[PATCH v2 1/2] The "keep_last_dots" mount option will, in a subsequent commit, control whether or not trailing periods '.' are stripped from path components during file lookup or file creation.

[Vasant Karasulli <vkarasulli@xxxxxxx>]

Suggested-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Vasant Karasulli <vkarasulli@xxxxxxx>
Co-developed-by: David Disseldorp <ddiss@xxxxxxx>
Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
---
 fs/exfat/exfat_fs.h | 3 ++-
 fs/exfat/super.c    | 7 +++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 619e5b4bed10..c6800b880920 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -203,7 +203,8 @@ struct exfat_mount_options {
 	/* on error: continue, panic, remount-ro */
 	enum exfat_error_mode errors;
 	unsigned utf8:1, /* Use of UTF-8 character set */
-		 discard:1; /* Issue discard requests on deletions */
+		 discard:1, /* Issue discard requests on deletions */
+		 keep_last_dots:1; /* Keep trailing periods in paths */
 	int time_offset; /* Offset of timestamps from UTC (in minutes) */
 };
 
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index 8c9fb7dcec16..4c3f80ed17b1 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -174,6 +174,8 @@ static int exfat_show_options(struct seq_file *m, struct dentry *root)
 		seq_puts(m, ",errors=remount-ro");
 	if (opts->discard)
 		seq_puts(m, ",discard");
+	if (opts->keep_last_dots)
+		seq_puts(m, ",keep_last_dots");
 	if (opts->time_offset)
 		seq_printf(m, ",time_offset=%d", opts->time_offset);
 	return 0;
@@ -217,6 +219,7 @@ enum {
 	Opt_charset,
 	Opt_errors,
 	Opt_discard,
+	Opt_keep_last_dots,
 	Opt_time_offset,
 
 	/* Deprecated options */
@@ -243,6 +246,7 @@ static const struct fs_parameter_spec exfat_parameters[] = {
 	fsparam_string("iocharset",		Opt_charset),
 	fsparam_enum("errors",			Opt_errors, exfat_param_enums),
 	fsparam_flag("discard",			Opt_discard),
+	fsparam_flag("keep_last_dots",		Opt_keep_last_dots),
 	fsparam_s32("time_offset",		Opt_time_offset),
 	__fsparam(NULL, "utf8",			Opt_utf8, fs_param_deprecated,
 		  NULL),
@@ -297,6 +301,9 @@ static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
 	case Opt_discard:
 		opts->discard = 1;
 		break;
+	case Opt_keep_last_dots:
+		opts->keep_last_dots = 1;
+		break;
 	case Opt_time_offset:
 		/*
 		 * Make the limit 24 just in case someone invents something
-- 
2.32.0