[ 088/167] [PATCH] nfs: Enclose hostname in brackets when needed innfs_do_root_mount

From: Ben Hutchings
Date: Wed May 09 2012 - 02:18:58 EST

3.2-stable review patch. If anyone has any objections, please let me know.


From: Jan Kara <jack@xxxxxxx>

commit 98a2139f4f4d7b5fcc3a54c7fddbe88612abed20 upstream.

When hostname contains colon (e.g. when it is an IPv6 address) it needs
to be enclosed in brackets to make parsing of NFS device string possible.
Fix nfs_do_root_mount() to enclose hostname properly when needed. NFS code
actually does not need this as it does not parse the string passed by
nfs_do_root_mount() but the device string is exposed to userspace in

CC: Josh Boyer <jwboyer@xxxxxxxxxx>
CC: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
fs/nfs/super.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 37412f7..1e6715f 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2767,11 +2767,15 @@ static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
char *root_devname;
size_t len;

- len = strlen(hostname) + 3;
+ len = strlen(hostname) + 5;
root_devname = kmalloc(len, GFP_KERNEL);
if (root_devname == NULL)
return ERR_PTR(-ENOMEM);
- snprintf(root_devname, len, "%s:/", hostname);
+ /* Does hostname needs to be enclosed in brackets? */
+ if (strchr(hostname, ':'))
+ snprintf(root_devname, len, "[%s]:/", hostname);
+ else
+ snprintf(root_devname, len, "%s:/", hostname);
root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
return root_mnt;

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/