fs/adfs: super: limit idlen according to directory type
Limit idlen according to the directory type, as idlen (the size of a
fragment ID) can not be more than 16 with the "new directory" layout.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index b124343..d029ae1 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -54,6 +54,7 @@ void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...)
static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
{
+ unsigned int max_idlen;
int i;
/* sector size must be 256, 512 or 1024 bytes */
@@ -73,8 +74,13 @@ static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
return 1;
- /* idlen must be no greater than 19 v2 [1.0] */
- if (dr->idlen > 19)
+ /*
+ * Maximum idlen is limited to 16 bits for new directories by
+ * the three-byte storage of an indirect disc address. For
+ * big directories, idlen must be no greater than 19 v2 [1.0]
+ */
+ max_idlen = dr->format_version ? 19 : 16;
+ if (dr->idlen > max_idlen)
return 1;
/* reserved bytes should be zero */
