GFS2: Add origin indicator to glock callbacks
This patch adds a bool indicating whether the demote
request was originated locally or remotely. This is then
used by the iopen ->go_callback() to make 100% sure that
it will only respond to remote callbacks.
Since ->evict_inode() uses GL_NOCACHE when it attempts to
get an exclusive lock on the iopen lock, this may result
in extra scheduling of the workqueue in case that the
exclusive promotion request failed. This patch prevents
that from happening.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 6e30fd1..77d7927 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -912,7 +912,7 @@
*/
static void handle_callback(struct gfs2_glock *gl, unsigned int state,
- unsigned long delay)
+ unsigned long delay, bool remote)
{
int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
@@ -925,7 +925,7 @@
gl->gl_demote_state = LM_ST_UNLOCKED;
}
if (gl->gl_ops->go_callback)
- gl->gl_ops->go_callback(gl);
+ gl->gl_ops->go_callback(gl, remote);
trace_gfs2_demote_rq(gl);
}
@@ -1091,7 +1091,7 @@
spin_lock(&gl->gl_spin);
if (gh->gh_flags & GL_NOCACHE)
- handle_callback(gl, LM_ST_UNLOCKED, 0);
+ handle_callback(gl, LM_ST_UNLOCKED, 0, false);
list_del_init(&gh->gh_list);
if (find_first_holder(gl) == NULL) {
@@ -1296,7 +1296,7 @@
}
spin_lock(&gl->gl_spin);
- handle_callback(gl, state, delay);
+ handle_callback(gl, state, delay, true);
spin_unlock(&gl->gl_spin);
if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
gfs2_glock_put(gl);
@@ -1409,7 +1409,7 @@
spin_unlock(&lru_lock);
spin_lock(&gl->gl_spin);
if (demote_ok(gl))
- handle_callback(gl, LM_ST_UNLOCKED, 0);
+ handle_callback(gl, LM_ST_UNLOCKED, 0, false);
WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
smp_mb__after_clear_bit();
if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
@@ -1534,7 +1534,7 @@
spin_lock(&gl->gl_spin);
if (gl->gl_state != LM_ST_UNLOCKED)
- handle_callback(gl, LM_ST_UNLOCKED, 0);
+ handle_callback(gl, LM_ST_UNLOCKED, 0, false);
spin_unlock(&gl->gl_spin);
gfs2_glock_hold(gl);
if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)