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: (43 commits)
  ext4: Rename ext4dev to ext4
  ext4: Avoid double dirtying of super block in ext4_put_super()
  Update ext4 MAINTAINERS file
  Hook ext4 to the vfs fiemap interface.
  generic block based fiemap implementation
  ocfs2: fiemap support
  vfs: vfs-level fiemap interface
  ext4: fix xattr deadlock
  jbd2: Fix buffer head leak when writing the commit block
  ext4: Add debugging markers that can be used by systemtap
  jbd2: abort instead of waiting for nonexistent transaction
  ext4: fix initialization of UNINIT bitmap blocks
  ext4: Remove old legacy block allocator
  ext4: Use readahead when reading an inode from the inode table
  ext4: Improve the documentation for ext4's /proc tunables
  ext4: Combine proc file handling into a single set of functions
  ext4: move /proc setup and teardown out of mballoc.c
  ext4: Don't use 'struct dentry' for internal lookups
  ext4/jbd2: Avoid WARN() messages when failing to write to the superblock
  ext4: use percpu data structures for lg_prealloc_list
  ...

1 files changed, 20 insertions, 2 deletions

diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 91389c8aee8a..42895d369458 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -20,6 +20,7 @@
 #include <linux/time.h>
 #include <linux/fs.h>
 #include <linux/jbd2.h>
+#include <linux/marker.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
 
@@ -126,14 +127,29 @@ void __jbd2_log_wait_for_space(journal_t *journal)
 
 		/*
 		 * Test again, another process may have checkpointed while we
-		 * were waiting for the checkpoint lock
+		 * were waiting for the checkpoint lock. If there are no
+		 * outstanding transactions there is nothing to checkpoint and
+		 * we can't make progress. Abort the journal in this case.
 		 */
 		spin_lock(&journal->j_state_lock);
+		spin_lock(&journal->j_list_lock);
 		nblocks = jbd_space_needed(journal);
 		if (__jbd2_log_space_left(journal) < nblocks) {
+			int chkpt = journal->j_checkpoint_transactions != NULL;
+
+			spin_unlock(&journal->j_list_lock);
 			spin_unlock(&journal->j_state_lock);
-			jbd2_log_do_checkpoint(journal);
+			if (chkpt) {
+				jbd2_log_do_checkpoint(journal);
+			} else {
+				printk(KERN_ERR "%s: no transactions\n",
+				       __func__);
+				jbd2_journal_abort(journal, 0);
+			}
+
 			spin_lock(&journal->j_state_lock);
+		} else {
+			spin_unlock(&journal->j_list_lock);
 		}
 		mutex_unlock(&journal->j_checkpoint_mutex);
 	}
@@ -313,6 +329,8 @@ int jbd2_log_do_checkpoint(journal_t *journal)
 	 * journal straight away.
 	 */
 	result = jbd2_cleanup_journal_tail(journal);
+	trace_mark(jbd2_checkpoint, "dev %s need_checkpoint %d",
+		   journal->j_devname, result);
 	jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
 	if (result <= 0)
 		return result;