linux-stable.git/drivers/scsi/scsi_debug.c, branch linux-6.8.y

block: remove support for the host aware zone model

2023-12-20T03:17:43+00:00

When zones were first added the SCSI and ATA specs, two different
models were supported (in addition to the drive managed one that
is invisible to the host):

 - host managed where non-conventional zones there is strict requirement
   to write at the write pointer, or else an error is returned
 - host aware where a write point is maintained if writes always happen
   at it, otherwise it is left in an under-defined state and the
   sequential write preferred zones behave like conventional zones
   (probably very badly performing ones, though)

Not surprisingly this lukewarm model didn't prove to be very useful and
was finally removed from the ZBC and SBC specs (NVMe never implemented
it).  Due to to the easily disappearing write pointer host software
could never rely on the write pointer to actually be useful for say
recovery.

Fortunately only a few HDD prototypes shipped using this model which
never made it to mass production.  Drop the support before it is too
late.  Note that any such host aware prototype HDD can still be used
with Linux as we'll now treat it as a conventional HDD.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Link: https://lore.kernel.org/r/20231217165359.604246-4-hch@lst.de
Signed-off-by: Jens Axboe

scsi: scsi_debug: Delete some bogus error checking

2023-11-09T02:42:26+00:00

Smatch complains that "dentry" is never initialized.  These days everyone
initializes all their stack variables to zero so this means that it will
trigger a warning every time this function is run.

Really, debugfs functions are not supposed to be checked for errors in
normal code.  For example, if we updated this code to check the correct
variable then it would print a warning if CONFIG_DEBUGFS was disabled.  We
don't want that.  Just delete the check.

Fixes: f084fe52c640 ("scsi: scsi_debug: Add debugfs interface to fail target reset")
Signed-off-by: Dan Carpenter 
Link: https://lore.kernel.org/r/c602c9ad-5e35-4e18-a47f-87ed956a9ec2@moroto.mountain
Reviewed-by: Wenchao Hao 
Signed-off-by: Martin K. Petersen

scsi: scsi_debug: Fix some bugs in sdebug_error_write()

2023-11-09T02:42:26+00:00

There are two bug in this code:

 1) If count is zero, then it will lead to a NULL dereference.  The
    kmalloc() will successfully allocate zero bytes and the test for "if
    (buf[0] == '-')" will read beyond the end of the zero size buffer and
    Oops.

 2) The code does not ensure that the user's string is properly NUL
    terminated which could lead to a read overflow.

Fixes: a9996d722b11 ("scsi: scsi_debug: Add interface to manage error injection for a single device")
Signed-off-by: Dan Carpenter 
Link: https://lore.kernel.org/r/7733643d-e102-4581-8d29-769472011c97@moroto.mountain
Reviewed-by: Wenchao Hao 
Signed-off-by: Martin K. Petersen

scsi: scsi_debug: Add param to control sdev's allow_restart

2023-10-17T00:50:12+00:00

Add new module param "allow_restart" to control scsi_device's allow_restart
flag. This flag determines if EH is triggered after a command completes
with sense_key 0x6, ASC 0x4 and ASCQ 0x2. EH would be triggered if
allow_restart=1 in this condition.

The new param can be used with the error injection capability to test how
commands completing with sense_key 0x6, ASC 0x4 and ASCQ 0x2 are handled.

Signed-off-by: Wenchao Hao 
Link: https://lore.kernel.org/r/20231010092051.608007-11-haowenchao2@huawei.com
Tested-by: Douglas Gilbert 
Signed-off-by: Martin K. Petersen

scsi: scsi_debug: Add debugfs interface to fail target reset

2023-10-17T00:50:11+00:00

The interface is found at
/sys/kernel/debug/scsi_debug/target/fail_reset where 
identifies the target to inject errors on. It's a simple bool type
interface which would make this target's reset fail if set to 'Y'.

Signed-off-by: Wenchao Hao 
Link: https://lore.kernel.org/r/20231010092051.608007-10-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen

scsi: scsi_debug: Add new error injection type: Reset LUN failed

2023-10-17T00:50:11+00:00

Add error injection type 4 to make scsi_debug_device_reset() return FAILED.
Fail abort command format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x4                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this rule will be ignored                         |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+

Examples:

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "4 -10 0x12" > ${error}

will make the device return FAILED when trying to reset LUN with inquiry
command 10 times.

