From: NeilBrown <neilb@suse.de>
Date: Wed, 2 Sep 2009 00:10:03 +0000 (+1000)
Subject: Improve inode orphan handling.
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=12e95187dc819f0ca4e1efc5f3b58bbcce343b57;p=LaFS.git

Improve inode orphan handling.

And inode can be an orphan for an extended period of time and
should not be on the pending_orphans list all that time.
So we need to remove it if nothing needs doing for now, and
add it back on when it requires attention.
---

diff --git a/dir.c b/dir.c
index e336ef8..390d3ff 100644
--- a/dir.c
+++ b/dir.c
@@ -602,6 +602,7 @@ lafs_create(struct inode *dir, struct dentry *de, int mode,
 		goto abort_unlock;
 
 	ino->i_nlink = 1;
+	lafs_add_orphan(fs, db);
 	LAFSI(ino)->md.file.parent = dir->i_ino;
 	lafs_dirty_inode(ino);
 	lafs_inode_checkpin(ino);
@@ -610,7 +611,6 @@ lafs_create(struct inode *dir, struct dentry *de, int mode,
 			  ino->i_ino, DT_REG);
 	lafs_checkpoint_unlock(fs);
 	d_instantiate(de, ino); /* FIXME do I need to iput?? */
-	lafs_orphan_release(fs, db);
 	clear_bit(B_PinPending, &db->b.flags);
 	putdref(db, MKREF(inode_new));
 	return 0;
@@ -876,6 +876,7 @@ lafs_symlink(struct inode *dir, struct dentry *de,
 
 	ino->i_nlink = 1;
 	LAFSI(ino)->md.file.parent = dir->i_ino;
+	lafs_add_orphan(fs, inodb);
 
 	buf = map_dblock(b);
 	memcpy(buf, symlink, l);
@@ -894,7 +895,6 @@ lafs_symlink(struct inode *dir, struct dentry *de,
 			  ino->i_ino, DT_LNK);
 	lafs_checkpoint_unlock(fs);
 	d_instantiate(de, ino);
-	lafs_orphan_release(fs, inodb);
 	putdref(inodb, MKREF(inode_new));
 	return 0;
  abort_unlock:
@@ -953,7 +953,7 @@ lafs_mkdir(struct inode *dir, struct dentry *de, int mode)
 	lafs_dirty_inode(ino);
 	lafs_inode_checkpin(dir);
 	lafs_inode_checkpin(ino);
-	lafs_orphan_release(fs, inodb);
+	lafs_add_orphan(fs, inodb);
 	dir_create_commit(&doh, fs, dir, de->d_name.name, de->d_name.len,
 			  ino->i_ino, DT_DIR);
 	d_instantiate(de, ino);
@@ -1025,6 +1025,7 @@ lafs_mknod(struct inode *dir, struct dentry *de, int mode,
 
 	LAFSI(ino)->md.file.parent = dir->i_ino;
 	ino->i_nlink = 1;
+	lafs_add_orphan(fs, inodb);
 	lafs_dirty_inode(ino);
 	lafs_inode_checkpin(ino);
 
@@ -1033,7 +1034,6 @@ lafs_mknod(struct inode *dir, struct dentry *de, int mode,
 			  ino->i_ino, type);
 	lafs_checkpoint_unlock(fs);
 	d_instantiate(de, ino);
-	lafs_orphan_release(fs, inodb);
 	clear_bit(B_PinPending, &inodb->b.flags);
 	putdref(inodb, MKREF(inode_new));
 	return 0;
diff --git a/inode.c b/inode.c
index 4bf4fda..6af58c9 100644
--- a/inode.c
+++ b/inode.c
@@ -473,6 +473,9 @@ void lafs_delete_inode(struct inode *ino)
 	dprintk("DELETE INODE %d\n", (int)ino->i_ino);
 	spin_lock(&ino->i_data.private_lock);
 	b = LAFSI(ino)->dblock;
+	/* FIXME we use b unconditionally, so either we don't
+	 * need the test, or we need to make the block if it
+	 * doesn't exist.. */
 	if (b)
 		getdref_locked(b, MKREF(delete_inode));
 	spin_unlock(&ino->i_data.private_lock);
@@ -484,6 +487,7 @@ void lafs_delete_inode(struct inode *ino)
 
