Commit Graph

677442 Commits

Author SHA1 Message Date
Nicholas Bellinger 03db016a1b iscsi-target: Kill left-over iscsi_target_do_cleanup
With commit 25cdda95fd in place to address the initial login
PDU asynchronous socket close OOPs, go ahead and kill off the
left-over iscsi_target_do_cleanup() and ->login_cleanup_work.

Reported-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:58:04 -07:00
Bart Van Assche af90e84d1f xen/scsiback: Make TMF processing slightly faster
Target drivers must guarantee that struct se_cmd and struct se_tmr_req
exist as long as target_tmr_work() is in progress. Since the last
access by the LIO core is a call to .check_stop_free() and since the
Xen scsiback .check_stop_free() drops a reference to the TMF, it is
already guaranteed that the struct se_cmd that corresponds to the TMF
exists as long as target_tmr_work() is in progress. Hence change the
second argument of transport_generic_free_cmd() from 1 into 0.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: David Disseldorp <ddiss@suse.de>
Cc: xen-devel@lists.xenproject.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:58:03 -07:00
Bart Van Assche e3eac12442 xen/scsiback: Replace a waitqueue and a counter by a completion
This patch simplifies the implementation of the scsiback driver
but does not change its behavior.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: David Disseldorp <ddiss@suse.de>
Cc: xen-devel@lists.xenproject.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:58:02 -07:00
Bart Van Assche 9f4ab18ac5 xen/scsiback: Fix a TMR related use-after-free
scsiback_release_cmd() must not dereference se_cmd->se_tmr_req
because that memory is freed by target_free_cmd_mem() before
scsiback_release_cmd() is called. Fix this use-after-free by
inlining struct scsiback_tmr into struct vscsibk_pend.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: David Disseldorp <ddiss@suse.de>
Cc: xen-devel@lists.xenproject.org
Cc: <stable@vger.kernel.org> # 3.18+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:58:01 -07:00
Bart Van Assche 13fdd4458e IB/srpt: Make a debug statement in srpt_abort_cmd() more informative
Do not only report the state of the I/O context before srpt_abort_cmd()
was called but also the new state assigned by srpt_abort_cmd()

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Doug Ledford <dledford@redhat.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 22:58:01 -07:00
Bart Van Assche d877d7275b target: Fix a deadlock between the XCOPY code and iSCSI session shutdown
Move the code for parsing an XCOPY command from the context of
the iSCSI receiver thread to the context of the XCOPY workqueue.
Keep the simple XCOPY checks in the context of the iSCSI receiver
thread. Move the code for allocating and freeing struct xcopy_op
from the code that parses an XCOPY command to its caller.

This patch fixes the following deadlock:

======================================================
[ INFO: possible circular locking dependency detected ]
4.10.0-rc7-dbg+ #1 Not tainted
-------------------------------------------------------
rmdir/13321 is trying to acquire lock:
 (&sess->cmdsn_mutex){+.+.+.}, at: [<ffffffffa02cb47d>] iscsit_free_all_ooo_cmdsns+0x2d/0xb0 [iscsi_target_mod]

but task is already holding lock:
 (&sb->s_type->i_mutex_key#14){++++++}, at: [<ffffffff811c6e20>] vfs_rmdir+0x50/0x140

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:
-> #1 (&sb->s_type->i_mutex_key#14){++++++}:
 lock_acquire+0x71/0x90
 down_write+0x3f/0x70
 configfs_depend_item+0x3a/0xb0 [configfs]
 target_depend_item+0x13/0x20 [target_core_mod]
 target_xcopy_locate_se_dev_e4+0xdd/0x1a0 [target_core_mod]
 target_do_xcopy+0x34b/0x970 [target_core_mod]
 __target_execute_cmd+0x22/0xa0 [target_core_mod]
 target_execute_cmd+0x233/0x2c0 [target_core_mod]
 iscsit_execute_cmd+0x208/0x270 [iscsi_target_mod]
 iscsit_sequence_cmd+0x10b/0x190 [iscsi_target_mod]
 iscsit_get_rx_pdu+0x37d/0xcd0 [iscsi_target_mod]
 iscsi_target_rx_thread+0x6e/0xa0 [iscsi_target_mod]
 kthread+0x102/0x140
 ret_from_fork+0x31/0x40