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "4 -10 0xff" > ${error}

will make the device return FAILED when trying to reset LUN 10 times.

Usually we do not care about what command it is when trying to perform
reset LUN, so 0xff could be applied.

Signed-off-by: Wenchao Hao 
Link: https://lore.kernel.org/r/20231010092051.608007-9-haowenchao2@huawei.com
Tested-by: Douglas Gilbert 
Signed-off-by: Martin K. Petersen

scsi: scsi_debug: Add new error injection type: Abort Failed

2023-10-17T00:50:11+00:00

Add error injection type 3 to make scsi_debug_abort() return FAILED.  Fail
abort command format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x3                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this rule will be ignored                         |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+

Examples:

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "3 -10 0x12" > ${error}

will make the device return FAILED when aborting inquiry command 10 times.

Signed-off-by: Wenchao Hao 
Link: https://lore.kernel.org/r/20231010092051.608007-8-haowenchao2@huawei.com
Tested-by: Douglas Gilbert 
Signed-off-by: Martin K. Petersen

scsi: scsi_debug: Set command result and sense data if error is injected

2023-10-17T00:50:11+00:00

If a fail command error is injected, set the command's status and sense
data then finish this SCSI command.

Set SCSI command's status and sense data format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x2                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error Count                                           |
  |        |      |  0: the rule will be ignored                          |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+
  |   4    |  x8  | Host byte in scsi_cmd::status                         |
  |        |      | [scsi_cmd::status has 32 bits holding these 3 bytes]  |
  +--------+------+-------------------------------------------------------+
  |   5    |  x8  | Driver byte in scsi_cmd::status                       |
  +--------+------+-------------------------------------------------------+
  |   6    |  x8  | SCSI Status byte in scsi_cmd::status                  |
  +--------+------+-------------------------------------------------------+
  |   7    |  x8  | SCSI Sense Key in scsi_cmnd                           |
  +--------+------+-------------------------------------------------------+
  |   8    |  x8  | SCSI ASC in scsi_cmnd                                 |
  +--------+------+-------------------------------------------------------+
  |   9    |  x8  | SCSI ASCQ in scsi_cmnd                                |
  +--------+------+-------------------------------------------------------+

Examples:
    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "2 -10 0x88 0 0 0x2 0x3 0x11 0x0" >${error}

will make device's read command return with media error with additional
sense of "Unrecovered read error" (UNC):

Acked-by: Douglas Gilbert 
Signed-off-by: Wenchao Hao 
Link: https://lore.kernel.org/r/20231010092051.608007-7-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen

scsi: scsi_debug: Return failed value if error is injected

2023-10-17T00:50:11+00:00

If a fail queuecommand error is injected, return the failed value defined
in the rule from queuecommand.

Make queuecommand return format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x1                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this rule will be ignored                         |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+
  |   4    |  x32 | The queuecommand() return value we want               |
  +--------+------+-------------------------------------------------------+

Examples:

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "1 1 0x12 0x1055" > ${error}

will make each INQUIRY command sent to that device return 0x1055
(SCSI_MLQUEUE_HOST_BUSY).

Acked-by: Douglas Gilbert 
Signed-off-by: Wenchao Hao 
Link: https://lore.kernel.org/r/20231010092051.608007-6-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen

scsi: scsi_debug: Time out command if the error is injected

2023-10-17T00:50:11+00:00

If a timeout error is injected, return 0 from scsi_debug_queuecommand to
make the command time out.

Time out SCSI command format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x0                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this rule will be ignored                         |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+

Examples:

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "0 -10 0x12" > ${error}

will make the device's inquiry command time out 10 times.

    echo "0 1 0x12" > ${error}

will make the device's inquiry time out each time it is invoked on this
device.

Acked-by: Douglas Gilbert 
Signed-off-by: Wenchao Hao 
Link: https://lore.kernel.org/r/20231010092051.608007-5-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen