Commits
Martin K. Petersen committed c98a0eb0e90
[SCSI] sd: Logical Block Provisioning update SBC3r26 contains many changes to the Logical Block Provisioning interfaces (formerly known as Thin Provisioning ditto). This patch implements support for both the old and new schemes using the same heuristic as before (whether the LBP VPD page is present). The new code also allows the provisioning mode (i.e. choice of command) to be overridden on a per-device basis via sysfs. Two additional modes are supported in this version: - WRITE SAME(10) with the UNMAP bit set - WRITE SAME(10) without the UNMAP bit set. This allows us to support devices that predate the TP/LBP enhancements in SBC3 and which work by way zero-detection Switching between modes has been consolidated in a helper function that also updates the block layer topology according to the limitations of the chosen command. I experimented with trying WRITE SAME(16) if UNMAP fails, WRITE SAME(10) if WRITE SAME(16) fails, etc. but found several devices that got cranky. So for now we'll disable discard if one of the commands fail. The user still has the option of selecting a different mode in sysfs. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>