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, 8 insertions, 1 deletions

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index f2e449c595b..13c6237c5f6 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -28,6 +28,7 @@
 #include "meta_io.h"
 #include "util.h"
 #include "dir.h"
+#include "trace_gfs2.h"
 
 #define PULL 1
 
@@ -313,6 +314,7 @@ int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
                 gfs2_log_lock(sdp);
         }
         atomic_sub(blks, &sdp->sd_log_blks_free);
+        trace_gfs2_log_blocks(sdp, -blks);
         gfs2_log_unlock(sdp);
         mutex_unlock(&sdp->sd_log_reserve_mutex);
 
@@ -333,6 +335,7 @@ void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 
         gfs2_log_lock(sdp);
         atomic_add(blks, &sdp->sd_log_blks_free);
+        trace_gfs2_log_blocks(sdp, blks);
         gfs2_assert_withdraw(sdp,
                              atomic_read(&sdp->sd_log_blks_free) <= sdp->sd_jdesc->jd_blocks);
         gfs2_log_unlock(sdp);
@@ -558,6 +561,7 @@ static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
 
         gfs2_log_lock(sdp);
         atomic_add(dist, &sdp->sd_log_blks_free);
+        trace_gfs2_log_blocks(sdp, dist);
         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= sdp->sd_jdesc->jd_blocks);
         gfs2_log_unlock(sdp);
 
@@ -715,6 +719,7 @@ void __gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
                 up_write(&sdp->sd_log_flush_lock);
                 return;
         }
+        trace_gfs2_log_flush(sdp, 1);
 
         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
         INIT_LIST_HEAD(&ai->ai_ail1_list);
@@ -746,6 +751,7 @@ void __gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
                 gfs2_log_lock(sdp);
                 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
+                trace_gfs2_log_blocks(sdp, -1);
                 gfs2_log_unlock(sdp);
                 log_write_header(sdp, 0, PULL);
         }
@@ -763,7 +769,7 @@ void __gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
                 ai = NULL;
         }
         gfs2_log_unlock(sdp);
-
+        trace_gfs2_log_flush(sdp, 0);
         up_write(&sdp->sd_log_flush_lock);
 
         kfree(ai);
@@ -787,6 +793,7 @@ static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved);
         unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved;
         atomic_add(unused, &sdp->sd_log_blks_free);
+        trace_gfs2_log_blocks(sdp, unused);
         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
                              sdp->sd_jdesc->jd_blocks);
         sdp->sd_log_blks_reserved = reserved;