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>
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 977a8da..761af77 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -676,153 +676,6 @@
int max;
};
-static void *jbd2_history_skip_empty(struct jbd2_stats_proc_session *s,
- struct transaction_stats_s *ts,
- int first)
-{
- if (ts == s->stats + s->max)
- ts = s->stats;
- if (!first && ts == s->stats + s->start)
- return NULL;
- while (ts->ts_type == 0) {
- ts++;
- if (ts == s->stats + s->max)
- ts = s->stats;
- if (ts == s->stats + s->start)
- return NULL;
- }
- return ts;
-
-}
-
-static void *jbd2_seq_history_start(struct seq_file *seq, loff_t *pos)
-{
- struct jbd2_stats_proc_session *s = seq->private;
- struct transaction_stats_s *ts;
- int l = *pos;
-
- if (l == 0)
- return SEQ_START_TOKEN;
- ts = jbd2_history_skip_empty(s, s->stats + s->start, 1);
- if (!ts)
- return NULL;
- l--;
- while (l) {
- ts = jbd2_history_skip_empty(s, ++ts, 0);
- if (!ts)
- break;
- l--;
- }
- return ts;
-}
-
-static void *jbd2_seq_history_next(struct seq_file *seq, void *v, loff_t *pos)
-{
- struct jbd2_stats_proc_session *s = seq->private;
- struct transaction_stats_s *ts = v;
-
- ++*pos;
- if (v == SEQ_START_TOKEN)
- return jbd2_history_skip_empty(s, s->stats + s->start, 1);
- else
- return jbd2_history_skip_empty(s, ++ts, 0);
-}
-
-static int jbd2_seq_history_show(struct seq_file *seq, void *v)
-{
- struct transaction_stats_s *ts = v;
- if (v == SEQ_START_TOKEN) {
- seq_printf(seq, "%-4s %-5s %-5s %-5s %-5s %-5s %-5s %-6s %-5s "
- "%-5s %-5s %-5s %-5s %-5s\n", "R/C", "tid",
- "wait", "run", "lock", "flush", "log", "hndls",
- "block", "inlog", "ctime", "write", "drop",
- "close");
- return 0;
- }
- if (ts->ts_type == JBD2_STATS_RUN)
- seq_printf(seq, "%-4s %-5lu %-5u %-5u %-5u %-5u %-5u "
- "%-6lu %-5lu %-5lu\n", "R", ts->ts_tid,
- jiffies_to_msecs(ts->u.run.rs_wait),
- jiffies_to_msecs(ts->u.run.rs_running),
- jiffies_to_msecs(ts->u.run.rs_locked),
- jiffies_to_msecs(ts->u.run.rs_flushing),
- jiffies_to_msecs(ts->u.run.rs_logging),
- ts->u.run.rs_handle_count,
- ts->u.run.rs_blocks,
- ts->u.run.rs_blocks_logged);
- else if (ts->ts_type == JBD2_STATS_CHECKPOINT)
- seq_printf(seq, "%-4s %-5lu %48s %-5u %-5lu %-5lu %-5lu\n",
- "C", ts->ts_tid, " ",
- jiffies_to_msecs(ts->u.chp.cs_chp_time),
- ts->u.chp.cs_written, ts->u.chp.cs_dropped,
- ts->u.chp.cs_forced_to_close);
- else
- J_ASSERT(0);
- return 0;
-}
-
-static void jbd2_seq_history_stop(struct seq_file *seq, void *v)
-{
-}
-
-static const struct seq_operations jbd2_seq_history_ops = {
- .start = jbd2_seq_history_start,
- .next = jbd2_seq_history_next,
- .stop = jbd2_seq_history_stop,
- .show = jbd2_seq_history_show,
-};
-
-static int jbd2_seq_history_open(struct inode *inode, struct file *file)
-{
- journal_t *journal = PDE(inode)->data;
- struct jbd2_stats_proc_session *s;
- int rc, size;
-
- s = kmalloc(sizeof(*s), GFP_KERNEL);
- if (s == NULL)
- return -ENOMEM;
- size = sizeof(struct transaction_stats_s) * journal->j_history_max;
- s->stats = kmalloc(size, GFP_KERNEL);
- if (s->stats == NULL) {
- kfree(s);
- return -ENOMEM;
- }
- spin_lock(&journal->j_history_lock);
- memcpy(s->stats, journal->j_history, size);
- s->max = journal->j_history_max;
- s->start = journal->j_history_cur % s->max;
- spin_unlock(&journal->j_history_lock);
-
- rc = seq_open(file, &jbd2_seq_history_ops);
- if (rc == 0) {
- struct seq_file *m = file->private_data;
- m->private = s;
- } else {
- kfree(s->stats);
- kfree(s);
- }
- return rc;
-
