ocfs2: Remove delete inode vote

Ocfs2 currently does cluster-wide node messaging to check the open state of
an inode during delete. This patch removes that mechanism in favor of an
inode cluster lock which is taken at shared read when an inode is first read
and dropped in clear_inode(). This allows a deleting node to test the
liveness of an inode by attempting to take an exclusive lock.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 117 insertions, 2 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 31d519a6dbd2..ca4f0e0e7587 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -225,11 +225,17 @@ static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
         .flags          = 0,
 };
 
+static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
+        .get_osb        = ocfs2_get_inode_osb,
+        .flags          = 0,
+};
+
 static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
 {
         return lockres->l_type == OCFS2_LOCK_TYPE_META ||
                 lockres->l_type == OCFS2_LOCK_TYPE_DATA ||
-                lockres->l_type == OCFS2_LOCK_TYPE_RW;
+                lockres->l_type == OCFS2_LOCK_TYPE_RW ||
+                lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
 }
 
 static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
@@ -373,6 +379,9 @@ void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
                 case OCFS2_LOCK_TYPE_DATA:
                         ops = &ocfs2_inode_data_lops;
                         break;
+                case OCFS2_LOCK_TYPE_OPEN:
+                        ops = &ocfs2_inode_open_lops;
+                        break;
                 default:
                         mlog_bug_on_msg(1, "type: %d\n", type);
                         ops = NULL; /* thanks, gcc */
@@ -1129,6 +1138,12 @@ int ocfs2_create_new_inode_locks(struct inode *inode)
                 goto bail;
         }
 
+        ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_open_lockres, 0, 0);
+        if (ret) {
+                mlog_errno(ret);
+                goto bail;
+        }
+
 bail:
         mlog_exit(ret);
         return ret;
@@ -1182,6 +1197,99 @@ void ocfs2_rw_unlock(struct inode *inode, int write)
         mlog_exit_void();
 }
 
+/*
+ * ocfs2_open_lock always get PR mode lock.
+ */
+int ocfs2_open_lock(struct inode *inode)
+{
+        int status = 0;
+        struct ocfs2_lock_res *lockres;
+        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+        BUG_ON(!inode);
+
+        mlog_entry_void();
+
+        mlog(0, "inode %llu take PRMODE open lock\n",
+             (unsigned long long)OCFS2_I(inode)->ip_blkno);
+
+        if (ocfs2_mount_local(osb))
+                goto out;
+
+        lockres = &OCFS2_I(inode)->ip_open_lockres;
+
+        status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
+                                    LKM_PRMODE, 0, 0);
+        if (status < 0)
+                mlog_errno(status);
+
+out:
+        mlog_exit(status);
+        return status;
+}
+
+int ocfs2_try_open_lock(struct inode *inode, int write)
+{
+        int status = 0, level;
+        struct ocfs2_lock_res *lockres;
+        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+        BUG_ON(!inode);
+
+        mlog_entry_void();
+
+        mlog(0, "inode %llu try to take %s open lock\n",
+             (unsigned long long)OCFS2_I(inode)->ip_blkno,
+             write ? "EXMODE" : "PRMODE");
+
+        if (ocfs2_mount_local(osb))
+                goto out;
+
+        lockres = &OCFS2_I(inode)->ip_open_lockres;
+
+        level = write ? LKM_EXMODE : LKM_PRMODE;
+
+        /*
+         * The file system may already holding a PRMODE/EXMODE open lock.
+         * Since we pass LKM_NOQUEUE, the request won't block waiting on
+         * other nodes and the -EAGAIN will indicate to the caller that
+         * this inode is still in use.
+         */
+        status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
+                                    level, LKM_NOQUEUE, 0);
+
+out:
+        mlog_exit(status);
+        return status;
+}
+
+/*
+ * ocfs2_open_unlock unlock PR and EX mode open locks.
+ */
+void ocfs2_open_unlock(struct inode *inode)
+{
+        struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres;
+        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+        mlog_entry_void();
+
+        mlog(0, "inode %llu drop open lock\n",
+             (unsigned long long)OCFS2_I(inode)->ip_blkno);
+
+        if (ocfs2_mount_local(osb))
+                goto out;
+
+        if(lockres->l_ro_holders)
+                ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
+                                     LKM_PRMODE);
+        if(lockres->l_ex_holders)
+                ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
+                                     LKM_EXMODE);
+
+out:
+        mlog_exit_void();
+}
+
 int ocfs2_data_lock_full(struct inode *inode,
                          int write,
                          int arg_flags)
@@ -2455,13 +2563,20 @@ int ocfs2_drop_inode_locks(struct inode *inode)
          * ocfs2_clear_inode has done it for us. */
 
         err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
-                              &OCFS2_I(inode)->ip_data_lockres);
+                              &OCFS2_I(inode)->ip_open_lockres);
         if (err < 0)
                 mlog_errno(err);
 
         status = err;
 
         err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
+                              &OCFS2_I(inode)->ip_data_lockres);
+        if (err < 0)
+                mlog_errno(err);
+        if (err < 0 && !status)
+                status = err;
+
+        err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
                               &OCFS2_I(inode)->ip_meta_lockres);
         if (err < 0)
                 mlog_errno(err);