The vfs has long had a write lifetime hint mechanism that gives the
expected longevity on storage of the data being written. f2fs was the
original consumer of this and used the hint for flash data placement
(mostly to avoid write amplification by placing objects with similar
lifetimes in the same erase block). More recently the SCSI based UFS
(Universal Flash Storage) drivers have wanted to take advantage of
this as well, for the same reasons as f2fs, necessitating plumbing the
write hints through the block layer and then adding it to the SCSI
core. The vfs write_hints pull you've already taken plumbs this as
far as block and this pull request completes the SCSI core enabling
based on a recently agreed reuse of the old write command group
number. The additions to the scsi_debug driver are for emulating this
property so we can run tests on it in the absence of an actual UFS
device.
Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
-----BEGIN PGP SIGNATURE-----
iJwEABMIAEQWIQTnYEDbdso9F2cI+arnQslM7pishQUCZf3owyYcamFtZXMuYm90
dG9tbGV5QGhhbnNlbnBhcnRuZXJzaGlwLmNvbQAKCRDnQslM7pishdaeAQCdEb5j
d7sJiKTpSpgH0znAJ7UTvwUh6UJu/dj47D4qngEA43IULG8+L4GXDHL9mwCfeHC5
PU7UewCEqnRBSBTdiEw=
=9Xr2
-----END PGP SIGNATURE-----
Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull more SCSI updates from James Bottomley:
"The vfs has long had a write lifetime hint mechanism that gives the
expected longevity on storage of the data being written. f2fs was the
original consumer of this and used the hint for flash data placement
(mostly to avoid write amplification by placing objects with similar
lifetimes in the same erase block).
More recently the SCSI based UFS (Universal Flash Storage) drivers
have wanted to take advantage of this as well, for the same reasons as
f2fs, necessitating plumbing the write hints through the block layer
and then adding it to the SCSI core.
The vfs write_hints already taken plumbs this as far as block and this
completes the SCSI core enabling based on a recently agreed reuse of
the old write command group number. The additions to the scsi_debug
driver are for emulating this property so we can run tests on it in
the absence of an actual UFS device"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: scsi_debug: Maintain write statistics per group number
scsi: scsi_debug: Implement GET STREAM STATUS
scsi: scsi_debug: Implement the IO Advice Hints Grouping mode page
scsi: scsi_debug: Allocate the MODE SENSE response from the heap
scsi: scsi_debug: Rework subpage code error handling
scsi: scsi_debug: Rework page code error handling
scsi: scsi_debug: Support the block limits extension VPD page
scsi: scsi_debug: Reduce code duplication
scsi: sd: Translate data lifetime information
scsi: scsi_proto: Add structures and constants related to I/O groups and streams
scsi: core: Query the Block Limits Extension VPD page
Track per GROUP NUMBER how many write commands have been processed. Make
this information available in sysfs. Reset these statistics if any data
is written into the sysfs attribute.
Note: SCSI devices should only interpret the information in the GROUP
NUMBER field as a stream identifier if the ST_ENBLE bit has been set to
one. This patch follows a simpler approach: count the number of writes
per GROUP NUMBER whether or not the group number represents a stream
identifier.
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-20-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Implement the GET STREAM STATUS SCSI command. Report that the first
five stream indexes correspond to permanent streams.
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-19-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Implement an IO Advice Hints Grouping mode page with three permanent
streams. A permanent stream is a stream for which the device server does
not allow closing or otherwise modifying the configuration of that
stream. The stream identifier enable (ST_ENBLE) bit specifies whether
the stream identifier may be used in the GROUP NUMBER field of SCSI
WRITE commands.
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-18-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Make the MODE SENSE response buffer larger and allocate it from the heap.
This patch prepares for adding support for the IO Advice Hints Grouping
mode page.
Suggested-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-17-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Move the subpage code checks into the switch statement to make it easier
to add support for new page code / subpage code combinations.
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-16-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Instead of tracking whether or not the page code is valid in a boolean
variable, jump to error handling code if an unsupported page code is
encountered.
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-15-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
>From SBC-5 r05:
"Reduced stream control:
a) reduces the maximum number of streams that the device server supports;
and
b) increases the number of write commands that are able to specify a stream
to be written in any write command that contains the GROUP NUMBER field
in its CDB.
