xfs: refactor per-AG inode tagging functions

In preparation for adding another incore inode tree tag, refactor the
code that sets and clears tags from the per-AG inode tree and the tree
of per-AG structures, and remove the open-coded versions used by the
blockgc code.

Note: For reclaim, we now rely on the radix tree tags instead of the
reclaimable inode count more heavily than we used to.  The conversion
should be fine, but the logic isn't 100% identical.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/xfs_icache.c

@@ -207,46 +207,94 @@ xfs_reclaim_work_queue(
 	rcu_read_unlock();
 }
 
-static void
-xfs_perag_set_reclaim_tag(
+/*
+ * Background scanning to trim preallocated space. This is queued based on the
+ * 'speculative_prealloc_lifetime' tunable (5m by default).
+ */
+static inline void
+xfs_blockgc_queue(
 	struct xfs_perag	*pag)
+{
+	rcu_read_lock();
+	if (radix_tree_tagged(&pag->pag_ici_root, XFS_ICI_BLOCKGC_TAG))
+		queue_delayed_work(pag->pag_mount->m_gc_workqueue,
+				   &pag->pag_blockgc_work,
+				   msecs_to_jiffies(xfs_blockgc_secs * 1000));
+	rcu_read_unlock();
+}
+
+/* Set a tag on both the AG incore inode tree and the AG radix tree. */
+static void
+xfs_perag_set_inode_tag(
+	struct xfs_perag	*pag,
+	xfs_agino_t		agino,
+	unsigned int		tag)
 {
 	struct xfs_mount	*mp = pag->pag_mount;
+	bool			was_tagged;
 
 	lockdep_assert_held(&pag->pag_ici_lock);
-	if (pag->pag_ici_reclaimable++)
+
+	was_tagged = radix_tree_tagged(&pag->pag_ici_root, tag);
+	radix_tree_tag_set(&pag->pag_ici_root, agino, tag);
+
+	if (tag == XFS_ICI_RECLAIM_TAG)
+		pag->pag_ici_reclaimable++;
+
+	if (was_tagged)
 		return;
 
-	/* propagate the reclaim tag up into the perag radix tree */
+	/* propagate the tag up into the perag radix tree */
 	spin_lock(&mp->m_perag_lock);
-	radix_tree_tag_set(&mp->m_perag_tree, pag->pag_agno,
-			   XFS_ICI_RECLAIM_TAG);
+	radix_tree_tag_set(&mp->m_perag_tree, pag->pag_agno, tag);
 	spin_unlock(&mp->m_perag_lock);
 
-	/* schedule periodic background inode reclaim */
-	xfs_reclaim_work_queue(mp);
+	/* start background work */
+	switch (tag) {
+	case XFS_ICI_RECLAIM_TAG:
+		xfs_reclaim_work_queue(mp);
+		break;
+	case XFS_ICI_BLOCKGC_TAG:
+		xfs_blockgc_queue(pag);
+		break;
+	}
 
-	trace_xfs_perag_set_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
+	trace_xfs_perag_set_inode_tag(mp, pag->pag_agno, tag, _RET_IP_);
 }
 
+/* Clear a tag on both the AG incore inode tree and the AG radix tree. */
 static void
-xfs_perag_clear_reclaim_tag(
-	struct xfs_perag	*pag)
+xfs_perag_clear_inode_tag(
+	struct xfs_perag	*pag,
+	xfs_agino_t		agino,
+	unsigned int		tag)
 {
 	struct xfs_mount	*mp = pag->pag_mount;
 
 	lockdep_assert_held(&pag->pag_ici_lock);
-	if (--pag->pag_ici_reclaimable)
+
+	/*
+	 * Reclaim can signal (with a null agino) that it cleared its own tag
+	 * by removing the inode from the radix tree.
+	 */
+	if (agino != NULLAGINO)
+		radix_tree_tag_clear(&pag->pag_ici_root, agino, tag);
+	else
+		ASSERT(tag == XFS_ICI_RECLAIM_TAG);
+
+	if (tag == XFS_ICI_RECLAIM_TAG)
+		pag->pag_ici_reclaimable--;
+
+	if (radix_tree_tagged(&pag->pag_ici_root, tag))
 		return;
 
