[PATCH] jbd: fix I/O error handling

Fix a few buglets spotted by Jeff Mahoney <jeffm@suse.com>.  We're currently
only checking for I/O errors against journal buffers if they were locked when
they were first inspected.

We need to check buffer_uptodate() even if the buffers were already unlocked.

fs/jbd/commit.c

@@ -543,11 +543,12 @@ void journal_commit_transaction(journal_t *journal)
 		bh = jh2bh(jh);
 		if (buffer_locked(bh)) {
 			wait_on_buffer(bh);
-			if (unlikely(!buffer_uptodate(bh)))
-				err = -EIO;
 			goto wait_for_iobuf;
 		}
 
+		if (unlikely(!buffer_uptodate(bh)))
+			err = -EIO;
+
 		clear_buffer_jwrite(bh);
 
 		JBUFFER_TRACE(jh, "ph4: unfile after journal write");
@@ -603,11 +604,12 @@ void journal_commit_transaction(journal_t *journal)
 		bh = jh2bh(jh);
 		if (buffer_locked(bh)) {
 			wait_on_buffer(bh);
-			if (unlikely(!buffer_uptodate(bh)))
-				err = -EIO;
 			goto wait_for_ctlbuf;
 		}
 
+		if (unlikely(!buffer_uptodate(bh)))
+			err = -EIO;
+
 		BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
 		clear_buffer_jwrite(bh);
 		journal_unfile_buffer(journal, jh);