Merge branch 'linux-2.6'

6 files changed, 759 insertions, 82 deletions

diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 3fccde7ba008..6914598022ce 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -232,7 +232,8 @@ __flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count)
  * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it
  */
 static int __process_buffer(journal_t *journal, struct journal_head *jh,
-                        struct buffer_head **bhs, int *batch_count)
+                        struct buffer_head **bhs, int *batch_count,
+                        transaction_t *transaction)
 {
         struct buffer_head *bh = jh2bh(jh);
         int ret = 0;
@@ -250,6 +251,7 @@ static int __process_buffer(journal_t *journal, struct journal_head *jh,
                 transaction_t *t = jh->b_transaction;
                 tid_t tid = t->t_tid;
 
+                transaction->t_chp_stats.cs_forced_to_close++;
                 spin_unlock(&journal->j_list_lock);
                 jbd_unlock_bh_state(bh);
                 jbd2_log_start_commit(journal, tid);
@@ -279,6 +281,7 @@ static int __process_buffer(journal_t *journal, struct journal_head *jh,
                 bhs[*batch_count] = bh;
                 __buffer_relink_io(jh);
                 jbd_unlock_bh_state(bh);
+                transaction->t_chp_stats.cs_written++;
                 (*batch_count)++;
                 if (*batch_count == NR_BATCH) {
                         spin_unlock(&journal->j_list_lock);
@@ -322,6 +325,8 @@ int jbd2_log_do_checkpoint(journal_t *journal)
         if (!journal->j_checkpoint_transactions)
                 goto out;
         transaction = journal->j_checkpoint_transactions;
+        if (transaction->t_chp_stats.cs_chp_time == 0)
+                transaction->t_chp_stats.cs_chp_time = jiffies;
         this_tid = transaction->t_tid;
 restart:
         /*
@@ -346,8 +351,10 @@ restart:
                                 retry = 1;
                                 break;
                         }
-                        retry = __process_buffer(journal, jh, bhs,&batch_count);
-                        if (!retry && lock_need_resched(&journal->j_list_lock)){
+                        retry = __process_buffer(journal, jh, bhs, &batch_count,
+                                                 transaction);
+                        if (!retry && (need_resched() ||
+                                spin_needbreak(&journal->j_list_lock))) {
                                 spin_unlock(&journal->j_list_lock);
                                 retry = 1;
                                 break;
@@ -602,15 +609,15 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
 
         /*
          * There is one special case to worry about: if we have just pulled the
-         * buffer off a committing transaction's forget list, then even if the
-         * checkpoint list is empty, the transaction obviously cannot be
-         * dropped!
+         * buffer off a running or committing transaction's checkpoing list,
+         * then even if the checkpoint list is empty, the transaction obviously
+         * cannot be dropped!
          *
-         * The locking here around j_committing_transaction is a bit sleazy.
+         * The locking here around t_state is a bit sleazy.
          * See the comment at the end of jbd2_journal_commit_transaction().
          */
-        if (transaction == journal->j_committing_transaction) {
-                JBUFFER_TRACE(jh, "belongs to committing transaction");
+        if (transaction->t_state != T_FINISHED) {
+                JBUFFER_TRACE(jh, "belongs to running/committing transaction");
                 goto out;
         }
 
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 6986f334c643..4f302d279279 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -20,6 +20,8 @@
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
+#include <linux/jiffies.h>
+#include <linux/crc32.h>
 
 /*
  * Default IO end handler for temporary BJ_IO buffer_heads.
@@ -92,19 +94,23 @@ static int inverted_lock(journal_t *journal, struct buffer_head *bh)
         return 1;
 }
 
-/* Done it all: now write the commit record.  We should have
+/*
+ * Done it all: now submit the commit record.  We should have
  * cleaned up our previous buffers by now, so if we are in abort
  * mode we can now just skip the rest of the journal write
  * entirely.
  *
  * Returns 1 if the journal needs to be aborted or 0 on success
  */
-static int journal_write_commit_record(journal_t *journal,
-                                        transaction_t *commit_transaction)
+static int journal_submit_commit_record(journal_t *journal,
+                                        transaction_t *commit_transaction,
+                                        struct buffer_head **cbh,
+                                        __u32 crc32_sum)
 {
         struct journal_head *descriptor;
+        struct commit_header *tmp;
         struct buffer_head *bh;
-        int i, ret;
+        int ret;
         int barrier_done = 0;
 
         if (is_journal_aborted(journal))
@@ -116,21 +122,33 @@ static int journal_write_commit_record(journal_t *journal,
 
         bh = jh2bh(descriptor);
 
