Messages in this thread | | | Subject | Re: [PATCH v4] block: create ioctl to discard-or-zeroout a range of blocks | From | "Martin K. Petersen" <> | Date | Mon, 07 Dec 2015 20:16:37 -0500 |
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>>>>> "Darrick" == Darrick J Wong <darrick.wong@oracle.com> writes:
Darrick> Create a new ioctl to expose the block layer's newfound ability Darrick> to issue either a zeroing discard, a WRITE SAME with a zero Darrick> page, or a regular write with the zero page. This BLKZEROOUT2 Darrick> ioctl takes {start, length, flags} as parameters. So far, the Darrick> only flag available is to enable the zeroing discard part -- Darrick> without it, the call invokes the old BLKZEROOUT behavior. Darrick> start and length have the same meaning as in BLKZEROOUT.
Darrick> Furthermore, because BLKZEROOUT2 issues commands directly to Darrick> the storage device, we must invalidate the page cache (as a Darrick> regular O_DIRECT write would do) to avoid returning stale cache Darrick> contents at a later time.
Jens? Christoph?
-- Martin K. Petersen Oracle Linux Engineering
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