diff options
Diffstat (limited to 'fs/overlayfs/readdir.c')
| -rw-r--r-- | fs/overlayfs/readdir.c | 32 |
1 files changed, 28 insertions, 4 deletions
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 6918b98faeb6..9b0078aabaf9 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -1051,7 +1051,9 @@ int ovl_check_d_type_supported(struct path *realpath) return rdd.d_type_supported; } -static void ovl_workdir_cleanup_recurse(struct path *path, int level) +#define OVL_INCOMPATDIR_NAME "incompat" + +static int ovl_workdir_cleanup_recurse(struct path *path, int level) { int err; struct inode *dir = path->dentry->d_inode; @@ -1065,6 +1067,19 @@ static void ovl_workdir_cleanup_recurse(struct path *path, int level) .root = &root, .is_lowest = false, }; + bool incompat = false; + + /* + * The "work/incompat" directory is treated specially - if it is not + * empty, instead of printing a generic error and mounting read-only, + * we will error about incompat features and fail the mount. + * + * When called from ovl_indexdir_cleanup(), path->dentry->d_name.name + * starts with '#'. + */ + if (level == 2 && + !strcmp(path->dentry->d_name.name, OVL_INCOMPATDIR_NAME)) + incompat = true; err = ovl_dir_read(path, &rdd); if (err) @@ -1079,17 +1094,25 @@ static void ovl_workdir_cleanup_recurse(struct path *path, int level) continue; if (p->len == 2 && p->name[1] == '.') continue; + } else if (incompat) { + pr_err("overlay with incompat feature '%s' cannot be mounted\n", + p->name); + err = -EINVAL; + break; } dentry = lookup_one_len(p->name, path->dentry, p->len); if (IS_ERR(dentry)) continue; if (dentry->d_inode) - ovl_workdir_cleanup(dir, path->mnt, dentry, level); + err = ovl_workdir_cleanup(dir, path->mnt, dentry, level); dput(dentry); + if (err) + break; } inode_unlock(dir); out: ovl_cache_free(&list); + return err; } int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, @@ -1106,9 +1129,10 @@ int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, struct path path = { .mnt = mnt, .dentry = dentry }; inode_unlock(dir); - ovl_workdir_cleanup_recurse(&path, level + 1); + err = ovl_workdir_cleanup_recurse(&path, level + 1); inode_lock_nested(dir, I_MUTEX_PARENT); - err = ovl_cleanup(dir, dentry); + if (!err) + err = ovl_cleanup(dir, dentry); } return err; |