[PATCH 1/7] docs: sysfs-block: sort alphabetically

Eric Biggers
2021-12-01T08:47:29Z

Sort the documentation for the files alphabetically by file path so that
there is a logical order and it's clear where to add new files.

With two small exceptions, this patch doesn't change the documentation
itself and just reorders it:

- In /sys/block/<disk>/<part>/stat, I replaced <part> with <partition>
to be consistent with the other files.
- The description for /sys/block/<disk>/<part>/stat referred to another
file "above", which I reworded.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
Documentation/ABI/testing/sysfs-block | 385 ++++++++++++++------------
1 file changed, 203 insertions(+), 182 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index b16b0c45a272e..9febd53a5ebe8 100644
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -1,31 +1,37 @@
-What: /sys/block/<disk>/stat
-Date: February 2008
-Contact: Jerome Marchand <jmarchan@redhat.com>
+What: /sys/block/<disk>/alignment_offset
+Date: April 2009
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
- The /sys/block/<disk>/stat files displays the I/O
- statistics of disk <disk>. They contain 11 fields:
+ Storage devices may report a physical block size that is
+ bigger than the logical block size (for instance a drive
+ with 4KB physical sectors exposing 512-byte logical
+ blocks to the operating system). This parameter
+ indicates how many bytes the beginning of the device is
+ offset from the disk's natural alignment.

- == ==============================================
- 1 reads completed successfully
- 2 reads merged
- 3 sectors read
- 4 time spent reading (ms)
- 5 writes completed
- 6 writes merged
- 7 sectors written
- 8 time spent writing (ms)
- 9 I/Os currently in progress
- 10 time spent doing I/Os (ms)
- 11 weighted time spent doing I/Os (ms)
- 12 discards completed
- 13 discards merged
- 14 sectors discarded
- 15 time spent discarding (ms)
- 16 flush requests completed
- 17 time spent flushing (ms)
- == ==============================================

- For more details refer Documentation/admin-guide/iostats.rst
+What: /sys/block/<disk>/discard_alignment
+Date: May 2011
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Devices that support discard functionality may
+ internally allocate space in units that are bigger than
+ the exported logical block size. The discard_alignment
+ parameter indicates how many bytes the beginning of the
+ device is offset from the internal allocation unit's
+ natural alignment.
+
+
+What: /sys/block/<disk>/diskseq
+Date: February 2021
+Contact: Matteo Croce <mcroce@microsoft.com>
+Description:
+ The /sys/block/<disk>/diskseq files reports the disk
+ sequence number, which is a monotonically increasing
+ number assigned to every drive.
+ Some devices, like the loop device, refresh such number
+ every time the backing file is changed.
+ The value type is 64 bit unsigned.

What: /sys/block/<disk>/inflight
@@ -44,26 +50,12 @@ Description:
and for SCSI device also its queue_depth.

-What: /sys/block/<disk>/diskseq
-Date: February 2021
-Contact: Matteo Croce <mcroce@microsoft.com>
-Description:
- The /sys/block/<disk>/diskseq files reports the disk
- sequence number, which is a monotonically increasing
- number assigned to every drive.
- Some devices, like the loop device, refresh such number
- every time the backing file is changed.
- The value type is 64 bit unsigned.
-
-
-What: /sys/block/<disk>/<part>/stat
-Date: February 2008
-Contact: Jerome Marchand <jmarchan@redhat.com>
+What: /sys/block/<disk>/integrity/device_is_integrity_capable
+Date: July 2014
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
- The /sys/block/<disk>/<part>/stat files display the
- I/O statistics of partition <part>. The format is the
- same as the above-written /sys/block/<disk>/stat
- format.
+ Indicates whether a storage device is capable of storing
+ integrity metadata. Set if the device is T10 PI-capable.

What: /sys/block/<disk>/integrity/format
@@ -74,6 +66,15 @@ Description:
E.g. T10-DIF-TYPE1-CRC.

+What: /sys/block/<disk>/integrity/protection_interval_bytes
+Date: July 2015
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Describes the number of data bytes which are protected
+ by one integrity tuple. Typically the device's logical
+ block size.
+
+
What: /sys/block/<disk>/integrity/read_verify
Date: June 2008
Contact: Martin K. Petersen <martin.petersen@oracle.com>
@@ -91,21 +92,6 @@ Description:
512 bytes of data.