-        /* AKPM: buglet - add `i' to tmp! */
-        for (i = 0; i < bh->b_size; i += 512) {
-                journal_header_t *tmp = (journal_header_t*)bh->b_data;
-                tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
-                tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK);
-                tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid);
+        tmp = (struct commit_header *)bh->b_data;
+        tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
+        tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK);
+        tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid);
+
+        if (JBD2_HAS_COMPAT_FEATURE(journal,
+                                    JBD2_FEATURE_COMPAT_CHECKSUM)) {
+                tmp->h_chksum_type      = JBD2_CRC32_CHKSUM;
+                tmp->h_chksum_size      = JBD2_CRC32_CHKSUM_SIZE;
+                tmp->h_chksum[0]        = cpu_to_be32(crc32_sum);
         }
 
-        JBUFFER_TRACE(descriptor, "write commit block");
+        JBUFFER_TRACE(descriptor, "submit commit block");
+        lock_buffer(bh);
+
         set_buffer_dirty(bh);
-        if (journal->j_flags & JBD2_BARRIER) {
+        set_buffer_uptodate(bh);
+        bh->b_end_io = journal_end_buffer_io_sync;
+
+        if (journal->j_flags & JBD2_BARRIER &&
+                !JBD2_HAS_COMPAT_FEATURE(journal,
+                                         JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
                 set_buffer_ordered(bh);
                 barrier_done = 1;
         }
-        ret = sync_dirty_buffer(bh);
+        ret = submit_bh(WRITE, bh);
+
         /* is it possible for another commit to fail at roughly
          * the same time as this one?  If so, we don't want to
          * trust the barrier flag in the super, but instead want
@@ -151,14 +169,72 @@ static int journal_write_commit_record(journal_t *journal,
                 clear_buffer_ordered(bh);
                 set_buffer_uptodate(bh);
                 set_buffer_dirty(bh);
-                ret = sync_dirty_buffer(bh);
+                ret = submit_bh(WRITE, bh);
         }
-        put_bh(bh);             /* One for getblk() */
-        jbd2_journal_put_journal_head(descriptor);
+        *cbh = bh;
+        return ret;
+}
+
+/*
+ * This function along with journal_submit_commit_record
+ * allows to write the commit record asynchronously.
+ */
+static int journal_wait_on_commit_record(struct buffer_head *bh)
+{
+        int ret = 0;
+
+        clear_buffer_dirty(bh);
+        wait_on_buffer(bh);
+
+        if (unlikely(!buffer_uptodate(bh)))
+                ret = -EIO;
+        put_bh(bh);            /* One for getblk() */
+        jbd2_journal_put_journal_head(bh2jh(bh));
 
-        return (ret == -EIO);
+        return ret;
 }
 
+/*
+ * Wait for all submitted IO to complete.
+ */
+static int journal_wait_on_locked_list(journal_t *journal,
+                                       transaction_t *commit_transaction)
+{
+        int ret = 0;
+        struct journal_head *jh;
+
+        while (commit_transaction->t_locked_list) {
+                struct buffer_head *bh;
+
+                jh = commit_transaction->t_locked_list->b_tprev;
+                bh = jh2bh(jh);
+                get_bh(bh);
+                if (buffer_locked(bh)) {
+                        spin_unlock(&journal->j_list_lock);
+                        wait_on_buffer(bh);
+                        if (unlikely(!buffer_uptodate(bh)))
+                                ret = -EIO;
+                        spin_lock(&journal->j_list_lock);
+                }
+                if (!inverted_lock(journal, bh)) {
+                        put_bh(bh);
+                        spin_lock(&journal->j_list_lock);
+                        continue;
+                }
+                if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) {
+                        __jbd2_journal_unfile_buffer(jh);
+                        jbd_unlock_bh_state(bh);
+                        jbd2_journal_remove_journal_head(bh);
+                        put_bh(bh);
+                } else {
+                        jbd_unlock_bh_state(bh);
+                }
+                put_bh(bh);
+                cond_resched_lock(&journal->j_list_lock);
+        }
+        return ret;
+  }
+
 static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
 {
         int i;
@@ -265,7 +341,7 @@ write_out_data:
                         put_bh(bh);
                 }
 
