Messages in this thread | | | Date | Fri, 02 Aug 2002 22:31:40 +0400 | From | Hans Reiser <> | Subject | Re: BIG files & file systems |
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Nikita Danilov wrote:
>Trond Myklebust writes: > > >>>>> " " == Nikita Danilov <Nikita@Namesys.COM> writes: > > > > > But there still is a problem with applications (if any) calling > > > seekdir/telldir directly... > > > > Agreed. Note however that the semantics for seekdir/telldir as > > specified by SUSv2 are much weaker than those in our current > > getdents()+lseek(). > > > > >From the Opengroup documentation for seekdir, it states that: > > > > On systems that conform to the Single UNIX Specification, Version 2, > > a subsequent call to readdir() may not be at the desired position if > > the value of loc was not obtained from an earlier call to telldir(), > > or if a call to rewinddir() occurred between the call to telldir() > > and the call to seekdir(). > > > > IOW assigning a unique offset to each and every entry in the directory > > is overkill (unless the user is calling telldir() for all those > > entries). > Forgive the really dumb question, but does this mean we can just store the last entry returned to readdir in the directory metadata, and completely ignore the value of loc?
> >Are you implying some kind of ->telldir() file operation that notifies >file-system that user has intention to later restart readdir from the >"current" position and changing glibc to call sys_telldir/sys_seekdir in >stead of lseek? This will allow file-systems like reiser4 that cannot >restart readdir from 32bitsful of data to, at least, allocate something >in kernel on call to ->telldir() and free in ->release(). > > > > > Cheers, > > Trond > >Nikita. > > > >
-- Hans
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