Nicolas Parpandet <n...@1g6.biz> writes: > Hello, > > I did some more investigations, (wireshark) > > The unlink of /tmp/crontab.vYPoHR/crontab is tranlated into a rename > nfs call ? (.nfs file)
That happens if the file is still open. > > NFS 670 V3 READDIRPLUS Reply (Call In 731) crontab .. . > NFS 210 V3 LOOKUP Call (Reply In 734), DH: > 0x038abb3d/.nfs000000000098008a00000019 > NFS 194 V3 LOOKUP Reply (Call In 733) Error: NFS3ERR_NOENT > NFS 254 V3 RENAME Call (Reply In 736), From DH: 0x038abb3d/crontab To > DH: 0x038abb3d/.nfs000000000098008a00000019 > NFS 338 V3 RENAME Reply (Call In 735) > > and after, it tries to remove the directory /tmp/crontab.0wuoNx : > NFS 198 V3 RMDIR Call (Reply In 738), DH: 0x954c28ec/crontab.0wuoNx > NFS 222 V3 RMDIR Reply (Call In 737) Error: NFS3ERR_NOTEMPTY > > but the file /tmp/crontab.0wuoNx/crontab was renamed instead of being removed > (nfs network, I cannot see .nfs000 file in fact), > this prevent the removing of the directory /tmp/crontab.0wuoNx (notempty) > > It seems a race condition, see "nfs silly rename" keyword, but I have > the problem with mysql temp files, and crontab temp file (crontab -e), I don't think it is a race condition exactly. More of an ordering problem. Unlinking a file before closing it is rarely useful (sometimes it is, but not here). > am I the only one doing mysql and crontabs over NFS !!!?!?, Probably. > does anybody have a solution ? Fix 'crontab' to close before unlinking... Is this the Debian/Ubuntu crontab program.... it looks a bit like it, but this bug was fixed 6 years ago. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=413962 Or use a tmpfs for /tmp/ rather than using NFS??? NeilBrown > > > Regards > > Nicolas > > > ----- Mail original ----- > De: "npa" <n...@1g6.biz> > À: linux-kernel@vger.kernel.org > Cc: "pcoustillas" <pcoustil...@1g6.biz> > Envoyé: Dimanche 4 Octobre 2015 09:57:26 > Objet: nfs race condition > > Hello, > > I'm doing some " crontab -e, exit with :x" on NFS mount point, > and there is a race condition whent removing temporary files : > > > 7701 write(2, "No modification made\n", 21) = 21 > 7701 open("/tmp/crontab.vYPoHR", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = > 4 > 7701 getdents(4, {{d_ino=73336409, d_off=1, d_reclen=24, d_name="."} > {d_ino=73335455, d_off=2, d_reclen=24, d_name=".."} {d_ino=73340547, d_off=3, > d_reclen=32, d_name="crontab"}}, 32768) = 80 > 7701 unlink("/tmp/crontab.vYPoHR/crontab") = 0 > 7701 getdents(4, {}, 32768) = 0 > 7701 close(4) = 0 > 7701 rmdir("/tmp/crontab.vYPoHR") = -1 ENOTEMPTY (Directory not empty) > 7701 write(2, "/tmp/crontab.vYPoHR: Directory n"..., 41) = 41 > 7701 socket(PF_FILE, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 4 > > The unlink is really done after the rmdir, > nfsv4 & nfsv3 over ipv6, so the rmdir fails and the directory isn't removed. > I have same problem with mysql temporary files. > > If I mount with "nocto,noac,lookupcache=none" : same problem > kernel version on server : 3.16.0-4-amd64 (debian8) > kernel version on client : 2.6.32-39-pve (proxmox), same thing with > 3.13.0-63-generic (ubuntu) > > Please answer me in CC, I'm not subscribed to the list. > > Regards > > Nicolas > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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