-What: /sys/block/<disk>/integrity/device_is_integrity_capable
-Date: July 2014
-Contact: Martin K. Petersen <martin.petersen@oracle.com>
-Description:
- Indicates whether a storage device is capable of storing
- integrity metadata. Set if the device is T10 PI-capable.
-
-What: /sys/block/<disk>/integrity/protection_interval_bytes
-Date: July 2015
-Contact: Martin K. Petersen <martin.petersen@oracle.com>
-Description:
- Describes the number of data bytes which are protected
- by one integrity tuple. Typically the device's logical
- block size.
-
What: /sys/block/<disk>/integrity/write_generate
Date: June 2008
Contact: Martin K. Petersen <martin.petersen@oracle.com>
@@ -114,16 +100,6 @@ Description:
generate checksums for write requests bound for
devices that support receiving integrity metadata.

-What: /sys/block/<disk>/alignment_offset
-Date: April 2009
-Contact: Martin K. Petersen <martin.petersen@oracle.com>
-Description:
- Storage devices may report a physical block size that is
- bigger than the logical block size (for instance a drive
- with 4KB physical sectors exposing 512-byte logical
- blocks to the operating system). This parameter
- indicates how many bytes the beginning of the device is
- offset from the disk's natural alignment.

What: /sys/block/<disk>/<partition>/alignment_offset
Date: April 2009
@@ -136,76 +112,6 @@ Description:
indicates how many bytes the beginning of the partition
is offset from the disk's natural alignment.

-What: /sys/block/<disk>/queue/logical_block_size
-Date: May 2009
-Contact: Martin K. Petersen <martin.petersen@oracle.com>
-Description:
- This is the smallest unit the storage device can
- address. It is typically 512 bytes.
-
-What: /sys/block/<disk>/queue/physical_block_size
-Date: May 2009
-Contact: Martin K. Petersen <martin.petersen@oracle.com>
-Description:
- This is the smallest unit a physical storage device can
- write atomically. It is usually the same as the logical
- block size but may be bigger. One example is SATA
- drives with 4KB sectors that expose a 512-byte logical
- block size to the operating system. For stacked block
- devices the physical_block_size variable contains the
- maximum physical_block_size of the component devices.
-
-What: /sys/block/<disk>/queue/minimum_io_size
-Date: April 2009
-Contact: Martin K. Petersen <martin.petersen@oracle.com>
-Description:
- Storage devices may report a granularity or preferred
- minimum I/O size which is the smallest request the
- device can perform without incurring a performance
- penalty. For disk drives this is often the physical
- block size. For RAID arrays it is often the stripe
- chunk size. A properly aligned multiple of
- minimum_io_size is the preferred request size for
- workloads where a high number of I/O operations is
- desired.
-
-What: /sys/block/<disk>/queue/optimal_io_size
-Date: April 2009
-Contact: Martin K. Petersen <martin.petersen@oracle.com>
-Description:
- Storage devices may report an optimal I/O size, which is
- the device's preferred unit for sustained I/O. This is
- rarely reported for disk drives. For RAID arrays it is
- usually the stripe width or the internal track size. A
- properly aligned multiple of optimal_io_size is the
- preferred request size for workloads where sustained
- throughput is desired. If no optimal I/O size is
- reported this file contains 0.
-
-What: /sys/block/<disk>/queue/nomerges
-Date: January 2010
-Contact:
-Description:
- Standard I/O elevator operations include attempts to
- merge contiguous I/Os. For known random I/O loads these
- attempts will always fail and result in extra cycles
- being spent in the kernel. This allows one to turn off
- this behavior on one of two ways: When set to 1, complex
- merge checks are disabled, but the simple one-shot merges
- with the previous I/O request are enabled. When set to 2,
- all merge tries are disabled. The default value is 0 -
- which enables all types of merge tries.
-
-What: /sys/block/<disk>/discard_alignment
-Date: May 2011
-Contact: Martin K. Petersen <martin.petersen@oracle.com>
-Description:
- Devices that support discard functionality may
- internally allocate space in units that are bigger than
- the exported logical block size. The discard_alignment
- parameter indicates how many bytes the beginning of the
- device is offset from the internal allocation unit's
- natural alignment.

What: /sys/block/<disk>/<partition>/discard_alignment
Date: May 2011
@@ -218,6 +124,30 @@ Description:
partition is offset from the internal allocation unit's
natural alignment.