-> #0 (&sess->cmdsn_mutex){+.+.+.}:
 __lock_acquire+0x10e6/0x1260
 lock_acquire+0x71/0x90
 mutex_lock_nested+0x5f/0x670
 iscsit_free_all_ooo_cmdsns+0x2d/0xb0 [iscsi_target_mod]
 iscsit_close_session+0xac/0x200 [iscsi_target_mod]
 lio_tpg_close_session+0x9f/0xb0 [iscsi_target_mod]
 target_shutdown_sessions+0xc3/0xd0 [target_core_mod]
 core_tpg_del_initiator_node_acl+0x91/0x140 [target_core_mod]
 target_fabric_nacl_base_release+0x20/0x30 [target_core_mod]
 config_item_release+0x5a/0xc0 [configfs]
 config_item_put+0x1d/0x1f [configfs]
 configfs_rmdir+0x1a6/0x300 [configfs]
 vfs_rmdir+0xb7/0x140
 do_rmdir+0x1f4/0x200
 SyS_rmdir+0x11/0x20
 entry_SYSCALL_64_fastpath+0x23/0xc6

other info that might help us debug this:

 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&sb->s_type->i_mutex_key#14);
                               lock(&sess->cmdsn_mutex);
                               lock(&sb->s_type->i_mutex_key#14);
  lock(&sess->cmdsn_mutex);

 *** DEADLOCK ***

3 locks held by rmdir/13321:
 #0:  (sb_writers#10){.+.+.+}, at: [<ffffffff811e1aff>] mnt_want_write+0x1f/0x50
 #1:  (&default_group_class[depth - 1]#2/1){+.+.+.}, at: [<ffffffff811cc8ce>] do_rmdir+0x15e/0x200
 #2:  (&sb->s_type->i_mutex_key#14){++++++}, at: [<ffffffff811c6e20>] vfs_rmdir+0x50/0x140

stack backtrace:
CPU: 2 PID: 13321 Comm: rmdir Not tainted 4.10.0-rc7-dbg+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
Call Trace:
 dump_stack+0x86/0xc3
 print_circular_bug+0x1c7/0x220
 __lock_acquire+0x10e6/0x1260
 lock_acquire+0x71/0x90
 mutex_lock_nested+0x5f/0x670
 iscsit_free_all_ooo_cmdsns+0x2d/0xb0 [iscsi_target_mod]
 iscsit_close_session+0xac/0x200 [iscsi_target_mod]
 lio_tpg_close_session+0x9f/0xb0 [iscsi_target_mod]
 target_shutdown_sessions+0xc3/0xd0 [target_core_mod]
 core_tpg_del_initiator_node_acl+0x91/0x140 [target_core_mod]
 target_fabric_nacl_base_release+0x20/0x30 [target_core_mod]
 config_item_release+0x5a/0xc0 [configfs]
 config_item_put+0x1d/0x1f [configfs]
 configfs_rmdir+0x1a6/0x300 [configfs]
 vfs_rmdir+0xb7/0x140
 do_rmdir+0x1f4/0x200
 SyS_rmdir+0x11/0x20
 entry_SYSCALL_64_fastpath+0x23/0xc6

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 22:58:00 -07:00
Bart Van Assche a85d667e58 target: Use {get,put}_unaligned_be*() instead of open coding these functions
Introduce the function get_unaligned_be24(). Use {get,put}_unaligned_be*()
where appropriate. This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:57:59 -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
Bart Van Assche 9f2f342892 target: Remove se_device.dev_list
The last user of se_device.dev_list was removed through commit
0fd97ccf45 ("target: kill struct se_subsystem_dev"). Hence
also remove se_device.dev_list.

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>
2017-07-06 22:57:58 -07:00
Bart Van Assche 3e182db787 target: Use symbolic value for WRITE_VERIFY_16
Now that a symbolic value has been introduced for WRITE_VERIFY_16,
use it. This patch does not change any functionality.

