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, 67 insertions, 26 deletions

diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 28ab56f2b98c..10d16a9e4fda 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -289,7 +289,6 @@ int ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
 		     (unsigned long long)fe->i_blkno);
 
 	OCFS2_I(inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
-	OCFS2_I(inode)->ip_orphaned_slot = OCFS2_INVALID_SLOT;
 	OCFS2_I(inode)->ip_attr = le32_to_cpu(fe->i_attr);
 
 	inode->i_nlink = le16_to_cpu(fe->i_links_count);
@@ -347,6 +346,9 @@ int ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
 
 		ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_meta_lockres,
 					  OCFS2_LOCK_TYPE_META, 0, inode);
+
+		ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_open_lockres,
+					  OCFS2_LOCK_TYPE_OPEN, 0, inode);
 	}
 
 	ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_rw_lockres,
@@ -421,7 +423,7 @@ static int ocfs2_read_locked_inode(struct inode *inode,
 	 * cluster lock before trusting anything anyway.
 	 */
 	can_lock = !(args->fi_flags & OCFS2_FI_FLAG_SYSFILE)
-		&& !(args->fi_flags & OCFS2_FI_FLAG_NOLOCK)
+		&& !(args->fi_flags & OCFS2_FI_FLAG_ORPHAN_RECOVERY)
 		&& !ocfs2_mount_local(osb);
 
 	/*
@@ -438,7 +440,17 @@ static int ocfs2_read_locked_inode(struct inode *inode,
 				  OCFS2_LOCK_TYPE_META,
 				  generation, inode);
 
+	ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_open_lockres,
+				  OCFS2_LOCK_TYPE_OPEN,
+				  0, inode);
+
 	if (can_lock) {
+		status = ocfs2_open_lock(inode);
+		if (status) {
+			make_bad_inode(inode);
+			mlog_errno(status);
+			return status;
+		}
 		status = ocfs2_meta_lock(inode, NULL, 0);
 		if (status) {
 			make_bad_inode(inode);
@@ -447,6 +459,14 @@ static int ocfs2_read_locked_inode(struct inode *inode,
 		}
 	}
 
+	if (args->fi_flags & OCFS2_FI_FLAG_ORPHAN_RECOVERY) {
+		status = ocfs2_try_open_lock(inode, 0);
+		if (status) {
+			make_bad_inode(inode);	
+			return status;
+		}
+	}
+
 	status = ocfs2_read_block(osb, args->fi_blkno, &bh, 0,
 				  can_lock ? inode : NULL);
 	if (status < 0) {
@@ -678,10 +698,10 @@ static int ocfs2_wipe_inode(struct inode *inode,
 	struct inode *orphan_dir_inode = NULL;
 	struct buffer_head *orphan_dir_bh = NULL;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	struct ocfs2_dinode *di;
 
-	/* We've already voted on this so it should be readonly - no
-	 * spinlock needed. */
-	orphaned_slot = OCFS2_I(inode)->ip_orphaned_slot;
+	di = (struct ocfs2_dinode *) di_bh->b_data;
+	orphaned_slot = le16_to_cpu(di->i_orphaned_slot);
 
 	status = ocfs2_check_orphan_recovery_state(osb, orphaned_slot);
 	if (status)
@@ -787,6 +807,35 @@ bail:
 	return ret;
 }
 
+static int ocfs2_request_delete(struct inode *inode)
+{
+	int status = 0;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+	if (ocfs2_inode_is_new(inode))
+		return 0;
+
+	if (ocfs2_node_map_is_only(osb, &osb->mounted_map,
+				   osb->node_num))
+		return 0;
+	/*
+	 * This is how ocfs2 determines whether an inode is still live
+	 * within the cluster. Every node takes a shared read lock on
+	 * the inode open lock in ocfs2_read_locked_inode(). When we
+	 * get to ->delete_inode(), each node tries to convert it's
+	 * lock to an exclusive. Trylocks are serialized by the inode
+	 * meta data lock. If the upconvert suceeds, we know the inode
+	 * is no longer live and can be deleted.
+	 *
+	 * Though we call this with the meta data lock held, the
+	 * trylock keeps us from ABBA deadlock.
+	 */
+	status = ocfs2_try_open_lock(inode, 1);
+	if (status < 0 && status != -EAGAIN)
+		mlog_errno(status);
+	return status;
+}
+
 /* Query the cluster to determine whether we should wipe an inode from
  * disk or not.
  *
@@ -839,11 +888,11 @@ static int ocfs2_query_inode_wipe(struct inode *inode,
 		goto bail;
 	}
 
