Comments on: Linux XFS Does not Support dirent::d_type

By: lightningrose

lightningrose — Sun, 11 Sep 2011 14:06:26 +0000

Thanks for this post, it was a great help to me. I'm the author of Select-o-Magic 3000 and I recently ran into this problem when I was building a home media server using XFS. An interesting thing I found is that when reading an XFS file system over a Samba NFS, d_type is filled in correctly, at least under Ubuntu v10.04 LTS.

By: Anonymous

Anonymous — Sat, 19 Jun 2010 13:26:09 +0000

readdir() isn’t threadsafe when accessing the same directory stream from different threads.

By: Anonymous

Anonymous — Wed, 19 Aug 2009 01:17:42 +0000

nfs, ext2, ext3 absolutely DO fill d_type correctly, at least under Linux, as well as cifs, ext4 and all other known file systems known to man

By: anonymous

anonymous — Sat, 06 Jun 2009 18:46:34 +0000

Well, obviously everything looks like DT_UNKNOWN, not like regular files.

This is not an xfs issue either, most filesystems do not support the d_type field (nfs, ext2/ext3 per default etc.), so apps relying on that field to have somethign besides DT_UNKNOWN is simply a buggy app.

Thirdly, one only needs to stat() when d_type is indeed DT_UNKNOWN, and then there are still many ways to avoid it.

and lastly, readdir_r is usually a bug, too (readdir is already threadsafe, per dirfd).