References: commit c2d26f18dc ("target: Add WRITE_VERIFY_16")
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: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:57:57 -07:00
Nicholas Bellinger eb5ae2335a qla2xxx: Convert QLA_TGT_ABTS to TARGET_SCF_LOOKUP_LUN_FROM_TAG
Following Himanshu's earlier patch to drop the redundant tag
lookup within __qlt_24xx_handle_abts(), go ahead and drop this
now QLA_TGT_ABTS can use TARGET_SCF_LOOKUP_LUN_FROM_TAG and
have target_submit_tmr() do this from common code.

Reviewed-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Acked-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 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
Jiang Yi 12f66e4a0f target: reject COMPARE_AND_WRITE if emulate_caw is not set
In struct se_dev_attrib, there is a field emulate_caw exposed
as a /sys/kernel/config/target/core/$HBA/$DEV/attrib/.

If this field is set zero, it means the corresponding struct se_device
does not support the scsi cmd COMPARE_AND_WRITE

In function sbc_parse_cdb(), go ahead and reject scsi COMPARE_AND_WRITE
if emulate_caw is not set, because it has been explicitly disabled
from user-space.

(Make pr_err ratelimited - nab)

Signed-off-by: Jiang Yi <jiangyilism@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-07-06 22:57:54 -07:00
Nicholas Bellinger eceb4459df iscsi-target: Avoid holding ->tpg_state_lock during param update
As originally reported by Jia-Ju, iscsit_tpg_enable_portal_group()
holds iscsi_portal_group->tpg_state_lock while updating AUTHMETHOD
via iscsi_update_param_value(), which performs a GFP_KERNEL
allocation.

However, since iscsit_tpg_enable_portal_group() is already protected
by iscsit_get_tpg() -> iscsi_portal_group->tpg_access_lock in it's
parent caller, ->tpg_state_lock only needs to be held when setting
TPG_STATE_ACTIVE.

Reported-by: Jia-Ju Bai <baijiaju1990@163.com>
Reviewed-by: Jia-Ju Bai <baijiaju1990@163.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08 23:26:38 -07:00
Nicholas Bellinger 9ae0e9ade5 target/configfs: Kill se_lun->lun_link_magic
Instead of using a hardcoded magic value in se_lun when verifying
a target config_item symlink source during target_fabric_mappedlun_link(),
go ahead and use target_fabric_port_item_ops directly instead.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08 23:26:38 -07:00
Nicholas Bellinger c17cd24959 target/configfs: Kill se_device->dev_link_magic
Instead of using a hardcoded magic value in se_device when verifying
a target config_item symlink source during target_fabric_port_link(),
go ahead and use target_core_dev_item_ops directly instead.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08 23:26:38 -07:00
Nicholas Bellinger 2237498f0b target/iblock: Convert WRITE_SAME to blkdev_issue_zeroout
The people who are actively using iblock_execute_write_same_direct() are
doing so in the context of ESX VAAI BlockZero, together with
EXTENDED_COPY and COMPARE_AND_WRITE primitives.

In practice though I've not seen any users of IBLOCK WRITE_SAME for
anything other than VAAI BlockZero, so just using blkdev_issue_zeroout()
when available, and falling back to iblock_execute_write_same() if the
WRITE_SAME buffer contains anything other than zeros should be OK.

(Hook up max_write_zeroes_sectors to signal LBPRZ feature bit in
 target_configure_unmap_from_queue - nab)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08 23:26:37 -07:00
Michael Cyr 464fd6419c ibmvscsis: Enable Logical Partition Migration Support
Changes to support a new mechanism from phyp to better synchronize the
logical partition migration (LPM) of the client partition.
This includes a new VIOCTL to register that we support this new
functionality, and 2 new Transport Event types, and finally another
new VIOCTL to let phyp know once we're ready for the Suspend.

Signed-off-by: Michael Cyr <mikecyr@us.ibm.com>
Signed-off-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08 23:26:37 -07:00
Byungchul Park 12bdcbd539 vhost/scsi: Don't reinvent the wheel but use existing llist API
Although llist provides proper APIs, they are not used. Make them used.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08 23:26:37 -07:00
Gustavo A. R. Silva fb418240ec target: remove dead code
Local variable _ret_ is assigned to a constant value and it is never
updated again. Remove this variable and the dead code it guards.

