1 files changed, 120 insertions, 51 deletions

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index ff498109048..8b674b1f3a5 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -39,6 +39,8 @@
 #include "super.h"
 #include "util.h"
 #include "bmap.h"
+#define CREATE_TRACE_POINTS
+#include "trace_gfs2.h"
 
 struct gfs2_gl_hash_bucket {
         struct hlist_head hb_list;
@@ -61,6 +63,7 @@ static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int
 static DECLARE_RWSEM(gfs2_umount_flush_sem);
 static struct dentry *gfs2_root;
 static struct workqueue_struct *glock_workqueue;
+struct workqueue_struct *gfs2_delete_workqueue;
 static LIST_HEAD(lru_list);
 static atomic_t lru_count = ATOMIC_INIT(0);
 static DEFINE_SPINLOCK(lru_lock);
@@ -155,7 +158,7 @@ static void glock_free(struct gfs2_glock *gl)
 
 	if (aspace)
 		gfs2_aspace_put(aspace);
-
+	trace_gfs2_glock_put(gl);
 	sdp->sd_lockstruct.ls_ops->lm_put_lock(gfs2_glock_cachep, gl);
 }
 
@@ -165,13 +168,33 @@ static void glock_free(struct gfs2_glock *gl)
  *
  */
 
-static void gfs2_glock_hold(struct gfs2_glock *gl)
+void gfs2_glock_hold(struct gfs2_glock *gl)
 {
 	GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0);
 	atomic_inc(&gl->gl_ref);
 }
 
 /**
+ * demote_ok - Check to see if it's ok to unlock a glock
+ * @gl: the glock
+ *
+ * Returns: 1 if it's ok
+ */
+
+static int demote_ok(const struct gfs2_glock *gl)
+{
+	const struct gfs2_glock_operations *glops = gl->gl_ops;
+
+	if (gl->gl_state == LM_ST_UNLOCKED)
+		return 0;
+	if (!list_empty(&gl->gl_holders))
+		return 0;
+	if (glops->go_demote_ok)
+		return glops->go_demote_ok(gl);
+	return 1;
+}
+
+/**
  * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
  * @gl: the glock
  *
@@ -179,8 +202,13 @@ static void gfs2_glock_hold(struct gfs2_glock *gl)
 
 static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
 {
+	int may_reclaim;
+	may_reclaim = (demote_ok(gl) &&
+		       (atomic_read(&gl->gl_ref) == 1 ||
+			(gl->gl_name.ln_type == LM_TYPE_INODE &&
+			 atomic_read(&gl->gl_ref) <= 2)));
 	spin_lock(&lru_lock);
-	if (list_empty(&gl->gl_lru) && gl->gl_state != LM_ST_UNLOCKED) {
+	if (list_empty(&gl->gl_lru) && may_reclaim) {
 		list_add_tail(&gl->gl_lru, &lru_list);
 		atomic_inc(&lru_count);
 	}
@@ -188,6 +216,21 @@ static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
 }
 
 /**
+ * gfs2_glock_put_nolock() - Decrement reference count on glock
+ * @gl: The glock to put
+ *
+ * This function should only be used if the caller has its own reference
+ * to the glock, in addition to the one it is dropping.
+ */
+
+void gfs2_glock_put_nolock(struct gfs2_glock *gl)
+{
+	if (atomic_dec_and_test(&gl->gl_ref))
+		GLOCK_BUG_ON(gl, 1);
+	gfs2_glock_schedule_for_reclaim(gl);
+}
+
+/**
  * gfs2_glock_put() - Decrement reference count on glock
  * @gl: The glock to put
  *
@@ -212,9 +255,9 @@ int gfs2_glock_put(struct gfs2_glock *gl)
 		rv = 1;
 		goto out;
 	}
-	/* 1 for being hashed, 1 for having state != LM_ST_UNLOCKED */
-	if (atomic_read(&gl->gl_ref) == 2)
-		gfs2_glock_schedule_for_reclaim(gl);
+	spin_lock(&gl->gl_spin);
+	gfs2_glock_schedule_for_reclaim(gl);
+	spin_unlock(&gl->gl_spin);
 	write_unlock(gl_lock_addr(gl->gl_hash));
 out:
 	return rv;
@@ -317,14 +360,17 @@ restart:
 						return 2;
 					gh->gh_error = ret;
 					list_del_init(&gh->gh_list);
+					trace_gfs2_glock_queue(gh, 0);
 					gfs2_holder_wake(gh);
 					goto restart;
 				}
 				set_bit(HIF_HOLDER, &gh->gh_iflags);
+				trace_gfs2_promote(gh, 1);
 				gfs2_holder_wake(gh);
 				goto restart;
 			}
 			set_bit(HIF_HOLDER, &gh->gh_iflags);
+			trace_gfs2_promote(gh, 0);
 			gfs2_holder_wake(gh);
 			continue;
 		}
@@ -354,6 +400,7 @@ static inline void do_error(struct gfs2_glock *gl, const int ret)
 		else
 			continue;
 		list_del_init(&gh->gh_list);
+		trace_gfs2_glock_queue(gh, 0);
 		gfs2_holder_wake(gh);
 	}
 }
@@ -392,7 +439,7 @@ static void state_change(struct gfs2_glock *gl, unsigned int new_state)
 		if (held2)
 			gfs2_glock_hold(gl);
 		else
-			gfs2_glock_put(gl);
+			gfs2_glock_put_nolock(gl);
 	}
 
