Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: Patch up how we claim metadata blocks for quota purposes
  ext4: Ensure zeroout blocks have no dirty metadata
  ext4: return correct wbc.nr_to_write in ext4_da_writepages
  ext4: Update documentation to correct the inode_readahead_blks option name
  jbd2: don't use __GFP_NOFAIL in journal_init_common()
  ext4: flush delalloc blocks when space is low
  fs-writeback: Add helper function to start writeback if idle
  ext4: Eliminate potential double free on error path
  ext4: fix unsigned long long printk warning in super.c
  ext4, jbd2: Add barriers for file systems with exernal journals
  ext4: replace BUG() with return -EIO in ext4_ext_get_blocks
  ext4: add module aliases for ext2 and ext3
  ext4: Don't ask about supporting ext2/3 in ext4 if ext4 is not configured
  ext4: remove unused #include <linux/version.h>

1 files changed, 11 insertions, 8 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 6a10238d2c63..1bc74b6f26d2 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -259,6 +259,7 @@ static int journal_submit_data_buffers(journal_t *journal,
                         ret = err;
                 spin_lock(&journal->j_list_lock);
                 J_ASSERT(jinode->i_transaction == commit_transaction);
+                commit_transaction->t_flushed_data_blocks = 1;
                 jinode->i_flags &= ~JI_COMMIT_RUNNING;
                 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
         }
@@ -708,8 +709,17 @@ start_journal_io:
                 }
         }
 
-        /* Done it all: now write the commit record asynchronously. */
+        /* 
+         * If the journal is not located on the file system device,
+         * then we must flush the file system device before we issue
+         * the commit record
+         */
+        if (commit_transaction->t_flushed_data_blocks &&
+            (journal->j_fs_dev != journal->j_dev) &&
+            (journal->j_flags & JBD2_BARRIER))
+                blkdev_issue_flush(journal->j_fs_dev, NULL);
 
+        /* 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,
@@ -720,13 +730,6 @@ start_journal_io:
                         blkdev_issue_flush(journal->j_dev, NULL);
         }
 
-        /*
-         * This is the right place to wait for data buffers both for ASYNC
-         * and !ASYNC commit. If commit is ASYNC, we need to wait only after
-         * the commit block went to disk (which happens above). If commit is
-         * SYNC, we need to wait for data buffers before we start writing
-         * commit block, which happens below in such setting.
-         */
         err = journal_finish_inode_data_buffers(journal, commit_transaction);
         if (err) {
                 printk(KERN_WARNING