scsi: target: Move cmd counter allocation

iSCSI needs to allocate its cmd counter per connection for MCS support
where we need to stop and wait on commands running on a connection instead
of per ses

scsi: target: Move cmd counter allocation

iSCSI needs to allocate its cmd counter per connection for MCS support
where we need to stop and wait on commands running on a connection instead
of per session. This moves the cmd counter allocation to
target_setup_session() which is used by drivers that need the stop+wait
behavior per session.

xcopy doesn't need stop+wait at all, so we will be OK moving the cmd
counter allocation outside of transport_init_session().

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230319015620.96006-3-michael.christie@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: target: core: Drop device-based RTPI

The code is not needed since target port-based RTPI allocation replaced it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Roman Bolshakov <r.

scsi: target: core: Drop device-based RTPI

The code is not needed since target port-based RTPI allocation replaced it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Link: https://lore.kernel.org/r/20230301084512.21956-4-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: target: core: Add RTPI field to target port

SAM-5 4.6.5.2 (Relative Port Identifier attribute) defines the attribute as
unique across SCSI target ports.

The change introduces RTPI attribute t

scsi: target: core: Add RTPI field to target port

SAM-5 4.6.5.2 (Relative Port Identifier attribute) defines the attribute as
unique across SCSI target ports.

The change introduces RTPI attribute to se_portal group. The value is
unique across all enabled SCSI target ports. It also limits number of SCSI
target ports to 65535.

Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Link: https://lore.kernel.org/r/20230301084512.21956-2-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: target: core: UA on all LUNs after reset

Allocate UNIT ATTENTION "BUS DEVICE RESET OCCURRED" on all LUNs on all
target ports of the device upon reception of TMF LUN RESET.

This change passes

scsi: target: core: UA on all LUNs after reset

Allocate UNIT ATTENTION "BUS DEVICE RESET OCCURRED" on all LUNs on all
target ports of the device upon reception of TMF LUN RESET.

This change passes libiscsi test SCSI.MultipathIO.Reset.

Link: https://lore.kernel.org/r/20220913163602.20597-1-d.bogdanov@yadro.com
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: target: Remove unused se_tmr_req_cache declaration

se_tmr_req_cache has been removed since commit c8e31f26feeb ("target: Add
SCF_SCSI_TMR_CDB usage and drop se_tmr_req_cache").

Remove extern.

scsi: target: Remove unused se_tmr_req_cache declaration

se_tmr_req_cache has been removed since commit c8e31f26feeb ("target: Add
SCF_SCSI_TMR_CDB usage and drop se_tmr_req_cache").

Remove extern.

Link: https://lore.kernel.org/r/20220913023722.547249-3-cuigaosheng1@huawei.com
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: target: Fix ordered tag handling

This patch fixes the following bugs:

1. If there are multiple ordered cmds queued and multiple simple cmds
completing, target_restart_delayed_cmds() could

scsi: target: Fix ordered tag handling

This patch fixes the following bugs:

1. If there are multiple ordered cmds queued and multiple simple cmds
completing, target_restart_delayed_cmds() could be called on different
CPUs and each instance could start a ordered cmd. They could then run in
different orders than they were queued.

2. target_restart_delayed_cmds() and target_handle_task_attr() can race
where:

1. target_handle_task_attr() has passed the simple_cmds == 0 check.

2. transport_complete_task_attr() then decrements simple_cmds to 0.

3. transport_complete_task_attr() runs target_restart_delayed_cmds() and
it does not see any cmds on the delayed_cmd_list.

4. target_handle_task_attr() adds the cmd to the delayed_cmd_list.

The cmd will then end up timing out.

3. If we are sent > 1 ordered cmds and simple_cmds == 0, we can execute
them out of order, because target_handle_task_attr() will hit that
simple_cmds check first and return false for all ordered cmds sent.

4. We run target_restart_delayed_cmds() after every cmd completion, so if
there is more than 1 simple cmd running, we start executing ordered cmds
after that first cmd instead of waiting for all of them to complete.

5. Ordered cmds are not supposed to start until HEAD OF QUEUE and all older
cmds have completed, and not just simple.

6. It's not a bug but it doesn't make sense to take the delayed_cmd_lock
for every cmd completion when ordered cmds are almost never used. Just
replacing that lock with an atomic increases IOPs by up to 10% when
completions are spread over multiple CPUs and there are multiple
sessions/ mqs/thread accessing the same device.

This patch moves the queued delayed handling to a per device work to
serialze the cmd executions for each device and adds a new counter to track
HEAD_OF_QUEUE and SIMPLE cmds. We can then check the new counter to
determine when to run the work on the completion path.

