[GFS2] Clean up the glock core

This patch implements a number of cleanups to the core of the
GFS2 glock code. As a result a lot of code is removed. It looks
like a really big change, but actually a large part of this patch
is either removing or moving existing code.

There are some new bits too though, such as the new run_queue()
function which is considerably streamlined. Highlights of this
patch include:

 o Fixes a cluster coherency bug during SH -> EX lock conversions
 o Removes the "glmutex" code in favour of a single bit lock
 o Removes the ->go_xmote_bh() for inodes since it was duplicating
   ->go_lock()
 o We now only use the ->lm_lock() function for both locks and
   unlocks (i.e. unlock is a lock with target mode LM_ST_UNLOCKED)
 o The fast path is considerably shortly, giving performance gains
   especially with lock_nolock
 o The glock_workqueue is now used for all the callbacks from the DLM
   which allows us to simplify the lock_dlm module (see following patch)
 o The way is now open to make further changes such as eliminating the two
   threads (gfs2_glockd and gfs2_scand) in favour of a more efficient
   scheme.

This patch has undergone extensive testing with various test suites
so it should be pretty stable by now.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>

1 files changed, 4 insertions, 5 deletions

diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h
index cdad3e6f8150..7389f8ef0a31 100644
--- a/fs/gfs2/glock.h
+++ b/fs/gfs2/glock.h
@@ -26,11 +26,8 @@
 #define GL_SKIP                 0x00000100
 #define GL_ATIME                0x00000200
 #define GL_NOCACHE              0x00000400
-#define GL_FLOCK                0x00000800
-#define GL_NOCANCEL             0x00001000
 
 #define GLR_TRYFAILED           13
-#define GLR_CANCELED            14
 
 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
 {
@@ -41,6 +38,8 @@ static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *
         spin_lock(&gl->gl_spin);
         pid = task_pid(current);
         list_for_each_entry(gh, &gl->gl_holders, gh_list) {
+                if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
+                        break;
                 if (gh->gh_owner_pid == pid)
                         goto out;
         }
@@ -70,7 +69,7 @@ static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
 {
         int ret;
         spin_lock(&gl->gl_spin);
-        ret = test_bit(GLF_DEMOTE, &gl->gl_flags) || !list_empty(&gl->gl_waiters3);
+        ret = test_bit(GLF_DEMOTE, &gl->gl_flags);
         spin_unlock(&gl->gl_spin);
         return ret;
 }
@@ -98,6 +97,7 @@ int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
+void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
 
 /**
  * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
@@ -130,7 +130,6 @@ int gfs2_lvb_hold(struct gfs2_glock *gl);
 void gfs2_lvb_unhold(struct gfs2_glock *gl);
 
 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
-
 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);