linux-ext4 - [PATCH 10/13] exfat: free the sbi and iocharset in ->kill

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Date:   Tue,  8 Aug 2023 09:15:57 -0700
From:   Christoph Hellwig <hch@....de>
To:     Al Viro <viro@...iv.linux.org.uk>,
        Christian Brauner <brauner@...nel.org>
Cc:     Namjae Jeon <linkinjeon@...nel.org>,
        Sungjong Seo <sj1557.seo@...sung.com>,
        "Theodore Ts'o" <tytso@....edu>,
        Andreas Dilger <adilger.kernel@...ger.ca>,
        Konstantin Komarov <almaz.alexandrovich@...agon-software.com>,
        "Darrick J. Wong" <djwong@...nel.org>,
        linux-fsdevel@...r.kernel.org, linux-ext4@...r.kernel.org,
        ntfs3@...ts.linux.dev, linux-xfs@...r.kernel.org
Subject: [PATCH 10/13] exfat: free the sbi and iocharset in ->kill_sb

As a rule of thumb everything allocated to the fs_context and moved into
the super_block should be freed by ->kill_sb so that the teardown
handling doesn't need to be duplicated between the fill_super error
path and put_super.  Implement an exfat-specific kill_sb method to do
that and share the code with the mount contex free helper for the
mount error handling case.

Signed-off-by: Christoph Hellwig <hch@....de>
---
 fs/exfat/super.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index 3c6aec96d0dc85..85b04a4064af1e 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -41,9 +41,7 @@ static void exfat_put_super(struct super_block *sb)
 	mutex_unlock(&sbi->s_lock);
 
 	unload_nls(sbi->nls_io);
-	exfat_free_iocharset(sbi);
 	exfat_free_upcase_table(sbi);
-	kfree(sbi);
 }
 
 static int exfat_sync_fs(struct super_block *sb, int wait)
@@ -703,9 +701,6 @@ static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
 
 check_nls_io:
 	unload_nls(sbi->nls_io);
-	exfat_free_iocharset(sbi);
-	sb->s_fs_info = NULL;
-	kfree(sbi);
 	return err;
 }
 
@@ -714,14 +709,18 @@ static int exfat_get_tree(struct fs_context *fc)
 	return get_tree_bdev(fc, exfat_fill_super);
 }
 
+static void exfat_free_sbi(struct exfat_sb_info *sbi)
+{
+	exfat_free_iocharset(sbi);
+	kfree(sbi);
+}
+
 static void exfat_free(struct fs_context *fc)
 {
 	struct exfat_sb_info *sbi = fc->s_fs_info;
 
-	if (sbi) {
-		exfat_free_iocharset(sbi);
-		kfree(sbi);
-	}
+	if (sbi)
+		exfat_free_sbi(sbi);
 }
 
 static int exfat_reconfigure(struct fs_context *fc)
@@ -766,12 +765,21 @@ static int exfat_init_fs_context(struct fs_context *fc)
 	return 0;
 }
 
+static void exfat_kill_sb(struct super_block *sb)
+{
+	struct exfat_sb_info *sbi = sb->s_fs_info;
+
+	kill_block_super(sb);
+	if (sbi)
+		exfat_free_sbi(sbi);
+}
+
 static struct file_system_type exfat_fs_type = {
 	.owner			= THIS_MODULE,
 	.name			= "exfat",
 	.init_fs_context	= exfat_init_fs_context,
 	.parameters		= exfat_parameters,
-	.kill_sb		= kill_block_super,
+	.kill_sb		= exfat_kill_sb,
 	.fs_flags		= FS_REQUIRES_DEV,
 };
 
-- 
2.39.2