diff options
Diffstat (limited to 'fs/overlayfs')
| -rw-r--r-- | fs/overlayfs/readdir.c | 32 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 25 |
2 files changed, 46 insertions, 11 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; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 4b38141c2985..f82defec02c1 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -705,8 +705,12 @@ retry: goto out_unlock; retried = true; - ovl_workdir_cleanup(dir, mnt, work, 0); + err = ovl_workdir_cleanup(dir, mnt, work, 0); dput(work); + if (err == -EINVAL) { + work = ERR_PTR(err); + goto out_unlock; + } goto retry; } @@ -1203,7 +1207,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs, struct path *workpath) { struct vfsmount *mnt = ovl_upper_mnt(ofs); - struct dentry *temp; + struct dentry *temp, *workdir; bool rename_whiteout; bool d_type; int fh_type; @@ -1213,10 +1217,13 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs, if (err) return err; - ofs->workdir = ovl_workdir_create(ofs, OVL_WORKDIR_NAME, false); - if (!ofs->workdir) + workdir = ovl_workdir_create(ofs, OVL_WORKDIR_NAME, false); + err = PTR_ERR(workdir); + if (IS_ERR_OR_NULL(workdir)) goto out; + ofs->workdir = workdir; + err = ovl_setup_trap(sb, ofs->workdir, &ofs->workdir_trap, "workdir"); if (err) goto out; @@ -1347,6 +1354,7 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs, struct ovl_entry *oe, struct path *upperpath) { struct vfsmount *mnt = ovl_upper_mnt(ofs); + struct dentry *indexdir; int err; err = mnt_want_write(mnt); @@ -1366,9 +1374,12 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs, ofs->workdir_trap = NULL; dput(ofs->workdir); ofs->workdir = NULL; - ofs->indexdir = ovl_workdir_create(ofs, OVL_INDEXDIR_NAME, true); - if (ofs->indexdir) { - ofs->workdir = dget(ofs->indexdir); + indexdir = ovl_workdir_create(ofs, OVL_INDEXDIR_NAME, true); + if (IS_ERR(indexdir)) { + err = PTR_ERR(indexdir); + } else if (indexdir) { + ofs->indexdir = indexdir; + ofs->workdir = dget(indexdir); err = ovl_setup_trap(sb, ofs->indexdir, &ofs->indexdir_trap, "indexdir"); |