Hi Trond, On Fri, Nov 6, 2009 at 12:41 AM, Daniel J Blueman <daniel.blueman@xxxxxxxxx> wrote: > 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. Is there opportunity to get this regression fix into 2.6.32-rc8, since -rc8 may be the (pen)ultimate before final? Thanks, 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
