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114 files changed, 2563 insertions, 2484 deletions
diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block new file mode 100644 index 000000000000..8dd3e84a8aad --- /dev/null +++ b/Documentation/ABI/stable/sysfs-block @@ -0,0 +1,676 @@ +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>/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 +Date: October 2009 +Contact: Jens Axboe <axboe@kernel.dk>, Nikanth Karthikesan <knikanth@suse.de> +Description: + Reports the number of I/O requests currently in progress + (pending / in flight) in a device driver. This can be less + than the number of requests queued in the block device queue. + The report contains 2 fields: one for read requests + and one for write requests. + The value type is unsigned int. + Cf. Documentation/block/stat.rst which contains a single value for + requests in flight. + This is related to /sys/block/<disk>/queue/nr_requests + and for SCSI device also its queue_depth. + + +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/format +Date: June 2008 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Metadata format for integrity capable block device. + 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> +Description: + Indicates whether the block layer should verify the + integrity of read requests serviced by devices that + support sending integrity metadata. + + +What: /sys/block/<disk>/integrity/tag_size +Date: June 2008 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Number of bytes of integrity tag space available per + 512 bytes of data. + + +What: /sys/block/<disk>/integrity/write_generate +Date: June 2008 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + Indicates whether the block layer should automatically + generate checksums for write requests bound for + devices that support receiving integrity metadata. + + +What: /sys/block/<disk>/<partition>/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 partition + is offset from the disk's natural alignment. + + +What: /sys/block/<disk>/<partition>/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 + 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/add_random +Date: June 2010 +Contact: linux-block@vger.kernel.org +Description: + [RW] This file allows to turn off the disk entropy contribution. + Default value of this file is '1'(on). + + +What: /sys/block/<disk>/queue/chunk_sectors +Date: September 2016 +Contact: Hannes Reinecke <hare@suse.com> +Description: + [RO] 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/dax +Date: June 2016 +Contact: linux-block@vger.kernel.org +Description: + [RO] This file indicates whether the device supports Direct + Access (DAX), used by CPU-addressable storage to bypass the + pagecache. It shows '1' if true, '0' if not. + + +What: /sys/block/<disk>/queue/discard_granularity +Date: May 2011 +Contact: Martin K. Petersen <martin.petersen@oracle.com> +Description: + [RO] Devices that support discard functionality may internally + allocate space using units that are bigger than the logical + block size. The discard_granularity parameter indicates the size + of the internal allocation unit in bytes if reported by the + device. Otherwise the discard_granularity will be set to match + the device's 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> +Description: + [RW] While discard_max_hw_bytes is the hardware limit for the + device, |