From 09e10322b71716adf567d453889ef0871cf226b9 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Sat, 13 Dec 2014 00:59:45 +0100 Subject: ovl: lookup ENAMETOOLONG on lower means ENOENT "Suppose you have in one of the lower layers a filesystem with ->lookup()-enforced upper limit on name length. Pretty much every local fs has one, but... they are not all equal. 255 characters is the common upper limit, but e.g. jffs2 stops at 254, minixfs upper limit is somewhere from 14 to 60, depending upon version, etc. You are doing a lookup for something that is present in upper layer, but happens to be too long for one of the lower layers. Too bad - ENAMETOOLONG for you..." Reported-by: Al Viro Signed-off-by: Miklos Szeredi --- fs/overlayfs/super.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 5dbc678..110c968 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -376,8 +376,14 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, opaque = false; this = ovl_lookup_real(lowerpath.dentry, &dentry->d_name); err = PTR_ERR(this); - if (IS_ERR(this)) + if (IS_ERR(this)) { + /* + * If it's positive, then treat ENAMETOOLONG as ENOENT. + */ + if (err == -ENAMETOOLONG && (upperdentry || ctr)) + continue; goto out_put; + } if (!this) continue; if (ovl_is_whiteout(this)) { -- cgit v1.1