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

Hook up ocfs2_flock(), using the new flock lock type in dlmglue.c. A new
mount option, "localflocks" is added so that users can revert to old
functionality as need be.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 1104f14c3183..4a091f586646 100644
--- 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;
 }