplete the memory and the next user might hit the more
   aggressive reclaim

 - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic
   allocation without any attempt to free memory from the current
   context but can wake kswapd to reclaim memory if the zone is below
   the low watermark. Can be used from either atomic contexts or when
   the request is a performance optimization and there is another
   fallback for a slow path.

 - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) -
   non sleeping allocation with an expensive fallback so it can access
   some portion of memory reserves. Usually used from interrupt/bh
   context with an expensive slow path fallback.

 - GFP_KERNEL - both background and direct reclaim are allowed and the
   _default_ page allocator behavior is used. That means that !costly
   allocation requests are basically nofail but there is no guarantee of
   that behavior so failures have to be checked properly by callers
   (e.g. OOM killer victim is allowed to fail currently).

 - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior
   and all allocation requests fail early rather than cause disruptive
   reclaim (one round of reclaim in this implementation). The OOM killer
   is not invoked.

 - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator
   behavior and all allocation requests try really hard. The request
   will fail if the reclaim cannot make any progress. The OOM killer
   won't be triggered.

 - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior
   and all allocation requests will loop endlessly until they succeed.
   This might be really dangerous especially for larger orders.

Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL
because they already had their semantic.  No new users are added.
__alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if
there is no progress and we have already passed the OOM point.

This means that all the reclaim opportunities have been exhausted except
the most disruptive one (the OOM killer) and a user defined fallback
behavior is more sensible than keep retrying in the page allocator.

[akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c]
[mhocko@suse.com: semantic fix]
  Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz
[mhocko@kernel.org: address other thing spotted by Vlastimil]
  Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:03 -07:00
Mike Christie
402242c904 target: fix SAM_STAT_BUSY/TASK_SET_FULL handling
If the scsi status was not SAM_STAT_GOOD or there was no transport
sense, we would ignore the scsi status and do a generic not ready
LUN communication failure check condition failure.

The problem is that LUN COMM failure is treated as a hard error
sometimes and will cause apps to get IO errors instead of the OS's SCSI
layer retrying. For example, the tcmu daemon will return SAM_STAT_QUEUE_FULL
when memory runs low and can still make progress but wants the initiator to
reduce the work load. Windows will fail this error directly the app
instead of retrying.

This patch is based on Nick's "target/iblock: Use -EAGAIN/-ENOMEM to
propigate SAM BUSY/TASK_SET_FULL" patch here:

http://comments.gmane.org/gmane.linux.scsi.target.devel/11301

but instead of only setting SAM_STAT_GOOD, SAM_STAT_TASK_SET_FULL
and SAM_STAT_BUSY as success, it sets all non check condition status
as success so they are passed back to the initiator, so passthrough
type backends can return all SCSI status codes. Since only passthrough
uses this, I was not sure if we wanted to add checks for non-passthrough
and specific codes.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 23:11:48 -07:00
Mike Christie
1a44417548 target: remove transport_complete
transport_complete is no longer used, so drop the code.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 23:11:47 -07:00
Mike Christie
c6d66aba98 target: add helper to copy sense to se_cmd buffer
This adds a helper to copy sense from backend module buffer to
the se_cmd's sense buffer.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 23:11:45 -07:00
Mike Christie
9fe3698450 target: do not require a transport_complete for SCF_TRANSPORT_TASK_SENSE
tcmu needs to pass raw sense to target_complete_cmd, but a a
transport_complete callout is akward to implement for it.

This moves the check for SCF_TRANSPORT_TASK_SENSE so any backend
can pass sense.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 23:11:44 -07:00
Jiang Yi
1d6ef27659 target: Fix COMPARE_AND_WRITE caw_sem leak during se_cmd quiesce
This patch addresses a COMPARE_AND_WRITE se_device->caw_sem leak,
that would be triggered during normal se_cmd shutdown or abort
via __transport_wait_for_tasks().

This would occur because target_complete_cmd() would catch this
early and do complete_all(&cmd->t_transport_stop_comp), but since
target_complete_ok_work() or target_complete_failure_work() are
never called to invoke se_cmd->transport_complete_callback(),
the COMPARE_AND_WRITE specific callbacks never release caw_sem.

To address this special case, go ahead and release caw_sem
directly from target_complete_cmd().

