1 files changed, 41 insertions, 11 deletions

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index b3ed58551e74..384cae623ed3 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -422,11 +422,11 @@ void gfs2_holder_uninit(struct gfs2_holder *gh)
 static void gfs2_holder_wake(struct gfs2_holder *gh)
 {
         clear_bit(HIF_WAIT, &gh->gh_iflags);
-        smp_mb();
+        smp_mb__after_clear_bit();
         wake_up_bit(&gh->gh_iflags, HIF_WAIT);
 }
 
-static int holder_wait(void *word)
+static int just_schedule(void *word)
 {
         schedule();
         return 0;
@@ -435,7 +435,20 @@ static int holder_wait(void *word)
 static void wait_on_holder(struct gfs2_holder *gh)
 {
         might_sleep();
-        wait_on_bit(&gh->gh_iflags, HIF_WAIT, holder_wait, TASK_UNINTERRUPTIBLE);
+        wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE);
+}
+
+static void gfs2_demote_wake(struct gfs2_glock *gl)
+{
+        clear_bit(GLF_DEMOTE, &gl->gl_flags);
+        smp_mb__after_clear_bit();
+        wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
+}
+
+static void wait_on_demote(struct gfs2_glock *gl)
+{
+        might_sleep();
+        wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE);
 }
 
 /**
@@ -528,7 +541,7 @@ static int rq_demote(struct gfs2_glock *gl)
 
         if (gl->gl_state == gl->gl_demote_state ||
             gl->gl_state == LM_ST_UNLOCKED) {
-                clear_bit(GLF_DEMOTE, &gl->gl_flags);
+                gfs2_demote_wake(gl);
                 return 0;
         }
         set_bit(GLF_LOCK, &gl->gl_flags);
@@ -666,12 +679,22 @@ static void gfs2_glmutex_unlock(struct gfs2_glock *gl)
  * practise: LM_ST_SHARED and LM_ST_UNLOCKED
  */
 
-static void handle_callback(struct gfs2_glock *gl, unsigned int state)
+static void handle_callback(struct gfs2_glock *gl, unsigned int state, int remote)
 {
         spin_lock(&gl->gl_spin);
         if (test_and_set_bit(GLF_DEMOTE, &gl->gl_flags) == 0) {
                 gl->gl_demote_state = state;
                 gl->gl_demote_time = jiffies;
+                if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN &&
+                    gl->gl_object) {
+                        struct inode *inode = igrab(gl->gl_object);
+                        spin_unlock(&gl->gl_spin);
+                        if (inode) {
+                                d_prune_aliases(inode);
+                                iput(inode);
+                        }
+                        return;
+                }
         } else if (gl->gl_demote_state != LM_ST_UNLOCKED) {
                 gl->gl_demote_state = state;
         }
@@ -740,7 +763,7 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
                 if (ret & LM_OUT_CANCELED)
                         op_done = 0;
                 else
-                        clear_bit(GLF_DEMOTE, &gl->gl_flags);
+                        gfs2_demote_wake(gl);
         } else {
                 spin_lock(&gl->gl_spin);
                 list_del_init(&gh->gh_list);
@@ -848,7 +871,7 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
         gfs2_assert_warn(sdp, !ret);
 
         state_change(gl, LM_ST_UNLOCKED);
-        clear_bit(GLF_DEMOTE, &gl->gl_flags);
+        gfs2_demote_wake(gl);
 
         if (glops->go_inval)
                 glops->go_inval(gl, DIO_METADATA);
@@ -1174,7 +1197,7 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
         const struct gfs2_glock_operations *glops = gl->gl_ops;
 
         if (gh->gh_flags & GL_NOCACHE)
-                handle_callback(gl, LM_ST_UNLOCKED);
+                handle_callback(gl, LM_ST_UNLOCKED, 0);
 
         gfs2_glmutex_lock(gl);
 
@@ -1196,6 +1219,13 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
         spin_unlock(&gl->gl_spin);
 }
 
+void gfs2_glock_dq_wait(struct gfs2_holder *gh)
+{
+        struct gfs2_glock *gl = gh->gh_gl;
+        gfs2_glock_dq(gh);
+        wait_on_demote(gl);
+}
+
 /**
  * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
  * @gh: the holder structure
@@ -1456,7 +1486,7 @@ static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
         if (!gl)
                 return;
 
-        handle_callback(gl, state);
+        handle_callback(gl, state, 1);
 
         spin_lock(&gl->gl_spin);
         run_queue(gl);
@@ -1596,7 +1626,7 @@ void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
         if (gfs2_glmutex_trylock(gl)) {
                 if (list_empty(&gl->gl_holders) &&
                     gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
-                        handle_callback(gl, LM_ST_UNLOCKED);
+                        handle_callback(gl, LM_ST_UNLOCKED, 0);
                 gfs2_glmutex_unlock(gl);
         }
 
@@ -1709,7 +1739,7 @@ static void clear_glock(struct gfs2_glock *gl)
         if (gfs2_glmutex_trylock(gl)) {
                 if (list_empty(&gl->gl_holders) &&
                     gl->gl_state != LM_ST_UNLOCKED)
-                        handle_callback(gl, LM_ST_UNLOCKED);
+                        handle_callback(gl, LM_ST_UNLOCKED, 0);
                 gfs2_glmutex_unlock(gl);
         }
 }