[PATCH v3 06/15] hfsplus: fix remount issue

[Vyacheslav Dubeyko <slava@dubeyko.com>]

From: Vyacheslav Dubeyko <slava@dubeyko.com>
Subject: [PATCH v3 06/15] hfsplus: fix remount issue

Current implementation of HFS+ driver has small issue
with remount option. Namely, for example, you are
unable to remount from RO mode into RW mode by means
of command "mount -o remount,rw /dev/loop0 /mnt/hfsplus".
Trying to execute sequence of commands is resulted
with error message:

mount /dev/loop0 /mnt/hfsplus
mount -o remount,ro /dev/loop0 /mnt/hfsplus
mount -o remount,rw /dev/loop0 /mnt/hfsplus

mount: you must specify the filesystem type

mount -t hfsplus -o remount,rw /dev/loop0 /mnt/hfsplus

mount: /mnt/hfsplus not mounted or bad option

The reason of such issue is failure of mount syscall:

mount("/dev/loop0", "/mnt/hfsplus", 0x2282a60, MS_MGC_VAL|MS_REMOUNT, NULL) = -1 EINVAL (Invalid argument)

Namely, hfsplus_parse_options_remount() method receives
empty "input" argument and return false in such case.
As a result, hfsplus_remount() returns -EINVAL error
code.

This patch fixes the issue by means of return true
for the case of empty "input" argument in
hfsplus_parse_options_remount() method.

Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
CC: Al Viro <viro@zeniv.linux.org.uk>
CC: Christoph Hellwig <hch@infradead.org>
CC: Hin-Tak Leung <htl10@users.sourceforge.net>
---
 fs/hfsplus/options.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
index 4ad835e..60829cd 100644
--- a/fs/hfsplus/options.c
+++ b/fs/hfsplus/options.c
@@ -76,7 +76,7 @@ int hfsplus_parse_options_remount(char *input, struct hfsplus_sb_info *sbi)
 	int token;
 
 	if (!input)
-		return 0;
+		return 1;
 
 	while ((p = strsep(&input, ",")) != NULL) {
 		if (!*p)
-- 
1.7.9.5