Link: https://lore.kernel.org/r/20210930020422.92578-3-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: target: Fix ordered tag handling

[ Upstream commit ed1227e080990ffec5bf39006ec8a57358e6689a ]

This patch fixes the following bugs:

1. If there are multiple ordered cmds queued and multiple s

scsi: target: Fix ordered tag handling

[ Upstream commit ed1227e080990ffec5bf39006ec8a57358e6689a ]

This patch fixes the following bugs:

1. If there are multiple ordered cmds queued and multiple simple cmds
completing, target_restart_delayed_cmds() could be called on different
CPUs and each instance could start a ordered cmd. They could then run in
different orders than they were queued.

2. target_restart_delayed_cmds() and target_handle_task_attr() can race
where:

1. target_handle_task_attr() has passed the simple_cmds == 0 check.

2. transport_complete_task_attr() then decrements simple_cmds to 0.

3. transport_complete_task_attr() runs target_restart_delayed_cmds() and
it does not see any cmds on the delayed_cmd_list.

4. target_handle_task_attr() adds the cmd to the delayed_cmd_list.

The cmd will then end up timing out.

3. If we are sent > 1 ordered cmds and simple_cmds == 0, we can execute
them out of order, because target_handle_task_attr() will hit that
simple_cmds check first and return false for all ordered cmds sent.

4. We run target_restart_delayed_cmds() after every cmd completion, so if
there is more than 1 simple cmd running, we start executing ordered cmds
after that first cmd instead of waiting for all of them to complete.

5. Ordered cmds are not supposed to start until HEAD OF QUEUE and all older
cmds have completed, and not just simple.

6. It's not a bug but it doesn't make sense to take the delayed_cmd_lock
for every cmd completion when ordered cmds are almost never used. Just
replacing that lock with an atomic increases IOPs by up to 10% when
completions are spread over multiple CPUs and there are multiple
sessions/ mqs/thread accessing the same device.

This patch moves the queued delayed handling to a per device work to
serialze the cmd executions for each device and adds a new counter to track
HEAD_OF_QUEUE and SIMPLE cmds. We can then check the new counter to
determine when to run the work on the completion path.

Link: https://lore.kernel.org/r/20210930020422.92578-3-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

scsi: target: core: Make completion affinity configurable

It may not always be best to complete the IO on same CPU as it was
submitted on. This commit allows userspace to configure it.

This has bee

scsi: target: core: Make completion affinity configurable

It may not always be best to complete the IO on same CPU as it was
submitted on. This commit allows userspace to configure it.

This has been useful for vhost-scsi where we have a single thread for
submissions and completions. If we force the completion on the submission
CPU we may be adding conflicts with what the user has setup in the lower
levels with settings like the block layer rq_affinity or the driver's IRQ
or softirq (the network's rps_cpus value) settings.

We may also want to set it up where the vhost thread runs on CPU N and does
its submissions/completions there, and then have LIO do its completion
booking on CPU M, but can't configure the lower levels due to issues like
using dm-multipath with lots of paths (the path selector can throw commands
all over the system because it's only taking into account latency/throughput
at its level).

The new setting is in:

/sys/kernel/config/target/$fabric/$target/param/cmd_completion_affinity

Writing:

-1 -> Gives the current default behavior of completing on the
submission CPU.

-2 -> Completes the cmd on the CPU the lower layers sent it to us from.

> 0 -> Completes on the CPU userspace has specified.

Link: https://lore.kernel.org/r/20210227170006.5077-26-michael.christie@oracle.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: target: core: Add workqueue based cmd submission

loop and vhost/scsi do their target cmd submission from driver
workqueues. This allows them to avoid an issue where the backend may block
waiti

scsi: target: core: Add workqueue based cmd submission

loop and vhost/scsi do their target cmd submission from driver
workqueues. This allows them to avoid an issue where the backend may block
waiting for resources like tags/requests, mem/locks, etc and that ends up
blocking their entire submission path and for the case of vhost-scsi both
the submission and completion path.

This patch adds a helper drivers can use to submit from a LIO workqueue.
This code will then be extended in the next patches to fix the plugging of
backend devices.

We are only converting vhost/loop initially, but the workqueue based
submission will work for other drivers and have similar benefits where the
main target loops will not end up blocking one some backend resource.

Link: https://lore.kernel.org/r/20210227170006.5077-17-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Bodo Stroesser <bostroesser@gmail.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: target: Fix xcopy sess release leak

transport_init_session can allocate memory via percpu_ref_init, and
target_xcopy_release_pt never frees it. This adds a
transport_uninit_session function to

scsi: target: Fix xcopy sess release leak

transport_init_session can allocate memory via percpu_ref_init, and
target_xcopy_release_pt never frees it. This adds a
transport_uninit_session function to handle cleanup of resources allocated
in the init function.

Link: https://lore.kernel.org/r/1593654203-12442-3-git-send-email-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

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, on

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>

show more ...

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

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>

show more ...

scsi: target: prefer dbroot of /etc/target over /var/target

The target database root directory, dbroot, has defaulted to /var/target
for a while, but its main client, targetcli-fb, has been moving i

scsi: target: prefer dbroot of /etc/target over /var/target

The target database root directory, dbroot, has defaulted to /var/target
for a while, but its main client, targetcli-fb, has been moving it to
/etc/target for quite some time. With the plethora of target drivers now
appearing, it has become more difficult to initialize this attribute
before use by any child drivers.