-	status = ocfs2_request_delete_vote(inode);
-	/* -EBUSY means that other nodes are still using the
+	status = ocfs2_request_delete(inode);
+	/* -EAGAIN means that other nodes are still using the
 	 * inode. We're done here though, so avoid doing anything on
 	 * disk and let them worry about deleting it. */
-	if (status == -EBUSY) {
+	if (status == -EAGAIN) {
 		status = 0;
 		mlog(0, "Skipping delete of %llu because it is in use on"
 		     "other nodes\n", (unsigned long long)oi->ip_blkno);
@@ -854,21 +903,10 @@ static int ocfs2_query_inode_wipe(struct inode *inode,
 		goto bail;
 	}
 
-	spin_lock(&oi->ip_lock);
-	if (oi->ip_orphaned_slot == OCFS2_INVALID_SLOT) {
-		/* Nobody knew which slot this inode was orphaned
-		 * into. This may happen during node death and
-		 * recovery knows how to clean it up so we can safely
-		 * ignore this inode for now on. */
-		mlog(0, "Nobody knew where inode %llu was orphaned!\n",
-		     (unsigned long long)oi->ip_blkno);
-	} else {
-		*wipe = 1;
-
-		mlog(0, "Inode %llu is ok to wipe from orphan dir %d\n",
-		     (unsigned long long)oi->ip_blkno, oi->ip_orphaned_slot);
-	}
-	spin_unlock(&oi->ip_lock);
+	*wipe = 1;
+	mlog(0, "Inode %llu is ok to wipe from orphan dir %u\n",
+	     (unsigned long long)oi->ip_blkno,
+	     le16_to_cpu(di->i_orphaned_slot));
 
 bail:
 	return status;
@@ -1001,11 +1039,16 @@ void ocfs2_clear_inode(struct inode *inode)
 	mlog_bug_on_msg(OCFS2_SB(inode->i_sb) == NULL,
 			"Inode=%lu\n", inode->i_ino);
 
+	/* For remove delete_inode vote, we hold open lock before,
+	 * now it is time to unlock PR and EX open locks. */
+	ocfs2_open_unlock(inode);
+
 	/* Do these before all the other work so that we don't bounce
 	 * the vote thread while waiting to destroy the locks. */
 	ocfs2_mark_lockres_freeing(&oi->ip_rw_lockres);
 	ocfs2_mark_lockres_freeing(&oi->ip_meta_lockres);
 	ocfs2_mark_lockres_freeing(&oi->ip_data_lockres);
+	ocfs2_mark_lockres_freeing(&oi->ip_open_lockres);
 
 	/* We very well may get a clear_inode before all an inodes
 	 * metadata has hit disk. Of course, we can't drop any cluster
@@ -1030,6 +1073,7 @@ void ocfs2_clear_inode(struct inode *inode)
 	ocfs2_lock_res_free(&oi->ip_rw_lockres);
 	ocfs2_lock_res_free(&oi->ip_meta_lockres);
 	ocfs2_lock_res_free(&oi->ip_data_lockres);
+	ocfs2_lock_res_free(&oi->ip_open_lockres);
 
 	ocfs2_metadata_cache_purge(inode);
 
@@ -1086,9 +1130,6 @@ void ocfs2_drop_inode(struct inode *inode)
 	mlog(0, "Drop inode %llu, nlink = %u, ip_flags = 0x%x\n",
 	     (unsigned long long)oi->ip_blkno, inode->i_nlink, oi->ip_flags);
 
-	/* Testing ip_orphaned_slot here wouldn't work because we may
-	 * not have gotten a delete_inode vote from any other nodes
-	 * yet. */
 	if (oi->ip_flags & OCFS2_INODE_MAYBE_ORPHANED)
 		generic_delete_inode(inode);
 	else