tree 7cdc0b3f4b87d26c8f91125edaea8723764526bf
parent 860dd4424f344400b491b212ee4acb3a358ba9d9
author Huacai Chen <chenhc@lemote.com> 1511270618 +0100
committer Martin K. Petersen <martin.petersen@oracle.com> 1511323557 -0500

scsi: use dma_get_cache_alignment() as minimum DMA alignment

In non-coherent DMA mode, kernel uses cache flushing operations to
maintain I/O coherency, so scsi's block queue should be aligned to the
value returned by dma_get_cache_alignment().  Otherwise, If a DMA buffer
and a kernel structure share a same cache line, and if the kernel
structure has dirty data, cache_invalidate (no writeback) will cause
data corruption.

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhc@lemote.com>
[hch: rebased and updated the comment and changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>