If the RSCS bit (see 6.6.5) is set to one, then the device server shall:
a) support per group stream identifier usage as described in 4.32.2;
b) support the IO Advice Hints Grouping mode page (see 6.5.7); and
c) set the MAXIMUM NUMBER OF STREAMS field (see 6.6.5) to a value that is
less than 64.
Device servers that set the RSCS bit to one may support other features
(e.g., permanent streams (see 4.32.4)).
4.32.4 Permanent streams
A permanent stream is a stream for which the device server does not allow
closing or otherwise modifying the configuration of that stream. The PERM
bit (see 5.9.2.3) indicates whether a stream is a permanent stream. If a
STREAM CONTROL command (see 5.32) specifies the closing of a permanent
stream, the device server terminates that command with CHECK CONDITION
status instead of closing the specified stream. A permanent stream is always
an open stream. Device severs should assign the lowest numbered stream
identifiers to permanent streams."
Report that reduced stream control is supported.
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-14-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
All VPD pages have the page code in byte one. Reduce code duplication by
storing the VPD page code once.
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-13-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Now that the driver core can properly handle constant struct bus_type, move
the pseudo_lld_bus variable to be a constant structure as well, placing it
into read-only memory which can not be modified at runtime.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240203-bus_cleanup-scsi-v1-3-6f552fb24f71@marliere.net
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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 <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20231217165359.604246-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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: f084fe52c6 ("scsi: scsi_debug: Add debugfs interface to fail target reset")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/c602c9ad-5e35-4e18-a47f-87ed956a9ec2@moroto.mountain
Reviewed-by: Wenchao Hao <haowenchao2@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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: a9996d722b ("scsi: scsi_debug: Add interface to manage error injection for a single device")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/7733643d-e102-4581-8d29-769472011c97@moroto.mountain
Reviewed-by: Wenchao Hao <haowenchao2@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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 <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-11-haowenchao2@huawei.com
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The interface is found at
/sys/kernel/debug/scsi_debug/target<h:c:t>/fail_reset where <h:c:t>
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 <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-10-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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 <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-9-haowenchao2@huawei.com
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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 <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-8-haowenchao2@huawei.com
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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 <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-7-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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 <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-6-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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 <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-5-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The grammar to remove error injection is a line with fixed 3 columns
separated by spaces.
First column is fixed to "-". It tells this is a removal operation. Second
column is the error code to match. Third column is the scsi command to
match.
For example the following command would remove timeout injection of inquiry
command:
echo "- 0 0x12" > /sys/kernel/debug/scsi_debug/0:0:0:1/error
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-4-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This new facility uses the debugfs pseudo file system which is typically
mounted under the /sys/kernel/debug directory and requires root permissions
to access.
The interface file is found at /sys/kernel/debug/scsi_debug/<h:c:t:l>/error
where <h:c:t:l> identifies the device (logical unit (LU)) to inject errors
on.
For the following description the ${error} environment variable is assumed
to be set to/sys/kernel/debug/scsi_debug/1:0:0:0/error where 1:0:0:0 is a
pseudo device (LU) owned by the scsi_debug driver. Rules are written to
${error} in the normal sysfs fashion (e.g. 'echo "0 -2 0x12" > ${error}').
More than one rule can be active on a device at a time and inactive rules
(i.e. those whose error count is 0) remain in the rule listing. The
existing rules can be read with 'cat ${error}' with oneline output for each
rule.
The interface format is line-by-line, each line is an error injection rule.
Each rule contains integers separated by spaces, the first three columns
correspond to "Error code", "Error count" and "SCSI command", other
columns depend on Error code.
General rule format:
+--------+------+-------------------------------------------------------+
| Column | Type | Description |
+--------+------+-------------------------------------------------------+
| 1 | u8 | Error code |
| | | 0: timeout SCSI command |
| | | 1: fail queuecommand, make queuecommand return |
| | | given value |
| | | 2: fail command, finish command with SCSI status, |
| | | sense key and ASC/ASCQ values |
| | | 3: make abort commands for specific command fail |
| | | 4: make reset lun for specific command fail |
+--------+------+-------------------------------------------------------+
| 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 |
+--------+------+-------------------------------------------------------+
| ... | xxx | Error type specific fields |
+--------+------+-------------------------------------------------------+
Notes:
- When multiple error inject rules are added for the same SCSI command,
the one with smaller error code will take effect (and the others will be
ignored).