(Remove '&& success' from check, to release caw_sem regardless
 of scsi_status - nab)

Signed-off-by: Jiang Yi <jiangyilism@gmail.com>
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 23:11:32 -07:00
Bart Van Assche
c00e622023 target: Introduce a function that shows the command state
Introduce target_show_cmd() and use it where appropriate. If
transport_wait_for_tasks() takes too long, make it show the
state of the command it is waiting for.

(Add missing brackets around multi-line conditions - nab)

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:58:04 -07:00
Bart Van Assche
f2b72d6a8e target: Fix transport_init_se_cmd()
Avoid that aborting a command before it has been submitted onto
a workqueue triggers the following warning:

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 3 PID: 46 Comm: kworker/u8:1 Not tainted 4.12.0-rc2-dbg+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
Workqueue: tmr-iblock target_tmr_work [target_core_mod]
Call Trace:
 dump_stack+0x86/0xcf
 register_lock_class+0xe8/0x570
 __lock_acquire+0xa1/0x11d0
 lock_acquire+0x59/0x80
 flush_work+0x42/0x2b0
 __cancel_work_timer+0x10c/0x180
 cancel_work_sync+0xb/0x10
 core_tmr_lun_reset+0x352/0x740 [target_core_mod]
 target_tmr_work+0xd6/0x130 [target_core_mod]
 process_one_work+0x1ca/0x3f0
 worker_thread+0x49/0x3b0
 kthread+0x109/0x140
 ret_from_fork+0x31/0x40

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:57:59 -07:00
Nicholas Bellinger
5465e7d3b9 target: Add TARGET_SCF_LOOKUP_LUN_FROM_TAG support for ABORT_TASK
This patch introduces support in target_submit_tmr() for locating a
unpacked_lun from an existing se_cmd->tag during ABORT_TASK.

When TARGET_SCF_LOOKUP_LUN_FROM_TAG is set, target_submit_tmr()
will do the extra lookup via target_lookup_lun_from_tag() and
subsequently invoke transport_lookup_tmr_lun() so a proper
percpu se_lun->lun_ref is taken before workqueue dispatch into
se_device->tmr_wq happens.

Aside from the extra target_lookup_lun_from_tag(), the existing
code-path remains unchanged.

Reviewed-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: Quinn Tran <quinn.tran@cavium.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:57:56 -07:00
Nicholas Bellinger
eeb64d239e target: Add support for TMR percpu reference counting
This patch introduces TMR percpu reference counting using
se_lun->lun_ref in transport_lookup_tmr_lun(), following
how existing non TMR per se_lun reference counting works
within transport_lookup_cmd_lun().

It also adds explicit transport_lun_remove_cmd() calls to
drop the reference in the three tmr related locations that
invoke transport_cmd_check_stop_to_fabric();

   - target_tmr_work() during normal ->queue_tm_rsp()
   - target_complete_tmr_failure() during error ->queue_tm_rsp()
   - transport_generic_handle_tmr() during early failure

Also, note the exception paths in transport_generic_free_cmd()
and transport_cmd_finish_abort() already check SCF_SE_LUN_CMD,
and will invoke transport_lun_remove_cmd() when necessary.

Reviewed-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: Quinn Tran <quinn.tran@cavium.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:57:55 -07:00
Nicholas Bellinger
73d4e580cc target: Fix kref->refcount underflow in transport_cmd_finish_abort
This patch fixes a se_cmd->cmd_kref underflow during CMD_T_ABORTED
when a fabric driver drops it's second reference from below the
target_core_tmr.c based callers of transport_cmd_finish_abort().

Recently with the conversion of kref to refcount_t, this bug was
manifesting itself as:

[705519.601034] refcount_t: underflow; use-after-free.
[705519.604034] INFO: NMI handler (kgdb_nmi_handler) took too long to run: 20116.512 msecs
[705539.719111] ------------[ cut here ]------------
[705539.719117] WARNING: CPU: 3 PID: 26510 at lib/refcount.c:184 refcount_sub_and_test+0x33/0x51

Since the original kref atomic_t based kref_put() didn't check for
underflow and only invoked the final callback when zero was reached,
this bug did not manifest in practice since all se_cmd memory is
using preallocated tags.

To address this, go ahead and propigate the existing return from
transport_put_cmd() up via transport_cmd_finish_abort(), and
change transport_cmd_finish_abort() + core_tmr_handle_tas_abort()
callers to only do their local target_put_sess_cmd() if necessary.

Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: stable@vger.kernel.org # 3.14+
Tested-by: Gary Guo <ghg@datera.io>
Tested-by: Chu Yuan Lin <cyl@datera.io>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08 22:24:18 -07:00
Nicholas Bellinger
4ff83daa02 target: Re-add check to reject control WRITEs with overflow data
During v4.3 when the overflow/underflow check was relaxed by
commit c72c525022:

  commit c72c525022
  Author: Roland Dreier <roland@purestorage.com>
  Date:   Wed Jul 22 15:08:18 2015 -0700

       target: allow underflow/overflow for PR OUT etc. commands

to allow underflow/overflow for Windows compliance + FCP, a
consequence was to allow control CDBs to process overflow
data for iscsi-target with immediate data as well.

As per Roland's original change, continue to allow underflow
cases for control CDBs to make Windows compliance + FCP happy,
but until overflow for control CDBs is supported tree-wide,
explicitly reject all control WRITEs with overflow following
pre v4.3.y logic.

Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org> # v4.3+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-05-15 20:20:29 -07:00
Markus Elfring
df6751f340 target: Use kmalloc_array() in transport_kmap_data_sg()
A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus use the corresponding function "kmalloc_array".

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-05-01 22:21:33 -07:00
Nicholas Bellinger
fa7e25cf13 target: Fix unknown fabric callback queue-full errors
This patch fixes a set of queue-full response handling
bugs, where outgoing responses are leaked when a fabric
driver is propagating non -EAGAIN or -ENOMEM errors
to target-core.

It introduces TRANSPORT_COMPLETE_QF_ERR state used to
signal when CHECK_CONDITION status should be generated,
when fabric driver ->write_pending(), ->queue_data_in(),
or ->queue_status() callbacks fail with non -EAGAIN or
-ENOMEM errors, and data-transfer should not be retried.

Note all fabric driver -EAGAIN and -ENOMEM errors are
still retried indefinately with associated data-transfer
callbacks, following existing queue-full logic.

Also fix two missing ->queue_status() queue-full cases
related to CMD_T_ABORTED w/ TAS status handling.

Reported-by: Potnuri Bharat Teja <bharat@chelsio.com>
Reviewed-by: Potnuri Bharat Teja <bharat@chelsio.com>
Tested-by: Potnuri Bharat Teja <bharat@chelsio.com>
Cc: Potnuri Bharat Teja <bharat@chelsio.com>
Reported-by: Steve Wise <swise@opengridcomputing.com>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-03-30 20:34:31 -07:00
Nicholas Bellinger
9c28ca4ff8 target: Drop pointless tfo->check_stop_free check
All in-tree fabric drivers provide a tfo->check_stop_free(),
so there is no need to do the extra check within existing
transport_cmd_check_stop_to_fabric() code.

Just to be sure, add a check in target_fabric_tf_ops_check()
to notify any out-of-tree drivers that might be missing it.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-03-18 14:42:50 -07:00
Nicholas Bellinger
bd4e2d2907 target: Fix NULL dereference during LUN lookup + active I/O shutdown
When transport_clear_lun_ref() is shutting down a se_lun via
configfs with new I/O in-flight, it's possible to trigger a
NULL pointer dereference in transport_lookup_cmd_lun() due
to the fact percpu_ref_get() doesn't do any __PERCPU_REF_DEAD
checking before incrementing lun->lun_ref.count after
lun->lun_ref has switched to atomic_t mode.

This results in a NULL pointer dereference as LUN shutdown
code in core_tpg_remove_lun() continues running after the
existing ->release() -> core_tpg_lun_ref_release() callback
completes, and clears the RCU protected se_lun->lun_se_dev
pointer.

