bcachefs: Fix casefold lookups

Add casefolding to bch2_lookup_trans:

During the delay between when casefolding was written and when it was
merged, the main filesystem lookup path grew self healing - which meant
it was no longer using bch2_dirent_lookup_trans(), where casefolding on
lookups happens.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Author: Kent Overstreet

fs/bcachefs/dirent.c

@@ -13,8 +13,8 @@
 
 #include <linux/dcache.h>
 
-static int bch2_casefold(struct btree_trans *trans, const struct bch_hash_info *info,
-				const struct qstr *str, struct qstr *out_cf)
+int bch2_casefold(struct btree_trans *trans, const struct bch_hash_info *info,
+		  const struct qstr *str, struct qstr *out_cf)
 {
 	*out_cf = (struct qstr) QSTR_INIT(NULL, 0);
 
@@ -35,18 +35,6 @@ static int bch2_casefold(struct btree_trans *trans, const struct bch_hash_info *
 #endif
 }
 
-static inline int bch2_maybe_casefold(struct btree_trans *trans,
-				      const struct bch_hash_info *info,
-				      const struct qstr *str, struct qstr *out_cf)
-{
-	if (likely(!info->cf_encoding)) {
-		*out_cf = *str;
-		return 0;
-	} else {
-		return bch2_casefold(trans, info, str, out_cf);
-	}
-}
-
 static unsigned bch2_dirent_name_bytes(struct bkey_s_c_dirent d)
 {
 	if (bkey_val_bytes(d.k) < offsetof(struct bch_dirent, d_name))

fs/bcachefs/dirent.h

@@ -23,6 +23,21 @@ struct bch_fs;
 struct bch_hash_info;
 struct bch_inode_info;
 
+int bch2_casefold(struct btree_trans *, const struct bch_hash_info *,
+		  const struct qstr *, struct qstr *);
+
+static inline int bch2_maybe_casefold(struct btree_trans *trans,
+				      const struct bch_hash_info *info,
+				      const struct qstr *str, struct qstr *out_cf)
+{
+	if (likely(!info->cf_encoding)) {
+		*out_cf = *str;
+		return 0;
+	} else {
+		return bch2_casefold(trans, info, str, out_cf);
+	}
+}
+
 struct qstr bch2_dirent_get_name(struct bkey_s_c_dirent d);
 
 static inline unsigned dirent_val_u64s(unsigned len, unsigned cf_len)

fs/bcachefs/fs.c

@@ -648,13 +648,18 @@ static struct bch_inode_info *bch2_lookup_trans(struct btree_trans *trans,
 			const struct qstr *name)
 {
 	struct bch_fs *c = trans->c;
-	struct btree_iter dirent_iter = {};
 	subvol_inum inum = {};
 	struct printbuf buf = PRINTBUF;
 
+	struct qstr lookup_name;
+	int ret = bch2_maybe_casefold(trans, dir_hash_info, name, &lookup_name);
+	if (ret)
+		return ERR_PTR(ret);
+
+	struct btree_iter dirent_iter = {};
 	struct bkey_s_c k = bch2_hash_lookup(trans, &dirent_iter, bch2_dirent_hash_desc,
-					     dir_hash_info, dir, name, 0);
-	int ret = bkey_err(k);
+					     dir_hash_info, dir, &lookup_name, 0);
+	ret = bkey_err(k);
 	if (ret)
 		return ERR_PTR(ret);