-	/* clear the reclaim tag from the perag radix tree */
+	/* clear the tag from the perag radix tree */
 	spin_lock(&mp->m_perag_lock);
-	radix_tree_tag_clear(&mp->m_perag_tree, pag->pag_agno,
-			     XFS_ICI_RECLAIM_TAG);
+	radix_tree_tag_clear(&mp->m_perag_tree, pag->pag_agno, tag);
 	spin_unlock(&mp->m_perag_lock);
-	trace_xfs_perag_clear_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
-}
 
+	trace_xfs_perag_clear_inode_tag(mp, pag->pag_agno, tag, _RET_IP_);
+}
 
 /*
  * We set the inode flag atomically with the radix tree tag.
@@ -254,7 +302,7 @@ xfs_perag_clear_reclaim_tag(
  * can go away.
  */
 void
-xfs_inode_set_reclaim_tag(
+xfs_inode_mark_reclaimable(
 	struct xfs_inode	*ip)
 {
 	struct xfs_mount	*mp = ip->i_mount;
@@ -264,9 +312,8 @@ xfs_inode_set_reclaim_tag(
 	spin_lock(&pag->pag_ici_lock);
 	spin_lock(&ip->i_flags_lock);
 
-	radix_tree_tag_set(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino),
-			   XFS_ICI_RECLAIM_TAG);
-	xfs_perag_set_reclaim_tag(pag);
+	xfs_perag_set_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino),
+			XFS_ICI_RECLAIM_TAG);
 	__xfs_iflags_set(ip, XFS_IRECLAIMABLE);
 
 	spin_unlock(&ip->i_flags_lock);
@@ -274,17 +321,6 @@ xfs_inode_set_reclaim_tag(
 	xfs_perag_put(pag);
 }
 
-STATIC void
-xfs_inode_clear_reclaim_tag(
-	struct xfs_perag	*pag,
-	xfs_ino_t		ino)
-{
-	radix_tree_tag_clear(&pag->pag_ici_root,
-			     XFS_INO_TO_AGINO(pag->pag_mount, ino),
-			     XFS_ICI_RECLAIM_TAG);
-	xfs_perag_clear_reclaim_tag(pag);
-}
-
 static inline void
 xfs_inew_wait(
 	struct xfs_inode	*ip)
@@ -483,7 +519,9 @@ xfs_iget_cache_hit(
 		 */
 		ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS;
 		ip->i_flags |= XFS_INEW;
-		xfs_inode_clear_reclaim_tag(pag, ip->i_ino);
+		xfs_perag_clear_inode_tag(pag,
+				XFS_INO_TO_AGINO(pag->pag_mount, ino),
+				XFS_ICI_RECLAIM_TAG);
 		inode->i_state = I_NEW;
 		ip->i_sick = 0;
 		ip->i_checked = 0;
@@ -957,7 +995,7 @@ xfs_reclaim_inode(
 	if (!radix_tree_delete(&pag->pag_ici_root,
 				XFS_INO_TO_AGINO(ip->i_mount, ino)))
 		ASSERT(0);
-	xfs_perag_clear_reclaim_tag(pag);
+	xfs_perag_clear_inode_tag(pag, NULLAGINO, XFS_ICI_RECLAIM_TAG);
 	spin_unlock(&pag->pag_ici_lock);
 
 	/*
@@ -1173,22 +1211,6 @@ xfs_inode_free_eofblocks(
 	return 0;
 }
 
-/*
- * Background scanning to trim preallocated space. This is queued based on the
- * 'speculative_prealloc_lifetime' tunable (5m by default).
- */
-static inline void
-xfs_blockgc_queue(
-	struct xfs_perag	*pag)
-{
-	rcu_read_lock();
-	if (radix_tree_tagged(&pag->pag_ici_root, XFS_ICI_BLOCKGC_TAG))
-		queue_delayed_work(pag->pag_mount->m_gc_workqueue,
-				   &pag->pag_blockgc_work,
-				   msecs_to_jiffies(xfs_blockgc_secs * 1000));
-	rcu_read_unlock();
-}
-
 static void
 xfs_blockgc_set_iflag(
 	struct xfs_inode	*ip,
@@ -1196,7 +1218,6 @@ xfs_blockgc_set_iflag(
 {
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_perag	*pag;
-	int			tagged;
 
 	ASSERT((iflag & ~(XFS_IEOFBLOCKS | XFS_ICOWBLOCKS)) == 0);
 
