2 files changed, 9 insertions, 2 deletions

diff --git a/Documentation/filesystems/nilfs2.txt b/Documentation/filesystems/nilfs2.txt
index d3e7673995eb..54f61c0ff442 100644
--- a/Documentation/filesystems/nilfs2.txt
+++ b/Documentation/filesystems/nilfs2.txt
@@ -49,7 +49,10 @@ Mount options
 NILFS2 supports the following mount options:
 (*) == default
 
-nobarrier               Disables barriers.
+barrier(*)              This enables/disables the use of write barriers.  This
+nobarrier               requires an IO stack which can support barriers, and
+                        if nilfs gets an error on a barrier write, it will
+                        disable again with a warning.
 errors=continue         Keep going on a filesystem error.
 errors=remount-ro(*)    Remount the filesystem read-only on an error.
 errors=panic            Panic and halt the machine if an error occurs.
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index f2cfbbab2346..13b0e955c028 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -603,7 +603,7 @@ static const struct export_operations nilfs_export_ops = {
 
 enum {
         Opt_err_cont, Opt_err_panic, Opt_err_ro,
-        Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
+        Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
         Opt_discard, Opt_err,
 };
 
@@ -611,6 +611,7 @@ static match_table_t tokens = {
         {Opt_err_cont, "errors=continue"},
         {Opt_err_panic, "errors=panic"},
         {Opt_err_ro, "errors=remount-ro"},
+        {Opt_barrier, "barrier"},
         {Opt_nobarrier, "nobarrier"},
         {Opt_snapshot, "cp=%u"},
         {Opt_order, "order=%s"},
@@ -636,6 +637,9 @@ static int parse_options(char *options, struct super_block *sb)
 
                 token = match_token(p, tokens, args);
                 switch (token) {
+                case Opt_barrier:
+                        nilfs_set_opt(sbi, BARRIER);
+                        break;
                 case Opt_nobarrier:
                         nilfs_clear_opt(sbi, BARRIER);
                         break;