ext4: Enable extents by default

Turn on extents feature by default in ext4 filesystem, to get wider
testing of extents feature in ext4dev.  This can be disabled using 
-o noextents.  

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 11 insertions, 1 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b806e689c4aa..9c8baf460588 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -734,7 +734,7 @@ enum {
         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
-        Opt_grpquota, Opt_extents,
+        Opt_grpquota, Opt_extents, Opt_noextents,
 };
 
 static match_table_t tokens = {
@@ -785,6 +785,7 @@ static match_table_t tokens = {
         {Opt_usrquota, "usrquota"},
         {Opt_barrier, "barrier=%u"},
         {Opt_extents, "extents"},
+        {Opt_noextents, "noextents"},
         {Opt_err, NULL},
         {Opt_resize, "resize"},
 };
@@ -1120,6 +1121,9 @@ clear_qf_name:
                 case Opt_extents:
                         set_opt (sbi->s_mount_opt, EXTENTS);
                         break;
+                case Opt_noextents:
+                        clear_opt (sbi->s_mount_opt, EXTENTS);
+                        break;
                 default:
                         printk (KERN_ERR
                                 "EXT4-fs: Unrecognized mount option \"%s\" "
@@ -1551,6 +1555,12 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 
         set_opt(sbi->s_mount_opt, RESERVATION);
 
+        /*
+         * turn on extents feature by default in ext4 filesystem
+         * User -o noextents to turn it off
+         */
+        set_opt(sbi->s_mount_opt, EXTENTS);
+
         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
                             NULL, 0))
                 goto failed_mount;