- If the same error (i.e. same Error code and SCSI command) is added, the
older one will be overwritten..
- Currently, the basic types are (u8/u16/u32/u64/s8/s16/s32/s64) and the
hexadecimal types (x8/x16/x32/x64).
- Where a hexadecimal value is expected (e.g. Column 3: SCSI command
opcode) the "0x" prefix is optional on the value (e.g. the INQUIRY
opcode can be given as '0x12' or '12').
- When the Error count is negative, reading ${error} will show that value
incrementing, stopping when it gets to 0.
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-3-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Create directory scsi_debug in the root of the debugfs filesystem. Prepare
to add interface for manage error injection.
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-2-haowenchao2@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The ramdisk rwlocks are not used anymore.
Fixes: 87c715dcde ("scsi: scsi_debug: Add per_host_store option")
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Link: https://lore.kernel.org/r/20230628150638.53218-1-mlombard@redhat.com
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Currently scsi_debug_device_reset() does not do much apart from setting the
SDEBUG_UA_POR ("Power on, reset, or bus device reset") flag, which is
eventually passed back to the SCSI midlayer later for a "unit attention"
command.
There is a report that blktest scsi/007 test fails due to commit
1107c7b24e ("scsi: scsi_debug: Dynamically allocate sdebug_queued_cmd").
The problem there is that there are dangling scsi_debug queued commands
when we attempt to remove the driver.
scsi/007 test triggers SCSI EH and attempts to abort a timed-out command.
Function scsi_debug_device_reset() is called as part of the EH, but does
not deal with outstanding erroneous command. Prior to the named commit,
removing the driver caused all dangling queued commands to be stopped -
this should have not been necessary.
Fix by aborting outstanding commands on a scsi_device basis from
scsi_debug_device_reset().
Fixes: 1107c7b24e ("scsi: scsi_debug: Dynamically allocate sdebug_queued_cmd")
Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/oe-lkp/202304071111.e762fcbd-yujie.liu@intel.com
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230416175654.159163-1-john.g.garry@oracle.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Smatch reports: drivers/scsi/scsi_debug.c:6996
scsi_debug_init() warn: missing error code 'ret'
Although it is unlikely that KMEM_CACHE might fail, but if it does then ret
might be zero. So to fix this explicitly mark ret as "-ENOMEM" and then
goto driver_unreg.
Fixes: 1107c7b24e ("scsi: scsi_debug: Dynamically allocate sdebug_queued_cmd")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Link: https://lore.kernel.org/r/20230406074607.3637097-1-harshit.m.mogalapalli@oracle.com
Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
John Garry <john.g.garry@oracle.com> says:
It's easy to get scsi_debug to error on throughput testing when we have
multiple shosts:
$ lsscsi
[7:0:0:0] disk Linux scsi_debug 0191
[0:0:0:0] disk Linux scsi_debug 0191
$ fio --filename=/dev/sda --filename=/dev/sdb --direct=1 --rw=read
--bs=4k --iodepth=256 --runtime=60 --numjobs=40 --time_based --name=jpg
--eta-newline=1 --readonly --ioengine=io_uring --hipri --exitall_on_error
jpg: (g=0): rw=read, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=io_uring, iodepth=256
...
fio-3.28
Starting 40 processes
[ 27.521809] hrtimer: interrupt took 33067 ns
[ 27.904660] sd 7:0:0:0: [sdb] tag#171 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK cmd_age=0s
[ 27.904660] sd 0:0:0:0: [sda] tag#58 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK cmd_age=0s
fio: io_u error [ 27.904667] sd 0:0:0:0: [sda] tag#58 CDB: Read(10) 28 00 00 00 27 00 00 01 18 00
on file /dev/sda[ 27.904670] sd 0:0:0:0: [sda] tag#62 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK cmd_age=0s
The issue is related to how the driver manages submit queues and tags. A
single array of submit queues - sdebug_q_arr - with its own set of tags is
shared among all shosts. As such, for occasions when we have more than one
host it is possible to overload the submit queues and run out of tags.
Another separate issue that we may reduce the shost submit queue depth,
sdebug_max_queue, dynamically causing the shost to be overloaded. How many
IOs which the shost may be sent is fixed at can_queue at init time, which
is the same initial value for sdebug_max_queue. So reducing
sdebug_max_queue means that the shost may be sent more IOs than it is
configured to handle, causing overloading.
