linux.git/Documentation/ABI/testing/sysfs-block, branch v5.9

block: add max_active_zones to blk-sysfs

2020-07-15T20:26:11+00:00

Add a new max_active zones definition in the sysfs documentation.
This definition will be common for all devices utilizing the zoned block
device support in the kernel.

Export max_active_zones according to this new definition for NVMe Zoned
Namespace devices, ZAC ATA devices (which are treated as SCSI devices by
the kernel), and ZBC SCSI devices.

Add the new max_active_zones member to struct request_queue, rather
than as a queue limit, since this property cannot be split across stacking
drivers.

For SCSI devices, even though max active zones is not part of the ZBC/ZAC
spec, export max_active_zones as 0, signifying "no limit".

Signed-off-by: Niklas Cassel 
Reviewed-by: Javier González 
Reviewed-by: Damien Le Moal 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Jens Axboe

block: add max_open_zones to blk-sysfs

2020-07-15T20:26:11+00:00

Add a new max_open_zones definition in the sysfs documentation.
This definition will be common for all devices utilizing the zoned block
device support in the kernel.

Export max open zones according to this new definition for NVMe Zoned
Namespace devices, ZAC ATA devices (which are treated as SCSI devices by
the kernel), and ZBC SCSI devices.

Add the new max_open_zones member to struct request_queue, rather
than as a queue limit, since this property cannot be split across stacking
drivers.

Signed-off-by: Niklas Cassel 
Reviewed-by: Javier González 
Reviewed-by: Damien Le Moal 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Jens Axboe

block: add iostat counters for flush requests

2019-11-21T16:06:47+00:00

Requests that triggers flushing volatile writeback cache to disk (barriers)
have significant effect to overall performance.

Block layer has sophisticated engine for combining several flush requests
into one. But there is no statistics for actual flushes executed by disk.
Requests which trigger flushes usually are barriers - zero-size writes.

This patch adds two iostat counters into /sys/class/block/$dev/stat and
/proc/diskstats - count of completed flush requests and their total time.

Signed-off-by: Konstantin Khlebnikov 
Signed-off-by: Jens Axboe

docs: admin-guide: add a series of orphaned documents

2019-07-15T14:03:02+00:00

There are lots of documents that belong to the admin-guide but
are on random places (most under Documentation root dir).

Move them to the admin guide.

Signed-off-by: Mauro Carvalho Chehab 
Acked-by: Alexandre Belloni 
Acked-by: Bartlomiej Zolnierkiewicz

block: add documentation for io_timeout

2019-01-05T02:19:51+00:00

Add documentation for /sys/block//queue/io_timeout.

Reviewed-by: Bart Van Assche 
Signed-off-by: Weiping Zhang 
Signed-off-by: Jens Axboe

block: update sysfs documentation

2018-12-17T02:53:06+00:00

Add the description of the zoned, nr_zones and chunk_sectors sysfs queue
attributes to Documentation/block/queue-sysfs.txt. The description of
the zoned and chunk_sector attributes are mostly copied from
ABI/testing/sysfs-block (added a typo fix). While at it, also fix a
typo in the description of the io_poll_delay attribute.

nr_zones description is also added to ABI/testing/sysfs-block and
contact email address updated for the zoned attribute.

Signed-off-by: Damien Le Moal 
Signed-off-by: Jens Axboe

block: remove the discard_zeroes_data flag

2017-04-08T17:25:38+00:00

Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can
kill this hack.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Jens Axboe

block: add support for REQ_OP_WRITE_ZEROES

2016-12-01T14:58:40+00:00

This adds a new block layer operation to zero out a range of
LBAs. This allows to implement zeroing for devices that don't use
either discard with a predictable zero pattern or WRITE SAME of zeroes.
The prominent example of that is NVMe with the Write Zeroes command,
but in the future, this should also help with improving the way
zeroing discards work. For this operation, suitable entry is exported in
sysfs which indicate the number of maximum bytes allowed in one
write zeroes operation by the device.

Signed-off-by: Chaitanya Kulkarni 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

blk-sysfs: Add 'chunk_sectors' to sysfs attributes

2016-10-18T16:02:02+00:00

The queue limits already have a 'chunk_sectors' setting, so
we should be presenting it via sysfs.

Signed-off-by: Hannes Reinecke 

[Damien: Updated Documentation/ABI/testing/sysfs-block]

Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Shaun Tancheff 
Tested-by: Shaun Tancheff 
Signed-off-by: Jens Axboe

block: Add 'zoned' queue limit

2016-10-18T16:02:00+00:00

Add the zoned queue limit to indicate the zoning model of a block device.
Defined values are 0 (BLK_ZONED_NONE) for regular block devices,
1 (BLK_ZONED_HA) for host-aware zone block devices and 2 (BLK_ZONED_HM)
for host-managed zone block devices. The standards defined drive managed
model is not defined here since these block devices do not provide any
command for accessing zone information. Drive managed model devices will
be reported as BLK_ZONED_NONE.

The helper functions blk_queue_zoned_model and bdev_zoned_model return
the zoned limit and the functions blk_queue_is_zoned and bdev_is_zoned
return a boolean for callers to test if a block device is zoned.

The zoned attribute is also exported as a string to applications via
sysfs. BLK_ZONED_NONE shows as "none", BLK_ZONED_HA as "host-aware" and
BLK_ZONED_HM as "host-managed".

Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Shaun Tancheff 
Tested-by: Shaun Tancheff 
Signed-off-by: Jens Axboe