writeback: improve readability of the wb_writeback() continue/break logic
And throw some comments in there, too.
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 916e834..15e375b 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -750,29 +750,32 @@
wrote += MAX_WRITEBACK_PAGES - wbc.nr_to_write;
/*
- * If we ran out of stuff to write, bail unless more_io got set
+ * If we consumed everything, see if we have more
*/
- if (wbc.nr_to_write > 0) {
- if (wbc.more_io) {
- if (wbc.nr_to_write < MAX_WRITEBACK_PAGES)
- continue;
- /*
- * Nothing written. Wait for some inode to
- * become available for writeback. Otherwise
- * we'll just busyloop.
- */
- spin_lock(&inode_lock);
- if (!list_empty(&wb->b_more_io)) {
- inode = list_entry(
- wb->b_more_io.prev,
- struct inode, i_list);
- inode_wait_for_writeback(inode);
- }
- spin_unlock(&inode_lock);
- continue;
- }
+ if (wbc.nr_to_write <= 0)
+ continue;
+ /*
+ * Didn't write everything and we don't have more IO, bail
+ */
+ if (!wbc.more_io)
break;
+ /*
+ * Did we write something? Try for more
+ */
+ if (wbc.nr_to_write < MAX_WRITEBACK_PAGES)
+ continue;
+ /*
+ * Nothing written. Wait for some inode to
+ * become available for writeback. Otherwise
+ * we'll just busyloop.
+ */
+ spin_lock(&inode_lock);
+ if (!list_empty(&wb->b_more_io)) {
+ inode = list_entry(wb->b_more_io.prev,
+ struct inode, i_list);
+ inode_wait_for_writeback(inode);
}
+ spin_unlock(&inode_lock);
}
return wrote;