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Diffstat (limited to 'fs/overlayfs/readdir.c')
-rw-r--r--fs/overlayfs/readdir.c37
1 files changed, 37 insertions, 0 deletions
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;
+}