From a425c037f3dd8a56469158ab5f37beb46402d958 Mon Sep 17 00:00:00 2001 From: hujianyang Date: Tue, 6 Jan 2015 16:10:01 +0800 Subject: ovl: Fix opaque regression in ovl_lookup Current multi-layer support overlayfs has a regression in .lookup(). If there is a directory in upperdir and a regular file has same name in lowerdir in a merged directory, lower file is hidden and upper directory is set to opaque in former case. But it is changed in present code. In lowerdir lookup path, if a found inode is not directory, the type checking of previous inode is missing. This inode will be copied to the lowerstack of ovl_entry directly. That will lead to several wrong conditions, for example, the reading of the directory in upperdir may return an error like: ls: reading directory .: Not a directory This patch makes the lowerdir lookup path check the opaque for non-directory file too. Signed-off-by: hujianyang Signed-off-by: Miklos Szeredi --- fs/overlayfs/super.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'fs/overlayfs') diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 6ca8ea8cb9b2..9e94f4acef1a 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -372,7 +372,6 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, bool opaque = false; struct path lowerpath = poe->lowerstack[i]; - opaque = false; this = ovl_lookup_real(lowerpath.dentry, &dentry->d_name); err = PTR_ERR(this); if (IS_ERR(this)) { @@ -395,20 +394,24 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, */ if (i < poe->numlower - 1 && ovl_is_opaquedir(this)) opaque = true; - /* - * If this is a non-directory then stop here. - * - * FIXME: check for opaqueness maybe better done in remove code. - */ - if (!S_ISDIR(this->d_inode->i_mode)) { - opaque = true; - } else if (prev && (!S_ISDIR(prev->d_inode->i_mode) || - !S_ISDIR(this->d_inode->i_mode))) { + + if (prev && (!S_ISDIR(prev->d_inode->i_mode) || + !S_ISDIR(this->d_inode->i_mode))) { + /* + * FIXME: check for upper-opaqueness maybe better done + * in remove code. + */ if (prev == upperdentry) upperopaque = true; dput(this); break; } + /* + * If this is a non-directory then stop here. + */ + if (!S_ISDIR(this->d_inode->i_mode)) + opaque = true; + stack[ctr].dentry = this; stack[ctr].mnt = lowerpath.mnt; ctr++; -- cgit v1.2.3-59-g8ed1b