bcachefs: Fix casefold opt via xattr interface

Changing the casefold option requires extra checks/work - factor out a
helper from bch2_fileattr_set() for the xattr code to use.

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

Author: Kent Overstreet

fs/bcachefs/fs.c

@@ -1664,33 +1664,9 @@ static int fssetxattr_inode_update_fn(struct btree_trans *trans,
 		return -EINVAL;
 
 	if (s->casefold != bch2_inode_casefold(c, bi)) {
-#ifdef CONFIG_UNICODE
-		int ret = 0;
-		/* Not supported on individual files. */
-		if (!S_ISDIR(bi->bi_mode))
-			return -EOPNOTSUPP;
-
-		/*
-		 * Make sure the dir is empty, as otherwise we'd need to
-		 * rehash everything and update the dirent keys.
-		 */
-		ret = bch2_empty_dir_trans(trans, inode_inum(inode));
-		if (ret < 0)
-			return ret;
-
-		ret = bch2_request_incompat_feature(c, bcachefs_metadata_version_casefolding);
+		int ret = bch2_inode_set_casefold(trans, inode_inum(inode), bi, s->casefold);
 		if (ret)
 			return ret;
-
-		bch2_check_set_feature(c, BCH_FEATURE_casefolding);
-
-		bi->bi_casefold = s->casefold + 1;
-		bi->bi_fields_set |= BIT(Inode_opt_casefold);
-
-#else
-		printk(KERN_ERR "Cannot use casefolding on a kernel without CONFIG_UNICODE\n");
-		return -EOPNOTSUPP;
-#endif
 	}
 
 	if (s->set_project) {

fs/bcachefs/inode.c

@@ -14,6 +14,7 @@
 #include "extent_update.h"
 #include "fs.h"
 #include "inode.h"
+#include "namei.h"
 #include "opts.h"
 #include "str_hash.h"
 #include "snapshot.h"
@@ -1204,6 +1205,41 @@ int bch2_inum_opts_get(struct btree_trans *trans, subvol_inum inum, struct bch_i
 	return 0;
 }
 
+int bch2_inode_set_casefold(struct btree_trans *trans, subvol_inum inum,
+			    struct bch_inode_unpacked *bi, unsigned v)
+{
+	struct bch_fs *c = trans->c;
+
+#ifdef CONFIG_UNICODE
+	int ret = 0;
+	/* Not supported on individual files. */
+	if (!S_ISDIR(bi->bi_mode))
+		return -EOPNOTSUPP;
+
+	/*
+	 * Make sure the dir is empty, as otherwise we'd need to
+	 * rehash everything and update the dirent keys.
+	 */
+	ret = bch2_empty_dir_trans(trans, inum);
+	if (ret < 0)
+		return ret;
+
+	ret = bch2_request_incompat_feature(c, bcachefs_metadata_version_casefolding);
+	if (ret)
+		return ret;
+
+	bch2_check_set_feature(c, BCH_FEATURE_casefolding);
+
+	bi->bi_casefold = v + 1;
+	bi->bi_fields_set |= BIT(Inode_opt_casefold);
+
+	return 0;
+#else
+	bch_err(c, "Cannot use casefolding on a kernel without CONFIG_UNICODE");
+	return -EOPNOTSUPP;
+#endif
+}
+
 static noinline int __bch2_inode_rm_snapshot(struct btree_trans *trans, u64 inum, u32 snapshot)
 {
 	struct bch_fs *c = trans->c;

fs/bcachefs/inode.h

@@ -292,7 +292,9 @@ static inline bool bch2_inode_should_have_single_bp(struct bch_inode_unpacked *i
 struct bch_opts bch2_inode_opts_to_opts(struct bch_inode_unpacked *);
 void bch2_inode_opts_get(struct bch_io_opts *, struct bch_fs *,
 			 struct bch_inode_unpacked *);
-int bch2_inum_opts_get(struct btree_trans*, subvol_inum, struct bch_io_opts *);
+int bch2_inum_opts_get(struct btree_trans *, subvol_inum, struct bch_io_opts *);
+int bch2_inode_set_casefold(struct btree_trans *, subvol_inum,
+			    struct bch_inode_unpacked *, unsigned);
 
 #include "rebalance.h"
 

fs/bcachefs/xattr.c

@@ -473,6 +473,12 @@ static int inode_opt_set_fn(struct btree_trans *trans,
 {
 	struct inode_opt_set *s = p;
 
+	if (s->id == Inode_opt_casefold) {
+		int ret = bch2_inode_set_casefold(trans, inode_inum(inode), bi, s->v);
+		if (ret)
+			return ret;
+	}
+
 	if (s->defined)
 		bi->bi_fields_set |= 1U << s->id;
 	else