-                if (lock_need_resched(&journal->j_list_lock)) {
+                if (need_resched() || spin_needbreak(&journal->j_list_lock)) {
                         spin_unlock(&journal->j_list_lock);
                         goto write_out_data;
                 }
@@ -274,7 +350,21 @@ write_out_data:
         journal_do_submit_data(wbuf, bufs);
 }
 
-static inline void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
+static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
+{
+        struct page *page = bh->b_page;
+        char *addr;
+        __u32 checksum;
+
+        addr = kmap_atomic(page, KM_USER0);
+        checksum = crc32_be(crc32_sum,
+                (void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
+        kunmap_atomic(addr, KM_USER0);
+
+        return checksum;
+}
+
+static void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
                                    unsigned long long block)
 {
         tag->t_blocknr = cpu_to_be32(block & (u32)~0);
@@ -290,6 +380,7 @@ static inline void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
  */
 void jbd2_journal_commit_transaction(journal_t *journal)
 {
+        struct transaction_stats_s stats;
         transaction_t *commit_transaction;
         struct journal_head *jh, *new_jh, *descriptor;
         struct buffer_head **wbuf = journal->j_wbuf;
@@ -305,6 +396,8 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         int tag_flag;
         int i;
         int tag_bytes = journal_tag_bytes(journal);
+        struct buffer_head *cbh = NULL; /* For transactional checksums */
+        __u32 crc32_sum = ~0;
 
         /*
          * First job: lock down the current transaction and wait for
@@ -337,6 +430,11 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         spin_lock(&journal->j_state_lock);
         commit_transaction->t_state = T_LOCKED;
 
+        stats.u.run.rs_wait = commit_transaction->t_max_wait;
+        stats.u.run.rs_locked = jiffies;
+        stats.u.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
+                                                stats.u.run.rs_locked);
+
         spin_lock(&commit_transaction->t_handle_lock);
         while (commit_transaction->t_updates) {
                 DEFINE_WAIT(wait);
@@ -407,6 +505,10 @@ void jbd2_journal_commit_transaction(journal_t *journal)
          */
         jbd2_journal_switch_revoke_table(journal);
 
+        stats.u.run.rs_flushing = jiffies;
+        stats.u.run.rs_locked = jbd2_time_diff(stats.u.run.rs_locked,
+                                               stats.u.run.rs_flushing);
+
         commit_transaction->t_state = T_FLUSH;
         journal->j_committing_transaction = commit_transaction;
         journal->j_running_transaction = NULL;
@@ -440,38 +542,15 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         journal_submit_data_buffers(journal, commit_transaction);
 
         /*
-         * Wait for all previously submitted IO to complete.
+         * Wait for all previously submitted IO to complete if commit
+         * record is to be written synchronously.
          */
         spin_lock(&journal->j_list_lock);
-        while (commit_transaction->t_locked_list) {
-                struct buffer_head *bh;
+        if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
+                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
+                err = journal_wait_on_locked_list(journal,
+                                                commit_transaction);
 
-                jh = commit_transaction->t_locked_list->b_tprev;
-                bh = jh2bh(jh);
-                get_bh(bh);
-                if (buffer_locked(bh)) {
-                        spin_unlock(&journal->j_list_lock);
-                        wait_on_buffer(bh);
-                        if (unlikely(!buffer_uptodate(bh)))
-                                err = -EIO;
-                        spin_lock(&journal->j_list_lock);
-                }
-                if (!inverted_lock(journal, bh)) {
-                        put_bh(bh);
-                        spin_lock(&journal->j_list_lock);
-                        continue;
-                }
-                if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) {
-                        __jbd2_journal_unfile_buffer(jh);
-                        jbd_unlock_bh_state(bh);
-                        jbd2_journal_remove_journal_head(bh);
-                        put_bh(bh);
-                } else {
-                        jbd_unlock_bh_state(bh);
-                }
-                put_bh(bh);
-                cond_resched_lock(&journal->j_list_lock);
-        }
         spin_unlock(&journal->j_list_lock);
 
         if (err)
@@ -498,6 +577,12 @@ void jbd2_journal_commit_transaction(journal_t *journal)
          */
         commit_transaction->t_state = T_COMMIT;
 
