1 files changed, 338 insertions, 0 deletions

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 6ddc5531587c..3667c91bc786 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -36,6 +36,7 @@
 #include <linux/poison.h>
 #include <linux/proc_fs.h>
 #include <linux/debugfs.h>
+#include <linux/seq_file.h>
 
 #include <asm/uaccess.h>
 #include <asm/page.h>
@@ -640,6 +641,312 @@ struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
         return jbd2_journal_add_journal_head(bh);
 }
 
+struct jbd2_stats_proc_session {
+        journal_t *journal;
+        struct transaction_stats_s *stats;
+        int start;
+        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 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;
+}
+
+static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        return NULL;
+}
+
+static int jbd2_seq_info_show(struct seq_file *seq, void *v)
+{
+        struct jbd2_stats_proc_session *s = seq->private;
+
+        if (v != SEQ_START_TOKEN)
+                return 0;
+        seq_printf(seq, "%lu transaction, each upto %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));
+        seq_printf(seq, "  %ums running transaction\n",
+            jiffies_to_msecs(s->stats->u.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));
+        seq_printf(seq, "  %ums flushing data (in ordered mode)\n",
+            jiffies_to_msecs(s->stats->u.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));
+        seq_printf(seq, "  %lu handles per transaction\n",
+            s->stats->u.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);
+        seq_printf(seq, "  %lu logged blocks per transaction\n",
+            s->stats->u.run.rs_blocks_logged / s->stats->ts_tid);
+        return 0;
+}
+
+static void jbd2_seq_info_stop(struct seq_file *seq, void *v)
+{
+}
+
+static struct seq_operations jbd2_seq_info_ops = {
+        .start  = jbd2_seq_info_start,
+        .next   = jbd2_seq_info_next,
+        .stop   = jbd2_seq_info_stop,
+        .show   = jbd2_seq_info_show,
+};
+
+static int jbd2_seq_info_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);
+        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_stats, size);
+        s->journal = journal;
+        spin_unlock(&journal->j_history_lock);
+
+        rc = seq_open(file, &jbd2_seq_info_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_info_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_info_fops = {
+        .owner          = THIS_MODULE,
+        .open           = jbd2_seq_info_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = jbd2_seq_info_release,
+};
+
+static struct proc_dir_entry *proc_jbd2_stats;
+
+static void jbd2_stats_proc_init(journal_t *journal)
+{
+        char name[BDEVNAME_SIZE];
+
+        snprintf(name, sizeof(name) - 1, "%s", bdevname(journal->j_dev, name));
+        journal->j_proc_entry = proc_mkdir(name, proc_jbd2_stats);
+        if (journal->j_proc_entry) {
+                struct proc_dir_entry *p;
+                p = create_proc_entry("history", S_IRUGO,
+                                journal->j_proc_entry);
+                if (p) {
+                        p->proc_fops = &jbd2_seq_history_fops;
+                        p->data = journal;
+                        p = create_proc_entry("info", S_IRUGO,
+                                                journal->j_proc_entry);
+                        if (p) {
+                                p->proc_fops = &jbd2_seq_info_fops;
+                                p->data = journal;
+                        }
+                }
+        }
+}
+
+static void jbd2_stats_proc_exit(journal_t *journal)
+{
+        char name[BDEVNAME_SIZE];
+
+        snprintf(name, sizeof(name) - 1, "%s", bdevname(journal->j_dev, name));
+        remove_proc_entry("info", journal->j_proc_entry);
+        remove_proc_entry("history", journal->j_proc_entry);
+        remove_proc_entry(name, 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
@@ -681,6 +988,9 @@ static journal_t * journal_init_common (void)
                 kfree(journal);
                 goto fail;
         }
+
+        journal_init_stats(journal);
+
         return journal;
 fail:
         return NULL;
@@ -735,6 +1045,7 @@ journal_t * jbd2_journal_init_dev(struct block_device *bdev,
         journal->j_fs_dev = fs_dev;
         journal->j_blk_offset = start;
         journal->j_maxlen = len;
+        jbd2_stats_proc_init(journal);
 
         bh = __getblk(journal->j_dev, start, journal->j_blocksize);
         J_ASSERT(bh != NULL);
@@ -773,6 +1084,7 @@ journal_t * jbd2_journal_init_inode (struct inode *inode)
 
         journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
         journal->j_blocksize = inode->i_sb->s_blocksize;
+        jbd2_stats_proc_init(journal);
 
         /* journal descriptor can store up to n blocks -bzzz */
         n = journal->j_blocksize / sizeof(journal_block_tag_t);
@@ -1153,6 +1465,8 @@ void jbd2_journal_destroy(journal_t *journal)
                 brelse(journal->j_sb_buffer);
         }
 
+        if (journal->j_proc_entry)
+                jbd2_stats_proc_exit(journal);
         if (journal->j_inode)
                 iput(journal->j_inode);
         if (journal->j_revoke)
@@ -1900,6 +2214,28 @@ static void __exit jbd2_remove_debugfs_entry(void)
 
 #endif
 
+#ifdef CONFIG_PROC_FS
+
+#define JBD2_STATS_PROC_NAME "fs/jbd2"
+
+static void __init jbd2_create_jbd_stats_proc_entry(void)
+{
+        proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL);
+}
+
+static void __exit jbd2_remove_jbd_stats_proc_entry(void)
+{
+        if (proc_jbd2_stats)
+                remove_proc_entry(JBD2_STATS_PROC_NAME, NULL);
+}
+
+#else
+
+#define jbd2_create_jbd_stats_proc_entry() do {} while (0)
+#define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
+
+#endif
+
 struct kmem_cache *jbd2_handle_cache;
 
 static int __init journal_init_handle_cache(void)
@@ -1955,6 +2291,7 @@ static int __init journal_init(void)
         if (ret != 0)
                 jbd2_journal_destroy_caches();
         jbd2_create_debugfs_entry();
+        jbd2_create_jbd_stats_proc_entry();
         return ret;
 }
 
@@ -1966,6 +2303,7 @@ static void __exit journal_exit(void)
                 printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n);
 #endif
         jbd2_remove_debugfs_entry();
+        jbd2_remove_jbd_stats_proc_entry();
         jbd2_journal_destroy_caches();
 }