On Thu, Nov 5, 2009 at 5:45 PM, Trond Myklebust <trond.myklebust@xxxxxxxxxx> wrote: > On Wed, 2009-11-04 at 09:36 +0000, Daniel J Blueman wrote: >> On Sun, Nov 1, 2009 at 12:47 PM, Daniel J Blueman >> <daniel.blueman@xxxxxxxxx> wrote: >> > Hi Trond, >> > >> > On Mon, Oct 26, 2009 at 1:19 PM, Trond Myklebust >> > <Trond.Myklebust@xxxxxxxxxx> wrote: >> >> On Sun, 2009-10-25 at 23:31 +0000, Daniel J Blueman wrote: >> >>> Since 2.6.30-rc, I've been experiencing various issues relating to >> >>> getcwd() returning ENOENT on NFS4 clients. I used an over-complicated >> >>> but reliable reproducer [1] (on Karmic RC against a 2.6.32-rc5 NFS4 >> >>> server) to bisect [2]. >> >>> >> >>> The impact of this regression is moderate (side-effects range from >> >>> benign to failure), so we should get a fix into 2.6.32 if at all >> >>> possible and strongly consider a 2.6.31 stable update. >> >>> >> >>> Thanks, >> >>> Daniel >> >>> >> >>> --- [1] >> >>> >> >>> $ apt-get source apt >> >>> $ cd apt-* >> >>> $ ./configure && make >> >>> [snip] >> >>> sh: getcwd() failed: No such file or directory >> >>> >> >>> --- [2] >> >>> >> >>> a65318bf3afc93ce49227e849d213799b072c5fd is first bad commit >> >>> commit a65318bf3afc93ce49227e849d213799b072c5fd >> >>> Author: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> >> >>> Date: Wed Mar 11 14:10:28 2009 -0400 >> >>> >> >>> NFSv4: Simplify some cache consistency post-op GETATTRs >> >> >> >> I'm having a lot of trouble seeing how this patch could result in >> >> ENOENT. All it should be doing is reducing the frequency with which we >> >> update some of the inode metadata. >> >> >> >> Have you ever been able to capture one of these errors using strace? >> > >> > Backing this patch out by hand against stock 2.6.32-rc5 (w/ 2.6.32-rc5 >> > on server) corrects the behaviour. It's readily reproducible [1]; >> > using 2.6.30, the issue is not seen, thus is a regression. >> > >> > To observe the change to user-level behaviour (after the reproducer commands): >> > # make clean >> > # strace -ffe getcwd make -n >list >> > [pid 3829] getcwd(0x7fffa269a380, 4096) = -1 ENOENT (No such file or directory) >> > make: getcwd: No such file or directory >> > >> > Would this help for me to log this via a bugzilla.kernel.org ticket? >> > >> > Thanks, >> > Daniel >> > >> > --- [1] >> > >> > booting eg: >> > http://mira.sunsite.utk.edu/ubuntu-releases/karmic/ubuntu-9.10-desktop-amd64.iso >> > >> > $ sudo bash >> > # apt-get install build-essential >> > # apt-get build-dep apt >> > # mount server:/ /mnt -tnfs4 && cd /mnt >> > # apt-get source apt >> > # cd apt-0.7.23.1ubuntu2 >> > # ./configure && make >> > -> "getcwd: No such file or directory" messages observed with cited >> > patch and not without >> >> For continuity with the mailing list thread, I've created a bug report >> of this at: >> >> http://bugzilla.kernel.org/show_bug.cgi?id=14541 > > I just committed the following patch into the above bugzilla entry. I > hope it suffices to fix the bug. > > Cheers > Trond > ------------------------------------------------------------------- > NFSv4: Fix a cache validation bug which causes getcwd() to return ENOENT > From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> > > Changeset a65318bf3afc93ce49227e849d213799b072c5fd (NFSv4: Simplify some > cache consistency post-op GETATTRs) incorrectly changed the getattr > bitmap for readdir(). > This causes the readdir() function to fail to return a > fileid/inode number, which again exposed a bug in the NFS readdir code that > causes spurious ENOENT errors to appear in applications (see > http://bugzilla.kernel.org/show_bug.cgi?id=14541). > > The immediate band aid is to revert the incorrect bitmap change, but more > long term, we should change the NFS readdir code to cope with the > fact that NFSv4 servers are not required to support fileids/inode numbers. > > Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> > --- > > fs/nfs/nfs4proc.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c > index ff37454..741a562 100644 > --- a/fs/nfs/nfs4proc.c > +++ b/fs/nfs/nfs4proc.c > @@ -2767,7 +2767,7 @@ static int _nfs4_proc_readdir(struct dentry *dentry, struct rpc_cred *cred, > .pages = &page, > .pgbase = 0, > .count = count, > - .bitmask = NFS_SERVER(dentry->d_inode)->cache_consistency_bitmask, > + .bitmask = NFS_SERVER(dentry->d_inode)->attr_bitmask, > }; > struct nfs4_readdir_res res; > struct rpc_message msg = { > This fixes the behaviour and passes some heavy testing with two good test-cases, with 2.6.32-rc6. As well, this would be good value for the stable stream. I've sync'd the bugzilla report. Thanks for your work on this, Trond! Daniel -- Daniel J Blueman -- 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