+
+What: /sys/block/<disk>/<partition>/stat
+Date: February 2008
+Contact: Jerome Marchand <jmarchan@redhat.com>
+Description:
+ The /sys/block/<disk>/<partition>/stat files display the
+ I/O statistics of partition <partition>. The format is the
+ same as the format of /sys/block/<disk>/stat.
+
+
+What: /sys/block/<disk>/queue/chunk_sectors
+Date: September 2016
+Contact: Hannes Reinecke <hare@suse.com>
+Description:
+ chunk_sectors has different meaning depending on the type
+ of the disk. For a RAID device (dm-raid), chunk_sectors
+ indicates the size in 512B sectors of the RAID volume
+ stripe segment. For a zoned block device, either
+ host-aware or host-managed, chunk_sectors indicates the
+ size in 512B sectors of the zones of the device, with
+ the eventual exception of the last zone of the device
+ which may be smaller.
+
+
What: /sys/block/<disk>/queue/discard_granularity
Date: May 2011
Contact: Martin K. Petersen <martin.petersen@oracle.com>
@@ -231,6 +161,7 @@ Description:
physical block size. A discard_granularity of 0 means
that the device does not support discard functionality.

+
What: /sys/block/<disk>/queue/discard_max_bytes
Date: May 2011
Contact: Martin K. Petersen <martin.petersen@oracle.com>
@@ -247,6 +178,7 @@ Description:
value of 0 means that the device does not support
discard functionality.

+
What: /sys/block/<disk>/queue/discard_zeroes_data
Date: May 2011
Contact: Martin K. Petersen <martin.petersen@oracle.com>
@@ -254,6 +186,111 @@ Description:
Will always return 0. Don't rely on any specific behavior
for discards, and don't read this file.

+
+What: /sys/block/<disk>/queue/io_timeout
+Date: November 2018
+Contact: Weiping Zhang <zhangweiping@didiglobal.com>
+Description:
+ io_timeout is the request timeout in milliseconds. If a request
+ does not complete in this time then the block driver timeout
+ handler is invoked. That timeout handler can decide to retry
+ the request, to fail it or to start a device recovery strategy.
+
+
+What: /sys/block/<disk>/queue/logical_block_size
+Date: May 2009
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ This is the smallest unit the storage device can
+ address. It is typically 512 bytes.
+
+
+What: /sys/block/<disk>/queue/max_active_zones
+Date: July 2020
+Contact: Niklas Cassel <niklas.cassel@wdc.com>
+Description:
+ For zoned block devices (zoned attribute indicating
+ "host-managed" or "host-aware"), the sum of zones belonging to
+ any of the zone states: EXPLICIT OPEN, IMPLICIT OPEN or CLOSED,
+ is limited by this value. If this value is 0, there is no limit.
+
+
+What: /sys/block/<disk>/queue/max_open_zones
+Date: July 2020
+Contact: Niklas Cassel <niklas.cassel@wdc.com>
+Description:
+ For zoned block devices (zoned attribute indicating
+ "host-managed" or "host-aware"), the sum of zones belonging to
+ any of the zone states: EXPLICIT OPEN or IMPLICIT OPEN,
+ is limited by this value. If this value is 0, there is no limit.
+
+
+What: /sys/block/<disk>/queue/minimum_io_size
+Date: April 2009
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Storage devices may report a granularity or preferred
+ minimum I/O size which is the smallest request the
+ device can perform without incurring a performance
+ penalty. For disk drives this is often the physical
+ block size. For RAID arrays it is often the stripe
+ chunk size. A properly aligned multiple of
+ minimum_io_size is the preferred request size for
+ workloads where a high number of I/O operations is
+ desired.
+
+
+What: /sys/block/<disk>/queue/nomerges
+Date: January 2010
+Contact:
+Description:
+ Standard I/O elevator operations include attempts to
+ merge contiguous I/Os. For known random I/O loads these
+ attempts will always fail and result in extra cycles
+ being spent in the kernel. This allows one to turn off
+ this behavior on one of two ways: When set to 1, complex
+ merge checks are disabled, but the simple one-shot merges
+ with the previous I/O request are enabled. When set to 2,
+ all merge tries are disabled. The default value is 0 -
+ which enables all types of merge tries.
+
+
+What: /sys/block/<disk>/queue/nr_zones
+Date: November 2018
+Contact: Damien Le Moal <damien.lemoal@wdc.com>
+Description:
+ nr_zones indicates the total number of zones of a zoned block
+ device ("host-aware" or "host-managed" zone model). For regular
+ block devices, the value is always 0.
+
+
+What: /sys/block/<disk>/queue/optimal_io_size
+Date: April 2009
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ Storage devices may report an optimal I/O size, which is
+ the device's preferred unit for sustained I/O. This is
+ rarely reported for disk drives. For RAID arrays it is
+ usually the stripe width or the internal track size. A
+ properly aligned multiple of optimal_io_size is the
+ preferred request size for workloads where sustained
+ throughput is desired. If no optimal I/O size is
+ reported this file contains 0.
+
+
+What: /sys/block/<disk>/queue/physical_block_size
+Date: May 2009
+Contact: Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+ This is the smallest unit a physical storage device can
+ write atomically. It is usually the same as the logical
+ block size but may be bigger. One example is SATA
+ drives with 4KB sectors that expose a 512-byte logical
+ block size to the operating system. For stacked block
+ devices the physical_block_size variable contains the
+ maximum physical_block_size of the component devices.
+
+
What: /sys/block/<disk>/queue/write_same_max_bytes
Date: January 2012
Contact: Martin K. Petersen <martin.petersen@oracle.com>
@@ -267,6 +304,7 @@ Description:
write_same_max_bytes is 0, write same is not supported
by the device.

