Commit fc22b34e authored by Milan Broz's avatar Milan Broz Committed by Jens Axboe
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docs: sysfs-block: Clarify integrity sysfs attributes 



The /sys/block/<disk>/integrity fields are historically set
if T10 protection Information is enabled.

It is not set if some upper layer uses integrity metadata.
Document it.

Signed-off-by: default avatarMilan Broz <gmazyland@gmail.com>
Co-developed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250318154447.370786-1-gmazyland@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 03c90afb

Documentation/ABI/stable/sysfs-block

+22 −1
Original line number Diff line number Diff line
@@ -109,6 +109,10 @@ 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.

		This flag is set to 1 if the storage media is formatted

		with T10 Protection Information. If the storage media is

		not formatted with T10 Protection Information, this flag

		is set to 0.





What:		/sys/block/<disk>/integrity/format
@@ -117,6 +121,13 @@ Contact: Martin K. Petersen <martin.petersen@oracle.com> 
Description:

		Metadata format for integrity capable block device.

		E.g. T10-DIF-TYPE1-CRC.

		This field describes the type of T10 Protection Information

		that the block device can send and receive.

		If the device can store application integrity metadata but

		no T10 Protection Information profile is used, this field

		contains "nop".

		If the device does not support integrity metadata, this

		field contains "none".





What:		/sys/block/<disk>/integrity/protection_interval_bytes
@@ -142,7 +153,17 @@ 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.

		protection_interval_bytes, which is typically

		the device's logical block size.

		This field describes the size of the application tag

		if the storage device is formatted with T10 Protection

		Information and permits use of the application tag.

		The tag_size is reported in bytes and indicates the

		space available for adding an opaque tag to each block

		(protection_interval_bytes).

		If the device does not support T10 Protection Information

		(even if the device provides application integrity

		metadata space), this field is set to 0.





What:		/sys/block/<disk>/integrity/write_generate