diff options
| author | Miklos Szeredi <mszeredi@suse.cz> | 2015-05-14 10:04:44 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-06-06 08:20:50 -0700 |
| commit | 5738c250f437599583ad9130e6fd6c10eb1d1ffa (patch) | |
| tree | 89a798820a6248cd589aed64f75f49ef8580e770 /fs | |
| parent | b8eadc722286edff2612768b5bc3555aa8494000 (diff) | |
ovl: don't remove non-empty opaque directory
commit d377c5eb54dd05aeb3094b7740252d19ba7791f7 upstream.
When removing an opaque directory we can't just call rmdir() to check for
emptiness, because the directory will need to be replaced with a whiteout.
The replacement is done with RENAME_EXCHANGE, which doesn't check
emptiness.
Solution is just to check emptiness by reading the directory. In the
future we could add a new rename flag to check for emptiness even for
RENAME_EXCHANGE to optimize this case.
Reported-by: Vincent Batts <vbatts@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Jordi Pujol Palomer <jordipujolp@gmail.com>
Fixes: 263b4a0fee43 ("ovl: dont replace opaque dir")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/overlayfs/dir.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index d139405d2bfa..2578a0c0677d 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -506,11 +506,25 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir) struct dentry *opaquedir = NULL; int err; - if (is_dir && OVL_TYPE_MERGE_OR_LOWER(ovl_path_type(dentry))) { - opaquedir = ovl_check_empty_and_clear(dentry); - err = PTR_ERR(opaquedir); - if (IS_ERR(opaquedir)) - goto out; + if (is_dir) { + if (OVL_TYPE_MERGE_OR_LOWER(ovl_path_type(dentry))) { + opaquedir = ovl_check_empty_and_clear(dentry); + err = PTR_ERR(opaquedir); + if (IS_ERR(opaquedir)) + goto out; + } else { + LIST_HEAD(list); + + /* + * When removing an empty opaque directory, then it + * makes no sense to replace it with an exact replica of + * itself. But emptiness still needs to be checked. + */ + err = ovl_check_empty_dir(dentry, &list); + ovl_cache_free(&list); + if (err) + goto out; + } } err = ovl_lock_rename_workdir(workdir, upperdir); |