+        stats.u.run.rs_logging = jiffies;
+        stats.u.run.rs_flushing = jbd2_time_diff(stats.u.run.rs_flushing,
+                                                 stats.u.run.rs_logging);
+        stats.u.run.rs_blocks = commit_transaction->t_outstanding_credits;
+        stats.u.run.rs_blocks_logged = 0;
+
         descriptor = NULL;
         bufs = 0;
         while (commit_transaction->t_buffers) {
@@ -639,6 +724,15 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 start_journal_io:
                         for (i = 0; i < bufs; i++) {
                                 struct buffer_head *bh = wbuf[i];
+                                /*
+                                 * Compute checksum.
+                                 */
+                                if (JBD2_HAS_COMPAT_FEATURE(journal,
+                                        JBD2_FEATURE_COMPAT_CHECKSUM)) {
+                                        crc32_sum =
+                                            jbd2_checksum_data(crc32_sum, bh);
+                                }
+
                                 lock_buffer(bh);
                                 clear_buffer_dirty(bh);
                                 set_buffer_uptodate(bh);
@@ -646,6 +740,7 @@ start_journal_io:
                                 submit_bh(WRITE, bh);
                         }
                         cond_resched();
+                        stats.u.run.rs_blocks_logged += bufs;
 
                         /* Force a new descriptor to be generated next
                            time round the loop. */
@@ -654,6 +749,23 @@ start_journal_io:
                 }
         }
 
+        /* Done it all: now write the commit record asynchronously. */
+
+        if (JBD2_HAS_INCOMPAT_FEATURE(journal,
+                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
+                err = journal_submit_commit_record(journal, commit_transaction,
+                                                 &cbh, crc32_sum);
+                if (err)
+                        __jbd2_journal_abort_hard(journal);
+
+                spin_lock(&journal->j_list_lock);
+                err = journal_wait_on_locked_list(journal,
+                                                commit_transaction);
+                spin_unlock(&journal->j_list_lock);
+                if (err)
+                        __jbd2_journal_abort_hard(journal);
+        }
+
         /* Lo and behold: we have just managed to send a transaction to
            the log.  Before we can commit it, wait for the IO so far to
            complete.  Control buffers being written are on the
@@ -753,8 +865,14 @@ wait_for_iobuf:
 
         jbd_debug(3, "JBD: commit phase 6\n");
 
-        if (journal_write_commit_record(journal, commit_transaction))
-                err = -EIO;
+        if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
+                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
+                err = journal_submit_commit_record(journal, commit_transaction,
+                                                &cbh, crc32_sum);
+                if (err)
+                        __jbd2_journal_abort_hard(journal);
+        }
+        err = journal_wait_on_commit_record(cbh);
 
         if (err)
                 jbd2_journal_abort(journal, err);
@@ -816,6 +934,7 @@ restart_loop:
                 cp_transaction = jh->b_cp_transaction;
                 if (cp_transaction) {
                         JBUFFER_TRACE(jh, "remove from old cp transaction");
+                        cp_transaction->t_chp_stats.cs_dropped++;
                         __jbd2_journal_remove_checkpoint(jh);
                 }
 
@@ -867,10 +986,10 @@ restart_loop:
         }
         spin_unlock(&journal->j_list_lock);
         /*
-         * This is a bit sleazy.  We borrow j_list_lock to protect
-         * journal->j_committing_transaction in __jbd2_journal_remove_checkpoint.
-         * Really, __jbd2_journal_remove_checkpoint should be using j_state_lock but
-         * it's a bit hassle to hold that across __jbd2_journal_remove_checkpoint
+         * This is a bit sleazy.  We use j_list_lock to protect transition
+         * of a transaction into T_FINISHED state and calling
+         * __jbd2_journal_drop_transaction(). Otherwise we could race with
+         * other checkpointing code processing the transaction...
          */
         spin_lock(&journal->j_state_lock);
         spin_lock(&journal->j_list_lock);
@@ -890,6 +1009,36 @@ restart_loop:
 
         J_ASSERT(commit_transaction->t_state == T_COMMIT);
 
