Messages in this thread | | | Date | Fri, 03 Dec 2010 21:01:33 +0300 | From | Kinsbursky Stanislav <> | Subject | Re: [PATCH] NFS: suppressing showing of default mount port value in /proc fixed |
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03.12.2010 20:35, Chuck Lever пишет: > > On Dec 3, 2010, at 12:11 PM, Stanislav Kinsbursky wrote: > >> Default value for mount server port is set to NFS_UNSPEC_PORT (-1) and will not >> be changed during parsing mount options for mound data version 6. This default >> value will be showed for mountport in /proc/mounts always since current default >> check is for zero value. This small mistake leads to big problem, because >> during umount.nfs execution from old user-space utils (at least nfs-utils >> 1.0.9) this value will be used as the server port to connect to. This request >> will be rejected (since port is 65535) and thus nfs mount point can't be >> unmounted. > > Note: this is only possible if /etc/mtab is a link to /proc/mounts. Not all systems have this configuration. >
I found it on CentOs 5.5 with RHEL6 kernel. Actually, the current patch has a specific flaw: if mount port is not passed by nfs utils using mount options version 6, then it will be set to 0 and showed in /proc/mounts as "mountport=0". Another fix solution is to call "nfs_set_port(sap, &args->nfs_server.port, 0);" when parsing mount options version 6 (like in done in default casein nfs_validate_mount_data) instead of changing nfs_show_mountd_options().
>> >> Kernel version affected: 2.6.37-rc4 >> >> Signed-off-by: Stanislav Kinsbursky<skinsbursky@parallels.com> >> >> --- >> fs/nfs/super.c | 3 ++- >> 1 files changed, 2 insertions(+), 1 deletions(-) >> >> diff --git a/fs/nfs/super.c b/fs/nfs/super.c >> index 6d6e21d..fd4cac8 100644 >> --- a/fs/nfs/super.c >> +++ b/fs/nfs/super.c >> @@ -681,7 +681,8 @@ static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss, >> >> if (nfss->mountd_version || showdefaults) >> seq_printf(m, ",mountvers=%u", nfss->mountd_version); >> - if (nfss->mountd_port || showdefaults) >> + if (nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT || >> + showdefaults) >> seq_printf(m, ",mountport=%u", nfss->mountd_port); >> >> nfs_show_mountd_netid(m, nfss, showdefaults); >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >
-- Best regards, Stanislav Kinsbursky -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@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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