vfs: d_obtain_alias() needs to use "/" as default name.
commit b911a6bdeef5848c468597d040e3407e0aee04ce upstream.
NFS appears to use d_obtain_alias() to create the root dentry rather than
d_make_root. This can cause 'prepend_path()' to complain that the root
has a weird name if an NFS filesystem is lazily unmounted. e.g. if
"/mnt" is an NFS mount then
{ cd /mnt; umount -l /mnt ; ls -l /proc/self/cwd; }
will cause a WARN message like
WARNING: at /home/git/linux/fs/dcache.c:2624 prepend_path+0x1d7/0x1e0()
...
Root dentry has weird name <>
to appear in kernel logs.
So change d_obtain_alias() to use "/" rather than "" as the anonymous
name.
Change-Id: I94a33d30e63e4f08960bfbace44d1a71912aab81
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: use named initialisers instead of QSTR_INIT()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/dcache.c b/fs/dcache.c
index cd63656..b3027cc 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1556,7 +1556,7 @@
*/
struct dentry *d_obtain_alias(struct inode *inode)
{
- static const struct qstr anonstring = { .name = "" };
+ static const struct qstr anonstring = { .name = "/", .len = 1 };
struct dentry *tmp;
struct dentry *res;