+        commit_transaction->t_start = jiffies;
+        stats.u.run.rs_logging = jbd2_time_diff(stats.u.run.rs_logging,
+                                                commit_transaction->t_start);
+
+        /*
+         * File the transaction for history
+         */
+        stats.ts_type = JBD2_STATS_RUN;
+        stats.ts_tid = commit_transaction->t_tid;
+        stats.u.run.rs_handle_count = commit_transaction->t_handle_count;
+        spin_lock(&journal->j_history_lock);
+        memcpy(journal->j_history + journal->j_history_cur, &stats,
+                        sizeof(stats));
+        if (++journal->j_history_cur == journal->j_history_max)
+                journal->j_history_cur = 0;
+
+        /*
+         * Calculate overall stats
+         */
+        journal->j_stats.ts_tid++;
+        journal->j_stats.u.run.rs_wait += stats.u.run.rs_wait;
+        journal->j_stats.u.run.rs_running += stats.u.run.rs_running;
+        journal->j_stats.u.run.rs_locked += stats.u.run.rs_locked;
+        journal->j_stats.u.run.rs_flushing += stats.u.run.rs_flushing;
+        journal->j_stats.u.run.rs_logging += stats.u.run.rs_logging;
+        journal->j_stats.u.run.rs_handle_count += stats.u.run.rs_handle_count;
+        journal->j_stats.u.run.rs_blocks += stats.u.run.rs_blocks;
+        journal->j_stats.u.run.rs_blocks_logged += stats.u.run.rs_blocks_logged;
+        spin_unlock(&journal->j_history_lock);
+
         commit_transaction->t_state = T_FINISHED;
         J_ASSERT(commit_transaction == journal->j_committing_transaction);
         journal->j_commit_sequence = commit_transaction->t_tid;
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 6ddc5531587c..96ba846992e9 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)
@@ -1264,6 +1578,32 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
         return 1;
 }
 
+/*
+ * jbd2_journal_clear_features () - Clear a given journal feature in the
+ *                                  superblock
+ * @journal: Journal to act on.
+ * @compat: bitmask of compatible features
+ * @ro: bitmask of features that force read-only mount
+ * @incompat: bitmask of incompatible features
+ *
+ * Clear a given journal feature as present on the
+ * superblock.
+ */
+void jbd2_journal_clear_features(journal_t *journal, unsigned long compat,
+                                unsigned long ro, unsigned long incompat)
+{
+        journal_superblock_t *sb;
+
+        jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
+                  compat, ro, incompat);
+
+        sb = journal->j_superblock;
+
+        sb->s_feature_compat    &= ~cpu_to_be32(compat);
+        sb->s_feature_ro_compat &= ~cpu_to_be32(ro);
+        sb->s_feature_incompat  &= ~cpu_to_be32(incompat);
+}
+EXPORT_SYMBOL(jbd2_journal_clear_features);
 
 /**
  * int jbd2_journal_update_format () - Update on-disk journal structure.
@@ -1633,7 +1973,7 @@ static int journal_init_jbd2_journal_head_cache(void)
         jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
                                 sizeof(struct journal_head),
                                 0,              /* offset */
-                                0,              /* flags */
+                                SLAB_TEMPORARY, /* flags */
                                 NULL);          /* ctor */
         retval = 0;
         if (jbd2_journal_head_cache == 0) {
@@ -1900,6 +2240,28 @@ 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)
@@ -1907,7 +2269,7 @@ static int __init journal_init_handle_cache(void)
         jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle",
                                 sizeof(handle_t),
                                 0,              /* offset */
-                                0,              /* flags */
+                                SLAB_TEMPORARY, /* flags */
                                 NULL);          /* ctor */
         if (jbd2_handle_cache == NULL) {
                 printk(KERN_EMERG "JBD: failed to create handle cache\n");
@@ -1955,6 +2317,7 @@ 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 +2329,7 @@ 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();
 }
 
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index d0ce627539ef..921680663fa2 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -21,6 +21,7 @@
 #include <linux/jbd2.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
+#include <linux/crc32.h>
 #endif
 
 /*
@@ -316,6 +317,37 @@ static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag
         return block;
 }
 
