gfs2: introduce new gfs2_glock_assert_withdraw

Before this patch, asserts based on glocks did not print the glock with
the error. This patch introduces a new macro, gfs2_glock_assert_withdraw
which first prints the glock, then takes the assert.

This also changes a few glock asserts to the new macro.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/glock.c

@@ -164,7 +164,7 @@ void gfs2_glock_free(struct gfs2_glock *gl)
 {
 	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 
-	BUG_ON(atomic_read(&gl->gl_revokes));
+	gfs2_glock_assert_withdraw(gl, atomic_read(&gl->gl_revokes) == 0);
 	rhashtable_remove_fast(&gl_hash_table, &gl->gl_node, ht_parms);
 	smp_mb();
 	wake_up_glock(gl);
@@ -626,7 +626,8 @@ __acquires(&gl->gl_lockref.lock)
 		 */
 		if ((atomic_read(&gl->gl_ail_count) != 0) &&
 		    (!cmpxchg(&sdp->sd_log_error, 0, -EIO))) {
-			gfs2_assert_warn(sdp, !atomic_read(&gl->gl_ail_count));
+			gfs2_glock_assert_warn(gl,
+					       !atomic_read(&gl->gl_ail_count));
 			gfs2_dump_glock(NULL, gl, true);
 		}
 		glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
@@ -1836,7 +1837,7 @@ void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
 	int ret;
 
 	ret = gfs2_truncatei_resume(ip);
-	gfs2_assert_withdraw(gl->gl_name.ln_sbd, ret == 0);
+	gfs2_glock_assert_withdraw(gl, ret == 0);
 
 	spin_lock(&gl->gl_lockref.lock);
 	clear_bit(GLF_LOCK, &gl->gl_flags);

fs/gfs2/glock.h

@@ -205,6 +205,15 @@ extern void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl,
 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) {		\
 			gfs2_dump_glock(NULL, gl, true);	\
 			BUG(); } } while(0)
+#define gfs2_glock_assert_warn(gl, x) do { if (unlikely(!(x))) {	\
+			gfs2_dump_glock(NULL, gl, true);		\
+			gfs2_assert_warn((gl)->gl_name.ln_sbd, (x)); } } \
+	while (0)
+#define gfs2_glock_assert_withdraw(gl, x) do { if (unlikely(!(x))) {	\
+			gfs2_dump_glock(NULL, gl, true);		\
+			gfs2_assert_withdraw((gl)->gl_name.ln_sbd, (x)); } } \
+	while (0)
+
 extern __printf(2, 3)
 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);