Am 06.07.2016 um 04:14 hat Eric Blake geschrieben: > On 07/05/2016 09:50 AM, Kevin Wolf wrote: > > From: Eric Blake <ebl...@redhat.com> > > > > Sector-based limits are awkward to think about; in our on-going > > quest to move to byte-based interfaces, convert max_discard and > > discard_alignment. Rename them, using 'pdiscard' as an aid to > > track which remaining discard interfaces need conversion, and so > > that the compiler will help us catch the change in semantics > > across any rebased code. The BlockLimits type is now completely > > byte-based; and in iscsi.c, sector_limits_lun2qemu() is no > > longer needed. > > > > > +++ b/include/block/block_int.h > > @@ -324,11 +324,17 @@ struct BlockDriver { > > }; > > > > typedef struct BlockLimits { > > - /* maximum number of sectors that can be discarded at once */ > > - int max_discard; > > - > > - /* optimal alignment for discard requests in sectors */ > > - int64_t discard_alignment; > > + /* maximum number of bytes that can be discarded at once (since it > > + * is signed, it must be < 2G, if set), should be multiple of > > + * pdiscard_alignment, but need not be power of 2. May be 0 if no > > + * inherent 32-bit limit */ > > + int32_t max_pdiscard; > > + > > + /* optimal alignment for discard requests in bytes, must be power > > + * of 2, less than max_pdiscard if that is set, and multiple of > > + * bs->request_alignment. May be 0 if bs->request_alignment is > > + * good enough */ > > + uint32_t pdiscard_alignment; > > Given the recent thread on an iscsi device with 15M optimum alignment > for zero and discards, I guess I have some followup patches to write if > we don't want to stall this pull request.
Please send a followup patch (series). Does this one actually change the behaviour or just document the behaviour that we already expected? Kevin
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