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authorMiklos Szeredi <mszeredi@suse.cz>2015-05-14 10:04:44 +0200
committerMiklos Szeredi <mszeredi@suse.cz>2015-05-14 10:04:44 +0200
commitd377c5eb54dd05aeb3094b7740252d19ba7791f7 (patch)
treee0af790ebf150f97fbb1ea79bdb0d5aa6f2a3474 /fs
parent030bbdbf4c833bc69f502eae58498bc5572db736 (diff)
downloadkernel-d377c5eb54dd05aeb3094b7740252d19ba7791f7.tar.gz
ovl: don't remove non-empty opaque directory
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") Cc: <stable@vger.kernel.org> # v4.0+
Diffstat (limited to 'fs')
-rw-r--r--fs/overlayfs/dir.c24
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);