+
What: /sys/block/<disk>/queue/write_zeroes_max_bytes
Date: November 2016
Contact: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
@@ -280,6 +318,7 @@ Description:
write_zeroes_max_bytes is 0, write zeroes is not supported
by the device.

+
What: /sys/block/<disk>/queue/zoned
Date: September 2016
Contact: Damien Le Moal <damien.lemoal@wdc.com>
@@ -297,50 +336,32 @@ Description:
zone commands, they will be treated as regular block
devices and zoned will report "none".

-What: /sys/block/<disk>/queue/nr_zones
-Date: November 2018
-Contact: Damien Le Moal <damien.lemoal@wdc.com>
-Description:
- nr_zones indicates the total number of zones of a zoned block
- device ("host-aware" or "host-managed" zone model). For regular
- block devices, the value is always 0.

-What: /sys/block/<disk>/queue/max_active_zones
-Date: July 2020
-Contact: Niklas Cassel <niklas.cassel@wdc.com>
-Description:
- For zoned block devices (zoned attribute indicating
- "host-managed" or "host-aware"), the sum of zones belonging to
- any of the zone states: EXPLICIT OPEN, IMPLICIT OPEN or CLOSED,
- is limited by this value. If this value is 0, there is no limit.
-
-What: /sys/block/<disk>/queue/max_open_zones
-Date: July 2020
-Contact: Niklas Cassel <niklas.cassel@wdc.com>
+What: /sys/block/<disk>/stat
+Date: February 2008
+Contact: Jerome Marchand <jmarchan@redhat.com>
Description:
- For zoned block devices (zoned attribute indicating
- "host-managed" or "host-aware"), the sum of zones belonging to
- any of the zone states: EXPLICIT OPEN or IMPLICIT OPEN,
- is limited by this value. If this value is 0, there is no limit.
+ The /sys/block/<disk>/stat files displays the I/O
+ statistics of disk <disk>. They contain 11 fields:

-What: /sys/block/<disk>/queue/chunk_sectors
-Date: September 2016
-Contact: Hannes Reinecke <hare@suse.com>
-Description:
- chunk_sectors has different meaning depending on the type
- of the disk. For a RAID device (dm-raid), chunk_sectors
- indicates the size in 512B sectors of the RAID volume
- stripe segment. For a zoned block device, either
- host-aware or host-managed, chunk_sectors indicates the
- size in 512B sectors of the zones of the device, with
- the eventual exception of the last zone of the device
- which may be smaller.
+ == ==============================================
+ 1 reads completed successfully
+ 2 reads merged
+ 3 sectors read
+ 4 time spent reading (ms)
+ 5 writes completed
+ 6 writes merged
+ 7 sectors written
+ 8 time spent writing (ms)
+ 9 I/Os currently in progress
+ 10 time spent doing I/Os (ms)
+ 11 weighted time spent doing I/Os (ms)
+ 12 discards completed
+ 13 discards merged
+ 14 sectors discarded
+ 15 time spent discarding (ms)
+ 16 flush requests completed
+ 17 time spent flushing (ms)
+ == ==============================================

-What: /sys/block/<disk>/queue/io_timeout
-Date: November 2018
-Contact: Weiping Zhang <zhangweiping@didiglobal.com>
-Description:
- io_timeout is the request timeout in milliseconds. If a request
- does not complete in this time then the block driver timeout
- handler is invoked. That timeout handler can decide to retry
- the request, to fail it or to start a device recovery strategy.
+ For more details refer Documentation/admin-guide/iostats.rst

base-commit: c2626d30f312afc341158e07bf088f5a23b4eeeb
--
2.34.1