During the OOPs, the state of lun->lun_ref in the process
which triggered the NULL pointer dereference looks like
the following on v4.1.y stable code:

struct se_lun {
  lun_link_magic = 4294932337,
  lun_status = TRANSPORT_LUN_STATUS_FREE,

  .....

  lun_se_dev = 0x0,
  lun_sep = 0x0,

  .....

  lun_ref = {
    count = {
      counter = 1
    },
    percpu_count_ptr = 3,
    release = 0xffffffffa02fa1e0 <core_tpg_lun_ref_release>,
    confirm_switch = 0x0,
    force_atomic = false,
    rcu = {
      next = 0xffff88154fa1a5d0,
      func = 0xffffffff8137c4c0 <percpu_ref_switch_to_atomic_rcu>
    }
  }
}

To address this bug, use percpu_ref_tryget_live() to ensure
once __PERCPU_REF_DEAD is visable on all CPUs and ->lun_ref
has switched to atomic_t, all new I/Os will fail to obtain
a new lun->lun_ref reference.

Also use an explicit percpu_ref_kill_and_confirm() callback
to block on ->lun_ref_comp to allow the first stage and
associated RCU grace period to complete, and then block on
->lun_ref_shutdown waiting for the final percpu_ref_put()
to drop the last reference via transport_lun_remove_cmd()
before continuing with core_tpg_remove_lun() shutdown.

Reported-by: Rob Millner <rlm@daterainc.com>
Tested-by: Rob Millner <rlm@daterainc.com>
Cc: Rob Millner <rlm@daterainc.com>
Tested-by: Vaibhav Tandon <vst@datera.io>
Cc: Vaibhav Tandon <vst@datera.io>
Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-26 16:08:44 -08:00
Bart Van Assche
e3b88ee95b target: Fix handling of aborted failed commands
If a target driver (e.g. tcm_qla2xxx) calls
transport_generic_request_failure() to report that receiving data
has failed and that SCSI command has already been aborted by the
initiator, ensure that the SCSI status ABORTED is sent back to the
initiator instead of the sense code provided by the target driver.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-20 13:28:09 -08:00
Bart Van Assche
b2c9652eba target: Remove command flag CMD_T_DEV_ACTIVE
The code that tests the CMD_T_DEV_ACTIVE flag has been removed. Hence
also remove the flag itself.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09 00:39:16 -08:00
Bart Van Assche
fd5e64def9 target: Remove command flag CMD_T_BUSY
The patch that reworks task management function handling guarantees
that target_remove_from_state_list() is always called with CMD_T_BUSY
cleared. Since that function is the only function that tests that flag
this means that that flag is now superfluous. Hence remove that flag.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09 00:39:15 -08:00
Bart Van Assche
6b6427b6fd target: Move session check from target_put_sess_cmd() into target_release_cmd_kref()
This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09 00:39:15 -08:00
Bart Van Assche
b1a2ecdad7 target: Inline transport_cmd_check_stop()
The function transport_cmd_check_stop() has two callers. These callers
invoke this function as follows:
* transport_cmd_check_stop(cmd, true, false)
* transport_cmd_check_stop(cmd, false, true)
Hence inline this function into its callers.

This patch does not change any functionality but improves source
code readability.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09 00:39:14 -08:00
Bart Van Assche
580ab13ac4 target: Remove an overly chatty debug message
Enabling dynamic debug for the target_core_mod kernel module
causes the system log to be spammed with the "Incremented ..."
message. Hence remove it.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09 00:39:13 -08:00
Bart Van Assche
a5eb307f37 target: Stop execution if CMD_T_STOP has been set
Stop execution if CMD_T_STOP has been set for a command just after
the command has been added to the device command list and before
.write_pending() is called. The following sequence can trigger this:
- transport_handle_cdb_direct() gets called. This function namely
  sets CMD_T_ACTIVE before it calls transport_generic_new_cmd().
- __transport_wait_for_tasks() is called concurrently. This function
  sets CMD_T_STOP for all active commands that have not been aborted.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09 00:39:12 -08:00
Bart Van Assche
2d4760ee47 target: Correct transport_wait_for_tasks() documentation
transport_wait_for_tasks() not only waits for command completion
but also sets CMD_T_STOP. Additionally, this function is not only
called by frontend drivers but also by the target core. Update
the transport_wait_for_tasks() documentation to reflect this.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-09 00:39:12 -08:00
Nicholas Bellinger
01d4d67355 target: Fix multi-session dynamic se_node_acl double free OOPs
This patch addresses a long-standing bug with multi-session
(eg: iscsi-target + iser-target) se_node_acl dynamic free
withini transport_deregister_session().