 	gl->gl_state = new_state;
@@ -422,6 +469,7 @@ static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
 	int rv;
 
 	spin_lock(&gl->gl_spin);
+	trace_gfs2_glock_state_change(gl, state);
 	state_change(gl, state);
 	gh = find_first_waiter(gl);
 
@@ -626,12 +674,35 @@ out:
 out_sched:
 	gfs2_glock_hold(gl);
 	if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
-		gfs2_glock_put(gl);
+		gfs2_glock_put_nolock(gl);
 out_unlock:
 	clear_bit(GLF_LOCK, &gl->gl_flags);
 	goto out;
 }
 
+static void delete_work_func(struct work_struct *work)
+{
+	struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);
+	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_inode *ip = NULL;
+	struct inode *inode;
+	u64 no_addr = 0;
+
+	spin_lock(&gl->gl_spin);
+	ip = (struct gfs2_inode *)gl->gl_object;
+	if (ip)
+		no_addr = ip->i_no_addr;
+	spin_unlock(&gl->gl_spin);
+	if (ip) {
+		inode = gfs2_ilookup(sdp->sd_vfs, no_addr);
+		if (inode) {
+			d_prune_aliases(inode);
+			iput(inode);
+		}
+	}
+	gfs2_glock_put(gl);
+}
+
 static void glock_work_func(struct work_struct *work)
 {
 	unsigned long delay = 0;
@@ -710,6 +781,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
 	gl->gl_sbd = sdp;
 	gl->gl_aspace = NULL;
 	INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
+	INIT_WORK(&gl->gl_delete, delete_work_func);
 
 	/* If this glock protects actual on-disk data or metadata blocks,
 	   create a VFS inode to manage the pages/buffers holding them. */
@@ -796,22 +868,37 @@ void gfs2_holder_uninit(struct gfs2_holder *gh)
 	gh->gh_ip = 0;
 }
 
-static int just_schedule(void *word)
+/**
+ * gfs2_glock_holder_wait
+ * @word: unused
+ *
+ * This function and gfs2_glock_demote_wait both show up in the WCHAN
+ * field. Thus I've separated these otherwise identical functions in
+ * order to be more informative to the user.
+ */
+
+static int gfs2_glock_holder_wait(void *word)
 {
         schedule();
         return 0;
 }
 
+static int gfs2_glock_demote_wait(void *word)
+{
+	schedule();
+	return 0;
+}
+
 static void wait_on_holder(struct gfs2_holder *gh)
 {
 	might_sleep();
-	wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE);
+	wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE);
 }
 
 static void wait_on_demote(struct gfs2_glock *gl)
 {
 	might_sleep();
-	wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE);
+	wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE);
 }
 
 /**
@@ -836,6 +923,9 @@ static void handle_callback(struct gfs2_glock *gl, unsigned int state,
 			gl->gl_demote_state != state) {
 		gl->gl_demote_state = LM_ST_UNLOCKED;
 	}
+	if (gl->gl_ops->go_callback)
+		gl->gl_ops->go_callback(gl);
+	trace_gfs2_demote_rq(gl);
 }
 
