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-rw-r--r--fs/gfs2/glock.c72
1 files changed, 46 insertions, 26 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 827136ee794..f041a89e1ab 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -174,6 +174,26 @@ static void gfs2_glock_hold(struct gfs2_glock *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;
+}
+
+/**
* gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
* @gl: the glock
*
@@ -181,8 +201,13 @@ 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);
}
@@ -190,6 +215,21 @@ 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.
+ */
+
+static 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
*
@@ -214,9 +254,9 @@ 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;
@@ -398,7 +438,7 @@ 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;
@@ -633,7 +673,7 @@ 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;
@@ -1274,26 +1314,6 @@ 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)
{