1 files changed, 27 insertions, 9 deletions

diff --git a/fs/bcachefs/compress.h b/fs/bcachefs/compress.h
index 052ea303241f..607fd5e232c9 100644
--- a/fs/bcachefs/compress.h
+++ b/fs/bcachefs/compress.h
@@ -4,12 +4,18 @@
 
 #include "extents_types.h"
 
+static const unsigned __bch2_compression_opt_to_type[] = {
+#define x(t, n) [BCH_COMPRESSION_OPT_##t] = BCH_COMPRESSION_TYPE_##t,
+	BCH_COMPRESSION_OPTS()
+#undef x
+};
+
 struct bch_compression_opt {
 	u8		type:4,
 			level:4;
 };
 
-static inline struct bch_compression_opt bch2_compression_decode(unsigned v)
+static inline struct bch_compression_opt __bch2_compression_decode(unsigned v)
 {
 	return (struct bch_compression_opt) {
 		.type	= v & 15,
@@ -17,17 +23,25 @@ static inline struct bch_compression_opt bch2_compression_decode(unsigned v)
 	};
 }
 
+static inline bool bch2_compression_opt_valid(unsigned v)
+{
+	struct bch_compression_opt opt = __bch2_compression_decode(v);
+
+	return opt.type < ARRAY_SIZE(__bch2_compression_opt_to_type) && !(!opt.type && opt.level);
+}
+
+static inline struct bch_compression_opt bch2_compression_decode(unsigned v)
+{
+	return bch2_compression_opt_valid(v)
+		? __bch2_compression_decode(v)
+		: (struct bch_compression_opt) { 0 };
+}
+
 static inline unsigned bch2_compression_encode(struct bch_compression_opt opt)
 {
 	return opt.type|(opt.level << 4);
 }
 
-static const unsigned __bch2_compression_opt_to_type[] = {
-#define x(t, n) [BCH_COMPRESSION_OPT_##t] = BCH_COMPRESSION_TYPE_##t,
-	BCH_COMPRESSION_OPTS()
-#undef x
-};
-
 static inline enum bch_compression_type bch2_compression_opt_to_type(unsigned v)
 {
 	return __bch2_compression_opt_to_type[bch2_compression_decode(v).type];
@@ -44,12 +58,16 @@ int bch2_check_set_has_compressed_data(struct bch_fs *, unsigned);
 void bch2_fs_compress_exit(struct bch_fs *);
 int bch2_fs_compress_init(struct bch_fs *);
 
+void bch2_compression_opt_to_text(struct printbuf *, u64);
+
 int bch2_opt_compression_parse(struct bch_fs *, const char *, u64 *, struct printbuf *);
 void bch2_opt_compression_to_text(struct printbuf *, struct bch_fs *, struct bch_sb *, u64);
+int bch2_opt_compression_validate(u64, struct printbuf *);
 
 #define bch2_opt_compression (struct bch_opt_fn) {		\
-	.parse		= bch2_opt_compression_parse,	\
-	.to_text	= bch2_opt_compression_to_text,	\
+	.parse		= bch2_opt_compression_parse,		\
+	.to_text	= bch2_opt_compression_to_text,		\
+	.validate	= bch2_opt_compression_validate,	\
 }
 
 #endif /* _BCACHEFS_COMPRESS_H */