Addresses-Coverity-ID: 140761
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08 23:26:37 -07:00
Nicholas Bellinger abb85a9b51 iscsi-target: Reject immediate data underflow larger than SCSI transfer length
When iscsi WRITE underflow occurs there are two different scenarios
that can happen.

Normally in practice, when an EDTL vs. SCSI CDB TRANSFER LENGTH
underflow is detected, the iscsi immediate data payload is the
smaller SCSI CDB TRANSFER LENGTH.

That is, when a host fabric LLD is using a fixed size EDTL for
a specific control CDB, the SCSI CDB TRANSFER LENGTH and actual
SCSI payload ends up being smaller than EDTL.  In iscsi, this
means the received iscsi immediate data payload matches the
smaller SCSI CDB TRANSFER LENGTH, because there is no more
SCSI payload to accept beyond SCSI CDB TRANSFER LENGTH.

However, it's possible for a malicous host to send a WRITE
underflow where EDTL is larger than SCSI CDB TRANSFER LENGTH,
but incoming iscsi immediate data actually matches EDTL.

In the wild, we've never had a iscsi host environment actually
try to do this.

For this special case, it's wrong to truncate part of the
control CDB payload and continue to process the command during
underflow when immediate data payload received was larger than
SCSI CDB TRANSFER LENGTH, so go ahead and reject and drop the
bogus payload as a defensive action.

Note this potential bug was originally relaxed by the following
for allowing WRITE underflow in MSFT FCP host environments:

   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

Cc: Roland Dreier <roland@purestorage.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: <stable@vger.kernel.org> # v4.3+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-06-08 22:25:29 -07:00
Nicholas Bellinger 105fa2f44e iscsi-target: Fix delayed logout processing greater than SECONDS_FOR_LOGOUT_COMP
This patch fixes a BUG() in iscsit_close_session() that could be
triggered when iscsit_logout_post_handler() execution from within
tx thread context was not run for more than SECONDS_FOR_LOGOUT_COMP
(15 seconds), and the TCP connection didn't already close before
then forcing tx thread context to automatically exit.

This would manifest itself during explicit logout as:

[33206.974254] 1 connection(s) still exist for iSCSI session to iqn.1993-08.org.debian:01:3f5523242179
[33206.980184] INFO: NMI handler (kgdb_nmi_handler) took too long to run: 2100.772 msecs
[33209.078643] ------------[ cut here ]------------
[33209.078646] kernel BUG at drivers/target/iscsi/iscsi_target.c:4346!

Normally when explicit logout attempt fails, the tx thread context
exits and iscsit_close_connection() from rx thread context does the
extra cleanup once it detects conn->conn_logout_remove has not been
cleared by the logout type specific post handlers.

To address this special case, if the logout post handler in tx thread
context detects conn->tx_thread_active has already been cleared, simply
return and exit in order for existing iscsit_close_connection()
logic from rx thread context do failed logout cleanup.

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: 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 22:25:14 -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
Jiang Yi 5e0cf5e6c4 iscsi-target: Always wait for kthread_should_stop() before kthread exit
There are three timing problems in the kthread usages of iscsi_target_mod:

 - np_thread of struct iscsi_np
 - rx_thread and tx_thread of struct iscsi_conn

In iscsit_close_connection(), it calls

 send_sig(SIGINT, conn->tx_thread, 1);
 kthread_stop(conn->tx_thread);

In conn->tx_thread, which is iscsi_target_tx_thread(), when it receive
SIGINT the kthread will exit without checking the return value of
kthread_should_stop().

So if iscsi_target_tx_thread() exit right between send_sig(SIGINT...)
and kthread_stop(...), the kthread_stop() will try to stop an already
stopped kthread.

This is invalid according to the documentation of kthread_stop().

(Fix -ECONNRESET logout handling in iscsi_target_tx_thread and
 early iscsi_target_rx_thread failure case - nab)

Signed-off-by: Jiang Yi <jiangyilism@gmail.com>
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2017-05-31 15:12:57 -07:00