Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Improve performance for ext4 by allowing multiple process to perform
  direct I/O writes to preallocated blocks by using a shared inode lock
  instead of taking an exclusive lock.

  In addition, multiple bug fixes and cleanups"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix incorrect options show of original mount_opt and extend mount_opt2
  ext4: Fix possible corruption when moving a directory
  ext4: init error handle resource before init group descriptors
  ext4: fix task hung in ext4_xattr_delete_inode
  jbd2: fix data missing when reusing bh which is ready to be checkpointed
  ext4: update s_journal_inum if it changes after journal replay
  ext4: fail ext4_iget if special inode unallocated
  ext4: fix function prototype mismatch for ext4_feat_ktype
  ext4: remove unnecessary variable initialization
  ext4: fix inode tree inconsistency caused by ENOMEM
  ext4: refuse to create ea block when umounted
  ext4: optimize ea_inode block expansion
  ext4: remove dead code in updating backup sb
  ext4: dio take shared inode lock when overwriting preallocated blocks
  ext4: don't show commit interval if it is zero
  ext4: use ext4_fc_tl_mem in fast-commit replay path
  ext4: improve xattr consistency checking and error reporting

1 files changed, 29 insertions, 21 deletions

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 6a404ac1c178f..15de1385012eb 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1010,36 +1010,28 @@ repeat:
 	 * ie. locked but not dirty) or tune2fs (which may actually have
 	 * the buffer dirtied, ugh.)  */
 
-	if (buffer_dirty(bh)) {
+	if (buffer_dirty(bh) && jh->b_transaction) {
+		warn_dirty_buffer(bh);
 		/*
-		 * First question: is this buffer already part of the current
-		 * transaction or the existing committing transaction?
-		 */
-		if (jh->b_transaction) {
-			J_ASSERT_JH(jh,
-				jh->b_transaction == transaction ||
-				jh->b_transaction ==
-					journal->j_committing_transaction);
-			if (jh->b_next_transaction)
-				J_ASSERT_JH(jh, jh->b_next_transaction ==
-							transaction);
-			warn_dirty_buffer(bh);
-		}
-		/*
-		 * In any case we need to clean the dirty flag and we must
-		 * do it under the buffer lock to be sure we don't race
-		 * with running write-out.
+		 * We need to clean the dirty flag and we must do it under the
+		 * buffer lock to be sure we don't race with running write-out.
 		 */
 		JBUFFER_TRACE(jh, "Journalling dirty buffer");
 		clear_buffer_dirty(bh);
+		/*
+		 * The buffer is going to be added to BJ_Reserved list now and
+		 * nothing guarantees jbd2_journal_dirty_metadata() will be
+		 * ever called for it. So we need to set jbddirty bit here to
+		 * make sure the buffer is dirtied and written out when the
+		 * journaling machinery is done with it.
+		 */
 		set_buffer_jbddirty(bh);
 	}
 
-	unlock_buffer(bh);
-
 	error = -EROFS;
 	if (is_handle_aborted(handle)) {
 		spin_unlock(&jh->b_state_lock);
+		unlock_buffer(bh);
 		goto out;
 	}
 	error = 0;
@@ -1049,8 +1041,10 @@ repeat:
 	 * b_next_transaction points to it
 	 */
 	if (jh->b_transaction == transaction ||
-	    jh->b_next_transaction == transaction)
+	    jh->b_next_transaction == transaction) {
+		unlock_buffer(bh);
 		goto done;
+	}
 
 	/*
 	 * this is the first time this transaction is touching this buffer,
@@ -1074,10 +1068,24 @@ repeat:
 		 */
 		smp_wmb();
 		spin_lock(&journal->j_list_lock);
+		if (test_clear_buffer_dirty(bh)) {
+			/*
+			 * Execute buffer dirty clearing and jh->b_transaction
+			 * assignment under journal->j_list_lock locked to
+			 * prevent bh being removed from checkpoint list if
+			 * the buffer is in an intermediate state (not dirty
+			 * and jh->b_transaction is NULL).
+			 */
+			JBUFFER_TRACE(jh, "Journalling dirty buffer");
+			set_buffer_jbddirty(bh);
+		}
 		__jbd2_journal_file_buffer(jh, transaction, BJ_Reserved);
 		spin_unlock(&journal->j_list_lock);
+		unlock_buffer(bh);
 		goto done;
 	}
+	unlock_buffer(bh);
+
 	/*
 	 * If there is already a copy-out version of this buffer, then we don't
 	 * need to make another one