diff options
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 1 | ||||
| -rw-r--r-- | fs/overlayfs/readdir.c | 37 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 15 |
3 files changed, 53 insertions, 0 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 99b4168..6a7090f 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -166,6 +166,7 @@ extern const struct file_operations ovl_dir_operations; int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list); void ovl_cache_free(struct list_head *list); +int ovl_check_d_type_supported(struct path *realpath); /* inode.c */ int ovl_setattr(struct dentry *dentry, struct iattr *attr); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index fdaf28f..18d0a16 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -43,6 +43,7 @@ struct ovl_readdir_data { struct ovl_cache_entry *first_maybe_whiteout; int count; int err; + bool d_type_supported; }; struct ovl_dir_file { @@ -577,3 +578,39 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list) } inode_unlock(upper->d_inode); } + +static int ovl_check_d_type(struct dir_context *ctx, const char *name, + int namelen, loff_t offset, u64 ino, + unsigned int d_type) +{ + struct ovl_readdir_data *rdd = + container_of(ctx, struct ovl_readdir_data, ctx); + + /* Even if d_type is not supported, DT_DIR is returned for . and .. */ + if (!strncmp(name, ".", namelen) || !strncmp(name, "..", namelen)) + return 0; + + if (d_type != DT_UNKNOWN) + rdd->d_type_supported = true; + + return 0; +} + +/* + * Returns 1 if d_type is supported, 0 not supported/unknown. Negative values + * if error is encountered. + */ +int ovl_check_d_type_supported(struct path *realpath) +{ + int err; + struct ovl_readdir_data rdd = { + .ctx.actor = ovl_check_d_type, + .d_type_supported = false, + }; + + err = ovl_dir_read(realpath, &rdd); + if (err) + return err; + + return rdd.d_type_supported; +} diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 6b0111a..ef64984 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1029,6 +1029,21 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) sb->s_flags |= MS_RDONLY; ufs->workdir = NULL; } + + /* + * Upper should support d_type, else whiteouts are visible. + * Given workdir and upper are on same fs, we can do + * iterate_dir() on workdir. + */ + err = ovl_check_d_type_supported(&workpath); + if (err < 0) + goto out_put_workdir; + + if (!err) { + pr_err("overlayfs: upper fs needs to support d_type.\n"); + err = -EINVAL; + goto out_put_workdir; + } } err = -ENOMEM; |