 	set_bit(I_Deleting, &LAFSI(ino)->iflags);
 	set_bit(B_Claimed, &b->b.flags);
+	lafs_add_orphan(fs, b);
 
 	inode_map_free(fs, LAFSI(ino)->filesys,  ino->i_ino);
 	// FIXME what to do on error (-ENOMEM )
@@ -566,12 +570,14 @@ void lafs_inode_handle_orphan(struct datablock *b)
  restart:
 
 	if (!test_bit(I_Trunc, &LAFSI(ino)->iflags)) {
-		if (ino->i_nlink == 0) {
-			LAFS_BUG(LAFSI(ino)->type != 0, &b->b);
+		if (test_bit(I_Deleting, &LAFSI(ino)->iflags)) {
+			LAFS_BUG(ino->i_nlink, &b->b);
 			lafs_erase_dblock(b);
 			clear_bit(I_Deleting, &LAFSI(ino)->iflags);
-		}
-		lafs_orphan_release(fs, b);
+		} else if (ino->i_nlink)
+			lafs_orphan_release(fs, b);
+		else
+			lafs_orphan_forget(fs, b);
 		return;
 	}
 
diff --git a/lafs.h b/lafs.h
index ed7a8fc..84b45d7 100644
--- a/lafs.h
+++ b/lafs.h
@@ -585,6 +585,8 @@ int lafs_make_orphan_nb(struct fs *fs, struct datablock *db);
 void lafs_orphan_release(struct fs *fs, struct datablock *b);
 long lafs_run_orphans(struct fs *fs);
 int lafs_drop_orphan(struct fs *fs, struct datablock *db);
+void lafs_add_orphan(struct fs *fs, struct datablock *db);
+void lafs_orphan_forget(struct fs *fs, struct datablock *db);
 struct datablock *lafs_find_orphan(struct inode *ino);
 
 /* Segment.c */
diff --git a/orphan.c b/orphan.c
index 96405c2..6594d37 100644
--- a/orphan.c
+++ b/orphan.c
@@ -532,6 +532,37 @@ int lafs_drop_orphan(struct fs *fs, struct datablock *db)
 	}
 }
 
+void lafs_add_orphan(struct fs *fs, struct datablock *db)
+{
+	/* This block is an orphan block but might not be
+	 * on the list any more.
+	 * It now needs orphan processing (probably nlink
+	 * has changed, or I_Deleting), so put it back
+	 * on the list.
+	 */
+	LAFS_BUG(!test_bit(B_Orphan, &db->b.flags), &db->b);
+	spin_lock(&fs->lock);
+	if (list_empty(&db->orphans)) {
+		list_add_tail(&db->orphans, &fs->pending_orphans);
+		getdref(db, MKREF(orphan_list));
+	}
+	spin_unlock(&fs->lock);
+}
+
+void lafs_orphan_forget(struct fs *fs, struct datablock *db)
+{
+	/* This is still and orphan, but we don't want to handle
+	 * it just now.  When we we, lafs_add_orphan will be called */
+	LAFS_BUG(!test_bit(B_Orphan, &db->b.flags), &db->b);
+	spin_lock(&fs->lock);
+	if (!list_empty(&db->orphans)) {
+		list_del_init(&db->orphans);
+		spin_unlock(&fs->lock);
+		putdref(db, MKREF(orphan_list));
+	} else
+		spin_unlock(&fs->lock);
+}
+
 struct datablock *lafs_find_orphan(struct inode *ino)
 {
 	/* I could walk the child tree of the inode, or