UBIFS: allow sync option in rootflags
When passing UBIFS parameters via kernel command line, the
sync option will be passed to UBIFS as a string, not as an
MS_SYNCHRONOUS flag. Teach UBIFS interpreting this flag.
Reported-by: Aurélien GÉRÔME <ag@debian.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 42b818d..d10fc88 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -940,6 +940,27 @@
};
/**
+ * parse_standard_option - parse a standard mount option.
+ * @option: the option to parse
+ *
+ * Normally, standard mount options like "sync" are passed to file-systems as
+ * flags. However, when a "rootflags=" kernel boot parameter is used, they may
+ * be present in the options string. This function tries to deal with this
+ * situation and parse standard options. Returns 0 if the option was not
+ * recognized, and the corresponding integer flag if it was.
+ *
+ * UBIFS is only interested in the "sync" option, so do not check for anything
+ * else.
+ */
+static int parse_standard_option(const char *option)
+{
+ ubifs_msg("parse %s", option);
+ if (!strcmp(option, "sync"))
+ return MS_SYNCHRONOUS;
+ return 0;
+}
+
+/**
* ubifs_parse_options - parse mount parameters.
* @c: UBIFS file-system description object
* @options: parameters to parse
@@ -1015,9 +1036,19 @@
break;
}
default:
- ubifs_err("unrecognized mount option \"%s\" "
- "or missing value", p);
- return -EINVAL;
+ {
+ unsigned long flag;
+ struct super_block *sb = c->vfs_sb;
+
+ flag = parse_standard_option(p);
+ if (!flag) {
+ ubifs_err("unrecognized mount option \"%s\" "
+ "or missing value", p);
+ return -EINVAL;
+ }
+ sb->s_flags |= flag;
+ break;
+ }
}
}
@@ -1908,6 +1939,7 @@
INIT_LIST_HEAD(&c->orph_list);
INIT_LIST_HEAD(&c->orph_new);
+ c->vfs_sb = sb;
c->highest_inum = UBIFS_FIRST_INO;
c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
@@ -1939,8 +1971,6 @@
if (err)
goto out_bdi;
- c->vfs_sb = sb;
-
sb->s_fs_info = c;
sb->s_magic = UBIFS_SUPER_MAGIC;
sb->s_blocksize = UBIFS_BLOCK_SIZE;