If the directory /etc/target exists, use that as the DB root. Otherwise,
fall back to using /var/target.

The ability to override this dbroot attribute still exists via sysfs.

Signed-off-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

target core: add device action configfs files

This patch adds a new group of files that are to be used to
have the kernel module execution some action. The next patch
will have target_core_user use

target core: add device action configfs files

This patch adds a new group of files that are to be used to
have the kernel module execution some action. The next patch
will have target_core_user use the group/files to be able to block
a device and to reset its memory buffer used to pass commands
between user/kernel space.

This type of file is different from the existing device attributes
in that they may be write only and when written to they result in
the kernel module executing some function. These need to be
separate from the normal device attributes which get/set device
values so userspace can continue to loop over all the attribs and
get/set them during initialization.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

show more ...

target-core: don't use "const char*" for a buffer that is written to

iscsi_parse_pr_out_transport_id launders the const away via a call to
strstr(), and then modifies the buffer (writing a nul byte)

target-core: don't use "const char*" for a buffer that is written to

iscsi_parse_pr_out_transport_id launders the const away via a call to
strstr(), and then modifies the buffer (writing a nul byte) through
the return value. It's cleaner to be honest and simply declare the
parameter as "char*", fixing up the call chain, and allowing us to
drop the cast in the return statement.

Amusingly, the two current callers found it necessary to cast a
non-const pointer to a const.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

show more ...

target: Move a declaration of a global variable into a header file

This patch avoids that sparse reports the following warning:

drivers/target/target_core_configfs.c:2267:33: warning: symbol 'targe

target: Move a declaration of a global variable into a header file

This patch avoids that sparse reports the following warning:

drivers/target/target_core_configfs.c:2267:33: warning: symbol 'target_core_dev_item_ops' was not declared. Should it be static?

Fixes: c17cd24959cd ("target/configfs: Kill se_device->dev_link_magic")
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>

show more ...

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

target: remove g_device_list

g_device_list is no longer needed because we now use the idr code
for lookups and seaches.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assc

target: remove g_device_list

g_device_list is no longer needed because we now use the idr code
for lookups and seaches.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

show more ...

target: add helper to iterate over devices

This adds a wrapper around idr_for_each so the xcopy code can loop over
the devices in the next patch.

Signed-off-by: Mike Christie <mchristi@redhat.com>

target: add helper to iterate over devices

This adds a wrapper around idr_for_each so the xcopy code can loop over
the devices in the next patch.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

show more ...

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: 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>

show more ...

target: Minimize #include directives

Remove superfluous #include directives from the include/target/*.h
files. Add missing #include directives to other *.h and *.c files.
Use forward declarations fo

target: Minimize #include directives

Remove superfluous #include directives from the include/target/*.h
files. Add missing #include directives to other *.h and *.c files.
Use forward declarations for structures where possible. This
change reduces the build time for make M=drivers/target on my
laptop from 27.1s to 18.7s or by about 30%.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>

show more ...

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 attribut

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>

show more ...

target: make target db location configurable

This commit adds the read-write attribute "dbroot",
in the top-level CONFIGFS (core) target directory,
normally /sys/kernel/config/target. This attribute

target: make target db location configurable

This commit adds the read-write attribute "dbroot",
in the top-level CONFIGFS (core) target directory,
normally /sys/kernel/config/target. This attribute
defaults to "/var/target" but can be changed by
writing a new pathname string to it. Changing this
attribute is only allowed when no fabric drivers
are loaded and the supplied value specifies an
existing directory.

Target modules that care about the target database
root directory will be modified to use this
attribute in a future commit.

Signed-off-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

show more ...

target: Remove enum transport_lunflags_table

se_dev_entry.lun_flags and se_lun.lun_access are only used for keeping
track of read-write vs. read-only state. Since this is an either/or thing
we can r

target: Remove enum transport_lunflags_table

se_dev_entry.lun_flags and se_lun.lun_access are only used for keeping
track of read-write vs. read-only state. Since this is an either/or thing
we can represent it as bool, and remove the unneeded enum
transport_lunflags_table, which is left over from when there were more
flags.

Change code that uses this enum to just use true/false, and make it clear
through variable and param names that true means read-only, false means
read-write.

Signed-off-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

show more ...

configfs: switch ->default groups to a linked list

Replace the current NULL-terminated array of default groups with a linked
list. This gets rid of lots of nasty code to size and/or dynamically
all

configfs: switch ->default groups to a linked list

Replace the current NULL-terminated array of default groups with a linked
list. This gets rid of lots of nasty code to size and/or dynamically
allocate the array.

While we're at it also provide a conveniant helper to remove the default
groups.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Felipe Balbi <balbi@kernel.org> [drivers/usb/gadget]
Acked-by: Joel Becker <jlbec@evilplan.org>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>

show more ...