This bug is caused when a storage endpoint is configured with
demo-mode (generate_node_acls = 1 + cache_dynamic_acls = 1)
initiators, and initiator login creates a new dynamic node acl
and attaches two sessions to it.

After that, demo-mode for the storage instance is disabled via
configfs (generate_node_acls = 0 + cache_dynamic_acls = 0) and
the existing dynamic acl is never converted to an explicit ACL.

The end result is dynamic acl resources are released twice when
the sessions are shutdown in transport_deregister_session().

If the storage instance is not changed to disable demo-mode,
or the dynamic acl is converted to an explict ACL, or there
is only a single session associated with the dynamic ACL,
the bug is not triggered.

To address this big, move the release of dynamic se_node_acl
memory into target_complete_nacl() so it's only freed once
when se_node_acl->acl_kref reaches zero.

(Drop unnecessary list_del_init usage - HCH)

Reported-by: Rob Millner <rlm@daterainc.com>
Tested-by: Rob Millner <rlm@daterainc.com>
Cc: Rob Millner <rlm@daterainc.com>
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-08 08:25:23 -08:00
Nicholas Bellinger
c54eeffbe9 target: Fix early transport_generic_handle_tmr abort scenario
This patch fixes a bug where incoming task management requests
can be explicitly aborted during an active LUN_RESET, but who's
struct work_struct are canceled in-flight before execution.

This occurs when core_tmr_drain_tmr_list() invokes cancel_work_sync()
for the incoming se_tmr_req->task_cmd->work, resulting in cmd->work
for target_tmr_work() never getting invoked and the aborted TMR
waiting indefinately within transport_wait_for_tasks().

To address this case, perform a CMD_T_ABORTED check early in
transport_generic_handle_tmr(), and invoke the normal path via
transport_cmd_check_stop_to_fabric() to complete any TMR kthreads
blocked waiting for CMD_T_STOP in transport_wait_for_tasks().

Also, move the TRANSPORT_ISTATE_PROCESSING assignment earlier
into transport_generic_handle_tmr() so the existing check in
core_tmr_drain_tmr_list() avoids attempting abort the incoming
se_tmr_req->task_cmd->work if it has already been queued into
se_device->tmr_wq.

Reported-by: Rob Millner <rlm@daterainc.com>
Tested-by: Rob Millner <rlm@daterainc.com>
Cc: Rob Millner <rlm@daterainc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-02-08 07:47:19 -08:00
David Disseldorp
e864212078 target: add XCOPY target/segment desc sense codes
As defined in http://www.t10.org/lists/asc-num.htm. To be used during
validation of XCOPY target and segment descriptor lists.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
2017-01-10 08:40:32 -08:00
Hannes Reinecke
1b4c59b7a1 target: fix potential race window in target_sess_cmd_list_waiting()
target_sess_cmd_list_waiting() might hit on a condition where
the kref for the command is already 0, but the destructor has
not been called yet (or is stuck in waiting for a spin lock).
Rather than leaving the command on the list we should explicitly
remove it to avoid race issues later on.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-21 01:19:41 -07:00
Nicholas Bellinger
61f36166c2 Revert "target: Fix residual overflow handling in target_complete_cmd_with_length"
This reverts commit c1ccbfe031.

Reverting this patch, as it incorrectly assumes the additional length
for INQUIRY in target_complete_cmd_with_length() is SCSI allocation
length, which breaks existing user-space code when SCSI allocation
length is smaller than additional length.

  root@scsi-mq:~# sg_inq --len=4 -vvvv /dev/sdb
  found bsg_major=253
  open /dev/sdb with flags=0x800
      inquiry cdb: 12 00 00 00 04 00
        duration=0 ms
      inquiry: pass-through requested 4 bytes (data-in) but got -28 bytes
      inquiry: pass-through can't get negative bytes, say it got none
      inquiry: got too few bytes (0)
  INQUIRY resid (32) should never exceed requested len=4
      inquiry: failed requesting 4 byte response: Malformed response to
               SCSI command [resid=32]

AFAICT the original change was not to address a specific host issue,
so go ahead and revert to original logic for now.

Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Sumit Rai <sumitrai96@gmail.com>
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:34 -07:00
Nicholas Bellinger
449a137846 target: Make EXTENDED_COPY 0xe4 failure return COPY TARGET DEVICE NOT REACHABLE
This patch addresses a bug where EXTENDED_COPY across multiple LUNs
results in a CHECK_CONDITION when the source + destination are not
located on the same physical node.

