From 03b9342ba877075b024e3932b43afa68e5d3f0fd Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 8 Nov 2012 16:09:37 -0800 Subject: [PATCH] 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. Signed-off-by: NeilBrown Cc: Trond Myklebust Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Al Viro [bwh: Backported to 3.2: use named initialisers instead of QSTR_INIT()] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- fs/dcache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/dcache.c b/fs/dcache.c index 8b64f383570b1..ecc07426fb552 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1563,7 +1563,7 @@ static struct dentry * d_find_any_alias(struct inode *inode) */ 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;