How does local readdir work on such file systems? :-) ps -----Original Message----- From: linux-nfs-owner@xxxxxxxxxxxxxxx [mailto:linux-nfs-owner@xxxxxxxxxxxxxxx] On Behalf Of Trond Myklebust Sent: Wednesday, March 23, 2011 2:34 PM To: J. Bruce Fields Cc: Bryan Schumaker; linux-nfs@xxxxxxxxxxxxxxx Subject: Re: [PATCH 3/3] NFS: Detect loops in a readdir due to bad cookies On Wed, 2011-03-23 at 14:25 -0400, J. Bruce Fields wrote: > On Wed, Mar 23, 2011 at 01:39:44PM -0400, Bryan Schumaker wrote: > > Some filesystems (such as ext4) can return the same cookie value for multiple > > Do the ext4 people know about this? (And what's the easiest way to > reproduce it?) They are aware of it. I don't know if they are aware how easy it is to reproduce. Bryan saw several 10s of instances of duplicate cookies when he was doing performance testing of readdir on a directory with 10^6 entries. Most of the time it didn't cause looping on the client since the looping behaviour depends on the distribution of those cookies in the client's readdir cache. However on occasion he did see looping in the client, and at least once he saw looping on the server too (in which a duplicate cookie caused the server to return files that it had already sent to the client). -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@xxxxxxxxxx www.netapp.com -- 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 ÿô.nlj·Ÿ®‰†+%ŠË±é¥Šwÿº{.nlj·¥Š{±þwìíè jg¬±¨ ¶‰šŽŠÝjÿ¾«þG«é¸ ¢·¦j:+v‰¨Šwèm¶Ÿÿþø®w¥þŠà£¢·hšâÿ†Ù
