udf: fix potential refcnt problem of nls module
When specifiying iocharset multiple times in a mount or once/multiple in
a remount, current option parsing may cause inaccurate refcount of nls
module. Also, in the failure cleanup of option parsing, the condition
of calling unload_nls is not sufficient.
Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/super.c b/fs/udf/super.c
index bf5f608..7949c33 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -477,7 +477,6 @@ static int udf_parse_options(char *options, struct udf_options *uopt,
uopt->session = 0xFFFFFFFF;
uopt->lastblock = 0;
uopt->anchor = 0;
- uopt->nls_map = NULL;
if (!options)
return 1;
@@ -575,8 +574,12 @@ static int udf_parse_options(char *options, struct udf_options *uopt,
break;
#ifdef CONFIG_UDF_NLS
case Opt_iocharset:
- uopt->nls_map = load_nls(args[0].from);
- uopt->flags |= (1 << UDF_FLAG_NLS_MAP);
+ if (!remount) {
+ if (uopt->nls_map)
+ unload_nls(uopt->nls_map);
+ uopt->nls_map = load_nls(args[0].from);
+ uopt->flags |= (1 << UDF_FLAG_NLS_MAP);
+ }
break;
#endif
case Opt_uforget:
@@ -627,6 +630,7 @@ static int udf_remount_fs(struct super_block *sb, int *flags, char *options)
uopt.umask = sbi->s_umask;
uopt.fmode = sbi->s_fmode;
uopt.dmode = sbi->s_dmode;
+ uopt.nls_map = NULL;
if (!udf_parse_options(options, &uopt, true))
return -EINVAL;
@@ -2095,6 +2099,7 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent)
uopt.umask = 0;
uopt.fmode = UDF_INVALID_MODE;
uopt.dmode = UDF_INVALID_MODE;
+ uopt.nls_map = NULL;
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
@@ -2275,8 +2280,8 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent)
iput(sbi->s_vat_inode);
parse_options_failure:
#ifdef CONFIG_UDF_NLS
- if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))
- unload_nls(sbi->s_nls_map);
+ if (uopt.nls_map)
+ unload_nls(uopt.nls_map);
#endif
if (lvid_open)
udf_close_lvid(sb);
