GFS2: Add tracepoints

This patch adds the ability to trace various aspects of the GFS2
filesystem. The trace points are divided into three groups,
glocks, logging and bmap. These points have been chosen because
they allow inspection of the major internal functions of GFS2
and they are also generic enough that they are unlikely to need
any major changes as the filesystem evolves.

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

1 files changed, 11 insertions, 1 deletions

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 2bf62bc..297421c 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -39,6 +39,8 @@
 #include "super.h"
 #include "util.h"
 #include "bmap.h"
+#define CREATE_TRACE_POINTS
+#include "trace_gfs2.h"
 
 struct gfs2_gl_hash_bucket {
         struct hlist_head hb_list;
@@ -155,7 +157,7 @@ static void glock_free(struct gfs2_glock *gl)
 
 	if (aspace)
 		gfs2_aspace_put(aspace);
-
+	trace_gfs2_glock_put(gl);
 	sdp->sd_lockstruct.ls_ops->lm_put_lock(gfs2_glock_cachep, gl);
 }
 
@@ -317,14 +319,17 @@ restart:
 						return 2;
 					gh->gh_error = ret;
 					list_del_init(&gh->gh_list);
+					trace_gfs2_glock_queue(gh, 0);
 					gfs2_holder_wake(gh);
 					goto restart;
 				}
 				set_bit(HIF_HOLDER, &gh->gh_iflags);
+				trace_gfs2_promote(gh, 1);
 				gfs2_holder_wake(gh);
 				goto restart;
 			}
 			set_bit(HIF_HOLDER, &gh->gh_iflags);
+			trace_gfs2_promote(gh, 0);
 			gfs2_holder_wake(gh);
 			continue;
 		}
@@ -354,6 +359,7 @@ static inline void do_error(struct gfs2_glock *gl, const int ret)
 		else
 			continue;
 		list_del_init(&gh->gh_list);
+		trace_gfs2_glock_queue(gh, 0);
 		gfs2_holder_wake(gh);
 	}
 }
@@ -422,6 +428,7 @@ static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
 	int rv;
 
 	spin_lock(&gl->gl_spin);
+	trace_gfs2_glock_state_change(gl, state);
 	state_change(gl, state);
 	gh = find_first_waiter(gl);
 
@@ -851,6 +858,7 @@ static void handle_callback(struct gfs2_glock *gl, unsigned int state,
 			gl->gl_demote_state != state) {
 		gl->gl_demote_state = LM_ST_UNLOCKED;
 	}
+	trace_gfs2_demote_rq(gl);
 }
 
 /**
@@ -936,6 +944,7 @@ fail:
 			goto do_cancel;
 		return;
 	}
+	trace_gfs2_glock_queue(gh, 1);
 	list_add_tail(&gh->gh_list, insert_pt);
 do_cancel:
 	gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
@@ -1032,6 +1041,7 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
 		    !test_bit(GLF_DEMOTE, &gl->gl_flags))
 			fast_path = 1;
 	}
+	trace_gfs2_glock_queue(gh, 0);
 	spin_unlock(&gl->gl_spin);
 	if (likely(fast_path))
 		return;