linux-toradex.git/drivers/target/target_core_configfs.c, branch v6.11

scsi: target: Fix SELinux error when systemd-modules loads the target module

2024-04-06T01:37:54+00:00

If the systemd-modules service loads the target module, the credentials of
that userspace process will be used to validate the access to the target db
directory.  SELinux will prevent it, reporting an error like the following:

kernel: audit: type=1400 audit(1676301082.205:4): avc: denied  { read }
for  pid=1020 comm="systemd-modules" name="target" dev="dm-3"
ino=4657583 scontext=system_u:system_r:systemd_modules_load_t:s0
tcontext=system_u:object_r:targetd_etc_rw_t:s0 tclass=dir permissive=0

Fix the error by using the kernel credentials to access the db directory

Signed-off-by: Maurizio Lombardi 
Link: https://lore.kernel.org/r/20240215143944.847184-2-mlombard@redhat.com
Reviewed-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: target: Fix unmap setup during configuration

2024-02-13T01:42:00+00:00

This issue was found and also debugged by Carl Lei .

If the device is not enabled, iblock/file will have not setup their
se_device to bdev/file mappings. If a user tries to config the unmap
settings at this time, we will then crash trying to access a NULL pointer
where the bdev/file should be.

This patch adds a check to make sure the device is configured before
we try to call the configure_unmap callout.

Fixes: 34bd1dcacf0d ("scsi: target: Detect UNMAP support post configuration")
Reported-by: Carl Lei 
Signed-off-by: Mike Christie 
Link: https://lore.kernel.org/r/20240209215247.5213-1-michael.christie@oracle.com
Reviewed-by: Maurizio Lombardi 
Signed-off-by: Martin K. Petersen

Merge patch series "scsi: target: Allow userspace to config cmd submission"

2023-10-13T19:56:37+00:00

Mike Christie  says:

The following patches were made over Linus's tree but apply over
Martin's branches. They allow userspace to configure how fabric
drivers submit cmds to backend drivers.

Right now loop and vhost use a worker thread, and the other drivers
submit from the contexts they receive/process the cmd from. For
multiple LUN cases where the target can queue more cmds than the
backend can handle then deferring to a worker thread is safest because
the backend driver can block when doing things like waiting for a free
request/tag. Deferring also helps when the target has to handle
transport level requests from the recv context.

For cases where the backend devices can queue everything the target
sends, then there is no need to defer to a workqueue and you can see a
perf boost of up to 26% for small IO workloads. For a nvme device and
vhost-scsi I can see with 4K IOs:

fio jobs        1       2       4       8       10
--------------------------------------------------
workqueue
submit        94K     190K    394K    770K    890K

direct
submit       128K     252K    488K    950K    -

Link: https://lore.kernel.org/r/1b1f7a5c-0988-45f9-b103-dfed2c0405b1@oracle.com
Signed-off-by: Martin K. Petersen

scsi: target: Allow userspace to request direct submissions

2023-10-13T19:53:58+00:00

This allows userspace to request the fabric drivers do direct submissions
if they support it. With the new device file, submit_type, users can
write 0 - 2 to control how commands are submitted to the backend:

 0 - TARGET_FABRIC_DEFAULT_SUBMIT - LIO will use the fabric's default
     submission type. This is the default for compat.

 1 - TARGET_DIRECT_SUBMIT - LIO will submit the cmd to the backend from the
     calling context if the fabric the cmd was received on supports it,
     else it will use the fabric's default type.

 2 - TARGET_QUEUE_SUBMIT - LIO will queue the cmd to the LIO submission
     workqueue which will pass it to the backend.

When using an NVMe drive and vhost-scsi with direct submission we see
around a 20% improvement in 4K I/Os:

fio jobs        1       2       4       8       10
--------------------------------------------------
defer           94K     190K    394K    770K    890K
direct          128K    252K    488K    950K    -

And when using the queueing mode, we now no longer see issues like where
the iSCSI tx thread is blocked in the block layer waiting on a tag so it
can't respond to a nop or perform I/Os for other LUs.

Signed-off-by: Mike Christie 
Link: https://lore.kernel.org/r/20230928020907.5730-6-michael.christie@oracle.com
Signed-off-by: Martin K. Petersen

scsi: target: Replace strlcpy() with strscpy()

2023-09-05T09:55:20+00:00

strlcpy() reads the entire source buffer first.  This read may exceed the
destination size limit.  This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated [1].  In an effort
to remove strlcpy() completely [2], replace strlcpy() here with strscpy().

Direct replacement is safe here since return value of -errno is used to
check for truncation instead of sizeof(dest).

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh 
Link: https://lore.kernel.org/r/20230831143638.232596-1-azeemshaikh38@gmail.com
Reviewed-by: Kees Cook 
Signed-off-by: Martin K. Petersen

scsi: target: Replace all non-returning strlcpy() with strscpy()

2023-05-17T01:39:44+00:00

strlcpy() reads the entire source buffer first.  This read may exceed the
destination size limit.  This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated [1].  In an effort
to remove strlcpy() completely [2], replace strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh 
Link: https://lore.kernel.org/r/20230516025322.2804923-1-azeemshaikh38@gmail.com
Reviewed-by: Kees Cook 
Signed-off-by: Martin K. Petersen

scsi: target: Add default fabric ops callouts

2023-03-17T03:36:35+00:00

There are several callouts in target fabric ops that most of fabric drivers
fill with a function returning the same value.

Stop requiring such callouts to exist in the ops, fill them in TCM Core.

Signed-off-by: Dmitry Bogdanov 
Link: https://lore.kernel.org/r/20230313181110.20566-2-d.bogdanov@yadro.com
Signed-off-by: Martin K. Petersen

scsi: target: core: Send max transfer length in blocks

2022-11-24T02:16:19+00:00

A MAXIMUM TRANSFER LENGTH value indicates the maximum transfer length in
logical blocks that the device server accepts for a single command. Fix
function sending the length in sectors instead of blocks.

This patch also removes the special casing for fileio in block_size_store
since this logic in now unified in spc_emulate_evpd_b0() for all backends.

Reviewed-by: Konstantin Shelekhin 
Reviewed-by: Dmitriy Bogdanov 
Signed-off-by: Anastasia Kovaleva 
Link: https://lore.kernel.org/r/20221114102500.88892-2-a.kovaleva@yadro.com
Reviewed-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: target: Use kstrtobool() instead of strtobool()

2022-11-08T03:53:37+00:00

strtobool() is the same as kstrtobool().  However, the latter is more used
within the kernel.

In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.

While at it, include the corresponding header file ()

Signed-off-by: Christophe JAILLET 
Link: https://lore.kernel.org/r/fcddc0a53b4fc6e3c2e93592d3f61c5c63121855.1667336095.git.christophe.jaillet@wanadoo.fr
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Martin K. Petersen

scsi: target: core: Add emulate_rsoc attribute

2022-10-27T01:44:32+00:00

Allow support for RSOC to be turned off via the emulate_rsoc attibute.
This is just for testing purposes.

Reviewed-by: Roman Bolshakov 
Signed-off-by: Dmitry Bogdanov 
Link: https://lore.kernel.org/r/20220906103421.22348-5-d.bogdanov@yadro.com
Reviewed-by: Mike Christie 
Signed-off-by: Martin K. Petersen