[PATCH 2/2] ocfs2: cluster aware flock()

[linux-2.6-omap-h63xx.git] / fs / ocfs2 / super.c

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 1104f14c318366f4da5fc495c682f7798201a53a..4a091f586646a232ddf126c6072307d658e17f71 100644 (file)
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -153,6 +153,7 @@ enum {
        Opt_slot,
        Opt_commit,
        Opt_localalloc,
+       Opt_localflocks,
        Opt_err,
 };
 
@@ -170,6 +171,7 @@ static match_table_t tokens = {
        {Opt_slot, "preferred_slot=%u"},
        {Opt_commit, "commit=%u"},
        {Opt_localalloc, "localalloc=%d"},
+       {Opt_localflocks, "localflocks"},
        {Opt_err, NULL}
 };
 
@@ -848,6 +850,20 @@ static int ocfs2_parse_options(struct super_block *sb,
                        if (option >= 0 && (option <= ocfs2_local_alloc_size(sb) * 8))
                                mopt->localalloc_opt = option;
                        break;
+               case Opt_localflocks:
+                       /*
+                        * Changing this during remount could race
+                        * flock() requests, or "unbalance" existing
+                        * ones (e.g., a lock is taken in one mode but
+                        * dropped in the other). If users care enough
+                        * to flip locking modes during remount, we
+                        * could add a "local" flag to individual
+                        * flock structures for proper tracking of
+                        * state.
+                        */
+                       if (!is_remount)
+                               mopt->mount_opt |= OCFS2_MOUNT_LOCALFLOCKS;
+                       break;
                default:
                        mlog(ML_ERROR,
                             "Unrecognized mount option \"%s\" "
@@ -903,6 +919,9 @@ static int ocfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
        if (osb->local_alloc_size != OCFS2_DEFAULT_LOCAL_ALLOC_SIZE)
                seq_printf(s, ",localalloc=%d", osb->local_alloc_size);
 
+       if (opts & OCFS2_MOUNT_LOCALFLOCKS)
+               seq_printf(s, ",localflocks,");
+
        return 0;
 }