+/*
+ * calc_chksums calculates the checksums for the blocks described in the
+ * descriptor block.
+ */
+static int calc_chksums(journal_t *journal, struct buffer_head *bh,
+                        unsigned long *next_log_block, __u32 *crc32_sum)
+{
+        int i, num_blks, err;
+        unsigned long io_block;
+        struct buffer_head *obh;
+
+        num_blks = count_tags(journal, bh);
+        /* Calculate checksum of the descriptor block. */
+        *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size);
+
+        for (i = 0; i < num_blks; i++) {
+                io_block = (*next_log_block)++;
+                wrap(journal, *next_log_block);
+                err = jread(&obh, journal, io_block);
+                if (err) {
+                        printk(KERN_ERR "JBD: IO error %d recovering block "
+                                "%lu in log\n", err, io_block);
+                        return 1;
+                } else {
+                        *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data,
+                                     obh->b_size);
+                }
+        }
+        return 0;
+}
+
 static int do_one_pass(journal_t *journal,
                         struct recovery_info *info, enum passtype pass)
 {
@@ -328,6 +360,7 @@ static int do_one_pass(journal_t *journal,
         unsigned int            sequence;
         int                     blocktype;
         int                     tag_bytes = journal_tag_bytes(journal);
+        __u32                   crc32_sum = ~0; /* Transactional Checksums */
 
         /* Precompute the maximum metadata descriptors in a descriptor block */
         int                     MAX_BLOCKS_PER_DESC;
@@ -419,12 +452,26 @@ static int do_one_pass(journal_t *journal,
                 switch(blocktype) {
                 case JBD2_DESCRIPTOR_BLOCK:
                         /* If it is a valid descriptor block, replay it
-                         * in pass REPLAY; otherwise, just skip over the
-                         * blocks it describes. */
+                         * in pass REPLAY; if journal_checksums enabled, then
+                         * calculate checksums in PASS_SCAN, otherwise,
+                         * just skip over the blocks it describes. */
                         if (pass != PASS_REPLAY) {
+                                if (pass == PASS_SCAN &&
+                                    JBD2_HAS_COMPAT_FEATURE(journal,
+                                            JBD2_FEATURE_COMPAT_CHECKSUM) &&
+                                    !info->end_transaction) {
+                                        if (calc_chksums(journal, bh,
+                                                        &next_log_block,
+                                                        &crc32_sum)) {
+                                                put_bh(bh);
+                                                break;
+                                        }
+                                        put_bh(bh);
+                                        continue;
+                                }
                                 next_log_block += count_tags(journal, bh);
                                 wrap(journal, next_log_block);
-                                brelse(bh);
+                                put_bh(bh);
                                 continue;
                         }
 
@@ -516,9 +563,96 @@ static int do_one_pass(journal_t *journal,
                         continue;
 