-}
-
-static int jbd2_seq_history_release(struct inode *inode, struct file *file)
-{
- struct seq_file *seq = file->private_data;
- struct jbd2_stats_proc_session *s = seq->private;
-
- kfree(s->stats);
- kfree(s);
- return seq_release(inode, file);
-}
-
-static struct file_operations jbd2_seq_history_fops = {
- .owner = THIS_MODULE,
- .open = jbd2_seq_history_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = jbd2_seq_history_release,
-};
-
static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos)
{
return *pos ? NULL : SEQ_START_TOKEN;
@@ -839,29 +692,29 @@
if (v != SEQ_START_TOKEN)
return 0;
- seq_printf(seq, "%lu transaction, each upto %u blocks\n",
+ seq_printf(seq, "%lu transaction, each up to %u blocks\n",
s->stats->ts_tid,
s->journal->j_max_transaction_buffers);
if (s->stats->ts_tid == 0)
return 0;
seq_printf(seq, "average: \n %ums waiting for transaction\n",
- jiffies_to_msecs(s->stats->u.run.rs_wait / s->stats->ts_tid));
+ jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid));
seq_printf(seq, " %ums running transaction\n",
- jiffies_to_msecs(s->stats->u.run.rs_running / s->stats->ts_tid));
+ jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid));
seq_printf(seq, " %ums transaction was being locked\n",
- jiffies_to_msecs(s->stats->u.run.rs_locked / s->stats->ts_tid));
+ jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid));
seq_printf(seq, " %ums flushing data (in ordered mode)\n",
- jiffies_to_msecs(s->stats->u.run.rs_flushing / s->stats->ts_tid));
+ jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid));
seq_printf(seq, " %ums logging transaction\n",
- jiffies_to_msecs(s->stats->u.run.rs_logging / s->stats->ts_tid));
+ jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid));
seq_printf(seq, " %lluus average transaction commit time\n",
div_u64(s->journal->j_average_commit_time, 1000));
seq_printf(seq, " %lu handles per transaction\n",
- s->stats->u.run.rs_handle_count / s->stats->ts_tid);
+ s->stats->run.rs_handle_count / s->stats->ts_tid);
seq_printf(seq, " %lu blocks per transaction\n",
- s->stats->u.run.rs_blocks / s->stats->ts_tid);
+ s->stats->run.rs_blocks / s->stats->ts_tid);
seq_printf(seq, " %lu logged blocks per transaction\n",
- s->stats->u.run.rs_blocks_logged / s->stats->ts_tid);
+ s->stats->run.rs_blocks_logged / s->stats->ts_tid);
return 0;
}
@@ -931,8 +784,6 @@
{
journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats);
if (journal->j_proc_entry) {
- proc_create_data("history", S_IRUGO, journal->j_proc_entry,
- &jbd2_seq_history_fops, journal);
proc_create_data("info", S_IRUGO, journal->j_proc_entry,
&jbd2_seq_info_fops, journal);
}
@@ -941,27 +792,9 @@
static void jbd2_stats_proc_exit(journal_t *journal)
{
remove_proc_entry("info", journal->j_proc_entry);
- remove_proc_entry("history", journal->j_proc_entry);
remove_proc_entry(journal->j_devname, proc_jbd2_stats);
}
-static void journal_init_stats(journal_t *journal)
-{
- int size;
-
- if (!proc_jbd2_stats)
- return;
-
- journal->j_history_max = 100;
- size = sizeof(struct transaction_stats_s) * journal->j_history_max;
- journal->j_history = kzalloc(size, GFP_KERNEL);
- if (!journal->j_history) {
- journal->j_history_max = 0;
- return;
- }
- spin_lock_init(&journal->j_history_lock);
-}
-
/*
* Management for journal control blocks: functions to create and
* destroy journal_t structures, and to initialise and read existing
@@ -1006,7 +839,7 @@
goto fail;
}
- journal_init_stats(journal);
+ spin_lock_init(&journal->j_history_lock);
return journal;
fail: