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由 Christoph Hellwig 提交于
Add a logical block size attribute as various guest side tools only increase the filesystem sector size based on it, not the advisory physical block size. For scsi we already have support for a different logical block size in place for CDROMs that we can built upon. Only my recent block device characteristics VPD page needs some fixups. Note that we leave the logial block size for CDROMs hardcoded as the 2k value is expected for it in general. For virtio-blk we already have a feature flag claiming to support a variable logical block size that was added for the s390 kuli hypervisor. Interestingly it does not actually change the units in which the protocol works, which is still fixed at 512 bytes, but only communicates a different minimum I/O granularity. So all we need to do in virtio is to add a trap for unaligned I/O and round down the device size to the next multiple of the logical block size. IDE does not support any other logical block size than 512 bytes. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
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