@@ -1213,24 +1234,8 @@ xfs_blockgc_set_iflag(
 	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
 	spin_lock(&pag->pag_ici_lock);
 
-	tagged = radix_tree_tagged(&pag->pag_ici_root, XFS_ICI_BLOCKGC_TAG);
-	radix_tree_tag_set(&pag->pag_ici_root,
-			   XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino),
-			   XFS_ICI_BLOCKGC_TAG);
-	if (!tagged) {
-		/* propagate the blockgc tag up into the perag radix tree */
-		spin_lock(&ip->i_mount->m_perag_lock);
-		radix_tree_tag_set(&ip->i_mount->m_perag_tree,
-				   XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
-				   XFS_ICI_BLOCKGC_TAG);
-		spin_unlock(&ip->i_mount->m_perag_lock);
-
-		/* kick off background trimming */
-		xfs_blockgc_queue(pag);
-
-		trace_xfs_perag_set_blockgc(ip->i_mount, pag->pag_agno, -1,
-				_RET_IP_);
-	}
+	xfs_perag_set_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino),
+			XFS_ICI_BLOCKGC_TAG);
 
 	spin_unlock(&pag->pag_ici_lock);
 	xfs_perag_put(pag);
@@ -1266,19 +1271,8 @@ xfs_blockgc_clear_iflag(
 	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
 	spin_lock(&pag->pag_ici_lock);
 
-	radix_tree_tag_clear(&pag->pag_ici_root,
-			     XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino),
-			     XFS_ICI_BLOCKGC_TAG);
-	if (!radix_tree_tagged(&pag->pag_ici_root, XFS_ICI_BLOCKGC_TAG)) {
-		/* clear the blockgc tag from the perag radix tree */
-		spin_lock(&ip->i_mount->m_perag_lock);
-		radix_tree_tag_clear(&ip->i_mount->m_perag_tree,
-				     XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
-				     XFS_ICI_BLOCKGC_TAG);
-		spin_unlock(&ip->i_mount->m_perag_lock);
-		trace_xfs_perag_clear_blockgc(ip->i_mount, pag->pag_agno, -1,
-				_RET_IP_);
-	}
+	xfs_perag_clear_inode_tag(pag, XFS_INO_TO_AGINO(mp, ip->i_ino),
+			XFS_ICI_BLOCKGC_TAG);
 
 	spin_unlock(&pag->pag_ici_lock);
 	xfs_perag_put(pag);

fs/xfs/xfs_icache.h

@@ -39,7 +39,7 @@ void xfs_reclaim_inodes(struct xfs_mount *mp);
 int xfs_reclaim_inodes_count(struct xfs_mount *mp);
 long xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan);
 
-void xfs_inode_set_reclaim_tag(struct xfs_inode *ip);
+void xfs_inode_mark_reclaimable(struct xfs_inode *ip);
 
 int xfs_blockgc_free_dquots(struct xfs_mount *mp, struct xfs_dquot *udqp,
 		struct xfs_dquot *gdqp, struct xfs_dquot *pdqp,

fs/xfs/xfs_super.c

@@ -667,7 +667,7 @@ xfs_fs_destroy_inode(
 	 * reclaim path handles this more efficiently than we can here, so
 	 * simply let background reclaim tear down all inodes.
 	 */
-	xfs_inode_set_reclaim_tag(ip);
+	xfs_inode_mark_reclaimable(ip);
 }
 
 static void

fs/xfs/xfs_trace.h

@@ -153,10 +153,8 @@ DEFINE_EVENT(xfs_perag_class, name,	\
 DEFINE_PERAG_REF_EVENT(xfs_perag_get);
 DEFINE_PERAG_REF_EVENT(xfs_perag_get_tag);
 DEFINE_PERAG_REF_EVENT(xfs_perag_put);
-DEFINE_PERAG_REF_EVENT(xfs_perag_set_reclaim);
-DEFINE_PERAG_REF_EVENT(xfs_perag_clear_reclaim);
-DEFINE_PERAG_REF_EVENT(xfs_perag_set_blockgc);
-DEFINE_PERAG_REF_EVENT(xfs_perag_clear_blockgc);
+DEFINE_PERAG_REF_EVENT(xfs_perag_set_inode_tag);
+DEFINE_PERAG_REF_EVENT(xfs_perag_clear_inode_tag);
 
 DECLARE_EVENT_CLASS(xfs_ag_class,
 	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno),