[PATCH v3 2/2] hfsplus: extract hidden directory search into a helper function

[Zilin Guan <zilin@seu.edu.cn>]

In hfsplus_fill_super(), the process of looking up the hidden directory
involves initializing a catalog search, building a search key, reading
the b-tree record, and releasing the search data.

Currently, this logic is open-coded directly within the main superblock
initialization routine. This makes hfsplus_fill_super() quite lengthy
and its error handling paths less straightforward.

Extract the hidden directory search sequence into a new helper function,
hfsplus_get_hidden_dir_entry(). This improves overall code readability,
cleanly encapsulates the hfs_find_data lifecycle, and simplifies the
error exits in hfsplus_fill_super().

Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
---
 fs/hfsplus/super.c | 43 ++++++++++++++++++++++++++++++-------------
 1 file changed, 30 insertions(+), 13 deletions(-)

diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index f396fee19ab8..9a03e206660d 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -424,12 +424,35 @@ void hfsplus_prepare_volume_header_for_commit(struct hfsplus_vh *vhdr)
 	vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_INCNSTNT);
 }
 
+static inline int hfsplus_get_hidden_dir_entry(struct super_block *sb,
+					       const struct qstr *str,
+					       hfsplus_cat_entry *entry)
+{
+	struct hfs_find_data fd;
+	int err;
+
+	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
+	if (unlikely(err))
+		return err;
+
+	err = hfsplus_cat_build_key(sb, fd.search_key, HFSPLUS_ROOT_CNID, str);
+	if (unlikely(err))
+		goto free_fd;
+
+	err = hfs_brec_read(&fd, entry, sizeof(*entry));
+	if (err)
+		err = -ENOENT;
+
+free_fd:
+	hfs_find_exit(&fd);
+	return err;
+}
+
 static int hfsplus_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct hfsplus_vh *vhdr;
 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 	hfsplus_cat_entry entry;
-	struct hfs_find_data fd;
 	struct inode *root, *inode;
 	struct qstr str;
 	struct nls_table *nls;
@@ -565,16 +588,11 @@ static int hfsplus_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	str.len = sizeof(HFSP_HIDDENDIR_NAME) - 1;
 	str.name = HFSP_HIDDENDIR_NAME;
-	err = hfs_find_init(sbi->cat_tree, &fd);
-	if (err)
-		goto out_put_root;
-	err = hfsplus_cat_build_key(sb, fd.search_key, HFSPLUS_ROOT_CNID, &str);
-	if (unlikely(err < 0)) {
-		hfs_find_exit(&fd);
-		goto out_put_root;
-	}
-	if (!hfs_brec_read(&fd, &entry, sizeof(entry))) {
-		hfs_find_exit(&fd);
+	err = hfsplus_get_hidden_dir_entry(sb, &str, &entry);
+	if (err) {
+		if (err != -ENOENT)
+			goto out_put_root;
+	} else {
 		if (entry.type != cpu_to_be16(HFSPLUS_FOLDER)) {
 			err = -EIO;
 			goto out_put_root;
@@ -585,8 +603,7 @@ static int hfsplus_fill_super(struct super_block *sb, struct fs_context *fc)
 			goto out_put_root;
 		}
 		sbi->hidden_dir = inode;
-	} else
-		hfs_find_exit(&fd);
+	}
 
 	if (!sb_rdonly(sb)) {
 		/*
-- 
2.34.1