Messages in this thread | | | Subject | Re: [PATCH] block: fix blk_queue_alignment_offset | From | "Martin K. Petersen" <> | Date | Sun, 19 Jul 2009 22:19:55 -0400 |
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>>>>> "hch" == Christoph Hellwig <hch@lst.de> writes:
hch> We need to mask out bits inside the logical block, not outside of hch> it, otherwise we'll always get a 0 alignment_offset.
The alignment_offset only makes sense if physical_block_size > logical_block_size. For instance (63 * 512) & (4096 - 1) = 3584.
Your patch would yield 28672 = 4096 * 7 and that's incorrect; LBA 63 is not aligned on a 4KB boundary...
-- Martin K. Petersen Oracle Linux Engineering
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