jbd2: Use tracepoints for history file

The /proc/fs/jbd2/<dev>/history was maintained manually; by using
tracepoints, we can get all of the existing functionality of the /proc
file plus extra capabilities thanks to the ftrace infrastructure.  We
save memory as a bonus.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 7 insertions, 20 deletions

diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 52695d3dfd0b..f1011f7f3d41 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -464,9 +464,9 @@ struct handle_s
  */
 struct transaction_chp_stats_s {
         unsigned long           cs_chp_time;
-        unsigned long           cs_forced_to_close;
-        unsigned long           cs_written;
-        unsigned long           cs_dropped;
+        __u32                   cs_forced_to_close;
+        __u32                   cs_written;
+        __u32                   cs_dropped;
 };
 
 /* The transaction_t type is the guts of the journaling mechanism.  It
@@ -668,23 +668,16 @@ struct transaction_run_stats_s {
         unsigned long           rs_flushing;
         unsigned long           rs_logging;
 
-        unsigned long           rs_handle_count;
-        unsigned long           rs_blocks;
-        unsigned long           rs_blocks_logged;
+        __u32                   rs_handle_count;
+        __u32                   rs_blocks;
+        __u32                   rs_blocks_logged;
 };
 
 struct transaction_stats_s {
-        int                     ts_type;
         unsigned long           ts_tid;
-        union {
-                struct transaction_run_stats_s run;
-                struct transaction_chp_stats_s chp;
-        } u;
+        struct transaction_run_stats_s run;
 };
 
-#define JBD2_STATS_RUN          1
-#define JBD2_STATS_CHECKPOINT   2
-
 static inline unsigned long
 jbd2_time_diff(unsigned long start, unsigned long end)
 {
@@ -988,12 +981,6 @@ struct journal_s
         /*
          * Journal statistics
          */
-        struct transaction_stats_s *j_history;
-        int                     j_history_max;
-        int                     j_history_cur;
-        /*
-         * Protect the transactions statistics history
-         */
         spinlock_t              j_history_lock;
         struct proc_dir_entry   *j_proc_entry;
         struct transaction_stats_s j_stats;