linux-stable.git/include/target/target_core_base.h, branch v6.3

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: core: Dynamically set DPO and FUA in usage_bits

2022-10-27T01:47:24+00:00

libiscsi tests check the support of DPO & FUA bits in usage bits of RSOC
response.  This patch adds support for dynamic usage bits for each opcode.
Set support of DPO & FUA bits in usage_bits of RSOC response depending on
support DPOFUA in the backstore device.

Reviewed-by: Roman Bolshakov 
Reviewed-by: Konstantin Shelekhin 
Signed-off-by: Dmitry Bogdanov 
Link: https://lore.kernel.org/r/20220906103421.22348-7-d.bogdanov@yadro.com
Reviewed-by: Mike Christie 
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

scsi: target: core: Dynamic opcode support in RSOC

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

Report supported opcodes depending on a dynamic device configuration.

Reviewed-by: Roman Bolshakov 
Signed-off-by: Dmitry Bogdanov 
Link: https://lore.kernel.org/r/20220906103421.22348-4-d.bogdanov@yadro.com
Reviewed-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: target: core: Add support for RSOC command

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

Add support for REPORT SUPPORTED OPERATION CODES command according to SPC4.

Reviewed-by: Roman Bolshakov 
Signed-off-by: Dmitry Bogdanov 
Link: https://lore.kernel.org/r/20220906103421.22348-2-d.bogdanov@yadro.com
Reviewed-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: target: core: De-RCU of se_lun and se_lun acl

2022-08-01T23:36:02+00:00

se_lun and se_lun_acl are immutable pointers of struct se_dev_entry.
Remove RCU usage for access to those pointers.

Link: https://lore.kernel.org/r/20220727214125.19647-3-d.bogdanov@yadro.com
Reviewed-by: Mike Christie 
Signed-off-by: Dmitry Bogdanov 
Signed-off-by: Martin K. Petersen

scsi: target: Replace lun_tg_pt_gp_lock with rcu in I/O path

2021-10-19T02:38:36+00:00

We are only holding the lun_tg_pt_gp_lock in target_alua_state_check() to
make sure tg_pt_gp is not freed from under us while we copy the state,
delay, ID values. We can instead use RCU here to access the tg_pt_gp.

With this patch IOPs can increase up to 10% for jobs like:

  fio  --filename=/dev/sdX  --direct=1 --rw=randrw --bs=4k \
    --ioengine=libaio --iodepth=64  --numjobs=N

when there are multiple sessions (running that fio command to each /dev/sdX
or using multipath and there are over 8 paths), or more than 8 queues for
the loop or vhost with multiple threads case and numjobs > 8.

Link: https://lore.kernel.org/r/20210930020422.92578-5-michael.christie@oracle.com
Signed-off-by: Mike Christie 
Signed-off-by: Martin K. Petersen

scsi: target: Fix ordered tag handling

2021-10-19T02:38:35+00:00

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 
Signed-off-by: Martin K. Petersen

scsi: target: core: Add common tpg/enable attribute

2021-10-05T03:27:38+00:00

Many fabric modules provide their own implementation of enable attribute in
tpg.

Provide a way to remove code duplication in the fabric modules and
automatically add "enable" attribute if a fabric module has an
implementation of fabric_enable_tpg().

Link: https://lore.kernel.org/r/20210910084133.17956-2-d.bogdanov@yadro.com
Reviewed-by: Roman Bolshakov 
Reviewed-by: Mike Christie 
Signed-off-by: Dmitry Bogdanov 
Signed-off-by: Martin K. Petersen

scsi: target: Allows backend drivers to fail with specific sense codes

2021-08-18T02:28:40+00:00

Currently, backend drivers can fail I/O with SAM_STAT_CHECK_CONDITION which
gets us TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE.

Add a new helper that allows backend drivers to fail with specific sense
codes.

This is based on a patch from Mike Christie .

Cc: Mike Christie 
Link: https://lore.kernel.org/r/20210803145410.80147-2-s.samoylenko@yadro.com
Reviewed-by: David Disseldorp 
Signed-off-by: Sergey Samoylenko 
Signed-off-by: Martin K. Petersen