jbd2: Add function jbd2_trans_will_send_data_barrier()

Provide a function which returns whether a transaction with given tid
will send a flush to the filesystem device.  The function will be used
by ext4 to detect whether fsync needs to send a separate flush or not.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 9 insertions, 1 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 2d5095ecc25f..5b506e53c70b 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -677,6 +677,10 @@ start_journal_io:
                 err = 0;
         }
 
+        write_lock(&journal->j_state_lock);
+        J_ASSERT(commit_transaction->t_state == T_COMMIT);
+        commit_transaction->t_state = T_COMMIT_DFLUSH;
+        write_unlock(&journal->j_state_lock);
         /* 
          * If the journal is not located on the file system device,
          * then we must flush the file system device before we issue
@@ -804,6 +808,10 @@ wait_for_iobuf:
                 jbd2_journal_abort(journal, err);
 
         jbd_debug(3, "JBD: commit phase 5\n");
+        write_lock(&journal->j_state_lock);
+        J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH);
+        commit_transaction->t_state = T_COMMIT_JFLUSH;
+        write_unlock(&journal->j_state_lock);
 
         if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
                                        JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
@@ -959,7 +967,7 @@ restart_loop:
 
         jbd_debug(3, "JBD: commit phase 7\n");
 
-        J_ASSERT(commit_transaction->t_state == T_COMMIT);
+        J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH);
 
         commit_transaction->t_start = jiffies;
         stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,