                 case JBD2_COMMIT_BLOCK:
-                        /* Found an expected commit block: not much to
-                         * do other than move on to the next sequence
+                        /*     How to differentiate between interrupted commit
+                         *               and journal corruption ?
+                         *
+                         * {nth transaction}
+                         *        Checksum Verification Failed
+                         *                       |
+                         *               ____________________
+                         *              |                    |
+                         *      async_commit             sync_commit
+                         *              |                    |
+                         *              | GO TO NEXT    "Journal Corruption"
+                         *              | TRANSACTION
+                         *              |
+                         * {(n+1)th transanction}
+                         *              |
+                         *       _______|______________
+                         *      |                     |
+                         * Commit block found   Commit block not found
+                         *      |                     |
+                         * "Journal Corruption"       |
+                         *               _____________|_________
+                         *              |                       |
+                         *      nth trans corrupt       OR   nth trans
+                         *      and (n+1)th interrupted     interrupted
+                         *      before commit block
+                         *      could reach the disk.
+                         *      (Cannot find the difference in above
+                         *       mentioned conditions. Hence assume
+                         *       "Interrupted Commit".)
+                         */
+
+                        /* Found an expected commit block: if checksums
+                         * are present verify them in PASS_SCAN; else not
+                         * much to do other than move on to the next sequence
                          * number. */
+                        if (pass == PASS_SCAN &&
+                            JBD2_HAS_COMPAT_FEATURE(journal,
+                                    JBD2_FEATURE_COMPAT_CHECKSUM)) {
+                                int chksum_err, chksum_seen;
+                                struct commit_header *cbh =
+                                        (struct commit_header *)bh->b_data;
+                                unsigned found_chksum =
+                                        be32_to_cpu(cbh->h_chksum[0]);
+
+                                chksum_err = chksum_seen = 0;
+
+                                if (info->end_transaction) {
+                                        printk(KERN_ERR "JBD: Transaction %u "
+                                                "found to be corrupt.\n",
+                                                next_commit_ID - 1);
+                                        brelse(bh);
+                                        break;
+                                }
+
+                                if (crc32_sum == found_chksum &&
+                                    cbh->h_chksum_type == JBD2_CRC32_CHKSUM &&
+                                    cbh->h_chksum_size ==
+                                                JBD2_CRC32_CHKSUM_SIZE)
+                                       chksum_seen = 1;
+                                else if (!(cbh->h_chksum_type == 0 &&
+                                             cbh->h_chksum_size == 0 &&
+                                             found_chksum == 0 &&
+                                             !chksum_seen))
+                                /*
+                                 * If fs is mounted using an old kernel and then
+                                 * kernel with journal_chksum is used then we
+                                 * get a situation where the journal flag has
+                                 * checksum flag set but checksums are not
+                                 * present i.e chksum = 0, in the individual
+                                 * commit blocks.
+                                 * Hence to avoid checksum failures, in this
+                                 * situation, this extra check is added.
+                                 */
+                                                chksum_err = 1;
+
+                                if (chksum_err) {
+                                        info->end_transaction = next_commit_ID;
+
+                                        if (!JBD2_HAS_COMPAT_FEATURE(journal,
+                                           JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)){
+                                                printk(KERN_ERR
+                                                       "JBD: Transaction %u "
+                                                       "found to be corrupt.\n",
+                                                       next_commit_ID);
+                                                brelse(bh);
+                                                break;
+                                        }
+                                }
+                                crc32_sum = ~0;
+                        }
                         brelse(bh);
                         next_commit_ID++;
                         continue;
@@ -554,9 +688,10 @@ static int do_one_pass(journal_t *journal,
          * transaction marks the end of the valid log.
          */
 
-        if (pass == PASS_SCAN)
-                info->end_transaction = next_commit_ID;
-        else {
+        if (pass == PASS_SCAN) {
+                if (!info->end_transaction)
+                        info->end_transaction = next_commit_ID;
+        } else {
                 /* It's really bad news if different passes end up at
                  * different places (but possible due to IO errors). */
                 if (info->end_transaction != next_commit_ID) {
diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
index 3595fd432d5b..df36f42e19e1 100644
--- a/fs/jbd2/revoke.c
+++ b/fs/jbd2/revoke.c
@@ -171,13 +171,15 @@ int __init jbd2_journal_init_revoke_caches(void)
 {
         jbd2_revoke_record_cache = kmem_cache_create("jbd2_revoke_record",
                                            sizeof(struct jbd2_revoke_record_s),
-                                           0, SLAB_HWCACHE_ALIGN, NULL);
+                                           0,
+                                           SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
+                                           NULL);
         if (jbd2_revoke_record_cache == 0)
                 return -ENOMEM;
 
         jbd2_revoke_table_cache = kmem_cache_create("jbd2_revoke_table",
                                            sizeof(struct jbd2_revoke_table_s),
-                                           0, 0, NULL);
+                                           0, SLAB_TEMPORARY, NULL);
         if (jbd2_revoke_table_cache == 0) {
                 kmem_cache_destroy(jbd2_revoke_record_cache);
                 jbd2_revoke_record_cache = NULL;
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index b1fcf2b3dca3..b9b0b6f899b9 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -54,11 +54,13 @@ jbd2_get_transaction(journal_t *journal, transaction_t *transaction)
         spin_lock_init(&transaction->t_handle_lock);
 
         /* Set up the commit timer for the new transaction. */
-        journal->j_commit_timer.expires = transaction->t_expires;
+        journal->j_commit_timer.expires = round_jiffies(transaction->t_expires);
         add_timer(&journal->j_commit_timer);
 
