[GFS2] glock debugging and inode cache changes

This adds some extra debugging to glock.c and changes
inode.c's deallocation code to call the debugging code
at a suitable moment. I'm chasing down a particular bug
to do with deallocation at the moment and the code can
go again once the bug is fixed.

Also this includes the first part of some changes to unify
the Linux struct inode and GFS2's struct gfs2_inode. This
transformation will happen in small parts over the next short
period.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/glock.c

@@ -47,6 +47,7 @@ struct greedy {
 typedef void (*glock_examiner) (struct gfs2_glock * gl);
 
 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
+static int dump_glock(struct gfs2_glock *gl);
 
 /**
  * relaxed_state_ok - is a requested lock compatible with the current lock mode?
@@ -290,6 +291,8 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, uint64_t number,
 	spin_lock_init(&gl->gl_spin);
 
 	gl->gl_state = LM_ST_UNLOCKED;
+	gl->gl_owner = NULL;
+	gl->gl_ip = 0;
 	INIT_LIST_HEAD(&gl->gl_holders);
 	INIT_LIST_HEAD(&gl->gl_waiters1);
 	INIT_LIST_HEAD(&gl->gl_waiters2);
@@ -661,8 +664,11 @@ void gfs2_glmutex_lock(struct gfs2_glock *gl)
 	spin_lock(&gl->gl_spin);
 	if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
 		list_add_tail(&gh.gh_list, &gl->gl_waiters1);
-	else
+	else {
+		gl->gl_owner = current;
+		gl->gl_ip = (unsigned long)__builtin_return_address(0);
 		complete(&gh.gh_wait);
+	}
 	spin_unlock(&gl->gl_spin);
 
 	wait_for_completion(&gh.gh_wait);
@@ -683,6 +689,10 @@ static int gfs2_glmutex_trylock(struct gfs2_glock *gl)
 	spin_lock(&gl->gl_spin);
 	if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
 		acquired = 0;
+	else {
+		gl->gl_owner = current;
+		gl->gl_ip = (unsigned long)__builtin_return_address(0);
+	}
 	spin_unlock(&gl->gl_spin);
 
 	return acquired;
@@ -698,6 +708,8 @@ void gfs2_glmutex_unlock(struct gfs2_glock *gl)
 {
 	spin_lock(&gl->gl_spin);
 	clear_bit(GLF_LOCK, &gl->gl_flags);
+	gl->gl_owner = NULL;
+	gl->gl_ip = 0;
 	run_queue(gl);
 	BUG_ON(!spin_is_locked(&gl->gl_spin));
 	spin_unlock(&gl->gl_spin);
@@ -1173,7 +1185,7 @@ int gfs2_glock_nq(struct gfs2_holder *gh)
 	struct gfs2_sbd *sdp = gl->gl_sbd;
 	int error = 0;
 
- restart:
+restart:
 	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
 		set_bit(HIF_ABORTED, &gh->gh_iflags);
 		return -EIO;
@@ -1196,6 +1208,9 @@ int gfs2_glock_nq(struct gfs2_holder *gh)
 
 	clear_bit(GLF_PREFETCH, &gl->gl_flags);
 
+	if (error == GLR_TRYFAILED && (gh->gh_flags & GL_DUMP))
+		dump_glock(gl);
+
 	return error;
 }
 
@@ -2212,9 +2227,8 @@ static int dump_glock(struct gfs2_glock *gl)
 
 	spin_lock(&gl->gl_spin);
 
-	printk(KERN_INFO "Glock (%u, %llu)\n",
-		    gl->gl_name.ln_type,
-		    gl->gl_name.ln_number);
+	printk(KERN_INFO "Glock (%u, %llu)\n", gl->gl_name.ln_type,
+	       gl->gl_name.ln_number);
 	printk(KERN_INFO "  gl_flags =");
 	for (x = 0; x < 32; x++)
 		if (test_bit(x, &gl->gl_flags))
@@ -2222,6 +2236,8 @@ static int dump_glock(struct gfs2_glock *gl)
 	printk(" \n");
 	printk(KERN_INFO "  gl_ref = %d\n", atomic_read(&gl->gl_ref.refcount));
 	printk(KERN_INFO "  gl_state = %u\n", gl->gl_state);
+	printk(KERN_INFO "  gl_owner = %s\n", gl->gl_owner->comm);
+	print_symbol(KERN_INFO "  gl_ip = %s\n", gl->gl_ip);
 	printk(KERN_INFO "  req_gh = %s\n", (gl->gl_req_gh) ? "yes" : "no");
 	printk(KERN_INFO "  req_bh = %s\n", (gl->gl_req_bh) ? "yes" : "no");
 	printk(KERN_INFO "  lvb_count = %d\n", atomic_read(&gl->gl_lvb_count));