xfs: fix up quotacheck buffer list error handling
The quotacheck error handling of the delwri buffer list assumes the
resident buffers are locked and doesn't clear the _XBF_DELWRI_Q flag
on the buffers that are dequeued. This can lead to assert failures
on buffer release and possibly other locking problems.
Move this code to a delwri queue cancel helper function to
encapsulate the logic required to properly release buffers from a
delwri queue. Update the helper to clear the delwri queue flag and
call it from quotacheck.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index b620872..ba036c1 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1079,6 +1079,8 @@
xfs_buf_unlock(
struct xfs_buf *bp)
{
+ ASSERT(xfs_buf_islocked(bp));
+
XB_CLEAR_OWNER(bp);
up(&bp->b_sema);
@@ -1815,6 +1817,28 @@
}
/*
+ * Cancel a delayed write list.
+ *
+ * Remove each buffer from the list, clear the delwri queue flag and drop the
+ * associated buffer reference.
+ */
+void
+xfs_buf_delwri_cancel(
+ struct list_head *list)
+{
+ struct xfs_buf *bp;
+
+ while (!list_empty(list)) {
+ bp = list_first_entry(list, struct xfs_buf, b_list);
+
+ xfs_buf_lock(bp);
+ bp->b_flags &= ~_XBF_DELWRI_Q;
+ list_del_init(&bp->b_list);
+ xfs_buf_relse(bp);
+ }
+}
+
+/*
* Add a buffer to the delayed write list.
*
* This queues a buffer for writeout if it hasn't already been. Note that