ESX Host environments expect sense COPY_ABORTED w/ COPY TARGET DEVICE
NOT REACHABLE to be returned when this occurs, in order to signal
fallback to local copy method.

As described in section 6.3.3 of spc4r22:

  "If it is not possible to complete processing of a segment because the
   copy manager is unable to establish communications with a copy target
   device, because the copy target device does not respond to INQUIRY,
   or because the data returned in response to INQUIRY indicates
   an unsupported logical unit, then the EXTENDED COPY command shall be
   terminated with CHECK CONDITION status, with the sense key set to
   COPY ABORTED, and the additional sense code set to COPY TARGET DEVICE
   NOT REACHABLE."

Tested on v4.1.y with ESX v5.5u2+ with BlockCopy across multiple nodes.

Reported-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Cc: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Dinesh Israni <ddi@datera.io>
Signed-off-by: Dinesh Israni <ddi@datera.io>
Cc: Dinesh Israni <ddi@datera.io>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:32 -07:00
Nicholas Bellinger
527268df31 target: Re-add missing SCF_ACK_KREF assignment in v4.1.y
This patch fixes a regression in >= v4.1.y code where the original
SCF_ACK_KREF assignment in target_get_sess_cmd() was dropped upstream
in commit 054922bb, but the series for addressing TMR ABORT_TASK +
LUN_RESET with fabric session reinstatement in commit febe562c20 still
depends on this code in transport_cmd_finish_abort().

The regression manifests itself as a se_cmd->cmd_kref +1 leak, where
ABORT_TASK + LUN_RESET can hang indefinately for a specific I_T session
for drivers using SCF_ACK_KREF, resulting in hung kthreads.

This patch has been verified with v4.1.y code.

Reported-by: Vaibhav Tandon <vst@datera.io>
Tested-by: Vaibhav Tandon <vst@datera.io>
Cc: Vaibhav Tandon <vst@datera.io>
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-10-19 21:22:31 -07:00
Sumit Rai
c1ccbfe031 target: Fix residual overflow handling in target_complete_cmd_with_length
This patch fixes residual overflow handling to correctly set the
residual_count using SPDTL, instead of SCSI Allocation Length.

Allocation Length is the maximum value of the SPDTL and not substitute
for it, hence it shouldn’t be used to calculate ResidualCount except for
cases where SPDTL > Allocation Length and Data is truncated (in that
case both Alloc Len and SPDTL are same). (SPC 5r01 Section 4.2.5.6).

Thanks to Ajay Nair in assisting with this patch.

Signed-off-by: Sumit Rai <sumitrai96@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-23 23:34:54 -07:00
Nicholas Bellinger
410c29dfbf target: Fix ordered task CHECK_CONDITION early exception handling
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 <bryantly@linux.vnet.ibm.com>
Signed-off-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Signed-off-by: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 4.4+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-20 00:58:40 -07:00
Nicholas Bellinger
dff0ca9ea7 target: Fix ordered task target_setup_cmd_from_cdb exception hang
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 <mikecyr@linux.vnet.ibm.com>
Tested-by: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 4.4+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-20 00:58:38 -07:00
Nicholas Bellinger
064cdd2d91 target: Fix race between iscsi-target connection shutdown + ABORT_TASK
This patch fixes a race in iscsit_release_commands_from_conn() ->
iscsit_free_cmd() -> transport_generic_free_cmd() + wait_for_tasks=1,
where CMD_T_FABRIC_STOP could end up being set after the final
kref_put() is called from core_tmr_abort_task() context.

This results in transport_generic_free_cmd() blocking indefinately
on se_cmd->cmd_wait_comp, because the target_release_cmd_kref()
check for CMD_T_FABRIC_STOP returns false.

To address this bug, make iscsit_release_commands_from_conn()
do list_splice and set CMD_T_FABRIC_STOP early while holding
iscsi_conn->cmd_lock.  Also make iscsit_aborted_task() only
remove iscsi_cmd_t if CMD_T_FABRIC_STOP has not already been
set.

Finally in target_release_cmd_kref(), only honor fabric_stop
if CMD_T_ABORTED has been set.

