On Mar. 31, 2009, 22:42 +0300, "J. Bruce Fields" <bfields@xxxxxxxxxxxx> wrote: > On Tue, Mar 31, 2009 at 09:36:08PM +0300, Benny Halevy wrote: >> On Mar. 31, 2009, 4:44 +0300, "J. Bruce Fields" <bfields@xxxxxxxxxxxx> wrote: >>> On Mon, Mar 30, 2009 at 05:37:37PM +0300, Benny Halevy wrote: >>>> Bruce, >>>> >>>> As I mentioned in a reply to Trond, >>>> "nfsd41: support for 3-word long attribute bitmask" >>>> changes the server fattr encoding logic so it may send >>>> back a bitmap of length 1, even if the client sent a >>>> bitmap of length 2, if the second word of the bitmap >>>> is zero. Although I think this a valid implementation >>>> and other servers may do the same, it seems sub-optimal >>>> for the client's decoding of acl of fs_locations. >>> "suboptimal" means it does some extra memcpy'ing? >> Yes, I believe so. >> >>>> It's pretty easy to revert to the old behavior on the server >>>> by always returning at least two bitmap words, or, if we >>>> keep the bitmap length, not just the val, in nfsd4_decode_bitmap >>>> we can return a bitmap of the same length in the reply. >>> Odd thing to have to do, but OK. --b. >> What would you prefer to do? >> Revert to old behavior by returning at least two bitmap words >> or use the args bitmap length for encoding the res? > > Whichever requires the least code? I don't know. The former seems simpler to code. > > If the client really needs this, then it needs to be agreed on by more > than just the linux server. It's unfortunate if making this arbitrary > undocumented choice of result encoding makes a significant difference to > the client's performance. I think that currently it affects only getacl and I have no measurements of to what extent the effect of performance is. Benny > > --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