         J_ASSERT(journal->j_running_transaction == NULL);
         journal->j_running_transaction = transaction;
+        transaction->t_max_wait = 0;
+        transaction->t_start = jiffies;
 
         return transaction;
 }
@@ -85,6 +87,7 @@ static int start_this_handle(journal_t *journal, handle_t *handle)
         int nblocks = handle->h_buffer_credits;
         transaction_t *new_transaction = NULL;
         int ret = 0;
+        unsigned long ts = jiffies;
 
         if (nblocks > journal->j_max_transaction_buffers) {
                 printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n",
@@ -217,6 +220,12 @@ repeat_locked:
         /* OK, account for the buffers that this operation expects to
          * use and add the handle to the running transaction. */
 
+        if (time_after(transaction->t_start, ts)) {
+                ts = jbd2_time_diff(ts, transaction->t_start);
+                if (ts > transaction->t_max_wait)
+                        transaction->t_max_wait = ts;
+        }
+
         handle->h_transaction = transaction;
         transaction->t_outstanding_credits += nblocks;
         transaction->t_updates++;
@@ -232,6 +241,8 @@ out:
         return ret;
 }
 
+static struct lock_class_key jbd2_handle_key;
+
 /* Allocate a new handle.  This should probably be in a slab... */
 static handle_t *new_handle(int nblocks)
 {
@@ -242,6 +253,9 @@ static handle_t *new_handle(int nblocks)
         handle->h_buffer_credits = nblocks;
         handle->h_ref = 1;
 
+        lockdep_init_map(&handle->h_lockdep_map, "jbd2_handle",
+                                                &jbd2_handle_key, 0);
+
         return handle;
 }
 
@@ -284,7 +298,11 @@ handle_t *jbd2_journal_start(journal_t *journal, int nblocks)
                 jbd2_free_handle(handle);
                 current->journal_info = NULL;
                 handle = ERR_PTR(err);
+                goto out;
         }
+
+        lock_acquire(&handle->h_lockdep_map, 0, 0, 0, 2, _THIS_IP_);
+out:
         return handle;
 }
 
@@ -1164,7 +1182,7 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
         }
 
         /* That test should have eliminated the following case: */
-        J_ASSERT_JH(jh, jh->b_frozen_data == 0);
+        J_ASSERT_JH(jh, jh->b_frozen_data == NULL);
 
         JBUFFER_TRACE(jh, "file as BJ_Metadata");
         spin_lock(&journal->j_list_lock);
@@ -1410,6 +1428,8 @@ int jbd2_journal_stop(handle_t *handle)
                 spin_unlock(&journal->j_state_lock);
         }
 
+        lock_release(&handle->h_lockdep_map, 1, _THIS_IP_);
+
         jbd2_free_handle(handle);
         return err;
 }
@@ -1512,7 +1532,7 @@ void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh)
 
         J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
         if (jh->b_jlist != BJ_None)
-                J_ASSERT_JH(jh, transaction != 0);
+                J_ASSERT_JH(jh, transaction != NULL);
 
         switch (jh->b_jlist) {
         case BJ_None:
@@ -1581,11 +1601,11 @@ __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh)
         if (buffer_locked(bh) || buffer_dirty(bh))
                 goto out;
 
-        if (jh->b_next_transaction != 0)
+        if (jh->b_next_transaction != NULL)
                 goto out;
 
         spin_lock(&journal->j_list_lock);
-        if (jh->b_transaction != 0 && jh->b_cp_transaction == 0) {
+        if (jh->b_transaction != NULL && jh->b_cp_transaction == NULL) {
                 if (jh->b_jlist == BJ_SyncData || jh->b_jlist == BJ_Locked) {
                         /* A written-back ordered data buffer */
                         JBUFFER_TRACE(jh, "release data");
@@ -1593,7 +1613,7 @@ __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh)
                         jbd2_journal_remove_journal_head(bh);
                         __brelse(bh);
                 }
-        } else if (jh->b_cp_transaction != 0 && jh->b_transaction == 0) {
+        } else if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) {
                 /* written-back checkpointed metadata buffer */
                 if (jh->b_jlist == BJ_None) {
                         JBUFFER_TRACE(jh, "remove from checkpoint list");
@@ -1953,7 +1973,7 @@ void __jbd2_journal_file_buffer(struct journal_head *jh,
 
         J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
         J_ASSERT_JH(jh, jh->b_transaction == transaction ||
-                                jh->b_transaction == 0);
+                                jh->b_transaction == NULL);
 
         if (jh->b_transaction && jh->b_jlist == jlist)
                 return;