Messages in this thread | | | Subject | Re: [PATCH] UBIFS: fill f_fsid | From | Artem Bityutskiy <> | Date | Mon, 01 Sep 2008 14:16:50 +0300 |
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On Mon, 2008-09-01 at 10:43 +0100, David Woodhouse wrote: > > UBIFS stores 16-bit UUID in the superblock, and it is a good > > idea to return part of it in 'f_fsid' filed of kstatfs structure. > > I think you mean a 16-byte UUID, not 16-bit?
Oh, right.
> > > + memcpy(&buf->f_fsid, c->uuid, sizeof(__kernel_fsid_t)); > > For btrfs I xor the first 64 bits with the second 64 bits, and put > _that_ into f_fsid. You're just putting the first 64 bits in and > ignoring the second 64 bits. Neither is really _better_ than the other; > you just alter the circumstances in which you get collisions. But I > suppose we might as well be consistent about how we do it?
Well, xor-ing should not make the random UUID more random, but for consistency purposes sure, I may use xor as well.
> Alternatively, there's space in the struct statfs to export a couple > more uint32_ts, and thus the _whole_ of the uuid. Perhaps we should do > that?
You mean f_spare? I do not think any application would use it so I doubt it is good idea to use it.
-- Best regards, Artem Bityutskiy (Битюцкий Артём)
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