Cc: Mike Christie <mchristi@redhat.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org # 3.14+
Tested-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-20 00:58:34 -07:00
Nicholas Bellinger
5e2c956b8a target: Fix missing complete during ABORT_TASK + CMD_T_FABRIC_STOP
During transport_generic_free_cmd() with a concurrent TMR
ABORT_TASK and shutdown CMD_T_FABRIC_STOP bit set, the
caller will be blocked on se_cmd->cmd_wait_stop completion
until the final kref_put() -> target_release_cmd_kref()
has been invoked to call complete().

However, when ABORT_TASK is completed with FUNCTION_COMPLETE
in core_tmr_abort_task(), the aborted se_cmd will have already
been removed from se_sess->sess_cmd_list via list_del_init().

This results in target_release_cmd_kref() hitting the
legacy list_empty() == true check, invoking ->release_cmd()
but skipping complete() to wakeup se_cmd->cmd_wait_stop
blocked earlier in transport_generic_free_cmd() code.

To address this bug, it's safe to go ahead and drop the
original list_empty() check so that fabric_stop invokes
the complete() as expected, since list_del_init() can
safely be used on a empty list.

Cc: Mike Christie <mchristi@redhat.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org # 3.14+
Tested-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-20 00:58:26 -07:00
Linus Torvalds
9ba55cf7cf Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "Here are the outstanding target pending updates for v4.7-rc1.

  The highlights this round include:

   - Allow external PR/ALUA metadata path be defined at runtime via top
     level configfs attribute (Lee)
   - Fix target session shutdown bug for ib_srpt multi-channel (hch)
   - Make TFO close_session() and shutdown_session() optional (hch)
   - Drop se_sess->sess_kref + convert tcm_qla2xxx to internal kref
     (hch)
   - Add tcm_qla2xxx endpoint attribute for basic FC jammer (Laurence)
   - Refactor iscsi-target RX/TX PDU encode/decode into common code
     (Varun)
   - Extend iscsit_transport with xmit_pdu, release_cmd, get_rx_pdu,
     validate_parameters, and get_r2t_ttt for generic ISO offload
     (Varun)
   - Initial merge of cxgb iscsi-segment offload target driver (Varun)

  The bulk of the changes are Chelsio's new driver, along with a number
  of iscsi-target common code improvements made by Varun + Co along the
  way"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (29 commits)
  iscsi-target: Fix early sk_data_ready LOGIN_FLAGS_READY race
  cxgbit: Use type ISCSI_CXGBIT + cxgbit tpg_np attribute
  iscsi-target: Convert transport drivers to signal rdma_shutdown
  iscsi-target: Make iscsi_tpg_np driver show/store use generic code
  tcm_qla2xxx Add SCSI command jammer/discard capability
  iscsi-target: graceful disconnect on invalid mapping to iovec
  target: need_to_release is always false, remove redundant check and kfree
  target: remove sess_kref and ->shutdown_session
  iscsi-target: remove usage of ->shutdown_session
  tcm_qla2xxx: introduce a private sess_kref
  target: make close_session optional
  target: make ->shutdown_session optional
  target: remove acl_stop
  target: consolidate and fix session shutdown
  cxgbit: add files for cxgbit.ko
  iscsi-target: export symbols
  iscsi-target: call complete on conn_logout_comp
  iscsi-target: clear tx_thread_active
  iscsi-target: add new offload transport type
  iscsi-target: use conn_transport->transport_type in text rsp
  ...
2016-05-28 12:04:17 -07:00
Christoph Hellwig
e64aa657c3 target: enhance and export target_alloc_sgl/target_free_sgl
The SRP target driver will need to allocate and chain it's own SGLs soon.
For this export target_alloc_sgl, and add a new argument to it so that it
can allocate an additional chain entry that doesn't point to a page.  Also
export transport_free_sgl after renaming it to target_free_sgl to free
these SGLs again.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-05-13 13:37:19 -04:00
Christoph Hellwig
d94331fab6 target: remove sess_kref and ->shutdown_session
Both of them are unused now that drivers handle any delayed session
shutdown internally.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-05-10 01:19:49 -07:00
Christoph Hellwig
36ec2ddc0d target: make close_session optional
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-05-10 01:19:26 -07:00