ext4: Use WRITE_SYNC for commits which are caused by fsync()

If a commit is triggered by fsync(), set a flag indicating the journal
blocks associated with the transaction should be flushed out using
WRITE_SYNC.

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

2 files changed, 6 insertions, 1 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 62804e57a44c..4ea72377c7a2 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -367,6 +367,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         int tag_bytes = journal_tag_bytes(journal);
         struct buffer_head *cbh = NULL; /* For transactional checksums */
         __u32 crc32_sum = ~0;
+        int write_op = WRITE;
 
         /*
          * First job: lock down the current transaction and wait for
@@ -401,6 +402,8 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         spin_lock(&journal->j_state_lock);
         commit_transaction->t_state = T_LOCKED;
 
+        if (commit_transaction->t_synchronous_commit)
+                write_op = WRITE_SYNC;
         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,
@@ -680,7 +683,7 @@ start_journal_io:
                                 clear_buffer_dirty(bh);
                                 set_buffer_uptodate(bh);
                                 bh->b_end_io = journal_end_buffer_io_sync;
-                                submit_bh(WRITE, bh);
+                                submit_bh(write_op, bh);
                         }
                         cond_resched();
                         stats.u.run.rs_blocks_logged += bufs;
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 28ce21d8598e..996ffda06bf3 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1315,6 +1315,8 @@ int jbd2_journal_stop(handle_t *handle)
                 }
         }
 
+        if (handle->h_sync)
+                transaction->t_synchronous_commit = 1;
         current->journal_info = NULL;
         spin_lock(&journal->j_state_lock);
         spin_lock(&transaction->t_handle_lock);