 /**
@@ -921,6 +1011,7 @@ fail:
 			goto do_cancel;
 		return;
 	}
+	trace_gfs2_glock_queue(gh, 1);
 	list_add_tail(&gh->gh_list, insert_pt);
 do_cancel:
 	gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
@@ -1017,6 +1108,7 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
 		    !test_bit(GLF_DEMOTE, &gl->gl_flags))
 			fast_path = 1;
 	}
+	trace_gfs2_glock_queue(gh, 0);
 	spin_unlock(&gl->gl_spin);
 	if (likely(fast_path))
 		return;
@@ -1249,33 +1341,12 @@ void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
 		gfs2_glock_put(gl);
 }
 
-/**
- * demote_ok - Check to see if it's ok to unlock a glock
- * @gl: the glock
- *
- * Returns: 1 if it's ok
- */
-
-static int demote_ok(const struct gfs2_glock *gl)
-{
-	const struct gfs2_glock_operations *glops = gl->gl_ops;
-
-	if (gl->gl_state == LM_ST_UNLOCKED)
-		return 0;
-	if (!list_empty(&gl->gl_holders))
-		return 0;
-	if (glops->go_demote_ok)
-		return glops->go_demote_ok(gl);
-	return 1;
-}
-
 
 static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask)
 {
 	struct gfs2_glock *gl;
 	int may_demote;
 	int nr_skipped = 0;
-	int got_ref = 0;
 	LIST_HEAD(skipped);
 
 	if (nr == 0)
@@ -1290,37 +1361,29 @@ static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask)
 		list_del_init(&gl->gl_lru);
 		atomic_dec(&lru_count);
 
+		/* Check if glock is about to be freed */
+		if (atomic_read(&gl->gl_ref) == 0)
+			continue;
+
 		/* Test for being demotable */
 		if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
 			gfs2_glock_hold(gl);
-			got_ref = 1;
 			spin_unlock(&lru_lock);
 			spin_lock(&gl->gl_spin);
 			may_demote = demote_ok(gl);
-			spin_unlock(&gl->gl_spin);
-			clear_bit(GLF_LOCK, &gl->gl_flags);
 			if (may_demote) {
 				handle_callback(gl, LM_ST_UNLOCKED, 0);
 				nr--;
-				if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
-					gfs2_glock_put(gl);
-				got_ref = 0;
 			}
+			if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
+				gfs2_glock_put_nolock(gl);
+			spin_unlock(&gl->gl_spin);
+			clear_bit(GLF_LOCK, &gl->gl_flags);
 			spin_lock(&lru_lock);
-			if (may_demote)
-				continue;
-		}
-		if (list_empty(&gl->gl_lru) &&
-		    (atomic_read(&gl->gl_ref) <= (2 + got_ref))) {
-			nr_skipped++;
-			list_add(&gl->gl_lru, &skipped);
-		}
-		if (got_ref) {
-			spin_unlock(&lru_lock);
-			gfs2_glock_put(gl);
-			spin_lock(&lru_lock);
-			got_ref = 0;
+			continue;
 		}
+		nr_skipped++;
+		list_add(&gl->gl_lru, &skipped);
 	}
 	list_splice(&skipped, &lru_list);
 	atomic_add(nr_skipped, &lru_count);
@@ -1702,6 +1765,11 @@ int __init gfs2_glock_init(void)
 	glock_workqueue = create_workqueue("glock_workqueue");
 	if (IS_ERR(glock_workqueue))
 		return PTR_ERR(glock_workqueue);
+	gfs2_delete_workqueue = create_workqueue("delete_workqueue");
+	if (IS_ERR(gfs2_delete_workqueue)) {
+		destroy_workqueue(glock_workqueue);
+		return PTR_ERR(gfs2_delete_workqueue);
+	}
 
 	register_shrinker(&glock_shrinker);
 
@@ -1712,6 +1780,7 @@ void gfs2_glock_exit(void)
 {
 	unregister_shrinker(&glock_shrinker);
 	destroy_workqueue(glock_workqueue);
+	destroy_workqueue(gfs2_delete_workqueue);
 }
 
 static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)