This series removes the scsi_debug submit queue concept and uses
pre-existing APIs to manage and examine tags, like scsi_block_requests()
and blk_mq_tagset_busy_iter(). Using standard APIs makes the driver more
maintainable and extensible in future.
A restriction is also added to allow sdebug_max_queue only be modified when
no shosts are present, i.e. we need to remove shosts, modify
sdebug_max_queue, and then re-add the shosts.
Link: https://lore.kernel.org/r/20230327074310.1862889-1-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
It's easy to get scsi_debug to error on throughput testing when we have
multiple shosts:
$ lsscsi
[7:0:0:0] disk Linux scsi_debug 0191
[0:0:0:0] disk Linux scsi_debug 0191
$ fio --filename=/dev/sda --filename=/dev/sdb --direct=1 --rw=read --bs=4k
--iodepth=256 --runtime=60 --numjobs=40 --time_based --name=jpg
--eta-newline=1 --readonly --ioengine=io_uring --hipri --exitall_on_error
jpg: (g=0): rw=read, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=io_uring, iodepth=256
...
fio-3.28
Starting 40 processes
[ 27.521809] hrtimer: interrupt took 33067 ns
[ 27.904660] sd 7:0:0:0: [sdb] tag#171 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK cmd_age=0s
[ 27.904660] sd 0:0:0:0: [sda] tag#58 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK cmd_age=0s
fio: io_u error [ 27.904667] sd 0:0:0:0: [sda] tag#58 CDB: Read(10) 28 00 00 00 27 00 00 01 18 00
on file /dev/sda[ 27.904670] sd 0:0:0:0: [sda] tag#62 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK cmd_age=0s
The issue is related to how the driver manages submit queues and tags. A
single array of submit queues - sdebug_q_arr - with its own set of tags is
shared among all shosts. As such, for occasions when we have more than one
shost it is possible to overload the submit queues and run out of tags.
The struct sdebug_queue is to manage tags and hold the associated
queued command entry pointer (for that tag).
Since the tagset iters are now used for functions like
sdebug_blk_mq_poll(), there is no need to manage these queues. Indeed,
blk-mq already provides what we need for managing tags and queues.
Drop sdebug_queue and all its usage in the driver.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-12-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The shost->can_queue value is initially used to set per-HW queue context
tag depth in the block layer. This ensures that the shost is not sent too
many commands which it can deal with. However lowering sdebug_max_queue
separately means that we can easily overload the shost, as in the following
example:
$ cat /sys/bus/pseudo/drivers/scsi_debug/max_queue
192
$ cat /sys/class/scsi_host/host0/can_queue
192
$ echo 100 > /sys/bus/pseudo/drivers/scsi_debug/max_queue
$ cat /sys/class/scsi_host/host0/can_queue
192
$ fio --filename=/dev/sda --direct=1 --rw=read --bs=4k --iodepth=256
--runtime=1200 --numjobs=10 --time_based --group_reporting
--name=iops-test-job --eta-newline=1 --readonly --ioengine=io_uring
--hipri --exitall_on_error
iops-test-job: (g=0): rw=read, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=io_uring, iodepth=256
...
fio-3.28
Starting 10 processes
[ 111.269885] scsi_io_completion_action: 400 callbacks suppressed
[ 111.269885] blk_print_req_error: 400 callbacks suppressed
[ 111.269889] I/O error, dev sda, sector 440 op 0x0:(READ) flags 0x1200000 phys_seg 1 prio class 2
[ 111.269892] sd 0:0:0:0: [sda] tag#132 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK cmd_age=0s
[ 111.269897] sd 0:0:0:0: [sda] tag#132 CDB: Read(10) 28 00 00 00 01 68 00 00 08 00
[ 111.277058] I/O error, dev sda, sector 360 op 0x0:(READ) flags 0x1200000 phys_seg 1 prio class 2
[...]
Ensure that this cannot happen by allowing sdebug_max_queue be modified
only when we have no shosts. As such, any shost->can_queue value will match
sdebug_max_queue, and sdebug_max_queue cannot be modified separately.
Since retired_max_queue is no longer set, remove support.
Continue to apply the restriction that sdebug_host_max_queue cannot be
modified when sdebug_host_max_queue is set. Adding support for that would
mean extra code, and no one has complained about this restriction
previously.
A command like the following may be used to remove a shost:
echo -1 > /sys/bus/pseudo/drivers/scsi_debug/add_host
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-11-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The functions to update ndelay and delay value first check whether we have
any in-flight IO for any host. It does this by checking if any tag is used
in the global submit queues.
We can achieve the same by setting the host as blocked and then ensuring
that we have no in-flight commands with scsi_host_busy().
Note that scsi_host_busy() checks SCMD_STATE_INFLIGHT flag, which is only
set per command after we ensure that the host is not blocked, i.e. we see
more commands active after the check for scsi_host_busy() returns 0.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-10-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Instead of iterating all deferred commands in the submission queue
structures, use blk_mq_tagset_busy_iter(), which is a standard API for
this.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-9-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Instead of iterating all deferred commands in the submission queue
structures, use blk_mq_tagset_busy_iter(), which is a standard API for
this.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-8-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Eventually we will drop the sdebug_queue struct as it is not really
required, so start with making the sdebug_queued_cmd dynamically allocated
for the lifetime of the scsi_cmnd in the driver.
As an interim measure, make sdebug_queued_cmd.sd_dp a pointer to struct
sdebug_defer. Also keep a value of the index allocated in
sdebug_queued_cmd.qc_arr in struct sdebug_queued_cmd.
To deal with an races in accessing the scsi cmnd allocated struct
sdebug_queued_cmd, add a spinlock for the scsi command in its priv area.
Races may be between scheduling a command for completion, aborting a
command, and the command actually completing and freeing the struct
sdebug_queued_cmd.
[mkp: typo fix]
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-7-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The feature to block queues is quite dubious, since it races with in-flight
IO. Indeed, it seems unnecessary for block queues for any times we do so.
Anyway, to keep the same behaviour, use standard SCSI API to stop IO being
sent - scsi_{un}block_requests().
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-6-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
There is no reason that calls to block_unblock_all_queues() from different
context can't race with one another, so protect with the
sdebug_host_list_mutex. There's no need for a more fine-grained per shost
locking here (and we don't have a per-host lock anyway).
Also simplify some touched code in sdebug_change_qdepth().
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-5-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The shost list lock, sdebug_host_list_lock, is a spinlock. We would only
lock in non-atomic context in this driver, so use a mutex instead, which is
friendlier if we need to schedule when iterating.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-4-john.g.garry@oracle.com
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In clear_luns_changed_on_target(), we iter all devices for all shosts to
conditionally clear the SDEBUG_UA_LUNS_CHANGED flag in the per-device
uas_bm.
One condition to see whether we clear the flag is to test whether the host
for the device under consideration is the same as the matching device's
(devip) host. This check will only ever pass for devices for the same
shost, so only iter the devices for the matching device shost.
We can now drop the spinlock'ing of the sdebug_host_list_lock in the same
function. This will allow us to use a mutex instead of the spinlock for the
global shost lock, as clear_luns_changed_on_target() could be called in
non-blocking context, in scsi_debug_queuecommand() -> make_ua() ->
clear_luns_changed_on_target() (which is why required a spinlock).
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-3-john.g.garry@oracle.com
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
There is a report that the blktests scsi/004 test for "TASK SET FULL" (TSF)
now fails.
The condition upon we should issue this TSF is when the sdev queue is
full. The check for a full queue has an off-by-1 error. Previously we would
increment the number of requests in the queue after testing if the queue
would be full, i.e. test if one less than full. Since we now use
scsi_device_busy() to count the number of requests in the queue, this would
already account for the current request, so fix the test for queue full
accordingly.
Fixes: 151f0ec9dd ("scsi: scsi_debug: Drop sdebug_dev_info.num_in_q")
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/oe-lkp/202303201334.18b30edc-oliver.sang@intel.com
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-2-john.g.garry@oracle.com
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
If there is no driver match function, the driver core assumes that each
candidate pair (driver, device) matches, see driver_match_device().
Drop the pseudo_lld bus match function that always returned 1. This results
in the same behaviour as when there is no match function.
[mkp+jgg: patch description]
Signed-off-by: Lizhe <sensor1010@163.com>
Link: https://lore.kernel.org/r/20230319042732.278691-1-sensor1010@163.com
Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Currently commands completed via poll mode are not included in the
statistics gathering for deferred completions and missed CPUs.
Poll mode completions should be treated the same as other deferred
completion types, so add poll mode completions to the statistics.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-12-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The command abort feature allows us to test aborting a command which has
timed-out.
The idea is that for specific commands we just don't call scsi_done() and
allow the request to timeout, which ensures SCSI EH kicks-in we try to
abort the command.
Since commit 4a0c6f432d ("scsi: scsi_debug: Add new defer type for
mq_poll") this does not seem to work. The issue is that we clear the
sd_dp->aborted flag in schedule_resp() before the completion callback has
run. When the completion callback actually runs, it calls scsi_done() as
normal as sd_dp->aborted unset. This is all very racy.
Fix by not clearing sd_dp->aborted in schedule_resp(). Also move the call
to blk_abort_request() from schedule_resp() to sdebug_q_cmd_complete(),
which makes the code have a more logical sequence.
I also note that this feature only works for commands which are classed as
"SDEG_RES_IMMED_MASK", but only practically triggered with prior RW
commands. So for my experiment I need to run fio to trigger the error on
the "nth" command (see inject_on_this_cmd()), and then run something like
sg_sync to queue a command to actually trigger the abort.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-11-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In schedule_resp(), under certain conditions we check whether the
per-device queue is full (num_in_q == queue depth - 1) and we may inject a
"task set full" (TSF) error if it is.
However how we read num_in_q is racy - many threads may see the same "queue
is full" value (and also issue a TSF).
There is per-queue locking in reading per-device num_in_q, but that would
not help.
Replace how we read num_in_q at this location with a call to
scsi_device_busy(). Calling scsi_device_busy() is likewise racy (as reading
num_in_q), so nothing lost or gained. Calling scsi_device_busy() is also
slow as it needs to read all bits in the per-device budget bitmap, but we
can live with that since we're just a simulator and it's only under a
certain configs which we would see this.
Also move the "task set full" print earlier as it would only be called now
under this condition. However, previously it may not have been called -
like returning early - but keep it simple and always call it.
At this point we can drop sdebug_dev_info.num_in_q - it is difficult to
maintain properly and adds extra normal case command processing.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-10-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The per-device num_in_q value cannot exceed the device queue depth, so drop
the check.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-9-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The check for device pointer for the SCSI command is unnecessary, so drop
it.
The only caller is scsi_try_host_reset() -> eh_host_reset_handler(), and
there that pointer cannot be NULL.
Indeed, there is already code later in the same function which does not
check the device pointer for the SCSI command.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-8-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The checks for SCSI cmnd, SCSI device, and SCSI host are unnecessary, so
drop them. Likewise, drop the NULL check for sdbg_host.
The only caller is scsi_try_bus_reset() -> eh_bus_reset_handler(), and
there those pointers cannot be NULL.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-7-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The checks for SCSI cmnd, SCSI device, and SCSI host are unnecessary, so
drop them. Likewise, drop the NULL check for sdbg_host.
The only caller is scsi_try_target_reset() -> eh_target_reset_handler(),
and there those pointers cannot be NULL.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-6-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The SCSI cmnd pointer arg would never be NULL, so drop the check. In
addition, its SCSI device pointer would never be NULL (so drop that check
also).
The only caller is scsi_try_bus_device_reset(), and the command and its
device pointer could not be NULL when calling eh_device_reset_handler()
there.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-5-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The SCSI cmnd pointer arg would never be NULL, so drop the check. In
addition, its SCSI device pointer would never be NULL.
The only caller is scsi_send_eh_cmnd() -> scsi_abort_eh_cmnd() ->
scsi_try_to_abort_cmd() -> scsi_try_to_abort_cmd(), and in the origin of
that chain those pointers cannot be NULL.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-4-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In sdebug_device_create(), the devip->sdbg_host pointer is needlessly set
twice, so stop doing that.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-3-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This driver stores just a pointer to the driver host structure in
host->hostdata[]. Most other drivers actually have the driver host
structure allocated in host->hostdata[], but this driver is different as we
allocate that memory separately before allocating the shost memory.
However there is no need to allocate this memory only in host->hostdata[]
when we can already look up the driver host structure from shost->dma_dev,
so add a macro for this - shost_to_sdebug_host(). Rename to_sdebug_host()
-> dev_to_sdebug_host() to avoid ambiguity.
Also remove a check for !sdbg_host in find_build_dev_info(), as this cannot
be true. Other similar checks will be later removed.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230313093114.1498305-2-john.g.garry@oracle.com
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
