In message <20080429133201.GA9938@xxxxxxxxxxxxxxxxxxxxx>, bsn.0007@xxxxxxxxx writes: > Hi, > > I went through Bharata's RFC post on glibc based Union Mount readdir solution > (http://lkml.org/lkml/2008/3/11/34) and have come up with patches > against glibc to implement the same. [...] The last set of discussions on glibc support ended, as I understood it, with the glibc people objecting to such "special-purpose" code in glibc. See <http://lkml.org/lkml/2008/3/11/66>. So has anything changed behind the scenes, or is this idea unlikely to be merged into glibc any time soon, if ever. (Personally I'd love to rip out the readdir-related code from unionfs if glibc supported the same.) > Patch 1. readdir support for union mounted directories. > I am caching the dirent names in a list to aid duplicate elimination. > And this cache is stored in DIRP. For duplicate elimination I am using > strcmp(). I am not sure if this works universally with different types > of filesystems. Any suggestions here would be welcome. [...] You might consider using a hash table instead of a list; it'll be faster in case where there are a lot of whiteouts/duplicates to process. Also, I'll reiterate my previous concern that I think you may need to also handle "opaque directories". See the discussion in section 5.1 "Creation and deletion of whiteouts", in the original union mounts paper: <http://www.usenix.org/publications/library/proceedings/neworl/full_papers/mckusick.a> Cheers, Erez. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
