linux-stable.git/include/target, branch v6.18.49

usb: gadget: f_tcm: keep port count until LUN teardown completes

2026-09-02T12:31:48+00:00

commit c39d0916da47d94909391876c9e5bd429ea7b1b9 upstream.

tcm_usbg_drop_nexus() permits session removal once tpg_port_count
reaches zero. However, usbg_port_unlink() currently decrements that
count from the fabric_pre_unlink() callback, before core_dev_del_lun()
waits for active se_lun references to drain.

If removal of the last LUN races a nexus removal, the latter can observe
a zero port count and call target_remove_session(). This frees
sess_cmd_map while an in-flight struct usbg_cmd, including its work item,
can still be accessed.

Overlapping the last-LUN unlink with nexus removal reproduces this
lifetime violation as a DEBUG_OBJECTS "free active" warning for
usbg_cmd_work, followed by a target-core BUG/Oops.

The generic target-core unlink path has no callback after
core_dev_del_lun() completes. Add an optional fabric_post_unlink()
callback and use it for the f_tcm port count. The count now remains
nonzero until core_dev_del_lun() has finished draining active LUN
references, preventing nexus removal from freeing the session during
command completion.

Fixes: c52661d60f63 ("usb-gadget: Initial merge of target module for UASP + BOT")
Cc: stable@vger.kernel.org
Signed-off-by: Shuangpeng Bai 
Link: https://patch.msgid.link/20260807060733.3186624-1-shuangpeng.kernel@gmail.com
Signed-off-by: Greg Kroah-Hartman

scsi: target: Fix LUN/device R/W and total command stats

2025-12-18T13:02:48+00:00

[ Upstream commit 95aa2041c654161d1b5c1eca5379d67d91ef1cf2 ]

In commit 9cf2317b795d ("scsi: target: Move I/O path stats to per CPU")
I saw we sometimes use %u and also misread the spec. As a result I
thought all the stats were supposed to be 32-bit only. However, for the
majority of cases we support currently, the spec specifies u64 bit
stats. This patch converts the stats changed in the commit above to u64.

Fixes: 9cf2317b795d ("scsi: target: Move I/O path stats to per CPU")
Signed-off-by: Mike Christie 
Reviewed-by: Dmitry Bogdanov 
Link: https://patch.msgid.link/20250917221338.14813-2-michael.christie@oracle.com
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: target: core: Constify enabled() in struct target_opcode_descriptor

2025-05-21T02:11:03+00:00

Constify the first argument of the enabled() function in struct
target_opcode_descriptor.

This is the first step in order to constify struct
target_opcode_descriptor.

Signed-off-by: Christophe JAILLET 
Link: https://lore.kernel.org/r/4290cf1dbe100c1b1edf2ede5e5aef19b04ee7f2.1747592774.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Martin K. Petersen

scsi: target: Move delayed/ordered tracking to per CPU

2025-04-29T01:47:55+00:00

The atomic use from the delayed/ordered tracking is causing perf issues
when using higher perf backend devices and multiple queues.  This moves
the values to a per CPU counter. Combined with the per CPU stats patch,
this improves IOPS by up to 33% for 8K IOS when using 4 or more queues
from the initiator.

Signed-off-by: Mike Christie 
Link: https://lore.kernel.org/r/20250424032741.16216-3-michael.christie@oracle.com
Reviewed-by: Hannes Reinecke 
Signed-off-by: Martin K. Petersen

scsi: target: Move I/O path stats to per CPU

2025-04-29T01:47:55+00:00

The atomic use in the main I/O path is causing perf issues when using
higher performance backend devices and multiple queues. This moves the
stats to per CPU. Combined with the next patch that moves the
non_ordered/delayed_cmd_count to per CPU, IOPS by up to 33% for 8K IOS
when using 4 or more queues.

Signed-off-by: Mike Christie 
Link: https://lore.kernel.org/r/20250424032741.16216-2-michael.christie@oracle.com
Reviewed-by: Hannes Reinecke 
Signed-off-by: Martin K. Petersen

scsi: target: iscsi: switch to using the crc32c library

2024-12-02T01:23:02+00:00

Now that the crc32c() library function directly takes advantage of
architecture-specific optimizations, it is unnecessary to go through the
crypto API.  Just use crc32c().  This is much simpler, and it improves
performance due to eliminating the crypto API overhead.

Reviewed-by: Ard Biesheuvel 
Reviewed-by: Martin K. Petersen 
Link: https://lore.kernel.org/r/20241202010844.144356-20-ebiggers@kernel.org
Signed-off-by: Eric Biggers

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23+00:00

asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

scsi: target: core: Unexport target_queue_submission()

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

target_queue_submission() is not called by drivers anymore so unexport it.

Signed-off-by: Mike Christie 
Link: https://lore.kernel.org/r/20230928020907.5730-7-michael.christie@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: core: Kill transport_handle_cdb_direct()

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

Move the code from transport_handle_cdb_direct() to target_submit() and
have iSCSI call target_submit().

Signed-off-by: Mike Christie 
Link: https://lore.kernel.org/r/20230928020907.5730-5-michael.christie@oracle.com
Signed-off-by: Martin K. Petersen